drivers/scsi/storvsc_drv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * Authors:
   6  *   Haiyang Zhang <haiyangz@microsoft.com>
   7  *   Hank Janssen  <hjanssen@microsoft.com>
   8  *   K. Y. Srinivasan <kys@microsoft.com>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/wait.h>
  13 #include <linux/sched.h>
  14 #include <linux/completion.h>
  15 #include <linux/string.h>
  16 #include <linux/mm.h>
  17 #include <linux/delay.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21 #include <linux/device.h>
  22 #include <linux/hyperv.h>
  23 #include <linux/blkdev.h>
  24 #include <scsi/scsi.h>
  25 #include <scsi/scsi_cmnd.h>
  26 #include <scsi/scsi_host.h>
  27 #include <scsi/scsi_device.h>
  28 #include <scsi/scsi_tcq.h>
  29 #include <scsi/scsi_eh.h>
  30 #include <scsi/scsi_devinfo.h>
  31 #include <scsi/scsi_dbg.h>
  32 #include <scsi/scsi_transport_fc.h>
  33 #include <scsi/scsi_transport.h>
  34
  35 /*
  36  * All wire protocol details (storage protocol between the guest and the host)
  37  * are consolidated here.
  38  *
  39  * Begin protocol definitions.
  40  */
  41
  42 /*
  43  * Version history:
  44  * V1 Beta: 0.1
  45  * V1 RC < 2008/1/31: 1.0
  46  * V1 RC > 2008/1/31:  2.0
  47  * Win7: 4.2
  48  * Win8: 5.1
  49  * Win8.1: 6.0
  50  * Win10: 6.2
  51  */
  52
  53 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  54                                                 (((MINOR_) & 0xff)))
  55
  56 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  57 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  58 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  59 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  60 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  61
  62 /*  Packet structure describing virtual storage requests. */
  63 enum vstor_packet_operation {
  64         VSTOR_OPERATION_COMPLETE_IO             = 1,
  65         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  66         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  67         VSTOR_OPERATION_RESET_LUN               = 4,
  68         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  69         VSTOR_OPERATION_RESET_BUS               = 6,
  70         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  71         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  72         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  73         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  74         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  75         VSTOR_OPERATION_FCHBA_DATA              = 12,
  76         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  77         VSTOR_OPERATION_MAXIMUM                 = 13
  78 };
  79
  80 /*
  81  * WWN packet for Fibre Channel HBA
  82  */
  83
  84 struct hv_fc_wwn_packet {
  85         u8      primary_active;
  86         u8      reserved1[3];
  87         u8      primary_port_wwn[8];
  88         u8      primary_node_wwn[8];
  89         u8      secondary_port_wwn[8];
  90         u8      secondary_node_wwn[8];
  91 };
  92
  93
  94
  95 /*
  96  * SRB Flag Bits
  97  */
  98
  99 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 100 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 101 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 102 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 103 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 104 #define SRB_FLAGS_DATA_IN                       0x00000040
 105 #define SRB_FLAGS_DATA_OUT                      0x00000080
 106 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 107 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 108 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 109 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 110 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 111
 112 /*
 113  * This flag indicates the request is part of the workflow for processing a D3.
 114  */
 115 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 116 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 117 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 118 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 119 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 120 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 121 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 122 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 123 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 124 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 125 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 126
 127 #define SP_UNTAGGED                     ((unsigned char) ~0)
 128 #define SRB_SIMPLE_TAG_REQUEST          0x20
 129
 130 /*
 131  * Platform neutral description of a scsi request -
 132  * this remains the same across the write regardless of 32/64 bit
 133  * note: it's patterned off the SCSI_PASS_THROUGH structure
 134  */
 135 #define STORVSC_MAX_CMD_LEN                     0x10
 136
 137 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 138 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 139
 140 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 141 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 142
 143 /*
 144  * Sense buffer size changed in win8; have a run-time
 145  * variable to track the size we should use.  This value will
 146  * likely change during protocol negotiation but it is valid
 147  * to start by assuming pre-Win8.
 148  */
 149 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 150
 151 /*
 152  * The storage protocol version is determined during the
 153  * initial exchange with the host.  It will indicate which
 154  * storage functionality is available in the host.
 155 */
 156 static int vmstor_proto_version;
 157
 158 #define STORVSC_LOGGING_NONE    0
 159 #define STORVSC_LOGGING_ERROR   1
 160 #define STORVSC_LOGGING_WARN    2
 161
 162 static int logging_level = STORVSC_LOGGING_ERROR;
 163 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 164 MODULE_PARM_DESC(logging_level,
 165         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 166
 167 static inline bool do_logging(int level)
 168 {
 169         return logging_level >= level;
 170 }
 171
 172 #define storvsc_log(dev, level, fmt, ...)                       \
 173 do {                                                            \
 174         if (do_logging(level))                                  \
 175                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 176 } while (0)
 177
 178 struct vmscsi_win8_extension {
 179         /*
 180          * The following were added in Windows 8
 181          */
 182         u16 reserve;
 183         u8  queue_tag;
 184         u8  queue_action;
 185         u32 srb_flags;
 186         u32 time_out_value;
 187         u32 queue_sort_ey;
 188 } __packed;
 189
 190 struct vmscsi_request {
 191         u16 length;
 192         u8 srb_status;
 193         u8 scsi_status;
 194
 195         u8  port_number;
 196         u8  path_id;
 197         u8  target_id;
 198         u8  lun;
 199
 200         u8  cdb_length;
 201         u8  sense_info_length;
 202         u8  data_in;
 203         u8  reserved;
 204
 205         u32 data_transfer_length;
 206
 207         union {
 208                 u8 cdb[STORVSC_MAX_CMD_LEN];
 209                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 210                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 211         };
 212         /*
 213          * The following was added in win8.
 214          */
 215         struct vmscsi_win8_extension win8_extension;
 216
 217 } __attribute((packed));
 218
 219
 220 /*
 221  * The size of the vmscsi_request has changed in win8. The
 222  * additional size is because of new elements added to the
 223  * structure. These elements are valid only when we are talking
 224  * to a win8 host.
 225  * Track the correction to size we need to apply. This value
 226  * will likely change during protocol negotiation but it is
 227  * valid to start by assuming pre-Win8.
 228  */
 229 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 230
 231 /*
 232  * The list of storage protocols in order of preference.
 233  */
 234 struct vmstor_protocol {
 235         int protocol_version;
 236         int sense_buffer_size;
 237         int vmscsi_size_delta;
 238 };
 239
 240
 241 static const struct vmstor_protocol vmstor_protocols[] = {
 242         {
 243                 VMSTOR_PROTO_VERSION_WIN10,
 244                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 245                 0
 246         },
 247         {
 248                 VMSTOR_PROTO_VERSION_WIN8_1,
 249                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 250                 0
 251         },
 252         {
 253                 VMSTOR_PROTO_VERSION_WIN8,
 254                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 255                 0
 256         },
 257         {
 258                 VMSTOR_PROTO_VERSION_WIN7,
 259                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 260                 sizeof(struct vmscsi_win8_extension),
 261         },
 262         {
 263                 VMSTOR_PROTO_VERSION_WIN6,
 264                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 265                 sizeof(struct vmscsi_win8_extension),
 266         }
 267 };
 268
 269
 270 /*
 271  * This structure is sent during the initialization phase to get the different
 272  * properties of the channel.
 273  */
 274
 275 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 276
 277 struct vmstorage_channel_properties {
 278         u32 reserved;
 279         u16 max_channel_cnt;
 280         u16 reserved1;
 281
 282         u32 flags;
 283         u32   max_transfer_bytes;
 284
 285         u64  reserved2;
 286 } __packed;
 287
 288 /*  This structure is sent during the storage protocol negotiations. */
 289 struct vmstorage_protocol_version {
 290         /* Major (MSW) and minor (LSW) version numbers. */
 291         u16 major_minor;
 292
 293         /*
 294          * Revision number is auto-incremented whenever this file is changed
 295          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 296          * definitely indicate incompatibility--but it does indicate mismatched
 297          * builds.
 298          * This is only used on the windows side. Just set it to 0.
 299          */
 300         u16 revision;
 301 } __packed;
 302
 303 /* Channel Property Flags */
 304 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 305 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 306
 307 struct vstor_packet {
 308         /* Requested operation type */
 309         enum vstor_packet_operation operation;
 310
 311         /*  Flags - see below for values */
 312         u32 flags;
 313
 314         /* Status of the request returned from the server side. */
 315         u32 status;
 316
 317         /* Data payload area */
 318         union {
 319                 /*
 320                  * Structure used to forward SCSI commands from the
 321                  * client to the server.
 322                  */
 323                 struct vmscsi_request vm_srb;
 324
 325                 /* Structure used to query channel properties. */
 326                 struct vmstorage_channel_properties storage_channel_properties;
 327
 328                 /* Used during version negotiations. */
 329                 struct vmstorage_protocol_version version;
 330
 331                 /* Fibre channel address packet */
 332                 struct hv_fc_wwn_packet wwn_packet;
 333
 334                 /* Number of sub-channels to create */
 335                 u16 sub_channel_count;
 336
 337                 /* This will be the maximum of the union members */
 338                 u8  buffer[0x34];
 339         };
 340 } __packed;
 341
 342 /*
 343  * Packet Flags:
 344  *
 345  * This flag indicates that the server should send back a completion for this
 346  * packet.
 347  */
 348
 349 #define REQUEST_COMPLETION_FLAG 0x1
 350
 351 /* Matches Windows-end */
 352 enum storvsc_request_type {
 353         WRITE_TYPE = 0,
 354         READ_TYPE,
 355         UNKNOWN_TYPE,
 356 };
 357
 358 /*
 359  * SRB status codes and masks; a subset of the codes used here.
 360  */
 361
 362 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 363 #define SRB_STATUS_QUEUE_FROZEN         0x40
 364 #define SRB_STATUS_INVALID_LUN  0x20
 365 #define SRB_STATUS_SUCCESS      0x01
 366 #define SRB_STATUS_ABORTED      0x02
 367 #define SRB_STATUS_ERROR        0x04
 368 #define SRB_STATUS_DATA_OVERRUN 0x12
 369
 370 #define SRB_STATUS(status) \
 371         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 372 /*
 373  * This is the end of Protocol specific defines.
 374  */
 375
 376 static int storvsc_ringbuffer_size = (128 * 1024);
 377 static u32 max_outstanding_req_per_channel;
 378 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 379
 380 static int storvsc_vcpus_per_sub_channel = 4;
 381
 382 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 383 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 384
 385 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 386 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 387
 388 static int ring_avail_percent_lowater = 10;
 389 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 390 MODULE_PARM_DESC(ring_avail_percent_lowater,
 391                 "Select a channel if available ring size > this in percent");
 392
 393 /*
 394  * Timeout in seconds for all devices managed by this driver.
 395  */
 396 static int storvsc_timeout = 180;
 397
 398 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 399 static struct scsi_transport_template *fc_transport_template;
 400 #endif
 401
 402 static void storvsc_on_channel_callback(void *context);
 403
 404 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 405 #define STORVSC_MAX_TARGETS                             2
 406 #define STORVSC_MAX_CHANNELS                            8
 407
 408 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 409 #define STORVSC_FC_MAX_TARGETS                          128
 410 #define STORVSC_FC_MAX_CHANNELS                         8
 411
 412 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 413 #define STORVSC_IDE_MAX_TARGETS                         1
 414 #define STORVSC_IDE_MAX_CHANNELS                        1
 415
 416 struct storvsc_cmd_request {
 417         struct scsi_cmnd *cmd;
 418
 419         struct hv_device *device;
 420
 421         /* Synchronize the request/response if needed */
 422         struct completion wait_event;
 423
 424         struct vmbus_channel_packet_multipage_buffer mpb;
 425         struct vmbus_packet_mpb_array *payload;
 426         u32 payload_sz;
 427
 428         struct vstor_packet vstor_packet;
 429 };
 430
 431
 432 /* A storvsc device is a device object that contains a vmbus channel */
 433 struct storvsc_device {
 434         struct hv_device *device;
 435
 436         bool     destroy;
 437         bool     drain_notify;
 438         atomic_t num_outstanding_req;
 439         struct Scsi_Host *host;
 440
 441         wait_queue_head_t waiting_to_drain;
 442
 443         /*
 444          * Each unique Port/Path/Target represents 1 channel ie scsi
 445          * controller. In reality, the pathid, targetid is always 0
 446          * and the port is set by us
 447          */
 448         unsigned int port_number;
 449         unsigned char path_id;
 450         unsigned char target_id;
 451
 452         /*
 453          * Max I/O, the device can support.
 454          */
 455         u32   max_transfer_bytes;
 456         /*
 457          * Number of sub-channels we will open.
 458          */
 459         u16 num_sc;
 460         struct vmbus_channel **stor_chns;
 461         /*
 462          * Mask of CPUs bound to subchannels.
 463          */
 464         struct cpumask alloced_cpus;
 465         /* Used for vsc/vsp channel reset process */
 466         struct storvsc_cmd_request init_request;
 467         struct storvsc_cmd_request reset_request;
 468         /*
 469          * Currently active port and node names for FC devices.
 470          */
 471         u64 node_name;
 472         u64 port_name;
 473 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 474         struct fc_rport *rport;
 475 #endif
 476 };
 477
 478 struct hv_host_device {
 479         struct hv_device *dev;
 480         unsigned int port;
 481         unsigned char path;
 482         unsigned char target;
 483         struct workqueue_struct *handle_error_wq;
 484         struct work_struct host_scan_work;
 485         struct Scsi_Host *host;
 486 };
 487
 488 struct storvsc_scan_work {
 489         struct work_struct work;
 490         struct Scsi_Host *host;
 491         u8 lun;
 492         u8 tgt_id;
 493 };
 494
 495 static void storvsc_device_scan(struct work_struct *work)
 496 {
 497         struct storvsc_scan_work *wrk;
 498         struct scsi_device *sdev;
 499
 500         wrk = container_of(work, struct storvsc_scan_work, work);
 501
 502         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 503         if (!sdev)
 504                 goto done;
 505         scsi_rescan_device(&sdev->sdev_gendev);
 506         scsi_device_put(sdev);
 507
 508 done:
 509         kfree(wrk);
 510 }
 511
 512 static void storvsc_host_scan(struct work_struct *work)
 513 {
 514         struct Scsi_Host *host;
 515         struct scsi_device *sdev;
 516         struct hv_host_device *host_device =
 517                 container_of(work, struct hv_host_device, host_scan_work);
 518
 519         host = host_device->host;
 520         /*
 521          * Before scanning the host, first check to see if any of the
 522          * currrently known devices have been hot removed. We issue a
 523          * "unit ready" command against all currently known devices.
 524          * This I/O will result in an error for devices that have been
 525          * removed. As part of handling the I/O error, we remove the device.
 526          *
 527          * When a LUN is added or removed, the host sends us a signal to
 528          * scan the host. Thus we are forced to discover the LUNs that
 529          * may have been removed this way.
 530          */
 531         mutex_lock(&host->scan_mutex);
 532         shost_for_each_device(sdev, host)
 533                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 534         mutex_unlock(&host->scan_mutex);
 535         /*
 536          * Now scan the host to discover LUNs that may have been added.
 537          */
 538         scsi_scan_host(host);
 539 }
 540
 541 static void storvsc_remove_lun(struct work_struct *work)
 542 {
 543         struct storvsc_scan_work *wrk;
 544         struct scsi_device *sdev;
 545
 546         wrk = container_of(work, struct storvsc_scan_work, work);
 547         if (!scsi_host_get(wrk->host))
 548                 goto done;
 549
 550         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 551
 552         if (sdev) {
 553                 scsi_remove_device(sdev);
 554                 scsi_device_put(sdev);
 555         }
 556         scsi_host_put(wrk->host);
 557
 558 done:
 559         kfree(wrk);
 560 }
 561
 562
 563 /*
 564  * We can get incoming messages from the host that are not in response to
 565  * messages that we have sent out. An example of this would be messages
 566  * received by the guest to notify dynamic addition/removal of LUNs. To
 567  * deal with potential race conditions where the driver may be in the
 568  * midst of being unloaded when we might receive an unsolicited message
 569  * from the host, we have implemented a mechanism to gurantee sequential
 570  * consistency:
 571  *
 572  * 1) Once the device is marked as being destroyed, we will fail all
 573  *    outgoing messages.
 574  * 2) We permit incoming messages when the device is being destroyed,
 575  *    only to properly account for messages already sent out.
 576  */
 577
 578 static inline struct storvsc_device *get_out_stor_device(
 579                                         struct hv_device *device)
 580 {
 581         struct storvsc_device *stor_device;
 582
 583         stor_device = hv_get_drvdata(device);
 584
 585         if (stor_device && stor_device->destroy)
 586                 stor_device = NULL;
 587
 588         return stor_device;
 589 }
 590
 591
 592 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 593 {
 594         dev->drain_notify = true;
 595         wait_event(dev->waiting_to_drain,
 596                    atomic_read(&dev->num_outstanding_req) == 0);
 597         dev->drain_notify = false;
 598 }
 599
 600 static inline struct storvsc_device *get_in_stor_device(
 601                                         struct hv_device *device)
 602 {
 603         struct storvsc_device *stor_device;
 604
 605         stor_device = hv_get_drvdata(device);
 606
 607         if (!stor_device)
 608                 goto get_in_err;
 609
 610         /*
 611          * If the device is being destroyed; allow incoming
 612          * traffic only to cleanup outstanding requests.
 613          */
 614
 615         if (stor_device->destroy  &&
 616                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 617                 stor_device = NULL;
 618
 619 get_in_err:
 620         return stor_device;
 621
 622 }
 623
 624 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 625                                       u32 new)
 626 {
 627         struct storvsc_device *stor_device;
 628         struct vmbus_channel *cur_chn;
 629         bool old_is_alloced = false;
 630         struct hv_device *device;
 631         unsigned long flags;
 632         int cpu;
 633
 634         device = channel->primary_channel ?
 635                         channel->primary_channel->device_obj
 636                                 : channel->device_obj;
 637         stor_device = get_out_stor_device(device);
 638         if (!stor_device)
 639                 return;
 640
 641         /* See storvsc_do_io() -> get_og_chn(). */
 642         spin_lock_irqsave(&device->channel->lock, flags);
 643
 644         /*
 645          * Determines if the storvsc device has other channels assigned to
 646          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 647          * array.
 648          */
 649         if (device->channel != channel && device->channel->target_cpu == old) {
 650                 cur_chn = device->channel;
 651                 old_is_alloced = true;
 652                 goto old_is_alloced;
 653         }
 654         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 655                 if (cur_chn == channel)
 656                         continue;
 657                 if (cur_chn->target_cpu == old) {
 658                         old_is_alloced = true;
 659                         goto old_is_alloced;
 660                 }
 661         }
 662
 663 old_is_alloced:
 664         if (old_is_alloced)
 665                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 666         else
 667                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 668
 669         /* "Flush" the stor_chns array. */
 670         for_each_possible_cpu(cpu) {
 671                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 672                                         cpu, &stor_device->alloced_cpus))
 673                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 674         }
 675
 676         WRITE_ONCE(stor_device->stor_chns[new], channel);
 677         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 678
 679         spin_unlock_irqrestore(&device->channel->lock, flags);
 680 }
 681
 682 static void handle_sc_creation(struct vmbus_channel *new_sc)
 683 {
 684         struct hv_device *device = new_sc->primary_channel->device_obj;
 685         struct device *dev = &device->device;
 686         struct storvsc_device *stor_device;
 687         struct vmstorage_channel_properties props;
 688         int ret;
 689
 690         stor_device = get_out_stor_device(device);
 691         if (!stor_device)
 692                 return;
 693
 694         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 695
 696         ret = vmbus_open(new_sc,
 697                          storvsc_ringbuffer_size,
 698                          storvsc_ringbuffer_size,
 699                          (void *)&props,
 700                          sizeof(struct vmstorage_channel_properties),
 701                          storvsc_on_channel_callback, new_sc);
 702
 703         /* In case vmbus_open() fails, we don't use the sub-channel. */
 704         if (ret != 0) {
 705                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 706                 return;
 707         }
 708
 709         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 710
 711         /* Add the sub-channel to the array of available channels. */
 712         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 713         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 714 }
 715
 716 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 717 {
 718         struct device *dev = &device->device;
 719         struct storvsc_device *stor_device;
 720         int num_sc;
 721         struct storvsc_cmd_request *request;
 722         struct vstor_packet *vstor_packet;
 723         int ret, t;
 724
 725         /*
 726          * If the number of CPUs is artificially restricted, such as
 727          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 728          * sub-channels >= the number of CPUs. These sub-channels
 729          * should not be created. The primary channel is already created
 730          * and assigned to one CPU, so check against # CPUs - 1.
 731          */
 732         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 733         if (!num_sc)
 734                 return;
 735
 736         stor_device = get_out_stor_device(device);
 737         if (!stor_device)
 738                 return;
 739
 740         stor_device->num_sc = num_sc;
 741         request = &stor_device->init_request;
 742         vstor_packet = &request->vstor_packet;
 743
 744         /*
 745          * Establish a handler for dealing with subchannels.
 746          */
 747         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 748
 749         /*
 750          * Request the host to create sub-channels.
 751          */
 752         memset(request, 0, sizeof(struct storvsc_cmd_request));
 753         init_completion(&request->wait_event);
 754         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 755         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 756         vstor_packet->sub_channel_count = num_sc;
 757
 758         ret = vmbus_sendpacket(device->channel, vstor_packet,
 759                                (sizeof(struct vstor_packet) -
 760                                vmscsi_size_delta),
 761                                (unsigned long)request,
 762                                VM_PKT_DATA_INBAND,
 763                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 764
 765         if (ret != 0) {
 766                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 767                 return;
 768         }
 769
 770         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 771         if (t == 0) {
 772                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 773                 return;
 774         }
 775
 776         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 777             vstor_packet->status != 0) {
 778                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 779                         vstor_packet->operation, vstor_packet->status);
 780                 return;
 781         }
 782
 783         /*
 784          * We need to do nothing here, because vmbus_process_offer()
 785          * invokes channel->sc_creation_callback, which will open and use
 786          * the sub-channel(s).
 787          */
 788 }
 789
 790 static void cache_wwn(struct storvsc_device *stor_device,
 791                       struct vstor_packet *vstor_packet)
 792 {
 793         /*
 794          * Cache the currently active port and node ww names.
 795          */
 796         if (vstor_packet->wwn_packet.primary_active) {
 797                 stor_device->node_name =
 798                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 799                 stor_device->port_name =
 800                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 801         } else {
 802                 stor_device->node_name =
 803                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 804                 stor_device->port_name =
 805                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 806         }
 807 }
 808
 809
 810 static int storvsc_execute_vstor_op(struct hv_device *device,
 811                                     struct storvsc_cmd_request *request,
 812                                     bool status_check)
 813 {
 814         struct vstor_packet *vstor_packet;
 815         int ret, t;
 816
 817         vstor_packet = &request->vstor_packet;
 818
 819         init_completion(&request->wait_event);
 820         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 821
 822         ret = vmbus_sendpacket(device->channel, vstor_packet,
 823                                (sizeof(struct vstor_packet) -
 824                                vmscsi_size_delta),
 825                                (unsigned long)request,
 826                                VM_PKT_DATA_INBAND,
 827                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 828         if (ret != 0)
 829                 return ret;
 830
 831         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 832         if (t == 0)
 833                 return -ETIMEDOUT;
 834
 835         if (!status_check)
 836                 return ret;
 837
 838         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 839             vstor_packet->status != 0)
 840                 return -EINVAL;
 841
 842         return ret;
 843 }
 844
 845 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 846 {
 847         struct storvsc_device *stor_device;
 848         struct storvsc_cmd_request *request;
 849         struct vstor_packet *vstor_packet;
 850         int ret, i;
 851         int max_chns;
 852         bool process_sub_channels = false;
 853
 854         stor_device = get_out_stor_device(device);
 855         if (!stor_device)
 856                 return -ENODEV;
 857
 858         request = &stor_device->init_request;
 859         vstor_packet = &request->vstor_packet;
 860
 861         /*
 862          * Now, initiate the vsc/vsp initialization protocol on the open
 863          * channel
 864          */
 865         memset(request, 0, sizeof(struct storvsc_cmd_request));
 866         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 867         ret = storvsc_execute_vstor_op(device, request, true);
 868         if (ret)
 869                 return ret;
 870         /*
 871          * Query host supported protocol version.
 872          */
 873
 874         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 875                 /* reuse the packet for version range supported */
 876                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 877                 vstor_packet->operation =
 878                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 879
 880                 vstor_packet->version.major_minor =
 881                         vmstor_protocols[i].protocol_version;
 882
 883                 /*
 884                  * The revision number is only used in Windows; set it to 0.
 885                  */
 886                 vstor_packet->version.revision = 0;
 887                 ret = storvsc_execute_vstor_op(device, request, false);
 888                 if (ret != 0)
 889                         return ret;
 890
 891                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 892                         return -EINVAL;
 893
 894                 if (vstor_packet->status == 0) {
 895                         vmstor_proto_version =
 896                                 vmstor_protocols[i].protocol_version;
 897
 898                         sense_buffer_size =
 899                                 vmstor_protocols[i].sense_buffer_size;
 900
 901                         vmscsi_size_delta =
 902                                 vmstor_protocols[i].vmscsi_size_delta;
 903
 904                         break;
 905                 }
 906         }
 907
 908         if (vstor_packet->status != 0)
 909                 return -EINVAL;
 910
 911
 912         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 913         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 914         ret = storvsc_execute_vstor_op(device, request, true);
 915         if (ret != 0)
 916                 return ret;
 917
 918         /*
 919          * Check to see if multi-channel support is there.
 920          * Hosts that implement protocol version of 5.1 and above
 921          * support multi-channel.
 922          */
 923         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 924
 925         /*
 926          * Allocate state to manage the sub-channels.
 927          * We allocate an array based on the numbers of possible CPUs
 928          * (Hyper-V does not support cpu online/offline).
 929          * This Array will be sparseley populated with unique
 930          * channels - primary + sub-channels.
 931          * We will however populate all the slots to evenly distribute
 932          * the load.
 933          */
 934         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 935                                          GFP_KERNEL);
 936         if (stor_device->stor_chns == NULL)
 937                 return -ENOMEM;
 938
 939         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 940
 941         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 942         cpumask_set_cpu(device->channel->target_cpu,
 943                         &stor_device->alloced_cpus);
 944
 945         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 946                 if (vstor_packet->storage_channel_properties.flags &
 947                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 948                         process_sub_channels = true;
 949         }
 950         stor_device->max_transfer_bytes =
 951                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 952
 953         if (!is_fc)
 954                 goto done;
 955
 956         /*
 957          * For FC devices retrieve FC HBA data.
 958          */
 959         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 960         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 961         ret = storvsc_execute_vstor_op(device, request, true);
 962         if (ret != 0)
 963                 return ret;
 964
 965         /*
 966          * Cache the currently active port and node ww names.
 967          */
 968         cache_wwn(stor_device, vstor_packet);
 969
 970 done:
 971
 972         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 973         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 974         ret = storvsc_execute_vstor_op(device, request, true);
 975         if (ret != 0)
 976                 return ret;
 977
 978         if (process_sub_channels)
 979                 handle_multichannel_storage(device, max_chns);
 980
 981         return ret;
 982 }
 983
 984 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 985                                 struct scsi_cmnd *scmnd,
 986                                 struct Scsi_Host *host,
 987                                 u8 asc, u8 ascq)
 988 {
 989         struct storvsc_scan_work *wrk;
 990         void (*process_err_fn)(struct work_struct *work);
 991         struct hv_host_device *host_dev = shost_priv(host);
 992         bool do_work = false;
 993
 994         switch (SRB_STATUS(vm_srb->srb_status)) {
 995         case SRB_STATUS_ERROR:
 996                 /*
 997                  * Let upper layer deal with error when
 998                  * sense message is present.
 999                  */
1000
1001                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1002                         break;
1003                 /*
1004                  * If there is an error; offline the device since all
1005                  * error recovery strategies would have already been
1006                  * deployed on the host side. However, if the command
1007                  * were a pass-through command deal with it appropriately.
1008                  */
1009                 switch (scmnd->cmnd[0]) {
1010                 case ATA_16:
1011                 case ATA_12:
1012                         set_host_byte(scmnd, DID_PASSTHROUGH);
1013                         break;
1014                 /*
1015                  * On Some Windows hosts TEST_UNIT_READY command can return
1016                  * SRB_STATUS_ERROR, let the upper level code deal with it
1017                  * based on the sense information.
1018                  */
1019                 case TEST_UNIT_READY:
1020                         break;
1021                 default:
1022                         set_host_byte(scmnd, DID_ERROR);
1023                 }
1024                 break;
1025         case SRB_STATUS_INVALID_LUN:
1026                 set_host_byte(scmnd, DID_NO_CONNECT);
1027                 do_work = true;
1028                 process_err_fn = storvsc_remove_lun;
1029                 break;
1030         case SRB_STATUS_ABORTED:
1031                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
1032                     (asc == 0x2a) && (ascq == 0x9)) {
1033                         do_work = true;
1034                         process_err_fn = storvsc_device_scan;
1035                         /*
1036                          * Retry the I/O that trigerred this.
1037                          */
1038                         set_host_byte(scmnd, DID_REQUEUE);
1039                 }
1040                 break;
1041         }
1042
1043         if (!do_work)
1044                 return;
1045
1046         /*
1047          * We need to schedule work to process this error; schedule it.
1048          */
1049         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1050         if (!wrk) {
1051                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1052                 return;
1053         }
1054
1055         wrk->host = host;
1056         wrk->lun = vm_srb->lun;
1057         wrk->tgt_id = vm_srb->target_id;
1058         INIT_WORK(&wrk->work, process_err_fn);
1059         queue_work(host_dev->handle_error_wq, &wrk->work);
1060 }
1061
1062
1063 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1064                                        struct storvsc_device *stor_dev)
1065 {
1066         struct scsi_cmnd *scmnd = cmd_request->cmd;
1067         struct scsi_sense_hdr sense_hdr;
1068         struct vmscsi_request *vm_srb;
1069         u32 data_transfer_length;
1070         struct Scsi_Host *host;
1071         u32 payload_sz = cmd_request->payload_sz;
1072         void *payload = cmd_request->payload;
1073
1074         host = stor_dev->host;
1075
1076         vm_srb = &cmd_request->vstor_packet.vm_srb;
1077         data_transfer_length = vm_srb->data_transfer_length;
1078
1079         scmnd->result = vm_srb->scsi_status;
1080
1081         if (scmnd->result) {
1082                 if (scsi_normalize_sense(scmnd->sense_buffer,
1083                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1084                     !(sense_hdr.sense_key == NOT_READY &&
1085                                  sense_hdr.asc == 0x03A) &&
1086                     do_logging(STORVSC_LOGGING_ERROR))
1087                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1088                                              &sense_hdr);
1089         }
1090
1091         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1092                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1093                                          sense_hdr.ascq);
1094                 /*
1095                  * The Windows driver set data_transfer_length on
1096                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1097                  * is untouched.  In these cases we set it to 0.
1098                  */
1099                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1100                         data_transfer_length = 0;
1101         }
1102
1103         scsi_set_resid(scmnd,
1104                 cmd_request->payload->range.len - data_transfer_length);
1105
1106         scmnd->scsi_done(scmnd);
1107
1108         if (payload_sz >
1109                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1110                 kfree(payload);
1111 }
1112
1113 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1114                                   struct vstor_packet *vstor_packet,
1115                                   struct storvsc_cmd_request *request)
1116 {
1117         struct vstor_packet *stor_pkt;
1118         struct hv_device *device = stor_device->device;
1119
1120         stor_pkt = &request->vstor_packet;
1121
1122         /*
1123          * The current SCSI handling on the host side does
1124          * not correctly handle:
1125          * INQUIRY command with page code parameter set to 0x80
1126          * MODE_SENSE command with cmd[2] == 0x1c
1127          *
1128          * Setup srb and scsi status so this won't be fatal.
1129          * We do this so we can distinguish truly fatal failues
1130          * (srb status == 0x4) and off-line the device in that case.
1131          */
1132
1133         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1134            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1135                 vstor_packet->vm_srb.scsi_status = 0;
1136                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1137         }
1138
1139
1140         /* Copy over the status...etc */
1141         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1142         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1143         stor_pkt->vm_srb.sense_info_length =
1144         vstor_packet->vm_srb.sense_info_length;
1145
1146         if (vstor_packet->vm_srb.scsi_status != 0 ||
1147             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1148                 storvsc_log(device, STORVSC_LOGGING_WARN,
1149                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1150                         stor_pkt->vm_srb.cdb[0],
1151                         vstor_packet->vm_srb.scsi_status,
1152                         vstor_packet->vm_srb.srb_status);
1153
1154         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1155                 /* CHECK_CONDITION */
1156                 if (vstor_packet->vm_srb.srb_status &
1157                         SRB_STATUS_AUTOSENSE_VALID) {
1158                         /* autosense data available */
1159
1160                         storvsc_log(device, STORVSC_LOGGING_WARN,
1161                                 "stor pkt %p autosense data valid - len %d\n",
1162                                 request, vstor_packet->vm_srb.sense_info_length);
1163
1164                         memcpy(request->cmd->sense_buffer,
1165                                vstor_packet->vm_srb.sense_data,
1166                                vstor_packet->vm_srb.sense_info_length);
1167
1168                 }
1169         }
1170
1171         stor_pkt->vm_srb.data_transfer_length =
1172         vstor_packet->vm_srb.data_transfer_length;
1173
1174         storvsc_command_completion(request, stor_device);
1175
1176         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1177                 stor_device->drain_notify)
1178                 wake_up(&stor_device->waiting_to_drain);
1179
1180
1181 }
1182
1183 static void storvsc_on_receive(struct storvsc_device *stor_device,
1184                              struct vstor_packet *vstor_packet,
1185                              struct storvsc_cmd_request *request)
1186 {
1187         struct hv_host_device *host_dev;
1188         switch (vstor_packet->operation) {
1189         case VSTOR_OPERATION_COMPLETE_IO:
1190                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1191                 break;
1192
1193         case VSTOR_OPERATION_REMOVE_DEVICE:
1194         case VSTOR_OPERATION_ENUMERATE_BUS:
1195                 host_dev = shost_priv(stor_device->host);
1196                 queue_work(
1197                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1198                 break;
1199
1200         case VSTOR_OPERATION_FCHBA_DATA:
1201                 cache_wwn(stor_device, vstor_packet);
1202 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1203                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1204                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1205 #endif
1206                 break;
1207         default:
1208                 break;
1209         }
1210 }
1211
1212 static void storvsc_on_channel_callback(void *context)
1213 {
1214         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1215         const struct vmpacket_descriptor *desc;
1216         struct hv_device *device;
1217         struct storvsc_device *stor_device;
1218
1219         if (channel->primary_channel != NULL)
1220                 device = channel->primary_channel->device_obj;
1221         else
1222                 device = channel->device_obj;
1223
1224         stor_device = get_in_stor_device(device);
1225         if (!stor_device)
1226                 return;
1227
1228         foreach_vmbus_pkt(desc, channel) {
1229                 void *packet = hv_pkt_data(desc);
1230                 struct storvsc_cmd_request *request;
1231
1232                 request = (struct storvsc_cmd_request *)
1233                         ((unsigned long)desc->trans_id);
1234
1235                 if (request == &stor_device->init_request ||
1236                     request == &stor_device->reset_request) {
1237                         memcpy(&request->vstor_packet, packet,
1238                                (sizeof(struct vstor_packet) - vmscsi_size_delta));
1239                         complete(&request->wait_event);
1240                 } else {
1241                         storvsc_on_receive(stor_device, packet, request);
1242                 }
1243         }
1244 }
1245
1246 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1247                                   bool is_fc)
1248 {
1249         struct vmstorage_channel_properties props;
1250         int ret;
1251
1252         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1253
1254         ret = vmbus_open(device->channel,
1255                          ring_size,
1256                          ring_size,
1257                          (void *)&props,
1258                          sizeof(struct vmstorage_channel_properties),
1259                          storvsc_on_channel_callback, device->channel);
1260
1261         if (ret != 0)
1262                 return ret;
1263
1264         ret = storvsc_channel_init(device, is_fc);
1265
1266         return ret;
1267 }
1268
1269 static int storvsc_dev_remove(struct hv_device *device)
1270 {
1271         struct storvsc_device *stor_device;
1272
1273         stor_device = hv_get_drvdata(device);
1274
1275         stor_device->destroy = true;
1276
1277         /* Make sure flag is set before waiting */
1278         wmb();
1279
1280         /*
1281          * At this point, all outbound traffic should be disable. We
1282          * only allow inbound traffic (responses) to proceed so that
1283          * outstanding requests can be completed.
1284          */
1285
1286         storvsc_wait_to_drain(stor_device);
1287
1288         /*
1289          * Since we have already drained, we don't need to busy wait
1290          * as was done in final_release_stor_device()
1291          * Note that we cannot set the ext pointer to NULL until
1292          * we have drained - to drain the outgoing packets, we need to
1293          * allow incoming packets.
1294          */
1295         hv_set_drvdata(device, NULL);
1296
1297         /* Close the channel */
1298         vmbus_close(device->channel);
1299
1300         kfree(stor_device->stor_chns);
1301         kfree(stor_device);
1302         return 0;
1303 }
1304
1305 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1306                                         u16 q_num)
1307 {
1308         u16 slot = 0;
1309         u16 hash_qnum;
1310         const struct cpumask *node_mask;
1311         int num_channels, tgt_cpu;
1312
1313         if (stor_device->num_sc == 0) {
1314                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1315                 return stor_device->device->channel;
1316         }
1317
1318         /*
1319          * Our channel array is sparsley populated and we
1320          * initiated I/O on a processor/hw-q that does not
1321          * currently have a designated channel. Fix this.
1322          * The strategy is simple:
1323          * I. Ensure NUMA locality
1324          * II. Distribute evenly (best effort)
1325          */
1326
1327         node_mask = cpumask_of_node(cpu_to_node(q_num));
1328
1329         num_channels = 0;
1330         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1331                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1332                         num_channels++;
1333         }
1334         if (num_channels == 0) {
1335                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1336                 return stor_device->device->channel;
1337         }
1338
1339         hash_qnum = q_num;
1340         while (hash_qnum >= num_channels)
1341                 hash_qnum -= num_channels;
1342
1343         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1344                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1345                         continue;
1346                 if (slot == hash_qnum)
1347                         break;
1348                 slot++;
1349         }
1350
1351         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1352
1353         return stor_device->stor_chns[q_num];
1354 }
1355
1356
1357 static int storvsc_do_io(struct hv_device *device,
1358                          struct storvsc_cmd_request *request, u16 q_num)
1359 {
1360         struct storvsc_device *stor_device;
1361         struct vstor_packet *vstor_packet;
1362         struct vmbus_channel *outgoing_channel, *channel;
1363         unsigned long flags;
1364         int ret = 0;
1365         const struct cpumask *node_mask;
1366         int tgt_cpu;
1367
1368         vstor_packet = &request->vstor_packet;
1369         stor_device = get_out_stor_device(device);
1370
1371         if (!stor_device)
1372                 return -ENODEV;
1373
1374
1375         request->device  = device;
1376         /*
1377          * Select an appropriate channel to send the request out.
1378          */
1379         /* See storvsc_change_target_cpu(). */
1380         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1381         if (outgoing_channel != NULL) {
1382                 if (outgoing_channel->target_cpu == q_num) {
1383                         /*
1384                          * Ideally, we want to pick a different channel if
1385                          * available on the same NUMA node.
1386                          */
1387                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1388                         for_each_cpu_wrap(tgt_cpu,
1389                                  &stor_device->alloced_cpus, q_num + 1) {
1390                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1391                                         continue;
1392                                 if (tgt_cpu == q_num)
1393                                         continue;
1394                                 channel = READ_ONCE(
1395                                         stor_device->stor_chns[tgt_cpu]);
1396                                 if (channel == NULL)
1397                                         continue;
1398                                 if (hv_get_avail_to_write_percent(
1399                                                         &channel->outbound)
1400                                                 > ring_avail_percent_lowater) {
1401                                         outgoing_channel = channel;
1402                                         goto found_channel;
1403                                 }
1404                         }
1405
1406                         /*
1407                          * All the other channels on the same NUMA node are
1408                          * busy. Try to use the channel on the current CPU
1409                          */
1410                         if (hv_get_avail_to_write_percent(
1411                                                 &outgoing_channel->outbound)
1412                                         > ring_avail_percent_lowater)
1413                                 goto found_channel;
1414
1415                         /*
1416                          * If we reach here, all the channels on the current
1417                          * NUMA node are busy. Try to find a channel in
1418                          * other NUMA nodes
1419                          */
1420                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1421                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1422                                         continue;
1423                                 channel = READ_ONCE(
1424                                         stor_device->stor_chns[tgt_cpu]);
1425                                 if (channel == NULL)
1426                                         continue;
1427                                 if (hv_get_avail_to_write_percent(
1428                                                         &channel->outbound)
1429                                                 > ring_avail_percent_lowater) {
1430                                         outgoing_channel = channel;
1431                                         goto found_channel;
1432                                 }
1433                         }
1434                 }
1435         } else {
1436                 spin_lock_irqsave(&device->channel->lock, flags);
1437                 outgoing_channel = stor_device->stor_chns[q_num];
1438                 if (outgoing_channel != NULL) {
1439                         spin_unlock_irqrestore(&device->channel->lock, flags);
1440                         goto found_channel;
1441                 }
1442                 outgoing_channel = get_og_chn(stor_device, q_num);
1443                 spin_unlock_irqrestore(&device->channel->lock, flags);
1444         }
1445
1446 found_channel:
1447         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1448
1449         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1450                                         vmscsi_size_delta);
1451
1452
1453         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1454
1455
1456         vstor_packet->vm_srb.data_transfer_length =
1457         request->payload->range.len;
1458
1459         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1460
1461         if (request->payload->range.len) {
1462
1463                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1464                                 request->payload, request->payload_sz,
1465                                 vstor_packet,
1466                                 (sizeof(struct vstor_packet) -
1467                                 vmscsi_size_delta),
1468                                 (unsigned long)request);
1469         } else {
1470                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1471                                (sizeof(struct vstor_packet) -
1472                                 vmscsi_size_delta),
1473                                (unsigned long)request,
1474                                VM_PKT_DATA_INBAND,
1475                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1476         }
1477
1478         if (ret != 0)
1479                 return ret;
1480
1481         atomic_inc(&stor_device->num_outstanding_req);
1482
1483         return ret;
1484 }
1485
1486 static int storvsc_device_alloc(struct scsi_device *sdevice)
1487 {
1488         /*
1489          * Set blist flag to permit the reading of the VPD pages even when
1490          * the target may claim SPC-2 compliance. MSFT targets currently
1491          * claim SPC-2 compliance while they implement post SPC-2 features.
1492          * With this flag we can correctly handle WRITE_SAME_16 issues.
1493          *
1494          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1495          * still supports REPORT LUN.
1496          */
1497         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1498
1499         return 0;
1500 }
1501
1502 static int storvsc_device_configure(struct scsi_device *sdevice)
1503 {
1504         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1505
1506         sdevice->no_write_same = 1;
1507
1508         /*
1509          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1510          * if the device is a MSFT virtual device.  If the host is
1511          * WIN10 or newer, allow write_same.
1512          */
1513         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1514                 switch (vmstor_proto_version) {
1515                 case VMSTOR_PROTO_VERSION_WIN8:
1516                 case VMSTOR_PROTO_VERSION_WIN8_1:
1517                         sdevice->scsi_level = SCSI_SPC_3;
1518                         break;
1519                 }
1520
1521                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1522                         sdevice->no_write_same = 0;
1523         }
1524
1525         return 0;
1526 }
1527
1528 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1529                            sector_t capacity, int *info)
1530 {
1531         sector_t nsect = capacity;
1532         sector_t cylinders = nsect;
1533         int heads, sectors_pt;
1534
1535         /*
1536          * We are making up these values; let us keep it simple.
1537          */
1538         heads = 0xff;
1539         sectors_pt = 0x3f;      /* Sectors per track */
1540         sector_div(cylinders, heads * sectors_pt);
1541         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1542                 cylinders = 0xffff;
1543
1544         info[0] = heads;
1545         info[1] = sectors_pt;
1546         info[2] = (int)cylinders;
1547
1548         return 0;
1549 }
1550
1551 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1552 {
1553         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1554         struct hv_device *device = host_dev->dev;
1555
1556         struct storvsc_device *stor_device;
1557         struct storvsc_cmd_request *request;
1558         struct vstor_packet *vstor_packet;
1559         int ret, t;
1560
1561
1562         stor_device = get_out_stor_device(device);
1563         if (!stor_device)
1564                 return FAILED;
1565
1566         request = &stor_device->reset_request;
1567         vstor_packet = &request->vstor_packet;
1568
1569         init_completion(&request->wait_event);
1570
1571         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1572         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1573         vstor_packet->vm_srb.path_id = stor_device->path_id;
1574
1575         ret = vmbus_sendpacket(device->channel, vstor_packet,
1576                                (sizeof(struct vstor_packet) -
1577                                 vmscsi_size_delta),
1578                                (unsigned long)&stor_device->reset_request,
1579                                VM_PKT_DATA_INBAND,
1580                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1581         if (ret != 0)
1582                 return FAILED;
1583
1584         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1585         if (t == 0)
1586                 return TIMEOUT_ERROR;
1587
1588
1589         /*
1590          * At this point, all outstanding requests in the adapter
1591          * should have been flushed out and return to us
1592          * There is a potential race here where the host may be in
1593          * the process of responding when we return from here.
1594          * Just wait for all in-transit packets to be accounted for
1595          * before we return from here.
1596          */
1597         storvsc_wait_to_drain(stor_device);
1598
1599         return SUCCESS;
1600 }
1601
1602 /*
1603  * The host guarantees to respond to each command, although I/O latencies might
1604  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1605  * chance to perform EH.
1606  */
1607 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1608 {
1609 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1610         if (scmnd->device->host->transportt == fc_transport_template)
1611                 return fc_eh_timed_out(scmnd);
1612 #endif
1613         return BLK_EH_RESET_TIMER;
1614 }
1615
1616 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1617 {
1618         bool allowed = true;
1619         u8 scsi_op = scmnd->cmnd[0];
1620
1621         switch (scsi_op) {
1622         /* the host does not handle WRITE_SAME, log accident usage */
1623         case WRITE_SAME:
1624         /*
1625          * smartd sends this command and the host does not handle
1626          * this. So, don't send it.
1627          */
1628         case SET_WINDOW:
1629                 scmnd->result = ILLEGAL_REQUEST << 16;
1630                 allowed = false;
1631                 break;
1632         default:
1633                 break;
1634         }
1635         return allowed;
1636 }
1637
1638 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1639 {
1640         int ret;
1641         struct hv_host_device *host_dev = shost_priv(host);
1642         struct hv_device *dev = host_dev->dev;
1643         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1644         int i;
1645         struct scatterlist *sgl;
1646         unsigned int sg_count = 0;
1647         struct vmscsi_request *vm_srb;
1648         struct scatterlist *cur_sgl;
1649         struct vmbus_packet_mpb_array  *payload;
1650         u32 payload_sz;
1651         u32 length;
1652
1653         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1654                 /*
1655                  * On legacy hosts filter unimplemented commands.
1656                  * Future hosts are expected to correctly handle
1657                  * unsupported commands. Furthermore, it is
1658                  * possible that some of the currently
1659                  * unsupported commands maybe supported in
1660                  * future versions of the host.
1661                  */
1662                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1663                         scmnd->scsi_done(scmnd);
1664                         return 0;
1665                 }
1666         }
1667
1668         /* Setup the cmd request */
1669         cmd_request->cmd = scmnd;
1670
1671         vm_srb = &cmd_request->vstor_packet.vm_srb;
1672         vm_srb->win8_extension.time_out_value = 60;
1673
1674         vm_srb->win8_extension.srb_flags |=
1675                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1676
1677         if (scmnd->device->tagged_supported) {
1678                 vm_srb->win8_extension.srb_flags |=
1679                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1680                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1681                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1682         }
1683
1684         /* Build the SRB */
1685         switch (scmnd->sc_data_direction) {
1686         case DMA_TO_DEVICE:
1687                 vm_srb->data_in = WRITE_TYPE;
1688                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1689                 break;
1690         case DMA_FROM_DEVICE:
1691                 vm_srb->data_in = READ_TYPE;
1692                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1693                 break;
1694         case DMA_NONE:
1695                 vm_srb->data_in = UNKNOWN_TYPE;
1696                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1697                 break;
1698         default:
1699                 /*
1700                  * This is DMA_BIDIRECTIONAL or something else we are never
1701                  * supposed to see here.
1702                  */
1703                 WARN(1, "Unexpected data direction: %d\n",
1704                      scmnd->sc_data_direction);
1705                 return -EINVAL;
1706         }
1707
1708
1709         vm_srb->port_number = host_dev->port;
1710         vm_srb->path_id = scmnd->device->channel;
1711         vm_srb->target_id = scmnd->device->id;
1712         vm_srb->lun = scmnd->device->lun;
1713
1714         vm_srb->cdb_length = scmnd->cmd_len;
1715
1716         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1717
1718         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1719         sg_count = scsi_sg_count(scmnd);
1720
1721         length = scsi_bufflen(scmnd);
1722         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1723         payload_sz = sizeof(cmd_request->mpb);
1724
1725         if (sg_count) {
1726                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1727
1728                         payload_sz = (sg_count * sizeof(u64) +
1729                                       sizeof(struct vmbus_packet_mpb_array));
1730                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1731                         if (!payload)
1732                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1733                 }
1734
1735                 payload->range.len = length;
1736                 payload->range.offset = sgl[0].offset;
1737
1738                 cur_sgl = sgl;
1739                 for (i = 0; i < sg_count; i++) {
1740                         payload->range.pfn_array[i] =
1741                                 page_to_pfn(sg_page((cur_sgl)));
1742                         cur_sgl = sg_next(cur_sgl);
1743                 }
1744         }
1745
1746         cmd_request->payload = payload;
1747         cmd_request->payload_sz = payload_sz;
1748
1749         /* Invokes the vsc to start an IO */
1750         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1751         put_cpu();
1752
1753         if (ret == -EAGAIN) {
1754                 if (payload_sz > sizeof(cmd_request->mpb))
1755                         kfree(payload);
1756                 /* no more space */
1757                 return SCSI_MLQUEUE_DEVICE_BUSY;
1758         }
1759
1760         return 0;
1761 }
1762
1763 static struct scsi_host_template scsi_driver = {
1764         .module =               THIS_MODULE,
1765         .name =                 "storvsc_host_t",
1766         .cmd_size =             sizeof(struct storvsc_cmd_request),
1767         .bios_param =           storvsc_get_chs,
1768         .queuecommand =         storvsc_queuecommand,
1769         .eh_host_reset_handler =        storvsc_host_reset_handler,
1770         .proc_name =            "storvsc_host",
1771         .eh_timed_out =         storvsc_eh_timed_out,
1772         .slave_alloc =          storvsc_device_alloc,
1773         .slave_configure =      storvsc_device_configure,
1774         .cmd_per_lun =          2048,
1775         .this_id =              -1,
1776         /* Make sure we dont get a sg segment crosses a page boundary */
1777         .dma_boundary =         PAGE_SIZE-1,
1778         /* Ensure there are no gaps in presented sgls */
1779         .virt_boundary_mask =   PAGE_SIZE-1,
1780         .no_write_same =        1,
1781         .track_queue_depth =    1,
1782         .change_queue_depth =   storvsc_change_queue_depth,
1783 };
1784
1785 enum {
1786         SCSI_GUID,
1787         IDE_GUID,
1788         SFC_GUID,
1789 };
1790
1791 static const struct hv_vmbus_device_id id_table[] = {
1792         /* SCSI guid */
1793         { HV_SCSI_GUID,
1794           .driver_data = SCSI_GUID
1795         },
1796         /* IDE guid */
1797         { HV_IDE_GUID,
1798           .driver_data = IDE_GUID
1799         },
1800         /* Fibre Channel GUID */
1801         {
1802           HV_SYNTHFC_GUID,
1803           .driver_data = SFC_GUID
1804         },
1805         { },
1806 };
1807
1808 MODULE_DEVICE_TABLE(vmbus, id_table);
1809
1810 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1811
1812 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1813 {
1814         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1815 }
1816
1817 static int storvsc_probe(struct hv_device *device,
1818                         const struct hv_vmbus_device_id *dev_id)
1819 {
1820         int ret;
1821         int num_cpus = num_online_cpus();
1822         struct Scsi_Host *host;
1823         struct hv_host_device *host_dev;
1824         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1825         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1826         int target = 0;
1827         struct storvsc_device *stor_device;
1828         int max_luns_per_target;
1829         int max_targets;
1830         int max_channels;
1831         int max_sub_channels = 0;
1832
1833         /*
1834          * Based on the windows host we are running on,
1835          * set state to properly communicate with the host.
1836          */
1837
1838         if (vmbus_proto_version < VERSION_WIN8) {
1839                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1840                 max_targets = STORVSC_IDE_MAX_TARGETS;
1841                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1842         } else {
1843                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1844                 max_targets = STORVSC_MAX_TARGETS;
1845                 max_channels = STORVSC_MAX_CHANNELS;
1846                 /*
1847                  * On Windows8 and above, we support sub-channels for storage
1848                  * on SCSI and FC controllers.
1849                  * The number of sub-channels offerred is based on the number of
1850                  * VCPUs in the guest.
1851                  */
1852                 if (!dev_is_ide)
1853                         max_sub_channels =
1854                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1855         }
1856
1857         scsi_driver.can_queue = max_outstanding_req_per_channel *
1858                                 (max_sub_channels + 1) *
1859                                 (100 - ring_avail_percent_lowater) / 100;
1860
1861         host = scsi_host_alloc(&scsi_driver,
1862                                sizeof(struct hv_host_device));
1863         if (!host)
1864                 return -ENOMEM;
1865
1866         host_dev = shost_priv(host);
1867         memset(host_dev, 0, sizeof(struct hv_host_device));
1868
1869         host_dev->port = host->host_no;
1870         host_dev->dev = device;
1871         host_dev->host = host;
1872
1873
1874         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1875         if (!stor_device) {
1876                 ret = -ENOMEM;
1877                 goto err_out0;
1878         }
1879
1880         stor_device->destroy = false;
1881         init_waitqueue_head(&stor_device->waiting_to_drain);
1882         stor_device->device = device;
1883         stor_device->host = host;
1884         hv_set_drvdata(device, stor_device);
1885
1886         stor_device->port_number = host->host_no;
1887         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1888         if (ret)
1889                 goto err_out1;
1890
1891         host_dev->path = stor_device->path_id;
1892         host_dev->target = stor_device->target_id;
1893
1894         switch (dev_id->driver_data) {
1895         case SFC_GUID:
1896                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1897                 host->max_id = STORVSC_FC_MAX_TARGETS;
1898                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1899 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1900                 host->transportt = fc_transport_template;
1901 #endif
1902                 break;
1903
1904         case SCSI_GUID:
1905                 host->max_lun = max_luns_per_target;
1906                 host->max_id = max_targets;
1907                 host->max_channel = max_channels - 1;
1908                 break;
1909
1910         default:
1911                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1912                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1913                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1914                 break;
1915         }
1916         /* max cmd length */
1917         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1918
1919         /*
1920          * set the table size based on the info we got
1921          * from the host.
1922          */
1923         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1924         /*
1925          * For non-IDE disks, the host supports multiple channels.
1926          * Set the number of HW queues we are supporting.
1927          */
1928         if (!dev_is_ide)
1929                 host->nr_hw_queues = num_present_cpus();
1930
1931         /*
1932          * Set the error handler work queue.
1933          */
1934         host_dev->handle_error_wq =
1935                         alloc_ordered_workqueue("storvsc_error_wq_%d",
1936                                                 WQ_MEM_RECLAIM,
1937                                                 host->host_no);
1938         if (!host_dev->handle_error_wq)
1939                 goto err_out2;
1940         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
1941         /* Register the HBA and start the scsi bus scan */
1942         ret = scsi_add_host(host, &device->device);
1943         if (ret != 0)
1944                 goto err_out3;
1945
1946         if (!dev_is_ide) {
1947                 scsi_scan_host(host);
1948         } else {
1949                 target = (device->dev_instance.b[5] << 8 |
1950                          device->dev_instance.b[4]);
1951                 ret = scsi_add_device(host, 0, target, 0);
1952                 if (ret)
1953                         goto err_out4;
1954         }
1955 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1956         if (host->transportt == fc_transport_template) {
1957                 struct fc_rport_identifiers ids = {
1958                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
1959                 };
1960
1961                 fc_host_node_name(host) = stor_device->node_name;
1962                 fc_host_port_name(host) = stor_device->port_name;
1963                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
1964                 if (!stor_device->rport) {
1965                         ret = -ENOMEM;
1966                         goto err_out4;
1967                 }
1968         }
1969 #endif
1970         return 0;
1971
1972 err_out4:
1973         scsi_remove_host(host);
1974
1975 err_out3:
1976         destroy_workqueue(host_dev->handle_error_wq);
1977
1978 err_out2:
1979         /*
1980          * Once we have connected with the host, we would need to
1981          * to invoke storvsc_dev_remove() to rollback this state and
1982          * this call also frees up the stor_device; hence the jump around
1983          * err_out1 label.
1984          */
1985         storvsc_dev_remove(device);
1986         goto err_out0;
1987
1988 err_out1:
1989         kfree(stor_device->stor_chns);
1990         kfree(stor_device);
1991
1992 err_out0:
1993         scsi_host_put(host);
1994         return ret;
1995 }
1996
1997 /* Change a scsi target's queue depth */
1998 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
1999 {
2000         if (queue_depth > scsi_driver.can_queue)
2001                 queue_depth = scsi_driver.can_queue;
2002
2003         return scsi_change_queue_depth(sdev, queue_depth);
2004 }
2005
2006 static int storvsc_remove(struct hv_device *dev)
2007 {
2008         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2009         struct Scsi_Host *host = stor_device->host;
2010         struct hv_host_device *host_dev = shost_priv(host);
2011
2012 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2013         if (host->transportt == fc_transport_template) {
2014                 fc_remote_port_delete(stor_device->rport);
2015                 fc_remove_host(host);
2016         }
2017 #endif
2018         destroy_workqueue(host_dev->handle_error_wq);
2019         scsi_remove_host(host);
2020         storvsc_dev_remove(dev);
2021         scsi_host_put(host);
2022
2023         return 0;
2024 }
2025
2026 static int storvsc_suspend(struct hv_device *hv_dev)
2027 {
2028         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2029         struct Scsi_Host *host = stor_device->host;
2030         struct hv_host_device *host_dev = shost_priv(host);
2031
2032         storvsc_wait_to_drain(stor_device);
2033
2034         drain_workqueue(host_dev->handle_error_wq);
2035
2036         vmbus_close(hv_dev->channel);
2037
2038         kfree(stor_device->stor_chns);
2039         stor_device->stor_chns = NULL;
2040
2041         cpumask_clear(&stor_device->alloced_cpus);
2042
2043         return 0;
2044 }
2045
2046 static int storvsc_resume(struct hv_device *hv_dev)
2047 {
2048         int ret;
2049
2050         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2051                                      hv_dev_is_fc(hv_dev));
2052         return ret;
2053 }
2054
2055 static struct hv_driver storvsc_drv = {
2056         .name = KBUILD_MODNAME,
2057         .id_table = id_table,
2058         .probe = storvsc_probe,
2059         .remove = storvsc_remove,
2060         .suspend = storvsc_suspend,
2061         .resume = storvsc_resume,
2062         .driver = {
2063                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2064         },
2065 };
2066
2067 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2068 static struct fc_function_template fc_transport_functions = {
2069         .show_host_node_name = 1,
2070         .show_host_port_name = 1,
2071 };
2072 #endif
2073
2074 static int __init storvsc_drv_init(void)
2075 {
2076         int ret;
2077
2078         /*
2079          * Divide the ring buffer data size (which is 1 page less
2080          * than the ring buffer size since that page is reserved for
2081          * the ring buffer indices) by the max request size (which is
2082          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2083          */
2084         max_outstanding_req_per_channel =
2085                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2086                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2087                 sizeof(struct vstor_packet) + sizeof(u64) -
2088                 vmscsi_size_delta,
2089                 sizeof(u64)));
2090
2091 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2092         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2093         if (!fc_transport_template)
2094                 return -ENODEV;
2095 #endif
2096
2097         ret = vmbus_driver_register(&storvsc_drv);
2098
2099 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2100         if (ret)
2101                 fc_release_transport(fc_transport_template);
2102 #endif
2103
2104         return ret;
2105 }
2106
2107 static void __exit storvsc_drv_exit(void)
2108 {
2109         vmbus_driver_unregister(&storvsc_drv);
2110 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2111         fc_release_transport(fc_transport_template);
2112 #endif
2113 }
2114
2115 MODULE_LICENSE("GPL");
2116 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2117 module_init(storvsc_drv_init);
2118 module_exit(storvsc_drv_exit);