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 <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/kernel.h>
  35 #include <linux/syscore_ops.h>
  36 #include <clocksource/hyperv_timer.h>
  37 #include "hyperv_vmbus.h"
  38
  39 struct vmbus_dynid {
  40         struct list_head node;
  41         struct hv_vmbus_device_id id;
  42 };
  43
  44 static struct acpi_device  *hv_acpi_dev;
  45
  46 static struct completion probe_event;
  47
  48 static int hyperv_cpuhp_online;
  49
  50 static void *hv_panic_page;
  51
  52 /*
  53  * Boolean to control whether to report panic messages over Hyper-V.
  54  *
  55  * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
  56  */
  57 static int sysctl_record_panic_msg = 1;
  58
  59 static int hyperv_report_reg(void)
  60 {
  61         return !sysctl_record_panic_msg || !hv_panic_page;
  62 }
  63
  64 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  65                               void *args)
  66 {
  67         struct pt_regs *regs;
  68
  69         vmbus_initiate_unload(true);
  70
  71         /*
  72          * Hyper-V should be notified only once about a panic.  If we will be
  73          * doing hyperv_report_panic_msg() later with kmsg data, don't do
  74          * the notification here.
  75          */
  76         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE
  77             && hyperv_report_reg()) {
  78                 regs = current_pt_regs();
  79                 hyperv_report_panic(regs, val, false);
  80         }
  81         return NOTIFY_DONE;
  82 }
  83
  84 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  85                             void *args)
  86 {
  87         struct die_args *die = (struct die_args *)args;
  88         struct pt_regs *regs = die->regs;
  89
  90         /*
  91          * Hyper-V should be notified only once about a panic.  If we will be
  92          * doing hyperv_report_panic_msg() later with kmsg data, don't do
  93          * the notification here.
  94          */
  95         if (hyperv_report_reg())
  96                 hyperv_report_panic(regs, val, true);
  97         return NOTIFY_DONE;
  98 }
  99
 100 static struct notifier_block hyperv_die_block = {
 101         .notifier_call = hyperv_die_event,
 102 };
 103 static struct notifier_block hyperv_panic_block = {
 104         .notifier_call = hyperv_panic_event,
 105 };
 106
 107 static const char *fb_mmio_name = "fb_range";
 108 static struct resource *fb_mmio;
 109 static struct resource *hyperv_mmio;
 110 static DEFINE_MUTEX(hyperv_mmio_lock);
 111
 112 static int vmbus_exists(void)
 113 {
 114         if (hv_acpi_dev == NULL)
 115                 return -ENODEV;
 116
 117         return 0;
 118 }
 119
 120 static u8 channel_monitor_group(const struct vmbus_channel *channel)
 121 {
 122         return (u8)channel->offermsg.monitorid / 32;
 123 }
 124
 125 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
 126 {
 127         return (u8)channel->offermsg.monitorid % 32;
 128 }
 129
 130 static u32 channel_pending(const struct vmbus_channel *channel,
 131                            const struct hv_monitor_page *monitor_page)
 132 {
 133         u8 monitor_group = channel_monitor_group(channel);
 134
 135         return monitor_page->trigger_group[monitor_group].pending;
 136 }
 137
 138 static u32 channel_latency(const struct vmbus_channel *channel,
 139                            const struct hv_monitor_page *monitor_page)
 140 {
 141         u8 monitor_group = channel_monitor_group(channel);
 142         u8 monitor_offset = channel_monitor_offset(channel);
 143
 144         return monitor_page->latency[monitor_group][monitor_offset];
 145 }
 146
 147 static u32 channel_conn_id(struct vmbus_channel *channel,
 148                            struct hv_monitor_page *monitor_page)
 149 {
 150         u8 monitor_group = channel_monitor_group(channel);
 151         u8 monitor_offset = channel_monitor_offset(channel);
 152         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 153 }
 154
 155 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 156                        char *buf)
 157 {
 158         struct hv_device *hv_dev = device_to_hv_device(dev);
 159
 160         if (!hv_dev->channel)
 161                 return -ENODEV;
 162         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 163 }
 164 static DEVICE_ATTR_RO(id);
 165
 166 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 167                           char *buf)
 168 {
 169         struct hv_device *hv_dev = device_to_hv_device(dev);
 170
 171         if (!hv_dev->channel)
 172                 return -ENODEV;
 173         return sprintf(buf, "%d\n", hv_dev->channel->state);
 174 }
 175 static DEVICE_ATTR_RO(state);
 176
 177 static ssize_t monitor_id_show(struct device *dev,
 178                                struct device_attribute *dev_attr, char *buf)
 179 {
 180         struct hv_device *hv_dev = device_to_hv_device(dev);
 181
 182         if (!hv_dev->channel)
 183                 return -ENODEV;
 184         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 185 }
 186 static DEVICE_ATTR_RO(monitor_id);
 187
 188 static ssize_t class_id_show(struct device *dev,
 189                                struct device_attribute *dev_attr, char *buf)
 190 {
 191         struct hv_device *hv_dev = device_to_hv_device(dev);
 192
 193         if (!hv_dev->channel)
 194                 return -ENODEV;
 195         return sprintf(buf, "{%pUl}\n",
 196                        &hv_dev->channel->offermsg.offer.if_type);
 197 }
 198 static DEVICE_ATTR_RO(class_id);
 199
 200 static ssize_t device_id_show(struct device *dev,
 201                               struct device_attribute *dev_attr, char *buf)
 202 {
 203         struct hv_device *hv_dev = device_to_hv_device(dev);
 204
 205         if (!hv_dev->channel)
 206                 return -ENODEV;
 207         return sprintf(buf, "{%pUl}\n",
 208                        &hv_dev->channel->offermsg.offer.if_instance);
 209 }
 210 static DEVICE_ATTR_RO(device_id);
 211
 212 static ssize_t modalias_show(struct device *dev,
 213                              struct device_attribute *dev_attr, char *buf)
 214 {
 215         struct hv_device *hv_dev = device_to_hv_device(dev);
 216
 217         return sprintf(buf, "vmbus:%*phN\n", UUID_SIZE, &hv_dev->dev_type);
 218 }
 219 static DEVICE_ATTR_RO(modalias);
 220
 221 #ifdef CONFIG_NUMA
 222 static ssize_t numa_node_show(struct device *dev,
 223                               struct device_attribute *attr, char *buf)
 224 {
 225         struct hv_device *hv_dev = device_to_hv_device(dev);
 226
 227         if (!hv_dev->channel)
 228                 return -ENODEV;
 229
 230         return sprintf(buf, "%d\n", hv_dev->channel->numa_node);
 231 }
 232 static DEVICE_ATTR_RO(numa_node);
 233 #endif
 234
 235 static ssize_t server_monitor_pending_show(struct device *dev,
 236                                            struct device_attribute *dev_attr,
 237                                            char *buf)
 238 {
 239         struct hv_device *hv_dev = device_to_hv_device(dev);
 240
 241         if (!hv_dev->channel)
 242                 return -ENODEV;
 243         return sprintf(buf, "%d\n",
 244                        channel_pending(hv_dev->channel,
 245                                        vmbus_connection.monitor_pages[0]));
 246 }
 247 static DEVICE_ATTR_RO(server_monitor_pending);
 248
 249 static ssize_t client_monitor_pending_show(struct device *dev,
 250                                            struct device_attribute *dev_attr,
 251                                            char *buf)
 252 {
 253         struct hv_device *hv_dev = device_to_hv_device(dev);
 254
 255         if (!hv_dev->channel)
 256                 return -ENODEV;
 257         return sprintf(buf, "%d\n",
 258                        channel_pending(hv_dev->channel,
 259                                        vmbus_connection.monitor_pages[1]));
 260 }
 261 static DEVICE_ATTR_RO(client_monitor_pending);
 262
 263 static ssize_t server_monitor_latency_show(struct device *dev,
 264                                            struct device_attribute *dev_attr,
 265                                            char *buf)
 266 {
 267         struct hv_device *hv_dev = device_to_hv_device(dev);
 268
 269         if (!hv_dev->channel)
 270                 return -ENODEV;
 271         return sprintf(buf, "%d\n",
 272                        channel_latency(hv_dev->channel,
 273                                        vmbus_connection.monitor_pages[0]));
 274 }
 275 static DEVICE_ATTR_RO(server_monitor_latency);
 276
 277 static ssize_t client_monitor_latency_show(struct device *dev,
 278                                            struct device_attribute *dev_attr,
 279                                            char *buf)
 280 {
 281         struct hv_device *hv_dev = device_to_hv_device(dev);
 282
 283         if (!hv_dev->channel)
 284                 return -ENODEV;
 285         return sprintf(buf, "%d\n",
 286                        channel_latency(hv_dev->channel,
 287                                        vmbus_connection.monitor_pages[1]));
 288 }
 289 static DEVICE_ATTR_RO(client_monitor_latency);
 290
 291 static ssize_t server_monitor_conn_id_show(struct device *dev,
 292                                            struct device_attribute *dev_attr,
 293                                            char *buf)
 294 {
 295         struct hv_device *hv_dev = device_to_hv_device(dev);
 296
 297         if (!hv_dev->channel)
 298                 return -ENODEV;
 299         return sprintf(buf, "%d\n",
 300                        channel_conn_id(hv_dev->channel,
 301                                        vmbus_connection.monitor_pages[0]));
 302 }
 303 static DEVICE_ATTR_RO(server_monitor_conn_id);
 304
 305 static ssize_t client_monitor_conn_id_show(struct device *dev,
 306                                            struct device_attribute *dev_attr,
 307                                            char *buf)
 308 {
 309         struct hv_device *hv_dev = device_to_hv_device(dev);
 310
 311         if (!hv_dev->channel)
 312                 return -ENODEV;
 313         return sprintf(buf, "%d\n",
 314                        channel_conn_id(hv_dev->channel,
 315                                        vmbus_connection.monitor_pages[1]));
 316 }
 317 static DEVICE_ATTR_RO(client_monitor_conn_id);
 318
 319 static ssize_t out_intr_mask_show(struct device *dev,
 320                                   struct device_attribute *dev_attr, char *buf)
 321 {
 322         struct hv_device *hv_dev = device_to_hv_device(dev);
 323         struct hv_ring_buffer_debug_info outbound;
 324         int ret;
 325
 326         if (!hv_dev->channel)
 327                 return -ENODEV;
 328
 329         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 330                                           &outbound);
 331         if (ret < 0)
 332                 return ret;
 333
 334         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 335 }
 336 static DEVICE_ATTR_RO(out_intr_mask);
 337
 338 static ssize_t out_read_index_show(struct device *dev,
 339                                    struct device_attribute *dev_attr, char *buf)
 340 {
 341         struct hv_device *hv_dev = device_to_hv_device(dev);
 342         struct hv_ring_buffer_debug_info outbound;
 343         int ret;
 344
 345         if (!hv_dev->channel)
 346                 return -ENODEV;
 347
 348         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 349                                           &outbound);
 350         if (ret < 0)
 351                 return ret;
 352         return sprintf(buf, "%d\n", outbound.current_read_index);
 353 }
 354 static DEVICE_ATTR_RO(out_read_index);
 355
 356 static ssize_t out_write_index_show(struct device *dev,
 357                                     struct device_attribute *dev_attr,
 358                                     char *buf)
 359 {
 360         struct hv_device *hv_dev = device_to_hv_device(dev);
 361         struct hv_ring_buffer_debug_info outbound;
 362         int ret;
 363
 364         if (!hv_dev->channel)
 365                 return -ENODEV;
 366
 367         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 368                                           &outbound);
 369         if (ret < 0)
 370                 return ret;
 371         return sprintf(buf, "%d\n", outbound.current_write_index);
 372 }
 373 static DEVICE_ATTR_RO(out_write_index);
 374
 375 static ssize_t out_read_bytes_avail_show(struct device *dev,
 376                                          struct device_attribute *dev_attr,
 377                                          char *buf)
 378 {
 379         struct hv_device *hv_dev = device_to_hv_device(dev);
 380         struct hv_ring_buffer_debug_info outbound;
 381         int ret;
 382
 383         if (!hv_dev->channel)
 384                 return -ENODEV;
 385
 386         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 387                                           &outbound);
 388         if (ret < 0)
 389                 return ret;
 390         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 391 }
 392 static DEVICE_ATTR_RO(out_read_bytes_avail);
 393
 394 static ssize_t out_write_bytes_avail_show(struct device *dev,
 395                                           struct device_attribute *dev_attr,
 396                                           char *buf)
 397 {
 398         struct hv_device *hv_dev = device_to_hv_device(dev);
 399         struct hv_ring_buffer_debug_info outbound;
 400         int ret;
 401
 402         if (!hv_dev->channel)
 403                 return -ENODEV;
 404
 405         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 406                                           &outbound);
 407         if (ret < 0)
 408                 return ret;
 409         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 410 }
 411 static DEVICE_ATTR_RO(out_write_bytes_avail);
 412
 413 static ssize_t in_intr_mask_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_interrupt_mask);
 428 }
 429 static DEVICE_ATTR_RO(in_intr_mask);
 430
 431 static ssize_t in_read_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_read_index);
 446 }
 447 static DEVICE_ATTR_RO(in_read_index);
 448
 449 static ssize_t in_write_index_show(struct device *dev,
 450                                    struct device_attribute *dev_attr, char *buf)
 451 {
 452         struct hv_device *hv_dev = device_to_hv_device(dev);
 453         struct hv_ring_buffer_debug_info inbound;
 454         int ret;
 455
 456         if (!hv_dev->channel)
 457                 return -ENODEV;
 458
 459         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 460         if (ret < 0)
 461                 return ret;
 462
 463         return sprintf(buf, "%d\n", inbound.current_write_index);
 464 }
 465 static DEVICE_ATTR_RO(in_write_index);
 466
 467 static ssize_t in_read_bytes_avail_show(struct device *dev,
 468                                         struct device_attribute *dev_attr,
 469                                         char *buf)
 470 {
 471         struct hv_device *hv_dev = device_to_hv_device(dev);
 472         struct hv_ring_buffer_debug_info inbound;
 473         int ret;
 474
 475         if (!hv_dev->channel)
 476                 return -ENODEV;
 477
 478         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 479         if (ret < 0)
 480                 return ret;
 481
 482         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 483 }
 484 static DEVICE_ATTR_RO(in_read_bytes_avail);
 485
 486 static ssize_t in_write_bytes_avail_show(struct device *dev,
 487                                          struct device_attribute *dev_attr,
 488                                          char *buf)
 489 {
 490         struct hv_device *hv_dev = device_to_hv_device(dev);
 491         struct hv_ring_buffer_debug_info inbound;
 492         int ret;
 493
 494         if (!hv_dev->channel)
 495                 return -ENODEV;
 496
 497         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 498         if (ret < 0)
 499                 return ret;
 500
 501         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 502 }
 503 static DEVICE_ATTR_RO(in_write_bytes_avail);
 504
 505 static ssize_t channel_vp_mapping_show(struct device *dev,
 506                                        struct device_attribute *dev_attr,
 507                                        char *buf)
 508 {
 509         struct hv_device *hv_dev = device_to_hv_device(dev);
 510         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 511         unsigned long flags;
 512         int buf_size = PAGE_SIZE, n_written, tot_written;
 513         struct list_head *cur;
 514
 515         if (!channel)
 516                 return -ENODEV;
 517
 518         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 519                 channel->offermsg.child_relid, channel->target_cpu);
 520
 521         spin_lock_irqsave(&channel->lock, flags);
 522
 523         list_for_each(cur, &channel->sc_list) {
 524                 if (tot_written >= buf_size - 1)
 525                         break;
 526
 527                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 528                 n_written = scnprintf(buf + tot_written,
 529                                      buf_size - tot_written,
 530                                      "%u:%u\n",
 531                                      cur_sc->offermsg.child_relid,
 532                                      cur_sc->target_cpu);
 533                 tot_written += n_written;
 534         }
 535
 536         spin_unlock_irqrestore(&channel->lock, flags);
 537
 538         return tot_written;
 539 }
 540 static DEVICE_ATTR_RO(channel_vp_mapping);
 541
 542 static ssize_t vendor_show(struct device *dev,
 543                            struct device_attribute *dev_attr,
 544                            char *buf)
 545 {
 546         struct hv_device *hv_dev = device_to_hv_device(dev);
 547         return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
 548 }
 549 static DEVICE_ATTR_RO(vendor);
 550
 551 static ssize_t device_show(struct device *dev,
 552                            struct device_attribute *dev_attr,
 553                            char *buf)
 554 {
 555         struct hv_device *hv_dev = device_to_hv_device(dev);
 556         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 557 }
 558 static DEVICE_ATTR_RO(device);
 559
 560 static ssize_t driver_override_store(struct device *dev,
 561                                      struct device_attribute *attr,
 562                                      const char *buf, size_t count)
 563 {
 564         struct hv_device *hv_dev = device_to_hv_device(dev);
 565         char *driver_override, *old, *cp;
 566
 567         /* We need to keep extra room for a newline */
 568         if (count >= (PAGE_SIZE - 1))
 569                 return -EINVAL;
 570
 571         driver_override = kstrndup(buf, count, GFP_KERNEL);
 572         if (!driver_override)
 573                 return -ENOMEM;
 574
 575         cp = strchr(driver_override, '\n');
 576         if (cp)
 577                 *cp = '\0';
 578
 579         device_lock(dev);
 580         old = hv_dev->driver_override;
 581         if (strlen(driver_override)) {
 582                 hv_dev->driver_override = driver_override;
 583         } else {
 584                 kfree(driver_override);
 585                 hv_dev->driver_override = NULL;
 586         }
 587         device_unlock(dev);
 588
 589         kfree(old);
 590
 591         return count;
 592 }
 593
 594 static ssize_t driver_override_show(struct device *dev,
 595                                     struct device_attribute *attr, char *buf)
 596 {
 597         struct hv_device *hv_dev = device_to_hv_device(dev);
 598         ssize_t len;
 599
 600         device_lock(dev);
 601         len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
 602         device_unlock(dev);
 603
 604         return len;
 605 }
 606 static DEVICE_ATTR_RW(driver_override);
 607
 608 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 609 static struct attribute *vmbus_dev_attrs[] = {
 610         &dev_attr_id.attr,
 611         &dev_attr_state.attr,
 612         &dev_attr_monitor_id.attr,
 613         &dev_attr_class_id.attr,
 614         &dev_attr_device_id.attr,
 615         &dev_attr_modalias.attr,
 616 #ifdef CONFIG_NUMA
 617         &dev_attr_numa_node.attr,
 618 #endif
 619         &dev_attr_server_monitor_pending.attr,
 620         &dev_attr_client_monitor_pending.attr,
 621         &dev_attr_server_monitor_latency.attr,
 622         &dev_attr_client_monitor_latency.attr,
 623         &dev_attr_server_monitor_conn_id.attr,
 624         &dev_attr_client_monitor_conn_id.attr,
 625         &dev_attr_out_intr_mask.attr,
 626         &dev_attr_out_read_index.attr,
 627         &dev_attr_out_write_index.attr,
 628         &dev_attr_out_read_bytes_avail.attr,
 629         &dev_attr_out_write_bytes_avail.attr,
 630         &dev_attr_in_intr_mask.attr,
 631         &dev_attr_in_read_index.attr,
 632         &dev_attr_in_write_index.attr,
 633         &dev_attr_in_read_bytes_avail.attr,
 634         &dev_attr_in_write_bytes_avail.attr,
 635         &dev_attr_channel_vp_mapping.attr,
 636         &dev_attr_vendor.attr,
 637         &dev_attr_device.attr,
 638         &dev_attr_driver_override.attr,
 639         NULL,
 640 };
 641
 642 /*
 643  * Device-level attribute_group callback function. Returns the permission for
 644  * each attribute, and returns 0 if an attribute is not visible.
 645  */
 646 static umode_t vmbus_dev_attr_is_visible(struct kobject *kobj,
 647                                          struct attribute *attr, int idx)
 648 {
 649         struct device *dev = kobj_to_dev(kobj);
 650         const struct hv_device *hv_dev = device_to_hv_device(dev);
 651
 652         /* Hide the monitor attributes if the monitor mechanism is not used. */
 653         if (!hv_dev->channel->offermsg.monitor_allocated &&
 654             (attr == &dev_attr_monitor_id.attr ||
 655              attr == &dev_attr_server_monitor_pending.attr ||
 656              attr == &dev_attr_client_monitor_pending.attr ||
 657              attr == &dev_attr_server_monitor_latency.attr ||
 658              attr == &dev_attr_client_monitor_latency.attr ||
 659              attr == &dev_attr_server_monitor_conn_id.attr ||
 660              attr == &dev_attr_client_monitor_conn_id.attr))
 661                 return 0;
 662
 663         return attr->mode;
 664 }
 665
 666 static const struct attribute_group vmbus_dev_group = {
 667         .attrs = vmbus_dev_attrs,
 668         .is_visible = vmbus_dev_attr_is_visible
 669 };
 670 __ATTRIBUTE_GROUPS(vmbus_dev);
 671
 672 /*
 673  * vmbus_uevent - add uevent for our device
 674  *
 675  * This routine is invoked when a device is added or removed on the vmbus to
 676  * generate a uevent to udev in the userspace. The udev will then look at its
 677  * rule and the uevent generated here to load the appropriate driver
 678  *
 679  * The alias string will be of the form vmbus:guid where guid is the string
 680  * representation of the device guid (each byte of the guid will be
 681  * represented with two hex characters.
 682  */
 683 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 684 {
 685         struct hv_device *dev = device_to_hv_device(device);
 686         const char *format = "MODALIAS=vmbus:%*phN";
 687
 688         return add_uevent_var(env, format, UUID_SIZE, &dev->dev_type);
 689 }
 690
 691 static const struct hv_vmbus_device_id *
 692 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
 693 {
 694         if (id == NULL)
 695                 return NULL; /* empty device table */
 696
 697         for (; !guid_is_null(&id->guid); id++)
 698                 if (guid_equal(&id->guid, guid))
 699                         return id;
 700
 701         return NULL;
 702 }
 703
 704 static const struct hv_vmbus_device_id *
 705 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
 706 {
 707         const struct hv_vmbus_device_id *id = NULL;
 708         struct vmbus_dynid *dynid;
 709
 710         spin_lock(&drv->dynids.lock);
 711         list_for_each_entry(dynid, &drv->dynids.list, node) {
 712                 if (guid_equal(&dynid->id.guid, guid)) {
 713                         id = &dynid->id;
 714                         break;
 715                 }
 716         }
 717         spin_unlock(&drv->dynids.lock);
 718
 719         return id;
 720 }
 721
 722 static const struct hv_vmbus_device_id vmbus_device_null;
 723
 724 /*
 725  * Return a matching hv_vmbus_device_id pointer.
 726  * If there is no match, return NULL.
 727  */
 728 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 729                                                         struct hv_device *dev)
 730 {
 731         const guid_t *guid = &dev->dev_type;
 732         const struct hv_vmbus_device_id *id;
 733
 734         /* When driver_override is set, only bind to the matching driver */
 735         if (dev->driver_override && strcmp(dev->driver_override, drv->name))
 736                 return NULL;
 737
 738         /* Look at the dynamic ids first, before the static ones */
 739         id = hv_vmbus_dynid_match(drv, guid);
 740         if (!id)
 741                 id = hv_vmbus_dev_match(drv->id_table, guid);
 742
 743         /* driver_override will always match, send a dummy id */
 744         if (!id && dev->driver_override)
 745                 id = &vmbus_device_null;
 746
 747         return id;
 748 }
 749
 750 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
 751 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
 752 {
 753         struct vmbus_dynid *dynid;
 754
 755         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
 756         if (!dynid)
 757                 return -ENOMEM;
 758
 759         dynid->id.guid = *guid;
 760
 761         spin_lock(&drv->dynids.lock);
 762         list_add_tail(&dynid->node, &drv->dynids.list);
 763         spin_unlock(&drv->dynids.lock);
 764
 765         return driver_attach(&drv->driver);
 766 }
 767
 768 static void vmbus_free_dynids(struct hv_driver *drv)
 769 {
 770         struct vmbus_dynid *dynid, *n;
 771
 772         spin_lock(&drv->dynids.lock);
 773         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 774                 list_del(&dynid->node);
 775                 kfree(dynid);
 776         }
 777         spin_unlock(&drv->dynids.lock);
 778 }
 779
 780 /*
 781  * store_new_id - sysfs frontend to vmbus_add_dynid()
 782  *
 783  * Allow GUIDs to be added to an existing driver via sysfs.
 784  */
 785 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
 786                             size_t count)
 787 {
 788         struct hv_driver *drv = drv_to_hv_drv(driver);
 789         guid_t guid;
 790         ssize_t retval;
 791
 792         retval = guid_parse(buf, &guid);
 793         if (retval)
 794                 return retval;
 795
 796         if (hv_vmbus_dynid_match(drv, &guid))
 797                 return -EEXIST;
 798
 799         retval = vmbus_add_dynid(drv, &guid);
 800         if (retval)
 801                 return retval;
 802         return count;
 803 }
 804 static DRIVER_ATTR_WO(new_id);
 805
 806 /*
 807  * store_remove_id - remove a PCI device ID from this driver
 808  *
 809  * Removes a dynamic pci device ID to this driver.
 810  */
 811 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 812                                size_t count)
 813 {
 814         struct hv_driver *drv = drv_to_hv_drv(driver);
 815         struct vmbus_dynid *dynid, *n;
 816         guid_t guid;
 817         ssize_t retval;
 818
 819         retval = guid_parse(buf, &guid);
 820         if (retval)
 821                 return retval;
 822
 823         retval = -ENODEV;
 824         spin_lock(&drv->dynids.lock);
 825         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 826                 struct hv_vmbus_device_id *id = &dynid->id;
 827
 828                 if (guid_equal(&id->guid, &guid)) {
 829                         list_del(&dynid->node);
 830                         kfree(dynid);
 831                         retval = count;
 832                         break;
 833                 }
 834         }
 835         spin_unlock(&drv->dynids.lock);
 836
 837         return retval;
 838 }
 839 static DRIVER_ATTR_WO(remove_id);
 840
 841 static struct attribute *vmbus_drv_attrs[] = {
 842         &driver_attr_new_id.attr,
 843         &driver_attr_remove_id.attr,
 844         NULL,
 845 };
 846 ATTRIBUTE_GROUPS(vmbus_drv);
 847
 848
 849 /*
 850  * vmbus_match - Attempt to match the specified device to the specified driver
 851  */
 852 static int vmbus_match(struct device *device, struct device_driver *driver)
 853 {
 854         struct hv_driver *drv = drv_to_hv_drv(driver);
 855         struct hv_device *hv_dev = device_to_hv_device(device);
 856
 857         /* The hv_sock driver handles all hv_sock offers. */
 858         if (is_hvsock_channel(hv_dev->channel))
 859                 return drv->hvsock;
 860
 861         if (hv_vmbus_get_id(drv, hv_dev))
 862                 return 1;
 863
 864         return 0;
 865 }
 866
 867 /*
 868  * vmbus_probe - Add the new vmbus's child device
 869  */
 870 static int vmbus_probe(struct device *child_device)
 871 {
 872         int ret = 0;
 873         struct hv_driver *drv =
 874                         drv_to_hv_drv(child_device->driver);
 875         struct hv_device *dev = device_to_hv_device(child_device);
 876         const struct hv_vmbus_device_id *dev_id;
 877
 878         dev_id = hv_vmbus_get_id(drv, dev);
 879         if (drv->probe) {
 880                 ret = drv->probe(dev, dev_id);
 881                 if (ret != 0)
 882                         pr_err("probe failed for device %s (%d)\n",
 883                                dev_name(child_device), ret);
 884
 885         } else {
 886                 pr_err("probe not set for driver %s\n",
 887                        dev_name(child_device));
 888                 ret = -ENODEV;
 889         }
 890         return ret;
 891 }
 892
 893 /*
 894  * vmbus_remove - Remove a vmbus device
 895  */
 896 static int vmbus_remove(struct device *child_device)
 897 {
 898         struct hv_driver *drv;
 899         struct hv_device *dev = device_to_hv_device(child_device);
 900
 901         if (child_device->driver) {
 902                 drv = drv_to_hv_drv(child_device->driver);
 903                 if (drv->remove)
 904                         drv->remove(dev);
 905         }
 906
 907         return 0;
 908 }
 909
 910
 911 /*
 912  * vmbus_shutdown - Shutdown a vmbus device
 913  */
 914 static void vmbus_shutdown(struct device *child_device)
 915 {
 916         struct hv_driver *drv;
 917         struct hv_device *dev = device_to_hv_device(child_device);
 918
 919
 920         /* The device may not be attached yet */
 921         if (!child_device->driver)
 922                 return;
 923
 924         drv = drv_to_hv_drv(child_device->driver);
 925
 926         if (drv->shutdown)
 927                 drv->shutdown(dev);
 928 }
 929
 930 #ifdef CONFIG_PM_SLEEP
 931 /*
 932  * vmbus_suspend - Suspend a vmbus device
 933  */
 934 static int vmbus_suspend(struct device *child_device)
 935 {
 936         struct hv_driver *drv;
 937         struct hv_device *dev = device_to_hv_device(child_device);
 938
 939         /* The device may not be attached yet */
 940         if (!child_device->driver)
 941                 return 0;
 942
 943         drv = drv_to_hv_drv(child_device->driver);
 944         if (!drv->suspend)
 945                 return -EOPNOTSUPP;
 946
 947         return drv->suspend(dev);
 948 }
 949
 950 /*
 951  * vmbus_resume - Resume a vmbus device
 952  */
 953 static int vmbus_resume(struct device *child_device)
 954 {
 955         struct hv_driver *drv;
 956         struct hv_device *dev = device_to_hv_device(child_device);
 957
 958         /* The device may not be attached yet */
 959         if (!child_device->driver)
 960                 return 0;
 961
 962         drv = drv_to_hv_drv(child_device->driver);
 963         if (!drv->resume)
 964                 return -EOPNOTSUPP;
 965
 966         return drv->resume(dev);
 967 }
 968 #else
 969 #define vmbus_suspend NULL
 970 #define vmbus_resume NULL
 971 #endif /* CONFIG_PM_SLEEP */
 972
 973 /*
 974  * vmbus_device_release - Final callback release of the vmbus child device
 975  */
 976 static void vmbus_device_release(struct device *device)
 977 {
 978         struct hv_device *hv_dev = device_to_hv_device(device);
 979         struct vmbus_channel *channel = hv_dev->channel;
 980
 981         hv_debug_rm_dev_dir(hv_dev);
 982
 983         mutex_lock(&vmbus_connection.channel_mutex);
 984         hv_process_channel_removal(channel);
 985         mutex_unlock(&vmbus_connection.channel_mutex);
 986         kfree(hv_dev);
 987 }
 988
 989 /*
 990  * Note: we must use the "noirq" ops: see the comment before vmbus_bus_pm.
 991  *
 992  * suspend_noirq/resume_noirq are set to NULL to support Suspend-to-Idle: we
 993  * shouldn't suspend the vmbus devices upon Suspend-to-Idle, otherwise there
 994  * is no way to wake up a Generation-2 VM.
 995  *
 996  * The other 4 ops are for hibernation.
 997  */
 998
 999 static const struct dev_pm_ops vmbus_pm = {
1000         .suspend_noirq  = NULL,
1001         .resume_noirq   = NULL,
1002         .freeze_noirq   = vmbus_suspend,
1003         .thaw_noirq     = vmbus_resume,
1004         .poweroff_noirq = vmbus_suspend,
1005         .restore_noirq  = vmbus_resume,
1006 };
1007
1008 /* The one and only one */
1009 static struct bus_type  hv_bus = {
1010         .name =         "vmbus",
1011         .match =                vmbus_match,
1012         .shutdown =             vmbus_shutdown,
1013         .remove =               vmbus_remove,
1014         .probe =                vmbus_probe,
1015         .uevent =               vmbus_uevent,
1016         .dev_groups =           vmbus_dev_groups,
1017         .drv_groups =           vmbus_drv_groups,
1018         .pm =                   &vmbus_pm,
1019 };
1020
1021 struct onmessage_work_context {
1022         struct work_struct work;
1023         struct {
1024                 struct hv_message_header header;
1025                 u8 payload[];
1026         } msg;
1027 };
1028
1029 static void vmbus_onmessage_work(struct work_struct *work)
1030 {
1031         struct onmessage_work_context *ctx;
1032
1033         /* Do not process messages if we're in DISCONNECTED state */
1034         if (vmbus_connection.conn_state == DISCONNECTED)
1035                 return;
1036
1037         ctx = container_of(work, struct onmessage_work_context,
1038                            work);
1039         vmbus_onmessage((struct vmbus_channel_message_header *)
1040                         &ctx->msg.payload);
1041         kfree(ctx);
1042 }
1043
1044 void vmbus_on_msg_dpc(unsigned long data)
1045 {
1046         struct hv_per_cpu_context *hv_cpu = (void *)data;
1047         void *page_addr = hv_cpu->synic_message_page;
1048         struct hv_message *msg = (struct hv_message *)page_addr +
1049                                   VMBUS_MESSAGE_SINT;
1050         struct vmbus_channel_message_header *hdr;
1051         const struct vmbus_channel_message_table_entry *entry;
1052         struct onmessage_work_context *ctx;
1053         u32 message_type = msg->header.message_type;
1054
1055         /*
1056          * 'enum vmbus_channel_message_type' is supposed to always be 'u32' as
1057          * it is being used in 'struct vmbus_channel_message_header' definition
1058          * which is supposed to match hypervisor ABI.
1059          */
1060         BUILD_BUG_ON(sizeof(enum vmbus_channel_message_type) != sizeof(u32));
1061
1062         if (message_type == HVMSG_NONE)
1063                 /* no msg */
1064                 return;
1065
1066         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
1067
1068         trace_vmbus_on_msg_dpc(hdr);
1069
1070         if (hdr->msgtype >= CHANNELMSG_COUNT) {
1071                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
1072                 goto msg_handled;
1073         }
1074
1075         if (msg->header.payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) {
1076                 WARN_ONCE(1, "payload size is too large (%d)\n",
1077                           msg->header.payload_size);
1078                 goto msg_handled;
1079         }
1080
1081         entry = &channel_message_table[hdr->msgtype];
1082
1083         if (!entry->message_handler)
1084                 goto msg_handled;
1085
1086         if (msg->header.payload_size < entry->min_payload_len) {
1087                 WARN_ONCE(1, "message too short: msgtype=%d len=%d\n",
1088                           hdr->msgtype, msg->header.payload_size);
1089                 goto msg_handled;
1090         }
1091
1092         if (entry->handler_type == VMHT_BLOCKING) {
1093                 ctx = kmalloc(sizeof(*ctx) + msg->header.payload_size,
1094                               GFP_ATOMIC);
1095                 if (ctx == NULL)
1096                         return;
1097
1098                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
1099                 memcpy(&ctx->msg, msg, sizeof(msg->header) +
1100                        msg->header.payload_size);
1101
1102                 /*
1103                  * The host can generate a rescind message while we
1104                  * may still be handling the original offer. We deal with
1105                  * this condition by relying on the synchronization provided
1106                  * by offer_in_progress and by channel_mutex.  See also the
1107                  * inline comments in vmbus_onoffer_rescind().
1108                  */
1109                 switch (hdr->msgtype) {
1110                 case CHANNELMSG_RESCIND_CHANNELOFFER:
1111                         /*
1112                          * If we are handling the rescind message;
1113                          * schedule the work on the global work queue.
1114                          *
1115                          * The OFFER message and the RESCIND message should
1116                          * not be handled by the same serialized work queue,
1117                          * because the OFFER handler may call vmbus_open(),
1118                          * which tries to open the channel by sending an
1119                          * OPEN_CHANNEL message to the host and waits for
1120                          * the host's response; however, if the host has
1121                          * rescinded the channel before it receives the
1122                          * OPEN_CHANNEL message, the host just silently
1123                          * ignores the OPEN_CHANNEL message; as a result,
1124                          * the guest's OFFER handler hangs for ever, if we
1125                          * handle the RESCIND message in the same serialized
1126                          * work queue: the RESCIND handler can not start to
1127                          * run before the OFFER handler finishes.
1128                          */
1129                         schedule_work(&ctx->work);
1130                         break;
1131
1132                 case CHANNELMSG_OFFERCHANNEL:
1133                         /*
1134                          * The host sends the offer message of a given channel
1135                          * before sending the rescind message of the same
1136                          * channel.  These messages are sent to the guest's
1137                          * connect CPU; the guest then starts processing them
1138                          * in the tasklet handler on this CPU:
1139                          *
1140                          * VMBUS_CONNECT_CPU
1141                          *
1142                          * [vmbus_on_msg_dpc()]
1143                          * atomic_inc()  // CHANNELMSG_OFFERCHANNEL
1144                          * queue_work()
1145                          * ...
1146                          * [vmbus_on_msg_dpc()]
1147                          * schedule_work()  // CHANNELMSG_RESCIND_CHANNELOFFER
1148                          *
1149                          * We rely on the memory-ordering properties of the
1150                          * queue_work() and schedule_work() primitives, which
1151                          * guarantee that the atomic increment will be visible
1152                          * to the CPUs which will execute the offer & rescind
1153                          * works by the time these works will start execution.
1154                          */
1155                         atomic_inc(&vmbus_connection.offer_in_progress);
1156                         fallthrough;
1157
1158                 default:
1159                         queue_work(vmbus_connection.work_queue, &ctx->work);
1160                 }
1161         } else
1162                 entry->message_handler(hdr);
1163
1164 msg_handled:
1165         vmbus_signal_eom(msg, message_type);
1166 }
1167
1168 #ifdef CONFIG_PM_SLEEP
1169 /*
1170  * Fake RESCIND_CHANNEL messages to clean up hv_sock channels by force for
1171  * hibernation, because hv_sock connections can not persist across hibernation.
1172  */
1173 static void vmbus_force_channel_rescinded(struct vmbus_channel *channel)
1174 {
1175         struct onmessage_work_context *ctx;
1176         struct vmbus_channel_rescind_offer *rescind;
1177
1178         WARN_ON(!is_hvsock_channel(channel));
1179
1180         /*
1181          * Allocation size is small and the allocation should really not fail,
1182          * otherwise the state of the hv_sock connections ends up in limbo.
1183          */
1184         ctx = kzalloc(sizeof(*ctx) + sizeof(*rescind),
1185                       GFP_KERNEL | __GFP_NOFAIL);
1186
1187         /*
1188          * So far, these are not really used by Linux. Just set them to the
1189          * reasonable values conforming to the definitions of the fields.
1190          */
1191         ctx->msg.header.message_type = 1;
1192         ctx->msg.header.payload_size = sizeof(*rescind);
1193
1194         /* These values are actually used by Linux. */
1195         rescind = (struct vmbus_channel_rescind_offer *)ctx->msg.payload;
1196         rescind->header.msgtype = CHANNELMSG_RESCIND_CHANNELOFFER;
1197         rescind->child_relid = channel->offermsg.child_relid;
1198
1199         INIT_WORK(&ctx->work, vmbus_onmessage_work);
1200
1201         queue_work(vmbus_connection.work_queue, &ctx->work);
1202 }
1203 #endif /* CONFIG_PM_SLEEP */
1204
1205 /*
1206  * Schedule all channels with events pending
1207  */
1208 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1209 {
1210         unsigned long *recv_int_page;
1211         u32 maxbits, relid;
1212
1213         if (vmbus_proto_version < VERSION_WIN8) {
1214                 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1215                 recv_int_page = vmbus_connection.recv_int_page;
1216         } else {
1217                 /*
1218                  * When the host is win8 and beyond, the event page
1219                  * can be directly checked to get the id of the channel
1220                  * that has the interrupt pending.
1221                  */
1222                 void *page_addr = hv_cpu->synic_event_page;
1223                 union hv_synic_event_flags *event
1224                         = (union hv_synic_event_flags *)page_addr +
1225                                                  VMBUS_MESSAGE_SINT;
1226
1227                 maxbits = HV_EVENT_FLAGS_COUNT;
1228                 recv_int_page = event->flags;
1229         }
1230
1231         if (unlikely(!recv_int_page))
1232                 return;
1233
1234         for_each_set_bit(relid, recv_int_page, maxbits) {
1235                 void (*callback_fn)(void *context);
1236                 struct vmbus_channel *channel;
1237
1238                 if (!sync_test_and_clear_bit(relid, recv_int_page))
1239                         continue;
1240
1241                 /* Special case - vmbus channel protocol msg */
1242                 if (relid == 0)
1243                         continue;
1244
1245                 /*
1246                  * Pairs with the kfree_rcu() in vmbus_chan_release().
1247                  * Guarantees that the channel data structure doesn't
1248                  * get freed while the channel pointer below is being
1249                  * dereferenced.
1250                  */
1251                 rcu_read_lock();
1252
1253                 /* Find channel based on relid */
1254                 channel = relid2channel(relid);
1255                 if (channel == NULL)
1256                         goto sched_unlock_rcu;
1257
1258                 if (channel->rescind)
1259                         goto sched_unlock_rcu;
1260
1261                 /*
1262                  * Make sure that the ring buffer data structure doesn't get
1263                  * freed while we dereference the ring buffer pointer.  Test
1264                  * for the channel's onchannel_callback being NULL within a
1265                  * sched_lock critical section.  See also the inline comments
1266                  * in vmbus_reset_channel_cb().
1267                  */
1268                 spin_lock(&channel->sched_lock);
1269
1270                 callback_fn = channel->onchannel_callback;
1271                 if (unlikely(callback_fn == NULL))
1272                         goto sched_unlock;
1273
1274                 trace_vmbus_chan_sched(channel);
1275
1276                 ++channel->interrupts;
1277
1278                 switch (channel->callback_mode) {
1279                 case HV_CALL_ISR:
1280                         (*callback_fn)(channel->channel_callback_context);
1281                         break;
1282
1283                 case HV_CALL_BATCHED:
1284                         hv_begin_read(&channel->inbound);
1285                         fallthrough;
1286                 case HV_CALL_DIRECT:
1287                         tasklet_schedule(&channel->callback_event);
1288                 }
1289
1290 sched_unlock:
1291                 spin_unlock(&channel->sched_lock);
1292 sched_unlock_rcu:
1293                 rcu_read_unlock();
1294         }
1295 }
1296
1297 static void vmbus_isr(void)
1298 {
1299         struct hv_per_cpu_context *hv_cpu
1300                 = this_cpu_ptr(hv_context.cpu_context);
1301         void *page_addr = hv_cpu->synic_event_page;
1302         struct hv_message *msg;
1303         union hv_synic_event_flags *event;
1304         bool handled = false;
1305
1306         if (unlikely(page_addr == NULL))
1307                 return;
1308
1309         event = (union hv_synic_event_flags *)page_addr +
1310                                          VMBUS_MESSAGE_SINT;
1311         /*
1312          * Check for events before checking for messages. This is the order
1313          * in which events and messages are checked in Windows guests on
1314          * Hyper-V, and the Windows team suggested we do the same.
1315          */
1316
1317         if ((vmbus_proto_version == VERSION_WS2008) ||
1318                 (vmbus_proto_version == VERSION_WIN7)) {
1319
1320                 /* Since we are a child, we only need to check bit 0 */
1321                 if (sync_test_and_clear_bit(0, event->flags))
1322                         handled = true;
1323         } else {
1324                 /*
1325                  * Our host is win8 or above. The signaling mechanism
1326                  * has changed and we can directly look at the event page.
1327                  * If bit n is set then we have an interrup on the channel
1328                  * whose id is n.
1329                  */
1330                 handled = true;
1331         }
1332
1333         if (handled)
1334                 vmbus_chan_sched(hv_cpu);
1335
1336         page_addr = hv_cpu->synic_message_page;
1337         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1338
1339         /* Check if there are actual msgs to be processed */
1340         if (msg->header.message_type != HVMSG_NONE) {
1341                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED) {
1342                         hv_stimer0_isr();
1343                         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
1344                 } else
1345                         tasklet_schedule(&hv_cpu->msg_dpc);
1346         }
1347
1348         add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1349 }
1350
1351 /*
1352  * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1353  * buffer and call into Hyper-V to transfer the data.
1354  */
1355 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1356                          enum kmsg_dump_reason reason)
1357 {
1358         size_t bytes_written;
1359         phys_addr_t panic_pa;
1360
1361         /* We are only interested in panics. */
1362         if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1363                 return;
1364
1365         panic_pa = virt_to_phys(hv_panic_page);
1366
1367         /*
1368          * Write dump contents to the page. No need to synchronize; panic should
1369          * be single-threaded.
1370          */
1371         kmsg_dump_get_buffer(dumper, false, hv_panic_page, HV_HYP_PAGE_SIZE,
1372                              &bytes_written);
1373         if (bytes_written)
1374                 hyperv_report_panic_msg(panic_pa, bytes_written);
1375 }
1376
1377 static struct kmsg_dumper hv_kmsg_dumper = {
1378         .dump = hv_kmsg_dump,
1379 };
1380
1381 static struct ctl_table_header *hv_ctl_table_hdr;
1382
1383 /*
1384  * sysctl option to allow the user to control whether kmsg data should be
1385  * reported to Hyper-V on panic.
1386  */
1387 static struct ctl_table hv_ctl_table[] = {
1388         {
1389                 .procname       = "hyperv_record_panic_msg",
1390                 .data           = &sysctl_record_panic_msg,
1391                 .maxlen         = sizeof(int),
1392                 .mode           = 0644,
1393                 .proc_handler   = proc_dointvec_minmax,
1394                 .extra1         = SYSCTL_ZERO,
1395                 .extra2         = SYSCTL_ONE
1396         },
1397         {}
1398 };
1399
1400 static struct ctl_table hv_root_table[] = {
1401         {
1402                 .procname       = "kernel",
1403                 .mode           = 0555,
1404                 .child          = hv_ctl_table
1405         },
1406         {}
1407 };
1408
1409 /*
1410  * vmbus_bus_init -Main vmbus driver initialization routine.
1411  *
1412  * Here, we
1413  *      - initialize the vmbus driver context
1414  *      - invoke the vmbus hv main init routine
1415  *      - retrieve the channel offers
1416  */
1417 static int vmbus_bus_init(void)
1418 {
1419         int ret;
1420
1421         ret = hv_init();
1422         if (ret != 0) {
1423                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1424                 return ret;
1425         }
1426
1427         ret = bus_register(&hv_bus);
1428         if (ret)
1429                 return ret;
1430
1431         hv_setup_vmbus_irq(vmbus_isr);
1432
1433         ret = hv_synic_alloc();
1434         if (ret)
1435                 goto err_alloc;
1436
1437         /*
1438          * Initialize the per-cpu interrupt state and stimer state.
1439          * Then connect to the host.
1440          */
1441         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1442                                 hv_synic_init, hv_synic_cleanup);
1443         if (ret < 0)
1444                 goto err_cpuhp;
1445         hyperv_cpuhp_online = ret;
1446
1447         ret = vmbus_connect();
1448         if (ret)
1449                 goto err_connect;
1450
1451         /*
1452          * Only register if the crash MSRs are available
1453          */
1454         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1455                 u64 hyperv_crash_ctl;
1456                 /*
1457                  * Sysctl registration is not fatal, since by default
1458                  * reporting is enabled.
1459                  */
1460                 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1461                 if (!hv_ctl_table_hdr)
1462                         pr_err("Hyper-V: sysctl table register error");
1463
1464                 /*
1465                  * Register for panic kmsg callback only if the right
1466                  * capability is supported by the hypervisor.
1467                  */
1468                 hv_get_crash_ctl(hyperv_crash_ctl);
1469                 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1470                         hv_panic_page = (void *)hv_alloc_hyperv_zeroed_page();
1471                         if (hv_panic_page) {
1472                                 ret = kmsg_dump_register(&hv_kmsg_dumper);
1473                                 if (ret) {
1474                                         pr_err("Hyper-V: kmsg dump register "
1475                                                 "error 0x%x\n", ret);
1476                                         hv_free_hyperv_page(
1477                                             (unsigned long)hv_panic_page);
1478                                         hv_panic_page = NULL;
1479                                 }
1480                         } else
1481                                 pr_err("Hyper-V: panic message page memory "
1482                                         "allocation failed");
1483                 }
1484
1485                 register_die_notifier(&hyperv_die_block);
1486         }
1487
1488         /*
1489          * Always register the panic notifier because we need to unload
1490          * the VMbus channel connection to prevent any VMbus
1491          * activity after the VM panics.
1492          */
1493         atomic_notifier_chain_register(&panic_notifier_list,
1494                                &hyperv_panic_block);
1495
1496         vmbus_request_offers();
1497
1498         return 0;
1499
1500 err_connect:
1501         cpuhp_remove_state(hyperv_cpuhp_online);
1502 err_cpuhp:
1503         hv_synic_free();
1504 err_alloc:
1505         hv_remove_vmbus_irq();
1506
1507         bus_unregister(&hv_bus);
1508         unregister_sysctl_table(hv_ctl_table_hdr);
1509         hv_ctl_table_hdr = NULL;
1510         return ret;
1511 }
1512
1513 /**
1514  * __vmbus_child_driver_register() - Register a vmbus's driver
1515  * @hv_driver: Pointer to driver structure you want to register
1516  * @owner: owner module of the drv
1517  * @mod_name: module name string
1518  *
1519  * Registers the given driver with Linux through the 'driver_register()' call
1520  * and sets up the hyper-v vmbus handling for this driver.
1521  * It will return the state of the 'driver_register()' call.
1522  *
1523  */
1524 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1525 {
1526         int ret;
1527
1528         pr_info("registering driver %s\n", hv_driver->name);
1529
1530         ret = vmbus_exists();
1531         if (ret < 0)
1532                 return ret;
1533
1534         hv_driver->driver.name = hv_driver->name;
1535         hv_driver->driver.owner = owner;
1536         hv_driver->driver.mod_name = mod_name;
1537         hv_driver->driver.bus = &hv_bus;
1538
1539         spin_lock_init(&hv_driver->dynids.lock);
1540         INIT_LIST_HEAD(&hv_driver->dynids.list);
1541
1542         ret = driver_register(&hv_driver->driver);
1543
1544         return ret;
1545 }
1546 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1547
1548 /**
1549  * vmbus_driver_unregister() - Unregister a vmbus's driver
1550  * @hv_driver: Pointer to driver structure you want to
1551  *             un-register
1552  *
1553  * Un-register the given driver that was previous registered with a call to
1554  * vmbus_driver_register()
1555  */
1556 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1557 {
1558         pr_info("unregistering driver %s\n", hv_driver->name);
1559
1560         if (!vmbus_exists()) {
1561                 driver_unregister(&hv_driver->driver);
1562                 vmbus_free_dynids(hv_driver);
1563         }
1564 }
1565 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1566
1567
1568 /*
1569  * Called when last reference to channel is gone.
1570  */
1571 static void vmbus_chan_release(struct kobject *kobj)
1572 {
1573         struct vmbus_channel *channel
1574                 = container_of(kobj, struct vmbus_channel, kobj);
1575
1576         kfree_rcu(channel, rcu);
1577 }
1578
1579 struct vmbus_chan_attribute {
1580         struct attribute attr;
1581         ssize_t (*show)(struct vmbus_channel *chan, char *buf);
1582         ssize_t (*store)(struct vmbus_channel *chan,
1583                          const char *buf, size_t count);
1584 };
1585 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1586         struct vmbus_chan_attribute chan_attr_##_name \
1587                 = __ATTR(_name, _mode, _show, _store)
1588 #define VMBUS_CHAN_ATTR_RW(_name) \
1589         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1590 #define VMBUS_CHAN_ATTR_RO(_name) \
1591         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1592 #define VMBUS_CHAN_ATTR_WO(_name) \
1593         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1594
1595 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1596                                     struct attribute *attr, char *buf)
1597 {
1598         const struct vmbus_chan_attribute *attribute
1599                 = container_of(attr, struct vmbus_chan_attribute, attr);
1600         struct vmbus_channel *chan
1601                 = container_of(kobj, struct vmbus_channel, kobj);
1602
1603         if (!attribute->show)
1604                 return -EIO;
1605
1606         return attribute->show(chan, buf);
1607 }
1608
1609 static ssize_t vmbus_chan_attr_store(struct kobject *kobj,
1610                                      struct attribute *attr, const char *buf,
1611                                      size_t count)
1612 {
1613         const struct vmbus_chan_attribute *attribute
1614                 = container_of(attr, struct vmbus_chan_attribute, attr);
1615         struct vmbus_channel *chan
1616                 = container_of(kobj, struct vmbus_channel, kobj);
1617
1618         if (!attribute->store)
1619                 return -EIO;
1620
1621         return attribute->store(chan, buf, count);
1622 }
1623
1624 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1625         .show = vmbus_chan_attr_show,
1626         .store = vmbus_chan_attr_store,
1627 };
1628
1629 static ssize_t out_mask_show(struct vmbus_channel *channel, char *buf)
1630 {
1631         struct hv_ring_buffer_info *rbi = &channel->outbound;
1632         ssize_t ret;
1633
1634         mutex_lock(&rbi->ring_buffer_mutex);
1635         if (!rbi->ring_buffer) {
1636                 mutex_unlock(&rbi->ring_buffer_mutex);
1637                 return -EINVAL;
1638         }
1639
1640         ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1641         mutex_unlock(&rbi->ring_buffer_mutex);
1642         return ret;
1643 }
1644 static VMBUS_CHAN_ATTR_RO(out_mask);
1645
1646 static ssize_t in_mask_show(struct vmbus_channel *channel, char *buf)
1647 {
1648         struct hv_ring_buffer_info *rbi = &channel->inbound;
1649         ssize_t ret;
1650
1651         mutex_lock(&rbi->ring_buffer_mutex);
1652         if (!rbi->ring_buffer) {
1653                 mutex_unlock(&rbi->ring_buffer_mutex);
1654                 return -EINVAL;
1655         }
1656
1657         ret = sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1658         mutex_unlock(&rbi->ring_buffer_mutex);
1659         return ret;
1660 }
1661 static VMBUS_CHAN_ATTR_RO(in_mask);
1662
1663 static ssize_t read_avail_show(struct vmbus_channel *channel, char *buf)
1664 {
1665         struct hv_ring_buffer_info *rbi = &channel->inbound;
1666         ssize_t ret;
1667
1668         mutex_lock(&rbi->ring_buffer_mutex);
1669         if (!rbi->ring_buffer) {
1670                 mutex_unlock(&rbi->ring_buffer_mutex);
1671                 return -EINVAL;
1672         }
1673
1674         ret = sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1675         mutex_unlock(&rbi->ring_buffer_mutex);
1676         return ret;
1677 }
1678 static VMBUS_CHAN_ATTR_RO(read_avail);
1679
1680 static ssize_t write_avail_show(struct vmbus_channel *channel, char *buf)
1681 {
1682         struct hv_ring_buffer_info *rbi = &channel->outbound;
1683         ssize_t ret;
1684
1685         mutex_lock(&rbi->ring_buffer_mutex);
1686         if (!rbi->ring_buffer) {
1687                 mutex_unlock(&rbi->ring_buffer_mutex);
1688                 return -EINVAL;
1689         }
1690
1691         ret = sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1692         mutex_unlock(&rbi->ring_buffer_mutex);
1693         return ret;
1694 }
1695 static VMBUS_CHAN_ATTR_RO(write_avail);
1696
1697 static ssize_t target_cpu_show(struct vmbus_channel *channel, char *buf)
1698 {
1699         return sprintf(buf, "%u\n", channel->target_cpu);
1700 }
1701 static ssize_t target_cpu_store(struct vmbus_channel *channel,
1702                                 const char *buf, size_t count)
1703 {
1704         u32 target_cpu, origin_cpu;
1705         ssize_t ret = count;
1706
1707         if (vmbus_proto_version < VERSION_WIN10_V4_1)
1708                 return -EIO;
1709
1710         if (sscanf(buf, "%uu", &target_cpu) != 1)
1711                 return -EIO;
1712
1713         /* Validate target_cpu for the cpumask_test_cpu() operation below. */
1714         if (target_cpu >= nr_cpumask_bits)
1715                 return -EINVAL;
1716
1717         /* No CPUs should come up or down during this. */
1718         cpus_read_lock();
1719
1720         if (!cpumask_test_cpu(target_cpu, cpu_online_mask)) {
1721                 cpus_read_unlock();
1722                 return -EINVAL;
1723         }
1724
1725         /*
1726          * Synchronizes target_cpu_store() and channel closure:
1727          *
1728          * { Initially: state = CHANNEL_OPENED }
1729          *
1730          * CPU1                         CPU2
1731          *
1732          * [target_cpu_store()]         [vmbus_disconnect_ring()]
1733          *
1734          * LOCK channel_mutex           LOCK channel_mutex
1735          * LOAD r1 = state              LOAD r2 = state
1736          * IF (r1 == CHANNEL_OPENED)    IF (r2 == CHANNEL_OPENED)
1737          *   SEND MODIFYCHANNEL           STORE state = CHANNEL_OPEN
1738          *   [...]                        SEND CLOSECHANNEL
1739          * UNLOCK channel_mutex         UNLOCK channel_mutex
1740          *
1741          * Forbids: r1 == r2 == CHANNEL_OPENED (i.e., CPU1's LOCK precedes
1742          *              CPU2's LOCK) && CPU2's SEND precedes CPU1's SEND
1743          *
1744          * Note.  The host processes the channel messages "sequentially", in
1745          * the order in which they are received on a per-partition basis.
1746          */
1747         mutex_lock(&vmbus_connection.channel_mutex);
1748
1749         /*
1750          * Hyper-V will ignore MODIFYCHANNEL messages for "non-open" channels;
1751          * avoid sending the message and fail here for such channels.
1752          */
1753         if (channel->state != CHANNEL_OPENED_STATE) {
1754                 ret = -EIO;
1755                 goto cpu_store_unlock;
1756         }
1757
1758         origin_cpu = channel->target_cpu;
1759         if (target_cpu == origin_cpu)
1760                 goto cpu_store_unlock;
1761
1762         if (vmbus_send_modifychannel(channel->offermsg.child_relid,
1763                                      hv_cpu_number_to_vp_number(target_cpu))) {
1764                 ret = -EIO;
1765                 goto cpu_store_unlock;
1766         }
1767
1768         /*
1769          * Warning.  At this point, there is *no* guarantee that the host will
1770          * have successfully processed the vmbus_send_modifychannel() request.
1771          * See the header comment of vmbus_send_modifychannel() for more info.
1772          *
1773          * Lags in the processing of the above vmbus_send_modifychannel() can
1774          * result in missed interrupts if the "old" target CPU is taken offline
1775          * before Hyper-V starts sending interrupts to the "new" target CPU.
1776          * But apart from this offlining scenario, the code tolerates such
1777          * lags.  It will function correctly even if a channel interrupt comes
1778          * in on a CPU that is different from the channel target_cpu value.
1779          */
1780
1781         channel->target_cpu = target_cpu;
1782         channel->target_vp = hv_cpu_number_to_vp_number(target_cpu);
1783         channel->numa_node = cpu_to_node(target_cpu);
1784
1785         /* See init_vp_index(). */
1786         if (hv_is_perf_channel(channel))
1787                 hv_update_alloced_cpus(origin_cpu, target_cpu);
1788
1789         /* Currently set only for storvsc channels. */
1790         if (channel->change_target_cpu_callback) {
1791                 (*channel->change_target_cpu_callback)(channel,
1792                                 origin_cpu, target_cpu);
1793         }
1794
1795 cpu_store_unlock:
1796         mutex_unlock(&vmbus_connection.channel_mutex);
1797         cpus_read_unlock();
1798         return ret;
1799 }
1800 static VMBUS_CHAN_ATTR(cpu, 0644, target_cpu_show, target_cpu_store);
1801
1802 static ssize_t channel_pending_show(struct vmbus_channel *channel,
1803                                     char *buf)
1804 {
1805         return sprintf(buf, "%d\n",
1806                        channel_pending(channel,
1807                                        vmbus_connection.monitor_pages[1]));
1808 }
1809 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1810
1811 static ssize_t channel_latency_show(struct vmbus_channel *channel,
1812                                     char *buf)
1813 {
1814         return sprintf(buf, "%d\n",
1815                        channel_latency(channel,
1816                                        vmbus_connection.monitor_pages[1]));
1817 }
1818 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1819
1820 static ssize_t channel_interrupts_show(struct vmbus_channel *channel, char *buf)
1821 {
1822         return sprintf(buf, "%llu\n", channel->interrupts);
1823 }
1824 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1825
1826 static ssize_t channel_events_show(struct vmbus_channel *channel, char *buf)
1827 {
1828         return sprintf(buf, "%llu\n", channel->sig_events);
1829 }
1830 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1831
1832 static ssize_t channel_intr_in_full_show(struct vmbus_channel *channel,
1833                                          char *buf)
1834 {
1835         return sprintf(buf, "%llu\n",
1836                        (unsigned long long)channel->intr_in_full);
1837 }
1838 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1839
1840 static ssize_t channel_intr_out_empty_show(struct vmbus_channel *channel,
1841                                            char *buf)
1842 {
1843         return sprintf(buf, "%llu\n",
1844                        (unsigned long long)channel->intr_out_empty);
1845 }
1846 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1847
1848 static ssize_t channel_out_full_first_show(struct vmbus_channel *channel,
1849                                            char *buf)
1850 {
1851         return sprintf(buf, "%llu\n",
1852                        (unsigned long long)channel->out_full_first);
1853 }
1854 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1855
1856 static ssize_t channel_out_full_total_show(struct vmbus_channel *channel,
1857                                            char *buf)
1858 {
1859         return sprintf(buf, "%llu\n",
1860                        (unsigned long long)channel->out_full_total);
1861 }
1862 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1863
1864 static ssize_t subchannel_monitor_id_show(struct vmbus_channel *channel,
1865                                           char *buf)
1866 {
1867         return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1868 }
1869 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1870
1871 static ssize_t subchannel_id_show(struct vmbus_channel *channel,
1872                                   char *buf)
1873 {
1874         return sprintf(buf, "%u\n",
1875                        channel->offermsg.offer.sub_channel_index);
1876 }
1877 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1878
1879 static struct attribute *vmbus_chan_attrs[] = {
1880         &chan_attr_out_mask.attr,
1881         &chan_attr_in_mask.attr,
1882         &chan_attr_read_avail.attr,
1883         &chan_attr_write_avail.attr,
1884         &chan_attr_cpu.attr,
1885         &chan_attr_pending.attr,
1886         &chan_attr_latency.attr,
1887         &chan_attr_interrupts.attr,
1888         &chan_attr_events.attr,
1889         &chan_attr_intr_in_full.attr,
1890         &chan_attr_intr_out_empty.attr,
1891         &chan_attr_out_full_first.attr,
1892         &chan_attr_out_full_total.attr,
1893         &chan_attr_monitor_id.attr,
1894         &chan_attr_subchannel_id.attr,
1895         NULL
1896 };
1897
1898 /*
1899  * Channel-level attribute_group callback function. Returns the permission for
1900  * each attribute, and returns 0 if an attribute is not visible.
1901  */
1902 static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
1903                                           struct attribute *attr, int idx)
1904 {
1905         const struct vmbus_channel *channel =
1906                 container_of(kobj, struct vmbus_channel, kobj);
1907
1908         /* Hide the monitor attributes if the monitor mechanism is not used. */
1909         if (!channel->offermsg.monitor_allocated &&
1910             (attr == &chan_attr_pending.attr ||
1911              attr == &chan_attr_latency.attr ||
1912              attr == &chan_attr_monitor_id.attr))
1913                 return 0;
1914
1915         return attr->mode;
1916 }
1917
1918 static struct attribute_group vmbus_chan_group = {
1919         .attrs = vmbus_chan_attrs,
1920         .is_visible = vmbus_chan_attr_is_visible
1921 };
1922
1923 static struct kobj_type vmbus_chan_ktype = {
1924         .sysfs_ops = &vmbus_chan_sysfs_ops,
1925         .release = vmbus_chan_release,
1926 };
1927
1928 /*
1929  * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1930  */
1931 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1932 {
1933         const struct device *device = &dev->device;
1934         struct kobject *kobj = &channel->kobj;
1935         u32 relid = channel->offermsg.child_relid;
1936         int ret;
1937
1938         kobj->kset = dev->channels_kset;
1939         ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1940                                    "%u", relid);
1941         if (ret)
1942                 return ret;
1943
1944         ret = sysfs_create_group(kobj, &vmbus_chan_group);
1945
1946         if (ret) {
1947                 /*
1948                  * The calling functions' error handling paths will cleanup the
1949                  * empty channel directory.
1950                  */
1951                 dev_err(device, "Unable to set up channel sysfs files\n");
1952                 return ret;
1953         }
1954
1955         kobject_uevent(kobj, KOBJ_ADD);
1956
1957         return 0;
1958 }
1959
1960 /*
1961  * vmbus_remove_channel_attr_group - remove the channel's attribute group
1962  */
1963 void vmbus_remove_channel_attr_group(struct vmbus_channel *channel)
1964 {
1965         sysfs_remove_group(&channel->kobj, &vmbus_chan_group);
1966 }
1967
1968 /*
1969  * vmbus_device_create - Creates and registers a new child device
1970  * on the vmbus.
1971  */
1972 struct hv_device *vmbus_device_create(const guid_t *type,
1973                                       const guid_t *instance,
1974                                       struct vmbus_channel *channel)
1975 {
1976         struct hv_device *child_device_obj;
1977
1978         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1979         if (!child_device_obj) {
1980                 pr_err("Unable to allocate device object for child device\n");
1981                 return NULL;
1982         }
1983
1984         child_device_obj->channel = channel;
1985         guid_copy(&child_device_obj->dev_type, type);
1986         guid_copy(&child_device_obj->dev_instance, instance);
1987         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1988
1989         return child_device_obj;
1990 }
1991
1992 /*
1993  * vmbus_device_register - Register the child device
1994  */
1995 int vmbus_device_register(struct hv_device *child_device_obj)
1996 {
1997         struct kobject *kobj = &child_device_obj->device.kobj;
1998         int ret;
1999
2000         dev_set_name(&child_device_obj->device, "%pUl",
2001                      &child_device_obj->channel->offermsg.offer.if_instance);
2002
2003         child_device_obj->device.bus = &hv_bus;
2004         child_device_obj->device.parent = &hv_acpi_dev->dev;
2005         child_device_obj->device.release = vmbus_device_release;
2006
2007         /*
2008          * Register with the LDM. This will kick off the driver/device
2009          * binding...which will eventually call vmbus_match() and vmbus_probe()
2010          */
2011         ret = device_register(&child_device_obj->device);
2012         if (ret) {
2013                 pr_err("Unable to register child device\n");
2014                 return ret;
2015         }
2016
2017         child_device_obj->channels_kset = kset_create_and_add("channels",
2018                                                               NULL, kobj);
2019         if (!child_device_obj->channels_kset) {
2020                 ret = -ENOMEM;
2021                 goto err_dev_unregister;
2022         }
2023
2024         ret = vmbus_add_channel_kobj(child_device_obj,
2025                                      child_device_obj->channel);
2026         if (ret) {
2027                 pr_err("Unable to register primary channeln");
2028                 goto err_kset_unregister;
2029         }
2030         hv_debug_add_dev_dir(child_device_obj);
2031
2032         return 0;
2033
2034 err_kset_unregister:
2035         kset_unregister(child_device_obj->channels_kset);
2036
2037 err_dev_unregister:
2038         device_unregister(&child_device_obj->device);
2039         return ret;
2040 }
2041
2042 /*
2043  * vmbus_device_unregister - Remove the specified child device
2044  * from the vmbus.
2045  */
2046 void vmbus_device_unregister(struct hv_device *device_obj)
2047 {
2048         pr_debug("child device %s unregistered\n",
2049                 dev_name(&device_obj->device));
2050
2051         kset_unregister(device_obj->channels_kset);
2052
2053         /*
2054          * Kick off the process of unregistering the device.
2055          * This will call vmbus_remove() and eventually vmbus_device_release()
2056          */
2057         device_unregister(&device_obj->device);
2058 }
2059
2060
2061 /*
2062  * VMBUS is an acpi enumerated device. Get the information we
2063  * need from DSDT.
2064  */
2065 #define VTPM_BASE_ADDRESS 0xfed40000
2066 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
2067 {
2068         resource_size_t start = 0;
2069         resource_size_t end = 0;
2070         struct resource *new_res;
2071         struct resource **old_res = &hyperv_mmio;
2072         struct resource **prev_res = NULL;
2073
2074         switch (res->type) {
2075
2076         /*
2077          * "Address" descriptors are for bus windows. Ignore
2078          * "memory" descriptors, which are for registers on
2079          * devices.
2080          */
2081         case ACPI_RESOURCE_TYPE_ADDRESS32:
2082                 start = res->data.address32.address.minimum;
2083                 end = res->data.address32.address.maximum;
2084                 break;
2085
2086         case ACPI_RESOURCE_TYPE_ADDRESS64:
2087                 start = res->data.address64.address.minimum;
2088                 end = res->data.address64.address.maximum;
2089                 break;
2090
2091         default:
2092                 /* Unused resource type */
2093                 return AE_OK;
2094
2095         }
2096         /*
2097          * Ignore ranges that are below 1MB, as they're not
2098          * necessary or useful here.
2099          */
2100         if (end < 0x100000)
2101                 return AE_OK;
2102
2103         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
2104         if (!new_res)
2105                 return AE_NO_MEMORY;
2106
2107         /* If this range overlaps the virtual TPM, truncate it. */
2108         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
2109                 end = VTPM_BASE_ADDRESS;
2110
2111         new_res->name = "hyperv mmio";
2112         new_res->flags = IORESOURCE_MEM;
2113         new_res->start = start;
2114         new_res->end = end;
2115
2116         /*
2117          * If two ranges are adjacent, merge them.
2118          */
2119         do {
2120                 if (!*old_res) {
2121                         *old_res = new_res;
2122                         break;
2123                 }
2124
2125                 if (((*old_res)->end + 1) == new_res->start) {
2126                         (*old_res)->end = new_res->end;
2127                         kfree(new_res);
2128                         break;
2129                 }
2130
2131                 if ((*old_res)->start == new_res->end + 1) {
2132                         (*old_res)->start = new_res->start;
2133                         kfree(new_res);
2134                         break;
2135                 }
2136
2137                 if ((*old_res)->start > new_res->end) {
2138                         new_res->sibling = *old_res;
2139                         if (prev_res)
2140                                 (*prev_res)->sibling = new_res;
2141                         *old_res = new_res;
2142                         break;
2143                 }
2144
2145                 prev_res = old_res;
2146                 old_res = &(*old_res)->sibling;
2147
2148         } while (1);
2149
2150         return AE_OK;
2151 }
2152
2153 static int vmbus_acpi_remove(struct acpi_device *device)
2154 {
2155         struct resource *cur_res;
2156         struct resource *next_res;
2157
2158         if (hyperv_mmio) {
2159                 if (fb_mmio) {
2160                         __release_region(hyperv_mmio, fb_mmio->start,
2161                                          resource_size(fb_mmio));
2162                         fb_mmio = NULL;
2163                 }
2164
2165                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
2166                         next_res = cur_res->sibling;
2167                         kfree(cur_res);
2168                 }
2169         }
2170
2171         return 0;
2172 }
2173
2174 static void vmbus_reserve_fb(void)
2175 {
2176         int size;
2177         /*
2178          * Make a claim for the frame buffer in the resource tree under the
2179          * first node, which will be the one below 4GB.  The length seems to
2180          * be underreported, particularly in a Generation 1 VM.  So start out
2181          * reserving a larger area and make it smaller until it succeeds.
2182          */
2183
2184         if (screen_info.lfb_base) {
2185                 if (efi_enabled(EFI_BOOT))
2186                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
2187                 else
2188                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
2189
2190                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
2191                         fb_mmio = __request_region(hyperv_mmio,
2192                                                    screen_info.lfb_base, size,
2193                                                    fb_mmio_name, 0);
2194                 }
2195         }
2196 }
2197
2198 /**
2199  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
2200  * @new:                If successful, supplied a pointer to the
2201  *                      allocated MMIO space.
2202  * @device_obj:         Identifies the caller
2203  * @min:                Minimum guest physical address of the
2204  *                      allocation
2205  * @max:                Maximum guest physical address
2206  * @size:               Size of the range to be allocated
2207  * @align:              Alignment of the range to be allocated
2208  * @fb_overlap_ok:      Whether this allocation can be allowed
2209  *                      to overlap the video frame buffer.
2210  *
2211  * This function walks the resources granted to VMBus by the
2212  * _CRS object in the ACPI namespace underneath the parent
2213  * "bridge" whether that's a root PCI bus in the Generation 1
2214  * case or a Module Device in the Generation 2 case.  It then
2215  * attempts to allocate from the global MMIO pool in a way that
2216  * matches the constraints supplied in these parameters and by
2217  * that _CRS.
2218  *
2219  * Return: 0 on success, -errno on failure
2220  */
2221 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
2222                         resource_size_t min, resource_size_t max,
2223                         resource_size_t size, resource_size_t align,
2224                         bool fb_overlap_ok)
2225 {
2226         struct resource *iter, *shadow;
2227         resource_size_t range_min, range_max, start;
2228         const char *dev_n = dev_name(&device_obj->device);
2229         int retval;
2230
2231         retval = -ENXIO;
2232         mutex_lock(&hyperv_mmio_lock);
2233
2234         /*
2235          * If overlaps with frame buffers are allowed, then first attempt to
2236          * make the allocation from within the reserved region.  Because it
2237          * is already reserved, no shadow allocation is necessary.
2238          */
2239         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
2240             !(max < fb_mmio->start)) {
2241
2242                 range_min = fb_mmio->start;
2243                 range_max = fb_mmio->end;
2244                 start = (range_min + align - 1) & ~(align - 1);
2245                 for (; start + size - 1 <= range_max; start += align) {
2246                         *new = request_mem_region_exclusive(start, size, dev_n);
2247                         if (*new) {
2248                                 retval = 0;
2249                                 goto exit;
2250                         }
2251                 }
2252         }
2253
2254         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2255                 if ((iter->start >= max) || (iter->end <= min))
2256                         continue;
2257
2258                 range_min = iter->start;
2259                 range_max = iter->end;
2260                 start = (range_min + align - 1) & ~(align - 1);
2261                 for (; start + size - 1 <= range_max; start += align) {
2262                         shadow = __request_region(iter, start, size, NULL,
2263                                                   IORESOURCE_BUSY);
2264                         if (!shadow)
2265                                 continue;
2266
2267                         *new = request_mem_region_exclusive(start, size, dev_n);
2268                         if (*new) {
2269                                 shadow->name = (char *)*new;
2270                                 retval = 0;
2271                                 goto exit;
2272                         }
2273
2274                         __release_region(iter, start, size);
2275                 }
2276         }
2277
2278 exit:
2279         mutex_unlock(&hyperv_mmio_lock);
2280         return retval;
2281 }
2282 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
2283
2284 /**
2285  * vmbus_free_mmio() - Free a memory-mapped I/O range.
2286  * @start:              Base address of region to release.
2287  * @size:               Size of the range to be allocated
2288  *
2289  * This function releases anything requested by
2290  * vmbus_mmio_allocate().
2291  */
2292 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
2293 {
2294         struct resource *iter;
2295
2296         mutex_lock(&hyperv_mmio_lock);
2297         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
2298                 if ((iter->start >= start + size) || (iter->end <= start))
2299                         continue;
2300
2301                 __release_region(iter, start, size);
2302         }
2303         release_mem_region(start, size);
2304         mutex_unlock(&hyperv_mmio_lock);
2305
2306 }
2307 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
2308
2309 static int vmbus_acpi_add(struct acpi_device *device)
2310 {
2311         acpi_status result;
2312         int ret_val = -ENODEV;
2313         struct acpi_device *ancestor;
2314
2315         hv_acpi_dev = device;
2316
2317         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
2318                                         vmbus_walk_resources, NULL);
2319
2320         if (ACPI_FAILURE(result))
2321                 goto acpi_walk_err;
2322         /*
2323          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
2324          * firmware) is the VMOD that has the mmio ranges. Get that.
2325          */
2326         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
2327                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
2328                                              vmbus_walk_resources, NULL);
2329
2330                 if (ACPI_FAILURE(result))
2331                         continue;
2332                 if (hyperv_mmio) {
2333                         vmbus_reserve_fb();
2334                         break;
2335                 }
2336         }
2337         ret_val = 0;
2338
2339 acpi_walk_err:
2340         complete(&probe_event);
2341         if (ret_val)
2342                 vmbus_acpi_remove(device);
2343         return ret_val;
2344 }
2345
2346 #ifdef CONFIG_PM_SLEEP
2347 static int vmbus_bus_suspend(struct device *dev)
2348 {
2349         struct vmbus_channel *channel, *sc;
2350         unsigned long flags;
2351
2352         while (atomic_read(&vmbus_connection.offer_in_progress) != 0) {
2353                 /*
2354                  * We wait here until the completion of any channel
2355                  * offers that are currently in progress.
2356                  */
2357                 msleep(1);
2358         }
2359
2360         mutex_lock(&vmbus_connection.channel_mutex);
2361         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2362                 if (!is_hvsock_channel(channel))
2363                         continue;
2364
2365                 vmbus_force_channel_rescinded(channel);
2366         }
2367         mutex_unlock(&vmbus_connection.channel_mutex);
2368
2369         /*
2370          * Wait until all the sub-channels and hv_sock channels have been
2371          * cleaned up. Sub-channels should be destroyed upon suspend, otherwise
2372          * they would conflict with the new sub-channels that will be created
2373          * in the resume path. hv_sock channels should also be destroyed, but
2374          * a hv_sock channel of an established hv_sock connection can not be
2375          * really destroyed since it may still be referenced by the userspace
2376          * application, so we just force the hv_sock channel to be rescinded
2377          * by vmbus_force_channel_rescinded(), and the userspace application
2378          * will thoroughly destroy the channel after hibernation.
2379          *
2380          * Note: the counter nr_chan_close_on_suspend may never go above 0 if
2381          * the VM has no sub-channel and hv_sock channel, e.g. a 1-vCPU VM.
2382          */
2383         if (atomic_read(&vmbus_connection.nr_chan_close_on_suspend) > 0)
2384                 wait_for_completion(&vmbus_connection.ready_for_suspend_event);
2385
2386         WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) != 0);
2387
2388         mutex_lock(&vmbus_connection.channel_mutex);
2389
2390         list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
2391                 /*
2392                  * Remove the channel from the array of channels and invalidate
2393                  * the channel's relid.  Upon resume, vmbus_onoffer() will fix
2394                  * up the relid (and other fields, if necessary) and add the
2395                  * channel back to the array.
2396                  */
2397                 vmbus_channel_unmap_relid(channel);
2398                 channel->offermsg.child_relid = INVALID_RELID;
2399
2400                 if (is_hvsock_channel(channel)) {
2401                         if (!channel->rescind) {
2402                                 pr_err("hv_sock channel not rescinded!\n");
2403                                 WARN_ON_ONCE(1);
2404                         }
2405                         continue;
2406                 }
2407
2408                 spin_lock_irqsave(&channel->lock, flags);
2409                 list_for_each_entry(sc, &channel->sc_list, sc_list) {
2410                         pr_err("Sub-channel not deleted!\n");
2411                         WARN_ON_ONCE(1);
2412                 }
2413                 spin_unlock_irqrestore(&channel->lock, flags);
2414
2415                 atomic_inc(&vmbus_connection.nr_chan_fixup_on_resume);
2416         }
2417
2418         mutex_unlock(&vmbus_connection.channel_mutex);
2419
2420         vmbus_initiate_unload(false);
2421
2422         /* Reset the event for the next resume. */
2423         reinit_completion(&vmbus_connection.ready_for_resume_event);
2424
2425         return 0;
2426 }
2427
2428 static int vmbus_bus_resume(struct device *dev)
2429 {
2430         struct vmbus_channel_msginfo *msginfo;
2431         size_t msgsize;
2432         int ret;
2433
2434         /*
2435          * We only use the 'vmbus_proto_version', which was in use before
2436          * hibernation, to re-negotiate with the host.
2437          */
2438         if (!vmbus_proto_version) {
2439                 pr_err("Invalid proto version = 0x%x\n", vmbus_proto_version);
2440                 return -EINVAL;
2441         }
2442
2443         msgsize = sizeof(*msginfo) +
2444                   sizeof(struct vmbus_channel_initiate_contact);
2445
2446         msginfo = kzalloc(msgsize, GFP_KERNEL);
2447
2448         if (msginfo == NULL)
2449                 return -ENOMEM;
2450
2451         ret = vmbus_negotiate_version(msginfo, vmbus_proto_version);
2452
2453         kfree(msginfo);
2454
2455         if (ret != 0)
2456                 return ret;
2457
2458         WARN_ON(atomic_read(&vmbus_connection.nr_chan_fixup_on_resume) == 0);
2459
2460         vmbus_request_offers();
2461
2462         wait_for_completion(&vmbus_connection.ready_for_resume_event);
2463
2464         /* Reset the event for the next suspend. */
2465         reinit_completion(&vmbus_connection.ready_for_suspend_event);
2466
2467         return 0;
2468 }
2469 #else
2470 #define vmbus_bus_suspend NULL
2471 #define vmbus_bus_resume NULL
2472 #endif /* CONFIG_PM_SLEEP */
2473
2474 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
2475         {"VMBUS", 0},
2476         {"VMBus", 0},
2477         {"", 0},
2478 };
2479 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
2480
2481 /*
2482  * Note: we must use the "no_irq" ops, otherwise hibernation can not work with
2483  * PCI device assignment, because "pci_dev_pm_ops" uses the "noirq" ops: in
2484  * the resume path, the pci "noirq" restore op runs before "non-noirq" op (see
2485  * resume_target_kernel() -> dpm_resume_start(), and hibernation_restore() ->
2486  * dpm_resume_end()). This means vmbus_bus_resume() and the pci-hyperv's
2487  * resume callback must also run via the "noirq" ops.
2488  *
2489  * Set suspend_noirq/resume_noirq to NULL for Suspend-to-Idle: see the comment
2490  * earlier in this file before vmbus_pm.
2491  */
2492
2493 static const struct dev_pm_ops vmbus_bus_pm = {
2494         .suspend_noirq  = NULL,
2495         .resume_noirq   = NULL,
2496         .freeze_noirq   = vmbus_bus_suspend,
2497         .thaw_noirq     = vmbus_bus_resume,
2498         .poweroff_noirq = vmbus_bus_suspend,
2499         .restore_noirq  = vmbus_bus_resume
2500 };
2501
2502 static struct acpi_driver vmbus_acpi_driver = {
2503         .name = "vmbus",
2504         .ids = vmbus_acpi_device_ids,
2505         .ops = {
2506                 .add = vmbus_acpi_add,
2507                 .remove = vmbus_acpi_remove,
2508         },
2509         .drv.pm = &vmbus_bus_pm,
2510 };
2511
2512 static void hv_kexec_handler(void)
2513 {
2514         hv_stimer_global_cleanup();
2515         vmbus_initiate_unload(false);
2516         /* Make sure conn_state is set as hv_synic_cleanup checks for it */
2517         mb();
2518         cpuhp_remove_state(hyperv_cpuhp_online);
2519         hyperv_cleanup();
2520 };
2521
2522 static void hv_crash_handler(struct pt_regs *regs)
2523 {
2524         int cpu;
2525
2526         vmbus_initiate_unload(true);
2527         /*
2528          * In crash handler we can't schedule synic cleanup for all CPUs,
2529          * doing the cleanup for current CPU only. This should be sufficient
2530          * for kdump.
2531          */
2532         cpu = smp_processor_id();
2533         hv_stimer_cleanup(cpu);
2534         hv_synic_disable_regs(cpu);
2535         hyperv_cleanup();
2536 };
2537
2538 static int hv_synic_suspend(void)
2539 {
2540         /*
2541          * When we reach here, all the non-boot CPUs have been offlined.
2542          * If we're in a legacy configuration where stimer Direct Mode is
2543          * not enabled, the stimers on the non-boot CPUs have been unbound
2544          * in hv_synic_cleanup() -> hv_stimer_legacy_cleanup() ->
2545          * hv_stimer_cleanup() -> clockevents_unbind_device().
2546          *
2547          * hv_synic_suspend() only runs on CPU0 with interrupts disabled.
2548          * Here we do not call hv_stimer_legacy_cleanup() on CPU0 because:
2549          * 1) it's unnecessary as interrupts remain disabled between
2550          * syscore_suspend() and syscore_resume(): see create_image() and
2551          * resume_target_kernel()
2552          * 2) the stimer on CPU0 is automatically disabled later by
2553          * syscore_suspend() -> timekeeping_suspend() -> tick_suspend() -> ...
2554          * -> clockevents_shutdown() -> ... -> hv_ce_shutdown()
2555          * 3) a warning would be triggered if we call
2556          * clockevents_unbind_device(), which may sleep, in an
2557          * interrupts-disabled context.
2558          */
2559
2560         hv_synic_disable_regs(0);
2561
2562         return 0;
2563 }
2564
2565 static void hv_synic_resume(void)
2566 {
2567         hv_synic_enable_regs(0);
2568
2569         /*
2570          * Note: we don't need to call hv_stimer_init(0), because the timer
2571          * on CPU0 is not unbound in hv_synic_suspend(), and the timer is
2572          * automatically re-enabled in timekeeping_resume().
2573          */
2574 }
2575
2576 /* The callbacks run only on CPU0, with irqs_disabled. */
2577 static struct syscore_ops hv_synic_syscore_ops = {
2578         .suspend = hv_synic_suspend,
2579         .resume = hv_synic_resume,
2580 };
2581
2582 static int __init hv_acpi_init(void)
2583 {
2584         int ret, t;
2585
2586         if (!hv_is_hyperv_initialized())
2587                 return -ENODEV;
2588
2589         init_completion(&probe_event);
2590
2591         /*
2592          * Get ACPI resources first.
2593          */
2594         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2595
2596         if (ret)
2597                 return ret;
2598
2599         t = wait_for_completion_timeout(&probe_event, 5*HZ);
2600         if (t == 0) {
2601                 ret = -ETIMEDOUT;
2602                 goto cleanup;
2603         }
2604         hv_debug_init();
2605
2606         ret = vmbus_bus_init();
2607         if (ret)
2608                 goto cleanup;
2609
2610         hv_setup_kexec_handler(hv_kexec_handler);
2611         hv_setup_crash_handler(hv_crash_handler);
2612
2613         register_syscore_ops(&hv_synic_syscore_ops);
2614
2615         return 0;
2616
2617 cleanup:
2618         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2619         hv_acpi_dev = NULL;
2620         return ret;
2621 }
2622
2623 static void __exit vmbus_exit(void)
2624 {
2625         int cpu;
2626
2627         unregister_syscore_ops(&hv_synic_syscore_ops);
2628
2629         hv_remove_kexec_handler();
2630         hv_remove_crash_handler();
2631         vmbus_connection.conn_state = DISCONNECTED;
2632         hv_stimer_global_cleanup();
2633         vmbus_disconnect();
2634         hv_remove_vmbus_irq();
2635         for_each_online_cpu(cpu) {
2636                 struct hv_per_cpu_context *hv_cpu
2637                         = per_cpu_ptr(hv_context.cpu_context, cpu);
2638
2639                 tasklet_kill(&hv_cpu->msg_dpc);
2640         }
2641         hv_debug_rm_all_dir();
2642
2643         vmbus_free_channels();
2644         kfree(vmbus_connection.channels);
2645
2646         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2647                 kmsg_dump_unregister(&hv_kmsg_dumper);
2648                 unregister_die_notifier(&hyperv_die_block);
2649                 atomic_notifier_chain_unregister(&panic_notifier_list,
2650                                                  &hyperv_panic_block);
2651         }
2652
2653         free_page((unsigned long)hv_panic_page);
2654         unregister_sysctl_table(hv_ctl_table_hdr);
2655         hv_ctl_table_hdr = NULL;
2656         bus_unregister(&hv_bus);
2657
2658         cpuhp_remove_state(hyperv_cpuhp_online);
2659         hv_synic_free();
2660         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2661 }
2662
2663
2664 MODULE_LICENSE("GPL");
2665 MODULE_DESCRIPTION("Microsoft Hyper-V VMBus Driver");
2666
2667 subsys_initcall(hv_acpi_init);
2668 module_exit(vmbus_exit);