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Merge tag 'mvebu-fixes-5.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/gcleme...
[mirror_ubuntu-hirsute-kernel.git] / drivers / hv / vmbus_drv.c
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 <linux/delay.h>
27 #include <linux/notifier.h>
28 #include <linux/ptrace.h>
29 #include <linux/screen_info.h>
30 #include <linux/kdebug.h>
31 #include <linux/efi.h>
32 #include <linux/random.h>
33 #include <linux/kernel.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 /* Values parsed from ACPI DSDT */
52 static int vmbus_irq;
53 int vmbus_interrupt;
54
55 /*
56 * Boolean to control whether to report panic messages over Hyper-V.
57 *
58 * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
59 */
60 static int sysctl_record_panic_msg = 1;
61
62 static int hyperv_report_reg(void)
63 {
64 return !sysctl_record_panic_msg || !hv_panic_page;
65 }
66
67 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
68 void *args)
69 {
70 struct pt_regs *regs;
71
72 vmbus_initiate_unload(true);
73
74 /*
75 * Hyper-V should be notified only once about a panic. If we will be
76 * doing hyperv_report_panic_msg() later with kmsg data, don't do
77 * the notification here.
78 */
79 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
80 && hyperv_report_reg()) {
81 regs = current_pt_regs();
82 hyperv_report_panic(regs, val, false);
83 }
84 return NOTIFY_DONE;
85 }
86
87 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
88 void *args)
89 {
90 struct die_args *die = args;
91 struct pt_regs *regs = die->regs;
92
93 /* Don't notify Hyper-V if the die event is other than oops */
94 if (val != DIE_OOPS)
95 return NOTIFY_DONE;
96
97 /*
98 * Hyper-V should be notified only once about a panic. If we will be
99 * doing hyperv_report_panic_msg() later with kmsg data, don't do
100 * the notification here.
101 */
102 if (hyperv_report_reg())
103 hyperv_report_panic(regs, val, true);
104 return NOTIFY_DONE;
105 }
106
107 static struct notifier_block hyperv_die_block = {
108 .notifier_call = hyperv_die_event,
109 };
110 static struct notifier_block hyperv_panic_block = {
111 .notifier_call = hyperv_panic_event,
112 };
113
114 static const char *fb_mmio_name = "fb_range";
115 static struct resource *fb_mmio;
116 static struct resource *hyperv_mmio;
117 static DEFINE_MUTEX(hyperv_mmio_lock);
118
119 static int vmbus_exists(void)
120 {
121 if (hv_acpi_dev == NULL)
122 return -ENODEV;
123
124 return 0;
125 }
126
127 static u8 channel_monitor_group(const struct vmbus_channel *channel)
128 {
129 return (u8)channel->offermsg.monitorid / 32;
130 }
131
132 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
133 {
134 return (u8)channel->offermsg.monitorid % 32;
135 }
136
137 static u32 channel_pending(const struct vmbus_channel *channel,
138 const struct hv_monitor_page *monitor_page)
139 {
140 u8 monitor_group = channel_monitor_group(channel);
141
142 return monitor_page->trigger_group[monitor_group].pending;
143 }
144
145 static u32 channel_latency(const struct vmbus_channel *channel,
146 const struct hv_monitor_page *monitor_page)
147 {
148 u8 monitor_group = channel_monitor_group(channel);
149 u8 monitor_offset = channel_monitor_offset(channel);
150
151 return monitor_page->latency[monitor_group][monitor_offset];
152 }
153
154 static u32 channel_conn_id(struct vmbus_channel *channel,
155 struct hv_monitor_page *monitor_page)
156 {
157 u8 monitor_group = channel_monitor_group(channel);
158 u8 monitor_offset = channel_monitor_offset(channel);
159 return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
160 }
161
162 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
163 char *buf)
164 {
165 struct hv_device *hv_dev = device_to_hv_device(dev);
166
167 if (!hv_dev->channel)
168 return -ENODEV;
169 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
170 }
171 static DEVICE_ATTR_RO(id);
172
173 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
174 char *buf)
175 {
176 struct hv_device *hv_dev = device_to_hv_device(dev);
177
178 if (!hv_dev->channel)
179 return -ENODEV;
180 return sprintf(buf, "%d\n", hv_dev->channel->state);
181 }
182 static DEVICE_ATTR_RO(state);
183
184 static ssize_t monitor_id_show(struct device *dev,
185 struct device_attribute *dev_attr, char *buf)
186 {
187 struct hv_device *hv_dev = device_to_hv_device(dev);
188
189 if (!hv_dev->channel)
190 return -ENODEV;
191 return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
192 }
193 static DEVICE_ATTR_RO(monitor_id);
194
195 static ssize_t class_id_show(struct device *dev,
196 struct device_attribute *dev_attr, char *buf)
197 {
198 struct hv_device *hv_dev = device_to_hv_device(dev);
199
200 if (!hv_dev->channel)
201 return -ENODEV;
202 return sprintf(buf, "{%pUl}\n",
203 &hv_dev->channel->offermsg.offer.if_type);
204 }
205 static DEVICE_ATTR_RO(class_id);
206
207 static ssize_t device_id_show(struct device *dev,
208 struct device_attribute *dev_attr, char *buf)
209 {
210 struct hv_device *hv_dev = device_to_hv_device(dev);
211
212 if (!hv_dev->channel)
213 return -ENODEV;
214 return sprintf(buf, "{%pUl}\n",
215 &hv_dev->channel->offermsg.offer.if_instance);
216 }
217 static DEVICE_ATTR_RO(device_id);
218
219 static ssize_t modalias_show(struct device *dev,
220 struct device_attribute *dev_attr, char *buf)
221 {
222 struct hv_device *hv_dev = device_to_hv_device(dev);
223
224 return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
225 }
226 static DEVICE_ATTR_RO(modalias);
227
228 #ifdef CONFIG_NUMA
229 static ssize_t numa_node_show(struct device *dev,
230 struct device_attribute *attr, char *buf)
231 {
232 struct hv_device *hv_dev = device_to_hv_device(dev);
233
234 if (!hv_dev->channel)
235 return -ENODEV;
236
237 return sprintf(buf, "%d\n", cpu_to_node(hv_dev->channel->target_cpu));
238 }
239 static DEVICE_ATTR_RO(numa_node);
240 #endif
241
242 static ssize_t server_monitor_pending_show(struct device *dev,
243 struct device_attribute *dev_attr,
244 char *buf)
245 {
246 struct hv_device *hv_dev = device_to_hv_device(dev);
247
248 if (!hv_dev->channel)
249 return -ENODEV;
250 return sprintf(buf, "%d\n",
251 channel_pending(hv_dev->channel,
252 vmbus_connection.monitor_pages[0]));
253 }
254 static DEVICE_ATTR_RO(server_monitor_pending);
255
256 static ssize_t client_monitor_pending_show(struct device *dev,
257 struct device_attribute *dev_attr,
258 char *buf)
259 {
260 struct hv_device *hv_dev = device_to_hv_device(dev);
261
262 if (!hv_dev->channel)
263 return -ENODEV;
264 return sprintf(buf, "%d\n",
265 channel_pending(hv_dev->channel,
266 vmbus_connection.monitor_pages[1]));
267 }
268 static DEVICE_ATTR_RO(client_monitor_pending);
269
270 static ssize_t server_monitor_latency_show(struct device *dev,
271 struct device_attribute *dev_attr,
272 char *buf)
273 {
274 struct hv_device *hv_dev = device_to_hv_device(dev);
275
276 if (!hv_dev->channel)
277 return -ENODEV;
278 return sprintf(buf, "%d\n",
279 channel_latency(hv_dev->channel,
280 vmbus_connection.monitor_pages[0]));
281 }
282 static DEVICE_ATTR_RO(server_monitor_latency);
283
284 static ssize_t client_monitor_latency_show(struct device *dev,
285 struct device_attribute *dev_attr,
286 char *buf)
287 {
288 struct hv_device *hv_dev = device_to_hv_device(dev);
289
290 if (!hv_dev->channel)
291 return -ENODEV;
292 return sprintf(buf, "%d\n",
293 channel_latency(hv_dev->channel,
294 vmbus_connection.monitor_pages[1]));
295 }
296 static DEVICE_ATTR_RO(client_monitor_latency);
297
298 static ssize_t server_monitor_conn_id_show(struct device *dev,
299 struct device_attribute *dev_attr,
300 char *buf)
301 {
302 struct hv_device *hv_dev = device_to_hv_device(dev);
303
304 if (!hv_dev->channel)
305 return -ENODEV;
306 return sprintf(buf, "%d\n",
307 channel_conn_id(hv_dev->channel,
308 vmbus_connection.monitor_pages[0]));
309 }
310 static DEVICE_ATTR_RO(server_monitor_conn_id);
311
312 static ssize_t client_monitor_conn_id_show(struct device *dev,
313 struct device_attribute *dev_attr,
314 char *buf)
315 {
316 struct hv_device *hv_dev = device_to_hv_device(dev);
317
318 if (!hv_dev->channel)
319 return -ENODEV;
320 return sprintf(buf, "%d\n",
321 channel_conn_id(hv_dev->channel,
322 vmbus_connection.monitor_pages[1]));
323 }
324 static DEVICE_ATTR_RO(client_monitor_conn_id);
325
326 static ssize_t out_intr_mask_show(struct device *dev,
327 struct device_attribute *dev_attr, char *buf)
328 {
329 struct hv_device *hv_dev = device_to_hv_device(dev);
330 struct hv_ring_buffer_debug_info outbound;
331 int ret;
332
333 if (!hv_dev->channel)
334 return -ENODEV;
335
336 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
337 &outbound);
338 if (ret < 0)
339 return ret;
340
341 return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
342 }
343 static DEVICE_ATTR_RO(out_intr_mask);
344
345 static ssize_t out_read_index_show(struct device *dev,
346 struct device_attribute *dev_attr, char *buf)
347 {
348 struct hv_device *hv_dev = device_to_hv_device(dev);
349 struct hv_ring_buffer_debug_info outbound;
350 int ret;
351
352 if (!hv_dev->channel)
353 return -ENODEV;
354
355 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
356 &outbound);
357 if (ret < 0)
358 return ret;
359 return sprintf(buf, "%d\n", outbound.current_read_index);
360 }
361 static DEVICE_ATTR_RO(out_read_index);
362
363 static ssize_t out_write_index_show(struct device *dev,
364 struct device_attribute *dev_attr,
365 char *buf)
366 {
367 struct hv_device *hv_dev = device_to_hv_device(dev);
368 struct hv_ring_buffer_debug_info outbound;
369 int ret;
370
371 if (!hv_dev->channel)
372 return -ENODEV;
373
374 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
375 &outbound);
376 if (ret < 0)
377 return ret;
378 return sprintf(buf, "%d\n", outbound.current_write_index);
379 }
380 static DEVICE_ATTR_RO(out_write_index);
381
382 static ssize_t out_read_bytes_avail_show(struct device *dev,
383 struct device_attribute *dev_attr,
384 char *buf)
385 {
386 struct hv_device *hv_dev = device_to_hv_device(dev);
387 struct hv_ring_buffer_debug_info outbound;
388 int ret;
389
390 if (!hv_dev->channel)
391 return -ENODEV;
392
393 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
394 &outbound);
395 if (ret < 0)
396 return ret;
397 return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
398 }
399 static DEVICE_ATTR_RO(out_read_bytes_avail);
400
401 static ssize_t out_write_bytes_avail_show(struct device *dev,
402 struct device_attribute *dev_attr,
403 char *buf)
404 {
405 struct hv_device *hv_dev = device_to_hv_device(dev);
406 struct hv_ring_buffer_debug_info outbound;
407 int ret;
408
409 if (!hv_dev->channel)
410 return -ENODEV;
411
412 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
413 &outbound);
414 if (ret < 0)
415 return ret;
416 return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
417 }
418 static DEVICE_ATTR_RO(out_write_bytes_avail);
419
420 static ssize_t in_intr_mask_show(struct device *dev,
421 struct device_attribute *dev_attr, char *buf)
422 {
423 struct hv_device *hv_dev = device_to_hv_device(dev);
424 struct hv_ring_buffer_debug_info inbound;
425 int ret;
426
427 if (!hv_dev->channel)
428 return -ENODEV;
429
430 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
431 if (ret < 0)
432 return ret;
433
434 return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
435 }
436 static DEVICE_ATTR_RO(in_intr_mask);
437
438 static ssize_t in_read_index_show(struct device *dev,
439 struct device_attribute *dev_attr, char *buf)
440 {
441 struct hv_device *hv_dev = device_to_hv_device(dev);
442 struct hv_ring_buffer_debug_info inbound;
443 int ret;
444
445 if (!hv_dev->channel)
446 return -ENODEV;
447
448 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
449 if (ret < 0)
450 return ret;
451
452 return sprintf(buf, "%d\n", inbound.current_read_index);
453 }
454 static DEVICE_ATTR_RO(in_read_index);
455
456 static ssize_t in_write_index_show(struct device *dev,
457 struct device_attribute *dev_attr, char *buf)
458 {
459 struct hv_device *hv_dev = device_to_hv_device(dev);
460 struct hv_ring_buffer_debug_info inbound;
461 int ret;
462
463 if (!hv_dev->channel)
464 return -ENODEV;
465
466 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
467 if (ret < 0)
468 return ret;
469
470 return sprintf(buf, "%d\n", inbound.current_write_index);
471 }
472 static DEVICE_ATTR_RO(in_write_index);
473
474 static ssize_t in_read_bytes_avail_show(struct device *dev,
475 struct device_attribute *dev_attr,
476 char *buf)
477 {
478 struct hv_device *hv_dev = device_to_hv_device(dev);
479 struct hv_ring_buffer_debug_info inbound;
480 int ret;
481
482 if (!hv_dev->channel)
483 return -ENODEV;
484
485 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
486 if (ret < 0)
487 return ret;
488
489 return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
490 }
491 static DEVICE_ATTR_RO(in_read_bytes_avail);
492
493 static ssize_t in_write_bytes_avail_show(struct device *dev,
494 struct device_attribute *dev_attr,
495 char *buf)
496 {
497 struct hv_device *hv_dev = device_to_hv_device(dev);
498 struct hv_ring_buffer_debug_info inbound;
499 int ret;
500
501 if (!hv_dev->channel)
502 return -ENODEV;
503
504 ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
505 if (ret < 0)
506 return ret;
507
508 return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
509 }
510 static DEVICE_ATTR_RO(in_write_bytes_avail);
511
512 static ssize_t channel_vp_mapping_show(struct device *dev,
513 struct device_attribute *dev_attr,
514 char *buf)
515 {
516 struct hv_device *hv_dev = device_to_hv_device(dev);
517 struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
518 int buf_size = PAGE_SIZE, n_written, tot_written;
519 struct list_head *cur;
520
521 if (!channel)
522 return -ENODEV;
523
524 mutex_lock(&vmbus_connection.channel_mutex);
525
526 tot_written = snprintf(buf, buf_size, "%u:%u\n",
527 channel->offermsg.child_relid, channel->target_cpu);
528
529 list_for_each(cur, &channel->sc_list) {
530 if (tot_written >= buf_size - 1)
531 break;
532
533 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
534 n_written = scnprintf(buf + tot_written,
535 buf_size - tot_written,
536 "%u:%u\n",
537 cur_sc->offermsg.child_relid,
538 cur_sc->target_cpu);
539 tot_written += n_written;
540 }
541
542 mutex_unlock(&vmbus_connection.channel_mutex);
543
544 return tot_written;
545 }
546 static DEVICE_ATTR_RO(channel_vp_mapping);
547
548 static ssize_t vendor_show(struct device *dev,
549 struct device_attribute *dev_attr,
550 char *buf)
551 {
552 struct hv_device *hv_dev = device_to_hv_device(dev);
553 return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
554 }
555 static DEVICE_ATTR_RO(vendor);
556
557 static ssize_t device_show(struct device *dev,
558 struct device_attribute *dev_attr,
559 char *buf)
560 {
561 struct hv_device *hv_dev = device_to_hv_device(dev);
562 return sprintf(buf, "0x%x\n", hv_dev->device_id);
563 }
564 static DEVICE_ATTR_RO(device);
565
566 static ssize_t driver_override_store(struct device *dev,
567 struct device_attribute *attr,
568 const char *buf, size_t count)
569 {
570 struct hv_device *hv_dev = device_to_hv_device(dev);
571 char *driver_override, *old, *cp;
572
573 /* We need to keep extra room for a newline */
574 if (count >= (PAGE_SIZE - 1))
575 return -EINVAL;
576
577 driver_override = kstrndup(buf, count, GFP_KERNEL);
578 if (!driver_override)
579 return -ENOMEM;
580
581 cp = strchr(driver_override, '\n');
582 if (cp)
583 *cp = '\0';
584
585 device_lock(dev);
586 old = hv_dev->driver_override;
587 if (strlen(driver_override)) {
588 hv_dev->driver_override = driver_override;
589 } else {
590 kfree(driver_override);
591 hv_dev->driver_override = NULL;
592 }
593 device_unlock(dev);
594
595 kfree(old);
596
597 return count;
598 }
599
600 static ssize_t driver_override_show(struct device *dev,
601 struct device_attribute *attr, char *buf)
602 {
603 struct hv_device *hv_dev = device_to_hv_device(dev);
604 ssize_t len;
605
606 device_lock(dev);
607 len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
608 device_unlock(dev);
609
610 return len;
611 }
612 static DEVICE_ATTR_RW(driver_override);
613
614 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
615 static struct attribute *vmbus_dev_attrs[] = {
616 &dev_attr_id.attr,
617 &dev_attr_state.attr,
618 &dev_attr_monitor_id.attr,
619 &dev_attr_class_id.attr,
620 &dev_attr_device_id.attr,
621 &dev_attr_modalias.attr,
622 #ifdef CONFIG_NUMA
623 &dev_attr_numa_node.attr,
624 #endif
625 &dev_attr_server_monitor_pending.attr,
626 &dev_attr_client_monitor_pending.attr,
627 &dev_attr_server_monitor_latency.attr,
628 &dev_attr_client_monitor_latency.attr,
629 &dev_attr_server_monitor_conn_id.attr,
630 &dev_attr_client_monitor_conn_id.attr,
631 &dev_attr_out_intr_mask.attr,
632 &dev_attr_out_read_index.attr,
633 &dev_attr_out_write_index.attr,
634 &dev_attr_out_read_bytes_avail.attr,
635 &dev_attr_out_write_bytes_avail.attr,
636 &dev_attr_in_intr_mask.attr,
637 &dev_attr_in_read_index.attr,
638 &dev_attr_in_write_index.attr,
639 &dev_attr_in_read_bytes_avail.attr,
640 &dev_attr_in_write_bytes_avail.attr,
641 &dev_attr_channel_vp_mapping.attr,
642 &dev_attr_vendor.attr,
643 &dev_attr_device.attr,
644 &dev_attr_driver_override.attr,
645 NULL,
646 };
647
648 /*
649 * Device-level attribute_group callback function. Returns the permission for
650 * each attribute, and returns 0 if an attribute is not visible.
651 */
652 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
653 struct attribute *attr, int idx)
654 {
655 struct device *dev = kobj_to_dev(kobj);
656 const struct hv_device *hv_dev = device_to_hv_device(dev);
657
658 /* Hide the monitor attributes if the monitor mechanism is not used. */
659 if (!hv_dev->channel->offermsg.monitor_allocated &&
660 (attr == &dev_attr_monitor_id.attr ||
661 attr == &dev_attr_server_monitor_pending.attr ||
662 attr == &dev_attr_client_monitor_pending.attr ||
663 attr == &dev_attr_server_monitor_latency.attr ||
664 attr == &dev_attr_client_monitor_latency.attr ||
665 attr == &dev_attr_server_monitor_conn_id.attr ||
666 attr == &dev_attr_client_monitor_conn_id.attr))
667 return 0;
668
669 return attr->mode;
670 }
671
672 static const struct attribute_group vmbus_dev_group = {
673 .attrs = vmbus_dev_attrs,
674 .is_visible = vmbus_dev_attr_is_visible
675 };
676 __ATTRIBUTE_GROUPS(vmbus_dev);
677
678 /*
679 * vmbus_uevent - add uevent for our device
680 *
681 * This routine is invoked when a device is added or removed on the vmbus to
682 * generate a uevent to udev in the userspace. The udev will then look at its
683 * rule and the uevent generated here to load the appropriate driver
684 *
685 * The alias string will be of the form vmbus:guid where guid is the string
686 * representation of the device guid (each byte of the guid will be
687 * represented with two hex characters.
688 */
689 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
690 {
691 struct hv_device *dev = device_to_hv_device(device);
692 const char *format = "MODALIAS=vmbus:%*phN";
693
694 return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
695 }
696
697 static const struct hv_vmbus_device_id *
698 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
699 {
700 if (id == NULL)
701 return NULL; /* empty device table */
702
703 for (; !guid_is_null(&id->guid); id++)
704 if (guid_equal(&id->guid, guid))
705 return id;
706
707 return NULL;
708 }
709
710 static const struct hv_vmbus_device_id *
711 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
712 {
713 const struct hv_vmbus_device_id *id = NULL;
714 struct vmbus_dynid *dynid;
715
716 spin_lock(&drv->dynids.lock);
717 list_for_each_entry(dynid, &drv->dynids.list, node) {
718 if (guid_equal(&dynid->id.guid, guid)) {
719 id = &dynid->id;
720 break;
721 }
722 }
723 spin_unlock(&drv->dynids.lock);
724
725 return id;
726 }
727
728 static const struct hv_vmbus_device_id vmbus_device_null;
729
730 /*
731 * Return a matching hv_vmbus_device_id pointer.
732 * If there is no match, return NULL.
733 */
734 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
735 struct hv_device *dev)
736 {
737 const guid_t *guid = &dev->dev_type;
738 const struct hv_vmbus_device_id *id;
739
740 /* When driver_override is set, only bind to the matching driver */
741 if (dev->driver_override && strcmp(dev->driver_override, drv->name))
742 return NULL;
743
744 /* Look at the dynamic ids first, before the static ones */
745 id = hv_vmbus_dynid_match(drv, guid);
746 if (!id)
747 id = hv_vmbus_dev_match(drv->id_table, guid);
748
749 /* driver_override will always match, send a dummy id */
750 if (!id && dev->driver_override)
751 id = &vmbus_device_null;
752
753 return id;
754 }
755
756 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
757 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
758 {
759 struct vmbus_dynid *dynid;
760
761 dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
762 if (!dynid)
763 return -ENOMEM;
764
765 dynid->id.guid = *guid;
766
767 spin_lock(&drv->dynids.lock);
768 list_add_tail(&dynid->node, &drv->dynids.list);
769 spin_unlock(&drv->dynids.lock);
770
771 return driver_attach(&drv->driver);
772 }
773
774 static void vmbus_free_dynids(struct hv_driver *drv)
775 {
776 struct vmbus_dynid *dynid, *n;
777
778 spin_lock(&drv->dynids.lock);
779 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
780 list_del(&dynid->node);
781 kfree(dynid);
782 }
783 spin_unlock(&drv->dynids.lock);
784 }
785
786 /*
787 * store_new_id - sysfs frontend to vmbus_add_dynid()
788 *
789 * Allow GUIDs to be added to an existing driver via sysfs.
790 */
791 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
792 size_t count)
793 {
794 struct hv_driver *drv = drv_to_hv_drv(driver);
795 guid_t guid;
796 ssize_t retval;
797
798 retval = guid_parse(buf, &guid);
799 if (retval)
800 return retval;
801
802 if (hv_vmbus_dynid_match(drv, &guid))
803 return -EEXIST;
804
805 retval = vmbus_add_dynid(drv, &guid);
806 if (retval)
807 return retval;
808 return count;
809 }
810 static DRIVER_ATTR_WO(new_id);
811
812 /*
813 * store_remove_id - remove a PCI device ID from this driver
814 *
815 * Removes a dynamic pci device ID to this driver.
816 */
817 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
818 size_t count)
819 {
820 struct hv_driver *drv = drv_to_hv_drv(driver);
821 struct vmbus_dynid *dynid, *n;
822 guid_t guid;
823 ssize_t retval;
824
825 retval = guid_parse(buf, &guid);
826 if (retval)
827 return retval;
828
829 retval = -ENODEV;
830 spin_lock(&drv->dynids.lock);
831 list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
832 struct hv_vmbus_device_id *id = &dynid->id;
833
834 if (guid_equal(&id->guid, &guid)) {
835 list_del(&dynid->node);
836 kfree(dynid);
837 retval = count;
838 break;
839 }
840 }
841 spin_unlock(&drv->dynids.lock);
842
843 return retval;
844 }
845 static DRIVER_ATTR_WO(remove_id);
846
847 static struct attribute *vmbus_drv_attrs[] = {
848 &driver_attr_new_id.attr,
849 &driver_attr_remove_id.attr,
850 NULL,
851 };
852 ATTRIBUTE_GROUPS(vmbus_drv);
853
854
855 /*
856 * vmbus_match - Attempt to match the specified device to the specified driver
857 */
858 static int vmbus_match(struct device *device, struct device_driver *driver)
859 {
860 struct hv_driver *drv = drv_to_hv_drv(driver);
861 struct hv_device *hv_dev = device_to_hv_device(device);
862
863 /* The hv_sock driver handles all hv_sock offers. */
864 if (is_hvsock_channel(hv_dev->channel))
865 return drv->hvsock;
866
867 if (hv_vmbus_get_id(drv, hv_dev))
868 return 1;
869
870 return 0;
871 }
872
873 /*
874 * vmbus_probe - Add the new vmbus's child device
875 */
876 static int vmbus_probe(struct device *child_device)
877 {
878 int ret = 0;
879 struct hv_driver *drv =
880 drv_to_hv_drv(child_device->driver);
881 struct hv_device *dev = device_to_hv_device(child_device);
882 const struct hv_vmbus_device_id *dev_id;
883
884 dev_id = hv_vmbus_get_id(drv, dev);
885 if (drv->probe) {
886 ret = drv->probe(dev, dev_id);
887 if (ret != 0)
888 pr_err("probe failed for device %s (%d)\n",
889 dev_name(child_device), ret);
890
891 } else {
892 pr_err("probe not set for driver %s\n",
893 dev_name(child_device));
894 ret = -ENODEV;
895 }
896 return ret;
897 }
898
899 /*
900 * vmbus_remove - Remove a vmbus device
901 */
902 static int vmbus_remove(struct device *child_device)
903 {
904 struct hv_driver *drv;
905 struct hv_device *dev = device_to_hv_device(child_device);
906
907 if (child_device->driver) {
908 drv = drv_to_hv_drv(child_device->driver);
909 if (drv->remove)
910 drv->remove(dev);
911 }
912
913 return 0;
914 }
915
916
917 /*
918 * vmbus_shutdown - Shutdown a vmbus device
919 */
920 static void vmbus_shutdown(struct device *child_device)
921 {
922 struct hv_driver *drv;
923 struct hv_device *dev = device_to_hv_device(child_device);
924
925
926 /* The device may not be attached yet */
927 if (!child_device->driver)
928 return;
929
930 drv = drv_to_hv_drv(child_device->driver);
931
932 if (drv->shutdown)
933 drv->shutdown(dev);
934 }
935
936 #ifdef CONFIG_PM_SLEEP
937 /*
938 * vmbus_suspend - Suspend a vmbus device
939 */
940 static int vmbus_suspend(struct device *child_device)
941 {
942 struct hv_driver *drv;
943 struct hv_device *dev = device_to_hv_device(child_device);
944
945 /* The device may not be attached yet */
946 if (!child_device->driver)
947 return 0;
948
949 drv = drv_to_hv_drv(child_device->driver);
950 if (!drv->suspend)
951 return -EOPNOTSUPP;
952
953 return drv->suspend(dev);
954 }
955
956 /*
957 * vmbus_resume - Resume a vmbus device
958 */
959 static int vmbus_resume(struct device *child_device)
960 {
961 struct hv_driver *drv;
962 struct hv_device *dev = device_to_hv_device(child_device);
963
964 /* The device may not be attached yet */
965 if (!child_device->driver)
966 return 0;
967
968 drv = drv_to_hv_drv(child_device->driver);
969 if (!drv->resume)
970 return -EOPNOTSUPP;
971
972 return drv->resume(dev);
973 }
974 #else
975 #define vmbus_suspend NULL
976 #define vmbus_resume NULL
977 #endif /* CONFIG_PM_SLEEP */
978
979 /*
980 * vmbus_device_release - Final callback release of the vmbus child device
981 */
982 static void vmbus_device_release(struct device *device)
983 {
984 struct hv_device *hv_dev = device_to_hv_device(device);
985 struct vmbus_channel *channel = hv_dev->channel;
986
987 hv_debug_rm_dev_dir(hv_dev);
988
989 mutex_lock(&vmbus_connection.channel_mutex);
990 hv_process_channel_removal(channel);
991 mutex_unlock(&vmbus_connection.channel_mutex);
992 kfree(hv_dev);
993 }
994
995 /*
996 * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
997 *
998 * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
999 * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
1000 * is no way to wake up a Generation-2 VM.
1001 *
1002 * The other 4 ops are for hibernation.
1003 */
1004
1005 static const struct dev_pm_ops vmbus_pm = {
1006 .suspend_noirq = NULL,
1007 .resume_noirq = NULL,
1008 .freeze_noirq = vmbus_suspend,
1009 .thaw_noirq = vmbus_resume,
1010 .poweroff_noirq = vmbus_suspend,
1011 .restore_noirq = vmbus_resume,
1012 };
1013
1014 /* The one and only one */
1015 static struct bus_type hv_bus = {
1016 .name = "vmbus",
1017 .match = vmbus_match,
1018 .shutdown = vmbus_shutdown,
1019 .remove = vmbus_remove,
1020 .probe = vmbus_probe,
1021 .uevent = vmbus_uevent,
1022 .dev_groups = vmbus_dev_groups,
1023 .drv_groups = vmbus_drv_groups,
1024 .pm = &vmbus_pm,
1025 };
1026
1027 struct onmessage_work_context {
1028 struct work_struct work;
1029 struct {
1030 struct hv_message_header header;
1031 u8 payload[];
1032 } msg;
1033 };
1034
1035 static void vmbus_onmessage_work(struct work_struct *work)
1036 {
1037 struct onmessage_work_context *ctx;
1038
1039 /* Do not process messages if we're in DISCONNECTED state */
1040 if (vmbus_connection.conn_state == DISCONNECTED)
1041 return;
1042
1043 ctx = container_of(work, struct onmessage_work_context,
1044 work);
1045 vmbus_onmessage((struct vmbus_channel_message_header *)
1046 &ctx->msg.payload);
1047 kfree(ctx);
1048 }
1049
1050 void vmbus_on_msg_dpc(unsigned long data)
1051 {
1052 struct hv_per_cpu_context *hv_cpu = (void *)data;
1053 void *page_addr = hv_cpu->synic_message_page;
1054 struct hv_message *msg = (struct hv_message *)page_addr +
1055 VMBUS_MESSAGE_SINT;
1056 struct vmbus_channel_message_header *hdr;
1057 const struct vmbus_channel_message_table_entry *entry;
1058 struct onmessage_work_context *ctx;
1059 u32 message_type = msg->header.message_type;
1060
1061 /*
1062 * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1063 * it is being used in 'struct vmbus_channel_message_header' definition
1064 * which is supposed to match hypervisor ABI.
1065 */
1066 BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1067
1068 if (message_type == HVMSG_NONE)
1069 /* no msg */
1070 return;
1071
1072 hdr = (struct vmbus_channel_message_header *)msg->u.payload;
1073
1074 trace_vmbus_on_msg_dpc(hdr);
1075
1076 if (hdr->msgtype >= CHANNELMSG_COUNT) {
1077 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1078 goto msg_handled;
1079 }
1080
1081 if (msg->header.payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1082 WARN_ONCE(1, "payload size is too large (%d)\n",
1083 msg->header.payload_size);
1084 goto msg_handled;
1085 }
1086
1087 entry = &channel_message_table[hdr->msgtype];
1088
1089 if (!entry->message_handler)
1090 goto msg_handled;
1091
1092 if (msg->header.payload_size < entry->min_payload_len) {
1093 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n",
1094 hdr->msgtype, msg->header.payload_size);
1095 goto msg_handled;
1096 }
1097
1098 if (entry->handler_type == VMHT_BLOCKING) {
1099 ctx = kmalloc(sizeof(*ctx) + msg->header.payload_size,
1100 GFP_ATOMIC);
1101 if (ctx == NULL)
1102 return;
1103
1104 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1105 memcpy(&ctx->msg, msg, sizeof(msg->header) +
1106 msg->header.payload_size);
1107
1108 /*
1109 * The host can generate a rescind message while we
1110 * may still be handling the original offer. We deal with
1111 * this condition by relying on the synchronization provided
1112 * by offer_in_progress and by channel_mutex. See also the
1113 * inline comments in vmbus_onoffer_rescind().
1114 */
1115 switch (hdr->msgtype) {
1116 case CHANNELMSG_RESCIND_CHANNELOFFER:
1117 /*
1118 * If we are handling the rescind message;
1119 * schedule the work on the global work queue.
1120 *
1121 * The OFFER message and the RESCIND message should
1122 * not be handled by the same serialized work queue,
1123 * because the OFFER handler may call vmbus_open(),
1124 * which tries to open the channel by sending an
1125 * OPEN_CHANNEL message to the host and waits for
1126 * the host's response; however, if the host has
1127 * rescinded the channel before it receives the
1128 * OPEN_CHANNEL message, the host just silently
1129 * ignores the OPEN_CHANNEL message; as a result,
1130 * the guest's OFFER handler hangs for ever, if we
1131 * handle the RESCIND message in the same serialized
1132 * work queue: the RESCIND handler can not start to
1133 * run before the OFFER handler finishes.
1134 */
1135 schedule_work(&ctx->work);
1136 break;
1137
1138 case CHANNELMSG_OFFERCHANNEL:
1139 /*
1140 * The host sends the offer message of a given channel
1141 * before sending the rescind message of the same
1142 * channel. These messages are sent to the guest's
1143 * connect CPU; the guest then starts processing them
1144 * in the tasklet handler on this CPU:
1145 *
1146 * VMBUS_CONNECT_CPU
1147 *
1148 * [vmbus_on_msg_dpc()]
1149 * atomic_inc() // CHANNELMSG_OFFERCHANNEL
1150 * queue_work()
1151 * ...
1152 * [vmbus_on_msg_dpc()]
1153 * schedule_work() // CHANNELMSG_RESCIND_CHANNELOFFER
1154 *
1155 * We rely on the memory-ordering properties of the
1156 * queue_work() and schedule_work() primitives, which
1157 * guarantee that the atomic increment will be visible
1158 * to the CPUs which will execute the offer & rescind
1159 * works by the time these works will start execution.
1160 */
1161 atomic_inc(&vmbus_connection.offer_in_progress);
1162 fallthrough;
1163
1164 default:
1165 queue_work(vmbus_connection.work_queue, &ctx->work);
1166 }
1167 } else
1168 entry->message_handler(hdr);
1169
1170 msg_handled:
1171 vmbus_signal_eom(msg, message_type);
1172 }
1173
1174 #ifdef CONFIG_PM_SLEEP
1175 /*
1176 * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1177 * hibernation, because hv_sock connections can not persist across hibernation.
1178 */
1179 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1180 {
1181 struct onmessage_work_context *ctx;
1182 struct vmbus_channel_rescind_offer *rescind;
1183
1184 WARN_ON(!is_hvsock_channel(channel));
1185
1186 /*
1187 * Allocation size is small and the allocation should really not fail,
1188 * otherwise the state of the hv_sock connections ends up in limbo.
1189 */
1190 ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1191 GFP_KERNEL | __GFP_NOFAIL);
1192
1193 /*
1194 * So far, these are not really used by Linux. Just set them to the
1195 * reasonable values conforming to the definitions of the fields.
1196 */
1197 ctx->msg.header.message_type = 1;
1198 ctx->msg.header.payload_size = sizeof(*rescind);
1199
1200 /* These values are actually used by Linux. */
1201 rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
1202 rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1203 rescind->child_relid = channel->offermsg.child_relid;
1204
1205 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1206
1207 queue_work(vmbus_connection.work_queue, &ctx->work);
1208 }
1209 #endif /* CONFIG_PM_SLEEP */
1210
1211 /*
1212 * Schedule all channels with events pending
1213 */
1214 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1215 {
1216 unsigned long *recv_int_page;
1217 u32 maxbits, relid;
1218
1219 if (vmbus_proto_version < VERSION_WIN8) {
1220 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1221 recv_int_page = vmbus_connection.recv_int_page;
1222 } else {
1223 /*
1224 * When the host is win8 and beyond, the event page
1225 * can be directly checked to get the id of the channel
1226 * that has the interrupt pending.
1227 */
1228 void *page_addr = hv_cpu->synic_event_page;
1229 union hv_synic_event_flags *event
1230 = (union hv_synic_event_flags *)page_addr +
1231 VMBUS_MESSAGE_SINT;
1232
1233 maxbits = HV_EVENT_FLAGS_COUNT;
1234 recv_int_page = event->flags;
1235 }
1236
1237 if (unlikely(!recv_int_page))
1238 return;
1239
1240 for_each_set_bit(relid, recv_int_page, maxbits) {
1241 void (*callback_fn)(void *context);
1242 struct vmbus_channel *channel;
1243
1244 if (!sync_test_and_clear_bit(relid, recv_int_page))
1245 continue;
1246
1247 /* Special case - vmbus channel protocol msg */
1248 if (relid == 0)
1249 continue;
1250
1251 /*
1252 * Pairs with the kfree_rcu() in vmbus_chan_release().
1253 * Guarantees that the channel data structure doesn't
1254 * get freed while the channel pointer below is being
1255 * dereferenced.
1256 */
1257 rcu_read_lock();
1258
1259 /* Find channel based on relid */
1260 channel = relid2channel(relid);
1261 if (channel == NULL)
1262 goto sched_unlock_rcu;
1263
1264 if (channel->rescind)
1265 goto sched_unlock_rcu;
1266
1267 /*
1268 * Make sure that the ring buffer data structure doesn't get
1269 * freed while we dereference the ring buffer pointer. Test
1270 * for the channel's onchannel_callback being NULL within a
1271 * sched_lock critical section. See also the inline comments
1272 * in vmbus_reset_channel_cb().
1273 */
1274 spin_lock(&channel->sched_lock);
1275
1276 callback_fn = channel->onchannel_callback;
1277 if (unlikely(callback_fn == NULL))
1278 goto sched_unlock;
1279
1280 trace_vmbus_chan_sched(channel);
1281
1282 ++channel->interrupts;
1283
1284 switch (channel->callback_mode) {
1285 case HV_CALL_ISR:
1286 (*callback_fn)(channel->channel_callback_context);
1287 break;
1288
1289 case HV_CALL_BATCHED:
1290 hv_begin_read(&channel->inbound);
1291 fallthrough;
1292 case HV_CALL_DIRECT:
1293 tasklet_schedule(&channel->callback_event);
1294 }
1295
1296 sched_unlock:
1297 spin_unlock(&channel->sched_lock);
1298 sched_unlock_rcu:
1299 rcu_read_unlock();
1300 }
1301 }
1302
1303 static void vmbus_isr(void)
1304 {
1305 struct hv_per_cpu_context *hv_cpu
1306 = this_cpu_ptr(hv_context.cpu_context);
1307 void *page_addr = hv_cpu->synic_event_page;
1308 struct hv_message *msg;
1309 union hv_synic_event_flags *event;
1310 bool handled = false;
1311
1312 if (unlikely(page_addr == NULL))
1313 return;
1314
1315 event = (union hv_synic_event_flags *)page_addr +
1316 VMBUS_MESSAGE_SINT;
1317 /*
1318 * Check for events before checking for messages. This is the order
1319 * in which events and messages are checked in Windows guests on
1320 * Hyper-V, and the Windows team suggested we do the same.
1321 */
1322
1323 if ((vmbus_proto_version == VERSION_WS2008) ||
1324 (vmbus_proto_version == VERSION_WIN7)) {
1325
1326 /* Since we are a child, we only need to check bit 0 */
1327 if (sync_test_and_clear_bit(0, event->flags))
1328 handled = true;
1329 } else {
1330 /*
1331 * Our host is win8 or above. The signaling mechanism
1332 * has changed and we can directly look at the event page.
1333 * If bit n is set then we have an interrup on the channel
1334 * whose id is n.
1335 */
1336 handled = true;
1337 }
1338
1339 if (handled)
1340 vmbus_chan_sched(hv_cpu);
1341
1342 page_addr = hv_cpu->synic_message_page;
1343 msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1344
1345 /* Check if there are actual msgs to be processed */
1346 if (msg->header.message_type != HVMSG_NONE) {
1347 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1348 hv_stimer0_isr();
1349 vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1350 } else
1351 tasklet_schedule(&hv_cpu->msg_dpc);
1352 }
1353
1354 add_interrupt_randomness(hv_get_vector(), 0);
1355 }
1356
1357 /*
1358 * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1359 * buffer and call into Hyper-V to transfer the data.
1360 */
1361 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1362 enum kmsg_dump_reason reason)
1363 {
1364 size_t bytes_written;
1365 phys_addr_t panic_pa;
1366
1367 /* We are only interested in panics. */
1368 if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1369 return;
1370
1371 panic_pa = virt_to_phys(hv_panic_page);
1372
1373 /*
1374 * Write dump contents to the page. No need to synchronize; panic should
1375 * be single-threaded.
1376 */
1377 kmsg_dump_get_buffer(dumper, false, hv_panic_page, HV_HYP_PAGE_SIZE,
1378 &bytes_written);
1379 if (bytes_written)
1380 hyperv_report_panic_msg(panic_pa, bytes_written);
1381 }
1382
1383 static struct kmsg_dumper hv_kmsg_dumper = {
1384 .dump = hv_kmsg_dump,
1385 };
1386
1387 static struct ctl_table_header *hv_ctl_table_hdr;
1388
1389 /*
1390 * sysctl option to allow the user to control whether kmsg data should be
1391 * reported to Hyper-V on panic.
1392 */
1393 static struct ctl_table hv_ctl_table[] = {
1394 {
1395 .procname = "hyperv_record_panic_msg",
1396 .data = &sysctl_record_panic_msg,
1397 .maxlen = sizeof(int),
1398 .mode = 0644,
1399 .proc_handler = proc_dointvec_minmax,
1400 .extra1 = SYSCTL_ZERO,
1401 .extra2 = SYSCTL_ONE
1402 },
1403 {}
1404 };
1405
1406 static struct ctl_table hv_root_table[] = {
1407 {
1408 .procname = "kernel",
1409 .mode = 0555,
1410 .child = hv_ctl_table
1411 },
1412 {}
1413 };
1414
1415 /*
1416 * vmbus_bus_init -Main vmbus driver initialization routine.
1417 *
1418 * Here, we
1419 * - initialize the vmbus driver context
1420 * - invoke the vmbus hv main init routine
1421 * - retrieve the channel offers
1422 */
1423 static int vmbus_bus_init(void)
1424 {
1425 int ret;
1426
1427 ret = hv_init();
1428 if (ret != 0) {
1429 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1430 return ret;
1431 }
1432
1433 ret = bus_register(&hv_bus);
1434 if (ret)
1435 return ret;
1436
1437 ret = hv_setup_vmbus_irq(vmbus_irq, vmbus_isr);
1438 if (ret)
1439 goto err_setup;
1440
1441 ret = hv_synic_alloc();
1442 if (ret)
1443 goto err_alloc;
1444
1445 /*
1446 * Initialize the per-cpu interrupt state and stimer state.
1447 * Then connect to the host.
1448 */
1449 ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1450 hv_synic_init, hv_synic_cleanup);
1451 if (ret < 0)
1452 goto err_cpuhp;
1453 hyperv_cpuhp_online = ret;
1454
1455 ret = vmbus_connect();
1456 if (ret)
1457 goto err_connect;
1458
1459 /*
1460 * Only register if the crash MSRs are available
1461 */
1462 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1463 u64 hyperv_crash_ctl;
1464 /*
1465 * Sysctl registration is not fatal, since by default
1466 * reporting is enabled.
1467 */
1468 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1469 if (!hv_ctl_table_hdr)
1470 pr_err("Hyper-V: sysctl table register error");
1471
1472 /*
1473 * Register for panic kmsg callback only if the right
1474 * capability is supported by the hypervisor.
1475 */
1476 hv_get_crash_ctl(hyperv_crash_ctl);
1477 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1478 hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
1479 if (hv_panic_page) {
1480 ret = kmsg_dump_register(&hv_kmsg_dumper);
1481 if (ret) {
1482 pr_err("Hyper-V: kmsg dump register "
1483 "error 0x%x\n", ret);
1484 hv_free_hyperv_page(
1485 (unsigned long)hv_panic_page);
1486 hv_panic_page = NULL;
1487 }
1488 } else
1489 pr_err("Hyper-V: panic message page memory "
1490 "allocation failed");
1491 }
1492
1493 register_die_notifier(&hyperv_die_block);
1494 }
1495
1496 /*
1497 * Always register the panic notifier because we need to unload
1498 * the VMbus channel connection to prevent any VMbus
1499 * activity after the VM panics.
1500 */
1501 atomic_notifier_chain_register(&panic_notifier_list,
1502 &hyperv_panic_block);
1503
1504 vmbus_request_offers();
1505
1506 return 0;
1507
1508 err_connect:
1509 cpuhp_remove_state(hyperv_cpuhp_online);
1510 err_cpuhp:
1511 hv_synic_free();
1512 err_alloc:
1513 hv_remove_vmbus_irq();
1514 err_setup:
1515 bus_unregister(&hv_bus);
1516 unregister_sysctl_table(hv_ctl_table_hdr);
1517 hv_ctl_table_hdr = NULL;
1518 return ret;
1519 }
1520
1521 /**
1522 * __vmbus_child_driver_register() - Register a vmbus's driver
1523 * @hv_driver: Pointer to driver structure you want to register
1524 * @owner: owner module of the drv
1525 * @mod_name: module name string
1526 *
1527 * Registers the given driver with Linux through the 'driver_register()' call
1528 * and sets up the hyper-v vmbus handling for this driver.
1529 * It will return the state of the 'driver_register()' call.
1530 *
1531 */
1532 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1533 {
1534 int ret;
1535
1536 pr_info("registering driver %s\n", hv_driver->name);
1537
1538 ret = vmbus_exists();
1539 if (ret < 0)
1540 return ret;
1541
1542 hv_driver->driver.name = hv_driver->name;
1543 hv_driver->driver.owner = owner;
1544 hv_driver->driver.mod_name = mod_name;
1545 hv_driver->driver.bus = &hv_bus;
1546
1547 spin_lock_init(&hv_driver->dynids.lock);
1548 INIT_LIST_HEAD(&hv_driver->dynids.list);
1549
1550 ret = driver_register(&hv_driver->driver);
1551
1552 return ret;
1553 }
1554 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1555
1556 /**
1557 * vmbus_driver_unregister() - Unregister a vmbus's driver
1558 * @hv_driver: Pointer to driver structure you want to
1559 * un-register
1560 *
1561 * Un-register the given driver that was previous registered with a call to
1562 * vmbus_driver_register()
1563 */
1564 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1565 {
1566 pr_info("unregistering driver %s\n", hv_driver->name);
1567
1568 if (!vmbus_exists()) {
1569 driver_unregister(&hv_driver->driver);
1570 vmbus_free_dynids(hv_driver);
1571 }
1572 }
1573 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1574
1575
1576 /*
1577 * Called when last reference to channel is gone.
1578 */
1579 static void vmbus_chan_release(struct kobject *kobj)
1580 {
1581 struct vmbus_channel *channel
1582 = container_of(kobj, struct vmbus_channel, kobj);
1583
1584 kfree_rcu(channel, rcu);
1585 }
1586
1587 struct vmbus_chan_attribute {
1588 struct attribute attr;
1589 ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1590 ssize_t (*store)(struct vmbus_channel *chan,
1591 const char *buf, size_t count);
1592 };
1593 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1594 struct vmbus_chan_attribute chan_attr_##_name \
1595 = __ATTR(_name, _mode, _show, _store)
1596 #define VMBUS_CHAN_ATTR_RW(_name) \
1597 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1598 #define VMBUS_CHAN_ATTR_RO(_name) \
1599 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1600 #define VMBUS_CHAN_ATTR_WO(_name) \
1601 struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1602
1603 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1604 struct attribute *attr, char *buf)
1605 {
1606 const struct vmbus_chan_attribute *attribute
1607 = container_of(attr, struct vmbus_chan_attribute, attr);
1608 struct vmbus_channel *chan
1609 = container_of(kobj, struct vmbus_channel, kobj);
1610
1611 if (!attribute->show)
1612 return -EIO;
1613
1614 return attribute->show(chan, buf);
1615 }
1616
1617 static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1618 struct attribute *attr, const char *buf,
1619 size_t count)
1620 {
1621 const struct vmbus_chan_attribute *attribute
1622 = container_of(attr, struct vmbus_chan_attribute, attr);
1623 struct vmbus_channel *chan
1624 = container_of(kobj, struct vmbus_channel, kobj);
1625
1626 if (!attribute->store)
1627 return -EIO;
1628
1629 return attribute->store(chan, buf, count);
1630 }
1631
1632 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1633 .show = vmbus_chan_attr_show,
1634 .store = vmbus_chan_attr_store,
1635 };
1636
1637 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1638 {
1639 struct hv_ring_buffer_info *rbi = &channel->outbound;
1640 ssize_t ret;
1641
1642 mutex_lock(&rbi->ring_buffer_mutex);
1643 if (!rbi->ring_buffer) {
1644 mutex_unlock(&rbi->ring_buffer_mutex);
1645 return -EINVAL;
1646 }
1647
1648 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1649 mutex_unlock(&rbi->ring_buffer_mutex);
1650 return ret;
1651 }
1652 static VMBUS_CHAN_ATTR_RO(out_mask);
1653
1654 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1655 {
1656 struct hv_ring_buffer_info *rbi = &channel->inbound;
1657 ssize_t ret;
1658
1659 mutex_lock(&rbi->ring_buffer_mutex);
1660 if (!rbi->ring_buffer) {
1661 mutex_unlock(&rbi->ring_buffer_mutex);
1662 return -EINVAL;
1663 }
1664
1665 ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1666 mutex_unlock(&rbi->ring_buffer_mutex);
1667 return ret;
1668 }
1669 static VMBUS_CHAN_ATTR_RO(in_mask);
1670
1671 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1672 {
1673 struct hv_ring_buffer_info *rbi = &channel->inbound;
1674 ssize_t ret;
1675
1676 mutex_lock(&rbi->ring_buffer_mutex);
1677 if (!rbi->ring_buffer) {
1678 mutex_unlock(&rbi->ring_buffer_mutex);
1679 return -EINVAL;
1680 }
1681
1682 ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1683 mutex_unlock(&rbi->ring_buffer_mutex);
1684 return ret;
1685 }
1686 static VMBUS_CHAN_ATTR_RO(read_avail);
1687
1688 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1689 {
1690 struct hv_ring_buffer_info *rbi = &channel->outbound;
1691 ssize_t ret;
1692
1693 mutex_lock(&rbi->ring_buffer_mutex);
1694 if (!rbi->ring_buffer) {
1695 mutex_unlock(&rbi->ring_buffer_mutex);
1696 return -EINVAL;
1697 }
1698
1699 ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1700 mutex_unlock(&rbi->ring_buffer_mutex);
1701 return ret;
1702 }
1703 static VMBUS_CHAN_ATTR_RO(write_avail);
1704
1705 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1706 {
1707 return sprintf(buf, "%u\n", channel->target_cpu);
1708 }
1709 static ssize_t target_cpu_store(struct vmbus_channel *channel,
1710 const char *buf, size_t count)
1711 {
1712 u32 target_cpu, origin_cpu;
1713 ssize_t ret = count;
1714
1715 if (vmbus_proto_version < VERSION_WIN10_V4_1)
1716 return -EIO;
1717
1718 if (sscanf(buf, "%uu", &target_cpu) != 1)
1719 return -EIO;
1720
1721 /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1722 if (target_cpu >= nr_cpumask_bits)
1723 return -EINVAL;
1724
1725 /* No CPUs should come up or down during this. */
1726 cpus_read_lock();
1727
1728 if (!cpu_online(target_cpu)) {
1729 cpus_read_unlock();
1730 return -EINVAL;
1731 }
1732
1733 /*
1734 * Synchronizes target_cpu_store() and channel closure:
1735 *
1736 * { Initially: state = CHANNEL_OPENED }
1737 *
1738 * CPU1 CPU2
1739 *
1740 * [target_cpu_store()] [vmbus_disconnect_ring()]
1741 *
1742 * LOCK channel_mutex LOCK channel_mutex
1743 * LOAD r1 = state LOAD r2 = state
1744 * IF (r1 == CHANNEL_OPENED) IF (r2 == CHANNEL_OPENED)
1745 * SEND MODIFYCHANNEL STORE state = CHANNEL_OPEN
1746 * [...] SEND CLOSECHANNEL
1747 * UNLOCK channel_mutex UNLOCK channel_mutex
1748 *
1749 * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1750 * CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1751 *
1752 * Note. The host processes the channel messages "sequentially", in
1753 * the order in which they are received on a per-partition basis.
1754 */
1755 mutex_lock(&vmbus_connection.channel_mutex);
1756
1757 /*
1758 * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1759 * avoid sending the message and fail here for such channels.
1760 */
1761 if (channel->state != CHANNEL_OPENED_STATE) {
1762 ret = -EIO;
1763 goto cpu_store_unlock;
1764 }
1765
1766 origin_cpu = channel->target_cpu;
1767 if (target_cpu == origin_cpu)
1768 goto cpu_store_unlock;
1769
1770 if (vmbus_send_modifychannel(channel->offermsg.child_relid,
1771 hv_cpu_number_to_vp_number(target_cpu))) {
1772 ret = -EIO;
1773 goto cpu_store_unlock;
1774 }
1775
1776 /*
1777 * Warning. At this point, there is *no* guarantee that the host will
1778 * have successfully processed the vmbus_send_modifychannel() request.
1779 * See the header comment of vmbus_send_modifychannel() for more info.
1780 *
1781 * Lags in the processing of the above vmbus_send_modifychannel() can
1782 * result in missed interrupts if the "old" target CPU is taken offline
1783 * before Hyper-V starts sending interrupts to the "new" target CPU.
1784 * But apart from this offlining scenario, the code tolerates such
1785 * lags. It will function correctly even if a channel interrupt comes
1786 * in on a CPU that is different from the channel target_cpu value.
1787 */
1788
1789 channel->target_cpu = target_cpu;
1790
1791 /* See init_vp_index(). */
1792 if (hv_is_perf_channel(channel))
1793 hv_update_alloced_cpus(origin_cpu, target_cpu);
1794
1795 /* Currently set only for storvsc channels. */
1796 if (channel->change_target_cpu_callback) {
1797 (*channel->change_target_cpu_callback)(channel,
1798 origin_cpu, target_cpu);
1799 }
1800
1801 cpu_store_unlock:
1802 mutex_unlock(&vmbus_connection.channel_mutex);
1803 cpus_read_unlock();
1804 return ret;
1805 }
1806 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1807
1808 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1809 char *buf)
1810 {
1811 return sprintf(buf, "%d\n",
1812 channel_pending(channel,
1813 vmbus_connection.monitor_pages[1]));
1814 }
1815 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1816
1817 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1818 char *buf)
1819 {
1820 return sprintf(buf, "%d\n",
1821 channel_latency(channel,
1822 vmbus_connection.monitor_pages[1]));
1823 }
1824 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1825
1826 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1827 {
1828 return sprintf(buf, "%llu\n", channel->interrupts);
1829 }
1830 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1831
1832 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1833 {
1834 return sprintf(buf, "%llu\n", channel->sig_events);
1835 }
1836 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1837
1838 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1839 char *buf)
1840 {
1841 return sprintf(buf, "%llu\n",
1842 (unsigned long long)channel->intr_in_full);
1843 }
1844 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1845
1846 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1847 char *buf)
1848 {
1849 return sprintf(buf, "%llu\n",
1850 (unsigned long long)channel->intr_out_empty);
1851 }
1852 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1853
1854 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1855 char *buf)
1856 {
1857 return sprintf(buf, "%llu\n",
1858 (unsigned long long)channel->out_full_first);
1859 }
1860 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1861
1862 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1863 char *buf)
1864 {
1865 return sprintf(buf, "%llu\n",
1866 (unsigned long long)channel->out_full_total);
1867 }
1868 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1869
1870 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1871 char *buf)
1872 {
1873 return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1874 }
1875 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1876
1877 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1878 char *buf)
1879 {
1880 return sprintf(buf, "%u\n",
1881 channel->offermsg.offer.sub_channel_index);
1882 }
1883 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1884
1885 static struct attribute *vmbus_chan_attrs[] = {
1886 &chan_attr_out_mask.attr,
1887 &chan_attr_in_mask.attr,
1888 &chan_attr_read_avail.attr,
1889 &chan_attr_write_avail.attr,
1890 &chan_attr_cpu.attr,
1891 &chan_attr_pending.attr,
1892 &chan_attr_latency.attr,
1893 &chan_attr_interrupts.attr,
1894 &chan_attr_events.attr,
1895 &chan_attr_intr_in_full.attr,
1896 &chan_attr_intr_out_empty.attr,
1897 &chan_attr_out_full_first.attr,
1898 &chan_attr_out_full_total.attr,
1899 &chan_attr_monitor_id.attr,
1900 &chan_attr_subchannel_id.attr,
1901 NULL
1902 };
1903
1904 /*
1905 * Channel-level attribute_group callback function. Returns the permission for
1906 * each attribute, and returns 0 if an attribute is not visible.
1907 */
1908 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1909 struct attribute *attr, int idx)
1910 {
1911 const struct vmbus_channel *channel =
1912 container_of(kobj, struct vmbus_channel, kobj);
1913
1914 /* Hide the monitor attributes if the monitor mechanism is not used. */
1915 if (!channel->offermsg.monitor_allocated &&
1916 (attr == &chan_attr_pending.attr ||
1917 attr == &chan_attr_latency.attr ||
1918 attr == &chan_attr_monitor_id.attr))
1919 return 0;
1920
1921 return attr->mode;
1922 }
1923
1924 static struct attribute_group vmbus_chan_group = {
1925 .attrs = vmbus_chan_attrs,
1926 .is_visible = vmbus_chan_attr_is_visible
1927 };
1928
1929 static struct kobj_type vmbus_chan_ktype = {
1930 .sysfs_ops = &vmbus_chan_sysfs_ops,
1931 .release = vmbus_chan_release,
1932 };
1933
1934 /*
1935 * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1936 */
1937 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1938 {
1939 const struct device *device = &dev->device;
1940 struct kobject *kobj = &channel->kobj;
1941 u32 relid = channel->offermsg.child_relid;
1942 int ret;
1943
1944 kobj->kset = dev->channels_kset;
1945 ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1946 "%u", relid);
1947 if (ret)
1948 return ret;
1949
1950 ret = sysfs_create_group(kobj, &vmbus_chan_group);
1951
1952 if (ret) {
1953 /*
1954 * The calling functions' error handling paths will cleanup the
1955 * empty channel directory.
1956 */
1957 dev_err(device, "Unable to set up channel sysfs files\n");
1958 return ret;
1959 }
1960
1961 kobject_uevent(kobj, KOBJ_ADD);
1962
1963 return 0;
1964 }
1965
1966 /*
1967 * vmbus_remove_channel_attr_group - remove the channel's attribute group
1968 */
1969 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1970 {
1971 sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1972 }
1973
1974 /*
1975 * vmbus_device_create - Creates and registers a new child device
1976 * on the vmbus.
1977 */
1978 struct hv_device *vmbus_device_create(const guid_t *type,
1979 const guid_t *instance,
1980 struct vmbus_channel *channel)
1981 {
1982 struct hv_device *child_device_obj;
1983
1984 child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1985 if (!child_device_obj) {
1986 pr_err("Unable to allocate device object for child device\n");
1987 return NULL;
1988 }
1989
1990 child_device_obj->channel = channel;
1991 guid_copy(&child_device_obj->dev_type, type);
1992 guid_copy(&child_device_obj->dev_instance, instance);
1993 child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1994
1995 return child_device_obj;
1996 }
1997
1998 /*
1999 * vmbus_device_register - Register the child device
2000 */
2001 int vmbus_device_register(struct hv_device *child_device_obj)
2002 {
2003 struct kobject *kobj = &child_device_obj->device.kobj;
2004 int ret;
2005
2006 dev_set_name(&child_device_obj->device, "%pUl",
2007 &child_device_obj->channel->offermsg.offer.if_instance);
2008
2009 child_device_obj->device.bus = &hv_bus;
2010 child_device_obj->device.parent = &hv_acpi_dev->dev;
2011 child_device_obj->device.release = vmbus_device_release;
2012
2013 /*
2014 * Register with the LDM. This will kick off the driver/device
2015 * binding...which will eventually call vmbus_match() and vmbus_probe()
2016 */
2017 ret = device_register(&child_device_obj->device);
2018 if (ret) {
2019 pr_err("Unable to register child device\n");
2020 return ret;
2021 }
2022
2023 child_device_obj->channels_kset = kset_create_and_add("channels",
2024 NULL, kobj);
2025 if (!child_device_obj->channels_kset) {
2026 ret = -ENOMEM;
2027 goto err_dev_unregister;
2028 }
2029
2030 ret = vmbus_add_channel_kobj(child_device_obj,
2031 child_device_obj->channel);
2032 if (ret) {
2033 pr_err("Unable to register primary channeln");
2034 goto err_kset_unregister;
2035 }
2036 hv_debug_add_dev_dir(child_device_obj);
2037
2038 return 0;
2039
2040 err_kset_unregister:
2041 kset_unregister(child_device_obj->channels_kset);
2042
2043 err_dev_unregister:
2044 device_unregister(&child_device_obj->device);
2045 return ret;
2046 }
2047
2048 /*
2049 * vmbus_device_unregister - Remove the specified child device
2050 * from the vmbus.
2051 */
2052 void vmbus_device_unregister(struct hv_device *device_obj)
2053 {
2054 pr_debug("child device %s unregistered\n",
2055 dev_name(&device_obj->device));
2056
2057 kset_unregister(device_obj->channels_kset);
2058
2059 /*
2060 * Kick off the process of unregistering the device.
2061 * This will call vmbus_remove() and eventually vmbus_device_release()
2062 */
2063 device_unregister(&device_obj->device);
2064 }
2065
2066
2067 /*
2068 * VMBUS is an acpi enumerated device. Get the information we
2069 * need from DSDT.
2070 */
2071 #define VTPM_BASE_ADDRESS 0xfed40000
2072 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
2073 {
2074 resource_size_t start = 0;
2075 resource_size_t end = 0;
2076 struct resource *new_res;
2077 struct resource **old_res = &hyperv_mmio;
2078 struct resource **prev_res = NULL;
2079 struct resource r;
2080
2081 switch (res->type) {
2082
2083 /*
2084 * "Address" descriptors are for bus windows. Ignore
2085 * "memory" descriptors, which are for registers on
2086 * devices.
2087 */
2088 case ACPI_RESOURCE_TYPE_ADDRESS32:
2089 start = res->data.address32.address.minimum;
2090 end = res->data.address32.address.maximum;
2091 break;
2092
2093 case ACPI_RESOURCE_TYPE_ADDRESS64:
2094 start = res->data.address64.address.minimum;
2095 end = res->data.address64.address.maximum;
2096 break;
2097
2098 /*
2099 * The IRQ information is needed only on ARM64, which Hyper-V
2100 * sets up in the extended format. IRQ information is present
2101 * on x86/x64 in the non-extended format but it is not used by
2102 * Linux. So don't bother checking for the non-extended format.
2103 */
2104 case ACPI_RESOURCE_TYPE_EXTENDED_IRQ:
2105 if (!acpi_dev_resource_interrupt(res, 0, &r)) {
2106 pr_err("Unable to parse Hyper-V ACPI interrupt\n");
2107 return AE_ERROR;
2108 }
2109 /* ARM64 INTID for VMbus */
2110 vmbus_interrupt = res->data.extended_irq.interrupts[0];
2111 /* Linux IRQ number */
2112 vmbus_irq = r.start;
2113 return AE_OK;
2114
2115 default:
2116 /* Unused resource type */
2117 return AE_OK;
2118
2119 }
2120 /*
2121 * Ignore ranges that are below 1MB, as they're not
2122 * necessary or useful here.
2123 */
2124 if (end < 0x100000)
2125 return AE_OK;
2126
2127 new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2128 if (!new_res)
2129 return AE_NO_MEMORY;
2130
2131 /* If this range overlaps the virtual TPM, truncate it. */
2132 if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2133 end = VTPM_BASE_ADDRESS;
2134
2135 new_res->name = "hyperv mmio";
2136 new_res->flags = IORESOURCE_MEM;
2137 new_res->start = start;
2138 new_res->end = end;
2139
2140 /*
2141 * If two ranges are adjacent, merge them.
2142 */
2143 do {
2144 if (!*old_res) {
2145 *old_res = new_res;
2146 break;
2147 }
2148
2149 if (((*old_res)->end + 1) == new_res->start) {
2150 (*old_res)->end = new_res->end;
2151 kfree(new_res);
2152 break;
2153 }
2154
2155 if ((*old_res)->start == new_res->end + 1) {
2156 (*old_res)->start = new_res->start;
2157 kfree(new_res);
2158 break;
2159 }
2160
2161 if ((*old_res)->start > new_res->end) {
2162 new_res->sibling = *old_res;
2163 if (prev_res)
2164 (*prev_res)->sibling = new_res;
2165 *old_res = new_res;
2166 break;
2167 }
2168
2169 prev_res = old_res;
2170 old_res = &(*old_res)->sibling;
2171
2172 } while (1);
2173
2174 return AE_OK;
2175 }
2176
2177 static int vmbus_acpi_remove(struct acpi_device *device)
2178 {
2179 struct resource *cur_res;
2180 struct resource *next_res;
2181
2182 if (hyperv_mmio) {
2183 if (fb_mmio) {
2184 __release_region(hyperv_mmio, fb_mmio->start,
2185 resource_size(fb_mmio));
2186 fb_mmio = NULL;
2187 }
2188
2189 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2190 next_res = cur_res->sibling;
2191 kfree(cur_res);
2192 }
2193 }
2194
2195 return 0;
2196 }
2197
2198 static void vmbus_reserve_fb(void)
2199 {
2200 int size;
2201 /*
2202 * Make a claim for the frame buffer in the resource tree under the
2203 * first node, which will be the one below 4GB. The length seems to
2204 * be underreported, particularly in a Generation 1 VM. So start out
2205 * reserving a larger area and make it smaller until it succeeds.
2206 */
2207
2208 if (screen_info.lfb_base) {
2209 if (efi_enabled(EFI_BOOT))
2210 size = max_t(__u32, screen_info.lfb_size, 0x800000);
2211 else
2212 size = max_t(__u32, screen_info.lfb_size, 0x4000000);
2213
2214 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
2215 fb_mmio = __request_region(hyperv_mmio,
2216 screen_info.lfb_base, size,
2217 fb_mmio_name, 0);
2218 }
2219 }
2220 }
2221
2222 /**
2223 * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2224 * @new: If successful, supplied a pointer to the
2225 * allocated MMIO space.
2226 * @device_obj: Identifies the caller
2227 * @min: Minimum guest physical address of the
2228 * allocation
2229 * @max: Maximum guest physical address
2230 * @size: Size of the range to be allocated
2231 * @align: Alignment of the range to be allocated
2232 * @fb_overlap_ok: Whether this allocation can be allowed
2233 * to overlap the video frame buffer.
2234 *
2235 * This function walks the resources granted to VMBus by the
2236 * _CRS object in the ACPI namespace underneath the parent
2237 * "bridge" whether that's a root PCI bus in the Generation 1
2238 * case or a Module Device in the Generation 2 case. It then
2239 * attempts to allocate from the global MMIO pool in a way that
2240 * matches the constraints supplied in these parameters and by
2241 * that _CRS.
2242 *
2243 * Return: 0 on success, -errno on failure
2244 */
2245 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2246 resource_size_t min, resource_size_t max,
2247 resource_size_t size, resource_size_t align,
2248 bool fb_overlap_ok)
2249 {
2250 struct resource *iter, *shadow;
2251 resource_size_t range_min, range_max, start;
2252 const char *dev_n = dev_name(&device_obj->device);
2253 int retval;
2254
2255 retval = -ENXIO;
2256 mutex_lock(&hyperv_mmio_lock);
2257
2258 /*
2259 * If overlaps with frame buffers are allowed, then first attempt to
2260 * make the allocation from within the reserved region. Because it
2261 * is already reserved, no shadow allocation is necessary.
2262 */
2263 if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2264 !(max < fb_mmio->start)) {
2265
2266 range_min = fb_mmio->start;
2267 range_max = fb_mmio->end;
2268 start = (range_min + align - 1) & ~(align - 1);
2269 for (; start + size - 1 <= range_max; start += align) {
2270 *new = request_mem_region_exclusive(start, size, dev_n);
2271 if (*new) {
2272 retval = 0;
2273 goto exit;
2274 }
2275 }
2276 }
2277
2278 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2279 if ((iter->start >= max) || (iter->end <= min))
2280 continue;
2281
2282 range_min = iter->start;
2283 range_max = iter->end;
2284 start = (range_min + align - 1) & ~(align - 1);
2285 for (; start + size - 1 <= range_max; start += align) {
2286 shadow = __request_region(iter, start, size, NULL,
2287 IORESOURCE_BUSY);
2288 if (!shadow)
2289 continue;
2290
2291 *new = request_mem_region_exclusive(start, size, dev_n);
2292 if (*new) {
2293 shadow->name = (char *)*new;
2294 retval = 0;
2295 goto exit;
2296 }
2297
2298 __release_region(iter, start, size);
2299 }
2300 }
2301
2302 exit:
2303 mutex_unlock(&hyperv_mmio_lock);
2304 return retval;
2305 }
2306 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2307
2308 /**
2309 * vmbus_free_mmio() - Free a memory-mapped I/O range.
2310 * @start: Base address of region to release.
2311 * @size: Size of the range to be allocated
2312 *
2313 * This function releases anything requested by
2314 * vmbus_mmio_allocate().
2315 */
2316 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2317 {
2318 struct resource *iter;
2319
2320 mutex_lock(&hyperv_mmio_lock);
2321 for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2322 if ((iter->start >= start + size) || (iter->end <= start))
2323 continue;
2324
2325 __release_region(iter, start, size);
2326 }
2327 release_mem_region(start, size);
2328 mutex_unlock(&hyperv_mmio_lock);
2329
2330 }
2331 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2332
2333 static int vmbus_acpi_add(struct acpi_device *device)
2334 {
2335 acpi_status result;
2336 int ret_val = -ENODEV;
2337 struct acpi_device *ancestor;
2338
2339 hv_acpi_dev = device;
2340
2341 result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2342 vmbus_walk_resources, NULL);
2343
2344 if (ACPI_FAILURE(result))
2345 goto acpi_walk_err;
2346 /*
2347 * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2348 * firmware) is the VMOD that has the mmio ranges. Get that.
2349 */
2350 for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2351 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2352 vmbus_walk_resources, NULL);
2353
2354 if (ACPI_FAILURE(result))
2355 continue;
2356 if (hyperv_mmio) {
2357 vmbus_reserve_fb();
2358 break;
2359 }
2360 }
2361 ret_val = 0;
2362
2363 acpi_walk_err:
2364 complete(&probe_event);
2365 if (ret_val)
2366 vmbus_acpi_remove(device);
2367 return ret_val;
2368 }
2369
2370 #ifdef CONFIG_PM_SLEEP
2371 static int vmbus_bus_suspend(struct device *dev)
2372 {
2373 struct vmbus_channel *channel, *sc;
2374
2375 while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2376 /*
2377 * We wait here until the completion of any channel
2378 * offers that are currently in progress.
2379 */
2380 msleep(1);
2381 }
2382
2383 mutex_lock(&vmbus_connection.channel_mutex);
2384 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2385 if (!is_hvsock_channel(channel))
2386 continue;
2387
2388 vmbus_force_channel_rescinded(channel);
2389 }
2390 mutex_unlock(&vmbus_connection.channel_mutex);
2391
2392 /*
2393 * Wait until all the sub-channels and hv_sock channels have been
2394 * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2395 * they would conflict with the new sub-channels that will be created
2396 * in the resume path. hv_sock channels should also be destroyed, but
2397 * a hv_sock channel of an established hv_sock connection can not be
2398 * really destroyed since it may still be referenced by the userspace
2399 * application, so we just force the hv_sock channel to be rescinded
2400 * by vmbus_force_channel_rescinded(), and the userspace application
2401 * will thoroughly destroy the channel after hibernation.
2402 *
2403 * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2404 * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2405 */
2406 if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2407 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2408
2409 if (atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0) {
2410 pr_err("Can not suspend due to a previous failed resuming\n");
2411 return -EBUSY;
2412 }
2413
2414 mutex_lock(&vmbus_connection.channel_mutex);
2415
2416 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2417 /*
2418 * Remove the channel from the array of channels and invalidate
2419 * the channel's relid. Upon resume, vmbus_onoffer() will fix
2420 * up the relid (and other fields, if necessary) and add the
2421 * channel back to the array.
2422 */
2423 vmbus_channel_unmap_relid(channel);
2424 channel->offermsg.child_relid = INVALID_RELID;
2425
2426 if (is_hvsock_channel(channel)) {
2427 if (!channel->rescind) {
2428 pr_err("hv_sock channel not rescinded!\n");
2429 WARN_ON_ONCE(1);
2430 }
2431 continue;
2432 }
2433
2434 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2435 pr_err("Sub-channel not deleted!\n");
2436 WARN_ON_ONCE(1);
2437 }
2438
2439 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2440 }
2441
2442 mutex_unlock(&vmbus_connection.channel_mutex);
2443
2444 vmbus_initiate_unload(false);
2445
2446 /* Reset the event for the next resume. */
2447 reinit_completion(&vmbus_connection.ready_for_resume_event);
2448
2449 return 0;
2450 }
2451
2452 static int vmbus_bus_resume(struct device *dev)
2453 {
2454 struct vmbus_channel_msginfo *msginfo;
2455 size_t msgsize;
2456 int ret;
2457
2458 /*
2459 * We only use the 'vmbus_proto_version', which was in use before
2460 * hibernation, to re-negotiate with the host.
2461 */
2462 if (!vmbus_proto_version) {
2463 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2464 return -EINVAL;
2465 }
2466
2467 msgsize = sizeof(*msginfo) +
2468 sizeof(struct vmbus_channel_initiate_contact);
2469
2470 msginfo = kzalloc(msgsize, GFP_KERNEL);
2471
2472 if (msginfo == NULL)
2473 return -ENOMEM;
2474
2475 ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2476
2477 kfree(msginfo);
2478
2479 if (ret != 0)
2480 return ret;
2481
2482 WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2483
2484 vmbus_request_offers();
2485
2486 if (wait_for_completion_timeout(
2487 &vmbus_connection.ready_for_resume_event, 10 * HZ) == 0)
2488 pr_err("Some vmbus device is missing after suspending?\n");
2489
2490 /* Reset the event for the next suspend. */
2491 reinit_completion(&vmbus_connection.ready_for_suspend_event);
2492
2493 return 0;
2494 }
2495 #else
2496 #define vmbus_bus_suspend NULL
2497 #define vmbus_bus_resume NULL
2498 #endif /* CONFIG_PM_SLEEP */
2499
2500 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2501 {"VMBUS", 0},
2502 {"VMBus", 0},
2503 {"", 0},
2504 };
2505 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2506
2507 /*
2508 * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2509 * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2510 * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2511 * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2512 * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2513 * resume callback must also run via the "noirq" ops.
2514 *
2515 * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2516 * earlier in this file before vmbus_pm.
2517 */
2518
2519 static const struct dev_pm_ops vmbus_bus_pm = {
2520 .suspend_noirq = NULL,
2521 .resume_noirq = NULL,
2522 .freeze_noirq = vmbus_bus_suspend,
2523 .thaw_noirq = vmbus_bus_resume,
2524 .poweroff_noirq = vmbus_bus_suspend,
2525 .restore_noirq = vmbus_bus_resume
2526 };
2527
2528 static struct acpi_driver vmbus_acpi_driver = {
2529 .name = "vmbus",
2530 .ids = vmbus_acpi_device_ids,
2531 .ops = {
2532 .add = vmbus_acpi_add,
2533 .remove = vmbus_acpi_remove,
2534 },
2535 .drv.pm = &vmbus_bus_pm,
2536 };
2537
2538 static void hv_kexec_handler(void)
2539 {
2540 hv_stimer_global_cleanup();
2541 vmbus_initiate_unload(false);
2542 /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2543 mb();
2544 cpuhp_remove_state(hyperv_cpuhp_online);
2545 hyperv_cleanup();
2546 };
2547
2548 static void hv_crash_handler(struct pt_regs *regs)
2549 {
2550 int cpu;
2551
2552 vmbus_initiate_unload(true);
2553 /*
2554 * In crash handler we can't schedule synic cleanup for all CPUs,
2555 * doing the cleanup for current CPU only. This should be sufficient
2556 * for kdump.
2557 */
2558 cpu = smp_processor_id();
2559 hv_stimer_cleanup(cpu);
2560 hv_synic_disable_regs(cpu);
2561 hyperv_cleanup();
2562 };
2563
2564 static int hv_synic_suspend(void)
2565 {
2566 /*
2567 * When we reach here, all the non-boot CPUs have been offlined.
2568 * If we're in a legacy configuration where stimer Direct Mode is
2569 * not enabled, the stimers on the non-boot CPUs have been unbound
2570 * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2571 * hv_stimer_cleanup() -> clockevents_unbind_device().
2572 *
2573 * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2574 * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2575 * 1) it's unnecessary as interrupts remain disabled between
2576 * syscore_suspend() and syscore_resume(): see create_image() and
2577 * resume_target_kernel()
2578 * 2) the stimer on CPU0 is automatically disabled later by
2579 * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2580 * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2581 * 3) a warning would be triggered if we call
2582 * clockevents_unbind_device(), which may sleep, in an
2583 * interrupts-disabled context.
2584 */
2585
2586 hv_synic_disable_regs(0);
2587
2588 return 0;
2589 }
2590
2591 static void hv_synic_resume(void)
2592 {
2593 hv_synic_enable_regs(0);
2594
2595 /*
2596 * Note: we don't need to call hv_stimer_init(0), because the timer
2597 * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2598 * automatically re-enabled in timekeeping_resume().
2599 */
2600 }
2601
2602 /* The callbacks run only on CPU0, with irqs_disabled. */
2603 static struct syscore_ops hv_synic_syscore_ops = {
2604 .suspend = hv_synic_suspend,
2605 .resume = hv_synic_resume,
2606 };
2607
2608 static int __init hv_acpi_init(void)
2609 {
2610 int ret, t;
2611
2612 if (!hv_is_hyperv_initialized())
2613 return -ENODEV;
2614
2615 init_completion(&probe_event);
2616
2617 /*
2618 * Get ACPI resources first.
2619 */
2620 ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2621
2622 if (ret)
2623 return ret;
2624
2625 t = wait_for_completion_timeout(&probe_event, 5*HZ);
2626 if (t == 0) {
2627 ret = -ETIMEDOUT;
2628 goto cleanup;
2629 }
2630 hv_debug_init();
2631
2632 ret = vmbus_bus_init();
2633 if (ret)
2634 goto cleanup;
2635
2636 hv_setup_kexec_handler(hv_kexec_handler);
2637 hv_setup_crash_handler(hv_crash_handler);
2638
2639 register_syscore_ops(&hv_synic_syscore_ops);
2640
2641 return 0;
2642
2643 cleanup:
2644 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2645 hv_acpi_dev = NULL;
2646 return ret;
2647 }
2648
2649 static void __exit vmbus_exit(void)
2650 {
2651 int cpu;
2652
2653 unregister_syscore_ops(&hv_synic_syscore_ops);
2654
2655 hv_remove_kexec_handler();
2656 hv_remove_crash_handler();
2657 vmbus_connection.conn_state = DISCONNECTED;
2658 hv_stimer_global_cleanup();
2659 vmbus_disconnect();
2660 hv_remove_vmbus_irq();
2661 for_each_online_cpu(cpu) {
2662 struct hv_per_cpu_context *hv_cpu
2663 = per_cpu_ptr(hv_context.cpu_context, cpu);
2664
2665 tasklet_kill(&hv_cpu->msg_dpc);
2666 }
2667 hv_debug_rm_all_dir();
2668
2669 vmbus_free_channels();
2670 kfree(vmbus_connection.channels);
2671
2672 if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2673 kmsg_dump_unregister(&hv_kmsg_dumper);
2674 unregister_die_notifier(&hyperv_die_block);
2675 atomic_notifier_chain_unregister(&panic_notifier_list,
2676 &hyperv_panic_block);
2677 }
2678
2679 free_page((unsigned long)hv_panic_page);
2680 unregister_sysctl_table(hv_ctl_table_hdr);
2681 hv_ctl_table_hdr = NULL;
2682 bus_unregister(&hv_bus);
2683
2684 cpuhp_remove_state(hyperv_cpuhp_online);
2685 hv_synic_free();
2686 acpi_bus_unregister_driver(&vmbus_acpi_driver);
2687 }
2688
2689
2690 MODULE_LICENSE("GPL");
2691 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2692
2693 subsys_initcall(hv_acpi_init);
2694 module_exit(vmbus_exit);
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