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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2009, Microsoft Corporation.
4 *
5 * Authors:
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
8 * K. Y. Srinivasan <kys@microsoft.com>
9 */
10#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/device.h>
15#include <linux/platform_device.h>
16#include <linux/interrupt.h>
17#include <linux/sysctl.h>
18#include <linux/slab.h>
19#include <linux/acpi.h>
20#include <linux/completion.h>
21#include <linux/hyperv.h>
22#include <linux/kernel_stat.h>
23#include <linux/of_address.h>
24#include <linux/clockchips.h>
25#include <linux/cpu.h>
26#include <linux/sched/isolation.h>
27#include <linux/sched/task_stack.h>
28
29#include <linux/delay.h>
30#include <linux/panic_notifier.h>
31#include <linux/ptrace.h>
32#include <linux/screen_info.h>
33#include <linux/efi.h>
34#include <linux/random.h>
35#include <linux/kernel.h>
36#include <linux/syscore_ops.h>
37#include <linux/dma-map-ops.h>
38#include <linux/pci.h>
39#include <clocksource/hyperv_timer.h>
40#include <asm/mshyperv.h>
41#include "hyperv_vmbus.h"
42
43struct vmbus_dynid {
44 struct list_head node;
45 struct hv_vmbus_device_id id;
46};
47
48static struct device *hv_dev;
49
50static int hyperv_cpuhp_online;
51
52static long __percpu *vmbus_evt;
53
54/* Values parsed from ACPI DSDT */
55int vmbus_irq;
56int vmbus_interrupt;
57
58/*
59 * The panic notifier below is responsible solely for unloading the
60 * vmbus connection, which is necessary in a panic event.
61 *
62 * Notice an intrincate relation of this notifier with Hyper-V
63 * framebuffer panic notifier exists - we need vmbus connection alive
64 * there in order to succeed, so we need to order both with each other
65 * [see hvfb_on_panic()] - this is done using notifiers' priorities.
66 */
67static int hv_panic_vmbus_unload(struct notifier_block *nb, unsigned long val,
68 void *args)
69{
70 vmbus_initiate_unload(true);
71 return NOTIFY_DONE;
72}
73static struct notifier_block hyperv_panic_vmbus_unload_block = {
74 .notifier_call = hv_panic_vmbus_unload,
75 .priority = INT_MIN + 1, /* almost the latest one to execute */
76};
77
78static const char *fb_mmio_name = "fb_range";
79static struct resource *fb_mmio;
80static struct resource *hyperv_mmio;
81static DEFINE_MUTEX(hyperv_mmio_lock);
82
83static int vmbus_exists(void)
84{
85 if (hv_dev == NULL)
86 return -ENODEV;
87
88 return 0;
89}
90
91static u8 channel_monitor_group(const struct vmbus_channel *channel)
92{
93 return (u8)channel->offermsg.monitorid / 32;
94}
95
96static u8 channel_monitor_offset(const struct vmbus_channel *channel)
97{
98 return (u8)channel->offermsg.monitorid % 32;
99}
100
101static u32 channel_pending(const struct vmbus_channel *channel,
102 const struct hv_monitor_page *monitor_page)
103{
104 u8 monitor_group = channel_monitor_group(channel);
105
106 return monitor_page->trigger_group[monitor_group].pending;
107}
108
109static u32 channel_latency(const struct vmbus_channel *channel,
110 const struct hv_monitor_page *monitor_page)
111{
112 u8 monitor_group = channel_monitor_group(channel);
113 u8 monitor_offset = channel_monitor_offset(channel);
114
115 return monitor_page->latency[monitor_group][monitor_offset];
116}
117
118static u32 channel_conn_id(struct vmbus_channel *channel,
119 struct hv_monitor_page *monitor_page)
120{
121 u8 monitor_group = channel_monitor_group(channel);
122 u8 monitor_offset = channel_monitor_offset(channel);
123
124 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
125}
126
127static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
128 char *buf)
129{
130 struct hv_device *hv_dev = device_to_hv_device(dev);
131
132 if (!hv_dev->channel)
133 return -ENODEV;
134 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
135}
136static DEVICE_ATTR_RO(id);
137
138static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
139 char *buf)
140{
141 struct hv_device *hv_dev = device_to_hv_device(dev);
142
143 if (!hv_dev->channel)
144 return -ENODEV;
145 return sprintf(buf, "%d\n", hv_dev->channel->state);
146}
147static DEVICE_ATTR_RO(state);
148
149static ssize_t monitor_id_show(struct device *dev,
150 struct device_attribute *dev_attr, char *buf)
151{
152 struct hv_device *hv_dev = device_to_hv_device(dev);
153
154 if (!hv_dev->channel)
155 return -ENODEV;
156 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
157}
158static DEVICE_ATTR_RO(monitor_id);
159
160static ssize_t class_id_show(struct device *dev,
161 struct device_attribute *dev_attr, char *buf)
162{
163 struct hv_device *hv_dev = device_to_hv_device(dev);
164
165 if (!hv_dev->channel)
166 return -ENODEV;
167 return sprintf(buf, "{%pUl}\n",
168 &hv_dev->channel->offermsg.offer.if_type);
169}
170static DEVICE_ATTR_RO(class_id);
171
172static ssize_t device_id_show(struct device *dev,
173 struct device_attribute *dev_attr, char *buf)
174{
175 struct hv_device *hv_dev = device_to_hv_device(dev);
176
177 if (!hv_dev->channel)
178 return -ENODEV;
179 return sprintf(buf, "{%pUl}\n",
180 &hv_dev->channel->offermsg.offer.if_instance);
181}
182static DEVICE_ATTR_RO(device_id);
183
184static ssize_t modalias_show(struct device *dev,
185 struct device_attribute *dev_attr, char *buf)
186{
187 struct hv_device *hv_dev = device_to_hv_device(dev);
188
189 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
190}
191static DEVICE_ATTR_RO(modalias);
192
193#ifdef CONFIG_NUMA
194static ssize_t numa_node_show(struct device *dev,
195 struct device_attribute *attr, char *buf)
196{
197 struct hv_device *hv_dev = device_to_hv_device(dev);
198
199 if (!hv_dev->channel)
200 return -ENODEV;
201
202 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
203}
204static DEVICE_ATTR_RO(numa_node);
205#endif
206
207static ssize_t server_monitor_pending_show(struct device *dev,
208 struct device_attribute *dev_attr,
209 char *buf)
210{
211 struct hv_device *hv_dev = device_to_hv_device(dev);
212
213 if (!hv_dev->channel)
214 return -ENODEV;
215 return sprintf(buf, "%d\n",
216 channel_pending(hv_dev->channel,
217 vmbus_connection.monitor_pages[0]));
218}
219static DEVICE_ATTR_RO(server_monitor_pending);
220
221static ssize_t client_monitor_pending_show(struct device *dev,
222 struct device_attribute *dev_attr,
223 char *buf)
224{
225 struct hv_device *hv_dev = device_to_hv_device(dev);
226
227 if (!hv_dev->channel)
228 return -ENODEV;
229 return sprintf(buf, "%d\n",
230 channel_pending(hv_dev->channel,
231 vmbus_connection.monitor_pages[1]));
232}
233static DEVICE_ATTR_RO(client_monitor_pending);
234
235static ssize_t server_monitor_latency_show(struct device *dev,
236 struct device_attribute *dev_attr,
237 char *buf)
238{
239 struct hv_device *hv_dev = device_to_hv_device(dev);
240
241 if (!hv_dev->channel)
242 return -ENODEV;
243 return sprintf(buf, "%d\n",
244 channel_latency(hv_dev->channel,
245 vmbus_connection.monitor_pages[0]));
246}
247static DEVICE_ATTR_RO(server_monitor_latency);
248
249static ssize_t client_monitor_latency_show(struct device *dev,
250 struct device_attribute *dev_attr,
251 char *buf)
252{
253 struct hv_device *hv_dev = device_to_hv_device(dev);
254
255 if (!hv_dev->channel)
256 return -ENODEV;
257 return sprintf(buf, "%d\n",
258 channel_latency(hv_dev->channel,
259 vmbus_connection.monitor_pages[1]));
260}
261static DEVICE_ATTR_RO(client_monitor_latency);
262
263static ssize_t server_monitor_conn_id_show(struct device *dev,
264 struct device_attribute *dev_attr,
265 char *buf)
266{
267 struct hv_device *hv_dev = device_to_hv_device(dev);
268
269 if (!hv_dev->channel)
270 return -ENODEV;
271 return sprintf(buf, "%d\n",
272 channel_conn_id(hv_dev->channel,
273 vmbus_connection.monitor_pages[0]));
274}
275static DEVICE_ATTR_RO(server_monitor_conn_id);
276
277static ssize_t client_monitor_conn_id_show(struct device *dev,
278 struct device_attribute *dev_attr,
279 char *buf)
280{
281 struct hv_device *hv_dev = device_to_hv_device(dev);
282
283 if (!hv_dev->channel)
284 return -ENODEV;
285 return sprintf(buf, "%d\n",
286 channel_conn_id(hv_dev->channel,
287 vmbus_connection.monitor_pages[1]));
288}
289static DEVICE_ATTR_RO(client_monitor_conn_id);
290
291static ssize_t out_intr_mask_show(struct device *dev,
292 struct device_attribute *dev_attr, char *buf)
293{
294 struct hv_device *hv_dev = device_to_hv_device(dev);
295 struct hv_ring_buffer_debug_info outbound;
296 int ret;
297
298 if (!hv_dev->channel)
299 return -ENODEV;
300
301 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
302 &outbound);
303 if (ret < 0)
304 return ret;
305
306 return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
307}
308static DEVICE_ATTR_RO(out_intr_mask);
309
310static ssize_t out_read_index_show(struct device *dev,
311 struct device_attribute *dev_attr, char *buf)
312{
313 struct hv_device *hv_dev = device_to_hv_device(dev);
314 struct hv_ring_buffer_debug_info outbound;
315 int ret;
316
317 if (!hv_dev->channel)
318 return -ENODEV;
319
320 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
321 &outbound);
322 if (ret < 0)
323 return ret;
324 return sprintf(buf, "%d\n", outbound.current_read_index);
325}
326static DEVICE_ATTR_RO(out_read_index);
327
328static ssize_t out_write_index_show(struct device *dev,
329 struct device_attribute *dev_attr,
330 char *buf)
331{
332 struct hv_device *hv_dev = device_to_hv_device(dev);
333 struct hv_ring_buffer_debug_info outbound;
334 int ret;
335
336 if (!hv_dev->channel)
337 return -ENODEV;
338
339 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
340 &outbound);
341 if (ret < 0)
342 return ret;
343 return sprintf(buf, "%d\n", outbound.current_write_index);
344}
345static DEVICE_ATTR_RO(out_write_index);
346
347static ssize_t out_read_bytes_avail_show(struct device *dev,
348 struct device_attribute *dev_attr,
349 char *buf)
350{
351 struct hv_device *hv_dev = device_to_hv_device(dev);
352 struct hv_ring_buffer_debug_info outbound;
353 int ret;
354
355 if (!hv_dev->channel)
356 return -ENODEV;
357
358 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
359 &outbound);
360 if (ret < 0)
361 return ret;
362 return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
363}
364static DEVICE_ATTR_RO(out_read_bytes_avail);
365
366static ssize_t out_write_bytes_avail_show(struct device *dev,
367 struct device_attribute *dev_attr,
368 char *buf)
369{
370 struct hv_device *hv_dev = device_to_hv_device(dev);
371 struct hv_ring_buffer_debug_info outbound;
372 int ret;
373
374 if (!hv_dev->channel)
375 return -ENODEV;
376
377 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
378 &outbound);
379 if (ret < 0)
380 return ret;
381 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
382}
383static DEVICE_ATTR_RO(out_write_bytes_avail);
384
385static ssize_t in_intr_mask_show(struct device *dev,
386 struct device_attribute *dev_attr, char *buf)
387{
388 struct hv_device *hv_dev = device_to_hv_device(dev);
389 struct hv_ring_buffer_debug_info inbound;
390 int ret;
391
392 if (!hv_dev->channel)
393 return -ENODEV;
394
395 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
396 if (ret < 0)
397 return ret;
398
399 return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
400}
401static DEVICE_ATTR_RO(in_intr_mask);
402
403static ssize_t in_read_index_show(struct device *dev,
404 struct device_attribute *dev_attr, char *buf)
405{
406 struct hv_device *hv_dev = device_to_hv_device(dev);
407 struct hv_ring_buffer_debug_info inbound;
408 int ret;
409
410 if (!hv_dev->channel)
411 return -ENODEV;
412
413 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
414 if (ret < 0)
415 return ret;
416
417 return sprintf(buf, "%d\n", inbound.current_read_index);
418}
419static DEVICE_ATTR_RO(in_read_index);
420
421static ssize_t in_write_index_show(struct device *dev,
422 struct device_attribute *dev_attr, char *buf)
423{
424 struct hv_device *hv_dev = device_to_hv_device(dev);
425 struct hv_ring_buffer_debug_info inbound;
426 int ret;
427
428 if (!hv_dev->channel)
429 return -ENODEV;
430
431 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
432 if (ret < 0)
433 return ret;
434
435 return sprintf(buf, "%d\n", inbound.current_write_index);
436}
437static DEVICE_ATTR_RO(in_write_index);
438
439static ssize_t in_read_bytes_avail_show(struct device *dev,
440 struct device_attribute *dev_attr,
441 char *buf)
442{
443 struct hv_device *hv_dev = device_to_hv_device(dev);
444 struct hv_ring_buffer_debug_info inbound;
445 int ret;
446
447 if (!hv_dev->channel)
448 return -ENODEV;
449
450 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
451 if (ret < 0)
452 return ret;
453
454 return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
455}
456static DEVICE_ATTR_RO(in_read_bytes_avail);
457
458static ssize_t in_write_bytes_avail_show(struct device *dev,
459 struct device_attribute *dev_attr,
460 char *buf)
461{
462 struct hv_device *hv_dev = device_to_hv_device(dev);
463 struct hv_ring_buffer_debug_info inbound;
464 int ret;
465
466 if (!hv_dev->channel)
467 return -ENODEV;
468
469 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
470 if (ret < 0)
471 return ret;
472
473 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
474}
475static DEVICE_ATTR_RO(in_write_bytes_avail);
476
477static ssize_t channel_vp_mapping_show(struct device *dev,
478 struct device_attribute *dev_attr,
479 char *buf)
480{
481 struct hv_device *hv_dev = device_to_hv_device(dev);
482 struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
483 int buf_size = PAGE_SIZE, n_written, tot_written;
484 struct list_head *cur;
485
486 if (!channel)
487 return -ENODEV;
488
489 mutex_lock(&vmbus_connection.channel_mutex);
490
491 tot_written = snprintf(buf, buf_size, "%u:%u\n",
492 channel->offermsg.child_relid, channel->target_cpu);
493
494 list_for_each(cur, &channel->sc_list) {
495 if (tot_written >= buf_size - 1)
496 break;
497
498 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
499 n_written = scnprintf(buf + tot_written,
500 buf_size - tot_written,
501 "%u:%u\n",
502 cur_sc->offermsg.child_relid,
503 cur_sc->target_cpu);
504 tot_written += n_written;
505 }
506
507 mutex_unlock(&vmbus_connection.channel_mutex);
508
509 return tot_written;
510}
511static DEVICE_ATTR_RO(channel_vp_mapping);
512
513static ssize_t vendor_show(struct device *dev,
514 struct device_attribute *dev_attr,
515 char *buf)
516{
517 struct hv_device *hv_dev = device_to_hv_device(dev);
518
519 return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
520}
521static DEVICE_ATTR_RO(vendor);
522
523static ssize_t device_show(struct device *dev,
524 struct device_attribute *dev_attr,
525 char *buf)
526{
527 struct hv_device *hv_dev = device_to_hv_device(dev);
528
529 return sprintf(buf, "0x%x\n", hv_dev->device_id);
530}
531static DEVICE_ATTR_RO(device);
532
533static ssize_t driver_override_store(struct device *dev,
534 struct device_attribute *attr,
535 const char *buf, size_t count)
536{
537 struct hv_device *hv_dev = device_to_hv_device(dev);
538 int ret;
539
540 ret = driver_set_override(dev, &hv_dev->driver_override, buf, count);
541 if (ret)
542 return ret;
543
544 return count;
545}
546
547static ssize_t driver_override_show(struct device *dev,
548 struct device_attribute *attr, char *buf)
549{
550 struct hv_device *hv_dev = device_to_hv_device(dev);
551 ssize_t len;
552
553 device_lock(dev);
554 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
555 device_unlock(dev);
556
557 return len;
558}
559static DEVICE_ATTR_RW(driver_override);
560
561/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
562static struct attribute *vmbus_dev_attrs[] = {
563 &dev_attr_id.attr,
564 &dev_attr_state.attr,
565 &dev_attr_monitor_id.attr,
566 &dev_attr_class_id.attr,
567 &dev_attr_device_id.attr,
568 &dev_attr_modalias.attr,
569#ifdef CONFIG_NUMA
570 &dev_attr_numa_node.attr,
571#endif
572 &dev_attr_server_monitor_pending.attr,
573 &dev_attr_client_monitor_pending.attr,
574 &dev_attr_server_monitor_latency.attr,
575 &dev_attr_client_monitor_latency.attr,
576 &dev_attr_server_monitor_conn_id.attr,
577 &dev_attr_client_monitor_conn_id.attr,
578 &dev_attr_out_intr_mask.attr,
579 &dev_attr_out_read_index.attr,
580 &dev_attr_out_write_index.attr,
581 &dev_attr_out_read_bytes_avail.attr,
582 &dev_attr_out_write_bytes_avail.attr,
583 &dev_attr_in_intr_mask.attr,
584 &dev_attr_in_read_index.attr,
585 &dev_attr_in_write_index.attr,
586 &dev_attr_in_read_bytes_avail.attr,
587 &dev_attr_in_write_bytes_avail.attr,
588 &dev_attr_channel_vp_mapping.attr,
589 &dev_attr_vendor.attr,
590 &dev_attr_device.attr,
591 &dev_attr_driver_override.attr,
592 NULL,
593};
594
595/*
596 * Device-level attribute_group callback function. Returns the permission for
597 * each attribute, and returns 0 if an attribute is not visible.
598 */
599static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
600 struct attribute *attr, int idx)
601{
602 struct device *dev = kobj_to_dev(kobj);
603 const struct hv_device *hv_dev = device_to_hv_device(dev);
604
605 /* Hide the monitor attributes if the monitor mechanism is not used. */
606 if (!hv_dev->channel->offermsg.monitor_allocated &&
607 (attr == &dev_attr_monitor_id.attr ||
608 attr == &dev_attr_server_monitor_pending.attr ||
609 attr == &dev_attr_client_monitor_pending.attr ||
610 attr == &dev_attr_server_monitor_latency.attr ||
611 attr == &dev_attr_client_monitor_latency.attr ||
612 attr == &dev_attr_server_monitor_conn_id.attr ||
613 attr == &dev_attr_client_monitor_conn_id.attr))
614 return 0;
615
616 return attr->mode;
617}
618
619static const struct attribute_group vmbus_dev_group = {
620 .attrs = vmbus_dev_attrs,
621 .is_visible = vmbus_dev_attr_is_visible
622};
623__ATTRIBUTE_GROUPS(vmbus_dev);
624
625/* Set up the attribute for /sys/bus/vmbus/hibernation */
626static ssize_t hibernation_show(const struct bus_type *bus, char *buf)
627{
628 return sprintf(buf, "%d\n", !!hv_is_hibernation_supported());
629}
630
631static BUS_ATTR_RO(hibernation);
632
633static struct attribute *vmbus_bus_attrs[] = {
634 &bus_attr_hibernation.attr,
635 NULL,
636};
637static const struct attribute_group vmbus_bus_group = {
638 .attrs = vmbus_bus_attrs,
639};
640__ATTRIBUTE_GROUPS(vmbus_bus);
641
642/*
643 * vmbus_uevent - add uevent for our device
644 *
645 * This routine is invoked when a device is added or removed on the vmbus to
646 * generate a uevent to udev in the userspace. The udev will then look at its
647 * rule and the uevent generated here to load the appropriate driver
648 *
649 * The alias string will be of the form vmbus:guid where guid is the string
650 * representation of the device guid (each byte of the guid will be
651 * represented with two hex characters.
652 */
653static int vmbus_uevent(const struct device *device, struct kobj_uevent_env *env)
654{
655 const struct hv_device *dev = device_to_hv_device(device);
656 const char *format = "MODALIAS=vmbus:%*phN";
657
658 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
659}
660
661static const struct hv_vmbus_device_id *
662hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
663{
664 if (id == NULL)
665 return NULL; /* empty device table */
666
667 for (; !guid_is_null(&id->guid); id++)
668 if (guid_equal(&id->guid, guid))
669 return id;
670
671 return NULL;
672}
673
674static const struct hv_vmbus_device_id *
675hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
676{
677 const struct hv_vmbus_device_id *id = NULL;
678 struct vmbus_dynid *dynid;
679
680 spin_lock(&drv->dynids.lock);
681 list_for_each_entry(dynid, &drv->dynids.list, node) {
682 if (guid_equal(&dynid->id.guid, guid)) {
683 id = &dynid->id;
684 break;
685 }
686 }
687 spin_unlock(&drv->dynids.lock);
688
689 return id;
690}
691
692static const struct hv_vmbus_device_id vmbus_device_null;
693
694/*
695 * Return a matching hv_vmbus_device_id pointer.
696 * If there is no match, return NULL.
697 */
698static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
699 struct hv_device *dev)
700{
701 const guid_t *guid = &dev->dev_type;
702 const struct hv_vmbus_device_id *id;
703
704 /* When driver_override is set, only bind to the matching driver */
705 if (dev->driver_override && strcmp(dev->driver_override, drv->name))
706 return NULL;
707
708 /* Look at the dynamic ids first, before the static ones */
709 id = hv_vmbus_dynid_match(drv, guid);
710 if (!id)
711 id = hv_vmbus_dev_match(drv->id_table, guid);
712
713 /* driver_override will always match, send a dummy id */
714 if (!id && dev->driver_override)
715 id = &vmbus_device_null;
716
717 return id;
718}
719
720/* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
721static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
722{
723 struct vmbus_dynid *dynid;
724
725 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
726 if (!dynid)
727 return -ENOMEM;
728
729 dynid->id.guid = *guid;
730
731 spin_lock(&drv->dynids.lock);
732 list_add_tail(&dynid->node, &drv->dynids.list);
733 spin_unlock(&drv->dynids.lock);
734
735 return driver_attach(&drv->driver);
736}
737
738static void vmbus_free_dynids(struct hv_driver *drv)
739{
740 struct vmbus_dynid *dynid, *n;
741
742 spin_lock(&drv->dynids.lock);
743 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
744 list_del(&dynid->node);
745 kfree(dynid);
746 }
747 spin_unlock(&drv->dynids.lock);
748}
749
750/*
751 * store_new_id - sysfs frontend to vmbus_add_dynid()
752 *
753 * Allow GUIDs to be added to an existing driver via sysfs.
754 */
755static ssize_t new_id_store(struct device_driver *driver, const char *buf,
756 size_t count)
757{
758 struct hv_driver *drv = drv_to_hv_drv(driver);
759 guid_t guid;
760 ssize_t retval;
761
762 retval = guid_parse(buf, &guid);
763 if (retval)
764 return retval;
765
766 if (hv_vmbus_dynid_match(drv, &guid))
767 return -EEXIST;
768
769 retval = vmbus_add_dynid(drv, &guid);
770 if (retval)
771 return retval;
772 return count;
773}
774static DRIVER_ATTR_WO(new_id);
775
776/*
777 * store_remove_id - remove a PCI device ID from this driver
778 *
779 * Removes a dynamic pci device ID to this driver.
780 */
781static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
782 size_t count)
783{
784 struct hv_driver *drv = drv_to_hv_drv(driver);
785 struct vmbus_dynid *dynid, *n;
786 guid_t guid;
787 ssize_t retval;
788
789 retval = guid_parse(buf, &guid);
790 if (retval)
791 return retval;
792
793 retval = -ENODEV;
794 spin_lock(&drv->dynids.lock);
795 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
796 struct hv_vmbus_device_id *id = &dynid->id;
797
798 if (guid_equal(&id->guid, &guid)) {
799 list_del(&dynid->node);
800 kfree(dynid);
801 retval = count;
802 break;
803 }
804 }
805 spin_unlock(&drv->dynids.lock);
806
807 return retval;
808}
809static DRIVER_ATTR_WO(remove_id);
810
811static struct attribute *vmbus_drv_attrs[] = {
812 &driver_attr_new_id.attr,
813 &driver_attr_remove_id.attr,
814 NULL,
815};
816ATTRIBUTE_GROUPS(vmbus_drv);
817
818
819/*
820 * vmbus_match - Attempt to match the specified device to the specified driver
821 */
822static int vmbus_match(struct device *device, struct device_driver *driver)
823{
824 struct hv_driver *drv = drv_to_hv_drv(driver);
825 struct hv_device *hv_dev = device_to_hv_device(device);
826
827 /* The hv_sock driver handles all hv_sock offers. */
828 if (is_hvsock_channel(hv_dev->channel))
829 return drv->hvsock;
830
831 if (hv_vmbus_get_id(drv, hv_dev))
832 return 1;
833
834 return 0;
835}
836
837/*
838 * vmbus_probe - Add the new vmbus's child device
839 */
840static int vmbus_probe(struct device *child_device)
841{
842 int ret = 0;
843 struct hv_driver *drv =
844 drv_to_hv_drv(child_device->driver);
845 struct hv_device *dev = device_to_hv_device(child_device);
846 const struct hv_vmbus_device_id *dev_id;
847
848 dev_id = hv_vmbus_get_id(drv, dev);
849 if (drv->probe) {
850 ret = drv->probe(dev, dev_id);
851 if (ret != 0)
852 pr_err("probe failed for device %s (%d)\n",
853 dev_name(child_device), ret);
854
855 } else {
856 pr_err("probe not set for driver %s\n",
857 dev_name(child_device));
858 ret = -ENODEV;
859 }
860 return ret;
861}
862
863/*
864 * vmbus_dma_configure -- Configure DMA coherence for VMbus device
865 */
866static int vmbus_dma_configure(struct device *child_device)
867{
868 /*
869 * On ARM64, propagate the DMA coherence setting from the top level
870 * VMbus ACPI device to the child VMbus device being added here.
871 * On x86/x64 coherence is assumed and these calls have no effect.
872 */
873 hv_setup_dma_ops(child_device,
874 device_get_dma_attr(hv_dev) == DEV_DMA_COHERENT);
875 return 0;
876}
877
878/*
879 * vmbus_remove - Remove a vmbus device
880 */
881static void vmbus_remove(struct device *child_device)
882{
883 struct hv_driver *drv;
884 struct hv_device *dev = device_to_hv_device(child_device);
885
886 if (child_device->driver) {
887 drv = drv_to_hv_drv(child_device->driver);
888 if (drv->remove)
889 drv->remove(dev);
890 }
891}
892
893/*
894 * vmbus_shutdown - Shutdown a vmbus device
895 */
896static void vmbus_shutdown(struct device *child_device)
897{
898 struct hv_driver *drv;
899 struct hv_device *dev = device_to_hv_device(child_device);
900
901
902 /* The device may not be attached yet */
903 if (!child_device->driver)
904 return;
905
906 drv = drv_to_hv_drv(child_device->driver);
907
908 if (drv->shutdown)
909 drv->shutdown(dev);
910}
911
912#ifdef CONFIG_PM_SLEEP
913/*
914 * vmbus_suspend - Suspend a vmbus device
915 */
916static int vmbus_suspend(struct device *child_device)
917{
918 struct hv_driver *drv;
919 struct hv_device *dev = device_to_hv_device(child_device);
920
921 /* The device may not be attached yet */
922 if (!child_device->driver)
923 return 0;
924
925 drv = drv_to_hv_drv(child_device->driver);
926 if (!drv->suspend)
927 return -EOPNOTSUPP;
928
929 return drv->suspend(dev);
930}
931
932/*
933 * vmbus_resume - Resume a vmbus device
934 */
935static int vmbus_resume(struct device *child_device)
936{
937 struct hv_driver *drv;
938 struct hv_device *dev = device_to_hv_device(child_device);
939
940 /* The device may not be attached yet */
941 if (!child_device->driver)
942 return 0;
943
944 drv = drv_to_hv_drv(child_device->driver);
945 if (!drv->resume)
946 return -EOPNOTSUPP;
947
948 return drv->resume(dev);
949}
950#else
951#define vmbus_suspend NULL
952#define vmbus_resume NULL
953#endif /* CONFIG_PM_SLEEP */
954
955/*
956 * vmbus_device_release - Final callback release of the vmbus child device
957 */
958static void vmbus_device_release(struct device *device)
959{
960 struct hv_device *hv_dev = device_to_hv_device(device);
961 struct vmbus_channel *channel = hv_dev->channel;
962
963 hv_debug_rm_dev_dir(hv_dev);
964
965 mutex_lock(&vmbus_connection.channel_mutex);
966 hv_process_channel_removal(channel);
967 mutex_unlock(&vmbus_connection.channel_mutex);
968 kfree(hv_dev);
969}
970
971/*
972 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
973 *
974 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
975 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
976 * is no way to wake up a Generation-2 VM.
977 *
978 * The other 4 ops are for hibernation.
979 */
980
981static const struct dev_pm_ops vmbus_pm = {
982 .suspend_noirq = NULL,
983 .resume_noirq = NULL,
984 .freeze_noirq = vmbus_suspend,
985 .thaw_noirq = vmbus_resume,
986 .poweroff_noirq = vmbus_suspend,
987 .restore_noirq = vmbus_resume,
988};
989
990/* The one and only one */
991static const struct bus_type hv_bus = {
992 .name = "vmbus",
993 .match = vmbus_match,
994 .shutdown = vmbus_shutdown,
995 .remove = vmbus_remove,
996 .probe = vmbus_probe,
997 .uevent = vmbus_uevent,
998 .dma_configure = vmbus_dma_configure,
999 .dev_groups = vmbus_dev_groups,
1000 .drv_groups = vmbus_drv_groups,
1001 .bus_groups = vmbus_bus_groups,
1002 .pm = &vmbus_pm,
1003};
1004
1005struct onmessage_work_context {
1006 struct work_struct work;
1007 struct {
1008 struct hv_message_header header;
1009 u8 payload[];
1010 } msg;
1011};
1012
1013static void vmbus_onmessage_work(struct work_struct *work)
1014{
1015 struct onmessage_work_context *ctx;
1016
1017 /* Do not process messages if we're in DISCONNECTED state */
1018 if (vmbus_connection.conn_state == DISCONNECTED)
1019 return;
1020
1021 ctx = container_of(work, struct onmessage_work_context,
1022 work);
1023 vmbus_onmessage((struct vmbus_channel_message_header *)
1024 &ctx->msg.payload);
1025 kfree(ctx);
1026}
1027
1028void vmbus_on_msg_dpc(unsigned long data)
1029{
1030 struct hv_per_cpu_context *hv_cpu = (void *)data;
1031 void *page_addr = hv_cpu->synic_message_page;
1032 struct hv_message msg_copy, *msg = (struct hv_message *)page_addr +
1033 VMBUS_MESSAGE_SINT;
1034 struct vmbus_channel_message_header *hdr;
1035 enum vmbus_channel_message_type msgtype;
1036 const struct vmbus_channel_message_table_entry *entry;
1037 struct onmessage_work_context *ctx;
1038 __u8 payload_size;
1039 u32 message_type;
1040
1041 /*
1042 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1043 * it is being used in 'struct vmbus_channel_message_header' definition
1044 * which is supposed to match hypervisor ABI.
1045 */
1046 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1047
1048 /*
1049 * Since the message is in memory shared with the host, an erroneous or
1050 * malicious Hyper-V could modify the message while vmbus_on_msg_dpc()
1051 * or individual message handlers are executing; to prevent this, copy
1052 * the message into private memory.
1053 */
1054 memcpy(&msg_copy, msg, sizeof(struct hv_message));
1055
1056 message_type = msg_copy.header.message_type;
1057 if (message_type == HVMSG_NONE)
1058 /* no msg */
1059 return;
1060
1061 hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload;
1062 msgtype = hdr->msgtype;
1063
1064 trace_vmbus_on_msg_dpc(hdr);
1065
1066 if (msgtype >= CHANNELMSG_COUNT) {
1067 WARN_ONCE(1, "unknown msgtype=%d\n", msgtype);
1068 goto msg_handled;
1069 }
1070
1071 payload_size = msg_copy.header.payload_size;
1072 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1073 WARN_ONCE(1, "payload size is too large (%d)\n", payload_size);
1074 goto msg_handled;
1075 }
1076
1077 entry = &channel_message_table[msgtype];
1078
1079 if (!entry->message_handler)
1080 goto msg_handled;
1081
1082 if (payload_size < entry->min_payload_len) {
1083 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size);
1084 goto msg_handled;
1085 }
1086
1087 if (entry->handler_type == VMHT_BLOCKING) {
1088 ctx = kmalloc(struct_size(ctx, msg.payload, payload_size), GFP_ATOMIC);
1089 if (ctx == NULL)
1090 return;
1091
1092 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1093 ctx->msg.header = msg_copy.header;
1094 memcpy(&ctx->msg.payload, msg_copy.u.payload, payload_size);
1095
1096 /*
1097 * The host can generate a rescind message while we
1098 * may still be handling the original offer. We deal with
1099 * this condition by relying on the synchronization provided
1100 * by offer_in_progress and by channel_mutex. See also the
1101 * inline comments in vmbus_onoffer_rescind().
1102 */
1103 switch (msgtype) {
1104 case CHANNELMSG_RESCIND_CHANNELOFFER:
1105 /*
1106 * If we are handling the rescind message;
1107 * schedule the work on the global work queue.
1108 *
1109 * The OFFER message and the RESCIND message should
1110 * not be handled by the same serialized work queue,
1111 * because the OFFER handler may call vmbus_open(),
1112 * which tries to open the channel by sending an
1113 * OPEN_CHANNEL message to the host and waits for
1114 * the host's response; however, if the host has
1115 * rescinded the channel before it receives the
1116 * OPEN_CHANNEL message, the host just silently
1117 * ignores the OPEN_CHANNEL message; as a result,
1118 * the guest's OFFER handler hangs for ever, if we
1119 * handle the RESCIND message in the same serialized
1120 * work queue: the RESCIND handler can not start to
1121 * run before the OFFER handler finishes.
1122 */
1123 if (vmbus_connection.ignore_any_offer_msg)
1124 break;
1125 queue_work(vmbus_connection.rescind_work_queue, &ctx->work);
1126 break;
1127
1128 case CHANNELMSG_OFFERCHANNEL:
1129 /*
1130 * The host sends the offer message of a given channel
1131 * before sending the rescind message of the same
1132 * channel. These messages are sent to the guest's
1133 * connect CPU; the guest then starts processing them
1134 * in the tasklet handler on this CPU:
1135 *
1136 * VMBUS_CONNECT_CPU
1137 *
1138 * [vmbus_on_msg_dpc()]
1139 * atomic_inc() // CHANNELMSG_OFFERCHANNEL
1140 * queue_work()
1141 * ...
1142 * [vmbus_on_msg_dpc()]
1143 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
1144 *
1145 * We rely on the memory-ordering properties of the
1146 * queue_work() and schedule_work() primitives, which
1147 * guarantee that the atomic increment will be visible
1148 * to the CPUs which will execute the offer & rescind
1149 * works by the time these works will start execution.
1150 */
1151 if (vmbus_connection.ignore_any_offer_msg)
1152 break;
1153 atomic_inc(&vmbus_connection.offer_in_progress);
1154 fallthrough;
1155
1156 default:
1157 queue_work(vmbus_connection.work_queue, &ctx->work);
1158 }
1159 } else
1160 entry->message_handler(hdr);
1161
1162msg_handled:
1163 vmbus_signal_eom(msg, message_type);
1164}
1165
1166#ifdef CONFIG_PM_SLEEP
1167/*
1168 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1169 * hibernation, because hv_sock connections can not persist across hibernation.
1170 */
1171static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1172{
1173 struct onmessage_work_context *ctx;
1174 struct vmbus_channel_rescind_offer *rescind;
1175
1176 WARN_ON(!is_hvsock_channel(channel));
1177
1178 /*
1179 * Allocation size is small and the allocation should really not fail,
1180 * otherwise the state of the hv_sock connections ends up in limbo.
1181 */
1182 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1183 GFP_KERNEL | __GFP_NOFAIL);
1184
1185 /*
1186 * So far, these are not really used by Linux. Just set them to the
1187 * reasonable values conforming to the definitions of the fields.
1188 */
1189 ctx->msg.header.message_type = 1;
1190 ctx->msg.header.payload_size = sizeof(*rescind);
1191
1192 /* These values are actually used by Linux. */
1193 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
1194 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1195 rescind->child_relid = channel->offermsg.child_relid;
1196
1197 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1198
1199 queue_work(vmbus_connection.work_queue, &ctx->work);
1200}
1201#endif /* CONFIG_PM_SLEEP */
1202
1203/*
1204 * Schedule all channels with events pending
1205 */
1206static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1207{
1208 unsigned long *recv_int_page;
1209 u32 maxbits, relid;
1210
1211 /*
1212 * The event page can be directly checked to get the id of
1213 * the channel that has the interrupt pending.
1214 */
1215 void *page_addr = hv_cpu->synic_event_page;
1216 union hv_synic_event_flags *event
1217 = (union hv_synic_event_flags *)page_addr +
1218 VMBUS_MESSAGE_SINT;
1219
1220 maxbits = HV_EVENT_FLAGS_COUNT;
1221 recv_int_page = event->flags;
1222
1223 if (unlikely(!recv_int_page))
1224 return;
1225
1226 for_each_set_bit(relid, recv_int_page, maxbits) {
1227 void (*callback_fn)(void *context);
1228 struct vmbus_channel *channel;
1229
1230 if (!sync_test_and_clear_bit(relid, recv_int_page))
1231 continue;
1232
1233 /* Special case - vmbus channel protocol msg */
1234 if (relid == 0)
1235 continue;
1236
1237 /*
1238 * Pairs with the kfree_rcu() in vmbus_chan_release().
1239 * Guarantees that the channel data structure doesn't
1240 * get freed while the channel pointer below is being
1241 * dereferenced.
1242 */
1243 rcu_read_lock();
1244
1245 /* Find channel based on relid */
1246 channel = relid2channel(relid);
1247 if (channel == NULL)
1248 goto sched_unlock_rcu;
1249
1250 if (channel->rescind)
1251 goto sched_unlock_rcu;
1252
1253 /*
1254 * Make sure that the ring buffer data structure doesn't get
1255 * freed while we dereference the ring buffer pointer. Test
1256 * for the channel's onchannel_callback being NULL within a
1257 * sched_lock critical section. See also the inline comments
1258 * in vmbus_reset_channel_cb().
1259 */
1260 spin_lock(&channel->sched_lock);
1261
1262 callback_fn = channel->onchannel_callback;
1263 if (unlikely(callback_fn == NULL))
1264 goto sched_unlock;
1265
1266 trace_vmbus_chan_sched(channel);
1267
1268 ++channel->interrupts;
1269
1270 switch (channel->callback_mode) {
1271 case HV_CALL_ISR:
1272 (*callback_fn)(channel->channel_callback_context);
1273 break;
1274
1275 case HV_CALL_BATCHED:
1276 hv_begin_read(&channel->inbound);
1277 fallthrough;
1278 case HV_CALL_DIRECT:
1279 tasklet_schedule(&channel->callback_event);
1280 }
1281
1282sched_unlock:
1283 spin_unlock(&channel->sched_lock);
1284sched_unlock_rcu:
1285 rcu_read_unlock();
1286 }
1287}
1288
1289static void vmbus_isr(void)
1290{
1291 struct hv_per_cpu_context *hv_cpu
1292 = this_cpu_ptr(hv_context.cpu_context);
1293 void *page_addr;
1294 struct hv_message *msg;
1295
1296 vmbus_chan_sched(hv_cpu);
1297
1298 page_addr = hv_cpu->synic_message_page;
1299 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1300
1301 /* Check if there are actual msgs to be processed */
1302 if (msg->header.message_type != HVMSG_NONE) {
1303 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1304 hv_stimer0_isr();
1305 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1306 } else
1307 tasklet_schedule(&hv_cpu->msg_dpc);
1308 }
1309
1310 add_interrupt_randomness(vmbus_interrupt);
1311}
1312
1313static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
1314{
1315 vmbus_isr();
1316 return IRQ_HANDLED;
1317}
1318
1319/*
1320 * vmbus_bus_init -Main vmbus driver initialization routine.
1321 *
1322 * Here, we
1323 * - initialize the vmbus driver context
1324 * - invoke the vmbus hv main init routine
1325 * - retrieve the channel offers
1326 */
1327static int vmbus_bus_init(void)
1328{
1329 int ret;
1330
1331 ret = hv_init();
1332 if (ret != 0) {
1333 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1334 return ret;
1335 }
1336
1337 ret = bus_register(&hv_bus);
1338 if (ret)
1339 return ret;
1340
1341 /*
1342 * VMbus interrupts are best modeled as per-cpu interrupts. If
1343 * on an architecture with support for per-cpu IRQs (e.g. ARM64),
1344 * allocate a per-cpu IRQ using standard Linux kernel functionality.
1345 * If not on such an architecture (e.g., x86/x64), then rely on
1346 * code in the arch-specific portion of the code tree to connect
1347 * the VMbus interrupt handler.
1348 */
1349
1350 if (vmbus_irq == -1) {
1351 hv_setup_vmbus_handler(vmbus_isr);
1352 } else {
1353 vmbus_evt = alloc_percpu(long);
1354 ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr,
1355 "Hyper-V VMbus", vmbus_evt);
1356 if (ret) {
1357 pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d",
1358 vmbus_irq, ret);
1359 free_percpu(vmbus_evt);
1360 goto err_setup;
1361 }
1362 }
1363
1364 ret = hv_synic_alloc();
1365 if (ret)
1366 goto err_alloc;
1367
1368 /*
1369 * Initialize the per-cpu interrupt state and stimer state.
1370 * Then connect to the host.
1371 */
1372 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1373 hv_synic_init, hv_synic_cleanup);
1374 if (ret < 0)
1375 goto err_alloc;
1376 hyperv_cpuhp_online = ret;
1377
1378 ret = vmbus_connect();
1379 if (ret)
1380 goto err_connect;
1381
1382 /*
1383 * Always register the vmbus unload panic notifier because we
1384 * need to shut the VMbus channel connection on panic.
1385 */
1386 atomic_notifier_chain_register(&panic_notifier_list,
1387 &hyperv_panic_vmbus_unload_block);
1388
1389 vmbus_request_offers();
1390
1391 return 0;
1392
1393err_connect:
1394 cpuhp_remove_state(hyperv_cpuhp_online);
1395err_alloc:
1396 hv_synic_free();
1397 if (vmbus_irq == -1) {
1398 hv_remove_vmbus_handler();
1399 } else {
1400 free_percpu_irq(vmbus_irq, vmbus_evt);
1401 free_percpu(vmbus_evt);
1402 }
1403err_setup:
1404 bus_unregister(&hv_bus);
1405 return ret;
1406}
1407
1408/**
1409 * __vmbus_driver_register() - Register a vmbus's driver
1410 * @hv_driver: Pointer to driver structure you want to register
1411 * @owner: owner module of the drv
1412 * @mod_name: module name string
1413 *
1414 * Registers the given driver with Linux through the 'driver_register()' call
1415 * and sets up the hyper-v vmbus handling for this driver.
1416 * It will return the state of the 'driver_register()' call.
1417 *
1418 */
1419int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1420{
1421 int ret;
1422
1423 pr_info("registering driver %s\n", hv_driver->name);
1424
1425 ret = vmbus_exists();
1426 if (ret < 0)
1427 return ret;
1428
1429 hv_driver->driver.name = hv_driver->name;
1430 hv_driver->driver.owner = owner;
1431 hv_driver->driver.mod_name = mod_name;
1432 hv_driver->driver.bus = &hv_bus;
1433
1434 spin_lock_init(&hv_driver->dynids.lock);
1435 INIT_LIST_HEAD(&hv_driver->dynids.list);
1436
1437 ret = driver_register(&hv_driver->driver);
1438
1439 return ret;
1440}
1441EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1442
1443/**
1444 * vmbus_driver_unregister() - Unregister a vmbus's driver
1445 * @hv_driver: Pointer to driver structure you want to
1446 * un-register
1447 *
1448 * Un-register the given driver that was previous registered with a call to
1449 * vmbus_driver_register()
1450 */
1451void vmbus_driver_unregister(struct hv_driver *hv_driver)
1452{
1453 pr_info("unregistering driver %s\n", hv_driver->name);
1454
1455 if (!vmbus_exists()) {
1456 driver_unregister(&hv_driver->driver);
1457 vmbus_free_dynids(hv_driver);
1458 }
1459}
1460EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1461
1462
1463/*
1464 * Called when last reference to channel is gone.
1465 */
1466static void vmbus_chan_release(struct kobject *kobj)
1467{
1468 struct vmbus_channel *channel
1469 = container_of(kobj, struct vmbus_channel, kobj);
1470
1471 kfree_rcu(channel, rcu);
1472}
1473
1474struct vmbus_chan_attribute {
1475 struct attribute attr;
1476 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1477 ssize_t (*store)(struct vmbus_channel *chan,
1478 const char *buf, size_t count);
1479};
1480#define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1481 struct vmbus_chan_attribute chan_attr_##_name \
1482 = __ATTR(_name, _mode, _show, _store)
1483#define VMBUS_CHAN_ATTR_RW(_name) \
1484 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1485#define VMBUS_CHAN_ATTR_RO(_name) \
1486 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1487#define VMBUS_CHAN_ATTR_WO(_name) \
1488 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1489
1490static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1491 struct attribute *attr, char *buf)
1492{
1493 const struct vmbus_chan_attribute *attribute
1494 = container_of(attr, struct vmbus_chan_attribute, attr);
1495 struct vmbus_channel *chan
1496 = container_of(kobj, struct vmbus_channel, kobj);
1497
1498 if (!attribute->show)
1499 return -EIO;
1500
1501 return attribute->show(chan, buf);
1502}
1503
1504static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1505 struct attribute *attr, const char *buf,
1506 size_t count)
1507{
1508 const struct vmbus_chan_attribute *attribute
1509 = container_of(attr, struct vmbus_chan_attribute, attr);
1510 struct vmbus_channel *chan
1511 = container_of(kobj, struct vmbus_channel, kobj);
1512
1513 if (!attribute->store)
1514 return -EIO;
1515
1516 return attribute->store(chan, buf, count);
1517}
1518
1519static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1520 .show = vmbus_chan_attr_show,
1521 .store = vmbus_chan_attr_store,
1522};
1523
1524static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1525{
1526 struct hv_ring_buffer_info *rbi = &channel->outbound;
1527 ssize_t ret;
1528
1529 mutex_lock(&rbi->ring_buffer_mutex);
1530 if (!rbi->ring_buffer) {
1531 mutex_unlock(&rbi->ring_buffer_mutex);
1532 return -EINVAL;
1533 }
1534
1535 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1536 mutex_unlock(&rbi->ring_buffer_mutex);
1537 return ret;
1538}
1539static VMBUS_CHAN_ATTR_RO(out_mask);
1540
1541static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1542{
1543 struct hv_ring_buffer_info *rbi = &channel->inbound;
1544 ssize_t ret;
1545
1546 mutex_lock(&rbi->ring_buffer_mutex);
1547 if (!rbi->ring_buffer) {
1548 mutex_unlock(&rbi->ring_buffer_mutex);
1549 return -EINVAL;
1550 }
1551
1552 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1553 mutex_unlock(&rbi->ring_buffer_mutex);
1554 return ret;
1555}
1556static VMBUS_CHAN_ATTR_RO(in_mask);
1557
1558static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1559{
1560 struct hv_ring_buffer_info *rbi = &channel->inbound;
1561 ssize_t ret;
1562
1563 mutex_lock(&rbi->ring_buffer_mutex);
1564 if (!rbi->ring_buffer) {
1565 mutex_unlock(&rbi->ring_buffer_mutex);
1566 return -EINVAL;
1567 }
1568
1569 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1570 mutex_unlock(&rbi->ring_buffer_mutex);
1571 return ret;
1572}
1573static VMBUS_CHAN_ATTR_RO(read_avail);
1574
1575static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1576{
1577 struct hv_ring_buffer_info *rbi = &channel->outbound;
1578 ssize_t ret;
1579
1580 mutex_lock(&rbi->ring_buffer_mutex);
1581 if (!rbi->ring_buffer) {
1582 mutex_unlock(&rbi->ring_buffer_mutex);
1583 return -EINVAL;
1584 }
1585
1586 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1587 mutex_unlock(&rbi->ring_buffer_mutex);
1588 return ret;
1589}
1590static VMBUS_CHAN_ATTR_RO(write_avail);
1591
1592static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1593{
1594 return sprintf(buf, "%u\n", channel->target_cpu);
1595}
1596static ssize_t target_cpu_store(struct vmbus_channel *channel,
1597 const char *buf, size_t count)
1598{
1599 u32 target_cpu, origin_cpu;
1600 ssize_t ret = count;
1601
1602 if (vmbus_proto_version < VERSION_WIN10_V4_1)
1603 return -EIO;
1604
1605 if (sscanf(buf, "%uu", &target_cpu) != 1)
1606 return -EIO;
1607
1608 /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1609 if (target_cpu >= nr_cpumask_bits)
1610 return -EINVAL;
1611
1612 if (!cpumask_test_cpu(target_cpu, housekeeping_cpumask(HK_TYPE_MANAGED_IRQ)))
1613 return -EINVAL;
1614
1615 /* No CPUs should come up or down during this. */
1616 cpus_read_lock();
1617
1618 if (!cpu_online(target_cpu)) {
1619 cpus_read_unlock();
1620 return -EINVAL;
1621 }
1622
1623 /*
1624 * Synchronizes target_cpu_store() and channel closure:
1625 *
1626 * { Initially: state = CHANNEL_OPENED }
1627 *
1628 * CPU1 CPU2
1629 *
1630 * [target_cpu_store()] [vmbus_disconnect_ring()]
1631 *
1632 * LOCK channel_mutex LOCK channel_mutex
1633 * LOAD r1 = state LOAD r2 = state
1634 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
1635 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
1636 * [...] SEND CLOSECHANNEL
1637 * UNLOCK channel_mutex UNLOCK channel_mutex
1638 *
1639 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1640 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1641 *
1642 * Note. The host processes the channel messages "sequentially", in
1643 * the order in which they are received on a per-partition basis.
1644 */
1645 mutex_lock(&vmbus_connection.channel_mutex);
1646
1647 /*
1648 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1649 * avoid sending the message and fail here for such channels.
1650 */
1651 if (channel->state != CHANNEL_OPENED_STATE) {
1652 ret = -EIO;
1653 goto cpu_store_unlock;
1654 }
1655
1656 origin_cpu = channel->target_cpu;
1657 if (target_cpu == origin_cpu)
1658 goto cpu_store_unlock;
1659
1660 if (vmbus_send_modifychannel(channel,
1661 hv_cpu_number_to_vp_number(target_cpu))) {
1662 ret = -EIO;
1663 goto cpu_store_unlock;
1664 }
1665
1666 /*
1667 * For version before VERSION_WIN10_V5_3, the following warning holds:
1668 *
1669 * Warning. At this point, there is *no* guarantee that the host will
1670 * have successfully processed the vmbus_send_modifychannel() request.
1671 * See the header comment of vmbus_send_modifychannel() for more info.
1672 *
1673 * Lags in the processing of the above vmbus_send_modifychannel() can
1674 * result in missed interrupts if the "old" target CPU is taken offline
1675 * before Hyper-V starts sending interrupts to the "new" target CPU.
1676 * But apart from this offlining scenario, the code tolerates such
1677 * lags. It will function correctly even if a channel interrupt comes
1678 * in on a CPU that is different from the channel target_cpu value.
1679 */
1680
1681 channel->target_cpu = target_cpu;
1682
1683 /* See init_vp_index(). */
1684 if (hv_is_perf_channel(channel))
1685 hv_update_allocated_cpus(origin_cpu, target_cpu);
1686
1687 /* Currently set only for storvsc channels. */
1688 if (channel->change_target_cpu_callback) {
1689 (*channel->change_target_cpu_callback)(channel,
1690 origin_cpu, target_cpu);
1691 }
1692
1693cpu_store_unlock:
1694 mutex_unlock(&vmbus_connection.channel_mutex);
1695 cpus_read_unlock();
1696 return ret;
1697}
1698static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1699
1700static ssize_t channel_pending_show(struct vmbus_channel *channel,
1701 char *buf)
1702{
1703 return sprintf(buf, "%d\n",
1704 channel_pending(channel,
1705 vmbus_connection.monitor_pages[1]));
1706}
1707static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL);
1708
1709static ssize_t channel_latency_show(struct vmbus_channel *channel,
1710 char *buf)
1711{
1712 return sprintf(buf, "%d\n",
1713 channel_latency(channel,
1714 vmbus_connection.monitor_pages[1]));
1715}
1716static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL);
1717
1718static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1719{
1720 return sprintf(buf, "%llu\n", channel->interrupts);
1721}
1722static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL);
1723
1724static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1725{
1726 return sprintf(buf, "%llu\n", channel->sig_events);
1727}
1728static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL);
1729
1730static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1731 char *buf)
1732{
1733 return sprintf(buf, "%llu\n",
1734 (unsigned long long)channel->intr_in_full);
1735}
1736static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1737
1738static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1739 char *buf)
1740{
1741 return sprintf(buf, "%llu\n",
1742 (unsigned long long)channel->intr_out_empty);
1743}
1744static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1745
1746static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1747 char *buf)
1748{
1749 return sprintf(buf, "%llu\n",
1750 (unsigned long long)channel->out_full_first);
1751}
1752static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1753
1754static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1755 char *buf)
1756{
1757 return sprintf(buf, "%llu\n",
1758 (unsigned long long)channel->out_full_total);
1759}
1760static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1761
1762static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1763 char *buf)
1764{
1765 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1766}
1767static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL);
1768
1769static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1770 char *buf)
1771{
1772 return sprintf(buf, "%u\n",
1773 channel->offermsg.offer.sub_channel_index);
1774}
1775static VMBUS_CHAN_ATTR_RO(subchannel_id);
1776
1777static struct attribute *vmbus_chan_attrs[] = {
1778 &chan_attr_out_mask.attr,
1779 &chan_attr_in_mask.attr,
1780 &chan_attr_read_avail.attr,
1781 &chan_attr_write_avail.attr,
1782 &chan_attr_cpu.attr,
1783 &chan_attr_pending.attr,
1784 &chan_attr_latency.attr,
1785 &chan_attr_interrupts.attr,
1786 &chan_attr_events.attr,
1787 &chan_attr_intr_in_full.attr,
1788 &chan_attr_intr_out_empty.attr,
1789 &chan_attr_out_full_first.attr,
1790 &chan_attr_out_full_total.attr,
1791 &chan_attr_monitor_id.attr,
1792 &chan_attr_subchannel_id.attr,
1793 NULL
1794};
1795
1796/*
1797 * Channel-level attribute_group callback function. Returns the permission for
1798 * each attribute, and returns 0 if an attribute is not visible.
1799 */
1800static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1801 struct attribute *attr, int idx)
1802{
1803 const struct vmbus_channel *channel =
1804 container_of(kobj, struct vmbus_channel, kobj);
1805
1806 /* Hide the monitor attributes if the monitor mechanism is not used. */
1807 if (!channel->offermsg.monitor_allocated &&
1808 (attr == &chan_attr_pending.attr ||
1809 attr == &chan_attr_latency.attr ||
1810 attr == &chan_attr_monitor_id.attr))
1811 return 0;
1812
1813 return attr->mode;
1814}
1815
1816static struct attribute_group vmbus_chan_group = {
1817 .attrs = vmbus_chan_attrs,
1818 .is_visible = vmbus_chan_attr_is_visible
1819};
1820
1821static struct kobj_type vmbus_chan_ktype = {
1822 .sysfs_ops = &vmbus_chan_sysfs_ops,
1823 .release = vmbus_chan_release,
1824};
1825
1826/*
1827 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1828 */
1829int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1830{
1831 const struct device *device = &dev->device;
1832 struct kobject *kobj = &channel->kobj;
1833 u32 relid = channel->offermsg.child_relid;
1834 int ret;
1835
1836 kobj->kset = dev->channels_kset;
1837 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1838 "%u", relid);
1839 if (ret) {
1840 kobject_put(kobj);
1841 return ret;
1842 }
1843
1844 ret = sysfs_create_group(kobj, &vmbus_chan_group);
1845
1846 if (ret) {
1847 /*
1848 * The calling functions' error handling paths will cleanup the
1849 * empty channel directory.
1850 */
1851 kobject_put(kobj);
1852 dev_err(device, "Unable to set up channel sysfs files\n");
1853 return ret;
1854 }
1855
1856 kobject_uevent(kobj, KOBJ_ADD);
1857
1858 return 0;
1859}
1860
1861/*
1862 * vmbus_remove_channel_attr_group - remove the channel's attribute group
1863 */
1864void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1865{
1866 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1867}
1868
1869/*
1870 * vmbus_device_create - Creates and registers a new child device
1871 * on the vmbus.
1872 */
1873struct hv_device *vmbus_device_create(const guid_t *type,
1874 const guid_t *instance,
1875 struct vmbus_channel *channel)
1876{
1877 struct hv_device *child_device_obj;
1878
1879 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1880 if (!child_device_obj) {
1881 pr_err("Unable to allocate device object for child device\n");
1882 return NULL;
1883 }
1884
1885 child_device_obj->channel = channel;
1886 guid_copy(&child_device_obj->dev_type, type);
1887 guid_copy(&child_device_obj->dev_instance, instance);
1888 child_device_obj->vendor_id = PCI_VENDOR_ID_MICROSOFT;
1889
1890 return child_device_obj;
1891}
1892
1893/*
1894 * vmbus_device_register - Register the child device
1895 */
1896int vmbus_device_register(struct hv_device *child_device_obj)
1897{
1898 struct kobject *kobj = &child_device_obj->device.kobj;
1899 int ret;
1900
1901 dev_set_name(&child_device_obj->device, "%pUl",
1902 &child_device_obj->channel->offermsg.offer.if_instance);
1903
1904 child_device_obj->device.bus = &hv_bus;
1905 child_device_obj->device.parent = hv_dev;
1906 child_device_obj->device.release = vmbus_device_release;
1907
1908 child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
1909 child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
1910 dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
1911
1912 /*
1913 * Register with the LDM. This will kick off the driver/device
1914 * binding...which will eventually call vmbus_match() and vmbus_probe()
1915 */
1916 ret = device_register(&child_device_obj->device);
1917 if (ret) {
1918 pr_err("Unable to register child device\n");
1919 put_device(&child_device_obj->device);
1920 return ret;
1921 }
1922
1923 child_device_obj->channels_kset = kset_create_and_add("channels",
1924 NULL, kobj);
1925 if (!child_device_obj->channels_kset) {
1926 ret = -ENOMEM;
1927 goto err_dev_unregister;
1928 }
1929
1930 ret = vmbus_add_channel_kobj(child_device_obj,
1931 child_device_obj->channel);
1932 if (ret) {
1933 pr_err("Unable to register primary channeln");
1934 goto err_kset_unregister;
1935 }
1936 hv_debug_add_dev_dir(child_device_obj);
1937
1938 return 0;
1939
1940err_kset_unregister:
1941 kset_unregister(child_device_obj->channels_kset);
1942
1943err_dev_unregister:
1944 device_unregister(&child_device_obj->device);
1945 return ret;
1946}
1947
1948/*
1949 * vmbus_device_unregister - Remove the specified child device
1950 * from the vmbus.
1951 */
1952void vmbus_device_unregister(struct hv_device *device_obj)
1953{
1954 pr_debug("child device %s unregistered\n",
1955 dev_name(&device_obj->device));
1956
1957 kset_unregister(device_obj->channels_kset);
1958
1959 /*
1960 * Kick off the process of unregistering the device.
1961 * This will call vmbus_remove() and eventually vmbus_device_release()
1962 */
1963 device_unregister(&device_obj->device);
1964}
1965
1966#ifdef CONFIG_ACPI
1967/*
1968 * VMBUS is an acpi enumerated device. Get the information we
1969 * need from DSDT.
1970 */
1971static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1972{
1973 resource_size_t start = 0;
1974 resource_size_t end = 0;
1975 struct resource *new_res;
1976 struct resource **old_res = &hyperv_mmio;
1977 struct resource **prev_res = NULL;
1978 struct resource r;
1979
1980 switch (res->type) {
1981
1982 /*
1983 * "Address" descriptors are for bus windows. Ignore
1984 * "memory" descriptors, which are for registers on
1985 * devices.
1986 */
1987 case ACPI_RESOURCE_TYPE_ADDRESS32:
1988 start = res->data.address32.address.minimum;
1989 end = res->data.address32.address.maximum;
1990 break;
1991
1992 case ACPI_RESOURCE_TYPE_ADDRESS64:
1993 start = res->data.address64.address.minimum;
1994 end = res->data.address64.address.maximum;
1995 break;
1996
1997 /*
1998 * The IRQ information is needed only on ARM64, which Hyper-V
1999 * sets up in the extended format. IRQ information is present
2000 * on x86/x64 in the non-extended format but it is not used by
2001 * Linux. So don't bother checking for the non-extended format.
2002 */
2003 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
2004 if (!acpi_dev_resource_interrupt(res, 0, &r)) {
2005 pr_err("Unable to parse Hyper-V ACPI interrupt\n");
2006 return AE_ERROR;
2007 }
2008 /* ARM64 INTID for VMbus */
2009 vmbus_interrupt = res->data.extended_irq.interrupts[0];
2010 /* Linux IRQ number */
2011 vmbus_irq = r.start;
2012 return AE_OK;
2013
2014 default:
2015 /* Unused resource type */
2016 return AE_OK;
2017
2018 }
2019 /*
2020 * Ignore ranges that are below 1MB, as they're not
2021 * necessary or useful here.
2022 */
2023 if (end < 0x100000)
2024 return AE_OK;
2025
2026 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2027 if (!new_res)
2028 return AE_NO_MEMORY;
2029
2030 /* If this range overlaps the virtual TPM, truncate it. */
2031 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2032 end = VTPM_BASE_ADDRESS;
2033
2034 new_res->name = "hyperv mmio";
2035 new_res->flags = IORESOURCE_MEM;
2036 new_res->start = start;
2037 new_res->end = end;
2038
2039 /*
2040 * If two ranges are adjacent, merge them.
2041 */
2042 do {
2043 if (!*old_res) {
2044 *old_res = new_res;
2045 break;
2046 }
2047
2048 if (((*old_res)->end + 1) == new_res->start) {
2049 (*old_res)->end = new_res->end;
2050 kfree(new_res);
2051 break;
2052 }
2053
2054 if ((*old_res)->start == new_res->end + 1) {
2055 (*old_res)->start = new_res->start;
2056 kfree(new_res);
2057 break;
2058 }
2059
2060 if ((*old_res)->start > new_res->end) {
2061 new_res->sibling = *old_res;
2062 if (prev_res)
2063 (*prev_res)->sibling = new_res;
2064 *old_res = new_res;
2065 break;
2066 }
2067
2068 prev_res = old_res;
2069 old_res = &(*old_res)->sibling;
2070
2071 } while (1);
2072
2073 return AE_OK;
2074}
2075#endif
2076
2077static void vmbus_mmio_remove(void)
2078{
2079 struct resource *cur_res;
2080 struct resource *next_res;
2081
2082 if (hyperv_mmio) {
2083 if (fb_mmio) {
2084 __release_region(hyperv_mmio, fb_mmio->start,
2085 resource_size(fb_mmio));
2086 fb_mmio = NULL;
2087 }
2088
2089 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2090 next_res = cur_res->sibling;
2091 kfree(cur_res);
2092 }
2093 }
2094}
2095
2096static void __maybe_unused vmbus_reserve_fb(void)
2097{
2098 resource_size_t start = 0, size;
2099 struct pci_dev *pdev;
2100
2101 if (efi_enabled(EFI_BOOT)) {
2102 /* Gen2 VM: get FB base from EFI framebuffer */
2103 if (IS_ENABLED(CONFIG_SYSFB)) {
2104 start = screen_info.lfb_base;
2105 size = max_t(__u32, screen_info.lfb_size, 0x800000);
2106 }
2107 } else {
2108 /* Gen1 VM: get FB base from PCI */
2109 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
2110 PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
2111 if (!pdev)
2112 return;
2113
2114 if (pdev->resource[0].flags & IORESOURCE_MEM) {
2115 start = pci_resource_start(pdev, 0);
2116 size = pci_resource_len(pdev, 0);
2117 }
2118
2119 /*
2120 * Release the PCI device so hyperv_drm or hyperv_fb driver can
2121 * grab it later.
2122 */
2123 pci_dev_put(pdev);
2124 }
2125
2126 if (!start)
2127 return;
2128
2129 /*
2130 * Make a claim for the frame buffer in the resource tree under the
2131 * first node, which will be the one below 4GB. The length seems to
2132 * be underreported, particularly in a Generation 1 VM. So start out
2133 * reserving a larger area and make it smaller until it succeeds.
2134 */
2135 for (; !fb_mmio && (size >= 0x100000); size >>= 1)
2136 fb_mmio = __request_region(hyperv_mmio, start, size, fb_mmio_name, 0);
2137}
2138
2139/**
2140 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2141 * @new: If successful, supplied a pointer to the
2142 * allocated MMIO space.
2143 * @device_obj: Identifies the caller
2144 * @min: Minimum guest physical address of the
2145 * allocation
2146 * @max: Maximum guest physical address
2147 * @size: Size of the range to be allocated
2148 * @align: Alignment of the range to be allocated
2149 * @fb_overlap_ok: Whether this allocation can be allowed
2150 * to overlap the video frame buffer.
2151 *
2152 * This function walks the resources granted to VMBus by the
2153 * _CRS object in the ACPI namespace underneath the parent
2154 * "bridge" whether that's a root PCI bus in the Generation 1
2155 * case or a Module Device in the Generation 2 case. It then
2156 * attempts to allocate from the global MMIO pool in a way that
2157 * matches the constraints supplied in these parameters and by
2158 * that _CRS.
2159 *
2160 * Return: 0 on success, -errno on failure
2161 */
2162int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2163 resource_size_t min, resource_size_t max,
2164 resource_size_t size, resource_size_t align,
2165 bool fb_overlap_ok)
2166{
2167 struct resource *iter, *shadow;
2168 resource_size_t range_min, range_max, start, end;
2169 const char *dev_n = dev_name(&device_obj->device);
2170 int retval;
2171
2172 retval = -ENXIO;
2173 mutex_lock(&hyperv_mmio_lock);
2174
2175 /*
2176 * If overlaps with frame buffers are allowed, then first attempt to
2177 * make the allocation from within the reserved region. Because it
2178 * is already reserved, no shadow allocation is necessary.
2179 */
2180 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2181 !(max < fb_mmio->start)) {
2182
2183 range_min = fb_mmio->start;
2184 range_max = fb_mmio->end;
2185 start = (range_min + align - 1) & ~(align - 1);
2186 for (; start + size - 1 <= range_max; start += align) {
2187 *new = request_mem_region_exclusive(start, size, dev_n);
2188 if (*new) {
2189 retval = 0;
2190 goto exit;
2191 }
2192 }
2193 }
2194
2195 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2196 if ((iter->start >= max) || (iter->end <= min))
2197 continue;
2198
2199 range_min = iter->start;
2200 range_max = iter->end;
2201 start = (range_min + align - 1) & ~(align - 1);
2202 for (; start + size - 1 <= range_max; start += align) {
2203 end = start + size - 1;
2204
2205 /* Skip the whole fb_mmio region if not fb_overlap_ok */
2206 if (!fb_overlap_ok && fb_mmio &&
2207 (((start >= fb_mmio->start) && (start <= fb_mmio->end)) ||
2208 ((end >= fb_mmio->start) && (end <= fb_mmio->end))))
2209 continue;
2210
2211 shadow = __request_region(iter, start, size, NULL,
2212 IORESOURCE_BUSY);
2213 if (!shadow)
2214 continue;
2215
2216 *new = request_mem_region_exclusive(start, size, dev_n);
2217 if (*new) {
2218 shadow->name = (char *)*new;
2219 retval = 0;
2220 goto exit;
2221 }
2222
2223 __release_region(iter, start, size);
2224 }
2225 }
2226
2227exit:
2228 mutex_unlock(&hyperv_mmio_lock);
2229 return retval;
2230}
2231EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2232
2233/**
2234 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2235 * @start: Base address of region to release.
2236 * @size: Size of the range to be allocated
2237 *
2238 * This function releases anything requested by
2239 * vmbus_mmio_allocate().
2240 */
2241void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2242{
2243 struct resource *iter;
2244
2245 mutex_lock(&hyperv_mmio_lock);
2246 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2247 if ((iter->start >= start + size) || (iter->end <= start))
2248 continue;
2249
2250 __release_region(iter, start, size);
2251 }
2252 release_mem_region(start, size);
2253 mutex_unlock(&hyperv_mmio_lock);
2254
2255}
2256EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2257
2258#ifdef CONFIG_ACPI
2259static int vmbus_acpi_add(struct platform_device *pdev)
2260{
2261 acpi_status result;
2262 int ret_val = -ENODEV;
2263 struct acpi_device *ancestor;
2264 struct acpi_device *device = ACPI_COMPANION(&pdev->dev);
2265
2266 hv_dev = &device->dev;
2267
2268 /*
2269 * Older versions of Hyper-V for ARM64 fail to include the _CCA
2270 * method on the top level VMbus device in the DSDT. But devices
2271 * are hardware coherent in all current Hyper-V use cases, so fix
2272 * up the ACPI device to behave as if _CCA is present and indicates
2273 * hardware coherence.
2274 */
2275 ACPI_COMPANION_SET(&device->dev, device);
2276 if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) &&
2277 device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) {
2278 pr_info("No ACPI _CCA found; assuming coherent device I/O\n");
2279 device->flags.cca_seen = true;
2280 device->flags.coherent_dma = true;
2281 }
2282
2283 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2284 vmbus_walk_resources, NULL);
2285
2286 if (ACPI_FAILURE(result))
2287 goto acpi_walk_err;
2288 /*
2289 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2290 * firmware) is the VMOD that has the mmio ranges. Get that.
2291 */
2292 for (ancestor = acpi_dev_parent(device);
2293 ancestor && ancestor->handle != ACPI_ROOT_OBJECT;
2294 ancestor = acpi_dev_parent(ancestor)) {
2295 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2296 vmbus_walk_resources, NULL);
2297
2298 if (ACPI_FAILURE(result))
2299 continue;
2300 if (hyperv_mmio) {
2301 vmbus_reserve_fb();
2302 break;
2303 }
2304 }
2305 ret_val = 0;
2306
2307acpi_walk_err:
2308 if (ret_val)
2309 vmbus_mmio_remove();
2310 return ret_val;
2311}
2312#else
2313static int vmbus_acpi_add(struct platform_device *pdev)
2314{
2315 return 0;
2316}
2317#endif
2318
2319static int vmbus_device_add(struct platform_device *pdev)
2320{
2321 struct resource **cur_res = &hyperv_mmio;
2322 struct of_range range;
2323 struct of_range_parser parser;
2324 struct device_node *np = pdev->dev.of_node;
2325 int ret;
2326
2327 hv_dev = &pdev->dev;
2328
2329 ret = of_range_parser_init(&parser, np);
2330 if (ret)
2331 return ret;
2332
2333 for_each_of_range(&parser, &range) {
2334 struct resource *res;
2335
2336 res = kzalloc(sizeof(*res), GFP_KERNEL);
2337 if (!res) {
2338 vmbus_mmio_remove();
2339 return -ENOMEM;
2340 }
2341
2342 res->name = "hyperv mmio";
2343 res->flags = range.flags;
2344 res->start = range.cpu_addr;
2345 res->end = range.cpu_addr + range.size;
2346
2347 *cur_res = res;
2348 cur_res = &res->sibling;
2349 }
2350
2351 return ret;
2352}
2353
2354static int vmbus_platform_driver_probe(struct platform_device *pdev)
2355{
2356 if (acpi_disabled)
2357 return vmbus_device_add(pdev);
2358 else
2359 return vmbus_acpi_add(pdev);
2360}
2361
2362static int vmbus_platform_driver_remove(struct platform_device *pdev)
2363{
2364 vmbus_mmio_remove();
2365 return 0;
2366}
2367
2368#ifdef CONFIG_PM_SLEEP
2369static int vmbus_bus_suspend(struct device *dev)
2370{
2371 struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(
2372 hv_context.cpu_context, VMBUS_CONNECT_CPU);
2373 struct vmbus_channel *channel, *sc;
2374
2375 tasklet_disable(&hv_cpu->msg_dpc);
2376 vmbus_connection.ignore_any_offer_msg = true;
2377 /* The tasklet_enable() takes care of providing a memory barrier */
2378 tasklet_enable(&hv_cpu->msg_dpc);
2379
2380 /* Drain all the workqueues as we are in suspend */
2381 drain_workqueue(vmbus_connection.rescind_work_queue);
2382 drain_workqueue(vmbus_connection.work_queue);
2383 drain_workqueue(vmbus_connection.handle_primary_chan_wq);
2384 drain_workqueue(vmbus_connection.handle_sub_chan_wq);
2385
2386 mutex_lock(&vmbus_connection.channel_mutex);
2387 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2388 if (!is_hvsock_channel(channel))
2389 continue;
2390
2391 vmbus_force_channel_rescinded(channel);
2392 }
2393 mutex_unlock(&vmbus_connection.channel_mutex);
2394
2395 /*
2396 * Wait until all the sub-channels and hv_sock channels have been
2397 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2398 * they would conflict with the new sub-channels that will be created
2399 * in the resume path. hv_sock channels should also be destroyed, but
2400 * a hv_sock channel of an established hv_sock connection can not be
2401 * really destroyed since it may still be referenced by the userspace
2402 * application, so we just force the hv_sock channel to be rescinded
2403 * by vmbus_force_channel_rescinded(), and the userspace application
2404 * will thoroughly destroy the channel after hibernation.
2405 *
2406 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2407 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2408 */
2409 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2410 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2411
2412 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
2413 pr_err("Can not suspend due to a previous failed resuming\n");
2414 return -EBUSY;
2415 }
2416
2417 mutex_lock(&vmbus_connection.channel_mutex);
2418
2419 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2420 /*
2421 * Remove the channel from the array of channels and invalidate
2422 * the channel's relid. Upon resume, vmbus_onoffer() will fix
2423 * up the relid (and other fields, if necessary) and add the
2424 * channel back to the array.
2425 */
2426 vmbus_channel_unmap_relid(channel);
2427 channel->offermsg.child_relid = INVALID_RELID;
2428
2429 if (is_hvsock_channel(channel)) {
2430 if (!channel->rescind) {
2431 pr_err("hv_sock channel not rescinded!\n");
2432 WARN_ON_ONCE(1);
2433 }
2434 continue;
2435 }
2436
2437 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2438 pr_err("Sub-channel not deleted!\n");
2439 WARN_ON_ONCE(1);
2440 }
2441
2442 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2443 }
2444
2445 mutex_unlock(&vmbus_connection.channel_mutex);
2446
2447 vmbus_initiate_unload(false);
2448
2449 /* Reset the event for the next resume. */
2450 reinit_completion(&vmbus_connection.ready_for_resume_event);
2451
2452 return 0;
2453}
2454
2455static int vmbus_bus_resume(struct device *dev)
2456{
2457 struct vmbus_channel_msginfo *msginfo;
2458 size_t msgsize;
2459 int ret;
2460
2461 vmbus_connection.ignore_any_offer_msg = false;
2462
2463 /*
2464 * We only use the 'vmbus_proto_version', which was in use before
2465 * hibernation, to re-negotiate with the host.
2466 */
2467 if (!vmbus_proto_version) {
2468 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2469 return -EINVAL;
2470 }
2471
2472 msgsize = sizeof(*msginfo) +
2473 sizeof(struct vmbus_channel_initiate_contact);
2474
2475 msginfo = kzalloc(msgsize, GFP_KERNEL);
2476
2477 if (msginfo == NULL)
2478 return -ENOMEM;
2479
2480 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2481
2482 kfree(msginfo);
2483
2484 if (ret != 0)
2485 return ret;
2486
2487 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2488
2489 vmbus_request_offers();
2490
2491 if (wait_for_completion_timeout(
2492 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0)
2493 pr_err("Some vmbus device is missing after suspending?\n");
2494
2495 /* Reset the event for the next suspend. */
2496 reinit_completion(&vmbus_connection.ready_for_suspend_event);
2497
2498 return 0;
2499}
2500#else
2501#define vmbus_bus_suspend NULL
2502#define vmbus_bus_resume NULL
2503#endif /* CONFIG_PM_SLEEP */
2504
2505static const __maybe_unused struct of_device_id vmbus_of_match[] = {
2506 {
2507 .compatible = "microsoft,vmbus",
2508 },
2509 {
2510 /* sentinel */
2511 },
2512};
2513MODULE_DEVICE_TABLE(of, vmbus_of_match);
2514
2515static const __maybe_unused struct acpi_device_id vmbus_acpi_device_ids[] = {
2516 {"VMBUS", 0},
2517 {"VMBus", 0},
2518 {"", 0},
2519};
2520MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2521
2522/*
2523 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2524 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2525 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2526 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2527 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2528 * resume callback must also run via the "noirq" ops.
2529 *
2530 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2531 * earlier in this file before vmbus_pm.
2532 */
2533
2534static const struct dev_pm_ops vmbus_bus_pm = {
2535 .suspend_noirq = NULL,
2536 .resume_noirq = NULL,
2537 .freeze_noirq = vmbus_bus_suspend,
2538 .thaw_noirq = vmbus_bus_resume,
2539 .poweroff_noirq = vmbus_bus_suspend,
2540 .restore_noirq = vmbus_bus_resume
2541};
2542
2543static struct platform_driver vmbus_platform_driver = {
2544 .probe = vmbus_platform_driver_probe,
2545 .remove = vmbus_platform_driver_remove,
2546 .driver = {
2547 .name = "vmbus",
2548 .acpi_match_table = ACPI_PTR(vmbus_acpi_device_ids),
2549 .of_match_table = of_match_ptr(vmbus_of_match),
2550 .pm = &vmbus_bus_pm,
2551 .probe_type = PROBE_FORCE_SYNCHRONOUS,
2552 }
2553};
2554
2555static void hv_kexec_handler(void)
2556{
2557 hv_stimer_global_cleanup();
2558 vmbus_initiate_unload(false);
2559 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2560 mb();
2561 cpuhp_remove_state(hyperv_cpuhp_online);
2562};
2563
2564static void hv_crash_handler(struct pt_regs *regs)
2565{
2566 int cpu;
2567
2568 vmbus_initiate_unload(true);
2569 /*
2570 * In crash handler we can't schedule synic cleanup for all CPUs,
2571 * doing the cleanup for current CPU only. This should be sufficient
2572 * for kdump.
2573 */
2574 cpu = smp_processor_id();
2575 hv_stimer_cleanup(cpu);
2576 hv_synic_disable_regs(cpu);
2577};
2578
2579static int hv_synic_suspend(void)
2580{
2581 /*
2582 * When we reach here, all the non-boot CPUs have been offlined.
2583 * If we're in a legacy configuration where stimer Direct Mode is
2584 * not enabled, the stimers on the non-boot CPUs have been unbound
2585 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2586 * hv_stimer_cleanup() -> clockevents_unbind_device().
2587 *
2588 * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2589 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2590 * 1) it's unnecessary as interrupts remain disabled between
2591 * syscore_suspend() and syscore_resume(): see create_image() and
2592 * resume_target_kernel()
2593 * 2) the stimer on CPU0 is automatically disabled later by
2594 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2595 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2596 * 3) a warning would be triggered if we call
2597 * clockevents_unbind_device(), which may sleep, in an
2598 * interrupts-disabled context.
2599 */
2600
2601 hv_synic_disable_regs(0);
2602
2603 return 0;
2604}
2605
2606static void hv_synic_resume(void)
2607{
2608 hv_synic_enable_regs(0);
2609
2610 /*
2611 * Note: we don't need to call hv_stimer_init(0), because the timer
2612 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2613 * automatically re-enabled in timekeeping_resume().
2614 */
2615}
2616
2617/* The callbacks run only on CPU0, with irqs_disabled. */
2618static struct syscore_ops hv_synic_syscore_ops = {
2619 .suspend = hv_synic_suspend,
2620 .resume = hv_synic_resume,
2621};
2622
2623static int __init hv_acpi_init(void)
2624{
2625 int ret;
2626
2627 if (!hv_is_hyperv_initialized())
2628 return -ENODEV;
2629
2630 if (hv_root_partition && !hv_nested)
2631 return 0;
2632
2633 /*
2634 * Get ACPI resources first.
2635 */
2636 ret = platform_driver_register(&vmbus_platform_driver);
2637 if (ret)
2638 return ret;
2639
2640 if (!hv_dev) {
2641 ret = -ENODEV;
2642 goto cleanup;
2643 }
2644
2645 /*
2646 * If we're on an architecture with a hardcoded hypervisor
2647 * vector (i.e. x86/x64), override the VMbus interrupt found
2648 * in the ACPI tables. Ensure vmbus_irq is not set since the
2649 * normal Linux IRQ mechanism is not used in this case.
2650 */
2651#ifdef HYPERVISOR_CALLBACK_VECTOR
2652 vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR;
2653 vmbus_irq = -1;
2654#endif
2655
2656 hv_debug_init();
2657
2658 ret = vmbus_bus_init();
2659 if (ret)
2660 goto cleanup;
2661
2662 hv_setup_kexec_handler(hv_kexec_handler);
2663 hv_setup_crash_handler(hv_crash_handler);
2664
2665 register_syscore_ops(&hv_synic_syscore_ops);
2666
2667 return 0;
2668
2669cleanup:
2670 platform_driver_unregister(&vmbus_platform_driver);
2671 hv_dev = NULL;
2672 return ret;
2673}
2674
2675static void __exit vmbus_exit(void)
2676{
2677 int cpu;
2678
2679 unregister_syscore_ops(&hv_synic_syscore_ops);
2680
2681 hv_remove_kexec_handler();
2682 hv_remove_crash_handler();
2683 vmbus_connection.conn_state = DISCONNECTED;
2684 hv_stimer_global_cleanup();
2685 vmbus_disconnect();
2686 if (vmbus_irq == -1) {
2687 hv_remove_vmbus_handler();
2688 } else {
2689 free_percpu_irq(vmbus_irq, vmbus_evt);
2690 free_percpu(vmbus_evt);
2691 }
2692 for_each_online_cpu(cpu) {
2693 struct hv_per_cpu_context *hv_cpu
2694 = per_cpu_ptr(hv_context.cpu_context, cpu);
2695
2696 tasklet_kill(&hv_cpu->msg_dpc);
2697 }
2698 hv_debug_rm_all_dir();
2699
2700 vmbus_free_channels();
2701 kfree(vmbus_connection.channels);
2702
2703 /*
2704 * The vmbus panic notifier is always registered, hence we should
2705 * also unconditionally unregister it here as well.
2706 */
2707 atomic_notifier_chain_unregister(&panic_notifier_list,
2708 &hyperv_panic_vmbus_unload_block);
2709
2710 bus_unregister(&hv_bus);
2711
2712 cpuhp_remove_state(hyperv_cpuhp_online);
2713 hv_synic_free();
2714 platform_driver_unregister(&vmbus_platform_driver);
2715}
2716
2717
2718MODULE_LICENSE("GPL");
2719MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2720
2721subsys_initcall(hv_acpi_init);
2722module_exit(vmbus_exit);