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 "hyperv_vmbus.h"
  45
  46 static struct acpi_device  *hv_acpi_dev;
  47
  48 static struct tasklet_struct msg_dpc;
  49 static struct completion probe_event;
  50
  51
  52 static void hyperv_report_panic(struct pt_regs *regs)
  53 {
  54         static bool panic_reported;
  55
  56         /*
  57          * We prefer to report panic on 'die' chain as we have proper
  58          * registers to report, but if we miss it (e.g. on BUG()) we need
  59          * to report it on 'panic'.
  60          */
  61         if (panic_reported)
  62                 return;
  63         panic_reported = true;
  64
  65         wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
  66         wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
  67         wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
  68         wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
  69         wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
  70
  71         /*
  72          * Let Hyper-V know there is crash data available
  73          */
  74         wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
  75 }
  76
  77 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  78                               void *args)
  79 {
  80         struct pt_regs *regs;
  81
  82         regs = current_pt_regs();
  83
  84         hyperv_report_panic(regs);
  85         return NOTIFY_DONE;
  86 }
  87
  88 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  89                             void *args)
  90 {
  91         struct die_args *die = (struct die_args *)args;
  92         struct pt_regs *regs = die->regs;
  93
  94         hyperv_report_panic(regs);
  95         return NOTIFY_DONE;
  96 }
  97
  98 static struct notifier_block hyperv_die_block = {
  99         .notifier_call = hyperv_die_event,
 100 };
 101 static struct notifier_block hyperv_panic_block = {
 102         .notifier_call = hyperv_panic_event,
 103 };
 104
 105 struct resource *hyperv_mmio;
 106
 107 static int vmbus_exists(void)
 108 {
 109         if (hv_acpi_dev == NULL)
 110                 return -ENODEV;
 111
 112         return 0;
 113 }
 114
 115 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 116 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 117 {
 118         int i;
 119         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 120                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 121 }
 122
 123 static u8 channel_monitor_group(struct vmbus_channel *channel)
 124 {
 125         return (u8)channel->offermsg.monitorid / 32;
 126 }
 127
 128 static u8 channel_monitor_offset(struct vmbus_channel *channel)
 129 {
 130         return (u8)channel->offermsg.monitorid % 32;
 131 }
 132
 133 static u32 channel_pending(struct vmbus_channel *channel,
 134                            struct hv_monitor_page *monitor_page)
 135 {
 136         u8 monitor_group = channel_monitor_group(channel);
 137         return monitor_page->trigger_group[monitor_group].pending;
 138 }
 139
 140 static u32 channel_latency(struct vmbus_channel *channel,
 141                            struct hv_monitor_page *monitor_page)
 142 {
 143         u8 monitor_group = channel_monitor_group(channel);
 144         u8 monitor_offset = channel_monitor_offset(channel);
 145         return monitor_page->latency[monitor_group][monitor_offset];
 146 }
 147
 148 static u32 channel_conn_id(struct vmbus_channel *channel,
 149                            struct hv_monitor_page *monitor_page)
 150 {
 151         u8 monitor_group = channel_monitor_group(channel);
 152         u8 monitor_offset = channel_monitor_offset(channel);
 153         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 154 }
 155
 156 static ssize_t id_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->offermsg.child_relid);
 164 }
 165 static DEVICE_ATTR_RO(id);
 166
 167 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 168                           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->state);
 175 }
 176 static DEVICE_ATTR_RO(state);
 177
 178 static ssize_t monitor_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, "%d\n", hv_dev->channel->offermsg.monitorid);
 186 }
 187 static DEVICE_ATTR_RO(monitor_id);
 188
 189 static ssize_t class_id_show(struct device *dev,
 190                                struct device_attribute *dev_attr, char *buf)
 191 {
 192         struct hv_device *hv_dev = device_to_hv_device(dev);
 193
 194         if (!hv_dev->channel)
 195                 return -ENODEV;
 196         return sprintf(buf, "{%pUl}\n",
 197                        hv_dev->channel->offermsg.offer.if_type.b);
 198 }
 199 static DEVICE_ATTR_RO(class_id);
 200
 201 static ssize_t device_id_show(struct device *dev,
 202                               struct device_attribute *dev_attr, char *buf)
 203 {
 204         struct hv_device *hv_dev = device_to_hv_device(dev);
 205
 206         if (!hv_dev->channel)
 207                 return -ENODEV;
 208         return sprintf(buf, "{%pUl}\n",
 209                        hv_dev->channel->offermsg.offer.if_instance.b);
 210 }
 211 static DEVICE_ATTR_RO(device_id);
 212
 213 static ssize_t modalias_show(struct device *dev,
 214                              struct device_attribute *dev_attr, char *buf)
 215 {
 216         struct hv_device *hv_dev = device_to_hv_device(dev);
 217         char alias_name[VMBUS_ALIAS_LEN + 1];
 218
 219         print_alias_name(hv_dev, alias_name);
 220         return sprintf(buf, "vmbus:%s\n", alias_name);
 221 }
 222 static DEVICE_ATTR_RO(modalias);
 223
 224 static ssize_t server_monitor_pending_show(struct device *dev,
 225                                            struct device_attribute *dev_attr,
 226                                            char *buf)
 227 {
 228         struct hv_device *hv_dev = device_to_hv_device(dev);
 229
 230         if (!hv_dev->channel)
 231                 return -ENODEV;
 232         return sprintf(buf, "%d\n",
 233                        channel_pending(hv_dev->channel,
 234                                        vmbus_connection.monitor_pages[1]));
 235 }
 236 static DEVICE_ATTR_RO(server_monitor_pending);
 237
 238 static ssize_t client_monitor_pending_show(struct device *dev,
 239                                            struct device_attribute *dev_attr,
 240                                            char *buf)
 241 {
 242         struct hv_device *hv_dev = device_to_hv_device(dev);
 243
 244         if (!hv_dev->channel)
 245                 return -ENODEV;
 246         return sprintf(buf, "%d\n",
 247                        channel_pending(hv_dev->channel,
 248                                        vmbus_connection.monitor_pages[1]));
 249 }
 250 static DEVICE_ATTR_RO(client_monitor_pending);
 251
 252 static ssize_t server_monitor_latency_show(struct device *dev,
 253                                            struct device_attribute *dev_attr,
 254                                            char *buf)
 255 {
 256         struct hv_device *hv_dev = device_to_hv_device(dev);
 257
 258         if (!hv_dev->channel)
 259                 return -ENODEV;
 260         return sprintf(buf, "%d\n",
 261                        channel_latency(hv_dev->channel,
 262                                        vmbus_connection.monitor_pages[0]));
 263 }
 264 static DEVICE_ATTR_RO(server_monitor_latency);
 265
 266 static ssize_t client_monitor_latency_show(struct device *dev,
 267                                            struct device_attribute *dev_attr,
 268                                            char *buf)
 269 {
 270         struct hv_device *hv_dev = device_to_hv_device(dev);
 271
 272         if (!hv_dev->channel)
 273                 return -ENODEV;
 274         return sprintf(buf, "%d\n",
 275                        channel_latency(hv_dev->channel,
 276                                        vmbus_connection.monitor_pages[1]));
 277 }
 278 static DEVICE_ATTR_RO(client_monitor_latency);
 279
 280 static ssize_t server_monitor_conn_id_show(struct device *dev,
 281                                            struct device_attribute *dev_attr,
 282                                            char *buf)
 283 {
 284         struct hv_device *hv_dev = device_to_hv_device(dev);
 285
 286         if (!hv_dev->channel)
 287                 return -ENODEV;
 288         return sprintf(buf, "%d\n",
 289                        channel_conn_id(hv_dev->channel,
 290                                        vmbus_connection.monitor_pages[0]));
 291 }
 292 static DEVICE_ATTR_RO(server_monitor_conn_id);
 293
 294 static ssize_t client_monitor_conn_id_show(struct device *dev,
 295                                            struct device_attribute *dev_attr,
 296                                            char *buf)
 297 {
 298         struct hv_device *hv_dev = device_to_hv_device(dev);
 299
 300         if (!hv_dev->channel)
 301                 return -ENODEV;
 302         return sprintf(buf, "%d\n",
 303                        channel_conn_id(hv_dev->channel,
 304                                        vmbus_connection.monitor_pages[1]));
 305 }
 306 static DEVICE_ATTR_RO(client_monitor_conn_id);
 307
 308 static ssize_t out_intr_mask_show(struct device *dev,
 309                                   struct device_attribute *dev_attr, char *buf)
 310 {
 311         struct hv_device *hv_dev = device_to_hv_device(dev);
 312         struct hv_ring_buffer_debug_info outbound;
 313
 314         if (!hv_dev->channel)
 315                 return -ENODEV;
 316         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 317         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 318 }
 319 static DEVICE_ATTR_RO(out_intr_mask);
 320
 321 static ssize_t out_read_index_show(struct device *dev,
 322                                    struct device_attribute *dev_attr, char *buf)
 323 {
 324         struct hv_device *hv_dev = device_to_hv_device(dev);
 325         struct hv_ring_buffer_debug_info outbound;
 326
 327         if (!hv_dev->channel)
 328                 return -ENODEV;
 329         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 330         return sprintf(buf, "%d\n", outbound.current_read_index);
 331 }
 332 static DEVICE_ATTR_RO(out_read_index);
 333
 334 static ssize_t out_write_index_show(struct device *dev,
 335                                     struct device_attribute *dev_attr,
 336                                     char *buf)
 337 {
 338         struct hv_device *hv_dev = device_to_hv_device(dev);
 339         struct hv_ring_buffer_debug_info outbound;
 340
 341         if (!hv_dev->channel)
 342                 return -ENODEV;
 343         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 344         return sprintf(buf, "%d\n", outbound.current_write_index);
 345 }
 346 static DEVICE_ATTR_RO(out_write_index);
 347
 348 static ssize_t out_read_bytes_avail_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
 355         if (!hv_dev->channel)
 356                 return -ENODEV;
 357         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 358         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 359 }
 360 static DEVICE_ATTR_RO(out_read_bytes_avail);
 361
 362 static ssize_t out_write_bytes_avail_show(struct device *dev,
 363                                           struct device_attribute *dev_attr,
 364                                           char *buf)
 365 {
 366         struct hv_device *hv_dev = device_to_hv_device(dev);
 367         struct hv_ring_buffer_debug_info outbound;
 368
 369         if (!hv_dev->channel)
 370                 return -ENODEV;
 371         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 372         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 373 }
 374 static DEVICE_ATTR_RO(out_write_bytes_avail);
 375
 376 static ssize_t in_intr_mask_show(struct device *dev,
 377                                  struct device_attribute *dev_attr, char *buf)
 378 {
 379         struct hv_device *hv_dev = device_to_hv_device(dev);
 380         struct hv_ring_buffer_debug_info inbound;
 381
 382         if (!hv_dev->channel)
 383                 return -ENODEV;
 384         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 385         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 386 }
 387 static DEVICE_ATTR_RO(in_intr_mask);
 388
 389 static ssize_t in_read_index_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         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 398         return sprintf(buf, "%d\n", inbound.current_read_index);
 399 }
 400 static DEVICE_ATTR_RO(in_read_index);
 401
 402 static ssize_t in_write_index_show(struct device *dev,
 403                                    struct device_attribute *dev_attr, char *buf)
 404 {
 405         struct hv_device *hv_dev = device_to_hv_device(dev);
 406         struct hv_ring_buffer_debug_info inbound;
 407
 408         if (!hv_dev->channel)
 409                 return -ENODEV;
 410         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 411         return sprintf(buf, "%d\n", inbound.current_write_index);
 412 }
 413 static DEVICE_ATTR_RO(in_write_index);
 414
 415 static ssize_t in_read_bytes_avail_show(struct device *dev,
 416                                         struct device_attribute *dev_attr,
 417                                         char *buf)
 418 {
 419         struct hv_device *hv_dev = device_to_hv_device(dev);
 420         struct hv_ring_buffer_debug_info inbound;
 421
 422         if (!hv_dev->channel)
 423                 return -ENODEV;
 424         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 425         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 426 }
 427 static DEVICE_ATTR_RO(in_read_bytes_avail);
 428
 429 static ssize_t in_write_bytes_avail_show(struct device *dev,
 430                                          struct device_attribute *dev_attr,
 431                                          char *buf)
 432 {
 433         struct hv_device *hv_dev = device_to_hv_device(dev);
 434         struct hv_ring_buffer_debug_info inbound;
 435
 436         if (!hv_dev->channel)
 437                 return -ENODEV;
 438         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 439         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 440 }
 441 static DEVICE_ATTR_RO(in_write_bytes_avail);
 442
 443 static ssize_t channel_vp_mapping_show(struct device *dev,
 444                                        struct device_attribute *dev_attr,
 445                                        char *buf)
 446 {
 447         struct hv_device *hv_dev = device_to_hv_device(dev);
 448         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 449         unsigned long flags;
 450         int buf_size = PAGE_SIZE, n_written, tot_written;
 451         struct list_head *cur;
 452
 453         if (!channel)
 454                 return -ENODEV;
 455
 456         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 457                 channel->offermsg.child_relid, channel->target_cpu);
 458
 459         spin_lock_irqsave(&channel->lock, flags);
 460
 461         list_for_each(cur, &channel->sc_list) {
 462                 if (tot_written >= buf_size - 1)
 463                         break;
 464
 465                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 466                 n_written = scnprintf(buf + tot_written,
 467                                      buf_size - tot_written,
 468                                      "%u:%u\n",
 469                                      cur_sc->offermsg.child_relid,
 470                                      cur_sc->target_cpu);
 471                 tot_written += n_written;
 472         }
 473
 474         spin_unlock_irqrestore(&channel->lock, flags);
 475
 476         return tot_written;
 477 }
 478 static DEVICE_ATTR_RO(channel_vp_mapping);
 479
 480 static ssize_t vendor_show(struct device *dev,
 481                            struct device_attribute *dev_attr,
 482                            char *buf)
 483 {
 484         struct hv_device *hv_dev = device_to_hv_device(dev);
 485         return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
 486 }
 487 static DEVICE_ATTR_RO(vendor);
 488
 489 static ssize_t device_show(struct device *dev,
 490                            struct device_attribute *dev_attr,
 491                            char *buf)
 492 {
 493         struct hv_device *hv_dev = device_to_hv_device(dev);
 494         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 495 }
 496 static DEVICE_ATTR_RO(device);
 497
 498 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 499 static struct attribute *vmbus_attrs[] = {
 500         &dev_attr_id.attr,
 501         &dev_attr_state.attr,
 502         &dev_attr_monitor_id.attr,
 503         &dev_attr_class_id.attr,
 504         &dev_attr_device_id.attr,
 505         &dev_attr_modalias.attr,
 506         &dev_attr_server_monitor_pending.attr,
 507         &dev_attr_client_monitor_pending.attr,
 508         &dev_attr_server_monitor_latency.attr,
 509         &dev_attr_client_monitor_latency.attr,
 510         &dev_attr_server_monitor_conn_id.attr,
 511         &dev_attr_client_monitor_conn_id.attr,
 512         &dev_attr_out_intr_mask.attr,
 513         &dev_attr_out_read_index.attr,
 514         &dev_attr_out_write_index.attr,
 515         &dev_attr_out_read_bytes_avail.attr,
 516         &dev_attr_out_write_bytes_avail.attr,
 517         &dev_attr_in_intr_mask.attr,
 518         &dev_attr_in_read_index.attr,
 519         &dev_attr_in_write_index.attr,
 520         &dev_attr_in_read_bytes_avail.attr,
 521         &dev_attr_in_write_bytes_avail.attr,
 522         &dev_attr_channel_vp_mapping.attr,
 523         &dev_attr_vendor.attr,
 524         &dev_attr_device.attr,
 525         NULL,
 526 };
 527 ATTRIBUTE_GROUPS(vmbus);
 528
 529 /*
 530  * vmbus_uevent - add uevent for our device
 531  *
 532  * This routine is invoked when a device is added or removed on the vmbus to
 533  * generate a uevent to udev in the userspace. The udev will then look at its
 534  * rule and the uevent generated here to load the appropriate driver
 535  *
 536  * The alias string will be of the form vmbus:guid where guid is the string
 537  * representation of the device guid (each byte of the guid will be
 538  * represented with two hex characters.
 539  */
 540 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 541 {
 542         struct hv_device *dev = device_to_hv_device(device);
 543         int ret;
 544         char alias_name[VMBUS_ALIAS_LEN + 1];
 545
 546         print_alias_name(dev, alias_name);
 547         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 548         return ret;
 549 }
 550
 551 static const uuid_le null_guid;
 552
 553 static inline bool is_null_guid(const uuid_le *guid)
 554 {
 555         if (uuid_le_cmp(*guid, null_guid))
 556                 return false;
 557         return true;
 558 }
 559
 560 /*
 561  * Return a matching hv_vmbus_device_id pointer.
 562  * If there is no match, return NULL.
 563  */
 564 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 565                                         const struct hv_vmbus_device_id *id,
 566                                         const uuid_le *guid)
 567 {
 568         for (; !is_null_guid(&id->guid); id++)
 569                 if (!uuid_le_cmp(id->guid, *guid))
 570                         return id;
 571
 572         return NULL;
 573 }
 574
 575
 576
 577 /*
 578  * vmbus_match - Attempt to match the specified device to the specified driver
 579  */
 580 static int vmbus_match(struct device *device, struct device_driver *driver)
 581 {
 582         struct hv_driver *drv = drv_to_hv_drv(driver);
 583         struct hv_device *hv_dev = device_to_hv_device(device);
 584
 585         /* The hv_sock driver handles all hv_sock offers. */
 586         if (is_hvsock_channel(hv_dev->channel))
 587                 return drv->hvsock;
 588
 589         if (hv_vmbus_get_id(drv->id_table, &hv_dev->dev_type))
 590                 return 1;
 591
 592         return 0;
 593 }
 594
 595 /*
 596  * vmbus_probe - Add the new vmbus's child device
 597  */
 598 static int vmbus_probe(struct device *child_device)
 599 {
 600         int ret = 0;
 601         struct hv_driver *drv =
 602                         drv_to_hv_drv(child_device->driver);
 603         struct hv_device *dev = device_to_hv_device(child_device);
 604         const struct hv_vmbus_device_id *dev_id;
 605
 606         dev_id = hv_vmbus_get_id(drv->id_table, &dev->dev_type);
 607         if (drv->probe) {
 608                 ret = drv->probe(dev, dev_id);
 609                 if (ret != 0)
 610                         pr_err("probe failed for device %s (%d)\n",
 611                                dev_name(child_device), ret);
 612
 613         } else {
 614                 pr_err("probe not set for driver %s\n",
 615                        dev_name(child_device));
 616                 ret = -ENODEV;
 617         }
 618         return ret;
 619 }
 620
 621 /*
 622  * vmbus_remove - Remove a vmbus device
 623  */
 624 static int vmbus_remove(struct device *child_device)
 625 {
 626         struct hv_driver *drv;
 627         struct hv_device *dev = device_to_hv_device(child_device);
 628
 629         if (child_device->driver) {
 630                 drv = drv_to_hv_drv(child_device->driver);
 631                 if (drv->remove)
 632                         drv->remove(dev);
 633         }
 634
 635         return 0;
 636 }
 637
 638
 639 /*
 640  * vmbus_shutdown - Shutdown a vmbus device
 641  */
 642 static void vmbus_shutdown(struct device *child_device)
 643 {
 644         struct hv_driver *drv;
 645         struct hv_device *dev = device_to_hv_device(child_device);
 646
 647
 648         /* The device may not be attached yet */
 649         if (!child_device->driver)
 650                 return;
 651
 652         drv = drv_to_hv_drv(child_device->driver);
 653
 654         if (drv->shutdown)
 655                 drv->shutdown(dev);
 656
 657         return;
 658 }
 659
 660
 661 /*
 662  * vmbus_device_release - Final callback release of the vmbus child device
 663  */
 664 static void vmbus_device_release(struct device *device)
 665 {
 666         struct hv_device *hv_dev = device_to_hv_device(device);
 667         struct vmbus_channel *channel = hv_dev->channel;
 668
 669         hv_process_channel_removal(channel,
 670                                    channel->offermsg.child_relid);
 671         kfree(hv_dev);
 672
 673 }
 674
 675 /* The one and only one */
 676 static struct bus_type  hv_bus = {
 677         .name =         "vmbus",
 678         .match =                vmbus_match,
 679         .shutdown =             vmbus_shutdown,
 680         .remove =               vmbus_remove,
 681         .probe =                vmbus_probe,
 682         .uevent =               vmbus_uevent,
 683         .dev_groups =           vmbus_groups,
 684 };
 685
 686 struct onmessage_work_context {
 687         struct work_struct work;
 688         struct hv_message msg;
 689 };
 690
 691 static void vmbus_onmessage_work(struct work_struct *work)
 692 {
 693         struct onmessage_work_context *ctx;
 694
 695         /* Do not process messages if we're in DISCONNECTED state */
 696         if (vmbus_connection.conn_state == DISCONNECTED)
 697                 return;
 698
 699         ctx = container_of(work, struct onmessage_work_context,
 700                            work);
 701         vmbus_onmessage(&ctx->msg);
 702         kfree(ctx);
 703 }
 704
 705 static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
 706 {
 707         struct clock_event_device *dev = hv_context.clk_evt[cpu];
 708
 709         if (dev->event_handler)
 710                 dev->event_handler(dev);
 711
 712         vmbus_signal_eom(msg);
 713 }
 714
 715 static void vmbus_on_msg_dpc(unsigned long data)
 716 {
 717         int cpu = smp_processor_id();
 718         void *page_addr = hv_context.synic_message_page[cpu];
 719         struct hv_message *msg = (struct hv_message *)page_addr +
 720                                   VMBUS_MESSAGE_SINT;
 721         struct vmbus_channel_message_header *hdr;
 722         struct vmbus_channel_message_table_entry *entry;
 723         struct onmessage_work_context *ctx;
 724
 725         if (msg->header.message_type == HVMSG_NONE)
 726                 /* no msg */
 727                 return;
 728
 729         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 730
 731         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 732                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 733                 goto msg_handled;
 734         }
 735
 736         entry = &channel_message_table[hdr->msgtype];
 737         if (entry->handler_type == VMHT_BLOCKING) {
 738                 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 739                 if (ctx == NULL)
 740                         return;
 741
 742                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
 743                 memcpy(&ctx->msg, msg, sizeof(*msg));
 744
 745                 queue_work(vmbus_connection.work_queue, &ctx->work);
 746         } else
 747                 entry->message_handler(hdr);
 748
 749 msg_handled:
 750         vmbus_signal_eom(msg);
 751 }
 752
 753 static void vmbus_isr(void)
 754 {
 755         int cpu = smp_processor_id();
 756         void *page_addr;
 757         struct hv_message *msg;
 758         union hv_synic_event_flags *event;
 759         bool handled = false;
 760
 761         page_addr = hv_context.synic_event_page[cpu];
 762         if (page_addr == NULL)
 763                 return;
 764
 765         event = (union hv_synic_event_flags *)page_addr +
 766                                          VMBUS_MESSAGE_SINT;
 767         /*
 768          * Check for events before checking for messages. This is the order
 769          * in which events and messages are checked in Windows guests on
 770          * Hyper-V, and the Windows team suggested we do the same.
 771          */
 772
 773         if ((vmbus_proto_version == VERSION_WS2008) ||
 774                 (vmbus_proto_version == VERSION_WIN7)) {
 775
 776                 /* Since we are a child, we only need to check bit 0 */
 777                 if (sync_test_and_clear_bit(0,
 778                         (unsigned long *) &event->flags32[0])) {
 779                         handled = true;
 780                 }
 781         } else {
 782                 /*
 783                  * Our host is win8 or above. The signaling mechanism
 784                  * has changed and we can directly look at the event page.
 785                  * If bit n is set then we have an interrup on the channel
 786                  * whose id is n.
 787                  */
 788                 handled = true;
 789         }
 790
 791         if (handled)
 792                 tasklet_schedule(hv_context.event_dpc[cpu]);
 793
 794
 795         page_addr = hv_context.synic_message_page[cpu];
 796         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 797
 798         /* Check if there are actual msgs to be processed */
 799         if (msg->header.message_type != HVMSG_NONE) {
 800                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
 801                         hv_process_timer_expiration(msg, cpu);
 802                 else
 803                         tasklet_schedule(&msg_dpc);
 804         }
 805 }
 806
 807
 808 /*
 809  * vmbus_bus_init -Main vmbus driver initialization routine.
 810  *
 811  * Here, we
 812  *      - initialize the vmbus driver context
 813  *      - invoke the vmbus hv main init routine
 814  *      - retrieve the channel offers
 815  */
 816 static int vmbus_bus_init(void)
 817 {
 818         int ret;
 819
 820         /* Hypervisor initialization...setup hypercall page..etc */
 821         ret = hv_init();
 822         if (ret != 0) {
 823                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 824                 return ret;
 825         }
 826
 827         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 828
 829         ret = bus_register(&hv_bus);
 830         if (ret)
 831                 goto err_cleanup;
 832
 833         hv_setup_vmbus_irq(vmbus_isr);
 834
 835         ret = hv_synic_alloc();
 836         if (ret)
 837                 goto err_alloc;
 838         /*
 839          * Initialize the per-cpu interrupt state and
 840          * connect to the host.
 841          */
 842         on_each_cpu(hv_synic_init, NULL, 1);
 843         ret = vmbus_connect();
 844         if (ret)
 845                 goto err_connect;
 846
 847         if (vmbus_proto_version > VERSION_WIN7)
 848                 cpu_hotplug_disable();
 849
 850         /*
 851          * Only register if the crash MSRs are available
 852          */
 853         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
 854                 register_die_notifier(&hyperv_die_block);
 855                 atomic_notifier_chain_register(&panic_notifier_list,
 856                                                &hyperv_panic_block);
 857         }
 858
 859         vmbus_request_offers();
 860
 861         return 0;
 862
 863 err_connect:
 864         on_each_cpu(hv_synic_cleanup, NULL, 1);
 865 err_alloc:
 866         hv_synic_free();
 867         hv_remove_vmbus_irq();
 868
 869         bus_unregister(&hv_bus);
 870
 871 err_cleanup:
 872         hv_cleanup();
 873
 874         return ret;
 875 }
 876
 877 /**
 878  * __vmbus_child_driver_register() - Register a vmbus's driver
 879  * @hv_driver: Pointer to driver structure you want to register
 880  * @owner: owner module of the drv
 881  * @mod_name: module name string
 882  *
 883  * Registers the given driver with Linux through the 'driver_register()' call
 884  * and sets up the hyper-v vmbus handling for this driver.
 885  * It will return the state of the 'driver_register()' call.
 886  *
 887  */
 888 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 889 {
 890         int ret;
 891
 892         pr_info("registering driver %s\n", hv_driver->name);
 893
 894         ret = vmbus_exists();
 895         if (ret < 0)
 896                 return ret;
 897
 898         hv_driver->driver.name = hv_driver->name;
 899         hv_driver->driver.owner = owner;
 900         hv_driver->driver.mod_name = mod_name;
 901         hv_driver->driver.bus = &hv_bus;
 902
 903         ret = driver_register(&hv_driver->driver);
 904
 905         return ret;
 906 }
 907 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 908
 909 /**
 910  * vmbus_driver_unregister() - Unregister a vmbus's driver
 911  * @hv_driver: Pointer to driver structure you want to
 912  *             un-register
 913  *
 914  * Un-register the given driver that was previous registered with a call to
 915  * vmbus_driver_register()
 916  */
 917 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 918 {
 919         pr_info("unregistering driver %s\n", hv_driver->name);
 920
 921         if (!vmbus_exists())
 922                 driver_unregister(&hv_driver->driver);
 923 }
 924 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 925
 926 /*
 927  * vmbus_device_create - Creates and registers a new child device
 928  * on the vmbus.
 929  */
 930 struct hv_device *vmbus_device_create(const uuid_le *type,
 931                                       const uuid_le *instance,
 932                                       struct vmbus_channel *channel)
 933 {
 934         struct hv_device *child_device_obj;
 935
 936         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 937         if (!child_device_obj) {
 938                 pr_err("Unable to allocate device object for child device\n");
 939                 return NULL;
 940         }
 941
 942         child_device_obj->channel = channel;
 943         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 944         memcpy(&child_device_obj->dev_instance, instance,
 945                sizeof(uuid_le));
 946         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
 947
 948
 949         return child_device_obj;
 950 }
 951
 952 /*
 953  * vmbus_device_register - Register the child device
 954  */
 955 int vmbus_device_register(struct hv_device *child_device_obj)
 956 {
 957         int ret = 0;
 958
 959         dev_set_name(&child_device_obj->device, "vmbus_%d",
 960                      child_device_obj->channel->id);
 961
 962         child_device_obj->device.bus = &hv_bus;
 963         child_device_obj->device.parent = &hv_acpi_dev->dev;
 964         child_device_obj->device.release = vmbus_device_release;
 965
 966         /*
 967          * Register with the LDM. This will kick off the driver/device
 968          * binding...which will eventually call vmbus_match() and vmbus_probe()
 969          */
 970         ret = device_register(&child_device_obj->device);
 971
 972         if (ret)
 973                 pr_err("Unable to register child device\n");
 974         else
 975                 pr_debug("child device %s registered\n",
 976                         dev_name(&child_device_obj->device));
 977
 978         return ret;
 979 }
 980
 981 /*
 982  * vmbus_device_unregister - Remove the specified child device
 983  * from the vmbus.
 984  */
 985 void vmbus_device_unregister(struct hv_device *device_obj)
 986 {
 987         pr_debug("child device %s unregistered\n",
 988                 dev_name(&device_obj->device));
 989
 990         /*
 991          * Kick off the process of unregistering the device.
 992          * This will call vmbus_remove() and eventually vmbus_device_release()
 993          */
 994         device_unregister(&device_obj->device);
 995 }
 996
 997
 998 /*
 999  * VMBUS is an acpi enumerated device. Get the information we
1000  * need from DSDT.
1001  */
1002 #define VTPM_BASE_ADDRESS 0xfed40000
1003 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1004 {
1005         resource_size_t start = 0;
1006         resource_size_t end = 0;
1007         struct resource *new_res;
1008         struct resource **old_res = &hyperv_mmio;
1009         struct resource **prev_res = NULL;
1010
1011         switch (res->type) {
1012
1013         /*
1014          * "Address" descriptors are for bus windows. Ignore
1015          * "memory" descriptors, which are for registers on
1016          * devices.
1017          */
1018         case ACPI_RESOURCE_TYPE_ADDRESS32:
1019                 start = res->data.address32.address.minimum;
1020                 end = res->data.address32.address.maximum;
1021                 break;
1022
1023         case ACPI_RESOURCE_TYPE_ADDRESS64:
1024                 start = res->data.address64.address.minimum;
1025                 end = res->data.address64.address.maximum;
1026                 break;
1027
1028         default:
1029                 /* Unused resource type */
1030                 return AE_OK;
1031
1032         }
1033         /*
1034          * Ignore ranges that are below 1MB, as they're not
1035          * necessary or useful here.
1036          */
1037         if (end < 0x100000)
1038                 return AE_OK;
1039
1040         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1041         if (!new_res)
1042                 return AE_NO_MEMORY;
1043
1044         /* If this range overlaps the virtual TPM, truncate it. */
1045         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1046                 end = VTPM_BASE_ADDRESS;
1047
1048         new_res->name = "hyperv mmio";
1049         new_res->flags = IORESOURCE_MEM;
1050         new_res->start = start;
1051         new_res->end = end;
1052
1053         /*
1054          * Stick ranges from higher in address space at the front of the list.
1055          * If two ranges are adjacent, merge them.
1056          */
1057         do {
1058                 if (!*old_res) {
1059                         *old_res = new_res;
1060                         break;
1061                 }
1062
1063                 if (((*old_res)->end + 1) == new_res->start) {
1064                         (*old_res)->end = new_res->end;
1065                         kfree(new_res);
1066                         break;
1067                 }
1068
1069                 if ((*old_res)->start == new_res->end + 1) {
1070                         (*old_res)->start = new_res->start;
1071                         kfree(new_res);
1072                         break;
1073                 }
1074
1075                 if ((*old_res)->end < new_res->start) {
1076                         new_res->sibling = *old_res;
1077                         if (prev_res)
1078                                 (*prev_res)->sibling = new_res;
1079                         *old_res = new_res;
1080                         break;
1081                 }
1082
1083                 prev_res = old_res;
1084                 old_res = &(*old_res)->sibling;
1085
1086         } while (1);
1087
1088         return AE_OK;
1089 }
1090
1091 static int vmbus_acpi_remove(struct acpi_device *device)
1092 {
1093         struct resource *cur_res;
1094         struct resource *next_res;
1095
1096         if (hyperv_mmio) {
1097                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1098                         next_res = cur_res->sibling;
1099                         kfree(cur_res);
1100                 }
1101         }
1102
1103         return 0;
1104 }
1105
1106 /**
1107  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1108  * @new:                If successful, supplied a pointer to the
1109  *                      allocated MMIO space.
1110  * @device_obj:         Identifies the caller
1111  * @min:                Minimum guest physical address of the
1112  *                      allocation
1113  * @max:                Maximum guest physical address
1114  * @size:               Size of the range to be allocated
1115  * @align:              Alignment of the range to be allocated
1116  * @fb_overlap_ok:      Whether this allocation can be allowed
1117  *                      to overlap the video frame buffer.
1118  *
1119  * This function walks the resources granted to VMBus by the
1120  * _CRS object in the ACPI namespace underneath the parent
1121  * "bridge" whether that's a root PCI bus in the Generation 1
1122  * case or a Module Device in the Generation 2 case.  It then
1123  * attempts to allocate from the global MMIO pool in a way that
1124  * matches the constraints supplied in these parameters and by
1125  * that _CRS.
1126  *
1127  * Return: 0 on success, -errno on failure
1128  */
1129 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1130                         resource_size_t min, resource_size_t max,
1131                         resource_size_t size, resource_size_t align,
1132                         bool fb_overlap_ok)
1133 {
1134         struct resource *iter;
1135         resource_size_t range_min, range_max, start, local_min, local_max;
1136         const char *dev_n = dev_name(&device_obj->device);
1137         u32 fb_end = screen_info.lfb_base + (screen_info.lfb_size << 1);
1138         int i;
1139
1140         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1141                 if ((iter->start >= max) || (iter->end <= min))
1142                         continue;
1143
1144                 range_min = iter->start;
1145                 range_max = iter->end;
1146
1147                 /* If this range overlaps the frame buffer, split it into
1148                    two tries. */
1149                 for (i = 0; i < 2; i++) {
1150                         local_min = range_min;
1151                         local_max = range_max;
1152                         if (fb_overlap_ok || (range_min >= fb_end) ||
1153                             (range_max <= screen_info.lfb_base)) {
1154                                 i++;
1155                         } else {
1156                                 if ((range_min <= screen_info.lfb_base) &&
1157                                     (range_max >= screen_info.lfb_base)) {
1158                                         /*
1159                                          * The frame buffer is in this window,
1160                                          * so trim this into the part that
1161                                          * preceeds the frame buffer.
1162                                          */
1163                                         local_max = screen_info.lfb_base - 1;
1164                                         range_min = fb_end;
1165                                 } else {
1166                                         range_min = fb_end;
1167                                         continue;
1168                                 }
1169                         }
1170
1171                         start = (local_min + align - 1) & ~(align - 1);
1172                         for (; start + size - 1 <= local_max; start += align) {
1173                                 *new = request_mem_region_exclusive(start, size,
1174                                                                     dev_n);
1175                                 if (*new)
1176                                         return 0;
1177                         }
1178                 }
1179         }
1180
1181         return -ENXIO;
1182 }
1183 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1184
1185 /**
1186  * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
1187  * @cpu_number: CPU number in Linux terms
1188  *
1189  * This function returns the mapping between the Linux processor
1190  * number and the hypervisor's virtual processor number, useful
1191  * in making hypercalls and such that talk about specific
1192  * processors.
1193  *
1194  * Return: Virtual processor number in Hyper-V terms
1195  */
1196 int vmbus_cpu_number_to_vp_number(int cpu_number)
1197 {
1198         return hv_context.vp_index[cpu_number];
1199 }
1200 EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
1201
1202 static int vmbus_acpi_add(struct acpi_device *device)
1203 {
1204         acpi_status result;
1205         int ret_val = -ENODEV;
1206         struct acpi_device *ancestor;
1207
1208         hv_acpi_dev = device;
1209
1210         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1211                                         vmbus_walk_resources, NULL);
1212
1213         if (ACPI_FAILURE(result))
1214                 goto acpi_walk_err;
1215         /*
1216          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1217          * firmware) is the VMOD that has the mmio ranges. Get that.
1218          */
1219         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1220                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1221                                              vmbus_walk_resources, NULL);
1222
1223                 if (ACPI_FAILURE(result))
1224                         continue;
1225                 if (hyperv_mmio)
1226                         break;
1227         }
1228         ret_val = 0;
1229
1230 acpi_walk_err:
1231         complete(&probe_event);
1232         if (ret_val)
1233                 vmbus_acpi_remove(device);
1234         return ret_val;
1235 }
1236
1237 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1238         {"VMBUS", 0},
1239         {"VMBus", 0},
1240         {"", 0},
1241 };
1242 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1243
1244 static struct acpi_driver vmbus_acpi_driver = {
1245         .name = "vmbus",
1246         .ids = vmbus_acpi_device_ids,
1247         .ops = {
1248                 .add = vmbus_acpi_add,
1249                 .remove = vmbus_acpi_remove,
1250         },
1251 };
1252
1253 static void hv_kexec_handler(void)
1254 {
1255         int cpu;
1256
1257         hv_synic_clockevents_cleanup();
1258         vmbus_initiate_unload(false);
1259         for_each_online_cpu(cpu)
1260                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1261         hv_cleanup();
1262 };
1263
1264 static void hv_crash_handler(struct pt_regs *regs)
1265 {
1266         vmbus_initiate_unload(true);
1267         /*
1268          * In crash handler we can't schedule synic cleanup for all CPUs,
1269          * doing the cleanup for current CPU only. This should be sufficient
1270          * for kdump.
1271          */
1272         hv_synic_cleanup(NULL);
1273         hv_cleanup();
1274 };
1275
1276 static int __init hv_acpi_init(void)
1277 {
1278         int ret, t;
1279
1280         if (x86_hyper != &x86_hyper_ms_hyperv)
1281                 return -ENODEV;
1282
1283         init_completion(&probe_event);
1284
1285         /*
1286          * Get ACPI resources first.
1287          */
1288         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1289
1290         if (ret)
1291                 return ret;
1292
1293         t = wait_for_completion_timeout(&probe_event, 5*HZ);
1294         if (t == 0) {
1295                 ret = -ETIMEDOUT;
1296                 goto cleanup;
1297         }
1298
1299         ret = vmbus_bus_init();
1300         if (ret)
1301                 goto cleanup;
1302
1303         hv_setup_kexec_handler(hv_kexec_handler);
1304         hv_setup_crash_handler(hv_crash_handler);
1305
1306         return 0;
1307
1308 cleanup:
1309         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1310         hv_acpi_dev = NULL;
1311         return ret;
1312 }
1313
1314 static void __exit vmbus_exit(void)
1315 {
1316         int cpu;
1317
1318         hv_remove_kexec_handler();
1319         hv_remove_crash_handler();
1320         vmbus_connection.conn_state = DISCONNECTED;
1321         hv_synic_clockevents_cleanup();
1322         vmbus_disconnect();
1323         hv_remove_vmbus_irq();
1324         tasklet_kill(&msg_dpc);
1325         vmbus_free_channels();
1326         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1327                 unregister_die_notifier(&hyperv_die_block);
1328                 atomic_notifier_chain_unregister(&panic_notifier_list,
1329                                                  &hyperv_panic_block);
1330         }
1331         bus_unregister(&hv_bus);
1332         hv_cleanup();
1333         for_each_online_cpu(cpu) {
1334                 tasklet_kill(hv_context.event_dpc[cpu]);
1335                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1336         }
1337         hv_synic_free();
1338         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1339         if (vmbus_proto_version > VERSION_WIN7)
1340                 cpu_hotplug_enable();
1341 }
1342
1343
1344 MODULE_LICENSE("GPL");
1345
1346 subsys_initcall(hv_acpi_init);
1347 module_exit(vmbus_exit);