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 static inline void free_stor_device(struct storvsc_device *device)
  55 {
  56         kfree(device);
  57 }
  58
  59 /* Get the stordevice object iff exists and its refcount > 0 */
  60 static inline struct storvsc_device *must_get_stor_device(
  61                                         struct hv_device *device)
  62 {
  63         struct storvsc_device *stor_device;
  64
  65         stor_device = (struct storvsc_device *)device->ext;
  66         if (stor_device && atomic_read(&stor_device->ref_count))
  67                 atomic_inc(&stor_device->ref_count);
  68         else
  69                 stor_device = NULL;
  70
  71         return stor_device;
  72 }
  73
  74 /* Drop ref count to 1 to effectively disable get_stor_device() */
  75 static inline struct storvsc_device *release_stor_device(
  76                                         struct hv_device *device)
  77 {
  78         struct storvsc_device *stor_device;
  79
  80         stor_device = (struct storvsc_device *)device->ext;
  81
  82         /* Busy wait until the ref drop to 2, then set it to 1 */
  83         while (atomic_cmpxchg(&stor_device->ref_count, 2, 1) != 2)
  84                 udelay(100);
  85
  86         return stor_device;
  87 }
  88
  89 /* Drop ref count to 0. No one can use stor_device object. */
  90 static inline struct storvsc_device *final_release_stor_device(
  91                         struct hv_device *device)
  92 {
  93         struct storvsc_device *stor_device;
  94
  95         stor_device = (struct storvsc_device *)device->ext;
  96
  97         /* Busy wait until the ref drop to 1, then set it to 0 */
  98         while (atomic_cmpxchg(&stor_device->ref_count, 1, 0) != 1)
  99                 udelay(100);
 100
 101         device->ext = NULL;
 102         return stor_device;
 103 }
 104
 105 static int storvsc_channel_init(struct hv_device *device)
 106 {
 107         struct storvsc_device *stor_device;
 108         struct hv_storvsc_request *request;
 109         struct vstor_packet *vstor_packet;
 110         int ret, t;
 111
 112         stor_device = get_stor_device(device);
 113         if (!stor_device)
 114                 return -1;
 115
 116         request = &stor_device->init_request;
 117         vstor_packet = &request->vstor_packet;
 118
 119         /*
 120          * Now, initiate the vsc/vsp initialization protocol on the open
 121          * channel
 122          */
 123         memset(request, 0, sizeof(struct hv_storvsc_request));
 124         init_completion(&request->wait_event);
 125         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 126         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 127
 128         DPRINT_INFO(STORVSC, "BEGIN_INITIALIZATION_OPERATION...");
 129
 130         ret = vmbus_sendpacket(device->channel, vstor_packet,
 131                                sizeof(struct vstor_packet),
 132                                (unsigned long)request,
 133                                VM_PKT_DATA_INBAND,
 134                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 135         if (ret != 0)
 136                 goto cleanup;
 137
 138         t = wait_for_completion_timeout(&request->wait_event, HZ);
 139         if (t == 0) {
 140                 ret = -ETIMEDOUT;
 141                 goto cleanup;
 142         }
 143
 144         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 145             vstor_packet->status != 0)
 146                 goto cleanup;
 147
 148         DPRINT_INFO(STORVSC, "QUERY_PROTOCOL_VERSION_OPERATION...");
 149
 150         /* reuse the packet for version range supported */
 151         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 152         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 153         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 154
 155         vstor_packet->version.major_minor = VMSTOR_PROTOCOL_VERSION_CURRENT;
 156         FILL_VMSTOR_REVISION(vstor_packet->version.revision);
 157
 158         ret = vmbus_sendpacket(device->channel, vstor_packet,
 159                                sizeof(struct vstor_packet),
 160                                (unsigned long)request,
 161                                VM_PKT_DATA_INBAND,
 162                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 163         if (ret != 0)
 164                 goto cleanup;
 165
 166         t = wait_for_completion_timeout(&request->wait_event, HZ);
 167         if (t == 0) {
 168                 ret = -ETIMEDOUT;
 169                 goto cleanup;
 170         }
 171
 172         /* TODO: Check returned version */
 173         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 174             vstor_packet->status != 0)
 175                 goto cleanup;
 176
 177         /* Query channel properties */
 178         DPRINT_INFO(STORVSC, "QUERY_PROPERTIES_OPERATION...");
 179
 180         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 181         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 182         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 183         vstor_packet->storage_channel_properties.port_number =
 184                                         stor_device->port_number;
 185
 186         ret = vmbus_sendpacket(device->channel, vstor_packet,
 187                                sizeof(struct vstor_packet),
 188                                (unsigned long)request,
 189                                VM_PKT_DATA_INBAND,
 190                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 191
 192         if (ret != 0)
 193                 goto cleanup;
 194
 195         t = wait_for_completion_timeout(&request->wait_event, HZ);
 196         if (t == 0) {
 197                 ret = -ETIMEDOUT;
 198                 goto cleanup;
 199         }
 200
 201         /* TODO: Check returned version */
 202         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 203             vstor_packet->status != 0)
 204                 goto cleanup;
 205
 206         stor_device->path_id = vstor_packet->storage_channel_properties.path_id;
 207         stor_device->target_id
 208                 = vstor_packet->storage_channel_properties.target_id;
 209
 210         DPRINT_INFO(STORVSC, "END_INITIALIZATION_OPERATION...");
 211
 212         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 213         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 214         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 215
 216         ret = vmbus_sendpacket(device->channel, vstor_packet,
 217                                sizeof(struct vstor_packet),
 218                                (unsigned long)request,
 219                                VM_PKT_DATA_INBAND,
 220                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 221
 222         if (ret != 0)
 223                 goto cleanup;
 224
 225         t = wait_for_completion_timeout(&request->wait_event, HZ);
 226         if (t == 0) {
 227                 ret = -ETIMEDOUT;
 228                 goto cleanup;
 229         }
 230
 231         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 232             vstor_packet->status != 0)
 233                 goto cleanup;
 234
 235         DPRINT_INFO(STORVSC, "**** storage channel up and running!! ****");
 236
 237 cleanup:
 238         put_stor_device(device);
 239         return ret;
 240 }
 241
 242 static void storvsc_on_io_completion(struct hv_device *device,
 243                                   struct vstor_packet *vstor_packet,
 244                                   struct hv_storvsc_request *request)
 245 {
 246         struct storvsc_device *stor_device;
 247         struct vstor_packet *stor_pkt;
 248
 249         stor_device = must_get_stor_device(device);
 250         if (!stor_device)
 251                 return;
 252
 253         stor_pkt = &request->vstor_packet;
 254
 255
 256         /* Copy over the status...etc */
 257         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 258         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 259         stor_pkt->vm_srb.sense_info_length =
 260         vstor_packet->vm_srb.sense_info_length;
 261
 262         if (vstor_packet->vm_srb.scsi_status != 0 ||
 263                 vstor_packet->vm_srb.srb_status != 1){
 264                 DPRINT_WARN(STORVSC,
 265                             "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
 266                             stor_pkt->vm_srb.cdb[0],
 267                             vstor_packet->vm_srb.scsi_status,
 268                             vstor_packet->vm_srb.srb_status);
 269         }
 270
 271         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 272                 /* CHECK_CONDITION */
 273                 if (vstor_packet->vm_srb.srb_status & 0x80) {
 274                         /* autosense data available */
 275                         DPRINT_WARN(STORVSC, "storvsc pkt %p autosense data "
 276                                     "valid - len %d\n", request,
 277                                     vstor_packet->vm_srb.sense_info_length);
 278
 279                         memcpy(request->sense_buffer,
 280                                vstor_packet->vm_srb.sense_data,
 281                                vstor_packet->vm_srb.sense_info_length);
 282
 283                 }
 284         }
 285
 286         stor_pkt->vm_srb.data_transfer_length =
 287         vstor_packet->vm_srb.data_transfer_length;
 288
 289         request->on_io_completion(request);
 290
 291         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
 292                 stor_device->drain_notify)
 293                 wake_up(&stor_device->waiting_to_drain);
 294
 295
 296         put_stor_device(device);
 297 }
 298
 299 static void storvsc_on_receive(struct hv_device *device,
 300                              struct vstor_packet *vstor_packet,
 301                              struct hv_storvsc_request *request)
 302 {
 303         switch (vstor_packet->operation) {
 304         case VSTOR_OPERATION_COMPLETE_IO:
 305                 storvsc_on_io_completion(device, vstor_packet, request);
 306                 break;
 307         case VSTOR_OPERATION_REMOVE_DEVICE:
 308                 DPRINT_INFO(STORVSC, "REMOVE_DEVICE_OPERATION");
 309                 /* TODO: */
 310                 break;
 311
 312         default:
 313                 DPRINT_INFO(STORVSC, "Unknown operation received - %d",
 314                             vstor_packet->operation);
 315                 break;
 316         }
 317 }
 318
 319 static void storvsc_on_channel_callback(void *context)
 320 {
 321         struct hv_device *device = (struct hv_device *)context;
 322         struct storvsc_device *stor_device;
 323         u32 bytes_recvd;
 324         u64 request_id;
 325         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
 326         struct hv_storvsc_request *request;
 327         int ret;
 328
 329
 330         stor_device = must_get_stor_device(device);
 331         if (!stor_device)
 332                 return;
 333
 334         do {
 335                 ret = vmbus_recvpacket(device->channel, packet,
 336                                        ALIGN(sizeof(struct vstor_packet), 8),
 337                                        &bytes_recvd, &request_id);
 338                 if (ret == 0 && bytes_recvd > 0) {
 339
 340                         request = (struct hv_storvsc_request *)
 341                                         (unsigned long)request_id;
 342
 343                         if ((request == &stor_device->init_request) ||
 344                             (request == &stor_device->reset_request)) {
 345
 346                                 memcpy(&request->vstor_packet, packet,
 347                                        sizeof(struct vstor_packet));
 348                                 complete(&request->wait_event);
 349                         } else {
 350                                 storvsc_on_receive(device,
 351                                                 (struct vstor_packet *)packet,
 352                                                 request);
 353                         }
 354                 } else {
 355                         break;
 356                 }
 357         } while (1);
 358
 359         put_stor_device(device);
 360         return;
 361 }
 362
 363 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
 364 {
 365         struct vmstorage_channel_properties props;
 366         int ret;
 367
 368         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 369
 370         /* Open the channel */
 371         ret = vmbus_open(device->channel,
 372                          ring_size,
 373                          ring_size,
 374                          (void *)&props,
 375                          sizeof(struct vmstorage_channel_properties),
 376                          storvsc_on_channel_callback, device);
 377
 378         if (ret != 0)
 379                 return -1;
 380
 381         ret = storvsc_channel_init(device);
 382
 383         return ret;
 384 }
 385
 386 int storvsc_dev_add(struct hv_device *device,
 387                                         void *additional_info)
 388 {
 389         struct storvsc_device *stor_device;
 390         struct storvsc_device_info *device_info;
 391         int ret = 0;
 392
 393         device_info = (struct storvsc_device_info *)additional_info;
 394         stor_device = alloc_stor_device(device);
 395         if (!stor_device) {
 396                 ret = -1;
 397                 goto cleanup;
 398         }
 399
 400         /* Save the channel properties to our storvsc channel */
 401
 402         /* FIXME: */
 403         /*
 404          * If we support more than 1 scsi channel, we need to set the
 405          * port number here to the scsi channel but how do we get the
 406          * scsi channel prior to the bus scan
 407          */
 408
 409         stor_device->port_number = device_info->port_number;
 410         /* Send it back up */
 411         ret = storvsc_connect_to_vsp(device, device_info->ring_buffer_size);
 412
 413         device_info->path_id = stor_device->path_id;
 414         device_info->target_id = stor_device->target_id;
 415
 416 cleanup:
 417         return ret;
 418 }
 419
 420 int storvsc_dev_remove(struct hv_device *device)
 421 {
 422         struct storvsc_device *stor_device;
 423
 424         DPRINT_INFO(STORVSC, "disabling storage device (%p)...",
 425                     device->ext);
 426
 427         stor_device = release_stor_device(device);
 428
 429         /*
 430          * At this point, all outbound traffic should be disable. We
 431          * only allow inbound traffic (responses) to proceed so that
 432          * outstanding requests can be completed.
 433          */
 434
 435         storvsc_wait_to_drain(stor_device);
 436
 437         stor_device = final_release_stor_device(device);
 438
 439         /* Close the channel */
 440         vmbus_close(device->channel);
 441
 442         free_stor_device(stor_device);
 443         return 0;
 444 }
 445
 446 int storvsc_do_io(struct hv_device *device,
 447                               struct hv_storvsc_request *request)
 448 {
 449         struct storvsc_device *stor_device;
 450         struct vstor_packet *vstor_packet;
 451         int ret = 0;
 452
 453         vstor_packet = &request->vstor_packet;
 454         stor_device = get_stor_device(device);
 455
 456         if (!stor_device)
 457                 return -2;
 458
 459
 460         request->device  = device;
 461
 462
 463         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
 464
 465         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
 466
 467
 468         vstor_packet->vm_srb.sense_info_length = SENSE_BUFFER_SIZE;
 469
 470
 471         vstor_packet->vm_srb.data_transfer_length =
 472         request->data_buffer.len;
 473
 474         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
 475
 476         if (request->data_buffer.len) {
 477                 ret = vmbus_sendpacket_multipagebuffer(device->channel,
 478                                 &request->data_buffer,
 479                                 vstor_packet,
 480                                 sizeof(struct vstor_packet),
 481                                 (unsigned long)request);
 482         } else {
 483                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 484                                        sizeof(struct vstor_packet),
 485                                        (unsigned long)request,
 486                                        VM_PKT_DATA_INBAND,
 487                                        VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 488         }
 489
 490         if (ret != 0)
 491                 return ret;
 492
 493         atomic_inc(&stor_device->num_outstanding_req);
 494
 495         put_stor_device(device);
 496         return ret;
 497 }
 498
 499 /*
 500  * The channel properties uniquely specify how the device is to be
 501  * presented to the guest. Map this information for use by the block
 502  * driver. For Linux guests on Hyper-V, we emulate a scsi HBA in the guest
 503  * (storvsc_drv) and so scsi devices in the guest  are handled by
 504  * native upper level Linux drivers. Consequently, Hyper-V
 505  * block driver, while being a generic block driver, presently does not
 506  * deal with anything other than devices that would need to be presented
 507  * to the guest as an IDE disk.
 508  *
 509  * This function maps the channel properties as embedded in the input
 510  * parameter device_info onto information necessary to register the
 511  * corresponding block device.
 512  *
 513  * Currently, there is no way to stop the emulation of the block device
 514  * on the host side. And so, to prevent the native IDE drivers in Linux
 515  * from taking over these devices (to be managedby Hyper-V block
 516  * driver), we will take over if need be the major of the IDE controllers.
 517  *
 518  */
 519
 520 int storvsc_get_major_info(struct storvsc_device_info *device_info,
 521                             struct storvsc_major_info *major_info)
 522 {
 523         static bool ide0_registered;
 524         static bool ide1_registered;
 525
 526         /*
 527          * For now we only support IDE disks.
 528          */
 529         major_info->devname = "ide";
 530         major_info->diskname = "hd";
 531
 532         if (device_info->path_id) {
 533                 major_info->major = 22;
 534                 if (!ide1_registered) {
 535                         major_info->do_register = true;
 536                         ide1_registered = true;
 537                 } else
 538                         major_info->do_register = false;
 539
 540                 if (device_info->target_id)
 541                         major_info->index = 3;
 542                 else
 543                         major_info->index = 2;
 544
 545                 return 0;
 546         } else {
 547                 major_info->major = 3;
 548                 if (!ide0_registered) {
 549                         major_info->do_register = true;
 550                         ide0_registered = true;
 551                 } else
 552                         major_info->do_register = false;
 553
 554                 if (device_info->target_id)
 555                         major_info->index = 1;
 556                 else
 557                         major_info->index = 0;
 558
 559                 return 0;
 560         }
 561
 562         return -ENODEV;
 563 }
 564