xref: /linux/drivers/hv/vmbus_drv.c (revision 293d5b43948309434568f4dcbb36cce4c3c51bd5)
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/interrupt.h>
29 #include <linux/sysctl.h>
30 #include <linux/slab.h>
31 #include <linux/acpi.h>
32 #include <linux/completion.h>
33 #include <linux/hyperv.h>
34 #include <linux/kernel_stat.h>
35 #include <linux/clockchips.h>
36 #include <linux/cpu.h>
37 #include <asm/hyperv.h>
38 #include <asm/hypervisor.h>
39 #include <asm/mshyperv.h>
40 #include <linux/notifier.h>
41 #include <linux/ptrace.h>
42 #include <linux/screen_info.h>
43 #include <linux/kdebug.h>
44 #include <linux/efi.h>
45 #include <linux/random.h>
46 #include "hyperv_vmbus.h"
47 
48 static struct acpi_device  *hv_acpi_dev;
49 
50 static struct completion probe_event;
51 
52 
53 static void hyperv_report_panic(struct pt_regs *regs)
54 {
55 	static bool panic_reported;
56 
57 	/*
58 	 * We prefer to report panic on 'die' chain as we have proper
59 	 * registers to report, but if we miss it (e.g. on BUG()) we need
60 	 * to report it on 'panic'.
61 	 */
62 	if (panic_reported)
63 		return;
64 	panic_reported = true;
65 
66 	wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
67 	wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
68 	wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
69 	wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
70 	wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
71 
72 	/*
73 	 * Let Hyper-V know there is crash data available
74 	 */
75 	wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
76 }
77 
78 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
79 			      void *args)
80 {
81 	struct pt_regs *regs;
82 
83 	regs = current_pt_regs();
84 
85 	hyperv_report_panic(regs);
86 	return NOTIFY_DONE;
87 }
88 
89 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
90 			    void *args)
91 {
92 	struct die_args *die = (struct die_args *)args;
93 	struct pt_regs *regs = die->regs;
94 
95 	hyperv_report_panic(regs);
96 	return NOTIFY_DONE;
97 }
98 
99 static struct notifier_block hyperv_die_block = {
100 	.notifier_call = hyperv_die_event,
101 };
102 static struct notifier_block hyperv_panic_block = {
103 	.notifier_call = hyperv_panic_event,
104 };
105 
106 static const char *fb_mmio_name = "fb_range";
107 static struct resource *fb_mmio;
108 struct resource *hyperv_mmio;
109 DEFINE_SEMAPHORE(hyperv_mmio_lock);
110 
111 static int vmbus_exists(void)
112 {
113 	if (hv_acpi_dev == NULL)
114 		return -ENODEV;
115 
116 	return 0;
117 }
118 
119 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
120 static 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 static u8 channel_monitor_group(struct vmbus_channel *channel)
128 {
129 	return (u8)channel->offermsg.monitorid / 32;
130 }
131 
132 static u8 channel_monitor_offset(struct vmbus_channel *channel)
133 {
134 	return (u8)channel->offermsg.monitorid % 32;
135 }
136 
137 static u32 channel_pending(struct vmbus_channel *channel,
138 			   struct hv_monitor_page *monitor_page)
139 {
140 	u8 monitor_group = channel_monitor_group(channel);
141 	return monitor_page->trigger_group[monitor_group].pending;
142 }
143 
144 static u32 channel_latency(struct vmbus_channel *channel,
145 			   struct hv_monitor_page *monitor_page)
146 {
147 	u8 monitor_group = channel_monitor_group(channel);
148 	u8 monitor_offset = channel_monitor_offset(channel);
149 	return monitor_page->latency[monitor_group][monitor_offset];
150 }
151 
152 static u32 channel_conn_id(struct vmbus_channel *channel,
153 			   struct hv_monitor_page *monitor_page)
154 {
155 	u8 monitor_group = channel_monitor_group(channel);
156 	u8 monitor_offset = channel_monitor_offset(channel);
157 	return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
158 }
159 
160 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
161 		       char *buf)
162 {
163 	struct hv_device *hv_dev = device_to_hv_device(dev);
164 
165 	if (!hv_dev->channel)
166 		return -ENODEV;
167 	return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
168 }
169 static DEVICE_ATTR_RO(id);
170 
171 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
172 			  char *buf)
173 {
174 	struct hv_device *hv_dev = device_to_hv_device(dev);
175 
176 	if (!hv_dev->channel)
177 		return -ENODEV;
178 	return sprintf(buf, "%d\n", hv_dev->channel->state);
179 }
180 static DEVICE_ATTR_RO(state);
181 
182 static ssize_t monitor_id_show(struct device *dev,
183 			       struct device_attribute *dev_attr, char *buf)
184 {
185 	struct hv_device *hv_dev = device_to_hv_device(dev);
186 
187 	if (!hv_dev->channel)
188 		return -ENODEV;
189 	return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
190 }
191 static DEVICE_ATTR_RO(monitor_id);
192 
193 static ssize_t class_id_show(struct device *dev,
194 			       struct device_attribute *dev_attr, char *buf)
195 {
196 	struct hv_device *hv_dev = device_to_hv_device(dev);
197 
198 	if (!hv_dev->channel)
199 		return -ENODEV;
200 	return sprintf(buf, "{%pUl}\n",
201 		       hv_dev->channel->offermsg.offer.if_type.b);
202 }
203 static DEVICE_ATTR_RO(class_id);
204 
205 static ssize_t device_id_show(struct device *dev,
206 			      struct device_attribute *dev_attr, char *buf)
207 {
208 	struct hv_device *hv_dev = device_to_hv_device(dev);
209 
210 	if (!hv_dev->channel)
211 		return -ENODEV;
212 	return sprintf(buf, "{%pUl}\n",
213 		       hv_dev->channel->offermsg.offer.if_instance.b);
214 }
215 static DEVICE_ATTR_RO(device_id);
216 
217 static ssize_t modalias_show(struct device *dev,
218 			     struct device_attribute *dev_attr, char *buf)
219 {
220 	struct hv_device *hv_dev = device_to_hv_device(dev);
221 	char alias_name[VMBUS_ALIAS_LEN + 1];
222 
223 	print_alias_name(hv_dev, alias_name);
224 	return sprintf(buf, "vmbus:%s\n", alias_name);
225 }
226 static DEVICE_ATTR_RO(modalias);
227 
228 static ssize_t server_monitor_pending_show(struct device *dev,
229 					   struct device_attribute *dev_attr,
230 					   char *buf)
231 {
232 	struct hv_device *hv_dev = device_to_hv_device(dev);
233 
234 	if (!hv_dev->channel)
235 		return -ENODEV;
236 	return sprintf(buf, "%d\n",
237 		       channel_pending(hv_dev->channel,
238 				       vmbus_connection.monitor_pages[1]));
239 }
240 static DEVICE_ATTR_RO(server_monitor_pending);
241 
242 static ssize_t client_monitor_pending_show(struct device *dev,
243 					   struct device_attribute *dev_attr,
244 					   char *buf)
245 {
246 	struct hv_device *hv_dev = device_to_hv_device(dev);
247 
248 	if (!hv_dev->channel)
249 		return -ENODEV;
250 	return sprintf(buf, "%d\n",
251 		       channel_pending(hv_dev->channel,
252 				       vmbus_connection.monitor_pages[1]));
253 }
254 static DEVICE_ATTR_RO(client_monitor_pending);
255 
256 static ssize_t server_monitor_latency_show(struct device *dev,
257 					   struct device_attribute *dev_attr,
258 					   char *buf)
259 {
260 	struct hv_device *hv_dev = device_to_hv_device(dev);
261 
262 	if (!hv_dev->channel)
263 		return -ENODEV;
264 	return sprintf(buf, "%d\n",
265 		       channel_latency(hv_dev->channel,
266 				       vmbus_connection.monitor_pages[0]));
267 }
268 static DEVICE_ATTR_RO(server_monitor_latency);
269 
270 static ssize_t client_monitor_latency_show(struct device *dev,
271 					   struct device_attribute *dev_attr,
272 					   char *buf)
273 {
274 	struct hv_device *hv_dev = device_to_hv_device(dev);
275 
276 	if (!hv_dev->channel)
277 		return -ENODEV;
278 	return sprintf(buf, "%d\n",
279 		       channel_latency(hv_dev->channel,
280 				       vmbus_connection.monitor_pages[1]));
281 }
282 static DEVICE_ATTR_RO(client_monitor_latency);
283 
284 static ssize_t server_monitor_conn_id_show(struct device *dev,
285 					   struct device_attribute *dev_attr,
286 					   char *buf)
287 {
288 	struct hv_device *hv_dev = device_to_hv_device(dev);
289 
290 	if (!hv_dev->channel)
291 		return -ENODEV;
292 	return sprintf(buf, "%d\n",
293 		       channel_conn_id(hv_dev->channel,
294 				       vmbus_connection.monitor_pages[0]));
295 }
296 static DEVICE_ATTR_RO(server_monitor_conn_id);
297 
298 static ssize_t client_monitor_conn_id_show(struct device *dev,
299 					   struct device_attribute *dev_attr,
300 					   char *buf)
301 {
302 	struct hv_device *hv_dev = device_to_hv_device(dev);
303 
304 	if (!hv_dev->channel)
305 		return -ENODEV;
306 	return sprintf(buf, "%d\n",
307 		       channel_conn_id(hv_dev->channel,
308 				       vmbus_connection.monitor_pages[1]));
309 }
310 static DEVICE_ATTR_RO(client_monitor_conn_id);
311 
312 static ssize_t out_intr_mask_show(struct device *dev,
313 				  struct device_attribute *dev_attr, char *buf)
314 {
315 	struct hv_device *hv_dev = device_to_hv_device(dev);
316 	struct hv_ring_buffer_debug_info outbound;
317 
318 	if (!hv_dev->channel)
319 		return -ENODEV;
320 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
321 	return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
322 }
323 static DEVICE_ATTR_RO(out_intr_mask);
324 
325 static ssize_t out_read_index_show(struct device *dev,
326 				   struct device_attribute *dev_attr, char *buf)
327 {
328 	struct hv_device *hv_dev = device_to_hv_device(dev);
329 	struct hv_ring_buffer_debug_info outbound;
330 
331 	if (!hv_dev->channel)
332 		return -ENODEV;
333 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
334 	return sprintf(buf, "%d\n", outbound.current_read_index);
335 }
336 static DEVICE_ATTR_RO(out_read_index);
337 
338 static ssize_t out_write_index_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 	struct hv_ring_buffer_debug_info outbound;
344 
345 	if (!hv_dev->channel)
346 		return -ENODEV;
347 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
348 	return sprintf(buf, "%d\n", outbound.current_write_index);
349 }
350 static DEVICE_ATTR_RO(out_write_index);
351 
352 static ssize_t out_read_bytes_avail_show(struct device *dev,
353 					 struct device_attribute *dev_attr,
354 					 char *buf)
355 {
356 	struct hv_device *hv_dev = device_to_hv_device(dev);
357 	struct hv_ring_buffer_debug_info outbound;
358 
359 	if (!hv_dev->channel)
360 		return -ENODEV;
361 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
362 	return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
363 }
364 static DEVICE_ATTR_RO(out_read_bytes_avail);
365 
366 static ssize_t out_write_bytes_avail_show(struct device *dev,
367 					  struct device_attribute *dev_attr,
368 					  char *buf)
369 {
370 	struct hv_device *hv_dev = device_to_hv_device(dev);
371 	struct hv_ring_buffer_debug_info outbound;
372 
373 	if (!hv_dev->channel)
374 		return -ENODEV;
375 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
376 	return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
377 }
378 static DEVICE_ATTR_RO(out_write_bytes_avail);
379 
380 static ssize_t in_intr_mask_show(struct device *dev,
381 				 struct device_attribute *dev_attr, char *buf)
382 {
383 	struct hv_device *hv_dev = device_to_hv_device(dev);
384 	struct hv_ring_buffer_debug_info inbound;
385 
386 	if (!hv_dev->channel)
387 		return -ENODEV;
388 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
389 	return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
390 }
391 static DEVICE_ATTR_RO(in_intr_mask);
392 
393 static ssize_t in_read_index_show(struct device *dev,
394 				  struct device_attribute *dev_attr, char *buf)
395 {
396 	struct hv_device *hv_dev = device_to_hv_device(dev);
397 	struct hv_ring_buffer_debug_info inbound;
398 
399 	if (!hv_dev->channel)
400 		return -ENODEV;
401 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
402 	return sprintf(buf, "%d\n", inbound.current_read_index);
403 }
404 static DEVICE_ATTR_RO(in_read_index);
405 
406 static ssize_t in_write_index_show(struct device *dev,
407 				   struct device_attribute *dev_attr, char *buf)
408 {
409 	struct hv_device *hv_dev = device_to_hv_device(dev);
410 	struct hv_ring_buffer_debug_info inbound;
411 
412 	if (!hv_dev->channel)
413 		return -ENODEV;
414 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
415 	return sprintf(buf, "%d\n", inbound.current_write_index);
416 }
417 static DEVICE_ATTR_RO(in_write_index);
418 
419 static ssize_t in_read_bytes_avail_show(struct device *dev,
420 					struct device_attribute *dev_attr,
421 					char *buf)
422 {
423 	struct hv_device *hv_dev = device_to_hv_device(dev);
424 	struct hv_ring_buffer_debug_info inbound;
425 
426 	if (!hv_dev->channel)
427 		return -ENODEV;
428 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
429 	return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
430 }
431 static DEVICE_ATTR_RO(in_read_bytes_avail);
432 
433 static ssize_t in_write_bytes_avail_show(struct device *dev,
434 					 struct device_attribute *dev_attr,
435 					 char *buf)
436 {
437 	struct hv_device *hv_dev = device_to_hv_device(dev);
438 	struct hv_ring_buffer_debug_info inbound;
439 
440 	if (!hv_dev->channel)
441 		return -ENODEV;
442 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
443 	return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
444 }
445 static DEVICE_ATTR_RO(in_write_bytes_avail);
446 
447 static ssize_t channel_vp_mapping_show(struct device *dev,
448 				       struct device_attribute *dev_attr,
449 				       char *buf)
450 {
451 	struct hv_device *hv_dev = device_to_hv_device(dev);
452 	struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
453 	unsigned long flags;
454 	int buf_size = PAGE_SIZE, n_written, tot_written;
455 	struct list_head *cur;
456 
457 	if (!channel)
458 		return -ENODEV;
459 
460 	tot_written = snprintf(buf, buf_size, "%u:%u\n",
461 		channel->offermsg.child_relid, channel->target_cpu);
462 
463 	spin_lock_irqsave(&channel->lock, flags);
464 
465 	list_for_each(cur, &channel->sc_list) {
466 		if (tot_written >= buf_size - 1)
467 			break;
468 
469 		cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
470 		n_written = scnprintf(buf + tot_written,
471 				     buf_size - tot_written,
472 				     "%u:%u\n",
473 				     cur_sc->offermsg.child_relid,
474 				     cur_sc->target_cpu);
475 		tot_written += n_written;
476 	}
477 
478 	spin_unlock_irqrestore(&channel->lock, flags);
479 
480 	return tot_written;
481 }
482 static DEVICE_ATTR_RO(channel_vp_mapping);
483 
484 static ssize_t vendor_show(struct device *dev,
485 			   struct device_attribute *dev_attr,
486 			   char *buf)
487 {
488 	struct hv_device *hv_dev = device_to_hv_device(dev);
489 	return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
490 }
491 static DEVICE_ATTR_RO(vendor);
492 
493 static ssize_t device_show(struct device *dev,
494 			   struct device_attribute *dev_attr,
495 			   char *buf)
496 {
497 	struct hv_device *hv_dev = device_to_hv_device(dev);
498 	return sprintf(buf, "0x%x\n", hv_dev->device_id);
499 }
500 static DEVICE_ATTR_RO(device);
501 
502 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
503 static struct attribute *vmbus_attrs[] = {
504 	&dev_attr_id.attr,
505 	&dev_attr_state.attr,
506 	&dev_attr_monitor_id.attr,
507 	&dev_attr_class_id.attr,
508 	&dev_attr_device_id.attr,
509 	&dev_attr_modalias.attr,
510 	&dev_attr_server_monitor_pending.attr,
511 	&dev_attr_client_monitor_pending.attr,
512 	&dev_attr_server_monitor_latency.attr,
513 	&dev_attr_client_monitor_latency.attr,
514 	&dev_attr_server_monitor_conn_id.attr,
515 	&dev_attr_client_monitor_conn_id.attr,
516 	&dev_attr_out_intr_mask.attr,
517 	&dev_attr_out_read_index.attr,
518 	&dev_attr_out_write_index.attr,
519 	&dev_attr_out_read_bytes_avail.attr,
520 	&dev_attr_out_write_bytes_avail.attr,
521 	&dev_attr_in_intr_mask.attr,
522 	&dev_attr_in_read_index.attr,
523 	&dev_attr_in_write_index.attr,
524 	&dev_attr_in_read_bytes_avail.attr,
525 	&dev_attr_in_write_bytes_avail.attr,
526 	&dev_attr_channel_vp_mapping.attr,
527 	&dev_attr_vendor.attr,
528 	&dev_attr_device.attr,
529 	NULL,
530 };
531 ATTRIBUTE_GROUPS(vmbus);
532 
533 /*
534  * vmbus_uevent - add uevent for our device
535  *
536  * This routine is invoked when a device is added or removed on the vmbus to
537  * generate a uevent to udev in the userspace. The udev will then look at its
538  * rule and the uevent generated here to load the appropriate driver
539  *
540  * The alias string will be of the form vmbus:guid where guid is the string
541  * representation of the device guid (each byte of the guid will be
542  * represented with two hex characters.
543  */
544 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
545 {
546 	struct hv_device *dev = device_to_hv_device(device);
547 	int ret;
548 	char alias_name[VMBUS_ALIAS_LEN + 1];
549 
550 	print_alias_name(dev, alias_name);
551 	ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
552 	return ret;
553 }
554 
555 static const uuid_le null_guid;
556 
557 static inline bool is_null_guid(const uuid_le *guid)
558 {
559 	if (uuid_le_cmp(*guid, null_guid))
560 		return false;
561 	return true;
562 }
563 
564 /*
565  * Return a matching hv_vmbus_device_id pointer.
566  * If there is no match, return NULL.
567  */
568 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
569 					const struct hv_vmbus_device_id *id,
570 					const uuid_le *guid)
571 {
572 	for (; !is_null_guid(&id->guid); id++)
573 		if (!uuid_le_cmp(id->guid, *guid))
574 			return id;
575 
576 	return NULL;
577 }
578 
579 
580 
581 /*
582  * vmbus_match - Attempt to match the specified device to the specified driver
583  */
584 static int vmbus_match(struct device *device, struct device_driver *driver)
585 {
586 	struct hv_driver *drv = drv_to_hv_drv(driver);
587 	struct hv_device *hv_dev = device_to_hv_device(device);
588 
589 	/* The hv_sock driver handles all hv_sock offers. */
590 	if (is_hvsock_channel(hv_dev->channel))
591 		return drv->hvsock;
592 
593 	if (hv_vmbus_get_id(drv->id_table, &hv_dev->dev_type))
594 		return 1;
595 
596 	return 0;
597 }
598 
599 /*
600  * vmbus_probe - Add the new vmbus's child device
601  */
602 static int vmbus_probe(struct device *child_device)
603 {
604 	int ret = 0;
605 	struct hv_driver *drv =
606 			drv_to_hv_drv(child_device->driver);
607 	struct hv_device *dev = device_to_hv_device(child_device);
608 	const struct hv_vmbus_device_id *dev_id;
609 
610 	dev_id = hv_vmbus_get_id(drv->id_table, &dev->dev_type);
611 	if (drv->probe) {
612 		ret = drv->probe(dev, dev_id);
613 		if (ret != 0)
614 			pr_err("probe failed for device %s (%d)\n",
615 			       dev_name(child_device), ret);
616 
617 	} else {
618 		pr_err("probe not set for driver %s\n",
619 		       dev_name(child_device));
620 		ret = -ENODEV;
621 	}
622 	return ret;
623 }
624 
625 /*
626  * vmbus_remove - Remove a vmbus device
627  */
628 static int vmbus_remove(struct device *child_device)
629 {
630 	struct hv_driver *drv;
631 	struct hv_device *dev = device_to_hv_device(child_device);
632 
633 	if (child_device->driver) {
634 		drv = drv_to_hv_drv(child_device->driver);
635 		if (drv->remove)
636 			drv->remove(dev);
637 	}
638 
639 	return 0;
640 }
641 
642 
643 /*
644  * vmbus_shutdown - Shutdown a vmbus device
645  */
646 static void vmbus_shutdown(struct device *child_device)
647 {
648 	struct hv_driver *drv;
649 	struct hv_device *dev = device_to_hv_device(child_device);
650 
651 
652 	/* The device may not be attached yet */
653 	if (!child_device->driver)
654 		return;
655 
656 	drv = drv_to_hv_drv(child_device->driver);
657 
658 	if (drv->shutdown)
659 		drv->shutdown(dev);
660 
661 	return;
662 }
663 
664 
665 /*
666  * vmbus_device_release - Final callback release of the vmbus child device
667  */
668 static void vmbus_device_release(struct device *device)
669 {
670 	struct hv_device *hv_dev = device_to_hv_device(device);
671 	struct vmbus_channel *channel = hv_dev->channel;
672 
673 	hv_process_channel_removal(channel,
674 				   channel->offermsg.child_relid);
675 	kfree(hv_dev);
676 
677 }
678 
679 /* The one and only one */
680 static struct bus_type  hv_bus = {
681 	.name =		"vmbus",
682 	.match =		vmbus_match,
683 	.shutdown =		vmbus_shutdown,
684 	.remove =		vmbus_remove,
685 	.probe =		vmbus_probe,
686 	.uevent =		vmbus_uevent,
687 	.dev_groups =		vmbus_groups,
688 };
689 
690 struct onmessage_work_context {
691 	struct work_struct work;
692 	struct hv_message msg;
693 };
694 
695 static void vmbus_onmessage_work(struct work_struct *work)
696 {
697 	struct onmessage_work_context *ctx;
698 
699 	/* Do not process messages if we're in DISCONNECTED state */
700 	if (vmbus_connection.conn_state == DISCONNECTED)
701 		return;
702 
703 	ctx = container_of(work, struct onmessage_work_context,
704 			   work);
705 	vmbus_onmessage(&ctx->msg);
706 	kfree(ctx);
707 }
708 
709 static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
710 {
711 	struct clock_event_device *dev = hv_context.clk_evt[cpu];
712 
713 	if (dev->event_handler)
714 		dev->event_handler(dev);
715 
716 	vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
717 }
718 
719 void vmbus_on_msg_dpc(unsigned long data)
720 {
721 	int cpu = smp_processor_id();
722 	void *page_addr = hv_context.synic_message_page[cpu];
723 	struct hv_message *msg = (struct hv_message *)page_addr +
724 				  VMBUS_MESSAGE_SINT;
725 	struct vmbus_channel_message_header *hdr;
726 	struct vmbus_channel_message_table_entry *entry;
727 	struct onmessage_work_context *ctx;
728 	u32 message_type = msg->header.message_type;
729 
730 	if (message_type == HVMSG_NONE)
731 		/* no msg */
732 		return;
733 
734 	hdr = (struct vmbus_channel_message_header *)msg->u.payload;
735 
736 	if (hdr->msgtype >= CHANNELMSG_COUNT) {
737 		WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
738 		goto msg_handled;
739 	}
740 
741 	entry = &channel_message_table[hdr->msgtype];
742 	if (entry->handler_type	== VMHT_BLOCKING) {
743 		ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
744 		if (ctx == NULL)
745 			return;
746 
747 		INIT_WORK(&ctx->work, vmbus_onmessage_work);
748 		memcpy(&ctx->msg, msg, sizeof(*msg));
749 
750 		queue_work(vmbus_connection.work_queue, &ctx->work);
751 	} else
752 		entry->message_handler(hdr);
753 
754 msg_handled:
755 	vmbus_signal_eom(msg, message_type);
756 }
757 
758 static void vmbus_isr(void)
759 {
760 	int cpu = smp_processor_id();
761 	void *page_addr;
762 	struct hv_message *msg;
763 	union hv_synic_event_flags *event;
764 	bool handled = false;
765 
766 	page_addr = hv_context.synic_event_page[cpu];
767 	if (page_addr == NULL)
768 		return;
769 
770 	event = (union hv_synic_event_flags *)page_addr +
771 					 VMBUS_MESSAGE_SINT;
772 	/*
773 	 * Check for events before checking for messages. This is the order
774 	 * in which events and messages are checked in Windows guests on
775 	 * Hyper-V, and the Windows team suggested we do the same.
776 	 */
777 
778 	if ((vmbus_proto_version == VERSION_WS2008) ||
779 		(vmbus_proto_version == VERSION_WIN7)) {
780 
781 		/* Since we are a child, we only need to check bit 0 */
782 		if (sync_test_and_clear_bit(0,
783 			(unsigned long *) &event->flags32[0])) {
784 			handled = true;
785 		}
786 	} else {
787 		/*
788 		 * Our host is win8 or above. The signaling mechanism
789 		 * has changed and we can directly look at the event page.
790 		 * If bit n is set then we have an interrup on the channel
791 		 * whose id is n.
792 		 */
793 		handled = true;
794 	}
795 
796 	if (handled)
797 		tasklet_schedule(hv_context.event_dpc[cpu]);
798 
799 
800 	page_addr = hv_context.synic_message_page[cpu];
801 	msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
802 
803 	/* Check if there are actual msgs to be processed */
804 	if (msg->header.message_type != HVMSG_NONE) {
805 		if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
806 			hv_process_timer_expiration(msg, cpu);
807 		else
808 			tasklet_schedule(hv_context.msg_dpc[cpu]);
809 	}
810 
811 	add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
812 }
813 
814 
815 /*
816  * vmbus_bus_init -Main vmbus driver initialization routine.
817  *
818  * Here, we
819  *	- initialize the vmbus driver context
820  *	- invoke the vmbus hv main init routine
821  *	- retrieve the channel offers
822  */
823 static int vmbus_bus_init(void)
824 {
825 	int ret;
826 
827 	/* Hypervisor initialization...setup hypercall page..etc */
828 	ret = hv_init();
829 	if (ret != 0) {
830 		pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
831 		return ret;
832 	}
833 
834 	ret = bus_register(&hv_bus);
835 	if (ret)
836 		goto err_cleanup;
837 
838 	hv_setup_vmbus_irq(vmbus_isr);
839 
840 	ret = hv_synic_alloc();
841 	if (ret)
842 		goto err_alloc;
843 	/*
844 	 * Initialize the per-cpu interrupt state and
845 	 * connect to the host.
846 	 */
847 	on_each_cpu(hv_synic_init, NULL, 1);
848 	ret = vmbus_connect();
849 	if (ret)
850 		goto err_connect;
851 
852 	if (vmbus_proto_version > VERSION_WIN7)
853 		cpu_hotplug_disable();
854 
855 	/*
856 	 * Only register if the crash MSRs are available
857 	 */
858 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
859 		register_die_notifier(&hyperv_die_block);
860 		atomic_notifier_chain_register(&panic_notifier_list,
861 					       &hyperv_panic_block);
862 	}
863 
864 	vmbus_request_offers();
865 
866 	return 0;
867 
868 err_connect:
869 	on_each_cpu(hv_synic_cleanup, NULL, 1);
870 err_alloc:
871 	hv_synic_free();
872 	hv_remove_vmbus_irq();
873 
874 	bus_unregister(&hv_bus);
875 
876 err_cleanup:
877 	hv_cleanup();
878 
879 	return ret;
880 }
881 
882 /**
883  * __vmbus_child_driver_register() - Register a vmbus's driver
884  * @hv_driver: Pointer to driver structure you want to register
885  * @owner: owner module of the drv
886  * @mod_name: module name string
887  *
888  * Registers the given driver with Linux through the 'driver_register()' call
889  * and sets up the hyper-v vmbus handling for this driver.
890  * It will return the state of the 'driver_register()' call.
891  *
892  */
893 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
894 {
895 	int ret;
896 
897 	pr_info("registering driver %s\n", hv_driver->name);
898 
899 	ret = vmbus_exists();
900 	if (ret < 0)
901 		return ret;
902 
903 	hv_driver->driver.name = hv_driver->name;
904 	hv_driver->driver.owner = owner;
905 	hv_driver->driver.mod_name = mod_name;
906 	hv_driver->driver.bus = &hv_bus;
907 
908 	ret = driver_register(&hv_driver->driver);
909 
910 	return ret;
911 }
912 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
913 
914 /**
915  * vmbus_driver_unregister() - Unregister a vmbus's driver
916  * @hv_driver: Pointer to driver structure you want to
917  *             un-register
918  *
919  * Un-register the given driver that was previous registered with a call to
920  * vmbus_driver_register()
921  */
922 void vmbus_driver_unregister(struct hv_driver *hv_driver)
923 {
924 	pr_info("unregistering driver %s\n", hv_driver->name);
925 
926 	if (!vmbus_exists())
927 		driver_unregister(&hv_driver->driver);
928 }
929 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
930 
931 /*
932  * vmbus_device_create - Creates and registers a new child device
933  * on the vmbus.
934  */
935 struct hv_device *vmbus_device_create(const uuid_le *type,
936 				      const uuid_le *instance,
937 				      struct vmbus_channel *channel)
938 {
939 	struct hv_device *child_device_obj;
940 
941 	child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
942 	if (!child_device_obj) {
943 		pr_err("Unable to allocate device object for child device\n");
944 		return NULL;
945 	}
946 
947 	child_device_obj->channel = channel;
948 	memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
949 	memcpy(&child_device_obj->dev_instance, instance,
950 	       sizeof(uuid_le));
951 	child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
952 
953 
954 	return child_device_obj;
955 }
956 
957 /*
958  * vmbus_device_register - Register the child device
959  */
960 int vmbus_device_register(struct hv_device *child_device_obj)
961 {
962 	int ret = 0;
963 
964 	dev_set_name(&child_device_obj->device, "vmbus_%d",
965 		     child_device_obj->channel->id);
966 
967 	child_device_obj->device.bus = &hv_bus;
968 	child_device_obj->device.parent = &hv_acpi_dev->dev;
969 	child_device_obj->device.release = vmbus_device_release;
970 
971 	/*
972 	 * Register with the LDM. This will kick off the driver/device
973 	 * binding...which will eventually call vmbus_match() and vmbus_probe()
974 	 */
975 	ret = device_register(&child_device_obj->device);
976 
977 	if (ret)
978 		pr_err("Unable to register child device\n");
979 	else
980 		pr_debug("child device %s registered\n",
981 			dev_name(&child_device_obj->device));
982 
983 	return ret;
984 }
985 
986 /*
987  * vmbus_device_unregister - Remove the specified child device
988  * from the vmbus.
989  */
990 void vmbus_device_unregister(struct hv_device *device_obj)
991 {
992 	pr_debug("child device %s unregistered\n",
993 		dev_name(&device_obj->device));
994 
995 	/*
996 	 * Kick off the process of unregistering the device.
997 	 * This will call vmbus_remove() and eventually vmbus_device_release()
998 	 */
999 	device_unregister(&device_obj->device);
1000 }
1001 
1002 
1003 /*
1004  * VMBUS is an acpi enumerated device. Get the information we
1005  * need from DSDT.
1006  */
1007 #define VTPM_BASE_ADDRESS 0xfed40000
1008 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1009 {
1010 	resource_size_t start = 0;
1011 	resource_size_t end = 0;
1012 	struct resource *new_res;
1013 	struct resource **old_res = &hyperv_mmio;
1014 	struct resource **prev_res = NULL;
1015 
1016 	switch (res->type) {
1017 
1018 	/*
1019 	 * "Address" descriptors are for bus windows. Ignore
1020 	 * "memory" descriptors, which are for registers on
1021 	 * devices.
1022 	 */
1023 	case ACPI_RESOURCE_TYPE_ADDRESS32:
1024 		start = res->data.address32.address.minimum;
1025 		end = res->data.address32.address.maximum;
1026 		break;
1027 
1028 	case ACPI_RESOURCE_TYPE_ADDRESS64:
1029 		start = res->data.address64.address.minimum;
1030 		end = res->data.address64.address.maximum;
1031 		break;
1032 
1033 	default:
1034 		/* Unused resource type */
1035 		return AE_OK;
1036 
1037 	}
1038 	/*
1039 	 * Ignore ranges that are below 1MB, as they're not
1040 	 * necessary or useful here.
1041 	 */
1042 	if (end < 0x100000)
1043 		return AE_OK;
1044 
1045 	new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1046 	if (!new_res)
1047 		return AE_NO_MEMORY;
1048 
1049 	/* If this range overlaps the virtual TPM, truncate it. */
1050 	if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1051 		end = VTPM_BASE_ADDRESS;
1052 
1053 	new_res->name = "hyperv mmio";
1054 	new_res->flags = IORESOURCE_MEM;
1055 	new_res->start = start;
1056 	new_res->end = end;
1057 
1058 	/*
1059 	 * If two ranges are adjacent, merge them.
1060 	 */
1061 	do {
1062 		if (!*old_res) {
1063 			*old_res = new_res;
1064 			break;
1065 		}
1066 
1067 		if (((*old_res)->end + 1) == new_res->start) {
1068 			(*old_res)->end = new_res->end;
1069 			kfree(new_res);
1070 			break;
1071 		}
1072 
1073 		if ((*old_res)->start == new_res->end + 1) {
1074 			(*old_res)->start = new_res->start;
1075 			kfree(new_res);
1076 			break;
1077 		}
1078 
1079 		if ((*old_res)->start > new_res->end) {
1080 			new_res->sibling = *old_res;
1081 			if (prev_res)
1082 				(*prev_res)->sibling = new_res;
1083 			*old_res = new_res;
1084 			break;
1085 		}
1086 
1087 		prev_res = old_res;
1088 		old_res = &(*old_res)->sibling;
1089 
1090 	} while (1);
1091 
1092 	return AE_OK;
1093 }
1094 
1095 static int vmbus_acpi_remove(struct acpi_device *device)
1096 {
1097 	struct resource *cur_res;
1098 	struct resource *next_res;
1099 
1100 	if (hyperv_mmio) {
1101 		if (fb_mmio) {
1102 			__release_region(hyperv_mmio, fb_mmio->start,
1103 					 resource_size(fb_mmio));
1104 			fb_mmio = NULL;
1105 		}
1106 
1107 		for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1108 			next_res = cur_res->sibling;
1109 			kfree(cur_res);
1110 		}
1111 	}
1112 
1113 	return 0;
1114 }
1115 
1116 static void vmbus_reserve_fb(void)
1117 {
1118 	int size;
1119 	/*
1120 	 * Make a claim for the frame buffer in the resource tree under the
1121 	 * first node, which will be the one below 4GB.  The length seems to
1122 	 * be underreported, particularly in a Generation 1 VM.  So start out
1123 	 * reserving a larger area and make it smaller until it succeeds.
1124 	 */
1125 
1126 	if (screen_info.lfb_base) {
1127 		if (efi_enabled(EFI_BOOT))
1128 			size = max_t(__u32, screen_info.lfb_size, 0x800000);
1129 		else
1130 			size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1131 
1132 		for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1133 			fb_mmio = __request_region(hyperv_mmio,
1134 						   screen_info.lfb_base, size,
1135 						   fb_mmio_name, 0);
1136 		}
1137 	}
1138 }
1139 
1140 /**
1141  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1142  * @new:		If successful, supplied a pointer to the
1143  *			allocated MMIO space.
1144  * @device_obj:		Identifies the caller
1145  * @min:		Minimum guest physical address of the
1146  *			allocation
1147  * @max:		Maximum guest physical address
1148  * @size:		Size of the range to be allocated
1149  * @align:		Alignment of the range to be allocated
1150  * @fb_overlap_ok:	Whether this allocation can be allowed
1151  *			to overlap the video frame buffer.
1152  *
1153  * This function walks the resources granted to VMBus by the
1154  * _CRS object in the ACPI namespace underneath the parent
1155  * "bridge" whether that's a root PCI bus in the Generation 1
1156  * case or a Module Device in the Generation 2 case.  It then
1157  * attempts to allocate from the global MMIO pool in a way that
1158  * matches the constraints supplied in these parameters and by
1159  * that _CRS.
1160  *
1161  * Return: 0 on success, -errno on failure
1162  */
1163 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1164 			resource_size_t min, resource_size_t max,
1165 			resource_size_t size, resource_size_t align,
1166 			bool fb_overlap_ok)
1167 {
1168 	struct resource *iter, *shadow;
1169 	resource_size_t range_min, range_max, start;
1170 	const char *dev_n = dev_name(&device_obj->device);
1171 	int retval;
1172 
1173 	retval = -ENXIO;
1174 	down(&hyperv_mmio_lock);
1175 
1176 	/*
1177 	 * If overlaps with frame buffers are allowed, then first attempt to
1178 	 * make the allocation from within the reserved region.  Because it
1179 	 * is already reserved, no shadow allocation is necessary.
1180 	 */
1181 	if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1182 	    !(max < fb_mmio->start)) {
1183 
1184 		range_min = fb_mmio->start;
1185 		range_max = fb_mmio->end;
1186 		start = (range_min + align - 1) & ~(align - 1);
1187 		for (; start + size - 1 <= range_max; start += align) {
1188 			*new = request_mem_region_exclusive(start, size, dev_n);
1189 			if (*new) {
1190 				retval = 0;
1191 				goto exit;
1192 			}
1193 		}
1194 	}
1195 
1196 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1197 		if ((iter->start >= max) || (iter->end <= min))
1198 			continue;
1199 
1200 		range_min = iter->start;
1201 		range_max = iter->end;
1202 		start = (range_min + align - 1) & ~(align - 1);
1203 		for (; start + size - 1 <= range_max; start += align) {
1204 			shadow = __request_region(iter, start, size, NULL,
1205 						  IORESOURCE_BUSY);
1206 			if (!shadow)
1207 				continue;
1208 
1209 			*new = request_mem_region_exclusive(start, size, dev_n);
1210 			if (*new) {
1211 				shadow->name = (char *)*new;
1212 				retval = 0;
1213 				goto exit;
1214 			}
1215 
1216 			__release_region(iter, start, size);
1217 		}
1218 	}
1219 
1220 exit:
1221 	up(&hyperv_mmio_lock);
1222 	return retval;
1223 }
1224 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1225 
1226 /**
1227  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1228  * @start:		Base address of region to release.
1229  * @size:		Size of the range to be allocated
1230  *
1231  * This function releases anything requested by
1232  * vmbus_mmio_allocate().
1233  */
1234 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1235 {
1236 	struct resource *iter;
1237 
1238 	down(&hyperv_mmio_lock);
1239 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1240 		if ((iter->start >= start + size) || (iter->end <= start))
1241 			continue;
1242 
1243 		__release_region(iter, start, size);
1244 	}
1245 	release_mem_region(start, size);
1246 	up(&hyperv_mmio_lock);
1247 
1248 }
1249 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1250 
1251 /**
1252  * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
1253  * @cpu_number: CPU number in Linux terms
1254  *
1255  * This function returns the mapping between the Linux processor
1256  * number and the hypervisor's virtual processor number, useful
1257  * in making hypercalls and such that talk about specific
1258  * processors.
1259  *
1260  * Return: Virtual processor number in Hyper-V terms
1261  */
1262 int vmbus_cpu_number_to_vp_number(int cpu_number)
1263 {
1264 	return hv_context.vp_index[cpu_number];
1265 }
1266 EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
1267 
1268 static int vmbus_acpi_add(struct acpi_device *device)
1269 {
1270 	acpi_status result;
1271 	int ret_val = -ENODEV;
1272 	struct acpi_device *ancestor;
1273 
1274 	hv_acpi_dev = device;
1275 
1276 	result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1277 					vmbus_walk_resources, NULL);
1278 
1279 	if (ACPI_FAILURE(result))
1280 		goto acpi_walk_err;
1281 	/*
1282 	 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1283 	 * firmware) is the VMOD that has the mmio ranges. Get that.
1284 	 */
1285 	for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1286 		result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1287 					     vmbus_walk_resources, NULL);
1288 
1289 		if (ACPI_FAILURE(result))
1290 			continue;
1291 		if (hyperv_mmio) {
1292 			vmbus_reserve_fb();
1293 			break;
1294 		}
1295 	}
1296 	ret_val = 0;
1297 
1298 acpi_walk_err:
1299 	complete(&probe_event);
1300 	if (ret_val)
1301 		vmbus_acpi_remove(device);
1302 	return ret_val;
1303 }
1304 
1305 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1306 	{"VMBUS", 0},
1307 	{"VMBus", 0},
1308 	{"", 0},
1309 };
1310 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1311 
1312 static struct acpi_driver vmbus_acpi_driver = {
1313 	.name = "vmbus",
1314 	.ids = vmbus_acpi_device_ids,
1315 	.ops = {
1316 		.add = vmbus_acpi_add,
1317 		.remove = vmbus_acpi_remove,
1318 	},
1319 };
1320 
1321 static void hv_kexec_handler(void)
1322 {
1323 	int cpu;
1324 
1325 	hv_synic_clockevents_cleanup();
1326 	vmbus_initiate_unload(false);
1327 	for_each_online_cpu(cpu)
1328 		smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1329 	hv_cleanup();
1330 };
1331 
1332 static void hv_crash_handler(struct pt_regs *regs)
1333 {
1334 	vmbus_initiate_unload(true);
1335 	/*
1336 	 * In crash handler we can't schedule synic cleanup for all CPUs,
1337 	 * doing the cleanup for current CPU only. This should be sufficient
1338 	 * for kdump.
1339 	 */
1340 	hv_synic_cleanup(NULL);
1341 	hv_cleanup();
1342 };
1343 
1344 static int __init hv_acpi_init(void)
1345 {
1346 	int ret, t;
1347 
1348 	if (x86_hyper != &x86_hyper_ms_hyperv)
1349 		return -ENODEV;
1350 
1351 	init_completion(&probe_event);
1352 
1353 	/*
1354 	 * Get ACPI resources first.
1355 	 */
1356 	ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1357 
1358 	if (ret)
1359 		return ret;
1360 
1361 	t = wait_for_completion_timeout(&probe_event, 5*HZ);
1362 	if (t == 0) {
1363 		ret = -ETIMEDOUT;
1364 		goto cleanup;
1365 	}
1366 
1367 	ret = vmbus_bus_init();
1368 	if (ret)
1369 		goto cleanup;
1370 
1371 	hv_setup_kexec_handler(hv_kexec_handler);
1372 	hv_setup_crash_handler(hv_crash_handler);
1373 
1374 	return 0;
1375 
1376 cleanup:
1377 	acpi_bus_unregister_driver(&vmbus_acpi_driver);
1378 	hv_acpi_dev = NULL;
1379 	return ret;
1380 }
1381 
1382 static void __exit vmbus_exit(void)
1383 {
1384 	int cpu;
1385 
1386 	hv_remove_kexec_handler();
1387 	hv_remove_crash_handler();
1388 	vmbus_connection.conn_state = DISCONNECTED;
1389 	hv_synic_clockevents_cleanup();
1390 	vmbus_disconnect();
1391 	hv_remove_vmbus_irq();
1392 	for_each_online_cpu(cpu)
1393 		tasklet_kill(hv_context.msg_dpc[cpu]);
1394 	vmbus_free_channels();
1395 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1396 		unregister_die_notifier(&hyperv_die_block);
1397 		atomic_notifier_chain_unregister(&panic_notifier_list,
1398 						 &hyperv_panic_block);
1399 	}
1400 	bus_unregister(&hv_bus);
1401 	hv_cleanup();
1402 	for_each_online_cpu(cpu) {
1403 		tasklet_kill(hv_context.event_dpc[cpu]);
1404 		smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1405 	}
1406 	hv_synic_free();
1407 	acpi_bus_unregister_driver(&vmbus_acpi_driver);
1408 	if (vmbus_proto_version > VERSION_WIN7)
1409 		cpu_hotplug_enable();
1410 }
1411 
1412 
1413 MODULE_LICENSE("GPL");
1414 
1415 subsys_initcall(hv_acpi_init);
1416 module_exit(vmbus_exit);
1417