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 #define SRB_STATUS_INTERNAL_ERROR       0x30
 322
 323 #define SRB_STATUS(status) \
 324         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 325 /*
 326  * This is the end of Protocol specific defines.
 327  */
 328
 329 static int storvsc_ringbuffer_size = (128 * 1024);
 330 static u32 max_outstanding_req_per_channel;
 331 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth);
 332
 333 static int storvsc_vcpus_per_sub_channel = 4;
 334 static unsigned int storvsc_max_hw_queues;
 335
 336 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 337 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 338
 339 module_param(storvsc_max_hw_queues, uint, 0644);
 340 MODULE_PARM_DESC(storvsc_max_hw_queues, "Maximum number of hardware queues");
 341
 342 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 343 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 344
 345 static int ring_avail_percent_lowater = 10;
 346 module_param(ring_avail_percent_lowater, int, S_IRUGO);
 347 MODULE_PARM_DESC(ring_avail_percent_lowater,
 348                 "Select a channel if available ring size > this in percent");
 349
 350 /*
 351  * Timeout in seconds for all devices managed by this driver.
 352  */
 353 static int storvsc_timeout = 180;
 354
 355 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 356 static struct scsi_transport_template *fc_transport_template;
 357 #endif
 358
 359 static struct scsi_host_template scsi_driver;
 360 static void storvsc_on_channel_callback(void *context);
 361
 362 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 363 #define STORVSC_MAX_TARGETS                             2
 364 #define STORVSC_MAX_CHANNELS                            8
 365
 366 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 367 #define STORVSC_FC_MAX_TARGETS                          128
 368 #define STORVSC_FC_MAX_CHANNELS                         8
 369 #define STORVSC_FC_MAX_XFER_SIZE                        ((u32)(512 * 1024))
 370
 371 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 372 #define STORVSC_IDE_MAX_TARGETS                         1
 373 #define STORVSC_IDE_MAX_CHANNELS                        1
 374
 375 /*
 376  * Upper bound on the size of a storvsc packet.
 377  */
 378 #define STORVSC_MAX_PKT_SIZE (sizeof(struct vmpacket_descriptor) +\
 379                               sizeof(struct vstor_packet))
 380
 381 struct storvsc_cmd_request {
 382         struct scsi_cmnd *cmd;
 383
 384         struct hv_device *device;
 385
 386         /* Synchronize the request/response if needed */
 387         struct completion wait_event;
 388
 389         struct vmbus_channel_packet_multipage_buffer mpb;
 390         struct vmbus_packet_mpb_array *payload;
 391         u32 payload_sz;
 392
 393         struct vstor_packet vstor_packet;
 394 };
 395
 396
 397 /* A storvsc device is a device object that contains a vmbus channel */
 398 struct storvsc_device {
 399         struct hv_device *device;
 400
 401         bool     destroy;
 402         bool     drain_notify;
 403         atomic_t num_outstanding_req;
 404         struct Scsi_Host *host;
 405
 406         wait_queue_head_t waiting_to_drain;
 407
 408         /*
 409          * Each unique Port/Path/Target represents 1 channel ie scsi
 410          * controller. In reality, the pathid, targetid is always 0
 411          * and the port is set by us
 412          */
 413         unsigned int port_number;
 414         unsigned char path_id;
 415         unsigned char target_id;
 416
 417         /*
 418          * Max I/O, the device can support.
 419          */
 420         u32   max_transfer_bytes;
 421         /*
 422          * Number of sub-channels we will open.
 423          */
 424         u16 num_sc;
 425         struct vmbus_channel **stor_chns;
 426         /*
 427          * Mask of CPUs bound to subchannels.
 428          */
 429         struct cpumask alloced_cpus;
 430         /*
 431          * Serializes modifications of stor_chns[] from storvsc_do_io()
 432          * and storvsc_change_target_cpu().
 433          */
 434         spinlock_t lock;
 435         /* Used for vsc/vsp channel reset process */
 436         struct storvsc_cmd_request init_request;
 437         struct storvsc_cmd_request reset_request;
 438         /*
 439          * Currently active port and node names for FC devices.
 440          */
 441         u64 node_name;
 442         u64 port_name;
 443 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 444         struct fc_rport *rport;
 445 #endif
 446 };
 447
 448 struct hv_host_device {
 449         struct hv_device *dev;
 450         unsigned int port;
 451         unsigned char path;
 452         unsigned char target;
 453         struct workqueue_struct *handle_error_wq;
 454         struct work_struct host_scan_work;
 455         struct Scsi_Host *host;
 456 };
 457
 458 struct storvsc_scan_work {
 459         struct work_struct work;
 460         struct Scsi_Host *host;
 461         u8 lun;
 462         u8 tgt_id;
 463 };
 464
 465 static void storvsc_device_scan(struct work_struct *work)
 466 {
 467         struct storvsc_scan_work *wrk;
 468         struct scsi_device *sdev;
 469
 470         wrk = container_of(work, struct storvsc_scan_work, work);
 471
 472         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 473         if (!sdev)
 474                 goto done;
 475         scsi_rescan_device(&sdev->sdev_gendev);
 476         scsi_device_put(sdev);
 477
 478 done:
 479         kfree(wrk);
 480 }
 481
 482 static void storvsc_host_scan(struct work_struct *work)
 483 {
 484         struct Scsi_Host *host;
 485         struct scsi_device *sdev;
 486         struct hv_host_device *host_device =
 487                 container_of(work, struct hv_host_device, host_scan_work);
 488
 489         host = host_device->host;
 490         /*
 491          * Before scanning the host, first check to see if any of the
 492          * currently known devices have been hot removed. We issue a
 493          * "unit ready" command against all currently known devices.
 494          * This I/O will result in an error for devices that have been
 495          * removed. As part of handling the I/O error, we remove the device.
 496          *
 497          * When a LUN is added or removed, the host sends us a signal to
 498          * scan the host. Thus we are forced to discover the LUNs that
 499          * may have been removed this way.
 500          */
 501         mutex_lock(&host->scan_mutex);
 502         shost_for_each_device(sdev, host)
 503                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 504         mutex_unlock(&host->scan_mutex);
 505         /*
 506          * Now scan the host to discover LUNs that may have been added.
 507          */
 508         scsi_scan_host(host);
 509 }
 510
 511 static void storvsc_remove_lun(struct work_struct *work)
 512 {
 513         struct storvsc_scan_work *wrk;
 514         struct scsi_device *sdev;
 515
 516         wrk = container_of(work, struct storvsc_scan_work, work);
 517         if (!scsi_host_get(wrk->host))
 518                 goto done;
 519
 520         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 521
 522         if (sdev) {
 523                 scsi_remove_device(sdev);
 524                 scsi_device_put(sdev);
 525         }
 526         scsi_host_put(wrk->host);
 527
 528 done:
 529         kfree(wrk);
 530 }
 531
 532
 533 /*
 534  * We can get incoming messages from the host that are not in response to
 535  * messages that we have sent out. An example of this would be messages
 536  * received by the guest to notify dynamic addition/removal of LUNs. To
 537  * deal with potential race conditions where the driver may be in the
 538  * midst of being unloaded when we might receive an unsolicited message
 539  * from the host, we have implemented a mechanism to gurantee sequential
 540  * consistency:
 541  *
 542  * 1) Once the device is marked as being destroyed, we will fail all
 543  *    outgoing messages.
 544  * 2) We permit incoming messages when the device is being destroyed,
 545  *    only to properly account for messages already sent out.
 546  */
 547
 548 static inline struct storvsc_device *get_out_stor_device(
 549                                         struct hv_device *device)
 550 {
 551         struct storvsc_device *stor_device;
 552
 553         stor_device = hv_get_drvdata(device);
 554
 555         if (stor_device && stor_device->destroy)
 556                 stor_device = NULL;
 557
 558         return stor_device;
 559 }
 560
 561
 562 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 563 {
 564         dev->drain_notify = true;
 565         wait_event(dev->waiting_to_drain,
 566                    atomic_read(&dev->num_outstanding_req) == 0);
 567         dev->drain_notify = false;
 568 }
 569
 570 static inline struct storvsc_device *get_in_stor_device(
 571                                         struct hv_device *device)
 572 {
 573         struct storvsc_device *stor_device;
 574
 575         stor_device = hv_get_drvdata(device);
 576
 577         if (!stor_device)
 578                 goto get_in_err;
 579
 580         /*
 581          * If the device is being destroyed; allow incoming
 582          * traffic only to cleanup outstanding requests.
 583          */
 584
 585         if (stor_device->destroy  &&
 586                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 587                 stor_device = NULL;
 588
 589 get_in_err:
 590         return stor_device;
 591
 592 }
 593
 594 static void storvsc_change_target_cpu(struct vmbus_channel *channel, u32 old,
 595                                       u32 new)
 596 {
 597         struct storvsc_device *stor_device;
 598         struct vmbus_channel *cur_chn;
 599         bool old_is_alloced = false;
 600         struct hv_device *device;
 601         unsigned long flags;
 602         int cpu;
 603
 604         device = channel->primary_channel ?
 605                         channel->primary_channel->device_obj
 606                                 : channel->device_obj;
 607         stor_device = get_out_stor_device(device);
 608         if (!stor_device)
 609                 return;
 610
 611         /* See storvsc_do_io() -> get_og_chn(). */
 612         spin_lock_irqsave(&stor_device->lock, flags);
 613
 614         /*
 615          * Determines if the storvsc device has other channels assigned to
 616          * the "old" CPU to update the alloced_cpus mask and the stor_chns
 617          * array.
 618          */
 619         if (device->channel != channel && device->channel->target_cpu == old) {
 620                 cur_chn = device->channel;
 621                 old_is_alloced = true;
 622                 goto old_is_alloced;
 623         }
 624         list_for_each_entry(cur_chn, &device->channel->sc_list, sc_list) {
 625                 if (cur_chn == channel)
 626                         continue;
 627                 if (cur_chn->target_cpu == old) {
 628                         old_is_alloced = true;
 629                         goto old_is_alloced;
 630                 }
 631         }
 632
 633 old_is_alloced:
 634         if (old_is_alloced)
 635                 WRITE_ONCE(stor_device->stor_chns[old], cur_chn);
 636         else
 637                 cpumask_clear_cpu(old, &stor_device->alloced_cpus);
 638
 639         /* "Flush" the stor_chns array. */
 640         for_each_possible_cpu(cpu) {
 641                 if (stor_device->stor_chns[cpu] && !cpumask_test_cpu(
 642                                         cpu, &stor_device->alloced_cpus))
 643                         WRITE_ONCE(stor_device->stor_chns[cpu], NULL);
 644         }
 645
 646         WRITE_ONCE(stor_device->stor_chns[new], channel);
 647         cpumask_set_cpu(new, &stor_device->alloced_cpus);
 648
 649         spin_unlock_irqrestore(&stor_device->lock, flags);
 650 }
 651
 652 static u64 storvsc_next_request_id(struct vmbus_channel *channel, u64 rqst_addr)
 653 {
 654         struct storvsc_cmd_request *request =
 655                 (struct storvsc_cmd_request *)(unsigned long)rqst_addr;
 656
 657         if (rqst_addr == VMBUS_RQST_INIT)
 658                 return VMBUS_RQST_INIT;
 659         if (rqst_addr == VMBUS_RQST_RESET)
 660                 return VMBUS_RQST_RESET;
 661
 662         /*
 663          * Cannot return an ID of 0, which is reserved for an unsolicited
 664          * message from Hyper-V.
 665          */
 666         return (u64)blk_mq_unique_tag(scsi_cmd_to_rq(request->cmd)) + 1;
 667 }
 668
 669 static void handle_sc_creation(struct vmbus_channel *new_sc)
 670 {
 671         struct hv_device *device = new_sc->primary_channel->device_obj;
 672         struct device *dev = &device->device;
 673         struct storvsc_device *stor_device;
 674         struct vmstorage_channel_properties props;
 675         int ret;
 676
 677         stor_device = get_out_stor_device(device);
 678         if (!stor_device)
 679                 return;
 680
 681         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 682         new_sc->max_pkt_size = STORVSC_MAX_PKT_SIZE;
 683
 684         new_sc->next_request_id_callback = storvsc_next_request_id;
 685
 686         ret = vmbus_open(new_sc,
 687                          storvsc_ringbuffer_size,
 688                          storvsc_ringbuffer_size,
 689                          (void *)&props,
 690                          sizeof(struct vmstorage_channel_properties),
 691                          storvsc_on_channel_callback, new_sc);
 692
 693         /* In case vmbus_open() fails, we don't use the sub-channel. */
 694         if (ret != 0) {
 695                 dev_err(dev, "Failed to open sub-channel: err=%d\n", ret);
 696                 return;
 697         }
 698
 699         new_sc->change_target_cpu_callback = storvsc_change_target_cpu;
 700
 701         /* Add the sub-channel to the array of available channels. */
 702         stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 703         cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 704 }
 705
 706 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 707 {
 708         struct device *dev = &device->device;
 709         struct storvsc_device *stor_device;
 710         int num_sc;
 711         struct storvsc_cmd_request *request;
 712         struct vstor_packet *vstor_packet;
 713         int ret, t;
 714
 715         /*
 716          * If the number of CPUs is artificially restricted, such as
 717          * with maxcpus=1 on the kernel boot line, Hyper-V could offer
 718          * sub-channels >= the number of CPUs. These sub-channels
 719          * should not be created. The primary channel is already created
 720          * and assigned to one CPU, so check against # CPUs - 1.
 721          */
 722         num_sc = min((int)(num_online_cpus() - 1), max_chns);
 723         if (!num_sc)
 724                 return;
 725
 726         stor_device = get_out_stor_device(device);
 727         if (!stor_device)
 728                 return;
 729
 730         stor_device->num_sc = num_sc;
 731         request = &stor_device->init_request;
 732         vstor_packet = &request->vstor_packet;
 733
 734         /*
 735          * Establish a handler for dealing with subchannels.
 736          */
 737         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 738
 739         /*
 740          * Request the host to create sub-channels.
 741          */
 742         memset(request, 0, sizeof(struct storvsc_cmd_request));
 743         init_completion(&request->wait_event);
 744         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 745         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 746         vstor_packet->sub_channel_count = num_sc;
 747
 748         ret = vmbus_sendpacket(device->channel, vstor_packet,
 749                                sizeof(struct vstor_packet),
 750                                VMBUS_RQST_INIT,
 751                                VM_PKT_DATA_INBAND,
 752                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 753
 754         if (ret != 0) {
 755                 dev_err(dev, "Failed to create sub-channel: err=%d\n", ret);
 756                 return;
 757         }
 758
 759         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 760         if (t == 0) {
 761                 dev_err(dev, "Failed to create sub-channel: timed out\n");
 762                 return;
 763         }
 764
 765         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 766             vstor_packet->status != 0) {
 767                 dev_err(dev, "Failed to create sub-channel: op=%d, sts=%d\n",
 768                         vstor_packet->operation, vstor_packet->status);
 769                 return;
 770         }
 771
 772         /*
 773          * We need to do nothing here, because vmbus_process_offer()
 774          * invokes channel->sc_creation_callback, which will open and use
 775          * the sub-channel(s).
 776          */
 777 }
 778
 779 static void cache_wwn(struct storvsc_device *stor_device,
 780                       struct vstor_packet *vstor_packet)
 781 {
 782         /*
 783          * Cache the currently active port and node ww names.
 784          */
 785         if (vstor_packet->wwn_packet.primary_active) {
 786                 stor_device->node_name =
 787                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 788                 stor_device->port_name =
 789                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 790         } else {
 791                 stor_device->node_name =
 792                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 793                 stor_device->port_name =
 794                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 795         }
 796 }
 797
 798
 799 static int storvsc_execute_vstor_op(struct hv_device *device,
 800                                     struct storvsc_cmd_request *request,
 801                                     bool status_check)
 802 {
 803         struct storvsc_device *stor_device;
 804         struct vstor_packet *vstor_packet;
 805         int ret, t;
 806
 807         stor_device = get_out_stor_device(device);
 808         if (!stor_device)
 809                 return -ENODEV;
 810
 811         vstor_packet = &request->vstor_packet;
 812
 813         init_completion(&request->wait_event);
 814         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 815
 816         ret = vmbus_sendpacket(device->channel, vstor_packet,
 817                                sizeof(struct vstor_packet),
 818                                VMBUS_RQST_INIT,
 819                                VM_PKT_DATA_INBAND,
 820                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 821         if (ret != 0)
 822                 return ret;
 823
 824         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 825         if (t == 0)
 826                 return -ETIMEDOUT;
 827
 828         if (!status_check)
 829                 return ret;
 830
 831         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 832             vstor_packet->status != 0)
 833                 return -EINVAL;
 834
 835         return ret;
 836 }
 837
 838 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 839 {
 840         struct storvsc_device *stor_device;
 841         struct storvsc_cmd_request *request;
 842         struct vstor_packet *vstor_packet;
 843         int ret, i;
 844         int max_chns;
 845         bool process_sub_channels = false;
 846
 847         stor_device = get_out_stor_device(device);
 848         if (!stor_device)
 849                 return -ENODEV;
 850
 851         request = &stor_device->init_request;
 852         vstor_packet = &request->vstor_packet;
 853
 854         /*
 855          * Now, initiate the vsc/vsp initialization protocol on the open
 856          * channel
 857          */
 858         memset(request, 0, sizeof(struct storvsc_cmd_request));
 859         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 860         ret = storvsc_execute_vstor_op(device, request, true);
 861         if (ret)
 862                 return ret;
 863         /*
 864          * Query host supported protocol version.
 865          */
 866
 867         for (i = 0; i < ARRAY_SIZE(protocol_version); i++) {
 868                 /* reuse the packet for version range supported */
 869                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 870                 vstor_packet->operation =
 871                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 872
 873                 vstor_packet->version.major_minor = protocol_version[i];
 874
 875                 /*
 876                  * The revision number is only used in Windows; set it to 0.
 877                  */
 878                 vstor_packet->version.revision = 0;
 879                 ret = storvsc_execute_vstor_op(device, request, false);
 880                 if (ret != 0)
 881                         return ret;
 882
 883                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 884                         return -EINVAL;
 885
 886                 if (vstor_packet->status == 0) {
 887                         vmstor_proto_version = protocol_version[i];
 888
 889                         break;
 890                 }
 891         }
 892
 893         if (vstor_packet->status != 0) {
 894                 dev_err(&device->device, "Obsolete Hyper-V version\n");
 895                 return -EINVAL;
 896         }
 897
 898
 899         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 900         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 901         ret = storvsc_execute_vstor_op(device, request, true);
 902         if (ret != 0)
 903                 return ret;
 904
 905         /*
 906          * Check to see if multi-channel support is there.
 907          * Hosts that implement protocol version of 5.1 and above
 908          * support multi-channel.
 909          */
 910         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 911
 912         /*
 913          * Allocate state to manage the sub-channels.
 914          * We allocate an array based on the numbers of possible CPUs
 915          * (Hyper-V does not support cpu online/offline).
 916          * This Array will be sparseley populated with unique
 917          * channels - primary + sub-channels.
 918          * We will however populate all the slots to evenly distribute
 919          * the load.
 920          */
 921         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 922                                          GFP_KERNEL);
 923         if (stor_device->stor_chns == NULL)
 924                 return -ENOMEM;
 925
 926         device->channel->change_target_cpu_callback = storvsc_change_target_cpu;
 927
 928         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 929         cpumask_set_cpu(device->channel->target_cpu,
 930                         &stor_device->alloced_cpus);
 931
 932         if (vstor_packet->storage_channel_properties.flags &
 933             STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 934                 process_sub_channels = true;
 935
 936         stor_device->max_transfer_bytes =
 937                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 938
 939         if (!is_fc)
 940                 goto done;
 941
 942         /*
 943          * For FC devices retrieve FC HBA data.
 944          */
 945         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 946         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 947         ret = storvsc_execute_vstor_op(device, request, true);
 948         if (ret != 0)
 949                 return ret;
 950
 951         /*
 952          * Cache the currently active port and node ww names.
 953          */
 954         cache_wwn(stor_device, vstor_packet);
 955
 956 done:
 957
 958         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 959         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 960         ret = storvsc_execute_vstor_op(device, request, true);
 961         if (ret != 0)
 962                 return ret;
 963
 964         if (process_sub_channels)
 965                 handle_multichannel_storage(device, max_chns);
 966
 967         return ret;
 968 }
 969
 970 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 971                                 struct scsi_cmnd *scmnd,
 972                                 struct Scsi_Host *host,
 973                                 u8 asc, u8 ascq)
 974 {
 975         struct storvsc_scan_work *wrk;
 976         void (*process_err_fn)(struct work_struct *work);
 977         struct hv_host_device *host_dev = shost_priv(host);
 978
 979         switch (SRB_STATUS(vm_srb->srb_status)) {
 980         case SRB_STATUS_ERROR:
 981         case SRB_STATUS_ABORTED:
 982         case SRB_STATUS_INVALID_REQUEST:
 983         case SRB_STATUS_INTERNAL_ERROR:
 984                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID) {
 985                         /* Check for capacity change */
 986                         if ((asc == 0x2a) && (ascq == 0x9)) {
 987                                 process_err_fn = storvsc_device_scan;
 988                                 /* Retry the I/O that triggered this. */
 989                                 set_host_byte(scmnd, DID_REQUEUE);
 990                                 goto do_work;
 991                         }
 992
 993                         /*
 994                          * Check for "Operating parameters have changed"
 995                          * due to Hyper-V changing the VHD/VHDX BlockSize
 996                          * when adding/removing a differencing disk. This
 997                          * causes discard_granularity to change, so do a
 998                          * rescan to pick up the new granularity. We don't
 999                          * want scsi_report_sense() to output a message
1000                          * that a sysadmin wouldn't know what to do with.
1001                          */
1002                         if ((asc == 0x3f) && (ascq != 0x03) &&
1003                                         (ascq != 0x0e)) {
1004                                 process_err_fn = storvsc_device_scan;
1005                                 set_host_byte(scmnd, DID_REQUEUE);
1006                                 goto do_work;
1007                         }
1008
1009                         /*
1010                          * Otherwise, let upper layer deal with the
1011                          * error when sense message is present
1012                          */
1013                         return;
1014                 }
1015
1016                 /*
1017                  * If there is an error; offline the device since all
1018                  * error recovery strategies would have already been
1019                  * deployed on the host side. However, if the command
1020                  * were a pass-through command deal with it appropriately.
1021                  */
1022                 switch (scmnd->cmnd[0]) {
1023                 case ATA_16:
1024                 case ATA_12:
1025                         set_host_byte(scmnd, DID_PASSTHROUGH);
1026                         break;
1027                 /*
1028                  * On some Hyper-V hosts TEST_UNIT_READY command can
1029                  * return SRB_STATUS_ERROR. Let the upper level code
1030                  * deal with it based on the sense information.
1031                  */
1032                 case TEST_UNIT_READY:
1033                         break;
1034                 default:
1035                         set_host_byte(scmnd, DID_ERROR);
1036                 }
1037                 return;
1038
1039         case SRB_STATUS_INVALID_LUN:
1040                 set_host_byte(scmnd, DID_NO_CONNECT);
1041                 process_err_fn = storvsc_remove_lun;
1042                 goto do_work;
1043
1044         }
1045         return;
1046
1047 do_work:
1048         /*
1049          * We need to schedule work to process this error; schedule it.
1050          */
1051         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1052         if (!wrk) {
1053                 set_host_byte(scmnd, DID_BAD_TARGET);
1054                 return;
1055         }
1056
1057         wrk->host = host;
1058         wrk->lun = vm_srb->lun;
1059         wrk->tgt_id = vm_srb->target_id;
1060         INIT_WORK(&wrk->work, process_err_fn);
1061         queue_work(host_dev->handle_error_wq, &wrk->work);
1062 }
1063
1064
1065 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
1066                                        struct storvsc_device *stor_dev)
1067 {
1068         struct scsi_cmnd *scmnd = cmd_request->cmd;
1069         struct scsi_sense_hdr sense_hdr;
1070         struct vmscsi_request *vm_srb;
1071         u32 data_transfer_length;
1072         struct Scsi_Host *host;
1073         u32 payload_sz = cmd_request->payload_sz;
1074         void *payload = cmd_request->payload;
1075         bool sense_ok;
1076
1077         host = stor_dev->host;
1078
1079         vm_srb = &cmd_request->vstor_packet.vm_srb;
1080         data_transfer_length = vm_srb->data_transfer_length;
1081
1082         scmnd->result = vm_srb->scsi_status;
1083
1084         if (scmnd->result) {
1085                 sense_ok = scsi_normalize_sense(scmnd->sense_buffer,
1086                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr);
1087
1088                 if (sense_ok && do_logging(STORVSC_LOGGING_WARN))
1089                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1090                                              &sense_hdr);
1091         }
1092
1093         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1094                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1095                                          sense_hdr.ascq);
1096                 /*
1097                  * The Windows driver set data_transfer_length on
1098                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1099                  * is untouched.  In these cases we set it to 0.
1100                  */
1101                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1102                         data_transfer_length = 0;
1103         }
1104
1105         /* Validate data_transfer_length (from Hyper-V) */
1106         if (data_transfer_length > cmd_request->payload->range.len)
1107                 data_transfer_length = cmd_request->payload->range.len;
1108
1109         scsi_set_resid(scmnd,
1110                 cmd_request->payload->range.len - data_transfer_length);
1111
1112         scsi_done(scmnd);
1113
1114         if (payload_sz >
1115                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1116                 kfree(payload);
1117 }
1118
1119 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1120                                   struct vstor_packet *vstor_packet,
1121                                   struct storvsc_cmd_request *request)
1122 {
1123         struct vstor_packet *stor_pkt;
1124         struct hv_device *device = stor_device->device;
1125
1126         stor_pkt = &request->vstor_packet;
1127
1128         /*
1129          * The current SCSI handling on the host side does
1130          * not correctly handle:
1131          * INQUIRY command with page code parameter set to 0x80
1132          * MODE_SENSE command with cmd[2] == 0x1c
1133          *
1134          * Setup srb and scsi status so this won't be fatal.
1135          * We do this so we can distinguish truly fatal failues
1136          * (srb status == 0x4) and off-line the device in that case.
1137          */
1138
1139         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1140            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1141                 vstor_packet->vm_srb.scsi_status = 0;
1142                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1143         }
1144
1145         /* Copy over the status...etc */
1146         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1147         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1148
1149         /*
1150          * Copy over the sense_info_length, but limit to the known max
1151          * size if Hyper-V returns a bad value.
1152          */
1153         stor_pkt->vm_srb.sense_info_length = min_t(u8, STORVSC_SENSE_BUFFER_SIZE,
1154                 vstor_packet->vm_srb.sense_info_length);
1155
1156         if (vstor_packet->vm_srb.scsi_status != 0 ||
1157             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS) {
1158
1159                 /*
1160                  * Log TEST_UNIT_READY errors only as warnings. Hyper-V can
1161                  * return errors when detecting devices using TEST_UNIT_READY,
1162                  * and logging these as errors produces unhelpful noise.
1163                  */
1164                 int loglevel = (stor_pkt->vm_srb.cdb[0] == TEST_UNIT_READY) ?
1165                         STORVSC_LOGGING_WARN : STORVSC_LOGGING_ERROR;
1166
1167                 storvsc_log(device, loglevel,
1168                         "tag#%d cmd 0x%x status: scsi 0x%x srb 0x%x hv 0x%x\n",
1169                         scsi_cmd_to_rq(request->cmd)->tag,
1170                         stor_pkt->vm_srb.cdb[0],
1171                         vstor_packet->vm_srb.scsi_status,
1172                         vstor_packet->vm_srb.srb_status,
1173                         vstor_packet->status);
1174         }
1175
1176         if (vstor_packet->vm_srb.scsi_status == SAM_STAT_CHECK_CONDITION &&
1177             (vstor_packet->vm_srb.srb_status & SRB_STATUS_AUTOSENSE_VALID))
1178                 memcpy(request->cmd->sense_buffer,
1179                        vstor_packet->vm_srb.sense_data,
1180                        stor_pkt->vm_srb.sense_info_length);
1181
1182         stor_pkt->vm_srb.data_transfer_length =
1183                 vstor_packet->vm_srb.data_transfer_length;
1184
1185         storvsc_command_completion(request, stor_device);
1186
1187         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1188                 stor_device->drain_notify)
1189                 wake_up(&stor_device->waiting_to_drain);
1190 }
1191
1192 static void storvsc_on_receive(struct storvsc_device *stor_device,
1193                              struct vstor_packet *vstor_packet,
1194                              struct storvsc_cmd_request *request)
1195 {
1196         struct hv_host_device *host_dev;
1197         switch (vstor_packet->operation) {
1198         case VSTOR_OPERATION_COMPLETE_IO:
1199                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1200                 break;
1201
1202         case VSTOR_OPERATION_REMOVE_DEVICE:
1203         case VSTOR_OPERATION_ENUMERATE_BUS:
1204                 host_dev = shost_priv(stor_device->host);
1205                 queue_work(
1206                         host_dev->handle_error_wq, &host_dev->host_scan_work);
1207                 break;
1208
1209         case VSTOR_OPERATION_FCHBA_DATA:
1210                 cache_wwn(stor_device, vstor_packet);
1211 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1212                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1213                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1214 #endif
1215                 break;
1216         default:
1217                 break;
1218         }
1219 }
1220
1221 static void storvsc_on_channel_callback(void *context)
1222 {
1223         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1224         const struct vmpacket_descriptor *desc;
1225         struct hv_device *device;
1226         struct storvsc_device *stor_device;
1227         struct Scsi_Host *shost;
1228         unsigned long time_limit = jiffies + msecs_to_jiffies(CALLBACK_TIMEOUT);
1229
1230         if (channel->primary_channel != NULL)
1231                 device = channel->primary_channel->device_obj;
1232         else
1233                 device = channel->device_obj;
1234
1235         stor_device = get_in_stor_device(device);
1236         if (!stor_device)
1237                 return;
1238
1239         shost = stor_device->host;
1240
1241         foreach_vmbus_pkt(desc, channel) {
1242                 struct vstor_packet *packet = hv_pkt_data(desc);
1243                 struct storvsc_cmd_request *request = NULL;
1244                 u32 pktlen = hv_pkt_datalen(desc);
1245                 u64 rqst_id = desc->trans_id;
1246                 u32 minlen = rqst_id ? sizeof(struct vstor_packet) :
1247                         sizeof(enum vstor_packet_operation);
1248
1249                 if (unlikely(time_after(jiffies, time_limit))) {
1250                         hv_pkt_iter_close(channel);
1251                         return;
1252                 }
1253
1254                 if (pktlen < minlen) {
1255                         dev_err(&device->device,
1256                                 "Invalid pkt: id=%llu, len=%u, minlen=%u\n",
1257                                 rqst_id, pktlen, minlen);
1258                         continue;
1259                 }
1260
1261                 if (rqst_id == VMBUS_RQST_INIT) {
1262                         request = &stor_device->init_request;
1263                 } else if (rqst_id == VMBUS_RQST_RESET) {
1264                         request = &stor_device->reset_request;
1265                 } else {
1266                         /* Hyper-V can send an unsolicited message with ID of 0 */
1267                         if (rqst_id == 0) {
1268                                 /*
1269                                  * storvsc_on_receive() looks at the vstor_packet in the message
1270                                  * from the ring buffer.
1271                                  *
1272                                  * - If the operation in the vstor_packet is COMPLETE_IO, then
1273                                  *   we call storvsc_on_io_completion(), and dereference the
1274                                  *   guest memory address.  Make sure we don't call
1275                                  *   storvsc_on_io_completion() with a guest memory address
1276                                  *   that is zero if Hyper-V were to construct and send such
1277                                  *   a bogus packet.
1278                                  *
1279                                  * - If the operation in the vstor_packet is FCHBA_DATA, then
1280                                  *   we call cache_wwn(), and access the data payload area of
1281                                  *   the packet (wwn_packet); however, there is no guarantee
1282                                  *   that the packet is big enough to contain such area.
1283                                  *   Future-proof the code by rejecting such a bogus packet.
1284                                  */
1285                                 if (packet->operation == VSTOR_OPERATION_COMPLETE_IO ||
1286                                     packet->operation == VSTOR_OPERATION_FCHBA_DATA) {
1287                                         dev_err(&device->device, "Invalid packet with ID of 0\n");
1288                                         continue;
1289                                 }
1290                         } else {
1291                                 struct scsi_cmnd *scmnd;
1292
1293                                 /* Transaction 'rqst_id' corresponds to tag 'rqst_id - 1' */
1294                                 scmnd = scsi_host_find_tag(shost, rqst_id - 1);
1295                                 if (scmnd == NULL) {
1296                                         dev_err(&device->device, "Incorrect transaction ID\n");
1297                                         continue;
1298                                 }
1299                                 request = (struct storvsc_cmd_request *)scsi_cmd_priv(scmnd);
1300                                 scsi_dma_unmap(scmnd);
1301                         }
1302
1303                         storvsc_on_receive(stor_device, packet, request);
1304                         continue;
1305                 }
1306
1307                 memcpy(&request->vstor_packet, packet,
1308                        sizeof(struct vstor_packet));
1309                 complete(&request->wait_event);
1310         }
1311 }
1312
1313 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1314                                   bool is_fc)
1315 {
1316         struct vmstorage_channel_properties props;
1317         int ret;
1318
1319         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1320
1321         device->channel->max_pkt_size = STORVSC_MAX_PKT_SIZE;
1322         device->channel->next_request_id_callback = storvsc_next_request_id;
1323
1324         ret = vmbus_open(device->channel,
1325                          ring_size,
1326                          ring_size,
1327                          (void *)&props,
1328                          sizeof(struct vmstorage_channel_properties),
1329                          storvsc_on_channel_callback, device->channel);
1330
1331         if (ret != 0)
1332                 return ret;
1333
1334         ret = storvsc_channel_init(device, is_fc);
1335
1336         return ret;
1337 }
1338
1339 static int storvsc_dev_remove(struct hv_device *device)
1340 {
1341         struct storvsc_device *stor_device;
1342
1343         stor_device = hv_get_drvdata(device);
1344
1345         stor_device->destroy = true;
1346
1347         /* Make sure flag is set before waiting */
1348         wmb();
1349
1350         /*
1351          * At this point, all outbound traffic should be disable. We
1352          * only allow inbound traffic (responses) to proceed so that
1353          * outstanding requests can be completed.
1354          */
1355
1356         storvsc_wait_to_drain(stor_device);
1357
1358         /*
1359          * Since we have already drained, we don't need to busy wait
1360          * as was done in final_release_stor_device()
1361          * Note that we cannot set the ext pointer to NULL until
1362          * we have drained - to drain the outgoing packets, we need to
1363          * allow incoming packets.
1364          */
1365         hv_set_drvdata(device, NULL);
1366
1367         /* Close the channel */
1368         vmbus_close(device->channel);
1369
1370         kfree(stor_device->stor_chns);
1371         kfree(stor_device);
1372         return 0;
1373 }
1374
1375 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1376                                         u16 q_num)
1377 {
1378         u16 slot = 0;
1379         u16 hash_qnum;
1380         const struct cpumask *node_mask;
1381         int num_channels, tgt_cpu;
1382
1383         if (stor_device->num_sc == 0) {
1384                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1385                 return stor_device->device->channel;
1386         }
1387
1388         /*
1389          * Our channel array is sparsley populated and we
1390          * initiated I/O on a processor/hw-q that does not
1391          * currently have a designated channel. Fix this.
1392          * The strategy is simple:
1393          * I. Ensure NUMA locality
1394          * II. Distribute evenly (best effort)
1395          */
1396
1397         node_mask = cpumask_of_node(cpu_to_node(q_num));
1398
1399         num_channels = 0;
1400         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1401                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1402                         num_channels++;
1403         }
1404         if (num_channels == 0) {
1405                 stor_device->stor_chns[q_num] = stor_device->device->channel;
1406                 return stor_device->device->channel;
1407         }
1408
1409         hash_qnum = q_num;
1410         while (hash_qnum >= num_channels)
1411                 hash_qnum -= num_channels;
1412
1413         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1414                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1415                         continue;
1416                 if (slot == hash_qnum)
1417                         break;
1418                 slot++;
1419         }
1420
1421         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1422
1423         return stor_device->stor_chns[q_num];
1424 }
1425
1426
1427 static int storvsc_do_io(struct hv_device *device,
1428                          struct storvsc_cmd_request *request, u16 q_num)
1429 {
1430         struct storvsc_device *stor_device;
1431         struct vstor_packet *vstor_packet;
1432         struct vmbus_channel *outgoing_channel, *channel;
1433         unsigned long flags;
1434         int ret = 0;
1435         const struct cpumask *node_mask;
1436         int tgt_cpu;
1437
1438         vstor_packet = &request->vstor_packet;
1439         stor_device = get_out_stor_device(device);
1440
1441         if (!stor_device)
1442                 return -ENODEV;
1443
1444
1445         request->device  = device;
1446         /*
1447          * Select an appropriate channel to send the request out.
1448          */
1449         /* See storvsc_change_target_cpu(). */
1450         outgoing_channel = READ_ONCE(stor_device->stor_chns[q_num]);
1451         if (outgoing_channel != NULL) {
1452                 if (outgoing_channel->target_cpu == q_num) {
1453                         /*
1454                          * Ideally, we want to pick a different channel if
1455                          * available on the same NUMA node.
1456                          */
1457                         node_mask = cpumask_of_node(cpu_to_node(q_num));
1458                         for_each_cpu_wrap(tgt_cpu,
1459                                  &stor_device->alloced_cpus, q_num + 1) {
1460                                 if (!cpumask_test_cpu(tgt_cpu, node_mask))
1461                                         continue;
1462                                 if (tgt_cpu == q_num)
1463                                         continue;
1464                                 channel = READ_ONCE(
1465                                         stor_device->stor_chns[tgt_cpu]);
1466                                 if (channel == NULL)
1467                                         continue;
1468                                 if (hv_get_avail_to_write_percent(
1469                                                         &channel->outbound)
1470                                                 > ring_avail_percent_lowater) {
1471                                         outgoing_channel = channel;
1472                                         goto found_channel;
1473                                 }
1474                         }
1475
1476                         /*
1477                          * All the other channels on the same NUMA node are
1478                          * busy. Try to use the channel on the current CPU
1479                          */
1480                         if (hv_get_avail_to_write_percent(
1481                                                 &outgoing_channel->outbound)
1482                                         > ring_avail_percent_lowater)
1483                                 goto found_channel;
1484
1485                         /*
1486                          * If we reach here, all the channels on the current
1487                          * NUMA node are busy. Try to find a channel in
1488                          * other NUMA nodes
1489                          */
1490                         for_each_cpu(tgt_cpu, &stor_device->alloced_cpus) {
1491                                 if (cpumask_test_cpu(tgt_cpu, node_mask))
1492                                         continue;
1493                                 channel = READ_ONCE(
1494                                         stor_device->stor_chns[tgt_cpu]);
1495                                 if (channel == NULL)
1496                                         continue;
1497                                 if (hv_get_avail_to_write_percent(
1498                                                         &channel->outbound)
1499                                                 > ring_avail_percent_lowater) {
1500                                         outgoing_channel = channel;
1501                                         goto found_channel;
1502                                 }
1503                         }
1504                 }
1505         } else {
1506                 spin_lock_irqsave(&stor_device->lock, flags);
1507                 outgoing_channel = stor_device->stor_chns[q_num];
1508                 if (outgoing_channel != NULL) {
1509                         spin_unlock_irqrestore(&stor_device->lock, flags);
1510                         goto found_channel;
1511                 }
1512                 outgoing_channel = get_og_chn(stor_device, q_num);
1513                 spin_unlock_irqrestore(&stor_device->lock, flags);
1514         }
1515
1516 found_channel:
1517         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1518
1519         vstor_packet->vm_srb.length = sizeof(struct vmscsi_request);
1520
1521
1522         vstor_packet->vm_srb.sense_info_length = STORVSC_SENSE_BUFFER_SIZE;
1523
1524
1525         vstor_packet->vm_srb.data_transfer_length =
1526         request->payload->range.len;
1527
1528         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1529
1530         if (request->payload->range.len) {
1531
1532                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1533                                 request->payload, request->payload_sz,
1534                                 vstor_packet,
1535                                 sizeof(struct vstor_packet),
1536                                 (unsigned long)request);
1537         } else {
1538                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1539                                sizeof(struct vstor_packet),
1540                                (unsigned long)request,
1541                                VM_PKT_DATA_INBAND,
1542                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1543         }
1544
1545         if (ret != 0)
1546                 return ret;
1547
1548         atomic_inc(&stor_device->num_outstanding_req);
1549
1550         return ret;
1551 }
1552
1553 static int storvsc_device_alloc(struct scsi_device *sdevice)
1554 {
1555         /*
1556          * Set blist flag to permit the reading of the VPD pages even when
1557          * the target may claim SPC-2 compliance. MSFT targets currently
1558          * claim SPC-2 compliance while they implement post SPC-2 features.
1559          * With this flag we can correctly handle WRITE_SAME_16 issues.
1560          *
1561          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1562          * still supports REPORT LUN.
1563          */
1564         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1565
1566         return 0;
1567 }
1568
1569 static int storvsc_device_configure(struct scsi_device *sdevice)
1570 {
1571         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1572
1573         /* storvsc devices don't support MAINTENANCE_IN SCSI cmd */
1574         sdevice->no_report_opcodes = 1;
1575         sdevice->no_write_same = 1;
1576
1577         /*
1578          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1579          * if the device is a MSFT virtual device.  If the host is
1580          * WIN10 or newer, allow write_same.
1581          */
1582         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1583                 switch (vmstor_proto_version) {
1584                 case VMSTOR_PROTO_VERSION_WIN8:
1585                 case VMSTOR_PROTO_VERSION_WIN8_1:
1586                         sdevice->scsi_level = SCSI_SPC_3;
1587                         break;
1588                 }
1589
1590                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1591                         sdevice->no_write_same = 0;
1592         }
1593
1594         return 0;
1595 }
1596
1597 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1598                            sector_t capacity, int *info)
1599 {
1600         sector_t nsect = capacity;
1601         sector_t cylinders = nsect;
1602         int heads, sectors_pt;
1603
1604         /*
1605          * We are making up these values; let us keep it simple.
1606          */
1607         heads = 0xff;
1608         sectors_pt = 0x3f;      /* Sectors per track */
1609         sector_div(cylinders, heads * sectors_pt);
1610         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1611                 cylinders = 0xffff;
1612
1613         info[0] = heads;
1614         info[1] = sectors_pt;
1615         info[2] = (int)cylinders;
1616
1617         return 0;
1618 }
1619
1620 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1621 {
1622         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1623         struct hv_device *device = host_dev->dev;
1624
1625         struct storvsc_device *stor_device;
1626         struct storvsc_cmd_request *request;
1627         struct vstor_packet *vstor_packet;
1628         int ret, t;
1629
1630         stor_device = get_out_stor_device(device);
1631         if (!stor_device)
1632                 return FAILED;
1633
1634         request = &stor_device->reset_request;
1635         vstor_packet = &request->vstor_packet;
1636         memset(vstor_packet, 0, sizeof(struct vstor_packet));
1637
1638         init_completion(&request->wait_event);
1639
1640         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1641         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1642         vstor_packet->vm_srb.path_id = stor_device->path_id;
1643
1644         ret = vmbus_sendpacket(device->channel, vstor_packet,
1645                                sizeof(struct vstor_packet),
1646                                VMBUS_RQST_RESET,
1647                                VM_PKT_DATA_INBAND,
1648                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1649         if (ret != 0)
1650                 return FAILED;
1651
1652         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1653         if (t == 0)
1654                 return TIMEOUT_ERROR;
1655
1656
1657         /*
1658          * At this point, all outstanding requests in the adapter
1659          * should have been flushed out and return to us
1660          * There is a potential race here where the host may be in
1661          * the process of responding when we return from here.
1662          * Just wait for all in-transit packets to be accounted for
1663          * before we return from here.
1664          */
1665         storvsc_wait_to_drain(stor_device);
1666
1667         return SUCCESS;
1668 }
1669
1670 /*
1671  * The host guarantees to respond to each command, although I/O latencies might
1672  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1673  * chance to perform EH.
1674  */
1675 static enum scsi_timeout_action storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1676 {
1677         return SCSI_EH_RESET_TIMER;
1678 }
1679
1680 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1681 {
1682         bool allowed = true;
1683         u8 scsi_op = scmnd->cmnd[0];
1684
1685         switch (scsi_op) {
1686         /* the host does not handle WRITE_SAME, log accident usage */
1687         case WRITE_SAME:
1688         /*
1689          * smartd sends this command and the host does not handle
1690          * this. So, don't send it.
1691          */
1692         case SET_WINDOW:
1693                 set_host_byte(scmnd, DID_ERROR);
1694                 allowed = false;
1695                 break;
1696         default:
1697                 break;
1698         }
1699         return allowed;
1700 }
1701
1702 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1703 {
1704         int ret;
1705         struct hv_host_device *host_dev = shost_priv(host);
1706         struct hv_device *dev = host_dev->dev;
1707         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1708         struct scatterlist *sgl;
1709         struct vmscsi_request *vm_srb;
1710         struct vmbus_packet_mpb_array  *payload;
1711         u32 payload_sz;
1712         u32 length;
1713
1714         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1715                 /*
1716                  * On legacy hosts filter unimplemented commands.
1717                  * Future hosts are expected to correctly handle
1718                  * unsupported commands. Furthermore, it is
1719                  * possible that some of the currently
1720                  * unsupported commands maybe supported in
1721                  * future versions of the host.
1722                  */
1723                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1724                         scsi_done(scmnd);
1725                         return 0;
1726                 }
1727         }
1728
1729         /* Setup the cmd request */
1730         cmd_request->cmd = scmnd;
1731
1732         memset(&cmd_request->vstor_packet, 0, sizeof(struct vstor_packet));
1733         vm_srb = &cmd_request->vstor_packet.vm_srb;
1734         vm_srb->time_out_value = 60;
1735
1736         vm_srb->srb_flags |=
1737                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1738
1739         if (scmnd->device->tagged_supported) {
1740                 vm_srb->srb_flags |=
1741                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1742                 vm_srb->queue_tag = SP_UNTAGGED;
1743                 vm_srb->queue_action = SRB_SIMPLE_TAG_REQUEST;
1744         }
1745
1746         /* Build the SRB */
1747         switch (scmnd->sc_data_direction) {
1748         case DMA_TO_DEVICE:
1749                 vm_srb->data_in = WRITE_TYPE;
1750                 vm_srb->srb_flags |= SRB_FLAGS_DATA_OUT;
1751                 break;
1752         case DMA_FROM_DEVICE:
1753                 vm_srb->data_in = READ_TYPE;
1754                 vm_srb->srb_flags |= SRB_FLAGS_DATA_IN;
1755                 break;
1756         case DMA_NONE:
1757                 vm_srb->data_in = UNKNOWN_TYPE;
1758                 vm_srb->srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1759                 break;
1760         default:
1761                 /*
1762                  * This is DMA_BIDIRECTIONAL or something else we are never
1763                  * supposed to see here.
1764                  */
1765                 WARN(1, "Unexpected data direction: %d\n",
1766                      scmnd->sc_data_direction);
1767                 return -EINVAL;
1768         }
1769
1770
1771         vm_srb->port_number = host_dev->port;
1772         vm_srb->path_id = scmnd->device->channel;
1773         vm_srb->target_id = scmnd->device->id;
1774         vm_srb->lun = scmnd->device->lun;
1775
1776         vm_srb->cdb_length = scmnd->cmd_len;
1777
1778         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1779
1780         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1781
1782         length = scsi_bufflen(scmnd);
1783         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1784         payload_sz = 0;
1785
1786         if (scsi_sg_count(scmnd)) {
1787                 unsigned long offset_in_hvpg = offset_in_hvpage(sgl->offset);
1788                 unsigned int hvpg_count = HVPFN_UP(offset_in_hvpg + length);
1789                 struct scatterlist *sg;
1790                 unsigned long hvpfn, hvpfns_to_add;
1791                 int j, i = 0, sg_count;
1792
1793                 payload_sz = (hvpg_count * sizeof(u64) +
1794                               sizeof(struct vmbus_packet_mpb_array));
1795
1796                 if (hvpg_count > MAX_PAGE_BUFFER_COUNT) {
1797                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1798                         if (!payload)
1799                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1800                 }
1801
1802                 payload->range.len = length;
1803                 payload->range.offset = offset_in_hvpg;
1804
1805                 sg_count = scsi_dma_map(scmnd);
1806                 if (sg_count < 0) {
1807                         ret = SCSI_MLQUEUE_DEVICE_BUSY;
1808                         goto err_free_payload;
1809                 }
1810
1811                 for_each_sg(sgl, sg, sg_count, j) {
1812                         /*
1813                          * Init values for the current sgl entry. hvpfns_to_add
1814                          * is in units of Hyper-V size pages. Handling the
1815                          * PAGE_SIZE != HV_HYP_PAGE_SIZE case also handles
1816                          * values of sgl->offset that are larger than PAGE_SIZE.
1817                          * Such offsets are handled even on other than the first
1818                          * sgl entry, provided they are a multiple of PAGE_SIZE.
1819                          */
1820                         hvpfn = HVPFN_DOWN(sg_dma_address(sg));
1821                         hvpfns_to_add = HVPFN_UP(sg_dma_address(sg) +
1822                                                  sg_dma_len(sg)) - hvpfn;
1823
1824                         /*
1825                          * Fill the next portion of the PFN array with
1826                          * sequential Hyper-V PFNs for the continguous physical
1827                          * memory described by the sgl entry. The end of the
1828                          * last sgl should be reached at the same time that
1829                          * the PFN array is filled.
1830                          */
1831                         while (hvpfns_to_add--)
1832                                 payload->range.pfn_array[i++] = hvpfn++;
1833                 }
1834         }
1835
1836         cmd_request->payload = payload;
1837         cmd_request->payload_sz = payload_sz;
1838
1839         /* Invokes the vsc to start an IO */
1840         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1841         put_cpu();
1842
1843         if (ret)
1844                 scsi_dma_unmap(scmnd);
1845
1846         if (ret == -EAGAIN) {
1847                 /* no more space */
1848                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
1849                 goto err_free_payload;
1850         }
1851
1852         return 0;
1853
1854 err_free_payload:
1855         if (payload_sz > sizeof(cmd_request->mpb))
1856                 kfree(payload);
1857
1858         return ret;
1859 }
1860
1861 static struct scsi_host_template scsi_driver = {
1862         .module =               THIS_MODULE,
1863         .name =                 "storvsc_host_t",
1864         .cmd_size =             sizeof(struct storvsc_cmd_request),
1865         .bios_param =           storvsc_get_chs,
1866         .queuecommand =         storvsc_queuecommand,
1867         .eh_host_reset_handler =        storvsc_host_reset_handler,
1868         .proc_name =            "storvsc_host",
1869         .eh_timed_out =         storvsc_eh_timed_out,
1870         .slave_alloc =          storvsc_device_alloc,
1871         .slave_configure =      storvsc_device_configure,
1872         .cmd_per_lun =          2048,
1873         .this_id =              -1,
1874         /* Ensure there are no gaps in presented sgls */
1875         .virt_boundary_mask =   HV_HYP_PAGE_SIZE - 1,
1876         .no_write_same =        1,
1877         .track_queue_depth =    1,
1878         .change_queue_depth =   storvsc_change_queue_depth,
1879 };
1880
1881 enum {
1882         SCSI_GUID,
1883         IDE_GUID,
1884         SFC_GUID,
1885 };
1886
1887 static const struct hv_vmbus_device_id id_table[] = {
1888         /* SCSI guid */
1889         { HV_SCSI_GUID,
1890           .driver_data = SCSI_GUID
1891         },
1892         /* IDE guid */
1893         { HV_IDE_GUID,
1894           .driver_data = IDE_GUID
1895         },
1896         /* Fibre Channel GUID */
1897         {
1898           HV_SYNTHFC_GUID,
1899           .driver_data = SFC_GUID
1900         },
1901         { },
1902 };
1903
1904 MODULE_DEVICE_TABLE(vmbus, id_table);
1905
1906 static const struct { guid_t guid; } fc_guid = { HV_SYNTHFC_GUID };
1907
1908 static bool hv_dev_is_fc(struct hv_device *hv_dev)
1909 {
1910         return guid_equal(&fc_guid.guid, &hv_dev->dev_type);
1911 }
1912
1913 static int storvsc_probe(struct hv_device *device,
1914                         const struct hv_vmbus_device_id *dev_id)
1915 {
1916         int ret;
1917         int num_cpus = num_online_cpus();
1918         int num_present_cpus = num_present_cpus();
1919         struct Scsi_Host *host;
1920         struct hv_host_device *host_dev;
1921         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1922         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1923         int target = 0;
1924         struct storvsc_device *stor_device;
1925         int max_sub_channels = 0;
1926         u32 max_xfer_bytes;
1927
1928         /*
1929          * We support sub-channels for storage on SCSI and FC controllers.
1930          * The number of sub-channels offerred is based on the number of
1931          * VCPUs in the guest.
1932          */
1933         if (!dev_is_ide)
1934                 max_sub_channels =
1935                         (num_cpus - 1) / storvsc_vcpus_per_sub_channel;
1936
1937         scsi_driver.can_queue = max_outstanding_req_per_channel *
1938                                 (max_sub_channels + 1) *
1939                                 (100 - ring_avail_percent_lowater) / 100;
1940
1941         host = scsi_host_alloc(&scsi_driver,
1942                                sizeof(struct hv_host_device));
1943         if (!host)
1944                 return -ENOMEM;
1945
1946         host_dev = shost_priv(host);
1947         memset(host_dev, 0, sizeof(struct hv_host_device));
1948
1949         host_dev->port = host->host_no;
1950         host_dev->dev = device;
1951         host_dev->host = host;
1952
1953
1954         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1955         if (!stor_device) {
1956                 ret = -ENOMEM;
1957                 goto err_out0;
1958         }
1959
1960         stor_device->destroy = false;
1961         init_waitqueue_head(&stor_device->waiting_to_drain);
1962         stor_device->device = device;
1963         stor_device->host = host;
1964         spin_lock_init(&stor_device->lock);
1965         hv_set_drvdata(device, stor_device);
1966         dma_set_min_align_mask(&device->device, HV_HYP_PAGE_SIZE - 1);
1967
1968         stor_device->port_number = host->host_no;
1969         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1970         if (ret)
1971                 goto err_out1;
1972
1973         host_dev->path = stor_device->path_id;
1974         host_dev->target = stor_device->target_id;
1975
1976         switch (dev_id->driver_data) {
1977         case SFC_GUID:
1978                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1979                 host->max_id = STORVSC_FC_MAX_TARGETS;
1980                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1981 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1982                 host->transportt = fc_transport_template;
1983 #endif
1984                 break;
1985
1986         case SCSI_GUID:
1987                 host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
1988                 host->max_id = STORVSC_MAX_TARGETS;
1989                 host->max_channel = STORVSC_MAX_CHANNELS - 1;
1990                 break;
1991
1992         default:
1993                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1994                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1995                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1996                 break;
1997         }
1998         /* max cmd length */
1999         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
2000         /*
2001          * Any reasonable Hyper-V configuration should provide
2002          * max_transfer_bytes value aligning to HV_HYP_PAGE_SIZE,
2003          * protecting it from any weird value.
2004          */
2005         max_xfer_bytes = round_down(stor_device->max_transfer_bytes, HV_HYP_PAGE_SIZE);
2006         if (is_fc)
2007                 max_xfer_bytes = min(max_xfer_bytes, STORVSC_FC_MAX_XFER_SIZE);
2008
2009         /* max_hw_sectors_kb */
2010         host->max_sectors = max_xfer_bytes >> 9;
2011         /*
2012          * There are 2 requirements for Hyper-V storvsc sgl segments,
2013          * based on which the below calculation for max segments is
2014          * done:
2015          *
2016          * 1. Except for the first and last sgl segment, all sgl segments
2017          *    should be align to HV_HYP_PAGE_SIZE, that also means the
2018          *    maximum number of segments in a sgl can be calculated by
2019          *    dividing the total max transfer length by HV_HYP_PAGE_SIZE.
2020          *
2021          * 2. Except for the first and last, each entry in the SGL must
2022          *    have an offset that is a multiple of HV_HYP_PAGE_SIZE.
2023          */
2024         host->sg_tablesize = (max_xfer_bytes >> HV_HYP_PAGE_SHIFT) + 1;
2025         /*
2026          * For non-IDE disks, the host supports multiple channels.
2027          * Set the number of HW queues we are supporting.
2028          */
2029         if (!dev_is_ide) {
2030                 if (storvsc_max_hw_queues > num_present_cpus) {
2031                         storvsc_max_hw_queues = 0;
2032                         storvsc_log(device, STORVSC_LOGGING_WARN,
2033                                 "Resetting invalid storvsc_max_hw_queues value to default.\n");
2034                 }
2035                 if (storvsc_max_hw_queues)
2036                         host->nr_hw_queues = storvsc_max_hw_queues;
2037                 else
2038                         host->nr_hw_queues = num_present_cpus;
2039         }
2040
2041         /*
2042          * Set the error handler work queue.
2043          */
2044         host_dev->handle_error_wq =
2045                         alloc_ordered_workqueue("storvsc_error_wq_%d",
2046                                                 0,
2047                                                 host->host_no);
2048         if (!host_dev->handle_error_wq) {
2049                 ret = -ENOMEM;
2050                 goto err_out2;
2051         }
2052         INIT_WORK(&host_dev->host_scan_work, storvsc_host_scan);
2053         /* Register the HBA and start the scsi bus scan */
2054         ret = scsi_add_host(host, &device->device);
2055         if (ret != 0)
2056                 goto err_out3;
2057
2058         if (!dev_is_ide) {
2059                 scsi_scan_host(host);
2060         } else {
2061                 target = (device->dev_instance.b[5] << 8 |
2062                          device->dev_instance.b[4]);
2063                 ret = scsi_add_device(host, 0, target, 0);
2064                 if (ret)
2065                         goto err_out4;
2066         }
2067 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2068         if (host->transportt == fc_transport_template) {
2069                 struct fc_rport_identifiers ids = {
2070                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
2071                 };
2072
2073                 fc_host_node_name(host) = stor_device->node_name;
2074                 fc_host_port_name(host) = stor_device->port_name;
2075                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
2076                 if (!stor_device->rport) {
2077                         ret = -ENOMEM;
2078                         goto err_out4;
2079                 }
2080         }
2081 #endif
2082         return 0;
2083
2084 err_out4:
2085         scsi_remove_host(host);
2086
2087 err_out3:
2088         destroy_workqueue(host_dev->handle_error_wq);
2089
2090 err_out2:
2091         /*
2092          * Once we have connected with the host, we would need to
2093          * invoke storvsc_dev_remove() to rollback this state and
2094          * this call also frees up the stor_device; hence the jump around
2095          * err_out1 label.
2096          */
2097         storvsc_dev_remove(device);
2098         goto err_out0;
2099
2100 err_out1:
2101         kfree(stor_device->stor_chns);
2102         kfree(stor_device);
2103
2104 err_out0:
2105         scsi_host_put(host);
2106         return ret;
2107 }
2108
2109 /* Change a scsi target's queue depth */
2110 static int storvsc_change_queue_depth(struct scsi_device *sdev, int queue_depth)
2111 {
2112         if (queue_depth > scsi_driver.can_queue)
2113                 queue_depth = scsi_driver.can_queue;
2114
2115         return scsi_change_queue_depth(sdev, queue_depth);
2116 }
2117
2118 static void storvsc_remove(struct hv_device *dev)
2119 {
2120         struct storvsc_device *stor_device = hv_get_drvdata(dev);
2121         struct Scsi_Host *host = stor_device->host;
2122         struct hv_host_device *host_dev = shost_priv(host);
2123
2124 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2125         if (host->transportt == fc_transport_template) {
2126                 fc_remote_port_delete(stor_device->rport);
2127                 fc_remove_host(host);
2128         }
2129 #endif
2130         destroy_workqueue(host_dev->handle_error_wq);
2131         scsi_remove_host(host);
2132         storvsc_dev_remove(dev);
2133         scsi_host_put(host);
2134 }
2135
2136 static int storvsc_suspend(struct hv_device *hv_dev)
2137 {
2138         struct storvsc_device *stor_device = hv_get_drvdata(hv_dev);
2139         struct Scsi_Host *host = stor_device->host;
2140         struct hv_host_device *host_dev = shost_priv(host);
2141
2142         storvsc_wait_to_drain(stor_device);
2143
2144         drain_workqueue(host_dev->handle_error_wq);
2145
2146         vmbus_close(hv_dev->channel);
2147
2148         kfree(stor_device->stor_chns);
2149         stor_device->stor_chns = NULL;
2150
2151         cpumask_clear(&stor_device->alloced_cpus);
2152
2153         return 0;
2154 }
2155
2156 static int storvsc_resume(struct hv_device *hv_dev)
2157 {
2158         int ret;
2159
2160         ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size,
2161                                      hv_dev_is_fc(hv_dev));
2162         return ret;
2163 }
2164
2165 static struct hv_driver storvsc_drv = {
2166         .name = KBUILD_MODNAME,
2167         .id_table = id_table,
2168         .probe = storvsc_probe,
2169         .remove = storvsc_remove,
2170         .suspend = storvsc_suspend,
2171         .resume = storvsc_resume,
2172         .driver = {
2173                 .probe_type = PROBE_PREFER_ASYNCHRONOUS,
2174         },
2175 };
2176
2177 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2178 static struct fc_function_template fc_transport_functions = {
2179         .show_host_node_name = 1,
2180         .show_host_port_name = 1,
2181 };
2182 #endif
2183
2184 static int __init storvsc_drv_init(void)
2185 {
2186         int ret;
2187
2188         /*
2189          * Divide the ring buffer data size (which is 1 page less
2190          * than the ring buffer size since that page is reserved for
2191          * the ring buffer indices) by the max request size (which is
2192          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
2193          */
2194         max_outstanding_req_per_channel =
2195                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
2196                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
2197                 sizeof(struct vstor_packet) + sizeof(u64),
2198                 sizeof(u64)));
2199
2200 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2201         fc_transport_template = fc_attach_transport(&fc_transport_functions);
2202         if (!fc_transport_template)
2203                 return -ENODEV;
2204 #endif
2205
2206         ret = vmbus_driver_register(&storvsc_drv);
2207
2208 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2209         if (ret)
2210                 fc_release_transport(fc_transport_template);
2211 #endif
2212
2213         return ret;
2214 }
2215
2216 static void __exit storvsc_drv_exit(void)
2217 {
2218         vmbus_driver_unregister(&storvsc_drv);
2219 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
2220         fc_release_transport(fc_transport_template);
2221 #endif
2222 }
2223
2224 MODULE_LICENSE("GPL");
2225 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
2226 module_init(storvsc_drv_init);
2227 module_exit(storvsc_drv_exit);