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. In the 8-bit field, the two high order bits
 360  * are flags, while the remaining 6 bits are an integer status code.  The
 361  * definitions here include only the subset of the integer status codes that
 362  * are tested for in this driver.
 363  */
 364 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 365 #define SRB_STATUS_QUEUE_FROZEN         0x40
 366
 367 /* SRB status integer codes */
 368 #define SRB_STATUS_SUCCESS              0x01
 369 #define SRB_STATUS_ABORTED              0x02
 370 #define SRB_STATUS_ERROR                0x04
 371 #define SRB_STATUS_INVALID_REQUEST      0x06
 372 #define SRB_STATUS_DATA_OVERRUN         0x12
 373 #define SRB_STATUS_INVALID_LUN          0x20
 374
 375 #define SRB_STATUS(status) \
 376         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 377 /*
 378  * This is the end of Protocol specific defines.
 379  */
 380
 381 static int storvsc_ringbuffer_size = (128 * 1024);
 382 static u32 max_outstanding_req_per_channel;
 383 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 384
 385 static int storvsc_vcpus_per_sub_channel = 4;
 386
 387 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 388 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 389
 390 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 391 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 392
 393 static int ring_avail_percent_lowater = 10;
 394 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 395 MODULE_PARM_DESC(ring_avail_percent_lowater,
 396                 "Select a channel if available ring size > this in percent");
 397
 398 /*
 399  * Timeout in seconds for all devices managed by this driver.
 400  */
 401 static int storvsc_timeout = 180;
 402
 403 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 404 static struct scsi_transport_template *fc_transport_template;
 405 #endif
 406
 407 static void storvsc_on_channel_callback(void *context);
 408
 409 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 410 #define STORVSC_MAX_TARGETS                             2
 411 #define STORVSC_MAX_CHANNELS                            8
 412
 413 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 414 #define STORVSC_FC_MAX_TARGETS                          128
 415 #define STORVSC_FC_MAX_CHANNELS                         8
 416
 417 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 418 #define STORVSC_IDE_MAX_TARGETS                         1
 419 #define STORVSC_IDE_MAX_CHANNELS                        1
 420
 421 struct storvsc_cmd_request {
 422         struct scsi_cmnd *cmd;
 423
 424         struct hv_device *device;
 425
 426         /* Synchronize the request/response if needed */
 427         struct completion wait_event;
 428
 429         struct vmbus_channel_packet_multipage_buffer mpb;
 430         struct vmbus_packet_mpb_array *payload;
 431         u32 payload_sz;
 432
 433         struct vstor_packet vstor_packet;
 434 };
 435
 436
 437 /* A storvsc device is a device object that contains a vmbus channel */
 438 struct storvsc_device {
 439         struct hv_device *device;
 440
 441         bool     destroy;
 442         bool     drain_notify;
 443         atomic_t num_outstanding_req;
 444         struct Scsi_Host *host;
 445
 446         wait_queue_head_t waiting_to_drain;
 447
 448         /*
 449          * Each unique Port/Path/Target represents 1 channel ie scsi
 450          * controller. In reality, the pathid, targetid is always 0
 451          * and the port is set by us
 452          */
 453         unsigned int port_number;
 454         unsigned char path_id;
 455         unsigned char target_id;
 456
 457         /*
 458          * Max I/O, the device can support.
 459          */
 460         u32   max_transfer_bytes;
 461         /*
 462          * Number of sub-channels we will open.
 463          */
 464         u16 num_sc;
 465         struct vmbus_channel **stor_chns;
 466         /*
 467          * Mask of CPUs bound to subchannels.
 468          */
 469         struct cpumask alloced_cpus;
 470         /*
 471          * Serializes modifications of stor_chns[] from storvsc_do_io()
 472          * and storvsc_change_target_cpu().
 473          */
 474         spinlock_t lock;
 475         /* Used for vsc/vsp channel reset process */
 476         struct storvsc_cmd_request init_request;
 477         struct storvsc_cmd_request reset_request;
 478         /*
 479          * Currently active port and node names for FC devices.
 480          */
 481         u64 node_name;
 482         u64 port_name;
 483 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 484         struct fc_rport *rport;
 485 #endif
 486 };
 487
 488 struct hv_host_device {
 489         struct hv_device *dev;
 490         unsigned int port;
 491         unsigned char path;
 492         unsigned char target;
 493         struct workqueue_struct *handle_error_wq;
 494         struct work_struct host_scan_work;
 495         struct Scsi_Host *host;
 496 };
 497
 498 struct storvsc_scan_work {
 499         struct work_struct work;
 500         struct Scsi_Host *host;
 501         u8 lun;
 502         u8 tgt_id;
 503 };
 504
 505 static void storvsc_device_scan(struct work_struct *work)
 506 {
 507         struct storvsc_scan_work *wrk;
 508         struct scsi_device *sdev;
 509
 510         wrk = container_of(work, struct storvsc_scan_work, work);
 511
 512         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 513         if (!sdev)
 514                 goto done;
 515         scsi_rescan_device(&sdev->sdev_gendev);
 516         scsi_device_put(sdev);
 517
 518 done:
 519         kfree(wrk);
 520 }
 521
 522 static void storvsc_host_scan(struct work_struct *work)
 523 {
 524         struct Scsi_Host *host;
 525         struct scsi_device *sdev;
 526         struct hv_host_device *host_device =
 527                 container_of(work, struct hv_host_device, host_scan_work);
 528
 529         host = host_device->host;
 530         /*
 531          * Before scanning the host, first check to see if any of the
 532          * currrently known devices have been hot removed. We issue a
 533          * "unit ready" command against all currently known devices.
 534          * This I/O will result in an error for devices that have been
 535          * removed. As part of handling the I/O error, we remove the device.
 536          *
 537          * When a LUN is added or removed, the host sends us a signal to
 538          * scan the host. Thus we are forced to discover the LUNs that
 539          * may have been removed this way.
 540          */
 541         mutex_lock(&host->scan_mutex);
 542         shost_for_each_device(sdev, host)
 543                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 544         mutex_unlock(&host->scan_mutex);
 545         /*
 546          * Now scan the host to discover LUNs that may have been added.
 547          */
 548         scsi_scan_host(host);
 549 }
 550
 551 static void storvsc_remove_lun(struct work_struct *work)
 552 {
 553         struct storvsc_scan_work *wrk;
 554         struct scsi_device *sdev;
 555
 556         wrk = container_of(work, struct storvsc_scan_work, work);
 557         if (!scsi_host_get(wrk->host))
 558                 goto done;
 559
 560         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 561
 562         if (sdev) {
 563                 scsi_remove_device(sdev);
 564                 scsi_device_put(sdev);
 565         }
 566         scsi_host_put(wrk->host);
 567
 568 done:
 569         kfree(wrk);
 570 }
 571
 572
 573 /*
 574  * We can get incoming messages from the host that are not in response to
 575  * messages that we have sent out. An example of this would be messages
 576  * received by the guest to notify dynamic addition/removal of LUNs. To
 577  * deal with potential race conditions where the driver may be in the
 578  * midst of being unloaded when we might receive an unsolicited message
 579  * from the host, we have implemented a mechanism to gurantee sequential
 580  * consistency:
 581  *
 582  * 1) Once the device is marked as being destroyed, we will fail all
 583  *    outgoing messages.
 584  * 2) We permit incoming messages when the device is being destroyed,
 585  *    only to properly account for messages already sent out.
 586  */
 587
 588 static inline struct storvsc_device *get_out_stor_device(
 589                                         struct hv_device *device)
 590 {
 591         struct storvsc_device *stor_device;
 592
 593         stor_device = hv_get_drvdata(device);
 594
 595         if (stor_device && stor_device->destroy)
 596                 stor_device = NULL;
 597
 598         return stor_device;
 599 }
 600
 601
 602 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 603 {
 604         dev->drain_notify = true;
 605         wait_event(dev->waiting_to_drain,
 606                    atomic_read(&dev->num_outstanding_req) == 0);
 607         dev->drain_notify = false;
 608 }
 609
 610 static inline struct storvsc_device *get_in_stor_device(
 611                                         struct hv_device *device)
 612 {
 613         struct storvsc_device *stor_device;
 614
 615         stor_device = hv_get_drvdata(device);
 616
 617         if (!stor_device)
 618                 goto get_in_err;
 619
 620         /*
 621          * If the device is being destroyed; allow incoming
 622          * traffic only to cleanup outstanding requests.
 623          */
 624
 625         if (stor_device->destroy  &&
 626                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 627                 stor_device = NULL;
 628
 629 get_in_err:
 630         return stor_device;
 631
 632 }
 633
 634 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 635                                       u32 new)
 636 {
 637         struct storvsc_device *stor_device;
 638         struct vmbus_channel *cur_chn;
 639         bool old_is_alloced = false;
 640         struct hv_device *device;
 641         unsigned long flags;
 642         int cpu;
 643
 644         device = channel->primary_channel ?
 645                         channel->primary_channel->device_obj
 646                                 : channel->device_obj;
 647         stor_device = get_out_stor_device(device);
 648         if (!stor_device)
 649                 return;
 650
 651         /* See storvsc_do_io() -> get_og_chn(). */
 652         spin_lock_irqsave(&stor_device->lock, flags);
 653
 654         /*
 655          * Determines if the storvsc device has other channels assigned to
 656          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 657          * array.
 658          */
 659         if (device->channel != channel && device->channel->target_cpu == old) {
 660                 cur_chn = device->channel;
 661                 old_is_alloced = true;
 662                 goto old_is_alloced;
 663         }
 664         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 665                 if (cur_chn == channel)
 666                         continue;
 667                 if (cur_chn->target_cpu == old) {
 668                         old_is_alloced = true;
 669                         goto old_is_alloced;
 670                 }
 671         }
 672
 673 old_is_alloced:
 674         if (old_is_alloced)
 675                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 676         else
 677                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 678
 679         /* "Flush" the stor_chns array. */
 680         for_each_possible_cpu(cpu) {
 681                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 682                                         cpu, &stor_device->alloced_cpus))
 683                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 684         }
 685
 686         WRITE_ONCE(stor_device->stor_chns[new], channel);
 687         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 688
 689         spin_unlock_irqrestore(&stor_device->lock, flags);
 690 }
 691
 692 static void handle_sc_creation(struct vmbus_channel *new_sc)
 693 {
 694         struct hv_device *device = new_sc->primary_channel->device_obj;
 695         struct device *dev = &device->device;
 696         struct storvsc_device *stor_device;
 697         struct vmstorage_channel_properties props;
 698         int ret;
 699
 700         stor_device = get_out_stor_device(device);
 701         if (!stor_device)
 702                 return;
 703
 704         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 705
 706         ret = vmbus_open(new_sc,
 707                          storvsc_ringbuffer_size,
 708                          storvsc_ringbuffer_size,
 709                          (void *)&props,
 710                          sizeof(struct vmstorage_channel_properties),
 711                          storvsc_on_channel_callback, new_sc);
 712
 713         /* In case vmbus_open() fails, we don't use the sub-channel. */
 714         if (ret != 0) {
 715                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 716                 return;
 717         }
 718
 719         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 720
 721         /* Add the sub-channel to the array of available channels. */
 722         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 723         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 724 }
 725
 726 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 727 {
 728         struct device *dev = &device->device;
 729         struct storvsc_device *stor_device;
 730         int num_sc;
 731         struct storvsc_cmd_request *request;
 732         struct vstor_packet *vstor_packet;
 733         int ret, t;
 734
 735         /*
 736          * If the number of CPUs is artificially restricted, such as
 737          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 738          * sub-channels >= the number of CPUs. These sub-channels
 739          * should not be created. The primary channel is already created
 740          * and assigned to one CPU, so check against # CPUs - 1.
 741          */
 742         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 743         if (!num_sc)
 744                 return;
 745
 746         stor_device = get_out_stor_device(device);
 747         if (!stor_device)
 748                 return;
 749
 750         stor_device->num_sc = num_sc;
 751         request = &stor_device->init_request;
 752         vstor_packet = &request->vstor_packet;
 753
 754         /*
 755          * Establish a handler for dealing with subchannels.
 756          */
 757         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 758
 759         /*
 760          * Request the host to create sub-channels.
 761          */
 762         memset(request, 0, sizeof(struct storvsc_cmd_request));
 763         init_completion(&request->wait_event);
 764         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 765         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 766         vstor_packet->sub_channel_count = num_sc;
 767
 768         ret = vmbus_sendpacket(device->channel, vstor_packet,
 769                                (sizeof(struct vstor_packet) -
 770                                vmscsi_size_delta),
 771                                (unsigned long)request,
 772                                VM_PKT_DATA_INBAND,
 773                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 774
 775         if (ret != 0) {
 776                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 777                 return;
 778         }
 779
 780         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 781         if (t == 0) {
 782                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 783                 return;
 784         }
 785
 786         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 787             vstor_packet->status != 0) {
 788                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 789                         vstor_packet->operation, vstor_packet->status);
 790                 return;
 791         }
 792
 793         /*
 794          * We need to do nothing here, because vmbus_process_offer()
 795          * invokes channel->sc_creation_callback, which will open and use
 796          * the sub-channel(s).
 797          */
 798 }
 799
 800 static void cache_wwn(struct storvsc_device *stor_device,
 801                       struct vstor_packet *vstor_packet)
 802 {
 803         /*
 804          * Cache the currently active port and node ww names.
 805          */
 806         if (vstor_packet->wwn_packet.primary_active) {
 807                 stor_device->node_name =
 808                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 809                 stor_device->port_name =
 810                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 811         } else {
 812                 stor_device->node_name =
 813                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 814                 stor_device->port_name =
 815                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 816         }
 817 }
 818
 819
 820 static int storvsc_execute_vstor_op(struct hv_device *device,
 821                                     struct storvsc_cmd_request *request,
 822                                     bool status_check)
 823 {
 824         struct vstor_packet *vstor_packet;
 825         int ret, t;
 826
 827         vstor_packet = &request->vstor_packet;
 828
 829         init_completion(&request->wait_event);
 830         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 831
 832         ret = vmbus_sendpacket(device->channel, vstor_packet,
 833                                (sizeof(struct vstor_packet) -
 834                                vmscsi_size_delta),
 835                                (unsigned long)request,
 836                                VM_PKT_DATA_INBAND,
 837                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 838         if (ret != 0)
 839                 return ret;
 840
 841         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 842         if (t == 0)
 843                 return -ETIMEDOUT;
 844
 845         if (!status_check)
 846                 return ret;
 847
 848         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 849             vstor_packet->status != 0)
 850                 return -EINVAL;
 851
 852         return ret;
 853 }
 854
 855 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 856 {
 857         struct storvsc_device *stor_device;
 858         struct storvsc_cmd_request *request;
 859         struct vstor_packet *vstor_packet;
 860         int ret, i;
 861         int max_chns;
 862         bool process_sub_channels = false;
 863
 864         stor_device = get_out_stor_device(device);
 865         if (!stor_device)
 866                 return -ENODEV;
 867
 868         request = &stor_device->init_request;
 869         vstor_packet = &request->vstor_packet;
 870
 871         /*
 872          * Now, initiate the vsc/vsp initialization protocol on the open
 873          * channel
 874          */
 875         memset(request, 0, sizeof(struct storvsc_cmd_request));
 876         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 877         ret = storvsc_execute_vstor_op(device, request, true);
 878         if (ret)
 879                 return ret;
 880         /*
 881          * Query host supported protocol version.
 882          */
 883
 884         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 885                 /* reuse the packet for version range supported */
 886                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 887                 vstor_packet->operation =
 888                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 889
 890                 vstor_packet->version.major_minor =
 891                         vmstor_protocols[i].protocol_version;
 892
 893                 /*
 894                  * The revision number is only used in Windows; set it to 0.
 895                  */
 896                 vstor_packet->version.revision = 0;
 897                 ret = storvsc_execute_vstor_op(device, request, false);
 898                 if (ret != 0)
 899                         return ret;
 900
 901                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 902                         return -EINVAL;
 903
 904                 if (vstor_packet->status == 0) {
 905                         vmstor_proto_version =
 906                                 vmstor_protocols[i].protocol_version;
 907
 908                         sense_buffer_size =
 909                                 vmstor_protocols[i].sense_buffer_size;
 910
 911                         vmscsi_size_delta =
 912                                 vmstor_protocols[i].vmscsi_size_delta;
 913
 914                         break;
 915                 }
 916         }
 917
 918         if (vstor_packet->status != 0)
 919                 return -EINVAL;
 920
 921
 922         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 923         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 924         ret = storvsc_execute_vstor_op(device, request, true);
 925         if (ret != 0)
 926                 return ret;
 927
 928         /*
 929          * Check to see if multi-channel support is there.
 930          * Hosts that implement protocol version of 5.1 and above
 931          * support multi-channel.
 932          */
 933         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 934
 935         /*
 936          * Allocate state to manage the sub-channels.
 937          * We allocate an array based on the numbers of possible CPUs
 938          * (Hyper-V does not support cpu online/offline).
 939          * This Array will be sparseley populated with unique
 940          * channels - primary + sub-channels.
 941          * We will however populate all the slots to evenly distribute
 942          * the load.
 943          */
 944         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 945                                          GFP_KERNEL);
 946         if (stor_device->stor_chns == NULL)
 947                 return -ENOMEM;
 948
 949         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 950
 951         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 952         cpumask_set_cpu(device->channel->target_cpu,
 953                         &stor_device->alloced_cpus);
 954
 955         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 956                 if (vstor_packet->storage_channel_properties.flags &
 957                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 958                         process_sub_channels = true;
 959         }
 960         stor_device->max_transfer_bytes =
 961                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 962
 963         if (!is_fc)
 964                 goto done;
 965
 966         /*
 967          * For FC devices retrieve FC HBA data.
 968          */
 969         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 970         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 971         ret = storvsc_execute_vstor_op(device, request, true);
 972         if (ret != 0)
 973                 return ret;
 974
 975         /*
 976          * Cache the currently active port and node ww names.
 977          */
 978         cache_wwn(stor_device, vstor_packet);
 979
 980 done:
 981
 982         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 983         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 984         ret = storvsc_execute_vstor_op(device, request, true);
 985         if (ret != 0)
 986                 return ret;
 987
 988         if (process_sub_channels)
 989                 handle_multichannel_storage(device, max_chns);
 990
 991         return ret;
 992 }
 993
 994 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 995                                 struct scsi_cmnd *scmnd,
 996                                 struct Scsi_Host *host,
 997                                 u8 asc, u8 ascq)
 998 {
 999         struct storvsc_scan_work *wrk;
1000         void (*process_err_fn)(struct work_struct *work);
1001         struct hv_host_device *host_dev = shost_priv(host);
1002
1003         switch (SRB_STATUS(vm_srb->srb_status)) {
1004         case SRB_STATUS_ERROR:
1005         case SRB_STATUS_ABORTED:
1006         case SRB_STATUS_INVALID_REQUEST:
1007                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
1008                         /* Check for capacity change */
1009                         if ((asc == 0x2a) && (ascq == 0x9)) {
1010                                 process_err_fn = storvsc_device_scan;
1011                                 /* Retry the I/O that triggered this. */
1012                                 set_host_byte(scmnd, DID_REQUEUE);
1013                                 goto do_work;
1014                         }
1015
1016                         /*
1017                          * Check for "Operating parameters have changed"
1018                          * due to Hyper-V changing the VHD/VHDX BlockSize
1019                          * when adding/removing a differencing disk. This
1020                          * causes discard_granularity to change, so do a
1021                          * rescan to pick up the new granularity. We don't
1022                          * want scsi_report_sense() to output a message
1023                          * that a sysadmin wouldn't know what to do with.
1024                          */
1025                         if ((asc == 0x3f) && (ascq != 0x03) &&
1026                                         (ascq != 0x0e)) {
1027                                 process_err_fn = storvsc_device_scan;
1028                                 set_host_byte(scmnd, DID_REQUEUE);
1029                                 goto do_work;
1030                         }
1031
1032                         /*
1033                          * Otherwise, let upper layer deal with the
1034                          * error when sense message is present
1035                          */
1036                         return;
1037                 }
1038
1039                 /*
1040                  * If there is an error; offline the device since all
1041                  * error recovery strategies would have already been
1042                  * deployed on the host side. However, if the command
1043                  * were a pass-through command deal with it appropriately.
1044                  */
1045                 switch (scmnd->cmnd[0]) {
1046                 case ATA_16:
1047                 case ATA_12:
1048                         set_host_byte(scmnd, DID_PASSTHROUGH);
1049                         break;
1050                 /*
1051                  * On some Hyper-V hosts TEST_UNIT_READY command can
1052                  * return SRB_STATUS_ERROR. Let the upper level code
1053                  * deal with it based on the sense information.
1054                  */
1055                 case TEST_UNIT_READY:
1056                         break;
1057                 default:
1058                         set_host_byte(scmnd, DID_ERROR);
1059                 }
1060                 return;
1061
1062         case SRB_STATUS_INVALID_LUN:
1063                 set_host_byte(scmnd, DID_NO_CONNECT);
1064                 process_err_fn = storvsc_remove_lun;
1065                 goto do_work;
1066
1067         }
1068         return;
1069
1070 do_work:
1071         /*
1072          * We need to schedule work to process this error; schedule it.
1073          */
1074         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1075         if (!wrk) {
1076                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1077                 return;
1078         }
1079
1080         wrk->host = host;
1081         wrk->lun = vm_srb->lun;
1082         wrk->tgt_id = vm_srb->target_id;
1083         INIT_WORK(&wrk->work, process_err_fn);
1084         queue_work(host_dev->handle_error_wq, &wrk->work);
1085 }
1086
1087
1088 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1089                                        struct storvsc_device *stor_dev)
1090 {
1091         struct scsi_cmnd *scmnd = cmd_request->cmd;
1092         struct scsi_sense_hdr sense_hdr;
1093         struct vmscsi_request *vm_srb;
1094         u32 data_transfer_length;
1095         struct Scsi_Host *host;
1096         u32 payload_sz = cmd_request->payload_sz;
1097         void *payload = cmd_request->payload;
1098
1099         host = stor_dev->host;
1100
1101         vm_srb = &cmd_request->vstor_packet.vm_srb;
1102         data_transfer_length = vm_srb->data_transfer_length;
1103
1104         scmnd->result = vm_srb->scsi_status;
1105
1106         if (scmnd->result) {
1107                 if (scsi_normalize_sense(scmnd->sense_buffer,
1108                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1109                     !(sense_hdr.sense_key == NOT_READY &&
1110                                  sense_hdr.asc == 0x03A) &&
1111                     do_logging(STORVSC_LOGGING_ERROR))
1112                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1113                                              &sense_hdr);
1114         }
1115
1116         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1117                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1118                                          sense_hdr.ascq);
1119                 /*
1120                  * The Windows driver set data_transfer_length on
1121                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1122                  * is untouched.  In these cases we set it to 0.
1123                  */
1124                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1125                         data_transfer_length = 0;
1126         }
1127
1128         /* Validate data_transfer_length (from Hyper-V) */
1129         if (data_transfer_length > cmd_request->payload->range.len)
1130                 data_transfer_length = cmd_request->payload->range.len;
1131
1132         scsi_set_resid(scmnd,
1133                 cmd_request->payload->range.len - data_transfer_length);
1134
1135         scmnd->scsi_done(scmnd);
1136
1137         if (payload_sz >
1138                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1139                 kfree(payload);
1140 }
1141
1142 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1143                                   struct vstor_packet *vstor_packet,
1144                                   struct storvsc_cmd_request *request)
1145 {
1146         struct vstor_packet *stor_pkt;
1147         struct hv_device *device = stor_device->device;
1148
1149         stor_pkt = &request->vstor_packet;
1150
1151         /*
1152          * The current SCSI handling on the host side does
1153          * not correctly handle:
1154          * INQUIRY command with page code parameter set to 0x80
1155          * MODE_SENSE command with cmd[2] == 0x1c
1156          *
1157          * Setup srb and scsi status so this won't be fatal.
1158          * We do this so we can distinguish truly fatal failues
1159          * (srb status == 0x4) and off-line the device in that case.
1160          */
1161
1162         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1163            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1164                 vstor_packet->vm_srb.scsi_status = 0;
1165                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1166         }
1167
1168
1169         /* Copy over the status...etc */
1170         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1171         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1172
1173         /* Validate sense_info_length (from Hyper-V) */
1174         if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
1175                 vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1176
1177         stor_pkt->vm_srb.sense_info_length =
1178         vstor_packet->vm_srb.sense_info_length;
1179
1180         if (vstor_packet->vm_srb.scsi_status != 0 ||
1181             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1182                 storvsc_log(device, STORVSC_LOGGING_WARN,
1183                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1184                         stor_pkt->vm_srb.cdb[0],
1185                         vstor_packet->vm_srb.scsi_status,
1186                         vstor_packet->vm_srb.srb_status);
1187
1188         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1189                 /* CHECK_CONDITION */
1190                 if (vstor_packet->vm_srb.srb_status &
1191                         SRB_STATUS_AUTOSENSE_VALID) {
1192                         /* autosense data available */
1193
1194                         storvsc_log(device, STORVSC_LOGGING_WARN,
1195                                 "stor pkt %p autosense data valid - len %d\n",
1196                                 request, vstor_packet->vm_srb.sense_info_length);
1197
1198                         memcpy(request->cmd->sense_buffer,
1199                                vstor_packet->vm_srb.sense_data,
1200                                vstor_packet->vm_srb.sense_info_length);
1201
1202                 }
1203         }
1204
1205         stor_pkt->vm_srb.data_transfer_length =
1206         vstor_packet->vm_srb.data_transfer_length;
1207
1208         storvsc_command_completion(request, stor_device);
1209
1210         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1211                 stor_device->drain_notify)
1212                 wake_up(&stor_device->waiting_to_drain);
1213
1214
1215 }
1216
1217 static void storvsc_on_receive(struct storvsc_device *stor_device,
1218                              struct vstor_packet *vstor_packet,
1219                              struct storvsc_cmd_request *request)
1220 {
1221         struct hv_host_device *host_dev;
1222         switch (vstor_packet->operation) {
1223         case VSTOR_OPERATION_COMPLETE_IO:
1224                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1225                 break;
1226
1227         case VSTOR_OPERATION_REMOVE_DEVICE:
1228         case VSTOR_OPERATION_ENUMERATE_BUS:
1229                 host_dev = shost_priv(stor_device->host);
1230                 queue_work(
1231                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1232                 break;
1233
1234         case VSTOR_OPERATION_FCHBA_DATA:
1235                 cache_wwn(stor_device, vstor_packet);
1236 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1237                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1238                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1239 #endif
1240                 break;
1241         default:
1242                 break;
1243         }
1244 }
1245
1246 static void storvsc_on_channel_callback(void *context)
1247 {
1248         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1249         const struct vmpacket_descriptor *desc;
1250         struct hv_device *device;
1251         struct storvsc_device *stor_device;
1252
1253         if (channel->primary_channel != NULL)
1254                 device = channel->primary_channel->device_obj;
1255         else
1256                 device = channel->device_obj;
1257
1258         stor_device = get_in_stor_device(device);
1259         if (!stor_device)
1260                 return;
1261
1262         foreach_vmbus_pkt(desc, channel) {
1263                 void *packet = hv_pkt_data(desc);
1264                 struct storvsc_cmd_request *request;
1265
1266                 request = (struct storvsc_cmd_request *)
1267                         ((unsigned long)desc->trans_id);
1268
1269                 if (request == &stor_device->init_request ||
1270                     request == &stor_device->reset_request) {
1271                         memcpy(&request->vstor_packet, packet,
1272                                (sizeof(struct vstor_packet) - vmscsi_size_delta));
1273                         complete(&request->wait_event);
1274                 } else {
1275                         storvsc_on_receive(stor_device, packet, request);
1276                 }
1277         }
1278 }
1279
1280 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1281                                   bool is_fc)
1282 {
1283         struct vmstorage_channel_properties props;
1284         int ret;
1285
1286         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1287
1288         ret = vmbus_open(device->channel,
1289                          ring_size,
1290                          ring_size,
1291                          (void *)&props,
1292                          sizeof(struct vmstorage_channel_properties),
1293                          storvsc_on_channel_callback, device->channel);
1294
1295         if (ret != 0)
1296                 return ret;
1297
1298         ret = storvsc_channel_init(device, is_fc);
1299
1300         return ret;
1301 }
1302
1303 static int storvsc_dev_remove(struct hv_device *device)
1304 {
1305         struct storvsc_device *stor_device;
1306
1307         stor_device = hv_get_drvdata(device);
1308
1309         stor_device->destroy = true;
1310
1311         /* Make sure flag is set before waiting */
1312         wmb();
1313
1314         /*
1315          * At this point, all outbound traffic should be disable. We
1316          * only allow inbound traffic (responses) to proceed so that
1317          * outstanding requests can be completed.
1318          */
1319
1320         storvsc_wait_to_drain(stor_device);
1321
1322         /*
1323          * Since we have already drained, we don't need to busy wait
1324          * as was done in final_release_stor_device()
1325          * Note that we cannot set the ext pointer to NULL until
1326          * we have drained - to drain the outgoing packets, we need to
1327          * allow incoming packets.
1328          */
1329         hv_set_drvdata(device, NULL);
1330
1331         /* Close the channel */
1332         vmbus_close(device->channel);
1333
1334         kfree(stor_device->stor_chns);
1335         kfree(stor_device);
1336         return 0;
1337 }
1338
1339 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1340                                         u16 q_num)
1341 {
1342         u16 slot = 0;
1343         u16 hash_qnum;
1344         const struct cpumask *node_mask;
1345         int num_channels, tgt_cpu;
1346
1347         if (stor_device->num_sc == 0) {
1348                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1349                 return stor_device->device->channel;
1350         }
1351
1352         /*
1353          * Our channel array is sparsley populated and we
1354          * initiated I/O on a processor/hw-q that does not
1355          * currently have a designated channel. Fix this.
1356          * The strategy is simple:
1357          * I. Ensure NUMA locality
1358          * II. Distribute evenly (best effort)
1359          */
1360
1361         node_mask = cpumask_of_node(cpu_to_node(q_num));
1362
1363         num_channels = 0;
1364         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1365                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1366                         num_channels++;
1367         }
1368         if (num_channels == 0) {
1369                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1370                 return stor_device->device->channel;
1371         }
1372
1373         hash_qnum = q_num;
1374         while (hash_qnum >= num_channels)
1375                 hash_qnum -= num_channels;
1376
1377         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1378                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1379                         continue;
1380                 if (slot == hash_qnum)
1381                         break;
1382                 slot++;
1383         }
1384
1385         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1386
1387         return stor_device->stor_chns[q_num];
1388 }
1389
1390
1391 static int storvsc_do_io(struct hv_device *device,
1392                          struct storvsc_cmd_request *request, u16 q_num)
1393 {
1394         struct storvsc_device *stor_device;
1395         struct vstor_packet *vstor_packet;
1396         struct vmbus_channel *outgoing_channel, *channel;
1397         unsigned long flags;
1398         int ret = 0;
1399         const struct cpumask *node_mask;
1400         int tgt_cpu;
1401
1402         vstor_packet = &request->vstor_packet;
1403         stor_device = get_out_stor_device(device);
1404
1405         if (!stor_device)
1406                 return -ENODEV;
1407
1408
1409         request->device  = device;
1410         /*
1411          * Select an appropriate channel to send the request out.
1412          */
1413         /* See storvsc_change_target_cpu(). */
1414         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1415         if (outgoing_channel != NULL) {
1416                 if (outgoing_channel->target_cpu == q_num) {
1417                         /*
1418                          * Ideally, we want to pick a different channel if
1419                          * available on the same NUMA node.
1420                          */
1421                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1422                         for_each_cpu_wrap(tgt_cpu,
1423                                  &stor_device->alloced_cpus, q_num + 1) {
1424                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1425                                         continue;
1426                                 if (tgt_cpu == q_num)
1427                                         continue;
1428                                 channel = READ_ONCE(
1429                                         stor_device->stor_chns[tgt_cpu]);
1430                                 if (channel == NULL)
1431                                         continue;
1432                                 if (hv_get_avail_to_write_percent(
1433                                                         &channel->outbound)
1434                                                 > ring_avail_percent_lowater) {
1435                                         outgoing_channel = channel;
1436                                         goto found_channel;
1437                                 }
1438                         }
1439
1440                         /*
1441                          * All the other channels on the same NUMA node are
1442                          * busy. Try to use the channel on the current CPU
1443                          */
1444                         if (hv_get_avail_to_write_percent(
1445                                                 &outgoing_channel->outbound)
1446                                         > ring_avail_percent_lowater)
1447                                 goto found_channel;
1448
1449                         /*
1450                          * If we reach here, all the channels on the current
1451                          * NUMA node are busy. Try to find a channel in
1452                          * other NUMA nodes
1453                          */
1454                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1455                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1456                                         continue;
1457                                 channel = READ_ONCE(
1458                                         stor_device->stor_chns[tgt_cpu]);
1459                                 if (channel == NULL)
1460                                         continue;
1461                                 if (hv_get_avail_to_write_percent(
1462                                                         &channel->outbound)
1463                                                 > ring_avail_percent_lowater) {
1464                                         outgoing_channel = channel;
1465                                         goto found_channel;
1466                                 }
1467                         }
1468                 }
1469         } else {
1470                 spin_lock_irqsave(&stor_device->lock, flags);
1471                 outgoing_channel = stor_device->stor_chns[q_num];
1472                 if (outgoing_channel != NULL) {
1473                         spin_unlock_irqrestore(&stor_device->lock, flags);
1474                         goto found_channel;
1475                 }
1476                 outgoing_channel = get_og_chn(stor_device, q_num);
1477                 spin_unlock_irqrestore(&stor_device->lock, flags);
1478         }
1479
1480 found_channel:
1481         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1482
1483         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1484                                         vmscsi_size_delta);
1485
1486
1487         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1488
1489
1490         vstor_packet->vm_srb.data_transfer_length =
1491         request->payload->range.len;
1492
1493         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1494
1495         if (request->payload->range.len) {
1496
1497                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1498                                 request->payload, request->payload_sz,
1499                                 vstor_packet,
1500                                 (sizeof(struct vstor_packet) -
1501                                 vmscsi_size_delta),
1502                                 (unsigned long)request);
1503         } else {
1504                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1505                                (sizeof(struct vstor_packet) -
1506                                 vmscsi_size_delta),
1507                                (unsigned long)request,
1508                                VM_PKT_DATA_INBAND,
1509                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1510         }
1511
1512         if (ret != 0)
1513                 return ret;
1514
1515         atomic_inc(&stor_device->num_outstanding_req);
1516
1517         return ret;
1518 }
1519
1520 static int storvsc_device_alloc(struct scsi_device *sdevice)
1521 {
1522         /*
1523          * Set blist flag to permit the reading of the VPD pages even when
1524          * the target may claim SPC-2 compliance. MSFT targets currently
1525          * claim SPC-2 compliance while they implement post SPC-2 features.
1526          * With this flag we can correctly handle WRITE_SAME_16 issues.
1527          *
1528          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1529          * still supports REPORT LUN.
1530          */
1531         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1532
1533         return 0;
1534 }
1535
1536 static int storvsc_device_configure(struct scsi_device *sdevice)
1537 {
1538         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1539
1540         /* storvsc devices don't support MAINTENANCE_IN SCSI cmd */
1541         sdevice->no_report_opcodes = 1;
1542         sdevice->no_write_same = 1;
1543
1544         /*
1545          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1546          * if the device is a MSFT virtual device.  If the host is
1547          * WIN10 or newer, allow write_same.
1548          */
1549         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1550                 switch (vmstor_proto_version) {
1551                 case VMSTOR_PROTO_VERSION_WIN8:
1552                 case VMSTOR_PROTO_VERSION_WIN8_1:
1553                         sdevice->scsi_level = SCSI_SPC_3;
1554                         break;
1555                 }
1556
1557                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1558                         sdevice->no_write_same = 0;
1559         }
1560
1561         return 0;
1562 }
1563
1564 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1565                            sector_t capacity, int *info)
1566 {
1567         sector_t nsect = capacity;
1568         sector_t cylinders = nsect;
1569         int heads, sectors_pt;
1570
1571         /*
1572          * We are making up these values; let us keep it simple.
1573          */
1574         heads = 0xff;
1575         sectors_pt = 0x3f;      /* Sectors per track */
1576         sector_div(cylinders, heads * sectors_pt);
1577         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1578                 cylinders = 0xffff;
1579
1580         info[0] = heads;
1581         info[1] = sectors_pt;
1582         info[2] = (int)cylinders;
1583
1584         return 0;
1585 }
1586
1587 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1588 {
1589         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1590         struct hv_device *device = host_dev->dev;
1591
1592         struct storvsc_device *stor_device;
1593         struct storvsc_cmd_request *request;
1594         struct vstor_packet *vstor_packet;
1595         int ret, t;
1596
1597
1598         stor_device = get_out_stor_device(device);
1599         if (!stor_device)
1600                 return FAILED;
1601
1602         request = &stor_device->reset_request;
1603         vstor_packet = &request->vstor_packet;
1604         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1605
1606         init_completion(&request->wait_event);
1607
1608         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1609         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1610         vstor_packet->vm_srb.path_id = stor_device->path_id;
1611
1612         ret = vmbus_sendpacket(device->channel, vstor_packet,
1613                                (sizeof(struct vstor_packet) -
1614                                 vmscsi_size_delta),
1615                                (unsigned long)&stor_device->reset_request,
1616                                VM_PKT_DATA_INBAND,
1617                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1618         if (ret != 0)
1619                 return FAILED;
1620
1621         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1622         if (t == 0)
1623                 return TIMEOUT_ERROR;
1624
1625
1626         /*
1627          * At this point, all outstanding requests in the adapter
1628          * should have been flushed out and return to us
1629          * There is a potential race here where the host may be in
1630          * the process of responding when we return from here.
1631          * Just wait for all in-transit packets to be accounted for
1632          * before we return from here.
1633          */
1634         storvsc_wait_to_drain(stor_device);
1635
1636         return SUCCESS;
1637 }
1638
1639 /*
1640  * The host guarantees to respond to each command, although I/O latencies might
1641  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1642  * chance to perform EH.
1643  */
1644 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1645 {
1646         return BLK_EH_RESET_TIMER;
1647 }
1648
1649 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1650 {
1651         bool allowed = true;
1652         u8 scsi_op = scmnd->cmnd[0];
1653
1654         switch (scsi_op) {
1655         /* the host does not handle WRITE_SAME, log accident usage */
1656         case WRITE_SAME:
1657         /*
1658          * smartd sends this command and the host does not handle
1659          * this. So, don't send it.
1660          */
1661         case SET_WINDOW:
1662                 scmnd->result = ILLEGAL_REQUEST << 16;
1663                 allowed = false;
1664                 break;
1665         default:
1666                 break;
1667         }
1668         return allowed;
1669 }
1670
1671 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1672 {
1673         int ret;
1674         struct hv_host_device *host_dev = shost_priv(host);
1675         struct hv_device *dev = host_dev->dev;
1676         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1677         int i;
1678         struct scatterlist *sgl;
1679         unsigned int sg_count = 0;
1680         struct vmscsi_request *vm_srb;
1681         struct scatterlist *cur_sgl;
1682         struct vmbus_packet_mpb_array  *payload;
1683         u32 payload_sz;
1684         u32 length;
1685
1686         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1687                 /*
1688                  * On legacy hosts filter unimplemented commands.
1689                  * Future hosts are expected to correctly handle
1690                  * unsupported commands. Furthermore, it is
1691                  * possible that some of the currently
1692                  * unsupported commands maybe supported in
1693                  * future versions of the host.
1694                  */
1695                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1696                         scmnd->scsi_done(scmnd);
1697                         return 0;
1698                 }
1699         }
1700
1701         /* Setup the cmd request */
1702         cmd_request->cmd = scmnd;
1703
1704         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1705         vm_srb = &cmd_request->vstor_packet.vm_srb;
1706         vm_srb->win8_extension.time_out_value = 60;
1707
1708         vm_srb->win8_extension.srb_flags |=
1709                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1710
1711         if (scmnd->device->tagged_supported) {
1712                 vm_srb->win8_extension.srb_flags |=
1713                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1714                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1715                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1716         }
1717
1718         /* Build the SRB */
1719         switch (scmnd->sc_data_direction) {
1720         case DMA_TO_DEVICE:
1721                 vm_srb->data_in = WRITE_TYPE;
1722                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1723                 break;
1724         case DMA_FROM_DEVICE:
1725                 vm_srb->data_in = READ_TYPE;
1726                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1727                 break;
1728         case DMA_NONE:
1729                 vm_srb->data_in = UNKNOWN_TYPE;
1730                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1731                 break;
1732         default:
1733                 /*
1734                  * This is DMA_BIDIRECTIONAL or something else we are never
1735                  * supposed to see here.
1736                  */
1737                 WARN(1, "Unexpected data direction: %d\n",
1738                      scmnd->sc_data_direction);
1739                 return -EINVAL;
1740         }
1741
1742
1743         vm_srb->port_number = host_dev->port;
1744         vm_srb->path_id = scmnd->device->channel;
1745         vm_srb->target_id = scmnd->device->id;
1746         vm_srb->lun = scmnd->device->lun;
1747
1748         vm_srb->cdb_length = scmnd->cmd_len;
1749
1750         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1751
1752         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1753         sg_count = scsi_sg_count(scmnd);
1754
1755         length = scsi_bufflen(scmnd);
1756         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1757         payload_sz = 0;
1758
1759         if (sg_count) {
1760                 unsigned int hvpgoff = 0;
1761                 unsigned long offset_in_hvpg = sgl->offset & ~HV_HYP_PAGE_MASK;
1762                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1763                 u64 hvpfn;
1764
1765                 payload_sz = (hvpg_count * sizeof(u64) +
1766                               sizeof(struct vmbus_packet_mpb_array));
1767
1768                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1769                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1770                         if (!payload)
1771                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1772                 }
1773
1774                 /*
1775                  * sgl is a list of PAGEs, and payload->range.pfn_array
1776                  * expects the page number in the unit of HV_HYP_PAGE_SIZE (the
1777                  * page size that Hyper-V uses, so here we need to divide PAGEs
1778                  * into HV_HYP_PAGE in case that PAGE_SIZE > HV_HYP_PAGE_SIZE.
1779                  * Besides, payload->range.offset should be the offset in one
1780                  * HV_HYP_PAGE.
1781                  */
1782                 payload->range.len = length;
1783                 payload->range.offset = offset_in_hvpg;
1784                 hvpgoff = sgl->offset >> HV_HYP_PAGE_SHIFT;
1785
1786                 cur_sgl = sgl;
1787                 for (i = 0; i < hvpg_count; i++) {
1788                         /*
1789                          * 'i' is the index of hv pages in the payload and
1790                          * 'hvpgoff' is the offset (in hv pages) of the first
1791                          * hv page in the the first page. The relationship
1792                          * between the sum of 'i' and 'hvpgoff' and the offset
1793                          * (in hv pages) in a payload page ('hvpgoff_in_page')
1794                          * is as follow:
1795                          *
1796                          * |------------------ PAGE -------------------|
1797                          * |   NR_HV_HYP_PAGES_IN_PAGE hvpgs in total  |
1798                          * |hvpg|hvpg| ...              |hvpg|... |hvpg|
1799                          * ^         ^                                 ^                 ^
1800                          * +-hvpgoff-+                                 +-hvpgoff_in_page-+
1801                          *           ^                                                   |
1802                          *           +--------------------- i ---------------------------+
1803                          */
1804                         unsigned int hvpgoff_in_page =
1805                                 (i + hvpgoff) % NR_HV_HYP_PAGES_IN_PAGE;
1806
1807                         /*
1808                          * Two cases that we need to fetch a page:
1809                          * 1) i == 0, the first step or
1810                          * 2) hvpgoff_in_page == 0, when we reach the boundary
1811                          *    of a page.
1812                          */
1813                         if (hvpgoff_in_page == 0 || i == 0) {
1814                                 hvpfn = page_to_hvpfn(sg_page(cur_sgl));
1815                                 cur_sgl = sg_next(cur_sgl);
1816                         }
1817
1818                         payload->range.pfn_array[i] = hvpfn + hvpgoff_in_page;
1819                 }
1820         }
1821
1822         cmd_request->payload = payload;
1823         cmd_request->payload_sz = payload_sz;
1824
1825         /* Invokes the vsc to start an IO */
1826         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1827         put_cpu();
1828
1829         if (ret == -EAGAIN) {
1830                 if (payload_sz > sizeof(cmd_request->mpb))
1831                         kfree(payload);
1832                 /* no more space */
1833                 return SCSI_MLQUEUE_DEVICE_BUSY;
1834         }
1835
1836         return 0;
1837 }
1838
1839 static struct scsi_host_template scsi_driver = {
1840         .module =               THIS_MODULE,
1841         .name =                 "storvsc_host_t",
1842         .cmd_size =             sizeof(struct storvsc_cmd_request),
1843         .bios_param =           storvsc_get_chs,
1844         .queuecommand =         storvsc_queuecommand,
1845         .eh_host_reset_handler =        storvsc_host_reset_handler,
1846         .proc_name =            "storvsc_host",
1847         .eh_timed_out =         storvsc_eh_timed_out,
1848         .slave_alloc =          storvsc_device_alloc,
1849         .slave_configure =      storvsc_device_configure,
1850         .cmd_per_lun =          2048,
1851         .this_id =              -1,
1852         /* Make sure we dont get a sg segment crosses a page boundary */
1853         .dma_boundary =         PAGE_SIZE-1,
1854         /* Ensure there are no gaps in presented sgls */
1855         .virt_boundary_mask =   PAGE_SIZE-1,
1856         .no_write_same =        1,
1857         .track_queue_depth =    1,
1858         .change_queue_depth =   storvsc_change_queue_depth,
1859 };
1860
1861 enum {
1862         SCSI_GUID,
1863         IDE_GUID,
1864         SFC_GUID,
1865 };
1866
1867 static const struct hv_vmbus_device_id id_table[] = {
1868         /* SCSI guid */
1869         { HV_SCSI_GUID,
1870           .driver_data = SCSI_GUID
1871         },
1872         /* IDE guid */
1873         { HV_IDE_GUID,
1874           .driver_data = IDE_GUID
1875         },
1876         /* Fibre Channel GUID */
1877         {
1878           HV_SYNTHFC_GUID,
1879           .driver_data = SFC_GUID
1880         },
1881         { },
1882 };
1883
1884 MODULE_DEVICE_TABLE(vmbus, id_table);
1885
1886 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1887
1888 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1889 {
1890         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1891 }
1892
1893 static int storvsc_probe(struct hv_device *device,
1894                         const struct hv_vmbus_device_id *dev_id)
1895 {
1896         int ret;
1897         int num_cpus = num_online_cpus();
1898         struct Scsi_Host *host;
1899         struct hv_host_device *host_dev;
1900         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1901         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1902         int target = 0;
1903         struct storvsc_device *stor_device;
1904         int max_luns_per_target;
1905         int max_targets;
1906         int max_channels;
1907         int max_sub_channels = 0;
1908
1909         /*
1910          * Based on the windows host we are running on,
1911          * set state to properly communicate with the host.
1912          */
1913
1914         if (vmbus_proto_version < VERSION_WIN8) {
1915                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1916                 max_targets = STORVSC_IDE_MAX_TARGETS;
1917                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1918         } else {
1919                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1920                 max_targets = STORVSC_MAX_TARGETS;
1921                 max_channels = STORVSC_MAX_CHANNELS;
1922                 /*
1923                  * On Windows8 and above, we support sub-channels for storage
1924                  * on SCSI and FC controllers.
1925                  * The number of sub-channels offerred is based on the number of
1926                  * VCPUs in the guest.
1927                  */
1928                 if (!dev_is_ide)
1929                         max_sub_channels =
1930                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1931         }
1932
1933         scsi_driver.can_queue = max_outstanding_req_per_channel *
1934                                 (max_sub_channels + 1) *
1935                                 (100 - ring_avail_percent_lowater) / 100;
1936
1937         host = scsi_host_alloc(&scsi_driver,
1938                                sizeof(struct hv_host_device));
1939         if (!host)
1940                 return -ENOMEM;
1941
1942         host_dev = shost_priv(host);
1943         memset(host_dev, 0, sizeof(struct hv_host_device));
1944
1945         host_dev->port = host->host_no;
1946         host_dev->dev = device;
1947         host_dev->host = host;
1948
1949
1950         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1951         if (!stor_device) {
1952                 ret = -ENOMEM;
1953                 goto err_out0;
1954         }
1955
1956         stor_device->destroy = false;
1957         init_waitqueue_head(&stor_device->waiting_to_drain);
1958         stor_device->device = device;
1959         stor_device->host = host;
1960         spin_lock_init(&stor_device->lock);
1961         hv_set_drvdata(device, stor_device);
1962
1963         stor_device->port_number = host->host_no;
1964         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1965         if (ret)
1966                 goto err_out1;
1967
1968         host_dev->path = stor_device->path_id;
1969         host_dev->target = stor_device->target_id;
1970
1971         switch (dev_id->driver_data) {
1972         case SFC_GUID:
1973                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1974                 host->max_id = STORVSC_FC_MAX_TARGETS;
1975                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1976 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1977                 host->transportt = fc_transport_template;
1978 #endif
1979                 break;
1980
1981         case SCSI_GUID:
1982                 host->max_lun = max_luns_per_target;
1983                 host->max_id = max_targets;
1984                 host->max_channel = max_channels - 1;
1985                 break;
1986
1987         default:
1988                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1989                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1990                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1991                 break;
1992         }
1993         /* max cmd length */
1994         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1995
1996         /*
1997          * set the table size based on the info we got
1998          * from the host.
1999          */
2000         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
2001         /*
2002          * For non-IDE disks, the host supports multiple channels.
2003          * Set the number of HW queues we are supporting.
2004          */
2005         if (!dev_is_ide)
2006                 host->nr_hw_queues = num_present_cpus();
2007
2008         /*
2009          * Set the error handler work queue.
2010          */
2011         host_dev->handle_error_wq =
2012                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2013                                                 0,
2014                                                 host->host_no);
2015         if (!host_dev->handle_error_wq) {
2016                 ret = -ENOMEM;
2017                 goto err_out2;
2018         }
2019         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2020         /* Register the HBA and start the scsi bus scan */
2021         ret = scsi_add_host(host, &device->device);
2022         if (ret != 0)
2023                 goto err_out3;
2024
2025         if (!dev_is_ide) {
2026                 scsi_scan_host(host);
2027         } else {
2028                 target = (device->dev_instance.b[5] << 8 |
2029                          device->dev_instance.b[4]);
2030                 ret = scsi_add_device(host, 0, target, 0);
2031                 if (ret)
2032                         goto err_out4;
2033         }
2034 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2035         if (host->transportt == fc_transport_template) {
2036                 struct fc_rport_identifiers ids = {
2037                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2038                 };
2039
2040                 fc_host_node_name(host) = stor_device->node_name;
2041                 fc_host_port_name(host) = stor_device->port_name;
2042                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2043                 if (!stor_device->rport) {
2044                         ret = -ENOMEM;
2045                         goto err_out4;
2046                 }
2047         }
2048 #endif
2049         return 0;
2050
2051 err_out4:
2052         scsi_remove_host(host);
2053
2054 err_out3:
2055         destroy_workqueue(host_dev->handle_error_wq);
2056
2057 err_out2:
2058         /*
2059          * Once we have connected with the host, we would need to
2060          * to invoke storvsc_dev_remove() to rollback this state and
2061          * this call also frees up the stor_device; hence the jump around
2062          * err_out1 label.
2063          */
2064         storvsc_dev_remove(device);
2065         goto err_out0;
2066
2067 err_out1:
2068         kfree(stor_device->stor_chns);
2069         kfree(stor_device);
2070
2071 err_out0:
2072         scsi_host_put(host);
2073         return ret;
2074 }
2075
2076 /* Change a scsi target's queue depth */
2077 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2078 {
2079         if (queue_depth > scsi_driver.can_queue)
2080                 queue_depth = scsi_driver.can_queue;
2081
2082         return scsi_change_queue_depth(sdev, queue_depth);
2083 }
2084
2085 static int storvsc_remove(struct hv_device *dev)
2086 {
2087         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2088         struct Scsi_Host *host = stor_device->host;
2089         struct hv_host_device *host_dev = shost_priv(host);
2090
2091 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2092         if (host->transportt == fc_transport_template) {
2093                 fc_remote_port_delete(stor_device->rport);
2094                 fc_remove_host(host);
2095         }
2096 #endif
2097         destroy_workqueue(host_dev->handle_error_wq);
2098         scsi_remove_host(host);
2099         storvsc_dev_remove(dev);
2100         scsi_host_put(host);
2101
2102         return 0;
2103 }
2104
2105 static int storvsc_suspend(struct hv_device *hv_dev)
2106 {
2107         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2108         struct Scsi_Host *host = stor_device->host;
2109         struct hv_host_device *host_dev = shost_priv(host);
2110
2111         storvsc_wait_to_drain(stor_device);
2112
2113         drain_workqueue(host_dev->handle_error_wq);
2114
2115         vmbus_close(hv_dev->channel);
2116
2117         kfree(stor_device->stor_chns);
2118         stor_device->stor_chns = NULL;
2119
2120         cpumask_clear(&stor_device->alloced_cpus);
2121
2122         return 0;
2123 }
2124
2125 static int storvsc_resume(struct hv_device *hv_dev)
2126 {
2127         int ret;
2128
2129         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2130                                      hv_dev_is_fc(hv_dev));
2131         return ret;
2132 }
2133
2134 static struct hv_driver storvsc_drv = {
2135         .name = KBUILD_MODNAME,
2136         .id_table = id_table,
2137         .probe = storvsc_probe,
2138         .remove = storvsc_remove,
2139         .suspend = storvsc_suspend,
2140         .resume = storvsc_resume,
2141         .driver = {
2142                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2143         },
2144 };
2145
2146 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2147 static struct fc_function_template fc_transport_functions = {
2148         .show_host_node_name = 1,
2149         .show_host_port_name = 1,
2150 };
2151 #endif
2152
2153 static int __init storvsc_drv_init(void)
2154 {
2155         int ret;
2156
2157         /*
2158          * Divide the ring buffer data size (which is 1 page less
2159          * than the ring buffer size since that page is reserved for
2160          * the ring buffer indices) by the max request size (which is
2161          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2162          */
2163         max_outstanding_req_per_channel =
2164                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2165                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2166                 sizeof(struct vstor_packet) + sizeof(u64) -
2167                 vmscsi_size_delta,
2168                 sizeof(u64)));
2169
2170 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2171         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2172         if (!fc_transport_template)
2173                 return -ENODEV;
2174 #endif
2175
2176         ret = vmbus_driver_register(&storvsc_drv);
2177
2178 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2179         if (ret)
2180                 fc_release_transport(fc_transport_template);
2181 #endif
2182
2183         return ret;
2184 }
2185
2186 static void __exit storvsc_drv_exit(void)
2187 {
2188         vmbus_driver_unregister(&storvsc_drv);
2189 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2190         fc_release_transport(fc_transport_template);
2191 #endif
2192 }
2193
2194 MODULE_LICENSE("GPL");
2195 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2196 module_init(storvsc_drv_init);
2197 module_exit(storvsc_drv_exit);