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[0]));
 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 struct hv_vmbus_device_id *
 658 hv_vmbus_dev_match(const struct hv_vmbus_device_id *id, const guid_t *guid)
 659 {
 660         if (id == NULL)
 661                 return NULL; /* empty device table */
 662
 663         for (; !guid_is_null(&id->guid); id++)
 664                 if (guid_equal(&id->guid, guid))
 665                         return id;
 666
 667         return NULL;
 668 }
 669
 670 static const struct hv_vmbus_device_id *
 671 hv_vmbus_dynid_match(struct hv_driver *drv, const guid_t *guid)
 672 {
 673         const struct hv_vmbus_device_id *id = NULL;
 674         struct vmbus_dynid *dynid;
 675
 676         spin_lock(&drv->dynids.lock);
 677         list_for_each_entry(dynid, &drv->dynids.list, node) {
 678                 if (guid_equal(&dynid->id.guid, guid)) {
 679                         id = &dynid->id;
 680                         break;
 681                 }
 682         }
 683         spin_unlock(&drv->dynids.lock);
 684
 685         return id;
 686 }
 687
 688 static const struct hv_vmbus_device_id vmbus_device_null;
 689
 690 /*
 691  * Return a matching hv_vmbus_device_id pointer.
 692  * If there is no match, return NULL.
 693  */
 694 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 695                                                         struct hv_device *dev)
 696 {
 697         const guid_t *guid = &dev->dev_type;
 698         const struct hv_vmbus_device_id *id;
 699
 700         /* When driver_override is set, only bind to the matching driver */
 701         if (dev->driver_override && strcmp(dev->driver_override, drv->name))
 702                 return NULL;
 703
 704         /* Look at the dynamic ids first, before the static ones */
 705         id = hv_vmbus_dynid_match(drv, guid);
 706         if (!id)
 707                 id = hv_vmbus_dev_match(drv->id_table, guid);
 708
 709         /* driver_override will always match, send a dummy id */
 710         if (!id && dev->driver_override)
 711                 id = &vmbus_device_null;
 712
 713         return id;
 714 }
 715
 716 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
 717 static int vmbus_add_dynid(struct hv_driver *drv, guid_t *guid)
 718 {
 719         struct vmbus_dynid *dynid;
 720
 721         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
 722         if (!dynid)
 723                 return -ENOMEM;
 724
 725         dynid->id.guid = *guid;
 726
 727         spin_lock(&drv->dynids.lock);
 728         list_add_tail(&dynid->node, &drv->dynids.list);
 729         spin_unlock(&drv->dynids.lock);
 730
 731         return driver_attach(&drv->driver);
 732 }
 733
 734 static void vmbus_free_dynids(struct hv_driver *drv)
 735 {
 736         struct vmbus_dynid *dynid, *n;
 737
 738         spin_lock(&drv->dynids.lock);
 739         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 740                 list_del(&dynid->node);
 741                 kfree(dynid);
 742         }
 743         spin_unlock(&drv->dynids.lock);
 744 }
 745
 746 /*
 747  * store_new_id - sysfs frontend to vmbus_add_dynid()
 748  *
 749  * Allow GUIDs to be added to an existing driver via sysfs.
 750  */
 751 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
 752                             size_t count)
 753 {
 754         struct hv_driver *drv = drv_to_hv_drv(driver);
 755         guid_t guid;
 756         ssize_t retval;
 757
 758         retval = guid_parse(buf, &guid);
 759         if (retval)
 760                 return retval;
 761
 762         if (hv_vmbus_dynid_match(drv, &guid))
 763                 return -EEXIST;
 764
 765         retval = vmbus_add_dynid(drv, &guid);
 766         if (retval)
 767                 return retval;
 768         return count;
 769 }
 770 static DRIVER_ATTR_WO(new_id);
 771
 772 /*
 773  * store_remove_id - remove a PCI device ID from this driver
 774  *
 775  * Removes a dynamic pci device ID to this driver.
 776  */
 777 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 778                                size_t count)
 779 {
 780         struct hv_driver *drv = drv_to_hv_drv(driver);
 781         struct vmbus_dynid *dynid, *n;
 782         guid_t guid;
 783         ssize_t retval;
 784
 785         retval = guid_parse(buf, &guid);
 786         if (retval)
 787                 return retval;
 788
 789         retval = -ENODEV;
 790         spin_lock(&drv->dynids.lock);
 791         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 792                 struct hv_vmbus_device_id *id = &dynid->id;
 793
 794                 if (guid_equal(&id->guid, &guid)) {
 795                         list_del(&dynid->node);
 796                         kfree(dynid);
 797                         retval = count;
 798                         break;
 799                 }
 800         }
 801         spin_unlock(&drv->dynids.lock);
 802
 803         return retval;
 804 }
 805 static DRIVER_ATTR_WO(remove_id);
 806
 807 static struct attribute *vmbus_drv_attrs[] = {
 808         &driver_attr_new_id.attr,
 809         &driver_attr_remove_id.attr,
 810         NULL,
 811 };
 812 ATTRIBUTE_GROUPS(vmbus_drv);
 813
 814
 815 /*
 816  * vmbus_match - Attempt to match the specified device to the specified driver
 817  */
 818 static int vmbus_match(struct device *device, struct device_driver *driver)
 819 {
 820         struct hv_driver *drv = drv_to_hv_drv(driver);
 821         struct hv_device *hv_dev = device_to_hv_device(device);
 822
 823         /* The hv_sock driver handles all hv_sock offers. */
 824         if (is_hvsock_channel(hv_dev->channel))
 825                 return drv->hvsock;
 826
 827         if (hv_vmbus_get_id(drv, hv_dev))
 828                 return 1;
 829
 830         return 0;
 831 }
 832
 833 /*
 834  * vmbus_probe - Add the new vmbus's child device
 835  */
 836 static int vmbus_probe(struct device *child_device)
 837 {
 838         int ret = 0;
 839         struct hv_driver *drv =
 840                         drv_to_hv_drv(child_device->driver);
 841         struct hv_device *dev = device_to_hv_device(child_device);
 842         const struct hv_vmbus_device_id *dev_id;
 843
 844         dev_id = hv_vmbus_get_id(drv, dev);
 845         if (drv->probe) {
 846                 ret = drv->probe(dev, dev_id);
 847                 if (ret != 0)
 848                         pr_err("probe failed for device %s (%d)\n",
 849                                dev_name(child_device), ret);
 850
 851         } else {
 852                 pr_err("probe not set for driver %s\n",
 853                        dev_name(child_device));
 854                 ret = -ENODEV;
 855         }
 856         return ret;
 857 }
 858
 859 /*
 860  * vmbus_remove - Remove a vmbus device
 861  */
 862 static int vmbus_remove(struct device *child_device)
 863 {
 864         struct hv_driver *drv;
 865         struct hv_device *dev = device_to_hv_device(child_device);
 866
 867         if (child_device->driver) {
 868                 drv = drv_to_hv_drv(child_device->driver);
 869                 if (drv->remove)
 870                         drv->remove(dev);
 871         }
 872
 873         return 0;
 874 }
 875
 876
 877 /*
 878  * vmbus_shutdown - Shutdown a vmbus device
 879  */
 880 static void vmbus_shutdown(struct device *child_device)
 881 {
 882         struct hv_driver *drv;
 883         struct hv_device *dev = device_to_hv_device(child_device);
 884
 885
 886         /* The device may not be attached yet */
 887         if (!child_device->driver)
 888                 return;
 889
 890         drv = drv_to_hv_drv(child_device->driver);
 891
 892         if (drv->shutdown)
 893                 drv->shutdown(dev);
 894 }
 895
 896
 897 /*
 898  * vmbus_device_release - Final callback release of the vmbus child device
 899  */
 900 static void vmbus_device_release(struct device *device)
 901 {
 902         struct hv_device *hv_dev = device_to_hv_device(device);
 903         struct vmbus_channel *channel = hv_dev->channel;
 904
 905         mutex_lock(&vmbus_connection.channel_mutex);
 906         hv_process_channel_removal(channel);
 907         mutex_unlock(&vmbus_connection.channel_mutex);
 908         kfree(hv_dev);
 909 }
 910
 911 /* The one and only one */
 912 static struct bus_type  hv_bus = {
 913         .name =         "vmbus",
 914         .match =                vmbus_match,
 915         .shutdown =             vmbus_shutdown,
 916         .remove =               vmbus_remove,
 917         .probe =                vmbus_probe,
 918         .uevent =               vmbus_uevent,
 919         .dev_groups =           vmbus_dev_groups,
 920         .drv_groups =           vmbus_drv_groups,
 921 };
 922
 923 struct onmessage_work_context {
 924         struct work_struct work;
 925         struct hv_message msg;
 926 };
 927
 928 static void vmbus_onmessage_work(struct work_struct *work)
 929 {
 930         struct onmessage_work_context *ctx;
 931
 932         /* Do not process messages if we're in DISCONNECTED state */
 933         if (vmbus_connection.conn_state == DISCONNECTED)
 934                 return;
 935
 936         ctx = container_of(work, struct onmessage_work_context,
 937                            work);
 938         vmbus_onmessage(&ctx->msg);
 939         kfree(ctx);
 940 }
 941
 942 static void hv_process_timer_expiration(struct hv_message *msg,
 943                                         struct hv_per_cpu_context *hv_cpu)
 944 {
 945         struct clock_event_device *dev = hv_cpu->clk_evt;
 946
 947         if (dev->event_handler)
 948                 dev->event_handler(dev);
 949
 950         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
 951 }
 952
 953 void vmbus_on_msg_dpc(unsigned long data)
 954 {
 955         struct hv_per_cpu_context *hv_cpu = (void *)data;
 956         void *page_addr = hv_cpu->synic_message_page;
 957         struct hv_message *msg = (struct hv_message *)page_addr +
 958                                   VMBUS_MESSAGE_SINT;
 959         struct vmbus_channel_message_header *hdr;
 960         const struct vmbus_channel_message_table_entry *entry;
 961         struct onmessage_work_context *ctx;
 962         u32 message_type = msg->header.message_type;
 963
 964         if (message_type == HVMSG_NONE)
 965                 /* no msg */
 966                 return;
 967
 968         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 969
 970         trace_vmbus_on_msg_dpc(hdr);
 971
 972         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 973                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 974                 goto msg_handled;
 975         }
 976
 977         entry = &channel_message_table[hdr->msgtype];
 978         if (entry->handler_type == VMHT_BLOCKING) {
 979                 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 980                 if (ctx == NULL)
 981                         return;
 982
 983                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
 984                 memcpy(&ctx->msg, msg, sizeof(*msg));
 985
 986                 /*
 987                  * The host can generate a rescind message while we
 988                  * may still be handling the original offer. We deal with
 989                  * this condition by ensuring the processing is done on the
 990                  * same CPU.
 991                  */
 992                 switch (hdr->msgtype) {
 993                 case CHANNELMSG_RESCIND_CHANNELOFFER:
 994                         /*
 995                          * If we are handling the rescind message;
 996                          * schedule the work on the global work queue.
 997                          */
 998                         schedule_work_on(vmbus_connection.connect_cpu,
 999                                          &ctx->work);
1000                         break;
1001
1002                 case CHANNELMSG_OFFERCHANNEL:
1003                         atomic_inc(&vmbus_connection.offer_in_progress);
1004                         queue_work_on(vmbus_connection.connect_cpu,
1005                                       vmbus_connection.work_queue,
1006                                       &ctx->work);
1007                         break;
1008
1009                 default:
1010                         queue_work(vmbus_connection.work_queue, &ctx->work);
1011                 }
1012         } else
1013                 entry->message_handler(hdr);
1014
1015 msg_handled:
1016         vmbus_signal_eom(msg, message_type);
1017 }
1018
1019
1020 /*
1021  * Direct callback for channels using other deferred processing
1022  */
1023 static void vmbus_channel_isr(struct vmbus_channel *channel)
1024 {
1025         void (*callback_fn)(void *);
1026
1027         callback_fn = READ_ONCE(channel->onchannel_callback);
1028         if (likely(callback_fn != NULL))
1029                 (*callback_fn)(channel->channel_callback_context);
1030 }
1031
1032 /*
1033  * Schedule all channels with events pending
1034  */
1035 static void vmbus_chan_sched(struct hv_per_cpu_context *hv_cpu)
1036 {
1037         unsigned long *recv_int_page;
1038         u32 maxbits, relid;
1039
1040         if (vmbus_proto_version < VERSION_WIN8) {
1041                 maxbits = MAX_NUM_CHANNELS_SUPPORTED;
1042                 recv_int_page = vmbus_connection.recv_int_page;
1043         } else {
1044                 /*
1045                  * When the host is win8 and beyond, the event page
1046                  * can be directly checked to get the id of the channel
1047                  * that has the interrupt pending.
1048                  */
1049                 void *page_addr = hv_cpu->synic_event_page;
1050                 union hv_synic_event_flags *event
1051                         = (union hv_synic_event_flags *)page_addr +
1052                                                  VMBUS_MESSAGE_SINT;
1053
1054                 maxbits = HV_EVENT_FLAGS_COUNT;
1055                 recv_int_page = event->flags;
1056         }
1057
1058         if (unlikely(!recv_int_page))
1059                 return;
1060
1061         for_each_set_bit(relid, recv_int_page, maxbits) {
1062                 struct vmbus_channel *channel;
1063
1064                 if (!sync_test_and_clear_bit(relid, recv_int_page))
1065                         continue;
1066
1067                 /* Special case - vmbus channel protocol msg */
1068                 if (relid == 0)
1069                         continue;
1070
1071                 rcu_read_lock();
1072
1073                 /* Find channel based on relid */
1074                 list_for_each_entry_rcu(channel, &hv_cpu->chan_list, percpu_list) {
1075                         if (channel->offermsg.child_relid != relid)
1076                                 continue;
1077
1078                         if (channel->rescind)
1079                                 continue;
1080
1081                         trace_vmbus_chan_sched(channel);
1082
1083                         ++channel->interrupts;
1084
1085                         switch (channel->callback_mode) {
1086                         case HV_CALL_ISR:
1087                                 vmbus_channel_isr(channel);
1088                                 break;
1089
1090                         case HV_CALL_BATCHED:
1091                                 hv_begin_read(&channel->inbound);
1092                                 /* fallthrough */
1093                         case HV_CALL_DIRECT:
1094                                 tasklet_schedule(&channel->callback_event);
1095                         }
1096                 }
1097
1098                 rcu_read_unlock();
1099         }
1100 }
1101
1102 static void vmbus_isr(void)
1103 {
1104         struct hv_per_cpu_context *hv_cpu
1105                 = this_cpu_ptr(hv_context.cpu_context);
1106         void *page_addr = hv_cpu->synic_event_page;
1107         struct hv_message *msg;
1108         union hv_synic_event_flags *event;
1109         bool handled = false;
1110
1111         if (unlikely(page_addr == NULL))
1112                 return;
1113
1114         event = (union hv_synic_event_flags *)page_addr +
1115                                          VMBUS_MESSAGE_SINT;
1116         /*
1117          * Check for events before checking for messages. This is the order
1118          * in which events and messages are checked in Windows guests on
1119          * Hyper-V, and the Windows team suggested we do the same.
1120          */
1121
1122         if ((vmbus_proto_version == VERSION_WS2008) ||
1123                 (vmbus_proto_version == VERSION_WIN7)) {
1124
1125                 /* Since we are a child, we only need to check bit 0 */
1126                 if (sync_test_and_clear_bit(0, event->flags))
1127                         handled = true;
1128         } else {
1129                 /*
1130                  * Our host is win8 or above. The signaling mechanism
1131                  * has changed and we can directly look at the event page.
1132                  * If bit n is set then we have an interrup on the channel
1133                  * whose id is n.
1134                  */
1135                 handled = true;
1136         }
1137
1138         if (handled)
1139                 vmbus_chan_sched(hv_cpu);
1140
1141         page_addr = hv_cpu->synic_message_page;
1142         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
1143
1144         /* Check if there are actual msgs to be processed */
1145         if (msg->header.message_type != HVMSG_NONE) {
1146                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
1147                         hv_process_timer_expiration(msg, hv_cpu);
1148                 else
1149                         tasklet_schedule(&hv_cpu->msg_dpc);
1150         }
1151
1152         add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
1153 }
1154
1155 /*
1156  * Boolean to control whether to report panic messages over Hyper-V.
1157  *
1158  * It can be set via /proc/sys/kernel/hyperv/record_panic_msg
1159  */
1160 static int sysctl_record_panic_msg = 1;
1161
1162 /*
1163  * Callback from kmsg_dump. Grab as much as possible from the end of the kmsg
1164  * buffer and call into Hyper-V to transfer the data.
1165  */
1166 static void hv_kmsg_dump(struct kmsg_dumper *dumper,
1167                          enum kmsg_dump_reason reason)
1168 {
1169         size_t bytes_written;
1170         phys_addr_t panic_pa;
1171
1172         /* We are only interested in panics. */
1173         if ((reason != KMSG_DUMP_PANIC) || (!sysctl_record_panic_msg))
1174                 return;
1175
1176         panic_pa = virt_to_phys(hv_panic_page);
1177
1178         /*
1179          * Write dump contents to the page. No need to synchronize; panic should
1180          * be single-threaded.
1181          */
1182         kmsg_dump_get_buffer(dumper, true, hv_panic_page, PAGE_SIZE,
1183                              &bytes_written);
1184         if (bytes_written)
1185                 hyperv_report_panic_msg(panic_pa, bytes_written);
1186 }
1187
1188 static struct kmsg_dumper hv_kmsg_dumper = {
1189         .dump = hv_kmsg_dump,
1190 };
1191
1192 static struct ctl_table_header *hv_ctl_table_hdr;
1193 static int zero;
1194 static int one = 1;
1195
1196 /*
1197  * sysctl option to allow the user to control whether kmsg data should be
1198  * reported to Hyper-V on panic.
1199  */
1200 static struct ctl_table hv_ctl_table[] = {
1201         {
1202                 .procname       = "hyperv_record_panic_msg",
1203                 .data           = &sysctl_record_panic_msg,
1204                 .maxlen         = sizeof(int),
1205                 .mode           = 0644,
1206                 .proc_handler   = proc_dointvec_minmax,
1207                 .extra1         = &zero,
1208                 .extra2         = &one
1209         },
1210         {}
1211 };
1212
1213 static struct ctl_table hv_root_table[] = {
1214         {
1215                 .procname       = "kernel",
1216                 .mode           = 0555,
1217                 .child          = hv_ctl_table
1218         },
1219         {}
1220 };
1221
1222 /*
1223  * vmbus_bus_init -Main vmbus driver initialization routine.
1224  *
1225  * Here, we
1226  *      - initialize the vmbus driver context
1227  *      - invoke the vmbus hv main init routine
1228  *      - retrieve the channel offers
1229  */
1230 static int vmbus_bus_init(void)
1231 {
1232         int ret;
1233
1234         /* Hypervisor initialization...setup hypercall page..etc */
1235         ret = hv_init();
1236         if (ret != 0) {
1237                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
1238                 return ret;
1239         }
1240
1241         ret = bus_register(&hv_bus);
1242         if (ret)
1243                 return ret;
1244
1245         hv_setup_vmbus_irq(vmbus_isr);
1246
1247         ret = hv_synic_alloc();
1248         if (ret)
1249                 goto err_alloc;
1250         /*
1251          * Initialize the per-cpu interrupt state and
1252          * connect to the host.
1253          */
1254         ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "hyperv/vmbus:online",
1255                                 hv_synic_init, hv_synic_cleanup);
1256         if (ret < 0)
1257                 goto err_alloc;
1258         hyperv_cpuhp_online = ret;
1259
1260         ret = vmbus_connect();
1261         if (ret)
1262                 goto err_connect;
1263
1264         /*
1265          * Only register if the crash MSRs are available
1266          */
1267         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1268                 u64 hyperv_crash_ctl;
1269                 /*
1270                  * Sysctl registration is not fatal, since by default
1271                  * reporting is enabled.
1272                  */
1273                 hv_ctl_table_hdr = register_sysctl_table(hv_root_table);
1274                 if (!hv_ctl_table_hdr)
1275                         pr_err("Hyper-V: sysctl table register error");
1276
1277                 /*
1278                  * Register for panic kmsg callback only if the right
1279                  * capability is supported by the hypervisor.
1280                  */
1281                 hv_get_crash_ctl(hyperv_crash_ctl);
1282                 if (hyperv_crash_ctl & HV_CRASH_CTL_CRASH_NOTIFY_MSG) {
1283                         hv_panic_page = (void *)get_zeroed_page(GFP_KERNEL);
1284                         if (hv_panic_page) {
1285                                 ret = kmsg_dump_register(&hv_kmsg_dumper);
1286                                 if (ret)
1287                                         pr_err("Hyper-V: kmsg dump register "
1288                                                 "error 0x%x\n", ret);
1289                         } else
1290                                 pr_err("Hyper-V: panic message page memory "
1291                                         "allocation failed");
1292                 }
1293
1294                 register_die_notifier(&hyperv_die_block);
1295                 atomic_notifier_chain_register(&panic_notifier_list,
1296                                                &hyperv_panic_block);
1297         }
1298
1299         vmbus_request_offers();
1300
1301         return 0;
1302
1303 err_connect:
1304         cpuhp_remove_state(hyperv_cpuhp_online);
1305 err_alloc:
1306         hv_synic_free();
1307         hv_remove_vmbus_irq();
1308
1309         bus_unregister(&hv_bus);
1310         free_page((unsigned long)hv_panic_page);
1311         unregister_sysctl_table(hv_ctl_table_hdr);
1312         hv_ctl_table_hdr = NULL;
1313         return ret;
1314 }
1315
1316 /**
1317  * __vmbus_child_driver_register() - Register a vmbus's driver
1318  * @hv_driver: Pointer to driver structure you want to register
1319  * @owner: owner module of the drv
1320  * @mod_name: module name string
1321  *
1322  * Registers the given driver with Linux through the 'driver_register()' call
1323  * and sets up the hyper-v vmbus handling for this driver.
1324  * It will return the state of the 'driver_register()' call.
1325  *
1326  */
1327 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1328 {
1329         int ret;
1330
1331         pr_info("registering driver %s\n", hv_driver->name);
1332
1333         ret = vmbus_exists();
1334         if (ret < 0)
1335                 return ret;
1336
1337         hv_driver->driver.name = hv_driver->name;
1338         hv_driver->driver.owner = owner;
1339         hv_driver->driver.mod_name = mod_name;
1340         hv_driver->driver.bus = &hv_bus;
1341
1342         spin_lock_init(&hv_driver->dynids.lock);
1343         INIT_LIST_HEAD(&hv_driver->dynids.list);
1344
1345         ret = driver_register(&hv_driver->driver);
1346
1347         return ret;
1348 }
1349 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1350
1351 /**
1352  * vmbus_driver_unregister() - Unregister a vmbus's driver
1353  * @hv_driver: Pointer to driver structure you want to
1354  *             un-register
1355  *
1356  * Un-register the given driver that was previous registered with a call to
1357  * vmbus_driver_register()
1358  */
1359 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1360 {
1361         pr_info("unregistering driver %s\n", hv_driver->name);
1362
1363         if (!vmbus_exists()) {
1364                 driver_unregister(&hv_driver->driver);
1365                 vmbus_free_dynids(hv_driver);
1366         }
1367 }
1368 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1369
1370
1371 /*
1372  * Called when last reference to channel is gone.
1373  */
1374 static void vmbus_chan_release(struct kobject *kobj)
1375 {
1376         struct vmbus_channel *channel
1377                 = container_of(kobj, struct vmbus_channel, kobj);
1378
1379         kfree_rcu(channel, rcu);
1380 }
1381
1382 struct vmbus_chan_attribute {
1383         struct attribute attr;
1384         ssize_t (*show)(const struct vmbus_channel *chan, char *buf);
1385         ssize_t (*store)(struct vmbus_channel *chan,
1386                          const char *buf, size_t count);
1387 };
1388 #define VMBUS_CHAN_ATTR(_name, _mode, _show, _store) \
1389         struct vmbus_chan_attribute chan_attr_##_name \
1390                 = __ATTR(_name, _mode, _show, _store)
1391 #define VMBUS_CHAN_ATTR_RW(_name) \
1392         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RW(_name)
1393 #define VMBUS_CHAN_ATTR_RO(_name) \
1394         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_RO(_name)
1395 #define VMBUS_CHAN_ATTR_WO(_name) \
1396         struct vmbus_chan_attribute chan_attr_##_name = __ATTR_WO(_name)
1397
1398 static ssize_t vmbus_chan_attr_show(struct kobject *kobj,
1399                                     struct attribute *attr, char *buf)
1400 {
1401         const struct vmbus_chan_attribute *attribute
1402                 = container_of(attr, struct vmbus_chan_attribute, attr);
1403         const struct vmbus_channel *chan
1404                 = container_of(kobj, struct vmbus_channel, kobj);
1405
1406         if (!attribute->show)
1407                 return -EIO;
1408
1409         if (chan->state != CHANNEL_OPENED_STATE)
1410                 return -EINVAL;
1411
1412         return attribute->show(chan, buf);
1413 }
1414
1415 static const struct sysfs_ops vmbus_chan_sysfs_ops = {
1416         .show = vmbus_chan_attr_show,
1417 };
1418
1419 static ssize_t out_mask_show(const struct vmbus_channel *channel, char *buf)
1420 {
1421         const struct hv_ring_buffer_info *rbi = &channel->outbound;
1422
1423         return sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1424 }
1425 static VMBUS_CHAN_ATTR_RO(out_mask);
1426
1427 static ssize_t in_mask_show(const struct vmbus_channel *channel, char *buf)
1428 {
1429         const struct hv_ring_buffer_info *rbi = &channel->inbound;
1430
1431         return sprintf(buf, "%u\n", rbi->ring_buffer->interrupt_mask);
1432 }
1433 static VMBUS_CHAN_ATTR_RO(in_mask);
1434
1435 static ssize_t read_avail_show(const struct vmbus_channel *channel, char *buf)
1436 {
1437         const struct hv_ring_buffer_info *rbi = &channel->inbound;
1438
1439         return sprintf(buf, "%u\n", hv_get_bytes_to_read(rbi));
1440 }
1441 static VMBUS_CHAN_ATTR_RO(read_avail);
1442
1443 static ssize_t write_avail_show(const struct vmbus_channel *channel, char *buf)
1444 {
1445         const struct hv_ring_buffer_info *rbi = &channel->outbound;
1446
1447         return sprintf(buf, "%u\n", hv_get_bytes_to_write(rbi));
1448 }
1449 static VMBUS_CHAN_ATTR_RO(write_avail);
1450
1451 static ssize_t show_target_cpu(const struct vmbus_channel *channel, char *buf)
1452 {
1453         return sprintf(buf, "%u\n", channel->target_cpu);
1454 }
1455 static VMBUS_CHAN_ATTR(cpu, S_IRUGO, show_target_cpu, NULL);
1456
1457 static ssize_t channel_pending_show(const struct vmbus_channel *channel,
1458                                     char *buf)
1459 {
1460         return sprintf(buf, "%d\n",
1461                        channel_pending(channel,
1462                                        vmbus_connection.monitor_pages[1]));
1463 }
1464 static VMBUS_CHAN_ATTR(pending, S_IRUGO, channel_pending_show, NULL);
1465
1466 static ssize_t channel_latency_show(const struct vmbus_channel *channel,
1467                                     char *buf)
1468 {
1469         return sprintf(buf, "%d\n",
1470                        channel_latency(channel,
1471                                        vmbus_connection.monitor_pages[1]));
1472 }
1473 static VMBUS_CHAN_ATTR(latency, S_IRUGO, channel_latency_show, NULL);
1474
1475 static ssize_t channel_interrupts_show(const struct vmbus_channel *channel, char *buf)
1476 {
1477         return sprintf(buf, "%llu\n", channel->interrupts);
1478 }
1479 static VMBUS_CHAN_ATTR(interrupts, S_IRUGO, channel_interrupts_show, NULL);
1480
1481 static ssize_t channel_events_show(const struct vmbus_channel *channel, char *buf)
1482 {
1483         return sprintf(buf, "%llu\n", channel->sig_events);
1484 }
1485 static VMBUS_CHAN_ATTR(events, S_IRUGO, channel_events_show, NULL);
1486
1487 static ssize_t channel_intr_in_full_show(const struct vmbus_channel *channel,
1488                                          char *buf)
1489 {
1490         return sprintf(buf, "%llu\n",
1491                        (unsigned long long)channel->intr_in_full);
1492 }
1493 static VMBUS_CHAN_ATTR(intr_in_full, 0444, channel_intr_in_full_show, NULL);
1494
1495 static ssize_t channel_intr_out_empty_show(const struct vmbus_channel *channel,
1496                                            char *buf)
1497 {
1498         return sprintf(buf, "%llu\n",
1499                        (unsigned long long)channel->intr_out_empty);
1500 }
1501 static VMBUS_CHAN_ATTR(intr_out_empty, 0444, channel_intr_out_empty_show, NULL);
1502
1503 static ssize_t channel_out_full_first_show(const struct vmbus_channel *channel,
1504                                            char *buf)
1505 {
1506         return sprintf(buf, "%llu\n",
1507                        (unsigned long long)channel->out_full_first);
1508 }
1509 static VMBUS_CHAN_ATTR(out_full_first, 0444, channel_out_full_first_show, NULL);
1510
1511 static ssize_t channel_out_full_total_show(const struct vmbus_channel *channel,
1512                                            char *buf)
1513 {
1514         return sprintf(buf, "%llu\n",
1515                        (unsigned long long)channel->out_full_total);
1516 }
1517 static VMBUS_CHAN_ATTR(out_full_total, 0444, channel_out_full_total_show, NULL);
1518
1519 static ssize_t subchannel_monitor_id_show(const struct vmbus_channel *channel,
1520                                           char *buf)
1521 {
1522         return sprintf(buf, "%u\n", channel->offermsg.monitorid);
1523 }
1524 static VMBUS_CHAN_ATTR(monitor_id, S_IRUGO, subchannel_monitor_id_show, NULL);
1525
1526 static ssize_t subchannel_id_show(const struct vmbus_channel *channel,
1527                                   char *buf)
1528 {
1529         return sprintf(buf, "%u\n",
1530                        channel->offermsg.offer.sub_channel_index);
1531 }
1532 static VMBUS_CHAN_ATTR_RO(subchannel_id);
1533
1534 static struct attribute *vmbus_chan_attrs[] = {
1535         &chan_attr_out_mask.attr,
1536         &chan_attr_in_mask.attr,
1537         &chan_attr_read_avail.attr,
1538         &chan_attr_write_avail.attr,
1539         &chan_attr_cpu.attr,
1540         &chan_attr_pending.attr,
1541         &chan_attr_latency.attr,
1542         &chan_attr_interrupts.attr,
1543         &chan_attr_events.attr,
1544         &chan_attr_intr_in_full.attr,
1545         &chan_attr_intr_out_empty.attr,
1546         &chan_attr_out_full_first.attr,
1547         &chan_attr_out_full_total.attr,
1548         &chan_attr_monitor_id.attr,
1549         &chan_attr_subchannel_id.attr,
1550         NULL
1551 };
1552
1553 static struct kobj_type vmbus_chan_ktype = {
1554         .sysfs_ops = &vmbus_chan_sysfs_ops,
1555         .release = vmbus_chan_release,
1556         .default_attrs = vmbus_chan_attrs,
1557 };
1558
1559 /*
1560  * vmbus_add_channel_kobj - setup a sub-directory under device/channels
1561  */
1562 int vmbus_add_channel_kobj(struct hv_device *dev, struct vmbus_channel *channel)
1563 {
1564         struct kobject *kobj = &channel->kobj;
1565         u32 relid = channel->offermsg.child_relid;
1566         int ret;
1567
1568         kobj->kset = dev->channels_kset;
1569         ret = kobject_init_and_add(kobj, &vmbus_chan_ktype, NULL,
1570                                    "%u", relid);
1571         if (ret)
1572                 return ret;
1573
1574         kobject_uevent(kobj, KOBJ_ADD);
1575
1576         return 0;
1577 }
1578
1579 /*
1580  * vmbus_device_create - Creates and registers a new child device
1581  * on the vmbus.
1582  */
1583 struct hv_device *vmbus_device_create(const guid_t *type,
1584                                       const guid_t *instance,
1585                                       struct vmbus_channel *channel)
1586 {
1587         struct hv_device *child_device_obj;
1588
1589         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1590         if (!child_device_obj) {
1591                 pr_err("Unable to allocate device object for child device\n");
1592                 return NULL;
1593         }
1594
1595         child_device_obj->channel = channel;
1596         guid_copy(&child_device_obj->dev_type, type);
1597         guid_copy(&child_device_obj->dev_instance, instance);
1598         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1599
1600         return child_device_obj;
1601 }
1602
1603 /*
1604  * vmbus_device_register - Register the child device
1605  */
1606 int vmbus_device_register(struct hv_device *child_device_obj)
1607 {
1608         struct kobject *kobj = &child_device_obj->device.kobj;
1609         int ret;
1610
1611         dev_set_name(&child_device_obj->device, "%pUl",
1612                      child_device_obj->channel->offermsg.offer.if_instance.b);
1613
1614         child_device_obj->device.bus = &hv_bus;
1615         child_device_obj->device.parent = &hv_acpi_dev->dev;
1616         child_device_obj->device.release = vmbus_device_release;
1617
1618         /*
1619          * Register with the LDM. This will kick off the driver/device
1620          * binding...which will eventually call vmbus_match() and vmbus_probe()
1621          */
1622         ret = device_register(&child_device_obj->device);
1623         if (ret) {
1624                 pr_err("Unable to register child device\n");
1625                 return ret;
1626         }
1627
1628         child_device_obj->channels_kset = kset_create_and_add("channels",
1629                                                               NULL, kobj);
1630         if (!child_device_obj->channels_kset) {
1631                 ret = -ENOMEM;
1632                 goto err_dev_unregister;
1633         }
1634
1635         ret = vmbus_add_channel_kobj(child_device_obj,
1636                                      child_device_obj->channel);
1637         if (ret) {
1638                 pr_err("Unable to register primary channeln");
1639                 goto err_kset_unregister;
1640         }
1641
1642         return 0;
1643
1644 err_kset_unregister:
1645         kset_unregister(child_device_obj->channels_kset);
1646
1647 err_dev_unregister:
1648         device_unregister(&child_device_obj->device);
1649         return ret;
1650 }
1651
1652 /*
1653  * vmbus_device_unregister - Remove the specified child device
1654  * from the vmbus.
1655  */
1656 void vmbus_device_unregister(struct hv_device *device_obj)
1657 {
1658         pr_debug("child device %s unregistered\n",
1659                 dev_name(&device_obj->device));
1660
1661         kset_unregister(device_obj->channels_kset);
1662
1663         /*
1664          * Kick off the process of unregistering the device.
1665          * This will call vmbus_remove() and eventually vmbus_device_release()
1666          */
1667         device_unregister(&device_obj->device);
1668 }
1669
1670
1671 /*
1672  * VMBUS is an acpi enumerated device. Get the information we
1673  * need from DSDT.
1674  */
1675 #define VTPM_BASE_ADDRESS 0xfed40000
1676 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1677 {
1678         resource_size_t start = 0;
1679         resource_size_t end = 0;
1680         struct resource *new_res;
1681         struct resource **old_res = &hyperv_mmio;
1682         struct resource **prev_res = NULL;
1683
1684         switch (res->type) {
1685
1686         /*
1687          * "Address" descriptors are for bus windows. Ignore
1688          * "memory" descriptors, which are for registers on
1689          * devices.
1690          */
1691         case ACPI_RESOURCE_TYPE_ADDRESS32:
1692                 start = res->data.address32.address.minimum;
1693                 end = res->data.address32.address.maximum;
1694                 break;
1695
1696         case ACPI_RESOURCE_TYPE_ADDRESS64:
1697                 start = res->data.address64.address.minimum;
1698                 end = res->data.address64.address.maximum;
1699                 break;
1700
1701         default:
1702                 /* Unused resource type */
1703                 return AE_OK;
1704
1705         }
1706         /*
1707          * Ignore ranges that are below 1MB, as they're not
1708          * necessary or useful here.
1709          */
1710         if (end < 0x100000)
1711                 return AE_OK;
1712
1713         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1714         if (!new_res)
1715                 return AE_NO_MEMORY;
1716
1717         /* If this range overlaps the virtual TPM, truncate it. */
1718         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1719                 end = VTPM_BASE_ADDRESS;
1720
1721         new_res->name = "hyperv mmio";
1722         new_res->flags = IORESOURCE_MEM;
1723         new_res->start = start;
1724         new_res->end = end;
1725
1726         /*
1727          * If two ranges are adjacent, merge them.
1728          */
1729         do {
1730                 if (!*old_res) {
1731                         *old_res = new_res;
1732                         break;
1733                 }
1734
1735                 if (((*old_res)->end + 1) == new_res->start) {
1736                         (*old_res)->end = new_res->end;
1737                         kfree(new_res);
1738                         break;
1739                 }
1740
1741                 if ((*old_res)->start == new_res->end + 1) {
1742                         (*old_res)->start = new_res->start;
1743                         kfree(new_res);
1744                         break;
1745                 }
1746
1747                 if ((*old_res)->start > new_res->end) {
1748                         new_res->sibling = *old_res;
1749                         if (prev_res)
1750                                 (*prev_res)->sibling = new_res;
1751                         *old_res = new_res;
1752                         break;
1753                 }
1754
1755                 prev_res = old_res;
1756                 old_res = &(*old_res)->sibling;
1757
1758         } while (1);
1759
1760         return AE_OK;
1761 }
1762
1763 static int vmbus_acpi_remove(struct acpi_device *device)
1764 {
1765         struct resource *cur_res;
1766         struct resource *next_res;
1767
1768         if (hyperv_mmio) {
1769                 if (fb_mmio) {
1770                         __release_region(hyperv_mmio, fb_mmio->start,
1771                                          resource_size(fb_mmio));
1772                         fb_mmio = NULL;
1773                 }
1774
1775                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1776                         next_res = cur_res->sibling;
1777                         kfree(cur_res);
1778                 }
1779         }
1780
1781         return 0;
1782 }
1783
1784 static void vmbus_reserve_fb(void)
1785 {
1786         int size;
1787         /*
1788          * Make a claim for the frame buffer in the resource tree under the
1789          * first node, which will be the one below 4GB.  The length seems to
1790          * be underreported, particularly in a Generation 1 VM.  So start out
1791          * reserving a larger area and make it smaller until it succeeds.
1792          */
1793
1794         if (screen_info.lfb_base) {
1795                 if (efi_enabled(EFI_BOOT))
1796                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
1797                 else
1798                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1799
1800                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1801                         fb_mmio = __request_region(hyperv_mmio,
1802                                                    screen_info.lfb_base, size,
1803                                                    fb_mmio_name, 0);
1804                 }
1805         }
1806 }
1807
1808 /**
1809  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1810  * @new:                If successful, supplied a pointer to the
1811  *                      allocated MMIO space.
1812  * @device_obj:         Identifies the caller
1813  * @min:                Minimum guest physical address of the
1814  *                      allocation
1815  * @max:                Maximum guest physical address
1816  * @size:               Size of the range to be allocated
1817  * @align:              Alignment of the range to be allocated
1818  * @fb_overlap_ok:      Whether this allocation can be allowed
1819  *                      to overlap the video frame buffer.
1820  *
1821  * This function walks the resources granted to VMBus by the
1822  * _CRS object in the ACPI namespace underneath the parent
1823  * "bridge" whether that's a root PCI bus in the Generation 1
1824  * case or a Module Device in the Generation 2 case.  It then
1825  * attempts to allocate from the global MMIO pool in a way that
1826  * matches the constraints supplied in these parameters and by
1827  * that _CRS.
1828  *
1829  * Return: 0 on success, -errno on failure
1830  */
1831 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1832                         resource_size_t min, resource_size_t max,
1833                         resource_size_t size, resource_size_t align,
1834                         bool fb_overlap_ok)
1835 {
1836         struct resource *iter, *shadow;
1837         resource_size_t range_min, range_max, start;
1838         const char *dev_n = dev_name(&device_obj->device);
1839         int retval;
1840
1841         retval = -ENXIO;
1842         down(&hyperv_mmio_lock);
1843
1844         /*
1845          * If overlaps with frame buffers are allowed, then first attempt to
1846          * make the allocation from within the reserved region.  Because it
1847          * is already reserved, no shadow allocation is necessary.
1848          */
1849         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1850             !(max < fb_mmio->start)) {
1851
1852                 range_min = fb_mmio->start;
1853                 range_max = fb_mmio->end;
1854                 start = (range_min + align - 1) & ~(align - 1);
1855                 for (; start + size - 1 <= range_max; start += align) {
1856                         *new = request_mem_region_exclusive(start, size, dev_n);
1857                         if (*new) {
1858                                 retval = 0;
1859                                 goto exit;
1860                         }
1861                 }
1862         }
1863
1864         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1865                 if ((iter->start >= max) || (iter->end <= min))
1866                         continue;
1867
1868                 range_min = iter->start;
1869                 range_max = iter->end;
1870                 start = (range_min + align - 1) & ~(align - 1);
1871                 for (; start + size - 1 <= range_max; start += align) {
1872                         shadow = __request_region(iter, start, size, NULL,
1873                                                   IORESOURCE_BUSY);
1874                         if (!shadow)
1875                                 continue;
1876
1877                         *new = request_mem_region_exclusive(start, size, dev_n);
1878                         if (*new) {
1879                                 shadow->name = (char *)*new;
1880                                 retval = 0;
1881                                 goto exit;
1882                         }
1883
1884                         __release_region(iter, start, size);
1885                 }
1886         }
1887
1888 exit:
1889         up(&hyperv_mmio_lock);
1890         return retval;
1891 }
1892 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1893
1894 /**
1895  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1896  * @start:              Base address of region to release.
1897  * @size:               Size of the range to be allocated
1898  *
1899  * This function releases anything requested by
1900  * vmbus_mmio_allocate().
1901  */
1902 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1903 {
1904         struct resource *iter;
1905
1906         down(&hyperv_mmio_lock);
1907         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1908                 if ((iter->start >= start + size) || (iter->end <= start))
1909                         continue;
1910
1911                 __release_region(iter, start, size);
1912         }
1913         release_mem_region(start, size);
1914         up(&hyperv_mmio_lock);
1915
1916 }
1917 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1918
1919 static int vmbus_acpi_add(struct acpi_device *device)
1920 {
1921         acpi_status result;
1922         int ret_val = -ENODEV;
1923         struct acpi_device *ancestor;
1924
1925         hv_acpi_dev = device;
1926
1927         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1928                                         vmbus_walk_resources, NULL);
1929
1930         if (ACPI_FAILURE(result))
1931                 goto acpi_walk_err;
1932         /*
1933          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1934          * firmware) is the VMOD that has the mmio ranges. Get that.
1935          */
1936         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1937                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1938                                              vmbus_walk_resources, NULL);
1939
1940                 if (ACPI_FAILURE(result))
1941                         continue;
1942                 if (hyperv_mmio) {
1943                         vmbus_reserve_fb();
1944                         break;
1945                 }
1946         }
1947         ret_val = 0;
1948
1949 acpi_walk_err:
1950         complete(&probe_event);
1951         if (ret_val)
1952                 vmbus_acpi_remove(device);
1953         return ret_val;
1954 }
1955
1956 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1957         {"VMBUS", 0},
1958         {"VMBus", 0},
1959         {"", 0},
1960 };
1961 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1962
1963 static struct acpi_driver vmbus_acpi_driver = {
1964         .name = "vmbus",
1965         .ids = vmbus_acpi_device_ids,
1966         .ops = {
1967                 .add = vmbus_acpi_add,
1968                 .remove = vmbus_acpi_remove,
1969         },
1970 };
1971
1972 static void hv_kexec_handler(void)
1973 {
1974         hv_synic_clockevents_cleanup();
1975         vmbus_initiate_unload(false);
1976         vmbus_connection.conn_state = DISCONNECTED;
1977         /* Make sure conn_state is set as hv_synic_cleanup checks for it */
1978         mb();
1979         cpuhp_remove_state(hyperv_cpuhp_online);
1980         hyperv_cleanup();
1981 };
1982
1983 static void hv_crash_handler(struct pt_regs *regs)
1984 {
1985         vmbus_initiate_unload(true);
1986         /*
1987          * In crash handler we can't schedule synic cleanup for all CPUs,
1988          * doing the cleanup for current CPU only. This should be sufficient
1989          * for kdump.
1990          */
1991         vmbus_connection.conn_state = DISCONNECTED;
1992         hv_synic_cleanup(smp_processor_id());
1993         hyperv_cleanup();
1994 };
1995
1996 static int __init hv_acpi_init(void)
1997 {
1998         int ret, t;
1999
2000         if (!hv_is_hyperv_initialized())
2001                 return -ENODEV;
2002
2003         init_completion(&probe_event);
2004
2005         /*
2006          * Get ACPI resources first.
2007          */
2008         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
2009
2010         if (ret)
2011                 return ret;
2012
2013         t = wait_for_completion_timeout(&probe_event, 5*HZ);
2014         if (t == 0) {
2015                 ret = -ETIMEDOUT;
2016                 goto cleanup;
2017         }
2018
2019         ret = vmbus_bus_init();
2020         if (ret)
2021                 goto cleanup;
2022
2023         hv_setup_kexec_handler(hv_kexec_handler);
2024         hv_setup_crash_handler(hv_crash_handler);
2025
2026         return 0;
2027
2028 cleanup:
2029         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2030         hv_acpi_dev = NULL;
2031         return ret;
2032 }
2033
2034 static void __exit vmbus_exit(void)
2035 {
2036         int cpu;
2037
2038         hv_remove_kexec_handler();
2039         hv_remove_crash_handler();
2040         vmbus_connection.conn_state = DISCONNECTED;
2041         hv_synic_clockevents_cleanup();
2042         vmbus_disconnect();
2043         hv_remove_vmbus_irq();
2044         for_each_online_cpu(cpu) {
2045                 struct hv_per_cpu_context *hv_cpu
2046                         = per_cpu_ptr(hv_context.cpu_context, cpu);
2047
2048                 tasklet_kill(&hv_cpu->msg_dpc);
2049         }
2050         vmbus_free_channels();
2051
2052         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
2053                 kmsg_dump_unregister(&hv_kmsg_dumper);
2054                 unregister_die_notifier(&hyperv_die_block);
2055                 atomic_notifier_chain_unregister(&panic_notifier_list,
2056                                                  &hyperv_panic_block);
2057         }
2058
2059         free_page((unsigned long)hv_panic_page);
2060         unregister_sysctl_table(hv_ctl_table_hdr);
2061         hv_ctl_table_hdr = NULL;
2062         bus_unregister(&hv_bus);
2063
2064         cpuhp_remove_state(hyperv_cpuhp_online);
2065         hv_synic_free();
2066         acpi_bus_unregister_driver(&vmbus_acpi_driver);
2067 }
2068
2069
2070 MODULE_LICENSE("GPL");
2071
2072 subsys_initcall(hv_acpi_init);
2073 module_exit(vmbus_exit);