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