xref: /openbmc/linux/drivers/hv/vmbus_drv.c (revision 715f23b6)
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/task_stack.h>
25 
26 #include <asm/mshyperv.h>
27 #include <linux/delay.h>
28 #include <linux/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/syscore_ops.h>
35 #include <clocksource/hyperv_timer.h>
36 #include "hyperv_vmbus.h"
37 
38 struct vmbus_dynid {
39 	struct list_head node;
40 	struct hv_vmbus_device_id id;
41 };
42 
43 static struct acpi_device  *hv_acpi_dev;
44 
45 static struct completion probe_event;
46 
47 static int hyperv_cpuhp_online;
48 
49 static void *hv_panic_page;
50 
51 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
52 			      void *args)
53 {
54 	struct pt_regs *regs;
55 
56 	regs = current_pt_regs();
57 
58 	hyperv_report_panic(regs, val);
59 	return NOTIFY_DONE;
60 }
61 
62 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
63 			    void *args)
64 {
65 	struct die_args *die = (struct die_args *)args;
66 	struct pt_regs *regs = die->regs;
67 
68 	hyperv_report_panic(regs, val);
69 	return NOTIFY_DONE;
70 }
71 
72 static struct notifier_block hyperv_die_block = {
73 	.notifier_call = hyperv_die_event,
74 };
75 static struct notifier_block hyperv_panic_block = {
76 	.notifier_call = hyperv_panic_event,
77 };
78 
79 static const char *fb_mmio_name = "fb_range";
80 static struct resource *fb_mmio;
81 static struct resource *hyperv_mmio;
82 static DEFINE_MUTEX(hyperv_mmio_lock);
83 
84 static int vmbus_exists(void)
85 {
86 	if (hv_acpi_dev == NULL)
87 		return -ENODEV;
88 
89 	return 0;
90 }
91 
92 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
93 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
94 {
95 	int i;
96 	for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
97 		sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
98 }
99 
100 static u8 channel_monitor_group(const struct vmbus_channel *channel)
101 {
102 	return (u8)channel->offermsg.monitorid / 32;
103 }
104 
105 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
106 {
107 	return (u8)channel->offermsg.monitorid % 32;
108 }
109 
110 static u32 channel_pending(const struct vmbus_channel *channel,
111 			   const struct hv_monitor_page *monitor_page)
112 {
113 	u8 monitor_group = channel_monitor_group(channel);
114 
115 	return monitor_page->trigger_group[monitor_group].pending;
116 }
117 
118 static u32 channel_latency(const struct vmbus_channel *channel,
119 			   const struct hv_monitor_page *monitor_page)
120 {
121 	u8 monitor_group = channel_monitor_group(channel);
122 	u8 monitor_offset = channel_monitor_offset(channel);
123 
124 	return monitor_page->latency[monitor_group][monitor_offset];
125 }
126 
127 static u32 channel_conn_id(struct vmbus_channel *channel,
128 			   struct hv_monitor_page *monitor_page)
129 {
130 	u8 monitor_group = channel_monitor_group(channel);
131 	u8 monitor_offset = channel_monitor_offset(channel);
132 	return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
133 }
134 
135 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
136 		       char *buf)
137 {
138 	struct hv_device *hv_dev = device_to_hv_device(dev);
139 
140 	if (!hv_dev->channel)
141 		return -ENODEV;
142 	return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
143 }
144 static DEVICE_ATTR_RO(id);
145 
146 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
147 			  char *buf)
148 {
149 	struct hv_device *hv_dev = device_to_hv_device(dev);
150 
151 	if (!hv_dev->channel)
152 		return -ENODEV;
153 	return sprintf(buf, "%d\n", hv_dev->channel->state);
154 }
155 static DEVICE_ATTR_RO(state);
156 
157 static ssize_t monitor_id_show(struct device *dev,
158 			       struct device_attribute *dev_attr, char *buf)
159 {
160 	struct hv_device *hv_dev = device_to_hv_device(dev);
161 
162 	if (!hv_dev->channel)
163 		return -ENODEV;
164 	return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
165 }
166 static DEVICE_ATTR_RO(monitor_id);
167 
168 static ssize_t class_id_show(struct device *dev,
169 			       struct device_attribute *dev_attr, char *buf)
170 {
171 	struct hv_device *hv_dev = device_to_hv_device(dev);
172 
173 	if (!hv_dev->channel)
174 		return -ENODEV;
175 	return sprintf(buf, "{%pUl}\n",
176 		       hv_dev->channel->offermsg.offer.if_type.b);
177 }
178 static DEVICE_ATTR_RO(class_id);
179 
180 static ssize_t device_id_show(struct device *dev,
181 			      struct device_attribute *dev_attr, char *buf)
182 {
183 	struct hv_device *hv_dev = device_to_hv_device(dev);
184 
185 	if (!hv_dev->channel)
186 		return -ENODEV;
187 	return sprintf(buf, "{%pUl}\n",
188 		       hv_dev->channel->offermsg.offer.if_instance.b);
189 }
190 static DEVICE_ATTR_RO(device_id);
191 
192 static ssize_t modalias_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 	char alias_name[VMBUS_ALIAS_LEN + 1];
197 
198 	print_alias_name(hv_dev, alias_name);
199 	return sprintf(buf, "vmbus:%s\n", alias_name);
200 }
201 static DEVICE_ATTR_RO(modalias);
202 
203 #ifdef CONFIG_NUMA
204 static ssize_t numa_node_show(struct device *dev,
205 			      struct device_attribute *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 
212 	return sprintf(buf, "%d\n", hv_dev->channel->numa_node);
213 }
214 static DEVICE_ATTR_RO(numa_node);
215 #endif
216 
217 static ssize_t server_monitor_pending_show(struct device *dev,
218 					   struct device_attribute *dev_attr,
219 					   char *buf)
220 {
221 	struct hv_device *hv_dev = device_to_hv_device(dev);
222 
223 	if (!hv_dev->channel)
224 		return -ENODEV;
225 	return sprintf(buf, "%d\n",
226 		       channel_pending(hv_dev->channel,
227 				       vmbus_connection.monitor_pages[0]));
228 }
229 static DEVICE_ATTR_RO(server_monitor_pending);
230 
231 static ssize_t client_monitor_pending_show(struct device *dev,
232 					   struct device_attribute *dev_attr,
233 					   char *buf)
234 {
235 	struct hv_device *hv_dev = device_to_hv_device(dev);
236 
237 	if (!hv_dev->channel)
238 		return -ENODEV;
239 	return sprintf(buf, "%d\n",
240 		       channel_pending(hv_dev->channel,
241 				       vmbus_connection.monitor_pages[1]));
242 }
243 static DEVICE_ATTR_RO(client_monitor_pending);
244 
245 static ssize_t server_monitor_latency_show(struct device *dev,
246 					   struct device_attribute *dev_attr,
247 					   char *buf)
248 {
249 	struct hv_device *hv_dev = device_to_hv_device(dev);
250 
251 	if (!hv_dev->channel)
252 		return -ENODEV;
253 	return sprintf(buf, "%d\n",
254 		       channel_latency(hv_dev->channel,
255 				       vmbus_connection.monitor_pages[0]));
256 }
257 static DEVICE_ATTR_RO(server_monitor_latency);
258 
259 static ssize_t client_monitor_latency_show(struct device *dev,
260 					   struct device_attribute *dev_attr,
261 					   char *buf)
262 {
263 	struct hv_device *hv_dev = device_to_hv_device(dev);
264 
265 	if (!hv_dev->channel)
266 		return -ENODEV;
267 	return sprintf(buf, "%d\n",
268 		       channel_latency(hv_dev->channel,
269 				       vmbus_connection.monitor_pages[1]));
270 }
271 static DEVICE_ATTR_RO(client_monitor_latency);
272 
273 static ssize_t server_monitor_conn_id_show(struct device *dev,
274 					   struct device_attribute *dev_attr,
275 					   char *buf)
276 {
277 	struct hv_device *hv_dev = device_to_hv_device(dev);
278 
279 	if (!hv_dev->channel)
280 		return -ENODEV;
281 	return sprintf(buf, "%d\n",
282 		       channel_conn_id(hv_dev->channel,
283 				       vmbus_connection.monitor_pages[0]));
284 }
285 static DEVICE_ATTR_RO(server_monitor_conn_id);
286 
287 static ssize_t client_monitor_conn_id_show(struct device *dev,
288 					   struct device_attribute *dev_attr,
289 					   char *buf)
290 {
291 	struct hv_device *hv_dev = device_to_hv_device(dev);
292 
293 	if (!hv_dev->channel)
294 		return -ENODEV;
295 	return sprintf(buf, "%d\n",
296 		       channel_conn_id(hv_dev->channel,
297 				       vmbus_connection.monitor_pages[1]));
298 }
299 static DEVICE_ATTR_RO(client_monitor_conn_id);
300 
301 static ssize_t out_intr_mask_show(struct device *dev,
302 				  struct device_attribute *dev_attr, char *buf)
303 {
304 	struct hv_device *hv_dev = device_to_hv_device(dev);
305 	struct hv_ring_buffer_debug_info outbound;
306 	int ret;
307 
308 	if (!hv_dev->channel)
309 		return -ENODEV;
310 
311 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
312 					  &outbound);
313 	if (ret < 0)
314 		return ret;
315 
316 	return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
317 }
318 static DEVICE_ATTR_RO(out_intr_mask);
319 
320 static ssize_t out_read_index_show(struct device *dev,
321 				   struct device_attribute *dev_attr, char *buf)
322 {
323 	struct hv_device *hv_dev = device_to_hv_device(dev);
324 	struct hv_ring_buffer_debug_info outbound;
325 	int ret;
326 
327 	if (!hv_dev->channel)
328 		return -ENODEV;
329 
330 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
331 					  &outbound);
332 	if (ret < 0)
333 		return ret;
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 	int ret;
345 
346 	if (!hv_dev->channel)
347 		return -ENODEV;
348 
349 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
350 					  &outbound);
351 	if (ret < 0)
352 		return ret;
353 	return sprintf(buf, "%d\n", outbound.current_write_index);
354 }
355 static DEVICE_ATTR_RO(out_write_index);
356 
357 static ssize_t out_read_bytes_avail_show(struct device *dev,
358 					 struct device_attribute *dev_attr,
359 					 char *buf)
360 {
361 	struct hv_device *hv_dev = device_to_hv_device(dev);
362 	struct hv_ring_buffer_debug_info outbound;
363 	int ret;
364 
365 	if (!hv_dev->channel)
366 		return -ENODEV;
367 
368 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
369 					  &outbound);
370 	if (ret < 0)
371 		return ret;
372 	return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
373 }
374 static DEVICE_ATTR_RO(out_read_bytes_avail);
375 
376 static ssize_t out_write_bytes_avail_show(struct device *dev,
377 					  struct device_attribute *dev_attr,
378 					  char *buf)
379 {
380 	struct hv_device *hv_dev = device_to_hv_device(dev);
381 	struct hv_ring_buffer_debug_info outbound;
382 	int ret;
383 
384 	if (!hv_dev->channel)
385 		return -ENODEV;
386 
387 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
388 					  &outbound);
389 	if (ret < 0)
390 		return ret;
391 	return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
392 }
393 static DEVICE_ATTR_RO(out_write_bytes_avail);
394 
395 static ssize_t in_intr_mask_show(struct device *dev,
396 				 struct device_attribute *dev_attr, char *buf)
397 {
398 	struct hv_device *hv_dev = device_to_hv_device(dev);
399 	struct hv_ring_buffer_debug_info inbound;
400 	int ret;
401 
402 	if (!hv_dev->channel)
403 		return -ENODEV;
404 
405 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
406 	if (ret < 0)
407 		return ret;
408 
409 	return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
410 }
411 static DEVICE_ATTR_RO(in_intr_mask);
412 
413 static ssize_t in_read_index_show(struct device *dev,
414 				  struct device_attribute *dev_attr, char *buf)
415 {
416 	struct hv_device *hv_dev = device_to_hv_device(dev);
417 	struct hv_ring_buffer_debug_info inbound;
418 	int ret;
419 
420 	if (!hv_dev->channel)
421 		return -ENODEV;
422 
423 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
424 	if (ret < 0)
425 		return ret;
426 
427 	return sprintf(buf, "%d\n", inbound.current_read_index);
428 }
429 static DEVICE_ATTR_RO(in_read_index);
430 
431 static ssize_t in_write_index_show(struct device *dev,
432 				   struct device_attribute *dev_attr, char *buf)
433 {
434 	struct hv_device *hv_dev = device_to_hv_device(dev);
435 	struct hv_ring_buffer_debug_info inbound;
436 	int ret;
437 
438 	if (!hv_dev->channel)
439 		return -ENODEV;
440 
441 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
442 	if (ret < 0)
443 		return ret;
444 
445 	return sprintf(buf, "%d\n", inbound.current_write_index);
446 }
447 static DEVICE_ATTR_RO(in_write_index);
448 
449 static ssize_t in_read_bytes_avail_show(struct device *dev,
450 					struct device_attribute *dev_attr,
451 					char *buf)
452 {
453 	struct hv_device *hv_dev = device_to_hv_device(dev);
454 	struct hv_ring_buffer_debug_info inbound;
455 	int ret;
456 
457 	if (!hv_dev->channel)
458 		return -ENODEV;
459 
460 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
461 	if (ret < 0)
462 		return ret;
463 
464 	return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
465 }
466 static DEVICE_ATTR_RO(in_read_bytes_avail);
467 
468 static ssize_t in_write_bytes_avail_show(struct device *dev,
469 					 struct device_attribute *dev_attr,
470 					 char *buf)
471 {
472 	struct hv_device *hv_dev = device_to_hv_device(dev);
473 	struct hv_ring_buffer_debug_info inbound;
474 	int ret;
475 
476 	if (!hv_dev->channel)
477 		return -ENODEV;
478 
479 	ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
480 	if (ret < 0)
481 		return ret;
482 
483 	return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
484 }
485 static DEVICE_ATTR_RO(in_write_bytes_avail);
486 
487 static ssize_t channel_vp_mapping_show(struct device *dev,
488 				       struct device_attribute *dev_attr,
489 				       char *buf)
490 {
491 	struct hv_device *hv_dev = device_to_hv_device(dev);
492 	struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
493 	unsigned long flags;
494 	int buf_size = PAGE_SIZE, n_written, tot_written;
495 	struct list_head *cur;
496 
497 	if (!channel)
498 		return -ENODEV;
499 
500 	tot_written = snprintf(buf, buf_size, "%u:%u\n",
501 		channel->offermsg.child_relid, channel->target_cpu);
502 
503 	spin_lock_irqsave(&channel->lock, flags);
504 
505 	list_for_each(cur, &channel->sc_list) {
506 		if (tot_written >= buf_size - 1)
507 			break;
508 
509 		cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
510 		n_written = scnprintf(buf + tot_written,
511 				     buf_size - tot_written,
512 				     "%u:%u\n",
513 				     cur_sc->offermsg.child_relid,
514 				     cur_sc->target_cpu);
515 		tot_written += n_written;
516 	}
517 
518 	spin_unlock_irqrestore(&channel->lock, flags);
519 
520 	return tot_written;
521 }
522 static DEVICE_ATTR_RO(channel_vp_mapping);
523 
524 static ssize_t vendor_show(struct device *dev,
525 			   struct device_attribute *dev_attr,
526 			   char *buf)
527 {
528 	struct hv_device *hv_dev = device_to_hv_device(dev);
529 	return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
530 }
531 static DEVICE_ATTR_RO(vendor);
532 
533 static ssize_t device_show(struct device *dev,
534 			   struct device_attribute *dev_attr,
535 			   char *buf)
536 {
537 	struct hv_device *hv_dev = device_to_hv_device(dev);
538 	return sprintf(buf, "0x%x\n", hv_dev->device_id);
539 }
540 static DEVICE_ATTR_RO(device);
541 
542 static ssize_t driver_override_store(struct device *dev,
543 				     struct device_attribute *attr,
544 				     const char *buf, size_t count)
545 {
546 	struct hv_device *hv_dev = device_to_hv_device(dev);
547 	char *driver_override, *old, *cp;
548 
549 	/* We need to keep extra room for a newline */
550 	if (count >= (PAGE_SIZE - 1))
551 		return -EINVAL;
552 
553 	driver_override = kstrndup(buf, count, GFP_KERNEL);
554 	if (!driver_override)
555 		return -ENOMEM;
556 
557 	cp = strchr(driver_override, '\n');
558 	if (cp)
559 		*cp = '\0';
560 
561 	device_lock(dev);
562 	old = hv_dev->driver_override;
563 	if (strlen(driver_override)) {
564 		hv_dev->driver_override = driver_override;
565 	} else {
566 		kfree(driver_override);
567 		hv_dev->driver_override = NULL;
568 	}
569 	device_unlock(dev);
570 
571 	kfree(old);
572 
573 	return count;
574 }
575 
576 static ssize_t driver_override_show(struct device *dev,
577 				    struct device_attribute *attr, char *buf)
578 {
579 	struct hv_device *hv_dev = device_to_hv_device(dev);
580 	ssize_t len;
581 
582 	device_lock(dev);
583 	len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
584 	device_unlock(dev);
585 
586 	return len;
587 }
588 static DEVICE_ATTR_RW(driver_override);
589 
590 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
591 static struct attribute *vmbus_dev_attrs[] = {
592 	&dev_attr_id.attr,
593 	&dev_attr_state.attr,
594 	&dev_attr_monitor_id.attr,
595 	&dev_attr_class_id.attr,
596 	&dev_attr_device_id.attr,
597 	&dev_attr_modalias.attr,
598 #ifdef CONFIG_NUMA
599 	&dev_attr_numa_node.attr,
600 #endif
601 	&dev_attr_server_monitor_pending.attr,
602 	&dev_attr_client_monitor_pending.attr,
603 	&dev_attr_server_monitor_latency.attr,
604 	&dev_attr_client_monitor_latency.attr,
605 	&dev_attr_server_monitor_conn_id.attr,
606 	&dev_attr_client_monitor_conn_id.attr,
607 	&dev_attr_out_intr_mask.attr,
608 	&dev_attr_out_read_index.attr,
609 	&dev_attr_out_write_index.attr,
610 	&dev_attr_out_read_bytes_avail.attr,
611 	&dev_attr_out_write_bytes_avail.attr,
612 	&dev_attr_in_intr_mask.attr,
613 	&dev_attr_in_read_index.attr,
614 	&dev_attr_in_write_index.attr,
615 	&dev_attr_in_read_bytes_avail.attr,
616 	&dev_attr_in_write_bytes_avail.attr,
617 	&dev_attr_channel_vp_mapping.attr,
618 	&dev_attr_vendor.attr,
619 	&dev_attr_device.attr,
620 	&dev_attr_driver_override.attr,
621 	NULL,
622 };
623 
624 /*
625  * Device-level attribute_group callback function. Returns the permission for
626  * each attribute, and returns 0 if an attribute is not visible.
627  */
628 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
629 					 struct attribute *attr, int idx)
630 {
631 	struct device *dev = kobj_to_dev(kobj);
632 	const struct hv_device *hv_dev = device_to_hv_device(dev);
633 
634 	/* Hide the monitor attributes if the monitor mechanism is not used. */
635 	if (!hv_dev->channel->offermsg.monitor_allocated &&
636 	    (attr == &dev_attr_monitor_id.attr ||
637 	     attr == &dev_attr_server_monitor_pending.attr ||
638 	     attr == &dev_attr_client_monitor_pending.attr ||
639 	     attr == &dev_attr_server_monitor_latency.attr ||
640 	     attr == &dev_attr_client_monitor_latency.attr ||
641 	     attr == &dev_attr_server_monitor_conn_id.attr ||
642 	     attr == &dev_attr_client_monitor_conn_id.attr))
643 		return 0;
644 
645 	return attr->mode;
646 }
647 
648 static const struct attribute_group vmbus_dev_group = {
649 	.attrs = vmbus_dev_attrs,
650 	.is_visible = vmbus_dev_attr_is_visible
651 };
652 __ATTRIBUTE_GROUPS(vmbus_dev);
653 
654 /*
655  * vmbus_uevent - add uevent for our device
656  *
657  * This routine is invoked when a device is added or removed on the vmbus to
658  * generate a uevent to udev in the userspace. The udev will then look at its
659  * rule and the uevent generated here to load the appropriate driver
660  *
661  * The alias string will be of the form vmbus:guid where guid is the string
662  * representation of the device guid (each byte of the guid will be
663  * represented with two hex characters.
664  */
665 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
666 {
667 	struct hv_device *dev = device_to_hv_device(device);
668 	int ret;
669 	char alias_name[VMBUS_ALIAS_LEN + 1];
670 
671 	print_alias_name(dev, alias_name);
672 	ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
673 	return ret;
674 }
675 
676 static const struct hv_vmbus_device_id *
677 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
678 {
679 	if (id == NULL)
680 		return NULL; /* empty device table */
681 
682 	for (; !guid_is_null(&id->guid); id++)
683 		if (guid_equal(&id->guid, guid))
684 			return id;
685 
686 	return NULL;
687 }
688 
689 static const struct hv_vmbus_device_id *
690 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
691 {
692 	const struct hv_vmbus_device_id *id = NULL;
693 	struct vmbus_dynid *dynid;
694 
695 	spin_lock(&drv->dynids.lock);
696 	list_for_each_entry(dynid, &drv->dynids.list, node) {
697 		if (guid_equal(&dynid->id.guid, guid)) {
698 			id = &dynid->id;
699 			break;
700 		}
701 	}
702 	spin_unlock(&drv->dynids.lock);
703 
704 	return id;
705 }
706 
707 static const struct hv_vmbus_device_id vmbus_device_null;
708 
709 /*
710  * Return a matching hv_vmbus_device_id pointer.
711  * If there is no match, return NULL.
712  */
713 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
714 							struct hv_device *dev)
715 {
716 	const guid_t *guid = &dev->dev_type;
717 	const struct hv_vmbus_device_id *id;
718 
719 	/* When driver_override is set, only bind to the matching driver */
720 	if (dev->driver_override && strcmp(dev->driver_override, drv->name))
721 		return NULL;
722 
723 	/* Look at the dynamic ids first, before the static ones */
724 	id = hv_vmbus_dynid_match(drv, guid);
725 	if (!id)
726 		id = hv_vmbus_dev_match(drv->id_table, guid);
727 
728 	/* driver_override will always match, send a dummy id */
729 	if (!id && dev->driver_override)
730 		id = &vmbus_device_null;
731 
732 	return id;
733 }
734 
735 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
736 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
737 {
738 	struct vmbus_dynid *dynid;
739 
740 	dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
741 	if (!dynid)
742 		return -ENOMEM;
743 
744 	dynid->id.guid = *guid;
745 
746 	spin_lock(&drv->dynids.lock);
747 	list_add_tail(&dynid->node, &drv->dynids.list);
748 	spin_unlock(&drv->dynids.lock);
749 
750 	return driver_attach(&drv->driver);
751 }
752 
753 static void vmbus_free_dynids(struct hv_driver *drv)
754 {
755 	struct vmbus_dynid *dynid, *n;
756 
757 	spin_lock(&drv->dynids.lock);
758 	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
759 		list_del(&dynid->node);
760 		kfree(dynid);
761 	}
762 	spin_unlock(&drv->dynids.lock);
763 }
764 
765 /*
766  * store_new_id - sysfs frontend to vmbus_add_dynid()
767  *
768  * Allow GUIDs to be added to an existing driver via sysfs.
769  */
770 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
771 			    size_t count)
772 {
773 	struct hv_driver *drv = drv_to_hv_drv(driver);
774 	guid_t guid;
775 	ssize_t retval;
776 
777 	retval = guid_parse(buf, &guid);
778 	if (retval)
779 		return retval;
780 
781 	if (hv_vmbus_dynid_match(drv, &guid))
782 		return -EEXIST;
783 
784 	retval = vmbus_add_dynid(drv, &guid);
785 	if (retval)
786 		return retval;
787 	return count;
788 }
789 static DRIVER_ATTR_WO(new_id);
790 
791 /*
792  * store_remove_id - remove a PCI device ID from this driver
793  *
794  * Removes a dynamic pci device ID to this driver.
795  */
796 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
797 			       size_t count)
798 {
799 	struct hv_driver *drv = drv_to_hv_drv(driver);
800 	struct vmbus_dynid *dynid, *n;
801 	guid_t guid;
802 	ssize_t retval;
803 
804 	retval = guid_parse(buf, &guid);
805 	if (retval)
806 		return retval;
807 
808 	retval = -ENODEV;
809 	spin_lock(&drv->dynids.lock);
810 	list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
811 		struct hv_vmbus_device_id *id = &dynid->id;
812 
813 		if (guid_equal(&id->guid, &guid)) {
814 			list_del(&dynid->node);
815 			kfree(dynid);
816 			retval = count;
817 			break;
818 		}
819 	}
820 	spin_unlock(&drv->dynids.lock);
821 
822 	return retval;
823 }
824 static DRIVER_ATTR_WO(remove_id);
825 
826 static struct attribute *vmbus_drv_attrs[] = {
827 	&driver_attr_new_id.attr,
828 	&driver_attr_remove_id.attr,
829 	NULL,
830 };
831 ATTRIBUTE_GROUPS(vmbus_drv);
832 
833 
834 /*
835  * vmbus_match - Attempt to match the specified device to the specified driver
836  */
837 static int vmbus_match(struct device *device, struct device_driver *driver)
838 {
839 	struct hv_driver *drv = drv_to_hv_drv(driver);
840 	struct hv_device *hv_dev = device_to_hv_device(device);
841 
842 	/* The hv_sock driver handles all hv_sock offers. */
843 	if (is_hvsock_channel(hv_dev->channel))
844 		return drv->hvsock;
845 
846 	if (hv_vmbus_get_id(drv, hv_dev))
847 		return 1;
848 
849 	return 0;
850 }
851 
852 /*
853  * vmbus_probe - Add the new vmbus's child device
854  */
855 static int vmbus_probe(struct device *child_device)
856 {
857 	int ret = 0;
858 	struct hv_driver *drv =
859 			drv_to_hv_drv(child_device->driver);
860 	struct hv_device *dev = device_to_hv_device(child_device);
861 	const struct hv_vmbus_device_id *dev_id;
862 
863 	dev_id = hv_vmbus_get_id(drv, dev);
864 	if (drv->probe) {
865 		ret = drv->probe(dev, dev_id);
866 		if (ret != 0)
867 			pr_err("probe failed for device %s (%d)\n",
868 			       dev_name(child_device), ret);
869 
870 	} else {
871 		pr_err("probe not set for driver %s\n",
872 		       dev_name(child_device));
873 		ret = -ENODEV;
874 	}
875 	return ret;
876 }
877 
878 /*
879  * vmbus_remove - Remove a vmbus device
880  */
881 static int vmbus_remove(struct device *child_device)
882 {
883 	struct hv_driver *drv;
884 	struct hv_device *dev = device_to_hv_device(child_device);
885 
886 	if (child_device->driver) {
887 		drv = drv_to_hv_drv(child_device->driver);
888 		if (drv->remove)
889 			drv->remove(dev);
890 	}
891 
892 	return 0;
893 }
894 
895 
896 /*
897  * vmbus_shutdown - Shutdown a vmbus device
898  */
899 static void vmbus_shutdown(struct device *child_device)
900 {
901 	struct hv_driver *drv;
902 	struct hv_device *dev = device_to_hv_device(child_device);
903 
904 
905 	/* The device may not be attached yet */
906 	if (!child_device->driver)
907 		return;
908 
909 	drv = drv_to_hv_drv(child_device->driver);
910 
911 	if (drv->shutdown)
912 		drv->shutdown(dev);
913 }
914 
915 #ifdef CONFIG_PM_SLEEP
916 /*
917  * vmbus_suspend - Suspend a vmbus device
918  */
919 static int vmbus_suspend(struct device *child_device)
920 {
921 	struct hv_driver *drv;
922 	struct hv_device *dev = device_to_hv_device(child_device);
923 
924 	/* The device may not be attached yet */
925 	if (!child_device->driver)
926 		return 0;
927 
928 	drv = drv_to_hv_drv(child_device->driver);
929 	if (!drv->suspend)
930 		return -EOPNOTSUPP;
931 
932 	return drv->suspend(dev);
933 }
934 
935 /*
936  * vmbus_resume - Resume a vmbus device
937  */
938 static int vmbus_resume(struct device *child_device)
939 {
940 	struct hv_driver *drv;
941 	struct hv_device *dev = device_to_hv_device(child_device);
942 
943 	/* The device may not be attached yet */
944 	if (!child_device->driver)
945 		return 0;
946 
947 	drv = drv_to_hv_drv(child_device->driver);
948 	if (!drv->resume)
949 		return -EOPNOTSUPP;
950 
951 	return drv->resume(dev);
952 }
953 #endif /* CONFIG_PM_SLEEP */
954 
955 /*
956  * vmbus_device_release - Final callback release of the vmbus child device
957  */
958 static void vmbus_device_release(struct device *device)
959 {
960 	struct hv_device *hv_dev = device_to_hv_device(device);
961 	struct vmbus_channel *channel = hv_dev->channel;
962 
963 	hv_debug_rm_dev_dir(hv_dev);
964 
965 	mutex_lock(&vmbus_connection.channel_mutex);
966 	hv_process_channel_removal(channel);
967 	mutex_unlock(&vmbus_connection.channel_mutex);
968 	kfree(hv_dev);
969 }
970 
971 /*
972  * Note: we must use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS rather than
973  * SET_SYSTEM_SLEEP_PM_OPS: see the comment before vmbus_bus_pm.
974  */
975 static const struct dev_pm_ops vmbus_pm = {
976 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(vmbus_suspend, vmbus_resume)
977 };
978 
979 /* The one and only one */
980 static struct bus_type  hv_bus = {
981 	.name =		"vmbus",
982 	.match =		vmbus_match,
983 	.shutdown =		vmbus_shutdown,
984 	.remove =		vmbus_remove,
985 	.probe =		vmbus_probe,
986 	.uevent =		vmbus_uevent,
987 	.dev_groups =		vmbus_dev_groups,
988 	.drv_groups =		vmbus_drv_groups,
989 	.pm =			&vmbus_pm,
990 };
991 
992 struct onmessage_work_context {
993 	struct work_struct work;
994 	struct hv_message msg;
995 };
996 
997 static void vmbus_onmessage_work(struct work_struct *work)
998 {
999 	struct onmessage_work_context *ctx;
1000 
1001 	/* Do not process messages if we're in DISCONNECTED state */
1002 	if (vmbus_connection.conn_state == DISCONNECTED)
1003 		return;
1004 
1005 	ctx = container_of(work, struct onmessage_work_context,
1006 			   work);
1007 	vmbus_onmessage(&ctx->msg);
1008 	kfree(ctx);
1009 }
1010 
1011 void vmbus_on_msg_dpc(unsigned long data)
1012 {
1013 	struct hv_per_cpu_context *hv_cpu = (void *)data;
1014 	void *page_addr = hv_cpu->synic_message_page;
1015 	struct hv_message *msg = (struct hv_message *)page_addr +
1016 				  VMBUS_MESSAGE_SINT;
1017 	struct vmbus_channel_message_header *hdr;
1018 	const struct vmbus_channel_message_table_entry *entry;
1019 	struct onmessage_work_context *ctx;
1020 	u32 message_type = msg->header.message_type;
1021 
1022 	if (message_type == HVMSG_NONE)
1023 		/* no msg */
1024 		return;
1025 
1026 	hdr = (struct vmbus_channel_message_header *)msg->u.payload;
1027 
1028 	trace_vmbus_on_msg_dpc(hdr);
1029 
1030 	if (hdr->msgtype >= CHANNELMSG_COUNT) {
1031 		WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1032 		goto msg_handled;
1033 	}
1034 
1035 	entry = &channel_message_table[hdr->msgtype];
1036 	if (entry->handler_type	== VMHT_BLOCKING) {
1037 		ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
1038 		if (ctx == NULL)
1039 			return;
1040 
1041 		INIT_WORK(&ctx->work, vmbus_onmessage_work);
1042 		memcpy(&ctx->msg, msg, sizeof(*msg));
1043 
1044 		/*
1045 		 * The host can generate a rescind message while we
1046 		 * may still be handling the original offer. We deal with
1047 		 * this condition by ensuring the processing is done on the
1048 		 * same CPU.
1049 		 */
1050 		switch (hdr->msgtype) {
1051 		case CHANNELMSG_RESCIND_CHANNELOFFER:
1052 			/*
1053 			 * If we are handling the rescind message;
1054 			 * schedule the work on the global work queue.
1055 			 */
1056 			schedule_work_on(vmbus_connection.connect_cpu,
1057 					 &ctx->work);
1058 			break;
1059 
1060 		case CHANNELMSG_OFFERCHANNEL:
1061 			atomic_inc(&vmbus_connection.offer_in_progress);
1062 			queue_work_on(vmbus_connection.connect_cpu,
1063 				      vmbus_connection.work_queue,
1064 				      &ctx->work);
1065 			break;
1066 
1067 		default:
1068 			queue_work(vmbus_connection.work_queue, &ctx->work);
1069 		}
1070 	} else
1071 		entry->message_handler(hdr);
1072 
1073 msg_handled:
1074 	vmbus_signal_eom(msg, message_type);
1075 }
1076 
1077 #ifdef CONFIG_PM_SLEEP
1078 /*
1079  * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1080  * hibernation, because hv_sock connections can not persist across hibernation.
1081  */
1082 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1083 {
1084 	struct onmessage_work_context *ctx;
1085 	struct vmbus_channel_rescind_offer *rescind;
1086 
1087 	WARN_ON(!is_hvsock_channel(channel));
1088 
1089 	/*
1090 	 * sizeof(*ctx) is small and the allocation should really not fail,
1091 	 * otherwise the state of the hv_sock connections ends up in limbo.
1092 	 */
1093 	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL);
1094 
1095 	/*
1096 	 * So far, these are not really used by Linux. Just set them to the
1097 	 * reasonable values conforming to the definitions of the fields.
1098 	 */
1099 	ctx->msg.header.message_type = 1;
1100 	ctx->msg.header.payload_size = sizeof(*rescind);
1101 
1102 	/* These values are actually used by Linux. */
1103 	rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.u.payload;
1104 	rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1105 	rescind->child_relid = channel->offermsg.child_relid;
1106 
1107 	INIT_WORK(&ctx->work, vmbus_onmessage_work);
1108 
1109 	queue_work_on(vmbus_connection.connect_cpu,
1110 		      vmbus_connection.work_queue,
1111 		      &ctx->work);
1112 }
1113 #endif /* CONFIG_PM_SLEEP */
1114 
1115 /*
1116  * Direct callback for channels using other deferred processing
1117  */
1118 static void vmbus_channel_isr(struct vmbus_channel *channel)
1119 {
1120 	void (*callback_fn)(void *);
1121 
1122 	callback_fn = READ_ONCE(channel->onchannel_callback);
1123 	if (likely(callback_fn != NULL))
1124 		(*callback_fn)(channel->channel_callback_context);
1125 }
1126 
1127 /*
1128  * Schedule all channels with events pending
1129  */
1130 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1131 {
1132 	unsigned long *recv_int_page;
1133 	u32 maxbits, relid;
1134 
1135 	if (vmbus_proto_version < VERSION_WIN8) {
1136 		maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1137 		recv_int_page = vmbus_connection.recv_int_page;
1138 	} else {
1139 		/*
1140 		 * When the host is win8 and beyond, the event page
1141 		 * can be directly checked to get the id of the channel
1142 		 * that has the interrupt pending.
1143 		 */
1144 		void *page_addr = hv_cpu->synic_event_page;
1145 		union hv_synic_event_flags *event
1146 			= (union hv_synic_event_flags *)page_addr +
1147 						 VMBUS_MESSAGE_SINT;
1148 
1149 		maxbits = HV_EVENT_FLAGS_COUNT;
1150 		recv_int_page = event->flags;
1151 	}
1152 
1153 	if (unlikely(!recv_int_page))
1154 		return;
1155 
1156 	for_each_set_bit(relid, recv_int_page, maxbits) {
1157 		struct vmbus_channel *channel;
1158 
1159 		if (!sync_test_and_clear_bit(relid, recv_int_page))
1160 			continue;
1161 
1162 		/* Special case - vmbus channel protocol msg */
1163 		if (relid == 0)
1164 			continue;
1165 
1166 		rcu_read_lock();
1167 
1168 		/* Find channel based on relid */
1169 		list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
1170 			if (channel->offermsg.child_relid != relid)
1171 				continue;
1172 
1173 			if (channel->rescind)
1174 				continue;
1175 
1176 			trace_vmbus_chan_sched(channel);
1177 
1178 			++channel->interrupts;
1179 
1180 			switch (channel->callback_mode) {
1181 			case HV_CALL_ISR:
1182 				vmbus_channel_isr(channel);
1183 				break;
1184 
1185 			case HV_CALL_BATCHED:
1186 				hv_begin_read(&channel->inbound);
1187 				/* fallthrough */
1188 			case HV_CALL_DIRECT:
1189 				tasklet_schedule(&channel->callback_event);
1190 			}
1191 		}
1192 
1193 		rcu_read_unlock();
1194 	}
1195 }
1196 
1197 static void vmbus_isr(void)
1198 {
1199 	struct hv_per_cpu_context *hv_cpu
1200 		= this_cpu_ptr(hv_context.cpu_context);
1201 	void *page_addr = hv_cpu->synic_event_page;
1202 	struct hv_message *msg;
1203 	union hv_synic_event_flags *event;
1204 	bool handled = false;
1205 
1206 	if (unlikely(page_addr == NULL))
1207 		return;
1208 
1209 	event = (union hv_synic_event_flags *)page_addr +
1210 					 VMBUS_MESSAGE_SINT;
1211 	/*
1212 	 * Check for events before checking for messages. This is the order
1213 	 * in which events and messages are checked in Windows guests on
1214 	 * Hyper-V, and the Windows team suggested we do the same.
1215 	 */
1216 
1217 	if ((vmbus_proto_version == VERSION_WS2008) ||
1218 		(vmbus_proto_version == VERSION_WIN7)) {
1219 
1220 		/* Since we are a child, we only need to check bit 0 */
1221 		if (sync_test_and_clear_bit(0, event->flags))
1222 			handled = true;
1223 	} else {
1224 		/*
1225 		 * Our host is win8 or above. The signaling mechanism
1226 		 * has changed and we can directly look at the event page.
1227 		 * If bit n is set then we have an interrup on the channel
1228 		 * whose id is n.
1229 		 */
1230 		handled = true;
1231 	}
1232 
1233 	if (handled)
1234 		vmbus_chan_sched(hv_cpu);
1235 
1236 	page_addr = hv_cpu->synic_message_page;
1237 	msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1238 
1239 	/* Check if there are actual msgs to be processed */
1240 	if (msg->header.message_type != HVMSG_NONE) {
1241 		if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1242 			hv_stimer0_isr();
1243 			vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1244 		} else
1245 			tasklet_schedule(&hv_cpu->msg_dpc);
1246 	}
1247 
1248 	add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1249 }
1250 
1251 /*
1252  * Boolean to control whether to report panic messages over Hyper-V.
1253  *
1254  * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
1255  */
1256 static int sysctl_record_panic_msg = 1;
1257 
1258 /*
1259  * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1260  * buffer and call into Hyper-V to transfer the data.
1261  */
1262 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1263 			 enum kmsg_dump_reason reason)
1264 {
1265 	size_t bytes_written;
1266 	phys_addr_t panic_pa;
1267 
1268 	/* We are only interested in panics. */
1269 	if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1270 		return;
1271 
1272 	panic_pa = virt_to_phys(hv_panic_page);
1273 
1274 	/*
1275 	 * Write dump contents to the page. No need to synchronize; panic should
1276 	 * be single-threaded.
1277 	 */
1278 	kmsg_dump_get_buffer(dumper, true, hv_panic_page, HV_HYP_PAGE_SIZE,
1279 			     &bytes_written);
1280 	if (bytes_written)
1281 		hyperv_report_panic_msg(panic_pa, bytes_written);
1282 }
1283 
1284 static struct kmsg_dumper hv_kmsg_dumper = {
1285 	.dump = hv_kmsg_dump,
1286 };
1287 
1288 static struct ctl_table_header *hv_ctl_table_hdr;
1289 
1290 /*
1291  * sysctl option to allow the user to control whether kmsg data should be
1292  * reported to Hyper-V on panic.
1293  */
1294 static struct ctl_table hv_ctl_table[] = {
1295 	{
1296 		.procname       = "hyperv_record_panic_msg",
1297 		.data           = &sysctl_record_panic_msg,
1298 		.maxlen         = sizeof(int),
1299 		.mode           = 0644,
1300 		.proc_handler   = proc_dointvec_minmax,
1301 		.extra1		= SYSCTL_ZERO,
1302 		.extra2		= SYSCTL_ONE
1303 	},
1304 	{}
1305 };
1306 
1307 static struct ctl_table hv_root_table[] = {
1308 	{
1309 		.procname	= "kernel",
1310 		.mode		= 0555,
1311 		.child		= hv_ctl_table
1312 	},
1313 	{}
1314 };
1315 
1316 /*
1317  * vmbus_bus_init -Main vmbus driver initialization routine.
1318  *
1319  * Here, we
1320  *	- initialize the vmbus driver context
1321  *	- invoke the vmbus hv main init routine
1322  *	- retrieve the channel offers
1323  */
1324 static int vmbus_bus_init(void)
1325 {
1326 	int ret;
1327 
1328 	/* Hypervisor initialization...setup hypercall page..etc */
1329 	ret = hv_init();
1330 	if (ret != 0) {
1331 		pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1332 		return ret;
1333 	}
1334 
1335 	ret = bus_register(&hv_bus);
1336 	if (ret)
1337 		return ret;
1338 
1339 	hv_setup_vmbus_irq(vmbus_isr);
1340 
1341 	ret = hv_synic_alloc();
1342 	if (ret)
1343 		goto err_alloc;
1344 
1345 	/*
1346 	 * Initialize the per-cpu interrupt state and stimer state.
1347 	 * Then connect to the host.
1348 	 */
1349 	ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1350 				hv_synic_init, hv_synic_cleanup);
1351 	if (ret < 0)
1352 		goto err_cpuhp;
1353 	hyperv_cpuhp_online = ret;
1354 
1355 	ret = vmbus_connect();
1356 	if (ret)
1357 		goto err_connect;
1358 
1359 	/*
1360 	 * Only register if the crash MSRs are available
1361 	 */
1362 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1363 		u64 hyperv_crash_ctl;
1364 		/*
1365 		 * Sysctl registration is not fatal, since by default
1366 		 * reporting is enabled.
1367 		 */
1368 		hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1369 		if (!hv_ctl_table_hdr)
1370 			pr_err("Hyper-V: sysctl table register error");
1371 
1372 		/*
1373 		 * Register for panic kmsg callback only if the right
1374 		 * capability is supported by the hypervisor.
1375 		 */
1376 		hv_get_crash_ctl(hyperv_crash_ctl);
1377 		if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1378 			hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
1379 			if (hv_panic_page) {
1380 				ret = kmsg_dump_register(&hv_kmsg_dumper);
1381 				if (ret)
1382 					pr_err("Hyper-V: kmsg dump register "
1383 						"error 0x%x\n", ret);
1384 			} else
1385 				pr_err("Hyper-V: panic message page memory "
1386 					"allocation failed");
1387 		}
1388 
1389 		register_die_notifier(&hyperv_die_block);
1390 		atomic_notifier_chain_register(&panic_notifier_list,
1391 					       &hyperv_panic_block);
1392 	}
1393 
1394 	vmbus_request_offers();
1395 
1396 	return 0;
1397 
1398 err_connect:
1399 	cpuhp_remove_state(hyperv_cpuhp_online);
1400 err_cpuhp:
1401 	hv_synic_free();
1402 err_alloc:
1403 	hv_remove_vmbus_irq();
1404 
1405 	bus_unregister(&hv_bus);
1406 	hv_free_hyperv_page((unsigned long)hv_panic_page);
1407 	unregister_sysctl_table(hv_ctl_table_hdr);
1408 	hv_ctl_table_hdr = NULL;
1409 	return ret;
1410 }
1411 
1412 /**
1413  * __vmbus_child_driver_register() - Register a vmbus's driver
1414  * @hv_driver: Pointer to driver structure you want to register
1415  * @owner: owner module of the drv
1416  * @mod_name: module name string
1417  *
1418  * Registers the given driver with Linux through the 'driver_register()' call
1419  * and sets up the hyper-v vmbus handling for this driver.
1420  * It will return the state of the 'driver_register()' call.
1421  *
1422  */
1423 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1424 {
1425 	int ret;
1426 
1427 	pr_info("registering driver %s\n", hv_driver->name);
1428 
1429 	ret = vmbus_exists();
1430 	if (ret < 0)
1431 		return ret;
1432 
1433 	hv_driver->driver.name = hv_driver->name;
1434 	hv_driver->driver.owner = owner;
1435 	hv_driver->driver.mod_name = mod_name;
1436 	hv_driver->driver.bus = &hv_bus;
1437 
1438 	spin_lock_init(&hv_driver->dynids.lock);
1439 	INIT_LIST_HEAD(&hv_driver->dynids.list);
1440 
1441 	ret = driver_register(&hv_driver->driver);
1442 
1443 	return ret;
1444 }
1445 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1446 
1447 /**
1448  * vmbus_driver_unregister() - Unregister a vmbus's driver
1449  * @hv_driver: Pointer to driver structure you want to
1450  *             un-register
1451  *
1452  * Un-register the given driver that was previous registered with a call to
1453  * vmbus_driver_register()
1454  */
1455 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1456 {
1457 	pr_info("unregistering driver %s\n", hv_driver->name);
1458 
1459 	if (!vmbus_exists()) {
1460 		driver_unregister(&hv_driver->driver);
1461 		vmbus_free_dynids(hv_driver);
1462 	}
1463 }
1464 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1465 
1466 
1467 /*
1468  * Called when last reference to channel is gone.
1469  */
1470 static void vmbus_chan_release(struct kobject *kobj)
1471 {
1472 	struct vmbus_channel *channel
1473 		= container_of(kobj, struct vmbus_channel, kobj);
1474 
1475 	kfree_rcu(channel, rcu);
1476 }
1477 
1478 struct vmbus_chan_attribute {
1479 	struct attribute attr;
1480 	ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1481 	ssize_t (*store)(struct vmbus_channel *chan,
1482 			 const char *buf, size_t count);
1483 };
1484 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1485 	struct vmbus_chan_attribute chan_attr_##_name \
1486 		= __ATTR(_name, _mode, _show, _store)
1487 #define VMBUS_CHAN_ATTR_RW(_name) \
1488 	struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1489 #define VMBUS_CHAN_ATTR_RO(_name) \
1490 	struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1491 #define VMBUS_CHAN_ATTR_WO(_name) \
1492 	struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1493 
1494 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1495 				    struct attribute *attr, char *buf)
1496 {
1497 	const struct vmbus_chan_attribute *attribute
1498 		= container_of(attr, struct vmbus_chan_attribute, attr);
1499 	struct vmbus_channel *chan
1500 		= container_of(kobj, struct vmbus_channel, kobj);
1501 
1502 	if (!attribute->show)
1503 		return -EIO;
1504 
1505 	return attribute->show(chan, buf);
1506 }
1507 
1508 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1509 	.show = vmbus_chan_attr_show,
1510 };
1511 
1512 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1513 {
1514 	struct hv_ring_buffer_info *rbi = &channel->outbound;
1515 	ssize_t ret;
1516 
1517 	mutex_lock(&rbi->ring_buffer_mutex);
1518 	if (!rbi->ring_buffer) {
1519 		mutex_unlock(&rbi->ring_buffer_mutex);
1520 		return -EINVAL;
1521 	}
1522 
1523 	ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1524 	mutex_unlock(&rbi->ring_buffer_mutex);
1525 	return ret;
1526 }
1527 static VMBUS_CHAN_ATTR_RO(out_mask);
1528 
1529 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1530 {
1531 	struct hv_ring_buffer_info *rbi = &channel->inbound;
1532 	ssize_t ret;
1533 
1534 	mutex_lock(&rbi->ring_buffer_mutex);
1535 	if (!rbi->ring_buffer) {
1536 		mutex_unlock(&rbi->ring_buffer_mutex);
1537 		return -EINVAL;
1538 	}
1539 
1540 	ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1541 	mutex_unlock(&rbi->ring_buffer_mutex);
1542 	return ret;
1543 }
1544 static VMBUS_CHAN_ATTR_RO(in_mask);
1545 
1546 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1547 {
1548 	struct hv_ring_buffer_info *rbi = &channel->inbound;
1549 	ssize_t ret;
1550 
1551 	mutex_lock(&rbi->ring_buffer_mutex);
1552 	if (!rbi->ring_buffer) {
1553 		mutex_unlock(&rbi->ring_buffer_mutex);
1554 		return -EINVAL;
1555 	}
1556 
1557 	ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1558 	mutex_unlock(&rbi->ring_buffer_mutex);
1559 	return ret;
1560 }
1561 static VMBUS_CHAN_ATTR_RO(read_avail);
1562 
1563 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1564 {
1565 	struct hv_ring_buffer_info *rbi = &channel->outbound;
1566 	ssize_t ret;
1567 
1568 	mutex_lock(&rbi->ring_buffer_mutex);
1569 	if (!rbi->ring_buffer) {
1570 		mutex_unlock(&rbi->ring_buffer_mutex);
1571 		return -EINVAL;
1572 	}
1573 
1574 	ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1575 	mutex_unlock(&rbi->ring_buffer_mutex);
1576 	return ret;
1577 }
1578 static VMBUS_CHAN_ATTR_RO(write_avail);
1579 
1580 static ssize_t show_target_cpu(struct vmbus_channel *channel, char *buf)
1581 {
1582 	return sprintf(buf, "%u\n", channel->target_cpu);
1583 }
1584 static VMBUS_CHAN_ATTR(cpu, S_IRUGO, show_target_cpu, NULL);
1585 
1586 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1587 				    char *buf)
1588 {
1589 	return sprintf(buf, "%d\n",
1590 		       channel_pending(channel,
1591 				       vmbus_connection.monitor_pages[1]));
1592 }
1593 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1594 
1595 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1596 				    char *buf)
1597 {
1598 	return sprintf(buf, "%d\n",
1599 		       channel_latency(channel,
1600 				       vmbus_connection.monitor_pages[1]));
1601 }
1602 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1603 
1604 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1605 {
1606 	return sprintf(buf, "%llu\n", channel->interrupts);
1607 }
1608 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1609 
1610 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1611 {
1612 	return sprintf(buf, "%llu\n", channel->sig_events);
1613 }
1614 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1615 
1616 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1617 					 char *buf)
1618 {
1619 	return sprintf(buf, "%llu\n",
1620 		       (unsigned long long)channel->intr_in_full);
1621 }
1622 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1623 
1624 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1625 					   char *buf)
1626 {
1627 	return sprintf(buf, "%llu\n",
1628 		       (unsigned long long)channel->intr_out_empty);
1629 }
1630 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1631 
1632 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1633 					   char *buf)
1634 {
1635 	return sprintf(buf, "%llu\n",
1636 		       (unsigned long long)channel->out_full_first);
1637 }
1638 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1639 
1640 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1641 					   char *buf)
1642 {
1643 	return sprintf(buf, "%llu\n",
1644 		       (unsigned long long)channel->out_full_total);
1645 }
1646 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1647 
1648 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1649 					  char *buf)
1650 {
1651 	return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1652 }
1653 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1654 
1655 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1656 				  char *buf)
1657 {
1658 	return sprintf(buf, "%u\n",
1659 		       channel->offermsg.offer.sub_channel_index);
1660 }
1661 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1662 
1663 static struct attribute *vmbus_chan_attrs[] = {
1664 	&chan_attr_out_mask.attr,
1665 	&chan_attr_in_mask.attr,
1666 	&chan_attr_read_avail.attr,
1667 	&chan_attr_write_avail.attr,
1668 	&chan_attr_cpu.attr,
1669 	&chan_attr_pending.attr,
1670 	&chan_attr_latency.attr,
1671 	&chan_attr_interrupts.attr,
1672 	&chan_attr_events.attr,
1673 	&chan_attr_intr_in_full.attr,
1674 	&chan_attr_intr_out_empty.attr,
1675 	&chan_attr_out_full_first.attr,
1676 	&chan_attr_out_full_total.attr,
1677 	&chan_attr_monitor_id.attr,
1678 	&chan_attr_subchannel_id.attr,
1679 	NULL
1680 };
1681 
1682 /*
1683  * Channel-level attribute_group callback function. Returns the permission for
1684  * each attribute, and returns 0 if an attribute is not visible.
1685  */
1686 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1687 					  struct attribute *attr, int idx)
1688 {
1689 	const struct vmbus_channel *channel =
1690 		container_of(kobj, struct vmbus_channel, kobj);
1691 
1692 	/* Hide the monitor attributes if the monitor mechanism is not used. */
1693 	if (!channel->offermsg.monitor_allocated &&
1694 	    (attr == &chan_attr_pending.attr ||
1695 	     attr == &chan_attr_latency.attr ||
1696 	     attr == &chan_attr_monitor_id.attr))
1697 		return 0;
1698 
1699 	return attr->mode;
1700 }
1701 
1702 static struct attribute_group vmbus_chan_group = {
1703 	.attrs = vmbus_chan_attrs,
1704 	.is_visible = vmbus_chan_attr_is_visible
1705 };
1706 
1707 static struct kobj_type vmbus_chan_ktype = {
1708 	.sysfs_ops = &vmbus_chan_sysfs_ops,
1709 	.release = vmbus_chan_release,
1710 };
1711 
1712 /*
1713  * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1714  */
1715 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1716 {
1717 	const struct device *device = &dev->device;
1718 	struct kobject *kobj = &channel->kobj;
1719 	u32 relid = channel->offermsg.child_relid;
1720 	int ret;
1721 
1722 	kobj->kset = dev->channels_kset;
1723 	ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1724 				   "%u", relid);
1725 	if (ret)
1726 		return ret;
1727 
1728 	ret = sysfs_create_group(kobj, &vmbus_chan_group);
1729 
1730 	if (ret) {
1731 		/*
1732 		 * The calling functions' error handling paths will cleanup the
1733 		 * empty channel directory.
1734 		 */
1735 		dev_err(device, "Unable to set up channel sysfs files\n");
1736 		return ret;
1737 	}
1738 
1739 	kobject_uevent(kobj, KOBJ_ADD);
1740 
1741 	return 0;
1742 }
1743 
1744 /*
1745  * vmbus_remove_channel_attr_group - remove the channel's attribute group
1746  */
1747 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1748 {
1749 	sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1750 }
1751 
1752 /*
1753  * vmbus_device_create - Creates and registers a new child device
1754  * on the vmbus.
1755  */
1756 struct hv_device *vmbus_device_create(const guid_t *type,
1757 				      const guid_t *instance,
1758 				      struct vmbus_channel *channel)
1759 {
1760 	struct hv_device *child_device_obj;
1761 
1762 	child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1763 	if (!child_device_obj) {
1764 		pr_err("Unable to allocate device object for child device\n");
1765 		return NULL;
1766 	}
1767 
1768 	child_device_obj->channel = channel;
1769 	guid_copy(&child_device_obj->dev_type, type);
1770 	guid_copy(&child_device_obj->dev_instance, instance);
1771 	child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1772 
1773 	return child_device_obj;
1774 }
1775 
1776 /*
1777  * vmbus_device_register - Register the child device
1778  */
1779 int vmbus_device_register(struct hv_device *child_device_obj)
1780 {
1781 	struct kobject *kobj = &child_device_obj->device.kobj;
1782 	int ret;
1783 
1784 	dev_set_name(&child_device_obj->device, "%pUl",
1785 		     child_device_obj->channel->offermsg.offer.if_instance.b);
1786 
1787 	child_device_obj->device.bus = &hv_bus;
1788 	child_device_obj->device.parent = &hv_acpi_dev->dev;
1789 	child_device_obj->device.release = vmbus_device_release;
1790 
1791 	/*
1792 	 * Register with the LDM. This will kick off the driver/device
1793 	 * binding...which will eventually call vmbus_match() and vmbus_probe()
1794 	 */
1795 	ret = device_register(&child_device_obj->device);
1796 	if (ret) {
1797 		pr_err("Unable to register child device\n");
1798 		return ret;
1799 	}
1800 
1801 	child_device_obj->channels_kset = kset_create_and_add("channels",
1802 							      NULL, kobj);
1803 	if (!child_device_obj->channels_kset) {
1804 		ret = -ENOMEM;
1805 		goto err_dev_unregister;
1806 	}
1807 
1808 	ret = vmbus_add_channel_kobj(child_device_obj,
1809 				     child_device_obj->channel);
1810 	if (ret) {
1811 		pr_err("Unable to register primary channeln");
1812 		goto err_kset_unregister;
1813 	}
1814 	hv_debug_add_dev_dir(child_device_obj);
1815 
1816 	return 0;
1817 
1818 err_kset_unregister:
1819 	kset_unregister(child_device_obj->channels_kset);
1820 
1821 err_dev_unregister:
1822 	device_unregister(&child_device_obj->device);
1823 	return ret;
1824 }
1825 
1826 /*
1827  * vmbus_device_unregister - Remove the specified child device
1828  * from the vmbus.
1829  */
1830 void vmbus_device_unregister(struct hv_device *device_obj)
1831 {
1832 	pr_debug("child device %s unregistered\n",
1833 		dev_name(&device_obj->device));
1834 
1835 	kset_unregister(device_obj->channels_kset);
1836 
1837 	/*
1838 	 * Kick off the process of unregistering the device.
1839 	 * This will call vmbus_remove() and eventually vmbus_device_release()
1840 	 */
1841 	device_unregister(&device_obj->device);
1842 }
1843 
1844 
1845 /*
1846  * VMBUS is an acpi enumerated device. Get the information we
1847  * need from DSDT.
1848  */
1849 #define VTPM_BASE_ADDRESS 0xfed40000
1850 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1851 {
1852 	resource_size_t start = 0;
1853 	resource_size_t end = 0;
1854 	struct resource *new_res;
1855 	struct resource **old_res = &hyperv_mmio;
1856 	struct resource **prev_res = NULL;
1857 
1858 	switch (res->type) {
1859 
1860 	/*
1861 	 * "Address" descriptors are for bus windows. Ignore
1862 	 * "memory" descriptors, which are for registers on
1863 	 * devices.
1864 	 */
1865 	case ACPI_RESOURCE_TYPE_ADDRESS32:
1866 		start = res->data.address32.address.minimum;
1867 		end = res->data.address32.address.maximum;
1868 		break;
1869 
1870 	case ACPI_RESOURCE_TYPE_ADDRESS64:
1871 		start = res->data.address64.address.minimum;
1872 		end = res->data.address64.address.maximum;
1873 		break;
1874 
1875 	default:
1876 		/* Unused resource type */
1877 		return AE_OK;
1878 
1879 	}
1880 	/*
1881 	 * Ignore ranges that are below 1MB, as they're not
1882 	 * necessary or useful here.
1883 	 */
1884 	if (end < 0x100000)
1885 		return AE_OK;
1886 
1887 	new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1888 	if (!new_res)
1889 		return AE_NO_MEMORY;
1890 
1891 	/* If this range overlaps the virtual TPM, truncate it. */
1892 	if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1893 		end = VTPM_BASE_ADDRESS;
1894 
1895 	new_res->name = "hyperv mmio";
1896 	new_res->flags = IORESOURCE_MEM;
1897 	new_res->start = start;
1898 	new_res->end = end;
1899 
1900 	/*
1901 	 * If two ranges are adjacent, merge them.
1902 	 */
1903 	do {
1904 		if (!*old_res) {
1905 			*old_res = new_res;
1906 			break;
1907 		}
1908 
1909 		if (((*old_res)->end + 1) == new_res->start) {
1910 			(*old_res)->end = new_res->end;
1911 			kfree(new_res);
1912 			break;
1913 		}
1914 
1915 		if ((*old_res)->start == new_res->end + 1) {
1916 			(*old_res)->start = new_res->start;
1917 			kfree(new_res);
1918 			break;
1919 		}
1920 
1921 		if ((*old_res)->start > new_res->end) {
1922 			new_res->sibling = *old_res;
1923 			if (prev_res)
1924 				(*prev_res)->sibling = new_res;
1925 			*old_res = new_res;
1926 			break;
1927 		}
1928 
1929 		prev_res = old_res;
1930 		old_res = &(*old_res)->sibling;
1931 
1932 	} while (1);
1933 
1934 	return AE_OK;
1935 }
1936 
1937 static int vmbus_acpi_remove(struct acpi_device *device)
1938 {
1939 	struct resource *cur_res;
1940 	struct resource *next_res;
1941 
1942 	if (hyperv_mmio) {
1943 		if (fb_mmio) {
1944 			__release_region(hyperv_mmio, fb_mmio->start,
1945 					 resource_size(fb_mmio));
1946 			fb_mmio = NULL;
1947 		}
1948 
1949 		for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1950 			next_res = cur_res->sibling;
1951 			kfree(cur_res);
1952 		}
1953 	}
1954 
1955 	return 0;
1956 }
1957 
1958 static void vmbus_reserve_fb(void)
1959 {
1960 	int size;
1961 	/*
1962 	 * Make a claim for the frame buffer in the resource tree under the
1963 	 * first node, which will be the one below 4GB.  The length seems to
1964 	 * be underreported, particularly in a Generation 1 VM.  So start out
1965 	 * reserving a larger area and make it smaller until it succeeds.
1966 	 */
1967 
1968 	if (screen_info.lfb_base) {
1969 		if (efi_enabled(EFI_BOOT))
1970 			size = max_t(__u32, screen_info.lfb_size, 0x800000);
1971 		else
1972 			size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1973 
1974 		for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1975 			fb_mmio = __request_region(hyperv_mmio,
1976 						   screen_info.lfb_base, size,
1977 						   fb_mmio_name, 0);
1978 		}
1979 	}
1980 }
1981 
1982 /**
1983  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1984  * @new:		If successful, supplied a pointer to the
1985  *			allocated MMIO space.
1986  * @device_obj:		Identifies the caller
1987  * @min:		Minimum guest physical address of the
1988  *			allocation
1989  * @max:		Maximum guest physical address
1990  * @size:		Size of the range to be allocated
1991  * @align:		Alignment of the range to be allocated
1992  * @fb_overlap_ok:	Whether this allocation can be allowed
1993  *			to overlap the video frame buffer.
1994  *
1995  * This function walks the resources granted to VMBus by the
1996  * _CRS object in the ACPI namespace underneath the parent
1997  * "bridge" whether that's a root PCI bus in the Generation 1
1998  * case or a Module Device in the Generation 2 case.  It then
1999  * attempts to allocate from the global MMIO pool in a way that
2000  * matches the constraints supplied in these parameters and by
2001  * that _CRS.
2002  *
2003  * Return: 0 on success, -errno on failure
2004  */
2005 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2006 			resource_size_t min, resource_size_t max,
2007 			resource_size_t size, resource_size_t align,
2008 			bool fb_overlap_ok)
2009 {
2010 	struct resource *iter, *shadow;
2011 	resource_size_t range_min, range_max, start;
2012 	const char *dev_n = dev_name(&device_obj->device);
2013 	int retval;
2014 
2015 	retval = -ENXIO;
2016 	mutex_lock(&hyperv_mmio_lock);
2017 
2018 	/*
2019 	 * If overlaps with frame buffers are allowed, then first attempt to
2020 	 * make the allocation from within the reserved region.  Because it
2021 	 * is already reserved, no shadow allocation is necessary.
2022 	 */
2023 	if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2024 	    !(max < fb_mmio->start)) {
2025 
2026 		range_min = fb_mmio->start;
2027 		range_max = fb_mmio->end;
2028 		start = (range_min + align - 1) & ~(align - 1);
2029 		for (; start + size - 1 <= range_max; start += align) {
2030 			*new = request_mem_region_exclusive(start, size, dev_n);
2031 			if (*new) {
2032 				retval = 0;
2033 				goto exit;
2034 			}
2035 		}
2036 	}
2037 
2038 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2039 		if ((iter->start >= max) || (iter->end <= min))
2040 			continue;
2041 
2042 		range_min = iter->start;
2043 		range_max = iter->end;
2044 		start = (range_min + align - 1) & ~(align - 1);
2045 		for (; start + size - 1 <= range_max; start += align) {
2046 			shadow = __request_region(iter, start, size, NULL,
2047 						  IORESOURCE_BUSY);
2048 			if (!shadow)
2049 				continue;
2050 
2051 			*new = request_mem_region_exclusive(start, size, dev_n);
2052 			if (*new) {
2053 				shadow->name = (char *)*new;
2054 				retval = 0;
2055 				goto exit;
2056 			}
2057 
2058 			__release_region(iter, start, size);
2059 		}
2060 	}
2061 
2062 exit:
2063 	mutex_unlock(&hyperv_mmio_lock);
2064 	return retval;
2065 }
2066 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2067 
2068 /**
2069  * vmbus_free_mmio() - Free a memory-mapped I/O range.
2070  * @start:		Base address of region to release.
2071  * @size:		Size of the range to be allocated
2072  *
2073  * This function releases anything requested by
2074  * vmbus_mmio_allocate().
2075  */
2076 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2077 {
2078 	struct resource *iter;
2079 
2080 	mutex_lock(&hyperv_mmio_lock);
2081 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2082 		if ((iter->start >= start + size) || (iter->end <= start))
2083 			continue;
2084 
2085 		__release_region(iter, start, size);
2086 	}
2087 	release_mem_region(start, size);
2088 	mutex_unlock(&hyperv_mmio_lock);
2089 
2090 }
2091 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2092 
2093 static int vmbus_acpi_add(struct acpi_device *device)
2094 {
2095 	acpi_status result;
2096 	int ret_val = -ENODEV;
2097 	struct acpi_device *ancestor;
2098 
2099 	hv_acpi_dev = device;
2100 
2101 	result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2102 					vmbus_walk_resources, NULL);
2103 
2104 	if (ACPI_FAILURE(result))
2105 		goto acpi_walk_err;
2106 	/*
2107 	 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2108 	 * firmware) is the VMOD that has the mmio ranges. Get that.
2109 	 */
2110 	for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2111 		result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2112 					     vmbus_walk_resources, NULL);
2113 
2114 		if (ACPI_FAILURE(result))
2115 			continue;
2116 		if (hyperv_mmio) {
2117 			vmbus_reserve_fb();
2118 			break;
2119 		}
2120 	}
2121 	ret_val = 0;
2122 
2123 acpi_walk_err:
2124 	complete(&probe_event);
2125 	if (ret_val)
2126 		vmbus_acpi_remove(device);
2127 	return ret_val;
2128 }
2129 
2130 #ifdef CONFIG_PM_SLEEP
2131 static int vmbus_bus_suspend(struct device *dev)
2132 {
2133 	struct vmbus_channel *channel, *sc;
2134 	unsigned long flags;
2135 
2136 	while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2137 		/*
2138 		 * We wait here until the completion of any channel
2139 		 * offers that are currently in progress.
2140 		 */
2141 		msleep(1);
2142 	}
2143 
2144 	mutex_lock(&vmbus_connection.channel_mutex);
2145 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2146 		if (!is_hvsock_channel(channel))
2147 			continue;
2148 
2149 		vmbus_force_channel_rescinded(channel);
2150 	}
2151 	mutex_unlock(&vmbus_connection.channel_mutex);
2152 
2153 	/*
2154 	 * Wait until all the sub-channels and hv_sock channels have been
2155 	 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2156 	 * they would conflict with the new sub-channels that will be created
2157 	 * in the resume path. hv_sock channels should also be destroyed, but
2158 	 * a hv_sock channel of an established hv_sock connection can not be
2159 	 * really destroyed since it may still be referenced by the userspace
2160 	 * application, so we just force the hv_sock channel to be rescinded
2161 	 * by vmbus_force_channel_rescinded(), and the userspace application
2162 	 * will thoroughly destroy the channel after hibernation.
2163 	 *
2164 	 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2165 	 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2166 	 */
2167 	if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2168 		wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2169 
2170 	WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0);
2171 
2172 	mutex_lock(&vmbus_connection.channel_mutex);
2173 
2174 	list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2175 		/*
2176 		 * Invalidate the field. Upon resume, vmbus_onoffer() will fix
2177 		 * up the field, and the other fields (if necessary).
2178 		 */
2179 		channel->offermsg.child_relid = INVALID_RELID;
2180 
2181 		if (is_hvsock_channel(channel)) {
2182 			if (!channel->rescind) {
2183 				pr_err("hv_sock channel not rescinded!\n");
2184 				WARN_ON_ONCE(1);
2185 			}
2186 			continue;
2187 		}
2188 
2189 		spin_lock_irqsave(&channel->lock, flags);
2190 		list_for_each_entry(sc, &channel->sc_list, sc_list) {
2191 			pr_err("Sub-channel not deleted!\n");
2192 			WARN_ON_ONCE(1);
2193 		}
2194 		spin_unlock_irqrestore(&channel->lock, flags);
2195 
2196 		atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2197 	}
2198 
2199 	mutex_unlock(&vmbus_connection.channel_mutex);
2200 
2201 	vmbus_initiate_unload(false);
2202 
2203 	vmbus_connection.conn_state = DISCONNECTED;
2204 
2205 	/* Reset the event for the next resume. */
2206 	reinit_completion(&vmbus_connection.ready_for_resume_event);
2207 
2208 	return 0;
2209 }
2210 
2211 static int vmbus_bus_resume(struct device *dev)
2212 {
2213 	struct vmbus_channel_msginfo *msginfo;
2214 	size_t msgsize;
2215 	int ret;
2216 
2217 	/*
2218 	 * We only use the 'vmbus_proto_version', which was in use before
2219 	 * hibernation, to re-negotiate with the host.
2220 	 */
2221 	if (!vmbus_proto_version) {
2222 		pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2223 		return -EINVAL;
2224 	}
2225 
2226 	msgsize = sizeof(*msginfo) +
2227 		  sizeof(struct vmbus_channel_initiate_contact);
2228 
2229 	msginfo = kzalloc(msgsize, GFP_KERNEL);
2230 
2231 	if (msginfo == NULL)
2232 		return -ENOMEM;
2233 
2234 	ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2235 
2236 	kfree(msginfo);
2237 
2238 	if (ret != 0)
2239 		return ret;
2240 
2241 	WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2242 
2243 	vmbus_request_offers();
2244 
2245 	wait_for_completion(&vmbus_connection.ready_for_resume_event);
2246 
2247 	/* Reset the event for the next suspend. */
2248 	reinit_completion(&vmbus_connection.ready_for_suspend_event);
2249 
2250 	return 0;
2251 }
2252 #endif /* CONFIG_PM_SLEEP */
2253 
2254 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2255 	{"VMBUS", 0},
2256 	{"VMBus", 0},
2257 	{"", 0},
2258 };
2259 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2260 
2261 /*
2262  * Note: we must use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS rather than
2263  * SET_SYSTEM_SLEEP_PM_OPS, otherwise NIC SR-IOV can not work, because the
2264  * "pci_dev_pm_ops" uses the "noirq" callbacks: in the resume path, the
2265  * pci "noirq" restore callback runs before "non-noirq" callbacks (see
2266  * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2267  * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2268  * resume callback must also run via the "noirq" callbacks.
2269  */
2270 static const struct dev_pm_ops vmbus_bus_pm = {
2271 	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(vmbus_bus_suspend, vmbus_bus_resume)
2272 };
2273 
2274 static struct acpi_driver vmbus_acpi_driver = {
2275 	.name = "vmbus",
2276 	.ids = vmbus_acpi_device_ids,
2277 	.ops = {
2278 		.add = vmbus_acpi_add,
2279 		.remove = vmbus_acpi_remove,
2280 	},
2281 	.drv.pm = &vmbus_bus_pm,
2282 };
2283 
2284 static void hv_kexec_handler(void)
2285 {
2286 	hv_stimer_global_cleanup();
2287 	vmbus_initiate_unload(false);
2288 	vmbus_connection.conn_state = DISCONNECTED;
2289 	/* Make sure conn_state is set as hv_synic_cleanup checks for it */
2290 	mb();
2291 	cpuhp_remove_state(hyperv_cpuhp_online);
2292 	hyperv_cleanup();
2293 };
2294 
2295 static void hv_crash_handler(struct pt_regs *regs)
2296 {
2297 	int cpu;
2298 
2299 	vmbus_initiate_unload(true);
2300 	/*
2301 	 * In crash handler we can't schedule synic cleanup for all CPUs,
2302 	 * doing the cleanup for current CPU only. This should be sufficient
2303 	 * for kdump.
2304 	 */
2305 	vmbus_connection.conn_state = DISCONNECTED;
2306 	cpu = smp_processor_id();
2307 	hv_stimer_cleanup(cpu);
2308 	hv_synic_disable_regs(cpu);
2309 	hyperv_cleanup();
2310 };
2311 
2312 static int hv_synic_suspend(void)
2313 {
2314 	/*
2315 	 * When we reach here, all the non-boot CPUs have been offlined.
2316 	 * If we're in a legacy configuration where stimer Direct Mode is
2317 	 * not enabled, the stimers on the non-boot CPUs have been unbound
2318 	 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2319 	 * hv_stimer_cleanup() -> clockevents_unbind_device().
2320 	 *
2321 	 * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2322 	 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2323 	 * 1) it's unnecessary as interrupts remain disabled between
2324 	 * syscore_suspend() and syscore_resume(): see create_image() and
2325 	 * resume_target_kernel()
2326 	 * 2) the stimer on CPU0 is automatically disabled later by
2327 	 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2328 	 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2329 	 * 3) a warning would be triggered if we call
2330 	 * clockevents_unbind_device(), which may sleep, in an
2331 	 * interrupts-disabled context.
2332 	 */
2333 
2334 	hv_synic_disable_regs(0);
2335 
2336 	return 0;
2337 }
2338 
2339 static void hv_synic_resume(void)
2340 {
2341 	hv_synic_enable_regs(0);
2342 
2343 	/*
2344 	 * Note: we don't need to call hv_stimer_init(0), because the timer
2345 	 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2346 	 * automatically re-enabled in timekeeping_resume().
2347 	 */
2348 }
2349 
2350 /* The callbacks run only on CPU0, with irqs_disabled. */
2351 static struct syscore_ops hv_synic_syscore_ops = {
2352 	.suspend = hv_synic_suspend,
2353 	.resume = hv_synic_resume,
2354 };
2355 
2356 static int __init hv_acpi_init(void)
2357 {
2358 	int ret, t;
2359 
2360 	if (!hv_is_hyperv_initialized())
2361 		return -ENODEV;
2362 
2363 	init_completion(&probe_event);
2364 
2365 	/*
2366 	 * Get ACPI resources first.
2367 	 */
2368 	ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2369 
2370 	if (ret)
2371 		return ret;
2372 
2373 	t = wait_for_completion_timeout(&probe_event, 5*HZ);
2374 	if (t == 0) {
2375 		ret = -ETIMEDOUT;
2376 		goto cleanup;
2377 	}
2378 	hv_debug_init();
2379 
2380 	ret = vmbus_bus_init();
2381 	if (ret)
2382 		goto cleanup;
2383 
2384 	hv_setup_kexec_handler(hv_kexec_handler);
2385 	hv_setup_crash_handler(hv_crash_handler);
2386 
2387 	register_syscore_ops(&hv_synic_syscore_ops);
2388 
2389 	return 0;
2390 
2391 cleanup:
2392 	acpi_bus_unregister_driver(&vmbus_acpi_driver);
2393 	hv_acpi_dev = NULL;
2394 	return ret;
2395 }
2396 
2397 static void __exit vmbus_exit(void)
2398 {
2399 	int cpu;
2400 
2401 	unregister_syscore_ops(&hv_synic_syscore_ops);
2402 
2403 	hv_remove_kexec_handler();
2404 	hv_remove_crash_handler();
2405 	vmbus_connection.conn_state = DISCONNECTED;
2406 	hv_stimer_global_cleanup();
2407 	vmbus_disconnect();
2408 	hv_remove_vmbus_irq();
2409 	for_each_online_cpu(cpu) {
2410 		struct hv_per_cpu_context *hv_cpu
2411 			= per_cpu_ptr(hv_context.cpu_context, cpu);
2412 
2413 		tasklet_kill(&hv_cpu->msg_dpc);
2414 	}
2415 	hv_debug_rm_all_dir();
2416 
2417 	vmbus_free_channels();
2418 
2419 	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2420 		kmsg_dump_unregister(&hv_kmsg_dumper);
2421 		unregister_die_notifier(&hyperv_die_block);
2422 		atomic_notifier_chain_unregister(&panic_notifier_list,
2423 						 &hyperv_panic_block);
2424 	}
2425 
2426 	free_page((unsigned long)hv_panic_page);
2427 	unregister_sysctl_table(hv_ctl_table_hdr);
2428 	hv_ctl_table_hdr = NULL;
2429 	bus_unregister(&hv_bus);
2430 
2431 	cpuhp_remove_state(hyperv_cpuhp_online);
2432 	hv_synic_free();
2433 	acpi_bus_unregister_driver(&vmbus_acpi_driver);
2434 }
2435 
2436 
2437 MODULE_LICENSE("GPL");
2438 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2439 
2440 subsys_initcall(hv_acpi_init);
2441 module_exit(vmbus_exit);
2442