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 <linux/random.h>
  46 #include "hyperv_vmbus.h"
  47
  48 struct vmbus_dynid {
  49         struct list_head node;
  50         struct hv_vmbus_device_id id;
  51 };
  52
  53 static struct acpi_device  *hv_acpi_dev;
  54
  55 static struct completion probe_event;
  56
  57
  58 static void hyperv_report_panic(struct pt_regs *regs)
  59 {
  60         static bool panic_reported;
  61
  62         /*
  63          * We prefer to report panic on 'die' chain as we have proper
  64          * registers to report, but if we miss it (e.g. on BUG()) we need
  65          * to report it on 'panic'.
  66          */
  67         if (panic_reported)
  68                 return;
  69         panic_reported = true;
  70
  71         wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
  72         wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
  73         wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
  74         wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
  75         wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
  76
  77         /*
  78          * Let Hyper-V know there is crash data available
  79          */
  80         wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
  81 }
  82
  83 static int hyperv_panic_event(struct notifier_block *nb, unsigned long val,
  84                               void *args)
  85 {
  86         struct pt_regs *regs;
  87
  88         regs = current_pt_regs();
  89
  90         hyperv_report_panic(regs);
  91         return NOTIFY_DONE;
  92 }
  93
  94 static int hyperv_die_event(struct notifier_block *nb, unsigned long val,
  95                             void *args)
  96 {
  97         struct die_args *die = (struct die_args *)args;
  98         struct pt_regs *regs = die->regs;
  99
 100         hyperv_report_panic(regs);
 101         return NOTIFY_DONE;
 102 }
 103
 104 static struct notifier_block hyperv_die_block = {
 105         .notifier_call = hyperv_die_event,
 106 };
 107 static struct notifier_block hyperv_panic_block = {
 108         .notifier_call = hyperv_panic_event,
 109 };
 110
 111 static const char *fb_mmio_name = "fb_range";
 112 static struct resource *fb_mmio;
 113 static struct resource *hyperv_mmio;
 114 static DEFINE_SEMAPHORE(hyperv_mmio_lock);
 115
 116 static int vmbus_exists(void)
 117 {
 118         if (hv_acpi_dev == NULL)
 119                 return -ENODEV;
 120
 121         return 0;
 122 }
 123
 124 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 125 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 126 {
 127         int i;
 128         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 129                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 130 }
 131
 132 static u8 channel_monitor_group(struct vmbus_channel *channel)
 133 {
 134         return (u8)channel->offermsg.monitorid / 32;
 135 }
 136
 137 static u8 channel_monitor_offset(struct vmbus_channel *channel)
 138 {
 139         return (u8)channel->offermsg.monitorid % 32;
 140 }
 141
 142 static u32 channel_pending(struct vmbus_channel *channel,
 143                            struct hv_monitor_page *monitor_page)
 144 {
 145         u8 monitor_group = channel_monitor_group(channel);
 146         return monitor_page->trigger_group[monitor_group].pending;
 147 }
 148
 149 static u32 channel_latency(struct vmbus_channel *channel,
 150                            struct hv_monitor_page *monitor_page)
 151 {
 152         u8 monitor_group = channel_monitor_group(channel);
 153         u8 monitor_offset = channel_monitor_offset(channel);
 154         return monitor_page->latency[monitor_group][monitor_offset];
 155 }
 156
 157 static u32 channel_conn_id(struct vmbus_channel *channel,
 158                            struct hv_monitor_page *monitor_page)
 159 {
 160         u8 monitor_group = channel_monitor_group(channel);
 161         u8 monitor_offset = channel_monitor_offset(channel);
 162         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 163 }
 164
 165 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 166                        char *buf)
 167 {
 168         struct hv_device *hv_dev = device_to_hv_device(dev);
 169
 170         if (!hv_dev->channel)
 171                 return -ENODEV;
 172         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 173 }
 174 static DEVICE_ATTR_RO(id);
 175
 176 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 177                           char *buf)
 178 {
 179         struct hv_device *hv_dev = device_to_hv_device(dev);
 180
 181         if (!hv_dev->channel)
 182                 return -ENODEV;
 183         return sprintf(buf, "%d\n", hv_dev->channel->state);
 184 }
 185 static DEVICE_ATTR_RO(state);
 186
 187 static ssize_t monitor_id_show(struct device *dev,
 188                                struct device_attribute *dev_attr, char *buf)
 189 {
 190         struct hv_device *hv_dev = device_to_hv_device(dev);
 191
 192         if (!hv_dev->channel)
 193                 return -ENODEV;
 194         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.monitorid);
 195 }
 196 static DEVICE_ATTR_RO(monitor_id);
 197
 198 static ssize_t class_id_show(struct device *dev,
 199                                struct device_attribute *dev_attr, char *buf)
 200 {
 201         struct hv_device *hv_dev = device_to_hv_device(dev);
 202
 203         if (!hv_dev->channel)
 204                 return -ENODEV;
 205         return sprintf(buf, "{%pUl}\n",
 206                        hv_dev->channel->offermsg.offer.if_type.b);
 207 }
 208 static DEVICE_ATTR_RO(class_id);
 209
 210 static ssize_t device_id_show(struct device *dev,
 211                               struct device_attribute *dev_attr, char *buf)
 212 {
 213         struct hv_device *hv_dev = device_to_hv_device(dev);
 214
 215         if (!hv_dev->channel)
 216                 return -ENODEV;
 217         return sprintf(buf, "{%pUl}\n",
 218                        hv_dev->channel->offermsg.offer.if_instance.b);
 219 }
 220 static DEVICE_ATTR_RO(device_id);
 221
 222 static ssize_t modalias_show(struct device *dev,
 223                              struct device_attribute *dev_attr, char *buf)
 224 {
 225         struct hv_device *hv_dev = device_to_hv_device(dev);
 226         char alias_name[VMBUS_ALIAS_LEN + 1];
 227
 228         print_alias_name(hv_dev, alias_name);
 229         return sprintf(buf, "vmbus:%s\n", alias_name);
 230 }
 231 static DEVICE_ATTR_RO(modalias);
 232
 233 static ssize_t server_monitor_pending_show(struct device *dev,
 234                                            struct device_attribute *dev_attr,
 235                                            char *buf)
 236 {
 237         struct hv_device *hv_dev = device_to_hv_device(dev);
 238
 239         if (!hv_dev->channel)
 240                 return -ENODEV;
 241         return sprintf(buf, "%d\n",
 242                        channel_pending(hv_dev->channel,
 243                                        vmbus_connection.monitor_pages[1]));
 244 }
 245 static DEVICE_ATTR_RO(server_monitor_pending);
 246
 247 static ssize_t client_monitor_pending_show(struct device *dev,
 248                                            struct device_attribute *dev_attr,
 249                                            char *buf)
 250 {
 251         struct hv_device *hv_dev = device_to_hv_device(dev);
 252
 253         if (!hv_dev->channel)
 254                 return -ENODEV;
 255         return sprintf(buf, "%d\n",
 256                        channel_pending(hv_dev->channel,
 257                                        vmbus_connection.monitor_pages[1]));
 258 }
 259 static DEVICE_ATTR_RO(client_monitor_pending);
 260
 261 static ssize_t server_monitor_latency_show(struct device *dev,
 262                                            struct device_attribute *dev_attr,
 263                                            char *buf)
 264 {
 265         struct hv_device *hv_dev = device_to_hv_device(dev);
 266
 267         if (!hv_dev->channel)
 268                 return -ENODEV;
 269         return sprintf(buf, "%d\n",
 270                        channel_latency(hv_dev->channel,
 271                                        vmbus_connection.monitor_pages[0]));
 272 }
 273 static DEVICE_ATTR_RO(server_monitor_latency);
 274
 275 static ssize_t client_monitor_latency_show(struct device *dev,
 276                                            struct device_attribute *dev_attr,
 277                                            char *buf)
 278 {
 279         struct hv_device *hv_dev = device_to_hv_device(dev);
 280
 281         if (!hv_dev->channel)
 282                 return -ENODEV;
 283         return sprintf(buf, "%d\n",
 284                        channel_latency(hv_dev->channel,
 285                                        vmbus_connection.monitor_pages[1]));
 286 }
 287 static DEVICE_ATTR_RO(client_monitor_latency);
 288
 289 static ssize_t server_monitor_conn_id_show(struct device *dev,
 290                                            struct device_attribute *dev_attr,
 291                                            char *buf)
 292 {
 293         struct hv_device *hv_dev = device_to_hv_device(dev);
 294
 295         if (!hv_dev->channel)
 296                 return -ENODEV;
 297         return sprintf(buf, "%d\n",
 298                        channel_conn_id(hv_dev->channel,
 299                                        vmbus_connection.monitor_pages[0]));
 300 }
 301 static DEVICE_ATTR_RO(server_monitor_conn_id);
 302
 303 static ssize_t client_monitor_conn_id_show(struct device *dev,
 304                                            struct device_attribute *dev_attr,
 305                                            char *buf)
 306 {
 307         struct hv_device *hv_dev = device_to_hv_device(dev);
 308
 309         if (!hv_dev->channel)
 310                 return -ENODEV;
 311         return sprintf(buf, "%d\n",
 312                        channel_conn_id(hv_dev->channel,
 313                                        vmbus_connection.monitor_pages[1]));
 314 }
 315 static DEVICE_ATTR_RO(client_monitor_conn_id);
 316
 317 static ssize_t out_intr_mask_show(struct device *dev,
 318                                   struct device_attribute *dev_attr, char *buf)
 319 {
 320         struct hv_device *hv_dev = device_to_hv_device(dev);
 321         struct hv_ring_buffer_debug_info outbound;
 322
 323         if (!hv_dev->channel)
 324                 return -ENODEV;
 325         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 326         return sprintf(buf, "%d\n", outbound.current_interrupt_mask);
 327 }
 328 static DEVICE_ATTR_RO(out_intr_mask);
 329
 330 static ssize_t out_read_index_show(struct device *dev,
 331                                    struct device_attribute *dev_attr, char *buf)
 332 {
 333         struct hv_device *hv_dev = device_to_hv_device(dev);
 334         struct hv_ring_buffer_debug_info outbound;
 335
 336         if (!hv_dev->channel)
 337                 return -ENODEV;
 338         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 339         return sprintf(buf, "%d\n", outbound.current_read_index);
 340 }
 341 static DEVICE_ATTR_RO(out_read_index);
 342
 343 static ssize_t out_write_index_show(struct device *dev,
 344                                     struct device_attribute *dev_attr,
 345                                     char *buf)
 346 {
 347         struct hv_device *hv_dev = device_to_hv_device(dev);
 348         struct hv_ring_buffer_debug_info outbound;
 349
 350         if (!hv_dev->channel)
 351                 return -ENODEV;
 352         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 353         return sprintf(buf, "%d\n", outbound.current_write_index);
 354 }
 355 static DEVICE_ATTR_RO(out_write_index);
 356
 357 static ssize_t out_read_bytes_avail_show(struct device *dev,
 358                                          struct device_attribute *dev_attr,
 359                                          char *buf)
 360 {
 361         struct hv_device *hv_dev = device_to_hv_device(dev);
 362         struct hv_ring_buffer_debug_info outbound;
 363
 364         if (!hv_dev->channel)
 365                 return -ENODEV;
 366         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 367         return sprintf(buf, "%d\n", outbound.bytes_avail_toread);
 368 }
 369 static DEVICE_ATTR_RO(out_read_bytes_avail);
 370
 371 static ssize_t out_write_bytes_avail_show(struct device *dev,
 372                                           struct device_attribute *dev_attr,
 373                                           char *buf)
 374 {
 375         struct hv_device *hv_dev = device_to_hv_device(dev);
 376         struct hv_ring_buffer_debug_info outbound;
 377
 378         if (!hv_dev->channel)
 379                 return -ENODEV;
 380         hv_ringbuffer_get_debuginfo(&hv_dev->channel->outbound, &outbound);
 381         return sprintf(buf, "%d\n", outbound.bytes_avail_towrite);
 382 }
 383 static DEVICE_ATTR_RO(out_write_bytes_avail);
 384
 385 static ssize_t in_intr_mask_show(struct device *dev,
 386                                  struct device_attribute *dev_attr, char *buf)
 387 {
 388         struct hv_device *hv_dev = device_to_hv_device(dev);
 389         struct hv_ring_buffer_debug_info inbound;
 390
 391         if (!hv_dev->channel)
 392                 return -ENODEV;
 393         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 394         return sprintf(buf, "%d\n", inbound.current_interrupt_mask);
 395 }
 396 static DEVICE_ATTR_RO(in_intr_mask);
 397
 398 static ssize_t in_read_index_show(struct device *dev,
 399                                   struct device_attribute *dev_attr, char *buf)
 400 {
 401         struct hv_device *hv_dev = device_to_hv_device(dev);
 402         struct hv_ring_buffer_debug_info inbound;
 403
 404         if (!hv_dev->channel)
 405                 return -ENODEV;
 406         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 407         return sprintf(buf, "%d\n", inbound.current_read_index);
 408 }
 409 static DEVICE_ATTR_RO(in_read_index);
 410
 411 static ssize_t in_write_index_show(struct device *dev,
 412                                    struct device_attribute *dev_attr, char *buf)
 413 {
 414         struct hv_device *hv_dev = device_to_hv_device(dev);
 415         struct hv_ring_buffer_debug_info inbound;
 416
 417         if (!hv_dev->channel)
 418                 return -ENODEV;
 419         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 420         return sprintf(buf, "%d\n", inbound.current_write_index);
 421 }
 422 static DEVICE_ATTR_RO(in_write_index);
 423
 424 static ssize_t in_read_bytes_avail_show(struct device *dev,
 425                                         struct device_attribute *dev_attr,
 426                                         char *buf)
 427 {
 428         struct hv_device *hv_dev = device_to_hv_device(dev);
 429         struct hv_ring_buffer_debug_info inbound;
 430
 431         if (!hv_dev->channel)
 432                 return -ENODEV;
 433         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 434         return sprintf(buf, "%d\n", inbound.bytes_avail_toread);
 435 }
 436 static DEVICE_ATTR_RO(in_read_bytes_avail);
 437
 438 static ssize_t in_write_bytes_avail_show(struct device *dev,
 439                                          struct device_attribute *dev_attr,
 440                                          char *buf)
 441 {
 442         struct hv_device *hv_dev = device_to_hv_device(dev);
 443         struct hv_ring_buffer_debug_info inbound;
 444
 445         if (!hv_dev->channel)
 446                 return -ENODEV;
 447         hv_ringbuffer_get_debuginfo(&hv_dev->channel->inbound, &inbound);
 448         return sprintf(buf, "%d\n", inbound.bytes_avail_towrite);
 449 }
 450 static DEVICE_ATTR_RO(in_write_bytes_avail);
 451
 452 static ssize_t channel_vp_mapping_show(struct device *dev,
 453                                        struct device_attribute *dev_attr,
 454                                        char *buf)
 455 {
 456         struct hv_device *hv_dev = device_to_hv_device(dev);
 457         struct vmbus_channel *channel = hv_dev->channel, *cur_sc;
 458         unsigned long flags;
 459         int buf_size = PAGE_SIZE, n_written, tot_written;
 460         struct list_head *cur;
 461
 462         if (!channel)
 463                 return -ENODEV;
 464
 465         tot_written = snprintf(buf, buf_size, "%u:%u\n",
 466                 channel->offermsg.child_relid, channel->target_cpu);
 467
 468         spin_lock_irqsave(&channel->lock, flags);
 469
 470         list_for_each(cur, &channel->sc_list) {
 471                 if (tot_written >= buf_size - 1)
 472                         break;
 473
 474                 cur_sc = list_entry(cur, struct vmbus_channel, sc_list);
 475                 n_written = scnprintf(buf + tot_written,
 476                                      buf_size - tot_written,
 477                                      "%u:%u\n",
 478                                      cur_sc->offermsg.child_relid,
 479                                      cur_sc->target_cpu);
 480                 tot_written += n_written;
 481         }
 482
 483         spin_unlock_irqrestore(&channel->lock, flags);
 484
 485         return tot_written;
 486 }
 487 static DEVICE_ATTR_RO(channel_vp_mapping);
 488
 489 static ssize_t vendor_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->vendor_id);
 495 }
 496 static DEVICE_ATTR_RO(vendor);
 497
 498 static ssize_t device_show(struct device *dev,
 499                            struct device_attribute *dev_attr,
 500                            char *buf)
 501 {
 502         struct hv_device *hv_dev = device_to_hv_device(dev);
 503         return sprintf(buf, "0x%x\n", hv_dev->device_id);
 504 }
 505 static DEVICE_ATTR_RO(device);
 506
 507 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 508 static struct attribute *vmbus_dev_attrs[] = {
 509         &dev_attr_id.attr,
 510         &dev_attr_state.attr,
 511         &dev_attr_monitor_id.attr,
 512         &dev_attr_class_id.attr,
 513         &dev_attr_device_id.attr,
 514         &dev_attr_modalias.attr,
 515         &dev_attr_server_monitor_pending.attr,
 516         &dev_attr_client_monitor_pending.attr,
 517         &dev_attr_server_monitor_latency.attr,
 518         &dev_attr_client_monitor_latency.attr,
 519         &dev_attr_server_monitor_conn_id.attr,
 520         &dev_attr_client_monitor_conn_id.attr,
 521         &dev_attr_out_intr_mask.attr,
 522         &dev_attr_out_read_index.attr,
 523         &dev_attr_out_write_index.attr,
 524         &dev_attr_out_read_bytes_avail.attr,
 525         &dev_attr_out_write_bytes_avail.attr,
 526         &dev_attr_in_intr_mask.attr,
 527         &dev_attr_in_read_index.attr,
 528         &dev_attr_in_write_index.attr,
 529         &dev_attr_in_read_bytes_avail.attr,
 530         &dev_attr_in_write_bytes_avail.attr,
 531         &dev_attr_channel_vp_mapping.attr,
 532         &dev_attr_vendor.attr,
 533         &dev_attr_device.attr,
 534         NULL,
 535 };
 536 ATTRIBUTE_GROUPS(vmbus_dev);
 537
 538 /*
 539  * vmbus_uevent - add uevent for our device
 540  *
 541  * This routine is invoked when a device is added or removed on the vmbus to
 542  * generate a uevent to udev in the userspace. The udev will then look at its
 543  * rule and the uevent generated here to load the appropriate driver
 544  *
 545  * The alias string will be of the form vmbus:guid where guid is the string
 546  * representation of the device guid (each byte of the guid will be
 547  * represented with two hex characters.
 548  */
 549 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 550 {
 551         struct hv_device *dev = device_to_hv_device(device);
 552         int ret;
 553         char alias_name[VMBUS_ALIAS_LEN + 1];
 554
 555         print_alias_name(dev, alias_name);
 556         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 557         return ret;
 558 }
 559
 560 static const uuid_le null_guid;
 561
 562 static inline bool is_null_guid(const uuid_le *guid)
 563 {
 564         if (uuid_le_cmp(*guid, null_guid))
 565                 return false;
 566         return true;
 567 }
 568
 569 /*
 570  * Return a matching hv_vmbus_device_id pointer.
 571  * If there is no match, return NULL.
 572  */
 573 static const struct hv_vmbus_device_id *hv_vmbus_get_id(struct hv_driver *drv,
 574                                         const uuid_le *guid)
 575 {
 576         const struct hv_vmbus_device_id *id = NULL;
 577         struct vmbus_dynid *dynid;
 578
 579         /* Look at the dynamic ids first, before the static ones */
 580         spin_lock(&drv->dynids.lock);
 581         list_for_each_entry(dynid, &drv->dynids.list, node) {
 582                 if (!uuid_le_cmp(dynid->id.guid, *guid)) {
 583                         id = &dynid->id;
 584                         break;
 585                 }
 586         }
 587         spin_unlock(&drv->dynids.lock);
 588
 589         if (id)
 590                 return id;
 591
 592         id = drv->id_table;
 593         if (id == NULL)
 594                 return NULL; /* empty device table */
 595
 596         for (; !is_null_guid(&id->guid); id++)
 597                 if (!uuid_le_cmp(id->guid, *guid))
 598                         return id;
 599
 600         return NULL;
 601 }
 602
 603 /* vmbus_add_dynid - add a new device ID to this driver and re-probe devices */
 604 static int vmbus_add_dynid(struct hv_driver *drv, uuid_le *guid)
 605 {
 606         struct vmbus_dynid *dynid;
 607
 608         dynid = kzalloc(sizeof(*dynid), GFP_KERNEL);
 609         if (!dynid)
 610                 return -ENOMEM;
 611
 612         dynid->id.guid = *guid;
 613
 614         spin_lock(&drv->dynids.lock);
 615         list_add_tail(&dynid->node, &drv->dynids.list);
 616         spin_unlock(&drv->dynids.lock);
 617
 618         return driver_attach(&drv->driver);
 619 }
 620
 621 static void vmbus_free_dynids(struct hv_driver *drv)
 622 {
 623         struct vmbus_dynid *dynid, *n;
 624
 625         spin_lock(&drv->dynids.lock);
 626         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 627                 list_del(&dynid->node);
 628                 kfree(dynid);
 629         }
 630         spin_unlock(&drv->dynids.lock);
 631 }
 632
 633 /* Parse string of form: 1b4e28ba-2fa1-11d2-883f-b9a761bde3f */
 634 static int get_uuid_le(const char *str, uuid_le *uu)
 635 {
 636         unsigned int b[16];
 637         int i;
 638
 639         if (strlen(str) < 37)
 640                 return -1;
 641
 642         for (i = 0; i < 36; i++) {
 643                 switch (i) {
 644                 case 8: case 13: case 18: case 23:
 645                         if (str[i] != '-')
 646                                 return -1;
 647                         break;
 648                 default:
 649                         if (!isxdigit(str[i]))
 650                                 return -1;
 651                 }
 652         }
 653
 654         /* unparse little endian output byte order */
 655         if (sscanf(str,
 656                    "%2x%2x%2x%2x-%2x%2x-%2x%2x-%2x%2x-%2x%2x%2x%2x%2x%2x",
 657                    &b[3], &b[2], &b[1], &b[0],
 658                    &b[5], &b[4], &b[7], &b[6], &b[8], &b[9],
 659                    &b[10], &b[11], &b[12], &b[13], &b[14], &b[15]) != 16)
 660                 return -1;
 661
 662         for (i = 0; i < 16; i++)
 663                 uu->b[i] = b[i];
 664         return 0;
 665 }
 666
 667 /*
 668  * store_new_id - sysfs frontend to vmbus_add_dynid()
 669  *
 670  * Allow GUIDs to be added to an existing driver via sysfs.
 671  */
 672 static ssize_t new_id_store(struct device_driver *driver, const char *buf,
 673                             size_t count)
 674 {
 675         struct hv_driver *drv = drv_to_hv_drv(driver);
 676         uuid_le guid = NULL_UUID_LE;
 677         ssize_t retval;
 678
 679         if (get_uuid_le(buf, &guid) != 0)
 680                 return -EINVAL;
 681
 682         if (hv_vmbus_get_id(drv, &guid))
 683                 return -EEXIST;
 684
 685         retval = vmbus_add_dynid(drv, &guid);
 686         if (retval)
 687                 return retval;
 688         return count;
 689 }
 690 static DRIVER_ATTR_WO(new_id);
 691
 692 /*
 693  * store_remove_id - remove a PCI device ID from this driver
 694  *
 695  * Removes a dynamic pci device ID to this driver.
 696  */
 697 static ssize_t remove_id_store(struct device_driver *driver, const char *buf,
 698                                size_t count)
 699 {
 700         struct hv_driver *drv = drv_to_hv_drv(driver);
 701         struct vmbus_dynid *dynid, *n;
 702         uuid_le guid = NULL_UUID_LE;
 703         size_t retval = -ENODEV;
 704
 705         if (get_uuid_le(buf, &guid))
 706                 return -EINVAL;
 707
 708         spin_lock(&drv->dynids.lock);
 709         list_for_each_entry_safe(dynid, n, &drv->dynids.list, node) {
 710                 struct hv_vmbus_device_id *id = &dynid->id;
 711
 712                 if (!uuid_le_cmp(id->guid, guid)) {
 713                         list_del(&dynid->node);
 714                         kfree(dynid);
 715                         retval = count;
 716                         break;
 717                 }
 718         }
 719         spin_unlock(&drv->dynids.lock);
 720
 721         return retval;
 722 }
 723 static DRIVER_ATTR_WO(remove_id);
 724
 725 static struct attribute *vmbus_drv_attrs[] = {
 726         &driver_attr_new_id.attr,
 727         &driver_attr_remove_id.attr,
 728         NULL,
 729 };
 730 ATTRIBUTE_GROUPS(vmbus_drv);
 731
 732
 733 /*
 734  * vmbus_match - Attempt to match the specified device to the specified driver
 735  */
 736 static int vmbus_match(struct device *device, struct device_driver *driver)
 737 {
 738         struct hv_driver *drv = drv_to_hv_drv(driver);
 739         struct hv_device *hv_dev = device_to_hv_device(device);
 740
 741         /* The hv_sock driver handles all hv_sock offers. */
 742         if (is_hvsock_channel(hv_dev->channel))
 743                 return drv->hvsock;
 744
 745         if (hv_vmbus_get_id(drv, &hv_dev->dev_type))
 746                 return 1;
 747
 748         return 0;
 749 }
 750
 751 /*
 752  * vmbus_probe - Add the new vmbus's child device
 753  */
 754 static int vmbus_probe(struct device *child_device)
 755 {
 756         int ret = 0;
 757         struct hv_driver *drv =
 758                         drv_to_hv_drv(child_device->driver);
 759         struct hv_device *dev = device_to_hv_device(child_device);
 760         const struct hv_vmbus_device_id *dev_id;
 761
 762         dev_id = hv_vmbus_get_id(drv, &dev->dev_type);
 763         if (drv->probe) {
 764                 ret = drv->probe(dev, dev_id);
 765                 if (ret != 0)
 766                         pr_err("probe failed for device %s (%d)\n",
 767                                dev_name(child_device), ret);
 768
 769         } else {
 770                 pr_err("probe not set for driver %s\n",
 771                        dev_name(child_device));
 772                 ret = -ENODEV;
 773         }
 774         return ret;
 775 }
 776
 777 /*
 778  * vmbus_remove - Remove a vmbus device
 779  */
 780 static int vmbus_remove(struct device *child_device)
 781 {
 782         struct hv_driver *drv;
 783         struct hv_device *dev = device_to_hv_device(child_device);
 784
 785         if (child_device->driver) {
 786                 drv = drv_to_hv_drv(child_device->driver);
 787                 if (drv->remove)
 788                         drv->remove(dev);
 789         }
 790
 791         return 0;
 792 }
 793
 794
 795 /*
 796  * vmbus_shutdown - Shutdown a vmbus device
 797  */
 798 static void vmbus_shutdown(struct device *child_device)
 799 {
 800         struct hv_driver *drv;
 801         struct hv_device *dev = device_to_hv_device(child_device);
 802
 803
 804         /* The device may not be attached yet */
 805         if (!child_device->driver)
 806                 return;
 807
 808         drv = drv_to_hv_drv(child_device->driver);
 809
 810         if (drv->shutdown)
 811                 drv->shutdown(dev);
 812
 813         return;
 814 }
 815
 816
 817 /*
 818  * vmbus_device_release - Final callback release of the vmbus child device
 819  */
 820 static void vmbus_device_release(struct device *device)
 821 {
 822         struct hv_device *hv_dev = device_to_hv_device(device);
 823         struct vmbus_channel *channel = hv_dev->channel;
 824
 825         hv_process_channel_removal(channel,
 826                                    channel->offermsg.child_relid);
 827         kfree(hv_dev);
 828
 829 }
 830
 831 /* The one and only one */
 832 static struct bus_type  hv_bus = {
 833         .name =         "vmbus",
 834         .match =                vmbus_match,
 835         .shutdown =             vmbus_shutdown,
 836         .remove =               vmbus_remove,
 837         .probe =                vmbus_probe,
 838         .uevent =               vmbus_uevent,
 839         .dev_groups =           vmbus_dev_groups,
 840         .drv_groups =           vmbus_drv_groups,
 841 };
 842
 843 struct onmessage_work_context {
 844         struct work_struct work;
 845         struct hv_message msg;
 846 };
 847
 848 static void vmbus_onmessage_work(struct work_struct *work)
 849 {
 850         struct onmessage_work_context *ctx;
 851
 852         /* Do not process messages if we're in DISCONNECTED state */
 853         if (vmbus_connection.conn_state == DISCONNECTED)
 854                 return;
 855
 856         ctx = container_of(work, struct onmessage_work_context,
 857                            work);
 858         vmbus_onmessage(&ctx->msg);
 859         kfree(ctx);
 860 }
 861
 862 static void hv_process_timer_expiration(struct hv_message *msg, int cpu)
 863 {
 864         struct clock_event_device *dev = hv_context.clk_evt[cpu];
 865
 866         if (dev->event_handler)
 867                 dev->event_handler(dev);
 868
 869         vmbus_signal_eom(msg, HVMSG_TIMER_EXPIRED);
 870 }
 871
 872 void vmbus_on_msg_dpc(unsigned long data)
 873 {
 874         int cpu = smp_processor_id();
 875         void *page_addr = hv_context.synic_message_page[cpu];
 876         struct hv_message *msg = (struct hv_message *)page_addr +
 877                                   VMBUS_MESSAGE_SINT;
 878         struct vmbus_channel_message_header *hdr;
 879         struct vmbus_channel_message_table_entry *entry;
 880         struct onmessage_work_context *ctx;
 881         u32 message_type = msg->header.message_type;
 882
 883         if (message_type == HVMSG_NONE)
 884                 /* no msg */
 885                 return;
 886
 887         hdr = (struct vmbus_channel_message_header *)msg->u.payload;
 888
 889         if (hdr->msgtype >= CHANNELMSG_COUNT) {
 890                 WARN_ONCE(1, "unknown msgtype=%d\n", hdr->msgtype);
 891                 goto msg_handled;
 892         }
 893
 894         entry = &channel_message_table[hdr->msgtype];
 895         if (entry->handler_type == VMHT_BLOCKING) {
 896                 ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 897                 if (ctx == NULL)
 898                         return;
 899
 900                 INIT_WORK(&ctx->work, vmbus_onmessage_work);
 901                 memcpy(&ctx->msg, msg, sizeof(*msg));
 902
 903                 queue_work(vmbus_connection.work_queue, &ctx->work);
 904         } else
 905                 entry->message_handler(hdr);
 906
 907 msg_handled:
 908         vmbus_signal_eom(msg, message_type);
 909 }
 910
 911 static void vmbus_isr(void)
 912 {
 913         int cpu = smp_processor_id();
 914         void *page_addr;
 915         struct hv_message *msg;
 916         union hv_synic_event_flags *event;
 917         bool handled = false;
 918
 919         page_addr = hv_context.synic_event_page[cpu];
 920         if (page_addr == NULL)
 921                 return;
 922
 923         event = (union hv_synic_event_flags *)page_addr +
 924                                          VMBUS_MESSAGE_SINT;
 925         /*
 926          * Check for events before checking for messages. This is the order
 927          * in which events and messages are checked in Windows guests on
 928          * Hyper-V, and the Windows team suggested we do the same.
 929          */
 930
 931         if ((vmbus_proto_version == VERSION_WS2008) ||
 932                 (vmbus_proto_version == VERSION_WIN7)) {
 933
 934                 /* Since we are a child, we only need to check bit 0 */
 935                 if (sync_test_and_clear_bit(0,
 936                         (unsigned long *) &event->flags32[0])) {
 937                         handled = true;
 938                 }
 939         } else {
 940                 /*
 941                  * Our host is win8 or above. The signaling mechanism
 942                  * has changed and we can directly look at the event page.
 943                  * If bit n is set then we have an interrup on the channel
 944                  * whose id is n.
 945                  */
 946                 handled = true;
 947         }
 948
 949         if (handled)
 950                 tasklet_schedule(hv_context.event_dpc[cpu]);
 951
 952
 953         page_addr = hv_context.synic_message_page[cpu];
 954         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 955
 956         /* Check if there are actual msgs to be processed */
 957         if (msg->header.message_type != HVMSG_NONE) {
 958                 if (msg->header.message_type == HVMSG_TIMER_EXPIRED)
 959                         hv_process_timer_expiration(msg, cpu);
 960                 else
 961                         tasklet_schedule(hv_context.msg_dpc[cpu]);
 962         }
 963
 964         add_interrupt_randomness(HYPERVISOR_CALLBACK_VECTOR, 0);
 965 }
 966
 967
 968 /*
 969  * vmbus_bus_init -Main vmbus driver initialization routine.
 970  *
 971  * Here, we
 972  *      - initialize the vmbus driver context
 973  *      - invoke the vmbus hv main init routine
 974  *      - retrieve the channel offers
 975  */
 976 static int vmbus_bus_init(void)
 977 {
 978         int ret;
 979
 980         /* Hypervisor initialization...setup hypercall page..etc */
 981         ret = hv_init();
 982         if (ret != 0) {
 983                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 984                 return ret;
 985         }
 986
 987         ret = bus_register(&hv_bus);
 988         if (ret)
 989                 goto err_cleanup;
 990
 991         hv_setup_vmbus_irq(vmbus_isr);
 992
 993         ret = hv_synic_alloc();
 994         if (ret)
 995                 goto err_alloc;
 996         /*
 997          * Initialize the per-cpu interrupt state and
 998          * connect to the host.
 999          */
1000         on_each_cpu(hv_synic_init, NULL, 1);
1001         ret = vmbus_connect();
1002         if (ret)
1003                 goto err_connect;
1004
1005         if (vmbus_proto_version > VERSION_WIN7)
1006                 cpu_hotplug_disable();
1007
1008         /*
1009          * Only register if the crash MSRs are available
1010          */
1011         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1012                 register_die_notifier(&hyperv_die_block);
1013                 atomic_notifier_chain_register(&panic_notifier_list,
1014                                                &hyperv_panic_block);
1015         }
1016
1017         vmbus_request_offers();
1018
1019         return 0;
1020
1021 err_connect:
1022         on_each_cpu(hv_synic_cleanup, NULL, 1);
1023 err_alloc:
1024         hv_synic_free();
1025         hv_remove_vmbus_irq();
1026
1027         bus_unregister(&hv_bus);
1028
1029 err_cleanup:
1030         hv_cleanup(false);
1031
1032         return ret;
1033 }
1034
1035 /**
1036  * __vmbus_child_driver_register() - Register a vmbus's driver
1037  * @hv_driver: Pointer to driver structure you want to register
1038  * @owner: owner module of the drv
1039  * @mod_name: module name string
1040  *
1041  * Registers the given driver with Linux through the 'driver_register()' call
1042  * and sets up the hyper-v vmbus handling for this driver.
1043  * It will return the state of the 'driver_register()' call.
1044  *
1045  */
1046 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
1047 {
1048         int ret;
1049
1050         pr_info("registering driver %s\n", hv_driver->name);
1051
1052         ret = vmbus_exists();
1053         if (ret < 0)
1054                 return ret;
1055
1056         hv_driver->driver.name = hv_driver->name;
1057         hv_driver->driver.owner = owner;
1058         hv_driver->driver.mod_name = mod_name;
1059         hv_driver->driver.bus = &hv_bus;
1060
1061         spin_lock_init(&hv_driver->dynids.lock);
1062         INIT_LIST_HEAD(&hv_driver->dynids.list);
1063
1064         ret = driver_register(&hv_driver->driver);
1065
1066         return ret;
1067 }
1068 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
1069
1070 /**
1071  * vmbus_driver_unregister() - Unregister a vmbus's driver
1072  * @hv_driver: Pointer to driver structure you want to
1073  *             un-register
1074  *
1075  * Un-register the given driver that was previous registered with a call to
1076  * vmbus_driver_register()
1077  */
1078 void vmbus_driver_unregister(struct hv_driver *hv_driver)
1079 {
1080         pr_info("unregistering driver %s\n", hv_driver->name);
1081
1082         if (!vmbus_exists()) {
1083                 driver_unregister(&hv_driver->driver);
1084                 vmbus_free_dynids(hv_driver);
1085         }
1086 }
1087 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
1088
1089 /*
1090  * vmbus_device_create - Creates and registers a new child device
1091  * on the vmbus.
1092  */
1093 struct hv_device *vmbus_device_create(const uuid_le *type,
1094                                       const uuid_le *instance,
1095                                       struct vmbus_channel *channel)
1096 {
1097         struct hv_device *child_device_obj;
1098
1099         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
1100         if (!child_device_obj) {
1101                 pr_err("Unable to allocate device object for child device\n");
1102                 return NULL;
1103         }
1104
1105         child_device_obj->channel = channel;
1106         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
1107         memcpy(&child_device_obj->dev_instance, instance,
1108                sizeof(uuid_le));
1109         child_device_obj->vendor_id = 0x1414; /* MSFT vendor ID */
1110
1111
1112         return child_device_obj;
1113 }
1114
1115 /*
1116  * vmbus_device_register - Register the child device
1117  */
1118 int vmbus_device_register(struct hv_device *child_device_obj)
1119 {
1120         int ret = 0;
1121
1122         dev_set_name(&child_device_obj->device, "%pUl",
1123                      child_device_obj->channel->offermsg.offer.if_instance.b);
1124
1125         child_device_obj->device.bus = &hv_bus;
1126         child_device_obj->device.parent = &hv_acpi_dev->dev;
1127         child_device_obj->device.release = vmbus_device_release;
1128
1129         /*
1130          * Register with the LDM. This will kick off the driver/device
1131          * binding...which will eventually call vmbus_match() and vmbus_probe()
1132          */
1133         ret = device_register(&child_device_obj->device);
1134
1135         if (ret)
1136                 pr_err("Unable to register child device\n");
1137         else
1138                 pr_debug("child device %s registered\n",
1139                         dev_name(&child_device_obj->device));
1140
1141         return ret;
1142 }
1143
1144 /*
1145  * vmbus_device_unregister - Remove the specified child device
1146  * from the vmbus.
1147  */
1148 void vmbus_device_unregister(struct hv_device *device_obj)
1149 {
1150         pr_debug("child device %s unregistered\n",
1151                 dev_name(&device_obj->device));
1152
1153         /*
1154          * Kick off the process of unregistering the device.
1155          * This will call vmbus_remove() and eventually vmbus_device_release()
1156          */
1157         device_unregister(&device_obj->device);
1158 }
1159
1160
1161 /*
1162  * VMBUS is an acpi enumerated device. Get the information we
1163  * need from DSDT.
1164  */
1165 #define VTPM_BASE_ADDRESS 0xfed40000
1166 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *ctx)
1167 {
1168         resource_size_t start = 0;
1169         resource_size_t end = 0;
1170         struct resource *new_res;
1171         struct resource **old_res = &hyperv_mmio;
1172         struct resource **prev_res = NULL;
1173
1174         switch (res->type) {
1175
1176         /*
1177          * "Address" descriptors are for bus windows. Ignore
1178          * "memory" descriptors, which are for registers on
1179          * devices.
1180          */
1181         case ACPI_RESOURCE_TYPE_ADDRESS32:
1182                 start = res->data.address32.address.minimum;
1183                 end = res->data.address32.address.maximum;
1184                 break;
1185
1186         case ACPI_RESOURCE_TYPE_ADDRESS64:
1187                 start = res->data.address64.address.minimum;
1188                 end = res->data.address64.address.maximum;
1189                 break;
1190
1191         default:
1192                 /* Unused resource type */
1193                 return AE_OK;
1194
1195         }
1196         /*
1197          * Ignore ranges that are below 1MB, as they're not
1198          * necessary or useful here.
1199          */
1200         if (end < 0x100000)
1201                 return AE_OK;
1202
1203         new_res = kzalloc(sizeof(*new_res), GFP_ATOMIC);
1204         if (!new_res)
1205                 return AE_NO_MEMORY;
1206
1207         /* If this range overlaps the virtual TPM, truncate it. */
1208         if (end > VTPM_BASE_ADDRESS && start < VTPM_BASE_ADDRESS)
1209                 end = VTPM_BASE_ADDRESS;
1210
1211         new_res->name = "hyperv mmio";
1212         new_res->flags = IORESOURCE_MEM;
1213         new_res->start = start;
1214         new_res->end = end;
1215
1216         /*
1217          * If two ranges are adjacent, merge them.
1218          */
1219         do {
1220                 if (!*old_res) {
1221                         *old_res = new_res;
1222                         break;
1223                 }
1224
1225                 if (((*old_res)->end + 1) == new_res->start) {
1226                         (*old_res)->end = new_res->end;
1227                         kfree(new_res);
1228                         break;
1229                 }
1230
1231                 if ((*old_res)->start == new_res->end + 1) {
1232                         (*old_res)->start = new_res->start;
1233                         kfree(new_res);
1234                         break;
1235                 }
1236
1237                 if ((*old_res)->start > new_res->end) {
1238                         new_res->sibling = *old_res;
1239                         if (prev_res)
1240                                 (*prev_res)->sibling = new_res;
1241                         *old_res = new_res;
1242                         break;
1243                 }
1244
1245                 prev_res = old_res;
1246                 old_res = &(*old_res)->sibling;
1247
1248         } while (1);
1249
1250         return AE_OK;
1251 }
1252
1253 static int vmbus_acpi_remove(struct acpi_device *device)
1254 {
1255         struct resource *cur_res;
1256         struct resource *next_res;
1257
1258         if (hyperv_mmio) {
1259                 if (fb_mmio) {
1260                         __release_region(hyperv_mmio, fb_mmio->start,
1261                                          resource_size(fb_mmio));
1262                         fb_mmio = NULL;
1263                 }
1264
1265                 for (cur_res = hyperv_mmio; cur_res; cur_res = next_res) {
1266                         next_res = cur_res->sibling;
1267                         kfree(cur_res);
1268                 }
1269         }
1270
1271         return 0;
1272 }
1273
1274 static void vmbus_reserve_fb(void)
1275 {
1276         int size;
1277         /*
1278          * Make a claim for the frame buffer in the resource tree under the
1279          * first node, which will be the one below 4GB.  The length seems to
1280          * be underreported, particularly in a Generation 1 VM.  So start out
1281          * reserving a larger area and make it smaller until it succeeds.
1282          */
1283
1284         if (screen_info.lfb_base) {
1285                 if (efi_enabled(EFI_BOOT))
1286                         size = max_t(__u32, screen_info.lfb_size, 0x800000);
1287                 else
1288                         size = max_t(__u32, screen_info.lfb_size, 0x4000000);
1289
1290                 for (; !fb_mmio && (size >= 0x100000); size >>= 1) {
1291                         fb_mmio = __request_region(hyperv_mmio,
1292                                                    screen_info.lfb_base, size,
1293                                                    fb_mmio_name, 0);
1294                 }
1295         }
1296 }
1297
1298 /**
1299  * vmbus_allocate_mmio() - Pick a memory-mapped I/O range.
1300  * @new:                If successful, supplied a pointer to the
1301  *                      allocated MMIO space.
1302  * @device_obj:         Identifies the caller
1303  * @min:                Minimum guest physical address of the
1304  *                      allocation
1305  * @max:                Maximum guest physical address
1306  * @size:               Size of the range to be allocated
1307  * @align:              Alignment of the range to be allocated
1308  * @fb_overlap_ok:      Whether this allocation can be allowed
1309  *                      to overlap the video frame buffer.
1310  *
1311  * This function walks the resources granted to VMBus by the
1312  * _CRS object in the ACPI namespace underneath the parent
1313  * "bridge" whether that's a root PCI bus in the Generation 1
1314  * case or a Module Device in the Generation 2 case.  It then
1315  * attempts to allocate from the global MMIO pool in a way that
1316  * matches the constraints supplied in these parameters and by
1317  * that _CRS.
1318  *
1319  * Return: 0 on success, -errno on failure
1320  */
1321 int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
1322                         resource_size_t min, resource_size_t max,
1323                         resource_size_t size, resource_size_t align,
1324                         bool fb_overlap_ok)
1325 {
1326         struct resource *iter, *shadow;
1327         resource_size_t range_min, range_max, start;
1328         const char *dev_n = dev_name(&device_obj->device);
1329         int retval;
1330
1331         retval = -ENXIO;
1332         down(&hyperv_mmio_lock);
1333
1334         /*
1335          * If overlaps with frame buffers are allowed, then first attempt to
1336          * make the allocation from within the reserved region.  Because it
1337          * is already reserved, no shadow allocation is necessary.
1338          */
1339         if (fb_overlap_ok && fb_mmio && !(min > fb_mmio->end) &&
1340             !(max < fb_mmio->start)) {
1341
1342                 range_min = fb_mmio->start;
1343                 range_max = fb_mmio->end;
1344                 start = (range_min + align - 1) & ~(align - 1);
1345                 for (; start + size - 1 <= range_max; start += align) {
1346                         *new = request_mem_region_exclusive(start, size, dev_n);
1347                         if (*new) {
1348                                 retval = 0;
1349                                 goto exit;
1350                         }
1351                 }
1352         }
1353
1354         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1355                 if ((iter->start >= max) || (iter->end <= min))
1356                         continue;
1357
1358                 range_min = iter->start;
1359                 range_max = iter->end;
1360                 start = (range_min + align - 1) & ~(align - 1);
1361                 for (; start + size - 1 <= range_max; start += align) {
1362                         shadow = __request_region(iter, start, size, NULL,
1363                                                   IORESOURCE_BUSY);
1364                         if (!shadow)
1365                                 continue;
1366
1367                         *new = request_mem_region_exclusive(start, size, dev_n);
1368                         if (*new) {
1369                                 shadow->name = (char *)*new;
1370                                 retval = 0;
1371                                 goto exit;
1372                         }
1373
1374                         __release_region(iter, start, size);
1375                 }
1376         }
1377
1378 exit:
1379         up(&hyperv_mmio_lock);
1380         return retval;
1381 }
1382 EXPORT_SYMBOL_GPL(vmbus_allocate_mmio);
1383
1384 /**
1385  * vmbus_free_mmio() - Free a memory-mapped I/O range.
1386  * @start:              Base address of region to release.
1387  * @size:               Size of the range to be allocated
1388  *
1389  * This function releases anything requested by
1390  * vmbus_mmio_allocate().
1391  */
1392 void vmbus_free_mmio(resource_size_t start, resource_size_t size)
1393 {
1394         struct resource *iter;
1395
1396         down(&hyperv_mmio_lock);
1397         for (iter = hyperv_mmio; iter; iter = iter->sibling) {
1398                 if ((iter->start >= start + size) || (iter->end <= start))
1399                         continue;
1400
1401                 __release_region(iter, start, size);
1402         }
1403         release_mem_region(start, size);
1404         up(&hyperv_mmio_lock);
1405
1406 }
1407 EXPORT_SYMBOL_GPL(vmbus_free_mmio);
1408
1409 /**
1410  * vmbus_cpu_number_to_vp_number() - Map CPU to VP.
1411  * @cpu_number: CPU number in Linux terms
1412  *
1413  * This function returns the mapping between the Linux processor
1414  * number and the hypervisor's virtual processor number, useful
1415  * in making hypercalls and such that talk about specific
1416  * processors.
1417  *
1418  * Return: Virtual processor number in Hyper-V terms
1419  */
1420 int vmbus_cpu_number_to_vp_number(int cpu_number)
1421 {
1422         return hv_context.vp_index[cpu_number];
1423 }
1424 EXPORT_SYMBOL_GPL(vmbus_cpu_number_to_vp_number);
1425
1426 static int vmbus_acpi_add(struct acpi_device *device)
1427 {
1428         acpi_status result;
1429         int ret_val = -ENODEV;
1430         struct acpi_device *ancestor;
1431
1432         hv_acpi_dev = device;
1433
1434         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
1435                                         vmbus_walk_resources, NULL);
1436
1437         if (ACPI_FAILURE(result))
1438                 goto acpi_walk_err;
1439         /*
1440          * Some ancestor of the vmbus acpi device (Gen1 or Gen2
1441          * firmware) is the VMOD that has the mmio ranges. Get that.
1442          */
1443         for (ancestor = device->parent; ancestor; ancestor = ancestor->parent) {
1444                 result = acpi_walk_resources(ancestor->handle, METHOD_NAME__CRS,
1445                                              vmbus_walk_resources, NULL);
1446
1447                 if (ACPI_FAILURE(result))
1448                         continue;
1449                 if (hyperv_mmio) {
1450                         vmbus_reserve_fb();
1451                         break;
1452                 }
1453         }
1454         ret_val = 0;
1455
1456 acpi_walk_err:
1457         complete(&probe_event);
1458         if (ret_val)
1459                 vmbus_acpi_remove(device);
1460         return ret_val;
1461 }
1462
1463 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
1464         {"VMBUS", 0},
1465         {"VMBus", 0},
1466         {"", 0},
1467 };
1468 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
1469
1470 static struct acpi_driver vmbus_acpi_driver = {
1471         .name = "vmbus",
1472         .ids = vmbus_acpi_device_ids,
1473         .ops = {
1474                 .add = vmbus_acpi_add,
1475                 .remove = vmbus_acpi_remove,
1476         },
1477 };
1478
1479 static void hv_kexec_handler(void)
1480 {
1481         int cpu;
1482
1483         hv_synic_clockevents_cleanup();
1484         vmbus_initiate_unload(false);
1485         for_each_online_cpu(cpu)
1486                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1487         hv_cleanup(false);
1488 };
1489
1490 static void hv_crash_handler(struct pt_regs *regs)
1491 {
1492         vmbus_initiate_unload(true);
1493         /*
1494          * In crash handler we can't schedule synic cleanup for all CPUs,
1495          * doing the cleanup for current CPU only. This should be sufficient
1496          * for kdump.
1497          */
1498         hv_synic_cleanup(NULL);
1499         hv_cleanup(true);
1500 };
1501
1502 static int __init hv_acpi_init(void)
1503 {
1504         int ret, t;
1505
1506         if (x86_hyper != &x86_hyper_ms_hyperv)
1507                 return -ENODEV;
1508
1509         init_completion(&probe_event);
1510
1511         /*
1512          * Get ACPI resources first.
1513          */
1514         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
1515
1516         if (ret)
1517                 return ret;
1518
1519         t = wait_for_completion_timeout(&probe_event, 5*HZ);
1520         if (t == 0) {
1521                 ret = -ETIMEDOUT;
1522                 goto cleanup;
1523         }
1524
1525         ret = vmbus_bus_init();
1526         if (ret)
1527                 goto cleanup;
1528
1529         hv_setup_kexec_handler(hv_kexec_handler);
1530         hv_setup_crash_handler(hv_crash_handler);
1531
1532         return 0;
1533
1534 cleanup:
1535         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1536         hv_acpi_dev = NULL;
1537         return ret;
1538 }
1539
1540 static void __exit vmbus_exit(void)
1541 {
1542         int cpu;
1543
1544         hv_remove_kexec_handler();
1545         hv_remove_crash_handler();
1546         vmbus_connection.conn_state = DISCONNECTED;
1547         hv_synic_clockevents_cleanup();
1548         vmbus_disconnect();
1549         hv_remove_vmbus_irq();
1550         for_each_online_cpu(cpu)
1551                 tasklet_kill(hv_context.msg_dpc[cpu]);
1552         vmbus_free_channels();
1553         if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
1554                 unregister_die_notifier(&hyperv_die_block);
1555                 atomic_notifier_chain_unregister(&panic_notifier_list,
1556                                                  &hyperv_panic_block);
1557         }
1558         bus_unregister(&hv_bus);
1559         hv_cleanup(false);
1560         for_each_online_cpu(cpu) {
1561                 tasklet_kill(hv_context.event_dpc[cpu]);
1562                 smp_call_function_single(cpu, hv_synic_cleanup, NULL, 1);
1563         }
1564         hv_synic_free();
1565         acpi_bus_unregister_driver(&vmbus_acpi_driver);
1566         if (vmbus_proto_version > VERSION_WIN7)
1567                 cpu_hotplug_enable();
1568 }
1569
1570
1571 MODULE_LICENSE("GPL");
1572
1573 subsys_initcall(hv_acpi_init);
1574 module_exit(vmbus_exit);