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  * The list of storage protocols in order of preference.
 221  */
 222 struct vmstor_protocol {
 223         int protocol_version;
 224         int sense_buffer_size;
 225         int vmscsi_size_delta;
 226 };
 227
 228
 229 static const struct vmstor_protocol vmstor_protocols[] = {
 230         {
 231                 VMSTOR_PROTO_VERSION_WIN10,
 232                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 233                 0
 234         },
 235         {
 236                 VMSTOR_PROTO_VERSION_WIN8_1,
 237                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 238                 0
 239         },
 240         {
 241                 VMSTOR_PROTO_VERSION_WIN8,
 242                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 243                 0
 244         },
 245         {
 246                 VMSTOR_PROTO_VERSION_WIN7,
 247                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 248                 sizeof(struct vmscsi_win8_extension),
 249         },
 250         {
 251                 VMSTOR_PROTO_VERSION_WIN6,
 252                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 253                 sizeof(struct vmscsi_win8_extension),
 254         }
 255 };
 256
 257
 258 /*
 259  * This structure is sent during the initialization phase to get the different
 260  * properties of the channel.
 261  */
 262
 263 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 264
 265 struct vmstorage_channel_properties {
 266         u32 reserved;
 267         u16 max_channel_cnt;
 268         u16 reserved1;
 269
 270         u32 flags;
 271         u32   max_transfer_bytes;
 272
 273         u64  reserved2;
 274 } __packed;
 275
 276 /*  This structure is sent during the storage protocol negotiations. */
 277 struct vmstorage_protocol_version {
 278         /* Major (MSW) and minor (LSW) version numbers. */
 279         u16 major_minor;
 280
 281         /*
 282          * Revision number is auto-incremented whenever this file is changed
 283          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 284          * definitely indicate incompatibility--but it does indicate mismatched
 285          * builds.
 286          * This is only used on the windows side. Just set it to 0.
 287          */
 288         u16 revision;
 289 } __packed;
 290
 291 /* Channel Property Flags */
 292 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 293 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 294
 295 struct vstor_packet {
 296         /* Requested operation type */
 297         enum vstor_packet_operation operation;
 298
 299         /*  Flags - see below for values */
 300         u32 flags;
 301
 302         /* Status of the request returned from the server side. */
 303         u32 status;
 304
 305         /* Data payload area */
 306         union {
 307                 /*
 308                  * Structure used to forward SCSI commands from the
 309                  * client to the server.
 310                  */
 311                 struct vmscsi_request vm_srb;
 312
 313                 /* Structure used to query channel properties. */
 314                 struct vmstorage_channel_properties storage_channel_properties;
 315
 316                 /* Used during version negotiations. */
 317                 struct vmstorage_protocol_version version;
 318
 319                 /* Fibre channel address packet */
 320                 struct hv_fc_wwn_packet wwn_packet;
 321
 322                 /* Number of sub-channels to create */
 323                 u16 sub_channel_count;
 324
 325                 /* This will be the maximum of the union members */
 326                 u8  buffer[0x34];
 327         };
 328 } __packed;
 329
 330 /*
 331  * Packet Flags:
 332  *
 333  * This flag indicates that the server should send back a completion for this
 334  * packet.
 335  */
 336
 337 #define REQUEST_COMPLETION_FLAG 0x1
 338
 339 /* Matches Windows-end */
 340 enum storvsc_request_type {
 341         WRITE_TYPE = 0,
 342         READ_TYPE,
 343         UNKNOWN_TYPE,
 344 };
 345
 346 /*
 347  * SRB status codes and masks; a subset of the codes used here.
 348  */
 349
 350 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 351 #define SRB_STATUS_QUEUE_FROZEN         0x40
 352 #define SRB_STATUS_INVALID_LUN  0x20
 353 #define SRB_STATUS_SUCCESS      0x01
 354 #define SRB_STATUS_ABORTED      0x02
 355 #define SRB_STATUS_ERROR        0x04
 356 #define SRB_STATUS_DATA_OVERRUN 0x12
 357
 358 #define SRB_STATUS(status) \
 359         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 360 /*
 361  * This is the end of Protocol specific defines.
 362  */
 363
 364 static int storvsc_ringbuffer_size = (128 * 1024);
 365 static u32 max_outstanding_req_per_channel;
 366 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 367
 368 static int storvsc_vcpus_per_sub_channel = 4;
 369
 370 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 371 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 372
 373 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 374 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 375
 376 static int ring_avail_percent_lowater = 10;
 377 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 378 MODULE_PARM_DESC(ring_avail_percent_lowater,
 379                 "Select a channel if available ring size > this in percent");
 380
 381 /*
 382  * Timeout in seconds for all devices managed by this driver.
 383  */
 384 static int storvsc_timeout = 180;
 385
 386 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 387 static struct scsi_transport_template *fc_transport_template;
 388 #endif
 389
 390 static struct scsi_host_template scsi_driver;
 391 static void storvsc_on_channel_callback(void *context);
 392
 393 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 394 #define STORVSC_MAX_TARGETS                             2
 395 #define STORVSC_MAX_CHANNELS                            8
 396
 397 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 398 #define STORVSC_FC_MAX_TARGETS                          128
 399 #define STORVSC_FC_MAX_CHANNELS                         8
 400
 401 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 402 #define STORVSC_IDE_MAX_TARGETS                         1
 403 #define STORVSC_IDE_MAX_CHANNELS                        1
 404
 405 struct storvsc_cmd_request {
 406         struct scsi_cmnd *cmd;
 407
 408         struct hv_device *device;
 409
 410         /* Synchronize the request/response if needed */
 411         struct completion wait_event;
 412
 413         struct vmbus_channel_packet_multipage_buffer mpb;
 414         struct vmbus_packet_mpb_array *payload;
 415         u32 payload_sz;
 416
 417         struct vstor_packet vstor_packet;
 418 };
 419
 420
 421 /* A storvsc device is a device object that contains a vmbus channel */
 422 struct storvsc_device {
 423         struct hv_device *device;
 424
 425         bool     destroy;
 426         bool     drain_notify;
 427         atomic_t num_outstanding_req;
 428         struct Scsi_Host *host;
 429
 430         wait_queue_head_t waiting_to_drain;
 431
 432         /*
 433          * Each unique Port/Path/Target represents 1 channel ie scsi
 434          * controller. In reality, the pathid, targetid is always 0
 435          * and the port is set by us
 436          */
 437         unsigned int port_number;
 438         unsigned char path_id;
 439         unsigned char target_id;
 440
 441         /*
 442          * The size of the vmscsi_request has changed in win8. The
 443          * additional size is because of new elements added to the
 444          * structure. These elements are valid only when we are talking
 445          * to a win8 host.
 446          * Track the correction to size we need to apply. This value
 447          * will likely change during protocol negotiation but it is
 448          * valid to start by assuming pre-Win8.
 449          */
 450         int vmscsi_size_delta;
 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         /*
 466          * Serializes modifications of stor_chns[] from storvsc_do_io()
 467          * and storvsc_change_target_cpu().
 468          */
 469         spinlock_t lock;
 470         /* Used for vsc/vsp channel reset process */
 471         struct storvsc_cmd_request init_request;
 472         struct storvsc_cmd_request reset_request;
 473         /*
 474          * Currently active port and node names for FC devices.
 475          */
 476         u64 node_name;
 477         u64 port_name;
 478 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 479         struct fc_rport *rport;
 480 #endif
 481 };
 482
 483 struct hv_host_device {
 484         struct hv_device *dev;
 485         unsigned int port;
 486         unsigned char path;
 487         unsigned char target;
 488         struct workqueue_struct *handle_error_wq;
 489         struct work_struct host_scan_work;
 490         struct Scsi_Host *host;
 491 };
 492
 493 struct storvsc_scan_work {
 494         struct work_struct work;
 495         struct Scsi_Host *host;
 496         u8 lun;
 497         u8 tgt_id;
 498 };
 499
 500 static void storvsc_device_scan(struct work_struct *work)
 501 {
 502         struct storvsc_scan_work *wrk;
 503         struct scsi_device *sdev;
 504
 505         wrk = container_of(work, struct storvsc_scan_work, work);
 506
 507         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 508         if (!sdev)
 509                 goto done;
 510         scsi_rescan_device(&sdev->sdev_gendev);
 511         scsi_device_put(sdev);
 512
 513 done:
 514         kfree(wrk);
 515 }
 516
 517 static void storvsc_host_scan(struct work_struct *work)
 518 {
 519         struct Scsi_Host *host;
 520         struct scsi_device *sdev;
 521         struct hv_host_device *host_device =
 522                 container_of(work, struct hv_host_device, host_scan_work);
 523
 524         host = host_device->host;
 525         /*
 526          * Before scanning the host, first check to see if any of the
 527          * currrently known devices have been hot removed. We issue a
 528          * "unit ready" command against all currently known devices.
 529          * This I/O will result in an error for devices that have been
 530          * removed. As part of handling the I/O error, we remove the device.
 531          *
 532          * When a LUN is added or removed, the host sends us a signal to
 533          * scan the host. Thus we are forced to discover the LUNs that
 534          * may have been removed this way.
 535          */
 536         mutex_lock(&host->scan_mutex);
 537         shost_for_each_device(sdev, host)
 538                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 539         mutex_unlock(&host->scan_mutex);
 540         /*
 541          * Now scan the host to discover LUNs that may have been added.
 542          */
 543         scsi_scan_host(host);
 544 }
 545
 546 static void storvsc_remove_lun(struct work_struct *work)
 547 {
 548         struct storvsc_scan_work *wrk;
 549         struct scsi_device *sdev;
 550
 551         wrk = container_of(work, struct storvsc_scan_work, work);
 552         if (!scsi_host_get(wrk->host))
 553                 goto done;
 554
 555         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 556
 557         if (sdev) {
 558                 scsi_remove_device(sdev);
 559                 scsi_device_put(sdev);
 560         }
 561         scsi_host_put(wrk->host);
 562
 563 done:
 564         kfree(wrk);
 565 }
 566
 567
 568 /*
 569  * We can get incoming messages from the host that are not in response to
 570  * messages that we have sent out. An example of this would be messages
 571  * received by the guest to notify dynamic addition/removal of LUNs. To
 572  * deal with potential race conditions where the driver may be in the
 573  * midst of being unloaded when we might receive an unsolicited message
 574  * from the host, we have implemented a mechanism to gurantee sequential
 575  * consistency:
 576  *
 577  * 1) Once the device is marked as being destroyed, we will fail all
 578  *    outgoing messages.
 579  * 2) We permit incoming messages when the device is being destroyed,
 580  *    only to properly account for messages already sent out.
 581  */
 582
 583 static inline struct storvsc_device *get_out_stor_device(
 584                                         struct hv_device *device)
 585 {
 586         struct storvsc_device *stor_device;
 587
 588         stor_device = hv_get_drvdata(device);
 589
 590         if (stor_device && stor_device->destroy)
 591                 stor_device = NULL;
 592
 593         return stor_device;
 594 }
 595
 596
 597 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 598 {
 599         dev->drain_notify = true;
 600         wait_event(dev->waiting_to_drain,
 601                    atomic_read(&dev->num_outstanding_req) == 0);
 602         dev->drain_notify = false;
 603 }
 604
 605 static inline struct storvsc_device *get_in_stor_device(
 606                                         struct hv_device *device)
 607 {
 608         struct storvsc_device *stor_device;
 609
 610         stor_device = hv_get_drvdata(device);
 611
 612         if (!stor_device)
 613                 goto get_in_err;
 614
 615         /*
 616          * If the device is being destroyed; allow incoming
 617          * traffic only to cleanup outstanding requests.
 618          */
 619
 620         if (stor_device->destroy  &&
 621                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 622                 stor_device = NULL;
 623
 624 get_in_err:
 625         return stor_device;
 626
 627 }
 628
 629 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 630                                       u32 new)
 631 {
 632         struct storvsc_device *stor_device;
 633         struct vmbus_channel *cur_chn;
 634         bool old_is_alloced = false;
 635         struct hv_device *device;
 636         unsigned long flags;
 637         int cpu;
 638
 639         device = channel->primary_channel ?
 640                         channel->primary_channel->device_obj
 641                                 : channel->device_obj;
 642         stor_device = get_out_stor_device(device);
 643         if (!stor_device)
 644                 return;
 645
 646         /* See storvsc_do_io() -> get_og_chn(). */
 647         spin_lock_irqsave(&stor_device->lock, flags);
 648
 649         /*
 650          * Determines if the storvsc device has other channels assigned to
 651          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 652          * array.
 653          */
 654         if (device->channel != channel && device->channel->target_cpu == old) {
 655                 cur_chn = device->channel;
 656                 old_is_alloced = true;
 657                 goto old_is_alloced;
 658         }
 659         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 660                 if (cur_chn == channel)
 661                         continue;
 662                 if (cur_chn->target_cpu == old) {
 663                         old_is_alloced = true;
 664                         goto old_is_alloced;
 665                 }
 666         }
 667
 668 old_is_alloced:
 669         if (old_is_alloced)
 670                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 671         else
 672                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 673
 674         /* "Flush" the stor_chns array. */
 675         for_each_possible_cpu(cpu) {
 676                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 677                                         cpu, &stor_device->alloced_cpus))
 678                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 679         }
 680
 681         WRITE_ONCE(stor_device->stor_chns[new], channel);
 682         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 683
 684         spin_unlock_irqrestore(&stor_device->lock, flags);
 685 }
 686
 687 static void handle_sc_creation(struct vmbus_channel *new_sc)
 688 {
 689         struct hv_device *device = new_sc->primary_channel->device_obj;
 690         struct device *dev = &device->device;
 691         struct storvsc_device *stor_device;
 692         struct vmstorage_channel_properties props;
 693         int ret;
 694
 695         stor_device = get_out_stor_device(device);
 696         if (!stor_device)
 697                 return;
 698
 699         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 700
 701         /*
 702          * The size of vmbus_requestor is an upper bound on the number of requests
 703          * that can be in-progress at any one time across all channels.
 704          */
 705         new_sc->rqstor_size = scsi_driver.can_queue;
 706
 707         ret = vmbus_open(new_sc,
 708                          storvsc_ringbuffer_size,
 709                          storvsc_ringbuffer_size,
 710                          (void *)&props,
 711                          sizeof(struct vmstorage_channel_properties),
 712                          storvsc_on_channel_callback, new_sc);
 713
 714         /* In case vmbus_open() fails, we don't use the sub-channel. */
 715         if (ret != 0) {
 716                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 717                 return;
 718         }
 719
 720         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 721
 722         /* Add the sub-channel to the array of available channels. */
 723         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 724         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 725 }
 726
 727 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 728 {
 729         struct device *dev = &device->device;
 730         struct storvsc_device *stor_device;
 731         int num_sc;
 732         struct storvsc_cmd_request *request;
 733         struct vstor_packet *vstor_packet;
 734         int ret, t;
 735
 736         /*
 737          * If the number of CPUs is artificially restricted, such as
 738          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 739          * sub-channels >= the number of CPUs. These sub-channels
 740          * should not be created. The primary channel is already created
 741          * and assigned to one CPU, so check against # CPUs - 1.
 742          */
 743         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 744         if (!num_sc)
 745                 return;
 746
 747         stor_device = get_out_stor_device(device);
 748         if (!stor_device)
 749                 return;
 750
 751         stor_device->num_sc = num_sc;
 752         request = &stor_device->init_request;
 753         vstor_packet = &request->vstor_packet;
 754
 755         /*
 756          * Establish a handler for dealing with subchannels.
 757          */
 758         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 759
 760         /*
 761          * Request the host to create sub-channels.
 762          */
 763         memset(request, 0, sizeof(struct storvsc_cmd_request));
 764         init_completion(&request->wait_event);
 765         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 766         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 767         vstor_packet->sub_channel_count = num_sc;
 768
 769         ret = vmbus_sendpacket(device->channel, vstor_packet,
 770                                (sizeof(struct vstor_packet) -
 771                                stor_device->vmscsi_size_delta),
 772                                (unsigned long)request,
 773                                VM_PKT_DATA_INBAND,
 774                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 775
 776         if (ret != 0) {
 777                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 778                 return;
 779         }
 780
 781         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 782         if (t == 0) {
 783                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 784                 return;
 785         }
 786
 787         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 788             vstor_packet->status != 0) {
 789                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 790                         vstor_packet->operation, vstor_packet->status);
 791                 return;
 792         }
 793
 794         /*
 795          * We need to do nothing here, because vmbus_process_offer()
 796          * invokes channel->sc_creation_callback, which will open and use
 797          * the sub-channel(s).
 798          */
 799 }
 800
 801 static void cache_wwn(struct storvsc_device *stor_device,
 802                       struct vstor_packet *vstor_packet)
 803 {
 804         /*
 805          * Cache the currently active port and node ww names.
 806          */
 807         if (vstor_packet->wwn_packet.primary_active) {
 808                 stor_device->node_name =
 809                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 810                 stor_device->port_name =
 811                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 812         } else {
 813                 stor_device->node_name =
 814                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 815                 stor_device->port_name =
 816                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 817         }
 818 }
 819
 820
 821 static int storvsc_execute_vstor_op(struct hv_device *device,
 822                                     struct storvsc_cmd_request *request,
 823                                     bool status_check)
 824 {
 825         struct storvsc_device *stor_device;
 826         struct vstor_packet *vstor_packet;
 827         int ret, t;
 828
 829         stor_device = get_out_stor_device(device);
 830         if (!stor_device)
 831                 return -ENODEV;
 832
 833         vstor_packet = &request->vstor_packet;
 834
 835         init_completion(&request->wait_event);
 836         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 837
 838         ret = vmbus_sendpacket(device->channel, vstor_packet,
 839                                (sizeof(struct vstor_packet) -
 840                                stor_device->vmscsi_size_delta),
 841                                (unsigned long)request,
 842                                VM_PKT_DATA_INBAND,
 843                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 844         if (ret != 0)
 845                 return ret;
 846
 847         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 848         if (t == 0)
 849                 return -ETIMEDOUT;
 850
 851         if (!status_check)
 852                 return ret;
 853
 854         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 855             vstor_packet->status != 0)
 856                 return -EINVAL;
 857
 858         return ret;
 859 }
 860
 861 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 862 {
 863         struct storvsc_device *stor_device;
 864         struct storvsc_cmd_request *request;
 865         struct vstor_packet *vstor_packet;
 866         int ret, i;
 867         int max_chns;
 868         bool process_sub_channels = false;
 869
 870         stor_device = get_out_stor_device(device);
 871         if (!stor_device)
 872                 return -ENODEV;
 873
 874         request = &stor_device->init_request;
 875         vstor_packet = &request->vstor_packet;
 876
 877         /*
 878          * Now, initiate the vsc/vsp initialization protocol on the open
 879          * channel
 880          */
 881         memset(request, 0, sizeof(struct storvsc_cmd_request));
 882         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 883         ret = storvsc_execute_vstor_op(device, request, true);
 884         if (ret)
 885                 return ret;
 886         /*
 887          * Query host supported protocol version.
 888          */
 889
 890         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 891                 /* reuse the packet for version range supported */
 892                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 893                 vstor_packet->operation =
 894                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 895
 896                 vstor_packet->version.major_minor =
 897                         vmstor_protocols[i].protocol_version;
 898
 899                 /*
 900                  * The revision number is only used in Windows; set it to 0.
 901                  */
 902                 vstor_packet->version.revision = 0;
 903                 ret = storvsc_execute_vstor_op(device, request, false);
 904                 if (ret != 0)
 905                         return ret;
 906
 907                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 908                         return -EINVAL;
 909
 910                 if (vstor_packet->status == 0) {
 911                         vmstor_proto_version =
 912                                 vmstor_protocols[i].protocol_version;
 913
 914                         sense_buffer_size =
 915                                 vmstor_protocols[i].sense_buffer_size;
 916
 917                         stor_device->vmscsi_size_delta =
 918                                 vmstor_protocols[i].vmscsi_size_delta;
 919
 920                         break;
 921                 }
 922         }
 923
 924         if (vstor_packet->status != 0)
 925                 return -EINVAL;
 926
 927
 928         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 929         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 930         ret = storvsc_execute_vstor_op(device, request, true);
 931         if (ret != 0)
 932                 return ret;
 933
 934         /*
 935          * Check to see if multi-channel support is there.
 936          * Hosts that implement protocol version of 5.1 and above
 937          * support multi-channel.
 938          */
 939         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 940
 941         /*
 942          * Allocate state to manage the sub-channels.
 943          * We allocate an array based on the numbers of possible CPUs
 944          * (Hyper-V does not support cpu online/offline).
 945          * This Array will be sparseley populated with unique
 946          * channels - primary + sub-channels.
 947          * We will however populate all the slots to evenly distribute
 948          * the load.
 949          */
 950         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 951                                          GFP_KERNEL);
 952         if (stor_device->stor_chns == NULL)
 953                 return -ENOMEM;
 954
 955         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 956
 957         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 958         cpumask_set_cpu(device->channel->target_cpu,
 959                         &stor_device->alloced_cpus);
 960
 961         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 962                 if (vstor_packet->storage_channel_properties.flags &
 963                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 964                         process_sub_channels = true;
 965         }
 966         stor_device->max_transfer_bytes =
 967                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 968
 969         if (!is_fc)
 970                 goto done;
 971
 972         /*
 973          * For FC devices retrieve FC HBA data.
 974          */
 975         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 976         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 977         ret = storvsc_execute_vstor_op(device, request, true);
 978         if (ret != 0)
 979                 return ret;
 980
 981         /*
 982          * Cache the currently active port and node ww names.
 983          */
 984         cache_wwn(stor_device, vstor_packet);
 985
 986 done:
 987
 988         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 989         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 990         ret = storvsc_execute_vstor_op(device, request, true);
 991         if (ret != 0)
 992                 return ret;
 993
 994         if (process_sub_channels)
 995                 handle_multichannel_storage(device, max_chns);
 996
 997         return ret;
 998 }
 999
1000 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1001                                 struct scsi_cmnd *scmnd,
1002                                 struct Scsi_Host *host,
1003                                 u8 asc, u8 ascq)
1004 {
1005         struct storvsc_scan_work *wrk;
1006         void (*process_err_fn)(struct work_struct *work);
1007         struct hv_host_device *host_dev = shost_priv(host);
1008         bool do_work = false;
1009
1010         switch (SRB_STATUS(vm_srb->srb_status)) {
1011         case SRB_STATUS_ERROR:
1012                 /*
1013                  * Let upper layer deal with error when
1014                  * sense message is present.
1015                  */
1016
1017                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1018                         break;
1019                 /*
1020                  * If there is an error; offline the device since all
1021                  * error recovery strategies would have already been
1022                  * deployed on the host side. However, if the command
1023                  * were a pass-through command deal with it appropriately.
1024                  */
1025                 switch (scmnd->cmnd[0]) {
1026                 case ATA_16:
1027                 case ATA_12:
1028                         set_host_byte(scmnd, DID_PASSTHROUGH);
1029                         break;
1030                 /*
1031                  * On Some Windows hosts TEST_UNIT_READY command can return
1032                  * SRB_STATUS_ERROR, let the upper level code deal with it
1033                  * based on the sense information.
1034                  */
1035                 case TEST_UNIT_READY:
1036                         break;
1037                 default:
1038                         set_host_byte(scmnd, DID_ERROR);
1039                 }
1040                 break;
1041         case SRB_STATUS_INVALID_LUN:
1042                 set_host_byte(scmnd, DID_NO_CONNECT);
1043                 do_work = true;
1044                 process_err_fn = storvsc_remove_lun;
1045                 break;
1046         case SRB_STATUS_ABORTED:
1047                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
1048                     (asc == 0x2a) && (ascq == 0x9)) {
1049                         do_work = true;
1050                         process_err_fn = storvsc_device_scan;
1051                         /*
1052                          * Retry the I/O that triggered this.
1053                          */
1054                         set_host_byte(scmnd, DID_REQUEUE);
1055                 }
1056                 break;
1057         }
1058
1059         if (!do_work)
1060                 return;
1061
1062         /*
1063          * We need to schedule work to process this error; schedule it.
1064          */
1065         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1066         if (!wrk) {
1067                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1068                 return;
1069         }
1070
1071         wrk->host = host;
1072         wrk->lun = vm_srb->lun;
1073         wrk->tgt_id = vm_srb->target_id;
1074         INIT_WORK(&wrk->work, process_err_fn);
1075         queue_work(host_dev->handle_error_wq, &wrk->work);
1076 }
1077
1078
1079 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1080                                        struct storvsc_device *stor_dev)
1081 {
1082         struct scsi_cmnd *scmnd = cmd_request->cmd;
1083         struct scsi_sense_hdr sense_hdr;
1084         struct vmscsi_request *vm_srb;
1085         u32 data_transfer_length;
1086         struct Scsi_Host *host;
1087         u32 payload_sz = cmd_request->payload_sz;
1088         void *payload = cmd_request->payload;
1089
1090         host = stor_dev->host;
1091
1092         vm_srb = &cmd_request->vstor_packet.vm_srb;
1093         data_transfer_length = vm_srb->data_transfer_length;
1094
1095         scmnd->result = vm_srb->scsi_status;
1096
1097         if (scmnd->result) {
1098                 if (scsi_normalize_sense(scmnd->sense_buffer,
1099                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1100                     !(sense_hdr.sense_key == NOT_READY &&
1101                                  sense_hdr.asc == 0x03A) &&
1102                     do_logging(STORVSC_LOGGING_ERROR))
1103                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1104                                              &sense_hdr);
1105         }
1106
1107         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1108                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1109                                          sense_hdr.ascq);
1110                 /*
1111                  * The Windows driver set data_transfer_length on
1112                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1113                  * is untouched.  In these cases we set it to 0.
1114                  */
1115                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1116                         data_transfer_length = 0;
1117         }
1118
1119         /* Validate data_transfer_length (from Hyper-V) */
1120         if (data_transfer_length > cmd_request->payload->range.len)
1121                 data_transfer_length = cmd_request->payload->range.len;
1122
1123         scsi_set_resid(scmnd,
1124                 cmd_request->payload->range.len - data_transfer_length);
1125
1126         scmnd->scsi_done(scmnd);
1127
1128         if (payload_sz >
1129                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1130                 kfree(payload);
1131 }
1132
1133 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1134                                   struct vstor_packet *vstor_packet,
1135                                   struct storvsc_cmd_request *request)
1136 {
1137         struct vstor_packet *stor_pkt;
1138         struct hv_device *device = stor_device->device;
1139
1140         stor_pkt = &request->vstor_packet;
1141
1142         /*
1143          * The current SCSI handling on the host side does
1144          * not correctly handle:
1145          * INQUIRY command with page code parameter set to 0x80
1146          * MODE_SENSE command with cmd[2] == 0x1c
1147          *
1148          * Setup srb and scsi status so this won't be fatal.
1149          * We do this so we can distinguish truly fatal failues
1150          * (srb status == 0x4) and off-line the device in that case.
1151          */
1152
1153         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1154            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1155                 vstor_packet->vm_srb.scsi_status = 0;
1156                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1157         }
1158
1159
1160         /* Copy over the status...etc */
1161         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1162         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1163
1164         /* Validate sense_info_length (from Hyper-V) */
1165         if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
1166                 vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1167
1168         stor_pkt->vm_srb.sense_info_length =
1169         vstor_packet->vm_srb.sense_info_length;
1170
1171         if (vstor_packet->vm_srb.scsi_status != 0 ||
1172             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1173                 storvsc_log(device, STORVSC_LOGGING_WARN,
1174                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1175                         stor_pkt->vm_srb.cdb[0],
1176                         vstor_packet->vm_srb.scsi_status,
1177                         vstor_packet->vm_srb.srb_status);
1178
1179         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1180                 /* CHECK_CONDITION */
1181                 if (vstor_packet->vm_srb.srb_status &
1182                         SRB_STATUS_AUTOSENSE_VALID) {
1183                         /* autosense data available */
1184
1185                         storvsc_log(device, STORVSC_LOGGING_WARN,
1186                                 "stor pkt %p autosense data valid - len %d\n",
1187                                 request, vstor_packet->vm_srb.sense_info_length);
1188
1189                         memcpy(request->cmd->sense_buffer,
1190                                vstor_packet->vm_srb.sense_data,
1191                                vstor_packet->vm_srb.sense_info_length);
1192
1193                 }
1194         }
1195
1196         stor_pkt->vm_srb.data_transfer_length =
1197         vstor_packet->vm_srb.data_transfer_length;
1198
1199         storvsc_command_completion(request, stor_device);
1200
1201         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1202                 stor_device->drain_notify)
1203                 wake_up(&stor_device->waiting_to_drain);
1204
1205
1206 }
1207
1208 static void storvsc_on_receive(struct storvsc_device *stor_device,
1209                              struct vstor_packet *vstor_packet,
1210                              struct storvsc_cmd_request *request)
1211 {
1212         struct hv_host_device *host_dev;
1213         switch (vstor_packet->operation) {
1214         case VSTOR_OPERATION_COMPLETE_IO:
1215                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1216                 break;
1217
1218         case VSTOR_OPERATION_REMOVE_DEVICE:
1219         case VSTOR_OPERATION_ENUMERATE_BUS:
1220                 host_dev = shost_priv(stor_device->host);
1221                 queue_work(
1222                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1223                 break;
1224
1225         case VSTOR_OPERATION_FCHBA_DATA:
1226                 cache_wwn(stor_device, vstor_packet);
1227 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1228                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1229                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1230 #endif
1231                 break;
1232         default:
1233                 break;
1234         }
1235 }
1236
1237 static void storvsc_on_channel_callback(void *context)
1238 {
1239         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1240         const struct vmpacket_descriptor *desc;
1241         struct hv_device *device;
1242         struct storvsc_device *stor_device;
1243
1244         if (channel->primary_channel != NULL)
1245                 device = channel->primary_channel->device_obj;
1246         else
1247                 device = channel->device_obj;
1248
1249         stor_device = get_in_stor_device(device);
1250         if (!stor_device)
1251                 return;
1252
1253         foreach_vmbus_pkt(desc, channel) {
1254                 void *packet = hv_pkt_data(desc);
1255                 struct storvsc_cmd_request *request;
1256                 u64 cmd_rqst;
1257
1258                 cmd_rqst = vmbus_request_addr(&channel->requestor,
1259                                               desc->trans_id);
1260                 if (cmd_rqst == VMBUS_RQST_ERROR) {
1261                         dev_err(&device->device,
1262                                 "Incorrect transaction id\n");
1263                         continue;
1264                 }
1265
1266                 request = (struct storvsc_cmd_request *)(unsigned long)cmd_rqst;
1267
1268                 if (hv_pkt_datalen(desc) < sizeof(struct vstor_packet) -
1269                                 stor_device->vmscsi_size_delta) {
1270                         dev_err(&device->device, "Invalid packet len\n");
1271                         continue;
1272                 }
1273
1274                 if (request == &stor_device->init_request ||
1275                     request == &stor_device->reset_request) {
1276                         memcpy(&request->vstor_packet, packet,
1277                                (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
1278                         complete(&request->wait_event);
1279                 } else {
1280                         storvsc_on_receive(stor_device, packet, request);
1281                 }
1282         }
1283 }
1284
1285 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1286                                   bool is_fc)
1287 {
1288         struct vmstorage_channel_properties props;
1289         int ret;
1290
1291         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1292
1293         /*
1294          * The size of vmbus_requestor is an upper bound on the number of requests
1295          * that can be in-progress at any one time across all channels.
1296          */
1297         device->channel->rqstor_size = scsi_driver.can_queue;
1298
1299         ret = vmbus_open(device->channel,
1300                          ring_size,
1301                          ring_size,
1302                          (void *)&props,
1303                          sizeof(struct vmstorage_channel_properties),
1304                          storvsc_on_channel_callback, device->channel);
1305
1306         if (ret != 0)
1307                 return ret;
1308
1309         ret = storvsc_channel_init(device, is_fc);
1310
1311         return ret;
1312 }
1313
1314 static int storvsc_dev_remove(struct hv_device *device)
1315 {
1316         struct storvsc_device *stor_device;
1317
1318         stor_device = hv_get_drvdata(device);
1319
1320         stor_device->destroy = true;
1321
1322         /* Make sure flag is set before waiting */
1323         wmb();
1324
1325         /*
1326          * At this point, all outbound traffic should be disable. We
1327          * only allow inbound traffic (responses) to proceed so that
1328          * outstanding requests can be completed.
1329          */
1330
1331         storvsc_wait_to_drain(stor_device);
1332
1333         /*
1334          * Since we have already drained, we don't need to busy wait
1335          * as was done in final_release_stor_device()
1336          * Note that we cannot set the ext pointer to NULL until
1337          * we have drained - to drain the outgoing packets, we need to
1338          * allow incoming packets.
1339          */
1340         hv_set_drvdata(device, NULL);
1341
1342         /* Close the channel */
1343         vmbus_close(device->channel);
1344
1345         kfree(stor_device->stor_chns);
1346         kfree(stor_device);
1347         return 0;
1348 }
1349
1350 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1351                                         u16 q_num)
1352 {
1353         u16 slot = 0;
1354         u16 hash_qnum;
1355         const struct cpumask *node_mask;
1356         int num_channels, tgt_cpu;
1357
1358         if (stor_device->num_sc == 0) {
1359                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1360                 return stor_device->device->channel;
1361         }
1362
1363         /*
1364          * Our channel array is sparsley populated and we
1365          * initiated I/O on a processor/hw-q that does not
1366          * currently have a designated channel. Fix this.
1367          * The strategy is simple:
1368          * I. Ensure NUMA locality
1369          * II. Distribute evenly (best effort)
1370          */
1371
1372         node_mask = cpumask_of_node(cpu_to_node(q_num));
1373
1374         num_channels = 0;
1375         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1376                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1377                         num_channels++;
1378         }
1379         if (num_channels == 0) {
1380                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1381                 return stor_device->device->channel;
1382         }
1383
1384         hash_qnum = q_num;
1385         while (hash_qnum >= num_channels)
1386                 hash_qnum -= num_channels;
1387
1388         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1389                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1390                         continue;
1391                 if (slot == hash_qnum)
1392                         break;
1393                 slot++;
1394         }
1395
1396         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1397
1398         return stor_device->stor_chns[q_num];
1399 }
1400
1401
1402 static int storvsc_do_io(struct hv_device *device,
1403                          struct storvsc_cmd_request *request, u16 q_num)
1404 {
1405         struct storvsc_device *stor_device;
1406         struct vstor_packet *vstor_packet;
1407         struct vmbus_channel *outgoing_channel, *channel;
1408         unsigned long flags;
1409         int ret = 0;
1410         const struct cpumask *node_mask;
1411         int tgt_cpu;
1412
1413         vstor_packet = &request->vstor_packet;
1414         stor_device = get_out_stor_device(device);
1415
1416         if (!stor_device)
1417                 return -ENODEV;
1418
1419
1420         request->device  = device;
1421         /*
1422          * Select an appropriate channel to send the request out.
1423          */
1424         /* See storvsc_change_target_cpu(). */
1425         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1426         if (outgoing_channel != NULL) {
1427                 if (outgoing_channel->target_cpu == q_num) {
1428                         /*
1429                          * Ideally, we want to pick a different channel if
1430                          * available on the same NUMA node.
1431                          */
1432                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1433                         for_each_cpu_wrap(tgt_cpu,
1434                                  &stor_device->alloced_cpus, q_num + 1) {
1435                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1436                                         continue;
1437                                 if (tgt_cpu == q_num)
1438                                         continue;
1439                                 channel = READ_ONCE(
1440                                         stor_device->stor_chns[tgt_cpu]);
1441                                 if (channel == NULL)
1442                                         continue;
1443                                 if (hv_get_avail_to_write_percent(
1444                                                         &channel->outbound)
1445                                                 > ring_avail_percent_lowater) {
1446                                         outgoing_channel = channel;
1447                                         goto found_channel;
1448                                 }
1449                         }
1450
1451                         /*
1452                          * All the other channels on the same NUMA node are
1453                          * busy. Try to use the channel on the current CPU
1454                          */
1455                         if (hv_get_avail_to_write_percent(
1456                                                 &outgoing_channel->outbound)
1457                                         > ring_avail_percent_lowater)
1458                                 goto found_channel;
1459
1460                         /*
1461                          * If we reach here, all the channels on the current
1462                          * NUMA node are busy. Try to find a channel in
1463                          * other NUMA nodes
1464                          */
1465                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1466                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1467                                         continue;
1468                                 channel = READ_ONCE(
1469                                         stor_device->stor_chns[tgt_cpu]);
1470                                 if (channel == NULL)
1471                                         continue;
1472                                 if (hv_get_avail_to_write_percent(
1473                                                         &channel->outbound)
1474                                                 > ring_avail_percent_lowater) {
1475                                         outgoing_channel = channel;
1476                                         goto found_channel;
1477                                 }
1478                         }
1479                 }
1480         } else {
1481                 spin_lock_irqsave(&stor_device->lock, flags);
1482                 outgoing_channel = stor_device->stor_chns[q_num];
1483                 if (outgoing_channel != NULL) {
1484                         spin_unlock_irqrestore(&stor_device->lock, flags);
1485                         goto found_channel;
1486                 }
1487                 outgoing_channel = get_og_chn(stor_device, q_num);
1488                 spin_unlock_irqrestore(&stor_device->lock, flags);
1489         }
1490
1491 found_channel:
1492         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1493
1494         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1495                                         stor_device->vmscsi_size_delta);
1496
1497
1498         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1499
1500
1501         vstor_packet->vm_srb.data_transfer_length =
1502         request->payload->range.len;
1503
1504         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1505
1506         if (request->payload->range.len) {
1507
1508                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1509                                 request->payload, request->payload_sz,
1510                                 vstor_packet,
1511                                 (sizeof(struct vstor_packet) -
1512                                 stor_device->vmscsi_size_delta),
1513                                 (unsigned long)request);
1514         } else {
1515                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1516                                (sizeof(struct vstor_packet) -
1517                                 stor_device->vmscsi_size_delta),
1518                                (unsigned long)request,
1519                                VM_PKT_DATA_INBAND,
1520                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1521         }
1522
1523         if (ret != 0)
1524                 return ret;
1525
1526         atomic_inc(&stor_device->num_outstanding_req);
1527
1528         return ret;
1529 }
1530
1531 static int storvsc_device_alloc(struct scsi_device *sdevice)
1532 {
1533         /*
1534          * Set blist flag to permit the reading of the VPD pages even when
1535          * the target may claim SPC-2 compliance. MSFT targets currently
1536          * claim SPC-2 compliance while they implement post SPC-2 features.
1537          * With this flag we can correctly handle WRITE_SAME_16 issues.
1538          *
1539          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1540          * still supports REPORT LUN.
1541          */
1542         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1543
1544         return 0;
1545 }
1546
1547 static int storvsc_device_configure(struct scsi_device *sdevice)
1548 {
1549         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1550
1551         sdevice->no_write_same = 1;
1552
1553         /*
1554          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1555          * if the device is a MSFT virtual device.  If the host is
1556          * WIN10 or newer, allow write_same.
1557          */
1558         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1559                 switch (vmstor_proto_version) {
1560                 case VMSTOR_PROTO_VERSION_WIN8:
1561                 case VMSTOR_PROTO_VERSION_WIN8_1:
1562                         sdevice->scsi_level = SCSI_SPC_3;
1563                         break;
1564                 }
1565
1566                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1567                         sdevice->no_write_same = 0;
1568         }
1569
1570         return 0;
1571 }
1572
1573 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1574                            sector_t capacity, int *info)
1575 {
1576         sector_t nsect = capacity;
1577         sector_t cylinders = nsect;
1578         int heads, sectors_pt;
1579
1580         /*
1581          * We are making up these values; let us keep it simple.
1582          */
1583         heads = 0xff;
1584         sectors_pt = 0x3f;      /* Sectors per track */
1585         sector_div(cylinders, heads * sectors_pt);
1586         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1587                 cylinders = 0xffff;
1588
1589         info[0] = heads;
1590         info[1] = sectors_pt;
1591         info[2] = (int)cylinders;
1592
1593         return 0;
1594 }
1595
1596 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1597 {
1598         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1599         struct hv_device *device = host_dev->dev;
1600
1601         struct storvsc_device *stor_device;
1602         struct storvsc_cmd_request *request;
1603         struct vstor_packet *vstor_packet;
1604         int ret, t;
1605
1606         stor_device = get_out_stor_device(device);
1607         if (!stor_device)
1608                 return FAILED;
1609
1610         request = &stor_device->reset_request;
1611         vstor_packet = &request->vstor_packet;
1612         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1613
1614         init_completion(&request->wait_event);
1615
1616         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1617         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1618         vstor_packet->vm_srb.path_id = stor_device->path_id;
1619
1620         ret = vmbus_sendpacket(device->channel, vstor_packet,
1621                                (sizeof(struct vstor_packet) -
1622                                 stor_device->vmscsi_size_delta),
1623                                (unsigned long)&stor_device->reset_request,
1624                                VM_PKT_DATA_INBAND,
1625                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1626         if (ret != 0)
1627                 return FAILED;
1628
1629         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1630         if (t == 0)
1631                 return TIMEOUT_ERROR;
1632
1633
1634         /*
1635          * At this point, all outstanding requests in the adapter
1636          * should have been flushed out and return to us
1637          * There is a potential race here where the host may be in
1638          * the process of responding when we return from here.
1639          * Just wait for all in-transit packets to be accounted for
1640          * before we return from here.
1641          */
1642         storvsc_wait_to_drain(stor_device);
1643
1644         return SUCCESS;
1645 }
1646
1647 /*
1648  * The host guarantees to respond to each command, although I/O latencies might
1649  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1650  * chance to perform EH.
1651  */
1652 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1653 {
1654 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1655         if (scmnd->device->host->transportt == fc_transport_template)
1656                 return fc_eh_timed_out(scmnd);
1657 #endif
1658         return BLK_EH_RESET_TIMER;
1659 }
1660
1661 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1662 {
1663         bool allowed = true;
1664         u8 scsi_op = scmnd->cmnd[0];
1665
1666         switch (scsi_op) {
1667         /* the host does not handle WRITE_SAME, log accident usage */
1668         case WRITE_SAME:
1669         /*
1670          * smartd sends this command and the host does not handle
1671          * this. So, don't send it.
1672          */
1673         case SET_WINDOW:
1674                 scmnd->result = DID_ERROR << 16;
1675                 allowed = false;
1676                 break;
1677         default:
1678                 break;
1679         }
1680         return allowed;
1681 }
1682
1683 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1684 {
1685         int ret;
1686         struct hv_host_device *host_dev = shost_priv(host);
1687         struct hv_device *dev = host_dev->dev;
1688         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1689         int i;
1690         struct scatterlist *sgl;
1691         unsigned int sg_count = 0;
1692         struct vmscsi_request *vm_srb;
1693         struct scatterlist *cur_sgl;
1694         struct vmbus_packet_mpb_array  *payload;
1695         u32 payload_sz;
1696         u32 length;
1697
1698         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1699                 /*
1700                  * On legacy hosts filter unimplemented commands.
1701                  * Future hosts are expected to correctly handle
1702                  * unsupported commands. Furthermore, it is
1703                  * possible that some of the currently
1704                  * unsupported commands maybe supported in
1705                  * future versions of the host.
1706                  */
1707                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1708                         scmnd->scsi_done(scmnd);
1709                         return 0;
1710                 }
1711         }
1712
1713         /* Setup the cmd request */
1714         cmd_request->cmd = scmnd;
1715
1716         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1717         vm_srb = &cmd_request->vstor_packet.vm_srb;
1718         vm_srb->win8_extension.time_out_value = 60;
1719
1720         vm_srb->win8_extension.srb_flags |=
1721                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1722
1723         if (scmnd->device->tagged_supported) {
1724                 vm_srb->win8_extension.srb_flags |=
1725                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1726                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1727                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1728         }
1729
1730         /* Build the SRB */
1731         switch (scmnd->sc_data_direction) {
1732         case DMA_TO_DEVICE:
1733                 vm_srb->data_in = WRITE_TYPE;
1734                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1735                 break;
1736         case DMA_FROM_DEVICE:
1737                 vm_srb->data_in = READ_TYPE;
1738                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1739                 break;
1740         case DMA_NONE:
1741                 vm_srb->data_in = UNKNOWN_TYPE;
1742                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1743                 break;
1744         default:
1745                 /*
1746                  * This is DMA_BIDIRECTIONAL or something else we are never
1747                  * supposed to see here.
1748                  */
1749                 WARN(1, "Unexpected data direction: %d\n",
1750                      scmnd->sc_data_direction);
1751                 return -EINVAL;
1752         }
1753
1754
1755         vm_srb->port_number = host_dev->port;
1756         vm_srb->path_id = scmnd->device->channel;
1757         vm_srb->target_id = scmnd->device->id;
1758         vm_srb->lun = scmnd->device->lun;
1759
1760         vm_srb->cdb_length = scmnd->cmd_len;
1761
1762         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1763
1764         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1765         sg_count = scsi_sg_count(scmnd);
1766
1767         length = scsi_bufflen(scmnd);
1768         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1769         payload_sz = sizeof(cmd_request->mpb);
1770
1771         if (sg_count) {
1772                 unsigned int hvpgoff = 0;
1773                 unsigned long offset_in_hvpg = sgl->offset & ~HV_HYP_PAGE_MASK;
1774                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1775                 u64 hvpfn;
1776
1777                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1778
1779                         payload_sz = (hvpg_count * sizeof(u64) +
1780                                       sizeof(struct vmbus_packet_mpb_array));
1781                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1782                         if (!payload)
1783                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1784                 }
1785
1786                 /*
1787                  * sgl is a list of PAGEs, and payload->range.pfn_array
1788                  * expects the page number in the unit of HV_HYP_PAGE_SIZE (the
1789                  * page size that Hyper-V uses, so here we need to divide PAGEs
1790                  * into HV_HYP_PAGE in case that PAGE_SIZE > HV_HYP_PAGE_SIZE.
1791                  * Besides, payload->range.offset should be the offset in one
1792                  * HV_HYP_PAGE.
1793                  */
1794                 payload->range.len = length;
1795                 payload->range.offset = offset_in_hvpg;
1796                 hvpgoff = sgl->offset >> HV_HYP_PAGE_SHIFT;
1797
1798                 cur_sgl = sgl;
1799                 for (i = 0; i < hvpg_count; i++) {
1800                         /*
1801                          * 'i' is the index of hv pages in the payload and
1802                          * 'hvpgoff' is the offset (in hv pages) of the first
1803                          * hv page in the the first page. The relationship
1804                          * between the sum of 'i' and 'hvpgoff' and the offset
1805                          * (in hv pages) in a payload page ('hvpgoff_in_page')
1806                          * is as follow:
1807                          *
1808                          * |------------------ PAGE -------------------|
1809                          * |   NR_HV_HYP_PAGES_IN_PAGE hvpgs in total  |
1810                          * |hvpg|hvpg| ...              |hvpg|... |hvpg|
1811                          * ^         ^                                 ^                 ^
1812                          * +-hvpgoff-+                                 +-hvpgoff_in_page-+
1813                          *           ^                                                   |
1814                          *           +--------------------- i ---------------------------+
1815                          */
1816                         unsigned int hvpgoff_in_page =
1817                                 (i + hvpgoff) % NR_HV_HYP_PAGES_IN_PAGE;
1818
1819                         /*
1820                          * Two cases that we need to fetch a page:
1821                          * 1) i == 0, the first step or
1822                          * 2) hvpgoff_in_page == 0, when we reach the boundary
1823                          *    of a page.
1824                          */
1825                         if (hvpgoff_in_page == 0 || i == 0) {
1826                                 hvpfn = page_to_hvpfn(sg_page(cur_sgl));
1827                                 cur_sgl = sg_next(cur_sgl);
1828                         }
1829
1830                         payload->range.pfn_array[i] = hvpfn + hvpgoff_in_page;
1831                 }
1832         }
1833
1834         cmd_request->payload = payload;
1835         cmd_request->payload_sz = payload_sz;
1836
1837         /* Invokes the vsc to start an IO */
1838         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1839         put_cpu();
1840
1841         if (ret == -EAGAIN) {
1842                 if (payload_sz > sizeof(cmd_request->mpb))
1843                         kfree(payload);
1844                 /* no more space */
1845                 return SCSI_MLQUEUE_DEVICE_BUSY;
1846         }
1847
1848         return 0;
1849 }
1850
1851 static struct scsi_host_template scsi_driver = {
1852         .module =               THIS_MODULE,
1853         .name =                 "storvsc_host_t",
1854         .cmd_size =             sizeof(struct storvsc_cmd_request),
1855         .bios_param =           storvsc_get_chs,
1856         .queuecommand =         storvsc_queuecommand,
1857         .eh_host_reset_handler =        storvsc_host_reset_handler,
1858         .proc_name =            "storvsc_host",
1859         .eh_timed_out =         storvsc_eh_timed_out,
1860         .slave_alloc =          storvsc_device_alloc,
1861         .slave_configure =      storvsc_device_configure,
1862         .cmd_per_lun =          2048,
1863         .this_id =              -1,
1864         /* Make sure we dont get a sg segment crosses a page boundary */
1865         .dma_boundary =         PAGE_SIZE-1,
1866         /* Ensure there are no gaps in presented sgls */
1867         .virt_boundary_mask =   PAGE_SIZE-1,
1868         .no_write_same =        1,
1869         .track_queue_depth =    1,
1870         .change_queue_depth =   storvsc_change_queue_depth,
1871 };
1872
1873 enum {
1874         SCSI_GUID,
1875         IDE_GUID,
1876         SFC_GUID,
1877 };
1878
1879 static const struct hv_vmbus_device_id id_table[] = {
1880         /* SCSI guid */
1881         { HV_SCSI_GUID,
1882           .driver_data = SCSI_GUID
1883         },
1884         /* IDE guid */
1885         { HV_IDE_GUID,
1886           .driver_data = IDE_GUID
1887         },
1888         /* Fibre Channel GUID */
1889         {
1890           HV_SYNTHFC_GUID,
1891           .driver_data = SFC_GUID
1892         },
1893         { },
1894 };
1895
1896 MODULE_DEVICE_TABLE(vmbus, id_table);
1897
1898 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1899
1900 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1901 {
1902         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1903 }
1904
1905 static int storvsc_probe(struct hv_device *device,
1906                         const struct hv_vmbus_device_id *dev_id)
1907 {
1908         int ret;
1909         int num_cpus = num_online_cpus();
1910         struct Scsi_Host *host;
1911         struct hv_host_device *host_dev;
1912         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1913         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1914         int target = 0;
1915         struct storvsc_device *stor_device;
1916         int max_luns_per_target;
1917         int max_targets;
1918         int max_channels;
1919         int max_sub_channels = 0;
1920
1921         /*
1922          * Based on the windows host we are running on,
1923          * set state to properly communicate with the host.
1924          */
1925
1926         if (vmbus_proto_version < VERSION_WIN8) {
1927                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1928                 max_targets = STORVSC_IDE_MAX_TARGETS;
1929                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1930         } else {
1931                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1932                 max_targets = STORVSC_MAX_TARGETS;
1933                 max_channels = STORVSC_MAX_CHANNELS;
1934                 /*
1935                  * On Windows8 and above, we support sub-channels for storage
1936                  * on SCSI and FC controllers.
1937                  * The number of sub-channels offerred is based on the number of
1938                  * VCPUs in the guest.
1939                  */
1940                 if (!dev_is_ide)
1941                         max_sub_channels =
1942                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1943         }
1944
1945         scsi_driver.can_queue = max_outstanding_req_per_channel *
1946                                 (max_sub_channels + 1) *
1947                                 (100 - ring_avail_percent_lowater) / 100;
1948
1949         host = scsi_host_alloc(&scsi_driver,
1950                                sizeof(struct hv_host_device));
1951         if (!host)
1952                 return -ENOMEM;
1953
1954         host_dev = shost_priv(host);
1955         memset(host_dev, 0, sizeof(struct hv_host_device));
1956
1957         host_dev->port = host->host_no;
1958         host_dev->dev = device;
1959         host_dev->host = host;
1960
1961
1962         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1963         if (!stor_device) {
1964                 ret = -ENOMEM;
1965                 goto err_out0;
1966         }
1967
1968         stor_device->destroy = false;
1969         init_waitqueue_head(&stor_device->waiting_to_drain);
1970         stor_device->device = device;
1971         stor_device->host = host;
1972         stor_device->vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
1973         spin_lock_init(&stor_device->lock);
1974         hv_set_drvdata(device, stor_device);
1975
1976         stor_device->port_number = host->host_no;
1977         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1978         if (ret)
1979                 goto err_out1;
1980
1981         host_dev->path = stor_device->path_id;
1982         host_dev->target = stor_device->target_id;
1983
1984         switch (dev_id->driver_data) {
1985         case SFC_GUID:
1986                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1987                 host->max_id = STORVSC_FC_MAX_TARGETS;
1988                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1989 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1990                 host->transportt = fc_transport_template;
1991 #endif
1992                 break;
1993
1994         case SCSI_GUID:
1995                 host->max_lun = max_luns_per_target;
1996                 host->max_id = max_targets;
1997                 host->max_channel = max_channels - 1;
1998                 break;
1999
2000         default:
2001                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
2002                 host->max_id = STORVSC_IDE_MAX_TARGETS;
2003                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
2004                 break;
2005         }
2006         /* max cmd length */
2007         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2008
2009         /*
2010          * set the table size based on the info we got
2011          * from the host.
2012          */
2013         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
2014         /*
2015          * For non-IDE disks, the host supports multiple channels.
2016          * Set the number of HW queues we are supporting.
2017          */
2018         if (!dev_is_ide)
2019                 host->nr_hw_queues = num_present_cpus();
2020
2021         /*
2022          * Set the error handler work queue.
2023          */
2024         host_dev->handle_error_wq =
2025                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2026                                                 WQ_MEM_RECLAIM,
2027                                                 host->host_no);
2028         if (!host_dev->handle_error_wq) {
2029                 ret = -ENOMEM;
2030                 goto err_out2;
2031         }
2032         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2033         /* Register the HBA and start the scsi bus scan */
2034         ret = scsi_add_host(host, &device->device);
2035         if (ret != 0)
2036                 goto err_out3;
2037
2038         if (!dev_is_ide) {
2039                 scsi_scan_host(host);
2040         } else {
2041                 target = (device->dev_instance.b[5] << 8 |
2042                          device->dev_instance.b[4]);
2043                 ret = scsi_add_device(host, 0, target, 0);
2044                 if (ret)
2045                         goto err_out4;
2046         }
2047 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2048         if (host->transportt == fc_transport_template) {
2049                 struct fc_rport_identifiers ids = {
2050                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2051                 };
2052
2053                 fc_host_node_name(host) = stor_device->node_name;
2054                 fc_host_port_name(host) = stor_device->port_name;
2055                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2056                 if (!stor_device->rport) {
2057                         ret = -ENOMEM;
2058                         goto err_out4;
2059                 }
2060         }
2061 #endif
2062         return 0;
2063
2064 err_out4:
2065         scsi_remove_host(host);
2066
2067 err_out3:
2068         destroy_workqueue(host_dev->handle_error_wq);
2069
2070 err_out2:
2071         /*
2072          * Once we have connected with the host, we would need to
2073          * to invoke storvsc_dev_remove() to rollback this state and
2074          * this call also frees up the stor_device; hence the jump around
2075          * err_out1 label.
2076          */
2077         storvsc_dev_remove(device);
2078         goto err_out0;
2079
2080 err_out1:
2081         kfree(stor_device->stor_chns);
2082         kfree(stor_device);
2083
2084 err_out0:
2085         scsi_host_put(host);
2086         return ret;
2087 }
2088
2089 /* Change a scsi target's queue depth */
2090 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2091 {
2092         if (queue_depth > scsi_driver.can_queue)
2093                 queue_depth = scsi_driver.can_queue;
2094
2095         return scsi_change_queue_depth(sdev, queue_depth);
2096 }
2097
2098 static int storvsc_remove(struct hv_device *dev)
2099 {
2100         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2101         struct Scsi_Host *host = stor_device->host;
2102         struct hv_host_device *host_dev = shost_priv(host);
2103
2104 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2105         if (host->transportt == fc_transport_template) {
2106                 fc_remote_port_delete(stor_device->rport);
2107                 fc_remove_host(host);
2108         }
2109 #endif
2110         destroy_workqueue(host_dev->handle_error_wq);
2111         scsi_remove_host(host);
2112         storvsc_dev_remove(dev);
2113         scsi_host_put(host);
2114
2115         return 0;
2116 }
2117
2118 static int storvsc_suspend(struct hv_device *hv_dev)
2119 {
2120         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2121         struct Scsi_Host *host = stor_device->host;
2122         struct hv_host_device *host_dev = shost_priv(host);
2123
2124         storvsc_wait_to_drain(stor_device);
2125
2126         drain_workqueue(host_dev->handle_error_wq);
2127
2128         vmbus_close(hv_dev->channel);
2129
2130         kfree(stor_device->stor_chns);
2131         stor_device->stor_chns = NULL;
2132
2133         cpumask_clear(&stor_device->alloced_cpus);
2134
2135         return 0;
2136 }
2137
2138 static int storvsc_resume(struct hv_device *hv_dev)
2139 {
2140         int ret;
2141
2142         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2143                                      hv_dev_is_fc(hv_dev));
2144         return ret;
2145 }
2146
2147 static struct hv_driver storvsc_drv = {
2148         .name = KBUILD_MODNAME,
2149         .id_table = id_table,
2150         .probe = storvsc_probe,
2151         .remove = storvsc_remove,
2152         .suspend = storvsc_suspend,
2153         .resume = storvsc_resume,
2154         .driver = {
2155                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2156         },
2157 };
2158
2159 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2160 static struct fc_function_template fc_transport_functions = {
2161         .show_host_node_name = 1,
2162         .show_host_port_name = 1,
2163 };
2164 #endif
2165
2166 static int __init storvsc_drv_init(void)
2167 {
2168         int ret;
2169
2170         /*
2171          * Divide the ring buffer data size (which is 1 page less
2172          * than the ring buffer size since that page is reserved for
2173          * the ring buffer indices) by the max request size (which is
2174          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2175          *
2176          * The computation underestimates max_outstanding_req_per_channel
2177          * for Win7 and older hosts because it does not take into account
2178          * the vmscsi_size_delta correction to the max request size.
2179          */
2180         max_outstanding_req_per_channel =
2181                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2182                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2183                 sizeof(struct vstor_packet) + sizeof(u64),
2184                 sizeof(u64)));
2185
2186 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2187         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2188         if (!fc_transport_template)
2189                 return -ENODEV;
2190 #endif
2191
2192         ret = vmbus_driver_register(&storvsc_drv);
2193
2194 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2195         if (ret)
2196                 fc_release_transport(fc_transport_template);
2197 #endif
2198
2199         return ret;
2200 }
2201
2202 static void __exit storvsc_drv_exit(void)
2203 {
2204         vmbus_driver_unregister(&storvsc_drv);
2205 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2206         fc_release_transport(fc_transport_template);
2207 #endif
2208 }
2209
2210 MODULE_LICENSE("GPL");
2211 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2212 module_init(storvsc_drv_init);
2213 module_exit(storvsc_drv_exit);