linux/drivers/hv/vmbus_drv.c
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   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 <asm/hypervisor.h>
  38#include "hyperv_vmbus.h"
  39
  40
  41static struct acpi_device  *hv_acpi_dev;
  42
  43static struct tasklet_struct msg_dpc;
  44static struct tasklet_struct event_dpc;
  45static struct completion probe_event;
  46static int irq;
  47
  48struct hv_device_info {
  49        u32 chn_id;
  50        u32 chn_state;
  51        uuid_le chn_type;
  52        uuid_le chn_instance;
  53
  54        u32 monitor_id;
  55        u32 server_monitor_pending;
  56        u32 server_monitor_latency;
  57        u32 server_monitor_conn_id;
  58        u32 client_monitor_pending;
  59        u32 client_monitor_latency;
  60        u32 client_monitor_conn_id;
  61
  62        struct hv_dev_port_info inbound;
  63        struct hv_dev_port_info outbound;
  64};
  65
  66static int vmbus_exists(void)
  67{
  68        if (hv_acpi_dev == NULL)
  69                return -ENODEV;
  70
  71        return 0;
  72}
  73
  74
  75static void get_channel_info(struct hv_device *device,
  76                             struct hv_device_info *info)
  77{
  78        struct vmbus_channel_debug_info debug_info;
  79
  80        if (!device->channel)
  81                return;
  82
  83        vmbus_get_debug_info(device->channel, &debug_info);
  84
  85        info->chn_id = debug_info.relid;
  86        info->chn_state = debug_info.state;
  87        memcpy(&info->chn_type, &debug_info.interfacetype,
  88               sizeof(uuid_le));
  89        memcpy(&info->chn_instance, &debug_info.interface_instance,
  90               sizeof(uuid_le));
  91
  92        info->monitor_id = debug_info.monitorid;
  93
  94        info->server_monitor_pending = debug_info.servermonitor_pending;
  95        info->server_monitor_latency = debug_info.servermonitor_latency;
  96        info->server_monitor_conn_id = debug_info.servermonitor_connectionid;
  97
  98        info->client_monitor_pending = debug_info.clientmonitor_pending;
  99        info->client_monitor_latency = debug_info.clientmonitor_latency;
 100        info->client_monitor_conn_id = debug_info.clientmonitor_connectionid;
 101
 102        info->inbound.int_mask = debug_info.inbound.current_interrupt_mask;
 103        info->inbound.read_idx = debug_info.inbound.current_read_index;
 104        info->inbound.write_idx = debug_info.inbound.current_write_index;
 105        info->inbound.bytes_avail_toread =
 106                debug_info.inbound.bytes_avail_toread;
 107        info->inbound.bytes_avail_towrite =
 108                debug_info.inbound.bytes_avail_towrite;
 109
 110        info->outbound.int_mask =
 111                debug_info.outbound.current_interrupt_mask;
 112        info->outbound.read_idx = debug_info.outbound.current_read_index;
 113        info->outbound.write_idx = debug_info.outbound.current_write_index;
 114        info->outbound.bytes_avail_toread =
 115                debug_info.outbound.bytes_avail_toread;
 116        info->outbound.bytes_avail_towrite =
 117                debug_info.outbound.bytes_avail_towrite;
 118}
 119
 120#define VMBUS_ALIAS_LEN ((sizeof((struct hv_vmbus_device_id *)0)->guid) * 2)
 121static void print_alias_name(struct hv_device *hv_dev, char *alias_name)
 122{
 123        int i;
 124        for (i = 0; i < VMBUS_ALIAS_LEN; i += 2)
 125                sprintf(&alias_name[i], "%02x", hv_dev->dev_type.b[i/2]);
 126}
 127
 128/*
 129 * vmbus_show_device_attr - Show the device attribute in sysfs.
 130 *
 131 * This is invoked when user does a
 132 * "cat /sys/bus/vmbus/devices/<busdevice>/<attr name>"
 133 */
 134static ssize_t vmbus_show_device_attr(struct device *dev,
 135                                      struct device_attribute *dev_attr,
 136                                      char *buf)
 137{
 138        struct hv_device *hv_dev = device_to_hv_device(dev);
 139        struct hv_device_info *device_info;
 140        char alias_name[VMBUS_ALIAS_LEN + 1];
 141        int ret = 0;
 142
 143        device_info = kzalloc(sizeof(struct hv_device_info), GFP_KERNEL);
 144        if (!device_info)
 145                return ret;
 146
 147        get_channel_info(hv_dev, device_info);
 148
 149        if (!strcmp(dev_attr->attr.name, "class_id")) {
 150                ret = sprintf(buf, "{%pUl}\n", device_info->chn_type.b);
 151        } else if (!strcmp(dev_attr->attr.name, "device_id")) {
 152                ret = sprintf(buf, "{%pUl}\n", device_info->chn_instance.b);
 153        } else if (!strcmp(dev_attr->attr.name, "modalias")) {
 154                print_alias_name(hv_dev, alias_name);
 155                ret = sprintf(buf, "vmbus:%s\n", alias_name);
 156        } else if (!strcmp(dev_attr->attr.name, "state")) {
 157                ret = sprintf(buf, "%d\n", device_info->chn_state);
 158        } else if (!strcmp(dev_attr->attr.name, "id")) {
 159                ret = sprintf(buf, "%d\n", device_info->chn_id);
 160        } else if (!strcmp(dev_attr->attr.name, "out_intr_mask")) {
 161                ret = sprintf(buf, "%d\n", device_info->outbound.int_mask);
 162        } else if (!strcmp(dev_attr->attr.name, "out_read_index")) {
 163                ret = sprintf(buf, "%d\n", device_info->outbound.read_idx);
 164        } else if (!strcmp(dev_attr->attr.name, "out_write_index")) {
 165                ret = sprintf(buf, "%d\n", device_info->outbound.write_idx);
 166        } else if (!strcmp(dev_attr->attr.name, "out_read_bytes_avail")) {
 167                ret = sprintf(buf, "%d\n",
 168                               device_info->outbound.bytes_avail_toread);
 169        } else if (!strcmp(dev_attr->attr.name, "out_write_bytes_avail")) {
 170                ret = sprintf(buf, "%d\n",
 171                               device_info->outbound.bytes_avail_towrite);
 172        } else if (!strcmp(dev_attr->attr.name, "in_intr_mask")) {
 173                ret = sprintf(buf, "%d\n", device_info->inbound.int_mask);
 174        } else if (!strcmp(dev_attr->attr.name, "in_read_index")) {
 175                ret = sprintf(buf, "%d\n", device_info->inbound.read_idx);
 176        } else if (!strcmp(dev_attr->attr.name, "in_write_index")) {
 177                ret = sprintf(buf, "%d\n", device_info->inbound.write_idx);
 178        } else if (!strcmp(dev_attr->attr.name, "in_read_bytes_avail")) {
 179                ret = sprintf(buf, "%d\n",
 180                               device_info->inbound.bytes_avail_toread);
 181        } else if (!strcmp(dev_attr->attr.name, "in_write_bytes_avail")) {
 182                ret = sprintf(buf, "%d\n",
 183                               device_info->inbound.bytes_avail_towrite);
 184        } else if (!strcmp(dev_attr->attr.name, "monitor_id")) {
 185                ret = sprintf(buf, "%d\n", device_info->monitor_id);
 186        } else if (!strcmp(dev_attr->attr.name, "server_monitor_pending")) {
 187                ret = sprintf(buf, "%d\n", device_info->server_monitor_pending);
 188        } else if (!strcmp(dev_attr->attr.name, "server_monitor_latency")) {
 189                ret = sprintf(buf, "%d\n", device_info->server_monitor_latency);
 190        } else if (!strcmp(dev_attr->attr.name, "server_monitor_conn_id")) {
 191                ret = sprintf(buf, "%d\n",
 192                               device_info->server_monitor_conn_id);
 193        } else if (!strcmp(dev_attr->attr.name, "client_monitor_pending")) {
 194                ret = sprintf(buf, "%d\n", device_info->client_monitor_pending);
 195        } else if (!strcmp(dev_attr->attr.name, "client_monitor_latency")) {
 196                ret = sprintf(buf, "%d\n", device_info->client_monitor_latency);
 197        } else if (!strcmp(dev_attr->attr.name, "client_monitor_conn_id")) {
 198                ret = sprintf(buf, "%d\n",
 199                               device_info->client_monitor_conn_id);
 200        }
 201
 202        kfree(device_info);
 203        return ret;
 204}
 205
 206/* Set up per device attributes in /sys/bus/vmbus/devices/<bus device> */
 207static struct device_attribute vmbus_device_attrs[] = {
 208        __ATTR(id, S_IRUGO, vmbus_show_device_attr, NULL),
 209        __ATTR(state, S_IRUGO, vmbus_show_device_attr, NULL),
 210        __ATTR(class_id, S_IRUGO, vmbus_show_device_attr, NULL),
 211        __ATTR(device_id, S_IRUGO, vmbus_show_device_attr, NULL),
 212        __ATTR(monitor_id, S_IRUGO, vmbus_show_device_attr, NULL),
 213        __ATTR(modalias, S_IRUGO, vmbus_show_device_attr, NULL),
 214
 215        __ATTR(server_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 216        __ATTR(server_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 217        __ATTR(server_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 218
 219        __ATTR(client_monitor_pending, S_IRUGO, vmbus_show_device_attr, NULL),
 220        __ATTR(client_monitor_latency, S_IRUGO, vmbus_show_device_attr, NULL),
 221        __ATTR(client_monitor_conn_id, S_IRUGO, vmbus_show_device_attr, NULL),
 222
 223        __ATTR(out_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 224        __ATTR(out_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 225        __ATTR(out_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 226        __ATTR(out_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 227        __ATTR(out_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 228
 229        __ATTR(in_intr_mask, S_IRUGO, vmbus_show_device_attr, NULL),
 230        __ATTR(in_read_index, S_IRUGO, vmbus_show_device_attr, NULL),
 231        __ATTR(in_write_index, S_IRUGO, vmbus_show_device_attr, NULL),
 232        __ATTR(in_read_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 233        __ATTR(in_write_bytes_avail, S_IRUGO, vmbus_show_device_attr, NULL),
 234        __ATTR_NULL
 235};
 236
 237
 238/*
 239 * vmbus_uevent - add uevent for our device
 240 *
 241 * This routine is invoked when a device is added or removed on the vmbus to
 242 * generate a uevent to udev in the userspace. The udev will then look at its
 243 * rule and the uevent generated here to load the appropriate driver
 244 *
 245 * The alias string will be of the form vmbus:guid where guid is the string
 246 * representation of the device guid (each byte of the guid will be
 247 * represented with two hex characters.
 248 */
 249static int vmbus_uevent(struct device *device, struct kobj_uevent_env *env)
 250{
 251        struct hv_device *dev = device_to_hv_device(device);
 252        int ret;
 253        char alias_name[VMBUS_ALIAS_LEN + 1];
 254
 255        print_alias_name(dev, alias_name);
 256        ret = add_uevent_var(env, "MODALIAS=vmbus:%s", alias_name);
 257        return ret;
 258}
 259
 260static uuid_le null_guid;
 261
 262static inline bool is_null_guid(const __u8 *guid)
 263{
 264        if (memcmp(guid, &null_guid, sizeof(uuid_le)))
 265                return false;
 266        return true;
 267}
 268
 269/*
 270 * Return a matching hv_vmbus_device_id pointer.
 271 * If there is no match, return NULL.
 272 */
 273static const struct hv_vmbus_device_id *hv_vmbus_get_id(
 274                                        const struct hv_vmbus_device_id *id,
 275                                        __u8 *guid)
 276{
 277        for (; !is_null_guid(id->guid); id++)
 278                if (!memcmp(&id->guid, guid, sizeof(uuid_le)))
 279                        return id;
 280
 281        return NULL;
 282}
 283
 284
 285
 286/*
 287 * vmbus_match - Attempt to match the specified device to the specified driver
 288 */
 289static int vmbus_match(struct device *device, struct device_driver *driver)
 290{
 291        struct hv_driver *drv = drv_to_hv_drv(driver);
 292        struct hv_device *hv_dev = device_to_hv_device(device);
 293
 294        if (hv_vmbus_get_id(drv->id_table, hv_dev->dev_type.b))
 295                return 1;
 296
 297        return 0;
 298}
 299
 300/*
 301 * vmbus_probe - Add the new vmbus's child device
 302 */
 303static int vmbus_probe(struct device *child_device)
 304{
 305        int ret = 0;
 306        struct hv_driver *drv =
 307                        drv_to_hv_drv(child_device->driver);
 308        struct hv_device *dev = device_to_hv_device(child_device);
 309        const struct hv_vmbus_device_id *dev_id;
 310
 311        dev_id = hv_vmbus_get_id(drv->id_table, dev->dev_type.b);
 312        if (drv->probe) {
 313                ret = drv->probe(dev, dev_id);
 314                if (ret != 0)
 315                        pr_err("probe failed for device %s (%d)\n",
 316                               dev_name(child_device), ret);
 317
 318        } else {
 319                pr_err("probe not set for driver %s\n",
 320                       dev_name(child_device));
 321                ret = -ENODEV;
 322        }
 323        return ret;
 324}
 325
 326/*
 327 * vmbus_remove - Remove a vmbus device
 328 */
 329static int vmbus_remove(struct device *child_device)
 330{
 331        struct hv_driver *drv = drv_to_hv_drv(child_device->driver);
 332        struct hv_device *dev = device_to_hv_device(child_device);
 333
 334        if (drv->remove)
 335                drv->remove(dev);
 336        else
 337                pr_err("remove not set for driver %s\n",
 338                        dev_name(child_device));
 339
 340        return 0;
 341}
 342
 343
 344/*
 345 * vmbus_shutdown - Shutdown a vmbus device
 346 */
 347static void vmbus_shutdown(struct device *child_device)
 348{
 349        struct hv_driver *drv;
 350        struct hv_device *dev = device_to_hv_device(child_device);
 351
 352
 353        /* The device may not be attached yet */
 354        if (!child_device->driver)
 355                return;
 356
 357        drv = drv_to_hv_drv(child_device->driver);
 358
 359        if (drv->shutdown)
 360                drv->shutdown(dev);
 361
 362        return;
 363}
 364
 365
 366/*
 367 * vmbus_device_release - Final callback release of the vmbus child device
 368 */
 369static void vmbus_device_release(struct device *device)
 370{
 371        struct hv_device *hv_dev = device_to_hv_device(device);
 372
 373        kfree(hv_dev);
 374
 375}
 376
 377/* The one and only one */
 378static struct bus_type  hv_bus = {
 379        .name =         "vmbus",
 380        .match =                vmbus_match,
 381        .shutdown =             vmbus_shutdown,
 382        .remove =               vmbus_remove,
 383        .probe =                vmbus_probe,
 384        .uevent =               vmbus_uevent,
 385        .dev_attrs =    vmbus_device_attrs,
 386};
 387
 388static const char *driver_name = "hyperv";
 389
 390
 391struct onmessage_work_context {
 392        struct work_struct work;
 393        struct hv_message msg;
 394};
 395
 396static void vmbus_onmessage_work(struct work_struct *work)
 397{
 398        struct onmessage_work_context *ctx;
 399
 400        ctx = container_of(work, struct onmessage_work_context,
 401                           work);
 402        vmbus_onmessage(&ctx->msg);
 403        kfree(ctx);
 404}
 405
 406static void vmbus_on_msg_dpc(unsigned long data)
 407{
 408        int cpu = smp_processor_id();
 409        void *page_addr = hv_context.synic_message_page[cpu];
 410        struct hv_message *msg = (struct hv_message *)page_addr +
 411                                  VMBUS_MESSAGE_SINT;
 412        struct onmessage_work_context *ctx;
 413
 414        while (1) {
 415                if (msg->header.message_type == HVMSG_NONE) {
 416                        /* no msg */
 417                        break;
 418                } else {
 419                        ctx = kmalloc(sizeof(*ctx), GFP_ATOMIC);
 420                        if (ctx == NULL)
 421                                continue;
 422                        INIT_WORK(&ctx->work, vmbus_onmessage_work);
 423                        memcpy(&ctx->msg, msg, sizeof(*msg));
 424                        queue_work(vmbus_connection.work_queue, &ctx->work);
 425                }
 426
 427                msg->header.message_type = HVMSG_NONE;
 428
 429                /*
 430                 * Make sure the write to MessageType (ie set to
 431                 * HVMSG_NONE) happens before we read the
 432                 * MessagePending and EOMing. Otherwise, the EOMing
 433                 * will not deliver any more messages since there is
 434                 * no empty slot
 435                 */
 436                smp_mb();
 437
 438                if (msg->header.message_flags.msg_pending) {
 439                        /*
 440                         * This will cause message queue rescan to
 441                         * possibly deliver another msg from the
 442                         * hypervisor
 443                         */
 444                        wrmsrl(HV_X64_MSR_EOM, 0);
 445                }
 446        }
 447}
 448
 449static irqreturn_t vmbus_isr(int irq, void *dev_id)
 450{
 451        int cpu = smp_processor_id();
 452        void *page_addr;
 453        struct hv_message *msg;
 454        union hv_synic_event_flags *event;
 455        bool handled = false;
 456
 457        /*
 458         * Check for events before checking for messages. This is the order
 459         * in which events and messages are checked in Windows guests on
 460         * Hyper-V, and the Windows team suggested we do the same.
 461         */
 462
 463        page_addr = hv_context.synic_event_page[cpu];
 464        event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT;
 465
 466        /* Since we are a child, we only need to check bit 0 */
 467        if (sync_test_and_clear_bit(0, (unsigned long *) &event->flags32[0])) {
 468                handled = true;
 469                tasklet_schedule(&event_dpc);
 470        }
 471
 472        page_addr = hv_context.synic_message_page[cpu];
 473        msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT;
 474
 475        /* Check if there are actual msgs to be processed */
 476        if (msg->header.message_type != HVMSG_NONE) {
 477                handled = true;
 478                tasklet_schedule(&msg_dpc);
 479        }
 480
 481        if (handled)
 482                return IRQ_HANDLED;
 483        else
 484                return IRQ_NONE;
 485}
 486
 487/*
 488 * vmbus_bus_init -Main vmbus driver initialization routine.
 489 *
 490 * Here, we
 491 *      - initialize the vmbus driver context
 492 *      - invoke the vmbus hv main init routine
 493 *      - get the irq resource
 494 *      - retrieve the channel offers
 495 */
 496static int vmbus_bus_init(int irq)
 497{
 498        int ret;
 499        unsigned int vector;
 500
 501        /* Hypervisor initialization...setup hypercall page..etc */
 502        ret = hv_init();
 503        if (ret != 0) {
 504                pr_err("Unable to initialize the hypervisor - 0x%x\n", ret);
 505                return ret;
 506        }
 507
 508        tasklet_init(&msg_dpc, vmbus_on_msg_dpc, 0);
 509        tasklet_init(&event_dpc, vmbus_on_event, 0);
 510
 511        ret = bus_register(&hv_bus);
 512        if (ret)
 513                goto err_cleanup;
 514
 515        ret = request_irq(irq, vmbus_isr, 0, driver_name, hv_acpi_dev);
 516
 517        if (ret != 0) {
 518                pr_err("Unable to request IRQ %d\n",
 519                           irq);
 520                goto err_unregister;
 521        }
 522
 523        vector = IRQ0_VECTOR + irq;
 524
 525        /*
 526         * Notify the hypervisor of our irq and
 527         * connect to the host.
 528         */
 529        on_each_cpu(hv_synic_init, (void *)&vector, 1);
 530        ret = vmbus_connect();
 531        if (ret)
 532                goto err_irq;
 533
 534        vmbus_request_offers();
 535
 536        return 0;
 537
 538err_irq:
 539        free_irq(irq, hv_acpi_dev);
 540
 541err_unregister:
 542        bus_unregister(&hv_bus);
 543
 544err_cleanup:
 545        hv_cleanup();
 546
 547        return ret;
 548}
 549
 550/**
 551 * __vmbus_child_driver_register - Register a vmbus's driver
 552 * @drv: Pointer to driver structure you want to register
 553 * @owner: owner module of the drv
 554 * @mod_name: module name string
 555 *
 556 * Registers the given driver with Linux through the 'driver_register()' call
 557 * and sets up the hyper-v vmbus handling for this driver.
 558 * It will return the state of the 'driver_register()' call.
 559 *
 560 */
 561int __vmbus_driver_register(struct hv_driver *hv_driver, struct module *owner, const char *mod_name)
 562{
 563        int ret;
 564
 565        pr_info("registering driver %s\n", hv_driver->name);
 566
 567        ret = vmbus_exists();
 568        if (ret < 0)
 569                return ret;
 570
 571        hv_driver->driver.name = hv_driver->name;
 572        hv_driver->driver.owner = owner;
 573        hv_driver->driver.mod_name = mod_name;
 574        hv_driver->driver.bus = &hv_bus;
 575
 576        ret = driver_register(&hv_driver->driver);
 577
 578        vmbus_request_offers();
 579
 580        return ret;
 581}
 582EXPORT_SYMBOL_GPL(__vmbus_driver_register);
 583
 584/**
 585 * vmbus_driver_unregister() - Unregister a vmbus's driver
 586 * @drv: Pointer to driver structure you want to un-register
 587 *
 588 * Un-register the given driver that was previous registered with a call to
 589 * vmbus_driver_register()
 590 */
 591void vmbus_driver_unregister(struct hv_driver *hv_driver)
 592{
 593        pr_info("unregistering driver %s\n", hv_driver->name);
 594
 595        if (!vmbus_exists())
 596                driver_unregister(&hv_driver->driver);
 597}
 598EXPORT_SYMBOL_GPL(vmbus_driver_unregister);
 599
 600/*
 601 * vmbus_device_create - Creates and registers a new child device
 602 * on the vmbus.
 603 */
 604struct hv_device *vmbus_device_create(uuid_le *type,
 605                                            uuid_le *instance,
 606                                            struct vmbus_channel *channel)
 607{
 608        struct hv_device *child_device_obj;
 609
 610        child_device_obj = kzalloc(sizeof(struct hv_device), GFP_KERNEL);
 611        if (!child_device_obj) {
 612                pr_err("Unable to allocate device object for child device\n");
 613                return NULL;
 614        }
 615
 616        child_device_obj->channel = channel;
 617        memcpy(&child_device_obj->dev_type, type, sizeof(uuid_le));
 618        memcpy(&child_device_obj->dev_instance, instance,
 619               sizeof(uuid_le));
 620
 621
 622        return child_device_obj;
 623}
 624
 625/*
 626 * vmbus_device_register - Register the child device
 627 */
 628int vmbus_device_register(struct hv_device *child_device_obj)
 629{
 630        int ret = 0;
 631
 632        static atomic_t device_num = ATOMIC_INIT(0);
 633
 634        dev_set_name(&child_device_obj->device, "vmbus_0_%d",
 635                     atomic_inc_return(&device_num));
 636
 637        child_device_obj->device.bus = &hv_bus;
 638        child_device_obj->device.parent = &hv_acpi_dev->dev;
 639        child_device_obj->device.release = vmbus_device_release;
 640
 641        /*
 642         * Register with the LDM. This will kick off the driver/device
 643         * binding...which will eventually call vmbus_match() and vmbus_probe()
 644         */
 645        ret = device_register(&child_device_obj->device);
 646
 647        if (ret)
 648                pr_err("Unable to register child device\n");
 649        else
 650                pr_info("child device %s registered\n",
 651                        dev_name(&child_device_obj->device));
 652
 653        return ret;
 654}
 655
 656/*
 657 * vmbus_device_unregister - Remove the specified child device
 658 * from the vmbus.
 659 */
 660void vmbus_device_unregister(struct hv_device *device_obj)
 661{
 662        /*
 663         * Kick off the process of unregistering the device.
 664         * This will call vmbus_remove() and eventually vmbus_device_release()
 665         */
 666        device_unregister(&device_obj->device);
 667
 668        pr_info("child device %s unregistered\n",
 669                dev_name(&device_obj->device));
 670}
 671
 672
 673/*
 674 * VMBUS is an acpi enumerated device. Get the the IRQ information
 675 * from DSDT.
 676 */
 677
 678static acpi_status vmbus_walk_resources(struct acpi_resource *res, void *irq)
 679{
 680
 681        if (res->type == ACPI_RESOURCE_TYPE_IRQ) {
 682                struct acpi_resource_irq *irqp;
 683                irqp = &res->data.irq;
 684
 685                *((unsigned int *)irq) = irqp->interrupts[0];
 686        }
 687
 688        return AE_OK;
 689}
 690
 691static int vmbus_acpi_add(struct acpi_device *device)
 692{
 693        acpi_status result;
 694
 695        hv_acpi_dev = device;
 696
 697        result = acpi_walk_resources(device->handle, METHOD_NAME__CRS,
 698                                        vmbus_walk_resources, &irq);
 699
 700        if (ACPI_FAILURE(result)) {
 701                complete(&probe_event);
 702                return -ENODEV;
 703        }
 704        complete(&probe_event);
 705        return 0;
 706}
 707
 708static const struct acpi_device_id vmbus_acpi_device_ids[] = {
 709        {"VMBUS", 0},
 710        {"VMBus", 0},
 711        {"", 0},
 712};
 713MODULE_DEVICE_TABLE(acpi, vmbus_acpi_device_ids);
 714
 715static struct acpi_driver vmbus_acpi_driver = {
 716        .name = "vmbus",
 717        .ids = vmbus_acpi_device_ids,
 718        .ops = {
 719                .add = vmbus_acpi_add,
 720        },
 721};
 722
 723static int __init hv_acpi_init(void)
 724{
 725        int ret, t;
 726
 727        if (x86_hyper != &x86_hyper_ms_hyperv)
 728                return -ENODEV;
 729
 730        init_completion(&probe_event);
 731
 732        /*
 733         * Get irq resources first.
 734         */
 735
 736        ret = acpi_bus_register_driver(&vmbus_acpi_driver);
 737
 738        if (ret)
 739                return ret;
 740
 741        t = wait_for_completion_timeout(&probe_event, 5*HZ);
 742        if (t == 0) {
 743                ret = -ETIMEDOUT;
 744                goto cleanup;
 745        }
 746
 747        if (irq <= 0) {
 748                ret = -ENODEV;
 749                goto cleanup;
 750        }
 751
 752        ret = vmbus_bus_init(irq);
 753        if (ret)
 754                goto cleanup;
 755
 756        return 0;
 757
 758cleanup:
 759        acpi_bus_unregister_driver(&vmbus_acpi_driver);
 760        hv_acpi_dev = NULL;
 761        return ret;
 762}
 763
 764static void __exit vmbus_exit(void)
 765{
 766
 767        free_irq(irq, hv_acpi_dev);
 768        vmbus_free_channels();
 769        bus_unregister(&hv_bus);
 770        hv_cleanup();
 771        acpi_bus_unregister_driver(&vmbus_acpi_driver);
 772}
 773
 774
 775MODULE_LICENSE("GPL");
 776MODULE_VERSION(HV_DRV_VERSION);
 777
 778subsys_initcall(hv_acpi_init);
 779module_exit(vmbus_exit);
 780
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