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 <asm/hyperv.h>
  37 #include "hyperv_vmbus.h"
  38
  39
  40 static struct acpi_device  *hv_acpi_dev;
  41
  42 static struct tasklet_struct msg_dpc;
  43 static struct tasklet_struct event_dpc;
  44 static struct completion probe_event;
  45 static int irq;
  46
  47 struct hv_device_info {
  48         u32 chn_id;
  49         u32 chn_state;
  50         uuid_le chn_type;
  51         uuid_le chn_instance;
  52
  53         u32 monitor_id;
  54         u32 server_monitor_pending;
  55         u32 server_monitor_latency;
  56         u32 server_monitor_conn_id;
  57         u32 client_monitor_pending;
  58         u32 client_monitor_latency;
  59         u32 client_monitor_conn_id;
  60
  61         struct hv_dev_port_info inbound;
  62         struct hv_dev_port_info outbound;
  63 };
  64
  65 static int vmbus_exists(void)
  66 {
  67         if (hv_acpi_dev == NULL)
  68                 return -ENODEV;
  69
  70         return 0;
  71 }
  72
  73
  74 static void get_channel_info(struct hv_device *device,
  75                              struct hv_device_info *info)
  76 {
  77         struct vmbus_channel_debug_info debug_info;
  78
  79         if (!device->channel)
  80                 return;
  81
  82         vmbus_get_debug_info(device->channel, &debug_info);
  83
  84         info->chn_id = debug_info.relid;
  85         info->chn_state = debug_info.state;
  86         memcpy(&info->chn_type, &debug_info.interfacetype,
  87                sizeof(uuid_le));
  88         memcpy(&info->chn_instance, &debug_info.interface_instance,
  89                sizeof(uuid_le));
  90
  91         info->monitor_id = debug_info.monitorid;
  92
  93         info->server_monitor_pending = debug_info.servermonitor_pending;
  94         info->server_monitor_latency = debug_info.servermonitor_latency;
  95         info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
  96
  97         info->client_monitor_pending = debug_info.clientmonitor_pending;
  98         info->client_monitor_latency = debug_info.clientmonitor_latency;
  99         info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
 100
 101         info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
 102         info->inbound.read_idx = debug_info.inbound.current_read_index;
 103         info->inbound.write_idx = debug_info.inbound.current_write_index;
 104         info->inbound.bytes_avail_toread =
 105                 debug_info.inbound.bytes_avail_toread;
 106         info->inbound.bytes_avail_towrite =
 107                 debug_info.inbound.bytes_avail_towrite;
 108
 109         info->outbound.int_mask =
 110                 debug_info.outbound.current_interrupt_mask;
 111         info->outbound.read_idx = debug_info.outbound.current_read_index;
 112         info->outbound.write_idx = debug_info.outbound.current_write_index;
 113         info->outbound.bytes_avail_toread =
 114                 debug_info.outbound.bytes_avail_toread;
 115         info->outbound.bytes_avail_towrite =
 116                 debug_info.outbound.bytes_avail_towrite;
 117 }
 118
 119 #define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 120 static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 121 {
 122         int i;
 123         for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 124                 sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 125 }
 126
 127 /*
 128  * vmbus_show_device_attr - Show the device attribute in sysfs.
 129  *
 130  * This is invoked when user does a
 131  * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
 132  */
 133 static ssize_t vmbus_show_device_attr(struct device *dev,
 134                                       struct device_attribute *dev_attr,
 135                                       char *buf)
 136 {
 137         struct hv_device *hv_dev = device_to_hv_device(dev);
 138         struct hv_device_info *device_info;
 139         char alias_name[VMBUS_ALIAS_LEN + 1];
 140         int ret = 0;
 141
 142         device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
 143         if (!device_info)
 144                 return ret;
 145
 146         get_channel_info(hv_dev, device_info);
 147
 148         if (!strcmp(dev_attr->attr.name, "class_id")) {
 149                 ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
 150                                "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
 151                                device_info->chn_type.b[3],
 152                                device_info->chn_type.b[2],
 153                                device_info->chn_type.b[1],
 154                                device_info->chn_type.b[0],
 155                                device_info->chn_type.b[5],
 156                                device_info->chn_type.b[4],
 157                                device_info->chn_type.b[7],
 158                                device_info->chn_type.b[6],
 159                                device_info->chn_type.b[8],
 160                                device_info->chn_type.b[9],
 161                                device_info->chn_type.b[10],
 162                                device_info->chn_type.b[11],
 163                                device_info->chn_type.b[12],
 164                                device_info->chn_type.b[13],
 165                                device_info->chn_type.b[14],
 166                                device_info->chn_type.b[15]);
 167         } else if (!strcmp(dev_attr->attr.name, "device_id")) {
 168                 ret = sprintf(buf, "{%02x%02x%02x%02x-%02x%02x-%02x%02x-"
 169                                "%02x%02x%02x%02x%02x%02x%02x%02x}\n",
 170                                device_info->chn_instance.b[3],
 171                                device_info->chn_instance.b[2],
 172                                device_info->chn_instance.b[1],
 173                                device_info->chn_instance.b[0],
 174                                device_info->chn_instance.b[5],
 175                                device_info->chn_instance.b[4],
 176                                device_info->chn_instance.b[7],
 177                                device_info->chn_instance.b[6],
 178                                device_info->chn_instance.b[8],
 179                                device_info->chn_instance.b[9],
 180                                device_info->chn_instance.b[10],
 181                                device_info->chn_instance.b[11],
 182                                device_info->chn_instance.b[12],
 183                                device_info->chn_instance.b[13],
 184                                device_info->chn_instance.b[14],
 185                                device_info->chn_instance.b[15]);
 186         } else if (!strcmp(dev_attr->attr.name, "modalias")) {
 187                 print_alias_name(hv_dev, alias_name);
 188                 ret = sprintf(buf, "vmbus:%s\n", alias_name);
 189         } else if (!strcmp(dev_attr->attr.name, "state")) {
 190                 ret = sprintf(buf, "%d\n", device_info->chn_state);
 191         } else if (!strcmp(dev_attr->attr.name, "id")) {
 192                 ret = sprintf(buf, "%d\n", device_info->chn_id);
 193         } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
 194                 ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
 195         } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
 196                 ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
 197         } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
 198                 ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
 199         } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
 200                 ret = sprintf(buf, "%d\n",
 201                                device_info->outbound.bytes_avail_toread);
 202         } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
 203                 ret = sprintf(buf, "%d\n",
 204                                device_info->outbound.bytes_avail_towrite);
 205         } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
 206                 ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
 207         } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
 208                 ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
 209         } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
 210                 ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
 211         } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
 212                 ret = sprintf(buf, "%d\n",
 213                                device_info->inbound.bytes_avail_toread);
 214         } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
 215                 ret = sprintf(buf, "%d\n",
 216                                device_info->inbound.bytes_avail_towrite);
 217         } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
 218                 ret = sprintf(buf, "%d\n", device_info->monitor_id);
 219         } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
 220                 ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
 221         } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
 222                 ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
 223         } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
 224                 ret = sprintf(buf, "%d\n",
 225                                device_info->server_monitor_conn_id);
 226         } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
 227                 ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
 228         } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
 229                 ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
 230         } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
 231                 ret = sprintf(buf, "%d\n",
 232                                device_info->client_monitor_conn_id);
 233         }
 234
 235         kfree(device_info);
 236         return ret;
 237 }
 238
 239 /* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 240 static struct device_attribute vmbus_device_attrs[] = {
 241         __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
 242         __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
 243         __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
 244         __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
 245         __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
 246         __ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
 247
 248         __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 249         __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 250         __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 251
 252         __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 253         __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 254         __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 255
 256         __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 257         __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 258         __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 259         __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 260         __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 261
 262         __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 263         __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 264         __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 265         __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 266         __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 267         __ATTR_NULL
 268 };
 269
 270
 271 /*
 272  * vmbus_uevent - add uevent for our device
 273  *
 274  * This routine is invoked when a device is added or removed on the vmbus to
 275  * generate a uevent to udev in the userspace. The udev will then look at its
 276  * rule and the uevent generated here to load the appropriate driver
 277  *
 278  * The alias string will be of the form vmbus:guid where guid is the string
 279  * representation of the device guid (each byte of the guid will be
 280  * represented with two hex characters.
 281  */
 282 static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 283 {
 284         struct hv_device *dev = device_to_hv_device(device);
 285         int ret;
 286         char alias_name[VMBUS_ALIAS_LEN + 1];
 287
 288         print_alias_name(dev, alias_name);
 289         ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 290         return ret;
 291 }
 292
 293 static uuid_le null_guid;
 294
 295 static inline bool is_null_guid(const __u8 *guid)
 296 {
 297         if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 298                 return false;
 299         return true;
 300 }
 301
 302 /*
 303  * Return a matching hv_vmbus_device_id pointer.
 304  * If there is no match, return NULL.
 305  */
 306 static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 307                                         const struct hv_vmbus_device_id *id,
 308                                         __u8 *guid)
 309 {
 310         for (; !is_null_guid(id->guid); id++)
 311                 if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 312                         return id;
 313
 314         return NULL;
 315 }
 316
 317
 318
 319 /*
 320  * vmbus_match - Attempt to match the specified device to the specified driver
 321  */
 322 static int vmbus_match(struct device *device, struct device_driver *driver)
 323 {
 324         struct hv_driver *drv = drv_to_hv_drv(driver);
 325         struct hv_device *hv_dev = device_to_hv_device(device);
 326
 327         if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 328                 return 1;
 329
 330         return 0;
 331 }
 332
 333 /*
 334  * vmbus_probe - Add the new vmbus's child device
 335  */
 336 static int vmbus_probe(struct device *child_device)
 337 {
 338         int ret = 0;
 339         struct hv_driver *drv =
 340                         drv_to_hv_drv(child_device->driver);
 341         struct hv_device *dev = device_to_hv_device(child_device);
 342         const struct hv_vmbus_device_id *dev_id;
 343
 344         dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 345         if (drv->probe) {
 346                 ret = drv->probe(dev, dev_id);
 347                 if (ret != 0)
 348                         pr_err("probe failed for device %s (%d)\n",
 349                                dev_name(child_device), ret);
 350
 351         } else {
 352                 pr_err("probe not set for driver %s\n",
 353                        dev_name(child_device));
 354                 ret = -ENODEV;
 355         }
 356         return ret;
 357 }
 358
 359 /*
 360  * vmbus_remove - Remove a vmbus device
 361  */
 362 static int vmbus_remove(struct device *child_device)
 363 {
 364         struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
 365         struct hv_device *dev = device_to_hv_device(child_device);
 366
 367         if (drv->remove)
 368                 drv->remove(dev);
 369         else
 370                 pr_err("remove not set for driver %s\n",
 371                         dev_name(child_device));
 372
 373         return 0;
 374 }
 375
 376
 377 /*
 378  * vmbus_shutdown - Shutdown a vmbus device
 379  */
 380 static void vmbus_shutdown(struct device *child_device)
 381 {
 382         struct hv_driver *drv;
 383         struct hv_device *dev = device_to_hv_device(child_device);
 384
 385
 386         /* The device may not be attached yet */
 387         if (!child_device->driver)
 388                 return;
 389
 390         drv = drv_to_hv_drv(child_device->driver);
 391
 392         if (drv->shutdown)
 393                 drv->shutdown(dev);
 394
 395         return;
 396 }
 397
 398
 399 /*
 400  * vmbus_device_release - Final callback release of the vmbus child device
 401  */
 402 static void vmbus_device_release(struct device *device)
 403 {
 404         struct hv_device *hv_dev = device_to_hv_device(device);
 405
 406         kfree(hv_dev);
 407
 408 }
 409
 410 /* The one and only one */
 411 static struct bus_type  hv_bus = {
 412         .name =         "vmbus",
 413         .match =                vmbus_match,
 414         .shutdown =             vmbus_shutdown,
 415         .remove =               vmbus_remove,
 416         .probe =                vmbus_probe,
 417         .uevent =               vmbus_uevent,
 418         .dev_attrs =    vmbus_device_attrs,
 419 };
 420
 421 static const char *driver_name = "hyperv";
 422
 423
 424 struct onmessage_work_context {
 425         struct work_struct work;
 426         struct hv_message msg;
 427 };
 428
 429 static void vmbus_onmessage_work(struct work_struct *work)
 430 {
 431         struct onmessage_work_context *ctx;
 432
 433         ctx = container_of(work, struct onmessage_work_context,
 434                            work);
 435         vmbus_onmessage(&ctx->msg);
 436         kfree(ctx);
 437 }
 438
 439 static void vmbus_on_msg_dpc(unsigned long data)
 440 {
 441         int cpu = smp_processor_id();
 442         void *page_addr = hv_context.synic_message_page[cpu];
 443         struct hv_message *msg = (struct hv_message *)page_addr +
 444                                   VMBUS_MESSAGE_SINT;
 445         struct onmessage_work_context *ctx;
 446
 447         while (1) {
 448                 if (msg->header.message_type == HVMSG_NONE) {
 449                         /* no msg */
 450                         break;
 451                 } else {
 452                         ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 453                         if (ctx == NULL)
 454                                 continue;
 455                         INIT_WORK(&ctx->work, vmbus_onmessage_work);
 456                         memcpy(&ctx->msg, msg, sizeof(*msg));
 457                         queue_work(vmbus_connection.work_queue, &ctx->work);
 458                 }
 459
 460                 msg->header.message_type = HVMSG_NONE;
 461
 462                 /*
 463                  * Make sure the write to MessageType (ie set to
 464                  * HVMSG_NONE) happens before we read the
 465                  * MessagePending and EOMing. Otherwise, the EOMing
 466                  * will not deliver any more messages since there is
 467                  * no empty slot
 468                  */
 469                 smp_mb();
 470
 471                 if (msg->header.message_flags.msg_pending) {
 472                         /*
 473                          * This will cause message queue rescan to
 474                          * possibly deliver another msg from the
 475                          * hypervisor
 476                          */
 477                         wrmsrl(HV_X64_MSR_EOM, 0);
 478                 }
 479         }
 480 }
 481
 482 static irqreturn_t vmbus_isr(int irq, void *dev_id)
 483 {
 484         int cpu = smp_processor_id();
 485         void *page_addr;
 486         struct hv_message *msg;
 487         union hv_synic_event_flags *event;
 488         bool handled = false;
 489
 490         /*
 491          * Check for events before checking for messages. This is the order
 492          * in which events and messages are checked in Windows guests on
 493          * Hyper-V, and the Windows team suggested we do the same.
 494          */
 495
 496         page_addr = hv_context.synic_event_page[cpu];
 497         event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
 498
 499         /* Since we are a child, we only need to check bit 0 */
 500         if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
 501                 handled = true;
 502                 tasklet_schedule(&event_dpc);
 503         }
 504
 505         page_addr = hv_context.synic_message_page[cpu];
 506         msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 507
 508         /* Check if there are actual msgs to be processed */
 509         if (msg->header.message_type != HVMSG_NONE) {
 510                 handled = true;
 511                 tasklet_schedule(&msg_dpc);
 512         }
 513
 514         if (handled)
 515                 return IRQ_HANDLED;
 516         else
 517                 return IRQ_NONE;
 518 }
 519
 520 /*
 521  * vmbus_bus_init -Main vmbus driver initialization routine.
 522  *
 523  * Here, we
 524  *      - initialize the vmbus driver context
 525  *      - invoke the vmbus hv main init routine
 526  *      - get the irq resource
 527  *      - retrieve the channel offers
 528  */
 529 static int vmbus_bus_init(int irq)
 530 {
 531         int ret;
 532         unsigned int vector;
 533
 534         /* Hypervisor initialization...setup hypercall page..etc */
 535         ret = hv_init();
 536         if (ret != 0) {
 537                 pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 538                 return ret;
 539         }
 540
 541         tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 542         tasklet_init(&event_dpc, vmbus_on_event, 0);
 543
 544         ret = bus_register(&hv_bus);
 545         if (ret)
 546                 goto err_cleanup;
 547
 548         ret = request_irq(irq, vmbus_isr, IRQF_SAMPLE_RANDOM,
 549                         driver_name, hv_acpi_dev);
 550
 551         if (ret != 0) {
 552                 pr_err("Unable to request IRQ %d\n",
 553                            irq);
 554                 goto err_unregister;
 555         }
 556
 557         vector = IRQ0_VECTOR + irq;
 558
 559         /*
 560          * Notify the hypervisor of our irq and
 561          * connect to the host.
 562          */
 563         on_each_cpu(hv_synic_init, (void *)&vector, 1);
 564         ret = vmbus_connect();
 565         if (ret)
 566                 goto err_irq;
 567
 568         vmbus_request_offers();
 569
 570         return 0;
 571
 572 err_irq:
 573         free_irq(irq, hv_acpi_dev);
 574
 575 err_unregister:
 576         bus_unregister(&hv_bus);
 577
 578 err_cleanup:
 579         hv_cleanup();
 580
 581         return ret;
 582 }
 583
 584 /**
 585  * __vmbus_child_driver_register - Register a vmbus's driver
 586  * @drv: Pointer to driver structure you want to register
 587  * @owner: owner module of the drv
 588  * @mod_name: module name string
 589  *
 590  * Registers the given driver with Linux through the 'driver_register()' call
 591  * and sets up the hyper-v vmbus handling for this driver.
 592  * It will return the state of the 'driver_register()' call.
 593  *
 594  */
 595 int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 596 {
 597         int ret;
 598
 599         pr_info("registering driver %s\n", hv_driver->name);
 600
 601         ret = vmbus_exists();
 602         if (ret < 0)
 603                 return ret;
 604
 605         hv_driver->driver.name = hv_driver->name;
 606         hv_driver->driver.owner = owner;
 607         hv_driver->driver.mod_name = mod_name;
 608         hv_driver->driver.bus = &hv_bus;
 609
 610         ret = driver_register(&hv_driver->driver);
 611
 612         vmbus_request_offers();
 613
 614         return ret;
 615 }
 616 EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 617
 618 /**
 619  * vmbus_driver_unregister() - Unregister a vmbus's driver
 620  * @drv: Pointer to driver structure you want to un-register
 621  *
 622  * Un-register the given driver that was previous registered with a call to
 623  * vmbus_driver_register()
 624  */
 625 void vmbus_driver_unregister(struct hv_driver *hv_driver)
 626 {
 627         pr_info("unregistering driver %s\n", hv_driver->name);
 628
 629         if (!vmbus_exists())
 630                 driver_unregister(&hv_driver->driver);
 631 }
 632 EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 633
 634 /*
 635  * vmbus_device_create - Creates and registers a new child device
 636  * on the vmbus.
 637  */
 638 struct hv_device *vmbus_device_create(uuid_le *type,
 639                                             uuid_le *instance,
 640                                             struct vmbus_channel *channel)
 641 {
 642         struct hv_device *child_device_obj;
 643
 644         child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 645         if (!child_device_obj) {
 646                 pr_err("Unable to allocate device object for child device\n");
 647                 return NULL;
 648         }
 649
 650         child_device_obj->channel = channel;
 651         memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 652         memcpy(&child_device_obj->dev_instance, instance,
 653                sizeof(uuid_le));
 654
 655
 656         return child_device_obj;
 657 }
 658
 659 /*
 660  * vmbus_device_register - Register the child device
 661  */
 662 int vmbus_device_register(struct hv_device *child_device_obj)
 663 {
 664         int ret = 0;
 665
 666         static atomic_t device_num = ATOMIC_INIT(0);
 667
 668         dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 669                      atomic_inc_return(&device_num));
 670
 671         child_device_obj->device.bus = &hv_bus;
 672         child_device_obj->device.parent = &hv_acpi_dev->dev;
 673         child_device_obj->device.release = vmbus_device_release;
 674
 675         /*
 676          * Register with the LDM. This will kick off the driver/device
 677          * binding...which will eventually call vmbus_match() and vmbus_probe()
 678          */
 679         ret = device_register(&child_device_obj->device);
 680
 681         if (ret)
 682                 pr_err("Unable to register child device\n");
 683         else
 684                 pr_info("child device %s registered\n",
 685                         dev_name(&child_device_obj->device));
 686
 687         return ret;
 688 }
 689
 690 /*
 691  * vmbus_device_unregister - Remove the specified child device
 692  * from the vmbus.
 693  */
 694 void vmbus_device_unregister(struct hv_device *device_obj)
 695 {
 696         /*
 697          * Kick off the process of unregistering the device.
 698          * This will call vmbus_remove() and eventually vmbus_device_release()
 699          */
 700         device_unregister(&device_obj->device);
 701
 702         pr_info("child device %s unregistered\n",
 703                 dev_name(&device_obj->device));
 704 }
 705
 706
 707 /*
 708  * VMBUS is an acpi enumerated device. Get the the IRQ information
 709  * from DSDT.
 710  */
 711
 712 static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
 713 {
 714
 715         if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
 716                 struct acpi_resource_irq *irqp;
 717                 irqp = &res->data.irq;
 718
 719                 *((unsigned int *)irq) = irqp->interrupts[0];
 720         }
 721
 722         return AE_OK;
 723 }
 724
 725 static int vmbus_acpi_add(struct acpi_device *device)
 726 {
 727         acpi_status result;
 728
 729         hv_acpi_dev = device;
 730
 731         result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 732                                         vmbus_walk_resources, &irq);
 733
 734         if (ACPI_FAILURE(result)) {
 735                 complete(&probe_event);
 736                 return -ENODEV;
 737         }
 738         complete(&probe_event);
 739         return 0;
 740 }
 741
 742 static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 743         {"VMBUS", 0},
 744         {"VMBus", 0},
 745         {"", 0},
 746 };
 747 MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 748
 749 static struct acpi_driver vmbus_acpi_driver = {
 750         .name = "vmbus",
 751         .ids = vmbus_acpi_device_ids,
 752         .ops = {
 753                 .add = vmbus_acpi_add,
 754         },
 755 };
 756
 757 static int __init hv_acpi_init(void)
 758 {
 759         int ret, t;
 760
 761         init_completion(&probe_event);
 762
 763         /*
 764          * Get irq resources first.
 765          */
 766
 767         ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 768
 769         if (ret)
 770                 return ret;
 771
 772         t = wait_for_completion_timeout(&probe_event, 5*HZ);
 773         if (t == 0) {
 774                 ret = -ETIMEDOUT;
 775                 goto cleanup;
 776         }
 777
 778         if (irq <= 0) {
 779                 ret = -ENODEV;
 780                 goto cleanup;
 781         }
 782
 783         ret = vmbus_bus_init(irq);
 784         if (ret)
 785                 goto cleanup;
 786
 787         return 0;
 788
 789 cleanup:
 790         acpi_bus_unregister_driver(&vmbus_acpi_driver);
 791         hv_acpi_dev = NULL;
 792         return ret;
 793 }
 794
 795
 796 MODULE_LICENSE("GPL");
 797 MODULE_VERSION(HV_DRV_VERSION);
 798
 799 module_init(hv_acpi_init);