kernel/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_QUEUE_FROZEN         0x40
 353 #define SRB_STATUS_INVALID_LUN  0x20
 354 #define SRB_STATUS_SUCCESS      0x01
 355 #define SRB_STATUS_ABORTED      0x02
 356 #define SRB_STATUS_ERROR        0x04
 357
 358 #define SRB_STATUS(status) \
 359         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 360 /*
 361  * This is the end of Protocol specific defines.
 362  */
 363
 364 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 365 static u32 max_outstanding_req_per_channel;
 366
 367 static int storvsc_vcpus_per_sub_channel = 4;
 368
 369 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 370 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 371
 372 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 373 MODULE_PARM_DESC(vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 374 /*
 375  * Timeout in seconds for all devices managed by this driver.
 376  */
 377 static int storvsc_timeout = 180;
 378
 379 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 380
 381
 382 static void storvsc_on_channel_callback(void *context);
 383
 384 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 385 #define STORVSC_MAX_TARGETS                             2
 386 #define STORVSC_MAX_CHANNELS                            8
 387
 388 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 389 #define STORVSC_FC_MAX_TARGETS                          128
 390 #define STORVSC_FC_MAX_CHANNELS                         8
 391
 392 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 393 #define STORVSC_IDE_MAX_TARGETS                         1
 394 #define STORVSC_IDE_MAX_CHANNELS                        1
 395
 396 struct storvsc_cmd_request {
 397         struct scsi_cmnd *cmd;
 398
 399         struct hv_device *device;
 400
 401         /* Synchronize the request/response if needed */
 402         struct completion wait_event;
 403
 404         struct vmbus_channel_packet_multipage_buffer mpb;
 405         struct vmbus_packet_mpb_array *payload;
 406         u32 payload_sz;
 407
 408         struct vstor_packet vstor_packet;
 409 };
 410
 411
 412 /* A storvsc device is a device object that contains a vmbus channel */
 413 struct storvsc_device {
 414         struct hv_device *device;
 415
 416         bool     destroy;
 417         bool     drain_notify;
 418         bool     open_sub_channel;
 419         atomic_t num_outstanding_req;
 420         struct Scsi_Host *host;
 421
 422         wait_queue_head_t waiting_to_drain;
 423
 424         /*
 425          * Each unique Port/Path/Target represents 1 channel ie scsi
 426          * controller. In reality, the pathid, targetid is always 0
 427          * and the port is set by us
 428          */
 429         unsigned int port_number;
 430         unsigned char path_id;
 431         unsigned char target_id;
 432
 433         /*
 434          * Max I/O, the device can support.
 435          */
 436         u32   max_transfer_bytes;
 437         /* Used for vsc/vsp channel reset process */
 438         struct storvsc_cmd_request init_request;
 439         struct storvsc_cmd_request reset_request;
 440 };
 441
 442 struct hv_host_device {
 443         struct hv_device *dev;
 444         unsigned int port;
 445         unsigned char path;
 446         unsigned char target;
 447 };
 448
 449 struct storvsc_scan_work {
 450         struct work_struct work;
 451         struct Scsi_Host *host;
 452         uint lun;
 453 };
 454
 455 static void storvsc_device_scan(struct work_struct *work)
 456 {
 457         struct storvsc_scan_work *wrk;
 458         uint lun;
 459         struct scsi_device *sdev;
 460
 461         wrk = container_of(work, struct storvsc_scan_work, work);
 462         lun = wrk->lun;
 463
 464         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 465         if (!sdev)
 466                 goto done;
 467         scsi_rescan_device(&sdev->sdev_gendev);
 468         scsi_device_put(sdev);
 469
 470 done:
 471         kfree(wrk);
 472 }
 473
 474 static void storvsc_host_scan(struct work_struct *work)
 475 {
 476         struct storvsc_scan_work *wrk;
 477         struct Scsi_Host *host;
 478         struct scsi_device *sdev;
 479
 480         wrk = container_of(work, struct storvsc_scan_work, work);
 481         host = wrk->host;
 482
 483         /*
 484          * Before scanning the host, first check to see if any of the
 485          * currrently known devices have been hot removed. We issue a
 486          * "unit ready" command against all currently known devices.
 487          * This I/O will result in an error for devices that have been
 488          * removed. As part of handling the I/O error, we remove the device.
 489          *
 490          * When a LUN is added or removed, the host sends us a signal to
 491          * scan the host. Thus we are forced to discover the LUNs that
 492          * may have been removed this way.
 493          */
 494         mutex_lock(&host->scan_mutex);
 495         shost_for_each_device(sdev, host)
 496                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 497         mutex_unlock(&host->scan_mutex);
 498         /*
 499          * Now scan the host to discover LUNs that may have been added.
 500          */
 501         scsi_scan_host(host);
 502
 503         kfree(wrk);
 504 }
 505
 506 static void storvsc_remove_lun(struct work_struct *work)
 507 {
 508         struct storvsc_scan_work *wrk;
 509         struct scsi_device *sdev;
 510
 511         wrk = container_of(work, struct storvsc_scan_work, work);
 512         if (!scsi_host_get(wrk->host))
 513                 goto done;
 514
 515         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 516
 517         if (sdev) {
 518                 scsi_remove_device(sdev);
 519                 scsi_device_put(sdev);
 520         }
 521         scsi_host_put(wrk->host);
 522
 523 done:
 524         kfree(wrk);
 525 }
 526
 527
 528 /*
 529  * We can get incoming messages from the host that are not in response to
 530  * messages that we have sent out. An example of this would be messages
 531  * received by the guest to notify dynamic addition/removal of LUNs. To
 532  * deal with potential race conditions where the driver may be in the
 533  * midst of being unloaded when we might receive an unsolicited message
 534  * from the host, we have implemented a mechanism to gurantee sequential
 535  * consistency:
 536  *
 537  * 1) Once the device is marked as being destroyed, we will fail all
 538  *    outgoing messages.
 539  * 2) We permit incoming messages when the device is being destroyed,
 540  *    only to properly account for messages already sent out.
 541  */
 542
 543 static inline struct storvsc_device *get_out_stor_device(
 544                                         struct hv_device *device)
 545 {
 546         struct storvsc_device *stor_device;
 547
 548         stor_device = hv_get_drvdata(device);
 549
 550         if (stor_device && stor_device->destroy)
 551                 stor_device = NULL;
 552
 553         return stor_device;
 554 }
 555
 556
 557 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 558 {
 559         dev->drain_notify = true;
 560         wait_event(dev->waiting_to_drain,
 561                    atomic_read(&dev->num_outstanding_req) == 0);
 562         dev->drain_notify = false;
 563 }
 564
 565 static inline struct storvsc_device *get_in_stor_device(
 566                                         struct hv_device *device)
 567 {
 568         struct storvsc_device *stor_device;
 569
 570         stor_device = hv_get_drvdata(device);
 571
 572         if (!stor_device)
 573                 goto get_in_err;
 574
 575         /*
 576          * If the device is being destroyed; allow incoming
 577          * traffic only to cleanup outstanding requests.
 578          */
 579
 580         if (stor_device->destroy  &&
 581                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 582                 stor_device = NULL;
 583
 584 get_in_err:
 585         return stor_device;
 586
 587 }
 588
 589 static void handle_sc_creation(struct vmbus_channel *new_sc)
 590 {
 591         struct hv_device *device = new_sc->primary_channel->device_obj;
 592         struct storvsc_device *stor_device;
 593         struct vmstorage_channel_properties props;
 594
 595         stor_device = get_out_stor_device(device);
 596         if (!stor_device)
 597                 return;
 598
 599         if (stor_device->open_sub_channel == false)
 600                 return;
 601
 602         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 603
 604         vmbus_open(new_sc,
 605                    storvsc_ringbuffer_size,
 606                    storvsc_ringbuffer_size,
 607                    (void *)&props,
 608                    sizeof(struct vmstorage_channel_properties),
 609                    storvsc_on_channel_callback, new_sc);
 610 }
 611
 612 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 613 {
 614         struct storvsc_device *stor_device;
 615         int num_cpus = num_online_cpus();
 616         int num_sc;
 617         struct storvsc_cmd_request *request;
 618         struct vstor_packet *vstor_packet;
 619         int ret, t;
 620
 621         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 622         stor_device = get_out_stor_device(device);
 623         if (!stor_device)
 624                 return;
 625
 626         request = &stor_device->init_request;
 627         vstor_packet = &request->vstor_packet;
 628
 629         stor_device->open_sub_channel = true;
 630         /*
 631          * Establish a handler for dealing with subchannels.
 632          */
 633         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 634
 635         /*
 636          * Check to see if sub-channels have already been created. This
 637          * can happen when this driver is re-loaded after unloading.
 638          */
 639
 640         if (vmbus_are_subchannels_present(device->channel))
 641                 return;
 642
 643         stor_device->open_sub_channel = false;
 644         /*
 645          * Request the host to create sub-channels.
 646          */
 647         memset(request, 0, sizeof(struct storvsc_cmd_request));
 648         init_completion(&request->wait_event);
 649         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 650         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 651         vstor_packet->sub_channel_count = num_sc;
 652
 653         ret = vmbus_sendpacket(device->channel, vstor_packet,
 654                                (sizeof(struct vstor_packet) -
 655                                vmscsi_size_delta),
 656                                (unsigned long)request,
 657                                VM_PKT_DATA_INBAND,
 658                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 659
 660         if (ret != 0)
 661                 return;
 662
 663         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 664         if (t == 0)
 665                 return;
 666
 667         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 668             vstor_packet->status != 0)
 669                 return;
 670
 671         /*
 672          * Now that we created the sub-channels, invoke the check; this
 673          * may trigger the callback.
 674          */
 675         stor_device->open_sub_channel = true;
 676         vmbus_are_subchannels_present(device->channel);
 677 }
 678
 679 static int storvsc_channel_init(struct hv_device *device)
 680 {
 681         struct storvsc_device *stor_device;
 682         struct storvsc_cmd_request *request;
 683         struct vstor_packet *vstor_packet;
 684         int ret, t, i;
 685         int max_chns;
 686         bool process_sub_channels = false;
 687
 688         stor_device = get_out_stor_device(device);
 689         if (!stor_device)
 690                 return -ENODEV;
 691
 692         request = &stor_device->init_request;
 693         vstor_packet = &request->vstor_packet;
 694
 695         /*
 696          * Now, initiate the vsc/vsp initialization protocol on the open
 697          * channel
 698          */
 699         memset(request, 0, sizeof(struct storvsc_cmd_request));
 700         init_completion(&request->wait_event);
 701         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 702         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 703
 704         ret = vmbus_sendpacket(device->channel, vstor_packet,
 705                                (sizeof(struct vstor_packet) -
 706                                vmscsi_size_delta),
 707                                (unsigned long)request,
 708                                VM_PKT_DATA_INBAND,
 709                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 710         if (ret != 0)
 711                 goto cleanup;
 712
 713         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 714         if (t == 0) {
 715                 ret = -ETIMEDOUT;
 716                 goto cleanup;
 717         }
 718
 719         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 720             vstor_packet->status != 0) {
 721                 ret = -EINVAL;
 722                 goto cleanup;
 723         }
 724
 725
 726         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 727                 /* reuse the packet for version range supported */
 728                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 729                 vstor_packet->operation =
 730                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 731                 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 732
 733                 vstor_packet->version.major_minor =
 734                         vmstor_protocols[i].protocol_version;
 735
 736                 /*
 737                  * The revision number is only used in Windows; set it to 0.
 738                  */
 739                 vstor_packet->version.revision = 0;
 740
 741                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 742                                (sizeof(struct vstor_packet) -
 743                                 vmscsi_size_delta),
 744                                (unsigned long)request,
 745                                VM_PKT_DATA_INBAND,
 746                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 747                 if (ret != 0)
 748                         goto cleanup;
 749
 750                 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 751                 if (t == 0) {
 752                         ret = -ETIMEDOUT;
 753                         goto cleanup;
 754                 }
 755
 756                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO) {
 757                         ret = -EINVAL;
 758                         goto cleanup;
 759                 }
 760
 761                 if (vstor_packet->status == 0) {
 762                         vmstor_proto_version =
 763                                 vmstor_protocols[i].protocol_version;
 764
 765                         sense_buffer_size =
 766                                 vmstor_protocols[i].sense_buffer_size;
 767
 768                         vmscsi_size_delta =
 769                                 vmstor_protocols[i].vmscsi_size_delta;
 770
 771                         break;
 772                 }
 773         }
 774
 775         if (vstor_packet->status != 0) {
 776                 ret = -EINVAL;
 777                 goto cleanup;
 778         }
 779
 780
 781         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 782         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 783         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 784
 785         ret = vmbus_sendpacket(device->channel, vstor_packet,
 786                                (sizeof(struct vstor_packet) -
 787                                 vmscsi_size_delta),
 788                                (unsigned long)request,
 789                                VM_PKT_DATA_INBAND,
 790                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 791
 792         if (ret != 0)
 793                 goto cleanup;
 794
 795         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 796         if (t == 0) {
 797                 ret = -ETIMEDOUT;
 798                 goto cleanup;
 799         }
 800
 801         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 802             vstor_packet->status != 0) {
 803                 ret = -EINVAL;
 804                 goto cleanup;
 805         }
 806
 807         /*
 808          * Check to see if multi-channel support is there.
 809          * Hosts that implement protocol version of 5.1 and above
 810          * support multi-channel.
 811          */
 812         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 813         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 814                 if (vstor_packet->storage_channel_properties.flags &
 815                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 816                         process_sub_channels = true;
 817         }
 818         stor_device->max_transfer_bytes =
 819                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 820
 821         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 822         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 823         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 824
 825         ret = vmbus_sendpacket(device->channel, vstor_packet,
 826                                (sizeof(struct vstor_packet) -
 827                                 vmscsi_size_delta),
 828                                (unsigned long)request,
 829                                VM_PKT_DATA_INBAND,
 830                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 831
 832         if (ret != 0)
 833                 goto cleanup;
 834
 835         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 836         if (t == 0) {
 837                 ret = -ETIMEDOUT;
 838                 goto cleanup;
 839         }
 840
 841         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 842             vstor_packet->status != 0) {
 843                 ret = -EINVAL;
 844                 goto cleanup;
 845         }
 846
 847         if (process_sub_channels)
 848                 handle_multichannel_storage(device, max_chns);
 849
 850
 851 cleanup:
 852         return ret;
 853 }
 854
 855 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 856                                 struct scsi_cmnd *scmnd,
 857                                 struct Scsi_Host *host,
 858                                 u8 asc, u8 ascq)
 859 {
 860         struct storvsc_scan_work *wrk;
 861         void (*process_err_fn)(struct work_struct *work);
 862         bool do_work = false;
 863
 864         switch (SRB_STATUS(vm_srb->srb_status)) {
 865         case SRB_STATUS_ERROR:
 866                 /*
 867                  * If there is an error; offline the device since all
 868                  * error recovery strategies would have already been
 869                  * deployed on the host side. However, if the command
 870                  * were a pass-through command deal with it appropriately.
 871                  */
 872                 switch (scmnd->cmnd[0]) {
 873                 case ATA_16:
 874                 case ATA_12:
 875                         set_host_byte(scmnd, DID_PASSTHROUGH);
 876                         break;
 877                 /*
 878                  * On Some Windows hosts TEST_UNIT_READY command can return
 879                  * SRB_STATUS_ERROR, let the upper level code deal with it
 880                  * based on the sense information.
 881                  */
 882                 case TEST_UNIT_READY:
 883                         break;
 884                 default:
 885                         set_host_byte(scmnd, DID_TARGET_FAILURE);
 886                 }
 887                 break;
 888         case SRB_STATUS_INVALID_LUN:
 889                 do_work = true;
 890                 process_err_fn = storvsc_remove_lun;
 891                 break;
 892         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
 893                 if ((asc == 0x2a) && (ascq == 0x9)) {
 894                         do_work = true;
 895                         process_err_fn = storvsc_device_scan;
 896                         /*
 897                          * Retry the I/O that trigerred this.
 898                          */
 899                         set_host_byte(scmnd, DID_REQUEUE);
 900                 }
 901                 break;
 902         }
 903
 904         if (!do_work)
 905                 return;
 906
 907         /*
 908          * We need to schedule work to process this error; schedule it.
 909          */
 910         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 911         if (!wrk) {
 912                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 913                 return;
 914         }
 915
 916         wrk->host = host;
 917         wrk->lun = vm_srb->lun;
 918         INIT_WORK(&wrk->work, process_err_fn);
 919         schedule_work(&wrk->work);
 920 }
 921
 922
 923 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 924 {
 925         struct scsi_cmnd *scmnd = cmd_request->cmd;
 926         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
 927         struct scsi_sense_hdr sense_hdr;
 928         struct vmscsi_request *vm_srb;
 929         struct Scsi_Host *host;
 930         struct storvsc_device *stor_dev;
 931         struct hv_device *dev = host_dev->dev;
 932         u32 payload_sz = cmd_request->payload_sz;
 933         void *payload = cmd_request->payload;
 934
 935         stor_dev = get_in_stor_device(dev);
 936         host = stor_dev->host;
 937
 938         vm_srb = &cmd_request->vstor_packet.vm_srb;
 939
 940         scmnd->result = vm_srb->scsi_status;
 941
 942         if (scmnd->result) {
 943                 if (scsi_normalize_sense(scmnd->sense_buffer,
 944                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 945                         scsi_print_sense_hdr(scmnd->device, "storvsc",
 946                                              &sense_hdr);
 947         }
 948
 949         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
 950                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
 951                                          sense_hdr.ascq);
 952
 953         scsi_set_resid(scmnd,
 954                 cmd_request->payload->range.len -
 955                 vm_srb->data_transfer_length);
 956
 957         scmnd->scsi_done(scmnd);
 958
 959         if (payload_sz >
 960                 sizeof(struct vmbus_channel_packet_multipage_buffer))
 961                 kfree(payload);
 962 }
 963
 964 static void storvsc_on_io_completion(struct hv_device *device,
 965                                   struct vstor_packet *vstor_packet,
 966                                   struct storvsc_cmd_request *request)
 967 {
 968         struct storvsc_device *stor_device;
 969         struct vstor_packet *stor_pkt;
 970
 971         stor_device = hv_get_drvdata(device);
 972         stor_pkt = &request->vstor_packet;
 973
 974         /*
 975          * The current SCSI handling on the host side does
 976          * not correctly handle:
 977          * INQUIRY command with page code parameter set to 0x80
 978          * MODE_SENSE command with cmd[2] == 0x1c
 979          *
 980          * Setup srb and scsi status so this won't be fatal.
 981          * We do this so we can distinguish truly fatal failues
 982          * (srb status == 0x4) and off-line the device in that case.
 983          */
 984
 985         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
 986            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
 987                 vstor_packet->vm_srb.scsi_status = 0;
 988                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
 989         }
 990
 991
 992         /* Copy over the status...etc */
 993         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
 994         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
 995         stor_pkt->vm_srb.sense_info_length =
 996         vstor_packet->vm_srb.sense_info_length;
 997
 998
 999         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1000                 /* CHECK_CONDITION */
1001                 if (vstor_packet->vm_srb.srb_status &
1002                         SRB_STATUS_AUTOSENSE_VALID) {
1003                         /* autosense data available */
1004
1005                         memcpy(request->cmd->sense_buffer,
1006                                vstor_packet->vm_srb.sense_data,
1007                                vstor_packet->vm_srb.sense_info_length);
1008
1009                 }
1010         }
1011
1012         stor_pkt->vm_srb.data_transfer_length =
1013         vstor_packet->vm_srb.data_transfer_length;
1014
1015         storvsc_command_completion(request);
1016
1017         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1018                 stor_device->drain_notify)
1019                 wake_up(&stor_device->waiting_to_drain);
1020
1021
1022 }
1023
1024 static void storvsc_on_receive(struct hv_device *device,
1025                              struct vstor_packet *vstor_packet,
1026                              struct storvsc_cmd_request *request)
1027 {
1028         struct storvsc_scan_work *work;
1029         struct storvsc_device *stor_device;
1030
1031         switch (vstor_packet->operation) {
1032         case VSTOR_OPERATION_COMPLETE_IO:
1033                 storvsc_on_io_completion(device, vstor_packet, request);
1034                 break;
1035
1036         case VSTOR_OPERATION_REMOVE_DEVICE:
1037         case VSTOR_OPERATION_ENUMERATE_BUS:
1038                 stor_device = get_in_stor_device(device);
1039                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1040                 if (!work)
1041                         return;
1042
1043                 INIT_WORK(&work->work, storvsc_host_scan);
1044                 work->host = stor_device->host;
1045                 schedule_work(&work->work);
1046                 break;
1047
1048         default:
1049                 break;
1050         }
1051 }
1052
1053 static void storvsc_on_channel_callback(void *context)
1054 {
1055         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1056         struct hv_device *device;
1057         struct storvsc_device *stor_device;
1058         u32 bytes_recvd;
1059         u64 request_id;
1060         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1061         struct storvsc_cmd_request *request;
1062         int ret;
1063
1064         if (channel->primary_channel != NULL)
1065                 device = channel->primary_channel->device_obj;
1066         else
1067                 device = channel->device_obj;
1068
1069         stor_device = get_in_stor_device(device);
1070         if (!stor_device)
1071                 return;
1072
1073         do {
1074                 ret = vmbus_recvpacket(channel, packet,
1075                                        ALIGN((sizeof(struct vstor_packet) -
1076                                              vmscsi_size_delta), 8),
1077                                        &bytes_recvd, &request_id);
1078                 if (ret == 0 && bytes_recvd > 0) {
1079
1080                         request = (struct storvsc_cmd_request *)
1081                                         (unsigned long)request_id;
1082
1083                         if ((request == &stor_device->init_request) ||
1084                             (request == &stor_device->reset_request)) {
1085
1086                                 memcpy(&request->vstor_packet, packet,
1087                                        (sizeof(struct vstor_packet) -
1088                                         vmscsi_size_delta));
1089                                 complete(&request->wait_event);
1090                         } else {
1091                                 storvsc_on_receive(device,
1092                                                 (struct vstor_packet *)packet,
1093                                                 request);
1094                         }
1095                 } else {
1096                         break;
1097                 }
1098         } while (1);
1099
1100         return;
1101 }
1102
1103 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1104 {
1105         struct vmstorage_channel_properties props;
1106         int ret;
1107
1108         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1109
1110         ret = vmbus_open(device->channel,
1111                          ring_size,
1112                          ring_size,
1113                          (void *)&props,
1114                          sizeof(struct vmstorage_channel_properties),
1115                          storvsc_on_channel_callback, device->channel);
1116
1117         if (ret != 0)
1118                 return ret;
1119
1120         ret = storvsc_channel_init(device);
1121
1122         return ret;
1123 }
1124
1125 static int storvsc_dev_remove(struct hv_device *device)
1126 {
1127         struct storvsc_device *stor_device;
1128         unsigned long flags;
1129
1130         stor_device = hv_get_drvdata(device);
1131
1132         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1133         stor_device->destroy = true;
1134         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1135
1136         /*
1137          * At this point, all outbound traffic should be disable. We
1138          * only allow inbound traffic (responses) to proceed so that
1139          * outstanding requests can be completed.
1140          */
1141
1142         storvsc_wait_to_drain(stor_device);
1143
1144         /*
1145          * Since we have already drained, we don't need to busy wait
1146          * as was done in final_release_stor_device()
1147          * Note that we cannot set the ext pointer to NULL until
1148          * we have drained - to drain the outgoing packets, we need to
1149          * allow incoming packets.
1150          */
1151         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1152         hv_set_drvdata(device, NULL);
1153         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1154
1155         /* Close the channel */
1156         vmbus_close(device->channel);
1157
1158         kfree(stor_device);
1159         return 0;
1160 }
1161
1162 static int storvsc_do_io(struct hv_device *device,
1163                          struct storvsc_cmd_request *request)
1164 {
1165         struct storvsc_device *stor_device;
1166         struct vstor_packet *vstor_packet;
1167         struct vmbus_channel *outgoing_channel;
1168         int ret = 0;
1169
1170         vstor_packet = &request->vstor_packet;
1171         stor_device = get_out_stor_device(device);
1172
1173         if (!stor_device)
1174                 return -ENODEV;
1175
1176
1177         request->device  = device;
1178         /*
1179          * Select an an appropriate channel to send the request out.
1180          */
1181
1182         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1183
1184
1185         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1186
1187         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1188                                         vmscsi_size_delta);
1189
1190
1191         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1192
1193
1194         vstor_packet->vm_srb.data_transfer_length =
1195         request->payload->range.len;
1196
1197         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1198
1199         if (request->payload->range.len) {
1200
1201                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1202                                 request->payload, request->payload_sz,
1203                                 vstor_packet,
1204                                 (sizeof(struct vstor_packet) -
1205                                 vmscsi_size_delta),
1206                                 (unsigned long)request);
1207         } else {
1208                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1209                                (sizeof(struct vstor_packet) -
1210                                 vmscsi_size_delta),
1211                                (unsigned long)request,
1212                                VM_PKT_DATA_INBAND,
1213                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1214         }
1215
1216         if (ret != 0)
1217                 return ret;
1218
1219         atomic_inc(&stor_device->num_outstanding_req);
1220
1221         return ret;
1222 }
1223
1224 static int storvsc_device_configure(struct scsi_device *sdevice)
1225 {
1226
1227         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1228
1229         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1230
1231         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1232
1233         /* Ensure there are no gaps in presented sgls */
1234         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1235
1236         sdevice->no_write_same = 1;
1237
1238         /*
1239          * Add blist flags to permit the reading of the VPD pages even when
1240          * the target may claim SPC-2 compliance. MSFT targets currently
1241          * claim SPC-2 compliance while they implement post SPC-2 features.
1242          * With this patch we can correctly handle WRITE_SAME_16 issues.
1243          */
1244         sdevice->sdev_bflags |= msft_blist_flags;
1245
1246         /*
1247          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1248          * if the device is a MSFT virtual device.  If the host is
1249          * WIN10 or newer, allow write_same.
1250          */
1251         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1252                 switch (vmstor_proto_version) {
1253                 case VMSTOR_PROTO_VERSION_WIN8:
1254                 case VMSTOR_PROTO_VERSION_WIN8_1:
1255                         sdevice->scsi_level = SCSI_SPC_3;
1256                         break;
1257                 }
1258
1259                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1260                         sdevice->no_write_same = 0;
1261         }
1262
1263         return 0;
1264 }
1265
1266 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1267                            sector_t capacity, int *info)
1268 {
1269         sector_t nsect = capacity;
1270         sector_t cylinders = nsect;
1271         int heads, sectors_pt;
1272
1273         /*
1274          * We are making up these values; let us keep it simple.
1275          */
1276         heads = 0xff;
1277         sectors_pt = 0x3f;      /* Sectors per track */
1278         sector_div(cylinders, heads * sectors_pt);
1279         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1280                 cylinders = 0xffff;
1281
1282         info[0] = heads;
1283         info[1] = sectors_pt;
1284         info[2] = (int)cylinders;
1285
1286         return 0;
1287 }
1288
1289 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1290 {
1291         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1292         struct hv_device *device = host_dev->dev;
1293
1294         struct storvsc_device *stor_device;
1295         struct storvsc_cmd_request *request;
1296         struct vstor_packet *vstor_packet;
1297         int ret, t;
1298
1299
1300         stor_device = get_out_stor_device(device);
1301         if (!stor_device)
1302                 return FAILED;
1303
1304         request = &stor_device->reset_request;
1305         vstor_packet = &request->vstor_packet;
1306
1307         init_completion(&request->wait_event);
1308
1309         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1310         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1311         vstor_packet->vm_srb.path_id = stor_device->path_id;
1312
1313         ret = vmbus_sendpacket(device->channel, vstor_packet,
1314                                (sizeof(struct vstor_packet) -
1315                                 vmscsi_size_delta),
1316                                (unsigned long)&stor_device->reset_request,
1317                                VM_PKT_DATA_INBAND,
1318                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1319         if (ret != 0)
1320                 return FAILED;
1321
1322         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1323         if (t == 0)
1324                 return TIMEOUT_ERROR;
1325
1326
1327         /*
1328          * At this point, all outstanding requests in the adapter
1329          * should have been flushed out and return to us
1330          * There is a potential race here where the host may be in
1331          * the process of responding when we return from here.
1332          * Just wait for all in-transit packets to be accounted for
1333          * before we return from here.
1334          */
1335         storvsc_wait_to_drain(stor_device);
1336
1337         return SUCCESS;
1338 }
1339
1340 /*
1341  * The host guarantees to respond to each command, although I/O latencies might
1342  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1343  * chance to perform EH.
1344  */
1345 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1346 {
1347         return BLK_EH_RESET_TIMER;
1348 }
1349
1350 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1351 {
1352         bool allowed = true;
1353         u8 scsi_op = scmnd->cmnd[0];
1354
1355         switch (scsi_op) {
1356         /* the host does not handle WRITE_SAME, log accident usage */
1357         case WRITE_SAME:
1358         /*
1359          * smartd sends this command and the host does not handle
1360          * this. So, don't send it.
1361          */
1362         case SET_WINDOW:
1363                 scmnd->result = ILLEGAL_REQUEST << 16;
1364                 allowed = false;
1365                 break;
1366         default:
1367                 break;
1368         }
1369         return allowed;
1370 }
1371
1372 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1373 {
1374         int ret;
1375         struct hv_host_device *host_dev = shost_priv(host);
1376         struct hv_device *dev = host_dev->dev;
1377         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1378         int i;
1379         struct scatterlist *sgl;
1380         unsigned int sg_count = 0;
1381         struct vmscsi_request *vm_srb;
1382         struct scatterlist *cur_sgl;
1383         struct vmbus_packet_mpb_array  *payload;
1384         u32 payload_sz;
1385         u32 length;
1386
1387         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1388                 /*
1389                  * On legacy hosts filter unimplemented commands.
1390                  * Future hosts are expected to correctly handle
1391                  * unsupported commands. Furthermore, it is
1392                  * possible that some of the currently
1393                  * unsupported commands maybe supported in
1394                  * future versions of the host.
1395                  */
1396                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1397                         scmnd->scsi_done(scmnd);
1398                         return 0;
1399                 }
1400         }
1401
1402         /* Setup the cmd request */
1403         cmd_request->cmd = scmnd;
1404
1405         vm_srb = &cmd_request->vstor_packet.vm_srb;
1406         vm_srb->win8_extension.time_out_value = 60;
1407
1408         vm_srb->win8_extension.srb_flags |=
1409                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1410
1411         /* Build the SRB */
1412         switch (scmnd->sc_data_direction) {
1413         case DMA_TO_DEVICE:
1414                 vm_srb->data_in = WRITE_TYPE;
1415                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1416                 break;
1417         case DMA_FROM_DEVICE:
1418                 vm_srb->data_in = READ_TYPE;
1419                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1420                 break;
1421         case DMA_NONE:
1422                 vm_srb->data_in = UNKNOWN_TYPE;
1423                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1424                 break;
1425         default:
1426                 /*
1427                  * This is DMA_BIDIRECTIONAL or something else we are never
1428                  * supposed to see here.
1429                  */
1430                 WARN(1, "Unexpected data direction: %d\n",
1431                      scmnd->sc_data_direction);
1432                 return -EINVAL;
1433         }
1434
1435
1436         vm_srb->port_number = host_dev->port;
1437         vm_srb->path_id = scmnd->device->channel;
1438         vm_srb->target_id = scmnd->device->id;
1439         vm_srb->lun = scmnd->device->lun;
1440
1441         vm_srb->cdb_length = scmnd->cmd_len;
1442
1443         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1444
1445         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1446         sg_count = scsi_sg_count(scmnd);
1447
1448         length = scsi_bufflen(scmnd);
1449         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1450         payload_sz = sizeof(cmd_request->mpb);
1451
1452         if (sg_count) {
1453                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1454
1455                         payload_sz = (sg_count * sizeof(void *) +
1456                                       sizeof(struct vmbus_packet_mpb_array));
1457                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1458                         if (!payload)
1459                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1460                 }
1461
1462                 payload->range.len = length;
1463                 payload->range.offset = sgl[0].offset;
1464
1465                 cur_sgl = sgl;
1466                 for (i = 0; i < sg_count; i++) {
1467                         payload->range.pfn_array[i] =
1468                                 page_to_pfn(sg_page((cur_sgl)));
1469                         cur_sgl = sg_next(cur_sgl);
1470                 }
1471
1472         } else if (scsi_sglist(scmnd)) {
1473                 payload->range.len = length;
1474                 payload->range.offset =
1475                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1476                 payload->range.pfn_array[0] =
1477                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1478         }
1479
1480         cmd_request->payload = payload;
1481         cmd_request->payload_sz = payload_sz;
1482
1483         /* Invokes the vsc to start an IO */
1484         ret = storvsc_do_io(dev, cmd_request);
1485
1486         if (ret == -EAGAIN) {
1487                 /* no more space */
1488                 return SCSI_MLQUEUE_DEVICE_BUSY;
1489         }
1490
1491         return 0;
1492 }
1493
1494 static struct scsi_host_template scsi_driver = {
1495         .module =               THIS_MODULE,
1496         .name =                 "storvsc_host_t",
1497         .cmd_size =             sizeof(struct storvsc_cmd_request),
1498         .bios_param =           storvsc_get_chs,
1499         .queuecommand =         storvsc_queuecommand,
1500         .eh_host_reset_handler =        storvsc_host_reset_handler,
1501         .proc_name =            "storvsc_host",
1502         .eh_timed_out =         storvsc_eh_timed_out,
1503         .slave_configure =      storvsc_device_configure,
1504         .cmd_per_lun =          255,
1505         .this_id =              -1,
1506         .use_clustering =       ENABLE_CLUSTERING,
1507         /* Make sure we dont get a sg segment crosses a page boundary */
1508         .dma_boundary =         PAGE_SIZE-1,
1509         .no_write_same =        1,
1510 };
1511
1512 enum {
1513         SCSI_GUID,
1514         IDE_GUID,
1515         SFC_GUID,
1516 };
1517
1518 static const struct hv_vmbus_device_id id_table[] = {
1519         /* SCSI guid */
1520         { HV_SCSI_GUID,
1521           .driver_data = SCSI_GUID
1522         },
1523         /* IDE guid */
1524         { HV_IDE_GUID,
1525           .driver_data = IDE_GUID
1526         },
1527         /* Fibre Channel GUID */
1528         {
1529           HV_SYNTHFC_GUID,
1530           .driver_data = SFC_GUID
1531         },
1532         { },
1533 };
1534
1535 MODULE_DEVICE_TABLE(vmbus, id_table);
1536
1537 static int storvsc_probe(struct hv_device *device,
1538                         const struct hv_vmbus_device_id *dev_id)
1539 {
1540         int ret;
1541         int num_cpus = num_online_cpus();
1542         struct Scsi_Host *host;
1543         struct hv_host_device *host_dev;
1544         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1545         int target = 0;
1546         struct storvsc_device *stor_device;
1547         int max_luns_per_target;
1548         int max_targets;
1549         int max_channels;
1550         int max_sub_channels = 0;
1551
1552         /*
1553          * Based on the windows host we are running on,
1554          * set state to properly communicate with the host.
1555          */
1556
1557         if (vmbus_proto_version < VERSION_WIN8) {
1558                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1559                 max_targets = STORVSC_IDE_MAX_TARGETS;
1560                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1561         } else {
1562                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1563                 max_targets = STORVSC_MAX_TARGETS;
1564                 max_channels = STORVSC_MAX_CHANNELS;
1565                 /*
1566                  * On Windows8 and above, we support sub-channels for storage.
1567                  * The number of sub-channels offerred is based on the number of
1568                  * VCPUs in the guest.
1569                  */
1570                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1571         }
1572
1573         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1574                                  (max_sub_channels + 1));
1575
1576         host = scsi_host_alloc(&scsi_driver,
1577                                sizeof(struct hv_host_device));
1578         if (!host)
1579                 return -ENOMEM;
1580
1581         host_dev = shost_priv(host);
1582         memset(host_dev, 0, sizeof(struct hv_host_device));
1583
1584         host_dev->port = host->host_no;
1585         host_dev->dev = device;
1586
1587
1588         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1589         if (!stor_device) {
1590                 ret = -ENOMEM;
1591                 goto err_out0;
1592         }
1593
1594         stor_device->destroy = false;
1595         stor_device->open_sub_channel = false;
1596         init_waitqueue_head(&stor_device->waiting_to_drain);
1597         stor_device->device = device;
1598         stor_device->host = host;
1599         hv_set_drvdata(device, stor_device);
1600
1601         stor_device->port_number = host->host_no;
1602         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1603         if (ret)
1604                 goto err_out1;
1605
1606         host_dev->path = stor_device->path_id;
1607         host_dev->target = stor_device->target_id;
1608
1609         switch (dev_id->driver_data) {
1610         case SFC_GUID:
1611                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1612                 host->max_id = STORVSC_FC_MAX_TARGETS;
1613                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1614                 break;
1615
1616         case SCSI_GUID:
1617                 host->max_lun = max_luns_per_target;
1618                 host->max_id = max_targets;
1619                 host->max_channel = max_channels - 1;
1620                 break;
1621
1622         default:
1623                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1624                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1625                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1626                 break;
1627         }
1628         /* max cmd length */
1629         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1630
1631         /*
1632          * set the table size based on the info we got
1633          * from the host.
1634          */
1635         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1636
1637         /* Register the HBA and start the scsi bus scan */
1638         ret = scsi_add_host(host, &device->device);
1639         if (ret != 0)
1640                 goto err_out2;
1641
1642         if (!dev_is_ide) {
1643                 scsi_scan_host(host);
1644         } else {
1645                 target = (device->dev_instance.b[5] << 8 |
1646                          device->dev_instance.b[4]);
1647                 ret = scsi_add_device(host, 0, target, 0);
1648                 if (ret) {
1649                         scsi_remove_host(host);
1650                         goto err_out2;
1651                 }
1652         }
1653         return 0;
1654
1655 err_out2:
1656         /*
1657          * Once we have connected with the host, we would need to
1658          * to invoke storvsc_dev_remove() to rollback this state and
1659          * this call also frees up the stor_device; hence the jump around
1660          * err_out1 label.
1661          */
1662         storvsc_dev_remove(device);
1663         goto err_out0;
1664
1665 err_out1:
1666         kfree(stor_device);
1667
1668 err_out0:
1669         scsi_host_put(host);
1670         return ret;
1671 }
1672
1673 static int storvsc_remove(struct hv_device *dev)
1674 {
1675         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1676         struct Scsi_Host *host = stor_device->host;
1677
1678         scsi_remove_host(host);
1679         storvsc_dev_remove(dev);
1680         scsi_host_put(host);
1681
1682         return 0;
1683 }
1684
1685 static struct hv_driver storvsc_drv = {
1686         .name = KBUILD_MODNAME,
1687         .id_table = id_table,
1688         .probe = storvsc_probe,
1689         .remove = storvsc_remove,
1690 };
1691
1692 static int __init storvsc_drv_init(void)
1693 {
1694
1695         /*
1696          * Divide the ring buffer data size (which is 1 page less
1697          * than the ring buffer size since that page is reserved for
1698          * the ring buffer indices) by the max request size (which is
1699          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1700          */
1701         max_outstanding_req_per_channel =
1702                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1703                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1704                 sizeof(struct vstor_packet) + sizeof(u64) -
1705                 vmscsi_size_delta,
1706                 sizeof(u64)));
1707
1708         return vmbus_driver_register(&storvsc_drv);
1709 }
1710
1711 static void __exit storvsc_drv_exit(void)
1712 {
1713         vmbus_driver_unregister(&storvsc_drv);
1714 }
1715
1716 MODULE_LICENSE("GPL");
1717 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1718 module_init(storvsc_drv_init);
1719 module_exit(storvsc_drv_exit);