drivers/scsi/storvsc_drv.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/wait.h>
  25 #include <linux/sched.h>
  26 #include <linux/completion.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/device.h>
  34 #include <linux/hyperv.h>
  35 #include <linux/blkdev.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_tcq.h>
  41 #include <scsi/scsi_eh.h>
  42 #include <scsi/scsi_devinfo.h>
  43 #include <scsi/scsi_dbg.h>
  44
  45 /*
  46  * All wire protocol details (storage protocol between the guest and the host)
  47  * are consolidated here.
  48  *
  49  * Begin protocol definitions.
  50  */
  51
  52 /*
  53  * Version history:
  54  * V1 Beta: 0.1
  55  * V1 RC < 2008/1/31: 1.0
  56  * V1 RC > 2008/1/31:  2.0
  57  * Win7: 4.2
  58  * Win8: 5.1
  59  * Win8.1: 6.0
  60  * Win10: 6.2
  61  */
  62
  63 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  64                                                 (((MINOR_) & 0xff)))
  65
  66 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  67 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  68 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  69 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  70 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  71
  72 /*  Packet structure describing virtual storage requests. */
  73 enum vstor_packet_operation {
  74         VSTOR_OPERATION_COMPLETE_IO             = 1,
  75         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  76         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  77         VSTOR_OPERATION_RESET_LUN               = 4,
  78         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  79         VSTOR_OPERATION_RESET_BUS               = 6,
  80         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  81         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  82         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  83         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  84         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  85         VSTOR_OPERATION_FCHBA_DATA              = 12,
  86         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  87         VSTOR_OPERATION_MAXIMUM                 = 13
  88 };
  89
  90 /*
  91  * WWN packet for Fibre Channel HBA
  92  */
  93
  94 struct hv_fc_wwn_packet {
  95         bool    primary_active;
  96         u8      reserved1;
  97         u8      reserved2;
  98         u8      primary_port_wwn[8];
  99         u8      primary_node_wwn[8];
 100         u8      secondary_port_wwn[8];
 101         u8      secondary_node_wwn[8];
 102 };
 103
 104
 105
 106 /*
 107  * SRB Flag Bits
 108  */
 109
 110 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 111 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 112 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 113 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 114 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 115 #define SRB_FLAGS_DATA_IN                       0x00000040
 116 #define SRB_FLAGS_DATA_OUT                      0x00000080
 117 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 118 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 119 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 120 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 121 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 122
 123 /*
 124  * This flag indicates the request is part of the workflow for processing a D3.
 125  */
 126 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 127 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 128 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 129 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 130 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 131 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 132 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 133 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 134 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 135 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 136 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 137
 138
 139 /*
 140  * Platform neutral description of a scsi request -
 141  * this remains the same across the write regardless of 32/64 bit
 142  * note: it's patterned off the SCSI_PASS_THROUGH structure
 143  */
 144 #define STORVSC_MAX_CMD_LEN                     0x10
 145
 146 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 147 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 148
 149 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 150 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 151
 152 /*
 153  * Sense buffer size changed in win8; have a run-time
 154  * variable to track the size we should use.  This value will
 155  * likely change during protocol negotiation but it is valid
 156  * to start by assuming pre-Win8.
 157  */
 158 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 159
 160 /*
 161  * The storage protocol version is determined during the
 162  * initial exchange with the host.  It will indicate which
 163  * storage functionality is available in the host.
 164 */
 165 static int vmstor_proto_version;
 166
 167 struct vmscsi_win8_extension {
 168         /*
 169          * The following were added in Windows 8
 170          */
 171         u16 reserve;
 172         u8  queue_tag;
 173         u8  queue_action;
 174         u32 srb_flags;
 175         u32 time_out_value;
 176         u32 queue_sort_ey;
 177 } __packed;
 178
 179 struct vmscsi_request {
 180         u16 length;
 181         u8 srb_status;
 182         u8 scsi_status;
 183
 184         u8  port_number;
 185         u8  path_id;
 186         u8  target_id;
 187         u8  lun;
 188
 189         u8  cdb_length;
 190         u8  sense_info_length;
 191         u8  data_in;
 192         u8  reserved;
 193
 194         u32 data_transfer_length;
 195
 196         union {
 197                 u8 cdb[STORVSC_MAX_CMD_LEN];
 198                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 199                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 200         };
 201         /*
 202          * The following was added in win8.
 203          */
 204         struct vmscsi_win8_extension win8_extension;
 205
 206 } __attribute((packed));
 207
 208
 209 /*
 210  * The size of the vmscsi_request has changed in win8. The
 211  * additional size is because of new elements added to the
 212  * structure. These elements are valid only when we are talking
 213  * to a win8 host.
 214  * Track the correction to size we need to apply. This value
 215  * will likely change during protocol negotiation but it is
 216  * valid to start by assuming pre-Win8.
 217  */
 218 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 219
 220 /*
 221  * The list of storage protocols in order of preference.
 222  */
 223 struct vmstor_protocol {
 224         int protocol_version;
 225         int sense_buffer_size;
 226         int vmscsi_size_delta;
 227 };
 228
 229
 230 static const struct vmstor_protocol vmstor_protocols[] = {
 231         {
 232                 VMSTOR_PROTO_VERSION_WIN10,
 233                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 234                 0
 235         },
 236         {
 237                 VMSTOR_PROTO_VERSION_WIN8_1,
 238                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 239                 0
 240         },
 241         {
 242                 VMSTOR_PROTO_VERSION_WIN8,
 243                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 244                 0
 245         },
 246         {
 247                 VMSTOR_PROTO_VERSION_WIN7,
 248                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 249                 sizeof(struct vmscsi_win8_extension),
 250         },
 251         {
 252                 VMSTOR_PROTO_VERSION_WIN6,
 253                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 254                 sizeof(struct vmscsi_win8_extension),
 255         }
 256 };
 257
 258
 259 /*
 260  * This structure is sent during the intialization phase to get the different
 261  * properties of the channel.
 262  */
 263
 264 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 265
 266 struct vmstorage_channel_properties {
 267         u32 reserved;
 268         u16 max_channel_cnt;
 269         u16 reserved1;
 270
 271         u32 flags;
 272         u32   max_transfer_bytes;
 273
 274         u64  reserved2;
 275 } __packed;
 276
 277 /*  This structure is sent during the storage protocol negotiations. */
 278 struct vmstorage_protocol_version {
 279         /* Major (MSW) and minor (LSW) version numbers. */
 280         u16 major_minor;
 281
 282         /*
 283          * Revision number is auto-incremented whenever this file is changed
 284          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 285          * definitely indicate incompatibility--but it does indicate mismatched
 286          * builds.
 287          * This is only used on the windows side. Just set it to 0.
 288          */
 289         u16 revision;
 290 } __packed;
 291
 292 /* Channel Property Flags */
 293 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 294 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 295
 296 struct vstor_packet {
 297         /* Requested operation type */
 298         enum vstor_packet_operation operation;
 299
 300         /*  Flags - see below for values */
 301         u32 flags;
 302
 303         /* Status of the request returned from the server side. */
 304         u32 status;
 305
 306         /* Data payload area */
 307         union {
 308                 /*
 309                  * Structure used to forward SCSI commands from the
 310                  * client to the server.
 311                  */
 312                 struct vmscsi_request vm_srb;
 313
 314                 /* Structure used to query channel properties. */
 315                 struct vmstorage_channel_properties storage_channel_properties;
 316
 317                 /* Used during version negotiations. */
 318                 struct vmstorage_protocol_version version;
 319
 320                 /* Fibre channel address packet */
 321                 struct hv_fc_wwn_packet wwn_packet;
 322
 323                 /* Number of sub-channels to create */
 324                 u16 sub_channel_count;
 325
 326                 /* This will be the maximum of the union members */
 327                 u8  buffer[0x34];
 328         };
 329 } __packed;
 330
 331 /*
 332  * Packet Flags:
 333  *
 334  * This flag indicates that the server should send back a completion for this
 335  * packet.
 336  */
 337
 338 #define REQUEST_COMPLETION_FLAG 0x1
 339
 340 /* Matches Windows-end */
 341 enum storvsc_request_type {
 342         WRITE_TYPE = 0,
 343         READ_TYPE,
 344         UNKNOWN_TYPE,
 345 };
 346
 347 /*
 348  * SRB status codes and masks; a subset of the codes used here.
 349  */
 350
 351 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 352 #define SRB_STATUS_INVALID_LUN  0x20
 353 #define SRB_STATUS_SUCCESS      0x01
 354 #define SRB_STATUS_ABORTED      0x02
 355 #define SRB_STATUS_ERROR        0x04
 356
 357 /*
 358  * This is the end of Protocol specific defines.
 359  */
 360
 361 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 362 static u32 max_outstanding_req_per_channel;
 363
 364 static int storvsc_vcpus_per_sub_channel = 4;
 365
 366 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 367 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 368
 369 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 370 MODULE_PARM_DESC(vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 371 /*
 372  * Timeout in seconds for all devices managed by this driver.
 373  */
 374 static int storvsc_timeout = 180;
 375
 376 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 377
 378
 379 static void storvsc_on_channel_callback(void *context);
 380
 381 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 382 #define STORVSC_MAX_TARGETS                             2
 383 #define STORVSC_MAX_CHANNELS                            8
 384
 385 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 386 #define STORVSC_FC_MAX_TARGETS                          128
 387 #define STORVSC_FC_MAX_CHANNELS                         8
 388
 389 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 390 #define STORVSC_IDE_MAX_TARGETS                         1
 391 #define STORVSC_IDE_MAX_CHANNELS                        1
 392
 393 struct storvsc_cmd_request {
 394         struct scsi_cmnd *cmd;
 395
 396         struct hv_device *device;
 397
 398         /* Synchronize the request/response if needed */
 399         struct completion wait_event;
 400
 401         struct vmbus_channel_packet_multipage_buffer mpb;
 402         struct vmbus_packet_mpb_array *payload;
 403         u32 payload_sz;
 404
 405         struct vstor_packet vstor_packet;
 406 };
 407
 408
 409 /* A storvsc device is a device object that contains a vmbus channel */
 410 struct storvsc_device {
 411         struct hv_device *device;
 412
 413         bool     destroy;
 414         bool     drain_notify;
 415         bool     open_sub_channel;
 416         atomic_t num_outstanding_req;
 417         struct Scsi_Host *host;
 418
 419         wait_queue_head_t waiting_to_drain;
 420
 421         /*
 422          * Each unique Port/Path/Target represents 1 channel ie scsi
 423          * controller. In reality, the pathid, targetid is always 0
 424          * and the port is set by us
 425          */
 426         unsigned int port_number;
 427         unsigned char path_id;
 428         unsigned char target_id;
 429
 430         /*
 431          * Max I/O, the device can support.
 432          */
 433         u32   max_transfer_bytes;
 434         /* Used for vsc/vsp channel reset process */
 435         struct storvsc_cmd_request init_request;
 436         struct storvsc_cmd_request reset_request;
 437 };
 438
 439 struct hv_host_device {
 440         struct hv_device *dev;
 441         unsigned int port;
 442         unsigned char path;
 443         unsigned char target;
 444 };
 445
 446 struct storvsc_scan_work {
 447         struct work_struct work;
 448         struct Scsi_Host *host;
 449         uint lun;
 450 };
 451
 452 static void storvsc_device_scan(struct work_struct *work)
 453 {
 454         struct storvsc_scan_work *wrk;
 455         uint lun;
 456         struct scsi_device *sdev;
 457
 458         wrk = container_of(work, struct storvsc_scan_work, work);
 459         lun = wrk->lun;
 460
 461         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 462         if (!sdev)
 463                 goto done;
 464         scsi_rescan_device(&sdev->sdev_gendev);
 465         scsi_device_put(sdev);
 466
 467 done:
 468         kfree(wrk);
 469 }
 470
 471 static void storvsc_host_scan(struct work_struct *work)
 472 {
 473         struct storvsc_scan_work *wrk;
 474         struct Scsi_Host *host;
 475         struct scsi_device *sdev;
 476
 477         wrk = container_of(work, struct storvsc_scan_work, work);
 478         host = wrk->host;
 479
 480         /*
 481          * Before scanning the host, first check to see if any of the
 482          * currrently known devices have been hot removed. We issue a
 483          * "unit ready" command against all currently known devices.
 484          * This I/O will result in an error for devices that have been
 485          * removed. As part of handling the I/O error, we remove the device.
 486          *
 487          * When a LUN is added or removed, the host sends us a signal to
 488          * scan the host. Thus we are forced to discover the LUNs that
 489          * may have been removed this way.
 490          */
 491         mutex_lock(&host->scan_mutex);
 492         shost_for_each_device(sdev, host)
 493                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 494         mutex_unlock(&host->scan_mutex);
 495         /*
 496          * Now scan the host to discover LUNs that may have been added.
 497          */
 498         scsi_scan_host(host);
 499
 500         kfree(wrk);
 501 }
 502
 503 static void storvsc_remove_lun(struct work_struct *work)
 504 {
 505         struct storvsc_scan_work *wrk;
 506         struct scsi_device *sdev;
 507
 508         wrk = container_of(work, struct storvsc_scan_work, work);
 509         if (!scsi_host_get(wrk->host))
 510                 goto done;
 511
 512         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 513
 514         if (sdev) {
 515                 scsi_remove_device(sdev);
 516                 scsi_device_put(sdev);
 517         }
 518         scsi_host_put(wrk->host);
 519
 520 done:
 521         kfree(wrk);
 522 }
 523
 524
 525 /*
 526  * We can get incoming messages from the host that are not in response to
 527  * messages that we have sent out. An example of this would be messages
 528  * received by the guest to notify dynamic addition/removal of LUNs. To
 529  * deal with potential race conditions where the driver may be in the
 530  * midst of being unloaded when we might receive an unsolicited message
 531  * from the host, we have implemented a mechanism to gurantee sequential
 532  * consistency:
 533  *
 534  * 1) Once the device is marked as being destroyed, we will fail all
 535  *    outgoing messages.
 536  * 2) We permit incoming messages when the device is being destroyed,
 537  *    only to properly account for messages already sent out.
 538  */
 539
 540 static inline struct storvsc_device *get_out_stor_device(
 541                                         struct hv_device *device)
 542 {
 543         struct storvsc_device *stor_device;
 544
 545         stor_device = hv_get_drvdata(device);
 546
 547         if (stor_device && stor_device->destroy)
 548                 stor_device = NULL;
 549
 550         return stor_device;
 551 }
 552
 553
 554 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 555 {
 556         dev->drain_notify = true;
 557         wait_event(dev->waiting_to_drain,
 558                    atomic_read(&dev->num_outstanding_req) == 0);
 559         dev->drain_notify = false;
 560 }
 561
 562 static inline struct storvsc_device *get_in_stor_device(
 563                                         struct hv_device *device)
 564 {
 565         struct storvsc_device *stor_device;
 566
 567         stor_device = hv_get_drvdata(device);
 568
 569         if (!stor_device)
 570                 goto get_in_err;
 571
 572         /*
 573          * If the device is being destroyed; allow incoming
 574          * traffic only to cleanup outstanding requests.
 575          */
 576
 577         if (stor_device->destroy  &&
 578                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 579                 stor_device = NULL;
 580
 581 get_in_err:
 582         return stor_device;
 583
 584 }
 585
 586 static void handle_sc_creation(struct vmbus_channel *new_sc)
 587 {
 588         struct hv_device *device = new_sc->primary_channel->device_obj;
 589         struct storvsc_device *stor_device;
 590         struct vmstorage_channel_properties props;
 591
 592         stor_device = get_out_stor_device(device);
 593         if (!stor_device)
 594                 return;
 595
 596         if (stor_device->open_sub_channel == false)
 597                 return;
 598
 599         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 600
 601         vmbus_open(new_sc,
 602                    storvsc_ringbuffer_size,
 603                    storvsc_ringbuffer_size,
 604                    (void *)&props,
 605                    sizeof(struct vmstorage_channel_properties),
 606                    storvsc_on_channel_callback, new_sc);
 607 }
 608
 609 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 610 {
 611         struct storvsc_device *stor_device;
 612         int num_cpus = num_online_cpus();
 613         int num_sc;
 614         struct storvsc_cmd_request *request;
 615         struct vstor_packet *vstor_packet;
 616         int ret, t;
 617
 618         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 619         stor_device = get_out_stor_device(device);
 620         if (!stor_device)
 621                 return;
 622
 623         request = &stor_device->init_request;
 624         vstor_packet = &request->vstor_packet;
 625
 626         stor_device->open_sub_channel = true;
 627         /*
 628          * Establish a handler for dealing with subchannels.
 629          */
 630         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 631
 632         /*
 633          * Check to see if sub-channels have already been created. This
 634          * can happen when this driver is re-loaded after unloading.
 635          */
 636
 637         if (vmbus_are_subchannels_present(device->channel))
 638                 return;
 639
 640         stor_device->open_sub_channel = false;
 641         /*
 642          * Request the host to create sub-channels.
 643          */
 644         memset(request, 0, sizeof(struct storvsc_cmd_request));
 645         init_completion(&request->wait_event);
 646         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 647         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 648         vstor_packet->sub_channel_count = num_sc;
 649
 650         ret = vmbus_sendpacket(device->channel, vstor_packet,
 651                                (sizeof(struct vstor_packet) -
 652                                vmscsi_size_delta),
 653                                (unsigned long)request,
 654                                VM_PKT_DATA_INBAND,
 655                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 656
 657         if (ret != 0)
 658                 return;
 659
 660         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 661         if (t == 0)
 662                 return;
 663
 664         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 665             vstor_packet->status != 0)
 666                 return;
 667
 668         /*
 669          * Now that we created the sub-channels, invoke the check; this
 670          * may trigger the callback.
 671          */
 672         stor_device->open_sub_channel = true;
 673         vmbus_are_subchannels_present(device->channel);
 674 }
 675
 676 static int storvsc_channel_init(struct hv_device *device)
 677 {
 678         struct storvsc_device *stor_device;
 679         struct storvsc_cmd_request *request;
 680         struct vstor_packet *vstor_packet;
 681         int ret, t, i;
 682         int max_chns;
 683         bool process_sub_channels = false;
 684
 685         stor_device = get_out_stor_device(device);
 686         if (!stor_device)
 687                 return -ENODEV;
 688
 689         request = &stor_device->init_request;
 690         vstor_packet = &request->vstor_packet;
 691
 692         /*
 693          * Now, initiate the vsc/vsp initialization protocol on the open
 694          * channel
 695          */
 696         memset(request, 0, sizeof(struct storvsc_cmd_request));
 697         init_completion(&request->wait_event);
 698         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 699         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 700
 701         ret = vmbus_sendpacket(device->channel, vstor_packet,
 702                                (sizeof(struct vstor_packet) -
 703                                vmscsi_size_delta),
 704                                (unsigned long)request,
 705                                VM_PKT_DATA_INBAND,
 706                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 707         if (ret != 0)
 708                 goto cleanup;
 709
 710         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 711         if (t == 0) {
 712                 ret = -ETIMEDOUT;
 713                 goto cleanup;
 714         }
 715
 716         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 717             vstor_packet->status != 0) {
 718                 ret = -EINVAL;
 719                 goto cleanup;
 720         }
 721
 722
 723         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 724                 /* reuse the packet for version range supported */
 725                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 726                 vstor_packet->operation =
 727                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 728                 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 729
 730                 vstor_packet->version.major_minor =
 731                         vmstor_protocols[i].protocol_version;
 732
 733                 /*
 734                  * The revision number is only used in Windows; set it to 0.
 735                  */
 736                 vstor_packet->version.revision = 0;
 737
 738                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 739                                (sizeof(struct vstor_packet) -
 740                                 vmscsi_size_delta),
 741                                (unsigned long)request,
 742                                VM_PKT_DATA_INBAND,
 743                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 744                 if (ret != 0)
 745                         goto cleanup;
 746
 747                 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 748                 if (t == 0) {
 749                         ret = -ETIMEDOUT;
 750                         goto cleanup;
 751                 }
 752
 753                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO) {
 754                         ret = -EINVAL;
 755                         goto cleanup;
 756                 }
 757
 758                 if (vstor_packet->status == 0) {
 759                         vmstor_proto_version =
 760                                 vmstor_protocols[i].protocol_version;
 761
 762                         sense_buffer_size =
 763                                 vmstor_protocols[i].sense_buffer_size;
 764
 765                         vmscsi_size_delta =
 766                                 vmstor_protocols[i].vmscsi_size_delta;
 767
 768                         break;
 769                 }
 770         }
 771
 772         if (vstor_packet->status != 0) {
 773                 ret = -EINVAL;
 774                 goto cleanup;
 775         }
 776
 777
 778         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 779         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 780         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 781
 782         ret = vmbus_sendpacket(device->channel, vstor_packet,
 783                                (sizeof(struct vstor_packet) -
 784                                 vmscsi_size_delta),
 785                                (unsigned long)request,
 786                                VM_PKT_DATA_INBAND,
 787                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 788
 789         if (ret != 0)
 790                 goto cleanup;
 791
 792         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 793         if (t == 0) {
 794                 ret = -ETIMEDOUT;
 795                 goto cleanup;
 796         }
 797
 798         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 799             vstor_packet->status != 0) {
 800                 ret = -EINVAL;
 801                 goto cleanup;
 802         }
 803
 804         /*
 805          * Check to see if multi-channel support is there.
 806          * Hosts that implement protocol version of 5.1 and above
 807          * support multi-channel.
 808          */
 809         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 810         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 811                 if (vstor_packet->storage_channel_properties.flags &
 812                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 813                         process_sub_channels = true;
 814         }
 815         stor_device->max_transfer_bytes =
 816                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 817
 818         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 819         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 820         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 821
 822         ret = vmbus_sendpacket(device->channel, vstor_packet,
 823                                (sizeof(struct vstor_packet) -
 824                                 vmscsi_size_delta),
 825                                (unsigned long)request,
 826                                VM_PKT_DATA_INBAND,
 827                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 828
 829         if (ret != 0)
 830                 goto cleanup;
 831
 832         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 833         if (t == 0) {
 834                 ret = -ETIMEDOUT;
 835                 goto cleanup;
 836         }
 837
 838         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 839             vstor_packet->status != 0) {
 840                 ret = -EINVAL;
 841                 goto cleanup;
 842         }
 843
 844         if (process_sub_channels)
 845                 handle_multichannel_storage(device, max_chns);
 846
 847
 848 cleanup:
 849         return ret;
 850 }
 851
 852 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 853                                 struct scsi_cmnd *scmnd,
 854                                 struct Scsi_Host *host,
 855                                 u8 asc, u8 ascq)
 856 {
 857         struct storvsc_scan_work *wrk;
 858         void (*process_err_fn)(struct work_struct *work);
 859         bool do_work = false;
 860
 861         switch (vm_srb->srb_status) {
 862         case SRB_STATUS_ERROR:
 863                 /*
 864                  * If there is an error; offline the device since all
 865                  * error recovery strategies would have already been
 866                  * deployed on the host side. However, if the command
 867                  * were a pass-through command deal with it appropriately.
 868                  */
 869                 switch (scmnd->cmnd[0]) {
 870                 case ATA_16:
 871                 case ATA_12:
 872                         set_host_byte(scmnd, DID_PASSTHROUGH);
 873                         break;
 874                 /*
 875                  * On Some Windows hosts TEST_UNIT_READY command can return
 876                  * SRB_STATUS_ERROR, let the upper level code deal with it
 877                  * based on the sense information.
 878                  */
 879                 case TEST_UNIT_READY:
 880                         break;
 881                 default:
 882                         set_host_byte(scmnd, DID_TARGET_FAILURE);
 883                 }
 884                 break;
 885         case SRB_STATUS_INVALID_LUN:
 886                 do_work = true;
 887                 process_err_fn = storvsc_remove_lun;
 888                 break;
 889         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
 890                 if ((asc == 0x2a) && (ascq == 0x9)) {
 891                         do_work = true;
 892                         process_err_fn = storvsc_device_scan;
 893                         /*
 894                          * Retry the I/O that trigerred this.
 895                          */
 896                         set_host_byte(scmnd, DID_REQUEUE);
 897                 }
 898                 break;
 899         }
 900
 901         if (!do_work)
 902                 return;
 903
 904         /*
 905          * We need to schedule work to process this error; schedule it.
 906          */
 907         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 908         if (!wrk) {
 909                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 910                 return;
 911         }
 912
 913         wrk->host = host;
 914         wrk->lun = vm_srb->lun;
 915         INIT_WORK(&wrk->work, process_err_fn);
 916         schedule_work(&wrk->work);
 917 }
 918
 919
 920 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 921 {
 922         struct scsi_cmnd *scmnd = cmd_request->cmd;
 923         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
 924         struct scsi_sense_hdr sense_hdr;
 925         struct vmscsi_request *vm_srb;
 926         struct Scsi_Host *host;
 927         struct storvsc_device *stor_dev;
 928         struct hv_device *dev = host_dev->dev;
 929         u32 payload_sz = cmd_request->payload_sz;
 930         void *payload = cmd_request->payload;
 931
 932         stor_dev = get_in_stor_device(dev);
 933         host = stor_dev->host;
 934
 935         vm_srb = &cmd_request->vstor_packet.vm_srb;
 936
 937         scmnd->result = vm_srb->scsi_status;
 938
 939         if (scmnd->result) {
 940                 if (scsi_normalize_sense(scmnd->sense_buffer,
 941                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 942                         scsi_print_sense_hdr(scmnd->device, "storvsc",
 943                                              &sense_hdr);
 944         }
 945
 946         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
 947                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
 948                                          sense_hdr.ascq);
 949
 950         scsi_set_resid(scmnd,
 951                 cmd_request->payload->range.len -
 952                 vm_srb->data_transfer_length);
 953
 954         scmnd->scsi_done(scmnd);
 955
 956         if (payload_sz >
 957                 sizeof(struct vmbus_channel_packet_multipage_buffer))
 958                 kfree(payload);
 959 }
 960
 961 static void storvsc_on_io_completion(struct hv_device *device,
 962                                   struct vstor_packet *vstor_packet,
 963                                   struct storvsc_cmd_request *request)
 964 {
 965         struct storvsc_device *stor_device;
 966         struct vstor_packet *stor_pkt;
 967
 968         stor_device = hv_get_drvdata(device);
 969         stor_pkt = &request->vstor_packet;
 970
 971         /*
 972          * The current SCSI handling on the host side does
 973          * not correctly handle:
 974          * INQUIRY command with page code parameter set to 0x80
 975          * MODE_SENSE command with cmd[2] == 0x1c
 976          *
 977          * Setup srb and scsi status so this won't be fatal.
 978          * We do this so we can distinguish truly fatal failues
 979          * (srb status == 0x4) and off-line the device in that case.
 980          */
 981
 982         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 983            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 984                 vstor_packet->vm_srb.scsi_status = 0;
 985                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
 986         }
 987
 988
 989         /* Copy over the status...etc */
 990         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 991         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 992         stor_pkt->vm_srb.sense_info_length =
 993         vstor_packet->vm_srb.sense_info_length;
 994
 995
 996         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
 997                 /* CHECK_CONDITION */
 998                 if (vstor_packet->vm_srb.srb_status &
 999                         SRB_STATUS_AUTOSENSE_VALID) {
1000                         /* autosense data available */
1001
1002                         memcpy(request->cmd->sense_buffer,
1003                                vstor_packet->vm_srb.sense_data,
1004                                vstor_packet->vm_srb.sense_info_length);
1005
1006                 }
1007         }
1008
1009         stor_pkt->vm_srb.data_transfer_length =
1010         vstor_packet->vm_srb.data_transfer_length;
1011
1012         storvsc_command_completion(request);
1013
1014         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1015                 stor_device->drain_notify)
1016                 wake_up(&stor_device->waiting_to_drain);
1017
1018
1019 }
1020
1021 static void storvsc_on_receive(struct hv_device *device,
1022                              struct vstor_packet *vstor_packet,
1023                              struct storvsc_cmd_request *request)
1024 {
1025         struct storvsc_scan_work *work;
1026         struct storvsc_device *stor_device;
1027
1028         switch (vstor_packet->operation) {
1029         case VSTOR_OPERATION_COMPLETE_IO:
1030                 storvsc_on_io_completion(device, vstor_packet, request);
1031                 break;
1032
1033         case VSTOR_OPERATION_REMOVE_DEVICE:
1034         case VSTOR_OPERATION_ENUMERATE_BUS:
1035                 stor_device = get_in_stor_device(device);
1036                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1037                 if (!work)
1038                         return;
1039
1040                 INIT_WORK(&work->work, storvsc_host_scan);
1041                 work->host = stor_device->host;
1042                 schedule_work(&work->work);
1043                 break;
1044
1045         default:
1046                 break;
1047         }
1048 }
1049
1050 static void storvsc_on_channel_callback(void *context)
1051 {
1052         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1053         struct hv_device *device;
1054         struct storvsc_device *stor_device;
1055         u32 bytes_recvd;
1056         u64 request_id;
1057         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1058         struct storvsc_cmd_request *request;
1059         int ret;
1060
1061         if (channel->primary_channel != NULL)
1062                 device = channel->primary_channel->device_obj;
1063         else
1064                 device = channel->device_obj;
1065
1066         stor_device = get_in_stor_device(device);
1067         if (!stor_device)
1068                 return;
1069
1070         do {
1071                 ret = vmbus_recvpacket(channel, packet,
1072                                        ALIGN((sizeof(struct vstor_packet) -
1073                                              vmscsi_size_delta), 8),
1074                                        &bytes_recvd, &request_id);
1075                 if (ret == 0 && bytes_recvd > 0) {
1076
1077                         request = (struct storvsc_cmd_request *)
1078                                         (unsigned long)request_id;
1079
1080                         if ((request == &stor_device->init_request) ||
1081                             (request == &stor_device->reset_request)) {
1082
1083                                 memcpy(&request->vstor_packet, packet,
1084                                        (sizeof(struct vstor_packet) -
1085                                         vmscsi_size_delta));
1086                                 complete(&request->wait_event);
1087                         } else {
1088                                 storvsc_on_receive(device,
1089                                                 (struct vstor_packet *)packet,
1090                                                 request);
1091                         }
1092                 } else {
1093                         break;
1094                 }
1095         } while (1);
1096
1097         return;
1098 }
1099
1100 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1101 {
1102         struct vmstorage_channel_properties props;
1103         int ret;
1104
1105         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1106
1107         ret = vmbus_open(device->channel,
1108                          ring_size,
1109                          ring_size,
1110                          (void *)&props,
1111                          sizeof(struct vmstorage_channel_properties),
1112                          storvsc_on_channel_callback, device->channel);
1113
1114         if (ret != 0)
1115                 return ret;
1116
1117         ret = storvsc_channel_init(device);
1118
1119         return ret;
1120 }
1121
1122 static int storvsc_dev_remove(struct hv_device *device)
1123 {
1124         struct storvsc_device *stor_device;
1125         unsigned long flags;
1126
1127         stor_device = hv_get_drvdata(device);
1128
1129         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1130         stor_device->destroy = true;
1131         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1132
1133         /*
1134          * At this point, all outbound traffic should be disable. We
1135          * only allow inbound traffic (responses) to proceed so that
1136          * outstanding requests can be completed.
1137          */
1138
1139         storvsc_wait_to_drain(stor_device);
1140
1141         /*
1142          * Since we have already drained, we don't need to busy wait
1143          * as was done in final_release_stor_device()
1144          * Note that we cannot set the ext pointer to NULL until
1145          * we have drained - to drain the outgoing packets, we need to
1146          * allow incoming packets.
1147          */
1148         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1149         hv_set_drvdata(device, NULL);
1150         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1151
1152         /* Close the channel */
1153         vmbus_close(device->channel);
1154
1155         kfree(stor_device);
1156         return 0;
1157 }
1158
1159 static int storvsc_do_io(struct hv_device *device,
1160                          struct storvsc_cmd_request *request)
1161 {
1162         struct storvsc_device *stor_device;
1163         struct vstor_packet *vstor_packet;
1164         struct vmbus_channel *outgoing_channel;
1165         int ret = 0;
1166
1167         vstor_packet = &request->vstor_packet;
1168         stor_device = get_out_stor_device(device);
1169
1170         if (!stor_device)
1171                 return -ENODEV;
1172
1173
1174         request->device  = device;
1175         /*
1176          * Select an an appropriate channel to send the request out.
1177          */
1178
1179         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1180
1181
1182         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1183
1184         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1185                                         vmscsi_size_delta);
1186
1187
1188         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1189
1190
1191         vstor_packet->vm_srb.data_transfer_length =
1192         request->payload->range.len;
1193
1194         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1195
1196         if (request->payload->range.len) {
1197
1198                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1199                                 request->payload, request->payload_sz,
1200                                 vstor_packet,
1201                                 (sizeof(struct vstor_packet) -
1202                                 vmscsi_size_delta),
1203                                 (unsigned long)request);
1204         } else {
1205                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1206                                (sizeof(struct vstor_packet) -
1207                                 vmscsi_size_delta),
1208                                (unsigned long)request,
1209                                VM_PKT_DATA_INBAND,
1210                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1211         }
1212
1213         if (ret != 0)
1214                 return ret;
1215
1216         atomic_inc(&stor_device->num_outstanding_req);
1217
1218         return ret;
1219 }
1220
1221 static int storvsc_device_configure(struct scsi_device *sdevice)
1222 {
1223
1224         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1225
1226         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1227
1228         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1229
1230         /* Ensure there are no gaps in presented sgls */
1231         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1232
1233         sdevice->no_write_same = 1;
1234
1235         /*
1236          * Add blist flags to permit the reading of the VPD pages even when
1237          * the target may claim SPC-2 compliance. MSFT targets currently
1238          * claim SPC-2 compliance while they implement post SPC-2 features.
1239          * With this patch we can correctly handle WRITE_SAME_16 issues.
1240          */
1241         sdevice->sdev_bflags |= msft_blist_flags;
1242
1243         /*
1244          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1245          * if the device is a MSFT virtual device.  If the host is
1246          * WIN10 or newer, allow write_same.
1247          */
1248         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1249                 switch (vmstor_proto_version) {
1250                 case VMSTOR_PROTO_VERSION_WIN8:
1251                 case VMSTOR_PROTO_VERSION_WIN8_1:
1252                         sdevice->scsi_level = SCSI_SPC_3;
1253                         break;
1254                 }
1255
1256                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1257                         sdevice->no_write_same = 0;
1258         }
1259
1260         return 0;
1261 }
1262
1263 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1264                            sector_t capacity, int *info)
1265 {
1266         sector_t nsect = capacity;
1267         sector_t cylinders = nsect;
1268         int heads, sectors_pt;
1269
1270         /*
1271          * We are making up these values; let us keep it simple.
1272          */
1273         heads = 0xff;
1274         sectors_pt = 0x3f;      /* Sectors per track */
1275         sector_div(cylinders, heads * sectors_pt);
1276         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1277                 cylinders = 0xffff;
1278
1279         info[0] = heads;
1280         info[1] = sectors_pt;
1281         info[2] = (int)cylinders;
1282
1283         return 0;
1284 }
1285
1286 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1287 {
1288         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1289         struct hv_device *device = host_dev->dev;
1290
1291         struct storvsc_device *stor_device;
1292         struct storvsc_cmd_request *request;
1293         struct vstor_packet *vstor_packet;
1294         int ret, t;
1295
1296
1297         stor_device = get_out_stor_device(device);
1298         if (!stor_device)
1299                 return FAILED;
1300
1301         request = &stor_device->reset_request;
1302         vstor_packet = &request->vstor_packet;
1303
1304         init_completion(&request->wait_event);
1305
1306         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1307         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1308         vstor_packet->vm_srb.path_id = stor_device->path_id;
1309
1310         ret = vmbus_sendpacket(device->channel, vstor_packet,
1311                                (sizeof(struct vstor_packet) -
1312                                 vmscsi_size_delta),
1313                                (unsigned long)&stor_device->reset_request,
1314                                VM_PKT_DATA_INBAND,
1315                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1316         if (ret != 0)
1317                 return FAILED;
1318
1319         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1320         if (t == 0)
1321                 return TIMEOUT_ERROR;
1322
1323
1324         /*
1325          * At this point, all outstanding requests in the adapter
1326          * should have been flushed out and return to us
1327          * There is a potential race here where the host may be in
1328          * the process of responding when we return from here.
1329          * Just wait for all in-transit packets to be accounted for
1330          * before we return from here.
1331          */
1332         storvsc_wait_to_drain(stor_device);
1333
1334         return SUCCESS;
1335 }
1336
1337 /*
1338  * The host guarantees to respond to each command, although I/O latencies might
1339  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1340  * chance to perform EH.
1341  */
1342 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1343 {
1344         return BLK_EH_RESET_TIMER;
1345 }
1346
1347 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1348 {
1349         bool allowed = true;
1350         u8 scsi_op = scmnd->cmnd[0];
1351
1352         switch (scsi_op) {
1353         /* the host does not handle WRITE_SAME, log accident usage */
1354         case WRITE_SAME:
1355         /*
1356          * smartd sends this command and the host does not handle
1357          * this. So, don't send it.
1358          */
1359         case SET_WINDOW:
1360                 scmnd->result = ILLEGAL_REQUEST << 16;
1361                 allowed = false;
1362                 break;
1363         default:
1364                 break;
1365         }
1366         return allowed;
1367 }
1368
1369 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1370 {
1371         int ret;
1372         struct hv_host_device *host_dev = shost_priv(host);
1373         struct hv_device *dev = host_dev->dev;
1374         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1375         int i;
1376         struct scatterlist *sgl;
1377         unsigned int sg_count = 0;
1378         struct vmscsi_request *vm_srb;
1379         struct scatterlist *cur_sgl;
1380         struct vmbus_packet_mpb_array  *payload;
1381         u32 payload_sz;
1382         u32 length;
1383
1384         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1385                 /*
1386                  * On legacy hosts filter unimplemented commands.
1387                  * Future hosts are expected to correctly handle
1388                  * unsupported commands. Furthermore, it is
1389                  * possible that some of the currently
1390                  * unsupported commands maybe supported in
1391                  * future versions of the host.
1392                  */
1393                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1394                         scmnd->scsi_done(scmnd);
1395                         return 0;
1396                 }
1397         }
1398
1399         /* Setup the cmd request */
1400         cmd_request->cmd = scmnd;
1401
1402         vm_srb = &cmd_request->vstor_packet.vm_srb;
1403         vm_srb->win8_extension.time_out_value = 60;
1404
1405         vm_srb->win8_extension.srb_flags |=
1406                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1407
1408         /* Build the SRB */
1409         switch (scmnd->sc_data_direction) {
1410         case DMA_TO_DEVICE:
1411                 vm_srb->data_in = WRITE_TYPE;
1412                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1413                 break;
1414         case DMA_FROM_DEVICE:
1415                 vm_srb->data_in = READ_TYPE;
1416                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1417                 break;
1418         case DMA_NONE:
1419                 vm_srb->data_in = UNKNOWN_TYPE;
1420                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1421                 break;
1422         default:
1423                 /*
1424                  * This is DMA_BIDIRECTIONAL or something else we are never
1425                  * supposed to see here.
1426                  */
1427                 WARN(1, "Unexpected data direction: %d\n",
1428                      scmnd->sc_data_direction);
1429                 return -EINVAL;
1430         }
1431
1432
1433         vm_srb->port_number = host_dev->port;
1434         vm_srb->path_id = scmnd->device->channel;
1435         vm_srb->target_id = scmnd->device->id;
1436         vm_srb->lun = scmnd->device->lun;
1437
1438         vm_srb->cdb_length = scmnd->cmd_len;
1439
1440         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1441
1442         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1443         sg_count = scsi_sg_count(scmnd);
1444
1445         length = scsi_bufflen(scmnd);
1446         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1447         payload_sz = sizeof(cmd_request->mpb);
1448
1449         if (sg_count) {
1450                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1451
1452                         payload_sz = (sg_count * sizeof(void *) +
1453                                       sizeof(struct vmbus_packet_mpb_array));
1454                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1455                         if (!payload)
1456                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1457                 }
1458
1459                 payload->range.len = length;
1460                 payload->range.offset = sgl[0].offset;
1461
1462                 cur_sgl = sgl;
1463                 for (i = 0; i < sg_count; i++) {
1464                         payload->range.pfn_array[i] =
1465                                 page_to_pfn(sg_page((cur_sgl)));
1466                         cur_sgl = sg_next(cur_sgl);
1467                 }
1468
1469         } else if (scsi_sglist(scmnd)) {
1470                 payload->range.len = length;
1471                 payload->range.offset =
1472                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1473                 payload->range.pfn_array[0] =
1474                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1475         }
1476
1477         cmd_request->payload = payload;
1478         cmd_request->payload_sz = payload_sz;
1479
1480         /* Invokes the vsc to start an IO */
1481         ret = storvsc_do_io(dev, cmd_request);
1482
1483         if (ret == -EAGAIN) {
1484                 /* no more space */
1485                 return SCSI_MLQUEUE_DEVICE_BUSY;
1486         }
1487
1488         return 0;
1489 }
1490
1491 static struct scsi_host_template scsi_driver = {
1492         .module =               THIS_MODULE,
1493         .name =                 "storvsc_host_t",
1494         .cmd_size =             sizeof(struct storvsc_cmd_request),
1495         .bios_param =           storvsc_get_chs,
1496         .queuecommand =         storvsc_queuecommand,
1497         .eh_host_reset_handler =        storvsc_host_reset_handler,
1498         .proc_name =            "storvsc_host",
1499         .eh_timed_out =         storvsc_eh_timed_out,
1500         .slave_configure =      storvsc_device_configure,
1501         .cmd_per_lun =          255,
1502         .this_id =              -1,
1503         .use_clustering =       ENABLE_CLUSTERING,
1504         /* Make sure we dont get a sg segment crosses a page boundary */
1505         .dma_boundary =         PAGE_SIZE-1,
1506         .no_write_same =        1,
1507 };
1508
1509 enum {
1510         SCSI_GUID,
1511         IDE_GUID,
1512         SFC_GUID,
1513 };
1514
1515 static const struct hv_vmbus_device_id id_table[] = {
1516         /* SCSI guid */
1517         { HV_SCSI_GUID,
1518           .driver_data = SCSI_GUID
1519         },
1520         /* IDE guid */
1521         { HV_IDE_GUID,
1522           .driver_data = IDE_GUID
1523         },
1524         /* Fibre Channel GUID */
1525         {
1526           HV_SYNTHFC_GUID,
1527           .driver_data = SFC_GUID
1528         },
1529         { },
1530 };
1531
1532 MODULE_DEVICE_TABLE(vmbus, id_table);
1533
1534 static int storvsc_probe(struct hv_device *device,
1535                         const struct hv_vmbus_device_id *dev_id)
1536 {
1537         int ret;
1538         int num_cpus = num_online_cpus();
1539         struct Scsi_Host *host;
1540         struct hv_host_device *host_dev;
1541         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1542         int target = 0;
1543         struct storvsc_device *stor_device;
1544         int max_luns_per_target;
1545         int max_targets;
1546         int max_channels;
1547         int max_sub_channels = 0;
1548
1549         /*
1550          * Based on the windows host we are running on,
1551          * set state to properly communicate with the host.
1552          */
1553
1554         if (vmbus_proto_version < VERSION_WIN8) {
1555                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1556                 max_targets = STORVSC_IDE_MAX_TARGETS;
1557                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1558         } else {
1559                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1560                 max_targets = STORVSC_MAX_TARGETS;
1561                 max_channels = STORVSC_MAX_CHANNELS;
1562                 /*
1563                  * On Windows8 and above, we support sub-channels for storage.
1564                  * The number of sub-channels offerred is based on the number of
1565                  * VCPUs in the guest.
1566                  */
1567                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1568         }
1569
1570         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1571                                  (max_sub_channels + 1));
1572
1573         host = scsi_host_alloc(&scsi_driver,
1574                                sizeof(struct hv_host_device));
1575         if (!host)
1576                 return -ENOMEM;
1577
1578         host_dev = shost_priv(host);
1579         memset(host_dev, 0, sizeof(struct hv_host_device));
1580
1581         host_dev->port = host->host_no;
1582         host_dev->dev = device;
1583
1584
1585         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1586         if (!stor_device) {
1587                 ret = -ENOMEM;
1588                 goto err_out0;
1589         }
1590
1591         stor_device->destroy = false;
1592         stor_device->open_sub_channel = false;
1593         init_waitqueue_head(&stor_device->waiting_to_drain);
1594         stor_device->device = device;
1595         stor_device->host = host;
1596         hv_set_drvdata(device, stor_device);
1597
1598         stor_device->port_number = host->host_no;
1599         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1600         if (ret)
1601                 goto err_out1;
1602
1603         host_dev->path = stor_device->path_id;
1604         host_dev->target = stor_device->target_id;
1605
1606         switch (dev_id->driver_data) {
1607         case SFC_GUID:
1608                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1609                 host->max_id = STORVSC_FC_MAX_TARGETS;
1610                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1611                 break;
1612
1613         case SCSI_GUID:
1614                 host->max_lun = max_luns_per_target;
1615                 host->max_id = max_targets;
1616                 host->max_channel = max_channels - 1;
1617                 break;
1618
1619         default:
1620                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1621                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1622                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1623                 break;
1624         }
1625         /* max cmd length */
1626         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1627
1628         /*
1629          * set the table size based on the info we got
1630          * from the host.
1631          */
1632         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1633
1634         /* Register the HBA and start the scsi bus scan */
1635         ret = scsi_add_host(host, &device->device);
1636         if (ret != 0)
1637                 goto err_out2;
1638
1639         if (!dev_is_ide) {
1640                 scsi_scan_host(host);
1641         } else {
1642                 target = (device->dev_instance.b[5] << 8 |
1643                          device->dev_instance.b[4]);
1644                 ret = scsi_add_device(host, 0, target, 0);
1645                 if (ret) {
1646                         scsi_remove_host(host);
1647                         goto err_out2;
1648                 }
1649         }
1650         return 0;
1651
1652 err_out2:
1653         /*
1654          * Once we have connected with the host, we would need to
1655          * to invoke storvsc_dev_remove() to rollback this state and
1656          * this call also frees up the stor_device; hence the jump around
1657          * err_out1 label.
1658          */
1659         storvsc_dev_remove(device);
1660         goto err_out0;
1661
1662 err_out1:
1663         kfree(stor_device);
1664
1665 err_out0:
1666         scsi_host_put(host);
1667         return ret;
1668 }
1669
1670 static int storvsc_remove(struct hv_device *dev)
1671 {
1672         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1673         struct Scsi_Host *host = stor_device->host;
1674
1675         scsi_remove_host(host);
1676         storvsc_dev_remove(dev);
1677         scsi_host_put(host);
1678
1679         return 0;
1680 }
1681
1682 static struct hv_driver storvsc_drv = {
1683         .name = KBUILD_MODNAME,
1684         .id_table = id_table,
1685         .probe = storvsc_probe,
1686         .remove = storvsc_remove,
1687 };
1688
1689 static int __init storvsc_drv_init(void)
1690 {
1691
1692         /*
1693          * Divide the ring buffer data size (which is 1 page less
1694          * than the ring buffer size since that page is reserved for
1695          * the ring buffer indices) by the max request size (which is
1696          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1697          */
1698         max_outstanding_req_per_channel =
1699                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1700                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1701                 sizeof(struct vstor_packet) + sizeof(u64) -
1702                 vmscsi_size_delta,
1703                 sizeof(u64)));
1704
1705         return vmbus_driver_register(&storvsc_drv);
1706 }
1707
1708 static void __exit storvsc_drv_exit(void)
1709 {
1710         vmbus_driver_unregister(&storvsc_drv);
1711 }
1712
1713 MODULE_LICENSE("GPL");
1714 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1715 module_init(storvsc_drv_init);
1716 module_exit(storvsc_drv_exit);