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 <asm/hyperv.h>
  38 #include <asm/hypervisor.h>
  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/random.h>
  45 #include "hyperv_vmbus.h"
  46
  47 static struct acpi_device  *hv_acpi_dev;
  48
  49 static struct tasklet_struct msg_dpc;
  50 static struct completion probe_event;
  51 static int irq;
  52
  53
  54 static void hyperv_report_panic(struct pt_regs *regs)
  55 {
  56         static bool panic_reported;
  57
  58         /*
  59          * We prefer to report panic on 'die' chain as we have proper
  60          * registers to report, but if we miss it (e.g. on BUG()) we need
  61          * to report it on 'panic'.
  62          */
  63         if (panic_reported)
  64                 return;
  65         panic_reported = true;
  66
  67         wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
  68         wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
  69         wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
  70         wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
  71         wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
  72
  73         /*
  74          * Let Hyper-V know there is crash data available
  75          */
  76         wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
  77 }
  78
  79 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  80                               void *args)
  81 {
  82         struct pt_regs *regs;
  83
  84         regs = current_pt_regs();
  85
  86         hyperv_report_panic(regs);
  87         return NOTIFY_DONE;
  88 }
  89
  90 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  91                             void *args)
  92 {
  93         struct die_args *die = (struct die_args *)args;
  94         struct pt_regs *regs = die->regs;
  95
  96         hyperv_report_panic(regs);
  97         return NOTIFY_DONE;
  98 }
  99
 100 static struct notifier_block hyperv_die_block = {
 101         .notifier_call = hyperv_die_event,
 102 };
 103 static struct notifier_block hyperv_panic_block = {
 104         .notifier_call = hyperv_panic_event,
 105 };
 106
 107 struct resource *hyperv_mmio;
 108 DEFINE_SEMAPHORE(hyperv_mmio_lock);
 109
 110 static int vmbus_exists(void)
 111 {
 112         if (hv_acpi_dev == NULL)
 113                 return -ENODEV;
 114
 115         return 0;
 116 }
 117
 118 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 119 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 120 {
 121         int i;
 122         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 123                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 124 }
 125
 126 static u8 channel_monitor_group(struct vmbus_channel *channel)
 127 {
 128         return (u8)channel->offermsg.monitorid / 32;
 129 }
 130
 131 static u8 channel_monitor_offset(struct vmbus_channel *channel)
 132 {
 133         return (u8)channel->offermsg.monitorid % 32;
 134 }
 135
 136 static u32 channel_pending(struct vmbus_channel *channel,
 137                            struct hv_monitor_page *monitor_page)
 138 {
 139         u8 monitor_group = channel_monitor_group(channel);
 140         return monitor_page->trigger_group[monitor_group].pending;
 141 }
 142
 143 static u32 channel_latency(struct vmbus_channel *channel,
 144                            struct hv_monitor_page *monitor_page)
 145 {
 146         u8 monitor_group = channel_monitor_group(channel);
 147         u8 monitor_offset = channel_monitor_offset(channel);
 148         return monitor_page->latency[monitor_group][monitor_offset];
 149 }
 150
 151 static u32 channel_conn_id(struct vmbus_channel *channel,
 152                            struct hv_monitor_page *monitor_page)
 153 {
 154         u8 monitor_group = channel_monitor_group(channel);
 155         u8 monitor_offset = channel_monitor_offset(channel);
 156         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 157 }
 158
 159 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 160                        char *buf)
 161 {
 162         struct hv_device *hv_dev = device_to_hv_device(dev);
 163
 164         if (!hv_dev->channel)
 165                 return -ENODEV;
 166         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 167 }
 168 static DEVICE_ATTR_RO(id);
 169
 170 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 171                           char *buf)
 172 {
 173         struct hv_device *hv_dev = device_to_hv_device(dev);
 174
 175         if (!hv_dev->channel)
 176                 return -ENODEV;
 177         return sprintf(buf, "%d\n", hv_dev->channel->state);
 178 }
 179 static DEVICE_ATTR_RO(state);
 180
 181 static ssize_t monitor_id_show(struct device *dev,
 182                                struct device_attribute *dev_attr, char *buf)
 183 {
 184         struct hv_device *hv_dev = device_to_hv_device(dev);
 185
 186         if (!hv_dev->channel)
 187                 return -ENODEV;
 188         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 189 }
 190 static DEVICE_ATTR_RO(monitor_id);
 191
 192 static ssize_t class_id_show(struct device *dev,
 193                                struct device_attribute *dev_attr, char *buf)
 194 {
 195         struct hv_device *hv_dev = device_to_hv_device(dev);
 196
 197         if (!hv_dev->channel)
 198                 return -ENODEV;
 199         return sprintf(buf, "{%pUl}\n",
 200                        hv_dev->channel->offermsg.offer.if_type.b);
 201 }
 202 static DEVICE_ATTR_RO(class_id);
 203
 204 static ssize_t device_id_show(struct device *dev,
 205                               struct device_attribute *dev_attr, char *buf)
 206 {
 207         struct hv_device *hv_dev = device_to_hv_device(dev);
 208
 209         if (!hv_dev->channel)
 210                 return -ENODEV;
 211         return sprintf(buf, "{%pUl}\n",
 212                        hv_dev->channel->offermsg.offer.if_instance.b);
 213 }
 214 static DEVICE_ATTR_RO(device_id);
 215
 216 static ssize_t modalias_show(struct device *dev,
 217                              struct device_attribute *dev_attr, char *buf)
 218 {
 219         struct hv_device *hv_dev = device_to_hv_device(dev);
 220         char alias_name[VMBUS_ALIAS_LEN + 1];
 221
 222         print_alias_name(hv_dev, alias_name);
 223         return sprintf(buf, "vmbus:%s\n", alias_name);
 224 }
 225 static DEVICE_ATTR_RO(modalias);
 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
 317         if (!hv_dev->channel)
 318                 return -ENODEV;
 319         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 320                 return -EINVAL;
 321         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 322         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 323 }
 324 static DEVICE_ATTR_RO(out_intr_mask);
 325
 326 static ssize_t out_read_index_show(struct device *dev,
 327                                    struct device_attribute *dev_attr, char *buf)
 328 {
 329         struct hv_device *hv_dev = device_to_hv_device(dev);
 330         struct hv_ring_buffer_debug_info outbound;
 331
 332         if (!hv_dev->channel)
 333                 return -ENODEV;
 334         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 335                 return -EINVAL;
 336         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 337         return sprintf(buf, "%d\n", outbound.current_read_index);
 338 }
 339 static DEVICE_ATTR_RO(out_read_index);
 340
 341 static ssize_t out_write_index_show(struct device *dev,
 342                                     struct device_attribute *dev_attr,
 343                                     char *buf)
 344 {
 345         struct hv_device *hv_dev = device_to_hv_device(dev);
 346         struct hv_ring_buffer_debug_info outbound;
 347
 348         if (!hv_dev->channel)
 349                 return -ENODEV;
 350         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 351                 return -EINVAL;
 352         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 353         return sprintf(buf, "%d\n", outbound.current_write_index);
 354 }
 355 static DEVICE_ATTR_RO(out_write_index);
 356
 357 static ssize_t out_read_bytes_avail_show(struct device *dev,
 358                                          struct device_attribute *dev_attr,
 359                                          char *buf)
 360 {
 361         struct hv_device *hv_dev = device_to_hv_device(dev);
 362         struct hv_ring_buffer_debug_info outbound;
 363
 364         if (!hv_dev->channel)
 365                 return -ENODEV;
 366         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 367                 return -EINVAL;
 368         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 369         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 370 }
 371 static DEVICE_ATTR_RO(out_read_bytes_avail);
 372
 373 static ssize_t out_write_bytes_avail_show(struct device *dev,
 374                                           struct device_attribute *dev_attr,
 375                                           char *buf)
 376 {
 377         struct hv_device *hv_dev = device_to_hv_device(dev);
 378         struct hv_ring_buffer_debug_info outbound;
 379
 380         if (!hv_dev->channel)
 381                 return -ENODEV;
 382         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 383                 return -EINVAL;
 384         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 385         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 386 }
 387 static DEVICE_ATTR_RO(out_write_bytes_avail);
 388
 389 static ssize_t in_intr_mask_show(struct device *dev,
 390                                  struct device_attribute *dev_attr, char *buf)
 391 {
 392         struct hv_device *hv_dev = device_to_hv_device(dev);
 393         struct hv_ring_buffer_debug_info inbound;
 394
 395         if (!hv_dev->channel)
 396                 return -ENODEV;
 397         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 398                 return -EINVAL;
 399         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 400         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 401 }
 402 static DEVICE_ATTR_RO(in_intr_mask);
 403
 404 static ssize_t in_read_index_show(struct device *dev,
 405                                   struct device_attribute *dev_attr, char *buf)
 406 {
 407         struct hv_device *hv_dev = device_to_hv_device(dev);
 408         struct hv_ring_buffer_debug_info inbound;
 409
 410         if (!hv_dev->channel)
 411                 return -ENODEV;
 412         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 413                 return -EINVAL;
 414         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 415         return sprintf(buf, "%d\n", inbound.current_read_index);
 416 }
 417 static DEVICE_ATTR_RO(in_read_index);
 418
 419 static ssize_t in_write_index_show(struct device *dev,
 420                                    struct device_attribute *dev_attr, char *buf)
 421 {
 422         struct hv_device *hv_dev = device_to_hv_device(dev);
 423         struct hv_ring_buffer_debug_info inbound;
 424
 425         if (!hv_dev->channel)
 426                 return -ENODEV;
 427         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 428                 return -EINVAL;
 429         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 430         return sprintf(buf, "%d\n", inbound.current_write_index);
 431 }
 432 static DEVICE_ATTR_RO(in_write_index);
 433
 434 static ssize_t in_read_bytes_avail_show(struct device *dev,
 435                                         struct device_attribute *dev_attr,
 436                                         char *buf)
 437 {
 438         struct hv_device *hv_dev = device_to_hv_device(dev);
 439         struct hv_ring_buffer_debug_info inbound;
 440
 441         if (!hv_dev->channel)
 442                 return -ENODEV;
 443         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 444                 return -EINVAL;
 445         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 446         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 447 }
 448 static DEVICE_ATTR_RO(in_read_bytes_avail);
 449
 450 static ssize_t in_write_bytes_avail_show(struct device *dev,
 451                                          struct device_attribute *dev_attr,
 452                                          char *buf)
 453 {
 454         struct hv_device *hv_dev = device_to_hv_device(dev);
 455         struct hv_ring_buffer_debug_info inbound;
 456
 457         if (!hv_dev->channel)
 458                 return -ENODEV;
 459         if (hv_dev->channel->state != CHANNEL_OPENED_STATE)
 460                 return -EINVAL;
 461         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 462         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 463 }
 464 static DEVICE_ATTR_RO(in_write_bytes_avail);
 465
 466 static ssize_t channel_vp_mapping_show(struct device *dev,
 467                                        struct device_attribute *dev_attr,
 468                                        char *buf)
 469 {
 470         struct hv_device *hv_dev = device_to_hv_device(dev);
 471         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 472         unsigned long flags;
 473         int buf_size = PAGE_SIZE, n_written, tot_written;
 474         struct list_head *cur;
 475
 476         if (!channel)
 477                 return -ENODEV;
 478
 479         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 480                 channel->offermsg.child_relid, channel->target_cpu);
 481
 482         spin_lock_irqsave(&channel->lock, flags);
 483
 484         list_for_each(cur, &channel->sc_list) {
 485                 if (tot_written >= buf_size - 1)
 486                         break;
 487
 488                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 489                 n_written = scnprintf(buf + tot_written,
 490                                      buf_size - tot_written,
 491                                      "%u:%u\n",
 492                                      cur_sc->offermsg.child_relid,
 493                                      cur_sc->target_cpu);
 494                 tot_written += n_written;
 495         }
 496
 497         spin_unlock_irqrestore(&channel->lock, flags);
 498
 499         return tot_written;
 500 }
 501 static DEVICE_ATTR_RO(channel_vp_mapping);
 502
 503 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 504 static struct attribute *vmbus_attrs[] = {
 505         &dev_attr_id.attr,
 506         &dev_attr_state.attr,
 507         &dev_attr_monitor_id.attr,
 508         &dev_attr_class_id.attr,
 509         &dev_attr_device_id.attr,
 510         &dev_attr_modalias.attr,
 511         &dev_attr_server_monitor_pending.attr,
 512         &dev_attr_client_monitor_pending.attr,
 513         &dev_attr_server_monitor_latency.attr,
 514         &dev_attr_client_monitor_latency.attr,
 515         &dev_attr_server_monitor_conn_id.attr,
 516         &dev_attr_client_monitor_conn_id.attr,
 517         &dev_attr_out_intr_mask.attr,
 518         &dev_attr_out_read_index.attr,
 519         &dev_attr_out_write_index.attr,
 520         &dev_attr_out_read_bytes_avail.attr,
 521         &dev_attr_out_write_bytes_avail.attr,
 522         &dev_attr_in_intr_mask.attr,
 523         &dev_attr_in_read_index.attr,
 524         &dev_attr_in_write_index.attr,
 525         &dev_attr_in_read_bytes_avail.attr,
 526         &dev_attr_in_write_bytes_avail.attr,
 527         &dev_attr_channel_vp_mapping.attr,
 528         NULL,
 529 };
 530 ATTRIBUTE_GROUPS(vmbus);
 531
 532 /*
 533  * vmbus_uevent - add uevent for our device
 534  *
 535  * This routine is invoked when a device is added or removed on the vmbus to
 536  * generate a uevent to udev in the userspace. The udev will then look at its
 537  * rule and the uevent generated here to load the appropriate driver
 538  *
 539  * The alias string will be of the form vmbus:guid where guid is the string
 540  * representation of the device guid (each byte of the guid will be
 541  * represented with two hex characters.
 542  */
 543 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 544 {
 545         struct hv_device *dev = device_to_hv_device(device);
 546         int ret;
 547         char alias_name[VMBUS_ALIAS_LEN + 1];
 548
 549         print_alias_name(dev, alias_name);
 550         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 551         return ret;
 552 }
 553
 554 static const uuid_le null_guid;
 555
 556 static inline bool is_null_guid(const __u8 *guid)
 557 {
 558         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 559                 return false;
 560         return true;
 561 }
 562
 563 /*
 564  * Return a matching hv_vmbus_device_id pointer.
 565  * If there is no match, return NULL.
 566  */
 567 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 568                                         const struct hv_vmbus_device_id *id,
 569                                         const __u8 *guid)
 570 {
 571         for (; !is_null_guid(id->guid); id++)
 572                 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 573                         return id;
 574
 575         return NULL;
 576 }
 577
 578
 579
 580 /*
 581  * vmbus_match - Attempt to match the specified device to the specified driver
 582  */
 583 static int vmbus_match(struct device *device, struct device_driver *driver)
 584 {
 585         struct hv_driver *drv = drv_to_hv_drv(driver);
 586         struct hv_device *hv_dev = device_to_hv_device(device);
 587
 588         if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 589                 return 1;
 590
 591         return 0;
 592 }
 593
 594 /*
 595  * vmbus_probe - Add the new vmbus's child device
 596  */
 597 static int vmbus_probe(struct device *child_device)
 598 {
 599         int ret = 0;
 600         struct hv_driver *drv =
 601                         drv_to_hv_drv(child_device->driver);
 602         struct hv_device *dev = device_to_hv_device(child_device);
 603         const struct hv_vmbus_device_id *dev_id;
 604
 605         dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 606         if (drv->probe) {
 607                 ret = drv->probe(dev, dev_id);
 608                 if (ret != 0)
 609                         pr_err("probe failed for device %s (%d)\n",
 610                                dev_name(child_device), ret);
 611
 612         } else {
 613                 pr_err("probe not set for driver %s\n",
 614                        dev_name(child_device));
 615                 ret = -ENODEV;
 616         }
 617         return ret;
 618 }
 619
 620 /*
 621  * vmbus_remove - Remove a vmbus device
 622  */
 623 static int vmbus_remove(struct device *child_device)
 624 {
 625         struct hv_driver *drv;
 626         struct hv_device *dev = device_to_hv_device(child_device);
 627
 628         if (child_device->driver) {
 629                 drv = drv_to_hv_drv(child_device->driver);
 630                 if (drv->remove)
 631                         drv->remove(dev);
 632         }
 633
 634         return 0;
 635 }
 636
 637
 638 /*
 639  * vmbus_shutdown - Shutdown a vmbus device
 640  */
 641 static void vmbus_shutdown(struct device *child_device)
 642 {
 643         struct hv_driver *drv;
 644         struct hv_device *dev = device_to_hv_device(child_device);
 645
 646
 647         /* The device may not be attached yet */
 648         if (!child_device->driver)
 649                 return;
 650
 651         drv = drv_to_hv_drv(child_device->driver);
 652
 653         if (drv->shutdown)
 654                 drv->shutdown(dev);
 655
 656         return;
 657 }
 658
 659
 660 /*
 661  * vmbus_device_release - Final callback release of the vmbus child device
 662  */
 663 static void vmbus_device_release(struct device *device)
 664 {
 665         struct hv_device *hv_dev = device_to_hv_device(device);
 666         struct vmbus_channel *channel = hv_dev->channel;
 667
 668         hv_process_channel_removal(channel,
 669                                    channel->offermsg.child_relid);
 670         kfree(hv_dev);
 671
 672 }
 673
 674 /* The one and only one */
 675 static struct bus_type  hv_bus = {
 676         .name =         "vmbus",
 677         .match =                vmbus_match,
 678         .shutdown =             vmbus_shutdown,
 679         .remove =               vmbus_remove,
 680         .probe =                vmbus_probe,
 681         .uevent =               vmbus_uevent,
 682         .dev_groups =           vmbus_groups,
 683 };
 684
 685 struct onmessage_work_context {
 686         struct work_struct work;
 687         struct hv_message msg;
 688 };
 689
 690 static void vmbus_onmessage_work(struct work_struct *work)
 691 {
 692         struct onmessage_work_context *ctx;
 693
 694         /* Do not process messages if we're in DISCONNECTED state */
 695         if (vmbus_connection.conn_state == DISCONNECTED)
 696                 return;
 697
 698         ctx = container_of(work, struct onmessage_work_context,
 699                            work);
 700         vmbus_onmessage(&ctx->msg);
 701         kfree(ctx);
 702 }
 703
 704 static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
 705 {
 706         struct clock_event_device *dev = hv_context.clk_evt[cpu];
 707
 708         if (dev->event_handler)
 709                 dev->event_handler(dev);
 710
 711         msg->header.message_type = HVMSG_NONE;
 712
 713         /*
 714          * Make sure the write to MessageType (ie set to
 715          * HVMSG_NONE) happens before we read the
 716          * MessagePending and EOMing. Otherwise, the EOMing
 717          * will not deliver any more messages since there is
 718          * no empty slot
 719          */
 720         mb();
 721
 722         if (msg->header.message_flags.msg_pending) {
 723                 /*
 724                  * This will cause message queue rescan to
 725                  * possibly deliver another msg from the
 726                  * hypervisor
 727                  */
 728                 wrmsrl(HV_X64_MSR_EOM, 0);
 729         }
 730 }
 731
 732 static void vmbus_on_msg_dpc(unsigned long data)
 733 {
 734         int cpu = smp_processor_id();
 735         void *page_addr = hv_context.synic_message_page[cpu];
 736         struct hv_message *msg = (struct hv_message *)page_addr +
 737                                   VMBUS_MESSAGE_SINT;
 738         struct vmbus_channel_message_header *hdr;
 739         struct vmbus_channel_message_table_entry *entry;
 740         struct onmessage_work_context *ctx;
 741
 742         while (1) {
 743                 if (msg->header.message_type == HVMSG_NONE)
 744                         /* no msg */
 745                         break;
 746
 747                 hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 748
 749                 if (hdr->msgtype >= CHANNELMSG_COUNT) {
 750                         WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 751                         goto msg_handled;
 752                 }
 753
 754                 entry = &channel_message_table[hdr->msgtype];
 755                 if (entry->handler_type == VMHT_BLOCKING) {
 756                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 757                         if (ctx == NULL)
 758                                 continue;
 759
 760                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
 761                         memcpy(&ctx->msg, msg, sizeof(*msg));
 762
 763                         queue_work(vmbus_connection.work_queue, &ctx->work);
 764                 } else
 765                         entry->message_handler(hdr);
 766
 767 msg_handled:
 768                 msg->header.message_type = HVMSG_NONE;
 769
 770                 /*
 771                  * Make sure the write to MessageType (ie set to
 772                  * HVMSG_NONE) happens before we read the
 773                  * MessagePending and EOMing. Otherwise, the EOMing
 774                  * will not deliver any more messages since there is
 775                  * no empty slot
 776                  */
 777                 mb();
 778
 779                 if (msg->header.message_flags.msg_pending) {
 780                         /*
 781                          * This will cause message queue rescan to
 782                          * possibly deliver another msg from the
 783                          * hypervisor
 784                          */
 785                         wrmsrl(HV_X64_MSR_EOM, 0);
 786                 }
 787         }
 788 }
 789
 790 static void vmbus_isr(void)
 791 {
 792         int cpu = smp_processor_id();
 793         void *page_addr;
 794         struct hv_message *msg;
 795         union hv_synic_event_flags *event;
 796         bool handled = false;
 797
 798         page_addr = hv_context.synic_event_page[cpu];
 799         if (page_addr == NULL)
 800                 return;
 801
 802         event = (union hv_synic_event_flags *)page_addr +
 803                                          VMBUS_MESSAGE_SINT;
 804         /*
 805          * Check for events before checking for messages. This is the order
 806          * in which events and messages are checked in Windows guests on
 807          * Hyper-V, and the Windows team suggested we do the same.
 808          */
 809
 810         if ((vmbus_proto_version == VERSION_WS2008) ||
 811                 (vmbus_proto_version == VERSION_WIN7)) {
 812
 813                 /* Since we are a child, we only need to check bit 0 */
 814                 if (sync_test_and_clear_bit(0,
 815                         (unsigned long *) &event->flags32[0])) {
 816                         handled = true;
 817                 }
 818         } else {
 819                 /*
 820                  * Our host is win8 or above. The signaling mechanism
 821                  * has changed and we can directly look at the event page.
 822                  * If bit n is set then we have an interrup on the channel
 823                  * whose id is n.
 824                  */
 825                 handled = true;
 826         }
 827
 828         if (handled)
 829                 tasklet_schedule(hv_context.event_dpc[cpu]);
 830
 831
 832         page_addr = hv_context.synic_message_page[cpu];
 833         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 834
 835         /* Check if there are actual msgs to be processed */
 836         if (msg->header.message_type != HVMSG_NONE) {
 837                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
 838                         hv_process_timer_expiration(msg, cpu);
 839                 else
 840                         tasklet_schedule(&msg_dpc);
 841         }
 842
 843         add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
 844 }
 845
 846
 847 /*
 848  * vmbus_bus_init -Main vmbus driver initialization routine.
 849  *
 850  * Here, we
 851  *      - initialize the vmbus driver context
 852  *      - invoke the vmbus hv main init routine
 853  *      - get the irq resource
 854  *      - retrieve the channel offers
 855  */
 856 static int vmbus_bus_init(int irq)
 857 {
 858         int ret;
 859
 860         /* Hypervisor initialization...setup hypercall page..etc */
 861         ret = hv_init();
 862         if (ret != 0) {
 863                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 864                 return ret;
 865         }
 866
 867         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 868
 869         ret = bus_register(&hv_bus);
 870         if (ret)
 871                 goto err_cleanup;
 872
 873         hv_setup_vmbus_irq(vmbus_isr);
 874
 875         ret = hv_synic_alloc();
 876         if (ret)
 877                 goto err_alloc;
 878         /*
 879          * Initialize the per-cpu interrupt state and
 880          * connect to the host.
 881          */
 882         on_each_cpu(hv_synic_init, NULL, 1);
 883         ret = vmbus_connect();
 884         if (ret)
 885                 goto err_connect;
 886
 887         if (vmbus_proto_version > VERSION_WIN7)
 888                 cpu_hotplug_disable();
 889
 890         /*
 891          * Only register if the crash MSRs are available
 892          */
 893         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
 894                 register_die_notifier(&hyperv_die_block);
 895                 atomic_notifier_chain_register(&panic_notifier_list,
 896                                                &hyperv_panic_block);
 897         }
 898
 899         vmbus_request_offers();
 900
 901         return 0;
 902
 903 err_connect:
 904         on_each_cpu(hv_synic_cleanup, NULL, 1);
 905 err_alloc:
 906         hv_synic_free();
 907         hv_remove_vmbus_irq();
 908
 909         bus_unregister(&hv_bus);
 910
 911 err_cleanup:
 912         hv_cleanup(false);
 913
 914         return ret;
 915 }
 916
 917 /**
 918  * __vmbus_child_driver_register() - Register a vmbus's driver
 919  * @hv_driver: Pointer to driver structure you want to register
 920  * @owner: owner module of the drv
 921  * @mod_name: module name string
 922  *
 923  * Registers the given driver with Linux through the 'driver_register()' call
 924  * and sets up the hyper-v vmbus handling for this driver.
 925  * It will return the state of the 'driver_register()' call.
 926  *
 927  */
 928 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 929 {
 930         int ret;
 931
 932         pr_info("registering driver %s\n", hv_driver->name);
 933
 934         ret = vmbus_exists();
 935         if (ret < 0)
 936                 return ret;
 937
 938         hv_driver->driver.name = hv_driver->name;
 939         hv_driver->driver.owner = owner;
 940         hv_driver->driver.mod_name = mod_name;
 941         hv_driver->driver.bus = &hv_bus;
 942
 943         ret = driver_register(&hv_driver->driver);
 944
 945         return ret;
 946 }
 947 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 948
 949 /**
 950  * vmbus_driver_unregister() - Unregister a vmbus's driver
 951  * @hv_driver: Pointer to driver structure you want to
 952  *             un-register
 953  *
 954  * Un-register the given driver that was previous registered with a call to
 955  * vmbus_driver_register()
 956  */
 957 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 958 {
 959         pr_info("unregistering driver %s\n", hv_driver->name);
 960
 961         if (!vmbus_exists())
 962                 driver_unregister(&hv_driver->driver);
 963 }
 964 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 965
 966 /*
 967  * vmbus_device_create - Creates and registers a new child device
 968  * on the vmbus.
 969  */
 970 struct hv_device *vmbus_device_create(const uuid_le *type,
 971                                       const uuid_le *instance,
 972                                       struct vmbus_channel *channel)
 973 {
 974         struct hv_device *child_device_obj;
 975
 976         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 977         if (!child_device_obj) {
 978                 pr_err("Unable to allocate device object for child device\n");
 979                 return NULL;
 980         }
 981
 982         child_device_obj->channel = channel;
 983         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 984         memcpy(&child_device_obj->dev_instance, instance,
 985                sizeof(uuid_le));
 986
 987
 988         return child_device_obj;
 989 }
 990
 991 /*
 992  * vmbus_device_register - Register the child device
 993  */
 994 int vmbus_device_register(struct hv_device *child_device_obj)
 995 {
 996         int ret = 0;
 997
 998         dev_set_name(&child_device_obj->device, "vmbus_%d",
 999                      child_device_obj->channel->id);
1000
1001         child_device_obj->device.bus = &hv_bus;
1002         child_device_obj->device.parent = &hv_acpi_dev->dev;
1003         child_device_obj->device.release = vmbus_device_release;
1004
1005         /*
1006          * Register with the LDM. This will kick off the driver/device
1007          * binding...which will eventually call vmbus_match() and vmbus_probe()
1008          */
1009         ret = device_register(&child_device_obj->device);
1010
1011         if (ret)
1012                 pr_err("Unable to register child device\n");
1013         else
1014                 pr_debug("child device %s registered\n",
1015                         dev_name(&child_device_obj->device));
1016
1017         return ret;
1018 }
1019
1020 /*
1021  * vmbus_device_unregister - Remove the specified child device
1022  * from the vmbus.
1023  */
1024 void vmbus_device_unregister(struct hv_device *device_obj)
1025 {
1026         pr_debug("child device %s unregistered\n",
1027                 dev_name(&device_obj->device));
1028
1029         /*
1030          * Kick off the process of unregistering the device.
1031          * This will call vmbus_remove() and eventually vmbus_device_release()
1032          */
1033         device_unregister(&device_obj->device);
1034 }
1035
1036
1037 /*
1038  * VMBUS is an acpi enumerated device. Get the information we
1039  * need from DSDT.
1040  */
1041 #define VTPM_BASE_ADDRESS 0xfed40000
1042 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1043 {
1044         resource_size_t start = 0;
1045         resource_size_t end = 0;
1046         struct resource *new_res;
1047         struct resource **old_res = &hyperv_mmio;
1048         struct resource **prev_res = NULL;
1049
1050         switch (res->type) {
1051         case ACPI_RESOURCE_TYPE_IRQ:
1052                 irq = res->data.irq.interrupts[0];
1053                 return AE_OK;
1054
1055         /*
1056          * "Address" descriptors are for bus windows. Ignore
1057          * "memory" descriptors, which are for registers on
1058          * devices.
1059          */
1060         case ACPI_RESOURCE_TYPE_ADDRESS32:
1061                 start = res->data.address32.address.minimum;
1062                 end = res->data.address32.address.maximum;
1063                 break;
1064
1065         case ACPI_RESOURCE_TYPE_ADDRESS64:
1066                 start = res->data.address64.address.minimum;
1067                 end = res->data.address64.address.maximum;
1068                 break;
1069
1070         default:
1071                 /* Unused resource type */
1072                 return AE_OK;
1073
1074         }
1075         /*
1076          * Ignore ranges that are below 1MB, as they're not
1077          * necessary or useful here.
1078          */
1079         if (end < 0x100000)
1080                 return AE_OK;
1081
1082         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1083         if (!new_res)
1084                 return AE_NO_MEMORY;
1085
1086         /* If this range overlaps the virtual TPM, truncate it. */
1087         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1088                 end = VTPM_BASE_ADDRESS;
1089
1090         new_res->name = "hyperv mmio";
1091         new_res->flags = IORESOURCE_MEM;
1092         new_res->start = start;
1093         new_res->end = end;
1094
1095         do {
1096                 if (!*old_res) {
1097                         *old_res = new_res;
1098                         break;
1099                 }
1100
1101                 if ((*old_res)->end < new_res->start) {
1102                         new_res->sibling = *old_res;
1103                         if (prev_res)
1104                                 (*prev_res)->sibling = new_res;
1105                         *old_res = new_res;
1106                         break;
1107                 }
1108
1109                 prev_res = old_res;
1110                 old_res = &(*old_res)->sibling;
1111
1112         } while (1);
1113
1114         return AE_OK;
1115 }
1116
1117 static int vmbus_acpi_remove(struct acpi_device *device)
1118 {
1119         struct resource *cur_res;
1120         struct resource *next_res;
1121
1122         if (hyperv_mmio) {
1123                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1124                         next_res = cur_res->sibling;
1125                         kfree(cur_res);
1126                 }
1127         }
1128
1129         return 0;
1130 }
1131
1132 /**
1133  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1134  * @new:                If successful, supplied a pointer to the
1135  *                      allocated MMIO space.
1136  * @device_obj:         Identifies the caller
1137  * @min:                Minimum guest physical address of the
1138  *                      allocation
1139  * @max:                Maximum guest physical address
1140  * @size:               Size of the range to be allocated
1141  * @align:              Alignment of the range to be allocated
1142  * @fb_overlap_ok:      Whether this allocation can be allowed
1143  *                      to overlap the video frame buffer.
1144  *
1145  * This function walks the resources granted to VMBus by the
1146  * _CRS object in the ACPI namespace underneath the parent
1147  * "bridge" whether that's a root PCI bus in the Generation 1
1148  * case or a Module Device in the Generation 2 case.  It then
1149  * attempts to allocate from the global MMIO pool in a way that
1150  * matches the constraints supplied in these parameters and by
1151  * that _CRS.
1152  *
1153  * Return: 0 on success, -errno on failure
1154  */
1155 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1156                         resource_size_t min, resource_size_t max,
1157                         resource_size_t size, resource_size_t align,
1158                         bool fb_overlap_ok)
1159 {
1160         struct resource *iter;
1161         resource_size_t range_min, range_max, start, local_min, local_max;
1162         const char *dev_n = dev_name(&device_obj->device);
1163         u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1);
1164         int i, retval;
1165
1166         retval = -ENXIO;
1167         down(&hyperv_mmio_lock);
1168
1169         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1170                 if ((iter->start >= max) || (iter->end <= min))
1171                         continue;
1172
1173                 range_min = iter->start;
1174                 range_max = iter->end;
1175
1176                 /* If this range overlaps the frame buffer, split it into
1177                    two tries. */
1178                 for (i = 0; i < 2; i++) {
1179                         local_min = range_min;
1180                         local_max = range_max;
1181                         if (fb_overlap_ok || (range_min >= fb_end) ||
1182                             (range_max <= screen_info.lfb_base)) {
1183                                 i++;
1184                         } else {
1185                                 if ((range_min <= screen_info.lfb_base) &&
1186                                     (range_max >= screen_info.lfb_base)) {
1187                                         /*
1188                                          * The frame buffer is in this window,
1189                                          * so trim this into the part that
1190                                          * preceeds the frame buffer.
1191                                          */
1192                                         local_max = screen_info.lfb_base - 1;
1193                                         range_min = fb_end;
1194                                 } else {
1195                                         range_min = fb_end;
1196                                         continue;
1197                                 }
1198                         }
1199
1200                         start = (local_min + align - 1) & ~(align - 1);
1201                         for (; start + size - 1 <= local_max; start += align) {
1202                                 *new = request_mem_region_exclusive(start, size,
1203                                                                     dev_n);
1204                                 if (*new) {
1205                                         retval = 0;
1206                                         goto exit;
1207                                 }
1208                         }
1209                 }
1210         }
1211
1212 exit:
1213         up(&hyperv_mmio_lock);
1214         return retval;
1215 }
1216 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1217
1218 static int vmbus_acpi_add(struct acpi_device *device)
1219 {
1220         acpi_status result;
1221         int ret_val = -ENODEV;
1222         struct acpi_device *ancestor;
1223
1224         hv_acpi_dev = device;
1225
1226         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1227                                         vmbus_walk_resources, NULL);
1228
1229         if (ACPI_FAILURE(result))
1230                 goto acpi_walk_err;
1231         /*
1232          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1233          * firmware) is the VMOD that has the mmio ranges. Get that.
1234          */
1235         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1236                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1237                                              vmbus_walk_resources, NULL);
1238
1239                 if (ACPI_FAILURE(result))
1240                         continue;
1241                 if (hyperv_mmio)
1242                         break;
1243         }
1244         ret_val = 0;
1245
1246 acpi_walk_err:
1247         complete(&probe_event);
1248         if (ret_val)
1249                 vmbus_acpi_remove(device);
1250         return ret_val;
1251 }
1252
1253 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1254         {"VMBUS", 0},
1255         {"VMBus", 0},
1256         {"", 0},
1257 };
1258 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1259
1260 static struct acpi_driver vmbus_acpi_driver = {
1261         .name = "vmbus",
1262         .ids = vmbus_acpi_device_ids,
1263         .ops = {
1264                 .add = vmbus_acpi_add,
1265                 .remove = vmbus_acpi_remove,
1266         },
1267 };
1268
1269 static void hv_kexec_handler(void)
1270 {
1271         int cpu;
1272
1273         hv_synic_clockevents_cleanup();
1274         vmbus_initiate_unload();
1275         for_each_online_cpu(cpu)
1276                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1277         hv_cleanup(false);
1278 };
1279
1280 static void hv_crash_handler(struct pt_regs *regs)
1281 {
1282         vmbus_initiate_unload();
1283         /*
1284          * In crash handler we can't schedule synic cleanup for all CPUs,
1285          * doing the cleanup for current CPU only. This should be sufficient
1286          * for kdump.
1287          */
1288         hv_synic_cleanup(NULL);
1289         hv_cleanup(true);
1290 };
1291
1292 static int __init hv_acpi_init(void)
1293 {
1294         int ret, t;
1295
1296         if (x86_hyper != &x86_hyper_ms_hyperv)
1297                 return -ENODEV;
1298
1299         init_completion(&probe_event);
1300
1301         /*
1302          * Get irq resources first.
1303          */
1304         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1305
1306         if (ret)
1307                 return ret;
1308
1309         t = wait_for_completion_timeout(&probe_event, 5*HZ);
1310         if (t == 0) {
1311                 ret = -ETIMEDOUT;
1312                 goto cleanup;
1313         }
1314
1315         if (irq <= 0) {
1316                 ret = -ENODEV;
1317                 goto cleanup;
1318         }
1319
1320         ret = vmbus_bus_init(irq);
1321         if (ret)
1322                 goto cleanup;
1323
1324         hv_setup_kexec_handler(hv_kexec_handler);
1325         hv_setup_crash_handler(hv_crash_handler);
1326
1327         return 0;
1328
1329 cleanup:
1330         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1331         hv_acpi_dev = NULL;
1332         return ret;
1333 }
1334
1335 static void __exit vmbus_exit(void)
1336 {
1337         int cpu;
1338
1339         hv_remove_kexec_handler();
1340         hv_remove_crash_handler();
1341         vmbus_connection.conn_state = DISCONNECTED;
1342         hv_synic_clockevents_cleanup();
1343         vmbus_disconnect();
1344         hv_remove_vmbus_irq();
1345         tasklet_kill(&msg_dpc);
1346         vmbus_free_channels();
1347         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1348                 unregister_die_notifier(&hyperv_die_block);
1349                 atomic_notifier_chain_unregister(&panic_notifier_list,
1350                                                  &hyperv_panic_block);
1351         }
1352         bus_unregister(&hv_bus);
1353         hv_cleanup(false);
1354         for_each_online_cpu(cpu) {
1355                 tasklet_kill(hv_context.event_dpc[cpu]);
1356                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1357         }
1358         hv_synic_free();
1359         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1360         if (vmbus_proto_version > VERSION_WIN7)
1361                 cpu_hotplug_enable();
1362 }
1363
1364
1365 MODULE_LICENSE("GPL");
1366
1367 subsys_initcall(hv_acpi_init);
1368 module_exit(vmbus_exit);