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KVM: PPC: Book3S HV: Flush link stack on guest exit to host kernel
[linux/fpc-iii.git] / drivers / hv / vmbus_drv.c
blob53a60c81e220d805fbcf28ce49e95019b6320f0b
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_SEMAPHORE(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 mutex_lock(&vmbus_connection.channel_mutex);
964 hv_process_channel_removal(channel);
965 mutex_unlock(&vmbus_connection.channel_mutex);
966 kfree(hv_dev);
967 }
968
969 /*
970 * Note: we must use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS rather than
971 * SET_SYSTEM_SLEEP_PM_OPS: see the comment before vmbus_bus_pm.
972 */
973 static const struct dev_pm_ops vmbus_pm = {
974 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(vmbus_suspend, vmbus_resume)
975 };
976
977 /* The one and only one */
978 static struct bus_type hv_bus = {
979 .name = "vmbus",
980 .match = vmbus_match,
981 .shutdown = vmbus_shutdown,
982 .remove = vmbus_remove,
983 .probe = vmbus_probe,
984 .uevent = vmbus_uevent,
985 .dev_groups = vmbus_dev_groups,
986 .drv_groups = vmbus_drv_groups,
987 .pm = &vmbus_pm,
988 };
989
990 struct onmessage_work_context {
991 struct work_struct work;
992 struct hv_message msg;
993 };
994
995 static void vmbus_onmessage_work(struct work_struct *work)
996 {
997 struct onmessage_work_context *ctx;
998
999 /* Do not process messages if we're in DISCONNECTED state */
1000 if (vmbus_connection.conn_state == DISCONNECTED)
1001 return;
1002
1003 ctx = container_of(work, struct onmessage_work_context,
1004 work);
1005 vmbus_onmessage(&ctx->msg);
1006 kfree(ctx);
1007 }
1008
1009 void vmbus_on_msg_dpc(unsigned long data)
1010 {
1011 struct hv_per_cpu_context *hv_cpu = (void *)data;
1012 void *page_addr = hv_cpu->synic_message_page;
1013 struct hv_message *msg = (struct hv_message *)page_addr +
1014 VMBUS_MESSAGE_SINT;
1015 struct vmbus_channel_message_header *hdr;
1016 const struct vmbus_channel_message_table_entry *entry;
1017 struct onmessage_work_context *ctx;
1018 u32 message_type = msg->header.message_type;
1019
1020 if (message_type == HVMSG_NONE)
1021 /* no msg */
1022 return;
1023
1024 hdr = (struct vmbus_channel_message_header *)msg->u.payload;
1025
1026 trace_vmbus_on_msg_dpc(hdr);
1027
1028 if (hdr->msgtype >= CHANNELMSG_COUNT) {
1029 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1030 goto msg_handled;
1031 }
1032
1033 entry = &channel_message_table[hdr->msgtype];
1034 if (entry->handler_type == VMHT_BLOCKING) {
1035 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
1036 if (ctx == NULL)
1037 return;
1038
1039 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1040 memcpy(&ctx->msg, msg, sizeof(*msg));
1041
1042 /*
1043 * The host can generate a rescind message while we
1044 * may still be handling the original offer. We deal with
1045 * this condition by ensuring the processing is done on the
1046 * same CPU.
1047 */
1048 switch (hdr->msgtype) {
1049 case CHANNELMSG_RESCIND_CHANNELOFFER:
1050 /*
1051 * If we are handling the rescind message;
1052 * schedule the work on the global work queue.
1053 */
1054 schedule_work_on(vmbus_connection.connect_cpu,
1055 &ctx->work);
1056 break;
1057
1058 case CHANNELMSG_OFFERCHANNEL:
1059 atomic_inc(&vmbus_connection.offer_in_progress);
1060 queue_work_on(vmbus_connection.connect_cpu,
1061 vmbus_connection.work_queue,
1062 &ctx->work);
1063 break;
1064
1065 default:
1066 queue_work(vmbus_connection.work_queue, &ctx->work);
1067 }
1068 } else
1069 entry->message_handler(hdr);
1070
1071 msg_handled:
1072 vmbus_signal_eom(msg, message_type);
1073 }
1074
1075 #ifdef CONFIG_PM_SLEEP
1076 /*
1077 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1078 * hibernation, because hv_sock connections can not persist across hibernation.
1079 */
1080 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1081 {
1082 struct onmessage_work_context *ctx;
1083 struct vmbus_channel_rescind_offer *rescind;
1084
1085 WARN_ON(!is_hvsock_channel(channel));
1086
1087 /*
1088 * sizeof(*ctx) is small and the allocation should really not fail,
1089 * otherwise the state of the hv_sock connections ends up in limbo.
1090 */
1091 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL);
1092
1093 /*
1094 * So far, these are not really used by Linux. Just set them to the
1095 * reasonable values conforming to the definitions of the fields.
1096 */
1097 ctx->msg.header.message_type = 1;
1098 ctx->msg.header.payload_size = sizeof(*rescind);
1099
1100 /* These values are actually used by Linux. */
1101 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.u.payload;
1102 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1103 rescind->child_relid = channel->offermsg.child_relid;
1104
1105 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1106
1107 queue_work_on(vmbus_connection.connect_cpu,
1108 vmbus_connection.work_queue,
1109 &ctx->work);
1110 }
1111 #endif /* CONFIG_PM_SLEEP */
1112
1113 /*
1114 * Direct callback for channels using other deferred processing
1115 */
1116 static void vmbus_channel_isr(struct vmbus_channel *channel)
1117 {
1118 void (*callback_fn)(void *);
1119
1120 callback_fn = READ_ONCE(channel->onchannel_callback);
1121 if (likely(callback_fn != NULL))
1122 (*callback_fn)(channel->channel_callback_context);
1123 }
1124
1125 /*
1126 * Schedule all channels with events pending
1127 */
1128 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1129 {
1130 unsigned long *recv_int_page;
1131 u32 maxbits, relid;
1132
1133 if (vmbus_proto_version < VERSION_WIN8) {
1134 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1135 recv_int_page = vmbus_connection.recv_int_page;
1136 } else {
1137 /*
1138 * When the host is win8 and beyond, the event page
1139 * can be directly checked to get the id of the channel
1140 * that has the interrupt pending.
1141 */
1142 void *page_addr = hv_cpu->synic_event_page;
1143 union hv_synic_event_flags *event
1144 = (union hv_synic_event_flags *)page_addr +
1145 VMBUS_MESSAGE_SINT;
1146
1147 maxbits = HV_EVENT_FLAGS_COUNT;
1148 recv_int_page = event->flags;
1149 }
1150
1151 if (unlikely(!recv_int_page))
1152 return;
1153
1154 for_each_set_bit(relid, recv_int_page, maxbits) {
1155 struct vmbus_channel *channel;
1156
1157 if (!sync_test_and_clear_bit(relid, recv_int_page))
1158 continue;
1159
1160 /* Special case - vmbus channel protocol msg */
1161 if (relid == 0)
1162 continue;
1163
1164 rcu_read_lock();
1165
1166 /* Find channel based on relid */
1167 list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
1168 if (channel->offermsg.child_relid != relid)
1169 continue;
1170
1171 if (channel->rescind)
1172 continue;
1173
1174 trace_vmbus_chan_sched(channel);
1175
1176 ++channel->interrupts;
1177
1178 switch (channel->callback_mode) {
1179 case HV_CALL_ISR:
1180 vmbus_channel_isr(channel);
1181 break;
1182
1183 case HV_CALL_BATCHED:
1184 hv_begin_read(&channel->inbound);
1185 /* fallthrough */
1186 case HV_CALL_DIRECT:
1187 tasklet_schedule(&channel->callback_event);
1188 }
1189 }
1190
1191 rcu_read_unlock();
1192 }
1193 }
1194
1195 static void vmbus_isr(void)
1196 {
1197 struct hv_per_cpu_context *hv_cpu
1198 = this_cpu_ptr(hv_context.cpu_context);
1199 void *page_addr = hv_cpu->synic_event_page;
1200 struct hv_message *msg;
1201 union hv_synic_event_flags *event;
1202 bool handled = false;
1203
1204 if (unlikely(page_addr == NULL))
1205 return;
1206
1207 event = (union hv_synic_event_flags *)page_addr +
1208 VMBUS_MESSAGE_SINT;
1209 /*
1210 * Check for events before checking for messages. This is the order
1211 * in which events and messages are checked in Windows guests on
1212 * Hyper-V, and the Windows team suggested we do the same.
1213 */
1214
1215 if ((vmbus_proto_version == VERSION_WS2008) ||
1216 (vmbus_proto_version == VERSION_WIN7)) {
1217
1218 /* Since we are a child, we only need to check bit 0 */
1219 if (sync_test_and_clear_bit(0, event->flags))
1220 handled = true;
1221 } else {
1222 /*
1223 * Our host is win8 or above. The signaling mechanism
1224 * has changed and we can directly look at the event page.
1225 * If bit n is set then we have an interrup on the channel
1226 * whose id is n.
1227 */
1228 handled = true;
1229 }
1230
1231 if (handled)
1232 vmbus_chan_sched(hv_cpu);
1233
1234 page_addr = hv_cpu->synic_message_page;
1235 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1236
1237 /* Check if there are actual msgs to be processed */
1238 if (msg->header.message_type != HVMSG_NONE) {
1239 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1240 hv_stimer0_isr();
1241 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1242 } else
1243 tasklet_schedule(&hv_cpu->msg_dpc);
1244 }
1245
1246 add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1247 }
1248
1249 /*
1250 * Boolean to control whether to report panic messages over Hyper-V.
1251 *
1252 * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
1253 */
1254 static int sysctl_record_panic_msg = 1;
1255
1256 /*
1257 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1258 * buffer and call into Hyper-V to transfer the data.
1259 */
1260 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1261 enum kmsg_dump_reason reason)
1262 {
1263 size_t bytes_written;
1264 phys_addr_t panic_pa;
1265
1266 /* We are only interested in panics. */
1267 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1268 return;
1269
1270 panic_pa = virt_to_phys(hv_panic_page);
1271
1272 /*
1273 * Write dump contents to the page. No need to synchronize; panic should
1274 * be single-threaded.
1275 */
1276 kmsg_dump_get_buffer(dumper, true, hv_panic_page, PAGE_SIZE,
1277 &bytes_written);
1278 if (bytes_written)
1279 hyperv_report_panic_msg(panic_pa, bytes_written);
1280 }
1281
1282 static struct kmsg_dumper hv_kmsg_dumper = {
1283 .dump = hv_kmsg_dump,
1284 };
1285
1286 static struct ctl_table_header *hv_ctl_table_hdr;
1287
1288 /*
1289 * sysctl option to allow the user to control whether kmsg data should be
1290 * reported to Hyper-V on panic.
1291 */
1292 static struct ctl_table hv_ctl_table[] = {
1293 {
1294 .procname = "hyperv_record_panic_msg",
1295 .data = &sysctl_record_panic_msg,
1296 .maxlen = sizeof(int),
1297 .mode = 0644,
1298 .proc_handler = proc_dointvec_minmax,
1299 .extra1 = SYSCTL_ZERO,
1300 .extra2 = SYSCTL_ONE
1301 },
1302 {}
1303 };
1304
1305 static struct ctl_table hv_root_table[] = {
1306 {
1307 .procname = "kernel",
1308 .mode = 0555,
1309 .child = hv_ctl_table
1310 },
1311 {}
1312 };
1313
1314 /*
1315 * vmbus_bus_init -Main vmbus driver initialization routine.
1316 *
1317 * Here, we
1318 * - initialize the vmbus driver context
1319 * - invoke the vmbus hv main init routine
1320 * - retrieve the channel offers
1321 */
1322 static int vmbus_bus_init(void)
1323 {
1324 int ret;
1325
1326 /* Hypervisor initialization...setup hypercall page..etc */
1327 ret = hv_init();
1328 if (ret != 0) {
1329 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1330 return ret;
1331 }
1332
1333 ret = bus_register(&hv_bus);
1334 if (ret)
1335 return ret;
1336
1337 hv_setup_vmbus_irq(vmbus_isr);
1338
1339 ret = hv_synic_alloc();
1340 if (ret)
1341 goto err_alloc;
1342
1343 ret = hv_stimer_alloc(VMBUS_MESSAGE_SINT);
1344 if (ret < 0)
1345 goto err_alloc;
1346
1347 /*
1348 * Initialize the per-cpu interrupt state and stimer state.
1349 * Then connect to the host.
1350 */
1351 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1352 hv_synic_init, hv_synic_cleanup);
1353 if (ret < 0)
1354 goto err_cpuhp;
1355 hyperv_cpuhp_online = ret;
1356
1357 ret = vmbus_connect();
1358 if (ret)
1359 goto err_connect;
1360
1361 /*
1362 * Only register if the crash MSRs are available
1363 */
1364 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1365 u64 hyperv_crash_ctl;
1366 /*
1367 * Sysctl registration is not fatal, since by default
1368 * reporting is enabled.
1369 */
1370 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1371 if (!hv_ctl_table_hdr)
1372 pr_err("Hyper-V: sysctl table register error");
1373
1374 /*
1375 * Register for panic kmsg callback only if the right
1376 * capability is supported by the hypervisor.
1377 */
1378 hv_get_crash_ctl(hyperv_crash_ctl);
1379 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1380 hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
1381 if (hv_panic_page) {
1382 ret = kmsg_dump_register(&hv_kmsg_dumper);
1383 if (ret)
1384 pr_err("Hyper-V: kmsg dump register "
1385 "error 0x%x\n", ret);
1386 } else
1387 pr_err("Hyper-V: panic message page memory "
1388 "allocation failed");
1389 }
1390
1391 register_die_notifier(&hyperv_die_block);
1392 atomic_notifier_chain_register(&panic_notifier_list,
1393 &hyperv_panic_block);
1394 }
1395
1396 vmbus_request_offers();
1397
1398 return 0;
1399
1400 err_connect:
1401 cpuhp_remove_state(hyperv_cpuhp_online);
1402 err_cpuhp:
1403 hv_stimer_free();
1404 err_alloc:
1405 hv_synic_free();
1406 hv_remove_vmbus_irq();
1407
1408 bus_unregister(&hv_bus);
1409 free_page((unsigned long)hv_panic_page);
1410 unregister_sysctl_table(hv_ctl_table_hdr);
1411 hv_ctl_table_hdr = NULL;
1412 return ret;
1413 }
1414
1415 /**
1416 * __vmbus_child_driver_register() - Register a vmbus's driver
1417 * @hv_driver: Pointer to driver structure you want to register
1418 * @owner: owner module of the drv
1419 * @mod_name: module name string
1420 *
1421 * Registers the given driver with Linux through the 'driver_register()' call
1422 * and sets up the hyper-v vmbus handling for this driver.
1423 * It will return the state of the 'driver_register()' call.
1424 *
1425 */
1426 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1427 {
1428 int ret;
1429
1430 pr_info("registering driver %s\n", hv_driver->name);
1431
1432 ret = vmbus_exists();
1433 if (ret < 0)
1434 return ret;
1435
1436 hv_driver->driver.name = hv_driver->name;
1437 hv_driver->driver.owner = owner;
1438 hv_driver->driver.mod_name = mod_name;
1439 hv_driver->driver.bus = &hv_bus;
1440
1441 spin_lock_init(&hv_driver->dynids.lock);
1442 INIT_LIST_HEAD(&hv_driver->dynids.list);
1443
1444 ret = driver_register(&hv_driver->driver);
1445
1446 return ret;
1447 }
1448 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1449
1450 /**
1451 * vmbus_driver_unregister() - Unregister a vmbus's driver
1452 * @hv_driver: Pointer to driver structure you want to
1453 * un-register
1454 *
1455 * Un-register the given driver that was previous registered with a call to
1456 * vmbus_driver_register()
1457 */
1458 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1459 {
1460 pr_info("unregistering driver %s\n", hv_driver->name);
1461
1462 if (!vmbus_exists()) {
1463 driver_unregister(&hv_driver->driver);
1464 vmbus_free_dynids(hv_driver);
1465 }
1466 }
1467 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1468
1469
1470 /*
1471 * Called when last reference to channel is gone.
1472 */
1473 static void vmbus_chan_release(struct kobject *kobj)
1474 {
1475 struct vmbus_channel *channel
1476 = container_of(kobj, struct vmbus_channel, kobj);
1477
1478 kfree_rcu(channel, rcu);
1479 }
1480
1481 struct vmbus_chan_attribute {
1482 struct attribute attr;
1483 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1484 ssize_t (*store)(struct vmbus_channel *chan,
1485 const char *buf, size_t count);
1486 };
1487 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1488 struct vmbus_chan_attribute chan_attr_##_name \
1489 = __ATTR(_name, _mode, _show, _store)
1490 #define VMBUS_CHAN_ATTR_RW(_name) \
1491 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1492 #define VMBUS_CHAN_ATTR_RO(_name) \
1493 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1494 #define VMBUS_CHAN_ATTR_WO(_name) \
1495 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1496
1497 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1498 struct attribute *attr, char *buf)
1499 {
1500 const struct vmbus_chan_attribute *attribute
1501 = container_of(attr, struct vmbus_chan_attribute, attr);
1502 struct vmbus_channel *chan
1503 = container_of(kobj, struct vmbus_channel, kobj);
1504
1505 if (!attribute->show)
1506 return -EIO;
1507
1508 return attribute->show(chan, buf);
1509 }
1510
1511 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1512 .show = vmbus_chan_attr_show,
1513 };
1514
1515 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1516 {
1517 struct hv_ring_buffer_info *rbi = &channel->outbound;
1518 ssize_t ret;
1519
1520 mutex_lock(&rbi->ring_buffer_mutex);
1521 if (!rbi->ring_buffer) {
1522 mutex_unlock(&rbi->ring_buffer_mutex);
1523 return -EINVAL;
1524 }
1525
1526 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1527 mutex_unlock(&rbi->ring_buffer_mutex);
1528 return ret;
1529 }
1530 static VMBUS_CHAN_ATTR_RO(out_mask);
1531
1532 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1533 {
1534 struct hv_ring_buffer_info *rbi = &channel->inbound;
1535 ssize_t ret;
1536
1537 mutex_lock(&rbi->ring_buffer_mutex);
1538 if (!rbi->ring_buffer) {
1539 mutex_unlock(&rbi->ring_buffer_mutex);
1540 return -EINVAL;
1541 }
1542
1543 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1544 mutex_unlock(&rbi->ring_buffer_mutex);
1545 return ret;
1546 }
1547 static VMBUS_CHAN_ATTR_RO(in_mask);
1548
1549 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1550 {
1551 struct hv_ring_buffer_info *rbi = &channel->inbound;
1552 ssize_t ret;
1553
1554 mutex_lock(&rbi->ring_buffer_mutex);
1555 if (!rbi->ring_buffer) {
1556 mutex_unlock(&rbi->ring_buffer_mutex);
1557 return -EINVAL;
1558 }
1559
1560 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1561 mutex_unlock(&rbi->ring_buffer_mutex);
1562 return ret;
1563 }
1564 static VMBUS_CHAN_ATTR_RO(read_avail);
1565
1566 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1567 {
1568 struct hv_ring_buffer_info *rbi = &channel->outbound;
1569 ssize_t ret;
1570
1571 mutex_lock(&rbi->ring_buffer_mutex);
1572 if (!rbi->ring_buffer) {
1573 mutex_unlock(&rbi->ring_buffer_mutex);
1574 return -EINVAL;
1575 }
1576
1577 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1578 mutex_unlock(&rbi->ring_buffer_mutex);
1579 return ret;
1580 }
1581 static VMBUS_CHAN_ATTR_RO(write_avail);
1582
1583 static ssize_t show_target_cpu(struct vmbus_channel *channel, char *buf)
1584 {
1585 return sprintf(buf, "%u\n", channel->target_cpu);
1586 }
1587 static VMBUS_CHAN_ATTR(cpu, S_IRUGO, show_target_cpu, NULL);
1588
1589 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1590 char *buf)
1591 {
1592 return sprintf(buf, "%d\n",
1593 channel_pending(channel,
1594 vmbus_connection.monitor_pages[1]));
1595 }
1596 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1597
1598 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1599 char *buf)
1600 {
1601 return sprintf(buf, "%d\n",
1602 channel_latency(channel,
1603 vmbus_connection.monitor_pages[1]));
1604 }
1605 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1606
1607 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1608 {
1609 return sprintf(buf, "%llu\n", channel->interrupts);
1610 }
1611 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1612
1613 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1614 {
1615 return sprintf(buf, "%llu\n", channel->sig_events);
1616 }
1617 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1618
1619 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1620 char *buf)
1621 {
1622 return sprintf(buf, "%llu\n",
1623 (unsigned long long)channel->intr_in_full);
1624 }
1625 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1626
1627 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1628 char *buf)
1629 {
1630 return sprintf(buf, "%llu\n",
1631 (unsigned long long)channel->intr_out_empty);
1632 }
1633 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1634
1635 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1636 char *buf)
1637 {
1638 return sprintf(buf, "%llu\n",
1639 (unsigned long long)channel->out_full_first);
1640 }
1641 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1642
1643 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1644 char *buf)
1645 {
1646 return sprintf(buf, "%llu\n",
1647 (unsigned long long)channel->out_full_total);
1648 }
1649 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1650
1651 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1652 char *buf)
1653 {
1654 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1655 }
1656 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1657
1658 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1659 char *buf)
1660 {
1661 return sprintf(buf, "%u\n",
1662 channel->offermsg.offer.sub_channel_index);
1663 }
1664 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1665
1666 static struct attribute *vmbus_chan_attrs[] = {
1667 &chan_attr_out_mask.attr,
1668 &chan_attr_in_mask.attr,
1669 &chan_attr_read_avail.attr,
1670 &chan_attr_write_avail.attr,
1671 &chan_attr_cpu.attr,
1672 &chan_attr_pending.attr,
1673 &chan_attr_latency.attr,
1674 &chan_attr_interrupts.attr,
1675 &chan_attr_events.attr,
1676 &chan_attr_intr_in_full.attr,
1677 &chan_attr_intr_out_empty.attr,
1678 &chan_attr_out_full_first.attr,
1679 &chan_attr_out_full_total.attr,
1680 &chan_attr_monitor_id.attr,
1681 &chan_attr_subchannel_id.attr,
1682 NULL
1683 };
1684
1685 /*
1686 * Channel-level attribute_group callback function. Returns the permission for
1687 * each attribute, and returns 0 if an attribute is not visible.
1688 */
1689 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1690 struct attribute *attr, int idx)
1691 {
1692 const struct vmbus_channel *channel =
1693 container_of(kobj, struct vmbus_channel, kobj);
1694
1695 /* Hide the monitor attributes if the monitor mechanism is not used. */
1696 if (!channel->offermsg.monitor_allocated &&
1697 (attr == &chan_attr_pending.attr ||
1698 attr == &chan_attr_latency.attr ||
1699 attr == &chan_attr_monitor_id.attr))
1700 return 0;
1701
1702 return attr->mode;
1703 }
1704
1705 static struct attribute_group vmbus_chan_group = {
1706 .attrs = vmbus_chan_attrs,
1707 .is_visible = vmbus_chan_attr_is_visible
1708 };
1709
1710 static struct kobj_type vmbus_chan_ktype = {
1711 .sysfs_ops = &vmbus_chan_sysfs_ops,
1712 .release = vmbus_chan_release,
1713 };
1714
1715 /*
1716 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1717 */
1718 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1719 {
1720 const struct device *device = &dev->device;
1721 struct kobject *kobj = &channel->kobj;
1722 u32 relid = channel->offermsg.child_relid;
1723 int ret;
1724
1725 kobj->kset = dev->channels_kset;
1726 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1727 "%u", relid);
1728 if (ret)
1729 return ret;
1730
1731 ret = sysfs_create_group(kobj, &vmbus_chan_group);
1732
1733 if (ret) {
1734 /*
1735 * The calling functions' error handling paths will cleanup the
1736 * empty channel directory.
1737 */
1738 dev_err(device, "Unable to set up channel sysfs files\n");
1739 return ret;
1740 }
1741
1742 kobject_uevent(kobj, KOBJ_ADD);
1743
1744 return 0;
1745 }
1746
1747 /*
1748 * vmbus_remove_channel_attr_group - remove the channel's attribute group
1749 */
1750 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1751 {
1752 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1753 }
1754
1755 /*
1756 * vmbus_device_create - Creates and registers a new child device
1757 * on the vmbus.
1758 */
1759 struct hv_device *vmbus_device_create(const guid_t *type,
1760 const guid_t *instance,
1761 struct vmbus_channel *channel)
1762 {
1763 struct hv_device *child_device_obj;
1764
1765 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1766 if (!child_device_obj) {
1767 pr_err("Unable to allocate device object for child device\n");
1768 return NULL;
1769 }
1770
1771 child_device_obj->channel = channel;
1772 guid_copy(&child_device_obj->dev_type, type);
1773 guid_copy(&child_device_obj->dev_instance, instance);
1774 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1775
1776 return child_device_obj;
1777 }
1778
1779 /*
1780 * vmbus_device_register - Register the child device
1781 */
1782 int vmbus_device_register(struct hv_device *child_device_obj)
1783 {
1784 struct kobject *kobj = &child_device_obj->device.kobj;
1785 int ret;
1786
1787 dev_set_name(&child_device_obj->device, "%pUl",
1788 child_device_obj->channel->offermsg.offer.if_instance.b);
1789
1790 child_device_obj->device.bus = &hv_bus;
1791 child_device_obj->device.parent = &hv_acpi_dev->dev;
1792 child_device_obj->device.release = vmbus_device_release;
1793
1794 /*
1795 * Register with the LDM. This will kick off the driver/device
1796 * binding...which will eventually call vmbus_match() and vmbus_probe()
1797 */
1798 ret = device_register(&child_device_obj->device);
1799 if (ret) {
1800 pr_err("Unable to register child device\n");
1801 return ret;
1802 }
1803
1804 child_device_obj->channels_kset = kset_create_and_add("channels",
1805 NULL, kobj);
1806 if (!child_device_obj->channels_kset) {
1807 ret = -ENOMEM;
1808 goto err_dev_unregister;
1809 }
1810
1811 ret = vmbus_add_channel_kobj(child_device_obj,
1812 child_device_obj->channel);
1813 if (ret) {
1814 pr_err("Unable to register primary channeln");
1815 goto err_kset_unregister;
1816 }
1817
1818 return 0;
1819
1820 err_kset_unregister:
1821 kset_unregister(child_device_obj->channels_kset);
1822
1823 err_dev_unregister:
1824 device_unregister(&child_device_obj->device);
1825 return ret;
1826 }
1827
1828 /*
1829 * vmbus_device_unregister - Remove the specified child device
1830 * from the vmbus.
1831 */
1832 void vmbus_device_unregister(struct hv_device *device_obj)
1833 {
1834 pr_debug("child device %s unregistered\n",
1835 dev_name(&device_obj->device));
1836
1837 kset_unregister(device_obj->channels_kset);
1838
1839 /*
1840 * Kick off the process of unregistering the device.
1841 * This will call vmbus_remove() and eventually vmbus_device_release()
1842 */
1843 device_unregister(&device_obj->device);
1844 }
1845
1846
1847 /*
1848 * VMBUS is an acpi enumerated device. Get the information we
1849 * need from DSDT.
1850 */
1851 #define VTPM_BASE_ADDRESS 0xfed40000
1852 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1853 {
1854 resource_size_t start = 0;
1855 resource_size_t end = 0;
1856 struct resource *new_res;
1857 struct resource **old_res = &hyperv_mmio;
1858 struct resource **prev_res = NULL;
1859
1860 switch (res->type) {
1861
1862 /*
1863 * "Address" descriptors are for bus windows. Ignore
1864 * "memory" descriptors, which are for registers on
1865 * devices.
1866 */
1867 case ACPI_RESOURCE_TYPE_ADDRESS32:
1868 start = res->data.address32.address.minimum;
1869 end = res->data.address32.address.maximum;
1870 break;
1871
1872 case ACPI_RESOURCE_TYPE_ADDRESS64:
1873 start = res->data.address64.address.minimum;
1874 end = res->data.address64.address.maximum;
1875 break;
1876
1877 default:
1878 /* Unused resource type */
1879 return AE_OK;
1880
1881 }
1882 /*
1883 * Ignore ranges that are below 1MB, as they're not
1884 * necessary or useful here.
1885 */
1886 if (end < 0x100000)
1887 return AE_OK;
1888
1889 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1890 if (!new_res)
1891 return AE_NO_MEMORY;
1892
1893 /* If this range overlaps the virtual TPM, truncate it. */
1894 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1895 end = VTPM_BASE_ADDRESS;
1896
1897 new_res->name = "hyperv mmio";
1898 new_res->flags = IORESOURCE_MEM;
1899 new_res->start = start;
1900 new_res->end = end;
1901
1902 /*
1903 * If two ranges are adjacent, merge them.
1904 */
1905 do {
1906 if (!*old_res) {
1907 *old_res = new_res;
1908 break;
1909 }
1910
1911 if (((*old_res)->end + 1) == new_res->start) {
1912 (*old_res)->end = new_res->end;
1913 kfree(new_res);
1914 break;
1915 }
1916
1917 if ((*old_res)->start == new_res->end + 1) {
1918 (*old_res)->start = new_res->start;
1919 kfree(new_res);
1920 break;
1921 }
1922
1923 if ((*old_res)->start > new_res->end) {
1924 new_res->sibling = *old_res;
1925 if (prev_res)
1926 (*prev_res)->sibling = new_res;
1927 *old_res = new_res;
1928 break;
1929 }
1930
1931 prev_res = old_res;
1932 old_res = &(*old_res)->sibling;
1933
1934 } while (1);
1935
1936 return AE_OK;
1937 }
1938
1939 static int vmbus_acpi_remove(struct acpi_device *device)
1940 {
1941 struct resource *cur_res;
1942 struct resource *next_res;
1943
1944 if (hyperv_mmio) {
1945 if (fb_mmio) {
1946 __release_region(hyperv_mmio, fb_mmio->start,
1947 resource_size(fb_mmio));
1948 fb_mmio = NULL;
1949 }
1950
1951 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1952 next_res = cur_res->sibling;
1953 kfree(cur_res);
1954 }
1955 }
1956
1957 return 0;
1958 }
1959
1960 static void vmbus_reserve_fb(void)
1961 {
1962 int size;
1963 /*
1964 * Make a claim for the frame buffer in the resource tree under the
1965 * first node, which will be the one below 4GB. The length seems to
1966 * be underreported, particularly in a Generation 1 VM. So start out
1967 * reserving a larger area and make it smaller until it succeeds.
1968 */
1969
1970 if (screen_info.lfb_base) {
1971 if (efi_enabled(EFI_BOOT))
1972 size = max_t(__u32, screen_info.lfb_size, 0x800000);
1973 else
1974 size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1975
1976 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1977 fb_mmio = __request_region(hyperv_mmio,
1978 screen_info.lfb_base, size,
1979 fb_mmio_name, 0);
1980 }
1981 }
1982 }
1983
1984 /**
1985 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1986 * @new: If successful, supplied a pointer to the
1987 * allocated MMIO space.
1988 * @device_obj: Identifies the caller
1989 * @min: Minimum guest physical address of the
1990 * allocation
1991 * @max: Maximum guest physical address
1992 * @size: Size of the range to be allocated
1993 * @align: Alignment of the range to be allocated
1994 * @fb_overlap_ok: Whether this allocation can be allowed
1995 * to overlap the video frame buffer.
1996 *
1997 * This function walks the resources granted to VMBus by the
1998 * _CRS object in the ACPI namespace underneath the parent
1999 * "bridge" whether that's a root PCI bus in the Generation 1
2000 * case or a Module Device in the Generation 2 case. It then
2001 * attempts to allocate from the global MMIO pool in a way that
2002 * matches the constraints supplied in these parameters and by
2003 * that _CRS.
2004 *
2005 * Return: 0 on success, -errno on failure
2006 */
2007 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2008 resource_size_t min, resource_size_t max,
2009 resource_size_t size, resource_size_t align,
2010 bool fb_overlap_ok)
2011 {
2012 struct resource *iter, *shadow;
2013 resource_size_t range_min, range_max, start;
2014 const char *dev_n = dev_name(&device_obj->device);
2015 int retval;
2016
2017 retval = -ENXIO;
2018 down(&hyperv_mmio_lock);
2019
2020 /*
2021 * If overlaps with frame buffers are allowed, then first attempt to
2022 * make the allocation from within the reserved region. Because it
2023 * is already reserved, no shadow allocation is necessary.
2024 */
2025 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2026 !(max < fb_mmio->start)) {
2027
2028 range_min = fb_mmio->start;
2029 range_max = fb_mmio->end;
2030 start = (range_min + align - 1) & ~(align - 1);
2031 for (; start + size - 1 <= range_max; start += align) {
2032 *new = request_mem_region_exclusive(start, size, dev_n);
2033 if (*new) {
2034 retval = 0;
2035 goto exit;
2036 }
2037 }
2038 }
2039
2040 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2041 if ((iter->start >= max) || (iter->end <= min))
2042 continue;
2043
2044 range_min = iter->start;
2045 range_max = iter->end;
2046 start = (range_min + align - 1) & ~(align - 1);
2047 for (; start + size - 1 <= range_max; start += align) {
2048 shadow = __request_region(iter, start, size, NULL,
2049 IORESOURCE_BUSY);
2050 if (!shadow)
2051 continue;
2052
2053 *new = request_mem_region_exclusive(start, size, dev_n);
2054 if (*new) {
2055 shadow->name = (char *)*new;
2056 retval = 0;
2057 goto exit;
2058 }
2059
2060 __release_region(iter, start, size);
2061 }
2062 }
2063
2064 exit:
2065 up(&hyperv_mmio_lock);
2066 return retval;
2067 }
2068 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2069
2070 /**
2071 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2072 * @start: Base address of region to release.
2073 * @size: Size of the range to be allocated
2074 *
2075 * This function releases anything requested by
2076 * vmbus_mmio_allocate().
2077 */
2078 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2079 {
2080 struct resource *iter;
2081
2082 down(&hyperv_mmio_lock);
2083 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2084 if ((iter->start >= start + size) || (iter->end <= start))
2085 continue;
2086
2087 __release_region(iter, start, size);
2088 }
2089 release_mem_region(start, size);
2090 up(&hyperv_mmio_lock);
2091
2092 }
2093 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2094
2095 static int vmbus_acpi_add(struct acpi_device *device)
2096 {
2097 acpi_status result;
2098 int ret_val = -ENODEV;
2099 struct acpi_device *ancestor;
2100
2101 hv_acpi_dev = device;
2102
2103 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2104 vmbus_walk_resources, NULL);
2105
2106 if (ACPI_FAILURE(result))
2107 goto acpi_walk_err;
2108 /*
2109 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2110 * firmware) is the VMOD that has the mmio ranges. Get that.
2111 */
2112 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2113 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2114 vmbus_walk_resources, NULL);
2115
2116 if (ACPI_FAILURE(result))
2117 continue;
2118 if (hyperv_mmio) {
2119 vmbus_reserve_fb();
2120 break;
2121 }
2122 }
2123 ret_val = 0;
2124
2125 acpi_walk_err:
2126 complete(&probe_event);
2127 if (ret_val)
2128 vmbus_acpi_remove(device);
2129 return ret_val;
2130 }
2131
2132 #ifdef CONFIG_PM_SLEEP
2133 static int vmbus_bus_suspend(struct device *dev)
2134 {
2135 struct vmbus_channel *channel, *sc;
2136 unsigned long flags;
2137
2138 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2139 /*
2140 * We wait here until the completion of any channel
2141 * offers that are currently in progress.
2142 */
2143 msleep(1);
2144 }
2145
2146 mutex_lock(&vmbus_connection.channel_mutex);
2147 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2148 if (!is_hvsock_channel(channel))
2149 continue;
2150
2151 vmbus_force_channel_rescinded(channel);
2152 }
2153 mutex_unlock(&vmbus_connection.channel_mutex);
2154
2155 /*
2156 * Wait until all the sub-channels and hv_sock channels have been
2157 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2158 * they would conflict with the new sub-channels that will be created
2159 * in the resume path. hv_sock channels should also be destroyed, but
2160 * a hv_sock channel of an established hv_sock connection can not be
2161 * really destroyed since it may still be referenced by the userspace
2162 * application, so we just force the hv_sock channel to be rescinded
2163 * by vmbus_force_channel_rescinded(), and the userspace application
2164 * will thoroughly destroy the channel after hibernation.
2165 *
2166 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2167 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2168 */
2169 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2170 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2171
2172 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0);
2173
2174 mutex_lock(&vmbus_connection.channel_mutex);
2175
2176 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2177 /*
2178 * Invalidate the field. Upon resume, vmbus_onoffer() will fix
2179 * up the field, and the other fields (if necessary).
2180 */
2181 channel->offermsg.child_relid = INVALID_RELID;
2182
2183 if (is_hvsock_channel(channel)) {
2184 if (!channel->rescind) {
2185 pr_err("hv_sock channel not rescinded!\n");
2186 WARN_ON_ONCE(1);
2187 }
2188 continue;
2189 }
2190
2191 spin_lock_irqsave(&channel->lock, flags);
2192 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2193 pr_err("Sub-channel not deleted!\n");
2194 WARN_ON_ONCE(1);
2195 }
2196 spin_unlock_irqrestore(&channel->lock, flags);
2197
2198 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2199 }
2200
2201 mutex_unlock(&vmbus_connection.channel_mutex);
2202
2203 vmbus_initiate_unload(false);
2204
2205 vmbus_connection.conn_state = DISCONNECTED;
2206
2207 /* Reset the event for the next resume. */
2208 reinit_completion(&vmbus_connection.ready_for_resume_event);
2209
2210 return 0;
2211 }
2212
2213 static int vmbus_bus_resume(struct device *dev)
2214 {
2215 struct vmbus_channel_msginfo *msginfo;
2216 size_t msgsize;
2217 int ret;
2218
2219 /*
2220 * We only use the 'vmbus_proto_version', which was in use before
2221 * hibernation, to re-negotiate with the host.
2222 */
2223 if (vmbus_proto_version == VERSION_INVAL ||
2224 vmbus_proto_version == 0) {
2225 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2226 return -EINVAL;
2227 }
2228
2229 msgsize = sizeof(*msginfo) +
2230 sizeof(struct vmbus_channel_initiate_contact);
2231
2232 msginfo = kzalloc(msgsize, GFP_KERNEL);
2233
2234 if (msginfo == NULL)
2235 return -ENOMEM;
2236
2237 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2238
2239 kfree(msginfo);
2240
2241 if (ret != 0)
2242 return ret;
2243
2244 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2245
2246 vmbus_request_offers();
2247
2248 wait_for_completion(&vmbus_connection.ready_for_resume_event);
2249
2250 /* Reset the event for the next suspend. */
2251 reinit_completion(&vmbus_connection.ready_for_suspend_event);
2252
2253 return 0;
2254 }
2255 #endif /* CONFIG_PM_SLEEP */
2256
2257 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2258 {"VMBUS", 0},
2259 {"VMBus", 0},
2260 {"", 0},
2261 };
2262 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2263
2264 /*
2265 * Note: we must use SET_NOIRQ_SYSTEM_SLEEP_PM_OPS rather than
2266 * SET_SYSTEM_SLEEP_PM_OPS, otherwise NIC SR-IOV can not work, because the
2267 * "pci_dev_pm_ops" uses the "noirq" callbacks: in the resume path, the
2268 * pci "noirq" restore callback runs before "non-noirq" callbacks (see
2269 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2270 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2271 * resume callback must also run via the "noirq" callbacks.
2272 */
2273 static const struct dev_pm_ops vmbus_bus_pm = {
2274 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(vmbus_bus_suspend, vmbus_bus_resume)
2275 };
2276
2277 static struct acpi_driver vmbus_acpi_driver = {
2278 .name = "vmbus",
2279 .ids = vmbus_acpi_device_ids,
2280 .ops = {
2281 .add = vmbus_acpi_add,
2282 .remove = vmbus_acpi_remove,
2283 },
2284 .drv.pm = &vmbus_bus_pm,
2285 };
2286
2287 static void hv_kexec_handler(void)
2288 {
2289 hv_stimer_global_cleanup();
2290 vmbus_initiate_unload(false);
2291 vmbus_connection.conn_state = DISCONNECTED;
2292 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2293 mb();
2294 cpuhp_remove_state(hyperv_cpuhp_online);
2295 hyperv_cleanup();
2296 };
2297
2298 static void hv_crash_handler(struct pt_regs *regs)
2299 {
2300 int cpu;
2301
2302 vmbus_initiate_unload(true);
2303 /*
2304 * In crash handler we can't schedule synic cleanup for all CPUs,
2305 * doing the cleanup for current CPU only. This should be sufficient
2306 * for kdump.
2307 */
2308 vmbus_connection.conn_state = DISCONNECTED;
2309 cpu = smp_processor_id();
2310 hv_stimer_cleanup(cpu);
2311 hv_synic_cleanup(cpu);
2312 hyperv_cleanup();
2313 };
2314
2315 static int hv_synic_suspend(void)
2316 {
2317 /*
2318 * When we reach here, all the non-boot CPUs have been offlined, and
2319 * the stimers on them have been unbound in hv_synic_cleanup() ->
2320 * hv_stimer_cleanup() -> clockevents_unbind_device().
2321 *
2322 * hv_synic_suspend() only runs on CPU0 with interrupts disabled. Here
2323 * we do not unbind the stimer on CPU0 because: 1) it's unnecessary
2324 * because the interrupts remain disabled between syscore_suspend()
2325 * and syscore_resume(): see create_image() and 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(); 3) a warning
2329 * would be triggered if we call clockevents_unbind_device(), which
2330 * may sleep, in an interrupts-disabled context. So, we intentionally
2331 * don't call hv_stimer_cleanup(0) here.
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
2379 ret = vmbus_bus_init();
2380 if (ret)
2381 goto cleanup;
2382
2383 hv_setup_kexec_handler(hv_kexec_handler);
2384 hv_setup_crash_handler(hv_crash_handler);
2385
2386 register_syscore_ops(&hv_synic_syscore_ops);
2387
2388 return 0;
2389
2390 cleanup:
2391 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2392 hv_acpi_dev = NULL;
2393 return ret;
2394 }
2395
2396 static void __exit vmbus_exit(void)
2397 {
2398 int cpu;
2399
2400 unregister_syscore_ops(&hv_synic_syscore_ops);
2401
2402 hv_remove_kexec_handler();
2403 hv_remove_crash_handler();
2404 vmbus_connection.conn_state = DISCONNECTED;
2405 hv_stimer_global_cleanup();
2406 vmbus_disconnect();
2407 hv_remove_vmbus_irq();
2408 for_each_online_cpu(cpu) {
2409 struct hv_per_cpu_context *hv_cpu
2410 = per_cpu_ptr(hv_context.cpu_context, cpu);
2411
2412 tasklet_kill(&hv_cpu->msg_dpc);
2413 }
2414 vmbus_free_channels();
2415
2416 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2417 kmsg_dump_unregister(&hv_kmsg_dumper);
2418 unregister_die_notifier(&hyperv_die_block);
2419 atomic_notifier_chain_unregister(&panic_notifier_list,
2420 &hyperv_panic_block);
2421 }
2422
2423 free_page((unsigned long)hv_panic_page);
2424 unregister_sysctl_table(hv_ctl_table_hdr);
2425 hv_ctl_table_hdr = NULL;
2426 bus_unregister(&hv_bus);
2427
2428 cpuhp_remove_state(hyperv_cpuhp_online);
2429 hv_synic_free();
2430 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2431 }
2432
2433
2434 MODULE_LICENSE("GPL");
2435 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2436
2437 subsys_initcall(hv_acpi_init);
2438 module_exit(vmbus_exit);
Linux with added FPC-III support