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