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_out_stor_device() and get_in_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 *get_in_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_out_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_out_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 = (struct storvsc_device *)device->ext;
 236
 237         stor_pkt = &request->vstor_packet;
 238
 239
 240         /* Copy over the status...etc */
 241         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 242         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 243         stor_pkt->vm_srb.sense_info_length =
 244         vstor_packet->vm_srb.sense_info_length;
 245
 246         if (vstor_packet->vm_srb.scsi_status != 0 ||
 247                 vstor_packet->vm_srb.srb_status != 1){
 248                 DPRINT_WARN(STORVSC,
 249                             "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 250                             stor_pkt->vm_srb.cdb[0],
 251                             vstor_packet->vm_srb.scsi_status,
 252                             vstor_packet->vm_srb.srb_status);
 253         }
 254
 255         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 256                 /* CHECK_CONDITION */
 257                 if (vstor_packet->vm_srb.srb_status & 0x80) {
 258                         /* autosense data available */
 259                         DPRINT_WARN(STORVSC, "storvsc pkt %p autosense data "
 260                                     "valid - len %d\n", request,
 261                                     vstor_packet->vm_srb.sense_info_length);
 262
 263                         memcpy(request->sense_buffer,
 264                                vstor_packet->vm_srb.sense_data,
 265                                vstor_packet->vm_srb.sense_info_length);
 266
 267                 }
 268         }
 269
 270         stor_pkt->vm_srb.data_transfer_length =
 271         vstor_packet->vm_srb.data_transfer_length;
 272
 273         request->on_io_completion(request);
 274
 275         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 276                 stor_device->drain_notify)
 277                 wake_up(&stor_device->waiting_to_drain);
 278
 279
 280 }
 281
 282 static void storvsc_on_receive(struct hv_device *device,
 283                              struct vstor_packet *vstor_packet,
 284                              struct hv_storvsc_request *request)
 285 {
 286         switch (vstor_packet->operation) {
 287         case VSTOR_OPERATION_COMPLETE_IO:
 288                 storvsc_on_io_completion(device, vstor_packet, request);
 289                 break;
 290         case VSTOR_OPERATION_REMOVE_DEVICE:
 291
 292         default:
 293                 break;
 294         }
 295 }
 296
 297 static void storvsc_on_channel_callback(void *context)
 298 {
 299         struct hv_device *device = (struct hv_device *)context;
 300         struct storvsc_device *stor_device;
 301         u32 bytes_recvd;
 302         u64 request_id;
 303         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 304         struct hv_storvsc_request *request;
 305         int ret;
 306
 307
 308         stor_device = get_in_stor_device(device);
 309         if (!stor_device)
 310                 return;
 311
 312         do {
 313                 ret = vmbus_recvpacket(device->channel, packet,
 314                                        ALIGN(sizeof(struct vstor_packet), 8),
 315                                        &bytes_recvd, &request_id);
 316                 if (ret == 0 && bytes_recvd > 0) {
 317
 318                         request = (struct hv_storvsc_request *)
 319                                         (unsigned long)request_id;
 320
 321                         if ((request == &stor_device->init_request) ||
 322                             (request == &stor_device->reset_request)) {
 323
 324                                 memcpy(&request->vstor_packet, packet,
 325                                        sizeof(struct vstor_packet));
 326                                 complete(&request->wait_event);
 327                         } else {
 328                                 storvsc_on_receive(device,
 329                                                 (struct vstor_packet *)packet,
 330                                                 request);
 331                         }
 332                 } else {
 333                         break;
 334                 }
 335         } while (1);
 336
 337         put_stor_device(device);
 338         return;
 339 }
 340
 341 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 342 {
 343         struct vmstorage_channel_properties props;
 344         int ret;
 345
 346         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 347
 348         /* Open the channel */
 349         ret = vmbus_open(device->channel,
 350                          ring_size,
 351                          ring_size,
 352                          (void *)&props,
 353                          sizeof(struct vmstorage_channel_properties),
 354                          storvsc_on_channel_callback, device);
 355
 356         if (ret != 0)
 357                 return ret;
 358
 359         ret = storvsc_channel_init(device);
 360
 361         return ret;
 362 }
 363
 364 int storvsc_dev_add(struct hv_device *device,
 365                                         void *additional_info)
 366 {
 367         struct storvsc_device *stor_device;
 368         struct storvsc_device_info *device_info;
 369         int ret = 0;
 370
 371         device_info = (struct storvsc_device_info *)additional_info;
 372         stor_device = alloc_stor_device(device);
 373         if (!stor_device)
 374                 return -ENOMEM;
 375
 376         /* Save the channel properties to our storvsc channel */
 377
 378         /*
 379          * If we support more than 1 scsi channel, we need to set the
 380          * port number here to the scsi channel but how do we get the
 381          * scsi channel prior to the bus scan.
 382          *
 383          * The host does not support this.
 384          */
 385
 386         stor_device->port_number = device_info->port_number;
 387         /* Send it back up */
 388         ret = storvsc_connect_to_vsp(device, device_info->ring_buffer_size);
 389         if (ret) {
 390                 kfree(stor_device);
 391                 return ret;
 392         }
 393         device_info->path_id = stor_device->path_id;
 394         device_info->target_id = stor_device->target_id;
 395
 396         return ret;
 397 }
 398
 399 int storvsc_dev_remove(struct hv_device *device)
 400 {
 401         struct storvsc_device *stor_device;
 402
 403         stor_device = release_stor_device(device);
 404
 405         /*
 406          * At this point, all outbound traffic should be disable. We
 407          * only allow inbound traffic (responses) to proceed so that
 408          * outstanding requests can be completed.
 409          */
 410
 411         storvsc_wait_to_drain(stor_device);
 412
 413         stor_device = final_release_stor_device(device);
 414
 415         /* Close the channel */
 416         vmbus_close(device->channel);
 417
 418         kfree(stor_device);
 419         return 0;
 420 }
 421
 422 int storvsc_do_io(struct hv_device *device,
 423                               struct hv_storvsc_request *request)
 424 {
 425         struct storvsc_device *stor_device;
 426         struct vstor_packet *vstor_packet;
 427         int ret = 0;
 428
 429         vstor_packet = &request->vstor_packet;
 430         stor_device = get_out_stor_device(device);
 431
 432         if (!stor_device)
 433                 return -ENODEV;
 434
 435
 436         request->device  = device;
 437
 438
 439         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 440
 441         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
 442
 443
 444         vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
 445
 446
 447         vstor_packet->vm_srb.data_transfer_length =
 448         request->data_buffer.len;
 449
 450         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 451
 452         if (request->data_buffer.len) {
 453                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
 454                                 &request->data_buffer,
 455                                 vstor_packet,
 456                                 sizeof(struct vstor_packet),
 457                                 (unsigned long)request);
 458         } else {
 459                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 460                                        sizeof(struct vstor_packet),
 461                                        (unsigned long)request,
 462                                        VM_PKT_DATA_INBAND,
 463                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 464         }
 465
 466         if (ret != 0)
 467                 return ret;
 468
 469         atomic_inc(&stor_device->num_outstanding_req);
 470
 471         put_stor_device(device);
 472         return ret;
 473 }
 474
 475 /*
 476  * The channel properties uniquely specify how the device is to be
 477  * presented to the guest. Map this information for use by the block
 478  * driver. For Linux guests on Hyper-V, we emulate a scsi HBA in the guest
 479  * (storvsc_drv) and so scsi devices in the guest  are handled by
 480  * native upper level Linux drivers. Consequently, Hyper-V
 481  * block driver, while being a generic block driver, presently does not
 482  * deal with anything other than devices that would need to be presented
 483  * to the guest as an IDE disk.
 484  *
 485  * This function maps the channel properties as embedded in the input
 486  * parameter device_info onto information necessary to register the
 487  * corresponding block device.
 488  *
 489  * Currently, there is no way to stop the emulation of the block device
 490  * on the host side. And so, to prevent the native IDE drivers in Linux
 491  * from taking over these devices (to be managedby Hyper-V block
 492  * driver), we will take over if need be the major of the IDE controllers.
 493  *
 494  */
 495
 496 int storvsc_get_major_info(struct storvsc_device_info *device_info,
 497                             struct storvsc_major_info *major_info)
 498 {
 499         static bool ide0_registered;
 500         static bool ide1_registered;
 501
 502         /*
 503          * For now we only support IDE disks.
 504          */
 505         major_info->devname = "ide";
 506         major_info->diskname = "hd";
 507
 508         if (device_info->path_id) {
 509                 major_info->major = 22;
 510                 if (!ide1_registered) {
 511                         major_info->do_register = true;
 512                         ide1_registered = true;
 513                 } else
 514                         major_info->do_register = false;
 515
 516                 if (device_info->target_id)
 517                         major_info->index = 3;
 518                 else
 519                         major_info->index = 2;
 520
 521                 return 0;
 522         } else {
 523                 major_info->major = 3;
 524                 if (!ide0_registered) {
 525                         major_info->do_register = true;
 526                         ide0_registered = true;
 527                 } else
 528                         major_info->do_register = false;
 529
 530                 if (device_info->target_id)
 531                         major_info->index = 1;
 532                 else
 533                         major_info->index = 0;
 534
 535                 return 0;
 536         }
 537
 538         return -ENODEV;
 539 }