xref: /openbmc/linux/drivers/hv/vmbus_drv.c (revision 0edbfea5)
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 "hyperv_vmbus.h"
46 
47 static struct acpi_device  *hv_acpi_dev;
48 
49 static struct completion probe_event;
50 
51 
52 static void hyperv_report_panic(struct pt_regs *regs)
53 {
54 	static bool panic_reported;
55 
56 	/*
57 	 * We prefer to report panic on 'die' chain as we have proper
58 	 * registers to report, but if we miss it (e.g. on BUG()) we need
59 	 * to report it on 'panic'.
60 	 */
61 	if (panic_reported)
62 		return;
63 	panic_reported = true;
64 
65 	wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
66 	wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
67 	wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
68 	wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
69 	wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
70 
71 	/*
72 	 * Let Hyper-V know there is crash data available
73 	 */
74 	wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
75 }
76 
77 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
78 			      void *args)
79 {
80 	struct pt_regs *regs;
81 
82 	regs = current_pt_regs();
83 
84 	hyperv_report_panic(regs);
85 	return NOTIFY_DONE;
86 }
87 
88 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
89 			    void *args)
90 {
91 	struct die_args *die = (struct die_args *)args;
92 	struct pt_regs *regs = die->regs;
93 
94 	hyperv_report_panic(regs);
95 	return NOTIFY_DONE;
96 }
97 
98 static struct notifier_block hyperv_die_block = {
99 	.notifier_call = hyperv_die_event,
100 };
101 static struct notifier_block hyperv_panic_block = {
102 	.notifier_call = hyperv_panic_event,
103 };
104 
105 static const char *fb_mmio_name = "fb_range";
106 static struct resource *fb_mmio;
107 struct resource *hyperv_mmio;
108 DEFINE_SEMAPHORE(hyperv_mmio_lock);
109 
110 static int vmbus_exists(void)
111 {
112 	if (hv_acpi_dev == NULL)
113 		return -ENODEV;
114 
115 	return 0;
116 }
117 
118 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
119 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
120 {
121 	int i;
122 	for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
123 		sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
124 }
125 
126 static u8 channel_monitor_group(struct vmbus_channel *channel)
127 {
128 	return (u8)channel->offermsg.monitorid / 32;
129 }
130 
131 static u8 channel_monitor_offset(struct vmbus_channel *channel)
132 {
133 	return (u8)channel->offermsg.monitorid % 32;
134 }
135 
136 static u32 channel_pending(struct vmbus_channel *channel,
137 			   struct hv_monitor_page *monitor_page)
138 {
139 	u8 monitor_group = channel_monitor_group(channel);
140 	return monitor_page->trigger_group[monitor_group].pending;
141 }
142 
143 static u32 channel_latency(struct vmbus_channel *channel,
144 			   struct hv_monitor_page *monitor_page)
145 {
146 	u8 monitor_group = channel_monitor_group(channel);
147 	u8 monitor_offset = channel_monitor_offset(channel);
148 	return monitor_page->latency[monitor_group][monitor_offset];
149 }
150 
151 static u32 channel_conn_id(struct vmbus_channel *channel,
152 			   struct hv_monitor_page *monitor_page)
153 {
154 	u8 monitor_group = channel_monitor_group(channel);
155 	u8 monitor_offset = channel_monitor_offset(channel);
156 	return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
157 }
158 
159 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
160 		       char *buf)
161 {
162 	struct hv_device *hv_dev = device_to_hv_device(dev);
163 
164 	if (!hv_dev->channel)
165 		return -ENODEV;
166 	return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
167 }
168 static DEVICE_ATTR_RO(id);
169 
170 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
171 			  char *buf)
172 {
173 	struct hv_device *hv_dev = device_to_hv_device(dev);
174 
175 	if (!hv_dev->channel)
176 		return -ENODEV;
177 	return sprintf(buf, "%d\n", hv_dev->channel->state);
178 }
179 static DEVICE_ATTR_RO(state);
180 
181 static ssize_t monitor_id_show(struct device *dev,
182 			       struct device_attribute *dev_attr, char *buf)
183 {
184 	struct hv_device *hv_dev = device_to_hv_device(dev);
185 
186 	if (!hv_dev->channel)
187 		return -ENODEV;
188 	return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
189 }
190 static DEVICE_ATTR_RO(monitor_id);
191 
192 static ssize_t class_id_show(struct device *dev,
193 			       struct device_attribute *dev_attr, char *buf)
194 {
195 	struct hv_device *hv_dev = device_to_hv_device(dev);
196 
197 	if (!hv_dev->channel)
198 		return -ENODEV;
199 	return sprintf(buf, "{%pUl}\n",
200 		       hv_dev->channel->offermsg.offer.if_type.b);
201 }
202 static DEVICE_ATTR_RO(class_id);
203 
204 static ssize_t device_id_show(struct device *dev,
205 			      struct device_attribute *dev_attr, char *buf)
206 {
207 	struct hv_device *hv_dev = device_to_hv_device(dev);
208 
209 	if (!hv_dev->channel)
210 		return -ENODEV;
211 	return sprintf(buf, "{%pUl}\n",
212 		       hv_dev->channel->offermsg.offer.if_instance.b);
213 }
214 static DEVICE_ATTR_RO(device_id);
215 
216 static ssize_t modalias_show(struct device *dev,
217 			     struct device_attribute *dev_attr, char *buf)
218 {
219 	struct hv_device *hv_dev = device_to_hv_device(dev);
220 	char alias_name[VMBUS_ALIAS_LEN + 1];
221 
222 	print_alias_name(hv_dev, alias_name);
223 	return sprintf(buf, "vmbus:%s\n", alias_name);
224 }
225 static DEVICE_ATTR_RO(modalias);
226 
227 static ssize_t server_monitor_pending_show(struct device *dev,
228 					   struct device_attribute *dev_attr,
229 					   char *buf)
230 {
231 	struct hv_device *hv_dev = device_to_hv_device(dev);
232 
233 	if (!hv_dev->channel)
234 		return -ENODEV;
235 	return sprintf(buf, "%d\n",
236 		       channel_pending(hv_dev->channel,
237 				       vmbus_connection.monitor_pages[1]));
238 }
239 static DEVICE_ATTR_RO(server_monitor_pending);
240 
241 static ssize_t client_monitor_pending_show(struct device *dev,
242 					   struct device_attribute *dev_attr,
243 					   char *buf)
244 {
245 	struct hv_device *hv_dev = device_to_hv_device(dev);
246 
247 	if (!hv_dev->channel)
248 		return -ENODEV;
249 	return sprintf(buf, "%d\n",
250 		       channel_pending(hv_dev->channel,
251 				       vmbus_connection.monitor_pages[1]));
252 }
253 static DEVICE_ATTR_RO(client_monitor_pending);
254 
255 static ssize_t server_monitor_latency_show(struct device *dev,
256 					   struct device_attribute *dev_attr,
257 					   char *buf)
258 {
259 	struct hv_device *hv_dev = device_to_hv_device(dev);
260 
261 	if (!hv_dev->channel)
262 		return -ENODEV;
263 	return sprintf(buf, "%d\n",
264 		       channel_latency(hv_dev->channel,
265 				       vmbus_connection.monitor_pages[0]));
266 }
267 static DEVICE_ATTR_RO(server_monitor_latency);
268 
269 static ssize_t client_monitor_latency_show(struct device *dev,
270 					   struct device_attribute *dev_attr,
271 					   char *buf)
272 {
273 	struct hv_device *hv_dev = device_to_hv_device(dev);
274 
275 	if (!hv_dev->channel)
276 		return -ENODEV;
277 	return sprintf(buf, "%d\n",
278 		       channel_latency(hv_dev->channel,
279 				       vmbus_connection.monitor_pages[1]));
280 }
281 static DEVICE_ATTR_RO(client_monitor_latency);
282 
283 static ssize_t server_monitor_conn_id_show(struct device *dev,
284 					   struct device_attribute *dev_attr,
285 					   char *buf)
286 {
287 	struct hv_device *hv_dev = device_to_hv_device(dev);
288 
289 	if (!hv_dev->channel)
290 		return -ENODEV;
291 	return sprintf(buf, "%d\n",
292 		       channel_conn_id(hv_dev->channel,
293 				       vmbus_connection.monitor_pages[0]));
294 }
295 static DEVICE_ATTR_RO(server_monitor_conn_id);
296 
297 static ssize_t client_monitor_conn_id_show(struct device *dev,
298 					   struct device_attribute *dev_attr,
299 					   char *buf)
300 {
301 	struct hv_device *hv_dev = device_to_hv_device(dev);
302 
303 	if (!hv_dev->channel)
304 		return -ENODEV;
305 	return sprintf(buf, "%d\n",
306 		       channel_conn_id(hv_dev->channel,
307 				       vmbus_connection.monitor_pages[1]));
308 }
309 static DEVICE_ATTR_RO(client_monitor_conn_id);
310 
311 static ssize_t out_intr_mask_show(struct device *dev,
312 				  struct device_attribute *dev_attr, char *buf)
313 {
314 	struct hv_device *hv_dev = device_to_hv_device(dev);
315 	struct hv_ring_buffer_debug_info outbound;
316 
317 	if (!hv_dev->channel)
318 		return -ENODEV;
319 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
320 	return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
321 }
322 static DEVICE_ATTR_RO(out_intr_mask);
323 
324 static ssize_t out_read_index_show(struct device *dev,
325 				   struct device_attribute *dev_attr, char *buf)
326 {
327 	struct hv_device *hv_dev = device_to_hv_device(dev);
328 	struct hv_ring_buffer_debug_info outbound;
329 
330 	if (!hv_dev->channel)
331 		return -ENODEV;
332 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
333 	return sprintf(buf, "%d\n", outbound.current_read_index);
334 }
335 static DEVICE_ATTR_RO(out_read_index);
336 
337 static ssize_t out_write_index_show(struct device *dev,
338 				    struct device_attribute *dev_attr,
339 				    char *buf)
340 {
341 	struct hv_device *hv_dev = device_to_hv_device(dev);
342 	struct hv_ring_buffer_debug_info outbound;
343 
344 	if (!hv_dev->channel)
345 		return -ENODEV;
346 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
347 	return sprintf(buf, "%d\n", outbound.current_write_index);
348 }
349 static DEVICE_ATTR_RO(out_write_index);
350 
351 static ssize_t out_read_bytes_avail_show(struct device *dev,
352 					 struct device_attribute *dev_attr,
353 					 char *buf)
354 {
355 	struct hv_device *hv_dev = device_to_hv_device(dev);
356 	struct hv_ring_buffer_debug_info outbound;
357 
358 	if (!hv_dev->channel)
359 		return -ENODEV;
360 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
361 	return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
362 }
363 static DEVICE_ATTR_RO(out_read_bytes_avail);
364 
365 static ssize_t out_write_bytes_avail_show(struct device *dev,
366 					  struct device_attribute *dev_attr,
367 					  char *buf)
368 {
369 	struct hv_device *hv_dev = device_to_hv_device(dev);
370 	struct hv_ring_buffer_debug_info outbound;
371 
372 	if (!hv_dev->channel)
373 		return -ENODEV;
374 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
375 	return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
376 }
377 static DEVICE_ATTR_RO(out_write_bytes_avail);
378 
379 static ssize_t in_intr_mask_show(struct device *dev,
380 				 struct device_attribute *dev_attr, char *buf)
381 {
382 	struct hv_device *hv_dev = device_to_hv_device(dev);
383 	struct hv_ring_buffer_debug_info inbound;
384 
385 	if (!hv_dev->channel)
386 		return -ENODEV;
387 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
388 	return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
389 }
390 static DEVICE_ATTR_RO(in_intr_mask);
391 
392 static ssize_t in_read_index_show(struct device *dev,
393 				  struct device_attribute *dev_attr, char *buf)
394 {
395 	struct hv_device *hv_dev = device_to_hv_device(dev);
396 	struct hv_ring_buffer_debug_info inbound;
397 
398 	if (!hv_dev->channel)
399 		return -ENODEV;
400 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
401 	return sprintf(buf, "%d\n", inbound.current_read_index);
402 }
403 static DEVICE_ATTR_RO(in_read_index);
404 
405 static ssize_t in_write_index_show(struct device *dev,
406 				   struct device_attribute *dev_attr, char *buf)
407 {
408 	struct hv_device *hv_dev = device_to_hv_device(dev);
409 	struct hv_ring_buffer_debug_info inbound;
410 
411 	if (!hv_dev->channel)
412 		return -ENODEV;
413 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
414 	return sprintf(buf, "%d\n", inbound.current_write_index);
415 }
416 static DEVICE_ATTR_RO(in_write_index);
417 
418 static ssize_t in_read_bytes_avail_show(struct device *dev,
419 					struct device_attribute *dev_attr,
420 					char *buf)
421 {
422 	struct hv_device *hv_dev = device_to_hv_device(dev);
423 	struct hv_ring_buffer_debug_info inbound;
424 
425 	if (!hv_dev->channel)
426 		return -ENODEV;
427 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
428 	return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
429 }
430 static DEVICE_ATTR_RO(in_read_bytes_avail);
431 
432 static ssize_t in_write_bytes_avail_show(struct device *dev,
433 					 struct device_attribute *dev_attr,
434 					 char *buf)
435 {
436 	struct hv_device *hv_dev = device_to_hv_device(dev);
437 	struct hv_ring_buffer_debug_info inbound;
438 
439 	if (!hv_dev->channel)
440 		return -ENODEV;
441 	hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
442 	return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
443 }
444 static DEVICE_ATTR_RO(in_write_bytes_avail);
445 
446 static ssize_t channel_vp_mapping_show(struct device *dev,
447 				       struct device_attribute *dev_attr,
448 				       char *buf)
449 {
450 	struct hv_device *hv_dev = device_to_hv_device(dev);
451 	struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
452 	unsigned long flags;
453 	int buf_size = PAGE_SIZE, n_written, tot_written;
454 	struct list_head *cur;
455 
456 	if (!channel)
457 		return -ENODEV;
458 
459 	tot_written = snprintf(buf, buf_size, "%u:%u\n",
460 		channel->offermsg.child_relid, channel->target_cpu);
461 
462 	spin_lock_irqsave(&channel->lock, flags);
463 
464 	list_for_each(cur, &channel->sc_list) {
465 		if (tot_written >= buf_size - 1)
466 			break;
467 
468 		cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
469 		n_written = scnprintf(buf + tot_written,
470 				     buf_size - tot_written,
471 				     "%u:%u\n",
472 				     cur_sc->offermsg.child_relid,
473 				     cur_sc->target_cpu);
474 		tot_written += n_written;
475 	}
476 
477 	spin_unlock_irqrestore(&channel->lock, flags);
478 
479 	return tot_written;
480 }
481 static DEVICE_ATTR_RO(channel_vp_mapping);
482 
483 static ssize_t vendor_show(struct device *dev,
484 			   struct device_attribute *dev_attr,
485 			   char *buf)
486 {
487 	struct hv_device *hv_dev = device_to_hv_device(dev);
488 	return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
489 }
490 static DEVICE_ATTR_RO(vendor);
491 
492 static ssize_t device_show(struct device *dev,
493 			   struct device_attribute *dev_attr,
494 			   char *buf)
495 {
496 	struct hv_device *hv_dev = device_to_hv_device(dev);
497 	return sprintf(buf, "0x%x\n", hv_dev->device_id);
498 }
499 static DEVICE_ATTR_RO(device);
500 
501 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
502 static struct attribute *vmbus_attrs[] = {
503 	&dev_attr_id.attr,
504 	&dev_attr_state.attr,
505 	&dev_attr_monitor_id.attr,
506 	&dev_attr_class_id.attr,
507 	&dev_attr_device_id.attr,
508 	&dev_attr_modalias.attr,
509 	&dev_attr_server_monitor_pending.attr,
510 	&dev_attr_client_monitor_pending.attr,
511 	&dev_attr_server_monitor_latency.attr,
512 	&dev_attr_client_monitor_latency.attr,
513 	&dev_attr_server_monitor_conn_id.attr,
514 	&dev_attr_client_monitor_conn_id.attr,
515 	&dev_attr_out_intr_mask.attr,
516 	&dev_attr_out_read_index.attr,
517 	&dev_attr_out_write_index.attr,
518 	&dev_attr_out_read_bytes_avail.attr,
519 	&dev_attr_out_write_bytes_avail.attr,
520 	&dev_attr_in_intr_mask.attr,
521 	&dev_attr_in_read_index.attr,
522 	&dev_attr_in_write_index.attr,
523 	&dev_attr_in_read_bytes_avail.attr,
524 	&dev_attr_in_write_bytes_avail.attr,
525 	&dev_attr_channel_vp_mapping.attr,
526 	&dev_attr_vendor.attr,
527 	&dev_attr_device.attr,
528 	NULL,
529 };
530 ATTRIBUTE_GROUPS(vmbus);
531 
532 /*
533  * vmbus_uevent - add uevent for our device
534  *
535  * This routine is invoked when a device is added or removed on the vmbus to
536  * generate a uevent to udev in the userspace. The udev will then look at its
537  * rule and the uevent generated here to load the appropriate driver
538  *
539  * The alias string will be of the form vmbus:guid where guid is the string
540  * representation of the device guid (each byte of the guid will be
541  * represented with two hex characters.
542  */
543 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
544 {
545 	struct hv_device *dev = device_to_hv_device(device);
546 	int ret;
547 	char alias_name[VMBUS_ALIAS_LEN + 1];
548 
549 	print_alias_name(dev, alias_name);
550 	ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
551 	return ret;
552 }
553 
554 static const uuid_le null_guid;
555 
556 static inline bool is_null_guid(const uuid_le *guid)
557 {
558 	if (uuid_le_cmp(*guid, null_guid))
559 		return false;
560 	return true;
561 }
562 
563 /*
564  * Return a matching hv_vmbus_device_id pointer.
565  * If there is no match, return NULL.
566  */
567 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
568 					const struct hv_vmbus_device_id *id,
569 					const uuid_le *guid)
570 {
571 	for (; !is_null_guid(&id->guid); id++)
572 		if (!uuid_le_cmp(id->guid, *guid))
573 			return id;
574 
575 	return NULL;
576 }
577 
578 
579 
580 /*
581  * vmbus_match - Attempt to match the specified device to the specified driver
582  */
583 static int vmbus_match(struct device *device, struct device_driver *driver)
584 {
585 	struct hv_driver *drv = drv_to_hv_drv(driver);
586 	struct hv_device *hv_dev = device_to_hv_device(device);
587 
588 	/* The hv_sock driver handles all hv_sock offers. */
589 	if (is_hvsock_channel(hv_dev->channel))
590 		return drv->hvsock;
591 
592 	if (hv_vmbus_get_id(drv->id_table, &hv_dev->dev_type))
593 		return 1;
594 
595 	return 0;
596 }
597 
598 /*
599  * vmbus_probe - Add the new vmbus's child device
600  */
601 static int vmbus_probe(struct device *child_device)
602 {
603 	int ret = 0;
604 	struct hv_driver *drv =
605 			drv_to_hv_drv(child_device->driver);
606 	struct hv_device *dev = device_to_hv_device(child_device);
607 	const struct hv_vmbus_device_id *dev_id;
608 
609 	dev_id = hv_vmbus_get_id(drv->id_table, &dev->dev_type);
610 	if (drv->probe) {
611 		ret = drv->probe(dev, dev_id);
612 		if (ret != 0)
613 			pr_err("probe failed for device %s (%d)\n",
614 			       dev_name(child_device), ret);
615 
616 	} else {
617 		pr_err("probe not set for driver %s\n",
618 		       dev_name(child_device));
619 		ret = -ENODEV;
620 	}
621 	return ret;
622 }
623 
624 /*
625  * vmbus_remove - Remove a vmbus device
626  */
627 static int vmbus_remove(struct device *child_device)
628 {
629 	struct hv_driver *drv;
630 	struct hv_device *dev = device_to_hv_device(child_device);
631 
632 	if (child_device->driver) {
633 		drv = drv_to_hv_drv(child_device->driver);
634 		if (drv->remove)
635 			drv->remove(dev);
636 	}
637 
638 	return 0;
639 }
640 
641 
642 /*
643  * vmbus_shutdown - Shutdown a vmbus device
644  */
645 static void vmbus_shutdown(struct device *child_device)
646 {
647 	struct hv_driver *drv;
648 	struct hv_device *dev = device_to_hv_device(child_device);
649 
650 
651 	/* The device may not be attached yet */
652 	if (!child_device->driver)
653 		return;
654 
655 	drv = drv_to_hv_drv(child_device->driver);
656 
657 	if (drv->shutdown)
658 		drv->shutdown(dev);
659 
660 	return;
661 }
662 
663 
664 /*
665  * vmbus_device_release - Final callback release of the vmbus child device
666  */
667 static void vmbus_device_release(struct device *device)
668 {
669 	struct hv_device *hv_dev = device_to_hv_device(device);
670 	struct vmbus_channel *channel = hv_dev->channel;
671 
672 	hv_process_channel_removal(channel,
673 				   channel->offermsg.child_relid);
674 	kfree(hv_dev);
675 
676 }
677 
678 /* The one and only one */
679 static struct bus_type  hv_bus = {
680 	.name =		"vmbus",
681 	.match =		vmbus_match,
682 	.shutdown =		vmbus_shutdown,
683 	.remove =		vmbus_remove,
684 	.probe =		vmbus_probe,
685 	.uevent =		vmbus_uevent,
686 	.dev_groups =		vmbus_groups,
687 };
688 
689 struct onmessage_work_context {
690 	struct work_struct work;
691 	struct hv_message msg;
692 };
693 
694 static void vmbus_onmessage_work(struct work_struct *work)
695 {
696 	struct onmessage_work_context *ctx;
697 
698 	/* Do not process messages if we're in DISCONNECTED state */
699 	if (vmbus_connection.conn_state == DISCONNECTED)
700 		return;
701 
702 	ctx = container_of(work, struct onmessage_work_context,
703 			   work);
704 	vmbus_onmessage(&ctx->msg);
705 	kfree(ctx);
706 }
707 
708 static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
709 {
710 	struct clock_event_device *dev = hv_context.clk_evt[cpu];
711 
712 	if (dev->event_handler)
713 		dev->event_handler(dev);
714 
715 	vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
716 }
717 
718 void vmbus_on_msg_dpc(unsigned long data)
719 {
720 	int cpu = smp_processor_id();
721 	void *page_addr = hv_context.synic_message_page[cpu];
722 	struct hv_message *msg = (struct hv_message *)page_addr +
723 				  VMBUS_MESSAGE_SINT;
724 	struct vmbus_channel_message_header *hdr;
725 	struct vmbus_channel_message_table_entry *entry;
726 	struct onmessage_work_context *ctx;
727 	u32 message_type = msg->header.message_type;
728 
729 	if (message_type == HVMSG_NONE)
730 		/* no msg */
731 		return;
732 
733 	hdr = (struct vmbus_channel_message_header *)msg->u.payload;
734 
735 	if (hdr->msgtype >= CHANNELMSG_COUNT) {
736 		WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
737 		goto msg_handled;
738 	}
739 
740 	entry = &channel_message_table[hdr->msgtype];
741 	if (entry->handler_type	== VMHT_BLOCKING) {
742 		ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
743 		if (ctx == NULL)
744 			return;
745 
746 		INIT_WORK(&ctx->work, vmbus_onmessage_work);
747 		memcpy(&ctx->msg, msg, sizeof(*msg));
748 
749 		queue_work(vmbus_connection.work_queue, &ctx->work);
750 	} else
751 		entry->message_handler(hdr);
752 
753 msg_handled:
754 	vmbus_signal_eom(msg, message_type);
755 }
756 
757 static void vmbus_isr(void)
758 {
759 	int cpu = smp_processor_id();
760 	void *page_addr;
761 	struct hv_message *msg;
762 	union hv_synic_event_flags *event;
763 	bool handled = false;
764 
765 	page_addr = hv_context.synic_event_page[cpu];
766 	if (page_addr == NULL)
767 		return;
768 
769 	event = (union hv_synic_event_flags *)page_addr +
770 					 VMBUS_MESSAGE_SINT;
771 	/*
772 	 * Check for events before checking for messages. This is the order
773 	 * in which events and messages are checked in Windows guests on
774 	 * Hyper-V, and the Windows team suggested we do the same.
775 	 */
776 
777 	if ((vmbus_proto_version == VERSION_WS2008) ||
778 		(vmbus_proto_version == VERSION_WIN7)) {
779 
780 		/* Since we are a child, we only need to check bit 0 */
781 		if (sync_test_and_clear_bit(0,
782 			(unsigned long *) &event->flags32[0])) {
783 			handled = true;
784 		}
785 	} else {
786 		/*
787 		 * Our host is win8 or above. The signaling mechanism
788 		 * has changed and we can directly look at the event page.
789 		 * If bit n is set then we have an interrup on the channel
790 		 * whose id is n.
791 		 */
792 		handled = true;
793 	}
794 
795 	if (handled)
796 		tasklet_schedule(hv_context.event_dpc[cpu]);
797 
798 
799 	page_addr = hv_context.synic_message_page[cpu];
800 	msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
801 
802 	/* Check if there are actual msgs to be processed */
803 	if (msg->header.message_type != HVMSG_NONE) {
804 		if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
805 			hv_process_timer_expiration(msg, cpu);
806 		else
807 			tasklet_schedule(hv_context.msg_dpc[cpu]);
808 	}
809 }
810 
811 
812 /*
813  * vmbus_bus_init -Main vmbus driver initialization routine.
814  *
815  * Here, we
816  *	- initialize the vmbus driver context
817  *	- invoke the vmbus hv main init routine
818  *	- retrieve the channel offers
819  */
820 static int vmbus_bus_init(void)
821 {
822 	int ret;
823 
824 	/* Hypervisor initialization...setup hypercall page..etc */
825 	ret = hv_init();
826 	if (ret != 0) {
827 		pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
828 		return ret;
829 	}
830 
831 	ret = bus_register(&hv_bus);
832 	if (ret)
833 		goto err_cleanup;
834 
835 	hv_setup_vmbus_irq(vmbus_isr);
836 
837 	ret = hv_synic_alloc();
838 	if (ret)
839 		goto err_alloc;
840 	/*
841 	 * Initialize the per-cpu interrupt state and
842 	 * connect to the host.
843 	 */
844 	on_each_cpu(hv_synic_init, NULL, 1);
845 	ret = vmbus_connect();
846 	if (ret)
847 		goto err_connect;
848 
849 	if (vmbus_proto_version > VERSION_WIN7)
850 		cpu_hotplug_disable();
851 
852 	/*
853 	 * Only register if the crash MSRs are available
854 	 */
855 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
856 		register_die_notifier(&hyperv_die_block);
857 		atomic_notifier_chain_register(&panic_notifier_list,
858 					       &hyperv_panic_block);
859 	}
860 
861 	vmbus_request_offers();
862 
863 	return 0;
864 
865 err_connect:
866 	on_each_cpu(hv_synic_cleanup, NULL, 1);
867 err_alloc:
868 	hv_synic_free();
869 	hv_remove_vmbus_irq();
870 
871 	bus_unregister(&hv_bus);
872 
873 err_cleanup:
874 	hv_cleanup();
875 
876 	return ret;
877 }
878 
879 /**
880  * __vmbus_child_driver_register() - Register a vmbus's driver
881  * @hv_driver: Pointer to driver structure you want to register
882  * @owner: owner module of the drv
883  * @mod_name: module name string
884  *
885  * Registers the given driver with Linux through the 'driver_register()' call
886  * and sets up the hyper-v vmbus handling for this driver.
887  * It will return the state of the 'driver_register()' call.
888  *
889  */
890 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
891 {
892 	int ret;
893 
894 	pr_info("registering driver %s\n", hv_driver->name);
895 
896 	ret = vmbus_exists();
897 	if (ret < 0)
898 		return ret;
899 
900 	hv_driver->driver.name = hv_driver->name;
901 	hv_driver->driver.owner = owner;
902 	hv_driver->driver.mod_name = mod_name;
903 	hv_driver->driver.bus = &hv_bus;
904 
905 	ret = driver_register(&hv_driver->driver);
906 
907 	return ret;
908 }
909 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
910 
911 /**
912  * vmbus_driver_unregister() - Unregister a vmbus's driver
913  * @hv_driver: Pointer to driver structure you want to
914  *             un-register
915  *
916  * Un-register the given driver that was previous registered with a call to
917  * vmbus_driver_register()
918  */
919 void vmbus_driver_unregister(struct hv_driver *hv_driver)
920 {
921 	pr_info("unregistering driver %s\n", hv_driver->name);
922 
923 	if (!vmbus_exists())
924 		driver_unregister(&hv_driver->driver);
925 }
926 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
927 
928 /*
929  * vmbus_device_create - Creates and registers a new child device
930  * on the vmbus.
931  */
932 struct hv_device *vmbus_device_create(const uuid_le *type,
933 				      const uuid_le *instance,
934 				      struct vmbus_channel *channel)
935 {
936 	struct hv_device *child_device_obj;
937 
938 	child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
939 	if (!child_device_obj) {
940 		pr_err("Unable to allocate device object for child device\n");
941 		return NULL;
942 	}
943 
944 	child_device_obj->channel = channel;
945 	memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
946 	memcpy(&child_device_obj->dev_instance, instance,
947 	       sizeof(uuid_le));
948 	child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
949 
950 
951 	return child_device_obj;
952 }
953 
954 /*
955  * vmbus_device_register - Register the child device
956  */
957 int vmbus_device_register(struct hv_device *child_device_obj)
958 {
959 	int ret = 0;
960 
961 	dev_set_name(&child_device_obj->device, "vmbus_%d",
962 		     child_device_obj->channel->id);
963 
964 	child_device_obj->device.bus = &hv_bus;
965 	child_device_obj->device.parent = &hv_acpi_dev->dev;
966 	child_device_obj->device.release = vmbus_device_release;
967 
968 	/*
969 	 * Register with the LDM. This will kick off the driver/device
970 	 * binding...which will eventually call vmbus_match() and vmbus_probe()
971 	 */
972 	ret = device_register(&child_device_obj->device);
973 
974 	if (ret)
975 		pr_err("Unable to register child device\n");
976 	else
977 		pr_debug("child device %s registered\n",
978 			dev_name(&child_device_obj->device));
979 
980 	return ret;
981 }
982 
983 /*
984  * vmbus_device_unregister - Remove the specified child device
985  * from the vmbus.
986  */
987 void vmbus_device_unregister(struct hv_device *device_obj)
988 {
989 	pr_debug("child device %s unregistered\n",
990 		dev_name(&device_obj->device));
991 
992 	/*
993 	 * Kick off the process of unregistering the device.
994 	 * This will call vmbus_remove() and eventually vmbus_device_release()
995 	 */
996 	device_unregister(&device_obj->device);
997 }
998 
999 
1000 /*
1001  * VMBUS is an acpi enumerated device. Get the information we
1002  * need from DSDT.
1003  */
1004 #define VTPM_BASE_ADDRESS 0xfed40000
1005 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1006 {
1007 	resource_size_t start = 0;
1008 	resource_size_t end = 0;
1009 	struct resource *new_res;
1010 	struct resource **old_res = &hyperv_mmio;
1011 	struct resource **prev_res = NULL;
1012 
1013 	switch (res->type) {
1014 
1015 	/*
1016 	 * "Address" descriptors are for bus windows. Ignore
1017 	 * "memory" descriptors, which are for registers on
1018 	 * devices.
1019 	 */
1020 	case ACPI_RESOURCE_TYPE_ADDRESS32:
1021 		start = res->data.address32.address.minimum;
1022 		end = res->data.address32.address.maximum;
1023 		break;
1024 
1025 	case ACPI_RESOURCE_TYPE_ADDRESS64:
1026 		start = res->data.address64.address.minimum;
1027 		end = res->data.address64.address.maximum;
1028 		break;
1029 
1030 	default:
1031 		/* Unused resource type */
1032 		return AE_OK;
1033 
1034 	}
1035 	/*
1036 	 * Ignore ranges that are below 1MB, as they're not
1037 	 * necessary or useful here.
1038 	 */
1039 	if (end < 0x100000)
1040 		return AE_OK;
1041 
1042 	new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1043 	if (!new_res)
1044 		return AE_NO_MEMORY;
1045 
1046 	/* If this range overlaps the virtual TPM, truncate it. */
1047 	if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1048 		end = VTPM_BASE_ADDRESS;
1049 
1050 	new_res->name = "hyperv mmio";
1051 	new_res->flags = IORESOURCE_MEM;
1052 	new_res->start = start;
1053 	new_res->end = end;
1054 
1055 	/*
1056 	 * If two ranges are adjacent, merge them.
1057 	 */
1058 	do {
1059 		if (!*old_res) {
1060 			*old_res = new_res;
1061 			break;
1062 		}
1063 
1064 		if (((*old_res)->end + 1) == new_res->start) {
1065 			(*old_res)->end = new_res->end;
1066 			kfree(new_res);
1067 			break;
1068 		}
1069 
1070 		if ((*old_res)->start == new_res->end + 1) {
1071 			(*old_res)->start = new_res->start;
1072 			kfree(new_res);
1073 			break;
1074 		}
1075 
1076 		if ((*old_res)->start > new_res->end) {
1077 			new_res->sibling = *old_res;
1078 			if (prev_res)
1079 				(*prev_res)->sibling = new_res;
1080 			*old_res = new_res;
1081 			break;
1082 		}
1083 
1084 		prev_res = old_res;
1085 		old_res = &(*old_res)->sibling;
1086 
1087 	} while (1);
1088 
1089 	return AE_OK;
1090 }
1091 
1092 static int vmbus_acpi_remove(struct acpi_device *device)
1093 {
1094 	struct resource *cur_res;
1095 	struct resource *next_res;
1096 
1097 	if (hyperv_mmio) {
1098 		if (fb_mmio) {
1099 			__release_region(hyperv_mmio, fb_mmio->start,
1100 					 resource_size(fb_mmio));
1101 			fb_mmio = NULL;
1102 		}
1103 
1104 		for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1105 			next_res = cur_res->sibling;
1106 			kfree(cur_res);
1107 		}
1108 	}
1109 
1110 	return 0;
1111 }
1112 
1113 static void vmbus_reserve_fb(void)
1114 {
1115 	int size;
1116 	/*
1117 	 * Make a claim for the frame buffer in the resource tree under the
1118 	 * first node, which will be the one below 4GB.  The length seems to
1119 	 * be underreported, particularly in a Generation 1 VM.  So start out
1120 	 * reserving a larger area and make it smaller until it succeeds.
1121 	 */
1122 
1123 	if (screen_info.lfb_base) {
1124 		if (efi_enabled(EFI_BOOT))
1125 			size = max_t(__u32, screen_info.lfb_size, 0x800000);
1126 		else
1127 			size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1128 
1129 		for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1130 			fb_mmio = __request_region(hyperv_mmio,
1131 						   screen_info.lfb_base, size,
1132 						   fb_mmio_name, 0);
1133 		}
1134 	}
1135 }
1136 
1137 /**
1138  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1139  * @new:		If successful, supplied a pointer to the
1140  *			allocated MMIO space.
1141  * @device_obj:		Identifies the caller
1142  * @min:		Minimum guest physical address of the
1143  *			allocation
1144  * @max:		Maximum guest physical address
1145  * @size:		Size of the range to be allocated
1146  * @align:		Alignment of the range to be allocated
1147  * @fb_overlap_ok:	Whether this allocation can be allowed
1148  *			to overlap the video frame buffer.
1149  *
1150  * This function walks the resources granted to VMBus by the
1151  * _CRS object in the ACPI namespace underneath the parent
1152  * "bridge" whether that's a root PCI bus in the Generation 1
1153  * case or a Module Device in the Generation 2 case.  It then
1154  * attempts to allocate from the global MMIO pool in a way that
1155  * matches the constraints supplied in these parameters and by
1156  * that _CRS.
1157  *
1158  * Return: 0 on success, -errno on failure
1159  */
1160 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1161 			resource_size_t min, resource_size_t max,
1162 			resource_size_t size, resource_size_t align,
1163 			bool fb_overlap_ok)
1164 {
1165 	struct resource *iter, *shadow;
1166 	resource_size_t range_min, range_max, start;
1167 	const char *dev_n = dev_name(&device_obj->device);
1168 	int retval;
1169 
1170 	retval = -ENXIO;
1171 	down(&hyperv_mmio_lock);
1172 
1173 	/*
1174 	 * If overlaps with frame buffers are allowed, then first attempt to
1175 	 * make the allocation from within the reserved region.  Because it
1176 	 * is already reserved, no shadow allocation is necessary.
1177 	 */
1178 	if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1179 	    !(max < fb_mmio->start)) {
1180 
1181 		range_min = fb_mmio->start;
1182 		range_max = fb_mmio->end;
1183 		start = (range_min + align - 1) & ~(align - 1);
1184 		for (; start + size - 1 <= range_max; start += align) {
1185 			*new = request_mem_region_exclusive(start, size, dev_n);
1186 			if (*new) {
1187 				retval = 0;
1188 				goto exit;
1189 			}
1190 		}
1191 	}
1192 
1193 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1194 		if ((iter->start >= max) || (iter->end <= min))
1195 			continue;
1196 
1197 		range_min = iter->start;
1198 		range_max = iter->end;
1199 		start = (range_min + align - 1) & ~(align - 1);
1200 		for (; start + size - 1 <= range_max; start += align) {
1201 			shadow = __request_region(iter, start, size, NULL,
1202 						  IORESOURCE_BUSY);
1203 			if (!shadow)
1204 				continue;
1205 
1206 			*new = request_mem_region_exclusive(start, size, dev_n);
1207 			if (*new) {
1208 				shadow->name = (char *)*new;
1209 				retval = 0;
1210 				goto exit;
1211 			}
1212 
1213 			__release_region(iter, start, size);
1214 		}
1215 	}
1216 
1217 exit:
1218 	up(&hyperv_mmio_lock);
1219 	return retval;
1220 }
1221 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1222 
1223 /**
1224  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1225  * @start:		Base address of region to release.
1226  * @size:		Size of the range to be allocated
1227  *
1228  * This function releases anything requested by
1229  * vmbus_mmio_allocate().
1230  */
1231 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1232 {
1233 	struct resource *iter;
1234 
1235 	down(&hyperv_mmio_lock);
1236 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1237 		if ((iter->start >= start + size) || (iter->end <= start))
1238 			continue;
1239 
1240 		__release_region(iter, start, size);
1241 	}
1242 	release_mem_region(start, size);
1243 	up(&hyperv_mmio_lock);
1244 
1245 }
1246 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1247 
1248 /**
1249  * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
1250  * @cpu_number: CPU number in Linux terms
1251  *
1252  * This function returns the mapping between the Linux processor
1253  * number and the hypervisor's virtual processor number, useful
1254  * in making hypercalls and such that talk about specific
1255  * processors.
1256  *
1257  * Return: Virtual processor number in Hyper-V terms
1258  */
1259 int vmbus_cpu_number_to_vp_number(int cpu_number)
1260 {
1261 	return hv_context.vp_index[cpu_number];
1262 }
1263 EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
1264 
1265 static int vmbus_acpi_add(struct acpi_device *device)
1266 {
1267 	acpi_status result;
1268 	int ret_val = -ENODEV;
1269 	struct acpi_device *ancestor;
1270 
1271 	hv_acpi_dev = device;
1272 
1273 	result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1274 					vmbus_walk_resources, NULL);
1275 
1276 	if (ACPI_FAILURE(result))
1277 		goto acpi_walk_err;
1278 	/*
1279 	 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1280 	 * firmware) is the VMOD that has the mmio ranges. Get that.
1281 	 */
1282 	for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1283 		result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1284 					     vmbus_walk_resources, NULL);
1285 
1286 		if (ACPI_FAILURE(result))
1287 			continue;
1288 		if (hyperv_mmio) {
1289 			vmbus_reserve_fb();
1290 			break;
1291 		}
1292 	}
1293 	ret_val = 0;
1294 
1295 acpi_walk_err:
1296 	complete(&probe_event);
1297 	if (ret_val)
1298 		vmbus_acpi_remove(device);
1299 	return ret_val;
1300 }
1301 
1302 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1303 	{"VMBUS", 0},
1304 	{"VMBus", 0},
1305 	{"", 0},
1306 };
1307 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1308 
1309 static struct acpi_driver vmbus_acpi_driver = {
1310 	.name = "vmbus",
1311 	.ids = vmbus_acpi_device_ids,
1312 	.ops = {
1313 		.add = vmbus_acpi_add,
1314 		.remove = vmbus_acpi_remove,
1315 	},
1316 };
1317 
1318 static void hv_kexec_handler(void)
1319 {
1320 	int cpu;
1321 
1322 	hv_synic_clockevents_cleanup();
1323 	vmbus_initiate_unload(false);
1324 	for_each_online_cpu(cpu)
1325 		smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1326 	hv_cleanup();
1327 };
1328 
1329 static void hv_crash_handler(struct pt_regs *regs)
1330 {
1331 	vmbus_initiate_unload(true);
1332 	/*
1333 	 * In crash handler we can't schedule synic cleanup for all CPUs,
1334 	 * doing the cleanup for current CPU only. This should be sufficient
1335 	 * for kdump.
1336 	 */
1337 	hv_synic_cleanup(NULL);
1338 	hv_cleanup();
1339 };
1340 
1341 static int __init hv_acpi_init(void)
1342 {
1343 	int ret, t;
1344 
1345 	if (x86_hyper != &x86_hyper_ms_hyperv)
1346 		return -ENODEV;
1347 
1348 	init_completion(&probe_event);
1349 
1350 	/*
1351 	 * Get ACPI resources first.
1352 	 */
1353 	ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1354 
1355 	if (ret)
1356 		return ret;
1357 
1358 	t = wait_for_completion_timeout(&probe_event, 5*HZ);
1359 	if (t == 0) {
1360 		ret = -ETIMEDOUT;
1361 		goto cleanup;
1362 	}
1363 
1364 	ret = vmbus_bus_init();
1365 	if (ret)
1366 		goto cleanup;
1367 
1368 	hv_setup_kexec_handler(hv_kexec_handler);
1369 	hv_setup_crash_handler(hv_crash_handler);
1370 
1371 	return 0;
1372 
1373 cleanup:
1374 	acpi_bus_unregister_driver(&vmbus_acpi_driver);
1375 	hv_acpi_dev = NULL;
1376 	return ret;
1377 }
1378 
1379 static void __exit vmbus_exit(void)
1380 {
1381 	int cpu;
1382 
1383 	hv_remove_kexec_handler();
1384 	hv_remove_crash_handler();
1385 	vmbus_connection.conn_state = DISCONNECTED;
1386 	hv_synic_clockevents_cleanup();
1387 	vmbus_disconnect();
1388 	hv_remove_vmbus_irq();
1389 	for_each_online_cpu(cpu)
1390 		tasklet_kill(hv_context.msg_dpc[cpu]);
1391 	vmbus_free_channels();
1392 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1393 		unregister_die_notifier(&hyperv_die_block);
1394 		atomic_notifier_chain_unregister(&panic_notifier_list,
1395 						 &hyperv_panic_block);
1396 	}
1397 	bus_unregister(&hv_bus);
1398 	hv_cleanup();
1399 	for_each_online_cpu(cpu) {
1400 		tasklet_kill(hv_context.event_dpc[cpu]);
1401 		smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1402 	}
1403 	hv_synic_free();
1404 	acpi_bus_unregister_driver(&vmbus_acpi_driver);
1405 	if (vmbus_proto_version > VERSION_WIN7)
1406 		cpu_hotplug_enable();
1407 }
1408 
1409 
1410 MODULE_LICENSE("GPL");
1411 
1412 subsys_initcall(hv_acpi_init);
1413 module_exit(vmbus_exit);
1414