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 #include <scsi/scsi_transport_fc.h>
  45 #include <scsi/scsi_transport.h>
  46
  47 /*
  48  * All wire protocol details (storage protocol between the guest and the host)
  49  * are consolidated here.
  50  *
  51  * Begin protocol definitions.
  52  */
  53
  54 /*
  55  * Version history:
  56  * V1 Beta: 0.1
  57  * V1 RC < 2008/1/31: 1.0
  58  * V1 RC > 2008/1/31:  2.0
  59  * Win7: 4.2
  60  * Win8: 5.1
  61  * Win8.1: 6.0
  62  * Win10: 6.2
  63  */
  64
  65 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  66                                                 (((MINOR_) & 0xff)))
  67
  68 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  69 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  70 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  71 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  72 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  73
  74 /*  Packet structure describing virtual storage requests. */
  75 enum vstor_packet_operation {
  76         VSTOR_OPERATION_COMPLETE_IO             = 1,
  77         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  78         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  79         VSTOR_OPERATION_RESET_LUN               = 4,
  80         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  81         VSTOR_OPERATION_RESET_BUS               = 6,
  82         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  83         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  84         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  85         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  86         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  87         VSTOR_OPERATION_FCHBA_DATA              = 12,
  88         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  89         VSTOR_OPERATION_MAXIMUM                 = 13
  90 };
  91
  92 /*
  93  * WWN packet for Fibre Channel HBA
  94  */
  95
  96 struct hv_fc_wwn_packet {
  97         u8      primary_active;
  98         u8      reserved1[3];
  99         u8      primary_port_wwn[8];
 100         u8      primary_node_wwn[8];
 101         u8      secondary_port_wwn[8];
 102         u8      secondary_node_wwn[8];
 103 };
 104
 105
 106
 107 /*
 108  * SRB Flag Bits
 109  */
 110
 111 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 112 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 113 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 114 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 115 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 116 #define SRB_FLAGS_DATA_IN                       0x00000040
 117 #define SRB_FLAGS_DATA_OUT                      0x00000080
 118 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 119 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 120 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 121 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 122 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 123
 124 /*
 125  * This flag indicates the request is part of the workflow for processing a D3.
 126  */
 127 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 128 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 129 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 130 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 131 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 132 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 133 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 134 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 135 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 136 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 137 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 138
 139
 140 /*
 141  * Platform neutral description of a scsi request -
 142  * this remains the same across the write regardless of 32/64 bit
 143  * note: it's patterned off the SCSI_PASS_THROUGH structure
 144  */
 145 #define STORVSC_MAX_CMD_LEN                     0x10
 146
 147 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 148 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 149
 150 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 151 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 152
 153 /*
 154  * Sense buffer size changed in win8; have a run-time
 155  * variable to track the size we should use.  This value will
 156  * likely change during protocol negotiation but it is valid
 157  * to start by assuming pre-Win8.
 158  */
 159 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 160
 161 /*
 162  * The storage protocol version is determined during the
 163  * initial exchange with the host.  It will indicate which
 164  * storage functionality is available in the host.
 165 */
 166 static int vmstor_proto_version;
 167
 168 #define STORVSC_LOGGING_NONE    0
 169 #define STORVSC_LOGGING_ERROR   1
 170 #define STORVSC_LOGGING_WARN    2
 171
 172 static int logging_level = STORVSC_LOGGING_ERROR;
 173 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 174 MODULE_PARM_DESC(logging_level,
 175         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 176
 177 static inline bool do_logging(int level)
 178 {
 179         return logging_level >= level;
 180 }
 181
 182 #define storvsc_log(dev, level, fmt, ...)                       \
 183 do {                                                            \
 184         if (do_logging(level))                                  \
 185                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 186 } while (0)
 187
 188 struct vmscsi_win8_extension {
 189         /*
 190          * The following were added in Windows 8
 191          */
 192         u16 reserve;
 193         u8  queue_tag;
 194         u8  queue_action;
 195         u32 srb_flags;
 196         u32 time_out_value;
 197         u32 queue_sort_ey;
 198 } __packed;
 199
 200 struct vmscsi_request {
 201         u16 length;
 202         u8 srb_status;
 203         u8 scsi_status;
 204
 205         u8  port_number;
 206         u8  path_id;
 207         u8  target_id;
 208         u8  lun;
 209
 210         u8  cdb_length;
 211         u8  sense_info_length;
 212         u8  data_in;
 213         u8  reserved;
 214
 215         u32 data_transfer_length;
 216
 217         union {
 218                 u8 cdb[STORVSC_MAX_CMD_LEN];
 219                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 220                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 221         };
 222         /*
 223          * The following was added in win8.
 224          */
 225         struct vmscsi_win8_extension win8_extension;
 226
 227 } __attribute((packed));
 228
 229
 230 /*
 231  * The size of the vmscsi_request has changed in win8. The
 232  * additional size is because of new elements added to the
 233  * structure. These elements are valid only when we are talking
 234  * to a win8 host.
 235  * Track the correction to size we need to apply. This value
 236  * will likely change during protocol negotiation but it is
 237  * valid to start by assuming pre-Win8.
 238  */
 239 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 240
 241 /*
 242  * The list of storage protocols in order of preference.
 243  */
 244 struct vmstor_protocol {
 245         int protocol_version;
 246         int sense_buffer_size;
 247         int vmscsi_size_delta;
 248 };
 249
 250
 251 static const struct vmstor_protocol vmstor_protocols[] = {
 252         {
 253                 VMSTOR_PROTO_VERSION_WIN10,
 254                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 255                 0
 256         },
 257         {
 258                 VMSTOR_PROTO_VERSION_WIN8_1,
 259                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 260                 0
 261         },
 262         {
 263                 VMSTOR_PROTO_VERSION_WIN8,
 264                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 265                 0
 266         },
 267         {
 268                 VMSTOR_PROTO_VERSION_WIN7,
 269                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 270                 sizeof(struct vmscsi_win8_extension),
 271         },
 272         {
 273                 VMSTOR_PROTO_VERSION_WIN6,
 274                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 275                 sizeof(struct vmscsi_win8_extension),
 276         }
 277 };
 278
 279
 280 /*
 281  * This structure is sent during the intialization phase to get the different
 282  * properties of the channel.
 283  */
 284
 285 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 286
 287 struct vmstorage_channel_properties {
 288         u32 reserved;
 289         u16 max_channel_cnt;
 290         u16 reserved1;
 291
 292         u32 flags;
 293         u32   max_transfer_bytes;
 294
 295         u64  reserved2;
 296 } __packed;
 297
 298 /*  This structure is sent during the storage protocol negotiations. */
 299 struct vmstorage_protocol_version {
 300         /* Major (MSW) and minor (LSW) version numbers. */
 301         u16 major_minor;
 302
 303         /*
 304          * Revision number is auto-incremented whenever this file is changed
 305          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 306          * definitely indicate incompatibility--but it does indicate mismatched
 307          * builds.
 308          * This is only used on the windows side. Just set it to 0.
 309          */
 310         u16 revision;
 311 } __packed;
 312
 313 /* Channel Property Flags */
 314 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 315 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 316
 317 struct vstor_packet {
 318         /* Requested operation type */
 319         enum vstor_packet_operation operation;
 320
 321         /*  Flags - see below for values */
 322         u32 flags;
 323
 324         /* Status of the request returned from the server side. */
 325         u32 status;
 326
 327         /* Data payload area */
 328         union {
 329                 /*
 330                  * Structure used to forward SCSI commands from the
 331                  * client to the server.
 332                  */
 333                 struct vmscsi_request vm_srb;
 334
 335                 /* Structure used to query channel properties. */
 336                 struct vmstorage_channel_properties storage_channel_properties;
 337
 338                 /* Used during version negotiations. */
 339                 struct vmstorage_protocol_version version;
 340
 341                 /* Fibre channel address packet */
 342                 struct hv_fc_wwn_packet wwn_packet;
 343
 344                 /* Number of sub-channels to create */
 345                 u16 sub_channel_count;
 346
 347                 /* This will be the maximum of the union members */
 348                 u8  buffer[0x34];
 349         };
 350 } __packed;
 351
 352 /*
 353  * Packet Flags:
 354  *
 355  * This flag indicates that the server should send back a completion for this
 356  * packet.
 357  */
 358
 359 #define REQUEST_COMPLETION_FLAG 0x1
 360
 361 /* Matches Windows-end */
 362 enum storvsc_request_type {
 363         WRITE_TYPE = 0,
 364         READ_TYPE,
 365         UNKNOWN_TYPE,
 366 };
 367
 368 /*
 369  * SRB status codes and masks; a subset of the codes used here.
 370  */
 371
 372 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 373 #define SRB_STATUS_QUEUE_FROZEN         0x40
 374 #define SRB_STATUS_INVALID_LUN  0x20
 375 #define SRB_STATUS_SUCCESS      0x01
 376 #define SRB_STATUS_ABORTED      0x02
 377 #define SRB_STATUS_ERROR        0x04
 378
 379 #define SRB_STATUS(status) \
 380         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 381 /*
 382  * This is the end of Protocol specific defines.
 383  */
 384
 385 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 386 static u32 max_outstanding_req_per_channel;
 387
 388 static int storvsc_vcpus_per_sub_channel = 4;
 389
 390 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 391 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 392
 393 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 394 MODULE_PARM_DESC(vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 395 /*
 396  * Timeout in seconds for all devices managed by this driver.
 397  */
 398 static int storvsc_timeout = 180;
 399
 400 static int msft_blist_flags = BLIST_TRY_VPD_PAGES;
 401
 402 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 403 static struct scsi_transport_template *fc_transport_template;
 404 #endif
 405
 406 static void storvsc_on_channel_callback(void *context);
 407
 408 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 409 #define STORVSC_MAX_TARGETS                             2
 410 #define STORVSC_MAX_CHANNELS                            8
 411
 412 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 413 #define STORVSC_FC_MAX_TARGETS                          128
 414 #define STORVSC_FC_MAX_CHANNELS                         8
 415
 416 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 417 #define STORVSC_IDE_MAX_TARGETS                         1
 418 #define STORVSC_IDE_MAX_CHANNELS                        1
 419
 420 struct storvsc_cmd_request {
 421         struct scsi_cmnd *cmd;
 422
 423         struct hv_device *device;
 424
 425         /* Synchronize the request/response if needed */
 426         struct completion wait_event;
 427
 428         struct vmbus_channel_packet_multipage_buffer mpb;
 429         struct vmbus_packet_mpb_array *payload;
 430         u32 payload_sz;
 431
 432         struct vstor_packet vstor_packet;
 433 };
 434
 435
 436 /* A storvsc device is a device object that contains a vmbus channel */
 437 struct storvsc_device {
 438         struct hv_device *device;
 439
 440         bool     destroy;
 441         bool     drain_notify;
 442         bool     open_sub_channel;
 443         atomic_t num_outstanding_req;
 444         struct Scsi_Host *host;
 445
 446         wait_queue_head_t waiting_to_drain;
 447
 448         /*
 449          * Each unique Port/Path/Target represents 1 channel ie scsi
 450          * controller. In reality, the pathid, targetid is always 0
 451          * and the port is set by us
 452          */
 453         unsigned int port_number;
 454         unsigned char path_id;
 455         unsigned char target_id;
 456
 457         /*
 458          * Max I/O, the device can support.
 459          */
 460         u32   max_transfer_bytes;
 461         /* Used for vsc/vsp channel reset process */
 462         struct storvsc_cmd_request init_request;
 463         struct storvsc_cmd_request reset_request;
 464         /*
 465          * Currently active port and node names for FC devices.
 466          */
 467         u64 node_name;
 468         u64 port_name;
 469 };
 470
 471 struct hv_host_device {
 472         struct hv_device *dev;
 473         unsigned int port;
 474         unsigned char path;
 475         unsigned char target;
 476 };
 477
 478 struct storvsc_scan_work {
 479         struct work_struct work;
 480         struct Scsi_Host *host;
 481         uint lun;
 482 };
 483
 484 static void storvsc_device_scan(struct work_struct *work)
 485 {
 486         struct storvsc_scan_work *wrk;
 487         uint lun;
 488         struct scsi_device *sdev;
 489
 490         wrk = container_of(work, struct storvsc_scan_work, work);
 491         lun = wrk->lun;
 492
 493         sdev = scsi_device_lookup(wrk->host, 0, 0, lun);
 494         if (!sdev)
 495                 goto done;
 496         scsi_rescan_device(&sdev->sdev_gendev);
 497         scsi_device_put(sdev);
 498
 499 done:
 500         kfree(wrk);
 501 }
 502
 503 static void storvsc_host_scan(struct work_struct *work)
 504 {
 505         struct storvsc_scan_work *wrk;
 506         struct Scsi_Host *host;
 507         struct scsi_device *sdev;
 508
 509         wrk = container_of(work, struct storvsc_scan_work, work);
 510         host = wrk->host;
 511
 512         /*
 513          * Before scanning the host, first check to see if any of the
 514          * currrently known devices have been hot removed. We issue a
 515          * "unit ready" command against all currently known devices.
 516          * This I/O will result in an error for devices that have been
 517          * removed. As part of handling the I/O error, we remove the device.
 518          *
 519          * When a LUN is added or removed, the host sends us a signal to
 520          * scan the host. Thus we are forced to discover the LUNs that
 521          * may have been removed this way.
 522          */
 523         mutex_lock(&host->scan_mutex);
 524         shost_for_each_device(sdev, host)
 525                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 526         mutex_unlock(&host->scan_mutex);
 527         /*
 528          * Now scan the host to discover LUNs that may have been added.
 529          */
 530         scsi_scan_host(host);
 531
 532         kfree(wrk);
 533 }
 534
 535 static void storvsc_remove_lun(struct work_struct *work)
 536 {
 537         struct storvsc_scan_work *wrk;
 538         struct scsi_device *sdev;
 539
 540         wrk = container_of(work, struct storvsc_scan_work, work);
 541         if (!scsi_host_get(wrk->host))
 542                 goto done;
 543
 544         sdev = scsi_device_lookup(wrk->host, 0, 0, wrk->lun);
 545
 546         if (sdev) {
 547                 scsi_remove_device(sdev);
 548                 scsi_device_put(sdev);
 549         }
 550         scsi_host_put(wrk->host);
 551
 552 done:
 553         kfree(wrk);
 554 }
 555
 556
 557 /*
 558  * We can get incoming messages from the host that are not in response to
 559  * messages that we have sent out. An example of this would be messages
 560  * received by the guest to notify dynamic addition/removal of LUNs. To
 561  * deal with potential race conditions where the driver may be in the
 562  * midst of being unloaded when we might receive an unsolicited message
 563  * from the host, we have implemented a mechanism to gurantee sequential
 564  * consistency:
 565  *
 566  * 1) Once the device is marked as being destroyed, we will fail all
 567  *    outgoing messages.
 568  * 2) We permit incoming messages when the device is being destroyed,
 569  *    only to properly account for messages already sent out.
 570  */
 571
 572 static inline struct storvsc_device *get_out_stor_device(
 573                                         struct hv_device *device)
 574 {
 575         struct storvsc_device *stor_device;
 576
 577         stor_device = hv_get_drvdata(device);
 578
 579         if (stor_device && stor_device->destroy)
 580                 stor_device = NULL;
 581
 582         return stor_device;
 583 }
 584
 585
 586 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 587 {
 588         dev->drain_notify = true;
 589         wait_event(dev->waiting_to_drain,
 590                    atomic_read(&dev->num_outstanding_req) == 0);
 591         dev->drain_notify = false;
 592 }
 593
 594 static inline struct storvsc_device *get_in_stor_device(
 595                                         struct hv_device *device)
 596 {
 597         struct storvsc_device *stor_device;
 598
 599         stor_device = hv_get_drvdata(device);
 600
 601         if (!stor_device)
 602                 goto get_in_err;
 603
 604         /*
 605          * If the device is being destroyed; allow incoming
 606          * traffic only to cleanup outstanding requests.
 607          */
 608
 609         if (stor_device->destroy  &&
 610                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 611                 stor_device = NULL;
 612
 613 get_in_err:
 614         return stor_device;
 615
 616 }
 617
 618 static void handle_sc_creation(struct vmbus_channel *new_sc)
 619 {
 620         struct hv_device *device = new_sc->primary_channel->device_obj;
 621         struct storvsc_device *stor_device;
 622         struct vmstorage_channel_properties props;
 623
 624         stor_device = get_out_stor_device(device);
 625         if (!stor_device)
 626                 return;
 627
 628         if (stor_device->open_sub_channel == false)
 629                 return;
 630
 631         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 632
 633         vmbus_open(new_sc,
 634                    storvsc_ringbuffer_size,
 635                    storvsc_ringbuffer_size,
 636                    (void *)&props,
 637                    sizeof(struct vmstorage_channel_properties),
 638                    storvsc_on_channel_callback, new_sc);
 639 }
 640
 641 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 642 {
 643         struct storvsc_device *stor_device;
 644         int num_cpus = num_online_cpus();
 645         int num_sc;
 646         struct storvsc_cmd_request *request;
 647         struct vstor_packet *vstor_packet;
 648         int ret, t;
 649
 650         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 651         stor_device = get_out_stor_device(device);
 652         if (!stor_device)
 653                 return;
 654
 655         request = &stor_device->init_request;
 656         vstor_packet = &request->vstor_packet;
 657
 658         stor_device->open_sub_channel = true;
 659         /*
 660          * Establish a handler for dealing with subchannels.
 661          */
 662         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 663
 664         /*
 665          * Check to see if sub-channels have already been created. This
 666          * can happen when this driver is re-loaded after unloading.
 667          */
 668
 669         if (vmbus_are_subchannels_present(device->channel))
 670                 return;
 671
 672         stor_device->open_sub_channel = false;
 673         /*
 674          * Request the host to create sub-channels.
 675          */
 676         memset(request, 0, sizeof(struct storvsc_cmd_request));
 677         init_completion(&request->wait_event);
 678         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 679         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 680         vstor_packet->sub_channel_count = num_sc;
 681
 682         ret = vmbus_sendpacket(device->channel, vstor_packet,
 683                                (sizeof(struct vstor_packet) -
 684                                vmscsi_size_delta),
 685                                (unsigned long)request,
 686                                VM_PKT_DATA_INBAND,
 687                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 688
 689         if (ret != 0)
 690                 return;
 691
 692         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 693         if (t == 0)
 694                 return;
 695
 696         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 697             vstor_packet->status != 0)
 698                 return;
 699
 700         /*
 701          * Now that we created the sub-channels, invoke the check; this
 702          * may trigger the callback.
 703          */
 704         stor_device->open_sub_channel = true;
 705         vmbus_are_subchannels_present(device->channel);
 706 }
 707
 708 static void cache_wwn(struct storvsc_device *stor_device,
 709                       struct vstor_packet *vstor_packet)
 710 {
 711         /*
 712          * Cache the currently active port and node ww names.
 713          */
 714         if (vstor_packet->wwn_packet.primary_active) {
 715                 stor_device->node_name =
 716                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 717                 stor_device->port_name =
 718                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 719         } else {
 720                 stor_device->node_name =
 721                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 722                 stor_device->port_name =
 723                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 724         }
 725 }
 726
 727
 728 static int storvsc_execute_vstor_op(struct hv_device *device,
 729                                     struct storvsc_cmd_request *request,
 730                                     bool status_check)
 731 {
 732         struct vstor_packet *vstor_packet;
 733         int ret, t;
 734
 735         vstor_packet = &request->vstor_packet;
 736
 737         init_completion(&request->wait_event);
 738         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 739
 740         ret = vmbus_sendpacket(device->channel, vstor_packet,
 741                                (sizeof(struct vstor_packet) -
 742                                vmscsi_size_delta),
 743                                (unsigned long)request,
 744                                VM_PKT_DATA_INBAND,
 745                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 746         if (ret != 0)
 747                 return ret;
 748
 749         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 750         if (t == 0)
 751                 return -ETIMEDOUT;
 752
 753         if (!status_check)
 754                 return ret;
 755
 756         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 757             vstor_packet->status != 0)
 758                 return -EINVAL;
 759
 760         return ret;
 761 }
 762
 763 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 764 {
 765         struct storvsc_device *stor_device;
 766         struct storvsc_cmd_request *request;
 767         struct vstor_packet *vstor_packet;
 768         int ret, i;
 769         int max_chns;
 770         bool process_sub_channels = false;
 771
 772         stor_device = get_out_stor_device(device);
 773         if (!stor_device)
 774                 return -ENODEV;
 775
 776         request = &stor_device->init_request;
 777         vstor_packet = &request->vstor_packet;
 778
 779         /*
 780          * Now, initiate the vsc/vsp initialization protocol on the open
 781          * channel
 782          */
 783         memset(request, 0, sizeof(struct storvsc_cmd_request));
 784         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 785         ret = storvsc_execute_vstor_op(device, request, true);
 786         if (ret)
 787                 return ret;
 788         /*
 789          * Query host supported protocol version.
 790          */
 791
 792         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 793                 /* reuse the packet for version range supported */
 794                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 795                 vstor_packet->operation =
 796                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 797
 798                 vstor_packet->version.major_minor =
 799                         vmstor_protocols[i].protocol_version;
 800
 801                 /*
 802                  * The revision number is only used in Windows; set it to 0.
 803                  */
 804                 vstor_packet->version.revision = 0;
 805                 ret = storvsc_execute_vstor_op(device, request, false);
 806                 if (ret != 0)
 807                         return ret;
 808
 809                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 810                         return -EINVAL;
 811
 812                 if (vstor_packet->status == 0) {
 813                         vmstor_proto_version =
 814                                 vmstor_protocols[i].protocol_version;
 815
 816                         sense_buffer_size =
 817                                 vmstor_protocols[i].sense_buffer_size;
 818
 819                         vmscsi_size_delta =
 820                                 vmstor_protocols[i].vmscsi_size_delta;
 821
 822                         break;
 823                 }
 824         }
 825
 826         if (vstor_packet->status != 0)
 827                 return -EINVAL;
 828
 829
 830         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 831         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 832         ret = storvsc_execute_vstor_op(device, request, true);
 833         if (ret != 0)
 834                 return ret;
 835
 836         /*
 837          * Check to see if multi-channel support is there.
 838          * Hosts that implement protocol version of 5.1 and above
 839          * support multi-channel.
 840          */
 841         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 842         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 843                 if (vstor_packet->storage_channel_properties.flags &
 844                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 845                         process_sub_channels = true;
 846         }
 847         stor_device->max_transfer_bytes =
 848                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 849
 850         if (!is_fc)
 851                 goto done;
 852
 853         /*
 854          * For FC devices retrieve FC HBA data.
 855          */
 856         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 857         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 858         ret = storvsc_execute_vstor_op(device, request, true);
 859         if (ret != 0)
 860                 return ret;
 861
 862         /*
 863          * Cache the currently active port and node ww names.
 864          */
 865         cache_wwn(stor_device, vstor_packet);
 866
 867 done:
 868
 869         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 870         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 871         ret = storvsc_execute_vstor_op(device, request, true);
 872         if (ret != 0)
 873                 return ret;
 874
 875         if (process_sub_channels)
 876                 handle_multichannel_storage(device, max_chns);
 877
 878         return ret;
 879 }
 880
 881 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 882                                 struct scsi_cmnd *scmnd,
 883                                 struct Scsi_Host *host,
 884                                 u8 asc, u8 ascq)
 885 {
 886         struct storvsc_scan_work *wrk;
 887         void (*process_err_fn)(struct work_struct *work);
 888         bool do_work = false;
 889
 890         switch (SRB_STATUS(vm_srb->srb_status)) {
 891         case SRB_STATUS_ERROR:
 892                 /*
 893                  * If there is an error; offline the device since all
 894                  * error recovery strategies would have already been
 895                  * deployed on the host side. However, if the command
 896                  * were a pass-through command deal with it appropriately.
 897                  */
 898                 switch (scmnd->cmnd[0]) {
 899                 case ATA_16:
 900                 case ATA_12:
 901                         set_host_byte(scmnd, DID_PASSTHROUGH);
 902                         break;
 903                 /*
 904                  * On Some Windows hosts TEST_UNIT_READY command can return
 905                  * SRB_STATUS_ERROR, let the upper level code deal with it
 906                  * based on the sense information.
 907                  */
 908                 case TEST_UNIT_READY:
 909                         break;
 910                 default:
 911                         set_host_byte(scmnd, DID_TARGET_FAILURE);
 912                 }
 913                 break;
 914         case SRB_STATUS_INVALID_LUN:
 915                 do_work = true;
 916                 process_err_fn = storvsc_remove_lun;
 917                 break;
 918         case (SRB_STATUS_ABORTED | SRB_STATUS_AUTOSENSE_VALID):
 919                 if ((asc == 0x2a) && (ascq == 0x9)) {
 920                         do_work = true;
 921                         process_err_fn = storvsc_device_scan;
 922                         /*
 923                          * Retry the I/O that trigerred this.
 924                          */
 925                         set_host_byte(scmnd, DID_REQUEUE);
 926                 }
 927                 break;
 928         }
 929
 930         if (!do_work)
 931                 return;
 932
 933         /*
 934          * We need to schedule work to process this error; schedule it.
 935          */
 936         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 937         if (!wrk) {
 938                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 939                 return;
 940         }
 941
 942         wrk->host = host;
 943         wrk->lun = vm_srb->lun;
 944         INIT_WORK(&wrk->work, process_err_fn);
 945         schedule_work(&wrk->work);
 946 }
 947
 948
 949 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
 950                                        struct storvsc_device *stor_dev)
 951 {
 952         struct scsi_cmnd *scmnd = cmd_request->cmd;
 953         struct scsi_sense_hdr sense_hdr;
 954         struct vmscsi_request *vm_srb;
 955         struct Scsi_Host *host;
 956         u32 payload_sz = cmd_request->payload_sz;
 957         void *payload = cmd_request->payload;
 958
 959         host = stor_dev->host;
 960
 961         vm_srb = &cmd_request->vstor_packet.vm_srb;
 962
 963         scmnd->result = vm_srb->scsi_status;
 964
 965         if (scmnd->result) {
 966                 if (scsi_normalize_sense(scmnd->sense_buffer,
 967                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
 968                     do_logging(STORVSC_LOGGING_ERROR))
 969                         scsi_print_sense_hdr(scmnd->device, "storvsc",
 970                                              &sense_hdr);
 971         }
 972
 973         if (vm_srb->srb_status != SRB_STATUS_SUCCESS)
 974                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
 975                                          sense_hdr.ascq);
 976
 977         scsi_set_resid(scmnd,
 978                 cmd_request->payload->range.len -
 979                 vm_srb->data_transfer_length);
 980
 981         scmnd->scsi_done(scmnd);
 982
 983         if (payload_sz >
 984                 sizeof(struct vmbus_channel_packet_multipage_buffer))
 985                 kfree(payload);
 986 }
 987
 988 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
 989                                   struct vstor_packet *vstor_packet,
 990                                   struct storvsc_cmd_request *request)
 991 {
 992         struct vstor_packet *stor_pkt;
 993         struct hv_device *device = stor_device->device;
 994
 995         stor_pkt = &request->vstor_packet;
 996
 997         /*
 998          * The current SCSI handling on the host side does
 999          * not correctly handle:
1000          * INQUIRY command with page code parameter set to 0x80
1001          * MODE_SENSE command with cmd[2] == 0x1c
1002          *
1003          * Setup srb and scsi status so this won't be fatal.
1004          * We do this so we can distinguish truly fatal failues
1005          * (srb status == 0x4) and off-line the device in that case.
1006          */
1007
1008         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1009            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1010                 vstor_packet->vm_srb.scsi_status = 0;
1011                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1012         }
1013
1014
1015         /* Copy over the status...etc */
1016         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1017         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1018         stor_pkt->vm_srb.sense_info_length =
1019         vstor_packet->vm_srb.sense_info_length;
1020
1021         if (vstor_packet->vm_srb.scsi_status != 0 ||
1022             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1023                 storvsc_log(device, STORVSC_LOGGING_WARN,
1024                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1025                         stor_pkt->vm_srb.cdb[0],
1026                         vstor_packet->vm_srb.scsi_status,
1027                         vstor_packet->vm_srb.srb_status);
1028
1029         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1030                 /* CHECK_CONDITION */
1031                 if (vstor_packet->vm_srb.srb_status &
1032                         SRB_STATUS_AUTOSENSE_VALID) {
1033                         /* autosense data available */
1034
1035                         storvsc_log(device, STORVSC_LOGGING_WARN,
1036                                 "stor pkt %p autosense data valid - len %d\n",
1037                                 request, vstor_packet->vm_srb.sense_info_length);
1038
1039                         memcpy(request->cmd->sense_buffer,
1040                                vstor_packet->vm_srb.sense_data,
1041                                vstor_packet->vm_srb.sense_info_length);
1042
1043                 }
1044         }
1045
1046         stor_pkt->vm_srb.data_transfer_length =
1047         vstor_packet->vm_srb.data_transfer_length;
1048
1049         storvsc_command_completion(request, stor_device);
1050
1051         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1052                 stor_device->drain_notify)
1053                 wake_up(&stor_device->waiting_to_drain);
1054
1055
1056 }
1057
1058 static void storvsc_on_receive(struct storvsc_device *stor_device,
1059                              struct vstor_packet *vstor_packet,
1060                              struct storvsc_cmd_request *request)
1061 {
1062         struct storvsc_scan_work *work;
1063
1064         switch (vstor_packet->operation) {
1065         case VSTOR_OPERATION_COMPLETE_IO:
1066                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1067                 break;
1068
1069         case VSTOR_OPERATION_REMOVE_DEVICE:
1070         case VSTOR_OPERATION_ENUMERATE_BUS:
1071                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1072                 if (!work)
1073                         return;
1074
1075                 INIT_WORK(&work->work, storvsc_host_scan);
1076                 work->host = stor_device->host;
1077                 schedule_work(&work->work);
1078                 break;
1079
1080         case VSTOR_OPERATION_FCHBA_DATA:
1081                 cache_wwn(stor_device, vstor_packet);
1082 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1083                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1084                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1085 #endif
1086                 break;
1087         default:
1088                 break;
1089         }
1090 }
1091
1092 static void storvsc_on_channel_callback(void *context)
1093 {
1094         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1095         struct hv_device *device;
1096         struct storvsc_device *stor_device;
1097         u32 bytes_recvd;
1098         u64 request_id;
1099         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1100         struct storvsc_cmd_request *request;
1101         int ret;
1102
1103         if (channel->primary_channel != NULL)
1104                 device = channel->primary_channel->device_obj;
1105         else
1106                 device = channel->device_obj;
1107
1108         stor_device = get_in_stor_device(device);
1109         if (!stor_device)
1110                 return;
1111
1112         do {
1113                 ret = vmbus_recvpacket(channel, packet,
1114                                        ALIGN((sizeof(struct vstor_packet) -
1115                                              vmscsi_size_delta), 8),
1116                                        &bytes_recvd, &request_id);
1117                 if (ret == 0 && bytes_recvd > 0) {
1118
1119                         request = (struct storvsc_cmd_request *)
1120                                         (unsigned long)request_id;
1121
1122                         if ((request == &stor_device->init_request) ||
1123                             (request == &stor_device->reset_request)) {
1124
1125                                 memcpy(&request->vstor_packet, packet,
1126                                        (sizeof(struct vstor_packet) -
1127                                         vmscsi_size_delta));
1128                                 complete(&request->wait_event);
1129                         } else {
1130                                 storvsc_on_receive(stor_device,
1131                                                 (struct vstor_packet *)packet,
1132                                                 request);
1133                         }
1134                 } else {
1135                         break;
1136                 }
1137         } while (1);
1138
1139         return;
1140 }
1141
1142 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1143                                   bool is_fc)
1144 {
1145         struct vmstorage_channel_properties props;
1146         int ret;
1147
1148         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1149
1150         ret = vmbus_open(device->channel,
1151                          ring_size,
1152                          ring_size,
1153                          (void *)&props,
1154                          sizeof(struct vmstorage_channel_properties),
1155                          storvsc_on_channel_callback, device->channel);
1156
1157         if (ret != 0)
1158                 return ret;
1159
1160         ret = storvsc_channel_init(device, is_fc);
1161
1162         return ret;
1163 }
1164
1165 static int storvsc_dev_remove(struct hv_device *device)
1166 {
1167         struct storvsc_device *stor_device;
1168         unsigned long flags;
1169
1170         stor_device = hv_get_drvdata(device);
1171
1172         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1173         stor_device->destroy = true;
1174         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1175
1176         /*
1177          * At this point, all outbound traffic should be disable. We
1178          * only allow inbound traffic (responses) to proceed so that
1179          * outstanding requests can be completed.
1180          */
1181
1182         storvsc_wait_to_drain(stor_device);
1183
1184         /*
1185          * Since we have already drained, we don't need to busy wait
1186          * as was done in final_release_stor_device()
1187          * Note that we cannot set the ext pointer to NULL until
1188          * we have drained - to drain the outgoing packets, we need to
1189          * allow incoming packets.
1190          */
1191         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1192         hv_set_drvdata(device, NULL);
1193         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1194
1195         /* Close the channel */
1196         vmbus_close(device->channel);
1197
1198         kfree(stor_device);
1199         return 0;
1200 }
1201
1202 static int storvsc_do_io(struct hv_device *device,
1203                          struct storvsc_cmd_request *request)
1204 {
1205         struct storvsc_device *stor_device;
1206         struct vstor_packet *vstor_packet;
1207         struct vmbus_channel *outgoing_channel;
1208         int ret = 0;
1209
1210         vstor_packet = &request->vstor_packet;
1211         stor_device = get_out_stor_device(device);
1212
1213         if (!stor_device)
1214                 return -ENODEV;
1215
1216
1217         request->device  = device;
1218         /*
1219          * Select an an appropriate channel to send the request out.
1220          */
1221
1222         outgoing_channel = vmbus_get_outgoing_channel(device->channel);
1223
1224
1225         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1226
1227         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1228                                         vmscsi_size_delta);
1229
1230
1231         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1232
1233
1234         vstor_packet->vm_srb.data_transfer_length =
1235         request->payload->range.len;
1236
1237         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1238
1239         if (request->payload->range.len) {
1240
1241                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1242                                 request->payload, request->payload_sz,
1243                                 vstor_packet,
1244                                 (sizeof(struct vstor_packet) -
1245                                 vmscsi_size_delta),
1246                                 (unsigned long)request);
1247         } else {
1248                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1249                                (sizeof(struct vstor_packet) -
1250                                 vmscsi_size_delta),
1251                                (unsigned long)request,
1252                                VM_PKT_DATA_INBAND,
1253                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1254         }
1255
1256         if (ret != 0)
1257                 return ret;
1258
1259         atomic_inc(&stor_device->num_outstanding_req);
1260
1261         return ret;
1262 }
1263
1264 static int storvsc_device_configure(struct scsi_device *sdevice)
1265 {
1266
1267         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
1268
1269         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1270
1271         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1272
1273         /* Ensure there are no gaps in presented sgls */
1274         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1275
1276         sdevice->no_write_same = 1;
1277
1278         /*
1279          * Add blist flags to permit the reading of the VPD pages even when
1280          * the target may claim SPC-2 compliance. MSFT targets currently
1281          * claim SPC-2 compliance while they implement post SPC-2 features.
1282          * With this patch we can correctly handle WRITE_SAME_16 issues.
1283          */
1284         sdevice->sdev_bflags |= msft_blist_flags;
1285
1286         /*
1287          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1288          * if the device is a MSFT virtual device.  If the host is
1289          * WIN10 or newer, allow write_same.
1290          */
1291         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1292                 switch (vmstor_proto_version) {
1293                 case VMSTOR_PROTO_VERSION_WIN8:
1294                 case VMSTOR_PROTO_VERSION_WIN8_1:
1295                         sdevice->scsi_level = SCSI_SPC_3;
1296                         break;
1297                 }
1298
1299                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1300                         sdevice->no_write_same = 0;
1301         }
1302
1303         return 0;
1304 }
1305
1306 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1307                            sector_t capacity, int *info)
1308 {
1309         sector_t nsect = capacity;
1310         sector_t cylinders = nsect;
1311         int heads, sectors_pt;
1312
1313         /*
1314          * We are making up these values; let us keep it simple.
1315          */
1316         heads = 0xff;
1317         sectors_pt = 0x3f;      /* Sectors per track */
1318         sector_div(cylinders, heads * sectors_pt);
1319         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1320                 cylinders = 0xffff;
1321
1322         info[0] = heads;
1323         info[1] = sectors_pt;
1324         info[2] = (int)cylinders;
1325
1326         return 0;
1327 }
1328
1329 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1330 {
1331         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1332         struct hv_device *device = host_dev->dev;
1333
1334         struct storvsc_device *stor_device;
1335         struct storvsc_cmd_request *request;
1336         struct vstor_packet *vstor_packet;
1337         int ret, t;
1338
1339
1340         stor_device = get_out_stor_device(device);
1341         if (!stor_device)
1342                 return FAILED;
1343
1344         request = &stor_device->reset_request;
1345         vstor_packet = &request->vstor_packet;
1346
1347         init_completion(&request->wait_event);
1348
1349         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1350         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1351         vstor_packet->vm_srb.path_id = stor_device->path_id;
1352
1353         ret = vmbus_sendpacket(device->channel, vstor_packet,
1354                                (sizeof(struct vstor_packet) -
1355                                 vmscsi_size_delta),
1356                                (unsigned long)&stor_device->reset_request,
1357                                VM_PKT_DATA_INBAND,
1358                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1359         if (ret != 0)
1360                 return FAILED;
1361
1362         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1363         if (t == 0)
1364                 return TIMEOUT_ERROR;
1365
1366
1367         /*
1368          * At this point, all outstanding requests in the adapter
1369          * should have been flushed out and return to us
1370          * There is a potential race here where the host may be in
1371          * the process of responding when we return from here.
1372          * Just wait for all in-transit packets to be accounted for
1373          * before we return from here.
1374          */
1375         storvsc_wait_to_drain(stor_device);
1376
1377         return SUCCESS;
1378 }
1379
1380 /*
1381  * The host guarantees to respond to each command, although I/O latencies might
1382  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1383  * chance to perform EH.
1384  */
1385 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1386 {
1387         return BLK_EH_RESET_TIMER;
1388 }
1389
1390 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1391 {
1392         bool allowed = true;
1393         u8 scsi_op = scmnd->cmnd[0];
1394
1395         switch (scsi_op) {
1396         /* the host does not handle WRITE_SAME, log accident usage */
1397         case WRITE_SAME:
1398         /*
1399          * smartd sends this command and the host does not handle
1400          * this. So, don't send it.
1401          */
1402         case SET_WINDOW:
1403                 scmnd->result = ILLEGAL_REQUEST << 16;
1404                 allowed = false;
1405                 break;
1406         default:
1407                 break;
1408         }
1409         return allowed;
1410 }
1411
1412 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1413 {
1414         int ret;
1415         struct hv_host_device *host_dev = shost_priv(host);
1416         struct hv_device *dev = host_dev->dev;
1417         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1418         int i;
1419         struct scatterlist *sgl;
1420         unsigned int sg_count = 0;
1421         struct vmscsi_request *vm_srb;
1422         struct scatterlist *cur_sgl;
1423         struct vmbus_packet_mpb_array  *payload;
1424         u32 payload_sz;
1425         u32 length;
1426
1427         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1428                 /*
1429                  * On legacy hosts filter unimplemented commands.
1430                  * Future hosts are expected to correctly handle
1431                  * unsupported commands. Furthermore, it is
1432                  * possible that some of the currently
1433                  * unsupported commands maybe supported in
1434                  * future versions of the host.
1435                  */
1436                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1437                         scmnd->scsi_done(scmnd);
1438                         return 0;
1439                 }
1440         }
1441
1442         /* Setup the cmd request */
1443         cmd_request->cmd = scmnd;
1444
1445         vm_srb = &cmd_request->vstor_packet.vm_srb;
1446         vm_srb->win8_extension.time_out_value = 60;
1447
1448         vm_srb->win8_extension.srb_flags |=
1449                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1450
1451         /* Build the SRB */
1452         switch (scmnd->sc_data_direction) {
1453         case DMA_TO_DEVICE:
1454                 vm_srb->data_in = WRITE_TYPE;
1455                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1456                 break;
1457         case DMA_FROM_DEVICE:
1458                 vm_srb->data_in = READ_TYPE;
1459                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1460                 break;
1461         case DMA_NONE:
1462                 vm_srb->data_in = UNKNOWN_TYPE;
1463                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1464                 break;
1465         default:
1466                 /*
1467                  * This is DMA_BIDIRECTIONAL or something else we are never
1468                  * supposed to see here.
1469                  */
1470                 WARN(1, "Unexpected data direction: %d\n",
1471                      scmnd->sc_data_direction);
1472                 return -EINVAL;
1473         }
1474
1475
1476         vm_srb->port_number = host_dev->port;
1477         vm_srb->path_id = scmnd->device->channel;
1478         vm_srb->target_id = scmnd->device->id;
1479         vm_srb->lun = scmnd->device->lun;
1480
1481         vm_srb->cdb_length = scmnd->cmd_len;
1482
1483         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1484
1485         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1486         sg_count = scsi_sg_count(scmnd);
1487
1488         length = scsi_bufflen(scmnd);
1489         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1490         payload_sz = sizeof(cmd_request->mpb);
1491
1492         if (sg_count) {
1493                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1494
1495                         payload_sz = (sg_count * sizeof(void *) +
1496                                       sizeof(struct vmbus_packet_mpb_array));
1497                         payload = kmalloc(payload_sz, GFP_ATOMIC);
1498                         if (!payload)
1499                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1500                 }
1501
1502                 payload->range.len = length;
1503                 payload->range.offset = sgl[0].offset;
1504
1505                 cur_sgl = sgl;
1506                 for (i = 0; i < sg_count; i++) {
1507                         payload->range.pfn_array[i] =
1508                                 page_to_pfn(sg_page((cur_sgl)));
1509                         cur_sgl = sg_next(cur_sgl);
1510                 }
1511
1512         } else if (scsi_sglist(scmnd)) {
1513                 payload->range.len = length;
1514                 payload->range.offset =
1515                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
1516                 payload->range.pfn_array[0] =
1517                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
1518         }
1519
1520         cmd_request->payload = payload;
1521         cmd_request->payload_sz = payload_sz;
1522
1523         /* Invokes the vsc to start an IO */
1524         ret = storvsc_do_io(dev, cmd_request);
1525
1526         if (ret == -EAGAIN) {
1527                 /* no more space */
1528                 return SCSI_MLQUEUE_DEVICE_BUSY;
1529         }
1530
1531         return 0;
1532 }
1533
1534 static struct scsi_host_template scsi_driver = {
1535         .module =               THIS_MODULE,
1536         .name =                 "storvsc_host_t",
1537         .cmd_size =             sizeof(struct storvsc_cmd_request),
1538         .bios_param =           storvsc_get_chs,
1539         .queuecommand =         storvsc_queuecommand,
1540         .eh_host_reset_handler =        storvsc_host_reset_handler,
1541         .proc_name =            "storvsc_host",
1542         .eh_timed_out =         storvsc_eh_timed_out,
1543         .slave_configure =      storvsc_device_configure,
1544         .cmd_per_lun =          255,
1545         .this_id =              -1,
1546         .use_clustering =       ENABLE_CLUSTERING,
1547         /* Make sure we dont get a sg segment crosses a page boundary */
1548         .dma_boundary =         PAGE_SIZE-1,
1549         .no_write_same =        1,
1550 };
1551
1552 enum {
1553         SCSI_GUID,
1554         IDE_GUID,
1555         SFC_GUID,
1556 };
1557
1558 static const struct hv_vmbus_device_id id_table[] = {
1559         /* SCSI guid */
1560         { HV_SCSI_GUID,
1561           .driver_data = SCSI_GUID
1562         },
1563         /* IDE guid */
1564         { HV_IDE_GUID,
1565           .driver_data = IDE_GUID
1566         },
1567         /* Fibre Channel GUID */
1568         {
1569           HV_SYNTHFC_GUID,
1570           .driver_data = SFC_GUID
1571         },
1572         { },
1573 };
1574
1575 MODULE_DEVICE_TABLE(vmbus, id_table);
1576
1577 static int storvsc_probe(struct hv_device *device,
1578                         const struct hv_vmbus_device_id *dev_id)
1579 {
1580         int ret;
1581         int num_cpus = num_online_cpus();
1582         struct Scsi_Host *host;
1583         struct hv_host_device *host_dev;
1584         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1585         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1586         int target = 0;
1587         struct storvsc_device *stor_device;
1588         int max_luns_per_target;
1589         int max_targets;
1590         int max_channels;
1591         int max_sub_channels = 0;
1592
1593         /*
1594          * Based on the windows host we are running on,
1595          * set state to properly communicate with the host.
1596          */
1597
1598         if (vmbus_proto_version < VERSION_WIN8) {
1599                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1600                 max_targets = STORVSC_IDE_MAX_TARGETS;
1601                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1602         } else {
1603                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1604                 max_targets = STORVSC_MAX_TARGETS;
1605                 max_channels = STORVSC_MAX_CHANNELS;
1606                 /*
1607                  * On Windows8 and above, we support sub-channels for storage.
1608                  * The number of sub-channels offerred is based on the number of
1609                  * VCPUs in the guest.
1610                  */
1611                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1612         }
1613
1614         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1615                                  (max_sub_channels + 1));
1616
1617         host = scsi_host_alloc(&scsi_driver,
1618                                sizeof(struct hv_host_device));
1619         if (!host)
1620                 return -ENOMEM;
1621
1622         host_dev = shost_priv(host);
1623         memset(host_dev, 0, sizeof(struct hv_host_device));
1624
1625         host_dev->port = host->host_no;
1626         host_dev->dev = device;
1627
1628
1629         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1630         if (!stor_device) {
1631                 ret = -ENOMEM;
1632                 goto err_out0;
1633         }
1634
1635         stor_device->destroy = false;
1636         stor_device->open_sub_channel = false;
1637         init_waitqueue_head(&stor_device->waiting_to_drain);
1638         stor_device->device = device;
1639         stor_device->host = host;
1640         hv_set_drvdata(device, stor_device);
1641
1642         stor_device->port_number = host->host_no;
1643         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1644         if (ret)
1645                 goto err_out1;
1646
1647         host_dev->path = stor_device->path_id;
1648         host_dev->target = stor_device->target_id;
1649
1650         switch (dev_id->driver_data) {
1651         case SFC_GUID:
1652                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1653                 host->max_id = STORVSC_FC_MAX_TARGETS;
1654                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1655 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1656                 host->transportt = fc_transport_template;
1657 #endif
1658                 break;
1659
1660         case SCSI_GUID:
1661                 host->max_lun = max_luns_per_target;
1662                 host->max_id = max_targets;
1663                 host->max_channel = max_channels - 1;
1664                 break;
1665
1666         default:
1667                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1668                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1669                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1670                 break;
1671         }
1672         /* max cmd length */
1673         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1674
1675         /*
1676          * set the table size based on the info we got
1677          * from the host.
1678          */
1679         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1680
1681         /* Register the HBA and start the scsi bus scan */
1682         ret = scsi_add_host(host, &device->device);
1683         if (ret != 0)
1684                 goto err_out2;
1685
1686         if (!dev_is_ide) {
1687                 scsi_scan_host(host);
1688         } else {
1689                 target = (device->dev_instance.b[5] << 8 |
1690                          device->dev_instance.b[4]);
1691                 ret = scsi_add_device(host, 0, target, 0);
1692                 if (ret) {
1693                         scsi_remove_host(host);
1694                         goto err_out2;
1695                 }
1696         }
1697 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1698         if (host->transportt == fc_transport_template) {
1699                 fc_host_node_name(host) = stor_device->node_name;
1700                 fc_host_port_name(host) = stor_device->port_name;
1701         }
1702 #endif
1703         return 0;
1704
1705 err_out2:
1706         /*
1707          * Once we have connected with the host, we would need to
1708          * to invoke storvsc_dev_remove() to rollback this state and
1709          * this call also frees up the stor_device; hence the jump around
1710          * err_out1 label.
1711          */
1712         storvsc_dev_remove(device);
1713         goto err_out0;
1714
1715 err_out1:
1716         kfree(stor_device);
1717
1718 err_out0:
1719         scsi_host_put(host);
1720         return ret;
1721 }
1722
1723 static int storvsc_remove(struct hv_device *dev)
1724 {
1725         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1726         struct Scsi_Host *host = stor_device->host;
1727
1728 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1729         if (host->transportt == fc_transport_template)
1730                 fc_remove_host(host);
1731 #endif
1732         scsi_remove_host(host);
1733         storvsc_dev_remove(dev);
1734         scsi_host_put(host);
1735
1736         return 0;
1737 }
1738
1739 static struct hv_driver storvsc_drv = {
1740         .name = KBUILD_MODNAME,
1741         .id_table = id_table,
1742         .probe = storvsc_probe,
1743         .remove = storvsc_remove,
1744 };
1745
1746 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1747 static struct fc_function_template fc_transport_functions = {
1748         .show_host_node_name = 1,
1749         .show_host_port_name = 1,
1750 };
1751 #endif
1752
1753 static int __init storvsc_drv_init(void)
1754 {
1755         int ret;
1756
1757         /*
1758          * Divide the ring buffer data size (which is 1 page less
1759          * than the ring buffer size since that page is reserved for
1760          * the ring buffer indices) by the max request size (which is
1761          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1762          */
1763         max_outstanding_req_per_channel =
1764                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1765                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1766                 sizeof(struct vstor_packet) + sizeof(u64) -
1767                 vmscsi_size_delta,
1768                 sizeof(u64)));
1769
1770 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1771         fc_transport_template = fc_attach_transport(&fc_transport_functions);
1772         if (!fc_transport_template)
1773                 return -ENODEV;
1774
1775         /*
1776          * Install Hyper-V specific timeout handler.
1777          */
1778         fc_transport_template->eh_timed_out = storvsc_eh_timed_out;
1779 #endif
1780
1781         ret = vmbus_driver_register(&storvsc_drv);
1782
1783 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1784         if (ret)
1785                 fc_release_transport(fc_transport_template);
1786 #endif
1787
1788         return ret;
1789 }
1790
1791 static void __exit storvsc_drv_exit(void)
1792 {
1793         vmbus_driver_unregister(&storvsc_drv);
1794 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1795         fc_release_transport(fc_transport_template);
1796 #endif
1797 }
1798
1799 MODULE_LICENSE("GPL");
1800 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1801 module_init(storvsc_drv_init);
1802 module_exit(storvsc_drv_exit);