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 <linux/dma-mapping.h>
  25
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_cmnd.h>
  28 #include <scsi/scsi_host.h>
  29 #include <scsi/scsi_device.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_devinfo.h>
  33 #include <scsi/scsi_dbg.h>
  34 #include <scsi/scsi_transport_fc.h>
  35 #include <scsi/scsi_transport.h>
  36
  37 /*
  38  * All wire protocol details (storage protocol between the guest and the host)
  39  * are consolidated here.
  40  *
  41  * Begin protocol definitions.
  42  */
  43
  44 /*
  45  * Version history:
  46  * V1 Beta: 0.1
  47  * V1 RC < 2008/1/31: 1.0
  48  * V1 RC > 2008/1/31:  2.0
  49  * Win7: 4.2
  50  * Win8: 5.1
  51  * Win8.1: 6.0
  52  * Win10: 6.2
  53  */
  54
  55 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  56                                                 (((MINOR_) & 0xff)))
  57
  58 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  59 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  60 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  61 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  62 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  63
  64 /*  Packet structure describing virtual storage requests. */
  65 enum vstor_packet_operation {
  66         VSTOR_OPERATION_COMPLETE_IO             = 1,
  67         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  68         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  69         VSTOR_OPERATION_RESET_LUN               = 4,
  70         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  71         VSTOR_OPERATION_RESET_BUS               = 6,
  72         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  73         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  74         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  75         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  76         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  77         VSTOR_OPERATION_FCHBA_DATA              = 12,
  78         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  79         VSTOR_OPERATION_MAXIMUM                 = 13
  80 };
  81
  82 /*
  83  * WWN packet for Fibre Channel HBA
  84  */
  85
  86 struct hv_fc_wwn_packet {
  87         u8      primary_active;
  88         u8      reserved1[3];
  89         u8      primary_port_wwn[8];
  90         u8      primary_node_wwn[8];
  91         u8      secondary_port_wwn[8];
  92         u8      secondary_node_wwn[8];
  93 };
  94
  95
  96
  97 /*
  98  * SRB Flag Bits
  99  */
 100
 101 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 102 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 103 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 104 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 105 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 106 #define SRB_FLAGS_DATA_IN                       0x00000040
 107 #define SRB_FLAGS_DATA_OUT                      0x00000080
 108 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 109 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 110 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 111 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 112 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 113
 114 /*
 115  * This flag indicates the request is part of the workflow for processing a D3.
 116  */
 117 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 118 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 119 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 120 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 121 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 122 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 123 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 124 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 125 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 126 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 127 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 128
 129 #define SP_UNTAGGED                     ((unsigned char) ~0)
 130 #define SRB_SIMPLE_TAG_REQUEST          0x20
 131
 132 /*
 133  * Platform neutral description of a scsi request -
 134  * this remains the same across the write regardless of 32/64 bit
 135  * note: it's patterned off the SCSI_PASS_THROUGH structure
 136  */
 137 #define STORVSC_MAX_CMD_LEN                     0x10
 138
 139 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 140 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 141
 142 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 143 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 144
 145 /*
 146  * Sense buffer size changed in win8; have a run-time
 147  * variable to track the size we should use.  This value will
 148  * likely change during protocol negotiation but it is valid
 149  * to start by assuming pre-Win8.
 150  */
 151 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 152
 153 /*
 154  * The storage protocol version is determined during the
 155  * initial exchange with the host.  It will indicate which
 156  * storage functionality is available in the host.
 157 */
 158 static int vmstor_proto_version;
 159
 160 #define STORVSC_LOGGING_NONE    0
 161 #define STORVSC_LOGGING_ERROR   1
 162 #define STORVSC_LOGGING_WARN    2
 163
 164 static int logging_level = STORVSC_LOGGING_ERROR;
 165 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 166 MODULE_PARM_DESC(logging_level,
 167         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 168
 169 static inline bool do_logging(int level)
 170 {
 171         return logging_level >= level;
 172 }
 173
 174 #define storvsc_log(dev, level, fmt, ...)                       \
 175 do {                                                            \
 176         if (do_logging(level))                                  \
 177                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 178 } while (0)
 179
 180 struct vmscsi_win8_extension {
 181         /*
 182          * The following were added in Windows 8
 183          */
 184         u16 reserve;
 185         u8  queue_tag;
 186         u8  queue_action;
 187         u32 srb_flags;
 188         u32 time_out_value;
 189         u32 queue_sort_ey;
 190 } __packed;
 191
 192 struct vmscsi_request {
 193         u16 length;
 194         u8 srb_status;
 195         u8 scsi_status;
 196
 197         u8  port_number;
 198         u8  path_id;
 199         u8  target_id;
 200         u8  lun;
 201
 202         u8  cdb_length;
 203         u8  sense_info_length;
 204         u8  data_in;
 205         u8  reserved;
 206
 207         u32 data_transfer_length;
 208
 209         union {
 210                 u8 cdb[STORVSC_MAX_CMD_LEN];
 211                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 212                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 213         };
 214         /*
 215          * The following was added in win8.
 216          */
 217         struct vmscsi_win8_extension win8_extension;
 218
 219 } __attribute((packed));
 220
 221 /*
 222  * The list of storage protocols in order of preference.
 223  */
 224 struct vmstor_protocol {
 225         int protocol_version;
 226         int sense_buffer_size;
 227         int vmscsi_size_delta;
 228 };
 229
 230
 231 static const struct vmstor_protocol vmstor_protocols[] = {
 232         {
 233                 VMSTOR_PROTO_VERSION_WIN10,
 234                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 235                 0
 236         },
 237         {
 238                 VMSTOR_PROTO_VERSION_WIN8_1,
 239                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 240                 0
 241         },
 242         {
 243                 VMSTOR_PROTO_VERSION_WIN8,
 244                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 245                 0
 246         },
 247         {
 248                 VMSTOR_PROTO_VERSION_WIN7,
 249                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 250                 sizeof(struct vmscsi_win8_extension),
 251         },
 252         {
 253                 VMSTOR_PROTO_VERSION_WIN6,
 254                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 255                 sizeof(struct vmscsi_win8_extension),
 256         }
 257 };
 258
 259
 260 /*
 261  * This structure is sent during the initialization phase to get the different
 262  * properties of the channel.
 263  */
 264
 265 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 266
 267 struct vmstorage_channel_properties {
 268         u32 reserved;
 269         u16 max_channel_cnt;
 270         u16 reserved1;
 271
 272         u32 flags;
 273         u32   max_transfer_bytes;
 274
 275         u64  reserved2;
 276 } __packed;
 277
 278 /*  This structure is sent during the storage protocol negotiations. */
 279 struct vmstorage_protocol_version {
 280         /* Major (MSW) and minor (LSW) version numbers. */
 281         u16 major_minor;
 282
 283         /*
 284          * Revision number is auto-incremented whenever this file is changed
 285          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 286          * definitely indicate incompatibility--but it does indicate mismatched
 287          * builds.
 288          * This is only used on the windows side. Just set it to 0.
 289          */
 290         u16 revision;
 291 } __packed;
 292
 293 /* Channel Property Flags */
 294 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 295 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 296
 297 struct vstor_packet {
 298         /* Requested operation type */
 299         enum vstor_packet_operation operation;
 300
 301         /*  Flags - see below for values */
 302         u32 flags;
 303
 304         /* Status of the request returned from the server side. */
 305         u32 status;
 306
 307         /* Data payload area */
 308         union {
 309                 /*
 310                  * Structure used to forward SCSI commands from the
 311                  * client to the server.
 312                  */
 313                 struct vmscsi_request vm_srb;
 314
 315                 /* Structure used to query channel properties. */
 316                 struct vmstorage_channel_properties storage_channel_properties;
 317
 318                 /* Used during version negotiations. */
 319                 struct vmstorage_protocol_version version;
 320
 321                 /* Fibre channel address packet */
 322                 struct hv_fc_wwn_packet wwn_packet;
 323
 324                 /* Number of sub-channels to create */
 325                 u16 sub_channel_count;
 326
 327                 /* This will be the maximum of the union members */
 328                 u8  buffer[0x34];
 329         };
 330 } __packed;
 331
 332 /*
 333  * Packet Flags:
 334  *
 335  * This flag indicates that the server should send back a completion for this
 336  * packet.
 337  */
 338
 339 #define REQUEST_COMPLETION_FLAG 0x1
 340
 341 /* Matches Windows-end */
 342 enum storvsc_request_type {
 343         WRITE_TYPE = 0,
 344         READ_TYPE,
 345         UNKNOWN_TYPE,
 346 };
 347
 348 /*
 349  * SRB status codes and masks; a subset of the codes used here.
 350  */
 351
 352 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 353 #define SRB_STATUS_QUEUE_FROZEN         0x40
 354 #define SRB_STATUS_INVALID_LUN  0x20
 355 #define SRB_STATUS_SUCCESS      0x01
 356 #define SRB_STATUS_ABORTED      0x02
 357 #define SRB_STATUS_ERROR        0x04
 358 #define SRB_STATUS_DATA_OVERRUN 0x12
 359
 360 #define SRB_STATUS(status) \
 361         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 362 /*
 363  * This is the end of Protocol specific defines.
 364  */
 365
 366 static int storvsc_ringbuffer_size = (128 * 1024);
 367 static u32 max_outstanding_req_per_channel;
 368 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 369
 370 static int storvsc_vcpus_per_sub_channel = 4;
 371 static unsigned int storvsc_max_hw_queues;
 372
 373 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 374 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 375
 376 module_param(storvsc_max_hw_queues, uint, 0644);
 377 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 378
 379 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 380 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 381
 382 static int ring_avail_percent_lowater = 10;
 383 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 384 MODULE_PARM_DESC(ring_avail_percent_lowater,
 385                 "Select a channel if available ring size > this in percent");
 386
 387 /*
 388  * Timeout in seconds for all devices managed by this driver.
 389  */
 390 static int storvsc_timeout = 180;
 391
 392 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 393 static struct scsi_transport_template *fc_transport_template;
 394 #endif
 395
 396 static struct scsi_host_template scsi_driver;
 397 static void storvsc_on_channel_callback(void *context);
 398
 399 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 400 #define STORVSC_MAX_TARGETS                             2
 401 #define STORVSC_MAX_CHANNELS                            8
 402
 403 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 404 #define STORVSC_FC_MAX_TARGETS                          128
 405 #define STORVSC_FC_MAX_CHANNELS                         8
 406
 407 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 408 #define STORVSC_IDE_MAX_TARGETS                         1
 409 #define STORVSC_IDE_MAX_CHANNELS                        1
 410
 411 /*
 412  * Upper bound on the size of a storvsc packet. vmscsi_size_delta is not
 413  * included in the calculation because it is set after STORVSC_MAX_PKT_SIZE
 414  * is used in storvsc_connect_to_vsp
 415  */
 416 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
 417                               sizeof(struct vstor_packet))
 418
 419 struct storvsc_cmd_request {
 420         struct scsi_cmnd *cmd;
 421
 422         struct hv_device *device;
 423
 424         /* Synchronize the request/response if needed */
 425         struct completion wait_event;
 426
 427         struct vmbus_channel_packet_multipage_buffer mpb;
 428         struct vmbus_packet_mpb_array *payload;
 429         u32 payload_sz;
 430
 431         struct vstor_packet vstor_packet;
 432 };
 433
 434
 435 /* A storvsc device is a device object that contains a vmbus channel */
 436 struct storvsc_device {
 437         struct hv_device *device;
 438
 439         bool     destroy;
 440         bool     drain_notify;
 441         atomic_t num_outstanding_req;
 442         struct Scsi_Host *host;
 443
 444         wait_queue_head_t waiting_to_drain;
 445
 446         /*
 447          * Each unique Port/Path/Target represents 1 channel ie scsi
 448          * controller. In reality, the pathid, targetid is always 0
 449          * and the port is set by us
 450          */
 451         unsigned int port_number;
 452         unsigned char path_id;
 453         unsigned char target_id;
 454
 455         /*
 456          * The size of the vmscsi_request has changed in win8. The
 457          * additional size is because of new elements added to the
 458          * structure. These elements are valid only when we are talking
 459          * to a win8 host.
 460          * Track the correction to size we need to apply. This value
 461          * will likely change during protocol negotiation but it is
 462          * valid to start by assuming pre-Win8.
 463          */
 464         int vmscsi_size_delta;
 465
 466         /*
 467          * Max I/O, the device can support.
 468          */
 469         u32   max_transfer_bytes;
 470         /*
 471          * Number of sub-channels we will open.
 472          */
 473         u16 num_sc;
 474         struct vmbus_channel **stor_chns;
 475         /*
 476          * Mask of CPUs bound to subchannels.
 477          */
 478         struct cpumask alloced_cpus;
 479         /*
 480          * Serializes modifications of stor_chns[] from storvsc_do_io()
 481          * and storvsc_change_target_cpu().
 482          */
 483         spinlock_t lock;
 484         /* Used for vsc/vsp channel reset process */
 485         struct storvsc_cmd_request init_request;
 486         struct storvsc_cmd_request reset_request;
 487         /*
 488          * Currently active port and node names for FC devices.
 489          */
 490         u64 node_name;
 491         u64 port_name;
 492 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 493         struct fc_rport *rport;
 494 #endif
 495 };
 496
 497 struct hv_host_device {
 498         struct hv_device *dev;
 499         unsigned int port;
 500         unsigned char path;
 501         unsigned char target;
 502         struct workqueue_struct *handle_error_wq;
 503         struct work_struct host_scan_work;
 504         struct Scsi_Host *host;
 505 };
 506
 507 struct storvsc_scan_work {
 508         struct work_struct work;
 509         struct Scsi_Host *host;
 510         u8 lun;
 511         u8 tgt_id;
 512 };
 513
 514 static void storvsc_device_scan(struct work_struct *work)
 515 {
 516         struct storvsc_scan_work *wrk;
 517         struct scsi_device *sdev;
 518
 519         wrk = container_of(work, struct storvsc_scan_work, work);
 520
 521         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 522         if (!sdev)
 523                 goto done;
 524         scsi_rescan_device(&sdev->sdev_gendev);
 525         scsi_device_put(sdev);
 526
 527 done:
 528         kfree(wrk);
 529 }
 530
 531 static void storvsc_host_scan(struct work_struct *work)
 532 {
 533         struct Scsi_Host *host;
 534         struct scsi_device *sdev;
 535         struct hv_host_device *host_device =
 536                 container_of(work, struct hv_host_device, host_scan_work);
 537
 538         host = host_device->host;
 539         /*
 540          * Before scanning the host, first check to see if any of the
 541          * currrently known devices have been hot removed. We issue a
 542          * "unit ready" command against all currently known devices.
 543          * This I/O will result in an error for devices that have been
 544          * removed. As part of handling the I/O error, we remove the device.
 545          *
 546          * When a LUN is added or removed, the host sends us a signal to
 547          * scan the host. Thus we are forced to discover the LUNs that
 548          * may have been removed this way.
 549          */
 550         mutex_lock(&host->scan_mutex);
 551         shost_for_each_device(sdev, host)
 552                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 553         mutex_unlock(&host->scan_mutex);
 554         /*
 555          * Now scan the host to discover LUNs that may have been added.
 556          */
 557         scsi_scan_host(host);
 558 }
 559
 560 static void storvsc_remove_lun(struct work_struct *work)
 561 {
 562         struct storvsc_scan_work *wrk;
 563         struct scsi_device *sdev;
 564
 565         wrk = container_of(work, struct storvsc_scan_work, work);
 566         if (!scsi_host_get(wrk->host))
 567                 goto done;
 568
 569         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 570
 571         if (sdev) {
 572                 scsi_remove_device(sdev);
 573                 scsi_device_put(sdev);
 574         }
 575         scsi_host_put(wrk->host);
 576
 577 done:
 578         kfree(wrk);
 579 }
 580
 581
 582 /*
 583  * We can get incoming messages from the host that are not in response to
 584  * messages that we have sent out. An example of this would be messages
 585  * received by the guest to notify dynamic addition/removal of LUNs. To
 586  * deal with potential race conditions where the driver may be in the
 587  * midst of being unloaded when we might receive an unsolicited message
 588  * from the host, we have implemented a mechanism to gurantee sequential
 589  * consistency:
 590  *
 591  * 1) Once the device is marked as being destroyed, we will fail all
 592  *    outgoing messages.
 593  * 2) We permit incoming messages when the device is being destroyed,
 594  *    only to properly account for messages already sent out.
 595  */
 596
 597 static inline struct storvsc_device *get_out_stor_device(
 598                                         struct hv_device *device)
 599 {
 600         struct storvsc_device *stor_device;
 601
 602         stor_device = hv_get_drvdata(device);
 603
 604         if (stor_device && stor_device->destroy)
 605                 stor_device = NULL;
 606
 607         return stor_device;
 608 }
 609
 610
 611 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 612 {
 613         dev->drain_notify = true;
 614         wait_event(dev->waiting_to_drain,
 615                    atomic_read(&dev->num_outstanding_req) == 0);
 616         dev->drain_notify = false;
 617 }
 618
 619 static inline struct storvsc_device *get_in_stor_device(
 620                                         struct hv_device *device)
 621 {
 622         struct storvsc_device *stor_device;
 623
 624         stor_device = hv_get_drvdata(device);
 625
 626         if (!stor_device)
 627                 goto get_in_err;
 628
 629         /*
 630          * If the device is being destroyed; allow incoming
 631          * traffic only to cleanup outstanding requests.
 632          */
 633
 634         if (stor_device->destroy  &&
 635                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 636                 stor_device = NULL;
 637
 638 get_in_err:
 639         return stor_device;
 640
 641 }
 642
 643 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 644                                       u32 new)
 645 {
 646         struct storvsc_device *stor_device;
 647         struct vmbus_channel *cur_chn;
 648         bool old_is_alloced = false;
 649         struct hv_device *device;
 650         unsigned long flags;
 651         int cpu;
 652
 653         device = channel->primary_channel ?
 654                         channel->primary_channel->device_obj
 655                                 : channel->device_obj;
 656         stor_device = get_out_stor_device(device);
 657         if (!stor_device)
 658                 return;
 659
 660         /* See storvsc_do_io() -> get_og_chn(). */
 661         spin_lock_irqsave(&stor_device->lock, flags);
 662
 663         /*
 664          * Determines if the storvsc device has other channels assigned to
 665          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 666          * array.
 667          */
 668         if (device->channel != channel && device->channel->target_cpu == old) {
 669                 cur_chn = device->channel;
 670                 old_is_alloced = true;
 671                 goto old_is_alloced;
 672         }
 673         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 674                 if (cur_chn == channel)
 675                         continue;
 676                 if (cur_chn->target_cpu == old) {
 677                         old_is_alloced = true;
 678                         goto old_is_alloced;
 679                 }
 680         }
 681
 682 old_is_alloced:
 683         if (old_is_alloced)
 684                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 685         else
 686                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 687
 688         /* "Flush" the stor_chns array. */
 689         for_each_possible_cpu(cpu) {
 690                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 691                                         cpu, &stor_device->alloced_cpus))
 692                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 693         }
 694
 695         WRITE_ONCE(stor_device->stor_chns[new], channel);
 696         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 697
 698         spin_unlock_irqrestore(&stor_device->lock, flags);
 699 }
 700
 701 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 702 {
 703         struct storvsc_cmd_request *request =
 704                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
 705
 706         if (rqst_addr == VMBUS_RQST_INIT)
 707                 return VMBUS_RQST_INIT;
 708         if (rqst_addr == VMBUS_RQST_RESET)
 709                 return VMBUS_RQST_RESET;
 710
 711         /*
 712          * Cannot return an ID of 0, which is reserved for an unsolicited
 713          * message from Hyper-V.
 714          */
 715         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
 716 }
 717
 718 static void handle_sc_creation(struct vmbus_channel *new_sc)
 719 {
 720         struct hv_device *device = new_sc->primary_channel->device_obj;
 721         struct device *dev = &device->device;
 722         struct storvsc_device *stor_device;
 723         struct vmstorage_channel_properties props;
 724         int ret;
 725
 726         stor_device = get_out_stor_device(device);
 727         if (!stor_device)
 728                 return;
 729
 730         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 731         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
 732
 733         new_sc->next_request_id_callback = storvsc_next_request_id;
 734
 735         ret = vmbus_open(new_sc,
 736                          storvsc_ringbuffer_size,
 737                          storvsc_ringbuffer_size,
 738                          (void *)&props,
 739                          sizeof(struct vmstorage_channel_properties),
 740                          storvsc_on_channel_callback, new_sc);
 741
 742         /* In case vmbus_open() fails, we don't use the sub-channel. */
 743         if (ret != 0) {
 744                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 745                 return;
 746         }
 747
 748         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 749
 750         /* Add the sub-channel to the array of available channels. */
 751         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 752         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 753 }
 754
 755 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 756 {
 757         struct device *dev = &device->device;
 758         struct storvsc_device *stor_device;
 759         int num_sc;
 760         struct storvsc_cmd_request *request;
 761         struct vstor_packet *vstor_packet;
 762         int ret, t;
 763
 764         /*
 765          * If the number of CPUs is artificially restricted, such as
 766          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 767          * sub-channels >= the number of CPUs. These sub-channels
 768          * should not be created. The primary channel is already created
 769          * and assigned to one CPU, so check against # CPUs - 1.
 770          */
 771         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 772         if (!num_sc)
 773                 return;
 774
 775         stor_device = get_out_stor_device(device);
 776         if (!stor_device)
 777                 return;
 778
 779         stor_device->num_sc = num_sc;
 780         request = &stor_device->init_request;
 781         vstor_packet = &request->vstor_packet;
 782
 783         /*
 784          * Establish a handler for dealing with subchannels.
 785          */
 786         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 787
 788         /*
 789          * Request the host to create sub-channels.
 790          */
 791         memset(request, 0, sizeof(struct storvsc_cmd_request));
 792         init_completion(&request->wait_event);
 793         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 794         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 795         vstor_packet->sub_channel_count = num_sc;
 796
 797         ret = vmbus_sendpacket(device->channel, vstor_packet,
 798                                (sizeof(struct vstor_packet) -
 799                                stor_device->vmscsi_size_delta),
 800                                VMBUS_RQST_INIT,
 801                                VM_PKT_DATA_INBAND,
 802                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 803
 804         if (ret != 0) {
 805                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 806                 return;
 807         }
 808
 809         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 810         if (t == 0) {
 811                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 812                 return;
 813         }
 814
 815         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 816             vstor_packet->status != 0) {
 817                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 818                         vstor_packet->operation, vstor_packet->status);
 819                 return;
 820         }
 821
 822         /*
 823          * We need to do nothing here, because vmbus_process_offer()
 824          * invokes channel->sc_creation_callback, which will open and use
 825          * the sub-channel(s).
 826          */
 827 }
 828
 829 static void cache_wwn(struct storvsc_device *stor_device,
 830                       struct vstor_packet *vstor_packet)
 831 {
 832         /*
 833          * Cache the currently active port and node ww names.
 834          */
 835         if (vstor_packet->wwn_packet.primary_active) {
 836                 stor_device->node_name =
 837                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 838                 stor_device->port_name =
 839                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 840         } else {
 841                 stor_device->node_name =
 842                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 843                 stor_device->port_name =
 844                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 845         }
 846 }
 847
 848
 849 static int storvsc_execute_vstor_op(struct hv_device *device,
 850                                     struct storvsc_cmd_request *request,
 851                                     bool status_check)
 852 {
 853         struct storvsc_device *stor_device;
 854         struct vstor_packet *vstor_packet;
 855         int ret, t;
 856
 857         stor_device = get_out_stor_device(device);
 858         if (!stor_device)
 859                 return -ENODEV;
 860
 861         vstor_packet = &request->vstor_packet;
 862
 863         init_completion(&request->wait_event);
 864         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 865
 866         ret = vmbus_sendpacket(device->channel, vstor_packet,
 867                                (sizeof(struct vstor_packet) -
 868                                stor_device->vmscsi_size_delta),
 869                                VMBUS_RQST_INIT,
 870                                VM_PKT_DATA_INBAND,
 871                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 872         if (ret != 0)
 873                 return ret;
 874
 875         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 876         if (t == 0)
 877                 return -ETIMEDOUT;
 878
 879         if (!status_check)
 880                 return ret;
 881
 882         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 883             vstor_packet->status != 0)
 884                 return -EINVAL;
 885
 886         return ret;
 887 }
 888
 889 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 890 {
 891         struct storvsc_device *stor_device;
 892         struct storvsc_cmd_request *request;
 893         struct vstor_packet *vstor_packet;
 894         int ret, i;
 895         int max_chns;
 896         bool process_sub_channels = false;
 897
 898         stor_device = get_out_stor_device(device);
 899         if (!stor_device)
 900                 return -ENODEV;
 901
 902         request = &stor_device->init_request;
 903         vstor_packet = &request->vstor_packet;
 904
 905         /*
 906          * Now, initiate the vsc/vsp initialization protocol on the open
 907          * channel
 908          */
 909         memset(request, 0, sizeof(struct storvsc_cmd_request));
 910         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 911         ret = storvsc_execute_vstor_op(device, request, true);
 912         if (ret)
 913                 return ret;
 914         /*
 915          * Query host supported protocol version.
 916          */
 917
 918         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 919                 /* reuse the packet for version range supported */
 920                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 921                 vstor_packet->operation =
 922                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 923
 924                 vstor_packet->version.major_minor =
 925                         vmstor_protocols[i].protocol_version;
 926
 927                 /*
 928                  * The revision number is only used in Windows; set it to 0.
 929                  */
 930                 vstor_packet->version.revision = 0;
 931                 ret = storvsc_execute_vstor_op(device, request, false);
 932                 if (ret != 0)
 933                         return ret;
 934
 935                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 936                         return -EINVAL;
 937
 938                 if (vstor_packet->status == 0) {
 939                         vmstor_proto_version =
 940                                 vmstor_protocols[i].protocol_version;
 941
 942                         sense_buffer_size =
 943                                 vmstor_protocols[i].sense_buffer_size;
 944
 945                         stor_device->vmscsi_size_delta =
 946                                 vmstor_protocols[i].vmscsi_size_delta;
 947
 948                         break;
 949                 }
 950         }
 951
 952         if (vstor_packet->status != 0)
 953                 return -EINVAL;
 954
 955
 956         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 957         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 958         ret = storvsc_execute_vstor_op(device, request, true);
 959         if (ret != 0)
 960                 return ret;
 961
 962         /*
 963          * Check to see if multi-channel support is there.
 964          * Hosts that implement protocol version of 5.1 and above
 965          * support multi-channel.
 966          */
 967         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 968
 969         /*
 970          * Allocate state to manage the sub-channels.
 971          * We allocate an array based on the numbers of possible CPUs
 972          * (Hyper-V does not support cpu online/offline).
 973          * This Array will be sparseley populated with unique
 974          * channels - primary + sub-channels.
 975          * We will however populate all the slots to evenly distribute
 976          * the load.
 977          */
 978         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 979                                          GFP_KERNEL);
 980         if (stor_device->stor_chns == NULL)
 981                 return -ENOMEM;
 982
 983         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 984
 985         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 986         cpumask_set_cpu(device->channel->target_cpu,
 987                         &stor_device->alloced_cpus);
 988
 989         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 990                 if (vstor_packet->storage_channel_properties.flags &
 991                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 992                         process_sub_channels = true;
 993         }
 994         stor_device->max_transfer_bytes =
 995                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 996
 997         if (!is_fc)
 998                 goto done;
 999
1000         /*
1001          * For FC devices retrieve FC HBA data.
1002          */
1003         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1004         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
1005         ret = storvsc_execute_vstor_op(device, request, true);
1006         if (ret != 0)
1007                 return ret;
1008
1009         /*
1010          * Cache the currently active port and node ww names.
1011          */
1012         cache_wwn(stor_device, vstor_packet);
1013
1014 done:
1015
1016         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1017         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
1018         ret = storvsc_execute_vstor_op(device, request, true);
1019         if (ret != 0)
1020                 return ret;
1021
1022         if (process_sub_channels)
1023                 handle_multichannel_storage(device, max_chns);
1024
1025         return ret;
1026 }
1027
1028 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
1029                                 struct scsi_cmnd *scmnd,
1030                                 struct Scsi_Host *host,
1031                                 u8 asc, u8 ascq)
1032 {
1033         struct storvsc_scan_work *wrk;
1034         void (*process_err_fn)(struct work_struct *work);
1035         struct hv_host_device *host_dev = shost_priv(host);
1036
1037         /*
1038          * In some situations, Hyper-V sets multiple bits in the
1039          * srb_status, such as ABORTED and ERROR. So process them
1040          * individually, with the most specific bits first.
1041          */
1042
1043         if (vm_srb->srb_status & SRB_STATUS_INVALID_LUN) {
1044                 set_host_byte(scmnd, DID_NO_CONNECT);
1045                 process_err_fn = storvsc_remove_lun;
1046                 goto do_work;
1047         }
1048
1049         if (vm_srb->srb_status & SRB_STATUS_ABORTED) {
1050                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
1051                     /* Capacity data has changed */
1052                     (asc == 0x2a) && (ascq == 0x9)) {
1053                         process_err_fn = storvsc_device_scan;
1054                         /*
1055                          * Retry the I/O that triggered this.
1056                          */
1057                         set_host_byte(scmnd, DID_REQUEUE);
1058                         goto do_work;
1059                 }
1060         }
1061
1062         if (vm_srb->srb_status & SRB_STATUS_ERROR) {
1063                 /*
1064                  * Let upper layer deal with error when
1065                  * sense message is present.
1066                  */
1067                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
1068                         return;
1069
1070                 /*
1071                  * If there is an error; offline the device since all
1072                  * error recovery strategies would have already been
1073                  * deployed on the host side. However, if the command
1074                  * were a pass-through command deal with it appropriately.
1075                  */
1076                 switch (scmnd->cmnd[0]) {
1077                 case ATA_16:
1078                 case ATA_12:
1079                         set_host_byte(scmnd, DID_PASSTHROUGH);
1080                         break;
1081                 /*
1082                  * On some Hyper-V hosts TEST_UNIT_READY command can
1083                  * return SRB_STATUS_ERROR. Let the upper level code
1084                  * deal with it based on the sense information.
1085                  */
1086                 case TEST_UNIT_READY:
1087                         break;
1088                 default:
1089                         set_host_byte(scmnd, DID_ERROR);
1090                 }
1091         }
1092         return;
1093
1094 do_work:
1095         /*
1096          * We need to schedule work to process this error; schedule it.
1097          */
1098         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1099         if (!wrk) {
1100                 set_host_byte(scmnd, DID_TARGET_FAILURE);
1101                 return;
1102         }
1103
1104         wrk->host = host;
1105         wrk->lun = vm_srb->lun;
1106         wrk->tgt_id = vm_srb->target_id;
1107         INIT_WORK(&wrk->work, process_err_fn);
1108         queue_work(host_dev->handle_error_wq, &wrk->work);
1109 }
1110
1111
1112 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1113                                        struct storvsc_device *stor_dev)
1114 {
1115         struct scsi_cmnd *scmnd = cmd_request->cmd;
1116         struct scsi_sense_hdr sense_hdr;
1117         struct vmscsi_request *vm_srb;
1118         u32 data_transfer_length;
1119         struct Scsi_Host *host;
1120         u32 payload_sz = cmd_request->payload_sz;
1121         void *payload = cmd_request->payload;
1122         bool sense_ok;
1123
1124         host = stor_dev->host;
1125
1126         vm_srb = &cmd_request->vstor_packet.vm_srb;
1127         data_transfer_length = vm_srb->data_transfer_length;
1128
1129         scmnd->result = vm_srb->scsi_status;
1130
1131         if (scmnd->result) {
1132                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1133                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1134
1135                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1136                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1137                                              &sense_hdr);
1138         }
1139
1140         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1141                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1142                                          sense_hdr.ascq);
1143                 /*
1144                  * The Windows driver set data_transfer_length on
1145                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1146                  * is untouched.  In these cases we set it to 0.
1147                  */
1148                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1149                         data_transfer_length = 0;
1150         }
1151
1152         /* Validate data_transfer_length (from Hyper-V) */
1153         if (data_transfer_length > cmd_request->payload->range.len)
1154                 data_transfer_length = cmd_request->payload->range.len;
1155
1156         scsi_set_resid(scmnd,
1157                 cmd_request->payload->range.len - data_transfer_length);
1158
1159         scsi_done(scmnd);
1160
1161         if (payload_sz >
1162                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1163                 kfree(payload);
1164 }
1165
1166 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1167                                   struct vstor_packet *vstor_packet,
1168                                   struct storvsc_cmd_request *request)
1169 {
1170         struct vstor_packet *stor_pkt;
1171         struct hv_device *device = stor_device->device;
1172
1173         stor_pkt = &request->vstor_packet;
1174
1175         /*
1176          * The current SCSI handling on the host side does
1177          * not correctly handle:
1178          * INQUIRY command with page code parameter set to 0x80
1179          * MODE_SENSE command with cmd[2] == 0x1c
1180          *
1181          * Setup srb and scsi status so this won't be fatal.
1182          * We do this so we can distinguish truly fatal failues
1183          * (srb status == 0x4) and off-line the device in that case.
1184          */
1185
1186         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1187            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1188                 vstor_packet->vm_srb.scsi_status = 0;
1189                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1190         }
1191
1192         /* Copy over the status...etc */
1193         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1194         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1195
1196         /*
1197          * Copy over the sense_info_length, but limit to the known max
1198          * size if Hyper-V returns a bad value.
1199          */
1200         stor_pkt->vm_srb.sense_info_length = min_t(u8, sense_buffer_size,
1201                 vstor_packet->vm_srb.sense_info_length);
1202
1203         if (vstor_packet->vm_srb.scsi_status != 0 ||
1204             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1205
1206                 /*
1207                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1208                  * return errors when detecting devices using TEST_UNIT_READY,
1209                  * and logging these as errors produces unhelpful noise.
1210                  */
1211                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1212                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1213
1214                 storvsc_log(device, loglevel,
1215                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1216                         scsi_cmd_to_rq(request->cmd)->tag,
1217                         stor_pkt->vm_srb.cdb[0],
1218                         vstor_packet->vm_srb.scsi_status,
1219                         vstor_packet->vm_srb.srb_status,
1220                         vstor_packet->status);
1221         }
1222
1223         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1224             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1225                 memcpy(request->cmd->sense_buffer,
1226                        vstor_packet->vm_srb.sense_data,
1227                        stor_pkt->vm_srb.sense_info_length);
1228
1229         stor_pkt->vm_srb.data_transfer_length =
1230                 vstor_packet->vm_srb.data_transfer_length;
1231
1232         storvsc_command_completion(request, stor_device);
1233
1234         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1235                 stor_device->drain_notify)
1236                 wake_up(&stor_device->waiting_to_drain);
1237 }
1238
1239 static void storvsc_on_receive(struct storvsc_device *stor_device,
1240                              struct vstor_packet *vstor_packet,
1241                              struct storvsc_cmd_request *request)
1242 {
1243         struct hv_host_device *host_dev;
1244         switch (vstor_packet->operation) {
1245         case VSTOR_OPERATION_COMPLETE_IO:
1246                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1247                 break;
1248
1249         case VSTOR_OPERATION_REMOVE_DEVICE:
1250         case VSTOR_OPERATION_ENUMERATE_BUS:
1251                 host_dev = shost_priv(stor_device->host);
1252                 queue_work(
1253                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1254                 break;
1255
1256         case VSTOR_OPERATION_FCHBA_DATA:
1257                 cache_wwn(stor_device, vstor_packet);
1258 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1259                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1260                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1261 #endif
1262                 break;
1263         default:
1264                 break;
1265         }
1266 }
1267
1268 static void storvsc_on_channel_callback(void *context)
1269 {
1270         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1271         const struct vmpacket_descriptor *desc;
1272         struct hv_device *device;
1273         struct storvsc_device *stor_device;
1274         struct Scsi_Host *shost;
1275
1276         if (channel->primary_channel != NULL)
1277                 device = channel->primary_channel->device_obj;
1278         else
1279                 device = channel->device_obj;
1280
1281         stor_device = get_in_stor_device(device);
1282         if (!stor_device)
1283                 return;
1284
1285         shost = stor_device->host;
1286
1287         foreach_vmbus_pkt(desc, channel) {
1288                 struct vstor_packet *packet = hv_pkt_data(desc);
1289                 struct storvsc_cmd_request *request = NULL;
1290                 u32 pktlen = hv_pkt_datalen(desc);
1291                 u64 rqst_id = desc->trans_id;
1292                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) -
1293                         stor_device->vmscsi_size_delta : sizeof(enum vstor_packet_operation);
1294
1295                 if (pktlen < minlen) {
1296                         dev_err(&device->device,
1297                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1298                                 rqst_id, pktlen, minlen);
1299                         continue;
1300                 }
1301
1302                 if (rqst_id == VMBUS_RQST_INIT) {
1303                         request = &stor_device->init_request;
1304                 } else if (rqst_id == VMBUS_RQST_RESET) {
1305                         request = &stor_device->reset_request;
1306                 } else {
1307                         /* Hyper-V can send an unsolicited message with ID of 0 */
1308                         if (rqst_id == 0) {
1309                                 /*
1310                                  * storvsc_on_receive() looks at the vstor_packet in the message
1311                                  * from the ring buffer.
1312                                  *
1313                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1314                                  *   we call storvsc_on_io_completion(), and dereference the
1315                                  *   guest memory address.  Make sure we don't call
1316                                  *   storvsc_on_io_completion() with a guest memory address
1317                                  *   that is zero if Hyper-V were to construct and send such
1318                                  *   a bogus packet.
1319                                  *
1320                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1321                                  *   we call cache_wwn(), and access the data payload area of
1322                                  *   the packet (wwn_packet); however, there is no guarantee
1323                                  *   that the packet is big enough to contain such area.
1324                                  *   Future-proof the code by rejecting such a bogus packet.
1325                                  */
1326                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1327                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1328                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1329                                         continue;
1330                                 }
1331                         } else {
1332                                 struct scsi_cmnd *scmnd;
1333
1334                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1335                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1336                                 if (scmnd == NULL) {
1337                                         dev_err(&device->device, "Incorrect transaction ID\n");
1338                                         continue;
1339                                 }
1340                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1341                                 scsi_dma_unmap(scmnd);
1342                         }
1343
1344                         storvsc_on_receive(stor_device, packet, request);
1345                         continue;
1346                 }
1347
1348                 memcpy(&request->vstor_packet, packet,
1349                        (sizeof(struct vstor_packet) - stor_device->vmscsi_size_delta));
1350                 complete(&request->wait_event);
1351         }
1352 }
1353
1354 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1355                                   bool is_fc)
1356 {
1357         struct vmstorage_channel_properties props;
1358         int ret;
1359
1360         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1361
1362         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1363         device->channel->next_request_id_callback = storvsc_next_request_id;
1364
1365         ret = vmbus_open(device->channel,
1366                          ring_size,
1367                          ring_size,
1368                          (void *)&props,
1369                          sizeof(struct vmstorage_channel_properties),
1370                          storvsc_on_channel_callback, device->channel);
1371
1372         if (ret != 0)
1373                 return ret;
1374
1375         ret = storvsc_channel_init(device, is_fc);
1376
1377         return ret;
1378 }
1379
1380 static int storvsc_dev_remove(struct hv_device *device)
1381 {
1382         struct storvsc_device *stor_device;
1383
1384         stor_device = hv_get_drvdata(device);
1385
1386         stor_device->destroy = true;
1387
1388         /* Make sure flag is set before waiting */
1389         wmb();
1390
1391         /*
1392          * At this point, all outbound traffic should be disable. We
1393          * only allow inbound traffic (responses) to proceed so that
1394          * outstanding requests can be completed.
1395          */
1396
1397         storvsc_wait_to_drain(stor_device);
1398
1399         /*
1400          * Since we have already drained, we don't need to busy wait
1401          * as was done in final_release_stor_device()
1402          * Note that we cannot set the ext pointer to NULL until
1403          * we have drained - to drain the outgoing packets, we need to
1404          * allow incoming packets.
1405          */
1406         hv_set_drvdata(device, NULL);
1407
1408         /* Close the channel */
1409         vmbus_close(device->channel);
1410
1411         kfree(stor_device->stor_chns);
1412         kfree(stor_device);
1413         return 0;
1414 }
1415
1416 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1417                                         u16 q_num)
1418 {
1419         u16 slot = 0;
1420         u16 hash_qnum;
1421         const struct cpumask *node_mask;
1422         int num_channels, tgt_cpu;
1423
1424         if (stor_device->num_sc == 0) {
1425                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1426                 return stor_device->device->channel;
1427         }
1428
1429         /*
1430          * Our channel array is sparsley populated and we
1431          * initiated I/O on a processor/hw-q that does not
1432          * currently have a designated channel. Fix this.
1433          * The strategy is simple:
1434          * I. Ensure NUMA locality
1435          * II. Distribute evenly (best effort)
1436          */
1437
1438         node_mask = cpumask_of_node(cpu_to_node(q_num));
1439
1440         num_channels = 0;
1441         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1442                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1443                         num_channels++;
1444         }
1445         if (num_channels == 0) {
1446                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1447                 return stor_device->device->channel;
1448         }
1449
1450         hash_qnum = q_num;
1451         while (hash_qnum >= num_channels)
1452                 hash_qnum -= num_channels;
1453
1454         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1455                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1456                         continue;
1457                 if (slot == hash_qnum)
1458                         break;
1459                 slot++;
1460         }
1461
1462         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1463
1464         return stor_device->stor_chns[q_num];
1465 }
1466
1467
1468 static int storvsc_do_io(struct hv_device *device,
1469                          struct storvsc_cmd_request *request, u16 q_num)
1470 {
1471         struct storvsc_device *stor_device;
1472         struct vstor_packet *vstor_packet;
1473         struct vmbus_channel *outgoing_channel, *channel;
1474         unsigned long flags;
1475         int ret = 0;
1476         const struct cpumask *node_mask;
1477         int tgt_cpu;
1478
1479         vstor_packet = &request->vstor_packet;
1480         stor_device = get_out_stor_device(device);
1481
1482         if (!stor_device)
1483                 return -ENODEV;
1484
1485
1486         request->device  = device;
1487         /*
1488          * Select an appropriate channel to send the request out.
1489          */
1490         /* See storvsc_change_target_cpu(). */
1491         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1492         if (outgoing_channel != NULL) {
1493                 if (outgoing_channel->target_cpu == q_num) {
1494                         /*
1495                          * Ideally, we want to pick a different channel if
1496                          * available on the same NUMA node.
1497                          */
1498                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1499                         for_each_cpu_wrap(tgt_cpu,
1500                                  &stor_device->alloced_cpus, q_num + 1) {
1501                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1502                                         continue;
1503                                 if (tgt_cpu == q_num)
1504                                         continue;
1505                                 channel = READ_ONCE(
1506                                         stor_device->stor_chns[tgt_cpu]);
1507                                 if (channel == NULL)
1508                                         continue;
1509                                 if (hv_get_avail_to_write_percent(
1510                                                         &channel->outbound)
1511                                                 > ring_avail_percent_lowater) {
1512                                         outgoing_channel = channel;
1513                                         goto found_channel;
1514                                 }
1515                         }
1516
1517                         /*
1518                          * All the other channels on the same NUMA node are
1519                          * busy. Try to use the channel on the current CPU
1520                          */
1521                         if (hv_get_avail_to_write_percent(
1522                                                 &outgoing_channel->outbound)
1523                                         > ring_avail_percent_lowater)
1524                                 goto found_channel;
1525
1526                         /*
1527                          * If we reach here, all the channels on the current
1528                          * NUMA node are busy. Try to find a channel in
1529                          * other NUMA nodes
1530                          */
1531                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1532                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1533                                         continue;
1534                                 channel = READ_ONCE(
1535                                         stor_device->stor_chns[tgt_cpu]);
1536                                 if (channel == NULL)
1537                                         continue;
1538                                 if (hv_get_avail_to_write_percent(
1539                                                         &channel->outbound)
1540                                                 > ring_avail_percent_lowater) {
1541                                         outgoing_channel = channel;
1542                                         goto found_channel;
1543                                 }
1544                         }
1545                 }
1546         } else {
1547                 spin_lock_irqsave(&stor_device->lock, flags);
1548                 outgoing_channel = stor_device->stor_chns[q_num];
1549                 if (outgoing_channel != NULL) {
1550                         spin_unlock_irqrestore(&stor_device->lock, flags);
1551                         goto found_channel;
1552                 }
1553                 outgoing_channel = get_og_chn(stor_device, q_num);
1554                 spin_unlock_irqrestore(&stor_device->lock, flags);
1555         }
1556
1557 found_channel:
1558         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1559
1560         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1561                                         stor_device->vmscsi_size_delta);
1562
1563
1564         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1565
1566
1567         vstor_packet->vm_srb.data_transfer_length =
1568         request->payload->range.len;
1569
1570         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1571
1572         if (request->payload->range.len) {
1573
1574                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1575                                 request->payload, request->payload_sz,
1576                                 vstor_packet,
1577                                 (sizeof(struct vstor_packet) -
1578                                 stor_device->vmscsi_size_delta),
1579                                 (unsigned long)request);
1580         } else {
1581                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1582                                (sizeof(struct vstor_packet) -
1583                                 stor_device->vmscsi_size_delta),
1584                                (unsigned long)request,
1585                                VM_PKT_DATA_INBAND,
1586                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1587         }
1588
1589         if (ret != 0)
1590                 return ret;
1591
1592         atomic_inc(&stor_device->num_outstanding_req);
1593
1594         return ret;
1595 }
1596
1597 static int storvsc_device_alloc(struct scsi_device *sdevice)
1598 {
1599         /*
1600          * Set blist flag to permit the reading of the VPD pages even when
1601          * the target may claim SPC-2 compliance. MSFT targets currently
1602          * claim SPC-2 compliance while they implement post SPC-2 features.
1603          * With this flag we can correctly handle WRITE_SAME_16 issues.
1604          *
1605          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1606          * still supports REPORT LUN.
1607          */
1608         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1609
1610         return 0;
1611 }
1612
1613 static int storvsc_device_configure(struct scsi_device *sdevice)
1614 {
1615         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1616
1617         sdevice->no_write_same = 1;
1618
1619         /*
1620          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1621          * if the device is a MSFT virtual device.  If the host is
1622          * WIN10 or newer, allow write_same.
1623          */
1624         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1625                 switch (vmstor_proto_version) {
1626                 case VMSTOR_PROTO_VERSION_WIN8:
1627                 case VMSTOR_PROTO_VERSION_WIN8_1:
1628                         sdevice->scsi_level = SCSI_SPC_3;
1629                         break;
1630                 }
1631
1632                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1633                         sdevice->no_write_same = 0;
1634         }
1635
1636         return 0;
1637 }
1638
1639 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1640                            sector_t capacity, int *info)
1641 {
1642         sector_t nsect = capacity;
1643         sector_t cylinders = nsect;
1644         int heads, sectors_pt;
1645
1646         /*
1647          * We are making up these values; let us keep it simple.
1648          */
1649         heads = 0xff;
1650         sectors_pt = 0x3f;      /* Sectors per track */
1651         sector_div(cylinders, heads * sectors_pt);
1652         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1653                 cylinders = 0xffff;
1654
1655         info[0] = heads;
1656         info[1] = sectors_pt;
1657         info[2] = (int)cylinders;
1658
1659         return 0;
1660 }
1661
1662 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1663 {
1664         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1665         struct hv_device *device = host_dev->dev;
1666
1667         struct storvsc_device *stor_device;
1668         struct storvsc_cmd_request *request;
1669         struct vstor_packet *vstor_packet;
1670         int ret, t;
1671
1672         stor_device = get_out_stor_device(device);
1673         if (!stor_device)
1674                 return FAILED;
1675
1676         request = &stor_device->reset_request;
1677         vstor_packet = &request->vstor_packet;
1678         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1679
1680         init_completion(&request->wait_event);
1681
1682         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1683         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1684         vstor_packet->vm_srb.path_id = stor_device->path_id;
1685
1686         ret = vmbus_sendpacket(device->channel, vstor_packet,
1687                                (sizeof(struct vstor_packet) -
1688                                 stor_device->vmscsi_size_delta),
1689                                VMBUS_RQST_RESET,
1690                                VM_PKT_DATA_INBAND,
1691                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1692         if (ret != 0)
1693                 return FAILED;
1694
1695         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1696         if (t == 0)
1697                 return TIMEOUT_ERROR;
1698
1699
1700         /*
1701          * At this point, all outstanding requests in the adapter
1702          * should have been flushed out and return to us
1703          * There is a potential race here where the host may be in
1704          * the process of responding when we return from here.
1705          * Just wait for all in-transit packets to be accounted for
1706          * before we return from here.
1707          */
1708         storvsc_wait_to_drain(stor_device);
1709
1710         return SUCCESS;
1711 }
1712
1713 /*
1714  * The host guarantees to respond to each command, although I/O latencies might
1715  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1716  * chance to perform EH.
1717  */
1718 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1719 {
1720 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1721         if (scmnd->device->host->transportt == fc_transport_template)
1722                 return fc_eh_timed_out(scmnd);
1723 #endif
1724         return BLK_EH_RESET_TIMER;
1725 }
1726
1727 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1728 {
1729         bool allowed = true;
1730         u8 scsi_op = scmnd->cmnd[0];
1731
1732         switch (scsi_op) {
1733         /* the host does not handle WRITE_SAME, log accident usage */
1734         case WRITE_SAME:
1735         /*
1736          * smartd sends this command and the host does not handle
1737          * this. So, don't send it.
1738          */
1739         case SET_WINDOW:
1740                 set_host_byte(scmnd, DID_ERROR);
1741                 allowed = false;
1742                 break;
1743         default:
1744                 break;
1745         }
1746         return allowed;
1747 }
1748
1749 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1750 {
1751         int ret;
1752         struct hv_host_device *host_dev = shost_priv(host);
1753         struct hv_device *dev = host_dev->dev;
1754         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1755         struct scatterlist *sgl;
1756         struct vmscsi_request *vm_srb;
1757         struct vmbus_packet_mpb_array  *payload;
1758         u32 payload_sz;
1759         u32 length;
1760
1761         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1762                 /*
1763                  * On legacy hosts filter unimplemented commands.
1764                  * Future hosts are expected to correctly handle
1765                  * unsupported commands. Furthermore, it is
1766                  * possible that some of the currently
1767                  * unsupported commands maybe supported in
1768                  * future versions of the host.
1769                  */
1770                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1771                         scsi_done(scmnd);
1772                         return 0;
1773                 }
1774         }
1775
1776         /* Setup the cmd request */
1777         cmd_request->cmd = scmnd;
1778
1779         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1780         vm_srb = &cmd_request->vstor_packet.vm_srb;
1781         vm_srb->win8_extension.time_out_value = 60;
1782
1783         vm_srb->win8_extension.srb_flags |=
1784                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1785
1786         if (scmnd->device->tagged_supported) {
1787                 vm_srb->win8_extension.srb_flags |=
1788                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1789                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1790                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1791         }
1792
1793         /* Build the SRB */
1794         switch (scmnd->sc_data_direction) {
1795         case DMA_TO_DEVICE:
1796                 vm_srb->data_in = WRITE_TYPE;
1797                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1798                 break;
1799         case DMA_FROM_DEVICE:
1800                 vm_srb->data_in = READ_TYPE;
1801                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1802                 break;
1803         case DMA_NONE:
1804                 vm_srb->data_in = UNKNOWN_TYPE;
1805                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1806                 break;
1807         default:
1808                 /*
1809                  * This is DMA_BIDIRECTIONAL or something else we are never
1810                  * supposed to see here.
1811                  */
1812                 WARN(1, "Unexpected data direction: %d\n",
1813                      scmnd->sc_data_direction);
1814                 return -EINVAL;
1815         }
1816
1817
1818         vm_srb->port_number = host_dev->port;
1819         vm_srb->path_id = scmnd->device->channel;
1820         vm_srb->target_id = scmnd->device->id;
1821         vm_srb->lun = scmnd->device->lun;
1822
1823         vm_srb->cdb_length = scmnd->cmd_len;
1824
1825         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1826
1827         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1828
1829         length = scsi_bufflen(scmnd);
1830         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1831         payload_sz = sizeof(cmd_request->mpb);
1832
1833         if (scsi_sg_count(scmnd)) {
1834                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1835                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1836                 struct scatterlist *sg;
1837                 unsigned long hvpfn, hvpfns_to_add;
1838                 int j, i = 0, sg_count;
1839
1840                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1841
1842                         payload_sz = (hvpg_count * sizeof(u64) +
1843                                       sizeof(struct vmbus_packet_mpb_array));
1844                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1845                         if (!payload)
1846                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1847                 }
1848
1849                 payload->range.len = length;
1850                 payload->range.offset = offset_in_hvpg;
1851
1852                 sg_count = scsi_dma_map(scmnd);
1853                 if (sg_count < 0) {
1854                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1855                         goto err_free_payload;
1856                 }
1857
1858                 for_each_sg(sgl, sg, sg_count, j) {
1859                         /*
1860                          * Init values for the current sgl entry. hvpfns_to_add
1861                          * is in units of Hyper-V size pages. Handling the
1862                          * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1863                          * values of sgl->offset that are larger than PAGE_SIZE.
1864                          * Such offsets are handled even on other than the first
1865                          * sgl entry, provided they are a multiple of PAGE_SIZE.
1866                          */
1867                         hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1868                         hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1869                                                  sg_dma_len(sg)) - hvpfn;
1870
1871                         /*
1872                          * Fill the next portion of the PFN array with
1873                          * sequential Hyper-V PFNs for the continguous physical
1874                          * memory described by the sgl entry. The end of the
1875                          * last sgl should be reached at the same time that
1876                          * the PFN array is filled.
1877                          */
1878                         while (hvpfns_to_add--)
1879                                 payload->range.pfn_array[i++] = hvpfn++;
1880                 }
1881         }
1882
1883         cmd_request->payload = payload;
1884         cmd_request->payload_sz = payload_sz;
1885
1886         /* Invokes the vsc to start an IO */
1887         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1888         put_cpu();
1889
1890         if (ret == -EAGAIN) {
1891                 /* no more space */
1892                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1893                 goto err_free_payload;
1894         }
1895
1896         return 0;
1897
1898 err_free_payload:
1899         if (payload_sz > sizeof(cmd_request->mpb))
1900                 kfree(payload);
1901
1902         return ret;
1903 }
1904
1905 static struct scsi_host_template scsi_driver = {
1906         .module =               THIS_MODULE,
1907         .name =                 "storvsc_host_t",
1908         .cmd_size =             sizeof(struct storvsc_cmd_request),
1909         .bios_param =           storvsc_get_chs,
1910         .queuecommand =         storvsc_queuecommand,
1911         .eh_host_reset_handler =        storvsc_host_reset_handler,
1912         .proc_name =            "storvsc_host",
1913         .eh_timed_out =         storvsc_eh_timed_out,
1914         .slave_alloc =          storvsc_device_alloc,
1915         .slave_configure =      storvsc_device_configure,
1916         .cmd_per_lun =          2048,
1917         .this_id =              -1,
1918         /* Ensure there are no gaps in presented sgls */
1919         .virt_boundary_mask =   PAGE_SIZE-1,
1920         .no_write_same =        1,
1921         .track_queue_depth =    1,
1922         .change_queue_depth =   storvsc_change_queue_depth,
1923 };
1924
1925 enum {
1926         SCSI_GUID,
1927         IDE_GUID,
1928         SFC_GUID,
1929 };
1930
1931 static const struct hv_vmbus_device_id id_table[] = {
1932         /* SCSI guid */
1933         { HV_SCSI_GUID,
1934           .driver_data = SCSI_GUID
1935         },
1936         /* IDE guid */
1937         { HV_IDE_GUID,
1938           .driver_data = IDE_GUID
1939         },
1940         /* Fibre Channel GUID */
1941         {
1942           HV_SYNTHFC_GUID,
1943           .driver_data = SFC_GUID
1944         },
1945         { },
1946 };
1947
1948 MODULE_DEVICE_TABLE(vmbus, id_table);
1949
1950 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1951
1952 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1953 {
1954         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1955 }
1956
1957 static int storvsc_probe(struct hv_device *device,
1958                         const struct hv_vmbus_device_id *dev_id)
1959 {
1960         int ret;
1961         int num_cpus = num_online_cpus();
1962         int num_present_cpus = num_present_cpus();
1963         struct Scsi_Host *host;
1964         struct hv_host_device *host_dev;
1965         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1966         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1967         int target = 0;
1968         struct storvsc_device *stor_device;
1969         int max_luns_per_target;
1970         int max_targets;
1971         int max_channels;
1972         int max_sub_channels = 0;
1973
1974         /*
1975          * Based on the windows host we are running on,
1976          * set state to properly communicate with the host.
1977          */
1978
1979         if (vmbus_proto_version < VERSION_WIN8) {
1980                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1981                 max_targets = STORVSC_IDE_MAX_TARGETS;
1982                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1983         } else {
1984                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1985                 max_targets = STORVSC_MAX_TARGETS;
1986                 max_channels = STORVSC_MAX_CHANNELS;
1987                 /*
1988                  * On Windows8 and above, we support sub-channels for storage
1989                  * on SCSI and FC controllers.
1990                  * The number of sub-channels offerred is based on the number of
1991                  * VCPUs in the guest.
1992                  */
1993                 if (!dev_is_ide)
1994                         max_sub_channels =
1995                                 (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1996         }
1997
1998         scsi_driver.can_queue = max_outstanding_req_per_channel *
1999                                 (max_sub_channels + 1) *
2000                                 (100 - ring_avail_percent_lowater) / 100;
2001
2002         host = scsi_host_alloc(&scsi_driver,
2003                                sizeof(struct hv_host_device));
2004         if (!host)
2005                 return -ENOMEM;
2006
2007         host_dev = shost_priv(host);
2008         memset(host_dev, 0, sizeof(struct hv_host_device));
2009
2010         host_dev->port = host->host_no;
2011         host_dev->dev = device;
2012         host_dev->host = host;
2013
2014
2015         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
2016         if (!stor_device) {
2017                 ret = -ENOMEM;
2018                 goto err_out0;
2019         }
2020
2021         stor_device->destroy = false;
2022         init_waitqueue_head(&stor_device->waiting_to_drain);
2023         stor_device->device = device;
2024         stor_device->host = host;
2025         stor_device->vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
2026         spin_lock_init(&stor_device->lock);
2027         hv_set_drvdata(device, stor_device);
2028         dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
2029
2030         stor_device->port_number = host->host_no;
2031         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
2032         if (ret)
2033                 goto err_out1;
2034
2035         host_dev->path = stor_device->path_id;
2036         host_dev->target = stor_device->target_id;
2037
2038         switch (dev_id->driver_data) {
2039         case SFC_GUID:
2040                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
2041                 host->max_id = STORVSC_FC_MAX_TARGETS;
2042                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
2043 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2044                 host->transportt = fc_transport_template;
2045 #endif
2046                 break;
2047
2048         case SCSI_GUID:
2049                 host->max_lun = max_luns_per_target;
2050                 host->max_id = max_targets;
2051                 host->max_channel = max_channels - 1;
2052                 break;
2053
2054         default:
2055                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
2056                 host->max_id = STORVSC_IDE_MAX_TARGETS;
2057                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
2058                 break;
2059         }
2060         /* max cmd length */
2061         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2062
2063         /*
2064          * set the table size based on the info we got
2065          * from the host.
2066          */
2067         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
2068         /*
2069          * For non-IDE disks, the host supports multiple channels.
2070          * Set the number of HW queues we are supporting.
2071          */
2072         if (!dev_is_ide) {
2073                 if (storvsc_max_hw_queues > num_present_cpus) {
2074                         storvsc_max_hw_queues = 0;
2075                         storvsc_log(device, STORVSC_LOGGING_WARN,
2076                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2077                 }
2078                 if (storvsc_max_hw_queues)
2079                         host->nr_hw_queues = storvsc_max_hw_queues;
2080                 else
2081                         host->nr_hw_queues = num_present_cpus;
2082         }
2083
2084         /*
2085          * Set the error handler work queue.
2086          */
2087         host_dev->handle_error_wq =
2088                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2089                                                 WQ_MEM_RECLAIM,
2090                                                 host->host_no);
2091         if (!host_dev->handle_error_wq) {
2092                 ret = -ENOMEM;
2093                 goto err_out2;
2094         }
2095         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2096         /* Register the HBA and start the scsi bus scan */
2097         ret = scsi_add_host(host, &device->device);
2098         if (ret != 0)
2099                 goto err_out3;
2100
2101         if (!dev_is_ide) {
2102                 scsi_scan_host(host);
2103         } else {
2104                 target = (device->dev_instance.b[5] << 8 |
2105                          device->dev_instance.b[4]);
2106                 ret = scsi_add_device(host, 0, target, 0);
2107                 if (ret)
2108                         goto err_out4;
2109         }
2110 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2111         if (host->transportt == fc_transport_template) {
2112                 struct fc_rport_identifiers ids = {
2113                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2114                 };
2115
2116                 fc_host_node_name(host) = stor_device->node_name;
2117                 fc_host_port_name(host) = stor_device->port_name;
2118                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2119                 if (!stor_device->rport) {
2120                         ret = -ENOMEM;
2121                         goto err_out4;
2122                 }
2123         }
2124 #endif
2125         return 0;
2126
2127 err_out4:
2128         scsi_remove_host(host);
2129
2130 err_out3:
2131         destroy_workqueue(host_dev->handle_error_wq);
2132
2133 err_out2:
2134         /*
2135          * Once we have connected with the host, we would need to
2136          * to invoke storvsc_dev_remove() to rollback this state and
2137          * this call also frees up the stor_device; hence the jump around
2138          * err_out1 label.
2139          */
2140         storvsc_dev_remove(device);
2141         goto err_out0;
2142
2143 err_out1:
2144         kfree(stor_device->stor_chns);
2145         kfree(stor_device);
2146
2147 err_out0:
2148         scsi_host_put(host);
2149         return ret;
2150 }
2151
2152 /* Change a scsi target's queue depth */
2153 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2154 {
2155         if (queue_depth > scsi_driver.can_queue)
2156                 queue_depth = scsi_driver.can_queue;
2157
2158         return scsi_change_queue_depth(sdev, queue_depth);
2159 }
2160
2161 static int storvsc_remove(struct hv_device *dev)
2162 {
2163         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2164         struct Scsi_Host *host = stor_device->host;
2165         struct hv_host_device *host_dev = shost_priv(host);
2166
2167 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2168         if (host->transportt == fc_transport_template) {
2169                 fc_remote_port_delete(stor_device->rport);
2170                 fc_remove_host(host);
2171         }
2172 #endif
2173         destroy_workqueue(host_dev->handle_error_wq);
2174         scsi_remove_host(host);
2175         storvsc_dev_remove(dev);
2176         scsi_host_put(host);
2177
2178         return 0;
2179 }
2180
2181 static int storvsc_suspend(struct hv_device *hv_dev)
2182 {
2183         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2184         struct Scsi_Host *host = stor_device->host;
2185         struct hv_host_device *host_dev = shost_priv(host);
2186
2187         storvsc_wait_to_drain(stor_device);
2188
2189         drain_workqueue(host_dev->handle_error_wq);
2190
2191         vmbus_close(hv_dev->channel);
2192
2193         kfree(stor_device->stor_chns);
2194         stor_device->stor_chns = NULL;
2195
2196         cpumask_clear(&stor_device->alloced_cpus);
2197
2198         return 0;
2199 }
2200
2201 static int storvsc_resume(struct hv_device *hv_dev)
2202 {
2203         int ret;
2204
2205         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2206                                      hv_dev_is_fc(hv_dev));
2207         return ret;
2208 }
2209
2210 static struct hv_driver storvsc_drv = {
2211         .name = KBUILD_MODNAME,
2212         .id_table = id_table,
2213         .probe = storvsc_probe,
2214         .remove = storvsc_remove,
2215         .suspend = storvsc_suspend,
2216         .resume = storvsc_resume,
2217         .driver = {
2218                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2219         },
2220 };
2221
2222 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2223 static struct fc_function_template fc_transport_functions = {
2224         .show_host_node_name = 1,
2225         .show_host_port_name = 1,
2226 };
2227 #endif
2228
2229 static int __init storvsc_drv_init(void)
2230 {
2231         int ret;
2232
2233         /*
2234          * Divide the ring buffer data size (which is 1 page less
2235          * than the ring buffer size since that page is reserved for
2236          * the ring buffer indices) by the max request size (which is
2237          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2238          *
2239          * The computation underestimates max_outstanding_req_per_channel
2240          * for Win7 and older hosts because it does not take into account
2241          * the vmscsi_size_delta correction to the max request size.
2242          */
2243         max_outstanding_req_per_channel =
2244                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2245                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2246                 sizeof(struct vstor_packet) + sizeof(u64),
2247                 sizeof(u64)));
2248
2249 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2250         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2251         if (!fc_transport_template)
2252                 return -ENODEV;
2253 #endif
2254
2255         ret = vmbus_driver_register(&storvsc_drv);
2256
2257 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2258         if (ret)
2259                 fc_release_transport(fc_transport_template);
2260 #endif
2261
2262         return ret;
2263 }
2264
2265 static void __exit storvsc_drv_exit(void)
2266 {
2267         vmbus_driver_unregister(&storvsc_drv);
2268 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2269         fc_release_transport(fc_transport_template);
2270 #endif
2271 }
2272
2273 MODULE_LICENSE("GPL");
2274 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2275 module_init(storvsc_drv_init);
2276 module_exit(storvsc_drv_exit);