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/irq.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/sysctl.h>
  31 #include <linux/slab.h>
  32 #include <linux/acpi.h>
  33 #include <acpi/acpi_bus.h>
  34 #include <linux/completion.h>
  35 #include <linux/hyperv.h>
  36 #include <linux/kernel_stat.h>
  37 #include <asm/hyperv.h>
  38 #include <asm/hypervisor.h>
  39 #include <asm/mshyperv.h>
  40 #include "hyperv_vmbus.h"
  41
  42
  43 static struct acpi_device  *hv_acpi_dev;
  44
  45 static struct tasklet_struct msg_dpc;
  46 static struct completion probe_event;
  47 static int irq;
  48
  49 struct hv_device_info {
  50         struct hv_dev_port_info inbound;
  51         struct hv_dev_port_info outbound;
  52 };
  53
  54 static int vmbus_exists(void)
  55 {
  56         if (hv_acpi_dev == NULL)
  57                 return -ENODEV;
  58
  59         return 0;
  60 }
  61
  62
  63 static void get_channel_info(struct hv_device *device,
  64                              struct hv_device_info *info)
  65 {
  66         struct vmbus_channel_debug_info debug_info;
  67
  68         if (!device->channel)
  69                 return;
  70
  71         vmbus_get_debug_info(device->channel, &debug_info);
  72
  73         info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
  74         info->inbound.read_idx = debug_info.inbound.current_read_index;
  75         info->inbound.write_idx = debug_info.inbound.current_write_index;
  76         info->inbound.bytes_avail_toread =
  77                 debug_info.inbound.bytes_avail_toread;
  78         info->inbound.bytes_avail_towrite =
  79                 debug_info.inbound.bytes_avail_towrite;
  80
  81         info->outbound.int_mask =
  82                 debug_info.outbound.current_interrupt_mask;
  83         info->outbound.read_idx = debug_info.outbound.current_read_index;
  84         info->outbound.write_idx = debug_info.outbound.current_write_index;
  85         info->outbound.bytes_avail_toread =
  86                 debug_info.outbound.bytes_avail_toread;
  87         info->outbound.bytes_avail_towrite =
  88                 debug_info.outbound.bytes_avail_towrite;
  89 }
  90
  91 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
  92 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
  93 {
  94         int i;
  95         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
  96                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
  97 }
  98
  99 /*
 100  * vmbus_show_device_attr - Show the device attribute in sysfs.
 101  *
 102  * This is invoked when user does a
 103  * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
 104  */
 105 static ssize_t vmbus_show_device_attr(struct device *dev,
 106                                       struct device_attribute *dev_attr,
 107                                       char *buf)
 108 {
 109         struct hv_device *hv_dev = device_to_hv_device(dev);
 110         struct hv_device_info *device_info;
 111         int ret = 0;
 112
 113         device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
 114         if (!device_info)
 115                 return ret;
 116
 117         get_channel_info(hv_dev, device_info);
 118
 119         if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
 120                 ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
 121         } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
 122                 ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
 123         } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
 124                 ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
 125         } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
 126                 ret = sprintf(buf, "%d\n",
 127                                device_info->outbound.bytes_avail_toread);
 128         } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
 129                 ret = sprintf(buf, "%d\n",
 130                                device_info->outbound.bytes_avail_towrite);
 131         } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
 132                 ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
 133         } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
 134                 ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
 135         } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
 136                 ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
 137         } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
 138                 ret = sprintf(buf, "%d\n",
 139                                device_info->inbound.bytes_avail_toread);
 140         } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
 141                 ret = sprintf(buf, "%d\n",
 142                                device_info->inbound.bytes_avail_towrite);
 143         }
 144
 145         kfree(device_info);
 146         return ret;
 147 }
 148
 149 static u8 channel_monitor_group(struct vmbus_channel *channel)
 150 {
 151         return (u8)channel->offermsg.monitorid / 32;
 152 }
 153
 154 static u8 channel_monitor_offset(struct vmbus_channel *channel)
 155 {
 156         return (u8)channel->offermsg.monitorid % 32;
 157 }
 158
 159 static u32 channel_pending(struct vmbus_channel *channel,
 160                            struct hv_monitor_page *monitor_page)
 161 {
 162         u8 monitor_group = channel_monitor_group(channel);
 163         return monitor_page->trigger_group[monitor_group].pending;
 164 }
 165
 166 static u32 channel_latency(struct vmbus_channel *channel,
 167                            struct hv_monitor_page *monitor_page)
 168 {
 169         u8 monitor_group = channel_monitor_group(channel);
 170         u8 monitor_offset = channel_monitor_offset(channel);
 171         return monitor_page->latency[monitor_group][monitor_offset];
 172 }
 173
 174 static u32 channel_conn_id(struct vmbus_channel *channel,
 175                            struct hv_monitor_page *monitor_page)
 176 {
 177         u8 monitor_group = channel_monitor_group(channel);
 178         u8 monitor_offset = channel_monitor_offset(channel);
 179         return monitor_page->parameter[monitor_group][monitor_offset].connectionid.u.id;
 180 }
 181
 182 static ssize_t id_show(struct device *dev, struct device_attribute *dev_attr,
 183                        char *buf)
 184 {
 185         struct hv_device *hv_dev = device_to_hv_device(dev);
 186
 187         if (!hv_dev->channel)
 188                 return -ENODEV;
 189         return sprintf(buf, "%d\n", hv_dev->channel->offermsg.child_relid);
 190 }
 191 static DEVICE_ATTR_RO(id);
 192
 193 static ssize_t state_show(struct device *dev, struct device_attribute *dev_attr,
 194                           char *buf)
 195 {
 196         struct hv_device *hv_dev = device_to_hv_device(dev);
 197
 198         if (!hv_dev->channel)
 199                 return -ENODEV;
 200         return sprintf(buf, "%d\n", hv_dev->channel->state);
 201 }
 202 static DEVICE_ATTR_RO(state);
 203
 204 static ssize_t monitor_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, "%d\n", hv_dev->channel->offermsg.monitorid);
 212 }
 213 static DEVICE_ATTR_RO(monitor_id);
 214
 215 static ssize_t class_id_show(struct device *dev,
 216                                struct device_attribute *dev_attr, char *buf)
 217 {
 218         struct hv_device *hv_dev = device_to_hv_device(dev);
 219
 220         if (!hv_dev->channel)
 221                 return -ENODEV;
 222         return sprintf(buf, "{%pUl}\n",
 223                        hv_dev->channel->offermsg.offer.if_type.b);
 224 }
 225 static DEVICE_ATTR_RO(class_id);
 226
 227 static ssize_t device_id_show(struct device *dev,
 228                               struct device_attribute *dev_attr, char *buf)
 229 {
 230         struct hv_device *hv_dev = device_to_hv_device(dev);
 231
 232         if (!hv_dev->channel)
 233                 return -ENODEV;
 234         return sprintf(buf, "{%pUl}\n",
 235                        hv_dev->channel->offermsg.offer.if_instance.b);
 236 }
 237 static DEVICE_ATTR_RO(device_id);
 238
 239 static ssize_t modalias_show(struct device *dev,
 240                              struct device_attribute *dev_attr, char *buf)
 241 {
 242         struct hv_device *hv_dev = device_to_hv_device(dev);
 243         char alias_name[VMBUS_ALIAS_LEN + 1];
 244
 245         print_alias_name(hv_dev, alias_name);
 246         return sprintf(buf, "vmbus:%s\n", alias_name);
 247 }
 248 static DEVICE_ATTR_RO(modalias);
 249
 250 static ssize_t server_monitor_pending_show(struct device *dev,
 251                                            struct device_attribute *dev_attr,
 252                                            char *buf)
 253 {
 254         struct hv_device *hv_dev = device_to_hv_device(dev);
 255
 256         if (!hv_dev->channel)
 257                 return -ENODEV;
 258         return sprintf(buf, "%d\n",
 259                        channel_pending(hv_dev->channel,
 260                                        vmbus_connection.monitor_pages[1]));
 261 }
 262 static DEVICE_ATTR_RO(server_monitor_pending);
 263
 264 static ssize_t client_monitor_pending_show(struct device *dev,
 265                                            struct device_attribute *dev_attr,
 266                                            char *buf)
 267 {
 268         struct hv_device *hv_dev = device_to_hv_device(dev);
 269
 270         if (!hv_dev->channel)
 271                 return -ENODEV;
 272         return sprintf(buf, "%d\n",
 273                        channel_pending(hv_dev->channel,
 274                                        vmbus_connection.monitor_pages[1]));
 275 }
 276 static DEVICE_ATTR_RO(client_monitor_pending);
 277
 278 static ssize_t server_monitor_latency_show(struct device *dev,
 279                                            struct device_attribute *dev_attr,
 280                                            char *buf)
 281 {
 282         struct hv_device *hv_dev = device_to_hv_device(dev);
 283
 284         if (!hv_dev->channel)
 285                 return -ENODEV;
 286         return sprintf(buf, "%d\n",
 287                        channel_latency(hv_dev->channel,
 288                                        vmbus_connection.monitor_pages[0]));
 289 }
 290 static DEVICE_ATTR_RO(server_monitor_latency);
 291
 292 static ssize_t client_monitor_latency_show(struct device *dev,
 293                                            struct device_attribute *dev_attr,
 294                                            char *buf)
 295 {
 296         struct hv_device *hv_dev = device_to_hv_device(dev);
 297
 298         if (!hv_dev->channel)
 299                 return -ENODEV;
 300         return sprintf(buf, "%d\n",
 301                        channel_latency(hv_dev->channel,
 302                                        vmbus_connection.monitor_pages[1]));
 303 }
 304 static DEVICE_ATTR_RO(client_monitor_latency);
 305
 306 static ssize_t server_monitor_conn_id_show(struct device *dev,
 307                                            struct device_attribute *dev_attr,
 308                                            char *buf)
 309 {
 310         struct hv_device *hv_dev = device_to_hv_device(dev);
 311
 312         if (!hv_dev->channel)
 313                 return -ENODEV;
 314         return sprintf(buf, "%d\n",
 315                        channel_conn_id(hv_dev->channel,
 316                                        vmbus_connection.monitor_pages[0]));
 317 }
 318 static DEVICE_ATTR_RO(server_monitor_conn_id);
 319
 320 static ssize_t client_monitor_conn_id_show(struct device *dev,
 321                                            struct device_attribute *dev_attr,
 322                                            char *buf)
 323 {
 324         struct hv_device *hv_dev = device_to_hv_device(dev);
 325
 326         if (!hv_dev->channel)
 327                 return -ENODEV;
 328         return sprintf(buf, "%d\n",
 329                        channel_conn_id(hv_dev->channel,
 330                                        vmbus_connection.monitor_pages[1]));
 331 }
 332 static DEVICE_ATTR_RO(client_monitor_conn_id);
 333
 334 static struct attribute *vmbus_attrs[] = {
 335         &dev_attr_id.attr,
 336         &dev_attr_state.attr,
 337         &dev_attr_monitor_id.attr,
 338         &dev_attr_class_id.attr,
 339         &dev_attr_device_id.attr,
 340         &dev_attr_modalias.attr,
 341         &dev_attr_server_monitor_pending.attr,
 342         &dev_attr_client_monitor_pending.attr,
 343         &dev_attr_server_monitor_latency.attr,
 344         &dev_attr_client_monitor_latency.attr,
 345         &dev_attr_server_monitor_conn_id.attr,
 346         &dev_attr_client_monitor_conn_id.attr,
 347         NULL,
 348 };
 349 ATTRIBUTE_GROUPS(vmbus);
 350
 351 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 352 static struct device_attribute vmbus_device_attrs[] = {
 353         __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 354         __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 355         __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 356         __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 357         __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 358
 359         __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 360         __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 361         __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 362         __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 363         __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 364         __ATTR_NULL
 365 };
 366
 367
 368 /*
 369  * vmbus_uevent - add uevent for our device
 370  *
 371  * This routine is invoked when a device is added or removed on the vmbus to
 372  * generate a uevent to udev in the userspace. The udev will then look at its
 373  * rule and the uevent generated here to load the appropriate driver
 374  *
 375  * The alias string will be of the form vmbus:guid where guid is the string
 376  * representation of the device guid (each byte of the guid will be
 377  * represented with two hex characters.
 378  */
 379 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 380 {
 381         struct hv_device *dev = device_to_hv_device(device);
 382         int ret;
 383         char alias_name[VMBUS_ALIAS_LEN + 1];
 384
 385         print_alias_name(dev, alias_name);
 386         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 387         return ret;
 388 }
 389
 390 static uuid_le null_guid;
 391
 392 static inline bool is_null_guid(const __u8 *guid)
 393 {
 394         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 395                 return false;
 396         return true;
 397 }
 398
 399 /*
 400  * Return a matching hv_vmbus_device_id pointer.
 401  * If there is no match, return NULL.
 402  */
 403 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 404                                         const struct hv_vmbus_device_id *id,
 405                                         __u8 *guid)
 406 {
 407         for (; !is_null_guid(id->guid); id++)
 408                 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 409                         return id;
 410
 411         return NULL;
 412 }
 413
 414
 415
 416 /*
 417  * vmbus_match - Attempt to match the specified device to the specified driver
 418  */
 419 static int vmbus_match(struct device *device, struct device_driver *driver)
 420 {
 421         struct hv_driver *drv = drv_to_hv_drv(driver);
 422         struct hv_device *hv_dev = device_to_hv_device(device);
 423
 424         if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 425                 return 1;
 426
 427         return 0;
 428 }
 429
 430 /*
 431  * vmbus_probe - Add the new vmbus's child device
 432  */
 433 static int vmbus_probe(struct device *child_device)
 434 {
 435         int ret = 0;
 436         struct hv_driver *drv =
 437                         drv_to_hv_drv(child_device->driver);
 438         struct hv_device *dev = device_to_hv_device(child_device);
 439         const struct hv_vmbus_device_id *dev_id;
 440
 441         dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 442         if (drv->probe) {
 443                 ret = drv->probe(dev, dev_id);
 444                 if (ret != 0)
 445                         pr_err("probe failed for device %s (%d)\n",
 446                                dev_name(child_device), ret);
 447
 448         } else {
 449                 pr_err("probe not set for driver %s\n",
 450                        dev_name(child_device));
 451                 ret = -ENODEV;
 452         }
 453         return ret;
 454 }
 455
 456 /*
 457  * vmbus_remove - Remove a vmbus device
 458  */
 459 static int vmbus_remove(struct device *child_device)
 460 {
 461         struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
 462         struct hv_device *dev = device_to_hv_device(child_device);
 463
 464         if (drv->remove)
 465                 drv->remove(dev);
 466         else
 467                 pr_err("remove not set for driver %s\n",
 468                         dev_name(child_device));
 469
 470         return 0;
 471 }
 472
 473
 474 /*
 475  * vmbus_shutdown - Shutdown a vmbus device
 476  */
 477 static void vmbus_shutdown(struct device *child_device)
 478 {
 479         struct hv_driver *drv;
 480         struct hv_device *dev = device_to_hv_device(child_device);
 481
 482
 483         /* The device may not be attached yet */
 484         if (!child_device->driver)
 485                 return;
 486
 487         drv = drv_to_hv_drv(child_device->driver);
 488
 489         if (drv->shutdown)
 490                 drv->shutdown(dev);
 491
 492         return;
 493 }
 494
 495
 496 /*
 497  * vmbus_device_release - Final callback release of the vmbus child device
 498  */
 499 static void vmbus_device_release(struct device *device)
 500 {
 501         struct hv_device *hv_dev = device_to_hv_device(device);
 502
 503         kfree(hv_dev);
 504
 505 }
 506
 507 /* The one and only one */
 508 static struct bus_type  hv_bus = {
 509         .name =         "vmbus",
 510         .match =                vmbus_match,
 511         .shutdown =             vmbus_shutdown,
 512         .remove =               vmbus_remove,
 513         .probe =                vmbus_probe,
 514         .uevent =               vmbus_uevent,
 515         .dev_attrs =    vmbus_device_attrs,
 516         .dev_groups =           vmbus_groups,
 517 };
 518
 519 static const char *driver_name = "hyperv";
 520
 521
 522 struct onmessage_work_context {
 523         struct work_struct work;
 524         struct hv_message msg;
 525 };
 526
 527 static void vmbus_onmessage_work(struct work_struct *work)
 528 {
 529         struct onmessage_work_context *ctx;
 530
 531         ctx = container_of(work, struct onmessage_work_context,
 532                            work);
 533         vmbus_onmessage(&ctx->msg);
 534         kfree(ctx);
 535 }
 536
 537 static void vmbus_on_msg_dpc(unsigned long data)
 538 {
 539         int cpu = smp_processor_id();
 540         void *page_addr = hv_context.synic_message_page[cpu];
 541         struct hv_message *msg = (struct hv_message *)page_addr +
 542                                   VMBUS_MESSAGE_SINT;
 543         struct onmessage_work_context *ctx;
 544
 545         while (1) {
 546                 if (msg->header.message_type == HVMSG_NONE) {
 547                         /* no msg */
 548                         break;
 549                 } else {
 550                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 551                         if (ctx == NULL)
 552                                 continue;
 553                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
 554                         memcpy(&ctx->msg, msg, sizeof(*msg));
 555                         queue_work(vmbus_connection.work_queue, &ctx->work);
 556                 }
 557
 558                 msg->header.message_type = HVMSG_NONE;
 559
 560                 /*
 561                  * Make sure the write to MessageType (ie set to
 562                  * HVMSG_NONE) happens before we read the
 563                  * MessagePending and EOMing. Otherwise, the EOMing
 564                  * will not deliver any more messages since there is
 565                  * no empty slot
 566                  */
 567                 mb();
 568
 569                 if (msg->header.message_flags.msg_pending) {
 570                         /*
 571                          * This will cause message queue rescan to
 572                          * possibly deliver another msg from the
 573                          * hypervisor
 574                          */
 575                         wrmsrl(HV_X64_MSR_EOM, 0);
 576                 }
 577         }
 578 }
 579
 580 static irqreturn_t vmbus_isr(int irq, void *dev_id)
 581 {
 582         int cpu = smp_processor_id();
 583         void *page_addr;
 584         struct hv_message *msg;
 585         union hv_synic_event_flags *event;
 586         bool handled = false;
 587
 588         page_addr = hv_context.synic_event_page[cpu];
 589         if (page_addr == NULL)
 590                 return IRQ_NONE;
 591
 592         event = (union hv_synic_event_flags *)page_addr +
 593                                          VMBUS_MESSAGE_SINT;
 594         /*
 595          * Check for events before checking for messages. This is the order
 596          * in which events and messages are checked in Windows guests on
 597          * Hyper-V, and the Windows team suggested we do the same.
 598          */
 599
 600         if ((vmbus_proto_version == VERSION_WS2008) ||
 601                 (vmbus_proto_version == VERSION_WIN7)) {
 602
 603                 /* Since we are a child, we only need to check bit 0 */
 604                 if (sync_test_and_clear_bit(0,
 605                         (unsigned long *) &event->flags32[0])) {
 606                         handled = true;
 607                 }
 608         } else {
 609                 /*
 610                  * Our host is win8 or above. The signaling mechanism
 611                  * has changed and we can directly look at the event page.
 612                  * If bit n is set then we have an interrup on the channel
 613                  * whose id is n.
 614                  */
 615                 handled = true;
 616         }
 617
 618         if (handled)
 619                 tasklet_schedule(hv_context.event_dpc[cpu]);
 620
 621
 622         page_addr = hv_context.synic_message_page[cpu];
 623         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 624
 625         /* Check if there are actual msgs to be processed */
 626         if (msg->header.message_type != HVMSG_NONE) {
 627                 handled = true;
 628                 tasklet_schedule(&msg_dpc);
 629         }
 630
 631         if (handled)
 632                 return IRQ_HANDLED;
 633         else
 634                 return IRQ_NONE;
 635 }
 636
 637 /*
 638  * vmbus interrupt flow handler:
 639  * vmbus interrupts can concurrently occur on multiple CPUs and
 640  * can be handled concurrently.
 641  */
 642
 643 static void vmbus_flow_handler(unsigned int irq, struct irq_desc *desc)
 644 {
 645         kstat_incr_irqs_this_cpu(irq, desc);
 646
 647         desc->action->handler(irq, desc->action->dev_id);
 648 }
 649
 650 /*
 651  * vmbus_bus_init -Main vmbus driver initialization routine.
 652  *
 653  * Here, we
 654  *      - initialize the vmbus driver context
 655  *      - invoke the vmbus hv main init routine
 656  *      - get the irq resource
 657  *      - retrieve the channel offers
 658  */
 659 static int vmbus_bus_init(int irq)
 660 {
 661         int ret;
 662
 663         /* Hypervisor initialization...setup hypercall page..etc */
 664         ret = hv_init();
 665         if (ret != 0) {
 666                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 667                 return ret;
 668         }
 669
 670         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 671
 672         ret = bus_register(&hv_bus);
 673         if (ret)
 674                 goto err_cleanup;
 675
 676         ret = request_irq(irq, vmbus_isr, 0, driver_name, hv_acpi_dev);
 677
 678         if (ret != 0) {
 679                 pr_err("Unable to request IRQ %d\n",
 680                            irq);
 681                 goto err_unregister;
 682         }
 683
 684         /*
 685          * Vmbus interrupts can be handled concurrently on
 686          * different CPUs. Establish an appropriate interrupt flow
 687          * handler that can support this model.
 688          */
 689         irq_set_handler(irq, vmbus_flow_handler);
 690
 691         /*
 692          * Register our interrupt handler.
 693          */
 694         hv_register_vmbus_handler(irq, vmbus_isr);
 695
 696         ret = hv_synic_alloc();
 697         if (ret)
 698                 goto err_alloc;
 699         /*
 700          * Initialize the per-cpu interrupt state and
 701          * connect to the host.
 702          */
 703         on_each_cpu(hv_synic_init, NULL, 1);
 704         ret = vmbus_connect();
 705         if (ret)
 706                 goto err_alloc;
 707
 708         vmbus_request_offers();
 709
 710         return 0;
 711
 712 err_alloc:
 713         hv_synic_free();
 714         free_irq(irq, hv_acpi_dev);
 715
 716 err_unregister:
 717         bus_unregister(&hv_bus);
 718
 719 err_cleanup:
 720         hv_cleanup();
 721
 722         return ret;
 723 }
 724
 725 /**
 726  * __vmbus_child_driver_register - Register a vmbus's driver
 727  * @drv: Pointer to driver structure you want to register
 728  * @owner: owner module of the drv
 729  * @mod_name: module name string
 730  *
 731  * Registers the given driver with Linux through the 'driver_register()' call
 732  * and sets up the hyper-v vmbus handling for this driver.
 733  * It will return the state of the 'driver_register()' call.
 734  *
 735  */
 736 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 737 {
 738         int ret;
 739
 740         pr_info("registering driver %s\n", hv_driver->name);
 741
 742         ret = vmbus_exists();
 743         if (ret < 0)
 744                 return ret;
 745
 746         hv_driver->driver.name = hv_driver->name;
 747         hv_driver->driver.owner = owner;
 748         hv_driver->driver.mod_name = mod_name;
 749         hv_driver->driver.bus = &hv_bus;
 750
 751         ret = driver_register(&hv_driver->driver);
 752
 753         return ret;
 754 }
 755 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 756
 757 /**
 758  * vmbus_driver_unregister() - Unregister a vmbus's driver
 759  * @drv: Pointer to driver structure you want to un-register
 760  *
 761  * Un-register the given driver that was previous registered with a call to
 762  * vmbus_driver_register()
 763  */
 764 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 765 {
 766         pr_info("unregistering driver %s\n", hv_driver->name);
 767
 768         if (!vmbus_exists())
 769                 driver_unregister(&hv_driver->driver);
 770 }
 771 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 772
 773 /*
 774  * vmbus_device_create - Creates and registers a new child device
 775  * on the vmbus.
 776  */
 777 struct hv_device *vmbus_device_create(uuid_le *type,
 778                                             uuid_le *instance,
 779                                             struct vmbus_channel *channel)
 780 {
 781         struct hv_device *child_device_obj;
 782
 783         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 784         if (!child_device_obj) {
 785                 pr_err("Unable to allocate device object for child device\n");
 786                 return NULL;
 787         }
 788
 789         child_device_obj->channel = channel;
 790         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 791         memcpy(&child_device_obj->dev_instance, instance,
 792                sizeof(uuid_le));
 793
 794
 795         return child_device_obj;
 796 }
 797
 798 /*
 799  * vmbus_device_register - Register the child device
 800  */
 801 int vmbus_device_register(struct hv_device *child_device_obj)
 802 {
 803         int ret = 0;
 804
 805         static atomic_t device_num = ATOMIC_INIT(0);
 806
 807         dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 808                      atomic_inc_return(&device_num));
 809
 810         child_device_obj->device.bus = &hv_bus;
 811         child_device_obj->device.parent = &hv_acpi_dev->dev;
 812         child_device_obj->device.release = vmbus_device_release;
 813
 814         /*
 815          * Register with the LDM. This will kick off the driver/device
 816          * binding...which will eventually call vmbus_match() and vmbus_probe()
 817          */
 818         ret = device_register(&child_device_obj->device);
 819
 820         if (ret)
 821                 pr_err("Unable to register child device\n");
 822         else
 823                 pr_debug("child device %s registered\n",
 824                         dev_name(&child_device_obj->device));
 825
 826         return ret;
 827 }
 828
 829 /*
 830  * vmbus_device_unregister - Remove the specified child device
 831  * from the vmbus.
 832  */
 833 void vmbus_device_unregister(struct hv_device *device_obj)
 834 {
 835         pr_debug("child device %s unregistered\n",
 836                 dev_name(&device_obj->device));
 837
 838         /*
 839          * Kick off the process of unregistering the device.
 840          * This will call vmbus_remove() and eventually vmbus_device_release()
 841          */
 842         device_unregister(&device_obj->device);
 843 }
 844
 845
 846 /*
 847  * VMBUS is an acpi enumerated device. Get the the IRQ information
 848  * from DSDT.
 849  */
 850
 851 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
 852 {
 853
 854         if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
 855                 struct acpi_resource_irq *irqp;
 856                 irqp = &res->data.irq;
 857
 858                 *((unsigned int *)irq) = irqp->interrupts[0];
 859         }
 860
 861         return AE_OK;
 862 }
 863
 864 static int vmbus_acpi_add(struct acpi_device *device)
 865 {
 866         acpi_status result;
 867
 868         hv_acpi_dev = device;
 869
 870         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 871                                         vmbus_walk_resources, &irq);
 872
 873         if (ACPI_FAILURE(result)) {
 874                 complete(&probe_event);
 875                 return -ENODEV;
 876         }
 877         complete(&probe_event);
 878         return 0;
 879 }
 880
 881 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 882         {"VMBUS", 0},
 883         {"VMBus", 0},
 884         {"", 0},
 885 };
 886 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 887
 888 static struct acpi_driver vmbus_acpi_driver = {
 889         .name = "vmbus",
 890         .ids = vmbus_acpi_device_ids,
 891         .ops = {
 892                 .add = vmbus_acpi_add,
 893         },
 894 };
 895
 896 static int __init hv_acpi_init(void)
 897 {
 898         int ret, t;
 899
 900         if (x86_hyper != &x86_hyper_ms_hyperv)
 901                 return -ENODEV;
 902
 903         init_completion(&probe_event);
 904
 905         /*
 906          * Get irq resources first.
 907          */
 908
 909         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 910
 911         if (ret)
 912                 return ret;
 913
 914         t = wait_for_completion_timeout(&probe_event, 5*HZ);
 915         if (t == 0) {
 916                 ret = -ETIMEDOUT;
 917                 goto cleanup;
 918         }
 919
 920         if (irq <= 0) {
 921                 ret = -ENODEV;
 922                 goto cleanup;
 923         }
 924
 925         ret = vmbus_bus_init(irq);
 926         if (ret)
 927                 goto cleanup;
 928
 929         return 0;
 930
 931 cleanup:
 932         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 933         hv_acpi_dev = NULL;
 934         return ret;
 935 }
 936
 937 static void __exit vmbus_exit(void)
 938 {
 939
 940         free_irq(irq, hv_acpi_dev);
 941         vmbus_free_channels();
 942         bus_unregister(&hv_bus);
 943         hv_cleanup();
 944         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 945 }
 946
 947
 948 MODULE_LICENSE("GPL");
 949
 950 subsys_initcall(hv_acpi_init);
 951 module_exit(vmbus_exit);