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 #define SP_UNTAGGED                     ((unsigned char) ~0)
 139 #define SRB_SIMPLE_TAG_REQUEST          0x20
 140
 141 /*
 142  * Platform neutral description of a scsi request -
 143  * this remains the same across the write regardless of 32/64 bit
 144  * note: it's patterned off the SCSI_PASS_THROUGH structure
 145  */
 146 #define STORVSC_MAX_CMD_LEN                     0x10
 147
 148 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 149 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 150
 151 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 152 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 153
 154 /*
 155  * Sense buffer size changed in win8; have a run-time
 156  * variable to track the size we should use.  This value will
 157  * likely change during protocol negotiation but it is valid
 158  * to start by assuming pre-Win8.
 159  */
 160 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 161
 162 /*
 163  * The storage protocol version is determined during the
 164  * initial exchange with the host.  It will indicate which
 165  * storage functionality is available in the host.
 166 */
 167 static int vmstor_proto_version;
 168
 169 struct vmscsi_win8_extension {
 170         /*
 171          * The following were added in Windows 8
 172          */
 173         u16 reserve;
 174         u8  queue_tag;
 175         u8  queue_action;
 176         u32 srb_flags;
 177         u32 time_out_value;
 178         u32 queue_sort_ey;
 179 } __packed;
 180
 181 struct vmscsi_request {
 182         u16 length;
 183         u8 srb_status;
 184         u8 scsi_status;
 185
 186         u8  port_number;
 187         u8  path_id;
 188         u8  target_id;
 189         u8  lun;
 190
 191         u8  cdb_length;
 192         u8  sense_info_length;
 193         u8  data_in;
 194         u8  reserved;
 195
 196         u32 data_transfer_length;
 197
 198         union {
 199                 u8 cdb[STORVSC_MAX_CMD_LEN];
 200                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 201                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 202         };
 203         /*
 204          * The following was added in win8.
 205          */
 206         struct vmscsi_win8_extension win8_extension;
 207
 208 } __attribute((packed));
 209
 210
 211 /*
 212  * The size of the vmscsi_request has changed in win8. The
 213  * additional size is because of new elements added to the
 214  * structure. These elements are valid only when we are talking
 215  * to a win8 host.
 216  * Track the correction to size we need to apply. This value
 217  * will likely change during protocol negotiation but it is
 218  * valid to start by assuming pre-Win8.
 219  */
 220 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 221
 222 /*
 223  * The list of storage protocols in order of preference.
 224  */
 225 struct vmstor_protocol {
 226         int protocol_version;
 227         int sense_buffer_size;
 228         int vmscsi_size_delta;
 229 };
 230
 231
 232 static const struct vmstor_protocol vmstor_protocols[] = {
 233         {
 234                 VMSTOR_PROTO_VERSION_WIN10,
 235                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 236                 0
 237         },
 238         {
 239                 VMSTOR_PROTO_VERSION_WIN8_1,
 240                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 241                 0
 242         },
 243         {
 244                 VMSTOR_PROTO_VERSION_WIN8,
 245                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 246                 0
 247         },
 248         {
 249                 VMSTOR_PROTO_VERSION_WIN7,
 250                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 251                 sizeof(struct vmscsi_win8_extension),
 252         },
 253         {
 254                 VMSTOR_PROTO_VERSION_WIN6,
 255                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 256                 sizeof(struct vmscsi_win8_extension),
 257         }
 258 };
 259
 260
 261 /*
 262  * This structure is sent during the intialization phase to get the different
 263  * properties of the channel.
 264  */
 265
 266 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 267
 268 struct vmstorage_channel_properties {
 269         u32 reserved;
 270         u16 max_channel_cnt;
 271         u16 reserved1;
 272
 273         u32 flags;
 274         u32   max_transfer_bytes;
 275
 276         u64  reserved2;
 277 } __packed;
 278
 279 /*  This structure is sent during the storage protocol negotiations. */
 280 struct vmstorage_protocol_version {
 281         /* Major (MSW) and minor (LSW) version numbers. */
 282         u16 major_minor;
 283
 284         /*
 285          * Revision number is auto-incremented whenever this file is changed
 286          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 287          * definitely indicate incompatibility--but it does indicate mismatched
 288          * builds.
 289          * This is only used on the windows side. Just set it to 0.
 290          */
 291         u16 revision;
 292 } __packed;
 293
 294 /* Channel Property Flags */
 295 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 296 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 297
 298 struct vstor_packet {
 299         /* Requested operation type */
 300         enum vstor_packet_operation operation;
 301
 302         /*  Flags - see below for values */
 303         u32 flags;
 304
 305         /* Status of the request returned from the server side. */
 306         u32 status;
 307
 308         /* Data payload area */
 309         union {
 310                 /*
 311                  * Structure used to forward SCSI commands from the
 312                  * client to the server.
 313                  */
 314                 struct vmscsi_request vm_srb;
 315
 316                 /* Structure used to query channel properties. */
 317                 struct vmstorage_channel_properties storage_channel_properties;
 318
 319                 /* Used during version negotiations. */
 320                 struct vmstorage_protocol_version version;
 321
 322                 /* Fibre channel address packet */
 323                 struct hv_fc_wwn_packet wwn_packet;
 324
 325                 /* Number of sub-channels to create */
 326                 u16 sub_channel_count;
 327
 328                 /* This will be the maximum of the union members */
 329                 u8  buffer[0x34];
 330         };
 331 } __packed;
 332
 333 /*
 334  * Packet Flags:
 335  *
 336  * This flag indicates that the server should send back a completion for this
 337  * packet.
 338  */
 339
 340 #define REQUEST_COMPLETION_FLAG 0x1
 341
 342 /* Matches Windows-end */
 343 enum storvsc_request_type {
 344         WRITE_TYPE = 0,
 345         READ_TYPE,
 346         UNKNOWN_TYPE,
 347 };
 348
 349 /*
 350  * SRB status codes and masks; a subset of the codes used here.
 351  */
 352
 353 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 354 #define SRB_STATUS_QUEUE_FROZEN         0x40
 355 #define SRB_STATUS_INVALID_LUN  0x20
 356 #define SRB_STATUS_SUCCESS      0x01
 357 #define SRB_STATUS_ABORTED      0x02
 358 #define SRB_STATUS_ERROR        0x04
 359 #define SRB_STATUS_DATA_OVERRUN 0x12
 360
 361 #define SRB_STATUS(status) \
 362         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 363 /*
 364  * This is the end of Protocol specific defines.
 365  */
 366
 367 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 368 static u32 max_outstanding_req_per_channel;
 369
 370 static int storvsc_vcpus_per_sub_channel = 4;
 371
 372 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 373 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 374
 375 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 376 MODULE_PARM_DESC(vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 377 /*
 378  * Timeout in seconds for all devices managed by this driver.
 379  */
 380 static int storvsc_timeout = 180;
 381
 382
 383 static void storvsc_on_channel_callback(void *context);
 384
 385 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 386 #define STORVSC_MAX_TARGETS                             2
 387 #define STORVSC_MAX_CHANNELS                            8
 388
 389 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 390 #define STORVSC_FC_MAX_TARGETS                          128
 391 #define STORVSC_FC_MAX_CHANNELS                         8
 392
 393 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 394 #define STORVSC_IDE_MAX_TARGETS                         1
 395 #define STORVSC_IDE_MAX_CHANNELS                        1
 396
 397 struct storvsc_cmd_request {
 398         struct scsi_cmnd *cmd;
 399
 400         struct hv_device *device;
 401
 402         /* Synchronize the request/response if needed */
 403         struct completion wait_event;
 404
 405         struct vmbus_channel_packet_multipage_buffer mpb;
 406         struct vmbus_packet_mpb_array *payload;
 407         u32 payload_sz;
 408
 409         struct vstor_packet vstor_packet;
 410 };
 411
 412
 413 /* A storvsc device is a device object that contains a vmbus channel */
 414 struct storvsc_device {
 415         struct hv_device *device;
 416
 417         bool     destroy;
 418         bool     drain_notify;
 419         bool     open_sub_channel;
 420         atomic_t num_outstanding_req;
 421         struct Scsi_Host *host;
 422
 423         wait_queue_head_t waiting_to_drain;
 424
 425         /*
 426          * Each unique Port/Path/Target represents 1 channel ie scsi
 427          * controller. In reality, the pathid, targetid is always 0
 428          * and the port is set by us
 429          */
 430         unsigned int port_number;
 431         unsigned char path_id;
 432         unsigned char target_id;
 433
 434         /*
 435          * Max I/O, the device can support.
 436          */
 437         u32   max_transfer_bytes;
 438         /* Used for vsc/vsp channel reset process */
 439         struct storvsc_cmd_request init_request;
 440         struct storvsc_cmd_request reset_request;
 441 };
 442
 443 struct hv_host_device {
 444         struct hv_device *dev;
 445         unsigned int port;
 446         unsigned char path;
 447         unsigned char target;
 448 };
 449
 450 struct storvsc_scan_work {
 451         struct work_struct work;
 452         struct Scsi_Host *host;
 453         uint lun;
 454 };
 455
 456 static void storvsc_device_scan(struct work_struct *work)
 457 {
 458         struct storvsc_scan_work *wrk;
 459         uint lun;
 460         struct scsi_device *sdev;
 461
 462         wrk = container_of(work, struct storvsc_scan_work, work);
 463         lun = wrk->lun;
 464
 465         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 466         if (!sdev)
 467                 goto done;
 468         scsi_rescan_device(&sdev->sdev_gendev);
 469         scsi_device_put(sdev);
 470
 471 done:
 472         kfree(wrk);
 473 }
 474
 475 static void storvsc_host_scan(struct work_struct *work)
 476 {
 477         struct storvsc_scan_work *wrk;
 478         struct Scsi_Host *host;
 479         struct scsi_device *sdev;
 480
 481         wrk = container_of(work, struct storvsc_scan_work, work);
 482         host = wrk->host;
 483
 484         /*
 485          * Before scanning the host, first check to see if any of the
 486          * currrently known devices have been hot removed. We issue a
 487          * "unit ready" command against all currently known devices.
 488          * This I/O will result in an error for devices that have been
 489          * removed. As part of handling the I/O error, we remove the device.
 490          *
 491          * When a LUN is added or removed, the host sends us a signal to
 492          * scan the host. Thus we are forced to discover the LUNs that
 493          * may have been removed this way.
 494          */
 495         mutex_lock(&host->scan_mutex);
 496         shost_for_each_device(sdev, host)
 497                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 498         mutex_unlock(&host->scan_mutex);
 499         /*
 500          * Now scan the host to discover LUNs that may have been added.
 501          */
 502         scsi_scan_host(host);
 503
 504         kfree(wrk);
 505 }
 506
 507 static void storvsc_remove_lun(struct work_struct *work)
 508 {
 509         struct storvsc_scan_work *wrk;
 510         struct scsi_device *sdev;
 511
 512         wrk = container_of(work, struct storvsc_scan_work, work);
 513         if (!scsi_host_get(wrk->host))
 514                 goto done;
 515
 516         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 517
 518         if (sdev) {
 519                 scsi_remove_device(sdev);
 520                 scsi_device_put(sdev);
 521         }
 522         scsi_host_put(wrk->host);
 523
 524 done:
 525         kfree(wrk);
 526 }
 527
 528
 529 /*
 530  * We can get incoming messages from the host that are not in response to
 531  * messages that we have sent out. An example of this would be messages
 532  * received by the guest to notify dynamic addition/removal of LUNs. To
 533  * deal with potential race conditions where the driver may be in the
 534  * midst of being unloaded when we might receive an unsolicited message
 535  * from the host, we have implemented a mechanism to gurantee sequential
 536  * consistency:
 537  *
 538  * 1) Once the device is marked as being destroyed, we will fail all
 539  *    outgoing messages.
 540  * 2) We permit incoming messages when the device is being destroyed,
 541  *    only to properly account for messages already sent out.
 542  */
 543
 544 static inline struct storvsc_device *get_out_stor_device(
 545                                         struct hv_device *device)
 546 {
 547         struct storvsc_device *stor_device;
 548
 549         stor_device = hv_get_drvdata(device);
 550
 551         if (stor_device && stor_device->destroy)
 552                 stor_device = NULL;
 553
 554         return stor_device;
 555 }
 556
 557
 558 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 559 {
 560         dev->drain_notify = true;
 561         wait_event(dev->waiting_to_drain,
 562                    atomic_read(&dev->num_outstanding_req) == 0);
 563         dev->drain_notify = false;
 564 }
 565
 566 static inline struct storvsc_device *get_in_stor_device(
 567                                         struct hv_device *device)
 568 {
 569         struct storvsc_device *stor_device;
 570
 571         stor_device = hv_get_drvdata(device);
 572
 573         if (!stor_device)
 574                 goto get_in_err;
 575
 576         /*
 577          * If the device is being destroyed; allow incoming
 578          * traffic only to cleanup outstanding requests.
 579          */
 580
 581         if (stor_device->destroy  &&
 582                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 583                 stor_device = NULL;
 584
 585 get_in_err:
 586         return stor_device;
 587
 588 }
 589
 590 static void handle_sc_creation(struct vmbus_channel *new_sc)
 591 {
 592         struct hv_device *device = new_sc->primary_channel->device_obj;
 593         struct storvsc_device *stor_device;
 594         struct vmstorage_channel_properties props;
 595
 596         stor_device = get_out_stor_device(device);
 597         if (!stor_device)
 598                 return;
 599
 600         if (stor_device->open_sub_channel == false)
 601                 return;
 602
 603         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 604
 605         vmbus_open(new_sc,
 606                    storvsc_ringbuffer_size,
 607                    storvsc_ringbuffer_size,
 608                    (void *)&props,
 609                    sizeof(struct vmstorage_channel_properties),
 610                    storvsc_on_channel_callback, new_sc);
 611 }
 612
 613 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 614 {
 615         struct storvsc_device *stor_device;
 616         int num_sc;
 617         struct storvsc_cmd_request *request;
 618         struct vstor_packet *vstor_packet;
 619         int ret, t;
 620
 621         /*
 622          * If the number of CPUs is artificially restricted, such as
 623          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 624          * sub-channels >= the number of CPUs. These sub-channels
 625          * should not be created. The primary channel is already created
 626          * and assigned to one CPU, so check against # CPUs - 1.
 627          */
 628         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 629         if (!num_sc)
 630                 return;
 631
 632         stor_device = get_out_stor_device(device);
 633         if (!stor_device)
 634                 return;
 635
 636         request = &stor_device->init_request;
 637         vstor_packet = &request->vstor_packet;
 638
 639         stor_device->open_sub_channel = true;
 640         /*
 641          * Establish a handler for dealing with subchannels.
 642          */
 643         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 644
 645         /*
 646          * Check to see if sub-channels have already been created. This
 647          * can happen when this driver is re-loaded after unloading.
 648          */
 649
 650         if (vmbus_are_subchannels_present(device->channel))
 651                 return;
 652
 653         stor_device->open_sub_channel = false;
 654         /*
 655          * Request the host to create sub-channels.
 656          */
 657         memset(request, 0, sizeof(struct storvsc_cmd_request));
 658         init_completion(&request->wait_event);
 659         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 660         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 661         vstor_packet->sub_channel_count = num_sc;
 662
 663         ret = vmbus_sendpacket(device->channel, vstor_packet,
 664                                (sizeof(struct vstor_packet) -
 665                                vmscsi_size_delta),
 666                                (unsigned long)request,
 667                                VM_PKT_DATA_INBAND,
 668                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 669
 670         if (ret != 0)
 671                 return;
 672
 673         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 674         if (t == 0)
 675                 return;
 676
 677         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 678             vstor_packet->status != 0)
 679                 return;
 680
 681         /*
 682          * Now that we created the sub-channels, invoke the check; this
 683          * may trigger the callback.
 684          */
 685         stor_device->open_sub_channel = true;
 686         vmbus_are_subchannels_present(device->channel);
 687 }
 688
 689 static int storvsc_channel_init(struct hv_device *device)
 690 {
 691         struct storvsc_device *stor_device;
 692         struct storvsc_cmd_request *request;
 693         struct vstor_packet *vstor_packet;
 694         int ret, t, i;
 695         int max_chns;
 696         bool process_sub_channels = false;
 697
 698         stor_device = get_out_stor_device(device);
 699         if (!stor_device)
 700                 return -ENODEV;
 701
 702         request = &stor_device->init_request;
 703         vstor_packet = &request->vstor_packet;
 704
 705         /*
 706          * Now, initiate the vsc/vsp initialization protocol on the open
 707          * channel
 708          */
 709         memset(request, 0, sizeof(struct storvsc_cmd_request));
 710         init_completion(&request->wait_event);
 711         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 712         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 713
 714         ret = vmbus_sendpacket(device->channel, vstor_packet,
 715                                (sizeof(struct vstor_packet) -
 716                                vmscsi_size_delta),
 717                                (unsigned long)request,
 718                                VM_PKT_DATA_INBAND,
 719                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 720         if (ret != 0)
 721                 goto cleanup;
 722
 723         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 724         if (t == 0) {
 725                 ret = -ETIMEDOUT;
 726                 goto cleanup;
 727         }
 728
 729         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 730             vstor_packet->status != 0) {
 731                 ret = -EINVAL;
 732                 goto cleanup;
 733         }
 734
 735
 736         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 737                 /* reuse the packet for version range supported */
 738                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 739                 vstor_packet->operation =
 740                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 741                 vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 742
 743                 vstor_packet->version.major_minor =
 744                         vmstor_protocols[i].protocol_version;
 745
 746                 /*
 747                  * The revision number is only used in Windows; set it to 0.
 748                  */
 749                 vstor_packet->version.revision = 0;
 750
 751                 ret = vmbus_sendpacket(device->channel, vstor_packet,
 752                                (sizeof(struct vstor_packet) -
 753                                 vmscsi_size_delta),
 754                                (unsigned long)request,
 755                                VM_PKT_DATA_INBAND,
 756                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 757                 if (ret != 0)
 758                         goto cleanup;
 759
 760                 t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 761                 if (t == 0) {
 762                         ret = -ETIMEDOUT;
 763                         goto cleanup;
 764                 }
 765
 766                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO) {
 767                         ret = -EINVAL;
 768                         goto cleanup;
 769                 }
 770
 771                 if (vstor_packet->status == 0) {
 772                         vmstor_proto_version =
 773                                 vmstor_protocols[i].protocol_version;
 774
 775                         sense_buffer_size =
 776                                 vmstor_protocols[i].sense_buffer_size;
 777
 778                         vmscsi_size_delta =
 779                                 vmstor_protocols[i].vmscsi_size_delta;
 780
 781                         break;
 782                 }
 783         }
 784
 785         if (vstor_packet->status != 0) {
 786                 ret = -EINVAL;
 787                 goto cleanup;
 788         }
 789
 790
 791         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 792         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 793         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 794
 795         ret = vmbus_sendpacket(device->channel, vstor_packet,
 796                                (sizeof(struct vstor_packet) -
 797                                 vmscsi_size_delta),
 798                                (unsigned long)request,
 799                                VM_PKT_DATA_INBAND,
 800                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 801
 802         if (ret != 0)
 803                 goto cleanup;
 804
 805         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 806         if (t == 0) {
 807                 ret = -ETIMEDOUT;
 808                 goto cleanup;
 809         }
 810
 811         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 812             vstor_packet->status != 0) {
 813                 ret = -EINVAL;
 814                 goto cleanup;
 815         }
 816
 817         /*
 818          * Check to see if multi-channel support is there.
 819          * Hosts that implement protocol version of 5.1 and above
 820          * support multi-channel.
 821          */
 822         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 823         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 824                 if (vstor_packet->storage_channel_properties.flags &
 825                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 826                         process_sub_channels = true;
 827         }
 828         stor_device->max_transfer_bytes =
 829                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 830
 831         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 832         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 833         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 834
 835         ret = vmbus_sendpacket(device->channel, vstor_packet,
 836                                (sizeof(struct vstor_packet) -
 837                                 vmscsi_size_delta),
 838                                (unsigned long)request,
 839                                VM_PKT_DATA_INBAND,
 840                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 841
 842         if (ret != 0)
 843                 goto cleanup;
 844
 845         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 846         if (t == 0) {
 847                 ret = -ETIMEDOUT;
 848                 goto cleanup;
 849         }
 850
 851         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 852             vstor_packet->status != 0) {
 853                 ret = -EINVAL;
 854                 goto cleanup;
 855         }
 856
 857         if (process_sub_channels)
 858                 handle_multichannel_storage(device, max_chns);
 859
 860
 861 cleanup:
 862         return ret;
 863 }
 864
 865 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 866                                 struct scsi_cmnd *scmnd,
 867                                 struct Scsi_Host *host,
 868                                 u8 asc, u8 ascq)
 869 {
 870         struct storvsc_scan_work *wrk;
 871         void (*process_err_fn)(struct work_struct *work);
 872         bool do_work = false;
 873
 874         switch (SRB_STATUS(vm_srb->srb_status)) {
 875         case SRB_STATUS_ERROR:
 876                 /*
 877                  * Let upper layer deal with error when
 878                  * sense message is present.
 879                  */
 880
 881                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
 882                         break;
 883                 /*
 884                  * If there is an error; offline the device since all
 885                  * error recovery strategies would have already been
 886                  * deployed on the host side. However, if the command
 887                  * were a pass-through command deal with it appropriately.
 888                  */
 889                 switch (scmnd->cmnd[0]) {
 890                 case ATA_16:
 891                 case ATA_12:
 892                         set_host_byte(scmnd, DID_PASSTHROUGH);
 893                         break;
 894                 /*
 895                  * On Some Windows hosts TEST_UNIT_READY command can return
 896                  * SRB_STATUS_ERROR, let the upper level code deal with it
 897                  * based on the sense information.
 898                  */
 899                 case TEST_UNIT_READY:
 900                         break;
 901                 default:
 902                         set_host_byte(scmnd, DID_ERROR);
 903                 }
 904                 break;
 905         case SRB_STATUS_INVALID_LUN:
 906                 set_host_byte(scmnd, DID_NO_CONNECT);
 907                 do_work = true;
 908                 process_err_fn = storvsc_remove_lun;
 909                 break;
 910         case SRB_STATUS_ABORTED:
 911                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
 912                     (asc == 0x2a) && (ascq == 0x9)) {
 913                         do_work = true;
 914                         process_err_fn = storvsc_device_scan;
 915                         /*
 916                          * Retry the I/O that trigerred this.
 917                          */
 918                         set_host_byte(scmnd, DID_REQUEUE);
 919                 }
 920                 break;
 921         }
 922
 923         if (!do_work)
 924                 return;
 925
 926         /*
 927          * We need to schedule work to process this error; schedule it.
 928          */
 929         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 930         if (!wrk) {
 931                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 932                 return;
 933         }
 934
 935         wrk->host = host;
 936         wrk->lun = vm_srb->lun;
 937         INIT_WORK(&wrk->work, process_err_fn);
 938         schedule_work(&wrk->work);
 939 }
 940
 941
 942 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request)
 943 {
 944         struct scsi_cmnd *scmnd = cmd_request->cmd;
 945         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
 946         struct scsi_sense_hdr sense_hdr;
 947         struct vmscsi_request *vm_srb;
 948         u32 data_transfer_length;
 949         struct Scsi_Host *host;
 950         struct storvsc_device *stor_dev;
 951         struct hv_device *dev = host_dev->dev;
 952         u32 payload_sz = cmd_request->payload_sz;
 953         void *payload = cmd_request->payload;
 954
 955         stor_dev = get_in_stor_device(dev);
 956         host = stor_dev->host;
 957
 958         vm_srb = &cmd_request->vstor_packet.vm_srb;
 959         data_transfer_length = vm_srb->data_transfer_length;
 960
 961         scmnd->result = vm_srb->scsi_status;
 962
 963         if (scmnd->result) {
 964                 if (scsi_normalize_sense(scmnd->sense_buffer,
 965                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 966                         scsi_print_sense_hdr(scmnd->device, "storvsc",
 967                                              &sense_hdr);
 968         }
 969
 970         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
 971                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
 972                                          sense_hdr.ascq);
 973                 /*
 974                  * The Windows driver set data_transfer_length on
 975                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
 976                  * is untouched.  In these cases we set it to 0.
 977                  */
 978                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
 979                         data_transfer_length = 0;
 980         }
 981
 982         scsi_set_resid(scmnd,
 983                 cmd_request->payload->range.len - data_transfer_length);
 984
 985         scmnd->scsi_done(scmnd);
 986
 987         if (payload_sz >
 988                 sizeof(struct vmbus_channel_packet_multipage_buffer))
 989                 kfree(payload);
 990 }
 991
 992 static void storvsc_on_io_completion(struct hv_device *device,
 993                                   struct vstor_packet *vstor_packet,
 994                                   struct storvsc_cmd_request *request)
 995 {
 996         struct storvsc_device *stor_device;
 997         struct vstor_packet *stor_pkt;
 998
 999         stor_device = hv_get_drvdata(device);
1000         stor_pkt = &request->vstor_packet;
1001
1002         /*
1003          * The current SCSI handling on the host side does
1004          * not correctly handle:
1005          * INQUIRY command with page code parameter set to 0x80
1006          * MODE_SENSE command with cmd[2] == 0x1c
1007          *
1008          * Setup srb and scsi status so this won't be fatal.
1009          * We do this so we can distinguish truly fatal failues
1010          * (srb status == 0x4) and off-line the device in that case.
1011          */
1012
1013         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1014            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1015                 vstor_packet->vm_srb.scsi_status = 0;
1016                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1017         }
1018
1019
1020         /* Copy over the status...etc */
1021         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1022         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1023         stor_pkt->vm_srb.sense_info_length =
1024         vstor_packet->vm_srb.sense_info_length;
1025
1026
1027         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1028                 /* CHECK_CONDITION */
1029                 if (vstor_packet->vm_srb.srb_status &
1030                         SRB_STATUS_AUTOSENSE_VALID) {
1031                         /* autosense data available */
1032
1033                         memcpy(request->cmd->sense_buffer,
1034                                vstor_packet->vm_srb.sense_data,
1035                                vstor_packet->vm_srb.sense_info_length);
1036
1037                 }
1038         }
1039
1040         stor_pkt->vm_srb.data_transfer_length =
1041         vstor_packet->vm_srb.data_transfer_length;
1042
1043         storvsc_command_completion(request);
1044
1045         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1046                 stor_device->drain_notify)
1047                 wake_up(&stor_device->waiting_to_drain);
1048
1049
1050 }
1051
1052 static void storvsc_on_receive(struct hv_device *device,
1053                              struct vstor_packet *vstor_packet,
1054                              struct storvsc_cmd_request *request)
1055 {
1056         struct storvsc_scan_work *work;
1057         struct storvsc_device *stor_device;
1058
1059         switch (vstor_packet->operation) {
1060         case VSTOR_OPERATION_COMPLETE_IO:
1061                 storvsc_on_io_completion(device, vstor_packet, request);
1062                 break;
1063
1064         case VSTOR_OPERATION_REMOVE_DEVICE:
1065         case VSTOR_OPERATION_ENUMERATE_BUS:
1066                 stor_device = get_in_stor_device(device);
1067                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1068                 if (!work)
1069                         return;
1070
1071                 INIT_WORK(&work->work, storvsc_host_scan);
1072                 work->host = stor_device->host;
1073                 schedule_work(&work->work);
1074                 break;
1075
1076         default:
1077                 break;
1078         }
1079 }
1080
1081 static void storvsc_on_channel_callback(void *context)
1082 {
1083         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1084         struct hv_device *device;
1085         struct storvsc_device *stor_device;
1086         u32 bytes_recvd;
1087         u64 request_id;
1088         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1089         struct storvsc_cmd_request *request;
1090         int ret;
1091
1092         if (channel->primary_channel != NULL)
1093                 device = channel->primary_channel->device_obj;
1094         else
1095                 device = channel->device_obj;
1096
1097         stor_device = get_in_stor_device(device);
1098         if (!stor_device)
1099                 return;
1100
1101         do {
1102                 ret = vmbus_recvpacket(channel, packet,
1103                                        ALIGN((sizeof(struct vstor_packet) -
1104                                              vmscsi_size_delta), 8),
1105                                        &bytes_recvd, &request_id);
1106                 if (ret == 0 && bytes_recvd > 0) {
1107
1108                         request = (struct storvsc_cmd_request *)
1109                                         (unsigned long)request_id;
1110
1111                         if ((request == &stor_device->init_request) ||
1112                             (request == &stor_device->reset_request)) {
1113
1114                                 memcpy(&request->vstor_packet, packet,
1115                                        (sizeof(struct vstor_packet) -
1116                                         vmscsi_size_delta));
1117                                 complete(&request->wait_event);
1118                         } else {
1119                                 storvsc_on_receive(device,
1120                                                 (struct vstor_packet *)packet,
1121                                                 request);
1122                         }
1123                 } else {
1124                         break;
1125                 }
1126         } while (1);
1127
1128         return;
1129 }
1130
1131 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size)
1132 {
1133         struct vmstorage_channel_properties props;
1134         int ret;
1135
1136         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1137
1138         ret = vmbus_open(device->channel,
1139                          ring_size,
1140                          ring_size,
1141                          (void *)&props,
1142                          sizeof(struct vmstorage_channel_properties),
1143                          storvsc_on_channel_callback, device->channel);
1144
1145         if (ret != 0)
1146                 return ret;
1147
1148         ret = storvsc_channel_init(device);
1149
1150         return ret;
1151 }
1152
1153 static int storvsc_dev_remove(struct hv_device *device)
1154 {
1155         struct storvsc_device *stor_device;
1156         unsigned long flags;
1157
1158         stor_device = hv_get_drvdata(device);
1159
1160         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1161         stor_device->destroy = true;
1162         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1163
1164         /*
1165          * At this point, all outbound traffic should be disable. We
1166          * only allow inbound traffic (responses) to proceed so that
1167          * outstanding requests can be completed.
1168          */
1169
1170         storvsc_wait_to_drain(stor_device);
1171
1172         /*
1173          * Since we have already drained, we don't need to busy wait
1174          * as was done in final_release_stor_device()
1175          * Note that we cannot set the ext pointer to NULL until
1176          * we have drained - to drain the outgoing packets, we need to
1177          * allow incoming packets.
1178          */
1179         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1180         hv_set_drvdata(device, NULL);
1181         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1182
1183         /* Close the channel */
1184         vmbus_close(device->channel);
1185
1186         kfree(stor_device);
1187         return 0;
1188 }
1189
1190 static int storvsc_do_io(struct hv_device *device,
1191                          struct storvsc_cmd_request *request)
1192 {
1193         struct storvsc_device *stor_device;
1194         struct vstor_packet *vstor_packet;
1195         struct vmbus_channel *outgoing_channel;
1196         int ret = 0;
1197
1198         vstor_packet = &request->vstor_packet;
1199         stor_device = get_out_stor_device(device);
1200
1201         if (!stor_device)
1202                 return -ENODEV;
1203
1204
1205         request->device  = device;
1206         /*
1207          * Select an an appropriate channel to send the request out.
1208          */
1209
1210         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1211
1212
1213         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1214
1215         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1216                                         vmscsi_size_delta);
1217
1218
1219         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1220
1221
1222         vstor_packet->vm_srb.data_transfer_length =
1223         request->payload->range.len;
1224
1225         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1226
1227         if (request->payload->range.len) {
1228
1229                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1230                                 request->payload, request->payload_sz,
1231                                 vstor_packet,
1232                                 (sizeof(struct vstor_packet) -
1233                                 vmscsi_size_delta),
1234                                 (unsigned long)request);
1235         } else {
1236                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1237                                (sizeof(struct vstor_packet) -
1238                                 vmscsi_size_delta),
1239                                (unsigned long)request,
1240                                VM_PKT_DATA_INBAND,
1241                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1242         }
1243
1244         if (ret != 0)
1245                 return ret;
1246
1247         atomic_inc(&stor_device->num_outstanding_req);
1248
1249         return ret;
1250 }
1251
1252 static int storvsc_device_alloc(struct scsi_device *sdevice)
1253 {
1254         /*
1255          * Set blist flag to permit the reading of the VPD pages even when
1256          * the target may claim SPC-2 compliance. MSFT targets currently
1257          * claim SPC-2 compliance while they implement post SPC-2 features.
1258          * With this flag we can correctly handle WRITE_SAME_16 issues.
1259          *
1260          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1261          * still supports REPORT LUN.
1262          */
1263         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1264
1265         return 0;
1266 }
1267
1268 static int storvsc_device_configure(struct scsi_device *sdevice)
1269 {
1270
1271         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1272
1273         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1274
1275         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1276
1277         /* Ensure there are no gaps in presented sgls */
1278         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1279
1280         sdevice->no_write_same = 1;
1281
1282         /*
1283          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1284          * if the device is a MSFT virtual device.  If the host is
1285          * WIN10 or newer, allow write_same.
1286          */
1287         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1288                 switch (vmstor_proto_version) {
1289                 case VMSTOR_PROTO_VERSION_WIN8:
1290                 case VMSTOR_PROTO_VERSION_WIN8_1:
1291                         sdevice->scsi_level = SCSI_SPC_3;
1292                         break;
1293                 }
1294
1295                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1296                         sdevice->no_write_same = 0;
1297         }
1298
1299         return 0;
1300 }
1301
1302 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1303                            sector_t capacity, int *info)
1304 {
1305         sector_t nsect = capacity;
1306         sector_t cylinders = nsect;
1307         int heads, sectors_pt;
1308
1309         /*
1310          * We are making up these values; let us keep it simple.
1311          */
1312         heads = 0xff;
1313         sectors_pt = 0x3f;      /* Sectors per track */
1314         sector_div(cylinders, heads * sectors_pt);
1315         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1316                 cylinders = 0xffff;
1317
1318         info[0] = heads;
1319         info[1] = sectors_pt;
1320         info[2] = (int)cylinders;
1321
1322         return 0;
1323 }
1324
1325 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1326 {
1327         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1328         struct hv_device *device = host_dev->dev;
1329
1330         struct storvsc_device *stor_device;
1331         struct storvsc_cmd_request *request;
1332         struct vstor_packet *vstor_packet;
1333         int ret, t;
1334
1335
1336         stor_device = get_out_stor_device(device);
1337         if (!stor_device)
1338                 return FAILED;
1339
1340         request = &stor_device->reset_request;
1341         vstor_packet = &request->vstor_packet;
1342
1343         init_completion(&request->wait_event);
1344
1345         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1346         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1347         vstor_packet->vm_srb.path_id = stor_device->path_id;
1348
1349         ret = vmbus_sendpacket(device->channel, vstor_packet,
1350                                (sizeof(struct vstor_packet) -
1351                                 vmscsi_size_delta),
1352                                (unsigned long)&stor_device->reset_request,
1353                                VM_PKT_DATA_INBAND,
1354                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1355         if (ret != 0)
1356                 return FAILED;
1357
1358         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1359         if (t == 0)
1360                 return TIMEOUT_ERROR;
1361
1362
1363         /*
1364          * At this point, all outstanding requests in the adapter
1365          * should have been flushed out and return to us
1366          * There is a potential race here where the host may be in
1367          * the process of responding when we return from here.
1368          * Just wait for all in-transit packets to be accounted for
1369          * before we return from here.
1370          */
1371         storvsc_wait_to_drain(stor_device);
1372
1373         return SUCCESS;
1374 }
1375
1376 /*
1377  * The host guarantees to respond to each command, although I/O latencies might
1378  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1379  * chance to perform EH.
1380  */
1381 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1382 {
1383         return BLK_EH_RESET_TIMER;
1384 }
1385
1386 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1387 {
1388         bool allowed = true;
1389         u8 scsi_op = scmnd->cmnd[0];
1390
1391         switch (scsi_op) {
1392         /* the host does not handle WRITE_SAME, log accident usage */
1393         case WRITE_SAME:
1394         /*
1395          * smartd sends this command and the host does not handle
1396          * this. So, don't send it.
1397          */
1398         case SET_WINDOW:
1399                 scmnd->result = ILLEGAL_REQUEST << 16;
1400                 allowed = false;
1401                 break;
1402         default:
1403                 break;
1404         }
1405         return allowed;
1406 }
1407
1408 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1409 {
1410         int ret;
1411         struct hv_host_device *host_dev = shost_priv(host);
1412         struct hv_device *dev = host_dev->dev;
1413         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1414         int i;
1415         struct scatterlist *sgl;
1416         unsigned int sg_count = 0;
1417         struct vmscsi_request *vm_srb;
1418         struct scatterlist *cur_sgl;
1419         struct vmbus_packet_mpb_array  *payload;
1420         u32 payload_sz;
1421         u32 length;
1422
1423         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1424                 /*
1425                  * On legacy hosts filter unimplemented commands.
1426                  * Future hosts are expected to correctly handle
1427                  * unsupported commands. Furthermore, it is
1428                  * possible that some of the currently
1429                  * unsupported commands maybe supported in
1430                  * future versions of the host.
1431                  */
1432                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1433                         scmnd->scsi_done(scmnd);
1434                         return 0;
1435                 }
1436         }
1437
1438         /* Setup the cmd request */
1439         cmd_request->cmd = scmnd;
1440
1441         vm_srb = &cmd_request->vstor_packet.vm_srb;
1442         vm_srb->win8_extension.time_out_value = 60;
1443
1444         vm_srb->win8_extension.srb_flags |=
1445                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1446
1447         if (scmnd->device->tagged_supported) {
1448                 vm_srb->win8_extension.srb_flags |=
1449                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1450                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1451                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1452         }
1453
1454         /* Build the SRB */
1455         switch (scmnd->sc_data_direction) {
1456         case DMA_TO_DEVICE:
1457                 vm_srb->data_in = WRITE_TYPE;
1458                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1459                 break;
1460         case DMA_FROM_DEVICE:
1461                 vm_srb->data_in = READ_TYPE;
1462                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1463                 break;
1464         case DMA_NONE:
1465                 vm_srb->data_in = UNKNOWN_TYPE;
1466                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1467                 break;
1468         default:
1469                 /*
1470                  * This is DMA_BIDIRECTIONAL or something else we are never
1471                  * supposed to see here.
1472                  */
1473                 WARN(1, "Unexpected data direction: %d\n",
1474                      scmnd->sc_data_direction);
1475                 return -EINVAL;
1476         }
1477
1478
1479         vm_srb->port_number = host_dev->port;
1480         vm_srb->path_id = scmnd->device->channel;
1481         vm_srb->target_id = scmnd->device->id;
1482         vm_srb->lun = scmnd->device->lun;
1483
1484         vm_srb->cdb_length = scmnd->cmd_len;
1485
1486         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1487
1488         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1489         sg_count = scsi_sg_count(scmnd);
1490
1491         length = scsi_bufflen(scmnd);
1492         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1493         payload_sz = sizeof(cmd_request->mpb);
1494
1495         if (sg_count) {
1496                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1497
1498                         payload_sz = (sg_count * sizeof(void *) +
1499                                       sizeof(struct vmbus_packet_mpb_array));
1500                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1501                         if (!payload)
1502                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1503                 }
1504
1505                 payload->range.len = length;
1506                 payload->range.offset = sgl[0].offset;
1507
1508                 cur_sgl = sgl;
1509                 for (i = 0; i < sg_count; i++) {
1510                         payload->range.pfn_array[i] =
1511                                 page_to_pfn(sg_page((cur_sgl)));
1512                         cur_sgl = sg_next(cur_sgl);
1513                 }
1514
1515         } else if (scsi_sglist(scmnd)) {
1516                 payload->range.len = length;
1517                 payload->range.offset =
1518                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1519                 payload->range.pfn_array[0] =
1520                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1521         }
1522
1523         cmd_request->payload = payload;
1524         cmd_request->payload_sz = payload_sz;
1525
1526         /* Invokes the vsc to start an IO */
1527         ret = storvsc_do_io(dev, cmd_request);
1528
1529         if (ret == -EAGAIN) {
1530                 if (payload_sz > sizeof(cmd_request->mpb))
1531                         kfree(payload);
1532                 /* no more space */
1533                 return SCSI_MLQUEUE_DEVICE_BUSY;
1534         }
1535
1536         return 0;
1537 }
1538
1539 static struct scsi_host_template scsi_driver = {
1540         .module =               THIS_MODULE,
1541         .name =                 "storvsc_host_t",
1542         .cmd_size =             sizeof(struct storvsc_cmd_request),
1543         .bios_param =           storvsc_get_chs,
1544         .queuecommand =         storvsc_queuecommand,
1545         .eh_host_reset_handler =        storvsc_host_reset_handler,
1546         .proc_name =            "storvsc_host",
1547         .eh_timed_out =         storvsc_eh_timed_out,
1548         .slave_alloc =          storvsc_device_alloc,
1549         .slave_configure =      storvsc_device_configure,
1550         .cmd_per_lun =          2048,
1551         .this_id =              -1,
1552         .use_clustering =       ENABLE_CLUSTERING,
1553         /* Make sure we dont get a sg segment crosses a page boundary */
1554         .dma_boundary =         PAGE_SIZE-1,
1555         .no_write_same =        1,
1556 };
1557
1558 enum {
1559         SCSI_GUID,
1560         IDE_GUID,
1561         SFC_GUID,
1562 };
1563
1564 static const struct hv_vmbus_device_id id_table[] = {
1565         /* SCSI guid */
1566         { HV_SCSI_GUID,
1567           .driver_data = SCSI_GUID
1568         },
1569         /* IDE guid */
1570         { HV_IDE_GUID,
1571           .driver_data = IDE_GUID
1572         },
1573         /* Fibre Channel GUID */
1574         {
1575           HV_SYNTHFC_GUID,
1576           .driver_data = SFC_GUID
1577         },
1578         { },
1579 };
1580
1581 MODULE_DEVICE_TABLE(vmbus, id_table);
1582
1583 static int storvsc_probe(struct hv_device *device,
1584                         const struct hv_vmbus_device_id *dev_id)
1585 {
1586         int ret;
1587         int num_cpus = num_online_cpus();
1588         struct Scsi_Host *host;
1589         struct hv_host_device *host_dev;
1590         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1591         int target = 0;
1592         struct storvsc_device *stor_device;
1593         int max_luns_per_target;
1594         int max_targets;
1595         int max_channels;
1596         int max_sub_channels = 0;
1597
1598         /*
1599          * Based on the windows host we are running on,
1600          * set state to properly communicate with the host.
1601          */
1602
1603         if (vmbus_proto_version < VERSION_WIN8) {
1604                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1605                 max_targets = STORVSC_IDE_MAX_TARGETS;
1606                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1607         } else {
1608                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1609                 max_targets = STORVSC_MAX_TARGETS;
1610                 max_channels = STORVSC_MAX_CHANNELS;
1611                 /*
1612                  * On Windows8 and above, we support sub-channels for storage.
1613                  * The number of sub-channels offerred is based on the number of
1614                  * VCPUs in the guest.
1615                  */
1616                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1617         }
1618
1619         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1620                                  (max_sub_channels + 1));
1621
1622         host = scsi_host_alloc(&scsi_driver,
1623                                sizeof(struct hv_host_device));
1624         if (!host)
1625                 return -ENOMEM;
1626
1627         host_dev = shost_priv(host);
1628         memset(host_dev, 0, sizeof(struct hv_host_device));
1629
1630         host_dev->port = host->host_no;
1631         host_dev->dev = device;
1632
1633
1634         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1635         if (!stor_device) {
1636                 ret = -ENOMEM;
1637                 goto err_out0;
1638         }
1639
1640         stor_device->destroy = false;
1641         stor_device->open_sub_channel = false;
1642         init_waitqueue_head(&stor_device->waiting_to_drain);
1643         stor_device->device = device;
1644         stor_device->host = host;
1645         hv_set_drvdata(device, stor_device);
1646
1647         stor_device->port_number = host->host_no;
1648         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size);
1649         if (ret)
1650                 goto err_out1;
1651
1652         host_dev->path = stor_device->path_id;
1653         host_dev->target = stor_device->target_id;
1654
1655         switch (dev_id->driver_data) {
1656         case SFC_GUID:
1657                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1658                 host->max_id = STORVSC_FC_MAX_TARGETS;
1659                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1660                 break;
1661
1662         case SCSI_GUID:
1663                 host->max_lun = max_luns_per_target;
1664                 host->max_id = max_targets;
1665                 host->max_channel = max_channels - 1;
1666                 break;
1667
1668         default:
1669                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1670                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1671                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1672                 break;
1673         }
1674         /* max cmd length */
1675         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1676
1677         /*
1678          * set the table size based on the info we got
1679          * from the host.
1680          */
1681         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1682
1683         /* Register the HBA and start the scsi bus scan */
1684         ret = scsi_add_host(host, &device->device);
1685         if (ret != 0)
1686                 goto err_out2;
1687
1688         if (!dev_is_ide) {
1689                 scsi_scan_host(host);
1690         } else {
1691                 target = (device->dev_instance.b[5] << 8 |
1692                          device->dev_instance.b[4]);
1693                 ret = scsi_add_device(host, 0, target, 0);
1694                 if (ret) {
1695                         scsi_remove_host(host);
1696                         goto err_out2;
1697                 }
1698         }
1699         return 0;
1700
1701 err_out2:
1702         /*
1703          * Once we have connected with the host, we would need to
1704          * to invoke storvsc_dev_remove() to rollback this state and
1705          * this call also frees up the stor_device; hence the jump around
1706          * err_out1 label.
1707          */
1708         storvsc_dev_remove(device);
1709         goto err_out0;
1710
1711 err_out1:
1712         kfree(stor_device);
1713
1714 err_out0:
1715         scsi_host_put(host);
1716         return ret;
1717 }
1718
1719 static int storvsc_remove(struct hv_device *dev)
1720 {
1721         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1722         struct Scsi_Host *host = stor_device->host;
1723
1724         scsi_remove_host(host);
1725         storvsc_dev_remove(dev);
1726         scsi_host_put(host);
1727
1728         return 0;
1729 }
1730
1731 static struct hv_driver storvsc_drv = {
1732         .name = KBUILD_MODNAME,
1733         .id_table = id_table,
1734         .probe = storvsc_probe,
1735         .remove = storvsc_remove,
1736 };
1737
1738 static int __init storvsc_drv_init(void)
1739 {
1740
1741         /*
1742          * Divide the ring buffer data size (which is 1 page less
1743          * than the ring buffer size since that page is reserved for
1744          * the ring buffer indices) by the max request size (which is
1745          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1746          */
1747         max_outstanding_req_per_channel =
1748                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1749                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1750                 sizeof(struct vstor_packet) + sizeof(u64) -
1751                 vmscsi_size_delta,
1752                 sizeof(u64)));
1753
1754         return vmbus_driver_register(&storvsc_drv);
1755 }
1756
1757 static void __exit storvsc_drv_exit(void)
1758 {
1759         vmbus_driver_unregister(&storvsc_drv);
1760 }
1761
1762 MODULE_LICENSE("GPL");
1763 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1764 module_init(storvsc_drv_init);
1765 module_exit(storvsc_drv_exit);