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1/*
2 * Copyright (c) 2009, Microsoft Corporation.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
16 *
17 * Authors:
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
20 * K. Y. Srinivasan <kys@microsoft.com>
21 *
22 */
23#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24
25#include <linux/init.h>
26#include <linux/module.h>
27#include <linux/device.h>
28#include <linux/irq.h>
29#include <linux/interrupt.h>
30#include <linux/sysctl.h>
31#include <linux/slab.h>
32#include <linux/acpi.h>
33#include <acpi/acpi_bus.h>
34#include <linux/completion.h>
35#include <linux/hyperv.h>
36#include <asm/hyperv.h>
37#include "hyperv_vmbus.h"
38
39
40static struct acpi_device *hv_acpi_dev;
41
42static struct tasklet_struct msg_dpc;
43static struct tasklet_struct event_dpc;
44static struct completion probe_event;
45static int irq;
46
47struct hv_device_info {
48 u32 chn_id;
49 u32 chn_state;
50 uuid_le chn_type;
51 uuid_le chn_instance;
52
53 u32 monitor_id;
54 u32 server_monitor_pending;
55 u32 server_monitor_latency;
56 u32 server_monitor_conn_id;
57 u32 client_monitor_pending;
58 u32 client_monitor_latency;
59 u32 client_monitor_conn_id;
60
61 struct hv_dev_port_info inbound;
62 struct hv_dev_port_info outbound;
63};
64
65static int vmbus_exists(void)
66{
67 if (hv_acpi_dev == NULL)
68 return -ENODEV;
69
70 return 0;
71}
72
73
74static void get_channel_info(struct hv_device *device,
75 struct hv_device_info *info)
76{
77 struct vmbus_channel_debug_info debug_info;
78
79 if (!device->channel)
80 return;
81
82 vmbus_get_debug_info(device->channel, &debug_info);
83
84 info->chn_id = debug_info.relid;
85 info->chn_state = debug_info.state;
86 memcpy(&info->chn_type, &debug_info.interfacetype,
87 sizeof(uuid_le));
88 memcpy(&info->chn_instance, &debug_info.interface_instance,
89 sizeof(uuid_le));
90
91 info->monitor_id = debug_info.monitorid;
92
93 info->server_monitor_pending = debug_info.servermonitor_pending;
94 info->server_monitor_latency = debug_info.servermonitor_latency;
95 info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
96
97 info->client_monitor_pending = debug_info.clientmonitor_pending;
98 info->client_monitor_latency = debug_info.clientmonitor_latency;
99 info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
100
101 info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
102 info->inbound.read_idx = debug_info.inbound.current_read_index;
103 info->inbound.write_idx = debug_info.inbound.current_write_index;
104 info->inbound.bytes_avail_toread =
105 debug_info.inbound.bytes_avail_toread;
106 info->inbound.bytes_avail_towrite =
107 debug_info.inbound.bytes_avail_towrite;
108
109 info->outbound.int_mask =
110 debug_info.outbound.current_interrupt_mask;
111 info->outbound.read_idx = debug_info.outbound.current_read_index;
112 info->outbound.write_idx = debug_info.outbound.current_write_index;
113 info->outbound.bytes_avail_toread =
114 debug_info.outbound.bytes_avail_toread;
115 info->outbound.bytes_avail_towrite =
116 debug_info.outbound.bytes_avail_towrite;
117}
118
119#define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
120static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
121{
122 int i;
123 for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
124 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
125}
126
127/*
128 * vmbus_show_device_attr - Show the device attribute in sysfs.
129 *
130 * This is invoked when user does a
131 * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
132 */
133static ssize_t vmbus_show_device_attr(struct device *dev,
134 struct device_attribute *dev_attr,
135 char *buf)
136{
137 struct hv_device *hv_dev = device_to_hv_device(dev);
138 struct hv_device_info *device_info;
139 char alias_name[VMBUS_ALIAS_LEN + 1];
140 int ret = 0;
141
142 device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
143 if (!device_info)
144 return ret;
145
146 get_channel_info(hv_dev, device_info);
147
148 if (!strcmp(dev_attr->attr.name, "class_id")) {
149 ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
150 "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
151 device_info->chn_type.b[3],
152 device_info->chn_type.b[2],
153 device_info->chn_type.b[1],
154 device_info->chn_type.b[0],
155 device_info->chn_type.b[5],
156 device_info->chn_type.b[4],
157 device_info->chn_type.b[7],
158 device_info->chn_type.b[6],
159 device_info->chn_type.b[8],
160 device_info->chn_type.b[9],
161 device_info->chn_type.b[10],
162 device_info->chn_type.b[11],
163 device_info->chn_type.b[12],
164 device_info->chn_type.b[13],
165 device_info->chn_type.b[14],
166 device_info->chn_type.b[15]);
167 } else if (!strcmp(dev_attr->attr.name, "device_id")) {
168 ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
169 "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
170 device_info->chn_instance.b[3],
171 device_info->chn_instance.b[2],
172 device_info->chn_instance.b[1],
173 device_info->chn_instance.b[0],
174 device_info->chn_instance.b[5],
175 device_info->chn_instance.b[4],
176 device_info->chn_instance.b[7],
177 device_info->chn_instance.b[6],
178 device_info->chn_instance.b[8],
179 device_info->chn_instance.b[9],
180 device_info->chn_instance.b[10],
181 device_info->chn_instance.b[11],
182 device_info->chn_instance.b[12],
183 device_info->chn_instance.b[13],
184 device_info->chn_instance.b[14],
185 device_info->chn_instance.b[15]);
186 } else if (!strcmp(dev_attr->attr.name, "modalias")) {
187 print_alias_name(hv_dev, alias_name);
188 ret = sprintf(buf, "vmbus:%s\n", alias_name);
189 } else if (!strcmp(dev_attr->attr.name, "state")) {
190 ret = sprintf(buf, "%d\n", device_info->chn_state);
191 } else if (!strcmp(dev_attr->attr.name, "id")) {
192 ret = sprintf(buf, "%d\n", device_info->chn_id);
193 } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
194 ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
195 } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
196 ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
197 } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
198 ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
199 } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
200 ret = sprintf(buf, "%d\n",
201 device_info->outbound.bytes_avail_toread);
202 } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
203 ret = sprintf(buf, "%d\n",
204 device_info->outbound.bytes_avail_towrite);
205 } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
206 ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
207 } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
208 ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
209 } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
210 ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
211 } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
212 ret = sprintf(buf, "%d\n",
213 device_info->inbound.bytes_avail_toread);
214 } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
215 ret = sprintf(buf, "%d\n",
216 device_info->inbound.bytes_avail_towrite);
217 } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
218 ret = sprintf(buf, "%d\n", device_info->monitor_id);
219 } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
220 ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
221 } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
222 ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
223 } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
224 ret = sprintf(buf, "%d\n",
225 device_info->server_monitor_conn_id);
226 } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
227 ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
228 } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
229 ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
230 } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
231 ret = sprintf(buf, "%d\n",
232 device_info->client_monitor_conn_id);
233 }
234
235 kfree(device_info);
236 return ret;
237}
238
239/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
240static struct device_attribute vmbus_device_attrs[] = {
241 __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
242 __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
243 __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
244 __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
245 __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
246 __ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
247
248 __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
249 __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
250 __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
251
252 __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
253 __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
254 __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
255
256 __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
257 __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
258 __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
259 __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
260 __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
261
262 __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
263 __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
264 __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
265 __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
266 __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
267 __ATTR_NULL
268};
269
270
271/*
272 * vmbus_uevent - add uevent for our device
273 *
274 * This routine is invoked when a device is added or removed on the vmbus to
275 * generate a uevent to udev in the userspace. The udev will then look at its
276 * rule and the uevent generated here to load the appropriate driver
277 *
278 * The alias string will be of the form vmbus:guid where guid is the string
279 * representation of the device guid (each byte of the guid will be
280 * represented with two hex characters.
281 */
282static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
283{
284 struct hv_device *dev = device_to_hv_device(device);
285 int ret;
286 char alias_name[VMBUS_ALIAS_LEN + 1];
287
288 print_alias_name(dev, alias_name);
289 ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
290 return ret;
291}
292
293static uuid_le null_guid;
294
295static inline bool is_null_guid(const __u8 *guid)
296{
297 if (memcmp(guid, &null_guid, sizeof(uuid_le)))
298 return false;
299 return true;
300}
301
302/*
303 * Return a matching hv_vmbus_device_id pointer.
304 * If there is no match, return NULL.
305 */
306static const struct hv_vmbus_device_id *hv_vmbus_get_id(
307 const struct hv_vmbus_device_id *id,
308 __u8 *guid)
309{
310 for (; !is_null_guid(id->guid); id++)
311 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
312 return id;
313
314 return NULL;
315}
316
317
318
319/*
320 * vmbus_match - Attempt to match the specified device to the specified driver
321 */
322static int vmbus_match(struct device *device, struct device_driver *driver)
323{
324 struct hv_driver *drv = drv_to_hv_drv(driver);
325 struct hv_device *hv_dev = device_to_hv_device(device);
326
327 if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
328 return 1;
329
330 return 0;
331}
332
333/*
334 * vmbus_probe - Add the new vmbus's child device
335 */
336static int vmbus_probe(struct device *child_device)
337{
338 int ret = 0;
339 struct hv_driver *drv =
340 drv_to_hv_drv(child_device->driver);
341 struct hv_device *dev = device_to_hv_device(child_device);
342 const struct hv_vmbus_device_id *dev_id;
343
344 dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
345 if (drv->probe) {
346 ret = drv->probe(dev, dev_id);
347 if (ret != 0)
348 pr_err("probe failed for device %s (%d)\n",
349 dev_name(child_device), ret);
350
351 } else {
352 pr_err("probe not set for driver %s\n",
353 dev_name(child_device));
354 ret = -ENODEV;
355 }
356 return ret;
357}
358
359/*
360 * vmbus_remove - Remove a vmbus device
361 */
362static int vmbus_remove(struct device *child_device)
363{
364 struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
365 struct hv_device *dev = device_to_hv_device(child_device);
366
367 if (drv->remove)
368 drv->remove(dev);
369 else
370 pr_err("remove not set for driver %s\n",
371 dev_name(child_device));
372
373 return 0;
374}
375
376
377/*
378 * vmbus_shutdown - Shutdown a vmbus device
379 */
380static void vmbus_shutdown(struct device *child_device)
381{
382 struct hv_driver *drv;
383 struct hv_device *dev = device_to_hv_device(child_device);
384
385
386 /* The device may not be attached yet */
387 if (!child_device->driver)
388 return;
389
390 drv = drv_to_hv_drv(child_device->driver);
391
392 if (drv->shutdown)
393 drv->shutdown(dev);
394
395 return;
396}
397
398
399/*
400 * vmbus_device_release - Final callback release of the vmbus child device
401 */
402static void vmbus_device_release(struct device *device)
403{
404 struct hv_device *hv_dev = device_to_hv_device(device);
405
406 kfree(hv_dev);
407
408}
409
410/* The one and only one */
411static struct bus_type hv_bus = {
412 .name = "vmbus",
413 .match = vmbus_match,
414 .shutdown = vmbus_shutdown,
415 .remove = vmbus_remove,
416 .probe = vmbus_probe,
417 .uevent = vmbus_uevent,
418 .dev_attrs = vmbus_device_attrs,
419};
420
421static const char *driver_name = "hyperv";
422
423
424struct onmessage_work_context {
425 struct work_struct work;
426 struct hv_message msg;
427};
428
429static void vmbus_onmessage_work(struct work_struct *work)
430{
431 struct onmessage_work_context *ctx;
432
433 ctx = container_of(work, struct onmessage_work_context,
434 work);
435 vmbus_onmessage(&ctx->msg);
436 kfree(ctx);
437}
438
439static void vmbus_on_msg_dpc(unsigned long data)
440{
441 int cpu = smp_processor_id();
442 void *page_addr = hv_context.synic_message_page[cpu];
443 struct hv_message *msg = (struct hv_message *)page_addr +
444 VMBUS_MESSAGE_SINT;
445 struct onmessage_work_context *ctx;
446
447 while (1) {
448 if (msg->header.message_type == HVMSG_NONE) {
449 /* no msg */
450 break;
451 } else {
452 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
453 if (ctx == NULL)
454 continue;
455 INIT_WORK(&ctx->work, vmbus_onmessage_work);
456 memcpy(&ctx->msg, msg, sizeof(*msg));
457 queue_work(vmbus_connection.work_queue, &ctx->work);
458 }
459
460 msg->header.message_type = HVMSG_NONE;
461
462 /*
463 * Make sure the write to MessageType (ie set to
464 * HVMSG_NONE) happens before we read the
465 * MessagePending and EOMing. Otherwise, the EOMing
466 * will not deliver any more messages since there is
467 * no empty slot
468 */
469 smp_mb();
470
471 if (msg->header.message_flags.msg_pending) {
472 /*
473 * This will cause message queue rescan to
474 * possibly deliver another msg from the
475 * hypervisor
476 */
477 wrmsrl(HV_X64_MSR_EOM, 0);
478 }
479 }
480}
481
482static irqreturn_t vmbus_isr(int irq, void *dev_id)
483{
484 int cpu = smp_processor_id();
485 void *page_addr;
486 struct hv_message *msg;
487 union hv_synic_event_flags *event;
488 bool handled = false;
489
490 /*
491 * Check for events before checking for messages. This is the order
492 * in which events and messages are checked in Windows guests on
493 * Hyper-V, and the Windows team suggested we do the same.
494 */
495
496 page_addr = hv_context.synic_event_page[cpu];
497 event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
498
499 /* Since we are a child, we only need to check bit 0 */
500 if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
501 handled = true;
502 tasklet_schedule(&event_dpc);
503 }
504
505 page_addr = hv_context.synic_message_page[cpu];
506 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
507
508 /* Check if there are actual msgs to be processed */
509 if (msg->header.message_type != HVMSG_NONE) {
510 handled = true;
511 tasklet_schedule(&msg_dpc);
512 }
513
514 if (handled)
515 return IRQ_HANDLED;
516 else
517 return IRQ_NONE;
518}
519
520/*
521 * vmbus_bus_init -Main vmbus driver initialization routine.
522 *
523 * Here, we
524 * - initialize the vmbus driver context
525 * - invoke the vmbus hv main init routine
526 * - get the irq resource
527 * - retrieve the channel offers
528 */
529static int vmbus_bus_init(int irq)
530{
531 int ret;
532 unsigned int vector;
533
534 /* Hypervisor initialization...setup hypercall page..etc */
535 ret = hv_init();
536 if (ret != 0) {
537 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
538 return ret;
539 }
540
541 tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
542 tasklet_init(&event_dpc, vmbus_on_event, 0);
543
544 ret = bus_register(&hv_bus);
545 if (ret)
546 goto err_cleanup;
547
548 ret = request_irq(irq, vmbus_isr, IRQF_SAMPLE_RANDOM,
549 driver_name, hv_acpi_dev);
550
551 if (ret != 0) {
552 pr_err("Unable to request IRQ %d\n",
553 irq);
554 goto err_unregister;
555 }
556
557 vector = IRQ0_VECTOR + irq;
558
559 /*
560 * Notify the hypervisor of our irq and
561 * connect to the host.
562 */
563 on_each_cpu(hv_synic_init, (void *)&vector, 1);
564 ret = vmbus_connect();
565 if (ret)
566 goto err_irq;
567
568 vmbus_request_offers();
569
570 return 0;
571
572err_irq:
573 free_irq(irq, hv_acpi_dev);
574
575err_unregister:
576 bus_unregister(&hv_bus);
577
578err_cleanup:
579 hv_cleanup();
580
581 return ret;
582}
583
584/**
585 * __vmbus_child_driver_register - Register a vmbus's driver
586 * @drv: Pointer to driver structure you want to register
587 * @owner: owner module of the drv
588 * @mod_name: module name string
589 *
590 * Registers the given driver with Linux through the 'driver_register()' call
591 * and sets up the hyper-v vmbus handling for this driver.
592 * It will return the state of the 'driver_register()' call.
593 *
594 */
595int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
596{
597 int ret;
598
599 pr_info("registering driver %s\n", hv_driver->name);
600
601 ret = vmbus_exists();
602 if (ret < 0)
603 return ret;
604
605 hv_driver->driver.name = hv_driver->name;
606 hv_driver->driver.owner = owner;
607 hv_driver->driver.mod_name = mod_name;
608 hv_driver->driver.bus = &hv_bus;
609
610 ret = driver_register(&hv_driver->driver);
611
612 vmbus_request_offers();
613
614 return ret;
615}
616EXPORT_SYMBOL_GPL(__vmbus_driver_register);
617
618/**
619 * vmbus_driver_unregister() - Unregister a vmbus's driver
620 * @drv: Pointer to driver structure you want to un-register
621 *
622 * Un-register the given driver that was previous registered with a call to
623 * vmbus_driver_register()
624 */
625void vmbus_driver_unregister(struct hv_driver *hv_driver)
626{
627 pr_info("unregistering driver %s\n", hv_driver->name);
628
629 if (!vmbus_exists())
630 driver_unregister(&hv_driver->driver);
631}
632EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
633
634/*
635 * vmbus_device_create - Creates and registers a new child device
636 * on the vmbus.
637 */
638struct hv_device *vmbus_device_create(uuid_le *type,
639 uuid_le *instance,
640 struct vmbus_channel *channel)
641{
642 struct hv_device *child_device_obj;
643
644 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
645 if (!child_device_obj) {
646 pr_err("Unable to allocate device object for child device\n");
647 return NULL;
648 }
649
650 child_device_obj->channel = channel;
651 memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
652 memcpy(&child_device_obj->dev_instance, instance,
653 sizeof(uuid_le));
654
655
656 return child_device_obj;
657}
658
659/*
660 * vmbus_device_register - Register the child device
661 */
662int vmbus_device_register(struct hv_device *child_device_obj)
663{
664 int ret = 0;
665
666 static atomic_t device_num = ATOMIC_INIT(0);
667
668 dev_set_name(&child_device_obj->device, "vmbus_0_%d",
669 atomic_inc_return(&device_num));
670
671 child_device_obj->device.bus = &hv_bus;
672 child_device_obj->device.parent = &hv_acpi_dev->dev;
673 child_device_obj->device.release = vmbus_device_release;
674
675 /*
676 * Register with the LDM. This will kick off the driver/device
677 * binding...which will eventually call vmbus_match() and vmbus_probe()
678 */
679 ret = device_register(&child_device_obj->device);
680
681 if (ret)
682 pr_err("Unable to register child device\n");
683 else
684 pr_info("child device %s registered\n",
685 dev_name(&child_device_obj->device));
686
687 return ret;
688}
689
690/*
691 * vmbus_device_unregister - Remove the specified child device
692 * from the vmbus.
693 */
694void vmbus_device_unregister(struct hv_device *device_obj)
695{
696 /*
697 * Kick off the process of unregistering the device.
698 * This will call vmbus_remove() and eventually vmbus_device_release()
699 */
700 device_unregister(&device_obj->device);
701
702 pr_info("child device %s unregistered\n",
703 dev_name(&device_obj->device));
704}
705
706
707/*
708 * VMBUS is an acpi enumerated device. Get the the IRQ information
709 * from DSDT.
710 */
711
712static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
713{
714
715 if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
716 struct acpi_resource_irq *irqp;
717 irqp = &res->data.irq;
718
719 *((unsigned int *)irq) = irqp->interrupts[0];
720 }
721
722 return AE_OK;
723}
724
725static int vmbus_acpi_add(struct acpi_device *device)
726{
727 acpi_status result;
728
729 hv_acpi_dev = device;
730
731 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
732 vmbus_walk_resources, &irq);
733
734 if (ACPI_FAILURE(result)) {
735 complete(&probe_event);
736 return -ENODEV;
737 }
738 complete(&probe_event);
739 return 0;
740}
741
742static const struct acpi_device_id vmbus_acpi_device_ids[] = {
743 {"VMBUS", 0},
744 {"VMBus", 0},
745 {"", 0},
746};
747MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
748
749static struct acpi_driver vmbus_acpi_driver = {
750 .name = "vmbus",
751 .ids = vmbus_acpi_device_ids,
752 .ops = {
753 .add = vmbus_acpi_add,
754 },
755};
756
757static int __init hv_acpi_init(void)
758{
759 int ret, t;
760
761 init_completion(&probe_event);
762
763 /*
764 * Get irq resources first.
765 */
766
767 ret = acpi_bus_register_driver(&vmbus_acpi_driver);
768
769 if (ret)
770 return ret;
771
772 t = wait_for_completion_timeout(&probe_event, 5*HZ);
773 if (t == 0) {
774 ret = -ETIMEDOUT;
775 goto cleanup;
776 }
777
778 if (irq <= 0) {
779 ret = -ENODEV;
780 goto cleanup;
781 }
782
783 ret = vmbus_bus_init(irq);
784 if (ret)
785 goto cleanup;
786
787 return 0;
788
789cleanup:
790 acpi_bus_unregister_driver(&vmbus_acpi_driver);
791 hv_acpi_dev = NULL;
792 return ret;
793}
794
795static void __exit vmbus_exit(void)
796{
797
798 free_irq(irq, hv_acpi_dev);
799 vmbus_free_channels();
800 bus_unregister(&hv_bus);
801 hv_cleanup();
802 acpi_bus_unregister_driver(&vmbus_acpi_driver);
803}
804
805
806MODULE_LICENSE("GPL");
807MODULE_VERSION(HV_DRV_VERSION);
808
809subsys_initcall(hv_acpi_init);
810module_exit(vmbus_exit);
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/interrupt.h>
16#include <linux/sysctl.h>
17#include <linux/slab.h>
18#include <linux/acpi.h>
19#include <linux/completion.h>
20#include <linux/hyperv.h>
21#include <linux/kernel_stat.h>
22#include <linux/clockchips.h>
23#include <linux/cpu.h>
24#include <linux/sched/isolation.h>
25#include <linux/sched/task_stack.h>
26
27#include <linux/delay.h>
28#include <linux/panic_notifier.h>
29#include <linux/ptrace.h>
30#include <linux/screen_info.h>
31#include <linux/kdebug.h>
32#include <linux/efi.h>
33#include <linux/random.h>
34#include <linux/kernel.h>
35#include <linux/syscore_ops.h>
36#include <linux/dma-map-ops.h>
37#include <linux/pci.h>
38#include <clocksource/hyperv_timer.h>
39#include <asm/mshyperv.h>
40#include "hyperv_vmbus.h"
41
42struct vmbus_dynid {
43 struct list_head node;
44 struct hv_vmbus_device_id id;
45};
46
47static struct acpi_device *hv_acpi_dev;
48
49static int hyperv_cpuhp_online;
50
51static void *hv_panic_page;
52
53static long __percpu *vmbus_evt;
54
55/* Values parsed from ACPI DSDT */
56int vmbus_irq;
57int vmbus_interrupt;
58
59/*
60 * Boolean to control whether to report panic messages over Hyper-V.
61 *
62 * It can be set via /proc/sys/kernel/hyperv_record_panic_msg
63 */
64static int sysctl_record_panic_msg = 1;
65
66static int hyperv_report_reg(void)
67{
68 return !sysctl_record_panic_msg || !hv_panic_page;
69}
70
71/*
72 * The panic notifier below is responsible solely for unloading the
73 * vmbus connection, which is necessary in a panic event.
74 *
75 * Notice an intrincate relation of this notifier with Hyper-V
76 * framebuffer panic notifier exists - we need vmbus connection alive
77 * there in order to succeed, so we need to order both with each other
78 * [see hvfb_on_panic()] - this is done using notifiers' priorities.
79 */
80static int hv_panic_vmbus_unload(struct notifier_block *nb, unsigned long val,
81 void *args)
82{
83 vmbus_initiate_unload(true);
84 return NOTIFY_DONE;
85}
86static struct notifier_block hyperv_panic_vmbus_unload_block = {
87 .notifier_call = hv_panic_vmbus_unload,
88 .priority = INT_MIN + 1, /* almost the latest one to execute */
89};
90
91static int hv_die_panic_notify_crash(struct notifier_block *self,
92 unsigned long val, void *args);
93
94static struct notifier_block hyperv_die_report_block = {
95 .notifier_call = hv_die_panic_notify_crash,
96};
97static struct notifier_block hyperv_panic_report_block = {
98 .notifier_call = hv_die_panic_notify_crash,
99};
100
101/*
102 * The following callback works both as die and panic notifier; its
103 * goal is to provide panic information to the hypervisor unless the
104 * kmsg dumper is used [see hv_kmsg_dump()], which provides more
105 * information but isn't always available.
106 *
107 * Notice that both the panic/die report notifiers are registered only
108 * if we have the capability HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE set.
109 */
110static int hv_die_panic_notify_crash(struct notifier_block *self,
111 unsigned long val, void *args)
112{
113 struct pt_regs *regs;
114 bool is_die;
115
116 /* Don't notify Hyper-V unless we have a die oops event or panic. */
117 if (self == &hyperv_panic_report_block) {
118 is_die = false;
119 regs = current_pt_regs();
120 } else { /* die event */
121 if (val != DIE_OOPS)
122 return NOTIFY_DONE;
123
124 is_die = true;
125 regs = ((struct die_args *)args)->regs;
126 }
127
128 /*
129 * Hyper-V should be notified only once about a panic/die. If we will
130 * be calling hv_kmsg_dump() later with kmsg data, don't do the
131 * notification here.
132 */
133 if (hyperv_report_reg())
134 hyperv_report_panic(regs, val, is_die);
135
136 return NOTIFY_DONE;
137}
138
139static const char *fb_mmio_name = "fb_range";
140static struct resource *fb_mmio;
141static struct resource *hyperv_mmio;
142static DEFINE_MUTEX(hyperv_mmio_lock);
143
144static int vmbus_exists(void)
145{
146 if (hv_acpi_dev == NULL)
147 return -ENODEV;
148
149 return 0;
150}
151
152static u8 channel_monitor_group(const struct vmbus_channel *channel)
153{
154 return (u8)channel->offermsg.monitorid / 32;
155}
156
157static u8 channel_monitor_offset(const struct vmbus_channel *channel)
158{
159 return (u8)channel->offermsg.monitorid % 32;
160}
161
162static u32 channel_pending(const struct vmbus_channel *channel,
163 const struct hv_monitor_page *monitor_page)
164{
165 u8 monitor_group = channel_monitor_group(channel);
166
167 return monitor_page->trigger_group[monitor_group].pending;
168}
169
170static u32 channel_latency(const struct vmbus_channel *channel,
171 const struct hv_monitor_page *monitor_page)
172{
173 u8 monitor_group = channel_monitor_group(channel);
174 u8 monitor_offset = channel_monitor_offset(channel);
175
176 return monitor_page->latency[monitor_group][monitor_offset];
177}
178
179static u32 channel_conn_id(struct vmbus_channel *channel,
180 struct hv_monitor_page *monitor_page)
181{
182 u8 monitor_group = channel_monitor_group(channel);
183 u8 monitor_offset = channel_monitor_offset(channel);
184
185 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
186}
187
188static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
189 char *buf)
190{
191 struct hv_device *hv_dev = device_to_hv_device(dev);
192
193 if (!hv_dev->channel)
194 return -ENODEV;
195 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
196}
197static DEVICE_ATTR_RO(id);
198
199static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
200 char *buf)
201{
202 struct hv_device *hv_dev = device_to_hv_device(dev);
203
204 if (!hv_dev->channel)
205 return -ENODEV;
206 return sprintf(buf, "%d\n", hv_dev->channel->state);
207}
208static DEVICE_ATTR_RO(state);
209
210static ssize_t monitor_id_show(struct device *dev,
211 struct device_attribute *dev_attr, char *buf)
212{
213 struct hv_device *hv_dev = device_to_hv_device(dev);
214
215 if (!hv_dev->channel)
216 return -ENODEV;
217 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
218}
219static DEVICE_ATTR_RO(monitor_id);
220
221static ssize_t class_id_show(struct device *dev,
222 struct device_attribute *dev_attr, char *buf)
223{
224 struct hv_device *hv_dev = device_to_hv_device(dev);
225
226 if (!hv_dev->channel)
227 return -ENODEV;
228 return sprintf(buf, "{%pUl}\n",
229 &hv_dev->channel->offermsg.offer.if_type);
230}
231static DEVICE_ATTR_RO(class_id);
232
233static ssize_t device_id_show(struct device *dev,
234 struct device_attribute *dev_attr, char *buf)
235{
236 struct hv_device *hv_dev = device_to_hv_device(dev);
237
238 if (!hv_dev->channel)
239 return -ENODEV;
240 return sprintf(buf, "{%pUl}\n",
241 &hv_dev->channel->offermsg.offer.if_instance);
242}
243static DEVICE_ATTR_RO(device_id);
244
245static ssize_t modalias_show(struct device *dev,
246 struct device_attribute *dev_attr, char *buf)
247{
248 struct hv_device *hv_dev = device_to_hv_device(dev);
249
250 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
251}
252static DEVICE_ATTR_RO(modalias);
253
254#ifdef CONFIG_NUMA
255static ssize_t numa_node_show(struct device *dev,
256 struct device_attribute *attr, char *buf)
257{
258 struct hv_device *hv_dev = device_to_hv_device(dev);
259
260 if (!hv_dev->channel)
261 return -ENODEV;
262
263 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
264}
265static DEVICE_ATTR_RO(numa_node);
266#endif
267
268static ssize_t server_monitor_pending_show(struct device *dev,
269 struct device_attribute *dev_attr,
270 char *buf)
271{
272 struct hv_device *hv_dev = device_to_hv_device(dev);
273
274 if (!hv_dev->channel)
275 return -ENODEV;
276 return sprintf(buf, "%d\n",
277 channel_pending(hv_dev->channel,
278 vmbus_connection.monitor_pages[0]));
279}
280static DEVICE_ATTR_RO(server_monitor_pending);
281
282static ssize_t client_monitor_pending_show(struct device *dev,
283 struct device_attribute *dev_attr,
284 char *buf)
285{
286 struct hv_device *hv_dev = device_to_hv_device(dev);
287
288 if (!hv_dev->channel)
289 return -ENODEV;
290 return sprintf(buf, "%d\n",
291 channel_pending(hv_dev->channel,
292 vmbus_connection.monitor_pages[1]));
293}
294static DEVICE_ATTR_RO(client_monitor_pending);
295
296static ssize_t server_monitor_latency_show(struct device *dev,
297 struct device_attribute *dev_attr,
298 char *buf)
299{
300 struct hv_device *hv_dev = device_to_hv_device(dev);
301
302 if (!hv_dev->channel)
303 return -ENODEV;
304 return sprintf(buf, "%d\n",
305 channel_latency(hv_dev->channel,
306 vmbus_connection.monitor_pages[0]));
307}
308static DEVICE_ATTR_RO(server_monitor_latency);
309
310static ssize_t client_monitor_latency_show(struct device *dev,
311 struct device_attribute *dev_attr,
312 char *buf)
313{
314 struct hv_device *hv_dev = device_to_hv_device(dev);
315
316 if (!hv_dev->channel)
317 return -ENODEV;
318 return sprintf(buf, "%d\n",
319 channel_latency(hv_dev->channel,
320 vmbus_connection.monitor_pages[1]));
321}
322static DEVICE_ATTR_RO(client_monitor_latency);
323
324static ssize_t server_monitor_conn_id_show(struct device *dev,
325 struct device_attribute *dev_attr,
326 char *buf)
327{
328 struct hv_device *hv_dev = device_to_hv_device(dev);
329
330 if (!hv_dev->channel)
331 return -ENODEV;
332 return sprintf(buf, "%d\n",
333 channel_conn_id(hv_dev->channel,
334 vmbus_connection.monitor_pages[0]));
335}
336static DEVICE_ATTR_RO(server_monitor_conn_id);
337
338static ssize_t client_monitor_conn_id_show(struct device *dev,
339 struct device_attribute *dev_attr,
340 char *buf)
341{
342 struct hv_device *hv_dev = device_to_hv_device(dev);
343
344 if (!hv_dev->channel)
345 return -ENODEV;
346 return sprintf(buf, "%d\n",
347 channel_conn_id(hv_dev->channel,
348 vmbus_connection.monitor_pages[1]));
349}
350static DEVICE_ATTR_RO(client_monitor_conn_id);
351
352static ssize_t out_intr_mask_show(struct device *dev,
353 struct device_attribute *dev_attr, char *buf)
354{
355 struct hv_device *hv_dev = device_to_hv_device(dev);
356 struct hv_ring_buffer_debug_info outbound;
357 int ret;
358
359 if (!hv_dev->channel)
360 return -ENODEV;
361
362 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
363 &outbound);
364 if (ret < 0)
365 return ret;
366
367 return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
368}
369static DEVICE_ATTR_RO(out_intr_mask);
370
371static ssize_t out_read_index_show(struct device *dev,
372 struct device_attribute *dev_attr, char *buf)
373{
374 struct hv_device *hv_dev = device_to_hv_device(dev);
375 struct hv_ring_buffer_debug_info outbound;
376 int ret;
377
378 if (!hv_dev->channel)
379 return -ENODEV;
380
381 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
382 &outbound);
383 if (ret < 0)
384 return ret;
385 return sprintf(buf, "%d\n", outbound.current_read_index);
386}
387static DEVICE_ATTR_RO(out_read_index);
388
389static ssize_t out_write_index_show(struct device *dev,
390 struct device_attribute *dev_attr,
391 char *buf)
392{
393 struct hv_device *hv_dev = device_to_hv_device(dev);
394 struct hv_ring_buffer_debug_info outbound;
395 int ret;
396
397 if (!hv_dev->channel)
398 return -ENODEV;
399
400 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
401 &outbound);
402 if (ret < 0)
403 return ret;
404 return sprintf(buf, "%d\n", outbound.current_write_index);
405}
406static DEVICE_ATTR_RO(out_write_index);
407
408static ssize_t out_read_bytes_avail_show(struct device *dev,
409 struct device_attribute *dev_attr,
410 char *buf)
411{
412 struct hv_device *hv_dev = device_to_hv_device(dev);
413 struct hv_ring_buffer_debug_info outbound;
414 int ret;
415
416 if (!hv_dev->channel)
417 return -ENODEV;
418
419 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
420 &outbound);
421 if (ret < 0)
422 return ret;
423 return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
424}
425static DEVICE_ATTR_RO(out_read_bytes_avail);
426
427static ssize_t out_write_bytes_avail_show(struct device *dev,
428 struct device_attribute *dev_attr,
429 char *buf)
430{
431 struct hv_device *hv_dev = device_to_hv_device(dev);
432 struct hv_ring_buffer_debug_info outbound;
433 int ret;
434
435 if (!hv_dev->channel)
436 return -ENODEV;
437
438 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
439 &outbound);
440 if (ret < 0)
441 return ret;
442 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
443}
444static DEVICE_ATTR_RO(out_write_bytes_avail);
445
446static ssize_t in_intr_mask_show(struct device *dev,
447 struct device_attribute *dev_attr, char *buf)
448{
449 struct hv_device *hv_dev = device_to_hv_device(dev);
450 struct hv_ring_buffer_debug_info inbound;
451 int ret;
452
453 if (!hv_dev->channel)
454 return -ENODEV;
455
456 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
457 if (ret < 0)
458 return ret;
459
460 return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
461}
462static DEVICE_ATTR_RO(in_intr_mask);
463
464static ssize_t in_read_index_show(struct device *dev,
465 struct device_attribute *dev_attr, char *buf)
466{
467 struct hv_device *hv_dev = device_to_hv_device(dev);
468 struct hv_ring_buffer_debug_info inbound;
469 int ret;
470
471 if (!hv_dev->channel)
472 return -ENODEV;
473
474 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
475 if (ret < 0)
476 return ret;
477
478 return sprintf(buf, "%d\n", inbound.current_read_index);
479}
480static DEVICE_ATTR_RO(in_read_index);
481
482static ssize_t in_write_index_show(struct device *dev,
483 struct device_attribute *dev_attr, char *buf)
484{
485 struct hv_device *hv_dev = device_to_hv_device(dev);
486 struct hv_ring_buffer_debug_info inbound;
487 int ret;
488
489 if (!hv_dev->channel)
490 return -ENODEV;
491
492 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
493 if (ret < 0)
494 return ret;
495
496 return sprintf(buf, "%d\n", inbound.current_write_index);
497}
498static DEVICE_ATTR_RO(in_write_index);
499
500static ssize_t in_read_bytes_avail_show(struct device *dev,
501 struct device_attribute *dev_attr,
502 char *buf)
503{
504 struct hv_device *hv_dev = device_to_hv_device(dev);
505 struct hv_ring_buffer_debug_info inbound;
506 int ret;
507
508 if (!hv_dev->channel)
509 return -ENODEV;
510
511 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
512 if (ret < 0)
513 return ret;
514
515 return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
516}
517static DEVICE_ATTR_RO(in_read_bytes_avail);
518
519static ssize_t in_write_bytes_avail_show(struct device *dev,
520 struct device_attribute *dev_attr,
521 char *buf)
522{
523 struct hv_device *hv_dev = device_to_hv_device(dev);
524 struct hv_ring_buffer_debug_info inbound;
525 int ret;
526
527 if (!hv_dev->channel)
528 return -ENODEV;
529
530 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
531 if (ret < 0)
532 return ret;
533
534 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
535}
536static DEVICE_ATTR_RO(in_write_bytes_avail);
537
538static ssize_t channel_vp_mapping_show(struct device *dev,
539 struct device_attribute *dev_attr,
540 char *buf)
541{
542 struct hv_device *hv_dev = device_to_hv_device(dev);
543 struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
544 int buf_size = PAGE_SIZE, n_written, tot_written;
545 struct list_head *cur;
546
547 if (!channel)
548 return -ENODEV;
549
550 mutex_lock(&vmbus_connection.channel_mutex);
551
552 tot_written = snprintf(buf, buf_size, "%u:%u\n",
553 channel->offermsg.child_relid, channel->target_cpu);
554
555 list_for_each(cur, &channel->sc_list) {
556 if (tot_written >= buf_size - 1)
557 break;
558
559 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
560 n_written = scnprintf(buf + tot_written,
561 buf_size - tot_written,
562 "%u:%u\n",
563 cur_sc->offermsg.child_relid,
564 cur_sc->target_cpu);
565 tot_written += n_written;
566 }
567
568 mutex_unlock(&vmbus_connection.channel_mutex);
569
570 return tot_written;
571}
572static DEVICE_ATTR_RO(channel_vp_mapping);
573
574static ssize_t vendor_show(struct device *dev,
575 struct device_attribute *dev_attr,
576 char *buf)
577{
578 struct hv_device *hv_dev = device_to_hv_device(dev);
579
580 return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
581}
582static DEVICE_ATTR_RO(vendor);
583
584static ssize_t device_show(struct device *dev,
585 struct device_attribute *dev_attr,
586 char *buf)
587{
588 struct hv_device *hv_dev = device_to_hv_device(dev);
589
590 return sprintf(buf, "0x%x\n", hv_dev->device_id);
591}
592static DEVICE_ATTR_RO(device);
593
594static ssize_t driver_override_store(struct device *dev,
595 struct device_attribute *attr,
596 const char *buf, size_t count)
597{
598 struct hv_device *hv_dev = device_to_hv_device(dev);
599 int ret;
600
601 ret = driver_set_override(dev, &hv_dev->driver_override, buf, count);
602 if (ret)
603 return ret;
604
605 return count;
606}
607
608static ssize_t driver_override_show(struct device *dev,
609 struct device_attribute *attr, char *buf)
610{
611 struct hv_device *hv_dev = device_to_hv_device(dev);
612 ssize_t len;
613
614 device_lock(dev);
615 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
616 device_unlock(dev);
617
618 return len;
619}
620static DEVICE_ATTR_RW(driver_override);
621
622/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
623static struct attribute *vmbus_dev_attrs[] = {
624 &dev_attr_id.attr,
625 &dev_attr_state.attr,
626 &dev_attr_monitor_id.attr,
627 &dev_attr_class_id.attr,
628 &dev_attr_device_id.attr,
629 &dev_attr_modalias.attr,
630#ifdef CONFIG_NUMA
631 &dev_attr_numa_node.attr,
632#endif
633 &dev_attr_server_monitor_pending.attr,
634 &dev_attr_client_monitor_pending.attr,
635 &dev_attr_server_monitor_latency.attr,
636 &dev_attr_client_monitor_latency.attr,
637 &dev_attr_server_monitor_conn_id.attr,
638 &dev_attr_client_monitor_conn_id.attr,
639 &dev_attr_out_intr_mask.attr,
640 &dev_attr_out_read_index.attr,
641 &dev_attr_out_write_index.attr,
642 &dev_attr_out_read_bytes_avail.attr,
643 &dev_attr_out_write_bytes_avail.attr,
644 &dev_attr_in_intr_mask.attr,
645 &dev_attr_in_read_index.attr,
646 &dev_attr_in_write_index.attr,
647 &dev_attr_in_read_bytes_avail.attr,
648 &dev_attr_in_write_bytes_avail.attr,
649 &dev_attr_channel_vp_mapping.attr,
650 &dev_attr_vendor.attr,
651 &dev_attr_device.attr,
652 &dev_attr_driver_override.attr,
653 NULL,
654};
655
656/*
657 * Device-level attribute_group callback function. Returns the permission for
658 * each attribute, and returns 0 if an attribute is not visible.
659 */
660static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
661 struct attribute *attr, int idx)
662{
663 struct device *dev = kobj_to_dev(kobj);
664 const struct hv_device *hv_dev = device_to_hv_device(dev);
665
666 /* Hide the monitor attributes if the monitor mechanism is not used. */
667 if (!hv_dev->channel->offermsg.monitor_allocated &&
668 (attr == &dev_attr_monitor_id.attr ||
669 attr == &dev_attr_server_monitor_pending.attr ||
670 attr == &dev_attr_client_monitor_pending.attr ||
671 attr == &dev_attr_server_monitor_latency.attr ||
672 attr == &dev_attr_client_monitor_latency.attr ||
673 attr == &dev_attr_server_monitor_conn_id.attr ||
674 attr == &dev_attr_client_monitor_conn_id.attr))
675 return 0;
676
677 return attr->mode;
678}
679
680static const struct attribute_group vmbus_dev_group = {
681 .attrs = vmbus_dev_attrs,
682 .is_visible = vmbus_dev_attr_is_visible
683};
684__ATTRIBUTE_GROUPS(vmbus_dev);
685
686/* Set up the attribute for /sys/bus/vmbus/hibernation */
687static ssize_t hibernation_show(struct bus_type *bus, char *buf)
688{
689 return sprintf(buf, "%d\n", !!hv_is_hibernation_supported());
690}
691
692static BUS_ATTR_RO(hibernation);
693
694static struct attribute *vmbus_bus_attrs[] = {
695 &bus_attr_hibernation.attr,
696 NULL,
697};
698static const struct attribute_group vmbus_bus_group = {
699 .attrs = vmbus_bus_attrs,
700};
701__ATTRIBUTE_GROUPS(vmbus_bus);
702
703/*
704 * vmbus_uevent - add uevent for our device
705 *
706 * This routine is invoked when a device is added or removed on the vmbus to
707 * generate a uevent to udev in the userspace. The udev will then look at its
708 * rule and the uevent generated here to load the appropriate driver
709 *
710 * The alias string will be of the form vmbus:guid where guid is the string
711 * representation of the device guid (each byte of the guid will be
712 * represented with two hex characters.
713 */
714static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
715{
716 struct hv_device *dev = device_to_hv_device(device);
717 const char *format = "MODALIAS=vmbus:%*phN";
718
719 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
720}
721
722static const struct hv_vmbus_device_id *
723hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
724{
725 if (id == NULL)
726 return NULL; /* empty device table */
727
728 for (; !guid_is_null(&id->guid); id++)
729 if (guid_equal(&id->guid, guid))
730 return id;
731
732 return NULL;
733}
734
735static const struct hv_vmbus_device_id *
736hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
737{
738 const struct hv_vmbus_device_id *id = NULL;
739 struct vmbus_dynid *dynid;
740
741 spin_lock(&drv->dynids.lock);
742 list_for_each_entry(dynid, &drv->dynids.list, node) {
743 if (guid_equal(&dynid->id.guid, guid)) {
744 id = &dynid->id;
745 break;
746 }
747 }
748 spin_unlock(&drv->dynids.lock);
749
750 return id;
751}
752
753static const struct hv_vmbus_device_id vmbus_device_null;
754
755/*
756 * Return a matching hv_vmbus_device_id pointer.
757 * If there is no match, return NULL.
758 */
759static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
760 struct hv_device *dev)
761{
762 const guid_t *guid = &dev->dev_type;
763 const struct hv_vmbus_device_id *id;
764
765 /* When driver_override is set, only bind to the matching driver */
766 if (dev->driver_override && strcmp(dev->driver_override, drv->name))
767 return NULL;
768
769 /* Look at the dynamic ids first, before the static ones */
770 id = hv_vmbus_dynid_match(drv, guid);
771 if (!id)
772 id = hv_vmbus_dev_match(drv->id_table, guid);
773
774 /* driver_override will always match, send a dummy id */
775 if (!id && dev->driver_override)
776 id = &vmbus_device_null;
777
778 return id;
779}
780
781/* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
782static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
783{
784 struct vmbus_dynid *dynid;
785
786 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
787 if (!dynid)
788 return -ENOMEM;
789
790 dynid->id.guid = *guid;
791
792 spin_lock(&drv->dynids.lock);
793 list_add_tail(&dynid->node, &drv->dynids.list);
794 spin_unlock(&drv->dynids.lock);
795
796 return driver_attach(&drv->driver);
797}
798
799static void vmbus_free_dynids(struct hv_driver *drv)
800{
801 struct vmbus_dynid *dynid, *n;
802
803 spin_lock(&drv->dynids.lock);
804 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
805 list_del(&dynid->node);
806 kfree(dynid);
807 }
808 spin_unlock(&drv->dynids.lock);
809}
810
811/*
812 * store_new_id - sysfs frontend to vmbus_add_dynid()
813 *
814 * Allow GUIDs to be added to an existing driver via sysfs.
815 */
816static ssize_t new_id_store(struct device_driver *driver, const char *buf,
817 size_t count)
818{
819 struct hv_driver *drv = drv_to_hv_drv(driver);
820 guid_t guid;
821 ssize_t retval;
822
823 retval = guid_parse(buf, &guid);
824 if (retval)
825 return retval;
826
827 if (hv_vmbus_dynid_match(drv, &guid))
828 return -EEXIST;
829
830 retval = vmbus_add_dynid(drv, &guid);
831 if (retval)
832 return retval;
833 return count;
834}
835static DRIVER_ATTR_WO(new_id);
836
837/*
838 * store_remove_id - remove a PCI device ID from this driver
839 *
840 * Removes a dynamic pci device ID to this driver.
841 */
842static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
843 size_t count)
844{
845 struct hv_driver *drv = drv_to_hv_drv(driver);
846 struct vmbus_dynid *dynid, *n;
847 guid_t guid;
848 ssize_t retval;
849
850 retval = guid_parse(buf, &guid);
851 if (retval)
852 return retval;
853
854 retval = -ENODEV;
855 spin_lock(&drv->dynids.lock);
856 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
857 struct hv_vmbus_device_id *id = &dynid->id;
858
859 if (guid_equal(&id->guid, &guid)) {
860 list_del(&dynid->node);
861 kfree(dynid);
862 retval = count;
863 break;
864 }
865 }
866 spin_unlock(&drv->dynids.lock);
867
868 return retval;
869}
870static DRIVER_ATTR_WO(remove_id);
871
872static struct attribute *vmbus_drv_attrs[] = {
873 &driver_attr_new_id.attr,
874 &driver_attr_remove_id.attr,
875 NULL,
876};
877ATTRIBUTE_GROUPS(vmbus_drv);
878
879
880/*
881 * vmbus_match - Attempt to match the specified device to the specified driver
882 */
883static int vmbus_match(struct device *device, struct device_driver *driver)
884{
885 struct hv_driver *drv = drv_to_hv_drv(driver);
886 struct hv_device *hv_dev = device_to_hv_device(device);
887
888 /* The hv_sock driver handles all hv_sock offers. */
889 if (is_hvsock_channel(hv_dev->channel))
890 return drv->hvsock;
891
892 if (hv_vmbus_get_id(drv, hv_dev))
893 return 1;
894
895 return 0;
896}
897
898/*
899 * vmbus_probe - Add the new vmbus's child device
900 */
901static int vmbus_probe(struct device *child_device)
902{
903 int ret = 0;
904 struct hv_driver *drv =
905 drv_to_hv_drv(child_device->driver);
906 struct hv_device *dev = device_to_hv_device(child_device);
907 const struct hv_vmbus_device_id *dev_id;
908
909 dev_id = hv_vmbus_get_id(drv, dev);
910 if (drv->probe) {
911 ret = drv->probe(dev, dev_id);
912 if (ret != 0)
913 pr_err("probe failed for device %s (%d)\n",
914 dev_name(child_device), ret);
915
916 } else {
917 pr_err("probe not set for driver %s\n",
918 dev_name(child_device));
919 ret = -ENODEV;
920 }
921 return ret;
922}
923
924/*
925 * vmbus_dma_configure -- Configure DMA coherence for VMbus device
926 */
927static int vmbus_dma_configure(struct device *child_device)
928{
929 /*
930 * On ARM64, propagate the DMA coherence setting from the top level
931 * VMbus ACPI device to the child VMbus device being added here.
932 * On x86/x64 coherence is assumed and these calls have no effect.
933 */
934 hv_setup_dma_ops(child_device,
935 device_get_dma_attr(&hv_acpi_dev->dev) == DEV_DMA_COHERENT);
936 return 0;
937}
938
939/*
940 * vmbus_remove - Remove a vmbus device
941 */
942static void vmbus_remove(struct device *child_device)
943{
944 struct hv_driver *drv;
945 struct hv_device *dev = device_to_hv_device(child_device);
946
947 if (child_device->driver) {
948 drv = drv_to_hv_drv(child_device->driver);
949 if (drv->remove)
950 drv->remove(dev);
951 }
952}
953
954/*
955 * vmbus_shutdown - Shutdown a vmbus device
956 */
957static void vmbus_shutdown(struct device *child_device)
958{
959 struct hv_driver *drv;
960 struct hv_device *dev = device_to_hv_device(child_device);
961
962
963 /* The device may not be attached yet */
964 if (!child_device->driver)
965 return;
966
967 drv = drv_to_hv_drv(child_device->driver);
968
969 if (drv->shutdown)
970 drv->shutdown(dev);
971}
972
973#ifdef CONFIG_PM_SLEEP
974/*
975 * vmbus_suspend - Suspend a vmbus device
976 */
977static int vmbus_suspend(struct device *child_device)
978{
979 struct hv_driver *drv;
980 struct hv_device *dev = device_to_hv_device(child_device);
981
982 /* The device may not be attached yet */
983 if (!child_device->driver)
984 return 0;
985
986 drv = drv_to_hv_drv(child_device->driver);
987 if (!drv->suspend)
988 return -EOPNOTSUPP;
989
990 return drv->suspend(dev);
991}
992
993/*
994 * vmbus_resume - Resume a vmbus device
995 */
996static int vmbus_resume(struct device *child_device)
997{
998 struct hv_driver *drv;
999 struct hv_device *dev = device_to_hv_device(child_device);
1000
1001 /* The device may not be attached yet */
1002 if (!child_device->driver)
1003 return 0;
1004
1005 drv = drv_to_hv_drv(child_device->driver);
1006 if (!drv->resume)
1007 return -EOPNOTSUPP;
1008
1009 return drv->resume(dev);
1010}
1011#else
1012#define vmbus_suspend NULL
1013#define vmbus_resume NULL
1014#endif /* CONFIG_PM_SLEEP */
1015
1016/*
1017 * vmbus_device_release - Final callback release of the vmbus child device
1018 */
1019static void vmbus_device_release(struct device *device)
1020{
1021 struct hv_device *hv_dev = device_to_hv_device(device);
1022 struct vmbus_channel *channel = hv_dev->channel;
1023
1024 hv_debug_rm_dev_dir(hv_dev);
1025
1026 mutex_lock(&vmbus_connection.channel_mutex);
1027 hv_process_channel_removal(channel);
1028 mutex_unlock(&vmbus_connection.channel_mutex);
1029 kfree(hv_dev);
1030}
1031
1032/*
1033 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
1034 *
1035 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
1036 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
1037 * is no way to wake up a Generation-2 VM.
1038 *
1039 * The other 4 ops are for hibernation.
1040 */
1041
1042static const struct dev_pm_ops vmbus_pm = {
1043 .suspend_noirq = NULL,
1044 .resume_noirq = NULL,
1045 .freeze_noirq = vmbus_suspend,
1046 .thaw_noirq = vmbus_resume,
1047 .poweroff_noirq = vmbus_suspend,
1048 .restore_noirq = vmbus_resume,
1049};
1050
1051/* The one and only one */
1052static struct bus_type hv_bus = {
1053 .name = "vmbus",
1054 .match = vmbus_match,
1055 .shutdown = vmbus_shutdown,
1056 .remove = vmbus_remove,
1057 .probe = vmbus_probe,
1058 .uevent = vmbus_uevent,
1059 .dma_configure = vmbus_dma_configure,
1060 .dev_groups = vmbus_dev_groups,
1061 .drv_groups = vmbus_drv_groups,
1062 .bus_groups = vmbus_bus_groups,
1063 .pm = &vmbus_pm,
1064};
1065
1066struct onmessage_work_context {
1067 struct work_struct work;
1068 struct {
1069 struct hv_message_header header;
1070 u8 payload[];
1071 } msg;
1072};
1073
1074static void vmbus_onmessage_work(struct work_struct *work)
1075{
1076 struct onmessage_work_context *ctx;
1077
1078 /* Do not process messages if we're in DISCONNECTED state */
1079 if (vmbus_connection.conn_state == DISCONNECTED)
1080 return;
1081
1082 ctx = container_of(work, struct onmessage_work_context,
1083 work);
1084 vmbus_onmessage((struct vmbus_channel_message_header *)
1085 &ctx->msg.payload);
1086 kfree(ctx);
1087}
1088
1089void vmbus_on_msg_dpc(unsigned long data)
1090{
1091 struct hv_per_cpu_context *hv_cpu = (void *)data;
1092 void *page_addr = hv_cpu->synic_message_page;
1093 struct hv_message msg_copy, *msg = (struct hv_message *)page_addr +
1094 VMBUS_MESSAGE_SINT;
1095 struct vmbus_channel_message_header *hdr;
1096 enum vmbus_channel_message_type msgtype;
1097 const struct vmbus_channel_message_table_entry *entry;
1098 struct onmessage_work_context *ctx;
1099 __u8 payload_size;
1100 u32 message_type;
1101
1102 /*
1103 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1104 * it is being used in 'struct vmbus_channel_message_header' definition
1105 * which is supposed to match hypervisor ABI.
1106 */
1107 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1108
1109 /*
1110 * Since the message is in memory shared with the host, an erroneous or
1111 * malicious Hyper-V could modify the message while vmbus_on_msg_dpc()
1112 * or individual message handlers are executing; to prevent this, copy
1113 * the message into private memory.
1114 */
1115 memcpy(&msg_copy, msg, sizeof(struct hv_message));
1116
1117 message_type = msg_copy.header.message_type;
1118 if (message_type == HVMSG_NONE)
1119 /* no msg */
1120 return;
1121
1122 hdr = (struct vmbus_channel_message_header *)msg_copy.u.payload;
1123 msgtype = hdr->msgtype;
1124
1125 trace_vmbus_on_msg_dpc(hdr);
1126
1127 if (msgtype >= CHANNELMSG_COUNT) {
1128 WARN_ONCE(1, "unknown msgtype=%d\n", msgtype);
1129 goto msg_handled;
1130 }
1131
1132 payload_size = msg_copy.header.payload_size;
1133 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1134 WARN_ONCE(1, "payload size is too large (%d)\n", payload_size);
1135 goto msg_handled;
1136 }
1137
1138 entry = &channel_message_table[msgtype];
1139
1140 if (!entry->message_handler)
1141 goto msg_handled;
1142
1143 if (payload_size < entry->min_payload_len) {
1144 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n", msgtype, payload_size);
1145 goto msg_handled;
1146 }
1147
1148 if (entry->handler_type == VMHT_BLOCKING) {
1149 ctx = kmalloc(struct_size(ctx, msg.payload, payload_size), GFP_ATOMIC);
1150 if (ctx == NULL)
1151 return;
1152
1153 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1154 ctx->msg.header = msg_copy.header;
1155 memcpy(&ctx->msg.payload, msg_copy.u.payload, payload_size);
1156
1157 /*
1158 * The host can generate a rescind message while we
1159 * may still be handling the original offer. We deal with
1160 * this condition by relying on the synchronization provided
1161 * by offer_in_progress and by channel_mutex. See also the
1162 * inline comments in vmbus_onoffer_rescind().
1163 */
1164 switch (msgtype) {
1165 case CHANNELMSG_RESCIND_CHANNELOFFER:
1166 /*
1167 * If we are handling the rescind message;
1168 * schedule the work on the global work queue.
1169 *
1170 * The OFFER message and the RESCIND message should
1171 * not be handled by the same serialized work queue,
1172 * because the OFFER handler may call vmbus_open(),
1173 * which tries to open the channel by sending an
1174 * OPEN_CHANNEL message to the host and waits for
1175 * the host's response; however, if the host has
1176 * rescinded the channel before it receives the
1177 * OPEN_CHANNEL message, the host just silently
1178 * ignores the OPEN_CHANNEL message; as a result,
1179 * the guest's OFFER handler hangs for ever, if we
1180 * handle the RESCIND message in the same serialized
1181 * work queue: the RESCIND handler can not start to
1182 * run before the OFFER handler finishes.
1183 */
1184 if (vmbus_connection.ignore_any_offer_msg)
1185 break;
1186 queue_work(vmbus_connection.rescind_work_queue, &ctx->work);
1187 break;
1188
1189 case CHANNELMSG_OFFERCHANNEL:
1190 /*
1191 * The host sends the offer message of a given channel
1192 * before sending the rescind message of the same
1193 * channel. These messages are sent to the guest's
1194 * connect CPU; the guest then starts processing them
1195 * in the tasklet handler on this CPU:
1196 *
1197 * VMBUS_CONNECT_CPU
1198 *
1199 * [vmbus_on_msg_dpc()]
1200 * atomic_inc() // CHANNELMSG_OFFERCHANNEL
1201 * queue_work()
1202 * ...
1203 * [vmbus_on_msg_dpc()]
1204 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
1205 *
1206 * We rely on the memory-ordering properties of the
1207 * queue_work() and schedule_work() primitives, which
1208 * guarantee that the atomic increment will be visible
1209 * to the CPUs which will execute the offer & rescind
1210 * works by the time these works will start execution.
1211 */
1212 if (vmbus_connection.ignore_any_offer_msg)
1213 break;
1214 atomic_inc(&vmbus_connection.offer_in_progress);
1215 fallthrough;
1216
1217 default:
1218 queue_work(vmbus_connection.work_queue, &ctx->work);
1219 }
1220 } else
1221 entry->message_handler(hdr);
1222
1223msg_handled:
1224 vmbus_signal_eom(msg, message_type);
1225}
1226
1227#ifdef CONFIG_PM_SLEEP
1228/*
1229 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1230 * hibernation, because hv_sock connections can not persist across hibernation.
1231 */
1232static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1233{
1234 struct onmessage_work_context *ctx;
1235 struct vmbus_channel_rescind_offer *rescind;
1236
1237 WARN_ON(!is_hvsock_channel(channel));
1238
1239 /*
1240 * Allocation size is small and the allocation should really not fail,
1241 * otherwise the state of the hv_sock connections ends up in limbo.
1242 */
1243 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1244 GFP_KERNEL | __GFP_NOFAIL);
1245
1246 /*
1247 * So far, these are not really used by Linux. Just set them to the
1248 * reasonable values conforming to the definitions of the fields.
1249 */
1250 ctx->msg.header.message_type = 1;
1251 ctx->msg.header.payload_size = sizeof(*rescind);
1252
1253 /* These values are actually used by Linux. */
1254 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
1255 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1256 rescind->child_relid = channel->offermsg.child_relid;
1257
1258 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1259
1260 queue_work(vmbus_connection.work_queue, &ctx->work);
1261}
1262#endif /* CONFIG_PM_SLEEP */
1263
1264/*
1265 * Schedule all channels with events pending
1266 */
1267static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1268{
1269 unsigned long *recv_int_page;
1270 u32 maxbits, relid;
1271
1272 /*
1273 * The event page can be directly checked to get the id of
1274 * the channel that has the interrupt pending.
1275 */
1276 void *page_addr = hv_cpu->synic_event_page;
1277 union hv_synic_event_flags *event
1278 = (union hv_synic_event_flags *)page_addr +
1279 VMBUS_MESSAGE_SINT;
1280
1281 maxbits = HV_EVENT_FLAGS_COUNT;
1282 recv_int_page = event->flags;
1283
1284 if (unlikely(!recv_int_page))
1285 return;
1286
1287 for_each_set_bit(relid, recv_int_page, maxbits) {
1288 void (*callback_fn)(void *context);
1289 struct vmbus_channel *channel;
1290
1291 if (!sync_test_and_clear_bit(relid, recv_int_page))
1292 continue;
1293
1294 /* Special case - vmbus channel protocol msg */
1295 if (relid == 0)
1296 continue;
1297
1298 /*
1299 * Pairs with the kfree_rcu() in vmbus_chan_release().
1300 * Guarantees that the channel data structure doesn't
1301 * get freed while the channel pointer below is being
1302 * dereferenced.
1303 */
1304 rcu_read_lock();
1305
1306 /* Find channel based on relid */
1307 channel = relid2channel(relid);
1308 if (channel == NULL)
1309 goto sched_unlock_rcu;
1310
1311 if (channel->rescind)
1312 goto sched_unlock_rcu;
1313
1314 /*
1315 * Make sure that the ring buffer data structure doesn't get
1316 * freed while we dereference the ring buffer pointer. Test
1317 * for the channel's onchannel_callback being NULL within a
1318 * sched_lock critical section. See also the inline comments
1319 * in vmbus_reset_channel_cb().
1320 */
1321 spin_lock(&channel->sched_lock);
1322
1323 callback_fn = channel->onchannel_callback;
1324 if (unlikely(callback_fn == NULL))
1325 goto sched_unlock;
1326
1327 trace_vmbus_chan_sched(channel);
1328
1329 ++channel->interrupts;
1330
1331 switch (channel->callback_mode) {
1332 case HV_CALL_ISR:
1333 (*callback_fn)(channel->channel_callback_context);
1334 break;
1335
1336 case HV_CALL_BATCHED:
1337 hv_begin_read(&channel->inbound);
1338 fallthrough;
1339 case HV_CALL_DIRECT:
1340 tasklet_schedule(&channel->callback_event);
1341 }
1342
1343sched_unlock:
1344 spin_unlock(&channel->sched_lock);
1345sched_unlock_rcu:
1346 rcu_read_unlock();
1347 }
1348}
1349
1350static void vmbus_isr(void)
1351{
1352 struct hv_per_cpu_context *hv_cpu
1353 = this_cpu_ptr(hv_context.cpu_context);
1354 void *page_addr;
1355 struct hv_message *msg;
1356
1357 vmbus_chan_sched(hv_cpu);
1358
1359 page_addr = hv_cpu->synic_message_page;
1360 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1361
1362 /* Check if there are actual msgs to be processed */
1363 if (msg->header.message_type != HVMSG_NONE) {
1364 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1365 hv_stimer0_isr();
1366 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1367 } else
1368 tasklet_schedule(&hv_cpu->msg_dpc);
1369 }
1370
1371 add_interrupt_randomness(vmbus_interrupt);
1372}
1373
1374static irqreturn_t vmbus_percpu_isr(int irq, void *dev_id)
1375{
1376 vmbus_isr();
1377 return IRQ_HANDLED;
1378}
1379
1380/*
1381 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1382 * buffer and call into Hyper-V to transfer the data.
1383 */
1384static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1385 enum kmsg_dump_reason reason)
1386{
1387 struct kmsg_dump_iter iter;
1388 size_t bytes_written;
1389
1390 /* We are only interested in panics. */
1391 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1392 return;
1393
1394 /*
1395 * Write dump contents to the page. No need to synchronize; panic should
1396 * be single-threaded.
1397 */
1398 kmsg_dump_rewind(&iter);
1399 kmsg_dump_get_buffer(&iter, false, hv_panic_page, HV_HYP_PAGE_SIZE,
1400 &bytes_written);
1401 if (!bytes_written)
1402 return;
1403 /*
1404 * P3 to contain the physical address of the panic page & P4 to
1405 * contain the size of the panic data in that page. Rest of the
1406 * registers are no-op when the NOTIFY_MSG flag is set.
1407 */
1408 hv_set_register(HV_REGISTER_CRASH_P0, 0);
1409 hv_set_register(HV_REGISTER_CRASH_P1, 0);
1410 hv_set_register(HV_REGISTER_CRASH_P2, 0);
1411 hv_set_register(HV_REGISTER_CRASH_P3, virt_to_phys(hv_panic_page));
1412 hv_set_register(HV_REGISTER_CRASH_P4, bytes_written);
1413
1414 /*
1415 * Let Hyper-V know there is crash data available along with
1416 * the panic message.
1417 */
1418 hv_set_register(HV_REGISTER_CRASH_CTL,
1419 (HV_CRASH_CTL_CRASH_NOTIFY | HV_CRASH_CTL_CRASH_NOTIFY_MSG));
1420}
1421
1422static struct kmsg_dumper hv_kmsg_dumper = {
1423 .dump = hv_kmsg_dump,
1424};
1425
1426static void hv_kmsg_dump_register(void)
1427{
1428 int ret;
1429
1430 hv_panic_page = hv_alloc_hyperv_zeroed_page();
1431 if (!hv_panic_page) {
1432 pr_err("Hyper-V: panic message page memory allocation failed\n");
1433 return;
1434 }
1435
1436 ret = kmsg_dump_register(&hv_kmsg_dumper);
1437 if (ret) {
1438 pr_err("Hyper-V: kmsg dump register error 0x%x\n", ret);
1439 hv_free_hyperv_page((unsigned long)hv_panic_page);
1440 hv_panic_page = NULL;
1441 }
1442}
1443
1444static struct ctl_table_header *hv_ctl_table_hdr;
1445
1446/*
1447 * sysctl option to allow the user to control whether kmsg data should be
1448 * reported to Hyper-V on panic.
1449 */
1450static struct ctl_table hv_ctl_table[] = {
1451 {
1452 .procname = "hyperv_record_panic_msg",
1453 .data = &sysctl_record_panic_msg,
1454 .maxlen = sizeof(int),
1455 .mode = 0644,
1456 .proc_handler = proc_dointvec_minmax,
1457 .extra1 = SYSCTL_ZERO,
1458 .extra2 = SYSCTL_ONE
1459 },
1460 {}
1461};
1462
1463static struct ctl_table hv_root_table[] = {
1464 {
1465 .procname = "kernel",
1466 .mode = 0555,
1467 .child = hv_ctl_table
1468 },
1469 {}
1470};
1471
1472/*
1473 * vmbus_bus_init -Main vmbus driver initialization routine.
1474 *
1475 * Here, we
1476 * - initialize the vmbus driver context
1477 * - invoke the vmbus hv main init routine
1478 * - retrieve the channel offers
1479 */
1480static int vmbus_bus_init(void)
1481{
1482 int ret;
1483
1484 ret = hv_init();
1485 if (ret != 0) {
1486 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1487 return ret;
1488 }
1489
1490 ret = bus_register(&hv_bus);
1491 if (ret)
1492 return ret;
1493
1494 /*
1495 * VMbus interrupts are best modeled as per-cpu interrupts. If
1496 * on an architecture with support for per-cpu IRQs (e.g. ARM64),
1497 * allocate a per-cpu IRQ using standard Linux kernel functionality.
1498 * If not on such an architecture (e.g., x86/x64), then rely on
1499 * code in the arch-specific portion of the code tree to connect
1500 * the VMbus interrupt handler.
1501 */
1502
1503 if (vmbus_irq == -1) {
1504 hv_setup_vmbus_handler(vmbus_isr);
1505 } else {
1506 vmbus_evt = alloc_percpu(long);
1507 ret = request_percpu_irq(vmbus_irq, vmbus_percpu_isr,
1508 "Hyper-V VMbus", vmbus_evt);
1509 if (ret) {
1510 pr_err("Can't request Hyper-V VMbus IRQ %d, Err %d",
1511 vmbus_irq, ret);
1512 free_percpu(vmbus_evt);
1513 goto err_setup;
1514 }
1515 }
1516
1517 ret = hv_synic_alloc();
1518 if (ret)
1519 goto err_alloc;
1520
1521 /*
1522 * Initialize the per-cpu interrupt state and stimer state.
1523 * Then connect to the host.
1524 */
1525 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1526 hv_synic_init, hv_synic_cleanup);
1527 if (ret < 0)
1528 goto err_cpuhp;
1529 hyperv_cpuhp_online = ret;
1530
1531 ret = vmbus_connect();
1532 if (ret)
1533 goto err_connect;
1534
1535 if (hv_is_isolation_supported())
1536 sysctl_record_panic_msg = 0;
1537
1538 /*
1539 * Only register if the crash MSRs are available
1540 */
1541 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1542 u64 hyperv_crash_ctl;
1543 /*
1544 * Panic message recording (sysctl_record_panic_msg)
1545 * is enabled by default in non-isolated guests and
1546 * disabled by default in isolated guests; the panic
1547 * message recording won't be available in isolated
1548 * guests should the following registration fail.
1549 */
1550 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1551 if (!hv_ctl_table_hdr)
1552 pr_err("Hyper-V: sysctl table register error");
1553
1554 /*
1555 * Register for panic kmsg callback only if the right
1556 * capability is supported by the hypervisor.
1557 */
1558 hyperv_crash_ctl = hv_get_register(HV_REGISTER_CRASH_CTL);
1559 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG)
1560 hv_kmsg_dump_register();
1561
1562 register_die_notifier(&hyperv_die_report_block);
1563 atomic_notifier_chain_register(&panic_notifier_list,
1564 &hyperv_panic_report_block);
1565 }
1566
1567 /*
1568 * Always register the vmbus unload panic notifier because we
1569 * need to shut the VMbus channel connection on panic.
1570 */
1571 atomic_notifier_chain_register(&panic_notifier_list,
1572 &hyperv_panic_vmbus_unload_block);
1573
1574 vmbus_request_offers();
1575
1576 return 0;
1577
1578err_connect:
1579 cpuhp_remove_state(hyperv_cpuhp_online);
1580err_cpuhp:
1581 hv_synic_free();
1582err_alloc:
1583 if (vmbus_irq == -1) {
1584 hv_remove_vmbus_handler();
1585 } else {
1586 free_percpu_irq(vmbus_irq, vmbus_evt);
1587 free_percpu(vmbus_evt);
1588 }
1589err_setup:
1590 bus_unregister(&hv_bus);
1591 unregister_sysctl_table(hv_ctl_table_hdr);
1592 hv_ctl_table_hdr = NULL;
1593 return ret;
1594}
1595
1596/**
1597 * __vmbus_driver_register() - Register a vmbus's driver
1598 * @hv_driver: Pointer to driver structure you want to register
1599 * @owner: owner module of the drv
1600 * @mod_name: module name string
1601 *
1602 * Registers the given driver with Linux through the 'driver_register()' call
1603 * and sets up the hyper-v vmbus handling for this driver.
1604 * It will return the state of the 'driver_register()' call.
1605 *
1606 */
1607int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1608{
1609 int ret;
1610
1611 pr_info("registering driver %s\n", hv_driver->name);
1612
1613 ret = vmbus_exists();
1614 if (ret < 0)
1615 return ret;
1616
1617 hv_driver->driver.name = hv_driver->name;
1618 hv_driver->driver.owner = owner;
1619 hv_driver->driver.mod_name = mod_name;
1620 hv_driver->driver.bus = &hv_bus;
1621
1622 spin_lock_init(&hv_driver->dynids.lock);
1623 INIT_LIST_HEAD(&hv_driver->dynids.list);
1624
1625 ret = driver_register(&hv_driver->driver);
1626
1627 return ret;
1628}
1629EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1630
1631/**
1632 * vmbus_driver_unregister() - Unregister a vmbus's driver
1633 * @hv_driver: Pointer to driver structure you want to
1634 * un-register
1635 *
1636 * Un-register the given driver that was previous registered with a call to
1637 * vmbus_driver_register()
1638 */
1639void vmbus_driver_unregister(struct hv_driver *hv_driver)
1640{
1641 pr_info("unregistering driver %s\n", hv_driver->name);
1642
1643 if (!vmbus_exists()) {
1644 driver_unregister(&hv_driver->driver);
1645 vmbus_free_dynids(hv_driver);
1646 }
1647}
1648EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1649
1650
1651/*
1652 * Called when last reference to channel is gone.
1653 */
1654static void vmbus_chan_release(struct kobject *kobj)
1655{
1656 struct vmbus_channel *channel
1657 = container_of(kobj, struct vmbus_channel, kobj);
1658
1659 kfree_rcu(channel, rcu);
1660}
1661
1662struct vmbus_chan_attribute {
1663 struct attribute attr;
1664 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1665 ssize_t (*store)(struct vmbus_channel *chan,
1666 const char *buf, size_t count);
1667};
1668#define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1669 struct vmbus_chan_attribute chan_attr_##_name \
1670 = __ATTR(_name, _mode, _show, _store)
1671#define VMBUS_CHAN_ATTR_RW(_name) \
1672 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1673#define VMBUS_CHAN_ATTR_RO(_name) \
1674 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1675#define VMBUS_CHAN_ATTR_WO(_name) \
1676 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1677
1678static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1679 struct attribute *attr, char *buf)
1680{
1681 const struct vmbus_chan_attribute *attribute
1682 = container_of(attr, struct vmbus_chan_attribute, attr);
1683 struct vmbus_channel *chan
1684 = container_of(kobj, struct vmbus_channel, kobj);
1685
1686 if (!attribute->show)
1687 return -EIO;
1688
1689 return attribute->show(chan, buf);
1690}
1691
1692static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1693 struct attribute *attr, const char *buf,
1694 size_t count)
1695{
1696 const struct vmbus_chan_attribute *attribute
1697 = container_of(attr, struct vmbus_chan_attribute, attr);
1698 struct vmbus_channel *chan
1699 = container_of(kobj, struct vmbus_channel, kobj);
1700
1701 if (!attribute->store)
1702 return -EIO;
1703
1704 return attribute->store(chan, buf, count);
1705}
1706
1707static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1708 .show = vmbus_chan_attr_show,
1709 .store = vmbus_chan_attr_store,
1710};
1711
1712static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1713{
1714 struct hv_ring_buffer_info *rbi = &channel->outbound;
1715 ssize_t ret;
1716
1717 mutex_lock(&rbi->ring_buffer_mutex);
1718 if (!rbi->ring_buffer) {
1719 mutex_unlock(&rbi->ring_buffer_mutex);
1720 return -EINVAL;
1721 }
1722
1723 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1724 mutex_unlock(&rbi->ring_buffer_mutex);
1725 return ret;
1726}
1727static VMBUS_CHAN_ATTR_RO(out_mask);
1728
1729static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1730{
1731 struct hv_ring_buffer_info *rbi = &channel->inbound;
1732 ssize_t ret;
1733
1734 mutex_lock(&rbi->ring_buffer_mutex);
1735 if (!rbi->ring_buffer) {
1736 mutex_unlock(&rbi->ring_buffer_mutex);
1737 return -EINVAL;
1738 }
1739
1740 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1741 mutex_unlock(&rbi->ring_buffer_mutex);
1742 return ret;
1743}
1744static VMBUS_CHAN_ATTR_RO(in_mask);
1745
1746static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1747{
1748 struct hv_ring_buffer_info *rbi = &channel->inbound;
1749 ssize_t ret;
1750
1751 mutex_lock(&rbi->ring_buffer_mutex);
1752 if (!rbi->ring_buffer) {
1753 mutex_unlock(&rbi->ring_buffer_mutex);
1754 return -EINVAL;
1755 }
1756
1757 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1758 mutex_unlock(&rbi->ring_buffer_mutex);
1759 return ret;
1760}
1761static VMBUS_CHAN_ATTR_RO(read_avail);
1762
1763static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1764{
1765 struct hv_ring_buffer_info *rbi = &channel->outbound;
1766 ssize_t ret;
1767
1768 mutex_lock(&rbi->ring_buffer_mutex);
1769 if (!rbi->ring_buffer) {
1770 mutex_unlock(&rbi->ring_buffer_mutex);
1771 return -EINVAL;
1772 }
1773
1774 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1775 mutex_unlock(&rbi->ring_buffer_mutex);
1776 return ret;
1777}
1778static VMBUS_CHAN_ATTR_RO(write_avail);
1779
1780static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1781{
1782 return sprintf(buf, "%u\n", channel->target_cpu);
1783}
1784static ssize_t target_cpu_store(struct vmbus_channel *channel,
1785 const char *buf, size_t count)
1786{
1787 u32 target_cpu, origin_cpu;
1788 ssize_t ret = count;
1789
1790 if (vmbus_proto_version < VERSION_WIN10_V4_1)
1791 return -EIO;
1792
1793 if (sscanf(buf, "%uu", &target_cpu) != 1)
1794 return -EIO;
1795
1796 /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1797 if (target_cpu >= nr_cpumask_bits)
1798 return -EINVAL;
1799
1800 if (!cpumask_test_cpu(target_cpu, housekeeping_cpumask(HK_TYPE_MANAGED_IRQ)))
1801 return -EINVAL;
1802
1803 /* No CPUs should come up or down during this. */
1804 cpus_read_lock();
1805
1806 if (!cpu_online(target_cpu)) {
1807 cpus_read_unlock();
1808 return -EINVAL;
1809 }
1810
1811 /*
1812 * Synchronizes target_cpu_store() and channel closure:
1813 *
1814 * { Initially: state = CHANNEL_OPENED }
1815 *
1816 * CPU1 CPU2
1817 *
1818 * [target_cpu_store()] [vmbus_disconnect_ring()]
1819 *
1820 * LOCK channel_mutex LOCK channel_mutex
1821 * LOAD r1 = state LOAD r2 = state
1822 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
1823 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
1824 * [...] SEND CLOSECHANNEL
1825 * UNLOCK channel_mutex UNLOCK channel_mutex
1826 *
1827 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1828 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1829 *
1830 * Note. The host processes the channel messages "sequentially", in
1831 * the order in which they are received on a per-partition basis.
1832 */
1833 mutex_lock(&vmbus_connection.channel_mutex);
1834
1835 /*
1836 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1837 * avoid sending the message and fail here for such channels.
1838 */
1839 if (channel->state != CHANNEL_OPENED_STATE) {
1840 ret = -EIO;
1841 goto cpu_store_unlock;
1842 }
1843
1844 origin_cpu = channel->target_cpu;
1845 if (target_cpu == origin_cpu)
1846 goto cpu_store_unlock;
1847
1848 if (vmbus_send_modifychannel(channel,
1849 hv_cpu_number_to_vp_number(target_cpu))) {
1850 ret = -EIO;
1851 goto cpu_store_unlock;
1852 }
1853
1854 /*
1855 * For version before VERSION_WIN10_V5_3, the following warning holds:
1856 *
1857 * Warning. At this point, there is *no* guarantee that the host will
1858 * have successfully processed the vmbus_send_modifychannel() request.
1859 * See the header comment of vmbus_send_modifychannel() for more info.
1860 *
1861 * Lags in the processing of the above vmbus_send_modifychannel() can
1862 * result in missed interrupts if the "old" target CPU is taken offline
1863 * before Hyper-V starts sending interrupts to the "new" target CPU.
1864 * But apart from this offlining scenario, the code tolerates such
1865 * lags. It will function correctly even if a channel interrupt comes
1866 * in on a CPU that is different from the channel target_cpu value.
1867 */
1868
1869 channel->target_cpu = target_cpu;
1870
1871 /* See init_vp_index(). */
1872 if (hv_is_perf_channel(channel))
1873 hv_update_allocated_cpus(origin_cpu, target_cpu);
1874
1875 /* Currently set only for storvsc channels. */
1876 if (channel->change_target_cpu_callback) {
1877 (*channel->change_target_cpu_callback)(channel,
1878 origin_cpu, target_cpu);
1879 }
1880
1881cpu_store_unlock:
1882 mutex_unlock(&vmbus_connection.channel_mutex);
1883 cpus_read_unlock();
1884 return ret;
1885}
1886static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1887
1888static ssize_t channel_pending_show(struct vmbus_channel *channel,
1889 char *buf)
1890{
1891 return sprintf(buf, "%d\n",
1892 channel_pending(channel,
1893 vmbus_connection.monitor_pages[1]));
1894}
1895static VMBUS_CHAN_ATTR(pending, 0444, channel_pending_show, NULL);
1896
1897static ssize_t channel_latency_show(struct vmbus_channel *channel,
1898 char *buf)
1899{
1900 return sprintf(buf, "%d\n",
1901 channel_latency(channel,
1902 vmbus_connection.monitor_pages[1]));
1903}
1904static VMBUS_CHAN_ATTR(latency, 0444, channel_latency_show, NULL);
1905
1906static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1907{
1908 return sprintf(buf, "%llu\n", channel->interrupts);
1909}
1910static VMBUS_CHAN_ATTR(interrupts, 0444, channel_interrupts_show, NULL);
1911
1912static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1913{
1914 return sprintf(buf, "%llu\n", channel->sig_events);
1915}
1916static VMBUS_CHAN_ATTR(events, 0444, channel_events_show, NULL);
1917
1918static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1919 char *buf)
1920{
1921 return sprintf(buf, "%llu\n",
1922 (unsigned long long)channel->intr_in_full);
1923}
1924static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1925
1926static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1927 char *buf)
1928{
1929 return sprintf(buf, "%llu\n",
1930 (unsigned long long)channel->intr_out_empty);
1931}
1932static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1933
1934static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1935 char *buf)
1936{
1937 return sprintf(buf, "%llu\n",
1938 (unsigned long long)channel->out_full_first);
1939}
1940static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1941
1942static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1943 char *buf)
1944{
1945 return sprintf(buf, "%llu\n",
1946 (unsigned long long)channel->out_full_total);
1947}
1948static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1949
1950static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1951 char *buf)
1952{
1953 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1954}
1955static VMBUS_CHAN_ATTR(monitor_id, 0444, subchannel_monitor_id_show, NULL);
1956
1957static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1958 char *buf)
1959{
1960 return sprintf(buf, "%u\n",
1961 channel->offermsg.offer.sub_channel_index);
1962}
1963static VMBUS_CHAN_ATTR_RO(subchannel_id);
1964
1965static struct attribute *vmbus_chan_attrs[] = {
1966 &chan_attr_out_mask.attr,
1967 &chan_attr_in_mask.attr,
1968 &chan_attr_read_avail.attr,
1969 &chan_attr_write_avail.attr,
1970 &chan_attr_cpu.attr,
1971 &chan_attr_pending.attr,
1972 &chan_attr_latency.attr,
1973 &chan_attr_interrupts.attr,
1974 &chan_attr_events.attr,
1975 &chan_attr_intr_in_full.attr,
1976 &chan_attr_intr_out_empty.attr,
1977 &chan_attr_out_full_first.attr,
1978 &chan_attr_out_full_total.attr,
1979 &chan_attr_monitor_id.attr,
1980 &chan_attr_subchannel_id.attr,
1981 NULL
1982};
1983
1984/*
1985 * Channel-level attribute_group callback function. Returns the permission for
1986 * each attribute, and returns 0 if an attribute is not visible.
1987 */
1988static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1989 struct attribute *attr, int idx)
1990{
1991 const struct vmbus_channel *channel =
1992 container_of(kobj, struct vmbus_channel, kobj);
1993
1994 /* Hide the monitor attributes if the monitor mechanism is not used. */
1995 if (!channel->offermsg.monitor_allocated &&
1996 (attr == &chan_attr_pending.attr ||
1997 attr == &chan_attr_latency.attr ||
1998 attr == &chan_attr_monitor_id.attr))
1999 return 0;
2000
2001 return attr->mode;
2002}
2003
2004static struct attribute_group vmbus_chan_group = {
2005 .attrs = vmbus_chan_attrs,
2006 .is_visible = vmbus_chan_attr_is_visible
2007};
2008
2009static struct kobj_type vmbus_chan_ktype = {
2010 .sysfs_ops = &vmbus_chan_sysfs_ops,
2011 .release = vmbus_chan_release,
2012};
2013
2014/*
2015 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
2016 */
2017int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
2018{
2019 const struct device *device = &dev->device;
2020 struct kobject *kobj = &channel->kobj;
2021 u32 relid = channel->offermsg.child_relid;
2022 int ret;
2023
2024 kobj->kset = dev->channels_kset;
2025 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
2026 "%u", relid);
2027 if (ret) {
2028 kobject_put(kobj);
2029 return ret;
2030 }
2031
2032 ret = sysfs_create_group(kobj, &vmbus_chan_group);
2033
2034 if (ret) {
2035 /*
2036 * The calling functions' error handling paths will cleanup the
2037 * empty channel directory.
2038 */
2039 kobject_put(kobj);
2040 dev_err(device, "Unable to set up channel sysfs files\n");
2041 return ret;
2042 }
2043
2044 kobject_uevent(kobj, KOBJ_ADD);
2045
2046 return 0;
2047}
2048
2049/*
2050 * vmbus_remove_channel_attr_group - remove the channel's attribute group
2051 */
2052void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
2053{
2054 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
2055}
2056
2057/*
2058 * vmbus_device_create - Creates and registers a new child device
2059 * on the vmbus.
2060 */
2061struct hv_device *vmbus_device_create(const guid_t *type,
2062 const guid_t *instance,
2063 struct vmbus_channel *channel)
2064{
2065 struct hv_device *child_device_obj;
2066
2067 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
2068 if (!child_device_obj) {
2069 pr_err("Unable to allocate device object for child device\n");
2070 return NULL;
2071 }
2072
2073 child_device_obj->channel = channel;
2074 guid_copy(&child_device_obj->dev_type, type);
2075 guid_copy(&child_device_obj->dev_instance, instance);
2076 child_device_obj->vendor_id = PCI_VENDOR_ID_MICROSOFT;
2077
2078 return child_device_obj;
2079}
2080
2081/*
2082 * vmbus_device_register - Register the child device
2083 */
2084int vmbus_device_register(struct hv_device *child_device_obj)
2085{
2086 struct kobject *kobj = &child_device_obj->device.kobj;
2087 int ret;
2088
2089 dev_set_name(&child_device_obj->device, "%pUl",
2090 &child_device_obj->channel->offermsg.offer.if_instance);
2091
2092 child_device_obj->device.bus = &hv_bus;
2093 child_device_obj->device.parent = &hv_acpi_dev->dev;
2094 child_device_obj->device.release = vmbus_device_release;
2095
2096 child_device_obj->device.dma_parms = &child_device_obj->dma_parms;
2097 child_device_obj->device.dma_mask = &child_device_obj->dma_mask;
2098 dma_set_mask(&child_device_obj->device, DMA_BIT_MASK(64));
2099
2100 /*
2101 * Register with the LDM. This will kick off the driver/device
2102 * binding...which will eventually call vmbus_match() and vmbus_probe()
2103 */
2104 ret = device_register(&child_device_obj->device);
2105 if (ret) {
2106 pr_err("Unable to register child device\n");
2107 put_device(&child_device_obj->device);
2108 return ret;
2109 }
2110
2111 child_device_obj->channels_kset = kset_create_and_add("channels",
2112 NULL, kobj);
2113 if (!child_device_obj->channels_kset) {
2114 ret = -ENOMEM;
2115 goto err_dev_unregister;
2116 }
2117
2118 ret = vmbus_add_channel_kobj(child_device_obj,
2119 child_device_obj->channel);
2120 if (ret) {
2121 pr_err("Unable to register primary channeln");
2122 goto err_kset_unregister;
2123 }
2124 hv_debug_add_dev_dir(child_device_obj);
2125
2126 return 0;
2127
2128err_kset_unregister:
2129 kset_unregister(child_device_obj->channels_kset);
2130
2131err_dev_unregister:
2132 device_unregister(&child_device_obj->device);
2133 return ret;
2134}
2135
2136/*
2137 * vmbus_device_unregister - Remove the specified child device
2138 * from the vmbus.
2139 */
2140void vmbus_device_unregister(struct hv_device *device_obj)
2141{
2142 pr_debug("child device %s unregistered\n",
2143 dev_name(&device_obj->device));
2144
2145 kset_unregister(device_obj->channels_kset);
2146
2147 /*
2148 * Kick off the process of unregistering the device.
2149 * This will call vmbus_remove() and eventually vmbus_device_release()
2150 */
2151 device_unregister(&device_obj->device);
2152}
2153
2154
2155/*
2156 * VMBUS is an acpi enumerated device. Get the information we
2157 * need from DSDT.
2158 */
2159#define VTPM_BASE_ADDRESS 0xfed40000
2160static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
2161{
2162 resource_size_t start = 0;
2163 resource_size_t end = 0;
2164 struct resource *new_res;
2165 struct resource **old_res = &hyperv_mmio;
2166 struct resource **prev_res = NULL;
2167 struct resource r;
2168
2169 switch (res->type) {
2170
2171 /*
2172 * "Address" descriptors are for bus windows. Ignore
2173 * "memory" descriptors, which are for registers on
2174 * devices.
2175 */
2176 case ACPI_RESOURCE_TYPE_ADDRESS32:
2177 start = res->data.address32.address.minimum;
2178 end = res->data.address32.address.maximum;
2179 break;
2180
2181 case ACPI_RESOURCE_TYPE_ADDRESS64:
2182 start = res->data.address64.address.minimum;
2183 end = res->data.address64.address.maximum;
2184 break;
2185
2186 /*
2187 * The IRQ information is needed only on ARM64, which Hyper-V
2188 * sets up in the extended format. IRQ information is present
2189 * on x86/x64 in the non-extended format but it is not used by
2190 * Linux. So don't bother checking for the non-extended format.
2191 */
2192 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
2193 if (!acpi_dev_resource_interrupt(res, 0, &r)) {
2194 pr_err("Unable to parse Hyper-V ACPI interrupt\n");
2195 return AE_ERROR;
2196 }
2197 /* ARM64 INTID for VMbus */
2198 vmbus_interrupt = res->data.extended_irq.interrupts[0];
2199 /* Linux IRQ number */
2200 vmbus_irq = r.start;
2201 return AE_OK;
2202
2203 default:
2204 /* Unused resource type */
2205 return AE_OK;
2206
2207 }
2208 /*
2209 * Ignore ranges that are below 1MB, as they're not
2210 * necessary or useful here.
2211 */
2212 if (end < 0x100000)
2213 return AE_OK;
2214
2215 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2216 if (!new_res)
2217 return AE_NO_MEMORY;
2218
2219 /* If this range overlaps the virtual TPM, truncate it. */
2220 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2221 end = VTPM_BASE_ADDRESS;
2222
2223 new_res->name = "hyperv mmio";
2224 new_res->flags = IORESOURCE_MEM;
2225 new_res->start = start;
2226 new_res->end = end;
2227
2228 /*
2229 * If two ranges are adjacent, merge them.
2230 */
2231 do {
2232 if (!*old_res) {
2233 *old_res = new_res;
2234 break;
2235 }
2236
2237 if (((*old_res)->end + 1) == new_res->start) {
2238 (*old_res)->end = new_res->end;
2239 kfree(new_res);
2240 break;
2241 }
2242
2243 if ((*old_res)->start == new_res->end + 1) {
2244 (*old_res)->start = new_res->start;
2245 kfree(new_res);
2246 break;
2247 }
2248
2249 if ((*old_res)->start > new_res->end) {
2250 new_res->sibling = *old_res;
2251 if (prev_res)
2252 (*prev_res)->sibling = new_res;
2253 *old_res = new_res;
2254 break;
2255 }
2256
2257 prev_res = old_res;
2258 old_res = &(*old_res)->sibling;
2259
2260 } while (1);
2261
2262 return AE_OK;
2263}
2264
2265static void vmbus_acpi_remove(struct acpi_device *device)
2266{
2267 struct resource *cur_res;
2268 struct resource *next_res;
2269
2270 if (hyperv_mmio) {
2271 if (fb_mmio) {
2272 __release_region(hyperv_mmio, fb_mmio->start,
2273 resource_size(fb_mmio));
2274 fb_mmio = NULL;
2275 }
2276
2277 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2278 next_res = cur_res->sibling;
2279 kfree(cur_res);
2280 }
2281 }
2282}
2283
2284static void vmbus_reserve_fb(void)
2285{
2286 resource_size_t start = 0, size;
2287 struct pci_dev *pdev;
2288
2289 if (efi_enabled(EFI_BOOT)) {
2290 /* Gen2 VM: get FB base from EFI framebuffer */
2291 start = screen_info.lfb_base;
2292 size = max_t(__u32, screen_info.lfb_size, 0x800000);
2293 } else {
2294 /* Gen1 VM: get FB base from PCI */
2295 pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
2296 PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
2297 if (!pdev)
2298 return;
2299
2300 if (pdev->resource[0].flags & IORESOURCE_MEM) {
2301 start = pci_resource_start(pdev, 0);
2302 size = pci_resource_len(pdev, 0);
2303 }
2304
2305 /*
2306 * Release the PCI device so hyperv_drm or hyperv_fb driver can
2307 * grab it later.
2308 */
2309 pci_dev_put(pdev);
2310 }
2311
2312 if (!start)
2313 return;
2314
2315 /*
2316 * Make a claim for the frame buffer in the resource tree under the
2317 * first node, which will be the one below 4GB. The length seems to
2318 * be underreported, particularly in a Generation 1 VM. So start out
2319 * reserving a larger area and make it smaller until it succeeds.
2320 */
2321 for (; !fb_mmio && (size >= 0x100000); size >>= 1)
2322 fb_mmio = __request_region(hyperv_mmio, start, size, fb_mmio_name, 0);
2323}
2324
2325/**
2326 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2327 * @new: If successful, supplied a pointer to the
2328 * allocated MMIO space.
2329 * @device_obj: Identifies the caller
2330 * @min: Minimum guest physical address of the
2331 * allocation
2332 * @max: Maximum guest physical address
2333 * @size: Size of the range to be allocated
2334 * @align: Alignment of the range to be allocated
2335 * @fb_overlap_ok: Whether this allocation can be allowed
2336 * to overlap the video frame buffer.
2337 *
2338 * This function walks the resources granted to VMBus by the
2339 * _CRS object in the ACPI namespace underneath the parent
2340 * "bridge" whether that's a root PCI bus in the Generation 1
2341 * case or a Module Device in the Generation 2 case. It then
2342 * attempts to allocate from the global MMIO pool in a way that
2343 * matches the constraints supplied in these parameters and by
2344 * that _CRS.
2345 *
2346 * Return: 0 on success, -errno on failure
2347 */
2348int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2349 resource_size_t min, resource_size_t max,
2350 resource_size_t size, resource_size_t align,
2351 bool fb_overlap_ok)
2352{
2353 struct resource *iter, *shadow;
2354 resource_size_t range_min, range_max, start, end;
2355 const char *dev_n = dev_name(&device_obj->device);
2356 int retval;
2357
2358 retval = -ENXIO;
2359 mutex_lock(&hyperv_mmio_lock);
2360
2361 /*
2362 * If overlaps with frame buffers are allowed, then first attempt to
2363 * make the allocation from within the reserved region. Because it
2364 * is already reserved, no shadow allocation is necessary.
2365 */
2366 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2367 !(max < fb_mmio->start)) {
2368
2369 range_min = fb_mmio->start;
2370 range_max = fb_mmio->end;
2371 start = (range_min + align - 1) & ~(align - 1);
2372 for (; start + size - 1 <= range_max; start += align) {
2373 *new = request_mem_region_exclusive(start, size, dev_n);
2374 if (*new) {
2375 retval = 0;
2376 goto exit;
2377 }
2378 }
2379 }
2380
2381 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2382 if ((iter->start >= max) || (iter->end <= min))
2383 continue;
2384
2385 range_min = iter->start;
2386 range_max = iter->end;
2387 start = (range_min + align - 1) & ~(align - 1);
2388 for (; start + size - 1 <= range_max; start += align) {
2389 end = start + size - 1;
2390
2391 /* Skip the whole fb_mmio region if not fb_overlap_ok */
2392 if (!fb_overlap_ok && fb_mmio &&
2393 (((start >= fb_mmio->start) && (start <= fb_mmio->end)) ||
2394 ((end >= fb_mmio->start) && (end <= fb_mmio->end))))
2395 continue;
2396
2397 shadow = __request_region(iter, start, size, NULL,
2398 IORESOURCE_BUSY);
2399 if (!shadow)
2400 continue;
2401
2402 *new = request_mem_region_exclusive(start, size, dev_n);
2403 if (*new) {
2404 shadow->name = (char *)*new;
2405 retval = 0;
2406 goto exit;
2407 }
2408
2409 __release_region(iter, start, size);
2410 }
2411 }
2412
2413exit:
2414 mutex_unlock(&hyperv_mmio_lock);
2415 return retval;
2416}
2417EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2418
2419/**
2420 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2421 * @start: Base address of region to release.
2422 * @size: Size of the range to be allocated
2423 *
2424 * This function releases anything requested by
2425 * vmbus_mmio_allocate().
2426 */
2427void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2428{
2429 struct resource *iter;
2430
2431 mutex_lock(&hyperv_mmio_lock);
2432 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2433 if ((iter->start >= start + size) || (iter->end <= start))
2434 continue;
2435
2436 __release_region(iter, start, size);
2437 }
2438 release_mem_region(start, size);
2439 mutex_unlock(&hyperv_mmio_lock);
2440
2441}
2442EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2443
2444static int vmbus_acpi_add(struct acpi_device *device)
2445{
2446 acpi_status result;
2447 int ret_val = -ENODEV;
2448 struct acpi_device *ancestor;
2449
2450 hv_acpi_dev = device;
2451
2452 /*
2453 * Older versions of Hyper-V for ARM64 fail to include the _CCA
2454 * method on the top level VMbus device in the DSDT. But devices
2455 * are hardware coherent in all current Hyper-V use cases, so fix
2456 * up the ACPI device to behave as if _CCA is present and indicates
2457 * hardware coherence.
2458 */
2459 ACPI_COMPANION_SET(&device->dev, device);
2460 if (IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED) &&
2461 device_get_dma_attr(&device->dev) == DEV_DMA_NOT_SUPPORTED) {
2462 pr_info("No ACPI _CCA found; assuming coherent device I/O\n");
2463 device->flags.cca_seen = true;
2464 device->flags.coherent_dma = true;
2465 }
2466
2467 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2468 vmbus_walk_resources, NULL);
2469
2470 if (ACPI_FAILURE(result))
2471 goto acpi_walk_err;
2472 /*
2473 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2474 * firmware) is the VMOD that has the mmio ranges. Get that.
2475 */
2476 for (ancestor = acpi_dev_parent(device); ancestor;
2477 ancestor = acpi_dev_parent(ancestor)) {
2478 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2479 vmbus_walk_resources, NULL);
2480
2481 if (ACPI_FAILURE(result))
2482 continue;
2483 if (hyperv_mmio) {
2484 vmbus_reserve_fb();
2485 break;
2486 }
2487 }
2488 ret_val = 0;
2489
2490acpi_walk_err:
2491 if (ret_val)
2492 vmbus_acpi_remove(device);
2493 return ret_val;
2494}
2495
2496#ifdef CONFIG_PM_SLEEP
2497static int vmbus_bus_suspend(struct device *dev)
2498{
2499 struct hv_per_cpu_context *hv_cpu = per_cpu_ptr(
2500 hv_context.cpu_context, VMBUS_CONNECT_CPU);
2501 struct vmbus_channel *channel, *sc;
2502
2503 tasklet_disable(&hv_cpu->msg_dpc);
2504 vmbus_connection.ignore_any_offer_msg = true;
2505 /* The tasklet_enable() takes care of providing a memory barrier */
2506 tasklet_enable(&hv_cpu->msg_dpc);
2507
2508 /* Drain all the workqueues as we are in suspend */
2509 drain_workqueue(vmbus_connection.rescind_work_queue);
2510 drain_workqueue(vmbus_connection.work_queue);
2511 drain_workqueue(vmbus_connection.handle_primary_chan_wq);
2512 drain_workqueue(vmbus_connection.handle_sub_chan_wq);
2513
2514 mutex_lock(&vmbus_connection.channel_mutex);
2515 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2516 if (!is_hvsock_channel(channel))
2517 continue;
2518
2519 vmbus_force_channel_rescinded(channel);
2520 }
2521 mutex_unlock(&vmbus_connection.channel_mutex);
2522
2523 /*
2524 * Wait until all the sub-channels and hv_sock channels have been
2525 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2526 * they would conflict with the new sub-channels that will be created
2527 * in the resume path. hv_sock channels should also be destroyed, but
2528 * a hv_sock channel of an established hv_sock connection can not be
2529 * really destroyed since it may still be referenced by the userspace
2530 * application, so we just force the hv_sock channel to be rescinded
2531 * by vmbus_force_channel_rescinded(), and the userspace application
2532 * will thoroughly destroy the channel after hibernation.
2533 *
2534 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2535 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2536 */
2537 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2538 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2539
2540 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
2541 pr_err("Can not suspend due to a previous failed resuming\n");
2542 return -EBUSY;
2543 }
2544
2545 mutex_lock(&vmbus_connection.channel_mutex);
2546
2547 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2548 /*
2549 * Remove the channel from the array of channels and invalidate
2550 * the channel's relid. Upon resume, vmbus_onoffer() will fix
2551 * up the relid (and other fields, if necessary) and add the
2552 * channel back to the array.
2553 */
2554 vmbus_channel_unmap_relid(channel);
2555 channel->offermsg.child_relid = INVALID_RELID;
2556
2557 if (is_hvsock_channel(channel)) {
2558 if (!channel->rescind) {
2559 pr_err("hv_sock channel not rescinded!\n");
2560 WARN_ON_ONCE(1);
2561 }
2562 continue;
2563 }
2564
2565 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2566 pr_err("Sub-channel not deleted!\n");
2567 WARN_ON_ONCE(1);
2568 }
2569
2570 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2571 }
2572
2573 mutex_unlock(&vmbus_connection.channel_mutex);
2574
2575 vmbus_initiate_unload(false);
2576
2577 /* Reset the event for the next resume. */
2578 reinit_completion(&vmbus_connection.ready_for_resume_event);
2579
2580 return 0;
2581}
2582
2583static int vmbus_bus_resume(struct device *dev)
2584{
2585 struct vmbus_channel_msginfo *msginfo;
2586 size_t msgsize;
2587 int ret;
2588
2589 vmbus_connection.ignore_any_offer_msg = false;
2590
2591 /*
2592 * We only use the 'vmbus_proto_version', which was in use before
2593 * hibernation, to re-negotiate with the host.
2594 */
2595 if (!vmbus_proto_version) {
2596 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2597 return -EINVAL;
2598 }
2599
2600 msgsize = sizeof(*msginfo) +
2601 sizeof(struct vmbus_channel_initiate_contact);
2602
2603 msginfo = kzalloc(msgsize, GFP_KERNEL);
2604
2605 if (msginfo == NULL)
2606 return -ENOMEM;
2607
2608 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2609
2610 kfree(msginfo);
2611
2612 if (ret != 0)
2613 return ret;
2614
2615 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2616
2617 vmbus_request_offers();
2618
2619 if (wait_for_completion_timeout(
2620 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0)
2621 pr_err("Some vmbus device is missing after suspending?\n");
2622
2623 /* Reset the event for the next suspend. */
2624 reinit_completion(&vmbus_connection.ready_for_suspend_event);
2625
2626 return 0;
2627}
2628#else
2629#define vmbus_bus_suspend NULL
2630#define vmbus_bus_resume NULL
2631#endif /* CONFIG_PM_SLEEP */
2632
2633static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2634 {"VMBUS", 0},
2635 {"VMBus", 0},
2636 {"", 0},
2637};
2638MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2639
2640/*
2641 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2642 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2643 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2644 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2645 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2646 * resume callback must also run via the "noirq" ops.
2647 *
2648 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2649 * earlier in this file before vmbus_pm.
2650 */
2651
2652static const struct dev_pm_ops vmbus_bus_pm = {
2653 .suspend_noirq = NULL,
2654 .resume_noirq = NULL,
2655 .freeze_noirq = vmbus_bus_suspend,
2656 .thaw_noirq = vmbus_bus_resume,
2657 .poweroff_noirq = vmbus_bus_suspend,
2658 .restore_noirq = vmbus_bus_resume
2659};
2660
2661static struct acpi_driver vmbus_acpi_driver = {
2662 .name = "vmbus",
2663 .ids = vmbus_acpi_device_ids,
2664 .ops = {
2665 .add = vmbus_acpi_add,
2666 .remove = vmbus_acpi_remove,
2667 },
2668 .drv.pm = &vmbus_bus_pm,
2669 .drv.probe_type = PROBE_FORCE_SYNCHRONOUS,
2670};
2671
2672static void hv_kexec_handler(void)
2673{
2674 hv_stimer_global_cleanup();
2675 vmbus_initiate_unload(false);
2676 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2677 mb();
2678 cpuhp_remove_state(hyperv_cpuhp_online);
2679};
2680
2681static void hv_crash_handler(struct pt_regs *regs)
2682{
2683 int cpu;
2684
2685 vmbus_initiate_unload(true);
2686 /*
2687 * In crash handler we can't schedule synic cleanup for all CPUs,
2688 * doing the cleanup for current CPU only. This should be sufficient
2689 * for kdump.
2690 */
2691 cpu = smp_processor_id();
2692 hv_stimer_cleanup(cpu);
2693 hv_synic_disable_regs(cpu);
2694};
2695
2696static int hv_synic_suspend(void)
2697{
2698 /*
2699 * When we reach here, all the non-boot CPUs have been offlined.
2700 * If we're in a legacy configuration where stimer Direct Mode is
2701 * not enabled, the stimers on the non-boot CPUs have been unbound
2702 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2703 * hv_stimer_cleanup() -> clockevents_unbind_device().
2704 *
2705 * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2706 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2707 * 1) it's unnecessary as interrupts remain disabled between
2708 * syscore_suspend() and syscore_resume(): see create_image() and
2709 * resume_target_kernel()
2710 * 2) the stimer on CPU0 is automatically disabled later by
2711 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2712 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2713 * 3) a warning would be triggered if we call
2714 * clockevents_unbind_device(), which may sleep, in an
2715 * interrupts-disabled context.
2716 */
2717
2718 hv_synic_disable_regs(0);
2719
2720 return 0;
2721}
2722
2723static void hv_synic_resume(void)
2724{
2725 hv_synic_enable_regs(0);
2726
2727 /*
2728 * Note: we don't need to call hv_stimer_init(0), because the timer
2729 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2730 * automatically re-enabled in timekeeping_resume().
2731 */
2732}
2733
2734/* The callbacks run only on CPU0, with irqs_disabled. */
2735static struct syscore_ops hv_synic_syscore_ops = {
2736 .suspend = hv_synic_suspend,
2737 .resume = hv_synic_resume,
2738};
2739
2740static int __init hv_acpi_init(void)
2741{
2742 int ret;
2743
2744 if (!hv_is_hyperv_initialized())
2745 return -ENODEV;
2746
2747 if (hv_root_partition)
2748 return 0;
2749
2750 /*
2751 * Get ACPI resources first.
2752 */
2753 ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2754
2755 if (ret)
2756 return ret;
2757
2758 if (!hv_acpi_dev) {
2759 ret = -ENODEV;
2760 goto cleanup;
2761 }
2762
2763 /*
2764 * If we're on an architecture with a hardcoded hypervisor
2765 * vector (i.e. x86/x64), override the VMbus interrupt found
2766 * in the ACPI tables. Ensure vmbus_irq is not set since the
2767 * normal Linux IRQ mechanism is not used in this case.
2768 */
2769#ifdef HYPERVISOR_CALLBACK_VECTOR
2770 vmbus_interrupt = HYPERVISOR_CALLBACK_VECTOR;
2771 vmbus_irq = -1;
2772#endif
2773
2774 hv_debug_init();
2775
2776 ret = vmbus_bus_init();
2777 if (ret)
2778 goto cleanup;
2779
2780 hv_setup_kexec_handler(hv_kexec_handler);
2781 hv_setup_crash_handler(hv_crash_handler);
2782
2783 register_syscore_ops(&hv_synic_syscore_ops);
2784
2785 return 0;
2786
2787cleanup:
2788 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2789 hv_acpi_dev = NULL;
2790 return ret;
2791}
2792
2793static void __exit vmbus_exit(void)
2794{
2795 int cpu;
2796
2797 unregister_syscore_ops(&hv_synic_syscore_ops);
2798
2799 hv_remove_kexec_handler();
2800 hv_remove_crash_handler();
2801 vmbus_connection.conn_state = DISCONNECTED;
2802 hv_stimer_global_cleanup();
2803 vmbus_disconnect();
2804 if (vmbus_irq == -1) {
2805 hv_remove_vmbus_handler();
2806 } else {
2807 free_percpu_irq(vmbus_irq, vmbus_evt);
2808 free_percpu(vmbus_evt);
2809 }
2810 for_each_online_cpu(cpu) {
2811 struct hv_per_cpu_context *hv_cpu
2812 = per_cpu_ptr(hv_context.cpu_context, cpu);
2813
2814 tasklet_kill(&hv_cpu->msg_dpc);
2815 }
2816 hv_debug_rm_all_dir();
2817
2818 vmbus_free_channels();
2819 kfree(vmbus_connection.channels);
2820
2821 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2822 kmsg_dump_unregister(&hv_kmsg_dumper);
2823 unregister_die_notifier(&hyperv_die_report_block);
2824 atomic_notifier_chain_unregister(&panic_notifier_list,
2825 &hyperv_panic_report_block);
2826 }
2827
2828 /*
2829 * The vmbus panic notifier is always registered, hence we should
2830 * also unconditionally unregister it here as well.
2831 */
2832 atomic_notifier_chain_unregister(&panic_notifier_list,
2833 &hyperv_panic_vmbus_unload_block);
2834
2835 free_page((unsigned long)hv_panic_page);
2836 unregister_sysctl_table(hv_ctl_table_hdr);
2837 hv_ctl_table_hdr = NULL;
2838 bus_unregister(&hv_bus);
2839
2840 cpuhp_remove_state(hyperv_cpuhp_online);
2841 hv_synic_free();
2842 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2843}
2844
2845
2846MODULE_LICENSE("GPL");
2847MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2848
2849subsys_initcall(hv_acpi_init);
2850module_exit(vmbus_exit);