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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) Microsoft Corporation.
4 *
5 * Author:
6 * Jake Oshins <jakeo@microsoft.com>
7 *
8 * This driver acts as a paravirtual front-end for PCI Express root buses.
9 * When a PCI Express function (either an entire device or an SR-IOV
10 * Virtual Function) is being passed through to the VM, this driver exposes
11 * a new bus to the guest VM. This is modeled as a root PCI bus because
12 * no bridges are being exposed to the VM. In fact, with a "Generation 2"
13 * VM within Hyper-V, there may seem to be no PCI bus at all in the VM
14 * until a device as been exposed using this driver.
15 *
16 * Each root PCI bus has its own PCI domain, which is called "Segment" in
17 * the PCI Firmware Specifications. Thus while each device passed through
18 * to the VM using this front-end will appear at "device 0", the domain will
19 * be unique. Typically, each bus will have one PCI function on it, though
20 * this driver does support more than one.
21 *
22 * In order to map the interrupts from the device through to the guest VM,
23 * this driver also implements an IRQ Domain, which handles interrupts (either
24 * MSI or MSI-X) associated with the functions on the bus. As interrupts are
25 * set up, torn down, or reaffined, this driver communicates with the
26 * underlying hypervisor to adjust the mappings in the I/O MMU so that each
27 * interrupt will be delivered to the correct virtual processor at the right
28 * vector. This driver does not support level-triggered (line-based)
29 * interrupts, and will report that the Interrupt Line register in the
30 * function's configuration space is zero.
31 *
32 * The rest of this driver mostly maps PCI concepts onto underlying Hyper-V
33 * facilities. For instance, the configuration space of a function exposed
34 * by Hyper-V is mapped into a single page of memory space, and the
35 * read and write handlers for config space must be aware of this mechanism.
36 * Similarly, device setup and teardown involves messages sent to and from
37 * the PCI back-end driver in Hyper-V.
38 */
39
40#include <linux/kernel.h>
41#include <linux/module.h>
42#include <linux/pci.h>
43#include <linux/delay.h>
44#include <linux/semaphore.h>
45#include <linux/irqdomain.h>
46#include <asm/irqdomain.h>
47#include <asm/apic.h>
48#include <linux/irq.h>
49#include <linux/msi.h>
50#include <linux/hyperv.h>
51#include <linux/refcount.h>
52#include <asm/mshyperv.h>
53
54/*
55 * Protocol versions. The low word is the minor version, the high word the
56 * major version.
57 */
58
59#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (minor)))
60#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16)
61#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff)
62
63enum pci_protocol_version_t {
64 PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */
65 PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */
66 PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3), /* Vibranium */
67};
68
69#define CPU_AFFINITY_ALL -1ULL
70
71/*
72 * Supported protocol versions in the order of probing - highest go
73 * first.
74 */
75static enum pci_protocol_version_t pci_protocol_versions[] = {
76 PCI_PROTOCOL_VERSION_1_3,
77 PCI_PROTOCOL_VERSION_1_2,
78 PCI_PROTOCOL_VERSION_1_1,
79};
80
81#define PCI_CONFIG_MMIO_LENGTH 0x2000
82#define CFG_PAGE_OFFSET 0x1000
83#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
84
85#define MAX_SUPPORTED_MSI_MESSAGES 0x400
86
87#define STATUS_REVISION_MISMATCH 0xC0000059
88
89/* space for 32bit serial number as string */
90#define SLOT_NAME_SIZE 11
91
92/*
93 * Message Types
94 */
95
96enum pci_message_type {
97 /*
98 * Version 1.1
99 */
100 PCI_MESSAGE_BASE = 0x42490000,
101 PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0,
102 PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1,
103 PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4,
104 PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5,
105 PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6,
106 PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7,
107 PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8,
108 PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9,
109 PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA,
110 PCI_EJECT = PCI_MESSAGE_BASE + 0xB,
111 PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC,
112 PCI_REENABLE = PCI_MESSAGE_BASE + 0xD,
113 PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE,
114 PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF,
115 PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10,
116 PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11,
117 PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12,
118 PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13,
119 PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14,
120 PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15,
121 PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16,
122 PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17,
123 PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */
124 PCI_BUS_RELATIONS2 = PCI_MESSAGE_BASE + 0x19,
125 PCI_MESSAGE_MAXIMUM
126};
127
128/*
129 * Structures defining the virtual PCI Express protocol.
130 */
131
132union pci_version {
133 struct {
134 u16 minor_version;
135 u16 major_version;
136 } parts;
137 u32 version;
138} __packed;
139
140/*
141 * Function numbers are 8-bits wide on Express, as interpreted through ARI,
142 * which is all this driver does. This representation is the one used in
143 * Windows, which is what is expected when sending this back and forth with
144 * the Hyper-V parent partition.
145 */
146union win_slot_encoding {
147 struct {
148 u32 dev:5;
149 u32 func:3;
150 u32 reserved:24;
151 } bits;
152 u32 slot;
153} __packed;
154
155/*
156 * Pretty much as defined in the PCI Specifications.
157 */
158struct pci_function_description {
159 u16 v_id; /* vendor ID */
160 u16 d_id; /* device ID */
161 u8 rev;
162 u8 prog_intf;
163 u8 subclass;
164 u8 base_class;
165 u32 subsystem_id;
166 union win_slot_encoding win_slot;
167 u32 ser; /* serial number */
168} __packed;
169
170enum pci_device_description_flags {
171 HV_PCI_DEVICE_FLAG_NONE = 0x0,
172 HV_PCI_DEVICE_FLAG_NUMA_AFFINITY = 0x1,
173};
174
175struct pci_function_description2 {
176 u16 v_id; /* vendor ID */
177 u16 d_id; /* device ID */
178 u8 rev;
179 u8 prog_intf;
180 u8 subclass;
181 u8 base_class;
182 u32 subsystem_id;
183 union win_slot_encoding win_slot;
184 u32 ser; /* serial number */
185 u32 flags;
186 u16 virtual_numa_node;
187 u16 reserved;
188} __packed;
189
190/**
191 * struct hv_msi_desc
192 * @vector: IDT entry
193 * @delivery_mode: As defined in Intel's Programmer's
194 * Reference Manual, Volume 3, Chapter 8.
195 * @vector_count: Number of contiguous entries in the
196 * Interrupt Descriptor Table that are
197 * occupied by this Message-Signaled
198 * Interrupt. For "MSI", as first defined
199 * in PCI 2.2, this can be between 1 and
200 * 32. For "MSI-X," as first defined in PCI
201 * 3.0, this must be 1, as each MSI-X table
202 * entry would have its own descriptor.
203 * @reserved: Empty space
204 * @cpu_mask: All the target virtual processors.
205 */
206struct hv_msi_desc {
207 u8 vector;
208 u8 delivery_mode;
209 u16 vector_count;
210 u32 reserved;
211 u64 cpu_mask;
212} __packed;
213
214/**
215 * struct hv_msi_desc2 - 1.2 version of hv_msi_desc
216 * @vector: IDT entry
217 * @delivery_mode: As defined in Intel's Programmer's
218 * Reference Manual, Volume 3, Chapter 8.
219 * @vector_count: Number of contiguous entries in the
220 * Interrupt Descriptor Table that are
221 * occupied by this Message-Signaled
222 * Interrupt. For "MSI", as first defined
223 * in PCI 2.2, this can be between 1 and
224 * 32. For "MSI-X," as first defined in PCI
225 * 3.0, this must be 1, as each MSI-X table
226 * entry would have its own descriptor.
227 * @processor_count: number of bits enabled in array.
228 * @processor_array: All the target virtual processors.
229 */
230struct hv_msi_desc2 {
231 u8 vector;
232 u8 delivery_mode;
233 u16 vector_count;
234 u16 processor_count;
235 u16 processor_array[32];
236} __packed;
237
238/**
239 * struct tran_int_desc
240 * @reserved: unused, padding
241 * @vector_count: same as in hv_msi_desc
242 * @data: This is the "data payload" value that is
243 * written by the device when it generates
244 * a message-signaled interrupt, either MSI
245 * or MSI-X.
246 * @address: This is the address to which the data
247 * payload is written on interrupt
248 * generation.
249 */
250struct tran_int_desc {
251 u16 reserved;
252 u16 vector_count;
253 u32 data;
254 u64 address;
255} __packed;
256
257/*
258 * A generic message format for virtual PCI.
259 * Specific message formats are defined later in the file.
260 */
261
262struct pci_message {
263 u32 type;
264} __packed;
265
266struct pci_child_message {
267 struct pci_message message_type;
268 union win_slot_encoding wslot;
269} __packed;
270
271struct pci_incoming_message {
272 struct vmpacket_descriptor hdr;
273 struct pci_message message_type;
274} __packed;
275
276struct pci_response {
277 struct vmpacket_descriptor hdr;
278 s32 status; /* negative values are failures */
279} __packed;
280
281struct pci_packet {
282 void (*completion_func)(void *context, struct pci_response *resp,
283 int resp_packet_size);
284 void *compl_ctxt;
285
286 struct pci_message message[];
287};
288
289/*
290 * Specific message types supporting the PCI protocol.
291 */
292
293/*
294 * Version negotiation message. Sent from the guest to the host.
295 * The guest is free to try different versions until the host
296 * accepts the version.
297 *
298 * pci_version: The protocol version requested.
299 * is_last_attempt: If TRUE, this is the last version guest will request.
300 * reservedz: Reserved field, set to zero.
301 */
302
303struct pci_version_request {
304 struct pci_message message_type;
305 u32 protocol_version;
306} __packed;
307
308/*
309 * Bus D0 Entry. This is sent from the guest to the host when the virtual
310 * bus (PCI Express port) is ready for action.
311 */
312
313struct pci_bus_d0_entry {
314 struct pci_message message_type;
315 u32 reserved;
316 u64 mmio_base;
317} __packed;
318
319struct pci_bus_relations {
320 struct pci_incoming_message incoming;
321 u32 device_count;
322 struct pci_function_description func[];
323} __packed;
324
325struct pci_bus_relations2 {
326 struct pci_incoming_message incoming;
327 u32 device_count;
328 struct pci_function_description2 func[];
329} __packed;
330
331struct pci_q_res_req_response {
332 struct vmpacket_descriptor hdr;
333 s32 status; /* negative values are failures */
334 u32 probed_bar[PCI_STD_NUM_BARS];
335} __packed;
336
337struct pci_set_power {
338 struct pci_message message_type;
339 union win_slot_encoding wslot;
340 u32 power_state; /* In Windows terms */
341 u32 reserved;
342} __packed;
343
344struct pci_set_power_response {
345 struct vmpacket_descriptor hdr;
346 s32 status; /* negative values are failures */
347 union win_slot_encoding wslot;
348 u32 resultant_state; /* In Windows terms */
349 u32 reserved;
350} __packed;
351
352struct pci_resources_assigned {
353 struct pci_message message_type;
354 union win_slot_encoding wslot;
355 u8 memory_range[0x14][6]; /* not used here */
356 u32 msi_descriptors;
357 u32 reserved[4];
358} __packed;
359
360struct pci_resources_assigned2 {
361 struct pci_message message_type;
362 union win_slot_encoding wslot;
363 u8 memory_range[0x14][6]; /* not used here */
364 u32 msi_descriptor_count;
365 u8 reserved[70];
366} __packed;
367
368struct pci_create_interrupt {
369 struct pci_message message_type;
370 union win_slot_encoding wslot;
371 struct hv_msi_desc int_desc;
372} __packed;
373
374struct pci_create_int_response {
375 struct pci_response response;
376 u32 reserved;
377 struct tran_int_desc int_desc;
378} __packed;
379
380struct pci_create_interrupt2 {
381 struct pci_message message_type;
382 union win_slot_encoding wslot;
383 struct hv_msi_desc2 int_desc;
384} __packed;
385
386struct pci_delete_interrupt {
387 struct pci_message message_type;
388 union win_slot_encoding wslot;
389 struct tran_int_desc int_desc;
390} __packed;
391
392/*
393 * Note: the VM must pass a valid block id, wslot and bytes_requested.
394 */
395struct pci_read_block {
396 struct pci_message message_type;
397 u32 block_id;
398 union win_slot_encoding wslot;
399 u32 bytes_requested;
400} __packed;
401
402struct pci_read_block_response {
403 struct vmpacket_descriptor hdr;
404 u32 status;
405 u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
406} __packed;
407
408/*
409 * Note: the VM must pass a valid block id, wslot and byte_count.
410 */
411struct pci_write_block {
412 struct pci_message message_type;
413 u32 block_id;
414 union win_slot_encoding wslot;
415 u32 byte_count;
416 u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
417} __packed;
418
419struct pci_dev_inval_block {
420 struct pci_incoming_message incoming;
421 union win_slot_encoding wslot;
422 u64 block_mask;
423} __packed;
424
425struct pci_dev_incoming {
426 struct pci_incoming_message incoming;
427 union win_slot_encoding wslot;
428} __packed;
429
430struct pci_eject_response {
431 struct pci_message message_type;
432 union win_slot_encoding wslot;
433 u32 status;
434} __packed;
435
436static int pci_ring_size = (4 * PAGE_SIZE);
437
438/*
439 * Driver specific state.
440 */
441
442enum hv_pcibus_state {
443 hv_pcibus_init = 0,
444 hv_pcibus_probed,
445 hv_pcibus_installed,
446 hv_pcibus_removing,
447 hv_pcibus_removed,
448 hv_pcibus_maximum
449};
450
451struct hv_pcibus_device {
452 struct pci_sysdata sysdata;
453 /* Protocol version negotiated with the host */
454 enum pci_protocol_version_t protocol_version;
455 enum hv_pcibus_state state;
456 refcount_t remove_lock;
457 struct hv_device *hdev;
458 resource_size_t low_mmio_space;
459 resource_size_t high_mmio_space;
460 struct resource *mem_config;
461 struct resource *low_mmio_res;
462 struct resource *high_mmio_res;
463 struct completion *survey_event;
464 struct completion remove_event;
465 struct pci_bus *pci_bus;
466 spinlock_t config_lock; /* Avoid two threads writing index page */
467 spinlock_t device_list_lock; /* Protect lists below */
468 void __iomem *cfg_addr;
469
470 struct list_head resources_for_children;
471
472 struct list_head children;
473 struct list_head dr_list;
474
475 struct msi_domain_info msi_info;
476 struct msi_controller msi_chip;
477 struct irq_domain *irq_domain;
478
479 spinlock_t retarget_msi_interrupt_lock;
480
481 struct workqueue_struct *wq;
482
483 /* Highest slot of child device with resources allocated */
484 int wslot_res_allocated;
485
486 /* hypercall arg, must not cross page boundary */
487 struct hv_retarget_device_interrupt retarget_msi_interrupt_params;
488
489 /*
490 * Don't put anything here: retarget_msi_interrupt_params must be last
491 */
492};
493
494/*
495 * Tracks "Device Relations" messages from the host, which must be both
496 * processed in order and deferred so that they don't run in the context
497 * of the incoming packet callback.
498 */
499struct hv_dr_work {
500 struct work_struct wrk;
501 struct hv_pcibus_device *bus;
502};
503
504struct hv_pcidev_description {
505 u16 v_id; /* vendor ID */
506 u16 d_id; /* device ID */
507 u8 rev;
508 u8 prog_intf;
509 u8 subclass;
510 u8 base_class;
511 u32 subsystem_id;
512 union win_slot_encoding win_slot;
513 u32 ser; /* serial number */
514 u32 flags;
515 u16 virtual_numa_node;
516};
517
518struct hv_dr_state {
519 struct list_head list_entry;
520 u32 device_count;
521 struct hv_pcidev_description func[];
522};
523
524enum hv_pcichild_state {
525 hv_pcichild_init = 0,
526 hv_pcichild_requirements,
527 hv_pcichild_resourced,
528 hv_pcichild_ejecting,
529 hv_pcichild_maximum
530};
531
532struct hv_pci_dev {
533 /* List protected by pci_rescan_remove_lock */
534 struct list_head list_entry;
535 refcount_t refs;
536 enum hv_pcichild_state state;
537 struct pci_slot *pci_slot;
538 struct hv_pcidev_description desc;
539 bool reported_missing;
540 struct hv_pcibus_device *hbus;
541 struct work_struct wrk;
542
543 void (*block_invalidate)(void *context, u64 block_mask);
544 void *invalidate_context;
545
546 /*
547 * What would be observed if one wrote 0xFFFFFFFF to a BAR and then
548 * read it back, for each of the BAR offsets within config space.
549 */
550 u32 probed_bar[PCI_STD_NUM_BARS];
551};
552
553struct hv_pci_compl {
554 struct completion host_event;
555 s32 completion_status;
556};
557
558static void hv_pci_onchannelcallback(void *context);
559
560/**
561 * hv_pci_generic_compl() - Invoked for a completion packet
562 * @context: Set up by the sender of the packet.
563 * @resp: The response packet
564 * @resp_packet_size: Size in bytes of the packet
565 *
566 * This function is used to trigger an event and report status
567 * for any message for which the completion packet contains a
568 * status and nothing else.
569 */
570static void hv_pci_generic_compl(void *context, struct pci_response *resp,
571 int resp_packet_size)
572{
573 struct hv_pci_compl *comp_pkt = context;
574
575 if (resp_packet_size >= offsetofend(struct pci_response, status))
576 comp_pkt->completion_status = resp->status;
577 else
578 comp_pkt->completion_status = -1;
579
580 complete(&comp_pkt->host_event);
581}
582
583static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
584 u32 wslot);
585
586static void get_pcichild(struct hv_pci_dev *hpdev)
587{
588 refcount_inc(&hpdev->refs);
589}
590
591static void put_pcichild(struct hv_pci_dev *hpdev)
592{
593 if (refcount_dec_and_test(&hpdev->refs))
594 kfree(hpdev);
595}
596
597static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus);
598static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus);
599
600/*
601 * There is no good way to get notified from vmbus_onoffer_rescind(),
602 * so let's use polling here, since this is not a hot path.
603 */
604static int wait_for_response(struct hv_device *hdev,
605 struct completion *comp)
606{
607 while (true) {
608 if (hdev->channel->rescind) {
609 dev_warn_once(&hdev->device, "The device is gone.\n");
610 return -ENODEV;
611 }
612
613 if (wait_for_completion_timeout(comp, HZ / 10))
614 break;
615 }
616
617 return 0;
618}
619
620/**
621 * devfn_to_wslot() - Convert from Linux PCI slot to Windows
622 * @devfn: The Linux representation of PCI slot
623 *
624 * Windows uses a slightly different representation of PCI slot.
625 *
626 * Return: The Windows representation
627 */
628static u32 devfn_to_wslot(int devfn)
629{
630 union win_slot_encoding wslot;
631
632 wslot.slot = 0;
633 wslot.bits.dev = PCI_SLOT(devfn);
634 wslot.bits.func = PCI_FUNC(devfn);
635
636 return wslot.slot;
637}
638
639/**
640 * wslot_to_devfn() - Convert from Windows PCI slot to Linux
641 * @wslot: The Windows representation of PCI slot
642 *
643 * Windows uses a slightly different representation of PCI slot.
644 *
645 * Return: The Linux representation
646 */
647static int wslot_to_devfn(u32 wslot)
648{
649 union win_slot_encoding slot_no;
650
651 slot_no.slot = wslot;
652 return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func);
653}
654
655/*
656 * PCI Configuration Space for these root PCI buses is implemented as a pair
657 * of pages in memory-mapped I/O space. Writing to the first page chooses
658 * the PCI function being written or read. Once the first page has been
659 * written to, the following page maps in the entire configuration space of
660 * the function.
661 */
662
663/**
664 * _hv_pcifront_read_config() - Internal PCI config read
665 * @hpdev: The PCI driver's representation of the device
666 * @where: Offset within config space
667 * @size: Size of the transfer
668 * @val: Pointer to the buffer receiving the data
669 */
670static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where,
671 int size, u32 *val)
672{
673 unsigned long flags;
674 void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
675
676 /*
677 * If the attempt is to read the IDs or the ROM BAR, simulate that.
678 */
679 if (where + size <= PCI_COMMAND) {
680 memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size);
681 } else if (where >= PCI_CLASS_REVISION && where + size <=
682 PCI_CACHE_LINE_SIZE) {
683 memcpy(val, ((u8 *)&hpdev->desc.rev) + where -
684 PCI_CLASS_REVISION, size);
685 } else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <=
686 PCI_ROM_ADDRESS) {
687 memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where -
688 PCI_SUBSYSTEM_VENDOR_ID, size);
689 } else if (where >= PCI_ROM_ADDRESS && where + size <=
690 PCI_CAPABILITY_LIST) {
691 /* ROM BARs are unimplemented */
692 *val = 0;
693 } else if (where >= PCI_INTERRUPT_LINE && where + size <=
694 PCI_INTERRUPT_PIN) {
695 /*
696 * Interrupt Line and Interrupt PIN are hard-wired to zero
697 * because this front-end only supports message-signaled
698 * interrupts.
699 */
700 *val = 0;
701 } else if (where + size <= CFG_PAGE_SIZE) {
702 spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
703 /* Choose the function to be read. (See comment above) */
704 writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
705 /* Make sure the function was chosen before we start reading. */
706 mb();
707 /* Read from that function's config space. */
708 switch (size) {
709 case 1:
710 *val = readb(addr);
711 break;
712 case 2:
713 *val = readw(addr);
714 break;
715 default:
716 *val = readl(addr);
717 break;
718 }
719 /*
720 * Make sure the read was done before we release the spinlock
721 * allowing consecutive reads/writes.
722 */
723 mb();
724 spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
725 } else {
726 dev_err(&hpdev->hbus->hdev->device,
727 "Attempt to read beyond a function's config space.\n");
728 }
729}
730
731static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev)
732{
733 u16 ret;
734 unsigned long flags;
735 void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET +
736 PCI_VENDOR_ID;
737
738 spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
739
740 /* Choose the function to be read. (See comment above) */
741 writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
742 /* Make sure the function was chosen before we start reading. */
743 mb();
744 /* Read from that function's config space. */
745 ret = readw(addr);
746 /*
747 * mb() is not required here, because the spin_unlock_irqrestore()
748 * is a barrier.
749 */
750
751 spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
752
753 return ret;
754}
755
756/**
757 * _hv_pcifront_write_config() - Internal PCI config write
758 * @hpdev: The PCI driver's representation of the device
759 * @where: Offset within config space
760 * @size: Size of the transfer
761 * @val: The data being transferred
762 */
763static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where,
764 int size, u32 val)
765{
766 unsigned long flags;
767 void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
768
769 if (where >= PCI_SUBSYSTEM_VENDOR_ID &&
770 where + size <= PCI_CAPABILITY_LIST) {
771 /* SSIDs and ROM BARs are read-only */
772 } else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) {
773 spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
774 /* Choose the function to be written. (See comment above) */
775 writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
776 /* Make sure the function was chosen before we start writing. */
777 wmb();
778 /* Write to that function's config space. */
779 switch (size) {
780 case 1:
781 writeb(val, addr);
782 break;
783 case 2:
784 writew(val, addr);
785 break;
786 default:
787 writel(val, addr);
788 break;
789 }
790 /*
791 * Make sure the write was done before we release the spinlock
792 * allowing consecutive reads/writes.
793 */
794 mb();
795 spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
796 } else {
797 dev_err(&hpdev->hbus->hdev->device,
798 "Attempt to write beyond a function's config space.\n");
799 }
800}
801
802/**
803 * hv_pcifront_read_config() - Read configuration space
804 * @bus: PCI Bus structure
805 * @devfn: Device/function
806 * @where: Offset from base
807 * @size: Byte/word/dword
808 * @val: Value to be read
809 *
810 * Return: PCIBIOS_SUCCESSFUL on success
811 * PCIBIOS_DEVICE_NOT_FOUND on failure
812 */
813static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn,
814 int where, int size, u32 *val)
815{
816 struct hv_pcibus_device *hbus =
817 container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
818 struct hv_pci_dev *hpdev;
819
820 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
821 if (!hpdev)
822 return PCIBIOS_DEVICE_NOT_FOUND;
823
824 _hv_pcifront_read_config(hpdev, where, size, val);
825
826 put_pcichild(hpdev);
827 return PCIBIOS_SUCCESSFUL;
828}
829
830/**
831 * hv_pcifront_write_config() - Write configuration space
832 * @bus: PCI Bus structure
833 * @devfn: Device/function
834 * @where: Offset from base
835 * @size: Byte/word/dword
836 * @val: Value to be written to device
837 *
838 * Return: PCIBIOS_SUCCESSFUL on success
839 * PCIBIOS_DEVICE_NOT_FOUND on failure
840 */
841static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn,
842 int where, int size, u32 val)
843{
844 struct hv_pcibus_device *hbus =
845 container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
846 struct hv_pci_dev *hpdev;
847
848 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
849 if (!hpdev)
850 return PCIBIOS_DEVICE_NOT_FOUND;
851
852 _hv_pcifront_write_config(hpdev, where, size, val);
853
854 put_pcichild(hpdev);
855 return PCIBIOS_SUCCESSFUL;
856}
857
858/* PCIe operations */
859static struct pci_ops hv_pcifront_ops = {
860 .read = hv_pcifront_read_config,
861 .write = hv_pcifront_write_config,
862};
863
864/*
865 * Paravirtual backchannel
866 *
867 * Hyper-V SR-IOV provides a backchannel mechanism in software for
868 * communication between a VF driver and a PF driver. These
869 * "configuration blocks" are similar in concept to PCI configuration space,
870 * but instead of doing reads and writes in 32-bit chunks through a very slow
871 * path, packets of up to 128 bytes can be sent or received asynchronously.
872 *
873 * Nearly every SR-IOV device contains just such a communications channel in
874 * hardware, so using this one in software is usually optional. Using the
875 * software channel, however, allows driver implementers to leverage software
876 * tools that fuzz the communications channel looking for vulnerabilities.
877 *
878 * The usage model for these packets puts the responsibility for reading or
879 * writing on the VF driver. The VF driver sends a read or a write packet,
880 * indicating which "block" is being referred to by number.
881 *
882 * If the PF driver wishes to initiate communication, it can "invalidate" one or
883 * more of the first 64 blocks. This invalidation is delivered via a callback
884 * supplied by the VF driver by this driver.
885 *
886 * No protocol is implied, except that supplied by the PF and VF drivers.
887 */
888
889struct hv_read_config_compl {
890 struct hv_pci_compl comp_pkt;
891 void *buf;
892 unsigned int len;
893 unsigned int bytes_returned;
894};
895
896/**
897 * hv_pci_read_config_compl() - Invoked when a response packet
898 * for a read config block operation arrives.
899 * @context: Identifies the read config operation
900 * @resp: The response packet itself
901 * @resp_packet_size: Size in bytes of the response packet
902 */
903static void hv_pci_read_config_compl(void *context, struct pci_response *resp,
904 int resp_packet_size)
905{
906 struct hv_read_config_compl *comp = context;
907 struct pci_read_block_response *read_resp =
908 (struct pci_read_block_response *)resp;
909 unsigned int data_len, hdr_len;
910
911 hdr_len = offsetof(struct pci_read_block_response, bytes);
912 if (resp_packet_size < hdr_len) {
913 comp->comp_pkt.completion_status = -1;
914 goto out;
915 }
916
917 data_len = resp_packet_size - hdr_len;
918 if (data_len > 0 && read_resp->status == 0) {
919 comp->bytes_returned = min(comp->len, data_len);
920 memcpy(comp->buf, read_resp->bytes, comp->bytes_returned);
921 } else {
922 comp->bytes_returned = 0;
923 }
924
925 comp->comp_pkt.completion_status = read_resp->status;
926out:
927 complete(&comp->comp_pkt.host_event);
928}
929
930/**
931 * hv_read_config_block() - Sends a read config block request to
932 * the back-end driver running in the Hyper-V parent partition.
933 * @pdev: The PCI driver's representation for this device.
934 * @buf: Buffer into which the config block will be copied.
935 * @len: Size in bytes of buf.
936 * @block_id: Identifies the config block which has been requested.
937 * @bytes_returned: Size which came back from the back-end driver.
938 *
939 * Return: 0 on success, -errno on failure
940 */
941static int hv_read_config_block(struct pci_dev *pdev, void *buf,
942 unsigned int len, unsigned int block_id,
943 unsigned int *bytes_returned)
944{
945 struct hv_pcibus_device *hbus =
946 container_of(pdev->bus->sysdata, struct hv_pcibus_device,
947 sysdata);
948 struct {
949 struct pci_packet pkt;
950 char buf[sizeof(struct pci_read_block)];
951 } pkt;
952 struct hv_read_config_compl comp_pkt;
953 struct pci_read_block *read_blk;
954 int ret;
955
956 if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
957 return -EINVAL;
958
959 init_completion(&comp_pkt.comp_pkt.host_event);
960 comp_pkt.buf = buf;
961 comp_pkt.len = len;
962
963 memset(&pkt, 0, sizeof(pkt));
964 pkt.pkt.completion_func = hv_pci_read_config_compl;
965 pkt.pkt.compl_ctxt = &comp_pkt;
966 read_blk = (struct pci_read_block *)&pkt.pkt.message;
967 read_blk->message_type.type = PCI_READ_BLOCK;
968 read_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
969 read_blk->block_id = block_id;
970 read_blk->bytes_requested = len;
971
972 ret = vmbus_sendpacket(hbus->hdev->channel, read_blk,
973 sizeof(*read_blk), (unsigned long)&pkt.pkt,
974 VM_PKT_DATA_INBAND,
975 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
976 if (ret)
977 return ret;
978
979 ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event);
980 if (ret)
981 return ret;
982
983 if (comp_pkt.comp_pkt.completion_status != 0 ||
984 comp_pkt.bytes_returned == 0) {
985 dev_err(&hbus->hdev->device,
986 "Read Config Block failed: 0x%x, bytes_returned=%d\n",
987 comp_pkt.comp_pkt.completion_status,
988 comp_pkt.bytes_returned);
989 return -EIO;
990 }
991
992 *bytes_returned = comp_pkt.bytes_returned;
993 return 0;
994}
995
996/**
997 * hv_pci_write_config_compl() - Invoked when a response packet for a write
998 * config block operation arrives.
999 * @context: Identifies the write config operation
1000 * @resp: The response packet itself
1001 * @resp_packet_size: Size in bytes of the response packet
1002 */
1003static void hv_pci_write_config_compl(void *context, struct pci_response *resp,
1004 int resp_packet_size)
1005{
1006 struct hv_pci_compl *comp_pkt = context;
1007
1008 comp_pkt->completion_status = resp->status;
1009 complete(&comp_pkt->host_event);
1010}
1011
1012/**
1013 * hv_write_config_block() - Sends a write config block request to the
1014 * back-end driver running in the Hyper-V parent partition.
1015 * @pdev: The PCI driver's representation for this device.
1016 * @buf: Buffer from which the config block will be copied.
1017 * @len: Size in bytes of buf.
1018 * @block_id: Identifies the config block which is being written.
1019 *
1020 * Return: 0 on success, -errno on failure
1021 */
1022static int hv_write_config_block(struct pci_dev *pdev, void *buf,
1023 unsigned int len, unsigned int block_id)
1024{
1025 struct hv_pcibus_device *hbus =
1026 container_of(pdev->bus->sysdata, struct hv_pcibus_device,
1027 sysdata);
1028 struct {
1029 struct pci_packet pkt;
1030 char buf[sizeof(struct pci_write_block)];
1031 u32 reserved;
1032 } pkt;
1033 struct hv_pci_compl comp_pkt;
1034 struct pci_write_block *write_blk;
1035 u32 pkt_size;
1036 int ret;
1037
1038 if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
1039 return -EINVAL;
1040
1041 init_completion(&comp_pkt.host_event);
1042
1043 memset(&pkt, 0, sizeof(pkt));
1044 pkt.pkt.completion_func = hv_pci_write_config_compl;
1045 pkt.pkt.compl_ctxt = &comp_pkt;
1046 write_blk = (struct pci_write_block *)&pkt.pkt.message;
1047 write_blk->message_type.type = PCI_WRITE_BLOCK;
1048 write_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
1049 write_blk->block_id = block_id;
1050 write_blk->byte_count = len;
1051 memcpy(write_blk->bytes, buf, len);
1052 pkt_size = offsetof(struct pci_write_block, bytes) + len;
1053 /*
1054 * This quirk is required on some hosts shipped around 2018, because
1055 * these hosts don't check the pkt_size correctly (new hosts have been
1056 * fixed since early 2019). The quirk is also safe on very old hosts
1057 * and new hosts, because, on them, what really matters is the length
1058 * specified in write_blk->byte_count.
1059 */
1060 pkt_size += sizeof(pkt.reserved);
1061
1062 ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size,
1063 (unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND,
1064 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1065 if (ret)
1066 return ret;
1067
1068 ret = wait_for_response(hbus->hdev, &comp_pkt.host_event);
1069 if (ret)
1070 return ret;
1071
1072 if (comp_pkt.completion_status != 0) {
1073 dev_err(&hbus->hdev->device,
1074 "Write Config Block failed: 0x%x\n",
1075 comp_pkt.completion_status);
1076 return -EIO;
1077 }
1078
1079 return 0;
1080}
1081
1082/**
1083 * hv_register_block_invalidate() - Invoked when a config block invalidation
1084 * arrives from the back-end driver.
1085 * @pdev: The PCI driver's representation for this device.
1086 * @context: Identifies the device.
1087 * @block_invalidate: Identifies all of the blocks being invalidated.
1088 *
1089 * Return: 0 on success, -errno on failure
1090 */
1091static int hv_register_block_invalidate(struct pci_dev *pdev, void *context,
1092 void (*block_invalidate)(void *context,
1093 u64 block_mask))
1094{
1095 struct hv_pcibus_device *hbus =
1096 container_of(pdev->bus->sysdata, struct hv_pcibus_device,
1097 sysdata);
1098 struct hv_pci_dev *hpdev;
1099
1100 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
1101 if (!hpdev)
1102 return -ENODEV;
1103
1104 hpdev->block_invalidate = block_invalidate;
1105 hpdev->invalidate_context = context;
1106
1107 put_pcichild(hpdev);
1108 return 0;
1109
1110}
1111
1112/* Interrupt management hooks */
1113static void hv_int_desc_free(struct hv_pci_dev *hpdev,
1114 struct tran_int_desc *int_desc)
1115{
1116 struct pci_delete_interrupt *int_pkt;
1117 struct {
1118 struct pci_packet pkt;
1119 u8 buffer[sizeof(struct pci_delete_interrupt)];
1120 } ctxt;
1121
1122 memset(&ctxt, 0, sizeof(ctxt));
1123 int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;
1124 int_pkt->message_type.type =
1125 PCI_DELETE_INTERRUPT_MESSAGE;
1126 int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
1127 int_pkt->int_desc = *int_desc;
1128 vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt),
1129 (unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND, 0);
1130 kfree(int_desc);
1131}
1132
1133/**
1134 * hv_msi_free() - Free the MSI.
1135 * @domain: The interrupt domain pointer
1136 * @info: Extra MSI-related context
1137 * @irq: Identifies the IRQ.
1138 *
1139 * The Hyper-V parent partition and hypervisor are tracking the
1140 * messages that are in use, keeping the interrupt redirection
1141 * table up to date. This callback sends a message that frees
1142 * the IRT entry and related tracking nonsense.
1143 */
1144static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
1145 unsigned int irq)
1146{
1147 struct hv_pcibus_device *hbus;
1148 struct hv_pci_dev *hpdev;
1149 struct pci_dev *pdev;
1150 struct tran_int_desc *int_desc;
1151 struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq);
1152 struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
1153
1154 pdev = msi_desc_to_pci_dev(msi);
1155 hbus = info->data;
1156 int_desc = irq_data_get_irq_chip_data(irq_data);
1157 if (!int_desc)
1158 return;
1159
1160 irq_data->chip_data = NULL;
1161 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
1162 if (!hpdev) {
1163 kfree(int_desc);
1164 return;
1165 }
1166
1167 hv_int_desc_free(hpdev, int_desc);
1168 put_pcichild(hpdev);
1169}
1170
1171static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest,
1172 bool force)
1173{
1174 struct irq_data *parent = data->parent_data;
1175
1176 return parent->chip->irq_set_affinity(parent, dest, force);
1177}
1178
1179static void hv_irq_mask(struct irq_data *data)
1180{
1181 pci_msi_mask_irq(data);
1182}
1183
1184/**
1185 * hv_irq_unmask() - "Unmask" the IRQ by setting its current
1186 * affinity.
1187 * @data: Describes the IRQ
1188 *
1189 * Build new a destination for the MSI and make a hypercall to
1190 * update the Interrupt Redirection Table. "Device Logical ID"
1191 * is built out of this PCI bus's instance GUID and the function
1192 * number of the device.
1193 */
1194static void hv_irq_unmask(struct irq_data *data)
1195{
1196 struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
1197 struct irq_cfg *cfg = irqd_cfg(data);
1198 struct hv_retarget_device_interrupt *params;
1199 struct hv_pcibus_device *hbus;
1200 struct cpumask *dest;
1201 cpumask_var_t tmp;
1202 struct pci_bus *pbus;
1203 struct pci_dev *pdev;
1204 unsigned long flags;
1205 u32 var_size = 0;
1206 int cpu, nr_bank;
1207 u64 res;
1208
1209 dest = irq_data_get_effective_affinity_mask(data);
1210 pdev = msi_desc_to_pci_dev(msi_desc);
1211 pbus = pdev->bus;
1212 hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
1213
1214 spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);
1215
1216 params = &hbus->retarget_msi_interrupt_params;
1217 memset(params, 0, sizeof(*params));
1218 params->partition_id = HV_PARTITION_ID_SELF;
1219 params->int_entry.source = 1; /* MSI(-X) */
1220 hv_set_msi_entry_from_desc(¶ms->int_entry.msi_entry, msi_desc);
1221 params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
1222 (hbus->hdev->dev_instance.b[4] << 16) |
1223 (hbus->hdev->dev_instance.b[7] << 8) |
1224 (hbus->hdev->dev_instance.b[6] & 0xf8) |
1225 PCI_FUNC(pdev->devfn);
1226 params->int_target.vector = cfg->vector;
1227
1228 /*
1229 * Honoring apic->irq_delivery_mode set to dest_Fixed by
1230 * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
1231 * spurious interrupt storm. Not doing so does not seem to have a
1232 * negative effect (yet?).
1233 */
1234
1235 if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
1236 /*
1237 * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
1238 * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
1239 * with >64 VP support.
1240 * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED
1241 * is not sufficient for this hypercall.
1242 */
1243 params->int_target.flags |=
1244 HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
1245
1246 if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {
1247 res = 1;
1248 goto exit_unlock;
1249 }
1250
1251 cpumask_and(tmp, dest, cpu_online_mask);
1252 nr_bank = cpumask_to_vpset(¶ms->int_target.vp_set, tmp);
1253 free_cpumask_var(tmp);
1254
1255 if (nr_bank <= 0) {
1256 res = 1;
1257 goto exit_unlock;
1258 }
1259
1260 /*
1261 * var-sized hypercall, var-size starts after vp_mask (thus
1262 * vp_set.format does not count, but vp_set.valid_bank_mask
1263 * does).
1264 */
1265 var_size = 1 + nr_bank;
1266 } else {
1267 for_each_cpu_and(cpu, dest, cpu_online_mask) {
1268 params->int_target.vp_mask |=
1269 (1ULL << hv_cpu_number_to_vp_number(cpu));
1270 }
1271 }
1272
1273 res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),
1274 params, NULL);
1275
1276exit_unlock:
1277 spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
1278
1279 if (res) {
1280 dev_err(&hbus->hdev->device,
1281 "%s() failed: %#llx", __func__, res);
1282 return;
1283 }
1284
1285 pci_msi_unmask_irq(data);
1286}
1287
1288struct compose_comp_ctxt {
1289 struct hv_pci_compl comp_pkt;
1290 struct tran_int_desc int_desc;
1291};
1292
1293static void hv_pci_compose_compl(void *context, struct pci_response *resp,
1294 int resp_packet_size)
1295{
1296 struct compose_comp_ctxt *comp_pkt = context;
1297 struct pci_create_int_response *int_resp =
1298 (struct pci_create_int_response *)resp;
1299
1300 comp_pkt->comp_pkt.completion_status = resp->status;
1301 comp_pkt->int_desc = int_resp->int_desc;
1302 complete(&comp_pkt->comp_pkt.host_event);
1303}
1304
1305static u32 hv_compose_msi_req_v1(
1306 struct pci_create_interrupt *int_pkt, struct cpumask *affinity,
1307 u32 slot, u8 vector)
1308{
1309 int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
1310 int_pkt->wslot.slot = slot;
1311 int_pkt->int_desc.vector = vector;
1312 int_pkt->int_desc.vector_count = 1;
1313 int_pkt->int_desc.delivery_mode = dest_Fixed;
1314
1315 /*
1316 * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
1317 * hv_irq_unmask().
1318 */
1319 int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
1320
1321 return sizeof(*int_pkt);
1322}
1323
1324static u32 hv_compose_msi_req_v2(
1325 struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity,
1326 u32 slot, u8 vector)
1327{
1328 int cpu;
1329
1330 int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2;
1331 int_pkt->wslot.slot = slot;
1332 int_pkt->int_desc.vector = vector;
1333 int_pkt->int_desc.vector_count = 1;
1334 int_pkt->int_desc.delivery_mode = dest_Fixed;
1335
1336 /*
1337 * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
1338 * by subsequent retarget in hv_irq_unmask().
1339 */
1340 cpu = cpumask_first_and(affinity, cpu_online_mask);
1341 int_pkt->int_desc.processor_array[0] =
1342 hv_cpu_number_to_vp_number(cpu);
1343 int_pkt->int_desc.processor_count = 1;
1344
1345 return sizeof(*int_pkt);
1346}
1347
1348/**
1349 * hv_compose_msi_msg() - Supplies a valid MSI address/data
1350 * @data: Everything about this MSI
1351 * @msg: Buffer that is filled in by this function
1352 *
1353 * This function unpacks the IRQ looking for target CPU set, IDT
1354 * vector and mode and sends a message to the parent partition
1355 * asking for a mapping for that tuple in this partition. The
1356 * response supplies a data value and address to which that data
1357 * should be written to trigger that interrupt.
1358 */
1359static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
1360{
1361 struct irq_cfg *cfg = irqd_cfg(data);
1362 struct hv_pcibus_device *hbus;
1363 struct vmbus_channel *channel;
1364 struct hv_pci_dev *hpdev;
1365 struct pci_bus *pbus;
1366 struct pci_dev *pdev;
1367 struct cpumask *dest;
1368 struct compose_comp_ctxt comp;
1369 struct tran_int_desc *int_desc;
1370 struct {
1371 struct pci_packet pci_pkt;
1372 union {
1373 struct pci_create_interrupt v1;
1374 struct pci_create_interrupt2 v2;
1375 } int_pkts;
1376 } __packed ctxt;
1377
1378 u32 size;
1379 int ret;
1380
1381 pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data));
1382 dest = irq_data_get_effective_affinity_mask(data);
1383 pbus = pdev->bus;
1384 hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
1385 channel = hbus->hdev->channel;
1386 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
1387 if (!hpdev)
1388 goto return_null_message;
1389
1390 /* Free any previous message that might have already been composed. */
1391 if (data->chip_data) {
1392 int_desc = data->chip_data;
1393 data->chip_data = NULL;
1394 hv_int_desc_free(hpdev, int_desc);
1395 }
1396
1397 int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC);
1398 if (!int_desc)
1399 goto drop_reference;
1400
1401 memset(&ctxt, 0, sizeof(ctxt));
1402 init_completion(&comp.comp_pkt.host_event);
1403 ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
1404 ctxt.pci_pkt.compl_ctxt = ∁
1405
1406 switch (hbus->protocol_version) {
1407 case PCI_PROTOCOL_VERSION_1_1:
1408 size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
1409 dest,
1410 hpdev->desc.win_slot.slot,
1411 cfg->vector);
1412 break;
1413
1414 case PCI_PROTOCOL_VERSION_1_2:
1415 case PCI_PROTOCOL_VERSION_1_3:
1416 size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,
1417 dest,
1418 hpdev->desc.win_slot.slot,
1419 cfg->vector);
1420 break;
1421
1422 default:
1423 /* As we only negotiate protocol versions known to this driver,
1424 * this path should never hit. However, this is it not a hot
1425 * path so we print a message to aid future updates.
1426 */
1427 dev_err(&hbus->hdev->device,
1428 "Unexpected vPCI protocol, update driver.");
1429 goto free_int_desc;
1430 }
1431
1432 ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, &ctxt.int_pkts,
1433 size, (unsigned long)&ctxt.pci_pkt,
1434 VM_PKT_DATA_INBAND,
1435 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1436 if (ret) {
1437 dev_err(&hbus->hdev->device,
1438 "Sending request for interrupt failed: 0x%x",
1439 comp.comp_pkt.completion_status);
1440 goto free_int_desc;
1441 }
1442
1443 /*
1444 * Prevents hv_pci_onchannelcallback() from running concurrently
1445 * in the tasklet.
1446 */
1447 tasklet_disable(&channel->callback_event);
1448
1449 /*
1450 * Since this function is called with IRQ locks held, can't
1451 * do normal wait for completion; instead poll.
1452 */
1453 while (!try_wait_for_completion(&comp.comp_pkt.host_event)) {
1454 unsigned long flags;
1455
1456 /* 0xFFFF means an invalid PCI VENDOR ID. */
1457 if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) {
1458 dev_err_once(&hbus->hdev->device,
1459 "the device has gone\n");
1460 goto enable_tasklet;
1461 }
1462
1463 /*
1464 * Make sure that the ring buffer data structure doesn't get
1465 * freed while we dereference the ring buffer pointer. Test
1466 * for the channel's onchannel_callback being NULL within a
1467 * sched_lock critical section. See also the inline comments
1468 * in vmbus_reset_channel_cb().
1469 */
1470 spin_lock_irqsave(&channel->sched_lock, flags);
1471 if (unlikely(channel->onchannel_callback == NULL)) {
1472 spin_unlock_irqrestore(&channel->sched_lock, flags);
1473 goto enable_tasklet;
1474 }
1475 hv_pci_onchannelcallback(hbus);
1476 spin_unlock_irqrestore(&channel->sched_lock, flags);
1477
1478 if (hpdev->state == hv_pcichild_ejecting) {
1479 dev_err_once(&hbus->hdev->device,
1480 "the device is being ejected\n");
1481 goto enable_tasklet;
1482 }
1483
1484 udelay(100);
1485 }
1486
1487 tasklet_enable(&channel->callback_event);
1488
1489 if (comp.comp_pkt.completion_status < 0) {
1490 dev_err(&hbus->hdev->device,
1491 "Request for interrupt failed: 0x%x",
1492 comp.comp_pkt.completion_status);
1493 goto free_int_desc;
1494 }
1495
1496 /*
1497 * Record the assignment so that this can be unwound later. Using
1498 * irq_set_chip_data() here would be appropriate, but the lock it takes
1499 * is already held.
1500 */
1501 *int_desc = comp.int_desc;
1502 data->chip_data = int_desc;
1503
1504 /* Pass up the result. */
1505 msg->address_hi = comp.int_desc.address >> 32;
1506 msg->address_lo = comp.int_desc.address & 0xffffffff;
1507 msg->data = comp.int_desc.data;
1508
1509 put_pcichild(hpdev);
1510 return;
1511
1512enable_tasklet:
1513 tasklet_enable(&channel->callback_event);
1514free_int_desc:
1515 kfree(int_desc);
1516drop_reference:
1517 put_pcichild(hpdev);
1518return_null_message:
1519 msg->address_hi = 0;
1520 msg->address_lo = 0;
1521 msg->data = 0;
1522}
1523
1524/* HW Interrupt Chip Descriptor */
1525static struct irq_chip hv_msi_irq_chip = {
1526 .name = "Hyper-V PCIe MSI",
1527 .irq_compose_msi_msg = hv_compose_msi_msg,
1528 .irq_set_affinity = hv_set_affinity,
1529 .irq_ack = irq_chip_ack_parent,
1530 .irq_mask = hv_irq_mask,
1531 .irq_unmask = hv_irq_unmask,
1532};
1533
1534static irq_hw_number_t hv_msi_domain_ops_get_hwirq(struct msi_domain_info *info,
1535 msi_alloc_info_t *arg)
1536{
1537 return arg->msi_hwirq;
1538}
1539
1540static struct msi_domain_ops hv_msi_ops = {
1541 .get_hwirq = hv_msi_domain_ops_get_hwirq,
1542 .msi_prepare = pci_msi_prepare,
1543 .set_desc = pci_msi_set_desc,
1544 .msi_free = hv_msi_free,
1545};
1546
1547/**
1548 * hv_pcie_init_irq_domain() - Initialize IRQ domain
1549 * @hbus: The root PCI bus
1550 *
1551 * This function creates an IRQ domain which will be used for
1552 * interrupts from devices that have been passed through. These
1553 * devices only support MSI and MSI-X, not line-based interrupts
1554 * or simulations of line-based interrupts through PCIe's
1555 * fabric-layer messages. Because interrupts are remapped, we
1556 * can support multi-message MSI here.
1557 *
1558 * Return: '0' on success and error value on failure
1559 */
1560static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
1561{
1562 hbus->msi_info.chip = &hv_msi_irq_chip;
1563 hbus->msi_info.ops = &hv_msi_ops;
1564 hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
1565 MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
1566 MSI_FLAG_PCI_MSIX);
1567 hbus->msi_info.handler = handle_edge_irq;
1568 hbus->msi_info.handler_name = "edge";
1569 hbus->msi_info.data = hbus;
1570 hbus->irq_domain = pci_msi_create_irq_domain(hbus->sysdata.fwnode,
1571 &hbus->msi_info,
1572 x86_vector_domain);
1573 if (!hbus->irq_domain) {
1574 dev_err(&hbus->hdev->device,
1575 "Failed to build an MSI IRQ domain\n");
1576 return -ENODEV;
1577 }
1578
1579 return 0;
1580}
1581
1582/**
1583 * get_bar_size() - Get the address space consumed by a BAR
1584 * @bar_val: Value that a BAR returned after -1 was written
1585 * to it.
1586 *
1587 * This function returns the size of the BAR, rounded up to 1
1588 * page. It has to be rounded up because the hypervisor's page
1589 * table entry that maps the BAR into the VM can't specify an
1590 * offset within a page. The invariant is that the hypervisor
1591 * must place any BARs of smaller than page length at the
1592 * beginning of a page.
1593 *
1594 * Return: Size in bytes of the consumed MMIO space.
1595 */
1596static u64 get_bar_size(u64 bar_val)
1597{
1598 return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)),
1599 PAGE_SIZE);
1600}
1601
1602/**
1603 * survey_child_resources() - Total all MMIO requirements
1604 * @hbus: Root PCI bus, as understood by this driver
1605 */
1606static void survey_child_resources(struct hv_pcibus_device *hbus)
1607{
1608 struct hv_pci_dev *hpdev;
1609 resource_size_t bar_size = 0;
1610 unsigned long flags;
1611 struct completion *event;
1612 u64 bar_val;
1613 int i;
1614
1615 /* If nobody is waiting on the answer, don't compute it. */
1616 event = xchg(&hbus->survey_event, NULL);
1617 if (!event)
1618 return;
1619
1620 /* If the answer has already been computed, go with it. */
1621 if (hbus->low_mmio_space || hbus->high_mmio_space) {
1622 complete(event);
1623 return;
1624 }
1625
1626 spin_lock_irqsave(&hbus->device_list_lock, flags);
1627
1628 /*
1629 * Due to an interesting quirk of the PCI spec, all memory regions
1630 * for a child device are a power of 2 in size and aligned in memory,
1631 * so it's sufficient to just add them up without tracking alignment.
1632 */
1633 list_for_each_entry(hpdev, &hbus->children, list_entry) {
1634 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
1635 if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO)
1636 dev_err(&hbus->hdev->device,
1637 "There's an I/O BAR in this list!\n");
1638
1639 if (hpdev->probed_bar[i] != 0) {
1640 /*
1641 * A probed BAR has all the upper bits set that
1642 * can be changed.
1643 */
1644
1645 bar_val = hpdev->probed_bar[i];
1646 if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
1647 bar_val |=
1648 ((u64)hpdev->probed_bar[++i] << 32);
1649 else
1650 bar_val |= 0xffffffff00000000ULL;
1651
1652 bar_size = get_bar_size(bar_val);
1653
1654 if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
1655 hbus->high_mmio_space += bar_size;
1656 else
1657 hbus->low_mmio_space += bar_size;
1658 }
1659 }
1660 }
1661
1662 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
1663 complete(event);
1664}
1665
1666/**
1667 * prepopulate_bars() - Fill in BARs with defaults
1668 * @hbus: Root PCI bus, as understood by this driver
1669 *
1670 * The core PCI driver code seems much, much happier if the BARs
1671 * for a device have values upon first scan. So fill them in.
1672 * The algorithm below works down from large sizes to small,
1673 * attempting to pack the assignments optimally. The assumption,
1674 * enforced in other parts of the code, is that the beginning of
1675 * the memory-mapped I/O space will be aligned on the largest
1676 * BAR size.
1677 */
1678static void prepopulate_bars(struct hv_pcibus_device *hbus)
1679{
1680 resource_size_t high_size = 0;
1681 resource_size_t low_size = 0;
1682 resource_size_t high_base = 0;
1683 resource_size_t low_base = 0;
1684 resource_size_t bar_size;
1685 struct hv_pci_dev *hpdev;
1686 unsigned long flags;
1687 u64 bar_val;
1688 u32 command;
1689 bool high;
1690 int i;
1691
1692 if (hbus->low_mmio_space) {
1693 low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
1694 low_base = hbus->low_mmio_res->start;
1695 }
1696
1697 if (hbus->high_mmio_space) {
1698 high_size = 1ULL <<
1699 (63 - __builtin_clzll(hbus->high_mmio_space));
1700 high_base = hbus->high_mmio_res->start;
1701 }
1702
1703 spin_lock_irqsave(&hbus->device_list_lock, flags);
1704
1705 /*
1706 * Clear the memory enable bit, in case it's already set. This occurs
1707 * in the suspend path of hibernation, where the device is suspended,
1708 * resumed and suspended again: see hibernation_snapshot() and
1709 * hibernation_platform_enter().
1710 *
1711 * If the memory enable bit is already set, Hyper-V sliently ignores
1712 * the below BAR updates, and the related PCI device driver can not
1713 * work, because reading from the device register(s) always returns
1714 * 0xFFFFFFFF.
1715 */
1716 list_for_each_entry(hpdev, &hbus->children, list_entry) {
1717 _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command);
1718 command &= ~PCI_COMMAND_MEMORY;
1719 _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command);
1720 }
1721
1722 /* Pick addresses for the BARs. */
1723 do {
1724 list_for_each_entry(hpdev, &hbus->children, list_entry) {
1725 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
1726 bar_val = hpdev->probed_bar[i];
1727 if (bar_val == 0)
1728 continue;
1729 high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64;
1730 if (high) {
1731 bar_val |=
1732 ((u64)hpdev->probed_bar[i + 1]
1733 << 32);
1734 } else {
1735 bar_val |= 0xffffffffULL << 32;
1736 }
1737 bar_size = get_bar_size(bar_val);
1738 if (high) {
1739 if (high_size != bar_size) {
1740 i++;
1741 continue;
1742 }
1743 _hv_pcifront_write_config(hpdev,
1744 PCI_BASE_ADDRESS_0 + (4 * i),
1745 4,
1746 (u32)(high_base & 0xffffff00));
1747 i++;
1748 _hv_pcifront_write_config(hpdev,
1749 PCI_BASE_ADDRESS_0 + (4 * i),
1750 4, (u32)(high_base >> 32));
1751 high_base += bar_size;
1752 } else {
1753 if (low_size != bar_size)
1754 continue;
1755 _hv_pcifront_write_config(hpdev,
1756 PCI_BASE_ADDRESS_0 + (4 * i),
1757 4,
1758 (u32)(low_base & 0xffffff00));
1759 low_base += bar_size;
1760 }
1761 }
1762 if (high_size <= 1 && low_size <= 1) {
1763 /* Set the memory enable bit. */
1764 _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2,
1765 &command);
1766 command |= PCI_COMMAND_MEMORY;
1767 _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2,
1768 command);
1769 break;
1770 }
1771 }
1772
1773 high_size >>= 1;
1774 low_size >>= 1;
1775 } while (high_size || low_size);
1776
1777 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
1778}
1779
1780/*
1781 * Assign entries in sysfs pci slot directory.
1782 *
1783 * Note that this function does not need to lock the children list
1784 * because it is called from pci_devices_present_work which
1785 * is serialized with hv_eject_device_work because they are on the
1786 * same ordered workqueue. Therefore hbus->children list will not change
1787 * even when pci_create_slot sleeps.
1788 */
1789static void hv_pci_assign_slots(struct hv_pcibus_device *hbus)
1790{
1791 struct hv_pci_dev *hpdev;
1792 char name[SLOT_NAME_SIZE];
1793 int slot_nr;
1794
1795 list_for_each_entry(hpdev, &hbus->children, list_entry) {
1796 if (hpdev->pci_slot)
1797 continue;
1798
1799 slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot));
1800 snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser);
1801 hpdev->pci_slot = pci_create_slot(hbus->pci_bus, slot_nr,
1802 name, NULL);
1803 if (IS_ERR(hpdev->pci_slot)) {
1804 pr_warn("pci_create slot %s failed\n", name);
1805 hpdev->pci_slot = NULL;
1806 }
1807 }
1808}
1809
1810/*
1811 * Remove entries in sysfs pci slot directory.
1812 */
1813static void hv_pci_remove_slots(struct hv_pcibus_device *hbus)
1814{
1815 struct hv_pci_dev *hpdev;
1816
1817 list_for_each_entry(hpdev, &hbus->children, list_entry) {
1818 if (!hpdev->pci_slot)
1819 continue;
1820 pci_destroy_slot(hpdev->pci_slot);
1821 hpdev->pci_slot = NULL;
1822 }
1823}
1824
1825/*
1826 * Set NUMA node for the devices on the bus
1827 */
1828static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus)
1829{
1830 struct pci_dev *dev;
1831 struct pci_bus *bus = hbus->pci_bus;
1832 struct hv_pci_dev *hv_dev;
1833
1834 list_for_each_entry(dev, &bus->devices, bus_list) {
1835 hv_dev = get_pcichild_wslot(hbus, devfn_to_wslot(dev->devfn));
1836 if (!hv_dev)
1837 continue;
1838
1839 if (hv_dev->desc.flags & HV_PCI_DEVICE_FLAG_NUMA_AFFINITY)
1840 set_dev_node(&dev->dev, hv_dev->desc.virtual_numa_node);
1841
1842 put_pcichild(hv_dev);
1843 }
1844}
1845
1846/**
1847 * create_root_hv_pci_bus() - Expose a new root PCI bus
1848 * @hbus: Root PCI bus, as understood by this driver
1849 *
1850 * Return: 0 on success, -errno on failure
1851 */
1852static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
1853{
1854 /* Register the device */
1855 hbus->pci_bus = pci_create_root_bus(&hbus->hdev->device,
1856 0, /* bus number is always zero */
1857 &hv_pcifront_ops,
1858 &hbus->sysdata,
1859 &hbus->resources_for_children);
1860 if (!hbus->pci_bus)
1861 return -ENODEV;
1862
1863 hbus->pci_bus->msi = &hbus->msi_chip;
1864 hbus->pci_bus->msi->dev = &hbus->hdev->device;
1865
1866 pci_lock_rescan_remove();
1867 pci_scan_child_bus(hbus->pci_bus);
1868 hv_pci_assign_numa_node(hbus);
1869 pci_bus_assign_resources(hbus->pci_bus);
1870 hv_pci_assign_slots(hbus);
1871 pci_bus_add_devices(hbus->pci_bus);
1872 pci_unlock_rescan_remove();
1873 hbus->state = hv_pcibus_installed;
1874 return 0;
1875}
1876
1877struct q_res_req_compl {
1878 struct completion host_event;
1879 struct hv_pci_dev *hpdev;
1880};
1881
1882/**
1883 * q_resource_requirements() - Query Resource Requirements
1884 * @context: The completion context.
1885 * @resp: The response that came from the host.
1886 * @resp_packet_size: The size in bytes of resp.
1887 *
1888 * This function is invoked on completion of a Query Resource
1889 * Requirements packet.
1890 */
1891static void q_resource_requirements(void *context, struct pci_response *resp,
1892 int resp_packet_size)
1893{
1894 struct q_res_req_compl *completion = context;
1895 struct pci_q_res_req_response *q_res_req =
1896 (struct pci_q_res_req_response *)resp;
1897 int i;
1898
1899 if (resp->status < 0) {
1900 dev_err(&completion->hpdev->hbus->hdev->device,
1901 "query resource requirements failed: %x\n",
1902 resp->status);
1903 } else {
1904 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
1905 completion->hpdev->probed_bar[i] =
1906 q_res_req->probed_bar[i];
1907 }
1908 }
1909
1910 complete(&completion->host_event);
1911}
1912
1913/**
1914 * new_pcichild_device() - Create a new child device
1915 * @hbus: The internal struct tracking this root PCI bus.
1916 * @desc: The information supplied so far from the host
1917 * about the device.
1918 *
1919 * This function creates the tracking structure for a new child
1920 * device and kicks off the process of figuring out what it is.
1921 *
1922 * Return: Pointer to the new tracking struct
1923 */
1924static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
1925 struct hv_pcidev_description *desc)
1926{
1927 struct hv_pci_dev *hpdev;
1928 struct pci_child_message *res_req;
1929 struct q_res_req_compl comp_pkt;
1930 struct {
1931 struct pci_packet init_packet;
1932 u8 buffer[sizeof(struct pci_child_message)];
1933 } pkt;
1934 unsigned long flags;
1935 int ret;
1936
1937 hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL);
1938 if (!hpdev)
1939 return NULL;
1940
1941 hpdev->hbus = hbus;
1942
1943 memset(&pkt, 0, sizeof(pkt));
1944 init_completion(&comp_pkt.host_event);
1945 comp_pkt.hpdev = hpdev;
1946 pkt.init_packet.compl_ctxt = &comp_pkt;
1947 pkt.init_packet.completion_func = q_resource_requirements;
1948 res_req = (struct pci_child_message *)&pkt.init_packet.message;
1949 res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS;
1950 res_req->wslot.slot = desc->win_slot.slot;
1951
1952 ret = vmbus_sendpacket(hbus->hdev->channel, res_req,
1953 sizeof(struct pci_child_message),
1954 (unsigned long)&pkt.init_packet,
1955 VM_PKT_DATA_INBAND,
1956 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1957 if (ret)
1958 goto error;
1959
1960 if (wait_for_response(hbus->hdev, &comp_pkt.host_event))
1961 goto error;
1962
1963 hpdev->desc = *desc;
1964 refcount_set(&hpdev->refs, 1);
1965 get_pcichild(hpdev);
1966 spin_lock_irqsave(&hbus->device_list_lock, flags);
1967
1968 list_add_tail(&hpdev->list_entry, &hbus->children);
1969 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
1970 return hpdev;
1971
1972error:
1973 kfree(hpdev);
1974 return NULL;
1975}
1976
1977/**
1978 * get_pcichild_wslot() - Find device from slot
1979 * @hbus: Root PCI bus, as understood by this driver
1980 * @wslot: Location on the bus
1981 *
1982 * This function looks up a PCI device and returns the internal
1983 * representation of it. It acquires a reference on it, so that
1984 * the device won't be deleted while somebody is using it. The
1985 * caller is responsible for calling put_pcichild() to release
1986 * this reference.
1987 *
1988 * Return: Internal representation of a PCI device
1989 */
1990static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
1991 u32 wslot)
1992{
1993 unsigned long flags;
1994 struct hv_pci_dev *iter, *hpdev = NULL;
1995
1996 spin_lock_irqsave(&hbus->device_list_lock, flags);
1997 list_for_each_entry(iter, &hbus->children, list_entry) {
1998 if (iter->desc.win_slot.slot == wslot) {
1999 hpdev = iter;
2000 get_pcichild(hpdev);
2001 break;
2002 }
2003 }
2004 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2005
2006 return hpdev;
2007}
2008
2009/**
2010 * pci_devices_present_work() - Handle new list of child devices
2011 * @work: Work struct embedded in struct hv_dr_work
2012 *
2013 * "Bus Relations" is the Windows term for "children of this
2014 * bus." The terminology is preserved here for people trying to
2015 * debug the interaction between Hyper-V and Linux. This
2016 * function is called when the parent partition reports a list
2017 * of functions that should be observed under this PCI Express
2018 * port (bus).
2019 *
2020 * This function updates the list, and must tolerate being
2021 * called multiple times with the same information. The typical
2022 * number of child devices is one, with very atypical cases
2023 * involving three or four, so the algorithms used here can be
2024 * simple and inefficient.
2025 *
2026 * It must also treat the omission of a previously observed device as
2027 * notification that the device no longer exists.
2028 *
2029 * Note that this function is serialized with hv_eject_device_work(),
2030 * because both are pushed to the ordered workqueue hbus->wq.
2031 */
2032static void pci_devices_present_work(struct work_struct *work)
2033{
2034 u32 child_no;
2035 bool found;
2036 struct hv_pcidev_description *new_desc;
2037 struct hv_pci_dev *hpdev;
2038 struct hv_pcibus_device *hbus;
2039 struct list_head removed;
2040 struct hv_dr_work *dr_wrk;
2041 struct hv_dr_state *dr = NULL;
2042 unsigned long flags;
2043
2044 dr_wrk = container_of(work, struct hv_dr_work, wrk);
2045 hbus = dr_wrk->bus;
2046 kfree(dr_wrk);
2047
2048 INIT_LIST_HEAD(&removed);
2049
2050 /* Pull this off the queue and process it if it was the last one. */
2051 spin_lock_irqsave(&hbus->device_list_lock, flags);
2052 while (!list_empty(&hbus->dr_list)) {
2053 dr = list_first_entry(&hbus->dr_list, struct hv_dr_state,
2054 list_entry);
2055 list_del(&dr->list_entry);
2056
2057 /* Throw this away if the list still has stuff in it. */
2058 if (!list_empty(&hbus->dr_list)) {
2059 kfree(dr);
2060 continue;
2061 }
2062 }
2063 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2064
2065 if (!dr) {
2066 put_hvpcibus(hbus);
2067 return;
2068 }
2069
2070 /* First, mark all existing children as reported missing. */
2071 spin_lock_irqsave(&hbus->device_list_lock, flags);
2072 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2073 hpdev->reported_missing = true;
2074 }
2075 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2076
2077 /* Next, add back any reported devices. */
2078 for (child_no = 0; child_no < dr->device_count; child_no++) {
2079 found = false;
2080 new_desc = &dr->func[child_no];
2081
2082 spin_lock_irqsave(&hbus->device_list_lock, flags);
2083 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2084 if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) &&
2085 (hpdev->desc.v_id == new_desc->v_id) &&
2086 (hpdev->desc.d_id == new_desc->d_id) &&
2087 (hpdev->desc.ser == new_desc->ser)) {
2088 hpdev->reported_missing = false;
2089 found = true;
2090 }
2091 }
2092 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2093
2094 if (!found) {
2095 hpdev = new_pcichild_device(hbus, new_desc);
2096 if (!hpdev)
2097 dev_err(&hbus->hdev->device,
2098 "couldn't record a child device.\n");
2099 }
2100 }
2101
2102 /* Move missing children to a list on the stack. */
2103 spin_lock_irqsave(&hbus->device_list_lock, flags);
2104 do {
2105 found = false;
2106 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2107 if (hpdev->reported_missing) {
2108 found = true;
2109 put_pcichild(hpdev);
2110 list_move_tail(&hpdev->list_entry, &removed);
2111 break;
2112 }
2113 }
2114 } while (found);
2115 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2116
2117 /* Delete everything that should no longer exist. */
2118 while (!list_empty(&removed)) {
2119 hpdev = list_first_entry(&removed, struct hv_pci_dev,
2120 list_entry);
2121 list_del(&hpdev->list_entry);
2122
2123 if (hpdev->pci_slot)
2124 pci_destroy_slot(hpdev->pci_slot);
2125
2126 put_pcichild(hpdev);
2127 }
2128
2129 switch (hbus->state) {
2130 case hv_pcibus_installed:
2131 /*
2132 * Tell the core to rescan bus
2133 * because there may have been changes.
2134 */
2135 pci_lock_rescan_remove();
2136 pci_scan_child_bus(hbus->pci_bus);
2137 hv_pci_assign_numa_node(hbus);
2138 hv_pci_assign_slots(hbus);
2139 pci_unlock_rescan_remove();
2140 break;
2141
2142 case hv_pcibus_init:
2143 case hv_pcibus_probed:
2144 survey_child_resources(hbus);
2145 break;
2146
2147 default:
2148 break;
2149 }
2150
2151 put_hvpcibus(hbus);
2152 kfree(dr);
2153}
2154
2155/**
2156 * hv_pci_start_relations_work() - Queue work to start device discovery
2157 * @hbus: Root PCI bus, as understood by this driver
2158 * @dr: The list of children returned from host
2159 *
2160 * Return: 0 on success, -errno on failure
2161 */
2162static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
2163 struct hv_dr_state *dr)
2164{
2165 struct hv_dr_work *dr_wrk;
2166 unsigned long flags;
2167 bool pending_dr;
2168
2169 if (hbus->state == hv_pcibus_removing) {
2170 dev_info(&hbus->hdev->device,
2171 "PCI VMBus BUS_RELATIONS: ignored\n");
2172 return -ENOENT;
2173 }
2174
2175 dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
2176 if (!dr_wrk)
2177 return -ENOMEM;
2178
2179 INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
2180 dr_wrk->bus = hbus;
2181
2182 spin_lock_irqsave(&hbus->device_list_lock, flags);
2183 /*
2184 * If pending_dr is true, we have already queued a work,
2185 * which will see the new dr. Otherwise, we need to
2186 * queue a new work.
2187 */
2188 pending_dr = !list_empty(&hbus->dr_list);
2189 list_add_tail(&dr->list_entry, &hbus->dr_list);
2190 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2191
2192 if (pending_dr) {
2193 kfree(dr_wrk);
2194 } else {
2195 get_hvpcibus(hbus);
2196 queue_work(hbus->wq, &dr_wrk->wrk);
2197 }
2198
2199 return 0;
2200}
2201
2202/**
2203 * hv_pci_devices_present() - Handle list of new children
2204 * @hbus: Root PCI bus, as understood by this driver
2205 * @relations: Packet from host listing children
2206 *
2207 * Process a new list of devices on the bus. The list of devices is
2208 * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
2209 * whenever a new list of devices for this bus appears.
2210 */
2211static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
2212 struct pci_bus_relations *relations)
2213{
2214 struct hv_dr_state *dr;
2215 int i;
2216
2217 dr = kzalloc(struct_size(dr, func, relations->device_count),
2218 GFP_NOWAIT);
2219 if (!dr)
2220 return;
2221
2222 dr->device_count = relations->device_count;
2223 for (i = 0; i < dr->device_count; i++) {
2224 dr->func[i].v_id = relations->func[i].v_id;
2225 dr->func[i].d_id = relations->func[i].d_id;
2226 dr->func[i].rev = relations->func[i].rev;
2227 dr->func[i].prog_intf = relations->func[i].prog_intf;
2228 dr->func[i].subclass = relations->func[i].subclass;
2229 dr->func[i].base_class = relations->func[i].base_class;
2230 dr->func[i].subsystem_id = relations->func[i].subsystem_id;
2231 dr->func[i].win_slot = relations->func[i].win_slot;
2232 dr->func[i].ser = relations->func[i].ser;
2233 }
2234
2235 if (hv_pci_start_relations_work(hbus, dr))
2236 kfree(dr);
2237}
2238
2239/**
2240 * hv_pci_devices_present2() - Handle list of new children
2241 * @hbus: Root PCI bus, as understood by this driver
2242 * @relations: Packet from host listing children
2243 *
2244 * This function is the v2 version of hv_pci_devices_present()
2245 */
2246static void hv_pci_devices_present2(struct hv_pcibus_device *hbus,
2247 struct pci_bus_relations2 *relations)
2248{
2249 struct hv_dr_state *dr;
2250 int i;
2251
2252 dr = kzalloc(struct_size(dr, func, relations->device_count),
2253 GFP_NOWAIT);
2254 if (!dr)
2255 return;
2256
2257 dr->device_count = relations->device_count;
2258 for (i = 0; i < dr->device_count; i++) {
2259 dr->func[i].v_id = relations->func[i].v_id;
2260 dr->func[i].d_id = relations->func[i].d_id;
2261 dr->func[i].rev = relations->func[i].rev;
2262 dr->func[i].prog_intf = relations->func[i].prog_intf;
2263 dr->func[i].subclass = relations->func[i].subclass;
2264 dr->func[i].base_class = relations->func[i].base_class;
2265 dr->func[i].subsystem_id = relations->func[i].subsystem_id;
2266 dr->func[i].win_slot = relations->func[i].win_slot;
2267 dr->func[i].ser = relations->func[i].ser;
2268 dr->func[i].flags = relations->func[i].flags;
2269 dr->func[i].virtual_numa_node =
2270 relations->func[i].virtual_numa_node;
2271 }
2272
2273 if (hv_pci_start_relations_work(hbus, dr))
2274 kfree(dr);
2275}
2276
2277/**
2278 * hv_eject_device_work() - Asynchronously handles ejection
2279 * @work: Work struct embedded in internal device struct
2280 *
2281 * This function handles ejecting a device. Windows will
2282 * attempt to gracefully eject a device, waiting 60 seconds to
2283 * hear back from the guest OS that this completed successfully.
2284 * If this timer expires, the device will be forcibly removed.
2285 */
2286static void hv_eject_device_work(struct work_struct *work)
2287{
2288 struct pci_eject_response *ejct_pkt;
2289 struct hv_pcibus_device *hbus;
2290 struct hv_pci_dev *hpdev;
2291 struct pci_dev *pdev;
2292 unsigned long flags;
2293 int wslot;
2294 struct {
2295 struct pci_packet pkt;
2296 u8 buffer[sizeof(struct pci_eject_response)];
2297 } ctxt;
2298
2299 hpdev = container_of(work, struct hv_pci_dev, wrk);
2300 hbus = hpdev->hbus;
2301
2302 WARN_ON(hpdev->state != hv_pcichild_ejecting);
2303
2304 /*
2305 * Ejection can come before or after the PCI bus has been set up, so
2306 * attempt to find it and tear down the bus state, if it exists. This
2307 * must be done without constructs like pci_domain_nr(hbus->pci_bus)
2308 * because hbus->pci_bus may not exist yet.
2309 */
2310 wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
2311 pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot);
2312 if (pdev) {
2313 pci_lock_rescan_remove();
2314 pci_stop_and_remove_bus_device(pdev);
2315 pci_dev_put(pdev);
2316 pci_unlock_rescan_remove();
2317 }
2318
2319 spin_lock_irqsave(&hbus->device_list_lock, flags);
2320 list_del(&hpdev->list_entry);
2321 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2322
2323 if (hpdev->pci_slot)
2324 pci_destroy_slot(hpdev->pci_slot);
2325
2326 memset(&ctxt, 0, sizeof(ctxt));
2327 ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
2328 ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
2329 ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
2330 vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
2331 sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt,
2332 VM_PKT_DATA_INBAND, 0);
2333
2334 /* For the get_pcichild() in hv_pci_eject_device() */
2335 put_pcichild(hpdev);
2336 /* For the two refs got in new_pcichild_device() */
2337 put_pcichild(hpdev);
2338 put_pcichild(hpdev);
2339 /* hpdev has been freed. Do not use it any more. */
2340
2341 put_hvpcibus(hbus);
2342}
2343
2344/**
2345 * hv_pci_eject_device() - Handles device ejection
2346 * @hpdev: Internal device tracking struct
2347 *
2348 * This function is invoked when an ejection packet arrives. It
2349 * just schedules work so that we don't re-enter the packet
2350 * delivery code handling the ejection.
2351 */
2352static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
2353{
2354 struct hv_pcibus_device *hbus = hpdev->hbus;
2355 struct hv_device *hdev = hbus->hdev;
2356
2357 if (hbus->state == hv_pcibus_removing) {
2358 dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n");
2359 return;
2360 }
2361
2362 hpdev->state = hv_pcichild_ejecting;
2363 get_pcichild(hpdev);
2364 INIT_WORK(&hpdev->wrk, hv_eject_device_work);
2365 get_hvpcibus(hbus);
2366 queue_work(hbus->wq, &hpdev->wrk);
2367}
2368
2369/**
2370 * hv_pci_onchannelcallback() - Handles incoming packets
2371 * @context: Internal bus tracking struct
2372 *
2373 * This function is invoked whenever the host sends a packet to
2374 * this channel (which is private to this root PCI bus).
2375 */
2376static void hv_pci_onchannelcallback(void *context)
2377{
2378 const int packet_size = 0x100;
2379 int ret;
2380 struct hv_pcibus_device *hbus = context;
2381 u32 bytes_recvd;
2382 u64 req_id;
2383 struct vmpacket_descriptor *desc;
2384 unsigned char *buffer;
2385 int bufferlen = packet_size;
2386 struct pci_packet *comp_packet;
2387 struct pci_response *response;
2388 struct pci_incoming_message *new_message;
2389 struct pci_bus_relations *bus_rel;
2390 struct pci_bus_relations2 *bus_rel2;
2391 struct pci_dev_inval_block *inval;
2392 struct pci_dev_incoming *dev_message;
2393 struct hv_pci_dev *hpdev;
2394
2395 buffer = kmalloc(bufferlen, GFP_ATOMIC);
2396 if (!buffer)
2397 return;
2398
2399 while (1) {
2400 ret = vmbus_recvpacket_raw(hbus->hdev->channel, buffer,
2401 bufferlen, &bytes_recvd, &req_id);
2402
2403 if (ret == -ENOBUFS) {
2404 kfree(buffer);
2405 /* Handle large packet */
2406 bufferlen = bytes_recvd;
2407 buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
2408 if (!buffer)
2409 return;
2410 continue;
2411 }
2412
2413 /* Zero length indicates there are no more packets. */
2414 if (ret || !bytes_recvd)
2415 break;
2416
2417 /*
2418 * All incoming packets must be at least as large as a
2419 * response.
2420 */
2421 if (bytes_recvd <= sizeof(struct pci_response))
2422 continue;
2423 desc = (struct vmpacket_descriptor *)buffer;
2424
2425 switch (desc->type) {
2426 case VM_PKT_COMP:
2427
2428 /*
2429 * The host is trusted, and thus it's safe to interpret
2430 * this transaction ID as a pointer.
2431 */
2432 comp_packet = (struct pci_packet *)req_id;
2433 response = (struct pci_response *)buffer;
2434 comp_packet->completion_func(comp_packet->compl_ctxt,
2435 response,
2436 bytes_recvd);
2437 break;
2438
2439 case VM_PKT_DATA_INBAND:
2440
2441 new_message = (struct pci_incoming_message *)buffer;
2442 switch (new_message->message_type.type) {
2443 case PCI_BUS_RELATIONS:
2444
2445 bus_rel = (struct pci_bus_relations *)buffer;
2446 if (bytes_recvd <
2447 struct_size(bus_rel, func,
2448 bus_rel->device_count)) {
2449 dev_err(&hbus->hdev->device,
2450 "bus relations too small\n");
2451 break;
2452 }
2453
2454 hv_pci_devices_present(hbus, bus_rel);
2455 break;
2456
2457 case PCI_BUS_RELATIONS2:
2458
2459 bus_rel2 = (struct pci_bus_relations2 *)buffer;
2460 if (bytes_recvd <
2461 struct_size(bus_rel2, func,
2462 bus_rel2->device_count)) {
2463 dev_err(&hbus->hdev->device,
2464 "bus relations v2 too small\n");
2465 break;
2466 }
2467
2468 hv_pci_devices_present2(hbus, bus_rel2);
2469 break;
2470
2471 case PCI_EJECT:
2472
2473 dev_message = (struct pci_dev_incoming *)buffer;
2474 hpdev = get_pcichild_wslot(hbus,
2475 dev_message->wslot.slot);
2476 if (hpdev) {
2477 hv_pci_eject_device(hpdev);
2478 put_pcichild(hpdev);
2479 }
2480 break;
2481
2482 case PCI_INVALIDATE_BLOCK:
2483
2484 inval = (struct pci_dev_inval_block *)buffer;
2485 hpdev = get_pcichild_wslot(hbus,
2486 inval->wslot.slot);
2487 if (hpdev) {
2488 if (hpdev->block_invalidate) {
2489 hpdev->block_invalidate(
2490 hpdev->invalidate_context,
2491 inval->block_mask);
2492 }
2493 put_pcichild(hpdev);
2494 }
2495 break;
2496
2497 default:
2498 dev_warn(&hbus->hdev->device,
2499 "Unimplemented protocol message %x\n",
2500 new_message->message_type.type);
2501 break;
2502 }
2503 break;
2504
2505 default:
2506 dev_err(&hbus->hdev->device,
2507 "unhandled packet type %d, tid %llx len %d\n",
2508 desc->type, req_id, bytes_recvd);
2509 break;
2510 }
2511 }
2512
2513 kfree(buffer);
2514}
2515
2516/**
2517 * hv_pci_protocol_negotiation() - Set up protocol
2518 * @hdev: VMBus's tracking struct for this root PCI bus
2519 *
2520 * This driver is intended to support running on Windows 10
2521 * (server) and later versions. It will not run on earlier
2522 * versions, as they assume that many of the operations which
2523 * Linux needs accomplished with a spinlock held were done via
2524 * asynchronous messaging via VMBus. Windows 10 increases the
2525 * surface area of PCI emulation so that these actions can take
2526 * place by suspending a virtual processor for their duration.
2527 *
2528 * This function negotiates the channel protocol version,
2529 * failing if the host doesn't support the necessary protocol
2530 * level.
2531 */
2532static int hv_pci_protocol_negotiation(struct hv_device *hdev,
2533 enum pci_protocol_version_t version[],
2534 int num_version)
2535{
2536 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
2537 struct pci_version_request *version_req;
2538 struct hv_pci_compl comp_pkt;
2539 struct pci_packet *pkt;
2540 int ret;
2541 int i;
2542
2543 /*
2544 * Initiate the handshake with the host and negotiate
2545 * a version that the host can support. We start with the
2546 * highest version number and go down if the host cannot
2547 * support it.
2548 */
2549 pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL);
2550 if (!pkt)
2551 return -ENOMEM;
2552
2553 init_completion(&comp_pkt.host_event);
2554 pkt->completion_func = hv_pci_generic_compl;
2555 pkt->compl_ctxt = &comp_pkt;
2556 version_req = (struct pci_version_request *)&pkt->message;
2557 version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
2558
2559 for (i = 0; i < num_version; i++) {
2560 version_req->protocol_version = version[i];
2561 ret = vmbus_sendpacket(hdev->channel, version_req,
2562 sizeof(struct pci_version_request),
2563 (unsigned long)pkt, VM_PKT_DATA_INBAND,
2564 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
2565 if (!ret)
2566 ret = wait_for_response(hdev, &comp_pkt.host_event);
2567
2568 if (ret) {
2569 dev_err(&hdev->device,
2570 "PCI Pass-through VSP failed to request version: %d",
2571 ret);
2572 goto exit;
2573 }
2574
2575 if (comp_pkt.completion_status >= 0) {
2576 hbus->protocol_version = version[i];
2577 dev_info(&hdev->device,
2578 "PCI VMBus probing: Using version %#x\n",
2579 hbus->protocol_version);
2580 goto exit;
2581 }
2582
2583 if (comp_pkt.completion_status != STATUS_REVISION_MISMATCH) {
2584 dev_err(&hdev->device,
2585 "PCI Pass-through VSP failed version request: %#x",
2586 comp_pkt.completion_status);
2587 ret = -EPROTO;
2588 goto exit;
2589 }
2590
2591 reinit_completion(&comp_pkt.host_event);
2592 }
2593
2594 dev_err(&hdev->device,
2595 "PCI pass-through VSP failed to find supported version");
2596 ret = -EPROTO;
2597
2598exit:
2599 kfree(pkt);
2600 return ret;
2601}
2602
2603/**
2604 * hv_pci_free_bridge_windows() - Release memory regions for the
2605 * bus
2606 * @hbus: Root PCI bus, as understood by this driver
2607 */
2608static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus)
2609{
2610 /*
2611 * Set the resources back to the way they looked when they
2612 * were allocated by setting IORESOURCE_BUSY again.
2613 */
2614
2615 if (hbus->low_mmio_space && hbus->low_mmio_res) {
2616 hbus->low_mmio_res->flags |= IORESOURCE_BUSY;
2617 vmbus_free_mmio(hbus->low_mmio_res->start,
2618 resource_size(hbus->low_mmio_res));
2619 }
2620
2621 if (hbus->high_mmio_space && hbus->high_mmio_res) {
2622 hbus->high_mmio_res->flags |= IORESOURCE_BUSY;
2623 vmbus_free_mmio(hbus->high_mmio_res->start,
2624 resource_size(hbus->high_mmio_res));
2625 }
2626}
2627
2628/**
2629 * hv_pci_allocate_bridge_windows() - Allocate memory regions
2630 * for the bus
2631 * @hbus: Root PCI bus, as understood by this driver
2632 *
2633 * This function calls vmbus_allocate_mmio(), which is itself a
2634 * bit of a compromise. Ideally, we might change the pnp layer
2635 * in the kernel such that it comprehends either PCI devices
2636 * which are "grandchildren of ACPI," with some intermediate bus
2637 * node (in this case, VMBus) or change it such that it
2638 * understands VMBus. The pnp layer, however, has been declared
2639 * deprecated, and not subject to change.
2640 *
2641 * The workaround, implemented here, is to ask VMBus to allocate
2642 * MMIO space for this bus. VMBus itself knows which ranges are
2643 * appropriate by looking at its own ACPI objects. Then, after
2644 * these ranges are claimed, they're modified to look like they
2645 * would have looked if the ACPI and pnp code had allocated
2646 * bridge windows. These descriptors have to exist in this form
2647 * in order to satisfy the code which will get invoked when the
2648 * endpoint PCI function driver calls request_mem_region() or
2649 * request_mem_region_exclusive().
2650 *
2651 * Return: 0 on success, -errno on failure
2652 */
2653static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus)
2654{
2655 resource_size_t align;
2656 int ret;
2657
2658 if (hbus->low_mmio_space) {
2659 align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
2660 ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0,
2661 (u64)(u32)0xffffffff,
2662 hbus->low_mmio_space,
2663 align, false);
2664 if (ret) {
2665 dev_err(&hbus->hdev->device,
2666 "Need %#llx of low MMIO space. Consider reconfiguring the VM.\n",
2667 hbus->low_mmio_space);
2668 return ret;
2669 }
2670
2671 /* Modify this resource to become a bridge window. */
2672 hbus->low_mmio_res->flags |= IORESOURCE_WINDOW;
2673 hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY;
2674 pci_add_resource(&hbus->resources_for_children,
2675 hbus->low_mmio_res);
2676 }
2677
2678 if (hbus->high_mmio_space) {
2679 align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space));
2680 ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev,
2681 0x100000000, -1,
2682 hbus->high_mmio_space, align,
2683 false);
2684 if (ret) {
2685 dev_err(&hbus->hdev->device,
2686 "Need %#llx of high MMIO space. Consider reconfiguring the VM.\n",
2687 hbus->high_mmio_space);
2688 goto release_low_mmio;
2689 }
2690
2691 /* Modify this resource to become a bridge window. */
2692 hbus->high_mmio_res->flags |= IORESOURCE_WINDOW;
2693 hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY;
2694 pci_add_resource(&hbus->resources_for_children,
2695 hbus->high_mmio_res);
2696 }
2697
2698 return 0;
2699
2700release_low_mmio:
2701 if (hbus->low_mmio_res) {
2702 vmbus_free_mmio(hbus->low_mmio_res->start,
2703 resource_size(hbus->low_mmio_res));
2704 }
2705
2706 return ret;
2707}
2708
2709/**
2710 * hv_allocate_config_window() - Find MMIO space for PCI Config
2711 * @hbus: Root PCI bus, as understood by this driver
2712 *
2713 * This function claims memory-mapped I/O space for accessing
2714 * configuration space for the functions on this bus.
2715 *
2716 * Return: 0 on success, -errno on failure
2717 */
2718static int hv_allocate_config_window(struct hv_pcibus_device *hbus)
2719{
2720 int ret;
2721
2722 /*
2723 * Set up a region of MMIO space to use for accessing configuration
2724 * space.
2725 */
2726 ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1,
2727 PCI_CONFIG_MMIO_LENGTH, 0x1000, false);
2728 if (ret)
2729 return ret;
2730
2731 /*
2732 * vmbus_allocate_mmio() gets used for allocating both device endpoint
2733 * resource claims (those which cannot be overlapped) and the ranges
2734 * which are valid for the children of this bus, which are intended
2735 * to be overlapped by those children. Set the flag on this claim
2736 * meaning that this region can't be overlapped.
2737 */
2738
2739 hbus->mem_config->flags |= IORESOURCE_BUSY;
2740
2741 return 0;
2742}
2743
2744static void hv_free_config_window(struct hv_pcibus_device *hbus)
2745{
2746 vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
2747}
2748
2749static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs);
2750
2751/**
2752 * hv_pci_enter_d0() - Bring the "bus" into the D0 power state
2753 * @hdev: VMBus's tracking struct for this root PCI bus
2754 *
2755 * Return: 0 on success, -errno on failure
2756 */
2757static int hv_pci_enter_d0(struct hv_device *hdev)
2758{
2759 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
2760 struct pci_bus_d0_entry *d0_entry;
2761 struct hv_pci_compl comp_pkt;
2762 struct pci_packet *pkt;
2763 int ret;
2764
2765 /*
2766 * Tell the host that the bus is ready to use, and moved into the
2767 * powered-on state. This includes telling the host which region
2768 * of memory-mapped I/O space has been chosen for configuration space
2769 * access.
2770 */
2771 pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL);
2772 if (!pkt)
2773 return -ENOMEM;
2774
2775 init_completion(&comp_pkt.host_event);
2776 pkt->completion_func = hv_pci_generic_compl;
2777 pkt->compl_ctxt = &comp_pkt;
2778 d0_entry = (struct pci_bus_d0_entry *)&pkt->message;
2779 d0_entry->message_type.type = PCI_BUS_D0ENTRY;
2780 d0_entry->mmio_base = hbus->mem_config->start;
2781
2782 ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),
2783 (unsigned long)pkt, VM_PKT_DATA_INBAND,
2784 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
2785 if (!ret)
2786 ret = wait_for_response(hdev, &comp_pkt.host_event);
2787
2788 if (ret)
2789 goto exit;
2790
2791 if (comp_pkt.completion_status < 0) {
2792 dev_err(&hdev->device,
2793 "PCI Pass-through VSP failed D0 Entry with status %x\n",
2794 comp_pkt.completion_status);
2795 ret = -EPROTO;
2796 goto exit;
2797 }
2798
2799 ret = 0;
2800
2801exit:
2802 kfree(pkt);
2803 return ret;
2804}
2805
2806/**
2807 * hv_pci_query_relations() - Ask host to send list of child
2808 * devices
2809 * @hdev: VMBus's tracking struct for this root PCI bus
2810 *
2811 * Return: 0 on success, -errno on failure
2812 */
2813static int hv_pci_query_relations(struct hv_device *hdev)
2814{
2815 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
2816 struct pci_message message;
2817 struct completion comp;
2818 int ret;
2819
2820 /* Ask the host to send along the list of child devices */
2821 init_completion(&comp);
2822 if (cmpxchg(&hbus->survey_event, NULL, &comp))
2823 return -ENOTEMPTY;
2824
2825 memset(&message, 0, sizeof(message));
2826 message.type = PCI_QUERY_BUS_RELATIONS;
2827
2828 ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),
2829 0, VM_PKT_DATA_INBAND, 0);
2830 if (!ret)
2831 ret = wait_for_response(hdev, &comp);
2832
2833 return ret;
2834}
2835
2836/**
2837 * hv_send_resources_allocated() - Report local resource choices
2838 * @hdev: VMBus's tracking struct for this root PCI bus
2839 *
2840 * The host OS is expecting to be sent a request as a message
2841 * which contains all the resources that the device will use.
2842 * The response contains those same resources, "translated"
2843 * which is to say, the values which should be used by the
2844 * hardware, when it delivers an interrupt. (MMIO resources are
2845 * used in local terms.) This is nice for Windows, and lines up
2846 * with the FDO/PDO split, which doesn't exist in Linux. Linux
2847 * is deeply expecting to scan an emulated PCI configuration
2848 * space. So this message is sent here only to drive the state
2849 * machine on the host forward.
2850 *
2851 * Return: 0 on success, -errno on failure
2852 */
2853static int hv_send_resources_allocated(struct hv_device *hdev)
2854{
2855 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
2856 struct pci_resources_assigned *res_assigned;
2857 struct pci_resources_assigned2 *res_assigned2;
2858 struct hv_pci_compl comp_pkt;
2859 struct hv_pci_dev *hpdev;
2860 struct pci_packet *pkt;
2861 size_t size_res;
2862 int wslot;
2863 int ret;
2864
2865 size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
2866 ? sizeof(*res_assigned) : sizeof(*res_assigned2);
2867
2868 pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
2869 if (!pkt)
2870 return -ENOMEM;
2871
2872 ret = 0;
2873
2874 for (wslot = 0; wslot < 256; wslot++) {
2875 hpdev = get_pcichild_wslot(hbus, wslot);
2876 if (!hpdev)
2877 continue;
2878
2879 memset(pkt, 0, sizeof(*pkt) + size_res);
2880 init_completion(&comp_pkt.host_event);
2881 pkt->completion_func = hv_pci_generic_compl;
2882 pkt->compl_ctxt = &comp_pkt;
2883
2884 if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) {
2885 res_assigned =
2886 (struct pci_resources_assigned *)&pkt->message;
2887 res_assigned->message_type.type =
2888 PCI_RESOURCES_ASSIGNED;
2889 res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
2890 } else {
2891 res_assigned2 =
2892 (struct pci_resources_assigned2 *)&pkt->message;
2893 res_assigned2->message_type.type =
2894 PCI_RESOURCES_ASSIGNED2;
2895 res_assigned2->wslot.slot = hpdev->desc.win_slot.slot;
2896 }
2897 put_pcichild(hpdev);
2898
2899 ret = vmbus_sendpacket(hdev->channel, &pkt->message,
2900 size_res, (unsigned long)pkt,
2901 VM_PKT_DATA_INBAND,
2902 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
2903 if (!ret)
2904 ret = wait_for_response(hdev, &comp_pkt.host_event);
2905 if (ret)
2906 break;
2907
2908 if (comp_pkt.completion_status < 0) {
2909 ret = -EPROTO;
2910 dev_err(&hdev->device,
2911 "resource allocated returned 0x%x",
2912 comp_pkt.completion_status);
2913 break;
2914 }
2915
2916 hbus->wslot_res_allocated = wslot;
2917 }
2918
2919 kfree(pkt);
2920 return ret;
2921}
2922
2923/**
2924 * hv_send_resources_released() - Report local resources
2925 * released
2926 * @hdev: VMBus's tracking struct for this root PCI bus
2927 *
2928 * Return: 0 on success, -errno on failure
2929 */
2930static int hv_send_resources_released(struct hv_device *hdev)
2931{
2932 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
2933 struct pci_child_message pkt;
2934 struct hv_pci_dev *hpdev;
2935 int wslot;
2936 int ret;
2937
2938 for (wslot = hbus->wslot_res_allocated; wslot >= 0; wslot--) {
2939 hpdev = get_pcichild_wslot(hbus, wslot);
2940 if (!hpdev)
2941 continue;
2942
2943 memset(&pkt, 0, sizeof(pkt));
2944 pkt.message_type.type = PCI_RESOURCES_RELEASED;
2945 pkt.wslot.slot = hpdev->desc.win_slot.slot;
2946
2947 put_pcichild(hpdev);
2948
2949 ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,
2950 VM_PKT_DATA_INBAND, 0);
2951 if (ret)
2952 return ret;
2953
2954 hbus->wslot_res_allocated = wslot - 1;
2955 }
2956
2957 hbus->wslot_res_allocated = -1;
2958
2959 return 0;
2960}
2961
2962static void get_hvpcibus(struct hv_pcibus_device *hbus)
2963{
2964 refcount_inc(&hbus->remove_lock);
2965}
2966
2967static void put_hvpcibus(struct hv_pcibus_device *hbus)
2968{
2969 if (refcount_dec_and_test(&hbus->remove_lock))
2970 complete(&hbus->remove_event);
2971}
2972
2973#define HVPCI_DOM_MAP_SIZE (64 * 1024)
2974static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE);
2975
2976/*
2977 * PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0
2978 * as invalid for passthrough PCI devices of this driver.
2979 */
2980#define HVPCI_DOM_INVALID 0
2981
2982/**
2983 * hv_get_dom_num() - Get a valid PCI domain number
2984 * Check if the PCI domain number is in use, and return another number if
2985 * it is in use.
2986 *
2987 * @dom: Requested domain number
2988 *
2989 * return: domain number on success, HVPCI_DOM_INVALID on failure
2990 */
2991static u16 hv_get_dom_num(u16 dom)
2992{
2993 unsigned int i;
2994
2995 if (test_and_set_bit(dom, hvpci_dom_map) == 0)
2996 return dom;
2997
2998 for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) {
2999 if (test_and_set_bit(i, hvpci_dom_map) == 0)
3000 return i;
3001 }
3002
3003 return HVPCI_DOM_INVALID;
3004}
3005
3006/**
3007 * hv_put_dom_num() - Mark the PCI domain number as free
3008 * @dom: Domain number to be freed
3009 */
3010static void hv_put_dom_num(u16 dom)
3011{
3012 clear_bit(dom, hvpci_dom_map);
3013}
3014
3015/**
3016 * hv_pci_probe() - New VMBus channel probe, for a root PCI bus
3017 * @hdev: VMBus's tracking struct for this root PCI bus
3018 * @dev_id: Identifies the device itself
3019 *
3020 * Return: 0 on success, -errno on failure
3021 */
3022static int hv_pci_probe(struct hv_device *hdev,
3023 const struct hv_vmbus_device_id *dev_id)
3024{
3025 struct hv_pcibus_device *hbus;
3026 u16 dom_req, dom;
3027 char *name;
3028 bool enter_d0_retry = true;
3029 int ret;
3030
3031 /*
3032 * hv_pcibus_device contains the hypercall arguments for retargeting in
3033 * hv_irq_unmask(). Those must not cross a page boundary.
3034 */
3035 BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE);
3036
3037 /*
3038 * With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural
3039 * alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate
3040 * a 4KB buffer that is guaranteed to be 4KB-aligned. Here the size and
3041 * alignment of hbus is important because hbus's field
3042 * retarget_msi_interrupt_params must not cross a 4KB page boundary.
3043 *
3044 * Here we prefer kzalloc to get_zeroed_page(), because a buffer
3045 * allocated by the latter is not tracked and scanned by kmemleak, and
3046 * hence kmemleak reports the pointer contained in the hbus buffer
3047 * (i.e. the hpdev struct, which is created in new_pcichild_device() and
3048 * is tracked by hbus->children) as memory leak (false positive).
3049 *
3050 * If the kernel doesn't have 59bb47985c1d, get_zeroed_page() *must* be
3051 * used to allocate the hbus buffer and we can avoid the kmemleak false
3052 * positive by using kmemleak_alloc() and kmemleak_free() to ask
3053 * kmemleak to track and scan the hbus buffer.
3054 */
3055 hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
3056 if (!hbus)
3057 return -ENOMEM;
3058 hbus->state = hv_pcibus_init;
3059 hbus->wslot_res_allocated = -1;
3060
3061 /*
3062 * The PCI bus "domain" is what is called "segment" in ACPI and other
3063 * specs. Pull it from the instance ID, to get something usually
3064 * unique. In rare cases of collision, we will find out another number
3065 * not in use.
3066 *
3067 * Note that, since this code only runs in a Hyper-V VM, Hyper-V
3068 * together with this guest driver can guarantee that (1) The only
3069 * domain used by Gen1 VMs for something that looks like a physical
3070 * PCI bus (which is actually emulated by the hypervisor) is domain 0.
3071 * (2) There will be no overlap between domains (after fixing possible
3072 * collisions) in the same VM.
3073 */
3074 dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4];
3075 dom = hv_get_dom_num(dom_req);
3076
3077 if (dom == HVPCI_DOM_INVALID) {
3078 dev_err(&hdev->device,
3079 "Unable to use dom# 0x%hx or other numbers", dom_req);
3080 ret = -EINVAL;
3081 goto free_bus;
3082 }
3083
3084 if (dom != dom_req)
3085 dev_info(&hdev->device,
3086 "PCI dom# 0x%hx has collision, using 0x%hx",
3087 dom_req, dom);
3088
3089 hbus->sysdata.domain = dom;
3090
3091 hbus->hdev = hdev;
3092 refcount_set(&hbus->remove_lock, 1);
3093 INIT_LIST_HEAD(&hbus->children);
3094 INIT_LIST_HEAD(&hbus->dr_list);
3095 INIT_LIST_HEAD(&hbus->resources_for_children);
3096 spin_lock_init(&hbus->config_lock);
3097 spin_lock_init(&hbus->device_list_lock);
3098 spin_lock_init(&hbus->retarget_msi_interrupt_lock);
3099 init_completion(&hbus->remove_event);
3100 hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0,
3101 hbus->sysdata.domain);
3102 if (!hbus->wq) {
3103 ret = -ENOMEM;
3104 goto free_dom;
3105 }
3106
3107 ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
3108 hv_pci_onchannelcallback, hbus);
3109 if (ret)
3110 goto destroy_wq;
3111
3112 hv_set_drvdata(hdev, hbus);
3113
3114 ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions,
3115 ARRAY_SIZE(pci_protocol_versions));
3116 if (ret)
3117 goto close;
3118
3119 ret = hv_allocate_config_window(hbus);
3120 if (ret)
3121 goto close;
3122
3123 hbus->cfg_addr = ioremap(hbus->mem_config->start,
3124 PCI_CONFIG_MMIO_LENGTH);
3125 if (!hbus->cfg_addr) {
3126 dev_err(&hdev->device,
3127 "Unable to map a virtual address for config space\n");
3128 ret = -ENOMEM;
3129 goto free_config;
3130 }
3131
3132 name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance);
3133 if (!name) {
3134 ret = -ENOMEM;
3135 goto unmap;
3136 }
3137
3138 hbus->sysdata.fwnode = irq_domain_alloc_named_fwnode(name);
3139 kfree(name);
3140 if (!hbus->sysdata.fwnode) {
3141 ret = -ENOMEM;
3142 goto unmap;
3143 }
3144
3145 ret = hv_pcie_init_irq_domain(hbus);
3146 if (ret)
3147 goto free_fwnode;
3148
3149retry:
3150 ret = hv_pci_query_relations(hdev);
3151 if (ret)
3152 goto free_irq_domain;
3153
3154 ret = hv_pci_enter_d0(hdev);
3155 /*
3156 * In certain case (Kdump) the pci device of interest was
3157 * not cleanly shut down and resource is still held on host
3158 * side, the host could return invalid device status.
3159 * We need to explicitly request host to release the resource
3160 * and try to enter D0 again.
3161 * Since the hv_pci_bus_exit() call releases structures
3162 * of all its child devices, we need to start the retry from
3163 * hv_pci_query_relations() call, requesting host to send
3164 * the synchronous child device relations message before this
3165 * information is needed in hv_send_resources_allocated()
3166 * call later.
3167 */
3168 if (ret == -EPROTO && enter_d0_retry) {
3169 enter_d0_retry = false;
3170
3171 dev_err(&hdev->device, "Retrying D0 Entry\n");
3172
3173 /*
3174 * Hv_pci_bus_exit() calls hv_send_resources_released()
3175 * to free up resources of its child devices.
3176 * In the kdump kernel we need to set the
3177 * wslot_res_allocated to 255 so it scans all child
3178 * devices to release resources allocated in the
3179 * normal kernel before panic happened.
3180 */
3181 hbus->wslot_res_allocated = 255;
3182 ret = hv_pci_bus_exit(hdev, true);
3183
3184 if (ret == 0)
3185 goto retry;
3186
3187 dev_err(&hdev->device,
3188 "Retrying D0 failed with ret %d\n", ret);
3189 }
3190 if (ret)
3191 goto free_irq_domain;
3192
3193 ret = hv_pci_allocate_bridge_windows(hbus);
3194 if (ret)
3195 goto exit_d0;
3196
3197 ret = hv_send_resources_allocated(hdev);
3198 if (ret)
3199 goto free_windows;
3200
3201 prepopulate_bars(hbus);
3202
3203 hbus->state = hv_pcibus_probed;
3204
3205 ret = create_root_hv_pci_bus(hbus);
3206 if (ret)
3207 goto free_windows;
3208
3209 return 0;
3210
3211free_windows:
3212 hv_pci_free_bridge_windows(hbus);
3213exit_d0:
3214 (void) hv_pci_bus_exit(hdev, true);
3215free_irq_domain:
3216 irq_domain_remove(hbus->irq_domain);
3217free_fwnode:
3218 irq_domain_free_fwnode(hbus->sysdata.fwnode);
3219unmap:
3220 iounmap(hbus->cfg_addr);
3221free_config:
3222 hv_free_config_window(hbus);
3223close:
3224 vmbus_close(hdev->channel);
3225destroy_wq:
3226 destroy_workqueue(hbus->wq);
3227free_dom:
3228 hv_put_dom_num(hbus->sysdata.domain);
3229free_bus:
3230 kfree(hbus);
3231 return ret;
3232}
3233
3234static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
3235{
3236 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3237 struct {
3238 struct pci_packet teardown_packet;
3239 u8 buffer[sizeof(struct pci_message)];
3240 } pkt;
3241 struct hv_dr_state *dr;
3242 struct hv_pci_compl comp_pkt;
3243 int ret;
3244
3245 /*
3246 * After the host sends the RESCIND_CHANNEL message, it doesn't
3247 * access the per-channel ringbuffer any longer.
3248 */
3249 if (hdev->channel->rescind)
3250 return 0;
3251
3252 if (!keep_devs) {
3253 /* Delete any children which might still exist. */
3254 dr = kzalloc(sizeof(*dr), GFP_KERNEL);
3255 if (dr && hv_pci_start_relations_work(hbus, dr))
3256 kfree(dr);
3257 }
3258
3259 ret = hv_send_resources_released(hdev);
3260 if (ret) {
3261 dev_err(&hdev->device,
3262 "Couldn't send resources released packet(s)\n");
3263 return ret;
3264 }
3265
3266 memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet));
3267 init_completion(&comp_pkt.host_event);
3268 pkt.teardown_packet.completion_func = hv_pci_generic_compl;
3269 pkt.teardown_packet.compl_ctxt = &comp_pkt;
3270 pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT;
3271
3272 ret = vmbus_sendpacket(hdev->channel, &pkt.teardown_packet.message,
3273 sizeof(struct pci_message),
3274 (unsigned long)&pkt.teardown_packet,
3275 VM_PKT_DATA_INBAND,
3276 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
3277 if (ret)
3278 return ret;
3279
3280 if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0)
3281 return -ETIMEDOUT;
3282
3283 return 0;
3284}
3285
3286/**
3287 * hv_pci_remove() - Remove routine for this VMBus channel
3288 * @hdev: VMBus's tracking struct for this root PCI bus
3289 *
3290 * Return: 0 on success, -errno on failure
3291 */
3292static int hv_pci_remove(struct hv_device *hdev)
3293{
3294 struct hv_pcibus_device *hbus;
3295 int ret;
3296
3297 hbus = hv_get_drvdata(hdev);
3298 if (hbus->state == hv_pcibus_installed) {
3299 /* Remove the bus from PCI's point of view. */
3300 pci_lock_rescan_remove();
3301 pci_stop_root_bus(hbus->pci_bus);
3302 hv_pci_remove_slots(hbus);
3303 pci_remove_root_bus(hbus->pci_bus);
3304 pci_unlock_rescan_remove();
3305 hbus->state = hv_pcibus_removed;
3306 }
3307
3308 ret = hv_pci_bus_exit(hdev, false);
3309
3310 vmbus_close(hdev->channel);
3311
3312 iounmap(hbus->cfg_addr);
3313 hv_free_config_window(hbus);
3314 pci_free_resource_list(&hbus->resources_for_children);
3315 hv_pci_free_bridge_windows(hbus);
3316 irq_domain_remove(hbus->irq_domain);
3317 irq_domain_free_fwnode(hbus->sysdata.fwnode);
3318 put_hvpcibus(hbus);
3319 wait_for_completion(&hbus->remove_event);
3320 destroy_workqueue(hbus->wq);
3321
3322 hv_put_dom_num(hbus->sysdata.domain);
3323
3324 kfree(hbus);
3325 return ret;
3326}
3327
3328static int hv_pci_suspend(struct hv_device *hdev)
3329{
3330 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3331 enum hv_pcibus_state old_state;
3332 int ret;
3333
3334 /*
3335 * hv_pci_suspend() must make sure there are no pending work items
3336 * before calling vmbus_close(), since it runs in a process context
3337 * as a callback in dpm_suspend(). When it starts to run, the channel
3338 * callback hv_pci_onchannelcallback(), which runs in a tasklet
3339 * context, can be still running concurrently and scheduling new work
3340 * items onto hbus->wq in hv_pci_devices_present() and
3341 * hv_pci_eject_device(), and the work item handlers can access the
3342 * vmbus channel, which can be being closed by hv_pci_suspend(), e.g.
3343 * the work item handler pci_devices_present_work() ->
3344 * new_pcichild_device() writes to the vmbus channel.
3345 *
3346 * To eliminate the race, hv_pci_suspend() disables the channel
3347 * callback tasklet, sets hbus->state to hv_pcibus_removing, and
3348 * re-enables the tasklet. This way, when hv_pci_suspend() proceeds,
3349 * it knows that no new work item can be scheduled, and then it flushes
3350 * hbus->wq and safely closes the vmbus channel.
3351 */
3352 tasklet_disable(&hdev->channel->callback_event);
3353
3354 /* Change the hbus state to prevent new work items. */
3355 old_state = hbus->state;
3356 if (hbus->state == hv_pcibus_installed)
3357 hbus->state = hv_pcibus_removing;
3358
3359 tasklet_enable(&hdev->channel->callback_event);
3360
3361 if (old_state != hv_pcibus_installed)
3362 return -EINVAL;
3363
3364 flush_workqueue(hbus->wq);
3365
3366 ret = hv_pci_bus_exit(hdev, true);
3367 if (ret)
3368 return ret;
3369
3370 vmbus_close(hdev->channel);
3371
3372 return 0;
3373}
3374
3375static int hv_pci_resume(struct hv_device *hdev)
3376{
3377 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3378 enum pci_protocol_version_t version[1];
3379 int ret;
3380
3381 hbus->state = hv_pcibus_init;
3382
3383 ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
3384 hv_pci_onchannelcallback, hbus);
3385 if (ret)
3386 return ret;
3387
3388 /* Only use the version that was in use before hibernation. */
3389 version[0] = hbus->protocol_version;
3390 ret = hv_pci_protocol_negotiation(hdev, version, 1);
3391 if (ret)
3392 goto out;
3393
3394 ret = hv_pci_query_relations(hdev);
3395 if (ret)
3396 goto out;
3397
3398 ret = hv_pci_enter_d0(hdev);
3399 if (ret)
3400 goto out;
3401
3402 ret = hv_send_resources_allocated(hdev);
3403 if (ret)
3404 goto out;
3405
3406 prepopulate_bars(hbus);
3407
3408 hbus->state = hv_pcibus_installed;
3409 return 0;
3410out:
3411 vmbus_close(hdev->channel);
3412 return ret;
3413}
3414
3415static const struct hv_vmbus_device_id hv_pci_id_table[] = {
3416 /* PCI Pass-through Class ID */
3417 /* 44C4F61D-4444-4400-9D52-802E27EDE19F */
3418 { HV_PCIE_GUID, },
3419 { },
3420};
3421
3422MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table);
3423
3424static struct hv_driver hv_pci_drv = {
3425 .name = "hv_pci",
3426 .id_table = hv_pci_id_table,
3427 .probe = hv_pci_probe,
3428 .remove = hv_pci_remove,
3429 .suspend = hv_pci_suspend,
3430 .resume = hv_pci_resume,
3431};
3432
3433static void __exit exit_hv_pci_drv(void)
3434{
3435 vmbus_driver_unregister(&hv_pci_drv);
3436
3437 hvpci_block_ops.read_block = NULL;
3438 hvpci_block_ops.write_block = NULL;
3439 hvpci_block_ops.reg_blk_invalidate = NULL;
3440}
3441
3442static int __init init_hv_pci_drv(void)
3443{
3444 /* Set the invalid domain number's bit, so it will not be used */
3445 set_bit(HVPCI_DOM_INVALID, hvpci_dom_map);
3446
3447 /* Initialize PCI block r/w interface */
3448 hvpci_block_ops.read_block = hv_read_config_block;
3449 hvpci_block_ops.write_block = hv_write_config_block;
3450 hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate;
3451
3452 return vmbus_driver_register(&hv_pci_drv);
3453}
3454
3455module_init(init_hv_pci_drv);
3456module_exit(exit_hv_pci_drv);
3457
3458MODULE_DESCRIPTION("Hyper-V PCI");
3459MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) Microsoft Corporation.
4 *
5 * Author:
6 * Jake Oshins <jakeo@microsoft.com>
7 *
8 * This driver acts as a paravirtual front-end for PCI Express root buses.
9 * When a PCI Express function (either an entire device or an SR-IOV
10 * Virtual Function) is being passed through to the VM, this driver exposes
11 * a new bus to the guest VM. This is modeled as a root PCI bus because
12 * no bridges are being exposed to the VM. In fact, with a "Generation 2"
13 * VM within Hyper-V, there may seem to be no PCI bus at all in the VM
14 * until a device as been exposed using this driver.
15 *
16 * Each root PCI bus has its own PCI domain, which is called "Segment" in
17 * the PCI Firmware Specifications. Thus while each device passed through
18 * to the VM using this front-end will appear at "device 0", the domain will
19 * be unique. Typically, each bus will have one PCI function on it, though
20 * this driver does support more than one.
21 *
22 * In order to map the interrupts from the device through to the guest VM,
23 * this driver also implements an IRQ Domain, which handles interrupts (either
24 * MSI or MSI-X) associated with the functions on the bus. As interrupts are
25 * set up, torn down, or reaffined, this driver communicates with the
26 * underlying hypervisor to adjust the mappings in the I/O MMU so that each
27 * interrupt will be delivered to the correct virtual processor at the right
28 * vector. This driver does not support level-triggered (line-based)
29 * interrupts, and will report that the Interrupt Line register in the
30 * function's configuration space is zero.
31 *
32 * The rest of this driver mostly maps PCI concepts onto underlying Hyper-V
33 * facilities. For instance, the configuration space of a function exposed
34 * by Hyper-V is mapped into a single page of memory space, and the
35 * read and write handlers for config space must be aware of this mechanism.
36 * Similarly, device setup and teardown involves messages sent to and from
37 * the PCI back-end driver in Hyper-V.
38 */
39
40#include <linux/kernel.h>
41#include <linux/module.h>
42#include <linux/pci.h>
43#include <linux/pci-ecam.h>
44#include <linux/delay.h>
45#include <linux/semaphore.h>
46#include <linux/irq.h>
47#include <linux/msi.h>
48#include <linux/hyperv.h>
49#include <linux/refcount.h>
50#include <linux/irqdomain.h>
51#include <linux/acpi.h>
52#include <asm/mshyperv.h>
53
54/*
55 * Protocol versions. The low word is the minor version, the high word the
56 * major version.
57 */
58
59#define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (minor)))
60#define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16)
61#define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff)
62
63enum pci_protocol_version_t {
64 PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */
65 PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */
66 PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3), /* Vibranium */
67 PCI_PROTOCOL_VERSION_1_4 = PCI_MAKE_VERSION(1, 4), /* WS2022 */
68};
69
70#define CPU_AFFINITY_ALL -1ULL
71
72/*
73 * Supported protocol versions in the order of probing - highest go
74 * first.
75 */
76static enum pci_protocol_version_t pci_protocol_versions[] = {
77 PCI_PROTOCOL_VERSION_1_4,
78 PCI_PROTOCOL_VERSION_1_3,
79 PCI_PROTOCOL_VERSION_1_2,
80 PCI_PROTOCOL_VERSION_1_1,
81};
82
83#define PCI_CONFIG_MMIO_LENGTH 0x2000
84#define CFG_PAGE_OFFSET 0x1000
85#define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET)
86
87#define MAX_SUPPORTED_MSI_MESSAGES 0x400
88
89#define STATUS_REVISION_MISMATCH 0xC0000059
90
91/* space for 32bit serial number as string */
92#define SLOT_NAME_SIZE 11
93
94/*
95 * Size of requestor for VMbus; the value is based on the observation
96 * that having more than one request outstanding is 'rare', and so 64
97 * should be generous in ensuring that we don't ever run out.
98 */
99#define HV_PCI_RQSTOR_SIZE 64
100
101/*
102 * Message Types
103 */
104
105enum pci_message_type {
106 /*
107 * Version 1.1
108 */
109 PCI_MESSAGE_BASE = 0x42490000,
110 PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0,
111 PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1,
112 PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4,
113 PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5,
114 PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6,
115 PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7,
116 PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8,
117 PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9,
118 PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA,
119 PCI_EJECT = PCI_MESSAGE_BASE + 0xB,
120 PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC,
121 PCI_REENABLE = PCI_MESSAGE_BASE + 0xD,
122 PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE,
123 PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF,
124 PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10,
125 PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11,
126 PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12,
127 PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13,
128 PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14,
129 PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15,
130 PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16,
131 PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17,
132 PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */
133 PCI_BUS_RELATIONS2 = PCI_MESSAGE_BASE + 0x19,
134 PCI_RESOURCES_ASSIGNED3 = PCI_MESSAGE_BASE + 0x1A,
135 PCI_CREATE_INTERRUPT_MESSAGE3 = PCI_MESSAGE_BASE + 0x1B,
136 PCI_MESSAGE_MAXIMUM
137};
138
139/*
140 * Structures defining the virtual PCI Express protocol.
141 */
142
143union pci_version {
144 struct {
145 u16 minor_version;
146 u16 major_version;
147 } parts;
148 u32 version;
149} __packed;
150
151/*
152 * Function numbers are 8-bits wide on Express, as interpreted through ARI,
153 * which is all this driver does. This representation is the one used in
154 * Windows, which is what is expected when sending this back and forth with
155 * the Hyper-V parent partition.
156 */
157union win_slot_encoding {
158 struct {
159 u32 dev:5;
160 u32 func:3;
161 u32 reserved:24;
162 } bits;
163 u32 slot;
164} __packed;
165
166/*
167 * Pretty much as defined in the PCI Specifications.
168 */
169struct pci_function_description {
170 u16 v_id; /* vendor ID */
171 u16 d_id; /* device ID */
172 u8 rev;
173 u8 prog_intf;
174 u8 subclass;
175 u8 base_class;
176 u32 subsystem_id;
177 union win_slot_encoding win_slot;
178 u32 ser; /* serial number */
179} __packed;
180
181enum pci_device_description_flags {
182 HV_PCI_DEVICE_FLAG_NONE = 0x0,
183 HV_PCI_DEVICE_FLAG_NUMA_AFFINITY = 0x1,
184};
185
186struct pci_function_description2 {
187 u16 v_id; /* vendor ID */
188 u16 d_id; /* device ID */
189 u8 rev;
190 u8 prog_intf;
191 u8 subclass;
192 u8 base_class;
193 u32 subsystem_id;
194 union win_slot_encoding win_slot;
195 u32 ser; /* serial number */
196 u32 flags;
197 u16 virtual_numa_node;
198 u16 reserved;
199} __packed;
200
201/**
202 * struct hv_msi_desc
203 * @vector: IDT entry
204 * @delivery_mode: As defined in Intel's Programmer's
205 * Reference Manual, Volume 3, Chapter 8.
206 * @vector_count: Number of contiguous entries in the
207 * Interrupt Descriptor Table that are
208 * occupied by this Message-Signaled
209 * Interrupt. For "MSI", as first defined
210 * in PCI 2.2, this can be between 1 and
211 * 32. For "MSI-X," as first defined in PCI
212 * 3.0, this must be 1, as each MSI-X table
213 * entry would have its own descriptor.
214 * @reserved: Empty space
215 * @cpu_mask: All the target virtual processors.
216 */
217struct hv_msi_desc {
218 u8 vector;
219 u8 delivery_mode;
220 u16 vector_count;
221 u32 reserved;
222 u64 cpu_mask;
223} __packed;
224
225/**
226 * struct hv_msi_desc2 - 1.2 version of hv_msi_desc
227 * @vector: IDT entry
228 * @delivery_mode: As defined in Intel's Programmer's
229 * Reference Manual, Volume 3, Chapter 8.
230 * @vector_count: Number of contiguous entries in the
231 * Interrupt Descriptor Table that are
232 * occupied by this Message-Signaled
233 * Interrupt. For "MSI", as first defined
234 * in PCI 2.2, this can be between 1 and
235 * 32. For "MSI-X," as first defined in PCI
236 * 3.0, this must be 1, as each MSI-X table
237 * entry would have its own descriptor.
238 * @processor_count: number of bits enabled in array.
239 * @processor_array: All the target virtual processors.
240 */
241struct hv_msi_desc2 {
242 u8 vector;
243 u8 delivery_mode;
244 u16 vector_count;
245 u16 processor_count;
246 u16 processor_array[32];
247} __packed;
248
249/*
250 * struct hv_msi_desc3 - 1.3 version of hv_msi_desc
251 * Everything is the same as in 'hv_msi_desc2' except that the size of the
252 * 'vector' field is larger to support bigger vector values. For ex: LPI
253 * vectors on ARM.
254 */
255struct hv_msi_desc3 {
256 u32 vector;
257 u8 delivery_mode;
258 u8 reserved;
259 u16 vector_count;
260 u16 processor_count;
261 u16 processor_array[32];
262} __packed;
263
264/**
265 * struct tran_int_desc
266 * @reserved: unused, padding
267 * @vector_count: same as in hv_msi_desc
268 * @data: This is the "data payload" value that is
269 * written by the device when it generates
270 * a message-signaled interrupt, either MSI
271 * or MSI-X.
272 * @address: This is the address to which the data
273 * payload is written on interrupt
274 * generation.
275 */
276struct tran_int_desc {
277 u16 reserved;
278 u16 vector_count;
279 u32 data;
280 u64 address;
281} __packed;
282
283/*
284 * A generic message format for virtual PCI.
285 * Specific message formats are defined later in the file.
286 */
287
288struct pci_message {
289 u32 type;
290} __packed;
291
292struct pci_child_message {
293 struct pci_message message_type;
294 union win_slot_encoding wslot;
295} __packed;
296
297struct pci_incoming_message {
298 struct vmpacket_descriptor hdr;
299 struct pci_message message_type;
300} __packed;
301
302struct pci_response {
303 struct vmpacket_descriptor hdr;
304 s32 status; /* negative values are failures */
305} __packed;
306
307struct pci_packet {
308 void (*completion_func)(void *context, struct pci_response *resp,
309 int resp_packet_size);
310 void *compl_ctxt;
311
312 struct pci_message message[];
313};
314
315/*
316 * Specific message types supporting the PCI protocol.
317 */
318
319/*
320 * Version negotiation message. Sent from the guest to the host.
321 * The guest is free to try different versions until the host
322 * accepts the version.
323 *
324 * pci_version: The protocol version requested.
325 * is_last_attempt: If TRUE, this is the last version guest will request.
326 * reservedz: Reserved field, set to zero.
327 */
328
329struct pci_version_request {
330 struct pci_message message_type;
331 u32 protocol_version;
332} __packed;
333
334/*
335 * Bus D0 Entry. This is sent from the guest to the host when the virtual
336 * bus (PCI Express port) is ready for action.
337 */
338
339struct pci_bus_d0_entry {
340 struct pci_message message_type;
341 u32 reserved;
342 u64 mmio_base;
343} __packed;
344
345struct pci_bus_relations {
346 struct pci_incoming_message incoming;
347 u32 device_count;
348 struct pci_function_description func[];
349} __packed;
350
351struct pci_bus_relations2 {
352 struct pci_incoming_message incoming;
353 u32 device_count;
354 struct pci_function_description2 func[];
355} __packed;
356
357struct pci_q_res_req_response {
358 struct vmpacket_descriptor hdr;
359 s32 status; /* negative values are failures */
360 u32 probed_bar[PCI_STD_NUM_BARS];
361} __packed;
362
363struct pci_set_power {
364 struct pci_message message_type;
365 union win_slot_encoding wslot;
366 u32 power_state; /* In Windows terms */
367 u32 reserved;
368} __packed;
369
370struct pci_set_power_response {
371 struct vmpacket_descriptor hdr;
372 s32 status; /* negative values are failures */
373 union win_slot_encoding wslot;
374 u32 resultant_state; /* In Windows terms */
375 u32 reserved;
376} __packed;
377
378struct pci_resources_assigned {
379 struct pci_message message_type;
380 union win_slot_encoding wslot;
381 u8 memory_range[0x14][6]; /* not used here */
382 u32 msi_descriptors;
383 u32 reserved[4];
384} __packed;
385
386struct pci_resources_assigned2 {
387 struct pci_message message_type;
388 union win_slot_encoding wslot;
389 u8 memory_range[0x14][6]; /* not used here */
390 u32 msi_descriptor_count;
391 u8 reserved[70];
392} __packed;
393
394struct pci_create_interrupt {
395 struct pci_message message_type;
396 union win_slot_encoding wslot;
397 struct hv_msi_desc int_desc;
398} __packed;
399
400struct pci_create_int_response {
401 struct pci_response response;
402 u32 reserved;
403 struct tran_int_desc int_desc;
404} __packed;
405
406struct pci_create_interrupt2 {
407 struct pci_message message_type;
408 union win_slot_encoding wslot;
409 struct hv_msi_desc2 int_desc;
410} __packed;
411
412struct pci_create_interrupt3 {
413 struct pci_message message_type;
414 union win_slot_encoding wslot;
415 struct hv_msi_desc3 int_desc;
416} __packed;
417
418struct pci_delete_interrupt {
419 struct pci_message message_type;
420 union win_slot_encoding wslot;
421 struct tran_int_desc int_desc;
422} __packed;
423
424/*
425 * Note: the VM must pass a valid block id, wslot and bytes_requested.
426 */
427struct pci_read_block {
428 struct pci_message message_type;
429 u32 block_id;
430 union win_slot_encoding wslot;
431 u32 bytes_requested;
432} __packed;
433
434struct pci_read_block_response {
435 struct vmpacket_descriptor hdr;
436 u32 status;
437 u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
438} __packed;
439
440/*
441 * Note: the VM must pass a valid block id, wslot and byte_count.
442 */
443struct pci_write_block {
444 struct pci_message message_type;
445 u32 block_id;
446 union win_slot_encoding wslot;
447 u32 byte_count;
448 u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX];
449} __packed;
450
451struct pci_dev_inval_block {
452 struct pci_incoming_message incoming;
453 union win_slot_encoding wslot;
454 u64 block_mask;
455} __packed;
456
457struct pci_dev_incoming {
458 struct pci_incoming_message incoming;
459 union win_slot_encoding wslot;
460} __packed;
461
462struct pci_eject_response {
463 struct pci_message message_type;
464 union win_slot_encoding wslot;
465 u32 status;
466} __packed;
467
468static int pci_ring_size = (4 * PAGE_SIZE);
469
470/*
471 * Driver specific state.
472 */
473
474enum hv_pcibus_state {
475 hv_pcibus_init = 0,
476 hv_pcibus_probed,
477 hv_pcibus_installed,
478 hv_pcibus_removing,
479 hv_pcibus_maximum
480};
481
482struct hv_pcibus_device {
483#ifdef CONFIG_X86
484 struct pci_sysdata sysdata;
485#elif defined(CONFIG_ARM64)
486 struct pci_config_window sysdata;
487#endif
488 struct pci_host_bridge *bridge;
489 struct fwnode_handle *fwnode;
490 /* Protocol version negotiated with the host */
491 enum pci_protocol_version_t protocol_version;
492 enum hv_pcibus_state state;
493 struct hv_device *hdev;
494 resource_size_t low_mmio_space;
495 resource_size_t high_mmio_space;
496 struct resource *mem_config;
497 struct resource *low_mmio_res;
498 struct resource *high_mmio_res;
499 struct completion *survey_event;
500 struct pci_bus *pci_bus;
501 spinlock_t config_lock; /* Avoid two threads writing index page */
502 spinlock_t device_list_lock; /* Protect lists below */
503 void __iomem *cfg_addr;
504
505 struct list_head children;
506 struct list_head dr_list;
507
508 struct msi_domain_info msi_info;
509 struct irq_domain *irq_domain;
510
511 spinlock_t retarget_msi_interrupt_lock;
512
513 struct workqueue_struct *wq;
514
515 /* Highest slot of child device with resources allocated */
516 int wslot_res_allocated;
517
518 /* hypercall arg, must not cross page boundary */
519 struct hv_retarget_device_interrupt retarget_msi_interrupt_params;
520
521 /*
522 * Don't put anything here: retarget_msi_interrupt_params must be last
523 */
524};
525
526/*
527 * Tracks "Device Relations" messages from the host, which must be both
528 * processed in order and deferred so that they don't run in the context
529 * of the incoming packet callback.
530 */
531struct hv_dr_work {
532 struct work_struct wrk;
533 struct hv_pcibus_device *bus;
534};
535
536struct hv_pcidev_description {
537 u16 v_id; /* vendor ID */
538 u16 d_id; /* device ID */
539 u8 rev;
540 u8 prog_intf;
541 u8 subclass;
542 u8 base_class;
543 u32 subsystem_id;
544 union win_slot_encoding win_slot;
545 u32 ser; /* serial number */
546 u32 flags;
547 u16 virtual_numa_node;
548};
549
550struct hv_dr_state {
551 struct list_head list_entry;
552 u32 device_count;
553 struct hv_pcidev_description func[];
554};
555
556enum hv_pcichild_state {
557 hv_pcichild_init = 0,
558 hv_pcichild_requirements,
559 hv_pcichild_resourced,
560 hv_pcichild_ejecting,
561 hv_pcichild_maximum
562};
563
564struct hv_pci_dev {
565 /* List protected by pci_rescan_remove_lock */
566 struct list_head list_entry;
567 refcount_t refs;
568 enum hv_pcichild_state state;
569 struct pci_slot *pci_slot;
570 struct hv_pcidev_description desc;
571 bool reported_missing;
572 struct hv_pcibus_device *hbus;
573 struct work_struct wrk;
574
575 void (*block_invalidate)(void *context, u64 block_mask);
576 void *invalidate_context;
577
578 /*
579 * What would be observed if one wrote 0xFFFFFFFF to a BAR and then
580 * read it back, for each of the BAR offsets within config space.
581 */
582 u32 probed_bar[PCI_STD_NUM_BARS];
583};
584
585struct hv_pci_compl {
586 struct completion host_event;
587 s32 completion_status;
588};
589
590static void hv_pci_onchannelcallback(void *context);
591
592#ifdef CONFIG_X86
593#define DELIVERY_MODE APIC_DELIVERY_MODE_FIXED
594#define FLOW_HANDLER handle_edge_irq
595#define FLOW_NAME "edge"
596
597static int hv_pci_irqchip_init(void)
598{
599 return 0;
600}
601
602static struct irq_domain *hv_pci_get_root_domain(void)
603{
604 return x86_vector_domain;
605}
606
607static unsigned int hv_msi_get_int_vector(struct irq_data *data)
608{
609 struct irq_cfg *cfg = irqd_cfg(data);
610
611 return cfg->vector;
612}
613
614#define hv_msi_prepare pci_msi_prepare
615
616/**
617 * hv_arch_irq_unmask() - "Unmask" the IRQ by setting its current
618 * affinity.
619 * @data: Describes the IRQ
620 *
621 * Build new a destination for the MSI and make a hypercall to
622 * update the Interrupt Redirection Table. "Device Logical ID"
623 * is built out of this PCI bus's instance GUID and the function
624 * number of the device.
625 */
626static void hv_arch_irq_unmask(struct irq_data *data)
627{
628 struct msi_desc *msi_desc = irq_data_get_msi_desc(data);
629 struct hv_retarget_device_interrupt *params;
630 struct tran_int_desc *int_desc;
631 struct hv_pcibus_device *hbus;
632 const struct cpumask *dest;
633 cpumask_var_t tmp;
634 struct pci_bus *pbus;
635 struct pci_dev *pdev;
636 unsigned long flags;
637 u32 var_size = 0;
638 int cpu, nr_bank;
639 u64 res;
640
641 dest = irq_data_get_effective_affinity_mask(data);
642 pdev = msi_desc_to_pci_dev(msi_desc);
643 pbus = pdev->bus;
644 hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
645 int_desc = data->chip_data;
646
647 spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags);
648
649 params = &hbus->retarget_msi_interrupt_params;
650 memset(params, 0, sizeof(*params));
651 params->partition_id = HV_PARTITION_ID_SELF;
652 params->int_entry.source = HV_INTERRUPT_SOURCE_MSI;
653 params->int_entry.msi_entry.address.as_uint32 = int_desc->address & 0xffffffff;
654 params->int_entry.msi_entry.data.as_uint32 = int_desc->data;
655 params->device_id = (hbus->hdev->dev_instance.b[5] << 24) |
656 (hbus->hdev->dev_instance.b[4] << 16) |
657 (hbus->hdev->dev_instance.b[7] << 8) |
658 (hbus->hdev->dev_instance.b[6] & 0xf8) |
659 PCI_FUNC(pdev->devfn);
660 params->int_target.vector = hv_msi_get_int_vector(data);
661
662 /*
663 * Honoring apic->delivery_mode set to APIC_DELIVERY_MODE_FIXED by
664 * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a
665 * spurious interrupt storm. Not doing so does not seem to have a
666 * negative effect (yet?).
667 */
668
669 if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) {
670 /*
671 * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the
672 * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides
673 * with >64 VP support.
674 * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED
675 * is not sufficient for this hypercall.
676 */
677 params->int_target.flags |=
678 HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET;
679
680 if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) {
681 res = 1;
682 goto exit_unlock;
683 }
684
685 cpumask_and(tmp, dest, cpu_online_mask);
686 nr_bank = cpumask_to_vpset(¶ms->int_target.vp_set, tmp);
687 free_cpumask_var(tmp);
688
689 if (nr_bank <= 0) {
690 res = 1;
691 goto exit_unlock;
692 }
693
694 /*
695 * var-sized hypercall, var-size starts after vp_mask (thus
696 * vp_set.format does not count, but vp_set.valid_bank_mask
697 * does).
698 */
699 var_size = 1 + nr_bank;
700 } else {
701 for_each_cpu_and(cpu, dest, cpu_online_mask) {
702 params->int_target.vp_mask |=
703 (1ULL << hv_cpu_number_to_vp_number(cpu));
704 }
705 }
706
707 res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),
708 params, NULL);
709
710exit_unlock:
711 spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
712
713 /*
714 * During hibernation, when a CPU is offlined, the kernel tries
715 * to move the interrupt to the remaining CPUs that haven't
716 * been offlined yet. In this case, the below hv_do_hypercall()
717 * always fails since the vmbus channel has been closed:
718 * refer to cpu_disable_common() -> fixup_irqs() ->
719 * irq_migrate_all_off_this_cpu() -> migrate_one_irq().
720 *
721 * Suppress the error message for hibernation because the failure
722 * during hibernation does not matter (at this time all the devices
723 * have been frozen). Note: the correct affinity info is still updated
724 * into the irqdata data structure in migrate_one_irq() ->
725 * irq_do_set_affinity(), so later when the VM resumes,
726 * hv_pci_restore_msi_state() is able to correctly restore the
727 * interrupt with the correct affinity.
728 */
729 if (!hv_result_success(res) && hbus->state != hv_pcibus_removing)
730 dev_err(&hbus->hdev->device,
731 "%s() failed: %#llx", __func__, res);
732}
733#elif defined(CONFIG_ARM64)
734/*
735 * SPI vectors to use for vPCI; arch SPIs range is [32, 1019], but leaving a bit
736 * of room at the start to allow for SPIs to be specified through ACPI and
737 * starting with a power of two to satisfy power of 2 multi-MSI requirement.
738 */
739#define HV_PCI_MSI_SPI_START 64
740#define HV_PCI_MSI_SPI_NR (1020 - HV_PCI_MSI_SPI_START)
741#define DELIVERY_MODE 0
742#define FLOW_HANDLER NULL
743#define FLOW_NAME NULL
744#define hv_msi_prepare NULL
745
746struct hv_pci_chip_data {
747 DECLARE_BITMAP(spi_map, HV_PCI_MSI_SPI_NR);
748 struct mutex map_lock;
749};
750
751/* Hyper-V vPCI MSI GIC IRQ domain */
752static struct irq_domain *hv_msi_gic_irq_domain;
753
754/* Hyper-V PCI MSI IRQ chip */
755static struct irq_chip hv_arm64_msi_irq_chip = {
756 .name = "MSI",
757 .irq_set_affinity = irq_chip_set_affinity_parent,
758 .irq_eoi = irq_chip_eoi_parent,
759 .irq_mask = irq_chip_mask_parent,
760 .irq_unmask = irq_chip_unmask_parent
761};
762
763static unsigned int hv_msi_get_int_vector(struct irq_data *irqd)
764{
765 return irqd->parent_data->hwirq;
766}
767
768/*
769 * @nr_bm_irqs: Indicates the number of IRQs that were allocated from
770 * the bitmap.
771 * @nr_dom_irqs: Indicates the number of IRQs that were allocated from
772 * the parent domain.
773 */
774static void hv_pci_vec_irq_free(struct irq_domain *domain,
775 unsigned int virq,
776 unsigned int nr_bm_irqs,
777 unsigned int nr_dom_irqs)
778{
779 struct hv_pci_chip_data *chip_data = domain->host_data;
780 struct irq_data *d = irq_domain_get_irq_data(domain, virq);
781 int first = d->hwirq - HV_PCI_MSI_SPI_START;
782 int i;
783
784 mutex_lock(&chip_data->map_lock);
785 bitmap_release_region(chip_data->spi_map,
786 first,
787 get_count_order(nr_bm_irqs));
788 mutex_unlock(&chip_data->map_lock);
789 for (i = 0; i < nr_dom_irqs; i++) {
790 if (i)
791 d = irq_domain_get_irq_data(domain, virq + i);
792 irq_domain_reset_irq_data(d);
793 }
794
795 irq_domain_free_irqs_parent(domain, virq, nr_dom_irqs);
796}
797
798static void hv_pci_vec_irq_domain_free(struct irq_domain *domain,
799 unsigned int virq,
800 unsigned int nr_irqs)
801{
802 hv_pci_vec_irq_free(domain, virq, nr_irqs, nr_irqs);
803}
804
805static int hv_pci_vec_alloc_device_irq(struct irq_domain *domain,
806 unsigned int nr_irqs,
807 irq_hw_number_t *hwirq)
808{
809 struct hv_pci_chip_data *chip_data = domain->host_data;
810 int index;
811
812 /* Find and allocate region from the SPI bitmap */
813 mutex_lock(&chip_data->map_lock);
814 index = bitmap_find_free_region(chip_data->spi_map,
815 HV_PCI_MSI_SPI_NR,
816 get_count_order(nr_irqs));
817 mutex_unlock(&chip_data->map_lock);
818 if (index < 0)
819 return -ENOSPC;
820
821 *hwirq = index + HV_PCI_MSI_SPI_START;
822
823 return 0;
824}
825
826static int hv_pci_vec_irq_gic_domain_alloc(struct irq_domain *domain,
827 unsigned int virq,
828 irq_hw_number_t hwirq)
829{
830 struct irq_fwspec fwspec;
831 struct irq_data *d;
832 int ret;
833
834 fwspec.fwnode = domain->parent->fwnode;
835 fwspec.param_count = 2;
836 fwspec.param[0] = hwirq;
837 fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
838
839 ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
840 if (ret)
841 return ret;
842
843 /*
844 * Since the interrupt specifier is not coming from ACPI or DT, the
845 * trigger type will need to be set explicitly. Otherwise, it will be
846 * set to whatever is in the GIC configuration.
847 */
848 d = irq_domain_get_irq_data(domain->parent, virq);
849
850 return d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
851}
852
853static int hv_pci_vec_irq_domain_alloc(struct irq_domain *domain,
854 unsigned int virq, unsigned int nr_irqs,
855 void *args)
856{
857 irq_hw_number_t hwirq;
858 unsigned int i;
859 int ret;
860
861 ret = hv_pci_vec_alloc_device_irq(domain, nr_irqs, &hwirq);
862 if (ret)
863 return ret;
864
865 for (i = 0; i < nr_irqs; i++) {
866 ret = hv_pci_vec_irq_gic_domain_alloc(domain, virq + i,
867 hwirq + i);
868 if (ret) {
869 hv_pci_vec_irq_free(domain, virq, nr_irqs, i);
870 return ret;
871 }
872
873 irq_domain_set_hwirq_and_chip(domain, virq + i,
874 hwirq + i,
875 &hv_arm64_msi_irq_chip,
876 domain->host_data);
877 pr_debug("pID:%d vID:%u\n", (int)(hwirq + i), virq + i);
878 }
879
880 return 0;
881}
882
883/*
884 * Pick the first cpu as the irq affinity that can be temporarily used for
885 * composing MSI from the hypervisor. GIC will eventually set the right
886 * affinity for the irq and the 'unmask' will retarget the interrupt to that
887 * cpu.
888 */
889static int hv_pci_vec_irq_domain_activate(struct irq_domain *domain,
890 struct irq_data *irqd, bool reserve)
891{
892 int cpu = cpumask_first(cpu_present_mask);
893
894 irq_data_update_effective_affinity(irqd, cpumask_of(cpu));
895
896 return 0;
897}
898
899static const struct irq_domain_ops hv_pci_domain_ops = {
900 .alloc = hv_pci_vec_irq_domain_alloc,
901 .free = hv_pci_vec_irq_domain_free,
902 .activate = hv_pci_vec_irq_domain_activate,
903};
904
905static int hv_pci_irqchip_init(void)
906{
907 static struct hv_pci_chip_data *chip_data;
908 struct fwnode_handle *fn = NULL;
909 int ret = -ENOMEM;
910
911 chip_data = kzalloc(sizeof(*chip_data), GFP_KERNEL);
912 if (!chip_data)
913 return ret;
914
915 mutex_init(&chip_data->map_lock);
916 fn = irq_domain_alloc_named_fwnode("hv_vpci_arm64");
917 if (!fn)
918 goto free_chip;
919
920 /*
921 * IRQ domain once enabled, should not be removed since there is no
922 * way to ensure that all the corresponding devices are also gone and
923 * no interrupts will be generated.
924 */
925 hv_msi_gic_irq_domain = acpi_irq_create_hierarchy(0, HV_PCI_MSI_SPI_NR,
926 fn, &hv_pci_domain_ops,
927 chip_data);
928
929 if (!hv_msi_gic_irq_domain) {
930 pr_err("Failed to create Hyper-V arm64 vPCI MSI IRQ domain\n");
931 goto free_chip;
932 }
933
934 return 0;
935
936free_chip:
937 kfree(chip_data);
938 if (fn)
939 irq_domain_free_fwnode(fn);
940
941 return ret;
942}
943
944static struct irq_domain *hv_pci_get_root_domain(void)
945{
946 return hv_msi_gic_irq_domain;
947}
948
949/*
950 * SPIs are used for interrupts of PCI devices and SPIs is managed via GICD
951 * registers which Hyper-V already supports, so no hypercall needed.
952 */
953static void hv_arch_irq_unmask(struct irq_data *data) { }
954#endif /* CONFIG_ARM64 */
955
956/**
957 * hv_pci_generic_compl() - Invoked for a completion packet
958 * @context: Set up by the sender of the packet.
959 * @resp: The response packet
960 * @resp_packet_size: Size in bytes of the packet
961 *
962 * This function is used to trigger an event and report status
963 * for any message for which the completion packet contains a
964 * status and nothing else.
965 */
966static void hv_pci_generic_compl(void *context, struct pci_response *resp,
967 int resp_packet_size)
968{
969 struct hv_pci_compl *comp_pkt = context;
970
971 comp_pkt->completion_status = resp->status;
972 complete(&comp_pkt->host_event);
973}
974
975static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
976 u32 wslot);
977
978static void get_pcichild(struct hv_pci_dev *hpdev)
979{
980 refcount_inc(&hpdev->refs);
981}
982
983static void put_pcichild(struct hv_pci_dev *hpdev)
984{
985 if (refcount_dec_and_test(&hpdev->refs))
986 kfree(hpdev);
987}
988
989/*
990 * There is no good way to get notified from vmbus_onoffer_rescind(),
991 * so let's use polling here, since this is not a hot path.
992 */
993static int wait_for_response(struct hv_device *hdev,
994 struct completion *comp)
995{
996 while (true) {
997 if (hdev->channel->rescind) {
998 dev_warn_once(&hdev->device, "The device is gone.\n");
999 return -ENODEV;
1000 }
1001
1002 if (wait_for_completion_timeout(comp, HZ / 10))
1003 break;
1004 }
1005
1006 return 0;
1007}
1008
1009/**
1010 * devfn_to_wslot() - Convert from Linux PCI slot to Windows
1011 * @devfn: The Linux representation of PCI slot
1012 *
1013 * Windows uses a slightly different representation of PCI slot.
1014 *
1015 * Return: The Windows representation
1016 */
1017static u32 devfn_to_wslot(int devfn)
1018{
1019 union win_slot_encoding wslot;
1020
1021 wslot.slot = 0;
1022 wslot.bits.dev = PCI_SLOT(devfn);
1023 wslot.bits.func = PCI_FUNC(devfn);
1024
1025 return wslot.slot;
1026}
1027
1028/**
1029 * wslot_to_devfn() - Convert from Windows PCI slot to Linux
1030 * @wslot: The Windows representation of PCI slot
1031 *
1032 * Windows uses a slightly different representation of PCI slot.
1033 *
1034 * Return: The Linux representation
1035 */
1036static int wslot_to_devfn(u32 wslot)
1037{
1038 union win_slot_encoding slot_no;
1039
1040 slot_no.slot = wslot;
1041 return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func);
1042}
1043
1044/*
1045 * PCI Configuration Space for these root PCI buses is implemented as a pair
1046 * of pages in memory-mapped I/O space. Writing to the first page chooses
1047 * the PCI function being written or read. Once the first page has been
1048 * written to, the following page maps in the entire configuration space of
1049 * the function.
1050 */
1051
1052/**
1053 * _hv_pcifront_read_config() - Internal PCI config read
1054 * @hpdev: The PCI driver's representation of the device
1055 * @where: Offset within config space
1056 * @size: Size of the transfer
1057 * @val: Pointer to the buffer receiving the data
1058 */
1059static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where,
1060 int size, u32 *val)
1061{
1062 unsigned long flags;
1063 void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
1064
1065 /*
1066 * If the attempt is to read the IDs or the ROM BAR, simulate that.
1067 */
1068 if (where + size <= PCI_COMMAND) {
1069 memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size);
1070 } else if (where >= PCI_CLASS_REVISION && where + size <=
1071 PCI_CACHE_LINE_SIZE) {
1072 memcpy(val, ((u8 *)&hpdev->desc.rev) + where -
1073 PCI_CLASS_REVISION, size);
1074 } else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <=
1075 PCI_ROM_ADDRESS) {
1076 memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where -
1077 PCI_SUBSYSTEM_VENDOR_ID, size);
1078 } else if (where >= PCI_ROM_ADDRESS && where + size <=
1079 PCI_CAPABILITY_LIST) {
1080 /* ROM BARs are unimplemented */
1081 *val = 0;
1082 } else if (where >= PCI_INTERRUPT_LINE && where + size <=
1083 PCI_INTERRUPT_PIN) {
1084 /*
1085 * Interrupt Line and Interrupt PIN are hard-wired to zero
1086 * because this front-end only supports message-signaled
1087 * interrupts.
1088 */
1089 *val = 0;
1090 } else if (where + size <= CFG_PAGE_SIZE) {
1091 spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
1092 /* Choose the function to be read. (See comment above) */
1093 writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
1094 /* Make sure the function was chosen before we start reading. */
1095 mb();
1096 /* Read from that function's config space. */
1097 switch (size) {
1098 case 1:
1099 *val = readb(addr);
1100 break;
1101 case 2:
1102 *val = readw(addr);
1103 break;
1104 default:
1105 *val = readl(addr);
1106 break;
1107 }
1108 /*
1109 * Make sure the read was done before we release the spinlock
1110 * allowing consecutive reads/writes.
1111 */
1112 mb();
1113 spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
1114 } else {
1115 dev_err(&hpdev->hbus->hdev->device,
1116 "Attempt to read beyond a function's config space.\n");
1117 }
1118}
1119
1120static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev)
1121{
1122 u16 ret;
1123 unsigned long flags;
1124 void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET +
1125 PCI_VENDOR_ID;
1126
1127 spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
1128
1129 /* Choose the function to be read. (See comment above) */
1130 writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
1131 /* Make sure the function was chosen before we start reading. */
1132 mb();
1133 /* Read from that function's config space. */
1134 ret = readw(addr);
1135 /*
1136 * mb() is not required here, because the spin_unlock_irqrestore()
1137 * is a barrier.
1138 */
1139
1140 spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
1141
1142 return ret;
1143}
1144
1145/**
1146 * _hv_pcifront_write_config() - Internal PCI config write
1147 * @hpdev: The PCI driver's representation of the device
1148 * @where: Offset within config space
1149 * @size: Size of the transfer
1150 * @val: The data being transferred
1151 */
1152static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where,
1153 int size, u32 val)
1154{
1155 unsigned long flags;
1156 void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where;
1157
1158 if (where >= PCI_SUBSYSTEM_VENDOR_ID &&
1159 where + size <= PCI_CAPABILITY_LIST) {
1160 /* SSIDs and ROM BARs are read-only */
1161 } else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) {
1162 spin_lock_irqsave(&hpdev->hbus->config_lock, flags);
1163 /* Choose the function to be written. (See comment above) */
1164 writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr);
1165 /* Make sure the function was chosen before we start writing. */
1166 wmb();
1167 /* Write to that function's config space. */
1168 switch (size) {
1169 case 1:
1170 writeb(val, addr);
1171 break;
1172 case 2:
1173 writew(val, addr);
1174 break;
1175 default:
1176 writel(val, addr);
1177 break;
1178 }
1179 /*
1180 * Make sure the write was done before we release the spinlock
1181 * allowing consecutive reads/writes.
1182 */
1183 mb();
1184 spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags);
1185 } else {
1186 dev_err(&hpdev->hbus->hdev->device,
1187 "Attempt to write beyond a function's config space.\n");
1188 }
1189}
1190
1191/**
1192 * hv_pcifront_read_config() - Read configuration space
1193 * @bus: PCI Bus structure
1194 * @devfn: Device/function
1195 * @where: Offset from base
1196 * @size: Byte/word/dword
1197 * @val: Value to be read
1198 *
1199 * Return: PCIBIOS_SUCCESSFUL on success
1200 * PCIBIOS_DEVICE_NOT_FOUND on failure
1201 */
1202static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn,
1203 int where, int size, u32 *val)
1204{
1205 struct hv_pcibus_device *hbus =
1206 container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
1207 struct hv_pci_dev *hpdev;
1208
1209 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
1210 if (!hpdev)
1211 return PCIBIOS_DEVICE_NOT_FOUND;
1212
1213 _hv_pcifront_read_config(hpdev, where, size, val);
1214
1215 put_pcichild(hpdev);
1216 return PCIBIOS_SUCCESSFUL;
1217}
1218
1219/**
1220 * hv_pcifront_write_config() - Write configuration space
1221 * @bus: PCI Bus structure
1222 * @devfn: Device/function
1223 * @where: Offset from base
1224 * @size: Byte/word/dword
1225 * @val: Value to be written to device
1226 *
1227 * Return: PCIBIOS_SUCCESSFUL on success
1228 * PCIBIOS_DEVICE_NOT_FOUND on failure
1229 */
1230static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn,
1231 int where, int size, u32 val)
1232{
1233 struct hv_pcibus_device *hbus =
1234 container_of(bus->sysdata, struct hv_pcibus_device, sysdata);
1235 struct hv_pci_dev *hpdev;
1236
1237 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn));
1238 if (!hpdev)
1239 return PCIBIOS_DEVICE_NOT_FOUND;
1240
1241 _hv_pcifront_write_config(hpdev, where, size, val);
1242
1243 put_pcichild(hpdev);
1244 return PCIBIOS_SUCCESSFUL;
1245}
1246
1247/* PCIe operations */
1248static struct pci_ops hv_pcifront_ops = {
1249 .read = hv_pcifront_read_config,
1250 .write = hv_pcifront_write_config,
1251};
1252
1253/*
1254 * Paravirtual backchannel
1255 *
1256 * Hyper-V SR-IOV provides a backchannel mechanism in software for
1257 * communication between a VF driver and a PF driver. These
1258 * "configuration blocks" are similar in concept to PCI configuration space,
1259 * but instead of doing reads and writes in 32-bit chunks through a very slow
1260 * path, packets of up to 128 bytes can be sent or received asynchronously.
1261 *
1262 * Nearly every SR-IOV device contains just such a communications channel in
1263 * hardware, so using this one in software is usually optional. Using the
1264 * software channel, however, allows driver implementers to leverage software
1265 * tools that fuzz the communications channel looking for vulnerabilities.
1266 *
1267 * The usage model for these packets puts the responsibility for reading or
1268 * writing on the VF driver. The VF driver sends a read or a write packet,
1269 * indicating which "block" is being referred to by number.
1270 *
1271 * If the PF driver wishes to initiate communication, it can "invalidate" one or
1272 * more of the first 64 blocks. This invalidation is delivered via a callback
1273 * supplied by the VF driver by this driver.
1274 *
1275 * No protocol is implied, except that supplied by the PF and VF drivers.
1276 */
1277
1278struct hv_read_config_compl {
1279 struct hv_pci_compl comp_pkt;
1280 void *buf;
1281 unsigned int len;
1282 unsigned int bytes_returned;
1283};
1284
1285/**
1286 * hv_pci_read_config_compl() - Invoked when a response packet
1287 * for a read config block operation arrives.
1288 * @context: Identifies the read config operation
1289 * @resp: The response packet itself
1290 * @resp_packet_size: Size in bytes of the response packet
1291 */
1292static void hv_pci_read_config_compl(void *context, struct pci_response *resp,
1293 int resp_packet_size)
1294{
1295 struct hv_read_config_compl *comp = context;
1296 struct pci_read_block_response *read_resp =
1297 (struct pci_read_block_response *)resp;
1298 unsigned int data_len, hdr_len;
1299
1300 hdr_len = offsetof(struct pci_read_block_response, bytes);
1301 if (resp_packet_size < hdr_len) {
1302 comp->comp_pkt.completion_status = -1;
1303 goto out;
1304 }
1305
1306 data_len = resp_packet_size - hdr_len;
1307 if (data_len > 0 && read_resp->status == 0) {
1308 comp->bytes_returned = min(comp->len, data_len);
1309 memcpy(comp->buf, read_resp->bytes, comp->bytes_returned);
1310 } else {
1311 comp->bytes_returned = 0;
1312 }
1313
1314 comp->comp_pkt.completion_status = read_resp->status;
1315out:
1316 complete(&comp->comp_pkt.host_event);
1317}
1318
1319/**
1320 * hv_read_config_block() - Sends a read config block request to
1321 * the back-end driver running in the Hyper-V parent partition.
1322 * @pdev: The PCI driver's representation for this device.
1323 * @buf: Buffer into which the config block will be copied.
1324 * @len: Size in bytes of buf.
1325 * @block_id: Identifies the config block which has been requested.
1326 * @bytes_returned: Size which came back from the back-end driver.
1327 *
1328 * Return: 0 on success, -errno on failure
1329 */
1330static int hv_read_config_block(struct pci_dev *pdev, void *buf,
1331 unsigned int len, unsigned int block_id,
1332 unsigned int *bytes_returned)
1333{
1334 struct hv_pcibus_device *hbus =
1335 container_of(pdev->bus->sysdata, struct hv_pcibus_device,
1336 sysdata);
1337 struct {
1338 struct pci_packet pkt;
1339 char buf[sizeof(struct pci_read_block)];
1340 } pkt;
1341 struct hv_read_config_compl comp_pkt;
1342 struct pci_read_block *read_blk;
1343 int ret;
1344
1345 if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
1346 return -EINVAL;
1347
1348 init_completion(&comp_pkt.comp_pkt.host_event);
1349 comp_pkt.buf = buf;
1350 comp_pkt.len = len;
1351
1352 memset(&pkt, 0, sizeof(pkt));
1353 pkt.pkt.completion_func = hv_pci_read_config_compl;
1354 pkt.pkt.compl_ctxt = &comp_pkt;
1355 read_blk = (struct pci_read_block *)&pkt.pkt.message;
1356 read_blk->message_type.type = PCI_READ_BLOCK;
1357 read_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
1358 read_blk->block_id = block_id;
1359 read_blk->bytes_requested = len;
1360
1361 ret = vmbus_sendpacket(hbus->hdev->channel, read_blk,
1362 sizeof(*read_blk), (unsigned long)&pkt.pkt,
1363 VM_PKT_DATA_INBAND,
1364 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1365 if (ret)
1366 return ret;
1367
1368 ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event);
1369 if (ret)
1370 return ret;
1371
1372 if (comp_pkt.comp_pkt.completion_status != 0 ||
1373 comp_pkt.bytes_returned == 0) {
1374 dev_err(&hbus->hdev->device,
1375 "Read Config Block failed: 0x%x, bytes_returned=%d\n",
1376 comp_pkt.comp_pkt.completion_status,
1377 comp_pkt.bytes_returned);
1378 return -EIO;
1379 }
1380
1381 *bytes_returned = comp_pkt.bytes_returned;
1382 return 0;
1383}
1384
1385/**
1386 * hv_pci_write_config_compl() - Invoked when a response packet for a write
1387 * config block operation arrives.
1388 * @context: Identifies the write config operation
1389 * @resp: The response packet itself
1390 * @resp_packet_size: Size in bytes of the response packet
1391 */
1392static void hv_pci_write_config_compl(void *context, struct pci_response *resp,
1393 int resp_packet_size)
1394{
1395 struct hv_pci_compl *comp_pkt = context;
1396
1397 comp_pkt->completion_status = resp->status;
1398 complete(&comp_pkt->host_event);
1399}
1400
1401/**
1402 * hv_write_config_block() - Sends a write config block request to the
1403 * back-end driver running in the Hyper-V parent partition.
1404 * @pdev: The PCI driver's representation for this device.
1405 * @buf: Buffer from which the config block will be copied.
1406 * @len: Size in bytes of buf.
1407 * @block_id: Identifies the config block which is being written.
1408 *
1409 * Return: 0 on success, -errno on failure
1410 */
1411static int hv_write_config_block(struct pci_dev *pdev, void *buf,
1412 unsigned int len, unsigned int block_id)
1413{
1414 struct hv_pcibus_device *hbus =
1415 container_of(pdev->bus->sysdata, struct hv_pcibus_device,
1416 sysdata);
1417 struct {
1418 struct pci_packet pkt;
1419 char buf[sizeof(struct pci_write_block)];
1420 u32 reserved;
1421 } pkt;
1422 struct hv_pci_compl comp_pkt;
1423 struct pci_write_block *write_blk;
1424 u32 pkt_size;
1425 int ret;
1426
1427 if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX)
1428 return -EINVAL;
1429
1430 init_completion(&comp_pkt.host_event);
1431
1432 memset(&pkt, 0, sizeof(pkt));
1433 pkt.pkt.completion_func = hv_pci_write_config_compl;
1434 pkt.pkt.compl_ctxt = &comp_pkt;
1435 write_blk = (struct pci_write_block *)&pkt.pkt.message;
1436 write_blk->message_type.type = PCI_WRITE_BLOCK;
1437 write_blk->wslot.slot = devfn_to_wslot(pdev->devfn);
1438 write_blk->block_id = block_id;
1439 write_blk->byte_count = len;
1440 memcpy(write_blk->bytes, buf, len);
1441 pkt_size = offsetof(struct pci_write_block, bytes) + len;
1442 /*
1443 * This quirk is required on some hosts shipped around 2018, because
1444 * these hosts don't check the pkt_size correctly (new hosts have been
1445 * fixed since early 2019). The quirk is also safe on very old hosts
1446 * and new hosts, because, on them, what really matters is the length
1447 * specified in write_blk->byte_count.
1448 */
1449 pkt_size += sizeof(pkt.reserved);
1450
1451 ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size,
1452 (unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND,
1453 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1454 if (ret)
1455 return ret;
1456
1457 ret = wait_for_response(hbus->hdev, &comp_pkt.host_event);
1458 if (ret)
1459 return ret;
1460
1461 if (comp_pkt.completion_status != 0) {
1462 dev_err(&hbus->hdev->device,
1463 "Write Config Block failed: 0x%x\n",
1464 comp_pkt.completion_status);
1465 return -EIO;
1466 }
1467
1468 return 0;
1469}
1470
1471/**
1472 * hv_register_block_invalidate() - Invoked when a config block invalidation
1473 * arrives from the back-end driver.
1474 * @pdev: The PCI driver's representation for this device.
1475 * @context: Identifies the device.
1476 * @block_invalidate: Identifies all of the blocks being invalidated.
1477 *
1478 * Return: 0 on success, -errno on failure
1479 */
1480static int hv_register_block_invalidate(struct pci_dev *pdev, void *context,
1481 void (*block_invalidate)(void *context,
1482 u64 block_mask))
1483{
1484 struct hv_pcibus_device *hbus =
1485 container_of(pdev->bus->sysdata, struct hv_pcibus_device,
1486 sysdata);
1487 struct hv_pci_dev *hpdev;
1488
1489 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
1490 if (!hpdev)
1491 return -ENODEV;
1492
1493 hpdev->block_invalidate = block_invalidate;
1494 hpdev->invalidate_context = context;
1495
1496 put_pcichild(hpdev);
1497 return 0;
1498
1499}
1500
1501/* Interrupt management hooks */
1502static void hv_int_desc_free(struct hv_pci_dev *hpdev,
1503 struct tran_int_desc *int_desc)
1504{
1505 struct pci_delete_interrupt *int_pkt;
1506 struct {
1507 struct pci_packet pkt;
1508 u8 buffer[sizeof(struct pci_delete_interrupt)];
1509 } ctxt;
1510
1511 if (!int_desc->vector_count) {
1512 kfree(int_desc);
1513 return;
1514 }
1515 memset(&ctxt, 0, sizeof(ctxt));
1516 int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message;
1517 int_pkt->message_type.type =
1518 PCI_DELETE_INTERRUPT_MESSAGE;
1519 int_pkt->wslot.slot = hpdev->desc.win_slot.slot;
1520 int_pkt->int_desc = *int_desc;
1521 vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt),
1522 0, VM_PKT_DATA_INBAND, 0);
1523 kfree(int_desc);
1524}
1525
1526/**
1527 * hv_msi_free() - Free the MSI.
1528 * @domain: The interrupt domain pointer
1529 * @info: Extra MSI-related context
1530 * @irq: Identifies the IRQ.
1531 *
1532 * The Hyper-V parent partition and hypervisor are tracking the
1533 * messages that are in use, keeping the interrupt redirection
1534 * table up to date. This callback sends a message that frees
1535 * the IRT entry and related tracking nonsense.
1536 */
1537static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info,
1538 unsigned int irq)
1539{
1540 struct hv_pcibus_device *hbus;
1541 struct hv_pci_dev *hpdev;
1542 struct pci_dev *pdev;
1543 struct tran_int_desc *int_desc;
1544 struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq);
1545 struct msi_desc *msi = irq_data_get_msi_desc(irq_data);
1546
1547 pdev = msi_desc_to_pci_dev(msi);
1548 hbus = info->data;
1549 int_desc = irq_data_get_irq_chip_data(irq_data);
1550 if (!int_desc)
1551 return;
1552
1553 irq_data->chip_data = NULL;
1554 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
1555 if (!hpdev) {
1556 kfree(int_desc);
1557 return;
1558 }
1559
1560 hv_int_desc_free(hpdev, int_desc);
1561 put_pcichild(hpdev);
1562}
1563
1564static void hv_irq_mask(struct irq_data *data)
1565{
1566 pci_msi_mask_irq(data);
1567 if (data->parent_data->chip->irq_mask)
1568 irq_chip_mask_parent(data);
1569}
1570
1571static void hv_irq_unmask(struct irq_data *data)
1572{
1573 hv_arch_irq_unmask(data);
1574
1575 if (data->parent_data->chip->irq_unmask)
1576 irq_chip_unmask_parent(data);
1577 pci_msi_unmask_irq(data);
1578}
1579
1580struct compose_comp_ctxt {
1581 struct hv_pci_compl comp_pkt;
1582 struct tran_int_desc int_desc;
1583};
1584
1585static void hv_pci_compose_compl(void *context, struct pci_response *resp,
1586 int resp_packet_size)
1587{
1588 struct compose_comp_ctxt *comp_pkt = context;
1589 struct pci_create_int_response *int_resp =
1590 (struct pci_create_int_response *)resp;
1591
1592 if (resp_packet_size < sizeof(*int_resp)) {
1593 comp_pkt->comp_pkt.completion_status = -1;
1594 goto out;
1595 }
1596 comp_pkt->comp_pkt.completion_status = resp->status;
1597 comp_pkt->int_desc = int_resp->int_desc;
1598out:
1599 complete(&comp_pkt->comp_pkt.host_event);
1600}
1601
1602static u32 hv_compose_msi_req_v1(
1603 struct pci_create_interrupt *int_pkt,
1604 u32 slot, u8 vector, u16 vector_count)
1605{
1606 int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE;
1607 int_pkt->wslot.slot = slot;
1608 int_pkt->int_desc.vector = vector;
1609 int_pkt->int_desc.vector_count = vector_count;
1610 int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
1611
1612 /*
1613 * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in
1614 * hv_irq_unmask().
1615 */
1616 int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL;
1617
1618 return sizeof(*int_pkt);
1619}
1620
1621/*
1622 * The vCPU selected by hv_compose_multi_msi_req_get_cpu() and
1623 * hv_compose_msi_req_get_cpu() is a "dummy" vCPU because the final vCPU to be
1624 * interrupted is specified later in hv_irq_unmask() and communicated to Hyper-V
1625 * via the HVCALL_RETARGET_INTERRUPT hypercall. But the choice of dummy vCPU is
1626 * not irrelevant because Hyper-V chooses the physical CPU to handle the
1627 * interrupts based on the vCPU specified in message sent to the vPCI VSP in
1628 * hv_compose_msi_msg(). Hyper-V's choice of pCPU is not visible to the guest,
1629 * but assigning too many vPCI device interrupts to the same pCPU can cause a
1630 * performance bottleneck. So we spread out the dummy vCPUs to influence Hyper-V
1631 * to spread out the pCPUs that it selects.
1632 *
1633 * For the single-MSI and MSI-X cases, it's OK for hv_compose_msi_req_get_cpu()
1634 * to always return the same dummy vCPU, because a second call to
1635 * hv_compose_msi_msg() contains the "real" vCPU, causing Hyper-V to choose a
1636 * new pCPU for the interrupt. But for the multi-MSI case, the second call to
1637 * hv_compose_msi_msg() exits without sending a message to the vPCI VSP, so the
1638 * original dummy vCPU is used. This dummy vCPU must be round-robin'ed so that
1639 * the pCPUs are spread out. All interrupts for a multi-MSI device end up using
1640 * the same pCPU, even though the vCPUs will be spread out by later calls
1641 * to hv_irq_unmask(), but that is the best we can do now.
1642 *
1643 * With Hyper-V in Nov 2022, the HVCALL_RETARGET_INTERRUPT hypercall does *not*
1644 * cause Hyper-V to reselect the pCPU based on the specified vCPU. Such an
1645 * enhancement is planned for a future version. With that enhancement, the
1646 * dummy vCPU selection won't matter, and interrupts for the same multi-MSI
1647 * device will be spread across multiple pCPUs.
1648 */
1649
1650/*
1651 * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten
1652 * by subsequent retarget in hv_irq_unmask().
1653 */
1654static int hv_compose_msi_req_get_cpu(const struct cpumask *affinity)
1655{
1656 return cpumask_first_and(affinity, cpu_online_mask);
1657}
1658
1659/*
1660 * Make sure the dummy vCPU values for multi-MSI don't all point to vCPU0.
1661 */
1662static int hv_compose_multi_msi_req_get_cpu(void)
1663{
1664 static DEFINE_SPINLOCK(multi_msi_cpu_lock);
1665
1666 /* -1 means starting with CPU 0 */
1667 static int cpu_next = -1;
1668
1669 unsigned long flags;
1670 int cpu;
1671
1672 spin_lock_irqsave(&multi_msi_cpu_lock, flags);
1673
1674 cpu_next = cpumask_next_wrap(cpu_next, cpu_online_mask, nr_cpu_ids,
1675 false);
1676 cpu = cpu_next;
1677
1678 spin_unlock_irqrestore(&multi_msi_cpu_lock, flags);
1679
1680 return cpu;
1681}
1682
1683static u32 hv_compose_msi_req_v2(
1684 struct pci_create_interrupt2 *int_pkt, int cpu,
1685 u32 slot, u8 vector, u16 vector_count)
1686{
1687 int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2;
1688 int_pkt->wslot.slot = slot;
1689 int_pkt->int_desc.vector = vector;
1690 int_pkt->int_desc.vector_count = vector_count;
1691 int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
1692 int_pkt->int_desc.processor_array[0] =
1693 hv_cpu_number_to_vp_number(cpu);
1694 int_pkt->int_desc.processor_count = 1;
1695
1696 return sizeof(*int_pkt);
1697}
1698
1699static u32 hv_compose_msi_req_v3(
1700 struct pci_create_interrupt3 *int_pkt, int cpu,
1701 u32 slot, u32 vector, u16 vector_count)
1702{
1703 int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE3;
1704 int_pkt->wslot.slot = slot;
1705 int_pkt->int_desc.vector = vector;
1706 int_pkt->int_desc.reserved = 0;
1707 int_pkt->int_desc.vector_count = vector_count;
1708 int_pkt->int_desc.delivery_mode = DELIVERY_MODE;
1709 int_pkt->int_desc.processor_array[0] =
1710 hv_cpu_number_to_vp_number(cpu);
1711 int_pkt->int_desc.processor_count = 1;
1712
1713 return sizeof(*int_pkt);
1714}
1715
1716/**
1717 * hv_compose_msi_msg() - Supplies a valid MSI address/data
1718 * @data: Everything about this MSI
1719 * @msg: Buffer that is filled in by this function
1720 *
1721 * This function unpacks the IRQ looking for target CPU set, IDT
1722 * vector and mode and sends a message to the parent partition
1723 * asking for a mapping for that tuple in this partition. The
1724 * response supplies a data value and address to which that data
1725 * should be written to trigger that interrupt.
1726 */
1727static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
1728{
1729 struct hv_pcibus_device *hbus;
1730 struct vmbus_channel *channel;
1731 struct hv_pci_dev *hpdev;
1732 struct pci_bus *pbus;
1733 struct pci_dev *pdev;
1734 const struct cpumask *dest;
1735 struct compose_comp_ctxt comp;
1736 struct tran_int_desc *int_desc;
1737 struct msi_desc *msi_desc;
1738 /*
1739 * vector_count should be u16: see hv_msi_desc, hv_msi_desc2
1740 * and hv_msi_desc3. vector must be u32: see hv_msi_desc3.
1741 */
1742 u16 vector_count;
1743 u32 vector;
1744 struct {
1745 struct pci_packet pci_pkt;
1746 union {
1747 struct pci_create_interrupt v1;
1748 struct pci_create_interrupt2 v2;
1749 struct pci_create_interrupt3 v3;
1750 } int_pkts;
1751 } __packed ctxt;
1752 bool multi_msi;
1753 u64 trans_id;
1754 u32 size;
1755 int ret;
1756 int cpu;
1757
1758 msi_desc = irq_data_get_msi_desc(data);
1759 multi_msi = !msi_desc->pci.msi_attrib.is_msix &&
1760 msi_desc->nvec_used > 1;
1761
1762 /* Reuse the previous allocation */
1763 if (data->chip_data && multi_msi) {
1764 int_desc = data->chip_data;
1765 msg->address_hi = int_desc->address >> 32;
1766 msg->address_lo = int_desc->address & 0xffffffff;
1767 msg->data = int_desc->data;
1768 return;
1769 }
1770
1771 pdev = msi_desc_to_pci_dev(msi_desc);
1772 dest = irq_data_get_effective_affinity_mask(data);
1773 pbus = pdev->bus;
1774 hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata);
1775 channel = hbus->hdev->channel;
1776 hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn));
1777 if (!hpdev)
1778 goto return_null_message;
1779
1780 /* Free any previous message that might have already been composed. */
1781 if (data->chip_data && !multi_msi) {
1782 int_desc = data->chip_data;
1783 data->chip_data = NULL;
1784 hv_int_desc_free(hpdev, int_desc);
1785 }
1786
1787 int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC);
1788 if (!int_desc)
1789 goto drop_reference;
1790
1791 if (multi_msi) {
1792 /*
1793 * If this is not the first MSI of Multi MSI, we already have
1794 * a mapping. Can exit early.
1795 */
1796 if (msi_desc->irq != data->irq) {
1797 data->chip_data = int_desc;
1798 int_desc->address = msi_desc->msg.address_lo |
1799 (u64)msi_desc->msg.address_hi << 32;
1800 int_desc->data = msi_desc->msg.data +
1801 (data->irq - msi_desc->irq);
1802 msg->address_hi = msi_desc->msg.address_hi;
1803 msg->address_lo = msi_desc->msg.address_lo;
1804 msg->data = int_desc->data;
1805 put_pcichild(hpdev);
1806 return;
1807 }
1808 /*
1809 * The vector we select here is a dummy value. The correct
1810 * value gets sent to the hypervisor in unmask(). This needs
1811 * to be aligned with the count, and also not zero. Multi-msi
1812 * is powers of 2 up to 32, so 32 will always work here.
1813 */
1814 vector = 32;
1815 vector_count = msi_desc->nvec_used;
1816 cpu = hv_compose_multi_msi_req_get_cpu();
1817 } else {
1818 vector = hv_msi_get_int_vector(data);
1819 vector_count = 1;
1820 cpu = hv_compose_msi_req_get_cpu(dest);
1821 }
1822
1823 /*
1824 * hv_compose_msi_req_v1 and v2 are for x86 only, meaning 'vector'
1825 * can't exceed u8. Cast 'vector' down to u8 for v1/v2 explicitly
1826 * for better readability.
1827 */
1828 memset(&ctxt, 0, sizeof(ctxt));
1829 init_completion(&comp.comp_pkt.host_event);
1830 ctxt.pci_pkt.completion_func = hv_pci_compose_compl;
1831 ctxt.pci_pkt.compl_ctxt = ∁
1832
1833 switch (hbus->protocol_version) {
1834 case PCI_PROTOCOL_VERSION_1_1:
1835 size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1,
1836 hpdev->desc.win_slot.slot,
1837 (u8)vector,
1838 vector_count);
1839 break;
1840
1841 case PCI_PROTOCOL_VERSION_1_2:
1842 case PCI_PROTOCOL_VERSION_1_3:
1843 size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2,
1844 cpu,
1845 hpdev->desc.win_slot.slot,
1846 (u8)vector,
1847 vector_count);
1848 break;
1849
1850 case PCI_PROTOCOL_VERSION_1_4:
1851 size = hv_compose_msi_req_v3(&ctxt.int_pkts.v3,
1852 cpu,
1853 hpdev->desc.win_slot.slot,
1854 vector,
1855 vector_count);
1856 break;
1857
1858 default:
1859 /* As we only negotiate protocol versions known to this driver,
1860 * this path should never hit. However, this is it not a hot
1861 * path so we print a message to aid future updates.
1862 */
1863 dev_err(&hbus->hdev->device,
1864 "Unexpected vPCI protocol, update driver.");
1865 goto free_int_desc;
1866 }
1867
1868 ret = vmbus_sendpacket_getid(hpdev->hbus->hdev->channel, &ctxt.int_pkts,
1869 size, (unsigned long)&ctxt.pci_pkt,
1870 &trans_id, VM_PKT_DATA_INBAND,
1871 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1872 if (ret) {
1873 dev_err(&hbus->hdev->device,
1874 "Sending request for interrupt failed: 0x%x",
1875 comp.comp_pkt.completion_status);
1876 goto free_int_desc;
1877 }
1878
1879 /*
1880 * Prevents hv_pci_onchannelcallback() from running concurrently
1881 * in the tasklet.
1882 */
1883 tasklet_disable_in_atomic(&channel->callback_event);
1884
1885 /*
1886 * Since this function is called with IRQ locks held, can't
1887 * do normal wait for completion; instead poll.
1888 */
1889 while (!try_wait_for_completion(&comp.comp_pkt.host_event)) {
1890 unsigned long flags;
1891
1892 /* 0xFFFF means an invalid PCI VENDOR ID. */
1893 if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) {
1894 dev_err_once(&hbus->hdev->device,
1895 "the device has gone\n");
1896 goto enable_tasklet;
1897 }
1898
1899 /*
1900 * Make sure that the ring buffer data structure doesn't get
1901 * freed while we dereference the ring buffer pointer. Test
1902 * for the channel's onchannel_callback being NULL within a
1903 * sched_lock critical section. See also the inline comments
1904 * in vmbus_reset_channel_cb().
1905 */
1906 spin_lock_irqsave(&channel->sched_lock, flags);
1907 if (unlikely(channel->onchannel_callback == NULL)) {
1908 spin_unlock_irqrestore(&channel->sched_lock, flags);
1909 goto enable_tasklet;
1910 }
1911 hv_pci_onchannelcallback(hbus);
1912 spin_unlock_irqrestore(&channel->sched_lock, flags);
1913
1914 if (hpdev->state == hv_pcichild_ejecting) {
1915 dev_err_once(&hbus->hdev->device,
1916 "the device is being ejected\n");
1917 goto enable_tasklet;
1918 }
1919
1920 udelay(100);
1921 }
1922
1923 tasklet_enable(&channel->callback_event);
1924
1925 if (comp.comp_pkt.completion_status < 0) {
1926 dev_err(&hbus->hdev->device,
1927 "Request for interrupt failed: 0x%x",
1928 comp.comp_pkt.completion_status);
1929 goto free_int_desc;
1930 }
1931
1932 /*
1933 * Record the assignment so that this can be unwound later. Using
1934 * irq_set_chip_data() here would be appropriate, but the lock it takes
1935 * is already held.
1936 */
1937 *int_desc = comp.int_desc;
1938 data->chip_data = int_desc;
1939
1940 /* Pass up the result. */
1941 msg->address_hi = comp.int_desc.address >> 32;
1942 msg->address_lo = comp.int_desc.address & 0xffffffff;
1943 msg->data = comp.int_desc.data;
1944
1945 put_pcichild(hpdev);
1946 return;
1947
1948enable_tasklet:
1949 tasklet_enable(&channel->callback_event);
1950 /*
1951 * The completion packet on the stack becomes invalid after 'return';
1952 * remove the ID from the VMbus requestor if the identifier is still
1953 * mapped to/associated with the packet. (The identifier could have
1954 * been 're-used', i.e., already removed and (re-)mapped.)
1955 *
1956 * Cf. hv_pci_onchannelcallback().
1957 */
1958 vmbus_request_addr_match(channel, trans_id, (unsigned long)&ctxt.pci_pkt);
1959free_int_desc:
1960 kfree(int_desc);
1961drop_reference:
1962 put_pcichild(hpdev);
1963return_null_message:
1964 msg->address_hi = 0;
1965 msg->address_lo = 0;
1966 msg->data = 0;
1967}
1968
1969/* HW Interrupt Chip Descriptor */
1970static struct irq_chip hv_msi_irq_chip = {
1971 .name = "Hyper-V PCIe MSI",
1972 .irq_compose_msi_msg = hv_compose_msi_msg,
1973 .irq_set_affinity = irq_chip_set_affinity_parent,
1974#ifdef CONFIG_X86
1975 .irq_ack = irq_chip_ack_parent,
1976#elif defined(CONFIG_ARM64)
1977 .irq_eoi = irq_chip_eoi_parent,
1978#endif
1979 .irq_mask = hv_irq_mask,
1980 .irq_unmask = hv_irq_unmask,
1981};
1982
1983static struct msi_domain_ops hv_msi_ops = {
1984 .msi_prepare = hv_msi_prepare,
1985 .msi_free = hv_msi_free,
1986};
1987
1988/**
1989 * hv_pcie_init_irq_domain() - Initialize IRQ domain
1990 * @hbus: The root PCI bus
1991 *
1992 * This function creates an IRQ domain which will be used for
1993 * interrupts from devices that have been passed through. These
1994 * devices only support MSI and MSI-X, not line-based interrupts
1995 * or simulations of line-based interrupts through PCIe's
1996 * fabric-layer messages. Because interrupts are remapped, we
1997 * can support multi-message MSI here.
1998 *
1999 * Return: '0' on success and error value on failure
2000 */
2001static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus)
2002{
2003 hbus->msi_info.chip = &hv_msi_irq_chip;
2004 hbus->msi_info.ops = &hv_msi_ops;
2005 hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS |
2006 MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI |
2007 MSI_FLAG_PCI_MSIX);
2008 hbus->msi_info.handler = FLOW_HANDLER;
2009 hbus->msi_info.handler_name = FLOW_NAME;
2010 hbus->msi_info.data = hbus;
2011 hbus->irq_domain = pci_msi_create_irq_domain(hbus->fwnode,
2012 &hbus->msi_info,
2013 hv_pci_get_root_domain());
2014 if (!hbus->irq_domain) {
2015 dev_err(&hbus->hdev->device,
2016 "Failed to build an MSI IRQ domain\n");
2017 return -ENODEV;
2018 }
2019
2020 dev_set_msi_domain(&hbus->bridge->dev, hbus->irq_domain);
2021
2022 return 0;
2023}
2024
2025/**
2026 * get_bar_size() - Get the address space consumed by a BAR
2027 * @bar_val: Value that a BAR returned after -1 was written
2028 * to it.
2029 *
2030 * This function returns the size of the BAR, rounded up to 1
2031 * page. It has to be rounded up because the hypervisor's page
2032 * table entry that maps the BAR into the VM can't specify an
2033 * offset within a page. The invariant is that the hypervisor
2034 * must place any BARs of smaller than page length at the
2035 * beginning of a page.
2036 *
2037 * Return: Size in bytes of the consumed MMIO space.
2038 */
2039static u64 get_bar_size(u64 bar_val)
2040{
2041 return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)),
2042 PAGE_SIZE);
2043}
2044
2045/**
2046 * survey_child_resources() - Total all MMIO requirements
2047 * @hbus: Root PCI bus, as understood by this driver
2048 */
2049static void survey_child_resources(struct hv_pcibus_device *hbus)
2050{
2051 struct hv_pci_dev *hpdev;
2052 resource_size_t bar_size = 0;
2053 unsigned long flags;
2054 struct completion *event;
2055 u64 bar_val;
2056 int i;
2057
2058 /* If nobody is waiting on the answer, don't compute it. */
2059 event = xchg(&hbus->survey_event, NULL);
2060 if (!event)
2061 return;
2062
2063 /* If the answer has already been computed, go with it. */
2064 if (hbus->low_mmio_space || hbus->high_mmio_space) {
2065 complete(event);
2066 return;
2067 }
2068
2069 spin_lock_irqsave(&hbus->device_list_lock, flags);
2070
2071 /*
2072 * Due to an interesting quirk of the PCI spec, all memory regions
2073 * for a child device are a power of 2 in size and aligned in memory,
2074 * so it's sufficient to just add them up without tracking alignment.
2075 */
2076 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2077 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
2078 if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO)
2079 dev_err(&hbus->hdev->device,
2080 "There's an I/O BAR in this list!\n");
2081
2082 if (hpdev->probed_bar[i] != 0) {
2083 /*
2084 * A probed BAR has all the upper bits set that
2085 * can be changed.
2086 */
2087
2088 bar_val = hpdev->probed_bar[i];
2089 if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
2090 bar_val |=
2091 ((u64)hpdev->probed_bar[++i] << 32);
2092 else
2093 bar_val |= 0xffffffff00000000ULL;
2094
2095 bar_size = get_bar_size(bar_val);
2096
2097 if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64)
2098 hbus->high_mmio_space += bar_size;
2099 else
2100 hbus->low_mmio_space += bar_size;
2101 }
2102 }
2103 }
2104
2105 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2106 complete(event);
2107}
2108
2109/**
2110 * prepopulate_bars() - Fill in BARs with defaults
2111 * @hbus: Root PCI bus, as understood by this driver
2112 *
2113 * The core PCI driver code seems much, much happier if the BARs
2114 * for a device have values upon first scan. So fill them in.
2115 * The algorithm below works down from large sizes to small,
2116 * attempting to pack the assignments optimally. The assumption,
2117 * enforced in other parts of the code, is that the beginning of
2118 * the memory-mapped I/O space will be aligned on the largest
2119 * BAR size.
2120 */
2121static void prepopulate_bars(struct hv_pcibus_device *hbus)
2122{
2123 resource_size_t high_size = 0;
2124 resource_size_t low_size = 0;
2125 resource_size_t high_base = 0;
2126 resource_size_t low_base = 0;
2127 resource_size_t bar_size;
2128 struct hv_pci_dev *hpdev;
2129 unsigned long flags;
2130 u64 bar_val;
2131 u32 command;
2132 bool high;
2133 int i;
2134
2135 if (hbus->low_mmio_space) {
2136 low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
2137 low_base = hbus->low_mmio_res->start;
2138 }
2139
2140 if (hbus->high_mmio_space) {
2141 high_size = 1ULL <<
2142 (63 - __builtin_clzll(hbus->high_mmio_space));
2143 high_base = hbus->high_mmio_res->start;
2144 }
2145
2146 spin_lock_irqsave(&hbus->device_list_lock, flags);
2147
2148 /*
2149 * Clear the memory enable bit, in case it's already set. This occurs
2150 * in the suspend path of hibernation, where the device is suspended,
2151 * resumed and suspended again: see hibernation_snapshot() and
2152 * hibernation_platform_enter().
2153 *
2154 * If the memory enable bit is already set, Hyper-V silently ignores
2155 * the below BAR updates, and the related PCI device driver can not
2156 * work, because reading from the device register(s) always returns
2157 * 0xFFFFFFFF (PCI_ERROR_RESPONSE).
2158 */
2159 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2160 _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command);
2161 command &= ~PCI_COMMAND_MEMORY;
2162 _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command);
2163 }
2164
2165 /* Pick addresses for the BARs. */
2166 do {
2167 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2168 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
2169 bar_val = hpdev->probed_bar[i];
2170 if (bar_val == 0)
2171 continue;
2172 high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64;
2173 if (high) {
2174 bar_val |=
2175 ((u64)hpdev->probed_bar[i + 1]
2176 << 32);
2177 } else {
2178 bar_val |= 0xffffffffULL << 32;
2179 }
2180 bar_size = get_bar_size(bar_val);
2181 if (high) {
2182 if (high_size != bar_size) {
2183 i++;
2184 continue;
2185 }
2186 _hv_pcifront_write_config(hpdev,
2187 PCI_BASE_ADDRESS_0 + (4 * i),
2188 4,
2189 (u32)(high_base & 0xffffff00));
2190 i++;
2191 _hv_pcifront_write_config(hpdev,
2192 PCI_BASE_ADDRESS_0 + (4 * i),
2193 4, (u32)(high_base >> 32));
2194 high_base += bar_size;
2195 } else {
2196 if (low_size != bar_size)
2197 continue;
2198 _hv_pcifront_write_config(hpdev,
2199 PCI_BASE_ADDRESS_0 + (4 * i),
2200 4,
2201 (u32)(low_base & 0xffffff00));
2202 low_base += bar_size;
2203 }
2204 }
2205 if (high_size <= 1 && low_size <= 1) {
2206 /*
2207 * No need to set the PCI_COMMAND_MEMORY bit as
2208 * the core PCI driver doesn't require the bit
2209 * to be pre-set. Actually here we intentionally
2210 * keep the bit off so that the PCI BAR probing
2211 * in the core PCI driver doesn't cause Hyper-V
2212 * to unnecessarily unmap/map the virtual BARs
2213 * from/to the physical BARs multiple times.
2214 * This reduces the VM boot time significantly
2215 * if the BAR sizes are huge.
2216 */
2217 break;
2218 }
2219 }
2220
2221 high_size >>= 1;
2222 low_size >>= 1;
2223 } while (high_size || low_size);
2224
2225 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2226}
2227
2228/*
2229 * Assign entries in sysfs pci slot directory.
2230 *
2231 * Note that this function does not need to lock the children list
2232 * because it is called from pci_devices_present_work which
2233 * is serialized with hv_eject_device_work because they are on the
2234 * same ordered workqueue. Therefore hbus->children list will not change
2235 * even when pci_create_slot sleeps.
2236 */
2237static void hv_pci_assign_slots(struct hv_pcibus_device *hbus)
2238{
2239 struct hv_pci_dev *hpdev;
2240 char name[SLOT_NAME_SIZE];
2241 int slot_nr;
2242
2243 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2244 if (hpdev->pci_slot)
2245 continue;
2246
2247 slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot));
2248 snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser);
2249 hpdev->pci_slot = pci_create_slot(hbus->bridge->bus, slot_nr,
2250 name, NULL);
2251 if (IS_ERR(hpdev->pci_slot)) {
2252 pr_warn("pci_create slot %s failed\n", name);
2253 hpdev->pci_slot = NULL;
2254 }
2255 }
2256}
2257
2258/*
2259 * Remove entries in sysfs pci slot directory.
2260 */
2261static void hv_pci_remove_slots(struct hv_pcibus_device *hbus)
2262{
2263 struct hv_pci_dev *hpdev;
2264
2265 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2266 if (!hpdev->pci_slot)
2267 continue;
2268 pci_destroy_slot(hpdev->pci_slot);
2269 hpdev->pci_slot = NULL;
2270 }
2271}
2272
2273/*
2274 * Set NUMA node for the devices on the bus
2275 */
2276static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus)
2277{
2278 struct pci_dev *dev;
2279 struct pci_bus *bus = hbus->bridge->bus;
2280 struct hv_pci_dev *hv_dev;
2281
2282 list_for_each_entry(dev, &bus->devices, bus_list) {
2283 hv_dev = get_pcichild_wslot(hbus, devfn_to_wslot(dev->devfn));
2284 if (!hv_dev)
2285 continue;
2286
2287 if (hv_dev->desc.flags & HV_PCI_DEVICE_FLAG_NUMA_AFFINITY &&
2288 hv_dev->desc.virtual_numa_node < num_possible_nodes())
2289 /*
2290 * The kernel may boot with some NUMA nodes offline
2291 * (e.g. in a KDUMP kernel) or with NUMA disabled via
2292 * "numa=off". In those cases, adjust the host provided
2293 * NUMA node to a valid NUMA node used by the kernel.
2294 */
2295 set_dev_node(&dev->dev,
2296 numa_map_to_online_node(
2297 hv_dev->desc.virtual_numa_node));
2298
2299 put_pcichild(hv_dev);
2300 }
2301}
2302
2303/**
2304 * create_root_hv_pci_bus() - Expose a new root PCI bus
2305 * @hbus: Root PCI bus, as understood by this driver
2306 *
2307 * Return: 0 on success, -errno on failure
2308 */
2309static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus)
2310{
2311 int error;
2312 struct pci_host_bridge *bridge = hbus->bridge;
2313
2314 bridge->dev.parent = &hbus->hdev->device;
2315 bridge->sysdata = &hbus->sysdata;
2316 bridge->ops = &hv_pcifront_ops;
2317
2318 error = pci_scan_root_bus_bridge(bridge);
2319 if (error)
2320 return error;
2321
2322 pci_lock_rescan_remove();
2323 hv_pci_assign_numa_node(hbus);
2324 pci_bus_assign_resources(bridge->bus);
2325 hv_pci_assign_slots(hbus);
2326 pci_bus_add_devices(bridge->bus);
2327 pci_unlock_rescan_remove();
2328 hbus->state = hv_pcibus_installed;
2329 return 0;
2330}
2331
2332struct q_res_req_compl {
2333 struct completion host_event;
2334 struct hv_pci_dev *hpdev;
2335};
2336
2337/**
2338 * q_resource_requirements() - Query Resource Requirements
2339 * @context: The completion context.
2340 * @resp: The response that came from the host.
2341 * @resp_packet_size: The size in bytes of resp.
2342 *
2343 * This function is invoked on completion of a Query Resource
2344 * Requirements packet.
2345 */
2346static void q_resource_requirements(void *context, struct pci_response *resp,
2347 int resp_packet_size)
2348{
2349 struct q_res_req_compl *completion = context;
2350 struct pci_q_res_req_response *q_res_req =
2351 (struct pci_q_res_req_response *)resp;
2352 s32 status;
2353 int i;
2354
2355 status = (resp_packet_size < sizeof(*q_res_req)) ? -1 : resp->status;
2356 if (status < 0) {
2357 dev_err(&completion->hpdev->hbus->hdev->device,
2358 "query resource requirements failed: %x\n",
2359 status);
2360 } else {
2361 for (i = 0; i < PCI_STD_NUM_BARS; i++) {
2362 completion->hpdev->probed_bar[i] =
2363 q_res_req->probed_bar[i];
2364 }
2365 }
2366
2367 complete(&completion->host_event);
2368}
2369
2370/**
2371 * new_pcichild_device() - Create a new child device
2372 * @hbus: The internal struct tracking this root PCI bus.
2373 * @desc: The information supplied so far from the host
2374 * about the device.
2375 *
2376 * This function creates the tracking structure for a new child
2377 * device and kicks off the process of figuring out what it is.
2378 *
2379 * Return: Pointer to the new tracking struct
2380 */
2381static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus,
2382 struct hv_pcidev_description *desc)
2383{
2384 struct hv_pci_dev *hpdev;
2385 struct pci_child_message *res_req;
2386 struct q_res_req_compl comp_pkt;
2387 struct {
2388 struct pci_packet init_packet;
2389 u8 buffer[sizeof(struct pci_child_message)];
2390 } pkt;
2391 unsigned long flags;
2392 int ret;
2393
2394 hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL);
2395 if (!hpdev)
2396 return NULL;
2397
2398 hpdev->hbus = hbus;
2399
2400 memset(&pkt, 0, sizeof(pkt));
2401 init_completion(&comp_pkt.host_event);
2402 comp_pkt.hpdev = hpdev;
2403 pkt.init_packet.compl_ctxt = &comp_pkt;
2404 pkt.init_packet.completion_func = q_resource_requirements;
2405 res_req = (struct pci_child_message *)&pkt.init_packet.message;
2406 res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS;
2407 res_req->wslot.slot = desc->win_slot.slot;
2408
2409 ret = vmbus_sendpacket(hbus->hdev->channel, res_req,
2410 sizeof(struct pci_child_message),
2411 (unsigned long)&pkt.init_packet,
2412 VM_PKT_DATA_INBAND,
2413 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
2414 if (ret)
2415 goto error;
2416
2417 if (wait_for_response(hbus->hdev, &comp_pkt.host_event))
2418 goto error;
2419
2420 hpdev->desc = *desc;
2421 refcount_set(&hpdev->refs, 1);
2422 get_pcichild(hpdev);
2423 spin_lock_irqsave(&hbus->device_list_lock, flags);
2424
2425 list_add_tail(&hpdev->list_entry, &hbus->children);
2426 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2427 return hpdev;
2428
2429error:
2430 kfree(hpdev);
2431 return NULL;
2432}
2433
2434/**
2435 * get_pcichild_wslot() - Find device from slot
2436 * @hbus: Root PCI bus, as understood by this driver
2437 * @wslot: Location on the bus
2438 *
2439 * This function looks up a PCI device and returns the internal
2440 * representation of it. It acquires a reference on it, so that
2441 * the device won't be deleted while somebody is using it. The
2442 * caller is responsible for calling put_pcichild() to release
2443 * this reference.
2444 *
2445 * Return: Internal representation of a PCI device
2446 */
2447static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus,
2448 u32 wslot)
2449{
2450 unsigned long flags;
2451 struct hv_pci_dev *iter, *hpdev = NULL;
2452
2453 spin_lock_irqsave(&hbus->device_list_lock, flags);
2454 list_for_each_entry(iter, &hbus->children, list_entry) {
2455 if (iter->desc.win_slot.slot == wslot) {
2456 hpdev = iter;
2457 get_pcichild(hpdev);
2458 break;
2459 }
2460 }
2461 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2462
2463 return hpdev;
2464}
2465
2466/**
2467 * pci_devices_present_work() - Handle new list of child devices
2468 * @work: Work struct embedded in struct hv_dr_work
2469 *
2470 * "Bus Relations" is the Windows term for "children of this
2471 * bus." The terminology is preserved here for people trying to
2472 * debug the interaction between Hyper-V and Linux. This
2473 * function is called when the parent partition reports a list
2474 * of functions that should be observed under this PCI Express
2475 * port (bus).
2476 *
2477 * This function updates the list, and must tolerate being
2478 * called multiple times with the same information. The typical
2479 * number of child devices is one, with very atypical cases
2480 * involving three or four, so the algorithms used here can be
2481 * simple and inefficient.
2482 *
2483 * It must also treat the omission of a previously observed device as
2484 * notification that the device no longer exists.
2485 *
2486 * Note that this function is serialized with hv_eject_device_work(),
2487 * because both are pushed to the ordered workqueue hbus->wq.
2488 */
2489static void pci_devices_present_work(struct work_struct *work)
2490{
2491 u32 child_no;
2492 bool found;
2493 struct hv_pcidev_description *new_desc;
2494 struct hv_pci_dev *hpdev;
2495 struct hv_pcibus_device *hbus;
2496 struct list_head removed;
2497 struct hv_dr_work *dr_wrk;
2498 struct hv_dr_state *dr = NULL;
2499 unsigned long flags;
2500
2501 dr_wrk = container_of(work, struct hv_dr_work, wrk);
2502 hbus = dr_wrk->bus;
2503 kfree(dr_wrk);
2504
2505 INIT_LIST_HEAD(&removed);
2506
2507 /* Pull this off the queue and process it if it was the last one. */
2508 spin_lock_irqsave(&hbus->device_list_lock, flags);
2509 while (!list_empty(&hbus->dr_list)) {
2510 dr = list_first_entry(&hbus->dr_list, struct hv_dr_state,
2511 list_entry);
2512 list_del(&dr->list_entry);
2513
2514 /* Throw this away if the list still has stuff in it. */
2515 if (!list_empty(&hbus->dr_list)) {
2516 kfree(dr);
2517 continue;
2518 }
2519 }
2520 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2521
2522 if (!dr)
2523 return;
2524
2525 /* First, mark all existing children as reported missing. */
2526 spin_lock_irqsave(&hbus->device_list_lock, flags);
2527 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2528 hpdev->reported_missing = true;
2529 }
2530 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2531
2532 /* Next, add back any reported devices. */
2533 for (child_no = 0; child_no < dr->device_count; child_no++) {
2534 found = false;
2535 new_desc = &dr->func[child_no];
2536
2537 spin_lock_irqsave(&hbus->device_list_lock, flags);
2538 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2539 if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) &&
2540 (hpdev->desc.v_id == new_desc->v_id) &&
2541 (hpdev->desc.d_id == new_desc->d_id) &&
2542 (hpdev->desc.ser == new_desc->ser)) {
2543 hpdev->reported_missing = false;
2544 found = true;
2545 }
2546 }
2547 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2548
2549 if (!found) {
2550 hpdev = new_pcichild_device(hbus, new_desc);
2551 if (!hpdev)
2552 dev_err(&hbus->hdev->device,
2553 "couldn't record a child device.\n");
2554 }
2555 }
2556
2557 /* Move missing children to a list on the stack. */
2558 spin_lock_irqsave(&hbus->device_list_lock, flags);
2559 do {
2560 found = false;
2561 list_for_each_entry(hpdev, &hbus->children, list_entry) {
2562 if (hpdev->reported_missing) {
2563 found = true;
2564 put_pcichild(hpdev);
2565 list_move_tail(&hpdev->list_entry, &removed);
2566 break;
2567 }
2568 }
2569 } while (found);
2570 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2571
2572 /* Delete everything that should no longer exist. */
2573 while (!list_empty(&removed)) {
2574 hpdev = list_first_entry(&removed, struct hv_pci_dev,
2575 list_entry);
2576 list_del(&hpdev->list_entry);
2577
2578 if (hpdev->pci_slot)
2579 pci_destroy_slot(hpdev->pci_slot);
2580
2581 put_pcichild(hpdev);
2582 }
2583
2584 switch (hbus->state) {
2585 case hv_pcibus_installed:
2586 /*
2587 * Tell the core to rescan bus
2588 * because there may have been changes.
2589 */
2590 pci_lock_rescan_remove();
2591 pci_scan_child_bus(hbus->bridge->bus);
2592 hv_pci_assign_numa_node(hbus);
2593 hv_pci_assign_slots(hbus);
2594 pci_unlock_rescan_remove();
2595 break;
2596
2597 case hv_pcibus_init:
2598 case hv_pcibus_probed:
2599 survey_child_resources(hbus);
2600 break;
2601
2602 default:
2603 break;
2604 }
2605
2606 kfree(dr);
2607}
2608
2609/**
2610 * hv_pci_start_relations_work() - Queue work to start device discovery
2611 * @hbus: Root PCI bus, as understood by this driver
2612 * @dr: The list of children returned from host
2613 *
2614 * Return: 0 on success, -errno on failure
2615 */
2616static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus,
2617 struct hv_dr_state *dr)
2618{
2619 struct hv_dr_work *dr_wrk;
2620 unsigned long flags;
2621 bool pending_dr;
2622
2623 if (hbus->state == hv_pcibus_removing) {
2624 dev_info(&hbus->hdev->device,
2625 "PCI VMBus BUS_RELATIONS: ignored\n");
2626 return -ENOENT;
2627 }
2628
2629 dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT);
2630 if (!dr_wrk)
2631 return -ENOMEM;
2632
2633 INIT_WORK(&dr_wrk->wrk, pci_devices_present_work);
2634 dr_wrk->bus = hbus;
2635
2636 spin_lock_irqsave(&hbus->device_list_lock, flags);
2637 /*
2638 * If pending_dr is true, we have already queued a work,
2639 * which will see the new dr. Otherwise, we need to
2640 * queue a new work.
2641 */
2642 pending_dr = !list_empty(&hbus->dr_list);
2643 list_add_tail(&dr->list_entry, &hbus->dr_list);
2644 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2645
2646 if (pending_dr)
2647 kfree(dr_wrk);
2648 else
2649 queue_work(hbus->wq, &dr_wrk->wrk);
2650
2651 return 0;
2652}
2653
2654/**
2655 * hv_pci_devices_present() - Handle list of new children
2656 * @hbus: Root PCI bus, as understood by this driver
2657 * @relations: Packet from host listing children
2658 *
2659 * Process a new list of devices on the bus. The list of devices is
2660 * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS,
2661 * whenever a new list of devices for this bus appears.
2662 */
2663static void hv_pci_devices_present(struct hv_pcibus_device *hbus,
2664 struct pci_bus_relations *relations)
2665{
2666 struct hv_dr_state *dr;
2667 int i;
2668
2669 dr = kzalloc(struct_size(dr, func, relations->device_count),
2670 GFP_NOWAIT);
2671 if (!dr)
2672 return;
2673
2674 dr->device_count = relations->device_count;
2675 for (i = 0; i < dr->device_count; i++) {
2676 dr->func[i].v_id = relations->func[i].v_id;
2677 dr->func[i].d_id = relations->func[i].d_id;
2678 dr->func[i].rev = relations->func[i].rev;
2679 dr->func[i].prog_intf = relations->func[i].prog_intf;
2680 dr->func[i].subclass = relations->func[i].subclass;
2681 dr->func[i].base_class = relations->func[i].base_class;
2682 dr->func[i].subsystem_id = relations->func[i].subsystem_id;
2683 dr->func[i].win_slot = relations->func[i].win_slot;
2684 dr->func[i].ser = relations->func[i].ser;
2685 }
2686
2687 if (hv_pci_start_relations_work(hbus, dr))
2688 kfree(dr);
2689}
2690
2691/**
2692 * hv_pci_devices_present2() - Handle list of new children
2693 * @hbus: Root PCI bus, as understood by this driver
2694 * @relations: Packet from host listing children
2695 *
2696 * This function is the v2 version of hv_pci_devices_present()
2697 */
2698static void hv_pci_devices_present2(struct hv_pcibus_device *hbus,
2699 struct pci_bus_relations2 *relations)
2700{
2701 struct hv_dr_state *dr;
2702 int i;
2703
2704 dr = kzalloc(struct_size(dr, func, relations->device_count),
2705 GFP_NOWAIT);
2706 if (!dr)
2707 return;
2708
2709 dr->device_count = relations->device_count;
2710 for (i = 0; i < dr->device_count; i++) {
2711 dr->func[i].v_id = relations->func[i].v_id;
2712 dr->func[i].d_id = relations->func[i].d_id;
2713 dr->func[i].rev = relations->func[i].rev;
2714 dr->func[i].prog_intf = relations->func[i].prog_intf;
2715 dr->func[i].subclass = relations->func[i].subclass;
2716 dr->func[i].base_class = relations->func[i].base_class;
2717 dr->func[i].subsystem_id = relations->func[i].subsystem_id;
2718 dr->func[i].win_slot = relations->func[i].win_slot;
2719 dr->func[i].ser = relations->func[i].ser;
2720 dr->func[i].flags = relations->func[i].flags;
2721 dr->func[i].virtual_numa_node =
2722 relations->func[i].virtual_numa_node;
2723 }
2724
2725 if (hv_pci_start_relations_work(hbus, dr))
2726 kfree(dr);
2727}
2728
2729/**
2730 * hv_eject_device_work() - Asynchronously handles ejection
2731 * @work: Work struct embedded in internal device struct
2732 *
2733 * This function handles ejecting a device. Windows will
2734 * attempt to gracefully eject a device, waiting 60 seconds to
2735 * hear back from the guest OS that this completed successfully.
2736 * If this timer expires, the device will be forcibly removed.
2737 */
2738static void hv_eject_device_work(struct work_struct *work)
2739{
2740 struct pci_eject_response *ejct_pkt;
2741 struct hv_pcibus_device *hbus;
2742 struct hv_pci_dev *hpdev;
2743 struct pci_dev *pdev;
2744 unsigned long flags;
2745 int wslot;
2746 struct {
2747 struct pci_packet pkt;
2748 u8 buffer[sizeof(struct pci_eject_response)];
2749 } ctxt;
2750
2751 hpdev = container_of(work, struct hv_pci_dev, wrk);
2752 hbus = hpdev->hbus;
2753
2754 WARN_ON(hpdev->state != hv_pcichild_ejecting);
2755
2756 /*
2757 * Ejection can come before or after the PCI bus has been set up, so
2758 * attempt to find it and tear down the bus state, if it exists. This
2759 * must be done without constructs like pci_domain_nr(hbus->bridge->bus)
2760 * because hbus->bridge->bus may not exist yet.
2761 */
2762 wslot = wslot_to_devfn(hpdev->desc.win_slot.slot);
2763 pdev = pci_get_domain_bus_and_slot(hbus->bridge->domain_nr, 0, wslot);
2764 if (pdev) {
2765 pci_lock_rescan_remove();
2766 pci_stop_and_remove_bus_device(pdev);
2767 pci_dev_put(pdev);
2768 pci_unlock_rescan_remove();
2769 }
2770
2771 spin_lock_irqsave(&hbus->device_list_lock, flags);
2772 list_del(&hpdev->list_entry);
2773 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
2774
2775 if (hpdev->pci_slot)
2776 pci_destroy_slot(hpdev->pci_slot);
2777
2778 memset(&ctxt, 0, sizeof(ctxt));
2779 ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message;
2780 ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE;
2781 ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot;
2782 vmbus_sendpacket(hbus->hdev->channel, ejct_pkt,
2783 sizeof(*ejct_pkt), 0,
2784 VM_PKT_DATA_INBAND, 0);
2785
2786 /* For the get_pcichild() in hv_pci_eject_device() */
2787 put_pcichild(hpdev);
2788 /* For the two refs got in new_pcichild_device() */
2789 put_pcichild(hpdev);
2790 put_pcichild(hpdev);
2791 /* hpdev has been freed. Do not use it any more. */
2792}
2793
2794/**
2795 * hv_pci_eject_device() - Handles device ejection
2796 * @hpdev: Internal device tracking struct
2797 *
2798 * This function is invoked when an ejection packet arrives. It
2799 * just schedules work so that we don't re-enter the packet
2800 * delivery code handling the ejection.
2801 */
2802static void hv_pci_eject_device(struct hv_pci_dev *hpdev)
2803{
2804 struct hv_pcibus_device *hbus = hpdev->hbus;
2805 struct hv_device *hdev = hbus->hdev;
2806
2807 if (hbus->state == hv_pcibus_removing) {
2808 dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n");
2809 return;
2810 }
2811
2812 hpdev->state = hv_pcichild_ejecting;
2813 get_pcichild(hpdev);
2814 INIT_WORK(&hpdev->wrk, hv_eject_device_work);
2815 queue_work(hbus->wq, &hpdev->wrk);
2816}
2817
2818/**
2819 * hv_pci_onchannelcallback() - Handles incoming packets
2820 * @context: Internal bus tracking struct
2821 *
2822 * This function is invoked whenever the host sends a packet to
2823 * this channel (which is private to this root PCI bus).
2824 */
2825static void hv_pci_onchannelcallback(void *context)
2826{
2827 const int packet_size = 0x100;
2828 int ret;
2829 struct hv_pcibus_device *hbus = context;
2830 struct vmbus_channel *chan = hbus->hdev->channel;
2831 u32 bytes_recvd;
2832 u64 req_id, req_addr;
2833 struct vmpacket_descriptor *desc;
2834 unsigned char *buffer;
2835 int bufferlen = packet_size;
2836 struct pci_packet *comp_packet;
2837 struct pci_response *response;
2838 struct pci_incoming_message *new_message;
2839 struct pci_bus_relations *bus_rel;
2840 struct pci_bus_relations2 *bus_rel2;
2841 struct pci_dev_inval_block *inval;
2842 struct pci_dev_incoming *dev_message;
2843 struct hv_pci_dev *hpdev;
2844 unsigned long flags;
2845
2846 buffer = kmalloc(bufferlen, GFP_ATOMIC);
2847 if (!buffer)
2848 return;
2849
2850 while (1) {
2851 ret = vmbus_recvpacket_raw(chan, buffer, bufferlen,
2852 &bytes_recvd, &req_id);
2853
2854 if (ret == -ENOBUFS) {
2855 kfree(buffer);
2856 /* Handle large packet */
2857 bufferlen = bytes_recvd;
2858 buffer = kmalloc(bytes_recvd, GFP_ATOMIC);
2859 if (!buffer)
2860 return;
2861 continue;
2862 }
2863
2864 /* Zero length indicates there are no more packets. */
2865 if (ret || !bytes_recvd)
2866 break;
2867
2868 /*
2869 * All incoming packets must be at least as large as a
2870 * response.
2871 */
2872 if (bytes_recvd <= sizeof(struct pci_response))
2873 continue;
2874 desc = (struct vmpacket_descriptor *)buffer;
2875
2876 switch (desc->type) {
2877 case VM_PKT_COMP:
2878
2879 lock_requestor(chan, flags);
2880 req_addr = __vmbus_request_addr_match(chan, req_id,
2881 VMBUS_RQST_ADDR_ANY);
2882 if (req_addr == VMBUS_RQST_ERROR) {
2883 unlock_requestor(chan, flags);
2884 dev_err(&hbus->hdev->device,
2885 "Invalid transaction ID %llx\n",
2886 req_id);
2887 break;
2888 }
2889 comp_packet = (struct pci_packet *)req_addr;
2890 response = (struct pci_response *)buffer;
2891 /*
2892 * Call ->completion_func() within the critical section to make
2893 * sure that the packet pointer is still valid during the call:
2894 * here 'valid' means that there's a task still waiting for the
2895 * completion, and that the packet data is still on the waiting
2896 * task's stack. Cf. hv_compose_msi_msg().
2897 */
2898 comp_packet->completion_func(comp_packet->compl_ctxt,
2899 response,
2900 bytes_recvd);
2901 unlock_requestor(chan, flags);
2902 break;
2903
2904 case VM_PKT_DATA_INBAND:
2905
2906 new_message = (struct pci_incoming_message *)buffer;
2907 switch (new_message->message_type.type) {
2908 case PCI_BUS_RELATIONS:
2909
2910 bus_rel = (struct pci_bus_relations *)buffer;
2911 if (bytes_recvd < sizeof(*bus_rel) ||
2912 bytes_recvd <
2913 struct_size(bus_rel, func,
2914 bus_rel->device_count)) {
2915 dev_err(&hbus->hdev->device,
2916 "bus relations too small\n");
2917 break;
2918 }
2919
2920 hv_pci_devices_present(hbus, bus_rel);
2921 break;
2922
2923 case PCI_BUS_RELATIONS2:
2924
2925 bus_rel2 = (struct pci_bus_relations2 *)buffer;
2926 if (bytes_recvd < sizeof(*bus_rel2) ||
2927 bytes_recvd <
2928 struct_size(bus_rel2, func,
2929 bus_rel2->device_count)) {
2930 dev_err(&hbus->hdev->device,
2931 "bus relations v2 too small\n");
2932 break;
2933 }
2934
2935 hv_pci_devices_present2(hbus, bus_rel2);
2936 break;
2937
2938 case PCI_EJECT:
2939
2940 dev_message = (struct pci_dev_incoming *)buffer;
2941 if (bytes_recvd < sizeof(*dev_message)) {
2942 dev_err(&hbus->hdev->device,
2943 "eject message too small\n");
2944 break;
2945 }
2946 hpdev = get_pcichild_wslot(hbus,
2947 dev_message->wslot.slot);
2948 if (hpdev) {
2949 hv_pci_eject_device(hpdev);
2950 put_pcichild(hpdev);
2951 }
2952 break;
2953
2954 case PCI_INVALIDATE_BLOCK:
2955
2956 inval = (struct pci_dev_inval_block *)buffer;
2957 if (bytes_recvd < sizeof(*inval)) {
2958 dev_err(&hbus->hdev->device,
2959 "invalidate message too small\n");
2960 break;
2961 }
2962 hpdev = get_pcichild_wslot(hbus,
2963 inval->wslot.slot);
2964 if (hpdev) {
2965 if (hpdev->block_invalidate) {
2966 hpdev->block_invalidate(
2967 hpdev->invalidate_context,
2968 inval->block_mask);
2969 }
2970 put_pcichild(hpdev);
2971 }
2972 break;
2973
2974 default:
2975 dev_warn(&hbus->hdev->device,
2976 "Unimplemented protocol message %x\n",
2977 new_message->message_type.type);
2978 break;
2979 }
2980 break;
2981
2982 default:
2983 dev_err(&hbus->hdev->device,
2984 "unhandled packet type %d, tid %llx len %d\n",
2985 desc->type, req_id, bytes_recvd);
2986 break;
2987 }
2988 }
2989
2990 kfree(buffer);
2991}
2992
2993/**
2994 * hv_pci_protocol_negotiation() - Set up protocol
2995 * @hdev: VMBus's tracking struct for this root PCI bus.
2996 * @version: Array of supported channel protocol versions in
2997 * the order of probing - highest go first.
2998 * @num_version: Number of elements in the version array.
2999 *
3000 * This driver is intended to support running on Windows 10
3001 * (server) and later versions. It will not run on earlier
3002 * versions, as they assume that many of the operations which
3003 * Linux needs accomplished with a spinlock held were done via
3004 * asynchronous messaging via VMBus. Windows 10 increases the
3005 * surface area of PCI emulation so that these actions can take
3006 * place by suspending a virtual processor for their duration.
3007 *
3008 * This function negotiates the channel protocol version,
3009 * failing if the host doesn't support the necessary protocol
3010 * level.
3011 */
3012static int hv_pci_protocol_negotiation(struct hv_device *hdev,
3013 enum pci_protocol_version_t version[],
3014 int num_version)
3015{
3016 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3017 struct pci_version_request *version_req;
3018 struct hv_pci_compl comp_pkt;
3019 struct pci_packet *pkt;
3020 int ret;
3021 int i;
3022
3023 /*
3024 * Initiate the handshake with the host and negotiate
3025 * a version that the host can support. We start with the
3026 * highest version number and go down if the host cannot
3027 * support it.
3028 */
3029 pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL);
3030 if (!pkt)
3031 return -ENOMEM;
3032
3033 init_completion(&comp_pkt.host_event);
3034 pkt->completion_func = hv_pci_generic_compl;
3035 pkt->compl_ctxt = &comp_pkt;
3036 version_req = (struct pci_version_request *)&pkt->message;
3037 version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION;
3038
3039 for (i = 0; i < num_version; i++) {
3040 version_req->protocol_version = version[i];
3041 ret = vmbus_sendpacket(hdev->channel, version_req,
3042 sizeof(struct pci_version_request),
3043 (unsigned long)pkt, VM_PKT_DATA_INBAND,
3044 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
3045 if (!ret)
3046 ret = wait_for_response(hdev, &comp_pkt.host_event);
3047
3048 if (ret) {
3049 dev_err(&hdev->device,
3050 "PCI Pass-through VSP failed to request version: %d",
3051 ret);
3052 goto exit;
3053 }
3054
3055 if (comp_pkt.completion_status >= 0) {
3056 hbus->protocol_version = version[i];
3057 dev_info(&hdev->device,
3058 "PCI VMBus probing: Using version %#x\n",
3059 hbus->protocol_version);
3060 goto exit;
3061 }
3062
3063 if (comp_pkt.completion_status != STATUS_REVISION_MISMATCH) {
3064 dev_err(&hdev->device,
3065 "PCI Pass-through VSP failed version request: %#x",
3066 comp_pkt.completion_status);
3067 ret = -EPROTO;
3068 goto exit;
3069 }
3070
3071 reinit_completion(&comp_pkt.host_event);
3072 }
3073
3074 dev_err(&hdev->device,
3075 "PCI pass-through VSP failed to find supported version");
3076 ret = -EPROTO;
3077
3078exit:
3079 kfree(pkt);
3080 return ret;
3081}
3082
3083/**
3084 * hv_pci_free_bridge_windows() - Release memory regions for the
3085 * bus
3086 * @hbus: Root PCI bus, as understood by this driver
3087 */
3088static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus)
3089{
3090 /*
3091 * Set the resources back to the way they looked when they
3092 * were allocated by setting IORESOURCE_BUSY again.
3093 */
3094
3095 if (hbus->low_mmio_space && hbus->low_mmio_res) {
3096 hbus->low_mmio_res->flags |= IORESOURCE_BUSY;
3097 vmbus_free_mmio(hbus->low_mmio_res->start,
3098 resource_size(hbus->low_mmio_res));
3099 }
3100
3101 if (hbus->high_mmio_space && hbus->high_mmio_res) {
3102 hbus->high_mmio_res->flags |= IORESOURCE_BUSY;
3103 vmbus_free_mmio(hbus->high_mmio_res->start,
3104 resource_size(hbus->high_mmio_res));
3105 }
3106}
3107
3108/**
3109 * hv_pci_allocate_bridge_windows() - Allocate memory regions
3110 * for the bus
3111 * @hbus: Root PCI bus, as understood by this driver
3112 *
3113 * This function calls vmbus_allocate_mmio(), which is itself a
3114 * bit of a compromise. Ideally, we might change the pnp layer
3115 * in the kernel such that it comprehends either PCI devices
3116 * which are "grandchildren of ACPI," with some intermediate bus
3117 * node (in this case, VMBus) or change it such that it
3118 * understands VMBus. The pnp layer, however, has been declared
3119 * deprecated, and not subject to change.
3120 *
3121 * The workaround, implemented here, is to ask VMBus to allocate
3122 * MMIO space for this bus. VMBus itself knows which ranges are
3123 * appropriate by looking at its own ACPI objects. Then, after
3124 * these ranges are claimed, they're modified to look like they
3125 * would have looked if the ACPI and pnp code had allocated
3126 * bridge windows. These descriptors have to exist in this form
3127 * in order to satisfy the code which will get invoked when the
3128 * endpoint PCI function driver calls request_mem_region() or
3129 * request_mem_region_exclusive().
3130 *
3131 * Return: 0 on success, -errno on failure
3132 */
3133static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus)
3134{
3135 resource_size_t align;
3136 int ret;
3137
3138 if (hbus->low_mmio_space) {
3139 align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space));
3140 ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0,
3141 (u64)(u32)0xffffffff,
3142 hbus->low_mmio_space,
3143 align, false);
3144 if (ret) {
3145 dev_err(&hbus->hdev->device,
3146 "Need %#llx of low MMIO space. Consider reconfiguring the VM.\n",
3147 hbus->low_mmio_space);
3148 return ret;
3149 }
3150
3151 /* Modify this resource to become a bridge window. */
3152 hbus->low_mmio_res->flags |= IORESOURCE_WINDOW;
3153 hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY;
3154 pci_add_resource(&hbus->bridge->windows, hbus->low_mmio_res);
3155 }
3156
3157 if (hbus->high_mmio_space) {
3158 align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space));
3159 ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev,
3160 0x100000000, -1,
3161 hbus->high_mmio_space, align,
3162 false);
3163 if (ret) {
3164 dev_err(&hbus->hdev->device,
3165 "Need %#llx of high MMIO space. Consider reconfiguring the VM.\n",
3166 hbus->high_mmio_space);
3167 goto release_low_mmio;
3168 }
3169
3170 /* Modify this resource to become a bridge window. */
3171 hbus->high_mmio_res->flags |= IORESOURCE_WINDOW;
3172 hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY;
3173 pci_add_resource(&hbus->bridge->windows, hbus->high_mmio_res);
3174 }
3175
3176 return 0;
3177
3178release_low_mmio:
3179 if (hbus->low_mmio_res) {
3180 vmbus_free_mmio(hbus->low_mmio_res->start,
3181 resource_size(hbus->low_mmio_res));
3182 }
3183
3184 return ret;
3185}
3186
3187/**
3188 * hv_allocate_config_window() - Find MMIO space for PCI Config
3189 * @hbus: Root PCI bus, as understood by this driver
3190 *
3191 * This function claims memory-mapped I/O space for accessing
3192 * configuration space for the functions on this bus.
3193 *
3194 * Return: 0 on success, -errno on failure
3195 */
3196static int hv_allocate_config_window(struct hv_pcibus_device *hbus)
3197{
3198 int ret;
3199
3200 /*
3201 * Set up a region of MMIO space to use for accessing configuration
3202 * space.
3203 */
3204 ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1,
3205 PCI_CONFIG_MMIO_LENGTH, 0x1000, false);
3206 if (ret)
3207 return ret;
3208
3209 /*
3210 * vmbus_allocate_mmio() gets used for allocating both device endpoint
3211 * resource claims (those which cannot be overlapped) and the ranges
3212 * which are valid for the children of this bus, which are intended
3213 * to be overlapped by those children. Set the flag on this claim
3214 * meaning that this region can't be overlapped.
3215 */
3216
3217 hbus->mem_config->flags |= IORESOURCE_BUSY;
3218
3219 return 0;
3220}
3221
3222static void hv_free_config_window(struct hv_pcibus_device *hbus)
3223{
3224 vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH);
3225}
3226
3227static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs);
3228
3229/**
3230 * hv_pci_enter_d0() - Bring the "bus" into the D0 power state
3231 * @hdev: VMBus's tracking struct for this root PCI bus
3232 *
3233 * Return: 0 on success, -errno on failure
3234 */
3235static int hv_pci_enter_d0(struct hv_device *hdev)
3236{
3237 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3238 struct pci_bus_d0_entry *d0_entry;
3239 struct hv_pci_compl comp_pkt;
3240 struct pci_packet *pkt;
3241 int ret;
3242
3243 /*
3244 * Tell the host that the bus is ready to use, and moved into the
3245 * powered-on state. This includes telling the host which region
3246 * of memory-mapped I/O space has been chosen for configuration space
3247 * access.
3248 */
3249 pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL);
3250 if (!pkt)
3251 return -ENOMEM;
3252
3253 init_completion(&comp_pkt.host_event);
3254 pkt->completion_func = hv_pci_generic_compl;
3255 pkt->compl_ctxt = &comp_pkt;
3256 d0_entry = (struct pci_bus_d0_entry *)&pkt->message;
3257 d0_entry->message_type.type = PCI_BUS_D0ENTRY;
3258 d0_entry->mmio_base = hbus->mem_config->start;
3259
3260 ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry),
3261 (unsigned long)pkt, VM_PKT_DATA_INBAND,
3262 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
3263 if (!ret)
3264 ret = wait_for_response(hdev, &comp_pkt.host_event);
3265
3266 if (ret)
3267 goto exit;
3268
3269 if (comp_pkt.completion_status < 0) {
3270 dev_err(&hdev->device,
3271 "PCI Pass-through VSP failed D0 Entry with status %x\n",
3272 comp_pkt.completion_status);
3273 ret = -EPROTO;
3274 goto exit;
3275 }
3276
3277 ret = 0;
3278
3279exit:
3280 kfree(pkt);
3281 return ret;
3282}
3283
3284/**
3285 * hv_pci_query_relations() - Ask host to send list of child
3286 * devices
3287 * @hdev: VMBus's tracking struct for this root PCI bus
3288 *
3289 * Return: 0 on success, -errno on failure
3290 */
3291static int hv_pci_query_relations(struct hv_device *hdev)
3292{
3293 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3294 struct pci_message message;
3295 struct completion comp;
3296 int ret;
3297
3298 /* Ask the host to send along the list of child devices */
3299 init_completion(&comp);
3300 if (cmpxchg(&hbus->survey_event, NULL, &comp))
3301 return -ENOTEMPTY;
3302
3303 memset(&message, 0, sizeof(message));
3304 message.type = PCI_QUERY_BUS_RELATIONS;
3305
3306 ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message),
3307 0, VM_PKT_DATA_INBAND, 0);
3308 if (!ret)
3309 ret = wait_for_response(hdev, &comp);
3310
3311 return ret;
3312}
3313
3314/**
3315 * hv_send_resources_allocated() - Report local resource choices
3316 * @hdev: VMBus's tracking struct for this root PCI bus
3317 *
3318 * The host OS is expecting to be sent a request as a message
3319 * which contains all the resources that the device will use.
3320 * The response contains those same resources, "translated"
3321 * which is to say, the values which should be used by the
3322 * hardware, when it delivers an interrupt. (MMIO resources are
3323 * used in local terms.) This is nice for Windows, and lines up
3324 * with the FDO/PDO split, which doesn't exist in Linux. Linux
3325 * is deeply expecting to scan an emulated PCI configuration
3326 * space. So this message is sent here only to drive the state
3327 * machine on the host forward.
3328 *
3329 * Return: 0 on success, -errno on failure
3330 */
3331static int hv_send_resources_allocated(struct hv_device *hdev)
3332{
3333 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3334 struct pci_resources_assigned *res_assigned;
3335 struct pci_resources_assigned2 *res_assigned2;
3336 struct hv_pci_compl comp_pkt;
3337 struct hv_pci_dev *hpdev;
3338 struct pci_packet *pkt;
3339 size_t size_res;
3340 int wslot;
3341 int ret;
3342
3343 size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2)
3344 ? sizeof(*res_assigned) : sizeof(*res_assigned2);
3345
3346 pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL);
3347 if (!pkt)
3348 return -ENOMEM;
3349
3350 ret = 0;
3351
3352 for (wslot = 0; wslot < 256; wslot++) {
3353 hpdev = get_pcichild_wslot(hbus, wslot);
3354 if (!hpdev)
3355 continue;
3356
3357 memset(pkt, 0, sizeof(*pkt) + size_res);
3358 init_completion(&comp_pkt.host_event);
3359 pkt->completion_func = hv_pci_generic_compl;
3360 pkt->compl_ctxt = &comp_pkt;
3361
3362 if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) {
3363 res_assigned =
3364 (struct pci_resources_assigned *)&pkt->message;
3365 res_assigned->message_type.type =
3366 PCI_RESOURCES_ASSIGNED;
3367 res_assigned->wslot.slot = hpdev->desc.win_slot.slot;
3368 } else {
3369 res_assigned2 =
3370 (struct pci_resources_assigned2 *)&pkt->message;
3371 res_assigned2->message_type.type =
3372 PCI_RESOURCES_ASSIGNED2;
3373 res_assigned2->wslot.slot = hpdev->desc.win_slot.slot;
3374 }
3375 put_pcichild(hpdev);
3376
3377 ret = vmbus_sendpacket(hdev->channel, &pkt->message,
3378 size_res, (unsigned long)pkt,
3379 VM_PKT_DATA_INBAND,
3380 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
3381 if (!ret)
3382 ret = wait_for_response(hdev, &comp_pkt.host_event);
3383 if (ret)
3384 break;
3385
3386 if (comp_pkt.completion_status < 0) {
3387 ret = -EPROTO;
3388 dev_err(&hdev->device,
3389 "resource allocated returned 0x%x",
3390 comp_pkt.completion_status);
3391 break;
3392 }
3393
3394 hbus->wslot_res_allocated = wslot;
3395 }
3396
3397 kfree(pkt);
3398 return ret;
3399}
3400
3401/**
3402 * hv_send_resources_released() - Report local resources
3403 * released
3404 * @hdev: VMBus's tracking struct for this root PCI bus
3405 *
3406 * Return: 0 on success, -errno on failure
3407 */
3408static int hv_send_resources_released(struct hv_device *hdev)
3409{
3410 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3411 struct pci_child_message pkt;
3412 struct hv_pci_dev *hpdev;
3413 int wslot;
3414 int ret;
3415
3416 for (wslot = hbus->wslot_res_allocated; wslot >= 0; wslot--) {
3417 hpdev = get_pcichild_wslot(hbus, wslot);
3418 if (!hpdev)
3419 continue;
3420
3421 memset(&pkt, 0, sizeof(pkt));
3422 pkt.message_type.type = PCI_RESOURCES_RELEASED;
3423 pkt.wslot.slot = hpdev->desc.win_slot.slot;
3424
3425 put_pcichild(hpdev);
3426
3427 ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0,
3428 VM_PKT_DATA_INBAND, 0);
3429 if (ret)
3430 return ret;
3431
3432 hbus->wslot_res_allocated = wslot - 1;
3433 }
3434
3435 hbus->wslot_res_allocated = -1;
3436
3437 return 0;
3438}
3439
3440#define HVPCI_DOM_MAP_SIZE (64 * 1024)
3441static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE);
3442
3443/*
3444 * PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0
3445 * as invalid for passthrough PCI devices of this driver.
3446 */
3447#define HVPCI_DOM_INVALID 0
3448
3449/**
3450 * hv_get_dom_num() - Get a valid PCI domain number
3451 * Check if the PCI domain number is in use, and return another number if
3452 * it is in use.
3453 *
3454 * @dom: Requested domain number
3455 *
3456 * return: domain number on success, HVPCI_DOM_INVALID on failure
3457 */
3458static u16 hv_get_dom_num(u16 dom)
3459{
3460 unsigned int i;
3461
3462 if (test_and_set_bit(dom, hvpci_dom_map) == 0)
3463 return dom;
3464
3465 for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) {
3466 if (test_and_set_bit(i, hvpci_dom_map) == 0)
3467 return i;
3468 }
3469
3470 return HVPCI_DOM_INVALID;
3471}
3472
3473/**
3474 * hv_put_dom_num() - Mark the PCI domain number as free
3475 * @dom: Domain number to be freed
3476 */
3477static void hv_put_dom_num(u16 dom)
3478{
3479 clear_bit(dom, hvpci_dom_map);
3480}
3481
3482/**
3483 * hv_pci_probe() - New VMBus channel probe, for a root PCI bus
3484 * @hdev: VMBus's tracking struct for this root PCI bus
3485 * @dev_id: Identifies the device itself
3486 *
3487 * Return: 0 on success, -errno on failure
3488 */
3489static int hv_pci_probe(struct hv_device *hdev,
3490 const struct hv_vmbus_device_id *dev_id)
3491{
3492 struct pci_host_bridge *bridge;
3493 struct hv_pcibus_device *hbus;
3494 u16 dom_req, dom;
3495 char *name;
3496 bool enter_d0_retry = true;
3497 int ret;
3498
3499 /*
3500 * hv_pcibus_device contains the hypercall arguments for retargeting in
3501 * hv_irq_unmask(). Those must not cross a page boundary.
3502 */
3503 BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE);
3504
3505 bridge = devm_pci_alloc_host_bridge(&hdev->device, 0);
3506 if (!bridge)
3507 return -ENOMEM;
3508
3509 /*
3510 * With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural
3511 * alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate
3512 * a 4KB buffer that is guaranteed to be 4KB-aligned. Here the size and
3513 * alignment of hbus is important because hbus's field
3514 * retarget_msi_interrupt_params must not cross a 4KB page boundary.
3515 *
3516 * Here we prefer kzalloc to get_zeroed_page(), because a buffer
3517 * allocated by the latter is not tracked and scanned by kmemleak, and
3518 * hence kmemleak reports the pointer contained in the hbus buffer
3519 * (i.e. the hpdev struct, which is created in new_pcichild_device() and
3520 * is tracked by hbus->children) as memory leak (false positive).
3521 *
3522 * If the kernel doesn't have 59bb47985c1d, get_zeroed_page() *must* be
3523 * used to allocate the hbus buffer and we can avoid the kmemleak false
3524 * positive by using kmemleak_alloc() and kmemleak_free() to ask
3525 * kmemleak to track and scan the hbus buffer.
3526 */
3527 hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
3528 if (!hbus)
3529 return -ENOMEM;
3530
3531 hbus->bridge = bridge;
3532 hbus->state = hv_pcibus_init;
3533 hbus->wslot_res_allocated = -1;
3534
3535 /*
3536 * The PCI bus "domain" is what is called "segment" in ACPI and other
3537 * specs. Pull it from the instance ID, to get something usually
3538 * unique. In rare cases of collision, we will find out another number
3539 * not in use.
3540 *
3541 * Note that, since this code only runs in a Hyper-V VM, Hyper-V
3542 * together with this guest driver can guarantee that (1) The only
3543 * domain used by Gen1 VMs for something that looks like a physical
3544 * PCI bus (which is actually emulated by the hypervisor) is domain 0.
3545 * (2) There will be no overlap between domains (after fixing possible
3546 * collisions) in the same VM.
3547 */
3548 dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4];
3549 dom = hv_get_dom_num(dom_req);
3550
3551 if (dom == HVPCI_DOM_INVALID) {
3552 dev_err(&hdev->device,
3553 "Unable to use dom# 0x%x or other numbers", dom_req);
3554 ret = -EINVAL;
3555 goto free_bus;
3556 }
3557
3558 if (dom != dom_req)
3559 dev_info(&hdev->device,
3560 "PCI dom# 0x%x has collision, using 0x%x",
3561 dom_req, dom);
3562
3563 hbus->bridge->domain_nr = dom;
3564#ifdef CONFIG_X86
3565 hbus->sysdata.domain = dom;
3566#elif defined(CONFIG_ARM64)
3567 /*
3568 * Set the PCI bus parent to be the corresponding VMbus
3569 * device. Then the VMbus device will be assigned as the
3570 * ACPI companion in pcibios_root_bridge_prepare() and
3571 * pci_dma_configure() will propagate device coherence
3572 * information to devices created on the bus.
3573 */
3574 hbus->sysdata.parent = hdev->device.parent;
3575#endif
3576
3577 hbus->hdev = hdev;
3578 INIT_LIST_HEAD(&hbus->children);
3579 INIT_LIST_HEAD(&hbus->dr_list);
3580 spin_lock_init(&hbus->config_lock);
3581 spin_lock_init(&hbus->device_list_lock);
3582 spin_lock_init(&hbus->retarget_msi_interrupt_lock);
3583 hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0,
3584 hbus->bridge->domain_nr);
3585 if (!hbus->wq) {
3586 ret = -ENOMEM;
3587 goto free_dom;
3588 }
3589
3590 hdev->channel->next_request_id_callback = vmbus_next_request_id;
3591 hdev->channel->request_addr_callback = vmbus_request_addr;
3592 hdev->channel->rqstor_size = HV_PCI_RQSTOR_SIZE;
3593
3594 ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
3595 hv_pci_onchannelcallback, hbus);
3596 if (ret)
3597 goto destroy_wq;
3598
3599 hv_set_drvdata(hdev, hbus);
3600
3601 ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions,
3602 ARRAY_SIZE(pci_protocol_versions));
3603 if (ret)
3604 goto close;
3605
3606 ret = hv_allocate_config_window(hbus);
3607 if (ret)
3608 goto close;
3609
3610 hbus->cfg_addr = ioremap(hbus->mem_config->start,
3611 PCI_CONFIG_MMIO_LENGTH);
3612 if (!hbus->cfg_addr) {
3613 dev_err(&hdev->device,
3614 "Unable to map a virtual address for config space\n");
3615 ret = -ENOMEM;
3616 goto free_config;
3617 }
3618
3619 name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance);
3620 if (!name) {
3621 ret = -ENOMEM;
3622 goto unmap;
3623 }
3624
3625 hbus->fwnode = irq_domain_alloc_named_fwnode(name);
3626 kfree(name);
3627 if (!hbus->fwnode) {
3628 ret = -ENOMEM;
3629 goto unmap;
3630 }
3631
3632 ret = hv_pcie_init_irq_domain(hbus);
3633 if (ret)
3634 goto free_fwnode;
3635
3636retry:
3637 ret = hv_pci_query_relations(hdev);
3638 if (ret)
3639 goto free_irq_domain;
3640
3641 ret = hv_pci_enter_d0(hdev);
3642 /*
3643 * In certain case (Kdump) the pci device of interest was
3644 * not cleanly shut down and resource is still held on host
3645 * side, the host could return invalid device status.
3646 * We need to explicitly request host to release the resource
3647 * and try to enter D0 again.
3648 * Since the hv_pci_bus_exit() call releases structures
3649 * of all its child devices, we need to start the retry from
3650 * hv_pci_query_relations() call, requesting host to send
3651 * the synchronous child device relations message before this
3652 * information is needed in hv_send_resources_allocated()
3653 * call later.
3654 */
3655 if (ret == -EPROTO && enter_d0_retry) {
3656 enter_d0_retry = false;
3657
3658 dev_err(&hdev->device, "Retrying D0 Entry\n");
3659
3660 /*
3661 * Hv_pci_bus_exit() calls hv_send_resources_released()
3662 * to free up resources of its child devices.
3663 * In the kdump kernel we need to set the
3664 * wslot_res_allocated to 255 so it scans all child
3665 * devices to release resources allocated in the
3666 * normal kernel before panic happened.
3667 */
3668 hbus->wslot_res_allocated = 255;
3669 ret = hv_pci_bus_exit(hdev, true);
3670
3671 if (ret == 0)
3672 goto retry;
3673
3674 dev_err(&hdev->device,
3675 "Retrying D0 failed with ret %d\n", ret);
3676 }
3677 if (ret)
3678 goto free_irq_domain;
3679
3680 ret = hv_pci_allocate_bridge_windows(hbus);
3681 if (ret)
3682 goto exit_d0;
3683
3684 ret = hv_send_resources_allocated(hdev);
3685 if (ret)
3686 goto free_windows;
3687
3688 prepopulate_bars(hbus);
3689
3690 hbus->state = hv_pcibus_probed;
3691
3692 ret = create_root_hv_pci_bus(hbus);
3693 if (ret)
3694 goto free_windows;
3695
3696 return 0;
3697
3698free_windows:
3699 hv_pci_free_bridge_windows(hbus);
3700exit_d0:
3701 (void) hv_pci_bus_exit(hdev, true);
3702free_irq_domain:
3703 irq_domain_remove(hbus->irq_domain);
3704free_fwnode:
3705 irq_domain_free_fwnode(hbus->fwnode);
3706unmap:
3707 iounmap(hbus->cfg_addr);
3708free_config:
3709 hv_free_config_window(hbus);
3710close:
3711 vmbus_close(hdev->channel);
3712destroy_wq:
3713 destroy_workqueue(hbus->wq);
3714free_dom:
3715 hv_put_dom_num(hbus->bridge->domain_nr);
3716free_bus:
3717 kfree(hbus);
3718 return ret;
3719}
3720
3721static int hv_pci_bus_exit(struct hv_device *hdev, bool keep_devs)
3722{
3723 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3724 struct vmbus_channel *chan = hdev->channel;
3725 struct {
3726 struct pci_packet teardown_packet;
3727 u8 buffer[sizeof(struct pci_message)];
3728 } pkt;
3729 struct hv_pci_compl comp_pkt;
3730 struct hv_pci_dev *hpdev, *tmp;
3731 unsigned long flags;
3732 u64 trans_id;
3733 int ret;
3734
3735 /*
3736 * After the host sends the RESCIND_CHANNEL message, it doesn't
3737 * access the per-channel ringbuffer any longer.
3738 */
3739 if (chan->rescind)
3740 return 0;
3741
3742 if (!keep_devs) {
3743 struct list_head removed;
3744
3745 /* Move all present children to the list on stack */
3746 INIT_LIST_HEAD(&removed);
3747 spin_lock_irqsave(&hbus->device_list_lock, flags);
3748 list_for_each_entry_safe(hpdev, tmp, &hbus->children, list_entry)
3749 list_move_tail(&hpdev->list_entry, &removed);
3750 spin_unlock_irqrestore(&hbus->device_list_lock, flags);
3751
3752 /* Remove all children in the list */
3753 list_for_each_entry_safe(hpdev, tmp, &removed, list_entry) {
3754 list_del(&hpdev->list_entry);
3755 if (hpdev->pci_slot)
3756 pci_destroy_slot(hpdev->pci_slot);
3757 /* For the two refs got in new_pcichild_device() */
3758 put_pcichild(hpdev);
3759 put_pcichild(hpdev);
3760 }
3761 }
3762
3763 ret = hv_send_resources_released(hdev);
3764 if (ret) {
3765 dev_err(&hdev->device,
3766 "Couldn't send resources released packet(s)\n");
3767 return ret;
3768 }
3769
3770 memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet));
3771 init_completion(&comp_pkt.host_event);
3772 pkt.teardown_packet.completion_func = hv_pci_generic_compl;
3773 pkt.teardown_packet.compl_ctxt = &comp_pkt;
3774 pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT;
3775
3776 ret = vmbus_sendpacket_getid(chan, &pkt.teardown_packet.message,
3777 sizeof(struct pci_message),
3778 (unsigned long)&pkt.teardown_packet,
3779 &trans_id, VM_PKT_DATA_INBAND,
3780 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
3781 if (ret)
3782 return ret;
3783
3784 if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0) {
3785 /*
3786 * The completion packet on the stack becomes invalid after
3787 * 'return'; remove the ID from the VMbus requestor if the
3788 * identifier is still mapped to/associated with the packet.
3789 *
3790 * Cf. hv_pci_onchannelcallback().
3791 */
3792 vmbus_request_addr_match(chan, trans_id,
3793 (unsigned long)&pkt.teardown_packet);
3794 return -ETIMEDOUT;
3795 }
3796
3797 return 0;
3798}
3799
3800/**
3801 * hv_pci_remove() - Remove routine for this VMBus channel
3802 * @hdev: VMBus's tracking struct for this root PCI bus
3803 *
3804 * Return: 0 on success, -errno on failure
3805 */
3806static int hv_pci_remove(struct hv_device *hdev)
3807{
3808 struct hv_pcibus_device *hbus;
3809 int ret;
3810
3811 hbus = hv_get_drvdata(hdev);
3812 if (hbus->state == hv_pcibus_installed) {
3813 tasklet_disable(&hdev->channel->callback_event);
3814 hbus->state = hv_pcibus_removing;
3815 tasklet_enable(&hdev->channel->callback_event);
3816 destroy_workqueue(hbus->wq);
3817 hbus->wq = NULL;
3818 /*
3819 * At this point, no work is running or can be scheduled
3820 * on hbus-wq. We can't race with hv_pci_devices_present()
3821 * or hv_pci_eject_device(), it's safe to proceed.
3822 */
3823
3824 /* Remove the bus from PCI's point of view. */
3825 pci_lock_rescan_remove();
3826 pci_stop_root_bus(hbus->bridge->bus);
3827 hv_pci_remove_slots(hbus);
3828 pci_remove_root_bus(hbus->bridge->bus);
3829 pci_unlock_rescan_remove();
3830 }
3831
3832 ret = hv_pci_bus_exit(hdev, false);
3833
3834 vmbus_close(hdev->channel);
3835
3836 iounmap(hbus->cfg_addr);
3837 hv_free_config_window(hbus);
3838 hv_pci_free_bridge_windows(hbus);
3839 irq_domain_remove(hbus->irq_domain);
3840 irq_domain_free_fwnode(hbus->fwnode);
3841
3842 hv_put_dom_num(hbus->bridge->domain_nr);
3843
3844 kfree(hbus);
3845 return ret;
3846}
3847
3848static int hv_pci_suspend(struct hv_device *hdev)
3849{
3850 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3851 enum hv_pcibus_state old_state;
3852 int ret;
3853
3854 /*
3855 * hv_pci_suspend() must make sure there are no pending work items
3856 * before calling vmbus_close(), since it runs in a process context
3857 * as a callback in dpm_suspend(). When it starts to run, the channel
3858 * callback hv_pci_onchannelcallback(), which runs in a tasklet
3859 * context, can be still running concurrently and scheduling new work
3860 * items onto hbus->wq in hv_pci_devices_present() and
3861 * hv_pci_eject_device(), and the work item handlers can access the
3862 * vmbus channel, which can be being closed by hv_pci_suspend(), e.g.
3863 * the work item handler pci_devices_present_work() ->
3864 * new_pcichild_device() writes to the vmbus channel.
3865 *
3866 * To eliminate the race, hv_pci_suspend() disables the channel
3867 * callback tasklet, sets hbus->state to hv_pcibus_removing, and
3868 * re-enables the tasklet. This way, when hv_pci_suspend() proceeds,
3869 * it knows that no new work item can be scheduled, and then it flushes
3870 * hbus->wq and safely closes the vmbus channel.
3871 */
3872 tasklet_disable(&hdev->channel->callback_event);
3873
3874 /* Change the hbus state to prevent new work items. */
3875 old_state = hbus->state;
3876 if (hbus->state == hv_pcibus_installed)
3877 hbus->state = hv_pcibus_removing;
3878
3879 tasklet_enable(&hdev->channel->callback_event);
3880
3881 if (old_state != hv_pcibus_installed)
3882 return -EINVAL;
3883
3884 flush_workqueue(hbus->wq);
3885
3886 ret = hv_pci_bus_exit(hdev, true);
3887 if (ret)
3888 return ret;
3889
3890 vmbus_close(hdev->channel);
3891
3892 return 0;
3893}
3894
3895static int hv_pci_restore_msi_msg(struct pci_dev *pdev, void *arg)
3896{
3897 struct irq_data *irq_data;
3898 struct msi_desc *entry;
3899 int ret = 0;
3900
3901 msi_lock_descs(&pdev->dev);
3902 msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) {
3903 irq_data = irq_get_irq_data(entry->irq);
3904 if (WARN_ON_ONCE(!irq_data)) {
3905 ret = -EINVAL;
3906 break;
3907 }
3908
3909 hv_compose_msi_msg(irq_data, &entry->msg);
3910 }
3911 msi_unlock_descs(&pdev->dev);
3912
3913 return ret;
3914}
3915
3916/*
3917 * Upon resume, pci_restore_msi_state() -> ... -> __pci_write_msi_msg()
3918 * directly writes the MSI/MSI-X registers via MMIO, but since Hyper-V
3919 * doesn't trap and emulate the MMIO accesses, here hv_compose_msi_msg()
3920 * must be used to ask Hyper-V to re-create the IOMMU Interrupt Remapping
3921 * Table entries.
3922 */
3923static void hv_pci_restore_msi_state(struct hv_pcibus_device *hbus)
3924{
3925 pci_walk_bus(hbus->bridge->bus, hv_pci_restore_msi_msg, NULL);
3926}
3927
3928static int hv_pci_resume(struct hv_device *hdev)
3929{
3930 struct hv_pcibus_device *hbus = hv_get_drvdata(hdev);
3931 enum pci_protocol_version_t version[1];
3932 int ret;
3933
3934 hbus->state = hv_pcibus_init;
3935
3936 hdev->channel->next_request_id_callback = vmbus_next_request_id;
3937 hdev->channel->request_addr_callback = vmbus_request_addr;
3938 hdev->channel->rqstor_size = HV_PCI_RQSTOR_SIZE;
3939
3940 ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0,
3941 hv_pci_onchannelcallback, hbus);
3942 if (ret)
3943 return ret;
3944
3945 /* Only use the version that was in use before hibernation. */
3946 version[0] = hbus->protocol_version;
3947 ret = hv_pci_protocol_negotiation(hdev, version, 1);
3948 if (ret)
3949 goto out;
3950
3951 ret = hv_pci_query_relations(hdev);
3952 if (ret)
3953 goto out;
3954
3955 ret = hv_pci_enter_d0(hdev);
3956 if (ret)
3957 goto out;
3958
3959 ret = hv_send_resources_allocated(hdev);
3960 if (ret)
3961 goto out;
3962
3963 prepopulate_bars(hbus);
3964
3965 hv_pci_restore_msi_state(hbus);
3966
3967 hbus->state = hv_pcibus_installed;
3968 return 0;
3969out:
3970 vmbus_close(hdev->channel);
3971 return ret;
3972}
3973
3974static const struct hv_vmbus_device_id hv_pci_id_table[] = {
3975 /* PCI Pass-through Class ID */
3976 /* 44C4F61D-4444-4400-9D52-802E27EDE19F */
3977 { HV_PCIE_GUID, },
3978 { },
3979};
3980
3981MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table);
3982
3983static struct hv_driver hv_pci_drv = {
3984 .name = "hv_pci",
3985 .id_table = hv_pci_id_table,
3986 .probe = hv_pci_probe,
3987 .remove = hv_pci_remove,
3988 .suspend = hv_pci_suspend,
3989 .resume = hv_pci_resume,
3990};
3991
3992static void __exit exit_hv_pci_drv(void)
3993{
3994 vmbus_driver_unregister(&hv_pci_drv);
3995
3996 hvpci_block_ops.read_block = NULL;
3997 hvpci_block_ops.write_block = NULL;
3998 hvpci_block_ops.reg_blk_invalidate = NULL;
3999}
4000
4001static int __init init_hv_pci_drv(void)
4002{
4003 int ret;
4004
4005 if (!hv_is_hyperv_initialized())
4006 return -ENODEV;
4007
4008 ret = hv_pci_irqchip_init();
4009 if (ret)
4010 return ret;
4011
4012 /* Set the invalid domain number's bit, so it will not be used */
4013 set_bit(HVPCI_DOM_INVALID, hvpci_dom_map);
4014
4015 /* Initialize PCI block r/w interface */
4016 hvpci_block_ops.read_block = hv_read_config_block;
4017 hvpci_block_ops.write_block = hv_write_config_block;
4018 hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate;
4019
4020 return vmbus_driver_register(&hv_pci_drv);
4021}
4022
4023module_init(init_hv_pci_drv);
4024module_exit(exit_hv_pci_drv);
4025
4026MODULE_DESCRIPTION("Hyper-V PCI");
4027MODULE_LICENSE("GPL v2");