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 #define SP_UNTAGGED                     ((unsigned char) ~0)
 140 #define SRB_SIMPLE_TAG_REQUEST          0x20
 141
 142 /*
 143  * Platform neutral description of a scsi request -
 144  * this remains the same across the write regardless of 32/64 bit
 145  * note: it's patterned off the SCSI_PASS_THROUGH structure
 146  */
 147 #define STORVSC_MAX_CMD_LEN                     0x10
 148
 149 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 150 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 151
 152 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 153 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 154
 155 /*
 156  * Sense buffer size changed in win8; have a run-time
 157  * variable to track the size we should use.  This value will
 158  * likely change during protocol negotiation but it is valid
 159  * to start by assuming pre-Win8.
 160  */
 161 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 162
 163 /*
 164  * The storage protocol version is determined during the
 165  * initial exchange with the host.  It will indicate which
 166  * storage functionality is available in the host.
 167 */
 168 static int vmstor_proto_version;
 169
 170 #define STORVSC_LOGGING_NONE    0
 171 #define STORVSC_LOGGING_ERROR   1
 172 #define STORVSC_LOGGING_WARN    2
 173
 174 static int logging_level = STORVSC_LOGGING_ERROR;
 175 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 176 MODULE_PARM_DESC(logging_level,
 177         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 178
 179 static inline bool do_logging(int level)
 180 {
 181         return logging_level >= level;
 182 }
 183
 184 #define storvsc_log(dev, level, fmt, ...)                       \
 185 do {                                                            \
 186         if (do_logging(level))                                  \
 187                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 188 } while (0)
 189
 190 struct vmscsi_win8_extension {
 191         /*
 192          * The following were added in Windows 8
 193          */
 194         u16 reserve;
 195         u8  queue_tag;
 196         u8  queue_action;
 197         u32 srb_flags;
 198         u32 time_out_value;
 199         u32 queue_sort_ey;
 200 } __packed;
 201
 202 struct vmscsi_request {
 203         u16 length;
 204         u8 srb_status;
 205         u8 scsi_status;
 206
 207         u8  port_number;
 208         u8  path_id;
 209         u8  target_id;
 210         u8  lun;
 211
 212         u8  cdb_length;
 213         u8  sense_info_length;
 214         u8  data_in;
 215         u8  reserved;
 216
 217         u32 data_transfer_length;
 218
 219         union {
 220                 u8 cdb[STORVSC_MAX_CMD_LEN];
 221                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 222                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 223         };
 224         /*
 225          * The following was added in win8.
 226          */
 227         struct vmscsi_win8_extension win8_extension;
 228
 229 } __attribute((packed));
 230
 231
 232 /*
 233  * The size of the vmscsi_request has changed in win8. The
 234  * additional size is because of new elements added to the
 235  * structure. These elements are valid only when we are talking
 236  * to a win8 host.
 237  * Track the correction to size we need to apply. This value
 238  * will likely change during protocol negotiation but it is
 239  * valid to start by assuming pre-Win8.
 240  */
 241 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 242
 243 /*
 244  * The list of storage protocols in order of preference.
 245  */
 246 struct vmstor_protocol {
 247         int protocol_version;
 248         int sense_buffer_size;
 249         int vmscsi_size_delta;
 250 };
 251
 252
 253 static const struct vmstor_protocol vmstor_protocols[] = {
 254         {
 255                 VMSTOR_PROTO_VERSION_WIN10,
 256                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 257                 0
 258         },
 259         {
 260                 VMSTOR_PROTO_VERSION_WIN8_1,
 261                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 262                 0
 263         },
 264         {
 265                 VMSTOR_PROTO_VERSION_WIN8,
 266                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 267                 0
 268         },
 269         {
 270                 VMSTOR_PROTO_VERSION_WIN7,
 271                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 272                 sizeof(struct vmscsi_win8_extension),
 273         },
 274         {
 275                 VMSTOR_PROTO_VERSION_WIN6,
 276                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 277                 sizeof(struct vmscsi_win8_extension),
 278         }
 279 };
 280
 281
 282 /*
 283  * This structure is sent during the initialization phase to get the different
 284  * properties of the channel.
 285  */
 286
 287 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 288
 289 struct vmstorage_channel_properties {
 290         u32 reserved;
 291         u16 max_channel_cnt;
 292         u16 reserved1;
 293
 294         u32 flags;
 295         u32   max_transfer_bytes;
 296
 297         u64  reserved2;
 298 } __packed;
 299
 300 /*  This structure is sent during the storage protocol negotiations. */
 301 struct vmstorage_protocol_version {
 302         /* Major (MSW) and minor (LSW) version numbers. */
 303         u16 major_minor;
 304
 305         /*
 306          * Revision number is auto-incremented whenever this file is changed
 307          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 308          * definitely indicate incompatibility--but it does indicate mismatched
 309          * builds.
 310          * This is only used on the windows side. Just set it to 0.
 311          */
 312         u16 revision;
 313 } __packed;
 314
 315 /* Channel Property Flags */
 316 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 317 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 318
 319 struct vstor_packet {
 320         /* Requested operation type */
 321         enum vstor_packet_operation operation;
 322
 323         /*  Flags - see below for values */
 324         u32 flags;
 325
 326         /* Status of the request returned from the server side. */
 327         u32 status;
 328
 329         /* Data payload area */
 330         union {
 331                 /*
 332                  * Structure used to forward SCSI commands from the
 333                  * client to the server.
 334                  */
 335                 struct vmscsi_request vm_srb;
 336
 337                 /* Structure used to query channel properties. */
 338                 struct vmstorage_channel_properties storage_channel_properties;
 339
 340                 /* Used during version negotiations. */
 341                 struct vmstorage_protocol_version version;
 342
 343                 /* Fibre channel address packet */
 344                 struct hv_fc_wwn_packet wwn_packet;
 345
 346                 /* Number of sub-channels to create */
 347                 u16 sub_channel_count;
 348
 349                 /* This will be the maximum of the union members */
 350                 u8  buffer[0x34];
 351         };
 352 } __packed;
 353
 354 /*
 355  * Packet Flags:
 356  *
 357  * This flag indicates that the server should send back a completion for this
 358  * packet.
 359  */
 360
 361 #define REQUEST_COMPLETION_FLAG 0x1
 362
 363 /* Matches Windows-end */
 364 enum storvsc_request_type {
 365         WRITE_TYPE = 0,
 366         READ_TYPE,
 367         UNKNOWN_TYPE,
 368 };
 369
 370 /*
 371  * SRB status codes and masks; a subset of the codes used here.
 372  */
 373
 374 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 375 #define SRB_STATUS_QUEUE_FROZEN         0x40
 376 #define SRB_STATUS_INVALID_LUN  0x20
 377 #define SRB_STATUS_SUCCESS      0x01
 378 #define SRB_STATUS_ABORTED      0x02
 379 #define SRB_STATUS_ERROR        0x04
 380 #define SRB_STATUS_DATA_OVERRUN 0x12
 381
 382 #define SRB_STATUS(status) \
 383         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 384 /*
 385  * This is the end of Protocol specific defines.
 386  */
 387
 388 static int storvsc_ringbuffer_size = (128 * 1024);
 389 static u32 max_outstanding_req_per_channel;
 390
 391 static int storvsc_vcpus_per_sub_channel = 4;
 392
 393 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 394 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 395
 396 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 397 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 398
 399 static int ring_avail_percent_lowater = 10;
 400 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 401 MODULE_PARM_DESC(ring_avail_percent_lowater,
 402                 "Select a channel if available ring size > this in percent");
 403
 404 /*
 405  * Timeout in seconds for all devices managed by this driver.
 406  */
 407 static int storvsc_timeout = 180;
 408
 409 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 410 static struct scsi_transport_template *fc_transport_template;
 411 #endif
 412
 413 static void storvsc_on_channel_callback(void *context);
 414
 415 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 416 #define STORVSC_MAX_TARGETS                             2
 417 #define STORVSC_MAX_CHANNELS                            8
 418
 419 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 420 #define STORVSC_FC_MAX_TARGETS                          128
 421 #define STORVSC_FC_MAX_CHANNELS                         8
 422
 423 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 424 #define STORVSC_IDE_MAX_TARGETS                         1
 425 #define STORVSC_IDE_MAX_CHANNELS                        1
 426
 427 struct storvsc_cmd_request {
 428         struct scsi_cmnd *cmd;
 429
 430         struct hv_device *device;
 431
 432         /* Synchronize the request/response if needed */
 433         struct completion wait_event;
 434
 435         struct vmbus_channel_packet_multipage_buffer mpb;
 436         struct vmbus_packet_mpb_array *payload;
 437         u32 payload_sz;
 438
 439         struct vstor_packet vstor_packet;
 440 };
 441
 442
 443 /* A storvsc device is a device object that contains a vmbus channel */
 444 struct storvsc_device {
 445         struct hv_device *device;
 446
 447         bool     destroy;
 448         bool     drain_notify;
 449         atomic_t num_outstanding_req;
 450         struct Scsi_Host *host;
 451
 452         wait_queue_head_t waiting_to_drain;
 453
 454         /*
 455          * Each unique Port/Path/Target represents 1 channel ie scsi
 456          * controller. In reality, the pathid, targetid is always 0
 457          * and the port is set by us
 458          */
 459         unsigned int port_number;
 460         unsigned char path_id;
 461         unsigned char target_id;
 462
 463         /*
 464          * Max I/O, the device can support.
 465          */
 466         u32   max_transfer_bytes;
 467         /*
 468          * Number of sub-channels we will open.
 469          */
 470         u16 num_sc;
 471         struct vmbus_channel **stor_chns;
 472         /*
 473          * Mask of CPUs bound to subchannels.
 474          */
 475         struct cpumask alloced_cpus;
 476         /* Used for vsc/vsp channel reset process */
 477         struct storvsc_cmd_request init_request;
 478         struct storvsc_cmd_request reset_request;
 479         /*
 480          * Currently active port and node names for FC devices.
 481          */
 482         u64 node_name;
 483         u64 port_name;
 484 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 485         struct fc_rport *rport;
 486 #endif
 487 };
 488
 489 struct hv_host_device {
 490         struct hv_device *dev;
 491         unsigned int port;
 492         unsigned char path;
 493         unsigned char target;
 494         struct workqueue_struct *handle_error_wq;
 495         struct work_struct host_scan_work;
 496         struct Scsi_Host *host;
 497 };
 498
 499 struct storvsc_scan_work {
 500         struct work_struct work;
 501         struct Scsi_Host *host;
 502         u8 lun;
 503         u8 tgt_id;
 504 };
 505
 506 static void storvsc_device_scan(struct work_struct *work)
 507 {
 508         struct storvsc_scan_work *wrk;
 509         struct scsi_device *sdev;
 510
 511         wrk = container_of(work, struct storvsc_scan_work, work);
 512
 513         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 514         if (!sdev)
 515                 goto done;
 516         scsi_rescan_device(&sdev->sdev_gendev);
 517         scsi_device_put(sdev);
 518
 519 done:
 520         kfree(wrk);
 521 }
 522
 523 static void storvsc_host_scan(struct work_struct *work)
 524 {
 525         struct Scsi_Host *host;
 526         struct scsi_device *sdev;
 527         struct hv_host_device *host_device =
 528                 container_of(work, struct hv_host_device, host_scan_work);
 529
 530         host = host_device->host;
 531         /*
 532          * Before scanning the host, first check to see if any of the
 533          * currrently known devices have been hot removed. We issue a
 534          * "unit ready" command against all currently known devices.
 535          * This I/O will result in an error for devices that have been
 536          * removed. As part of handling the I/O error, we remove the device.
 537          *
 538          * When a LUN is added or removed, the host sends us a signal to
 539          * scan the host. Thus we are forced to discover the LUNs that
 540          * may have been removed this way.
 541          */
 542         mutex_lock(&host->scan_mutex);
 543         shost_for_each_device(sdev, host)
 544                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 545         mutex_unlock(&host->scan_mutex);
 546         /*
 547          * Now scan the host to discover LUNs that may have been added.
 548          */
 549         scsi_scan_host(host);
 550 }
 551
 552 static void storvsc_remove_lun(struct work_struct *work)
 553 {
 554         struct storvsc_scan_work *wrk;
 555         struct scsi_device *sdev;
 556
 557         wrk = container_of(work, struct storvsc_scan_work, work);
 558         if (!scsi_host_get(wrk->host))
 559                 goto done;
 560
 561         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 562
 563         if (sdev) {
 564                 scsi_remove_device(sdev);
 565                 scsi_device_put(sdev);
 566         }
 567         scsi_host_put(wrk->host);
 568
 569 done:
 570         kfree(wrk);
 571 }
 572
 573
 574 /*
 575  * We can get incoming messages from the host that are not in response to
 576  * messages that we have sent out. An example of this would be messages
 577  * received by the guest to notify dynamic addition/removal of LUNs. To
 578  * deal with potential race conditions where the driver may be in the
 579  * midst of being unloaded when we might receive an unsolicited message
 580  * from the host, we have implemented a mechanism to gurantee sequential
 581  * consistency:
 582  *
 583  * 1) Once the device is marked as being destroyed, we will fail all
 584  *    outgoing messages.
 585  * 2) We permit incoming messages when the device is being destroyed,
 586  *    only to properly account for messages already sent out.
 587  */
 588
 589 static inline struct storvsc_device *get_out_stor_device(
 590                                         struct hv_device *device)
 591 {
 592         struct storvsc_device *stor_device;
 593
 594         stor_device = hv_get_drvdata(device);
 595
 596         if (stor_device && stor_device->destroy)
 597                 stor_device = NULL;
 598
 599         return stor_device;
 600 }
 601
 602
 603 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 604 {
 605         dev->drain_notify = true;
 606         wait_event(dev->waiting_to_drain,
 607                    atomic_read(&dev->num_outstanding_req) == 0);
 608         dev->drain_notify = false;
 609 }
 610
 611 static inline struct storvsc_device *get_in_stor_device(
 612                                         struct hv_device *device)
 613 {
 614         struct storvsc_device *stor_device;
 615
 616         stor_device = hv_get_drvdata(device);
 617
 618         if (!stor_device)
 619                 goto get_in_err;
 620
 621         /*
 622          * If the device is being destroyed; allow incoming
 623          * traffic only to cleanup outstanding requests.
 624          */
 625
 626         if (stor_device->destroy  &&
 627                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 628                 stor_device = NULL;
 629
 630 get_in_err:
 631         return stor_device;
 632
 633 }
 634
 635 static void handle_sc_creation(struct vmbus_channel *new_sc)
 636 {
 637         struct hv_device *device = new_sc->primary_channel->device_obj;
 638         struct device *dev = &device->device;
 639         struct storvsc_device *stor_device;
 640         struct vmstorage_channel_properties props;
 641         int ret;
 642
 643         stor_device = get_out_stor_device(device);
 644         if (!stor_device)
 645                 return;
 646
 647         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 648
 649         ret = vmbus_open(new_sc,
 650                          storvsc_ringbuffer_size,
 651                          storvsc_ringbuffer_size,
 652                          (void *)&props,
 653                          sizeof(struct vmstorage_channel_properties),
 654                          storvsc_on_channel_callback, new_sc);
 655
 656         /* In case vmbus_open() fails, we don't use the sub-channel. */
 657         if (ret != 0) {
 658                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 659                 return;
 660         }
 661
 662         /* Add the sub-channel to the array of available channels. */
 663         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 664         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 665 }
 666
 667 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 668 {
 669         struct device *dev = &device->device;
 670         struct storvsc_device *stor_device;
 671         int num_sc;
 672         struct storvsc_cmd_request *request;
 673         struct vstor_packet *vstor_packet;
 674         int ret, t;
 675
 676         /*
 677          * If the number of CPUs is artificially restricted, such as
 678          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 679          * sub-channels >= the number of CPUs. These sub-channels
 680          * should not be created. The primary channel is already created
 681          * and assigned to one CPU, so check against # CPUs - 1.
 682          */
 683         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 684         if (!num_sc)
 685                 return;
 686
 687         stor_device = get_out_stor_device(device);
 688         if (!stor_device)
 689                 return;
 690
 691         stor_device->num_sc = num_sc;
 692         request = &stor_device->init_request;
 693         vstor_packet = &request->vstor_packet;
 694
 695         /*
 696          * Establish a handler for dealing with subchannels.
 697          */
 698         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 699
 700         /*
 701          * Request the host to create sub-channels.
 702          */
 703         memset(request, 0, sizeof(struct storvsc_cmd_request));
 704         init_completion(&request->wait_event);
 705         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 706         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 707         vstor_packet->sub_channel_count = num_sc;
 708
 709         ret = vmbus_sendpacket(device->channel, vstor_packet,
 710                                (sizeof(struct vstor_packet) -
 711                                vmscsi_size_delta),
 712                                (unsigned long)request,
 713                                VM_PKT_DATA_INBAND,
 714                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 715
 716         if (ret != 0) {
 717                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 718                 return;
 719         }
 720
 721         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 722         if (t == 0) {
 723                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 724                 return;
 725         }
 726
 727         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 728             vstor_packet->status != 0) {
 729                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 730                         vstor_packet->operation, vstor_packet->status);
 731                 return;
 732         }
 733
 734         /*
 735          * We need to do nothing here, because vmbus_process_offer()
 736          * invokes channel->sc_creation_callback, which will open and use
 737          * the sub-channel(s).
 738          */
 739 }
 740
 741 static void cache_wwn(struct storvsc_device *stor_device,
 742                       struct vstor_packet *vstor_packet)
 743 {
 744         /*
 745          * Cache the currently active port and node ww names.
 746          */
 747         if (vstor_packet->wwn_packet.primary_active) {
 748                 stor_device->node_name =
 749                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 750                 stor_device->port_name =
 751                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 752         } else {
 753                 stor_device->node_name =
 754                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 755                 stor_device->port_name =
 756                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 757         }
 758 }
 759
 760
 761 static int storvsc_execute_vstor_op(struct hv_device *device,
 762                                     struct storvsc_cmd_request *request,
 763                                     bool status_check)
 764 {
 765         struct vstor_packet *vstor_packet;
 766         int ret, t;
 767
 768         vstor_packet = &request->vstor_packet;
 769
 770         init_completion(&request->wait_event);
 771         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 772
 773         ret = vmbus_sendpacket(device->channel, vstor_packet,
 774                                (sizeof(struct vstor_packet) -
 775                                vmscsi_size_delta),
 776                                (unsigned long)request,
 777                                VM_PKT_DATA_INBAND,
 778                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 779         if (ret != 0)
 780                 return ret;
 781
 782         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 783         if (t == 0)
 784                 return -ETIMEDOUT;
 785
 786         if (!status_check)
 787                 return ret;
 788
 789         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 790             vstor_packet->status != 0)
 791                 return -EINVAL;
 792
 793         return ret;
 794 }
 795
 796 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 797 {
 798         struct storvsc_device *stor_device;
 799         struct storvsc_cmd_request *request;
 800         struct vstor_packet *vstor_packet;
 801         int ret, i;
 802         int max_chns;
 803         bool process_sub_channels = false;
 804
 805         stor_device = get_out_stor_device(device);
 806         if (!stor_device)
 807                 return -ENODEV;
 808
 809         request = &stor_device->init_request;
 810         vstor_packet = &request->vstor_packet;
 811
 812         /*
 813          * Now, initiate the vsc/vsp initialization protocol on the open
 814          * channel
 815          */
 816         memset(request, 0, sizeof(struct storvsc_cmd_request));
 817         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 818         ret = storvsc_execute_vstor_op(device, request, true);
 819         if (ret)
 820                 return ret;
 821         /*
 822          * Query host supported protocol version.
 823          */
 824
 825         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 826                 /* reuse the packet for version range supported */
 827                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 828                 vstor_packet->operation =
 829                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 830
 831                 vstor_packet->version.major_minor =
 832                         vmstor_protocols[i].protocol_version;
 833
 834                 /*
 835                  * The revision number is only used in Windows; set it to 0.
 836                  */
 837                 vstor_packet->version.revision = 0;
 838                 ret = storvsc_execute_vstor_op(device, request, false);
 839                 if (ret != 0)
 840                         return ret;
 841
 842                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 843                         return -EINVAL;
 844
 845                 if (vstor_packet->status == 0) {
 846                         vmstor_proto_version =
 847                                 vmstor_protocols[i].protocol_version;
 848
 849                         sense_buffer_size =
 850                                 vmstor_protocols[i].sense_buffer_size;
 851
 852                         vmscsi_size_delta =
 853                                 vmstor_protocols[i].vmscsi_size_delta;
 854
 855                         break;
 856                 }
 857         }
 858
 859         if (vstor_packet->status != 0)
 860                 return -EINVAL;
 861
 862
 863         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 864         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 865         ret = storvsc_execute_vstor_op(device, request, true);
 866         if (ret != 0)
 867                 return ret;
 868
 869         /*
 870          * Check to see if multi-channel support is there.
 871          * Hosts that implement protocol version of 5.1 and above
 872          * support multi-channel.
 873          */
 874         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 875
 876         /*
 877          * Allocate state to manage the sub-channels.
 878          * We allocate an array based on the numbers of possible CPUs
 879          * (Hyper-V does not support cpu online/offline).
 880          * This Array will be sparseley populated with unique
 881          * channels - primary + sub-channels.
 882          * We will however populate all the slots to evenly distribute
 883          * the load.
 884          */
 885         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 886                                          GFP_KERNEL);
 887         if (stor_device->stor_chns == NULL)
 888                 return -ENOMEM;
 889
 890         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 891         cpumask_set_cpu(device->channel->target_cpu,
 892                         &stor_device->alloced_cpus);
 893
 894         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 895                 if (vstor_packet->storage_channel_properties.flags &
 896                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 897                         process_sub_channels = true;
 898         }
 899         stor_device->max_transfer_bytes =
 900                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 901
 902         if (!is_fc)
 903                 goto done;
 904
 905         /*
 906          * For FC devices retrieve FC HBA data.
 907          */
 908         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 909         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 910         ret = storvsc_execute_vstor_op(device, request, true);
 911         if (ret != 0)
 912                 return ret;
 913
 914         /*
 915          * Cache the currently active port and node ww names.
 916          */
 917         cache_wwn(stor_device, vstor_packet);
 918
 919 done:
 920
 921         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 922         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 923         ret = storvsc_execute_vstor_op(device, request, true);
 924         if (ret != 0)
 925                 return ret;
 926
 927         if (process_sub_channels)
 928                 handle_multichannel_storage(device, max_chns);
 929
 930         return ret;
 931 }
 932
 933 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 934                                 struct scsi_cmnd *scmnd,
 935                                 struct Scsi_Host *host,
 936                                 u8 asc, u8 ascq)
 937 {
 938         struct storvsc_scan_work *wrk;
 939         void (*process_err_fn)(struct work_struct *work);
 940         struct hv_host_device *host_dev = shost_priv(host);
 941         bool do_work = false;
 942
 943         switch (SRB_STATUS(vm_srb->srb_status)) {
 944         case SRB_STATUS_ERROR:
 945                 /*
 946                  * Let upper layer deal with error when
 947                  * sense message is present.
 948                  */
 949
 950                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
 951                         break;
 952                 /*
 953                  * If there is an error; offline the device since all
 954                  * error recovery strategies would have already been
 955                  * deployed on the host side. However, if the command
 956                  * were a pass-through command deal with it appropriately.
 957                  */
 958                 switch (scmnd->cmnd[0]) {
 959                 case ATA_16:
 960                 case ATA_12:
 961                         set_host_byte(scmnd, DID_PASSTHROUGH);
 962                         break;
 963                 /*
 964                  * On Some Windows hosts TEST_UNIT_READY command can return
 965                  * SRB_STATUS_ERROR, let the upper level code deal with it
 966                  * based on the sense information.
 967                  */
 968                 case TEST_UNIT_READY:
 969                         break;
 970                 default:
 971                         set_host_byte(scmnd, DID_ERROR);
 972                 }
 973                 break;
 974         case SRB_STATUS_INVALID_LUN:
 975                 set_host_byte(scmnd, DID_NO_CONNECT);
 976                 do_work = true;
 977                 process_err_fn = storvsc_remove_lun;
 978                 break;
 979         case SRB_STATUS_ABORTED:
 980                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
 981                     (asc == 0x2a) && (ascq == 0x9)) {
 982                         do_work = true;
 983                         process_err_fn = storvsc_device_scan;
 984                         /*
 985                          * Retry the I/O that trigerred this.
 986                          */
 987                         set_host_byte(scmnd, DID_REQUEUE);
 988                 }
 989                 break;
 990         }
 991
 992         if (!do_work)
 993                 return;
 994
 995         /*
 996          * We need to schedule work to process this error; schedule it.
 997          */
 998         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 999         if (!wrk) {
1000                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1001                 return;
1002         }
1003
1004         wrk->host = host;
1005         wrk->lun = vm_srb->lun;
1006         wrk->tgt_id = vm_srb->target_id;
1007         INIT_WORK(&wrk->work, process_err_fn);
1008         queue_work(host_dev->handle_error_wq, &wrk->work);
1009 }
1010
1011
1012 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1013                                        struct storvsc_device *stor_dev)
1014 {
1015         struct scsi_cmnd *scmnd = cmd_request->cmd;
1016         struct scsi_sense_hdr sense_hdr;
1017         struct vmscsi_request *vm_srb;
1018         u32 data_transfer_length;
1019         struct Scsi_Host *host;
1020         u32 payload_sz = cmd_request->payload_sz;
1021         void *payload = cmd_request->payload;
1022
1023         host = stor_dev->host;
1024
1025         vm_srb = &cmd_request->vstor_packet.vm_srb;
1026         data_transfer_length = vm_srb->data_transfer_length;
1027
1028         scmnd->result = vm_srb->scsi_status;
1029
1030         if (scmnd->result) {
1031                 if (scsi_normalize_sense(scmnd->sense_buffer,
1032                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1033                     !(sense_hdr.sense_key == NOT_READY &&
1034                                  sense_hdr.asc == 0x03A) &&
1035                     do_logging(STORVSC_LOGGING_ERROR))
1036                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1037                                              &sense_hdr);
1038         }
1039
1040         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1041                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1042                                          sense_hdr.ascq);
1043                 /*
1044                  * The Windows driver set data_transfer_length on
1045                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1046                  * is untouched.  In these cases we set it to 0.
1047                  */
1048                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1049                         data_transfer_length = 0;
1050         }
1051
1052         scsi_set_resid(scmnd,
1053                 cmd_request->payload->range.len - data_transfer_length);
1054
1055         scmnd->scsi_done(scmnd);
1056
1057         if (payload_sz >
1058                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1059                 kfree(payload);
1060 }
1061
1062 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1063                                   struct vstor_packet *vstor_packet,
1064                                   struct storvsc_cmd_request *request)
1065 {
1066         struct vstor_packet *stor_pkt;
1067         struct hv_device *device = stor_device->device;
1068
1069         stor_pkt = &request->vstor_packet;
1070
1071         /*
1072          * The current SCSI handling on the host side does
1073          * not correctly handle:
1074          * INQUIRY command with page code parameter set to 0x80
1075          * MODE_SENSE command with cmd[2] == 0x1c
1076          *
1077          * Setup srb and scsi status so this won't be fatal.
1078          * We do this so we can distinguish truly fatal failues
1079          * (srb status == 0x4) and off-line the device in that case.
1080          */
1081
1082         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1083            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1084                 vstor_packet->vm_srb.scsi_status = 0;
1085                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1086         }
1087
1088
1089         /* Copy over the status...etc */
1090         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1091         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1092         stor_pkt->vm_srb.sense_info_length =
1093         vstor_packet->vm_srb.sense_info_length;
1094
1095         if (vstor_packet->vm_srb.scsi_status != 0 ||
1096             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1097                 storvsc_log(device, STORVSC_LOGGING_WARN,
1098                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1099                         stor_pkt->vm_srb.cdb[0],
1100                         vstor_packet->vm_srb.scsi_status,
1101                         vstor_packet->vm_srb.srb_status);
1102
1103         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1104                 /* CHECK_CONDITION */
1105                 if (vstor_packet->vm_srb.srb_status &
1106                         SRB_STATUS_AUTOSENSE_VALID) {
1107                         /* autosense data available */
1108
1109                         storvsc_log(device, STORVSC_LOGGING_WARN,
1110                                 "stor pkt %p autosense data valid - len %d\n",
1111                                 request, vstor_packet->vm_srb.sense_info_length);
1112
1113                         memcpy(request->cmd->sense_buffer,
1114                                vstor_packet->vm_srb.sense_data,
1115                                vstor_packet->vm_srb.sense_info_length);
1116
1117                 }
1118         }
1119
1120         stor_pkt->vm_srb.data_transfer_length =
1121         vstor_packet->vm_srb.data_transfer_length;
1122
1123         storvsc_command_completion(request, stor_device);
1124
1125         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1126                 stor_device->drain_notify)
1127                 wake_up(&stor_device->waiting_to_drain);
1128
1129
1130 }
1131
1132 static void storvsc_on_receive(struct storvsc_device *stor_device,
1133                              struct vstor_packet *vstor_packet,
1134                              struct storvsc_cmd_request *request)
1135 {
1136         struct hv_host_device *host_dev;
1137         switch (vstor_packet->operation) {
1138         case VSTOR_OPERATION_COMPLETE_IO:
1139                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1140                 break;
1141
1142         case VSTOR_OPERATION_REMOVE_DEVICE:
1143         case VSTOR_OPERATION_ENUMERATE_BUS:
1144                 host_dev = shost_priv(stor_device->host);
1145                 queue_work(
1146                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1147                 break;
1148
1149         case VSTOR_OPERATION_FCHBA_DATA:
1150                 cache_wwn(stor_device, vstor_packet);
1151 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1152                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1153                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1154 #endif
1155                 break;
1156         default:
1157                 break;
1158         }
1159 }
1160
1161 static void storvsc_on_channel_callback(void *context)
1162 {
1163         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1164         const struct vmpacket_descriptor *desc;
1165         struct hv_device *device;
1166         struct storvsc_device *stor_device;
1167
1168         if (channel->primary_channel != NULL)
1169                 device = channel->primary_channel->device_obj;
1170         else
1171                 device = channel->device_obj;
1172
1173         stor_device = get_in_stor_device(device);
1174         if (!stor_device)
1175                 return;
1176
1177         foreach_vmbus_pkt(desc, channel) {
1178                 void *packet = hv_pkt_data(desc);
1179                 struct storvsc_cmd_request *request;
1180
1181                 request = (struct storvsc_cmd_request *)
1182                         ((unsigned long)desc->trans_id);
1183
1184                 if (request == &stor_device->init_request ||
1185                     request == &stor_device->reset_request) {
1186                         memcpy(&request->vstor_packet, packet,
1187                                (sizeof(struct vstor_packet) - vmscsi_size_delta));
1188                         complete(&request->wait_event);
1189                 } else {
1190                         storvsc_on_receive(stor_device, packet, request);
1191                 }
1192         }
1193 }
1194
1195 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1196                                   bool is_fc)
1197 {
1198         struct vmstorage_channel_properties props;
1199         int ret;
1200
1201         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1202
1203         ret = vmbus_open(device->channel,
1204                          ring_size,
1205                          ring_size,
1206                          (void *)&props,
1207                          sizeof(struct vmstorage_channel_properties),
1208                          storvsc_on_channel_callback, device->channel);
1209
1210         if (ret != 0)
1211                 return ret;
1212
1213         ret = storvsc_channel_init(device, is_fc);
1214
1215         return ret;
1216 }
1217
1218 static int storvsc_dev_remove(struct hv_device *device)
1219 {
1220         struct storvsc_device *stor_device;
1221
1222         stor_device = hv_get_drvdata(device);
1223
1224         stor_device->destroy = true;
1225
1226         /* Make sure flag is set before waiting */
1227         wmb();
1228
1229         /*
1230          * At this point, all outbound traffic should be disable. We
1231          * only allow inbound traffic (responses) to proceed so that
1232          * outstanding requests can be completed.
1233          */
1234
1235         storvsc_wait_to_drain(stor_device);
1236
1237         /*
1238          * Since we have already drained, we don't need to busy wait
1239          * as was done in final_release_stor_device()
1240          * Note that we cannot set the ext pointer to NULL until
1241          * we have drained - to drain the outgoing packets, we need to
1242          * allow incoming packets.
1243          */
1244         hv_set_drvdata(device, NULL);
1245
1246         /* Close the channel */
1247         vmbus_close(device->channel);
1248
1249         kfree(stor_device->stor_chns);
1250         kfree(stor_device);
1251         return 0;
1252 }
1253
1254 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1255                                         u16 q_num)
1256 {
1257         u16 slot = 0;
1258         u16 hash_qnum;
1259         const struct cpumask *node_mask;
1260         int num_channels, tgt_cpu;
1261
1262         if (stor_device->num_sc == 0)
1263                 return stor_device->device->channel;
1264
1265         /*
1266          * Our channel array is sparsley populated and we
1267          * initiated I/O on a processor/hw-q that does not
1268          * currently have a designated channel. Fix this.
1269          * The strategy is simple:
1270          * I. Ensure NUMA locality
1271          * II. Distribute evenly (best effort)
1272          * III. Mapping is persistent.
1273          */
1274
1275         node_mask = cpumask_of_node(cpu_to_node(q_num));
1276
1277         num_channels = 0;
1278         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1279                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1280                         num_channels++;
1281         }
1282         if (num_channels == 0)
1283                 return stor_device->device->channel;
1284
1285         hash_qnum = q_num;
1286         while (hash_qnum >= num_channels)
1287                 hash_qnum -= num_channels;
1288
1289         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1290                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1291                         continue;
1292                 if (slot == hash_qnum)
1293                         break;
1294                 slot++;
1295         }
1296
1297         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1298
1299         return stor_device->stor_chns[q_num];
1300 }
1301
1302
1303 static int storvsc_do_io(struct hv_device *device,
1304                          struct storvsc_cmd_request *request, u16 q_num)
1305 {
1306         struct storvsc_device *stor_device;
1307         struct vstor_packet *vstor_packet;
1308         struct vmbus_channel *outgoing_channel, *channel;
1309         int ret = 0;
1310         const struct cpumask *node_mask;
1311         int tgt_cpu;
1312
1313         vstor_packet = &request->vstor_packet;
1314         stor_device = get_out_stor_device(device);
1315
1316         if (!stor_device)
1317                 return -ENODEV;
1318
1319
1320         request->device  = device;
1321         /*
1322          * Select an an appropriate channel to send the request out.
1323          */
1324         if (stor_device->stor_chns[q_num] != NULL) {
1325                 outgoing_channel = stor_device->stor_chns[q_num];
1326                 if (outgoing_channel->target_cpu == q_num) {
1327                         /*
1328                          * Ideally, we want to pick a different channel if
1329                          * available on the same NUMA node.
1330                          */
1331                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1332                         for_each_cpu_wrap(tgt_cpu,
1333                                  &stor_device->alloced_cpus, q_num + 1) {
1334                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1335                                         continue;
1336                                 if (tgt_cpu == q_num)
1337                                         continue;
1338                                 channel = stor_device->stor_chns[tgt_cpu];
1339                                 if (hv_get_avail_to_write_percent(
1340                                                         &channel->outbound)
1341                                                 > ring_avail_percent_lowater) {
1342                                         outgoing_channel = channel;
1343                                         goto found_channel;
1344                                 }
1345                         }
1346
1347                         /*
1348                          * All the other channels on the same NUMA node are
1349                          * busy. Try to use the channel on the current CPU
1350                          */
1351                         if (hv_get_avail_to_write_percent(
1352                                                 &outgoing_channel->outbound)
1353                                         > ring_avail_percent_lowater)
1354                                 goto found_channel;
1355
1356                         /*
1357                          * If we reach here, all the channels on the current
1358                          * NUMA node are busy. Try to find a channel in
1359                          * other NUMA nodes
1360                          */
1361                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1362                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1363                                         continue;
1364                                 channel = stor_device->stor_chns[tgt_cpu];
1365                                 if (hv_get_avail_to_write_percent(
1366                                                         &channel->outbound)
1367                                                 > ring_avail_percent_lowater) {
1368                                         outgoing_channel = channel;
1369                                         goto found_channel;
1370                                 }
1371                         }
1372                 }
1373         } else {
1374                 outgoing_channel = get_og_chn(stor_device, q_num);
1375         }
1376
1377 found_channel:
1378         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1379
1380         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1381                                         vmscsi_size_delta);
1382
1383
1384         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1385
1386
1387         vstor_packet->vm_srb.data_transfer_length =
1388         request->payload->range.len;
1389
1390         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1391
1392         if (request->payload->range.len) {
1393
1394                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1395                                 request->payload, request->payload_sz,
1396                                 vstor_packet,
1397                                 (sizeof(struct vstor_packet) -
1398                                 vmscsi_size_delta),
1399                                 (unsigned long)request);
1400         } else {
1401                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1402                                (sizeof(struct vstor_packet) -
1403                                 vmscsi_size_delta),
1404                                (unsigned long)request,
1405                                VM_PKT_DATA_INBAND,
1406                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1407         }
1408
1409         if (ret != 0)
1410                 return ret;
1411
1412         atomic_inc(&stor_device->num_outstanding_req);
1413
1414         return ret;
1415 }
1416
1417 static int storvsc_device_alloc(struct scsi_device *sdevice)
1418 {
1419         /*
1420          * Set blist flag to permit the reading of the VPD pages even when
1421          * the target may claim SPC-2 compliance. MSFT targets currently
1422          * claim SPC-2 compliance while they implement post SPC-2 features.
1423          * With this flag we can correctly handle WRITE_SAME_16 issues.
1424          *
1425          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1426          * still supports REPORT LUN.
1427          */
1428         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1429
1430         return 0;
1431 }
1432
1433 static int storvsc_device_configure(struct scsi_device *sdevice)
1434 {
1435         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1436
1437         /* Ensure there are no gaps in presented sgls */
1438         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1439
1440         sdevice->no_write_same = 1;
1441
1442         /*
1443          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1444          * if the device is a MSFT virtual device.  If the host is
1445          * WIN10 or newer, allow write_same.
1446          */
1447         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1448                 switch (vmstor_proto_version) {
1449                 case VMSTOR_PROTO_VERSION_WIN8:
1450                 case VMSTOR_PROTO_VERSION_WIN8_1:
1451                         sdevice->scsi_level = SCSI_SPC_3;
1452                         break;
1453                 }
1454
1455                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1456                         sdevice->no_write_same = 0;
1457         }
1458
1459         return 0;
1460 }
1461
1462 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1463                            sector_t capacity, int *info)
1464 {
1465         sector_t nsect = capacity;
1466         sector_t cylinders = nsect;
1467         int heads, sectors_pt;
1468
1469         /*
1470          * We are making up these values; let us keep it simple.
1471          */
1472         heads = 0xff;
1473         sectors_pt = 0x3f;      /* Sectors per track */
1474         sector_div(cylinders, heads * sectors_pt);
1475         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1476                 cylinders = 0xffff;
1477
1478         info[0] = heads;
1479         info[1] = sectors_pt;
1480         info[2] = (int)cylinders;
1481
1482         return 0;
1483 }
1484
1485 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1486 {
1487         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1488         struct hv_device *device = host_dev->dev;
1489
1490         struct storvsc_device *stor_device;
1491         struct storvsc_cmd_request *request;
1492         struct vstor_packet *vstor_packet;
1493         int ret, t;
1494
1495
1496         stor_device = get_out_stor_device(device);
1497         if (!stor_device)
1498                 return FAILED;
1499
1500         request = &stor_device->reset_request;
1501         vstor_packet = &request->vstor_packet;
1502
1503         init_completion(&request->wait_event);
1504
1505         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1506         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1507         vstor_packet->vm_srb.path_id = stor_device->path_id;
1508
1509         ret = vmbus_sendpacket(device->channel, vstor_packet,
1510                                (sizeof(struct vstor_packet) -
1511                                 vmscsi_size_delta),
1512                                (unsigned long)&stor_device->reset_request,
1513                                VM_PKT_DATA_INBAND,
1514                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1515         if (ret != 0)
1516                 return FAILED;
1517
1518         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1519         if (t == 0)
1520                 return TIMEOUT_ERROR;
1521
1522
1523         /*
1524          * At this point, all outstanding requests in the adapter
1525          * should have been flushed out and return to us
1526          * There is a potential race here where the host may be in
1527          * the process of responding when we return from here.
1528          * Just wait for all in-transit packets to be accounted for
1529          * before we return from here.
1530          */
1531         storvsc_wait_to_drain(stor_device);
1532
1533         return SUCCESS;
1534 }
1535
1536 /*
1537  * The host guarantees to respond to each command, although I/O latencies might
1538  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1539  * chance to perform EH.
1540  */
1541 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1542 {
1543 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1544         if (scmnd->device->host->transportt == fc_transport_template)
1545                 return fc_eh_timed_out(scmnd);
1546 #endif
1547         return BLK_EH_RESET_TIMER;
1548 }
1549
1550 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1551 {
1552         bool allowed = true;
1553         u8 scsi_op = scmnd->cmnd[0];
1554
1555         switch (scsi_op) {
1556         /* the host does not handle WRITE_SAME, log accident usage */
1557         case WRITE_SAME:
1558         /*
1559          * smartd sends this command and the host does not handle
1560          * this. So, don't send it.
1561          */
1562         case SET_WINDOW:
1563                 scmnd->result = ILLEGAL_REQUEST << 16;
1564                 allowed = false;
1565                 break;
1566         default:
1567                 break;
1568         }
1569         return allowed;
1570 }
1571
1572 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1573 {
1574         int ret;
1575         struct hv_host_device *host_dev = shost_priv(host);
1576         struct hv_device *dev = host_dev->dev;
1577         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1578         int i;
1579         struct scatterlist *sgl;
1580         unsigned int sg_count = 0;
1581         struct vmscsi_request *vm_srb;
1582         struct scatterlist *cur_sgl;
1583         struct vmbus_packet_mpb_array  *payload;
1584         u32 payload_sz;
1585         u32 length;
1586
1587         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1588                 /*
1589                  * On legacy hosts filter unimplemented commands.
1590                  * Future hosts are expected to correctly handle
1591                  * unsupported commands. Furthermore, it is
1592                  * possible that some of the currently
1593                  * unsupported commands maybe supported in
1594                  * future versions of the host.
1595                  */
1596                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1597                         scmnd->scsi_done(scmnd);
1598                         return 0;
1599                 }
1600         }
1601
1602         /* Setup the cmd request */
1603         cmd_request->cmd = scmnd;
1604
1605         vm_srb = &cmd_request->vstor_packet.vm_srb;
1606         vm_srb->win8_extension.time_out_value = 60;
1607
1608         vm_srb->win8_extension.srb_flags |=
1609                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1610
1611         if (scmnd->device->tagged_supported) {
1612                 vm_srb->win8_extension.srb_flags |=
1613                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1614                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1615                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1616         }
1617
1618         /* Build the SRB */
1619         switch (scmnd->sc_data_direction) {
1620         case DMA_TO_DEVICE:
1621                 vm_srb->data_in = WRITE_TYPE;
1622                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1623                 break;
1624         case DMA_FROM_DEVICE:
1625                 vm_srb->data_in = READ_TYPE;
1626                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1627                 break;
1628         case DMA_NONE:
1629                 vm_srb->data_in = UNKNOWN_TYPE;
1630                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1631                 break;
1632         default:
1633                 /*
1634                  * This is DMA_BIDIRECTIONAL or something else we are never
1635                  * supposed to see here.
1636                  */
1637                 WARN(1, "Unexpected data direction: %d\n",
1638                      scmnd->sc_data_direction);
1639                 return -EINVAL;
1640         }
1641
1642
1643         vm_srb->port_number = host_dev->port;
1644         vm_srb->path_id = scmnd->device->channel;
1645         vm_srb->target_id = scmnd->device->id;
1646         vm_srb->lun = scmnd->device->lun;
1647
1648         vm_srb->cdb_length = scmnd->cmd_len;
1649
1650         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1651
1652         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1653         sg_count = scsi_sg_count(scmnd);
1654
1655         length = scsi_bufflen(scmnd);
1656         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1657         payload_sz = sizeof(cmd_request->mpb);
1658
1659         if (sg_count) {
1660                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1661
1662                         payload_sz = (sg_count * sizeof(u64) +
1663                                       sizeof(struct vmbus_packet_mpb_array));
1664                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1665                         if (!payload)
1666                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1667                 }
1668
1669                 payload->range.len = length;
1670                 payload->range.offset = sgl[0].offset;
1671
1672                 cur_sgl = sgl;
1673                 for (i = 0; i < sg_count; i++) {
1674                         payload->range.pfn_array[i] =
1675                                 page_to_pfn(sg_page((cur_sgl)));
1676                         cur_sgl = sg_next(cur_sgl);
1677                 }
1678         }
1679
1680         cmd_request->payload = payload;
1681         cmd_request->payload_sz = payload_sz;
1682
1683         /* Invokes the vsc to start an IO */
1684         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1685         put_cpu();
1686
1687         if (ret == -EAGAIN) {
1688                 if (payload_sz > sizeof(cmd_request->mpb))
1689                         kfree(payload);
1690                 /* no more space */
1691                 return SCSI_MLQUEUE_DEVICE_BUSY;
1692         }
1693
1694         return 0;
1695 }
1696
1697 static struct scsi_host_template scsi_driver = {
1698         .module =               THIS_MODULE,
1699         .name =                 "storvsc_host_t",
1700         .cmd_size =             sizeof(struct storvsc_cmd_request),
1701         .bios_param =           storvsc_get_chs,
1702         .queuecommand =         storvsc_queuecommand,
1703         .eh_host_reset_handler =        storvsc_host_reset_handler,
1704         .proc_name =            "storvsc_host",
1705         .eh_timed_out =         storvsc_eh_timed_out,
1706         .slave_alloc =          storvsc_device_alloc,
1707         .slave_configure =      storvsc_device_configure,
1708         .cmd_per_lun =          2048,
1709         .this_id =              -1,
1710         /* Make sure we dont get a sg segment crosses a page boundary */
1711         .dma_boundary =         PAGE_SIZE-1,
1712         .no_write_same =        1,
1713         .track_queue_depth =    1,
1714 };
1715
1716 enum {
1717         SCSI_GUID,
1718         IDE_GUID,
1719         SFC_GUID,
1720 };
1721
1722 static const struct hv_vmbus_device_id id_table[] = {
1723         /* SCSI guid */
1724         { HV_SCSI_GUID,
1725           .driver_data = SCSI_GUID
1726         },
1727         /* IDE guid */
1728         { HV_IDE_GUID,
1729           .driver_data = IDE_GUID
1730         },
1731         /* Fibre Channel GUID */
1732         {
1733           HV_SYNTHFC_GUID,
1734           .driver_data = SFC_GUID
1735         },
1736         { },
1737 };
1738
1739 MODULE_DEVICE_TABLE(vmbus, id_table);
1740
1741 static int storvsc_probe(struct hv_device *device,
1742                         const struct hv_vmbus_device_id *dev_id)
1743 {
1744         int ret;
1745         int num_cpus = num_online_cpus();
1746         struct Scsi_Host *host;
1747         struct hv_host_device *host_dev;
1748         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1749         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1750         int target = 0;
1751         struct storvsc_device *stor_device;
1752         int max_luns_per_target;
1753         int max_targets;
1754         int max_channels;
1755         int max_sub_channels = 0;
1756
1757         /*
1758          * Based on the windows host we are running on,
1759          * set state to properly communicate with the host.
1760          */
1761
1762         if (vmbus_proto_version < VERSION_WIN8) {
1763                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1764                 max_targets = STORVSC_IDE_MAX_TARGETS;
1765                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1766         } else {
1767                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1768                 max_targets = STORVSC_MAX_TARGETS;
1769                 max_channels = STORVSC_MAX_CHANNELS;
1770                 /*
1771                  * On Windows8 and above, we support sub-channels for storage
1772                  * on SCSI and FC controllers.
1773                  * The number of sub-channels offerred is based on the number of
1774                  * VCPUs in the guest.
1775                  */
1776                 if (!dev_is_ide)
1777                         max_sub_channels =
1778                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1779         }
1780
1781         scsi_driver.can_queue = max_outstanding_req_per_channel *
1782                                 (max_sub_channels + 1) *
1783                                 (100 - ring_avail_percent_lowater) / 100;
1784
1785         host = scsi_host_alloc(&scsi_driver,
1786                                sizeof(struct hv_host_device));
1787         if (!host)
1788                 return -ENOMEM;
1789
1790         host_dev = shost_priv(host);
1791         memset(host_dev, 0, sizeof(struct hv_host_device));
1792
1793         host_dev->port = host->host_no;
1794         host_dev->dev = device;
1795         host_dev->host = host;
1796
1797
1798         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1799         if (!stor_device) {
1800                 ret = -ENOMEM;
1801                 goto err_out0;
1802         }
1803
1804         stor_device->destroy = false;
1805         init_waitqueue_head(&stor_device->waiting_to_drain);
1806         stor_device->device = device;
1807         stor_device->host = host;
1808         hv_set_drvdata(device, stor_device);
1809
1810         stor_device->port_number = host->host_no;
1811         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1812         if (ret)
1813                 goto err_out1;
1814
1815         host_dev->path = stor_device->path_id;
1816         host_dev->target = stor_device->target_id;
1817
1818         switch (dev_id->driver_data) {
1819         case SFC_GUID:
1820                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1821                 host->max_id = STORVSC_FC_MAX_TARGETS;
1822                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1823 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1824                 host->transportt = fc_transport_template;
1825 #endif
1826                 break;
1827
1828         case SCSI_GUID:
1829                 host->max_lun = max_luns_per_target;
1830                 host->max_id = max_targets;
1831                 host->max_channel = max_channels - 1;
1832                 break;
1833
1834         default:
1835                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1836                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1837                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1838                 break;
1839         }
1840         /* max cmd length */
1841         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1842
1843         /*
1844          * set the table size based on the info we got
1845          * from the host.
1846          */
1847         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1848         /*
1849          * Set the number of HW queues we are supporting.
1850          */
1851         if (stor_device->num_sc != 0)
1852                 host->nr_hw_queues = stor_device->num_sc + 1;
1853
1854         /*
1855          * Set the error handler work queue.
1856          */
1857         host_dev->handle_error_wq =
1858                         alloc_ordered_workqueue("storvsc_error_wq_%d",
1859                                                 WQ_MEM_RECLAIM,
1860                                                 host->host_no);
1861         if (!host_dev->handle_error_wq)
1862                 goto err_out2;
1863         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
1864         /* Register the HBA and start the scsi bus scan */
1865         ret = scsi_add_host(host, &device->device);
1866         if (ret != 0)
1867                 goto err_out3;
1868
1869         if (!dev_is_ide) {
1870                 scsi_scan_host(host);
1871         } else {
1872                 target = (device->dev_instance.b[5] << 8 |
1873                          device->dev_instance.b[4]);
1874                 ret = scsi_add_device(host, 0, target, 0);
1875                 if (ret)
1876                         goto err_out4;
1877         }
1878 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1879         if (host->transportt == fc_transport_template) {
1880                 struct fc_rport_identifiers ids = {
1881                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
1882                 };
1883
1884                 fc_host_node_name(host) = stor_device->node_name;
1885                 fc_host_port_name(host) = stor_device->port_name;
1886                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
1887                 if (!stor_device->rport) {
1888                         ret = -ENOMEM;
1889                         goto err_out4;
1890                 }
1891         }
1892 #endif
1893         return 0;
1894
1895 err_out4:
1896         scsi_remove_host(host);
1897
1898 err_out3:
1899         destroy_workqueue(host_dev->handle_error_wq);
1900
1901 err_out2:
1902         /*
1903          * Once we have connected with the host, we would need to
1904          * to invoke storvsc_dev_remove() to rollback this state and
1905          * this call also frees up the stor_device; hence the jump around
1906          * err_out1 label.
1907          */
1908         storvsc_dev_remove(device);
1909         goto err_out0;
1910
1911 err_out1:
1912         kfree(stor_device->stor_chns);
1913         kfree(stor_device);
1914
1915 err_out0:
1916         scsi_host_put(host);
1917         return ret;
1918 }
1919
1920 static int storvsc_remove(struct hv_device *dev)
1921 {
1922         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1923         struct Scsi_Host *host = stor_device->host;
1924         struct hv_host_device *host_dev = shost_priv(host);
1925
1926 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1927         if (host->transportt == fc_transport_template) {
1928                 fc_remote_port_delete(stor_device->rport);
1929                 fc_remove_host(host);
1930         }
1931 #endif
1932         destroy_workqueue(host_dev->handle_error_wq);
1933         scsi_remove_host(host);
1934         storvsc_dev_remove(dev);
1935         scsi_host_put(host);
1936
1937         return 0;
1938 }
1939
1940 static struct hv_driver storvsc_drv = {
1941         .name = KBUILD_MODNAME,
1942         .id_table = id_table,
1943         .probe = storvsc_probe,
1944         .remove = storvsc_remove,
1945         .driver = {
1946                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
1947         },
1948 };
1949
1950 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1951 static struct fc_function_template fc_transport_functions = {
1952         .show_host_node_name = 1,
1953         .show_host_port_name = 1,
1954 };
1955 #endif
1956
1957 static int __init storvsc_drv_init(void)
1958 {
1959         int ret;
1960
1961         /*
1962          * Divide the ring buffer data size (which is 1 page less
1963          * than the ring buffer size since that page is reserved for
1964          * the ring buffer indices) by the max request size (which is
1965          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1966          */
1967         max_outstanding_req_per_channel =
1968                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1969                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1970                 sizeof(struct vstor_packet) + sizeof(u64) -
1971                 vmscsi_size_delta,
1972                 sizeof(u64)));
1973
1974 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1975         fc_transport_template = fc_attach_transport(&fc_transport_functions);
1976         if (!fc_transport_template)
1977                 return -ENODEV;
1978 #endif
1979
1980         ret = vmbus_driver_register(&storvsc_drv);
1981
1982 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1983         if (ret)
1984                 fc_release_transport(fc_transport_template);
1985 #endif
1986
1987         return ret;
1988 }
1989
1990 static void __exit storvsc_drv_exit(void)
1991 {
1992         vmbus_driver_unregister(&storvsc_drv);
1993 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1994         fc_release_transport(fc_transport_template);
1995 #endif
1996 }
1997
1998 MODULE_LICENSE("GPL");
1999 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2000 module_init(storvsc_drv_init);
2001 module_exit(storvsc_drv_exit);