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 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  58 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  59 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  60 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  61 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  62
  63 /* channel callback timeout in ms */
  64 #define CALLBACK_TIMEOUT               2
  65
  66 /*  Packet structure describing virtual storage requests. */
  67 enum vstor_packet_operation {
  68         VSTOR_OPERATION_COMPLETE_IO             = 1,
  69         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  70         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  71         VSTOR_OPERATION_RESET_LUN               = 4,
  72         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  73         VSTOR_OPERATION_RESET_BUS               = 6,
  74         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  75         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  76         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  77         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  78         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  79         VSTOR_OPERATION_FCHBA_DATA              = 12,
  80         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  81         VSTOR_OPERATION_MAXIMUM                 = 13
  82 };
  83
  84 /*
  85  * WWN packet for Fibre Channel HBA
  86  */
  87
  88 struct hv_fc_wwn_packet {
  89         u8      primary_active;
  90         u8      reserved1[3];
  91         u8      primary_port_wwn[8];
  92         u8      primary_node_wwn[8];
  93         u8      secondary_port_wwn[8];
  94         u8      secondary_node_wwn[8];
  95 };
  96
  97
  98
  99 /*
 100  * SRB Flag Bits
 101  */
 102
 103 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 104 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 105 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 106 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 107 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 108 #define SRB_FLAGS_DATA_IN                       0x00000040
 109 #define SRB_FLAGS_DATA_OUT                      0x00000080
 110 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 111 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 112 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 113 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 114 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 115
 116 /*
 117  * This flag indicates the request is part of the workflow for processing a D3.
 118  */
 119 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 120 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 121 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 122 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 123 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 124 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 125 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 126 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 127 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 128 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 129 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 130
 131 #define SP_UNTAGGED                     ((unsigned char) ~0)
 132 #define SRB_SIMPLE_TAG_REQUEST          0x20
 133
 134 /*
 135  * Platform neutral description of a scsi request -
 136  * this remains the same across the write regardless of 32/64 bit
 137  * note: it's patterned off the SCSI_PASS_THROUGH structure
 138  */
 139 #define STORVSC_MAX_CMD_LEN                     0x10
 140
 141 /* Sense buffer size is the same for all versions since Windows 8 */
 142 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 143 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 144
 145 /*
 146  * The storage protocol version is determined during the
 147  * initial exchange with the host.  It will indicate which
 148  * storage functionality is available in the host.
 149 */
 150 static int vmstor_proto_version;
 151
 152 #define STORVSC_LOGGING_NONE    0
 153 #define STORVSC_LOGGING_ERROR   1
 154 #define STORVSC_LOGGING_WARN    2
 155
 156 static int logging_level = STORVSC_LOGGING_ERROR;
 157 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 158 MODULE_PARM_DESC(logging_level,
 159         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 160
 161 static inline bool do_logging(int level)
 162 {
 163         return logging_level >= level;
 164 }
 165
 166 #define storvsc_log(dev, level, fmt, ...)                       \
 167 do {                                                            \
 168         if (do_logging(level))                                  \
 169                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 170 } while (0)
 171
 172 struct vmscsi_request {
 173         u16 length;
 174         u8 srb_status;
 175         u8 scsi_status;
 176
 177         u8  port_number;
 178         u8  path_id;
 179         u8  target_id;
 180         u8  lun;
 181
 182         u8  cdb_length;
 183         u8  sense_info_length;
 184         u8  data_in;
 185         u8  reserved;
 186
 187         u32 data_transfer_length;
 188
 189         union {
 190                 u8 cdb[STORVSC_MAX_CMD_LEN];
 191                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 192                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 193         };
 194         /*
 195          * The following was added in win8.
 196          */
 197         u16 reserve;
 198         u8  queue_tag;
 199         u8  queue_action;
 200         u32 srb_flags;
 201         u32 time_out_value;
 202         u32 queue_sort_ey;
 203
 204 } __attribute((packed));
 205
 206 /*
 207  * The list of windows version in order of preference.
 208  */
 209
 210 static const int protocol_version[] = {
 211                 VMSTOR_PROTO_VERSION_WIN10,
 212                 VMSTOR_PROTO_VERSION_WIN8_1,
 213                 VMSTOR_PROTO_VERSION_WIN8,
 214 };
 215
 216
 217 /*
 218  * This structure is sent during the initialization phase to get the different
 219  * properties of the channel.
 220  */
 221
 222 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 223
 224 struct vmstorage_channel_properties {
 225         u32 reserved;
 226         u16 max_channel_cnt;
 227         u16 reserved1;
 228
 229         u32 flags;
 230         u32   max_transfer_bytes;
 231
 232         u64  reserved2;
 233 } __packed;
 234
 235 /*  This structure is sent during the storage protocol negotiations. */
 236 struct vmstorage_protocol_version {
 237         /* Major (MSW) and minor (LSW) version numbers. */
 238         u16 major_minor;
 239
 240         /*
 241          * Revision number is auto-incremented whenever this file is changed
 242          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 243          * definitely indicate incompatibility--but it does indicate mismatched
 244          * builds.
 245          * This is only used on the windows side. Just set it to 0.
 246          */
 247         u16 revision;
 248 } __packed;
 249
 250 /* Channel Property Flags */
 251 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 252 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 253
 254 struct vstor_packet {
 255         /* Requested operation type */
 256         enum vstor_packet_operation operation;
 257
 258         /*  Flags - see below for values */
 259         u32 flags;
 260
 261         /* Status of the request returned from the server side. */
 262         u32 status;
 263
 264         /* Data payload area */
 265         union {
 266                 /*
 267                  * Structure used to forward SCSI commands from the
 268                  * client to the server.
 269                  */
 270                 struct vmscsi_request vm_srb;
 271
 272                 /* Structure used to query channel properties. */
 273                 struct vmstorage_channel_properties storage_channel_properties;
 274
 275                 /* Used during version negotiations. */
 276                 struct vmstorage_protocol_version version;
 277
 278                 /* Fibre channel address packet */
 279                 struct hv_fc_wwn_packet wwn_packet;
 280
 281                 /* Number of sub-channels to create */
 282                 u16 sub_channel_count;
 283
 284                 /* This will be the maximum of the union members */
 285                 u8  buffer[0x34];
 286         };
 287 } __packed;
 288
 289 /*
 290  * Packet Flags:
 291  *
 292  * This flag indicates that the server should send back a completion for this
 293  * packet.
 294  */
 295
 296 #define REQUEST_COMPLETION_FLAG 0x1
 297
 298 /* Matches Windows-end */
 299 enum storvsc_request_type {
 300         WRITE_TYPE = 0,
 301         READ_TYPE,
 302         UNKNOWN_TYPE,
 303 };
 304
 305 /*
 306  * SRB status codes and masks. In the 8-bit field, the two high order bits
 307  * are flags, while the remaining 6 bits are an integer status code.  The
 308  * definitions here include only the subset of the integer status codes that
 309  * are tested for in this driver.
 310  */
 311 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 312 #define SRB_STATUS_QUEUE_FROZEN         0x40
 313
 314 /* SRB status integer codes */
 315 #define SRB_STATUS_SUCCESS              0x01
 316 #define SRB_STATUS_ABORTED              0x02
 317 #define SRB_STATUS_ERROR                0x04
 318 #define SRB_STATUS_INVALID_REQUEST      0x06
 319 #define SRB_STATUS_DATA_OVERRUN         0x12
 320 #define SRB_STATUS_INVALID_LUN          0x20
 321
 322 #define SRB_STATUS(status) \
 323         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 324 /*
 325  * This is the end of Protocol specific defines.
 326  */
 327
 328 static int storvsc_ringbuffer_size = (128 * 1024);
 329 static u32 max_outstanding_req_per_channel;
 330 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 331
 332 static int storvsc_vcpus_per_sub_channel = 4;
 333 static unsigned int storvsc_max_hw_queues;
 334
 335 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 336 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 337
 338 module_param(storvsc_max_hw_queues, uint, 0644);
 339 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 340
 341 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 342 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 343
 344 static int ring_avail_percent_lowater = 10;
 345 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 346 MODULE_PARM_DESC(ring_avail_percent_lowater,
 347                 "Select a channel if available ring size > this in percent");
 348
 349 /*
 350  * Timeout in seconds for all devices managed by this driver.
 351  */
 352 static int storvsc_timeout = 180;
 353
 354 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 355 static struct scsi_transport_template *fc_transport_template;
 356 #endif
 357
 358 static struct scsi_host_template scsi_driver;
 359 static void storvsc_on_channel_callback(void *context);
 360
 361 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 362 #define STORVSC_MAX_TARGETS                             2
 363 #define STORVSC_MAX_CHANNELS                            8
 364
 365 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 366 #define STORVSC_FC_MAX_TARGETS                          128
 367 #define STORVSC_FC_MAX_CHANNELS                         8
 368
 369 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 370 #define STORVSC_IDE_MAX_TARGETS                         1
 371 #define STORVSC_IDE_MAX_CHANNELS                        1
 372
 373 /*
 374  * Upper bound on the size of a storvsc packet.
 375  */
 376 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
 377                               sizeof(struct vstor_packet))
 378
 379 struct storvsc_cmd_request {
 380         struct scsi_cmnd *cmd;
 381
 382         struct hv_device *device;
 383
 384         /* Synchronize the request/response if needed */
 385         struct completion wait_event;
 386
 387         struct vmbus_channel_packet_multipage_buffer mpb;
 388         struct vmbus_packet_mpb_array *payload;
 389         u32 payload_sz;
 390
 391         struct vstor_packet vstor_packet;
 392 };
 393
 394
 395 /* A storvsc device is a device object that contains a vmbus channel */
 396 struct storvsc_device {
 397         struct hv_device *device;
 398
 399         bool     destroy;
 400         bool     drain_notify;
 401         atomic_t num_outstanding_req;
 402         struct Scsi_Host *host;
 403
 404         wait_queue_head_t waiting_to_drain;
 405
 406         /*
 407          * Each unique Port/Path/Target represents 1 channel ie scsi
 408          * controller. In reality, the pathid, targetid is always 0
 409          * and the port is set by us
 410          */
 411         unsigned int port_number;
 412         unsigned char path_id;
 413         unsigned char target_id;
 414
 415         /*
 416          * Max I/O, the device can support.
 417          */
 418         u32   max_transfer_bytes;
 419         /*
 420          * Number of sub-channels we will open.
 421          */
 422         u16 num_sc;
 423         struct vmbus_channel **stor_chns;
 424         /*
 425          * Mask of CPUs bound to subchannels.
 426          */
 427         struct cpumask alloced_cpus;
 428         /*
 429          * Serializes modifications of stor_chns[] from storvsc_do_io()
 430          * and storvsc_change_target_cpu().
 431          */
 432         spinlock_t lock;
 433         /* Used for vsc/vsp channel reset process */
 434         struct storvsc_cmd_request init_request;
 435         struct storvsc_cmd_request reset_request;
 436         /*
 437          * Currently active port and node names for FC devices.
 438          */
 439         u64 node_name;
 440         u64 port_name;
 441 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 442         struct fc_rport *rport;
 443 #endif
 444 };
 445
 446 struct hv_host_device {
 447         struct hv_device *dev;
 448         unsigned int port;
 449         unsigned char path;
 450         unsigned char target;
 451         struct workqueue_struct *handle_error_wq;
 452         struct work_struct host_scan_work;
 453         struct Scsi_Host *host;
 454 };
 455
 456 struct storvsc_scan_work {
 457         struct work_struct work;
 458         struct Scsi_Host *host;
 459         u8 lun;
 460         u8 tgt_id;
 461 };
 462
 463 static void storvsc_device_scan(struct work_struct *work)
 464 {
 465         struct storvsc_scan_work *wrk;
 466         struct scsi_device *sdev;
 467
 468         wrk = container_of(work, struct storvsc_scan_work, work);
 469
 470         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 471         if (!sdev)
 472                 goto done;
 473         scsi_rescan_device(&sdev->sdev_gendev);
 474         scsi_device_put(sdev);
 475
 476 done:
 477         kfree(wrk);
 478 }
 479
 480 static void storvsc_host_scan(struct work_struct *work)
 481 {
 482         struct Scsi_Host *host;
 483         struct scsi_device *sdev;
 484         struct hv_host_device *host_device =
 485                 container_of(work, struct hv_host_device, host_scan_work);
 486
 487         host = host_device->host;
 488         /*
 489          * Before scanning the host, first check to see if any of the
 490          * currently known devices have been hot removed. We issue a
 491          * "unit ready" command against all currently known devices.
 492          * This I/O will result in an error for devices that have been
 493          * removed. As part of handling the I/O error, we remove the device.
 494          *
 495          * When a LUN is added or removed, the host sends us a signal to
 496          * scan the host. Thus we are forced to discover the LUNs that
 497          * may have been removed this way.
 498          */
 499         mutex_lock(&host->scan_mutex);
 500         shost_for_each_device(sdev, host)
 501                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 502         mutex_unlock(&host->scan_mutex);
 503         /*
 504          * Now scan the host to discover LUNs that may have been added.
 505          */
 506         scsi_scan_host(host);
 507 }
 508
 509 static void storvsc_remove_lun(struct work_struct *work)
 510 {
 511         struct storvsc_scan_work *wrk;
 512         struct scsi_device *sdev;
 513
 514         wrk = container_of(work, struct storvsc_scan_work, work);
 515         if (!scsi_host_get(wrk->host))
 516                 goto done;
 517
 518         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 519
 520         if (sdev) {
 521                 scsi_remove_device(sdev);
 522                 scsi_device_put(sdev);
 523         }
 524         scsi_host_put(wrk->host);
 525
 526 done:
 527         kfree(wrk);
 528 }
 529
 530
 531 /*
 532  * We can get incoming messages from the host that are not in response to
 533  * messages that we have sent out. An example of this would be messages
 534  * received by the guest to notify dynamic addition/removal of LUNs. To
 535  * deal with potential race conditions where the driver may be in the
 536  * midst of being unloaded when we might receive an unsolicited message
 537  * from the host, we have implemented a mechanism to gurantee sequential
 538  * consistency:
 539  *
 540  * 1) Once the device is marked as being destroyed, we will fail all
 541  *    outgoing messages.
 542  * 2) We permit incoming messages when the device is being destroyed,
 543  *    only to properly account for messages already sent out.
 544  */
 545
 546 static inline struct storvsc_device *get_out_stor_device(
 547                                         struct hv_device *device)
 548 {
 549         struct storvsc_device *stor_device;
 550
 551         stor_device = hv_get_drvdata(device);
 552
 553         if (stor_device && stor_device->destroy)
 554                 stor_device = NULL;
 555
 556         return stor_device;
 557 }
 558
 559
 560 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 561 {
 562         dev->drain_notify = true;
 563         wait_event(dev->waiting_to_drain,
 564                    atomic_read(&dev->num_outstanding_req) == 0);
 565         dev->drain_notify = false;
 566 }
 567
 568 static inline struct storvsc_device *get_in_stor_device(
 569                                         struct hv_device *device)
 570 {
 571         struct storvsc_device *stor_device;
 572
 573         stor_device = hv_get_drvdata(device);
 574
 575         if (!stor_device)
 576                 goto get_in_err;
 577
 578         /*
 579          * If the device is being destroyed; allow incoming
 580          * traffic only to cleanup outstanding requests.
 581          */
 582
 583         if (stor_device->destroy  &&
 584                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 585                 stor_device = NULL;
 586
 587 get_in_err:
 588         return stor_device;
 589
 590 }
 591
 592 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 593                                       u32 new)
 594 {
 595         struct storvsc_device *stor_device;
 596         struct vmbus_channel *cur_chn;
 597         bool old_is_alloced = false;
 598         struct hv_device *device;
 599         unsigned long flags;
 600         int cpu;
 601
 602         device = channel->primary_channel ?
 603                         channel->primary_channel->device_obj
 604                                 : channel->device_obj;
 605         stor_device = get_out_stor_device(device);
 606         if (!stor_device)
 607                 return;
 608
 609         /* See storvsc_do_io() -> get_og_chn(). */
 610         spin_lock_irqsave(&stor_device->lock, flags);
 611
 612         /*
 613          * Determines if the storvsc device has other channels assigned to
 614          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 615          * array.
 616          */
 617         if (device->channel != channel && device->channel->target_cpu == old) {
 618                 cur_chn = device->channel;
 619                 old_is_alloced = true;
 620                 goto old_is_alloced;
 621         }
 622         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 623                 if (cur_chn == channel)
 624                         continue;
 625                 if (cur_chn->target_cpu == old) {
 626                         old_is_alloced = true;
 627                         goto old_is_alloced;
 628                 }
 629         }
 630
 631 old_is_alloced:
 632         if (old_is_alloced)
 633                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 634         else
 635                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 636
 637         /* "Flush" the stor_chns array. */
 638         for_each_possible_cpu(cpu) {
 639                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 640                                         cpu, &stor_device->alloced_cpus))
 641                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 642         }
 643
 644         WRITE_ONCE(stor_device->stor_chns[new], channel);
 645         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 646
 647         spin_unlock_irqrestore(&stor_device->lock, flags);
 648 }
 649
 650 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 651 {
 652         struct storvsc_cmd_request *request =
 653                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
 654
 655         if (rqst_addr == VMBUS_RQST_INIT)
 656                 return VMBUS_RQST_INIT;
 657         if (rqst_addr == VMBUS_RQST_RESET)
 658                 return VMBUS_RQST_RESET;
 659
 660         /*
 661          * Cannot return an ID of 0, which is reserved for an unsolicited
 662          * message from Hyper-V.
 663          */
 664         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
 665 }
 666
 667 static void handle_sc_creation(struct vmbus_channel *new_sc)
 668 {
 669         struct hv_device *device = new_sc->primary_channel->device_obj;
 670         struct device *dev = &device->device;
 671         struct storvsc_device *stor_device;
 672         struct vmstorage_channel_properties props;
 673         int ret;
 674
 675         stor_device = get_out_stor_device(device);
 676         if (!stor_device)
 677                 return;
 678
 679         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 680         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
 681
 682         new_sc->next_request_id_callback = storvsc_next_request_id;
 683
 684         ret = vmbus_open(new_sc,
 685                          storvsc_ringbuffer_size,
 686                          storvsc_ringbuffer_size,
 687                          (void *)&props,
 688                          sizeof(struct vmstorage_channel_properties),
 689                          storvsc_on_channel_callback, new_sc);
 690
 691         /* In case vmbus_open() fails, we don't use the sub-channel. */
 692         if (ret != 0) {
 693                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 694                 return;
 695         }
 696
 697         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 698
 699         /* Add the sub-channel to the array of available channels. */
 700         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 701         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 702 }
 703
 704 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 705 {
 706         struct device *dev = &device->device;
 707         struct storvsc_device *stor_device;
 708         int num_sc;
 709         struct storvsc_cmd_request *request;
 710         struct vstor_packet *vstor_packet;
 711         int ret, t;
 712
 713         /*
 714          * If the number of CPUs is artificially restricted, such as
 715          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 716          * sub-channels >= the number of CPUs. These sub-channels
 717          * should not be created. The primary channel is already created
 718          * and assigned to one CPU, so check against # CPUs - 1.
 719          */
 720         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 721         if (!num_sc)
 722                 return;
 723
 724         stor_device = get_out_stor_device(device);
 725         if (!stor_device)
 726                 return;
 727
 728         stor_device->num_sc = num_sc;
 729         request = &stor_device->init_request;
 730         vstor_packet = &request->vstor_packet;
 731
 732         /*
 733          * Establish a handler for dealing with subchannels.
 734          */
 735         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 736
 737         /*
 738          * Request the host to create sub-channels.
 739          */
 740         memset(request, 0, sizeof(struct storvsc_cmd_request));
 741         init_completion(&request->wait_event);
 742         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 743         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 744         vstor_packet->sub_channel_count = num_sc;
 745
 746         ret = vmbus_sendpacket(device->channel, vstor_packet,
 747                                sizeof(struct vstor_packet),
 748                                VMBUS_RQST_INIT,
 749                                VM_PKT_DATA_INBAND,
 750                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 751
 752         if (ret != 0) {
 753                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 754                 return;
 755         }
 756
 757         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 758         if (t == 0) {
 759                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 760                 return;
 761         }
 762
 763         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 764             vstor_packet->status != 0) {
 765                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 766                         vstor_packet->operation, vstor_packet->status);
 767                 return;
 768         }
 769
 770         /*
 771          * We need to do nothing here, because vmbus_process_offer()
 772          * invokes channel->sc_creation_callback, which will open and use
 773          * the sub-channel(s).
 774          */
 775 }
 776
 777 static void cache_wwn(struct storvsc_device *stor_device,
 778                       struct vstor_packet *vstor_packet)
 779 {
 780         /*
 781          * Cache the currently active port and node ww names.
 782          */
 783         if (vstor_packet->wwn_packet.primary_active) {
 784                 stor_device->node_name =
 785                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 786                 stor_device->port_name =
 787                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 788         } else {
 789                 stor_device->node_name =
 790                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 791                 stor_device->port_name =
 792                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 793         }
 794 }
 795
 796
 797 static int storvsc_execute_vstor_op(struct hv_device *device,
 798                                     struct storvsc_cmd_request *request,
 799                                     bool status_check)
 800 {
 801         struct storvsc_device *stor_device;
 802         struct vstor_packet *vstor_packet;
 803         int ret, t;
 804
 805         stor_device = get_out_stor_device(device);
 806         if (!stor_device)
 807                 return -ENODEV;
 808
 809         vstor_packet = &request->vstor_packet;
 810
 811         init_completion(&request->wait_event);
 812         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 813
 814         ret = vmbus_sendpacket(device->channel, vstor_packet,
 815                                sizeof(struct vstor_packet),
 816                                VMBUS_RQST_INIT,
 817                                VM_PKT_DATA_INBAND,
 818                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 819         if (ret != 0)
 820                 return ret;
 821
 822         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 823         if (t == 0)
 824                 return -ETIMEDOUT;
 825
 826         if (!status_check)
 827                 return ret;
 828
 829         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 830             vstor_packet->status != 0)
 831                 return -EINVAL;
 832
 833         return ret;
 834 }
 835
 836 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 837 {
 838         struct storvsc_device *stor_device;
 839         struct storvsc_cmd_request *request;
 840         struct vstor_packet *vstor_packet;
 841         int ret, i;
 842         int max_chns;
 843         bool process_sub_channels = false;
 844
 845         stor_device = get_out_stor_device(device);
 846         if (!stor_device)
 847                 return -ENODEV;
 848
 849         request = &stor_device->init_request;
 850         vstor_packet = &request->vstor_packet;
 851
 852         /*
 853          * Now, initiate the vsc/vsp initialization protocol on the open
 854          * channel
 855          */
 856         memset(request, 0, sizeof(struct storvsc_cmd_request));
 857         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 858         ret = storvsc_execute_vstor_op(device, request, true);
 859         if (ret)
 860                 return ret;
 861         /*
 862          * Query host supported protocol version.
 863          */
 864
 865         for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
 866                 /* reuse the packet for version range supported */
 867                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 868                 vstor_packet->operation =
 869                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 870
 871                 vstor_packet->version.major_minor = protocol_version[i];
 872
 873                 /*
 874                  * The revision number is only used in Windows; set it to 0.
 875                  */
 876                 vstor_packet->version.revision = 0;
 877                 ret = storvsc_execute_vstor_op(device, request, false);
 878                 if (ret != 0)
 879                         return ret;
 880
 881                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 882                         return -EINVAL;
 883
 884                 if (vstor_packet->status == 0) {
 885                         vmstor_proto_version = protocol_version[i];
 886
 887                         break;
 888                 }
 889         }
 890
 891         if (vstor_packet->status != 0) {
 892                 dev_err(&device->device, "Obsolete Hyper-V version\n");
 893                 return -EINVAL;
 894         }
 895
 896
 897         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 898         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 899         ret = storvsc_execute_vstor_op(device, request, true);
 900         if (ret != 0)
 901                 return ret;
 902
 903         /*
 904          * Check to see if multi-channel support is there.
 905          * Hosts that implement protocol version of 5.1 and above
 906          * support multi-channel.
 907          */
 908         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 909
 910         /*
 911          * Allocate state to manage the sub-channels.
 912          * We allocate an array based on the numbers of possible CPUs
 913          * (Hyper-V does not support cpu online/offline).
 914          * This Array will be sparseley populated with unique
 915          * channels - primary + sub-channels.
 916          * We will however populate all the slots to evenly distribute
 917          * the load.
 918          */
 919         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 920                                          GFP_KERNEL);
 921         if (stor_device->stor_chns == NULL)
 922                 return -ENOMEM;
 923
 924         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 925
 926         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 927         cpumask_set_cpu(device->channel->target_cpu,
 928                         &stor_device->alloced_cpus);
 929
 930         if (vstor_packet->storage_channel_properties.flags &
 931             STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 932                 process_sub_channels = true;
 933
 934         stor_device->max_transfer_bytes =
 935                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 936
 937         if (!is_fc)
 938                 goto done;
 939
 940         /*
 941          * For FC devices retrieve FC HBA data.
 942          */
 943         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 944         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 945         ret = storvsc_execute_vstor_op(device, request, true);
 946         if (ret != 0)
 947                 return ret;
 948
 949         /*
 950          * Cache the currently active port and node ww names.
 951          */
 952         cache_wwn(stor_device, vstor_packet);
 953
 954 done:
 955
 956         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 957         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 958         ret = storvsc_execute_vstor_op(device, request, true);
 959         if (ret != 0)
 960                 return ret;
 961
 962         if (process_sub_channels)
 963                 handle_multichannel_storage(device, max_chns);
 964
 965         return ret;
 966 }
 967
 968 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 969                                 struct scsi_cmnd *scmnd,
 970                                 struct Scsi_Host *host,
 971                                 u8 asc, u8 ascq)
 972 {
 973         struct storvsc_scan_work *wrk;
 974         void (*process_err_fn)(struct work_struct *work);
 975         struct hv_host_device *host_dev = shost_priv(host);
 976
 977         switch (SRB_STATUS(vm_srb->srb_status)) {
 978         case SRB_STATUS_ERROR:
 979         case SRB_STATUS_ABORTED:
 980         case SRB_STATUS_INVALID_REQUEST:
 981                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
 982                         /* Check for capacity change */
 983                         if ((asc == 0x2a) && (ascq == 0x9)) {
 984                                 process_err_fn = storvsc_device_scan;
 985                                 /* Retry the I/O that triggered this. */
 986                                 set_host_byte(scmnd, DID_REQUEUE);
 987                                 goto do_work;
 988                         }
 989
 990                         /*
 991                          * Check for "Operating parameters have changed"
 992                          * due to Hyper-V changing the VHD/VHDX BlockSize
 993                          * when adding/removing a differencing disk. This
 994                          * causes discard_granularity to change, so do a
 995                          * rescan to pick up the new granularity. We don't
 996                          * want scsi_report_sense() to output a message
 997                          * that a sysadmin wouldn't know what to do with.
 998                          */
 999                         if ((asc == 0x3f) && (ascq != 0x03) &&
1000                                         (ascq != 0x0e)) {
1001                                 process_err_fn = storvsc_device_scan;
1002                                 set_host_byte(scmnd, DID_REQUEUE);
1003                                 goto do_work;
1004                         }
1005
1006                         /*
1007                          * Otherwise, let upper layer deal with the
1008                          * error when sense message is present
1009                          */
1010                         return;
1011                 }
1012
1013                 /*
1014                  * If there is an error; offline the device since all
1015                  * error recovery strategies would have already been
1016                  * deployed on the host side. However, if the command
1017                  * were a pass-through command deal with it appropriately.
1018                  */
1019                 switch (scmnd->cmnd[0]) {
1020                 case ATA_16:
1021                 case ATA_12:
1022                         set_host_byte(scmnd, DID_PASSTHROUGH);
1023                         break;
1024                 /*
1025                  * On some Hyper-V hosts TEST_UNIT_READY command can
1026                  * return SRB_STATUS_ERROR. Let the upper level code
1027                  * deal with it based on the sense information.
1028                  */
1029                 case TEST_UNIT_READY:
1030                         break;
1031                 default:
1032                         set_host_byte(scmnd, DID_ERROR);
1033                 }
1034                 return;
1035
1036         case SRB_STATUS_INVALID_LUN:
1037                 set_host_byte(scmnd, DID_NO_CONNECT);
1038                 process_err_fn = storvsc_remove_lun;
1039                 goto do_work;
1040
1041         }
1042         return;
1043
1044 do_work:
1045         /*
1046          * We need to schedule work to process this error; schedule it.
1047          */
1048         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1049         if (!wrk) {
1050                 set_host_byte(scmnd, DID_BAD_TARGET);
1051                 return;
1052         }
1053
1054         wrk->host = host;
1055         wrk->lun = vm_srb->lun;
1056         wrk->tgt_id = vm_srb->target_id;
1057         INIT_WORK(&wrk->work, process_err_fn);
1058         queue_work(host_dev->handle_error_wq, &wrk->work);
1059 }
1060
1061
1062 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1063                                        struct storvsc_device *stor_dev)
1064 {
1065         struct scsi_cmnd *scmnd = cmd_request->cmd;
1066         struct scsi_sense_hdr sense_hdr;
1067         struct vmscsi_request *vm_srb;
1068         u32 data_transfer_length;
1069         struct Scsi_Host *host;
1070         u32 payload_sz = cmd_request->payload_sz;
1071         void *payload = cmd_request->payload;
1072         bool sense_ok;
1073
1074         host = stor_dev->host;
1075
1076         vm_srb = &cmd_request->vstor_packet.vm_srb;
1077         data_transfer_length = vm_srb->data_transfer_length;
1078
1079         scmnd->result = vm_srb->scsi_status;
1080
1081         if (scmnd->result) {
1082                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1083                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1084
1085                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1086                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1087                                              &sense_hdr);
1088         }
1089
1090         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1091                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1092                                          sense_hdr.ascq);
1093                 /*
1094                  * The Windows driver set data_transfer_length on
1095                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1096                  * is untouched.  In these cases we set it to 0.
1097                  */
1098                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1099                         data_transfer_length = 0;
1100         }
1101
1102         /* Validate data_transfer_length (from Hyper-V) */
1103         if (data_transfer_length > cmd_request->payload->range.len)
1104                 data_transfer_length = cmd_request->payload->range.len;
1105
1106         scsi_set_resid(scmnd,
1107                 cmd_request->payload->range.len - data_transfer_length);
1108
1109         scsi_done(scmnd);
1110
1111         if (payload_sz >
1112                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1113                 kfree(payload);
1114 }
1115
1116 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1117                                   struct vstor_packet *vstor_packet,
1118                                   struct storvsc_cmd_request *request)
1119 {
1120         struct vstor_packet *stor_pkt;
1121         struct hv_device *device = stor_device->device;
1122
1123         stor_pkt = &request->vstor_packet;
1124
1125         /*
1126          * The current SCSI handling on the host side does
1127          * not correctly handle:
1128          * INQUIRY command with page code parameter set to 0x80
1129          * MODE_SENSE command with cmd[2] == 0x1c
1130          *
1131          * Setup srb and scsi status so this won't be fatal.
1132          * We do this so we can distinguish truly fatal failues
1133          * (srb status == 0x4) and off-line the device in that case.
1134          */
1135
1136         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1137            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1138                 vstor_packet->vm_srb.scsi_status = 0;
1139                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1140         }
1141
1142         /* Copy over the status...etc */
1143         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1144         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1145
1146         /*
1147          * Copy over the sense_info_length, but limit to the known max
1148          * size if Hyper-V returns a bad value.
1149          */
1150         stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1151                 vstor_packet->vm_srb.sense_info_length);
1152
1153         if (vstor_packet->vm_srb.scsi_status != 0 ||
1154             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1155
1156                 /*
1157                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1158                  * return errors when detecting devices using TEST_UNIT_READY,
1159                  * and logging these as errors produces unhelpful noise.
1160                  */
1161                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1162                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1163
1164                 storvsc_log(device, loglevel,
1165                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1166                         scsi_cmd_to_rq(request->cmd)->tag,
1167                         stor_pkt->vm_srb.cdb[0],
1168                         vstor_packet->vm_srb.scsi_status,
1169                         vstor_packet->vm_srb.srb_status,
1170                         vstor_packet->status);
1171         }
1172
1173         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1174             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1175                 memcpy(request->cmd->sense_buffer,
1176                        vstor_packet->vm_srb.sense_data,
1177                        stor_pkt->vm_srb.sense_info_length);
1178
1179         stor_pkt->vm_srb.data_transfer_length =
1180                 vstor_packet->vm_srb.data_transfer_length;
1181
1182         storvsc_command_completion(request, stor_device);
1183
1184         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1185                 stor_device->drain_notify)
1186                 wake_up(&stor_device->waiting_to_drain);
1187 }
1188
1189 static void storvsc_on_receive(struct storvsc_device *stor_device,
1190                              struct vstor_packet *vstor_packet,
1191                              struct storvsc_cmd_request *request)
1192 {
1193         struct hv_host_device *host_dev;
1194         switch (vstor_packet->operation) {
1195         case VSTOR_OPERATION_COMPLETE_IO:
1196                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1197                 break;
1198
1199         case VSTOR_OPERATION_REMOVE_DEVICE:
1200         case VSTOR_OPERATION_ENUMERATE_BUS:
1201                 host_dev = shost_priv(stor_device->host);
1202                 queue_work(
1203                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1204                 break;
1205
1206         case VSTOR_OPERATION_FCHBA_DATA:
1207                 cache_wwn(stor_device, vstor_packet);
1208 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1209                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1210                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1211 #endif
1212                 break;
1213         default:
1214                 break;
1215         }
1216 }
1217
1218 static void storvsc_on_channel_callback(void *context)
1219 {
1220         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1221         const struct vmpacket_descriptor *desc;
1222         struct hv_device *device;
1223         struct storvsc_device *stor_device;
1224         struct Scsi_Host *shost;
1225         unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1226
1227         if (channel->primary_channel != NULL)
1228                 device = channel->primary_channel->device_obj;
1229         else
1230                 device = channel->device_obj;
1231
1232         stor_device = get_in_stor_device(device);
1233         if (!stor_device)
1234                 return;
1235
1236         shost = stor_device->host;
1237
1238         foreach_vmbus_pkt(desc, channel) {
1239                 struct vstor_packet *packet = hv_pkt_data(desc);
1240                 struct storvsc_cmd_request *request = NULL;
1241                 u32 pktlen = hv_pkt_datalen(desc);
1242                 u64 rqst_id = desc->trans_id;
1243                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1244                         sizeof(enum vstor_packet_operation);
1245
1246                 if (unlikely(time_after(jiffies, time_limit))) {
1247                         hv_pkt_iter_close(channel);
1248                         return;
1249                 }
1250
1251                 if (pktlen < minlen) {
1252                         dev_err(&device->device,
1253                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1254                                 rqst_id, pktlen, minlen);
1255                         continue;
1256                 }
1257
1258                 if (rqst_id == VMBUS_RQST_INIT) {
1259                         request = &stor_device->init_request;
1260                 } else if (rqst_id == VMBUS_RQST_RESET) {
1261                         request = &stor_device->reset_request;
1262                 } else {
1263                         /* Hyper-V can send an unsolicited message with ID of 0 */
1264                         if (rqst_id == 0) {
1265                                 /*
1266                                  * storvsc_on_receive() looks at the vstor_packet in the message
1267                                  * from the ring buffer.
1268                                  *
1269                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1270                                  *   we call storvsc_on_io_completion(), and dereference the
1271                                  *   guest memory address.  Make sure we don't call
1272                                  *   storvsc_on_io_completion() with a guest memory address
1273                                  *   that is zero if Hyper-V were to construct and send such
1274                                  *   a bogus packet.
1275                                  *
1276                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1277                                  *   we call cache_wwn(), and access the data payload area of
1278                                  *   the packet (wwn_packet); however, there is no guarantee
1279                                  *   that the packet is big enough to contain such area.
1280                                  *   Future-proof the code by rejecting such a bogus packet.
1281                                  */
1282                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1283                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1284                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1285                                         continue;
1286                                 }
1287                         } else {
1288                                 struct scsi_cmnd *scmnd;
1289
1290                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1291                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1292                                 if (scmnd == NULL) {
1293                                         dev_err(&device->device, "Incorrect transaction ID\n");
1294                                         continue;
1295                                 }
1296                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1297                                 scsi_dma_unmap(scmnd);
1298                         }
1299
1300                         storvsc_on_receive(stor_device, packet, request);
1301                         continue;
1302                 }
1303
1304                 memcpy(&request->vstor_packet, packet,
1305                        sizeof(struct vstor_packet));
1306                 complete(&request->wait_event);
1307         }
1308 }
1309
1310 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1311                                   bool is_fc)
1312 {
1313         struct vmstorage_channel_properties props;
1314         int ret;
1315
1316         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1317
1318         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1319         device->channel->next_request_id_callback = storvsc_next_request_id;
1320
1321         ret = vmbus_open(device->channel,
1322                          ring_size,
1323                          ring_size,
1324                          (void *)&props,
1325                          sizeof(struct vmstorage_channel_properties),
1326                          storvsc_on_channel_callback, device->channel);
1327
1328         if (ret != 0)
1329                 return ret;
1330
1331         ret = storvsc_channel_init(device, is_fc);
1332
1333         return ret;
1334 }
1335
1336 static int storvsc_dev_remove(struct hv_device *device)
1337 {
1338         struct storvsc_device *stor_device;
1339
1340         stor_device = hv_get_drvdata(device);
1341
1342         stor_device->destroy = true;
1343
1344         /* Make sure flag is set before waiting */
1345         wmb();
1346
1347         /*
1348          * At this point, all outbound traffic should be disable. We
1349          * only allow inbound traffic (responses) to proceed so that
1350          * outstanding requests can be completed.
1351          */
1352
1353         storvsc_wait_to_drain(stor_device);
1354
1355         /*
1356          * Since we have already drained, we don't need to busy wait
1357          * as was done in final_release_stor_device()
1358          * Note that we cannot set the ext pointer to NULL until
1359          * we have drained - to drain the outgoing packets, we need to
1360          * allow incoming packets.
1361          */
1362         hv_set_drvdata(device, NULL);
1363
1364         /* Close the channel */
1365         vmbus_close(device->channel);
1366
1367         kfree(stor_device->stor_chns);
1368         kfree(stor_device);
1369         return 0;
1370 }
1371
1372 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1373                                         u16 q_num)
1374 {
1375         u16 slot = 0;
1376         u16 hash_qnum;
1377         const struct cpumask *node_mask;
1378         int num_channels, tgt_cpu;
1379
1380         if (stor_device->num_sc == 0) {
1381                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1382                 return stor_device->device->channel;
1383         }
1384
1385         /*
1386          * Our channel array is sparsley populated and we
1387          * initiated I/O on a processor/hw-q that does not
1388          * currently have a designated channel. Fix this.
1389          * The strategy is simple:
1390          * I. Ensure NUMA locality
1391          * II. Distribute evenly (best effort)
1392          */
1393
1394         node_mask = cpumask_of_node(cpu_to_node(q_num));
1395
1396         num_channels = 0;
1397         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1398                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1399                         num_channels++;
1400         }
1401         if (num_channels == 0) {
1402                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1403                 return stor_device->device->channel;
1404         }
1405
1406         hash_qnum = q_num;
1407         while (hash_qnum >= num_channels)
1408                 hash_qnum -= num_channels;
1409
1410         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1411                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1412                         continue;
1413                 if (slot == hash_qnum)
1414                         break;
1415                 slot++;
1416         }
1417
1418         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1419
1420         return stor_device->stor_chns[q_num];
1421 }
1422
1423
1424 static int storvsc_do_io(struct hv_device *device,
1425                          struct storvsc_cmd_request *request, u16 q_num)
1426 {
1427         struct storvsc_device *stor_device;
1428         struct vstor_packet *vstor_packet;
1429         struct vmbus_channel *outgoing_channel, *channel;
1430         unsigned long flags;
1431         int ret = 0;
1432         const struct cpumask *node_mask;
1433         int tgt_cpu;
1434
1435         vstor_packet = &request->vstor_packet;
1436         stor_device = get_out_stor_device(device);
1437
1438         if (!stor_device)
1439                 return -ENODEV;
1440
1441
1442         request->device  = device;
1443         /*
1444          * Select an appropriate channel to send the request out.
1445          */
1446         /* See storvsc_change_target_cpu(). */
1447         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1448         if (outgoing_channel != NULL) {
1449                 if (outgoing_channel->target_cpu == q_num) {
1450                         /*
1451                          * Ideally, we want to pick a different channel if
1452                          * available on the same NUMA node.
1453                          */
1454                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1455                         for_each_cpu_wrap(tgt_cpu,
1456                                  &stor_device->alloced_cpus, q_num + 1) {
1457                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1458                                         continue;
1459                                 if (tgt_cpu == q_num)
1460                                         continue;
1461                                 channel = READ_ONCE(
1462                                         stor_device->stor_chns[tgt_cpu]);
1463                                 if (channel == NULL)
1464                                         continue;
1465                                 if (hv_get_avail_to_write_percent(
1466                                                         &channel->outbound)
1467                                                 > ring_avail_percent_lowater) {
1468                                         outgoing_channel = channel;
1469                                         goto found_channel;
1470                                 }
1471                         }
1472
1473                         /*
1474                          * All the other channels on the same NUMA node are
1475                          * busy. Try to use the channel on the current CPU
1476                          */
1477                         if (hv_get_avail_to_write_percent(
1478                                                 &outgoing_channel->outbound)
1479                                         > ring_avail_percent_lowater)
1480                                 goto found_channel;
1481
1482                         /*
1483                          * If we reach here, all the channels on the current
1484                          * NUMA node are busy. Try to find a channel in
1485                          * other NUMA nodes
1486                          */
1487                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1488                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1489                                         continue;
1490                                 channel = READ_ONCE(
1491                                         stor_device->stor_chns[tgt_cpu]);
1492                                 if (channel == NULL)
1493                                         continue;
1494                                 if (hv_get_avail_to_write_percent(
1495                                                         &channel->outbound)
1496                                                 > ring_avail_percent_lowater) {
1497                                         outgoing_channel = channel;
1498                                         goto found_channel;
1499                                 }
1500                         }
1501                 }
1502         } else {
1503                 spin_lock_irqsave(&stor_device->lock, flags);
1504                 outgoing_channel = stor_device->stor_chns[q_num];
1505                 if (outgoing_channel != NULL) {
1506                         spin_unlock_irqrestore(&stor_device->lock, flags);
1507                         goto found_channel;
1508                 }
1509                 outgoing_channel = get_og_chn(stor_device, q_num);
1510                 spin_unlock_irqrestore(&stor_device->lock, flags);
1511         }
1512
1513 found_channel:
1514         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1515
1516         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1517
1518
1519         vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1520
1521
1522         vstor_packet->vm_srb.data_transfer_length =
1523         request->payload->range.len;
1524
1525         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1526
1527         if (request->payload->range.len) {
1528
1529                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1530                                 request->payload, request->payload_sz,
1531                                 vstor_packet,
1532                                 sizeof(struct vstor_packet),
1533                                 (unsigned long)request);
1534         } else {
1535                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1536                                sizeof(struct vstor_packet),
1537                                (unsigned long)request,
1538                                VM_PKT_DATA_INBAND,
1539                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1540         }
1541
1542         if (ret != 0)
1543                 return ret;
1544
1545         atomic_inc(&stor_device->num_outstanding_req);
1546
1547         return ret;
1548 }
1549
1550 static int storvsc_device_alloc(struct scsi_device *sdevice)
1551 {
1552         /*
1553          * Set blist flag to permit the reading of the VPD pages even when
1554          * the target may claim SPC-2 compliance. MSFT targets currently
1555          * claim SPC-2 compliance while they implement post SPC-2 features.
1556          * With this flag we can correctly handle WRITE_SAME_16 issues.
1557          *
1558          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1559          * still supports REPORT LUN.
1560          */
1561         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1562
1563         return 0;
1564 }
1565
1566 static int storvsc_device_configure(struct scsi_device *sdevice)
1567 {
1568         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1569
1570         sdevice->no_write_same = 1;
1571
1572         /*
1573          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1574          * if the device is a MSFT virtual device.  If the host is
1575          * WIN10 or newer, allow write_same.
1576          */
1577         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1578                 switch (vmstor_proto_version) {
1579                 case VMSTOR_PROTO_VERSION_WIN8:
1580                 case VMSTOR_PROTO_VERSION_WIN8_1:
1581                         sdevice->scsi_level = SCSI_SPC_3;
1582                         break;
1583                 }
1584
1585                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1586                         sdevice->no_write_same = 0;
1587         }
1588
1589         return 0;
1590 }
1591
1592 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1593                            sector_t capacity, int *info)
1594 {
1595         sector_t nsect = capacity;
1596         sector_t cylinders = nsect;
1597         int heads, sectors_pt;
1598
1599         /*
1600          * We are making up these values; let us keep it simple.
1601          */
1602         heads = 0xff;
1603         sectors_pt = 0x3f;      /* Sectors per track */
1604         sector_div(cylinders, heads * sectors_pt);
1605         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1606                 cylinders = 0xffff;
1607
1608         info[0] = heads;
1609         info[1] = sectors_pt;
1610         info[2] = (int)cylinders;
1611
1612         return 0;
1613 }
1614
1615 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1616 {
1617         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1618         struct hv_device *device = host_dev->dev;
1619
1620         struct storvsc_device *stor_device;
1621         struct storvsc_cmd_request *request;
1622         struct vstor_packet *vstor_packet;
1623         int ret, t;
1624
1625         stor_device = get_out_stor_device(device);
1626         if (!stor_device)
1627                 return FAILED;
1628
1629         request = &stor_device->reset_request;
1630         vstor_packet = &request->vstor_packet;
1631         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1632
1633         init_completion(&request->wait_event);
1634
1635         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1636         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1637         vstor_packet->vm_srb.path_id = stor_device->path_id;
1638
1639         ret = vmbus_sendpacket(device->channel, vstor_packet,
1640                                sizeof(struct vstor_packet),
1641                                VMBUS_RQST_RESET,
1642                                VM_PKT_DATA_INBAND,
1643                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1644         if (ret != 0)
1645                 return FAILED;
1646
1647         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1648         if (t == 0)
1649                 return TIMEOUT_ERROR;
1650
1651
1652         /*
1653          * At this point, all outstanding requests in the adapter
1654          * should have been flushed out and return to us
1655          * There is a potential race here where the host may be in
1656          * the process of responding when we return from here.
1657          * Just wait for all in-transit packets to be accounted for
1658          * before we return from here.
1659          */
1660         storvsc_wait_to_drain(stor_device);
1661
1662         return SUCCESS;
1663 }
1664
1665 /*
1666  * The host guarantees to respond to each command, although I/O latencies might
1667  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1668  * chance to perform EH.
1669  */
1670 static enum scsi_timeout_action storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1671 {
1672 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1673         if (scmnd->device->host->transportt == fc_transport_template)
1674                 return fc_eh_timed_out(scmnd);
1675 #endif
1676         return SCSI_EH_RESET_TIMER;
1677 }
1678
1679 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1680 {
1681         bool allowed = true;
1682         u8 scsi_op = scmnd->cmnd[0];
1683
1684         switch (scsi_op) {
1685         /* the host does not handle WRITE_SAME, log accident usage */
1686         case WRITE_SAME:
1687         /*
1688          * smartd sends this command and the host does not handle
1689          * this. So, don't send it.
1690          */
1691         case SET_WINDOW:
1692                 set_host_byte(scmnd, DID_ERROR);
1693                 allowed = false;
1694                 break;
1695         default:
1696                 break;
1697         }
1698         return allowed;
1699 }
1700
1701 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1702 {
1703         int ret;
1704         struct hv_host_device *host_dev = shost_priv(host);
1705         struct hv_device *dev = host_dev->dev;
1706         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1707         struct scatterlist *sgl;
1708         struct vmscsi_request *vm_srb;
1709         struct vmbus_packet_mpb_array  *payload;
1710         u32 payload_sz;
1711         u32 length;
1712
1713         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1714                 /*
1715                  * On legacy hosts filter unimplemented commands.
1716                  * Future hosts are expected to correctly handle
1717                  * unsupported commands. Furthermore, it is
1718                  * possible that some of the currently
1719                  * unsupported commands maybe supported in
1720                  * future versions of the host.
1721                  */
1722                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1723                         scsi_done(scmnd);
1724                         return 0;
1725                 }
1726         }
1727
1728         /* Setup the cmd request */
1729         cmd_request->cmd = scmnd;
1730
1731         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1732         vm_srb = &cmd_request->vstor_packet.vm_srb;
1733         vm_srb->time_out_value = 60;
1734
1735         vm_srb->srb_flags |=
1736                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1737
1738         if (scmnd->device->tagged_supported) {
1739                 vm_srb->srb_flags |=
1740                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1741                 vm_srb->queue_tag = SP_UNTAGGED;
1742                 vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1743         }
1744
1745         /* Build the SRB */
1746         switch (scmnd->sc_data_direction) {
1747         case DMA_TO_DEVICE:
1748                 vm_srb->data_in = WRITE_TYPE;
1749                 vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1750                 break;
1751         case DMA_FROM_DEVICE:
1752                 vm_srb->data_in = READ_TYPE;
1753                 vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1754                 break;
1755         case DMA_NONE:
1756                 vm_srb->data_in = UNKNOWN_TYPE;
1757                 vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1758                 break;
1759         default:
1760                 /*
1761                  * This is DMA_BIDIRECTIONAL or something else we are never
1762                  * supposed to see here.
1763                  */
1764                 WARN(1, "Unexpected data direction: %d\n",
1765                      scmnd->sc_data_direction);
1766                 return -EINVAL;
1767         }
1768
1769
1770         vm_srb->port_number = host_dev->port;
1771         vm_srb->path_id = scmnd->device->channel;
1772         vm_srb->target_id = scmnd->device->id;
1773         vm_srb->lun = scmnd->device->lun;
1774
1775         vm_srb->cdb_length = scmnd->cmd_len;
1776
1777         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1778
1779         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1780
1781         length = scsi_bufflen(scmnd);
1782         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1783         payload_sz = 0;
1784
1785         if (scsi_sg_count(scmnd)) {
1786                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1787                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1788                 struct scatterlist *sg;
1789                 unsigned long hvpfn, hvpfns_to_add;
1790                 int j, i = 0, sg_count;
1791
1792                 payload_sz = (hvpg_count * sizeof(u64) +
1793                               sizeof(struct vmbus_packet_mpb_array));
1794
1795                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1796                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1797                         if (!payload)
1798                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1799                 }
1800
1801                 payload->range.len = length;
1802                 payload->range.offset = offset_in_hvpg;
1803
1804                 sg_count = scsi_dma_map(scmnd);
1805                 if (sg_count < 0) {
1806                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1807                         goto err_free_payload;
1808                 }
1809
1810                 for_each_sg(sgl, sg, sg_count, j) {
1811                         /*
1812                          * Init values for the current sgl entry. hvpfns_to_add
1813                          * is in units of Hyper-V size pages. Handling the
1814                          * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1815                          * values of sgl->offset that are larger than PAGE_SIZE.
1816                          * Such offsets are handled even on other than the first
1817                          * sgl entry, provided they are a multiple of PAGE_SIZE.
1818                          */
1819                         hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1820                         hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1821                                                  sg_dma_len(sg)) - hvpfn;
1822
1823                         /*
1824                          * Fill the next portion of the PFN array with
1825                          * sequential Hyper-V PFNs for the continguous physical
1826                          * memory described by the sgl entry. The end of the
1827                          * last sgl should be reached at the same time that
1828                          * the PFN array is filled.
1829                          */
1830                         while (hvpfns_to_add--)
1831                                 payload->range.pfn_array[i++] = hvpfn++;
1832                 }
1833         }
1834
1835         cmd_request->payload = payload;
1836         cmd_request->payload_sz = payload_sz;
1837
1838         /* Invokes the vsc to start an IO */
1839         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1840         put_cpu();
1841
1842         if (ret)
1843                 scsi_dma_unmap(scmnd);
1844
1845         if (ret == -EAGAIN) {
1846                 /* no more space */
1847                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1848                 goto err_free_payload;
1849         }
1850
1851         return 0;
1852
1853 err_free_payload:
1854         if (payload_sz > sizeof(cmd_request->mpb))
1855                 kfree(payload);
1856
1857         return ret;
1858 }
1859
1860 static struct scsi_host_template scsi_driver = {
1861         .module =               THIS_MODULE,
1862         .name =                 "storvsc_host_t",
1863         .cmd_size =             sizeof(struct storvsc_cmd_request),
1864         .bios_param =           storvsc_get_chs,
1865         .queuecommand =         storvsc_queuecommand,
1866         .eh_host_reset_handler =        storvsc_host_reset_handler,
1867         .proc_name =            "storvsc_host",
1868         .eh_timed_out =         storvsc_eh_timed_out,
1869         .slave_alloc =          storvsc_device_alloc,
1870         .slave_configure =      storvsc_device_configure,
1871         .cmd_per_lun =          2048,
1872         .this_id =              -1,
1873         /* Ensure there are no gaps in presented sgls */
1874         .virt_boundary_mask =   HV_HYP_PAGE_SIZE - 1,
1875         .no_write_same =        1,
1876         .track_queue_depth =    1,
1877         .change_queue_depth =   storvsc_change_queue_depth,
1878 };
1879
1880 enum {
1881         SCSI_GUID,
1882         IDE_GUID,
1883         SFC_GUID,
1884 };
1885
1886 static const struct hv_vmbus_device_id id_table[] = {
1887         /* SCSI guid */
1888         { HV_SCSI_GUID,
1889           .driver_data = SCSI_GUID
1890         },
1891         /* IDE guid */
1892         { HV_IDE_GUID,
1893           .driver_data = IDE_GUID
1894         },
1895         /* Fibre Channel GUID */
1896         {
1897           HV_SYNTHFC_GUID,
1898           .driver_data = SFC_GUID
1899         },
1900         { },
1901 };
1902
1903 MODULE_DEVICE_TABLE(vmbus, id_table);
1904
1905 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1906
1907 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1908 {
1909         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1910 }
1911
1912 static int storvsc_probe(struct hv_device *device,
1913                         const struct hv_vmbus_device_id *dev_id)
1914 {
1915         int ret;
1916         int num_cpus = num_online_cpus();
1917         int num_present_cpus = num_present_cpus();
1918         struct Scsi_Host *host;
1919         struct hv_host_device *host_dev;
1920         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1921         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1922         int target = 0;
1923         struct storvsc_device *stor_device;
1924         int max_sub_channels = 0;
1925         u32 max_xfer_bytes;
1926
1927         /*
1928          * We support sub-channels for storage on SCSI and FC controllers.
1929          * The number of sub-channels offerred is based on the number of
1930          * VCPUs in the guest.
1931          */
1932         if (!dev_is_ide)
1933                 max_sub_channels =
1934                         (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1935
1936         scsi_driver.can_queue = max_outstanding_req_per_channel *
1937                                 (max_sub_channels + 1) *
1938                                 (100 - ring_avail_percent_lowater) / 100;
1939
1940         host = scsi_host_alloc(&scsi_driver,
1941                                sizeof(struct hv_host_device));
1942         if (!host)
1943                 return -ENOMEM;
1944
1945         host_dev = shost_priv(host);
1946         memset(host_dev, 0, sizeof(struct hv_host_device));
1947
1948         host_dev->port = host->host_no;
1949         host_dev->dev = device;
1950         host_dev->host = host;
1951
1952
1953         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1954         if (!stor_device) {
1955                 ret = -ENOMEM;
1956                 goto err_out0;
1957         }
1958
1959         stor_device->destroy = false;
1960         init_waitqueue_head(&stor_device->waiting_to_drain);
1961         stor_device->device = device;
1962         stor_device->host = host;
1963         spin_lock_init(&stor_device->lock);
1964         hv_set_drvdata(device, stor_device);
1965         dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
1966
1967         stor_device->port_number = host->host_no;
1968         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1969         if (ret)
1970                 goto err_out1;
1971
1972         host_dev->path = stor_device->path_id;
1973         host_dev->target = stor_device->target_id;
1974
1975         switch (dev_id->driver_data) {
1976         case SFC_GUID:
1977                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1978                 host->max_id = STORVSC_FC_MAX_TARGETS;
1979                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1980 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1981                 host->transportt = fc_transport_template;
1982 #endif
1983                 break;
1984
1985         case SCSI_GUID:
1986                 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1987                 host->max_id = STORVSC_MAX_TARGETS;
1988                 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1989                 break;
1990
1991         default:
1992                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1993                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1994                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1995                 break;
1996         }
1997         /* max cmd length */
1998         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1999         /*
2000          * Any reasonable Hyper-V configuration should provide
2001          * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
2002          * protecting it from any weird value.
2003          */
2004         max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
2005         /* max_hw_sectors_kb */
2006         host->max_sectors = max_xfer_bytes >> 9;
2007         /*
2008          * There are 2 requirements for Hyper-V storvsc sgl segments,
2009          * based on which the below calculation for max segments is
2010          * done:
2011          *
2012          * 1. Except for the first and last sgl segment, all sgl segments
2013          *    should be align to HV_HYP_PAGE_SIZE, that also means the
2014          *    maximum number of segments in a sgl can be calculated by
2015          *    dividing the total max transfer length by HV_HYP_PAGE_SIZE.
2016          *
2017          * 2. Except for the first and last, each entry in the SGL must
2018          *    have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2019          */
2020         host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2021         /*
2022          * For non-IDE disks, the host supports multiple channels.
2023          * Set the number of HW queues we are supporting.
2024          */
2025         if (!dev_is_ide) {
2026                 if (storvsc_max_hw_queues > num_present_cpus) {
2027                         storvsc_max_hw_queues = 0;
2028                         storvsc_log(device, STORVSC_LOGGING_WARN,
2029                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2030                 }
2031                 if (storvsc_max_hw_queues)
2032                         host->nr_hw_queues = storvsc_max_hw_queues;
2033                 else
2034                         host->nr_hw_queues = num_present_cpus;
2035         }
2036
2037         /*
2038          * Set the error handler work queue.
2039          */
2040         host_dev->handle_error_wq =
2041                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2042                                                 0,
2043                                                 host->host_no);
2044         if (!host_dev->handle_error_wq) {
2045                 ret = -ENOMEM;
2046                 goto err_out2;
2047         }
2048         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2049         /* Register the HBA and start the scsi bus scan */
2050         ret = scsi_add_host(host, &device->device);
2051         if (ret != 0)
2052                 goto err_out3;
2053
2054         if (!dev_is_ide) {
2055                 scsi_scan_host(host);
2056         } else {
2057                 target = (device->dev_instance.b[5] << 8 |
2058                          device->dev_instance.b[4]);
2059                 ret = scsi_add_device(host, 0, target, 0);
2060                 if (ret)
2061                         goto err_out4;
2062         }
2063 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2064         if (host->transportt == fc_transport_template) {
2065                 struct fc_rport_identifiers ids = {
2066                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2067                 };
2068
2069                 fc_host_node_name(host) = stor_device->node_name;
2070                 fc_host_port_name(host) = stor_device->port_name;
2071                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2072                 if (!stor_device->rport) {
2073                         ret = -ENOMEM;
2074                         goto err_out4;
2075                 }
2076         }
2077 #endif
2078         return 0;
2079
2080 err_out4:
2081         scsi_remove_host(host);
2082
2083 err_out3:
2084         destroy_workqueue(host_dev->handle_error_wq);
2085
2086 err_out2:
2087         /*
2088          * Once we have connected with the host, we would need to
2089          * invoke storvsc_dev_remove() to rollback this state and
2090          * this call also frees up the stor_device; hence the jump around
2091          * err_out1 label.
2092          */
2093         storvsc_dev_remove(device);
2094         goto err_out0;
2095
2096 err_out1:
2097         kfree(stor_device->stor_chns);
2098         kfree(stor_device);
2099
2100 err_out0:
2101         scsi_host_put(host);
2102         return ret;
2103 }
2104
2105 /* Change a scsi target's queue depth */
2106 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2107 {
2108         if (queue_depth > scsi_driver.can_queue)
2109                 queue_depth = scsi_driver.can_queue;
2110
2111         return scsi_change_queue_depth(sdev, queue_depth);
2112 }
2113
2114 static void storvsc_remove(struct hv_device *dev)
2115 {
2116         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2117         struct Scsi_Host *host = stor_device->host;
2118         struct hv_host_device *host_dev = shost_priv(host);
2119
2120 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2121         if (host->transportt == fc_transport_template) {
2122                 fc_remote_port_delete(stor_device->rport);
2123                 fc_remove_host(host);
2124         }
2125 #endif
2126         destroy_workqueue(host_dev->handle_error_wq);
2127         scsi_remove_host(host);
2128         storvsc_dev_remove(dev);
2129         scsi_host_put(host);
2130 }
2131
2132 static int storvsc_suspend(struct hv_device *hv_dev)
2133 {
2134         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2135         struct Scsi_Host *host = stor_device->host;
2136         struct hv_host_device *host_dev = shost_priv(host);
2137
2138         storvsc_wait_to_drain(stor_device);
2139
2140         drain_workqueue(host_dev->handle_error_wq);
2141
2142         vmbus_close(hv_dev->channel);
2143
2144         kfree(stor_device->stor_chns);
2145         stor_device->stor_chns = NULL;
2146
2147         cpumask_clear(&stor_device->alloced_cpus);
2148
2149         return 0;
2150 }
2151
2152 static int storvsc_resume(struct hv_device *hv_dev)
2153 {
2154         int ret;
2155
2156         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2157                                      hv_dev_is_fc(hv_dev));
2158         return ret;
2159 }
2160
2161 static struct hv_driver storvsc_drv = {
2162         .name = KBUILD_MODNAME,
2163         .id_table = id_table,
2164         .probe = storvsc_probe,
2165         .remove = storvsc_remove,
2166         .suspend = storvsc_suspend,
2167         .resume = storvsc_resume,
2168         .driver = {
2169                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2170         },
2171 };
2172
2173 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2174 static struct fc_function_template fc_transport_functions = {
2175         .show_host_node_name = 1,
2176         .show_host_port_name = 1,
2177 };
2178 #endif
2179
2180 static int __init storvsc_drv_init(void)
2181 {
2182         int ret;
2183
2184         /*
2185          * Divide the ring buffer data size (which is 1 page less
2186          * than the ring buffer size since that page is reserved for
2187          * the ring buffer indices) by the max request size (which is
2188          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2189          */
2190         max_outstanding_req_per_channel =
2191                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2192                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2193                 sizeof(struct vstor_packet) + sizeof(u64),
2194                 sizeof(u64)));
2195
2196 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2197         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2198         if (!fc_transport_template)
2199                 return -ENODEV;
2200 #endif
2201
2202         ret = vmbus_driver_register(&storvsc_drv);
2203
2204 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2205         if (ret)
2206                 fc_release_transport(fc_transport_template);
2207 #endif
2208
2209         return ret;
2210 }
2211
2212 static void __exit storvsc_drv_exit(void)
2213 {
2214         vmbus_driver_unregister(&storvsc_drv);
2215 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2216         fc_release_transport(fc_transport_template);
2217 #endif
2218 }
2219
2220 MODULE_LICENSE("GPL");
2221 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2222 module_init(storvsc_drv_init);
2223 module_exit(storvsc_drv_exit);