drivers/hv/vmbus_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *   K. Y. Srinivasan <kys@microsoft.com>
  21  *
  22  */
  23 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  24
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/device.h>
  28 #include <linux/interrupt.h>
  29 #include <linux/sysctl.h>
  30 #include <linux/slab.h>
  31 #include <linux/acpi.h>
  32 #include <linux/completion.h>
  33 #include <linux/hyperv.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/clockchips.h>
  36 #include <linux/cpu.h>
  37 #include <linux/sched/task_stack.h>
  38
  39 #include <asm/mshyperv.h>
  40 #include <linux/notifier.h>
  41 #include <linux/ptrace.h>
  42 #include <linux/screen_info.h>
  43 #include <linux/kdebug.h>
  44 #include <linux/efi.h>
  45 #include <linux/random.h>
  46 #include "hyperv_vmbus.h"
  47
  48 struct vmbus_dynid {
  49         struct list_head node;
  50         struct hv_vmbus_device_id id;
  51 };
  52
  53 static struct acpi_device  *hv_acpi_dev;
  54
  55 static struct completion probe_event;
  56
  57 static int hyperv_cpuhp_online;
  58
  59 static void *hv_panic_page;
  60
  61 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  62                               void *args)
  63 {
  64         struct pt_regs *regs;
  65
  66         regs = current_pt_regs();
  67
  68         hyperv_report_panic(regs, val);
  69         return NOTIFY_DONE;
  70 }
  71
  72 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  73                             void *args)
  74 {
  75         struct die_args *die = (struct die_args *)args;
  76         struct pt_regs *regs = die->regs;
  77
  78         hyperv_report_panic(regs, val);
  79         return NOTIFY_DONE;
  80 }
  81
  82 static struct notifier_block hyperv_die_block = {
  83         .notifier_call = hyperv_die_event,
  84 };
  85 static struct notifier_block hyperv_panic_block = {
  86         .notifier_call = hyperv_panic_event,
  87 };
  88
  89 static const char *fb_mmio_name = "fb_range";
  90 static struct resource *fb_mmio;
  91 static struct resource *hyperv_mmio;
  92 static DEFINE_SEMAPHORE(hyperv_mmio_lock);
  93
  94 static int vmbus_exists(void)
  95 {
  96         if (hv_acpi_dev == NULL)
  97                 return -ENODEV;
  98
  99         return 0;
 100 }
 101
 102 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 103 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 104 {
 105         int i;
 106         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 107                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 108 }
 109
 110 static u8 channel_monitor_group(const struct vmbus_channel *channel)
 111 {
 112         return (u8)channel->offermsg.monitorid / 32;
 113 }
 114
 115 static u8 channel_monitor_offset(const struct vmbus_channel *channel)
 116 {
 117         return (u8)channel->offermsg.monitorid % 32;
 118 }
 119
 120 static u32 channel_pending(const struct vmbus_channel *channel,
 121                            const struct hv_monitor_page *monitor_page)
 122 {
 123         u8 monitor_group = channel_monitor_group(channel);
 124
 125         return monitor_page->trigger_group[monitor_group].pending;
 126 }
 127
 128 static u32 channel_latency(const struct vmbus_channel *channel,
 129                            const struct hv_monitor_page *monitor_page)
 130 {
 131         u8 monitor_group = channel_monitor_group(channel);
 132         u8 monitor_offset = channel_monitor_offset(channel);
 133
 134         return monitor_page->latency[monitor_group][monitor_offset];
 135 }
 136
 137 static u32 channel_conn_id(struct vmbus_channel *channel,
 138                            struct hv_monitor_page *monitor_page)
 139 {
 140         u8 monitor_group = channel_monitor_group(channel);
 141         u8 monitor_offset = channel_monitor_offset(channel);
 142         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 143 }
 144
 145 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 146                        char *buf)
 147 {
 148         struct hv_device *hv_dev = device_to_hv_device(dev);
 149
 150         if (!hv_dev->channel)
 151                 return -ENODEV;
 152         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 153 }
 154 static DEVICE_ATTR_RO(id);
 155
 156 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 157                           char *buf)
 158 {
 159         struct hv_device *hv_dev = device_to_hv_device(dev);
 160
 161         if (!hv_dev->channel)
 162                 return -ENODEV;
 163         return sprintf(buf, "%d\n", hv_dev->channel->state);
 164 }
 165 static DEVICE_ATTR_RO(state);
 166
 167 static ssize_t monitor_id_show(struct device *dev,
 168                                struct device_attribute *dev_attr, char *buf)
 169 {
 170         struct hv_device *hv_dev = device_to_hv_device(dev);
 171
 172         if (!hv_dev->channel)
 173                 return -ENODEV;
 174         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 175 }
 176 static DEVICE_ATTR_RO(monitor_id);
 177
 178 static ssize_t class_id_show(struct device *dev,
 179                                struct device_attribute *dev_attr, char *buf)
 180 {
 181         struct hv_device *hv_dev = device_to_hv_device(dev);
 182
 183         if (!hv_dev->channel)
 184                 return -ENODEV;
 185         return sprintf(buf, "{%pUl}\n",
 186                        hv_dev->channel->offermsg.offer.if_type.b);
 187 }
 188 static DEVICE_ATTR_RO(class_id);
 189
 190 static ssize_t device_id_show(struct device *dev,
 191                               struct device_attribute *dev_attr, char *buf)
 192 {
 193         struct hv_device *hv_dev = device_to_hv_device(dev);
 194
 195         if (!hv_dev->channel)
 196                 return -ENODEV;
 197         return sprintf(buf, "{%pUl}\n",
 198                        hv_dev->channel->offermsg.offer.if_instance.b);
 199 }
 200 static DEVICE_ATTR_RO(device_id);
 201
 202 static ssize_t modalias_show(struct device *dev,
 203                              struct device_attribute *dev_attr, char *buf)
 204 {
 205         struct hv_device *hv_dev = device_to_hv_device(dev);
 206         char alias_name[VMBUS_ALIAS_LEN + 1];
 207
 208         print_alias_name(hv_dev, alias_name);
 209         return sprintf(buf, "vmbus:%s\n", alias_name);
 210 }
 211 static DEVICE_ATTR_RO(modalias);
 212
 213 #ifdef CONFIG_NUMA
 214 static ssize_t numa_node_show(struct device *dev,
 215                               struct device_attribute *attr, char *buf)
 216 {
 217         struct hv_device *hv_dev = device_to_hv_device(dev);
 218
 219         if (!hv_dev->channel)
 220                 return -ENODEV;
 221
 222         return sprintf(buf, "%d\n", hv_dev->channel->numa_node);
 223 }
 224 static DEVICE_ATTR_RO(numa_node);
 225 #endif
 226
 227 static ssize_t server_monitor_pending_show(struct device *dev,
 228                                            struct device_attribute *dev_attr,
 229                                            char *buf)
 230 {
 231         struct hv_device *hv_dev = device_to_hv_device(dev);
 232
 233         if (!hv_dev->channel)
 234                 return -ENODEV;
 235         return sprintf(buf, "%d\n",
 236                        channel_pending(hv_dev->channel,
 237                                        vmbus_connection.monitor_pages[1]));
 238 }
 239 static DEVICE_ATTR_RO(server_monitor_pending);
 240
 241 static ssize_t client_monitor_pending_show(struct device *dev,
 242                                            struct device_attribute *dev_attr,
 243                                            char *buf)
 244 {
 245         struct hv_device *hv_dev = device_to_hv_device(dev);
 246
 247         if (!hv_dev->channel)
 248                 return -ENODEV;
 249         return sprintf(buf, "%d\n",
 250                        channel_pending(hv_dev->channel,
 251                                        vmbus_connection.monitor_pages[1]));
 252 }
 253 static DEVICE_ATTR_RO(client_monitor_pending);
 254
 255 static ssize_t server_monitor_latency_show(struct device *dev,
 256                                            struct device_attribute *dev_attr,
 257                                            char *buf)
 258 {
 259         struct hv_device *hv_dev = device_to_hv_device(dev);
 260
 261         if (!hv_dev->channel)
 262                 return -ENODEV;
 263         return sprintf(buf, "%d\n",
 264                        channel_latency(hv_dev->channel,
 265                                        vmbus_connection.monitor_pages[0]));
 266 }
 267 static DEVICE_ATTR_RO(server_monitor_latency);
 268
 269 static ssize_t client_monitor_latency_show(struct device *dev,
 270                                            struct device_attribute *dev_attr,
 271                                            char *buf)
 272 {
 273         struct hv_device *hv_dev = device_to_hv_device(dev);
 274
 275         if (!hv_dev->channel)
 276                 return -ENODEV;
 277         return sprintf(buf, "%d\n",
 278                        channel_latency(hv_dev->channel,
 279                                        vmbus_connection.monitor_pages[1]));
 280 }
 281 static DEVICE_ATTR_RO(client_monitor_latency);
 282
 283 static ssize_t server_monitor_conn_id_show(struct device *dev,
 284                                            struct device_attribute *dev_attr,
 285                                            char *buf)
 286 {
 287         struct hv_device *hv_dev = device_to_hv_device(dev);
 288
 289         if (!hv_dev->channel)
 290                 return -ENODEV;
 291         return sprintf(buf, "%d\n",
 292                        channel_conn_id(hv_dev->channel,
 293                                        vmbus_connection.monitor_pages[0]));
 294 }
 295 static DEVICE_ATTR_RO(server_monitor_conn_id);
 296
 297 static ssize_t client_monitor_conn_id_show(struct device *dev,
 298                                            struct device_attribute *dev_attr,
 299                                            char *buf)
 300 {
 301         struct hv_device *hv_dev = device_to_hv_device(dev);
 302
 303         if (!hv_dev->channel)
 304                 return -ENODEV;
 305         return sprintf(buf, "%d\n",
 306                        channel_conn_id(hv_dev->channel,
 307                                        vmbus_connection.monitor_pages[1]));
 308 }
 309 static DEVICE_ATTR_RO(client_monitor_conn_id);
 310
 311 static ssize_t out_intr_mask_show(struct device *dev,
 312                                   struct device_attribute *dev_attr, char *buf)
 313 {
 314         struct hv_device *hv_dev = device_to_hv_device(dev);
 315         struct hv_ring_buffer_debug_info outbound;
 316         int ret;
 317
 318         if (!hv_dev->channel)
 319                 return -ENODEV;
 320
 321         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 322                                           &outbound);
 323         if (ret < 0)
 324                 return ret;
 325
 326         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 327 }
 328 static DEVICE_ATTR_RO(out_intr_mask);
 329
 330 static ssize_t out_read_index_show(struct device *dev,
 331                                    struct device_attribute *dev_attr, char *buf)
 332 {
 333         struct hv_device *hv_dev = device_to_hv_device(dev);
 334         struct hv_ring_buffer_debug_info outbound;
 335         int ret;
 336
 337         if (!hv_dev->channel)
 338                 return -ENODEV;
 339
 340         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 341                                           &outbound);
 342         if (ret < 0)
 343                 return ret;
 344         return sprintf(buf, "%d\n", outbound.current_read_index);
 345 }
 346 static DEVICE_ATTR_RO(out_read_index);
 347
 348 static ssize_t out_write_index_show(struct device *dev,
 349                                     struct device_attribute *dev_attr,
 350                                     char *buf)
 351 {
 352         struct hv_device *hv_dev = device_to_hv_device(dev);
 353         struct hv_ring_buffer_debug_info outbound;
 354         int ret;
 355
 356         if (!hv_dev->channel)
 357                 return -ENODEV;
 358
 359         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 360                                           &outbound);
 361         if (ret < 0)
 362                 return ret;
 363         return sprintf(buf, "%d\n", outbound.current_write_index);
 364 }
 365 static DEVICE_ATTR_RO(out_write_index);
 366
 367 static ssize_t out_read_bytes_avail_show(struct device *dev,
 368                                          struct device_attribute *dev_attr,
 369                                          char *buf)
 370 {
 371         struct hv_device *hv_dev = device_to_hv_device(dev);
 372         struct hv_ring_buffer_debug_info outbound;
 373         int ret;
 374
 375         if (!hv_dev->channel)
 376                 return -ENODEV;
 377
 378         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 379                                           &outbound);
 380         if (ret < 0)
 381                 return ret;
 382         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 383 }
 384 static DEVICE_ATTR_RO(out_read_bytes_avail);
 385
 386 static ssize_t out_write_bytes_avail_show(struct device *dev,
 387                                           struct device_attribute *dev_attr,
 388                                           char *buf)
 389 {
 390         struct hv_device *hv_dev = device_to_hv_device(dev);
 391         struct hv_ring_buffer_debug_info outbound;
 392         int ret;
 393
 394         if (!hv_dev->channel)
 395                 return -ENODEV;
 396
 397         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound,
 398                                           &outbound);
 399         if (ret < 0)
 400                 return ret;
 401         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 402 }
 403 static DEVICE_ATTR_RO(out_write_bytes_avail);
 404
 405 static ssize_t in_intr_mask_show(struct device *dev,
 406                                  struct device_attribute *dev_attr, char *buf)
 407 {
 408         struct hv_device *hv_dev = device_to_hv_device(dev);
 409         struct hv_ring_buffer_debug_info inbound;
 410         int ret;
 411
 412         if (!hv_dev->channel)
 413                 return -ENODEV;
 414
 415         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 416         if (ret < 0)
 417                 return ret;
 418
 419         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 420 }
 421 static DEVICE_ATTR_RO(in_intr_mask);
 422
 423 static ssize_t in_read_index_show(struct device *dev,
 424                                   struct device_attribute *dev_attr, char *buf)
 425 {
 426         struct hv_device *hv_dev = device_to_hv_device(dev);
 427         struct hv_ring_buffer_debug_info inbound;
 428         int ret;
 429
 430         if (!hv_dev->channel)
 431                 return -ENODEV;
 432
 433         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 434         if (ret < 0)
 435                 return ret;
 436
 437         return sprintf(buf, "%d\n", inbound.current_read_index);
 438 }
 439 static DEVICE_ATTR_RO(in_read_index);
 440
 441 static ssize_t in_write_index_show(struct device *dev,
 442                                    struct device_attribute *dev_attr, char *buf)
 443 {
 444         struct hv_device *hv_dev = device_to_hv_device(dev);
 445         struct hv_ring_buffer_debug_info inbound;
 446         int ret;
 447
 448         if (!hv_dev->channel)
 449                 return -ENODEV;
 450
 451         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 452         if (ret < 0)
 453                 return ret;
 454
 455         return sprintf(buf, "%d\n", inbound.current_write_index);
 456 }
 457 static DEVICE_ATTR_RO(in_write_index);
 458
 459 static ssize_t in_read_bytes_avail_show(struct device *dev,
 460                                         struct device_attribute *dev_attr,
 461                                         char *buf)
 462 {
 463         struct hv_device *hv_dev = device_to_hv_device(dev);
 464         struct hv_ring_buffer_debug_info inbound;
 465         int ret;
 466
 467         if (!hv_dev->channel)
 468                 return -ENODEV;
 469
 470         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 471         if (ret < 0)
 472                 return ret;
 473
 474         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 475 }
 476 static DEVICE_ATTR_RO(in_read_bytes_avail);
 477
 478 static ssize_t in_write_bytes_avail_show(struct device *dev,
 479                                          struct device_attribute *dev_attr,
 480                                          char *buf)
 481 {
 482         struct hv_device *hv_dev = device_to_hv_device(dev);
 483         struct hv_ring_buffer_debug_info inbound;
 484         int ret;
 485
 486         if (!hv_dev->channel)
 487                 return -ENODEV;
 488
 489         ret = hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 490         if (ret < 0)
 491                 return ret;
 492
 493         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 494 }
 495 static DEVICE_ATTR_RO(in_write_bytes_avail);
 496
 497 static ssize_t channel_vp_mapping_show(struct device *dev,
 498                                        struct device_attribute *dev_attr,
 499                                        char *buf)
 500 {
 501         struct hv_device *hv_dev = device_to_hv_device(dev);
 502         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 503         unsigned long flags;
 504         int buf_size = PAGE_SIZE, n_written, tot_written;
 505         struct list_head *cur;
 506
 507         if (!channel)
 508                 return -ENODEV;
 509
 510         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 511                 channel->offermsg.child_relid, channel->target_cpu);
 512
 513         spin_lock_irqsave(&channel->lock, flags);
 514
 515         list_for_each(cur, &channel->sc_list) {
 516                 if (tot_written >= buf_size - 1)
 517                         break;
 518
 519                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 520                 n_written = scnprintf(buf + tot_written,
 521                                      buf_size - tot_written,
 522                                      "%u:%u\n",
 523                                      cur_sc->offermsg.child_relid,
 524                                      cur_sc->target_cpu);
 525                 tot_written += n_written;
 526         }
 527
 528         spin_unlock_irqrestore(&channel->lock, flags);
 529
 530         return tot_written;
 531 }
 532 static DEVICE_ATTR_RO(channel_vp_mapping);
 533
 534 static ssize_t vendor_show(struct device *dev,
 535                            struct device_attribute *dev_attr,
 536                            char *buf)
 537 {
 538         struct hv_device *hv_dev = device_to_hv_device(dev);
 539         return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
 540 }
 541 static DEVICE_ATTR_RO(vendor);
 542
 543 static ssize_t device_show(struct device *dev,
 544                            struct device_attribute *dev_attr,
 545                            char *buf)
 546 {
 547         struct hv_device *hv_dev = device_to_hv_device(dev);
 548         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 549 }
 550 static DEVICE_ATTR_RO(device);
 551
 552 static ssize_t driver_override_store(struct device *dev,
 553                                      struct device_attribute *attr,
 554                                      const char *buf, size_t count)
 555 {
 556         struct hv_device *hv_dev = device_to_hv_device(dev);
 557         char *driver_override, *old, *cp;
 558
 559         /* We need to keep extra room for a newline */
 560         if (count >= (PAGE_SIZE - 1))
 561                 return -EINVAL;
 562
 563         driver_override = kstrndup(buf, count, GFP_KERNEL);
 564         if (!driver_override)
 565                 return -ENOMEM;
 566
 567         cp = strchr(driver_override, '\n');
 568         if (cp)
 569                 *cp = '\0';
 570
 571         device_lock(dev);
 572         old = hv_dev->driver_override;
 573         if (strlen(driver_override)) {
 574                 hv_dev->driver_override = driver_override;
 575         } else {
 576                 kfree(driver_override);
 577                 hv_dev->driver_override = NULL;
 578         }
 579         device_unlock(dev);
 580
 581         kfree(old);
 582
 583         return count;
 584 }
 585
 586 static ssize_t driver_override_show(struct device *dev,
 587                                     struct device_attribute *attr, char *buf)
 588 {
 589         struct hv_device *hv_dev = device_to_hv_device(dev);
 590         ssize_t len;
 591
 592         device_lock(dev);
 593         len = snprintf(buf, PAGE_SIZE, "%s\n", hv_dev->driver_override);
 594         device_unlock(dev);
 595
 596         return len;
 597 }
 598 static DEVICE_ATTR_RW(driver_override);
 599
 600 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 601 static struct attribute *vmbus_dev_attrs[] = {
 602         &dev_attr_id.attr,
 603         &dev_attr_state.attr,
 604         &dev_attr_monitor_id.attr,
 605         &dev_attr_class_id.attr,
 606         &dev_attr_device_id.attr,
 607         &dev_attr_modalias.attr,
 608 #ifdef CONFIG_NUMA
 609         &dev_attr_numa_node.attr,
 610 #endif
 611         &dev_attr_server_monitor_pending.attr,
 612         &dev_attr_client_monitor_pending.attr,
 613         &dev_attr_server_monitor_latency.attr,
 614         &dev_attr_client_monitor_latency.attr,
 615         &dev_attr_server_monitor_conn_id.attr,
 616         &dev_attr_client_monitor_conn_id.attr,
 617         &dev_attr_out_intr_mask.attr,
 618         &dev_attr_out_read_index.attr,
 619         &dev_attr_out_write_index.attr,
 620         &dev_attr_out_read_bytes_avail.attr,
 621         &dev_attr_out_write_bytes_avail.attr,
 622         &dev_attr_in_intr_mask.attr,
 623         &dev_attr_in_read_index.attr,
 624         &dev_attr_in_write_index.attr,
 625         &dev_attr_in_read_bytes_avail.attr,
 626         &dev_attr_in_write_bytes_avail.attr,
 627         &dev_attr_channel_vp_mapping.attr,
 628         &dev_attr_vendor.attr,
 629         &dev_attr_device.attr,
 630         &dev_attr_driver_override.attr,
 631         NULL,
 632 };
 633 ATTRIBUTE_GROUPS(vmbus_dev);
 634
 635 /*
 636  * vmbus_uevent - add uevent for our device
 637  *
 638  * This routine is invoked when a device is added or removed on the vmbus to
 639  * generate a uevent to udev in the userspace. The udev will then look at its
 640  * rule and the uevent generated here to load the appropriate driver
 641  *
 642  * The alias string will be of the form vmbus:guid where guid is the string
 643  * representation of the device guid (each byte of the guid will be
 644  * represented with two hex characters.
 645  */
 646 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 647 {
 648         struct hv_device *dev = device_to_hv_device(device);
 649         int ret;
 650         char alias_name[VMBUS_ALIAS_LEN + 1];
 651
 652         print_alias_name(dev, alias_name);
 653         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 654         return ret;
 655 }
 656
 657 static const uuid_le null_guid;
 658
 659 static inline bool is_null_guid(const uuid_le *guid)
 660 {
 661         if (uuid_le_cmp(*guid, null_guid))
 662                 return false;
 663         return true;
 664 }
 665
 666 static const struct hv_vmbus_device_id *
 667 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const uuid_le *guid)
 668
 669 {
 670         if (id == NULL)
 671                 return NULL; /* empty device table */
 672
 673         for (; !is_null_guid(&id->guid); id++)
 674                 if (!uuid_le_cmp(id->guid, *guid))
 675                         return id;
 676
 677         return NULL;
 678 }
 679
 680 static const struct hv_vmbus_device_id *
 681 hv_vmbus_dynid_match(struct hv_driver *drv, const uuid_le *guid)
 682 {
 683         const struct hv_vmbus_device_id *id = NULL;
 684         struct vmbus_dynid *dynid;
 685
 686         spin_lock(&drv->dynids.lock);
 687         list_for_each_entry(dynid, &drv->dynids.list, node) {
 688                 if (!uuid_le_cmp(dynid->id.guid, *guid)) {
 689                         id = &dynid->id;
 690                         break;
 691                 }
 692         }
 693         spin_unlock(&drv->dynids.lock);
 694
 695         return id;
 696 }
 697
 698 static const struct hv_vmbus_device_id vmbus_device_null = {
 699         .guid = NULL_UUID_LE,
 700 };
 701
 702 /*
 703  * Return a matching hv_vmbus_device_id pointer.
 704  * If there is no match, return NULL.
 705  */
 706 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 707                                                         struct hv_device *dev)
 708 {
 709         const uuid_le *guid = &dev->dev_type;
 710         const struct hv_vmbus_device_id *id;
 711
 712         /* When driver_override is set, only bind to the matching driver */
 713         if (dev->driver_override && strcmp(dev->driver_override, drv->name))
 714                 return NULL;
 715
 716         /* Look at the dynamic ids first, before the static ones */
 717         id = hv_vmbus_dynid_match(drv, guid);
 718         if (!id)
 719                 id = hv_vmbus_dev_match(drv->id_table, guid);
 720
 721         /* driver_override will always match, send a dummy id */
 722         if (!id && dev->driver_override)
 723                 id = &vmbus_device_null;
 724
 725         return id;
 726 }
 727
 728 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
 729 static int vmbus_add_dynid(struct hv_driver *drv, uuid_le *guid)
 730 {
 731         struct vmbus_dynid *dynid;
 732
 733         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
 734         if (!dynid)
 735                 return -ENOMEM;
 736
 737         dynid->id.guid = *guid;
 738
 739         spin_lock(&drv->dynids.lock);
 740         list_add_tail(&dynid->node, &drv->dynids.list);
 741         spin_unlock(&drv->dynids.lock);
 742
 743         return driver_attach(&drv->driver);
 744 }
 745
 746 static void vmbus_free_dynids(struct hv_driver *drv)
 747 {
 748         struct vmbus_dynid *dynid, *n;
 749
 750         spin_lock(&drv->dynids.lock);
 751         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 752                 list_del(&dynid->node);
 753                 kfree(dynid);
 754         }
 755         spin_unlock(&drv->dynids.lock);
 756 }
 757
 758 /*
 759  * store_new_id - sysfs frontend to vmbus_add_dynid()
 760  *
 761  * Allow GUIDs to be added to an existing driver via sysfs.
 762  */
 763 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
 764                             size_t count)
 765 {
 766         struct hv_driver *drv = drv_to_hv_drv(driver);
 767         uuid_le guid;
 768         ssize_t retval;
 769
 770         retval = uuid_le_to_bin(buf, &guid);
 771         if (retval)
 772                 return retval;
 773
 774         if (hv_vmbus_dynid_match(drv, &guid))
 775                 return -EEXIST;
 776
 777         retval = vmbus_add_dynid(drv, &guid);
 778         if (retval)
 779                 return retval;
 780         return count;
 781 }
 782 static DRIVER_ATTR_WO(new_id);
 783
 784 /*
 785  * store_remove_id - remove a PCI device ID from this driver
 786  *
 787  * Removes a dynamic pci device ID to this driver.
 788  */
 789 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 790                                size_t count)
 791 {
 792         struct hv_driver *drv = drv_to_hv_drv(driver);
 793         struct vmbus_dynid *dynid, *n;
 794         uuid_le guid;
 795         ssize_t retval;
 796
 797         retval = uuid_le_to_bin(buf, &guid);
 798         if (retval)
 799                 return retval;
 800
 801         retval = -ENODEV;
 802         spin_lock(&drv->dynids.lock);
 803         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 804                 struct hv_vmbus_device_id *id = &dynid->id;
 805
 806                 if (!uuid_le_cmp(id->guid, guid)) {
 807                         list_del(&dynid->node);
 808                         kfree(dynid);
 809                         retval = count;
 810                         break;
 811                 }
 812         }
 813         spin_unlock(&drv->dynids.lock);
 814
 815         return retval;
 816 }
 817 static DRIVER_ATTR_WO(remove_id);
 818
 819 static struct attribute *vmbus_drv_attrs[] = {
 820         &driver_attr_new_id.attr,
 821         &driver_attr_remove_id.attr,
 822         NULL,
 823 };
 824 ATTRIBUTE_GROUPS(vmbus_drv);
 825
 826
 827 /*
 828  * vmbus_match - Attempt to match the specified device to the specified driver
 829  */
 830 static int vmbus_match(struct device *device, struct device_driver *driver)
 831 {
 832         struct hv_driver *drv = drv_to_hv_drv(driver);
 833         struct hv_device *hv_dev = device_to_hv_device(device);
 834
 835         /* The hv_sock driver handles all hv_sock offers. */
 836         if (is_hvsock_channel(hv_dev->channel))
 837                 return drv->hvsock;
 838
 839         if (hv_vmbus_get_id(drv, hv_dev))
 840                 return 1;
 841
 842         return 0;
 843 }
 844
 845 /*
 846  * vmbus_probe - Add the new vmbus's child device
 847  */
 848 static int vmbus_probe(struct device *child_device)
 849 {
 850         int ret = 0;
 851         struct hv_driver *drv =
 852                         drv_to_hv_drv(child_device->driver);
 853         struct hv_device *dev = device_to_hv_device(child_device);
 854         const struct hv_vmbus_device_id *dev_id;
 855
 856         dev_id = hv_vmbus_get_id(drv, dev);
 857         if (drv->probe) {
 858                 ret = drv->probe(dev, dev_id);
 859                 if (ret != 0)
 860                         pr_err("probe failed for device %s (%d)\n",
 861                                dev_name(child_device), ret);
 862
 863         } else {
 864                 pr_err("probe not set for driver %s\n",
 865                        dev_name(child_device));
 866                 ret = -ENODEV;
 867         }
 868         return ret;
 869 }
 870
 871 /*
 872  * vmbus_remove - Remove a vmbus device
 873  */
 874 static int vmbus_remove(struct device *child_device)
 875 {
 876         struct hv_driver *drv;
 877         struct hv_device *dev = device_to_hv_device(child_device);
 878
 879         if (child_device->driver) {
 880                 drv = drv_to_hv_drv(child_device->driver);
 881                 if (drv->remove)
 882                         drv->remove(dev);
 883         }
 884
 885         return 0;
 886 }
 887
 888
 889 /*
 890  * vmbus_shutdown - Shutdown a vmbus device
 891  */
 892 static void vmbus_shutdown(struct device *child_device)
 893 {
 894         struct hv_driver *drv;
 895         struct hv_device *dev = device_to_hv_device(child_device);
 896
 897
 898         /* The device may not be attached yet */
 899         if (!child_device->driver)
 900                 return;
 901
 902         drv = drv_to_hv_drv(child_device->driver);
 903
 904         if (drv->shutdown)
 905                 drv->shutdown(dev);
 906 }
 907
 908
 909 /*
 910  * vmbus_device_release - Final callback release of the vmbus child device
 911  */
 912 static void vmbus_device_release(struct device *device)
 913 {
 914         struct hv_device *hv_dev = device_to_hv_device(device);
 915         struct vmbus_channel *channel = hv_dev->channel;
 916
 917         mutex_lock(&vmbus_connection.channel_mutex);
 918         hv_process_channel_removal(channel);
 919         mutex_unlock(&vmbus_connection.channel_mutex);
 920         kfree(hv_dev);
 921 }
 922
 923 /* The one and only one */
 924 static struct bus_type  hv_bus = {
 925         .name =         "vmbus",
 926         .match =                vmbus_match,
 927         .shutdown =             vmbus_shutdown,
 928         .remove =               vmbus_remove,
 929         .probe =                vmbus_probe,
 930         .uevent =               vmbus_uevent,
 931         .dev_groups =           vmbus_dev_groups,
 932         .drv_groups =           vmbus_drv_groups,
 933 };
 934
 935 struct onmessage_work_context {
 936         struct work_struct work;
 937         struct hv_message msg;
 938 };
 939
 940 static void vmbus_onmessage_work(struct work_struct *work)
 941 {
 942         struct onmessage_work_context *ctx;
 943
 944         /* Do not process messages if we're in DISCONNECTED state */
 945         if (vmbus_connection.conn_state == DISCONNECTED)
 946                 return;
 947
 948         ctx = container_of(work, struct onmessage_work_context,
 949                            work);
 950         vmbus_onmessage(&ctx->msg);
 951         kfree(ctx);
 952 }
 953
 954 static void hv_process_timer_expiration(struct hv_message *msg,
 955                                         struct hv_per_cpu_context *hv_cpu)
 956 {
 957         struct clock_event_device *dev = hv_cpu->clk_evt;
 958
 959         if (dev->event_handler)
 960                 dev->event_handler(dev);
 961
 962         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
 963 }
 964
 965 void vmbus_on_msg_dpc(unsigned long data)
 966 {
 967         struct hv_per_cpu_context *hv_cpu = (void *)data;
 968         void *page_addr = hv_cpu->synic_message_page;
 969         struct hv_message *msg = (struct hv_message *)page_addr +
 970                                   VMBUS_MESSAGE_SINT;
 971         struct vmbus_channel_message_header *hdr;
 972         const struct vmbus_channel_message_table_entry *entry;
 973         struct onmessage_work_context *ctx;
 974         u32 message_type = msg->header.message_type;
 975
 976         if (message_type == HVMSG_NONE)
 977                 /* no msg */
 978                 return;
 979
 980         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 981
 982         trace_vmbus_on_msg_dpc(hdr);
 983
 984         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 985                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 986                 goto msg_handled;
 987         }
 988
 989         entry = &channel_message_table[hdr->msgtype];
 990         if (entry->handler_type == VMHT_BLOCKING) {
 991                 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 992                 if (ctx == NULL)
 993                         return;
 994
 995                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
 996                 memcpy(&ctx->msg, msg, sizeof(*msg));
 997
 998                 /*
 999                  * The host can generate a rescind message while we
1000                  * may still be handling the original offer. We deal with
1001                  * this condition by ensuring the processing is done on the
1002                  * same CPU.
1003                  */
1004                 switch (hdr->msgtype) {
1005                 case CHANNELMSG_RESCIND_CHANNELOFFER:
1006                         /*
1007                          * If we are handling the rescind message;
1008                          * schedule the work on the global work queue.
1009                          */
1010                         schedule_work_on(vmbus_connection.connect_cpu,
1011                                          &ctx->work);
1012                         break;
1013
1014                 case CHANNELMSG_OFFERCHANNEL:
1015                         atomic_inc(&vmbus_connection.offer_in_progress);
1016                         queue_work_on(vmbus_connection.connect_cpu,
1017                                       vmbus_connection.work_queue,
1018                                       &ctx->work);
1019                         break;
1020
1021                 default:
1022                         queue_work(vmbus_connection.work_queue, &ctx->work);
1023                 }
1024         } else
1025                 entry->message_handler(hdr);
1026
1027 msg_handled:
1028         vmbus_signal_eom(msg, message_type);
1029 }
1030
1031
1032 /*
1033  * Direct callback for channels using other deferred processing
1034  */
1035 static void vmbus_channel_isr(struct vmbus_channel *channel)
1036 {
1037         void (*callback_fn)(void *);
1038
1039         callback_fn = READ_ONCE(channel->onchannel_callback);
1040         if (likely(callback_fn != NULL))
1041                 (*callback_fn)(channel->channel_callback_context);
1042 }
1043
1044 /*
1045  * Schedule all channels with events pending
1046  */
1047 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1048 {
1049         unsigned long *recv_int_page;
1050         u32 maxbits, relid;
1051
1052         if (vmbus_proto_version < VERSION_WIN8) {
1053                 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1054                 recv_int_page = vmbus_connection.recv_int_page;
1055         } else {
1056                 /*
1057                  * When the host is win8 and beyond, the event page
1058                  * can be directly checked to get the id of the channel
1059                  * that has the interrupt pending.
1060                  */
1061                 void *page_addr = hv_cpu->synic_event_page;
1062                 union hv_synic_event_flags *event
1063                         = (union hv_synic_event_flags *)page_addr +
1064                                                  VMBUS_MESSAGE_SINT;
1065
1066                 maxbits = HV_EVENT_FLAGS_COUNT;
1067                 recv_int_page = event->flags;
1068         }
1069
1070         if (unlikely(!recv_int_page))
1071                 return;
1072
1073         for_each_set_bit(relid, recv_int_page, maxbits) {
1074                 struct vmbus_channel *channel;
1075
1076                 if (!sync_test_and_clear_bit(relid, recv_int_page))
1077                         continue;
1078
1079                 /* Special case - vmbus channel protocol msg */
1080                 if (relid == 0)
1081                         continue;
1082
1083                 rcu_read_lock();
1084
1085                 /* Find channel based on relid */
1086                 list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
1087                         if (channel->offermsg.child_relid != relid)
1088                                 continue;
1089
1090                         if (channel->rescind)
1091                                 continue;
1092
1093                         trace_vmbus_chan_sched(channel);
1094
1095                         ++channel->interrupts;
1096
1097                         switch (channel->callback_mode) {
1098                         case HV_CALL_ISR:
1099                                 vmbus_channel_isr(channel);
1100                                 break;
1101
1102                         case HV_CALL_BATCHED:
1103                                 hv_begin_read(&channel->inbound);
1104                                 /* fallthrough */
1105                         case HV_CALL_DIRECT:
1106                                 tasklet_schedule(&channel->callback_event);
1107                         }
1108                 }
1109
1110                 rcu_read_unlock();
1111         }
1112 }
1113
1114 static void vmbus_isr(void)
1115 {
1116         struct hv_per_cpu_context *hv_cpu
1117                 = this_cpu_ptr(hv_context.cpu_context);
1118         void *page_addr = hv_cpu->synic_event_page;
1119         struct hv_message *msg;
1120         union hv_synic_event_flags *event;
1121         bool handled = false;
1122
1123         if (unlikely(page_addr == NULL))
1124                 return;
1125
1126         event = (union hv_synic_event_flags *)page_addr +
1127                                          VMBUS_MESSAGE_SINT;
1128         /*
1129          * Check for events before checking for messages. This is the order
1130          * in which events and messages are checked in Windows guests on
1131          * Hyper-V, and the Windows team suggested we do the same.
1132          */
1133
1134         if ((vmbus_proto_version == VERSION_WS2008) ||
1135                 (vmbus_proto_version == VERSION_WIN7)) {
1136
1137                 /* Since we are a child, we only need to check bit 0 */
1138                 if (sync_test_and_clear_bit(0, event->flags))
1139                         handled = true;
1140         } else {
1141                 /*
1142                  * Our host is win8 or above. The signaling mechanism
1143                  * has changed and we can directly look at the event page.
1144                  * If bit n is set then we have an interrup on the channel
1145                  * whose id is n.
1146                  */
1147                 handled = true;
1148         }
1149
1150         if (handled)
1151                 vmbus_chan_sched(hv_cpu);
1152
1153         page_addr = hv_cpu->synic_message_page;
1154         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1155
1156         /* Check if there are actual msgs to be processed */
1157         if (msg->header.message_type != HVMSG_NONE) {
1158                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
1159                         hv_process_timer_expiration(msg, hv_cpu);
1160                 else
1161                         tasklet_schedule(&hv_cpu->msg_dpc);
1162         }
1163
1164         add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1165 }
1166
1167 /*
1168  * Boolean to control whether to report panic messages over Hyper-V.
1169  *
1170  * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
1171  */
1172 static int sysctl_record_panic_msg = 1;
1173
1174 /*
1175  * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1176  * buffer and call into Hyper-V to transfer the data.
1177  */
1178 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1179                          enum kmsg_dump_reason reason)
1180 {
1181         size_t bytes_written;
1182         phys_addr_t panic_pa;
1183
1184         /* We are only interested in panics. */
1185         if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1186                 return;
1187
1188         panic_pa = virt_to_phys(hv_panic_page);
1189
1190         /*
1191          * Write dump contents to the page. No need to synchronize; panic should
1192          * be single-threaded.
1193          */
1194         kmsg_dump_get_buffer(dumper, true, hv_panic_page, PAGE_SIZE,
1195                              &bytes_written);
1196         if (bytes_written)
1197                 hyperv_report_panic_msg(panic_pa, bytes_written);
1198 }
1199
1200 static struct kmsg_dumper hv_kmsg_dumper = {
1201         .dump = hv_kmsg_dump,
1202 };
1203
1204 static struct ctl_table_header *hv_ctl_table_hdr;
1205 static int zero;
1206 static int one = 1;
1207
1208 /*
1209  * sysctl option to allow the user to control whether kmsg data should be
1210  * reported to Hyper-V on panic.
1211  */
1212 static struct ctl_table hv_ctl_table[] = {
1213         {
1214                 .procname       = "hyperv_record_panic_msg",
1215                 .data           = &sysctl_record_panic_msg,
1216                 .maxlen         = sizeof(int),
1217                 .mode           = 0644,
1218                 .proc_handler   = proc_dointvec_minmax,
1219                 .extra1         = &zero,
1220                 .extra2         = &one
1221         },
1222         {}
1223 };
1224
1225 static struct ctl_table hv_root_table[] = {
1226         {
1227                 .procname       = "kernel",
1228                 .mode           = 0555,
1229                 .child          = hv_ctl_table
1230         },
1231         {}
1232 };
1233
1234 /*
1235  * vmbus_bus_init -Main vmbus driver initialization routine.
1236  *
1237  * Here, we
1238  *      - initialize the vmbus driver context
1239  *      - invoke the vmbus hv main init routine
1240  *      - retrieve the channel offers
1241  */
1242 static int vmbus_bus_init(void)
1243 {
1244         int ret;
1245
1246         /* Hypervisor initialization...setup hypercall page..etc */
1247         ret = hv_init();
1248         if (ret != 0) {
1249                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1250                 return ret;
1251         }
1252
1253         ret = bus_register(&hv_bus);
1254         if (ret)
1255                 return ret;
1256
1257         hv_setup_vmbus_irq(vmbus_isr);
1258
1259         ret = hv_synic_alloc();
1260         if (ret)
1261                 goto err_alloc;
1262         /*
1263          * Initialize the per-cpu interrupt state and
1264          * connect to the host.
1265          */
1266         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1267                                 hv_synic_init, hv_synic_cleanup);
1268         if (ret < 0)
1269                 goto err_alloc;
1270         hyperv_cpuhp_online = ret;
1271
1272         ret = vmbus_connect();
1273         if (ret)
1274                 goto err_connect;
1275
1276         /*
1277          * Only register if the crash MSRs are available
1278          */
1279         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1280                 u64 hyperv_crash_ctl;
1281                 /*
1282                  * Sysctl registration is not fatal, since by default
1283                  * reporting is enabled.
1284                  */
1285                 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1286                 if (!hv_ctl_table_hdr)
1287                         pr_err("Hyper-V: sysctl table register error");
1288
1289                 /*
1290                  * Register for panic kmsg callback only if the right
1291                  * capability is supported by the hypervisor.
1292                  */
1293                 hv_get_crash_ctl(hyperv_crash_ctl);
1294                 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1295                         hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
1296                         if (hv_panic_page) {
1297                                 ret = kmsg_dump_register(&hv_kmsg_dumper);
1298                                 if (ret)
1299                                         pr_err("Hyper-V: kmsg dump register "
1300                                                 "error 0x%x\n", ret);
1301                         } else
1302                                 pr_err("Hyper-V: panic message page memory "
1303                                         "allocation failed");
1304                 }
1305
1306                 register_die_notifier(&hyperv_die_block);
1307                 atomic_notifier_chain_register(&panic_notifier_list,
1308                                                &hyperv_panic_block);
1309         }
1310
1311         vmbus_request_offers();
1312
1313         return 0;
1314
1315 err_connect:
1316         cpuhp_remove_state(hyperv_cpuhp_online);
1317 err_alloc:
1318         hv_synic_free();
1319         hv_remove_vmbus_irq();
1320
1321         bus_unregister(&hv_bus);
1322         free_page((unsigned long)hv_panic_page);
1323         unregister_sysctl_table(hv_ctl_table_hdr);
1324         hv_ctl_table_hdr = NULL;
1325         return ret;
1326 }
1327
1328 /**
1329  * __vmbus_child_driver_register() - Register a vmbus's driver
1330  * @hv_driver: Pointer to driver structure you want to register
1331  * @owner: owner module of the drv
1332  * @mod_name: module name string
1333  *
1334  * Registers the given driver with Linux through the 'driver_register()' call
1335  * and sets up the hyper-v vmbus handling for this driver.
1336  * It will return the state of the 'driver_register()' call.
1337  *
1338  */
1339 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1340 {
1341         int ret;
1342
1343         pr_info("registering driver %s\n", hv_driver->name);
1344
1345         ret = vmbus_exists();
1346         if (ret < 0)
1347                 return ret;
1348
1349         hv_driver->driver.name = hv_driver->name;
1350         hv_driver->driver.owner = owner;
1351         hv_driver->driver.mod_name = mod_name;
1352         hv_driver->driver.bus = &hv_bus;
1353
1354         spin_lock_init(&hv_driver->dynids.lock);
1355         INIT_LIST_HEAD(&hv_driver->dynids.list);
1356
1357         ret = driver_register(&hv_driver->driver);
1358
1359         return ret;
1360 }
1361 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1362
1363 /**
1364  * vmbus_driver_unregister() - Unregister a vmbus's driver
1365  * @hv_driver: Pointer to driver structure you want to
1366  *             un-register
1367  *
1368  * Un-register the given driver that was previous registered with a call to
1369  * vmbus_driver_register()
1370  */
1371 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1372 {
1373         pr_info("unregistering driver %s\n", hv_driver->name);
1374
1375         if (!vmbus_exists()) {
1376                 driver_unregister(&hv_driver->driver);
1377                 vmbus_free_dynids(hv_driver);
1378         }
1379 }
1380 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1381
1382
1383 /*
1384  * Called when last reference to channel is gone.
1385  */
1386 static void vmbus_chan_release(struct kobject *kobj)
1387 {
1388         struct vmbus_channel *channel
1389                 = container_of(kobj, struct vmbus_channel, kobj);
1390
1391         kfree_rcu(channel, rcu);
1392 }
1393
1394 struct vmbus_chan_attribute {
1395         struct attribute attr;
1396         ssize_t (*show)(const struct vmbus_channel *chan, char *buf);
1397         ssize_t (*store)(struct vmbus_channel *chan,
1398                          const char *buf, size_t count);
1399 };
1400 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1401         struct vmbus_chan_attribute chan_attr_##_name \
1402                 = __ATTR(_name, _mode, _show, _store)
1403 #define VMBUS_CHAN_ATTR_RW(_name) \
1404         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1405 #define VMBUS_CHAN_ATTR_RO(_name) \
1406         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1407 #define VMBUS_CHAN_ATTR_WO(_name) \
1408         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1409
1410 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1411                                     struct attribute *attr, char *buf)
1412 {
1413         const struct vmbus_chan_attribute *attribute
1414                 = container_of(attr, struct vmbus_chan_attribute, attr);
1415         const struct vmbus_channel *chan
1416                 = container_of(kobj, struct vmbus_channel, kobj);
1417
1418         if (!attribute->show)
1419                 return -EIO;
1420
1421         if (chan->state != CHANNEL_OPENED_STATE)
1422                 return -EINVAL;
1423
1424         return attribute->show(chan, buf);
1425 }
1426
1427 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1428         .show = vmbus_chan_attr_show,
1429 };
1430
1431 static ssize_t out_mask_show(const struct vmbus_channel *channel, char *buf)
1432 {
1433         const struct hv_ring_buffer_info *rbi = &channel->outbound;
1434
1435         return sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1436 }
1437 static VMBUS_CHAN_ATTR_RO(out_mask);
1438
1439 static ssize_t in_mask_show(const struct vmbus_channel *channel, char *buf)
1440 {
1441         const struct hv_ring_buffer_info *rbi = &channel->inbound;
1442
1443         return sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1444 }
1445 static VMBUS_CHAN_ATTR_RO(in_mask);
1446
1447 static ssize_t read_avail_show(const struct vmbus_channel *channel, char *buf)
1448 {
1449         const struct hv_ring_buffer_info *rbi = &channel->inbound;
1450
1451         return sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1452 }
1453 static VMBUS_CHAN_ATTR_RO(read_avail);
1454
1455 static ssize_t write_avail_show(const struct vmbus_channel *channel, char *buf)
1456 {
1457         const struct hv_ring_buffer_info *rbi = &channel->outbound;
1458
1459         return sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1460 }
1461 static VMBUS_CHAN_ATTR_RO(write_avail);
1462
1463 static ssize_t show_target_cpu(const struct vmbus_channel *channel, char *buf)
1464 {
1465         return sprintf(buf, "%u\n", channel->target_cpu);
1466 }
1467 static VMBUS_CHAN_ATTR(cpu, S_IRUGO, show_target_cpu, NULL);
1468
1469 static ssize_t channel_pending_show(const struct vmbus_channel *channel,
1470                                     char *buf)
1471 {
1472         return sprintf(buf, "%d\n",
1473                        channel_pending(channel,
1474                                        vmbus_connection.monitor_pages[1]));
1475 }
1476 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1477
1478 static ssize_t channel_latency_show(const struct vmbus_channel *channel,
1479                                     char *buf)
1480 {
1481         return sprintf(buf, "%d\n",
1482                        channel_latency(channel,
1483                                        vmbus_connection.monitor_pages[1]));
1484 }
1485 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1486
1487 static ssize_t channel_interrupts_show(const struct vmbus_channel *channel, char *buf)
1488 {
1489         return sprintf(buf, "%llu\n", channel->interrupts);
1490 }
1491 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1492
1493 static ssize_t channel_events_show(const struct vmbus_channel *channel, char *buf)
1494 {
1495         return sprintf(buf, "%llu\n", channel->sig_events);
1496 }
1497 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1498
1499 static ssize_t subchannel_monitor_id_show(const struct vmbus_channel *channel,
1500                                           char *buf)
1501 {
1502         return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1503 }
1504 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1505
1506 static ssize_t subchannel_id_show(const struct vmbus_channel *channel,
1507                                   char *buf)
1508 {
1509         return sprintf(buf, "%u\n",
1510                        channel->offermsg.offer.sub_channel_index);
1511 }
1512 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1513
1514 static struct attribute *vmbus_chan_attrs[] = {
1515         &chan_attr_out_mask.attr,
1516         &chan_attr_in_mask.attr,
1517         &chan_attr_read_avail.attr,
1518         &chan_attr_write_avail.attr,
1519         &chan_attr_cpu.attr,
1520         &chan_attr_pending.attr,
1521         &chan_attr_latency.attr,
1522         &chan_attr_interrupts.attr,
1523         &chan_attr_events.attr,
1524         &chan_attr_monitor_id.attr,
1525         &chan_attr_subchannel_id.attr,
1526         NULL
1527 };
1528
1529 static struct kobj_type vmbus_chan_ktype = {
1530         .sysfs_ops = &vmbus_chan_sysfs_ops,
1531         .release = vmbus_chan_release,
1532         .default_attrs = vmbus_chan_attrs,
1533 };
1534
1535 /*
1536  * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1537  */
1538 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1539 {
1540         struct kobject *kobj = &channel->kobj;
1541         u32 relid = channel->offermsg.child_relid;
1542         int ret;
1543
1544         kobj->kset = dev->channels_kset;
1545         ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1546                                    "%u", relid);
1547         if (ret)
1548                 return ret;
1549
1550         kobject_uevent(kobj, KOBJ_ADD);
1551
1552         return 0;
1553 }
1554
1555 /*
1556  * vmbus_device_create - Creates and registers a new child device
1557  * on the vmbus.
1558  */
1559 struct hv_device *vmbus_device_create(const uuid_le *type,
1560                                       const uuid_le *instance,
1561                                       struct vmbus_channel *channel)
1562 {
1563         struct hv_device *child_device_obj;
1564
1565         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1566         if (!child_device_obj) {
1567                 pr_err("Unable to allocate device object for child device\n");
1568                 return NULL;
1569         }
1570
1571         child_device_obj->channel = channel;
1572         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
1573         memcpy(&child_device_obj->dev_instance, instance,
1574                sizeof(uuid_le));
1575         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1576
1577
1578         return child_device_obj;
1579 }
1580
1581 /*
1582  * vmbus_device_register - Register the child device
1583  */
1584 int vmbus_device_register(struct hv_device *child_device_obj)
1585 {
1586         struct kobject *kobj = &child_device_obj->device.kobj;
1587         int ret;
1588
1589         dev_set_name(&child_device_obj->device, "%pUl",
1590                      child_device_obj->channel->offermsg.offer.if_instance.b);
1591
1592         child_device_obj->device.bus = &hv_bus;
1593         child_device_obj->device.parent = &hv_acpi_dev->dev;
1594         child_device_obj->device.release = vmbus_device_release;
1595
1596         /*
1597          * Register with the LDM. This will kick off the driver/device
1598          * binding...which will eventually call vmbus_match() and vmbus_probe()
1599          */
1600         ret = device_register(&child_device_obj->device);
1601         if (ret) {
1602                 pr_err("Unable to register child device\n");
1603                 return ret;
1604         }
1605
1606         child_device_obj->channels_kset = kset_create_and_add("channels",
1607                                                               NULL, kobj);
1608         if (!child_device_obj->channels_kset) {
1609                 ret = -ENOMEM;
1610                 goto err_dev_unregister;
1611         }
1612
1613         ret = vmbus_add_channel_kobj(child_device_obj,
1614                                      child_device_obj->channel);
1615         if (ret) {
1616                 pr_err("Unable to register primary channeln");
1617                 goto err_kset_unregister;
1618         }
1619
1620         return 0;
1621
1622 err_kset_unregister:
1623         kset_unregister(child_device_obj->channels_kset);
1624
1625 err_dev_unregister:
1626         device_unregister(&child_device_obj->device);
1627         return ret;
1628 }
1629
1630 /*
1631  * vmbus_device_unregister - Remove the specified child device
1632  * from the vmbus.
1633  */
1634 void vmbus_device_unregister(struct hv_device *device_obj)
1635 {
1636         pr_debug("child device %s unregistered\n",
1637                 dev_name(&device_obj->device));
1638
1639         kset_unregister(device_obj->channels_kset);
1640
1641         /*
1642          * Kick off the process of unregistering the device.
1643          * This will call vmbus_remove() and eventually vmbus_device_release()
1644          */
1645         device_unregister(&device_obj->device);
1646 }
1647
1648
1649 /*
1650  * VMBUS is an acpi enumerated device. Get the information we
1651  * need from DSDT.
1652  */
1653 #define VTPM_BASE_ADDRESS 0xfed40000
1654 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1655 {
1656         resource_size_t start = 0;
1657         resource_size_t end = 0;
1658         struct resource *new_res;
1659         struct resource **old_res = &hyperv_mmio;
1660         struct resource **prev_res = NULL;
1661
1662         switch (res->type) {
1663
1664         /*
1665          * "Address" descriptors are for bus windows. Ignore
1666          * "memory" descriptors, which are for registers on
1667          * devices.
1668          */
1669         case ACPI_RESOURCE_TYPE_ADDRESS32:
1670                 start = res->data.address32.address.minimum;
1671                 end = res->data.address32.address.maximum;
1672                 break;
1673
1674         case ACPI_RESOURCE_TYPE_ADDRESS64:
1675                 start = res->data.address64.address.minimum;
1676                 end = res->data.address64.address.maximum;
1677                 break;
1678
1679         default:
1680                 /* Unused resource type */
1681                 return AE_OK;
1682
1683         }
1684         /*
1685          * Ignore ranges that are below 1MB, as they're not
1686          * necessary or useful here.
1687          */
1688         if (end < 0x100000)
1689                 return AE_OK;
1690
1691         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1692         if (!new_res)
1693                 return AE_NO_MEMORY;
1694
1695         /* If this range overlaps the virtual TPM, truncate it. */
1696         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1697                 end = VTPM_BASE_ADDRESS;
1698
1699         new_res->name = "hyperv mmio";
1700         new_res->flags = IORESOURCE_MEM;
1701         new_res->start = start;
1702         new_res->end = end;
1703
1704         /*
1705          * If two ranges are adjacent, merge them.
1706          */
1707         do {
1708                 if (!*old_res) {
1709                         *old_res = new_res;
1710                         break;
1711                 }
1712
1713                 if (((*old_res)->end + 1) == new_res->start) {
1714                         (*old_res)->end = new_res->end;
1715                         kfree(new_res);
1716                         break;
1717                 }
1718
1719                 if ((*old_res)->start == new_res->end + 1) {
1720                         (*old_res)->start = new_res->start;
1721                         kfree(new_res);
1722                         break;
1723                 }
1724
1725                 if ((*old_res)->start > new_res->end) {
1726                         new_res->sibling = *old_res;
1727                         if (prev_res)
1728                                 (*prev_res)->sibling = new_res;
1729                         *old_res = new_res;
1730                         break;
1731                 }
1732
1733                 prev_res = old_res;
1734                 old_res = &(*old_res)->sibling;
1735
1736         } while (1);
1737
1738         return AE_OK;
1739 }
1740
1741 static int vmbus_acpi_remove(struct acpi_device *device)
1742 {
1743         struct resource *cur_res;
1744         struct resource *next_res;
1745
1746         if (hyperv_mmio) {
1747                 if (fb_mmio) {
1748                         __release_region(hyperv_mmio, fb_mmio->start,
1749                                          resource_size(fb_mmio));
1750                         fb_mmio = NULL;
1751                 }
1752
1753                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1754                         next_res = cur_res->sibling;
1755                         kfree(cur_res);
1756                 }
1757         }
1758
1759         return 0;
1760 }
1761
1762 static void vmbus_reserve_fb(void)
1763 {
1764         int size;
1765         /*
1766          * Make a claim for the frame buffer in the resource tree under the
1767          * first node, which will be the one below 4GB.  The length seems to
1768          * be underreported, particularly in a Generation 1 VM.  So start out
1769          * reserving a larger area and make it smaller until it succeeds.
1770          */
1771
1772         if (screen_info.lfb_base) {
1773                 if (efi_enabled(EFI_BOOT))
1774                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
1775                 else
1776                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1777
1778                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1779                         fb_mmio = __request_region(hyperv_mmio,
1780                                                    screen_info.lfb_base, size,
1781                                                    fb_mmio_name, 0);
1782                 }
1783         }
1784 }
1785
1786 /**
1787  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1788  * @new:                If successful, supplied a pointer to the
1789  *                      allocated MMIO space.
1790  * @device_obj:         Identifies the caller
1791  * @min:                Minimum guest physical address of the
1792  *                      allocation
1793  * @max:                Maximum guest physical address
1794  * @size:               Size of the range to be allocated
1795  * @align:              Alignment of the range to be allocated
1796  * @fb_overlap_ok:      Whether this allocation can be allowed
1797  *                      to overlap the video frame buffer.
1798  *
1799  * This function walks the resources granted to VMBus by the
1800  * _CRS object in the ACPI namespace underneath the parent
1801  * "bridge" whether that's a root PCI bus in the Generation 1
1802  * case or a Module Device in the Generation 2 case.  It then
1803  * attempts to allocate from the global MMIO pool in a way that
1804  * matches the constraints supplied in these parameters and by
1805  * that _CRS.
1806  *
1807  * Return: 0 on success, -errno on failure
1808  */
1809 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1810                         resource_size_t min, resource_size_t max,
1811                         resource_size_t size, resource_size_t align,
1812                         bool fb_overlap_ok)
1813 {
1814         struct resource *iter, *shadow;
1815         resource_size_t range_min, range_max, start;
1816         const char *dev_n = dev_name(&device_obj->device);
1817         int retval;
1818
1819         retval = -ENXIO;
1820         down(&hyperv_mmio_lock);
1821
1822         /*
1823          * If overlaps with frame buffers are allowed, then first attempt to
1824          * make the allocation from within the reserved region.  Because it
1825          * is already reserved, no shadow allocation is necessary.
1826          */
1827         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1828             !(max < fb_mmio->start)) {
1829
1830                 range_min = fb_mmio->start;
1831                 range_max = fb_mmio->end;
1832                 start = (range_min + align - 1) & ~(align - 1);
1833                 for (; start + size - 1 <= range_max; start += align) {
1834                         *new = request_mem_region_exclusive(start, size, dev_n);
1835                         if (*new) {
1836                                 retval = 0;
1837                                 goto exit;
1838                         }
1839                 }
1840         }
1841
1842         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1843                 if ((iter->start >= max) || (iter->end <= min))
1844                         continue;
1845
1846                 range_min = iter->start;
1847                 range_max = iter->end;
1848                 start = (range_min + align - 1) & ~(align - 1);
1849                 for (; start + size - 1 <= range_max; start += align) {
1850                         shadow = __request_region(iter, start, size, NULL,
1851                                                   IORESOURCE_BUSY);
1852                         if (!shadow)
1853                                 continue;
1854
1855                         *new = request_mem_region_exclusive(start, size, dev_n);
1856                         if (*new) {
1857                                 shadow->name = (char *)*new;
1858                                 retval = 0;
1859                                 goto exit;
1860                         }
1861
1862                         __release_region(iter, start, size);
1863                 }
1864         }
1865
1866 exit:
1867         up(&hyperv_mmio_lock);
1868         return retval;
1869 }
1870 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1871
1872 /**
1873  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1874  * @start:              Base address of region to release.
1875  * @size:               Size of the range to be allocated
1876  *
1877  * This function releases anything requested by
1878  * vmbus_mmio_allocate().
1879  */
1880 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1881 {
1882         struct resource *iter;
1883
1884         down(&hyperv_mmio_lock);
1885         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1886                 if ((iter->start >= start + size) || (iter->end <= start))
1887                         continue;
1888
1889                 __release_region(iter, start, size);
1890         }
1891         release_mem_region(start, size);
1892         up(&hyperv_mmio_lock);
1893
1894 }
1895 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1896
1897 static int vmbus_acpi_add(struct acpi_device *device)
1898 {
1899         acpi_status result;
1900         int ret_val = -ENODEV;
1901         struct acpi_device *ancestor;
1902
1903         hv_acpi_dev = device;
1904
1905         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1906                                         vmbus_walk_resources, NULL);
1907
1908         if (ACPI_FAILURE(result))
1909                 goto acpi_walk_err;
1910         /*
1911          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1912          * firmware) is the VMOD that has the mmio ranges. Get that.
1913          */
1914         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1915                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1916                                              vmbus_walk_resources, NULL);
1917
1918                 if (ACPI_FAILURE(result))
1919                         continue;
1920                 if (hyperv_mmio) {
1921                         vmbus_reserve_fb();
1922                         break;
1923                 }
1924         }
1925         ret_val = 0;
1926
1927 acpi_walk_err:
1928         complete(&probe_event);
1929         if (ret_val)
1930                 vmbus_acpi_remove(device);
1931         return ret_val;
1932 }
1933
1934 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1935         {"VMBUS", 0},
1936         {"VMBus", 0},
1937         {"", 0},
1938 };
1939 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1940
1941 static struct acpi_driver vmbus_acpi_driver = {
1942         .name = "vmbus",
1943         .ids = vmbus_acpi_device_ids,
1944         .ops = {
1945                 .add = vmbus_acpi_add,
1946                 .remove = vmbus_acpi_remove,
1947         },
1948 };
1949
1950 static void hv_kexec_handler(void)
1951 {
1952         hv_synic_clockevents_cleanup();
1953         vmbus_initiate_unload(false);
1954         vmbus_connection.conn_state = DISCONNECTED;
1955         /* Make sure conn_state is set as hv_synic_cleanup checks for it */
1956         mb();
1957         cpuhp_remove_state(hyperv_cpuhp_online);
1958         hyperv_cleanup();
1959 };
1960
1961 static void hv_crash_handler(struct pt_regs *regs)
1962 {
1963         vmbus_initiate_unload(true);
1964         /*
1965          * In crash handler we can't schedule synic cleanup for all CPUs,
1966          * doing the cleanup for current CPU only. This should be sufficient
1967          * for kdump.
1968          */
1969         vmbus_connection.conn_state = DISCONNECTED;
1970         hv_synic_cleanup(smp_processor_id());
1971         hyperv_cleanup();
1972 };
1973
1974 static int __init hv_acpi_init(void)
1975 {
1976         int ret, t;
1977
1978         if (!hv_is_hyperv_initialized())
1979                 return -ENODEV;
1980
1981         init_completion(&probe_event);
1982
1983         /*
1984          * Get ACPI resources first.
1985          */
1986         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1987
1988         if (ret)
1989                 return ret;
1990
1991         t = wait_for_completion_timeout(&probe_event, 5*HZ);
1992         if (t == 0) {
1993                 ret = -ETIMEDOUT;
1994                 goto cleanup;
1995         }
1996
1997         ret = vmbus_bus_init();
1998         if (ret)
1999                 goto cleanup;
2000
2001         hv_setup_kexec_handler(hv_kexec_handler);
2002         hv_setup_crash_handler(hv_crash_handler);
2003
2004         return 0;
2005
2006 cleanup:
2007         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2008         hv_acpi_dev = NULL;
2009         return ret;
2010 }
2011
2012 static void __exit vmbus_exit(void)
2013 {
2014         int cpu;
2015
2016         hv_remove_kexec_handler();
2017         hv_remove_crash_handler();
2018         vmbus_connection.conn_state = DISCONNECTED;
2019         hv_synic_clockevents_cleanup();
2020         vmbus_disconnect();
2021         hv_remove_vmbus_irq();
2022         for_each_online_cpu(cpu) {
2023                 struct hv_per_cpu_context *hv_cpu
2024                         = per_cpu_ptr(hv_context.cpu_context, cpu);
2025
2026                 tasklet_kill(&hv_cpu->msg_dpc);
2027         }
2028         vmbus_free_channels();
2029
2030         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2031                 kmsg_dump_unregister(&hv_kmsg_dumper);
2032                 unregister_die_notifier(&hyperv_die_block);
2033                 atomic_notifier_chain_unregister(&panic_notifier_list,
2034                                                  &hyperv_panic_block);
2035         }
2036
2037         free_page((unsigned long)hv_panic_page);
2038         unregister_sysctl_table(hv_ctl_table_hdr);
2039         hv_ctl_table_hdr = NULL;
2040         bus_unregister(&hv_bus);
2041
2042         cpuhp_remove_state(hyperv_cpuhp_online);
2043         hv_synic_free();
2044         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2045 }
2046
2047
2048 MODULE_LICENSE("GPL");
2049
2050 subsys_initcall(hv_acpi_init);
2051 module_exit(vmbus_exit);