drivers/scsi/storvsc_drv.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * Authors:
   6  *   Haiyang Zhang <haiyangz@microsoft.com>
   7  *   Hank Janssen  <hjanssen@microsoft.com>
   8  *   K. Y. Srinivasan <kys@microsoft.com>
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/wait.h>
  13 #include <linux/sched.h>
  14 #include <linux/completion.h>
  15 #include <linux/string.h>
  16 #include <linux/mm.h>
  17 #include <linux/delay.h>
  18 #include <linux/init.h>
  19 #include <linux/slab.h>
  20 #include <linux/module.h>
  21 #include <linux/device.h>
  22 #include <linux/hyperv.h>
  23 #include <linux/blkdev.h>
  24 #include <scsi/scsi.h>
  25 #include <scsi/scsi_cmnd.h>
  26 #include <scsi/scsi_host.h>
  27 #include <scsi/scsi_device.h>
  28 #include <scsi/scsi_tcq.h>
  29 #include <scsi/scsi_eh.h>
  30 #include <scsi/scsi_devinfo.h>
  31 #include <scsi/scsi_dbg.h>
  32 #include <scsi/scsi_transport_fc.h>
  33 #include <scsi/scsi_transport.h>
  34
  35 /*
  36  * All wire protocol details (storage protocol between the guest and the host)
  37  * are consolidated here.
  38  *
  39  * Begin protocol definitions.
  40  */
  41
  42 /*
  43  * Version history:
  44  * V1 Beta: 0.1
  45  * V1 RC < 2008/1/31: 1.0
  46  * V1 RC > 2008/1/31:  2.0
  47  * Win7: 4.2
  48  * Win8: 5.1
  49  * Win8.1: 6.0
  50  * Win10: 6.2
  51  */
  52
  53 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  54                                                 (((MINOR_) & 0xff)))
  55
  56 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  57 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  58 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  59 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  60 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  61
  62 /*  Packet structure describing virtual storage requests. */
  63 enum vstor_packet_operation {
  64         VSTOR_OPERATION_COMPLETE_IO             = 1,
  65         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  66         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  67         VSTOR_OPERATION_RESET_LUN               = 4,
  68         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  69         VSTOR_OPERATION_RESET_BUS               = 6,
  70         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  71         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  72         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  73         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  74         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  75         VSTOR_OPERATION_FCHBA_DATA              = 12,
  76         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  77         VSTOR_OPERATION_MAXIMUM                 = 13
  78 };
  79
  80 /*
  81  * WWN packet for Fibre Channel HBA
  82  */
  83
  84 struct hv_fc_wwn_packet {
  85         u8      primary_active;
  86         u8      reserved1[3];
  87         u8      primary_port_wwn[8];
  88         u8      primary_node_wwn[8];
  89         u8      secondary_port_wwn[8];
  90         u8      secondary_node_wwn[8];
  91 };
  92
  93
  94
  95 /*
  96  * SRB Flag Bits
  97  */
  98
  99 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 100 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 101 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 102 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 103 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 104 #define SRB_FLAGS_DATA_IN                       0x00000040
 105 #define SRB_FLAGS_DATA_OUT                      0x00000080
 106 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 107 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 108 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 109 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 110 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 111
 112 /*
 113  * This flag indicates the request is part of the workflow for processing a D3.
 114  */
 115 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 116 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 117 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 118 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 119 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 120 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 121 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 122 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 123 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 124 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 125 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 126
 127 #define SP_UNTAGGED                     ((unsigned char) ~0)
 128 #define SRB_SIMPLE_TAG_REQUEST          0x20
 129
 130 /*
 131  * Platform neutral description of a scsi request -
 132  * this remains the same across the write regardless of 32/64 bit
 133  * note: it's patterned off the SCSI_PASS_THROUGH structure
 134  */
 135 #define STORVSC_MAX_CMD_LEN                     0x10
 136
 137 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 138 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 139
 140 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 141 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 142
 143 /*
 144  * Sense buffer size changed in win8; have a run-time
 145  * variable to track the size we should use.  This value will
 146  * likely change during protocol negotiation but it is valid
 147  * to start by assuming pre-Win8.
 148  */
 149 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 150
 151 /*
 152  * The storage protocol version is determined during the
 153  * initial exchange with the host.  It will indicate which
 154  * storage functionality is available in the host.
 155 */
 156 static int vmstor_proto_version;
 157
 158 #define STORVSC_LOGGING_NONE    0
 159 #define STORVSC_LOGGING_ERROR   1
 160 #define STORVSC_LOGGING_WARN    2
 161
 162 static int logging_level = STORVSC_LOGGING_ERROR;
 163 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 164 MODULE_PARM_DESC(logging_level,
 165         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 166
 167 static inline bool do_logging(int level)
 168 {
 169         return logging_level >= level;
 170 }
 171
 172 #define storvsc_log(dev, level, fmt, ...)                       \
 173 do {                                                            \
 174         if (do_logging(level))                                  \
 175                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 176 } while (0)
 177
 178 struct vmscsi_win8_extension {
 179         /*
 180          * The following were added in Windows 8
 181          */
 182         u16 reserve;
 183         u8  queue_tag;
 184         u8  queue_action;
 185         u32 srb_flags;
 186         u32 time_out_value;
 187         u32 queue_sort_ey;
 188 } __packed;
 189
 190 struct vmscsi_request {
 191         u16 length;
 192         u8 srb_status;
 193         u8 scsi_status;
 194
 195         u8  port_number;
 196         u8  path_id;
 197         u8  target_id;
 198         u8  lun;
 199
 200         u8  cdb_length;
 201         u8  sense_info_length;
 202         u8  data_in;
 203         u8  reserved;
 204
 205         u32 data_transfer_length;
 206
 207         union {
 208                 u8 cdb[STORVSC_MAX_CMD_LEN];
 209                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 210                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 211         };
 212         /*
 213          * The following was added in win8.
 214          */
 215         struct vmscsi_win8_extension win8_extension;
 216
 217 } __attribute((packed));
 218
 219
 220 /*
 221  * The size of the vmscsi_request has changed in win8. The
 222  * additional size is because of new elements added to the
 223  * structure. These elements are valid only when we are talking
 224  * to a win8 host.
 225  * Track the correction to size we need to apply. This value
 226  * will likely change during protocol negotiation but it is
 227  * valid to start by assuming pre-Win8.
 228  */
 229 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 230
 231 /*
 232  * The list of storage protocols in order of preference.
 233  */
 234 struct vmstor_protocol {
 235         int protocol_version;
 236         int sense_buffer_size;
 237         int vmscsi_size_delta;
 238 };
 239
 240
 241 static const struct vmstor_protocol vmstor_protocols[] = {
 242         {
 243                 VMSTOR_PROTO_VERSION_WIN10,
 244                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 245                 0
 246         },
 247         {
 248                 VMSTOR_PROTO_VERSION_WIN8_1,
 249                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 250                 0
 251         },
 252         {
 253                 VMSTOR_PROTO_VERSION_WIN8,
 254                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 255                 0
 256         },
 257         {
 258                 VMSTOR_PROTO_VERSION_WIN7,
 259                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 260                 sizeof(struct vmscsi_win8_extension),
 261         },
 262         {
 263                 VMSTOR_PROTO_VERSION_WIN6,
 264                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 265                 sizeof(struct vmscsi_win8_extension),
 266         }
 267 };
 268
 269
 270 /*
 271  * This structure is sent during the initialization phase to get the different
 272  * properties of the channel.
 273  */
 274
 275 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 276
 277 struct vmstorage_channel_properties {
 278         u32 reserved;
 279         u16 max_channel_cnt;
 280         u16 reserved1;
 281
 282         u32 flags;
 283         u32   max_transfer_bytes;
 284
 285         u64  reserved2;
 286 } __packed;
 287
 288 /*  This structure is sent during the storage protocol negotiations. */
 289 struct vmstorage_protocol_version {
 290         /* Major (MSW) and minor (LSW) version numbers. */
 291         u16 major_minor;
 292
 293         /*
 294          * Revision number is auto-incremented whenever this file is changed
 295          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 296          * definitely indicate incompatibility--but it does indicate mismatched
 297          * builds.
 298          * This is only used on the windows side. Just set it to 0.
 299          */
 300         u16 revision;
 301 } __packed;
 302
 303 /* Channel Property Flags */
 304 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 305 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 306
 307 struct vstor_packet {
 308         /* Requested operation type */
 309         enum vstor_packet_operation operation;
 310
 311         /*  Flags - see below for values */
 312         u32 flags;
 313
 314         /* Status of the request returned from the server side. */
 315         u32 status;
 316
 317         /* Data payload area */
 318         union {
 319                 /*
 320                  * Structure used to forward SCSI commands from the
 321                  * client to the server.
 322                  */
 323                 struct vmscsi_request vm_srb;
 324
 325                 /* Structure used to query channel properties. */
 326                 struct vmstorage_channel_properties storage_channel_properties;
 327
 328                 /* Used during version negotiations. */
 329                 struct vmstorage_protocol_version version;
 330
 331                 /* Fibre channel address packet */
 332                 struct hv_fc_wwn_packet wwn_packet;
 333
 334                 /* Number of sub-channels to create */
 335                 u16 sub_channel_count;
 336
 337                 /* This will be the maximum of the union members */
 338                 u8  buffer[0x34];
 339         };
 340 } __packed;
 341
 342 /*
 343  * Packet Flags:
 344  *
 345  * This flag indicates that the server should send back a completion for this
 346  * packet.
 347  */
 348
 349 #define REQUEST_COMPLETION_FLAG 0x1
 350
 351 /* Matches Windows-end */
 352 enum storvsc_request_type {
 353         WRITE_TYPE = 0,
 354         READ_TYPE,
 355         UNKNOWN_TYPE,
 356 };
 357
 358 /*
 359  * SRB status codes and masks; a subset of the codes used here.
 360  */
 361
 362 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 363 #define SRB_STATUS_QUEUE_FROZEN         0x40
 364 #define SRB_STATUS_INVALID_LUN  0x20
 365 #define SRB_STATUS_SUCCESS      0x01
 366 #define SRB_STATUS_ABORTED      0x02
 367 #define SRB_STATUS_ERROR        0x04
 368 #define SRB_STATUS_DATA_OVERRUN 0x12
 369
 370 #define SRB_STATUS(status) \
 371         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 372 /*
 373  * This is the end of Protocol specific defines.
 374  */
 375
 376 static int storvsc_ringbuffer_size = (128 * 1024);
 377 static u32 max_outstanding_req_per_channel;
 378 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 379
 380 static int storvsc_vcpus_per_sub_channel = 4;
 381
 382 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 383 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 384
 385 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 386 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 387
 388 static int ring_avail_percent_lowater = 10;
 389 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 390 MODULE_PARM_DESC(ring_avail_percent_lowater,
 391                 "Select a channel if available ring size > this in percent");
 392
 393 /*
 394  * Timeout in seconds for all devices managed by this driver.
 395  */
 396 static int storvsc_timeout = 180;
 397
 398 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 399 static struct scsi_transport_template *fc_transport_template;
 400 #endif
 401
 402 static void storvsc_on_channel_callback(void *context);
 403
 404 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 405 #define STORVSC_MAX_TARGETS                             2
 406 #define STORVSC_MAX_CHANNELS                            8
 407
 408 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 409 #define STORVSC_FC_MAX_TARGETS                          128
 410 #define STORVSC_FC_MAX_CHANNELS                         8
 411
 412 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 413 #define STORVSC_IDE_MAX_TARGETS                         1
 414 #define STORVSC_IDE_MAX_CHANNELS                        1
 415
 416 struct storvsc_cmd_request {
 417         struct scsi_cmnd *cmd;
 418
 419         struct hv_device *device;
 420
 421         /* Synchronize the request/response if needed */
 422         struct completion wait_event;
 423
 424         struct vmbus_channel_packet_multipage_buffer mpb;
 425         struct vmbus_packet_mpb_array *payload;
 426         u32 payload_sz;
 427
 428         struct vstor_packet vstor_packet;
 429 };
 430
 431
 432 /* A storvsc device is a device object that contains a vmbus channel */
 433 struct storvsc_device {
 434         struct hv_device *device;
 435
 436         bool     destroy;
 437         bool     drain_notify;
 438         atomic_t num_outstanding_req;
 439         struct Scsi_Host *host;
 440
 441         wait_queue_head_t waiting_to_drain;
 442
 443         /*
 444          * Each unique Port/Path/Target represents 1 channel ie scsi
 445          * controller. In reality, the pathid, targetid is always 0
 446          * and the port is set by us
 447          */
 448         unsigned int port_number;
 449         unsigned char path_id;
 450         unsigned char target_id;
 451
 452         /*
 453          * Max I/O, the device can support.
 454          */
 455         u32   max_transfer_bytes;
 456         /*
 457          * Number of sub-channels we will open.
 458          */
 459         u16 num_sc;
 460         struct vmbus_channel **stor_chns;
 461         /*
 462          * Mask of CPUs bound to subchannels.
 463          */
 464         struct cpumask alloced_cpus;
 465         /*
 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         ret = vmbus_open(new_sc,
 702                          storvsc_ringbuffer_size,
 703                          storvsc_ringbuffer_size,
 704                          (void *)&props,
 705                          sizeof(struct vmstorage_channel_properties),
 706                          storvsc_on_channel_callback, new_sc);
 707
 708         /* In case vmbus_open() fails, we don't use the sub-channel. */
 709         if (ret != 0) {
 710                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 711                 return;
 712         }
 713
 714         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 715
 716         /* Add the sub-channel to the array of available channels. */
 717         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 718         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 719 }
 720
 721 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 722 {
 723         struct device *dev = &device->device;
 724         struct storvsc_device *stor_device;
 725         int num_sc;
 726         struct storvsc_cmd_request *request;
 727         struct vstor_packet *vstor_packet;
 728         int ret, t;
 729
 730         /*
 731          * If the number of CPUs is artificially restricted, such as
 732          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 733          * sub-channels >= the number of CPUs. These sub-channels
 734          * should not be created. The primary channel is already created
 735          * and assigned to one CPU, so check against # CPUs - 1.
 736          */
 737         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 738         if (!num_sc)
 739                 return;
 740
 741         stor_device = get_out_stor_device(device);
 742         if (!stor_device)
 743                 return;
 744
 745         stor_device->num_sc = num_sc;
 746         request = &stor_device->init_request;
 747         vstor_packet = &request->vstor_packet;
 748
 749         /*
 750          * Establish a handler for dealing with subchannels.
 751          */
 752         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 753
 754         /*
 755          * Request the host to create sub-channels.
 756          */
 757         memset(request, 0, sizeof(struct storvsc_cmd_request));
 758         init_completion(&request->wait_event);
 759         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 760         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 761         vstor_packet->sub_channel_count = num_sc;
 762
 763         ret = vmbus_sendpacket(device->channel, vstor_packet,
 764                                (sizeof(struct vstor_packet) -
 765                                vmscsi_size_delta),
 766                                (unsigned long)request,
 767                                VM_PKT_DATA_INBAND,
 768                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 769
 770         if (ret != 0) {
 771                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 772                 return;
 773         }
 774
 775         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 776         if (t == 0) {
 777                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 778                 return;
 779         }
 780
 781         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 782             vstor_packet->status != 0) {
 783                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 784                         vstor_packet->operation, vstor_packet->status);
 785                 return;
 786         }
 787
 788         /*
 789          * We need to do nothing here, because vmbus_process_offer()
 790          * invokes channel->sc_creation_callback, which will open and use
 791          * the sub-channel(s).
 792          */
 793 }
 794
 795 static void cache_wwn(struct storvsc_device *stor_device,
 796                       struct vstor_packet *vstor_packet)
 797 {
 798         /*
 799          * Cache the currently active port and node ww names.
 800          */
 801         if (vstor_packet->wwn_packet.primary_active) {
 802                 stor_device->node_name =
 803                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 804                 stor_device->port_name =
 805                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 806         } else {
 807                 stor_device->node_name =
 808                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 809                 stor_device->port_name =
 810                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 811         }
 812 }
 813
 814
 815 static int storvsc_execute_vstor_op(struct hv_device *device,
 816                                     struct storvsc_cmd_request *request,
 817                                     bool status_check)
 818 {
 819         struct vstor_packet *vstor_packet;
 820         int ret, t;
 821
 822         vstor_packet = &request->vstor_packet;
 823
 824         init_completion(&request->wait_event);
 825         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 826
 827         ret = vmbus_sendpacket(device->channel, vstor_packet,
 828                                (sizeof(struct vstor_packet) -
 829                                vmscsi_size_delta),
 830                                (unsigned long)request,
 831                                VM_PKT_DATA_INBAND,
 832                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 833         if (ret != 0)
 834                 return ret;
 835
 836         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 837         if (t == 0)
 838                 return -ETIMEDOUT;
 839
 840         if (!status_check)
 841                 return ret;
 842
 843         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 844             vstor_packet->status != 0)
 845                 return -EINVAL;
 846
 847         return ret;
 848 }
 849
 850 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 851 {
 852         struct storvsc_device *stor_device;
 853         struct storvsc_cmd_request *request;
 854         struct vstor_packet *vstor_packet;
 855         int ret, i;
 856         int max_chns;
 857         bool process_sub_channels = false;
 858
 859         stor_device = get_out_stor_device(device);
 860         if (!stor_device)
 861                 return -ENODEV;
 862
 863         request = &stor_device->init_request;
 864         vstor_packet = &request->vstor_packet;
 865
 866         /*
 867          * Now, initiate the vsc/vsp initialization protocol on the open
 868          * channel
 869          */
 870         memset(request, 0, sizeof(struct storvsc_cmd_request));
 871         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 872         ret = storvsc_execute_vstor_op(device, request, true);
 873         if (ret)
 874                 return ret;
 875         /*
 876          * Query host supported protocol version.
 877          */
 878
 879         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 880                 /* reuse the packet for version range supported */
 881                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 882                 vstor_packet->operation =
 883                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 884
 885                 vstor_packet->version.major_minor =
 886                         vmstor_protocols[i].protocol_version;
 887
 888                 /*
 889                  * The revision number is only used in Windows; set it to 0.
 890                  */
 891                 vstor_packet->version.revision = 0;
 892                 ret = storvsc_execute_vstor_op(device, request, false);
 893                 if (ret != 0)
 894                         return ret;
 895
 896                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 897                         return -EINVAL;
 898
 899                 if (vstor_packet->status == 0) {
 900                         vmstor_proto_version =
 901                                 vmstor_protocols[i].protocol_version;
 902
 903                         sense_buffer_size =
 904                                 vmstor_protocols[i].sense_buffer_size;
 905
 906                         vmscsi_size_delta =
 907                                 vmstor_protocols[i].vmscsi_size_delta;
 908
 909                         break;
 910                 }
 911         }
 912
 913         if (vstor_packet->status != 0)
 914                 return -EINVAL;
 915
 916
 917         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 918         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 919         ret = storvsc_execute_vstor_op(device, request, true);
 920         if (ret != 0)
 921                 return ret;
 922
 923         /*
 924          * Check to see if multi-channel support is there.
 925          * Hosts that implement protocol version of 5.1 and above
 926          * support multi-channel.
 927          */
 928         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 929
 930         /*
 931          * Allocate state to manage the sub-channels.
 932          * We allocate an array based on the numbers of possible CPUs
 933          * (Hyper-V does not support cpu online/offline).
 934          * This Array will be sparseley populated with unique
 935          * channels - primary + sub-channels.
 936          * We will however populate all the slots to evenly distribute
 937          * the load.
 938          */
 939         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 940                                          GFP_KERNEL);
 941         if (stor_device->stor_chns == NULL)
 942                 return -ENOMEM;
 943
 944         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 945
 946         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 947         cpumask_set_cpu(device->channel->target_cpu,
 948                         &stor_device->alloced_cpus);
 949
 950         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 951                 if (vstor_packet->storage_channel_properties.flags &
 952                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 953                         process_sub_channels = true;
 954         }
 955         stor_device->max_transfer_bytes =
 956                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 957
 958         if (!is_fc)
 959                 goto done;
 960
 961         /*
 962          * For FC devices retrieve FC HBA data.
 963          */
 964         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 965         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 966         ret = storvsc_execute_vstor_op(device, request, true);
 967         if (ret != 0)
 968                 return ret;
 969
 970         /*
 971          * Cache the currently active port and node ww names.
 972          */
 973         cache_wwn(stor_device, vstor_packet);
 974
 975 done:
 976
 977         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 978         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 979         ret = storvsc_execute_vstor_op(device, request, true);
 980         if (ret != 0)
 981                 return ret;
 982
 983         if (process_sub_channels)
 984                 handle_multichannel_storage(device, max_chns);
 985
 986         return ret;
 987 }
 988
 989 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 990                                 struct scsi_cmnd *scmnd,
 991                                 struct Scsi_Host *host,
 992                                 u8 asc, u8 ascq)
 993 {
 994         struct storvsc_scan_work *wrk;
 995         void (*process_err_fn)(struct work_struct *work);
 996         struct hv_host_device *host_dev = shost_priv(host);
 997
 998         /*
 999          * In some situations, Hyper-V sets multiple bits in the
1000          * srb_status, such as ABORTED and ERROR. So process them
1001          * individually, with the most specific bits first.
1002          */
1003
1004         if (vm_srb->srb_status & SRB_STATUS_INVALID_LUN) {
1005                 set_host_byte(scmnd, DID_NO_CONNECT);
1006                 process_err_fn = storvsc_remove_lun;
1007                 goto do_work;
1008         }
1009
1010         if (vm_srb->srb_status & SRB_STATUS_ABORTED) {
1011                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
1012                     /* Capacity data has changed */
1013                     (asc == 0x2a) && (ascq == 0x9)) {
1014                         process_err_fn = storvsc_device_scan;
1015                         /*
1016                          * Retry the I/O that triggered this.
1017                          */
1018                         set_host_byte(scmnd, DID_REQUEUE);
1019                         goto do_work;
1020                 }
1021         }
1022
1023         if (vm_srb->srb_status & SRB_STATUS_ERROR) {
1024                 /*
1025                  * Let upper layer deal with error when
1026                  * sense message is present.
1027                  */
1028                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1029                         return;
1030
1031                 /*
1032                  * If there is an error; offline the device since all
1033                  * error recovery strategies would have already been
1034                  * deployed on the host side. However, if the command
1035                  * were a pass-through command deal with it appropriately.
1036                  */
1037                 switch (scmnd->cmnd[0]) {
1038                 case ATA_16:
1039                 case ATA_12:
1040                         set_host_byte(scmnd, DID_PASSTHROUGH);
1041                         break;
1042                 /*
1043                  * On some Hyper-V hosts TEST_UNIT_READY command can
1044                  * return SRB_STATUS_ERROR. Let the upper level code
1045                  * deal with it based on the sense information.
1046                  */
1047                 case TEST_UNIT_READY:
1048                         break;
1049                 default:
1050                         set_host_byte(scmnd, DID_ERROR);
1051                 }
1052         }
1053         return;
1054
1055 do_work:
1056         /*
1057          * We need to schedule work to process this error; schedule it.
1058          */
1059         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1060         if (!wrk) {
1061                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1062                 return;
1063         }
1064
1065         wrk->host = host;
1066         wrk->lun = vm_srb->lun;
1067         wrk->tgt_id = vm_srb->target_id;
1068         INIT_WORK(&wrk->work, process_err_fn);
1069         queue_work(host_dev->handle_error_wq, &wrk->work);
1070 }
1071
1072
1073 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1074                                        struct storvsc_device *stor_dev)
1075 {
1076         struct scsi_cmnd *scmnd = cmd_request->cmd;
1077         struct scsi_sense_hdr sense_hdr;
1078         struct vmscsi_request *vm_srb;
1079         u32 data_transfer_length;
1080         struct Scsi_Host *host;
1081         u32 payload_sz = cmd_request->payload_sz;
1082         void *payload = cmd_request->payload;
1083
1084         host = stor_dev->host;
1085
1086         vm_srb = &cmd_request->vstor_packet.vm_srb;
1087         data_transfer_length = vm_srb->data_transfer_length;
1088
1089         scmnd->result = vm_srb->scsi_status;
1090
1091         if (scmnd->result) {
1092                 if (scsi_normalize_sense(scmnd->sense_buffer,
1093                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1094                     !(sense_hdr.sense_key == NOT_READY &&
1095                                  sense_hdr.asc == 0x03A) &&
1096                     do_logging(STORVSC_LOGGING_ERROR))
1097                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1098                                              &sense_hdr);
1099         }
1100
1101         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1102                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1103                                          sense_hdr.ascq);
1104                 /*
1105                  * The Windows driver set data_transfer_length on
1106                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1107                  * is untouched.  In these cases we set it to 0.
1108                  */
1109                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1110                         data_transfer_length = 0;
1111         }
1112
1113         /* Validate data_transfer_length (from Hyper-V) */
1114         if (data_transfer_length > cmd_request->payload->range.len)
1115                 data_transfer_length = cmd_request->payload->range.len;
1116
1117         scsi_set_resid(scmnd,
1118                 cmd_request->payload->range.len - data_transfer_length);
1119
1120         scmnd->scsi_done(scmnd);
1121
1122         if (payload_sz >
1123                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1124                 kfree(payload);
1125 }
1126
1127 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1128                                   struct vstor_packet *vstor_packet,
1129                                   struct storvsc_cmd_request *request)
1130 {
1131         struct vstor_packet *stor_pkt;
1132         struct hv_device *device = stor_device->device;
1133
1134         stor_pkt = &request->vstor_packet;
1135
1136         /*
1137          * The current SCSI handling on the host side does
1138          * not correctly handle:
1139          * INQUIRY command with page code parameter set to 0x80
1140          * MODE_SENSE command with cmd[2] == 0x1c
1141          *
1142          * Setup srb and scsi status so this won't be fatal.
1143          * We do this so we can distinguish truly fatal failues
1144          * (srb status == 0x4) and off-line the device in that case.
1145          */
1146
1147         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1148            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1149                 vstor_packet->vm_srb.scsi_status = 0;
1150                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1151         }
1152
1153
1154         /* Copy over the status...etc */
1155         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1156         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1157
1158         /* Validate sense_info_length (from Hyper-V) */
1159         if (vstor_packet->vm_srb.sense_info_length > sense_buffer_size)
1160                 vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1161
1162         stor_pkt->vm_srb.sense_info_length =
1163         vstor_packet->vm_srb.sense_info_length;
1164
1165         if (vstor_packet->vm_srb.scsi_status != 0 ||
1166             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1167                 storvsc_log(device, STORVSC_LOGGING_WARN,
1168                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1169                         stor_pkt->vm_srb.cdb[0],
1170                         vstor_packet->vm_srb.scsi_status,
1171                         vstor_packet->vm_srb.srb_status);
1172
1173         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1174                 /* CHECK_CONDITION */
1175                 if (vstor_packet->vm_srb.srb_status &
1176                         SRB_STATUS_AUTOSENSE_VALID) {
1177                         /* autosense data available */
1178
1179                         storvsc_log(device, STORVSC_LOGGING_WARN,
1180                                 "stor pkt %p autosense data valid - len %d\n",
1181                                 request, vstor_packet->vm_srb.sense_info_length);
1182
1183                         memcpy(request->cmd->sense_buffer,
1184                                vstor_packet->vm_srb.sense_data,
1185                                vstor_packet->vm_srb.sense_info_length);
1186
1187                 }
1188         }
1189
1190         stor_pkt->vm_srb.data_transfer_length =
1191         vstor_packet->vm_srb.data_transfer_length;
1192
1193         storvsc_command_completion(request, stor_device);
1194
1195         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1196                 stor_device->drain_notify)
1197                 wake_up(&stor_device->waiting_to_drain);
1198
1199
1200 }
1201
1202 static void storvsc_on_receive(struct storvsc_device *stor_device,
1203                              struct vstor_packet *vstor_packet,
1204                              struct storvsc_cmd_request *request)
1205 {
1206         struct hv_host_device *host_dev;
1207         switch (vstor_packet->operation) {
1208         case VSTOR_OPERATION_COMPLETE_IO:
1209                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1210                 break;
1211
1212         case VSTOR_OPERATION_REMOVE_DEVICE:
1213         case VSTOR_OPERATION_ENUMERATE_BUS:
1214                 host_dev = shost_priv(stor_device->host);
1215                 queue_work(
1216                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1217                 break;
1218
1219         case VSTOR_OPERATION_FCHBA_DATA:
1220                 cache_wwn(stor_device, vstor_packet);
1221 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1222                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1223                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1224 #endif
1225                 break;
1226         default:
1227                 break;
1228         }
1229 }
1230
1231 static void storvsc_on_channel_callback(void *context)
1232 {
1233         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1234         const struct vmpacket_descriptor *desc;
1235         struct hv_device *device;
1236         struct storvsc_device *stor_device;
1237
1238         if (channel->primary_channel != NULL)
1239                 device = channel->primary_channel->device_obj;
1240         else
1241                 device = channel->device_obj;
1242
1243         stor_device = get_in_stor_device(device);
1244         if (!stor_device)
1245                 return;
1246
1247         foreach_vmbus_pkt(desc, channel) {
1248                 void *packet = hv_pkt_data(desc);
1249                 struct storvsc_cmd_request *request;
1250
1251                 request = (struct storvsc_cmd_request *)
1252                         ((unsigned long)desc->trans_id);
1253
1254                 if (request == &stor_device->init_request ||
1255                     request == &stor_device->reset_request) {
1256                         memcpy(&request->vstor_packet, packet,
1257                                (sizeof(struct vstor_packet) - vmscsi_size_delta));
1258                         complete(&request->wait_event);
1259                 } else {
1260                         storvsc_on_receive(stor_device, packet, request);
1261                 }
1262         }
1263 }
1264
1265 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1266                                   bool is_fc)
1267 {
1268         struct vmstorage_channel_properties props;
1269         int ret;
1270
1271         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1272
1273         ret = vmbus_open(device->channel,
1274                          ring_size,
1275                          ring_size,
1276                          (void *)&props,
1277                          sizeof(struct vmstorage_channel_properties),
1278                          storvsc_on_channel_callback, device->channel);
1279
1280         if (ret != 0)
1281                 return ret;
1282
1283         ret = storvsc_channel_init(device, is_fc);
1284
1285         return ret;
1286 }
1287
1288 static int storvsc_dev_remove(struct hv_device *device)
1289 {
1290         struct storvsc_device *stor_device;
1291
1292         stor_device = hv_get_drvdata(device);
1293
1294         stor_device->destroy = true;
1295
1296         /* Make sure flag is set before waiting */
1297         wmb();
1298
1299         /*
1300          * At this point, all outbound traffic should be disable. We
1301          * only allow inbound traffic (responses) to proceed so that
1302          * outstanding requests can be completed.
1303          */
1304
1305         storvsc_wait_to_drain(stor_device);
1306
1307         /*
1308          * Since we have already drained, we don't need to busy wait
1309          * as was done in final_release_stor_device()
1310          * Note that we cannot set the ext pointer to NULL until
1311          * we have drained - to drain the outgoing packets, we need to
1312          * allow incoming packets.
1313          */
1314         hv_set_drvdata(device, NULL);
1315
1316         /* Close the channel */
1317         vmbus_close(device->channel);
1318
1319         kfree(stor_device->stor_chns);
1320         kfree(stor_device);
1321         return 0;
1322 }
1323
1324 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1325                                         u16 q_num)
1326 {
1327         u16 slot = 0;
1328         u16 hash_qnum;
1329         const struct cpumask *node_mask;
1330         int num_channels, tgt_cpu;
1331
1332         if (stor_device->num_sc == 0) {
1333                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1334                 return stor_device->device->channel;
1335         }
1336
1337         /*
1338          * Our channel array is sparsley populated and we
1339          * initiated I/O on a processor/hw-q that does not
1340          * currently have a designated channel. Fix this.
1341          * The strategy is simple:
1342          * I. Ensure NUMA locality
1343          * II. Distribute evenly (best effort)
1344          */
1345
1346         node_mask = cpumask_of_node(cpu_to_node(q_num));
1347
1348         num_channels = 0;
1349         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1350                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1351                         num_channels++;
1352         }
1353         if (num_channels == 0) {
1354                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1355                 return stor_device->device->channel;
1356         }
1357
1358         hash_qnum = q_num;
1359         while (hash_qnum >= num_channels)
1360                 hash_qnum -= num_channels;
1361
1362         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1363                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1364                         continue;
1365                 if (slot == hash_qnum)
1366                         break;
1367                 slot++;
1368         }
1369
1370         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1371
1372         return stor_device->stor_chns[q_num];
1373 }
1374
1375
1376 static int storvsc_do_io(struct hv_device *device,
1377                          struct storvsc_cmd_request *request, u16 q_num)
1378 {
1379         struct storvsc_device *stor_device;
1380         struct vstor_packet *vstor_packet;
1381         struct vmbus_channel *outgoing_channel, *channel;
1382         unsigned long flags;
1383         int ret = 0;
1384         const struct cpumask *node_mask;
1385         int tgt_cpu;
1386
1387         vstor_packet = &request->vstor_packet;
1388         stor_device = get_out_stor_device(device);
1389
1390         if (!stor_device)
1391                 return -ENODEV;
1392
1393
1394         request->device  = device;
1395         /*
1396          * Select an appropriate channel to send the request out.
1397          */
1398         /* See storvsc_change_target_cpu(). */
1399         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1400         if (outgoing_channel != NULL) {
1401                 if (outgoing_channel->target_cpu == q_num) {
1402                         /*
1403                          * Ideally, we want to pick a different channel if
1404                          * available on the same NUMA node.
1405                          */
1406                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1407                         for_each_cpu_wrap(tgt_cpu,
1408                                  &stor_device->alloced_cpus, q_num + 1) {
1409                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1410                                         continue;
1411                                 if (tgt_cpu == q_num)
1412                                         continue;
1413                                 channel = READ_ONCE(
1414                                         stor_device->stor_chns[tgt_cpu]);
1415                                 if (channel == NULL)
1416                                         continue;
1417                                 if (hv_get_avail_to_write_percent(
1418                                                         &channel->outbound)
1419                                                 > ring_avail_percent_lowater) {
1420                                         outgoing_channel = channel;
1421                                         goto found_channel;
1422                                 }
1423                         }
1424
1425                         /*
1426                          * All the other channels on the same NUMA node are
1427                          * busy. Try to use the channel on the current CPU
1428                          */
1429                         if (hv_get_avail_to_write_percent(
1430                                                 &outgoing_channel->outbound)
1431                                         > ring_avail_percent_lowater)
1432                                 goto found_channel;
1433
1434                         /*
1435                          * If we reach here, all the channels on the current
1436                          * NUMA node are busy. Try to find a channel in
1437                          * other NUMA nodes
1438                          */
1439                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1440                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1441                                         continue;
1442                                 channel = READ_ONCE(
1443                                         stor_device->stor_chns[tgt_cpu]);
1444                                 if (channel == NULL)
1445                                         continue;
1446                                 if (hv_get_avail_to_write_percent(
1447                                                         &channel->outbound)
1448                                                 > ring_avail_percent_lowater) {
1449                                         outgoing_channel = channel;
1450                                         goto found_channel;
1451                                 }
1452                         }
1453                 }
1454         } else {
1455                 spin_lock_irqsave(&stor_device->lock, flags);
1456                 outgoing_channel = stor_device->stor_chns[q_num];
1457                 if (outgoing_channel != NULL) {
1458                         spin_unlock_irqrestore(&stor_device->lock, flags);
1459                         goto found_channel;
1460                 }
1461                 outgoing_channel = get_og_chn(stor_device, q_num);
1462                 spin_unlock_irqrestore(&stor_device->lock, flags);
1463         }
1464
1465 found_channel:
1466         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1467
1468         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1469                                         vmscsi_size_delta);
1470
1471
1472         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1473
1474
1475         vstor_packet->vm_srb.data_transfer_length =
1476         request->payload->range.len;
1477
1478         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1479
1480         if (request->payload->range.len) {
1481
1482                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1483                                 request->payload, request->payload_sz,
1484                                 vstor_packet,
1485                                 (sizeof(struct vstor_packet) -
1486                                 vmscsi_size_delta),
1487                                 (unsigned long)request);
1488         } else {
1489                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1490                                (sizeof(struct vstor_packet) -
1491                                 vmscsi_size_delta),
1492                                (unsigned long)request,
1493                                VM_PKT_DATA_INBAND,
1494                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1495         }
1496
1497         if (ret != 0)
1498                 return ret;
1499
1500         atomic_inc(&stor_device->num_outstanding_req);
1501
1502         return ret;
1503 }
1504
1505 static int storvsc_device_alloc(struct scsi_device *sdevice)
1506 {
1507         /*
1508          * Set blist flag to permit the reading of the VPD pages even when
1509          * the target may claim SPC-2 compliance. MSFT targets currently
1510          * claim SPC-2 compliance while they implement post SPC-2 features.
1511          * With this flag we can correctly handle WRITE_SAME_16 issues.
1512          *
1513          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1514          * still supports REPORT LUN.
1515          */
1516         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1517
1518         return 0;
1519 }
1520
1521 static int storvsc_device_configure(struct scsi_device *sdevice)
1522 {
1523         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1524
1525         sdevice->no_write_same = 1;
1526
1527         /*
1528          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1529          * if the device is a MSFT virtual device.  If the host is
1530          * WIN10 or newer, allow write_same.
1531          */
1532         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1533                 switch (vmstor_proto_version) {
1534                 case VMSTOR_PROTO_VERSION_WIN8:
1535                 case VMSTOR_PROTO_VERSION_WIN8_1:
1536                         sdevice->scsi_level = SCSI_SPC_3;
1537                         break;
1538                 }
1539
1540                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1541                         sdevice->no_write_same = 0;
1542         }
1543
1544         return 0;
1545 }
1546
1547 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1548                            sector_t capacity, int *info)
1549 {
1550         sector_t nsect = capacity;
1551         sector_t cylinders = nsect;
1552         int heads, sectors_pt;
1553
1554         /*
1555          * We are making up these values; let us keep it simple.
1556          */
1557         heads = 0xff;
1558         sectors_pt = 0x3f;      /* Sectors per track */
1559         sector_div(cylinders, heads * sectors_pt);
1560         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1561                 cylinders = 0xffff;
1562
1563         info[0] = heads;
1564         info[1] = sectors_pt;
1565         info[2] = (int)cylinders;
1566
1567         return 0;
1568 }
1569
1570 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1571 {
1572         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1573         struct hv_device *device = host_dev->dev;
1574
1575         struct storvsc_device *stor_device;
1576         struct storvsc_cmd_request *request;
1577         struct vstor_packet *vstor_packet;
1578         int ret, t;
1579
1580
1581         stor_device = get_out_stor_device(device);
1582         if (!stor_device)
1583                 return FAILED;
1584
1585         request = &stor_device->reset_request;
1586         vstor_packet = &request->vstor_packet;
1587         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1588
1589         init_completion(&request->wait_event);
1590
1591         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1592         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1593         vstor_packet->vm_srb.path_id = stor_device->path_id;
1594
1595         ret = vmbus_sendpacket(device->channel, vstor_packet,
1596                                (sizeof(struct vstor_packet) -
1597                                 vmscsi_size_delta),
1598                                (unsigned long)&stor_device->reset_request,
1599                                VM_PKT_DATA_INBAND,
1600                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1601         if (ret != 0)
1602                 return FAILED;
1603
1604         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1605         if (t == 0)
1606                 return TIMEOUT_ERROR;
1607
1608
1609         /*
1610          * At this point, all outstanding requests in the adapter
1611          * should have been flushed out and return to us
1612          * There is a potential race here where the host may be in
1613          * the process of responding when we return from here.
1614          * Just wait for all in-transit packets to be accounted for
1615          * before we return from here.
1616          */
1617         storvsc_wait_to_drain(stor_device);
1618
1619         return SUCCESS;
1620 }
1621
1622 /*
1623  * The host guarantees to respond to each command, although I/O latencies might
1624  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1625  * chance to perform EH.
1626  */
1627 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1628 {
1629 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1630         if (scmnd->device->host->transportt == fc_transport_template)
1631                 return fc_eh_timed_out(scmnd);
1632 #endif
1633         return BLK_EH_RESET_TIMER;
1634 }
1635
1636 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1637 {
1638         bool allowed = true;
1639         u8 scsi_op = scmnd->cmnd[0];
1640
1641         switch (scsi_op) {
1642         /* the host does not handle WRITE_SAME, log accident usage */
1643         case WRITE_SAME:
1644         /*
1645          * smartd sends this command and the host does not handle
1646          * this. So, don't send it.
1647          */
1648         case SET_WINDOW:
1649                 scmnd->result = ILLEGAL_REQUEST << 16;
1650                 allowed = false;
1651                 break;
1652         default:
1653                 break;
1654         }
1655         return allowed;
1656 }
1657
1658 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1659 {
1660         int ret;
1661         struct hv_host_device *host_dev = shost_priv(host);
1662         struct hv_device *dev = host_dev->dev;
1663         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1664         int i;
1665         struct scatterlist *sgl;
1666         unsigned int sg_count = 0;
1667         struct vmscsi_request *vm_srb;
1668         struct scatterlist *cur_sgl;
1669         struct vmbus_packet_mpb_array  *payload;
1670         u32 payload_sz;
1671         u32 length;
1672
1673         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1674                 /*
1675                  * On legacy hosts filter unimplemented commands.
1676                  * Future hosts are expected to correctly handle
1677                  * unsupported commands. Furthermore, it is
1678                  * possible that some of the currently
1679                  * unsupported commands maybe supported in
1680                  * future versions of the host.
1681                  */
1682                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1683                         scmnd->scsi_done(scmnd);
1684                         return 0;
1685                 }
1686         }
1687
1688         /* Setup the cmd request */
1689         cmd_request->cmd = scmnd;
1690
1691         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1692         vm_srb = &cmd_request->vstor_packet.vm_srb;
1693         vm_srb->win8_extension.time_out_value = 60;
1694
1695         vm_srb->win8_extension.srb_flags |=
1696                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1697
1698         if (scmnd->device->tagged_supported) {
1699                 vm_srb->win8_extension.srb_flags |=
1700                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1701                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1702                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1703         }
1704
1705         /* Build the SRB */
1706         switch (scmnd->sc_data_direction) {
1707         case DMA_TO_DEVICE:
1708                 vm_srb->data_in = WRITE_TYPE;
1709                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1710                 break;
1711         case DMA_FROM_DEVICE:
1712                 vm_srb->data_in = READ_TYPE;
1713                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1714                 break;
1715         case DMA_NONE:
1716                 vm_srb->data_in = UNKNOWN_TYPE;
1717                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1718                 break;
1719         default:
1720                 /*
1721                  * This is DMA_BIDIRECTIONAL or something else we are never
1722                  * supposed to see here.
1723                  */
1724                 WARN(1, "Unexpected data direction: %d\n",
1725                      scmnd->sc_data_direction);
1726                 return -EINVAL;
1727         }
1728
1729
1730         vm_srb->port_number = host_dev->port;
1731         vm_srb->path_id = scmnd->device->channel;
1732         vm_srb->target_id = scmnd->device->id;
1733         vm_srb->lun = scmnd->device->lun;
1734
1735         vm_srb->cdb_length = scmnd->cmd_len;
1736
1737         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1738
1739         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1740         sg_count = scsi_sg_count(scmnd);
1741
1742         length = scsi_bufflen(scmnd);
1743         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1744         payload_sz = sizeof(cmd_request->mpb);
1745
1746         if (sg_count) {
1747                 unsigned int hvpgoff = 0;
1748                 unsigned long offset_in_hvpg = sgl->offset & ~HV_HYP_PAGE_MASK;
1749                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1750                 u64 hvpfn;
1751
1752                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1753
1754                         payload_sz = (hvpg_count * sizeof(u64) +
1755                                       sizeof(struct vmbus_packet_mpb_array));
1756                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1757                         if (!payload)
1758                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1759                 }
1760
1761                 /*
1762                  * sgl is a list of PAGEs, and payload->range.pfn_array
1763                  * expects the page number in the unit of HV_HYP_PAGE_SIZE (the
1764                  * page size that Hyper-V uses, so here we need to divide PAGEs
1765                  * into HV_HYP_PAGE in case that PAGE_SIZE > HV_HYP_PAGE_SIZE.
1766                  * Besides, payload->range.offset should be the offset in one
1767                  * HV_HYP_PAGE.
1768                  */
1769                 payload->range.len = length;
1770                 payload->range.offset = offset_in_hvpg;
1771                 hvpgoff = sgl->offset >> HV_HYP_PAGE_SHIFT;
1772
1773                 cur_sgl = sgl;
1774                 for (i = 0; i < hvpg_count; i++) {
1775                         /*
1776                          * 'i' is the index of hv pages in the payload and
1777                          * 'hvpgoff' is the offset (in hv pages) of the first
1778                          * hv page in the the first page. The relationship
1779                          * between the sum of 'i' and 'hvpgoff' and the offset
1780                          * (in hv pages) in a payload page ('hvpgoff_in_page')
1781                          * is as follow:
1782                          *
1783                          * |------------------ PAGE -------------------|
1784                          * |   NR_HV_HYP_PAGES_IN_PAGE hvpgs in total  |
1785                          * |hvpg|hvpg| ...              |hvpg|... |hvpg|
1786                          * ^         ^                                 ^                 ^
1787                          * +-hvpgoff-+                                 +-hvpgoff_in_page-+
1788                          *           ^                                                   |
1789                          *           +--------------------- i ---------------------------+
1790                          */
1791                         unsigned int hvpgoff_in_page =
1792                                 (i + hvpgoff) % NR_HV_HYP_PAGES_IN_PAGE;
1793
1794                         /*
1795                          * Two cases that we need to fetch a page:
1796                          * 1) i == 0, the first step or
1797                          * 2) hvpgoff_in_page == 0, when we reach the boundary
1798                          *    of a page.
1799                          */
1800                         if (hvpgoff_in_page == 0 || i == 0) {
1801                                 hvpfn = page_to_hvpfn(sg_page(cur_sgl));
1802                                 cur_sgl = sg_next(cur_sgl);
1803                         }
1804
1805                         payload->range.pfn_array[i] = hvpfn + hvpgoff_in_page;
1806                 }
1807         }
1808
1809         cmd_request->payload = payload;
1810         cmd_request->payload_sz = payload_sz;
1811
1812         /* Invokes the vsc to start an IO */
1813         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1814         put_cpu();
1815
1816         if (ret == -EAGAIN) {
1817                 if (payload_sz > sizeof(cmd_request->mpb))
1818                         kfree(payload);
1819                 /* no more space */
1820                 return SCSI_MLQUEUE_DEVICE_BUSY;
1821         }
1822
1823         return 0;
1824 }
1825
1826 static struct scsi_host_template scsi_driver = {
1827         .module =               THIS_MODULE,
1828         .name =                 "storvsc_host_t",
1829         .cmd_size =             sizeof(struct storvsc_cmd_request),
1830         .bios_param =           storvsc_get_chs,
1831         .queuecommand =         storvsc_queuecommand,
1832         .eh_host_reset_handler =        storvsc_host_reset_handler,
1833         .proc_name =            "storvsc_host",
1834         .eh_timed_out =         storvsc_eh_timed_out,
1835         .slave_alloc =          storvsc_device_alloc,
1836         .slave_configure =      storvsc_device_configure,
1837         .cmd_per_lun =          2048,
1838         .this_id =              -1,
1839         /* Make sure we dont get a sg segment crosses a page boundary */
1840         .dma_boundary =         PAGE_SIZE-1,
1841         /* Ensure there are no gaps in presented sgls */
1842         .virt_boundary_mask =   PAGE_SIZE-1,
1843         .no_write_same =        1,
1844         .track_queue_depth =    1,
1845         .change_queue_depth =   storvsc_change_queue_depth,
1846 };
1847
1848 enum {
1849         SCSI_GUID,
1850         IDE_GUID,
1851         SFC_GUID,
1852 };
1853
1854 static const struct hv_vmbus_device_id id_table[] = {
1855         /* SCSI guid */
1856         { HV_SCSI_GUID,
1857           .driver_data = SCSI_GUID
1858         },
1859         /* IDE guid */
1860         { HV_IDE_GUID,
1861           .driver_data = IDE_GUID
1862         },
1863         /* Fibre Channel GUID */
1864         {
1865           HV_SYNTHFC_GUID,
1866           .driver_data = SFC_GUID
1867         },
1868         { },
1869 };
1870
1871 MODULE_DEVICE_TABLE(vmbus, id_table);
1872
1873 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1874
1875 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1876 {
1877         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1878 }
1879
1880 static int storvsc_probe(struct hv_device *device,
1881                         const struct hv_vmbus_device_id *dev_id)
1882 {
1883         int ret;
1884         int num_cpus = num_online_cpus();
1885         struct Scsi_Host *host;
1886         struct hv_host_device *host_dev;
1887         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1888         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1889         int target = 0;
1890         struct storvsc_device *stor_device;
1891         int max_luns_per_target;
1892         int max_targets;
1893         int max_channels;
1894         int max_sub_channels = 0;
1895
1896         /*
1897          * Based on the windows host we are running on,
1898          * set state to properly communicate with the host.
1899          */
1900
1901         if (vmbus_proto_version < VERSION_WIN8) {
1902                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1903                 max_targets = STORVSC_IDE_MAX_TARGETS;
1904                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1905         } else {
1906                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1907                 max_targets = STORVSC_MAX_TARGETS;
1908                 max_channels = STORVSC_MAX_CHANNELS;
1909                 /*
1910                  * On Windows8 and above, we support sub-channels for storage
1911                  * on SCSI and FC controllers.
1912                  * The number of sub-channels offerred is based on the number of
1913                  * VCPUs in the guest.
1914                  */
1915                 if (!dev_is_ide)
1916                         max_sub_channels =
1917                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1918         }
1919
1920         scsi_driver.can_queue = max_outstanding_req_per_channel *
1921                                 (max_sub_channels + 1) *
1922                                 (100 - ring_avail_percent_lowater) / 100;
1923
1924         host = scsi_host_alloc(&scsi_driver,
1925                                sizeof(struct hv_host_device));
1926         if (!host)
1927                 return -ENOMEM;
1928
1929         host_dev = shost_priv(host);
1930         memset(host_dev, 0, sizeof(struct hv_host_device));
1931
1932         host_dev->port = host->host_no;
1933         host_dev->dev = device;
1934         host_dev->host = host;
1935
1936
1937         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1938         if (!stor_device) {
1939                 ret = -ENOMEM;
1940                 goto err_out0;
1941         }
1942
1943         stor_device->destroy = false;
1944         init_waitqueue_head(&stor_device->waiting_to_drain);
1945         stor_device->device = device;
1946         stor_device->host = host;
1947         spin_lock_init(&stor_device->lock);
1948         hv_set_drvdata(device, stor_device);
1949
1950         stor_device->port_number = host->host_no;
1951         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1952         if (ret)
1953                 goto err_out1;
1954
1955         host_dev->path = stor_device->path_id;
1956         host_dev->target = stor_device->target_id;
1957
1958         switch (dev_id->driver_data) {
1959         case SFC_GUID:
1960                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1961                 host->max_id = STORVSC_FC_MAX_TARGETS;
1962                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1963 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1964                 host->transportt = fc_transport_template;
1965 #endif
1966                 break;
1967
1968         case SCSI_GUID:
1969                 host->max_lun = max_luns_per_target;
1970                 host->max_id = max_targets;
1971                 host->max_channel = max_channels - 1;
1972                 break;
1973
1974         default:
1975                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1976                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1977                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1978                 break;
1979         }
1980         /* max cmd length */
1981         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1982
1983         /*
1984          * set the table size based on the info we got
1985          * from the host.
1986          */
1987         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1988         /*
1989          * For non-IDE disks, the host supports multiple channels.
1990          * Set the number of HW queues we are supporting.
1991          */
1992         if (!dev_is_ide)
1993                 host->nr_hw_queues = num_present_cpus();
1994
1995         /*
1996          * Set the error handler work queue.
1997          */
1998         host_dev->handle_error_wq =
1999                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2000                                                 0,
2001                                                 host->host_no);
2002         if (!host_dev->handle_error_wq) {
2003                 ret = -ENOMEM;
2004                 goto err_out2;
2005         }
2006         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2007         /* Register the HBA and start the scsi bus scan */
2008         ret = scsi_add_host(host, &device->device);
2009         if (ret != 0)
2010                 goto err_out3;
2011
2012         if (!dev_is_ide) {
2013                 scsi_scan_host(host);
2014         } else {
2015                 target = (device->dev_instance.b[5] << 8 |
2016                          device->dev_instance.b[4]);
2017                 ret = scsi_add_device(host, 0, target, 0);
2018                 if (ret)
2019                         goto err_out4;
2020         }
2021 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2022         if (host->transportt == fc_transport_template) {
2023                 struct fc_rport_identifiers ids = {
2024                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2025                 };
2026
2027                 fc_host_node_name(host) = stor_device->node_name;
2028                 fc_host_port_name(host) = stor_device->port_name;
2029                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2030                 if (!stor_device->rport) {
2031                         ret = -ENOMEM;
2032                         goto err_out4;
2033                 }
2034         }
2035 #endif
2036         return 0;
2037
2038 err_out4:
2039         scsi_remove_host(host);
2040
2041 err_out3:
2042         destroy_workqueue(host_dev->handle_error_wq);
2043
2044 err_out2:
2045         /*
2046          * Once we have connected with the host, we would need to
2047          * to invoke storvsc_dev_remove() to rollback this state and
2048          * this call also frees up the stor_device; hence the jump around
2049          * err_out1 label.
2050          */
2051         storvsc_dev_remove(device);
2052         goto err_out0;
2053
2054 err_out1:
2055         kfree(stor_device->stor_chns);
2056         kfree(stor_device);
2057
2058 err_out0:
2059         scsi_host_put(host);
2060         return ret;
2061 }
2062
2063 /* Change a scsi target's queue depth */
2064 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2065 {
2066         if (queue_depth > scsi_driver.can_queue)
2067                 queue_depth = scsi_driver.can_queue;
2068
2069         return scsi_change_queue_depth(sdev, queue_depth);
2070 }
2071
2072 static int storvsc_remove(struct hv_device *dev)
2073 {
2074         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2075         struct Scsi_Host *host = stor_device->host;
2076         struct hv_host_device *host_dev = shost_priv(host);
2077
2078 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2079         if (host->transportt == fc_transport_template) {
2080                 fc_remote_port_delete(stor_device->rport);
2081                 fc_remove_host(host);
2082         }
2083 #endif
2084         destroy_workqueue(host_dev->handle_error_wq);
2085         scsi_remove_host(host);
2086         storvsc_dev_remove(dev);
2087         scsi_host_put(host);
2088
2089         return 0;
2090 }
2091
2092 static int storvsc_suspend(struct hv_device *hv_dev)
2093 {
2094         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2095         struct Scsi_Host *host = stor_device->host;
2096         struct hv_host_device *host_dev = shost_priv(host);
2097
2098         storvsc_wait_to_drain(stor_device);
2099
2100         drain_workqueue(host_dev->handle_error_wq);
2101
2102         vmbus_close(hv_dev->channel);
2103
2104         kfree(stor_device->stor_chns);
2105         stor_device->stor_chns = NULL;
2106
2107         cpumask_clear(&stor_device->alloced_cpus);
2108
2109         return 0;
2110 }
2111
2112 static int storvsc_resume(struct hv_device *hv_dev)
2113 {
2114         int ret;
2115
2116         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2117                                      hv_dev_is_fc(hv_dev));
2118         return ret;
2119 }
2120
2121 static struct hv_driver storvsc_drv = {
2122         .name = KBUILD_MODNAME,
2123         .id_table = id_table,
2124         .probe = storvsc_probe,
2125         .remove = storvsc_remove,
2126         .suspend = storvsc_suspend,
2127         .resume = storvsc_resume,
2128         .driver = {
2129                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2130         },
2131 };
2132
2133 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2134 static struct fc_function_template fc_transport_functions = {
2135         .show_host_node_name = 1,
2136         .show_host_port_name = 1,
2137 };
2138 #endif
2139
2140 static int __init storvsc_drv_init(void)
2141 {
2142         int ret;
2143
2144         /*
2145          * Divide the ring buffer data size (which is 1 page less
2146          * than the ring buffer size since that page is reserved for
2147          * the ring buffer indices) by the max request size (which is
2148          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2149          */
2150         max_outstanding_req_per_channel =
2151                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2152                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2153                 sizeof(struct vstor_packet) + sizeof(u64) -
2154                 vmscsi_size_delta,
2155                 sizeof(u64)));
2156
2157 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2158         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2159         if (!fc_transport_template)
2160                 return -ENODEV;
2161 #endif
2162
2163         ret = vmbus_driver_register(&storvsc_drv);
2164
2165 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2166         if (ret)
2167                 fc_release_transport(fc_transport_template);
2168 #endif
2169
2170         return ret;
2171 }
2172
2173 static void __exit storvsc_drv_exit(void)
2174 {
2175         vmbus_driver_unregister(&storvsc_drv);
2176 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2177         fc_release_transport(fc_transport_template);
2178 #endif
2179 }
2180
2181 MODULE_LICENSE("GPL");
2182 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2183 module_init(storvsc_drv_init);
2184 module_exit(storvsc_drv_exit);