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/efi.h>
  45 #include "hyperv_vmbus.h"
  46
  47 static struct acpi_device  *hv_acpi_dev;
  48
  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 static const char *fb_mmio_name = "fb_range";
 106 static struct resource *fb_mmio;
 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         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 320         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 321 }
 322 static DEVICE_ATTR_RO(out_intr_mask);
 323
 324 static ssize_t out_read_index_show(struct device *dev,
 325                                    struct device_attribute *dev_attr, char *buf)
 326 {
 327         struct hv_device *hv_dev = device_to_hv_device(dev);
 328         struct hv_ring_buffer_debug_info outbound;
 329
 330         if (!hv_dev->channel)
 331                 return -ENODEV;
 332         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 333         return sprintf(buf, "%d\n", outbound.current_read_index);
 334 }
 335 static DEVICE_ATTR_RO(out_read_index);
 336
 337 static ssize_t out_write_index_show(struct device *dev,
 338                                     struct device_attribute *dev_attr,
 339                                     char *buf)
 340 {
 341         struct hv_device *hv_dev = device_to_hv_device(dev);
 342         struct hv_ring_buffer_debug_info outbound;
 343
 344         if (!hv_dev->channel)
 345                 return -ENODEV;
 346         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 347         return sprintf(buf, "%d\n", outbound.current_write_index);
 348 }
 349 static DEVICE_ATTR_RO(out_write_index);
 350
 351 static ssize_t out_read_bytes_avail_show(struct device *dev,
 352                                          struct device_attribute *dev_attr,
 353                                          char *buf)
 354 {
 355         struct hv_device *hv_dev = device_to_hv_device(dev);
 356         struct hv_ring_buffer_debug_info outbound;
 357
 358         if (!hv_dev->channel)
 359                 return -ENODEV;
 360         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 361         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 362 }
 363 static DEVICE_ATTR_RO(out_read_bytes_avail);
 364
 365 static ssize_t out_write_bytes_avail_show(struct device *dev,
 366                                           struct device_attribute *dev_attr,
 367                                           char *buf)
 368 {
 369         struct hv_device *hv_dev = device_to_hv_device(dev);
 370         struct hv_ring_buffer_debug_info outbound;
 371
 372         if (!hv_dev->channel)
 373                 return -ENODEV;
 374         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 375         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 376 }
 377 static DEVICE_ATTR_RO(out_write_bytes_avail);
 378
 379 static ssize_t in_intr_mask_show(struct device *dev,
 380                                  struct device_attribute *dev_attr, char *buf)
 381 {
 382         struct hv_device *hv_dev = device_to_hv_device(dev);
 383         struct hv_ring_buffer_debug_info inbound;
 384
 385         if (!hv_dev->channel)
 386                 return -ENODEV;
 387         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 388         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 389 }
 390 static DEVICE_ATTR_RO(in_intr_mask);
 391
 392 static ssize_t in_read_index_show(struct device *dev,
 393                                   struct device_attribute *dev_attr, char *buf)
 394 {
 395         struct hv_device *hv_dev = device_to_hv_device(dev);
 396         struct hv_ring_buffer_debug_info inbound;
 397
 398         if (!hv_dev->channel)
 399                 return -ENODEV;
 400         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 401         return sprintf(buf, "%d\n", inbound.current_read_index);
 402 }
 403 static DEVICE_ATTR_RO(in_read_index);
 404
 405 static ssize_t in_write_index_show(struct device *dev,
 406                                    struct device_attribute *dev_attr, char *buf)
 407 {
 408         struct hv_device *hv_dev = device_to_hv_device(dev);
 409         struct hv_ring_buffer_debug_info inbound;
 410
 411         if (!hv_dev->channel)
 412                 return -ENODEV;
 413         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 414         return sprintf(buf, "%d\n", inbound.current_write_index);
 415 }
 416 static DEVICE_ATTR_RO(in_write_index);
 417
 418 static ssize_t in_read_bytes_avail_show(struct device *dev,
 419                                         struct device_attribute *dev_attr,
 420                                         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         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 428         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 429 }
 430 static DEVICE_ATTR_RO(in_read_bytes_avail);
 431
 432 static ssize_t in_write_bytes_avail_show(struct device *dev,
 433                                          struct device_attribute *dev_attr,
 434                                          char *buf)
 435 {
 436         struct hv_device *hv_dev = device_to_hv_device(dev);
 437         struct hv_ring_buffer_debug_info inbound;
 438
 439         if (!hv_dev->channel)
 440                 return -ENODEV;
 441         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 442         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 443 }
 444 static DEVICE_ATTR_RO(in_write_bytes_avail);
 445
 446 static ssize_t channel_vp_mapping_show(struct device *dev,
 447                                        struct device_attribute *dev_attr,
 448                                        char *buf)
 449 {
 450         struct hv_device *hv_dev = device_to_hv_device(dev);
 451         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 452         unsigned long flags;
 453         int buf_size = PAGE_SIZE, n_written, tot_written;
 454         struct list_head *cur;
 455
 456         if (!channel)
 457                 return -ENODEV;
 458
 459         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 460                 channel->offermsg.child_relid, channel->target_cpu);
 461
 462         spin_lock_irqsave(&channel->lock, flags);
 463
 464         list_for_each(cur, &channel->sc_list) {
 465                 if (tot_written >= buf_size - 1)
 466                         break;
 467
 468                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 469                 n_written = scnprintf(buf + tot_written,
 470                                      buf_size - tot_written,
 471                                      "%u:%u\n",
 472                                      cur_sc->offermsg.child_relid,
 473                                      cur_sc->target_cpu);
 474                 tot_written += n_written;
 475         }
 476
 477         spin_unlock_irqrestore(&channel->lock, flags);
 478
 479         return tot_written;
 480 }
 481 static DEVICE_ATTR_RO(channel_vp_mapping);
 482
 483 static ssize_t vendor_show(struct device *dev,
 484                            struct device_attribute *dev_attr,
 485                            char *buf)
 486 {
 487         struct hv_device *hv_dev = device_to_hv_device(dev);
 488         return sprintf(buf, "0x%x\n", hv_dev->vendor_id);
 489 }
 490 static DEVICE_ATTR_RO(vendor);
 491
 492 static ssize_t device_show(struct device *dev,
 493                            struct device_attribute *dev_attr,
 494                            char *buf)
 495 {
 496         struct hv_device *hv_dev = device_to_hv_device(dev);
 497         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 498 }
 499 static DEVICE_ATTR_RO(device);
 500
 501 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 502 static struct attribute *vmbus_attrs[] = {
 503         &dev_attr_id.attr,
 504         &dev_attr_state.attr,
 505         &dev_attr_monitor_id.attr,
 506         &dev_attr_class_id.attr,
 507         &dev_attr_device_id.attr,
 508         &dev_attr_modalias.attr,
 509         &dev_attr_server_monitor_pending.attr,
 510         &dev_attr_client_monitor_pending.attr,
 511         &dev_attr_server_monitor_latency.attr,
 512         &dev_attr_client_monitor_latency.attr,
 513         &dev_attr_server_monitor_conn_id.attr,
 514         &dev_attr_client_monitor_conn_id.attr,
 515         &dev_attr_out_intr_mask.attr,
 516         &dev_attr_out_read_index.attr,
 517         &dev_attr_out_write_index.attr,
 518         &dev_attr_out_read_bytes_avail.attr,
 519         &dev_attr_out_write_bytes_avail.attr,
 520         &dev_attr_in_intr_mask.attr,
 521         &dev_attr_in_read_index.attr,
 522         &dev_attr_in_write_index.attr,
 523         &dev_attr_in_read_bytes_avail.attr,
 524         &dev_attr_in_write_bytes_avail.attr,
 525         &dev_attr_channel_vp_mapping.attr,
 526         &dev_attr_vendor.attr,
 527         &dev_attr_device.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 uuid_le *guid)
 557 {
 558         if (uuid_le_cmp(*guid, null_guid))
 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 uuid_le *guid)
 570 {
 571         for (; !is_null_guid(&id->guid); id++)
 572                 if (!uuid_le_cmp(id->guid, *guid))
 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         /* The hv_sock driver handles all hv_sock offers. */
 589         if (is_hvsock_channel(hv_dev->channel))
 590                 return drv->hvsock;
 591
 592         if (hv_vmbus_get_id(drv->id_table, &hv_dev->dev_type))
 593                 return 1;
 594
 595         return 0;
 596 }
 597
 598 /*
 599  * vmbus_probe - Add the new vmbus's child device
 600  */
 601 static int vmbus_probe(struct device *child_device)
 602 {
 603         int ret = 0;
 604         struct hv_driver *drv =
 605                         drv_to_hv_drv(child_device->driver);
 606         struct hv_device *dev = device_to_hv_device(child_device);
 607         const struct hv_vmbus_device_id *dev_id;
 608
 609         dev_id = hv_vmbus_get_id(drv->id_table, &dev->dev_type);
 610         if (drv->probe) {
 611                 ret = drv->probe(dev, dev_id);
 612                 if (ret != 0)
 613                         pr_err("probe failed for device %s (%d)\n",
 614                                dev_name(child_device), ret);
 615
 616         } else {
 617                 pr_err("probe not set for driver %s\n",
 618                        dev_name(child_device));
 619                 ret = -ENODEV;
 620         }
 621         return ret;
 622 }
 623
 624 /*
 625  * vmbus_remove - Remove a vmbus device
 626  */
 627 static int vmbus_remove(struct device *child_device)
 628 {
 629         struct hv_driver *drv;
 630         struct hv_device *dev = device_to_hv_device(child_device);
 631
 632         if (child_device->driver) {
 633                 drv = drv_to_hv_drv(child_device->driver);
 634                 if (drv->remove)
 635                         drv->remove(dev);
 636         }
 637
 638         return 0;
 639 }
 640
 641
 642 /*
 643  * vmbus_shutdown - Shutdown a vmbus device
 644  */
 645 static void vmbus_shutdown(struct device *child_device)
 646 {
 647         struct hv_driver *drv;
 648         struct hv_device *dev = device_to_hv_device(child_device);
 649
 650
 651         /* The device may not be attached yet */
 652         if (!child_device->driver)
 653                 return;
 654
 655         drv = drv_to_hv_drv(child_device->driver);
 656
 657         if (drv->shutdown)
 658                 drv->shutdown(dev);
 659
 660         return;
 661 }
 662
 663
 664 /*
 665  * vmbus_device_release - Final callback release of the vmbus child device
 666  */
 667 static void vmbus_device_release(struct device *device)
 668 {
 669         struct hv_device *hv_dev = device_to_hv_device(device);
 670         struct vmbus_channel *channel = hv_dev->channel;
 671
 672         hv_process_channel_removal(channel,
 673                                    channel->offermsg.child_relid);
 674         kfree(hv_dev);
 675
 676 }
 677
 678 /* The one and only one */
 679 static struct bus_type  hv_bus = {
 680         .name =         "vmbus",
 681         .match =                vmbus_match,
 682         .shutdown =             vmbus_shutdown,
 683         .remove =               vmbus_remove,
 684         .probe =                vmbus_probe,
 685         .uevent =               vmbus_uevent,
 686         .dev_groups =           vmbus_groups,
 687 };
 688
 689 struct onmessage_work_context {
 690         struct work_struct work;
 691         struct hv_message msg;
 692 };
 693
 694 static void vmbus_onmessage_work(struct work_struct *work)
 695 {
 696         struct onmessage_work_context *ctx;
 697
 698         /* Do not process messages if we're in DISCONNECTED state */
 699         if (vmbus_connection.conn_state == DISCONNECTED)
 700                 return;
 701
 702         ctx = container_of(work, struct onmessage_work_context,
 703                            work);
 704         vmbus_onmessage(&ctx->msg);
 705         kfree(ctx);
 706 }
 707
 708 static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
 709 {
 710         struct clock_event_device *dev = hv_context.clk_evt[cpu];
 711
 712         if (dev->event_handler)
 713                 dev->event_handler(dev);
 714
 715         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
 716 }
 717
 718 void vmbus_on_msg_dpc(unsigned long data)
 719 {
 720         int cpu = smp_processor_id();
 721         void *page_addr = hv_context.synic_message_page[cpu];
 722         struct hv_message *msg = (struct hv_message *)page_addr +
 723                                   VMBUS_MESSAGE_SINT;
 724         struct vmbus_channel_message_header *hdr;
 725         struct vmbus_channel_message_table_entry *entry;
 726         struct onmessage_work_context *ctx;
 727         u32 message_type = msg->header.message_type;
 728
 729         if (message_type == HVMSG_NONE)
 730                 /* no msg */
 731                 return;
 732
 733         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 734
 735         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 736                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 737                 goto msg_handled;
 738         }
 739
 740         entry = &channel_message_table[hdr->msgtype];
 741         if (entry->handler_type == VMHT_BLOCKING) {
 742                 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 743                 if (ctx == NULL)
 744                         return;
 745
 746                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
 747                 memcpy(&ctx->msg, msg, sizeof(*msg));
 748
 749                 queue_work(vmbus_connection.work_queue, &ctx->work);
 750         } else
 751                 entry->message_handler(hdr);
 752
 753 msg_handled:
 754         vmbus_signal_eom(msg, message_type);
 755 }
 756
 757 static void vmbus_isr(void)
 758 {
 759         int cpu = smp_processor_id();
 760         void *page_addr;
 761         struct hv_message *msg;
 762         union hv_synic_event_flags *event;
 763         bool handled = false;
 764
 765         page_addr = hv_context.synic_event_page[cpu];
 766         if (page_addr == NULL)
 767                 return;
 768
 769         event = (union hv_synic_event_flags *)page_addr +
 770                                          VMBUS_MESSAGE_SINT;
 771         /*
 772          * Check for events before checking for messages. This is the order
 773          * in which events and messages are checked in Windows guests on
 774          * Hyper-V, and the Windows team suggested we do the same.
 775          */
 776
 777         if ((vmbus_proto_version == VERSION_WS2008) ||
 778                 (vmbus_proto_version == VERSION_WIN7)) {
 779
 780                 /* Since we are a child, we only need to check bit 0 */
 781                 if (sync_test_and_clear_bit(0,
 782                         (unsigned long *) &event->flags32[0])) {
 783                         handled = true;
 784                 }
 785         } else {
 786                 /*
 787                  * Our host is win8 or above. The signaling mechanism
 788                  * has changed and we can directly look at the event page.
 789                  * If bit n is set then we have an interrup on the channel
 790                  * whose id is n.
 791                  */
 792                 handled = true;
 793         }
 794
 795         if (handled)
 796                 tasklet_schedule(hv_context.event_dpc[cpu]);
 797
 798
 799         page_addr = hv_context.synic_message_page[cpu];
 800         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 801
 802         /* Check if there are actual msgs to be processed */
 803         if (msg->header.message_type != HVMSG_NONE) {
 804                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
 805                         hv_process_timer_expiration(msg, cpu);
 806                 else
 807                         tasklet_schedule(hv_context.msg_dpc[cpu]);
 808         }
 809 }
 810
 811
 812 /*
 813  * vmbus_bus_init -Main vmbus driver initialization routine.
 814  *
 815  * Here, we
 816  *      - initialize the vmbus driver context
 817  *      - invoke the vmbus hv main init routine
 818  *      - retrieve the channel offers
 819  */
 820 static int vmbus_bus_init(void)
 821 {
 822         int ret;
 823
 824         /* Hypervisor initialization...setup hypercall page..etc */
 825         ret = hv_init();
 826         if (ret != 0) {
 827                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 828                 return ret;
 829         }
 830
 831         ret = bus_register(&hv_bus);
 832         if (ret)
 833                 goto err_cleanup;
 834
 835         hv_setup_vmbus_irq(vmbus_isr);
 836
 837         ret = hv_synic_alloc();
 838         if (ret)
 839                 goto err_alloc;
 840         /*
 841          * Initialize the per-cpu interrupt state and
 842          * connect to the host.
 843          */
 844         on_each_cpu(hv_synic_init, NULL, 1);
 845         ret = vmbus_connect();
 846         if (ret)
 847                 goto err_connect;
 848
 849         if (vmbus_proto_version > VERSION_WIN7)
 850                 cpu_hotplug_disable();
 851
 852         /*
 853          * Only register if the crash MSRs are available
 854          */
 855         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
 856                 register_die_notifier(&hyperv_die_block);
 857                 atomic_notifier_chain_register(&panic_notifier_list,
 858                                                &hyperv_panic_block);
 859         }
 860
 861         vmbus_request_offers();
 862
 863         return 0;
 864
 865 err_connect:
 866         on_each_cpu(hv_synic_cleanup, NULL, 1);
 867 err_alloc:
 868         hv_synic_free();
 869         hv_remove_vmbus_irq();
 870
 871         bus_unregister(&hv_bus);
 872
 873 err_cleanup:
 874         hv_cleanup();
 875
 876         return ret;
 877 }
 878
 879 /**
 880  * __vmbus_child_driver_register() - Register a vmbus's driver
 881  * @hv_driver: Pointer to driver structure you want to register
 882  * @owner: owner module of the drv
 883  * @mod_name: module name string
 884  *
 885  * Registers the given driver with Linux through the 'driver_register()' call
 886  * and sets up the hyper-v vmbus handling for this driver.
 887  * It will return the state of the 'driver_register()' call.
 888  *
 889  */
 890 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 891 {
 892         int ret;
 893
 894         pr_info("registering driver %s\n", hv_driver->name);
 895
 896         ret = vmbus_exists();
 897         if (ret < 0)
 898                 return ret;
 899
 900         hv_driver->driver.name = hv_driver->name;
 901         hv_driver->driver.owner = owner;
 902         hv_driver->driver.mod_name = mod_name;
 903         hv_driver->driver.bus = &hv_bus;
 904
 905         ret = driver_register(&hv_driver->driver);
 906
 907         return ret;
 908 }
 909 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 910
 911 /**
 912  * vmbus_driver_unregister() - Unregister a vmbus's driver
 913  * @hv_driver: Pointer to driver structure you want to
 914  *             un-register
 915  *
 916  * Un-register the given driver that was previous registered with a call to
 917  * vmbus_driver_register()
 918  */
 919 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 920 {
 921         pr_info("unregistering driver %s\n", hv_driver->name);
 922
 923         if (!vmbus_exists())
 924                 driver_unregister(&hv_driver->driver);
 925 }
 926 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 927
 928 /*
 929  * vmbus_device_create - Creates and registers a new child device
 930  * on the vmbus.
 931  */
 932 struct hv_device *vmbus_device_create(const uuid_le *type,
 933                                       const uuid_le *instance,
 934                                       struct vmbus_channel *channel)
 935 {
 936         struct hv_device *child_device_obj;
 937
 938         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 939         if (!child_device_obj) {
 940                 pr_err("Unable to allocate device object for child device\n");
 941                 return NULL;
 942         }
 943
 944         child_device_obj->channel = channel;
 945         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 946         memcpy(&child_device_obj->dev_instance, instance,
 947                sizeof(uuid_le));
 948         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
 949
 950
 951         return child_device_obj;
 952 }
 953
 954 /*
 955  * vmbus_device_register - Register the child device
 956  */
 957 int vmbus_device_register(struct hv_device *child_device_obj)
 958 {
 959         int ret = 0;
 960
 961         dev_set_name(&child_device_obj->device, "vmbus_%d",
 962                      child_device_obj->channel->id);
 963
 964         child_device_obj->device.bus = &hv_bus;
 965         child_device_obj->device.parent = &hv_acpi_dev->dev;
 966         child_device_obj->device.release = vmbus_device_release;
 967
 968         /*
 969          * Register with the LDM. This will kick off the driver/device
 970          * binding...which will eventually call vmbus_match() and vmbus_probe()
 971          */
 972         ret = device_register(&child_device_obj->device);
 973
 974         if (ret)
 975                 pr_err("Unable to register child device\n");
 976         else
 977                 pr_debug("child device %s registered\n",
 978                         dev_name(&child_device_obj->device));
 979
 980         return ret;
 981 }
 982
 983 /*
 984  * vmbus_device_unregister - Remove the specified child device
 985  * from the vmbus.
 986  */
 987 void vmbus_device_unregister(struct hv_device *device_obj)
 988 {
 989         pr_debug("child device %s unregistered\n",
 990                 dev_name(&device_obj->device));
 991
 992         /*
 993          * Kick off the process of unregistering the device.
 994          * This will call vmbus_remove() and eventually vmbus_device_release()
 995          */
 996         device_unregister(&device_obj->device);
 997 }
 998
 999
1000 /*
1001  * VMBUS is an acpi enumerated device. Get the information we
1002  * need from DSDT.
1003  */
1004 #define VTPM_BASE_ADDRESS 0xfed40000
1005 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1006 {
1007         resource_size_t start = 0;
1008         resource_size_t end = 0;
1009         struct resource *new_res;
1010         struct resource **old_res = &hyperv_mmio;
1011         struct resource **prev_res = NULL;
1012
1013         switch (res->type) {
1014
1015         /*
1016          * "Address" descriptors are for bus windows. Ignore
1017          * "memory" descriptors, which are for registers on
1018          * devices.
1019          */
1020         case ACPI_RESOURCE_TYPE_ADDRESS32:
1021                 start = res->data.address32.address.minimum;
1022                 end = res->data.address32.address.maximum;
1023                 break;
1024
1025         case ACPI_RESOURCE_TYPE_ADDRESS64:
1026                 start = res->data.address64.address.minimum;
1027                 end = res->data.address64.address.maximum;
1028                 break;
1029
1030         default:
1031                 /* Unused resource type */
1032                 return AE_OK;
1033
1034         }
1035         /*
1036          * Ignore ranges that are below 1MB, as they're not
1037          * necessary or useful here.
1038          */
1039         if (end < 0x100000)
1040                 return AE_OK;
1041
1042         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1043         if (!new_res)
1044                 return AE_NO_MEMORY;
1045
1046         /* If this range overlaps the virtual TPM, truncate it. */
1047         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1048                 end = VTPM_BASE_ADDRESS;
1049
1050         new_res->name = "hyperv mmio";
1051         new_res->flags = IORESOURCE_MEM;
1052         new_res->start = start;
1053         new_res->end = end;
1054
1055         /*
1056          * If two ranges are adjacent, merge them.
1057          */
1058         do {
1059                 if (!*old_res) {
1060                         *old_res = new_res;
1061                         break;
1062                 }
1063
1064                 if (((*old_res)->end + 1) == new_res->start) {
1065                         (*old_res)->end = new_res->end;
1066                         kfree(new_res);
1067                         break;
1068                 }
1069
1070                 if ((*old_res)->start == new_res->end + 1) {
1071                         (*old_res)->start = new_res->start;
1072                         kfree(new_res);
1073                         break;
1074                 }
1075
1076                 if ((*old_res)->start > new_res->end) {
1077                         new_res->sibling = *old_res;
1078                         if (prev_res)
1079                                 (*prev_res)->sibling = new_res;
1080                         *old_res = new_res;
1081                         break;
1082                 }
1083
1084                 prev_res = old_res;
1085                 old_res = &(*old_res)->sibling;
1086
1087         } while (1);
1088
1089         return AE_OK;
1090 }
1091
1092 static int vmbus_acpi_remove(struct acpi_device *device)
1093 {
1094         struct resource *cur_res;
1095         struct resource *next_res;
1096
1097         if (hyperv_mmio) {
1098                 if (fb_mmio) {
1099                         __release_region(hyperv_mmio, fb_mmio->start,
1100                                          resource_size(fb_mmio));
1101                         fb_mmio = NULL;
1102                 }
1103
1104                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1105                         next_res = cur_res->sibling;
1106                         kfree(cur_res);
1107                 }
1108         }
1109
1110         return 0;
1111 }
1112
1113 static void vmbus_reserve_fb(void)
1114 {
1115         int size;
1116         /*
1117          * Make a claim for the frame buffer in the resource tree under the
1118          * first node, which will be the one below 4GB.  The length seems to
1119          * be underreported, particularly in a Generation 1 VM.  So start out
1120          * reserving a larger area and make it smaller until it succeeds.
1121          */
1122
1123         if (screen_info.lfb_base) {
1124                 if (efi_enabled(EFI_BOOT))
1125                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
1126                 else
1127                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1128
1129                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1130                         fb_mmio = __request_region(hyperv_mmio,
1131                                                    screen_info.lfb_base, size,
1132                                                    fb_mmio_name, 0);
1133                 }
1134         }
1135 }
1136
1137 /**
1138  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1139  * @new:                If successful, supplied a pointer to the
1140  *                      allocated MMIO space.
1141  * @device_obj:         Identifies the caller
1142  * @min:                Minimum guest physical address of the
1143  *                      allocation
1144  * @max:                Maximum guest physical address
1145  * @size:               Size of the range to be allocated
1146  * @align:              Alignment of the range to be allocated
1147  * @fb_overlap_ok:      Whether this allocation can be allowed
1148  *                      to overlap the video frame buffer.
1149  *
1150  * This function walks the resources granted to VMBus by the
1151  * _CRS object in the ACPI namespace underneath the parent
1152  * "bridge" whether that's a root PCI bus in the Generation 1
1153  * case or a Module Device in the Generation 2 case.  It then
1154  * attempts to allocate from the global MMIO pool in a way that
1155  * matches the constraints supplied in these parameters and by
1156  * that _CRS.
1157  *
1158  * Return: 0 on success, -errno on failure
1159  */
1160 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1161                         resource_size_t min, resource_size_t max,
1162                         resource_size_t size, resource_size_t align,
1163                         bool fb_overlap_ok)
1164 {
1165         struct resource *iter, *shadow;
1166         resource_size_t range_min, range_max, start;
1167         const char *dev_n = dev_name(&device_obj->device);
1168         int retval;
1169
1170         retval = -ENXIO;
1171         down(&hyperv_mmio_lock);
1172
1173         /*
1174          * If overlaps with frame buffers are allowed, then first attempt to
1175          * make the allocation from within the reserved region.  Because it
1176          * is already reserved, no shadow allocation is necessary.
1177          */
1178         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1179             !(max < fb_mmio->start)) {
1180
1181                 range_min = fb_mmio->start;
1182                 range_max = fb_mmio->end;
1183                 start = (range_min + align - 1) & ~(align - 1);
1184                 for (; start + size - 1 <= range_max; start += align) {
1185                         *new = request_mem_region_exclusive(start, size, dev_n);
1186                         if (*new) {
1187                                 retval = 0;
1188                                 goto exit;
1189                         }
1190                 }
1191         }
1192
1193         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1194                 if ((iter->start >= max) || (iter->end <= min))
1195                         continue;
1196
1197                 range_min = iter->start;
1198                 range_max = iter->end;
1199                 start = (range_min + align - 1) & ~(align - 1);
1200                 for (; start + size - 1 <= range_max; start += align) {
1201                         shadow = __request_region(iter, start, size, NULL,
1202                                                   IORESOURCE_BUSY);
1203                         if (!shadow)
1204                                 continue;
1205
1206                         *new = request_mem_region_exclusive(start, size, dev_n);
1207                         if (*new) {
1208                                 shadow->name = (char *)*new;
1209                                 retval = 0;
1210                                 goto exit;
1211                         }
1212
1213                         __release_region(iter, start, size);
1214                 }
1215         }
1216
1217 exit:
1218         up(&hyperv_mmio_lock);
1219         return retval;
1220 }
1221 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1222
1223 /**
1224  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1225  * @start:              Base address of region to release.
1226  * @size:               Size of the range to be allocated
1227  *
1228  * This function releases anything requested by
1229  * vmbus_mmio_allocate().
1230  */
1231 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1232 {
1233         struct resource *iter;
1234
1235         down(&hyperv_mmio_lock);
1236         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1237                 if ((iter->start >= start + size) || (iter->end <= start))
1238                         continue;
1239
1240                 __release_region(iter, start, size);
1241         }
1242         release_mem_region(start, size);
1243         up(&hyperv_mmio_lock);
1244
1245 }
1246 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1247
1248 /**
1249  * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
1250  * @cpu_number: CPU number in Linux terms
1251  *
1252  * This function returns the mapping between the Linux processor
1253  * number and the hypervisor's virtual processor number, useful
1254  * in making hypercalls and such that talk about specific
1255  * processors.
1256  *
1257  * Return: Virtual processor number in Hyper-V terms
1258  */
1259 int vmbus_cpu_number_to_vp_number(int cpu_number)
1260 {
1261         return hv_context.vp_index[cpu_number];
1262 }
1263 EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
1264
1265 static int vmbus_acpi_add(struct acpi_device *device)
1266 {
1267         acpi_status result;
1268         int ret_val = -ENODEV;
1269         struct acpi_device *ancestor;
1270
1271         hv_acpi_dev = device;
1272
1273         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1274                                         vmbus_walk_resources, NULL);
1275
1276         if (ACPI_FAILURE(result))
1277                 goto acpi_walk_err;
1278         /*
1279          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1280          * firmware) is the VMOD that has the mmio ranges. Get that.
1281          */
1282         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1283                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1284                                              vmbus_walk_resources, NULL);
1285
1286                 if (ACPI_FAILURE(result))
1287                         continue;
1288                 if (hyperv_mmio) {
1289                         vmbus_reserve_fb();
1290                         break;
1291                 }
1292         }
1293         ret_val = 0;
1294
1295 acpi_walk_err:
1296         complete(&probe_event);
1297         if (ret_val)
1298                 vmbus_acpi_remove(device);
1299         return ret_val;
1300 }
1301
1302 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1303         {"VMBUS", 0},
1304         {"VMBus", 0},
1305         {"", 0},
1306 };
1307 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1308
1309 static struct acpi_driver vmbus_acpi_driver = {
1310         .name = "vmbus",
1311         .ids = vmbus_acpi_device_ids,
1312         .ops = {
1313                 .add = vmbus_acpi_add,
1314                 .remove = vmbus_acpi_remove,
1315         },
1316 };
1317
1318 static void hv_kexec_handler(void)
1319 {
1320         int cpu;
1321
1322         hv_synic_clockevents_cleanup();
1323         vmbus_initiate_unload(false);
1324         for_each_online_cpu(cpu)
1325                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1326         hv_cleanup();
1327 };
1328
1329 static void hv_crash_handler(struct pt_regs *regs)
1330 {
1331         vmbus_initiate_unload(true);
1332         /*
1333          * In crash handler we can't schedule synic cleanup for all CPUs,
1334          * doing the cleanup for current CPU only. This should be sufficient
1335          * for kdump.
1336          */
1337         hv_synic_cleanup(NULL);
1338         hv_cleanup();
1339 };
1340
1341 static int __init hv_acpi_init(void)
1342 {
1343         int ret, t;
1344
1345         if (x86_hyper != &x86_hyper_ms_hyperv)
1346                 return -ENODEV;
1347
1348         init_completion(&probe_event);
1349
1350         /*
1351          * Get ACPI resources first.
1352          */
1353         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1354
1355         if (ret)
1356                 return ret;
1357
1358         t = wait_for_completion_timeout(&probe_event, 5*HZ);
1359         if (t == 0) {
1360                 ret = -ETIMEDOUT;
1361                 goto cleanup;
1362         }
1363
1364         ret = vmbus_bus_init();
1365         if (ret)
1366                 goto cleanup;
1367
1368         hv_setup_kexec_handler(hv_kexec_handler);
1369         hv_setup_crash_handler(hv_crash_handler);
1370
1371         return 0;
1372
1373 cleanup:
1374         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1375         hv_acpi_dev = NULL;
1376         return ret;
1377 }
1378
1379 static void __exit vmbus_exit(void)
1380 {
1381         int cpu;
1382
1383         hv_remove_kexec_handler();
1384         hv_remove_crash_handler();
1385         vmbus_connection.conn_state = DISCONNECTED;
1386         hv_synic_clockevents_cleanup();
1387         vmbus_disconnect();
1388         hv_remove_vmbus_irq();
1389         for_each_online_cpu(cpu)
1390                 tasklet_kill(hv_context.msg_dpc[cpu]);
1391         vmbus_free_channels();
1392         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1393                 unregister_die_notifier(&hyperv_die_block);
1394                 atomic_notifier_chain_unregister(&panic_notifier_list,
1395                                                  &hyperv_panic_block);
1396         }
1397         bus_unregister(&hv_bus);
1398         hv_cleanup();
1399         for_each_online_cpu(cpu) {
1400                 tasklet_kill(hv_context.event_dpc[cpu]);
1401                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1402         }
1403         hv_synic_free();
1404         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1405         if (vmbus_proto_version > VERSION_WIN7)
1406                 cpu_hotplug_enable();
1407 }
1408
1409
1410 MODULE_LICENSE("GPL");
1411
1412 subsys_initcall(hv_acpi_init);
1413 module_exit(vmbus_exit);