drivers/staging/hv/storvsc.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 #include <linux/kernel.h>
  24 #include <linux/sched.h>
  25 #include <linux/completion.h>
  26 #include <linux/string.h>
  27 #include <linux/slab.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30
  31 #include "hyperv.h"
  32 #include "hyperv_storage.h"
  33
  34
  35 static inline struct storvsc_device *alloc_stor_device(struct hv_device *device)
  36 {
  37         struct storvsc_device *stor_device;
  38
  39         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
  40         if (!stor_device)
  41                 return NULL;
  42
  43         /* Set to 2 to allow both inbound and outbound traffics */
  44         /* (ie get_stor_device() and must_get_stor_device()) to proceed. */
  45         atomic_cmpxchg(&stor_device->ref_count, 0, 2);
  46
  47         init_waitqueue_head(&stor_device->waiting_to_drain);
  48         stor_device->device = device;
  49         device->ext = stor_device;
  50
  51         return stor_device;
  52 }
  53
  54
  55 /* Get the stordevice object iff exists and its refcount > 0 */
  56 static inline struct storvsc_device *must_get_stor_device(
  57                                         struct hv_device *device)
  58 {
  59         struct storvsc_device *stor_device;
  60
  61         stor_device = (struct storvsc_device *)device->ext;
  62         if (stor_device && atomic_read(&stor_device->ref_count))
  63                 atomic_inc(&stor_device->ref_count);
  64         else
  65                 stor_device = NULL;
  66
  67         return stor_device;
  68 }
  69
  70 /* Drop ref count to 1 to effectively disable get_stor_device() */
  71 static inline struct storvsc_device *release_stor_device(
  72                                         struct hv_device *device)
  73 {
  74         struct storvsc_device *stor_device;
  75
  76         stor_device = (struct storvsc_device *)device->ext;
  77
  78         /* Busy wait until the ref drop to 2, then set it to 1 */
  79         while (atomic_cmpxchg(&stor_device->ref_count, 2, 1) != 2)
  80                 udelay(100);
  81
  82         return stor_device;
  83 }
  84
  85 /* Drop ref count to 0. No one can use stor_device object. */
  86 static inline struct storvsc_device *final_release_stor_device(
  87                         struct hv_device *device)
  88 {
  89         struct storvsc_device *stor_device;
  90
  91         stor_device = (struct storvsc_device *)device->ext;
  92
  93         /* Busy wait until the ref drop to 1, then set it to 0 */
  94         while (atomic_cmpxchg(&stor_device->ref_count, 1, 0) != 1)
  95                 udelay(100);
  96
  97         device->ext = NULL;
  98         return stor_device;
  99 }
 100
 101 static int storvsc_channel_init(struct hv_device *device)
 102 {
 103         struct storvsc_device *stor_device;
 104         struct hv_storvsc_request *request;
 105         struct vstor_packet *vstor_packet;
 106         int ret, t;
 107
 108         stor_device = get_stor_device(device);
 109         if (!stor_device)
 110                 return -ENODEV;
 111
 112         request = &stor_device->init_request;
 113         vstor_packet = &request->vstor_packet;
 114
 115         /*
 116          * Now, initiate the vsc/vsp initialization protocol on the open
 117          * channel
 118          */
 119         memset(request, 0, sizeof(struct hv_storvsc_request));
 120         init_completion(&request->wait_event);
 121         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 122         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 123
 124         ret = vmbus_sendpacket(device->channel, vstor_packet,
 125                                sizeof(struct vstor_packet),
 126                                (unsigned long)request,
 127                                VM_PKT_DATA_INBAND,
 128                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 129         if (ret != 0)
 130                 goto cleanup;
 131
 132         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 133         if (t == 0) {
 134                 ret = -ETIMEDOUT;
 135                 goto cleanup;
 136         }
 137
 138         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 139             vstor_packet->status != 0)
 140                 goto cleanup;
 141
 142
 143         /* reuse the packet for version range supported */
 144         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 145         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 146         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 147
 148         vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
 149         FILL_VMSTOR_REVISION(vstor_packet->version.revision);
 150
 151         ret = vmbus_sendpacket(device->channel, vstor_packet,
 152                                sizeof(struct vstor_packet),
 153                                (unsigned long)request,
 154                                VM_PKT_DATA_INBAND,
 155                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 156         if (ret != 0)
 157                 goto cleanup;
 158
 159         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 160         if (t == 0) {
 161                 ret = -ETIMEDOUT;
 162                 goto cleanup;
 163         }
 164
 165         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 166             vstor_packet->status != 0)
 167                 goto cleanup;
 168
 169
 170         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 171         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 172         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 173         vstor_packet->storage_channel_properties.port_number =
 174                                         stor_device->port_number;
 175
 176         ret = vmbus_sendpacket(device->channel, vstor_packet,
 177                                sizeof(struct vstor_packet),
 178                                (unsigned long)request,
 179                                VM_PKT_DATA_INBAND,
 180                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 181
 182         if (ret != 0)
 183                 goto cleanup;
 184
 185         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 186         if (t == 0) {
 187                 ret = -ETIMEDOUT;
 188                 goto cleanup;
 189         }
 190
 191         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 192             vstor_packet->status != 0)
 193                 goto cleanup;
 194
 195         stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 196         stor_device->target_id
 197                 = vstor_packet->storage_channel_properties.target_id;
 198
 199         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 200         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 201         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 202
 203         ret = vmbus_sendpacket(device->channel, vstor_packet,
 204                                sizeof(struct vstor_packet),
 205                                (unsigned long)request,
 206                                VM_PKT_DATA_INBAND,
 207                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 208
 209         if (ret != 0)
 210                 goto cleanup;
 211
 212         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 213         if (t == 0) {
 214                 ret = -ETIMEDOUT;
 215                 goto cleanup;
 216         }
 217
 218         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 219             vstor_packet->status != 0)
 220                 goto cleanup;
 221
 222
 223 cleanup:
 224         put_stor_device(device);
 225         return ret;
 226 }
 227
 228 static void storvsc_on_io_completion(struct hv_device *device,
 229                                   struct vstor_packet *vstor_packet,
 230                                   struct hv_storvsc_request *request)
 231 {
 232         struct storvsc_device *stor_device;
 233         struct vstor_packet *stor_pkt;
 234
 235         stor_device = must_get_stor_device(device);
 236         if (!stor_device)
 237                 return;
 238
 239         stor_pkt = &request->vstor_packet;
 240
 241
 242         /* Copy over the status...etc */
 243         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 244         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 245         stor_pkt->vm_srb.sense_info_length =
 246         vstor_packet->vm_srb.sense_info_length;
 247
 248         if (vstor_packet->vm_srb.scsi_status != 0 ||
 249                 vstor_packet->vm_srb.srb_status != 1){
 250                 DPRINT_WARN(STORVSC,
 251                             "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 252                             stor_pkt->vm_srb.cdb[0],
 253                             vstor_packet->vm_srb.scsi_status,
 254                             vstor_packet->vm_srb.srb_status);
 255         }
 256
 257         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 258                 /* CHECK_CONDITION */
 259                 if (vstor_packet->vm_srb.srb_status & 0x80) {
 260                         /* autosense data available */
 261                         DPRINT_WARN(STORVSC, "storvsc pkt %p autosense data "
 262                                     "valid - len %d\n", request,
 263                                     vstor_packet->vm_srb.sense_info_length);
 264
 265                         memcpy(request->sense_buffer,
 266                                vstor_packet->vm_srb.sense_data,
 267                                vstor_packet->vm_srb.sense_info_length);
 268
 269                 }
 270         }
 271
 272         stor_pkt->vm_srb.data_transfer_length =
 273         vstor_packet->vm_srb.data_transfer_length;
 274
 275         request->on_io_completion(request);
 276
 277         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 278                 stor_device->drain_notify)
 279                 wake_up(&stor_device->waiting_to_drain);
 280
 281
 282         put_stor_device(device);
 283 }
 284
 285 static void storvsc_on_receive(struct hv_device *device,
 286                              struct vstor_packet *vstor_packet,
 287                              struct hv_storvsc_request *request)
 288 {
 289         switch (vstor_packet->operation) {
 290         case VSTOR_OPERATION_COMPLETE_IO:
 291                 storvsc_on_io_completion(device, vstor_packet, request);
 292                 break;
 293         case VSTOR_OPERATION_REMOVE_DEVICE:
 294
 295         default:
 296                 break;
 297         }
 298 }
 299
 300 static void storvsc_on_channel_callback(void *context)
 301 {
 302         struct hv_device *device = (struct hv_device *)context;
 303         struct storvsc_device *stor_device;
 304         u32 bytes_recvd;
 305         u64 request_id;
 306         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 307         struct hv_storvsc_request *request;
 308         int ret;
 309
 310
 311         stor_device = must_get_stor_device(device);
 312         if (!stor_device)
 313                 return;
 314
 315         do {
 316                 ret = vmbus_recvpacket(device->channel, packet,
 317                                        ALIGN(sizeof(struct vstor_packet), 8),
 318                                        &bytes_recvd, &request_id);
 319                 if (ret == 0 && bytes_recvd > 0) {
 320
 321                         request = (struct hv_storvsc_request *)
 322                                         (unsigned long)request_id;
 323
 324                         if ((request == &stor_device->init_request) ||
 325                             (request == &stor_device->reset_request)) {
 326
 327                                 memcpy(&request->vstor_packet, packet,
 328                                        sizeof(struct vstor_packet));
 329                                 complete(&request->wait_event);
 330                         } else {
 331                                 storvsc_on_receive(device,
 332                                                 (struct vstor_packet *)packet,
 333                                                 request);
 334                         }
 335                 } else {
 336                         break;
 337                 }
 338         } while (1);
 339
 340         put_stor_device(device);
 341         return;
 342 }
 343
 344 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 345 {
 346         struct vmstorage_channel_properties props;
 347         int ret;
 348
 349         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 350
 351         /* Open the channel */
 352         ret = vmbus_open(device->channel,
 353                          ring_size,
 354                          ring_size,
 355                          (void *)&props,
 356                          sizeof(struct vmstorage_channel_properties),
 357                          storvsc_on_channel_callback, device);
 358
 359         if (ret != 0)
 360                 return ret;
 361
 362         ret = storvsc_channel_init(device);
 363
 364         return ret;
 365 }
 366
 367 int storvsc_dev_add(struct hv_device *device,
 368                                         void *additional_info)
 369 {
 370         struct storvsc_device *stor_device;
 371         struct storvsc_device_info *device_info;
 372         int ret = 0;
 373
 374         device_info = (struct storvsc_device_info *)additional_info;
 375         stor_device = alloc_stor_device(device);
 376         if (!stor_device)
 377                 return -ENOMEM;
 378
 379         /* Save the channel properties to our storvsc channel */
 380
 381         /*
 382          * If we support more than 1 scsi channel, we need to set the
 383          * port number here to the scsi channel but how do we get the
 384          * scsi channel prior to the bus scan.
 385          *
 386          * The host does not support this.
 387          */
 388
 389         stor_device->port_number = device_info->port_number;
 390         /* Send it back up */
 391         ret = storvsc_connect_to_vsp(device, device_info->ring_buffer_size);
 392         if (ret) {
 393                 kfree(stor_device);
 394                 return ret;
 395         }
 396         device_info->path_id = stor_device->path_id;
 397         device_info->target_id = stor_device->target_id;
 398
 399         return ret;
 400 }
 401
 402 int storvsc_dev_remove(struct hv_device *device)
 403 {
 404         struct storvsc_device *stor_device;
 405
 406         stor_device = release_stor_device(device);
 407
 408         /*
 409          * At this point, all outbound traffic should be disable. We
 410          * only allow inbound traffic (responses) to proceed so that
 411          * outstanding requests can be completed.
 412          */
 413
 414         storvsc_wait_to_drain(stor_device);
 415
 416         stor_device = final_release_stor_device(device);
 417
 418         /* Close the channel */
 419         vmbus_close(device->channel);
 420
 421         kfree(stor_device);
 422         return 0;
 423 }
 424
 425 int storvsc_do_io(struct hv_device *device,
 426                               struct hv_storvsc_request *request)
 427 {
 428         struct storvsc_device *stor_device;
 429         struct vstor_packet *vstor_packet;
 430         int ret = 0;
 431
 432         vstor_packet = &request->vstor_packet;
 433         stor_device = get_stor_device(device);
 434
 435         if (!stor_device)
 436                 return -ENODEV;
 437
 438
 439         request->device  = device;
 440
 441
 442         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 443
 444         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
 445
 446
 447         vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
 448
 449
 450         vstor_packet->vm_srb.data_transfer_length =
 451         request->data_buffer.len;
 452
 453         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 454
 455         if (request->data_buffer.len) {
 456                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
 457                                 &request->data_buffer,
 458                                 vstor_packet,
 459                                 sizeof(struct vstor_packet),
 460                                 (unsigned long)request);
 461         } else {
 462                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 463                                        sizeof(struct vstor_packet),
 464                                        (unsigned long)request,
 465                                        VM_PKT_DATA_INBAND,
 466                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 467         }
 468
 469         if (ret != 0)
 470                 return ret;
 471
 472         atomic_inc(&stor_device->num_outstanding_req);
 473
 474         put_stor_device(device);
 475         return ret;
 476 }
 477
 478 /*
 479  * The channel properties uniquely specify how the device is to be
 480  * presented to the guest. Map this information for use by the block
 481  * driver. For Linux guests on Hyper-V, we emulate a scsi HBA in the guest
 482  * (storvsc_drv) and so scsi devices in the guest  are handled by
 483  * native upper level Linux drivers. Consequently, Hyper-V
 484  * block driver, while being a generic block driver, presently does not
 485  * deal with anything other than devices that would need to be presented
 486  * to the guest as an IDE disk.
 487  *
 488  * This function maps the channel properties as embedded in the input
 489  * parameter device_info onto information necessary to register the
 490  * corresponding block device.
 491  *
 492  * Currently, there is no way to stop the emulation of the block device
 493  * on the host side. And so, to prevent the native IDE drivers in Linux
 494  * from taking over these devices (to be managedby Hyper-V block
 495  * driver), we will take over if need be the major of the IDE controllers.
 496  *
 497  */
 498
 499 int storvsc_get_major_info(struct storvsc_device_info *device_info,
 500                             struct storvsc_major_info *major_info)
 501 {
 502         static bool ide0_registered;
 503         static bool ide1_registered;
 504
 505         /*
 506          * For now we only support IDE disks.
 507          */
 508         major_info->devname = "ide";
 509         major_info->diskname = "hd";
 510
 511         if (device_info->path_id) {
 512                 major_info->major = 22;
 513                 if (!ide1_registered) {
 514                         major_info->do_register = true;
 515                         ide1_registered = true;
 516                 } else
 517                         major_info->do_register = false;
 518
 519                 if (device_info->target_id)
 520                         major_info->index = 3;
 521                 else
 522                         major_info->index = 2;
 523
 524                 return 0;
 525         } else {
 526                 major_info->major = 3;
 527                 if (!ide0_registered) {
 528                         major_info->do_register = true;
 529                         ide0_registered = true;
 530                 } else
 531                         major_info->do_register = false;
 532
 533                 if (device_info->target_id)
 534                         major_info->index = 1;
 535                 else
 536                         major_info->index = 0;
 537
 538                 return 0;
 539         }
 540
 541         return -ENODEV;
 542 }