drivers/scsi/storvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *   K. Y. Srinivasan <kys@microsoft.com>
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/wait.h>
  25 #include <linux/sched.h>
  26 #include <linux/completion.h>
  27 #include <linux/string.h>
  28 #include <linux/mm.h>
  29 #include <linux/delay.h>
  30 #include <linux/init.h>
  31 #include <linux/slab.h>
  32 #include <linux/module.h>
  33 #include <linux/device.h>
  34 #include <linux/hyperv.h>
  35 #include <linux/blkdev.h>
  36 #include <scsi/scsi.h>
  37 #include <scsi/scsi_cmnd.h>
  38 #include <scsi/scsi_host.h>
  39 #include <scsi/scsi_device.h>
  40 #include <scsi/scsi_tcq.h>
  41 #include <scsi/scsi_eh.h>
  42 #include <scsi/scsi_devinfo.h>
  43 #include <scsi/scsi_dbg.h>
  44 #include <scsi/scsi_transport_fc.h>
  45 #include <scsi/scsi_transport.h>
  46
  47 /*
  48  * All wire protocol details (storage protocol between the guest and the host)
  49  * are consolidated here.
  50  *
  51  * Begin protocol definitions.
  52  */
  53
  54 /*
  55  * Version history:
  56  * V1 Beta: 0.1
  57  * V1 RC < 2008/1/31: 1.0
  58  * V1 RC > 2008/1/31:  2.0
  59  * Win7: 4.2
  60  * Win8: 5.1
  61  * Win8.1: 6.0
  62  * Win10: 6.2
  63  */
  64
  65 #define VMSTOR_PROTO_VERSION(MAJOR_, MINOR_)    ((((MAJOR_) & 0xff) << 8) | \
  66                                                 (((MINOR_) & 0xff)))
  67
  68 #define VMSTOR_PROTO_VERSION_WIN6       VMSTOR_PROTO_VERSION(2, 0)
  69 #define VMSTOR_PROTO_VERSION_WIN7       VMSTOR_PROTO_VERSION(4, 2)
  70 #define VMSTOR_PROTO_VERSION_WIN8       VMSTOR_PROTO_VERSION(5, 1)
  71 #define VMSTOR_PROTO_VERSION_WIN8_1     VMSTOR_PROTO_VERSION(6, 0)
  72 #define VMSTOR_PROTO_VERSION_WIN10      VMSTOR_PROTO_VERSION(6, 2)
  73
  74 /*  Packet structure describing virtual storage requests. */
  75 enum vstor_packet_operation {
  76         VSTOR_OPERATION_COMPLETE_IO             = 1,
  77         VSTOR_OPERATION_REMOVE_DEVICE           = 2,
  78         VSTOR_OPERATION_EXECUTE_SRB             = 3,
  79         VSTOR_OPERATION_RESET_LUN               = 4,
  80         VSTOR_OPERATION_RESET_ADAPTER           = 5,
  81         VSTOR_OPERATION_RESET_BUS               = 6,
  82         VSTOR_OPERATION_BEGIN_INITIALIZATION    = 7,
  83         VSTOR_OPERATION_END_INITIALIZATION      = 8,
  84         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION  = 9,
  85         VSTOR_OPERATION_QUERY_PROPERTIES        = 10,
  86         VSTOR_OPERATION_ENUMERATE_BUS           = 11,
  87         VSTOR_OPERATION_FCHBA_DATA              = 12,
  88         VSTOR_OPERATION_CREATE_SUB_CHANNELS     = 13,
  89         VSTOR_OPERATION_MAXIMUM                 = 13
  90 };
  91
  92 /*
  93  * WWN packet for Fibre Channel HBA
  94  */
  95
  96 struct hv_fc_wwn_packet {
  97         u8      primary_active;
  98         u8      reserved1[3];
  99         u8      primary_port_wwn[8];
 100         u8      primary_node_wwn[8];
 101         u8      secondary_port_wwn[8];
 102         u8      secondary_node_wwn[8];
 103 };
 104
 105
 106
 107 /*
 108  * SRB Flag Bits
 109  */
 110
 111 #define SRB_FLAGS_QUEUE_ACTION_ENABLE           0x00000002
 112 #define SRB_FLAGS_DISABLE_DISCONNECT            0x00000004
 113 #define SRB_FLAGS_DISABLE_SYNCH_TRANSFER        0x00000008
 114 #define SRB_FLAGS_BYPASS_FROZEN_QUEUE           0x00000010
 115 #define SRB_FLAGS_DISABLE_AUTOSENSE             0x00000020
 116 #define SRB_FLAGS_DATA_IN                       0x00000040
 117 #define SRB_FLAGS_DATA_OUT                      0x00000080
 118 #define SRB_FLAGS_NO_DATA_TRANSFER              0x00000000
 119 #define SRB_FLAGS_UNSPECIFIED_DIRECTION (SRB_FLAGS_DATA_IN | SRB_FLAGS_DATA_OUT)
 120 #define SRB_FLAGS_NO_QUEUE_FREEZE               0x00000100
 121 #define SRB_FLAGS_ADAPTER_CACHE_ENABLE          0x00000200
 122 #define SRB_FLAGS_FREE_SENSE_BUFFER             0x00000400
 123
 124 /*
 125  * This flag indicates the request is part of the workflow for processing a D3.
 126  */
 127 #define SRB_FLAGS_D3_PROCESSING                 0x00000800
 128 #define SRB_FLAGS_IS_ACTIVE                     0x00010000
 129 #define SRB_FLAGS_ALLOCATED_FROM_ZONE           0x00020000
 130 #define SRB_FLAGS_SGLIST_FROM_POOL              0x00040000
 131 #define SRB_FLAGS_BYPASS_LOCKED_QUEUE           0x00080000
 132 #define SRB_FLAGS_NO_KEEP_AWAKE                 0x00100000
 133 #define SRB_FLAGS_PORT_DRIVER_ALLOCSENSE        0x00200000
 134 #define SRB_FLAGS_PORT_DRIVER_SENSEHASPORT      0x00400000
 135 #define SRB_FLAGS_DONT_START_NEXT_PACKET        0x00800000
 136 #define SRB_FLAGS_PORT_DRIVER_RESERVED          0x0F000000
 137 #define SRB_FLAGS_CLASS_DRIVER_RESERVED         0xF0000000
 138
 139 #define SP_UNTAGGED                     ((unsigned char) ~0)
 140 #define SRB_SIMPLE_TAG_REQUEST          0x20
 141
 142 /*
 143  * Platform neutral description of a scsi request -
 144  * this remains the same across the write regardless of 32/64 bit
 145  * note: it's patterned off the SCSI_PASS_THROUGH structure
 146  */
 147 #define STORVSC_MAX_CMD_LEN                     0x10
 148
 149 #define POST_WIN7_STORVSC_SENSE_BUFFER_SIZE     0x14
 150 #define PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE      0x12
 151
 152 #define STORVSC_SENSE_BUFFER_SIZE               0x14
 153 #define STORVSC_MAX_BUF_LEN_WITH_PADDING        0x14
 154
 155 /*
 156  * Sense buffer size changed in win8; have a run-time
 157  * variable to track the size we should use.  This value will
 158  * likely change during protocol negotiation but it is valid
 159  * to start by assuming pre-Win8.
 160  */
 161 static int sense_buffer_size = PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE;
 162
 163 /*
 164  * The storage protocol version is determined during the
 165  * initial exchange with the host.  It will indicate which
 166  * storage functionality is available in the host.
 167 */
 168 static int vmstor_proto_version;
 169
 170 #define STORVSC_LOGGING_NONE    0
 171 #define STORVSC_LOGGING_ERROR   1
 172 #define STORVSC_LOGGING_WARN    2
 173
 174 static int logging_level = STORVSC_LOGGING_ERROR;
 175 module_param(logging_level, int, S_IRUGO|S_IWUSR);
 176 MODULE_PARM_DESC(logging_level,
 177         "Logging level, 0 - None, 1 - Error (default), 2 - Warning.");
 178
 179 static inline bool do_logging(int level)
 180 {
 181         return logging_level >= level;
 182 }
 183
 184 #define storvsc_log(dev, level, fmt, ...)                       \
 185 do {                                                            \
 186         if (do_logging(level))                                  \
 187                 dev_warn(&(dev)->device, fmt, ##__VA_ARGS__);   \
 188 } while (0)
 189
 190 struct vmscsi_win8_extension {
 191         /*
 192          * The following were added in Windows 8
 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 } __packed;
 201
 202 struct vmscsi_request {
 203         u16 length;
 204         u8 srb_status;
 205         u8 scsi_status;
 206
 207         u8  port_number;
 208         u8  path_id;
 209         u8  target_id;
 210         u8  lun;
 211
 212         u8  cdb_length;
 213         u8  sense_info_length;
 214         u8  data_in;
 215         u8  reserved;
 216
 217         u32 data_transfer_length;
 218
 219         union {
 220                 u8 cdb[STORVSC_MAX_CMD_LEN];
 221                 u8 sense_data[STORVSC_SENSE_BUFFER_SIZE];
 222                 u8 reserved_array[STORVSC_MAX_BUF_LEN_WITH_PADDING];
 223         };
 224         /*
 225          * The following was added in win8.
 226          */
 227         struct vmscsi_win8_extension win8_extension;
 228
 229 } __attribute((packed));
 230
 231
 232 /*
 233  * The size of the vmscsi_request has changed in win8. The
 234  * additional size is because of new elements added to the
 235  * structure. These elements are valid only when we are talking
 236  * to a win8 host.
 237  * Track the correction to size we need to apply. This value
 238  * will likely change during protocol negotiation but it is
 239  * valid to start by assuming pre-Win8.
 240  */
 241 static int vmscsi_size_delta = sizeof(struct vmscsi_win8_extension);
 242
 243 /*
 244  * The list of storage protocols in order of preference.
 245  */
 246 struct vmstor_protocol {
 247         int protocol_version;
 248         int sense_buffer_size;
 249         int vmscsi_size_delta;
 250 };
 251
 252
 253 static const struct vmstor_protocol vmstor_protocols[] = {
 254         {
 255                 VMSTOR_PROTO_VERSION_WIN10,
 256                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 257                 0
 258         },
 259         {
 260                 VMSTOR_PROTO_VERSION_WIN8_1,
 261                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 262                 0
 263         },
 264         {
 265                 VMSTOR_PROTO_VERSION_WIN8,
 266                 POST_WIN7_STORVSC_SENSE_BUFFER_SIZE,
 267                 0
 268         },
 269         {
 270                 VMSTOR_PROTO_VERSION_WIN7,
 271                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 272                 sizeof(struct vmscsi_win8_extension),
 273         },
 274         {
 275                 VMSTOR_PROTO_VERSION_WIN6,
 276                 PRE_WIN8_STORVSC_SENSE_BUFFER_SIZE,
 277                 sizeof(struct vmscsi_win8_extension),
 278         }
 279 };
 280
 281
 282 /*
 283  * This structure is sent during the initialization phase to get the different
 284  * properties of the channel.
 285  */
 286
 287 #define STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL          0x1
 288
 289 struct vmstorage_channel_properties {
 290         u32 reserved;
 291         u16 max_channel_cnt;
 292         u16 reserved1;
 293
 294         u32 flags;
 295         u32   max_transfer_bytes;
 296
 297         u64  reserved2;
 298 } __packed;
 299
 300 /*  This structure is sent during the storage protocol negotiations. */
 301 struct vmstorage_protocol_version {
 302         /* Major (MSW) and minor (LSW) version numbers. */
 303         u16 major_minor;
 304
 305         /*
 306          * Revision number is auto-incremented whenever this file is changed
 307          * (See FILL_VMSTOR_REVISION macro above).  Mismatch does not
 308          * definitely indicate incompatibility--but it does indicate mismatched
 309          * builds.
 310          * This is only used on the windows side. Just set it to 0.
 311          */
 312         u16 revision;
 313 } __packed;
 314
 315 /* Channel Property Flags */
 316 #define STORAGE_CHANNEL_REMOVABLE_FLAG          0x1
 317 #define STORAGE_CHANNEL_EMULATED_IDE_FLAG       0x2
 318
 319 struct vstor_packet {
 320         /* Requested operation type */
 321         enum vstor_packet_operation operation;
 322
 323         /*  Flags - see below for values */
 324         u32 flags;
 325
 326         /* Status of the request returned from the server side. */
 327         u32 status;
 328
 329         /* Data payload area */
 330         union {
 331                 /*
 332                  * Structure used to forward SCSI commands from the
 333                  * client to the server.
 334                  */
 335                 struct vmscsi_request vm_srb;
 336
 337                 /* Structure used to query channel properties. */
 338                 struct vmstorage_channel_properties storage_channel_properties;
 339
 340                 /* Used during version negotiations. */
 341                 struct vmstorage_protocol_version version;
 342
 343                 /* Fibre channel address packet */
 344                 struct hv_fc_wwn_packet wwn_packet;
 345
 346                 /* Number of sub-channels to create */
 347                 u16 sub_channel_count;
 348
 349                 /* This will be the maximum of the union members */
 350                 u8  buffer[0x34];
 351         };
 352 } __packed;
 353
 354 /*
 355  * Packet Flags:
 356  *
 357  * This flag indicates that the server should send back a completion for this
 358  * packet.
 359  */
 360
 361 #define REQUEST_COMPLETION_FLAG 0x1
 362
 363 /* Matches Windows-end */
 364 enum storvsc_request_type {
 365         WRITE_TYPE = 0,
 366         READ_TYPE,
 367         UNKNOWN_TYPE,
 368 };
 369
 370 /*
 371  * SRB status codes and masks; a subset of the codes used here.
 372  */
 373
 374 #define SRB_STATUS_AUTOSENSE_VALID      0x80
 375 #define SRB_STATUS_QUEUE_FROZEN         0x40
 376 #define SRB_STATUS_INVALID_LUN  0x20
 377 #define SRB_STATUS_SUCCESS      0x01
 378 #define SRB_STATUS_ABORTED      0x02
 379 #define SRB_STATUS_ERROR        0x04
 380 #define SRB_STATUS_DATA_OVERRUN 0x12
 381
 382 #define SRB_STATUS(status) \
 383         (status & ~(SRB_STATUS_AUTOSENSE_VALID | SRB_STATUS_QUEUE_FROZEN))
 384 /*
 385  * This is the end of Protocol specific defines.
 386  */
 387
 388 static int storvsc_ringbuffer_size = (256 * PAGE_SIZE);
 389 static u32 max_outstanding_req_per_channel;
 390
 391 static int storvsc_vcpus_per_sub_channel = 4;
 392
 393 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 394 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 395
 396 module_param(storvsc_vcpus_per_sub_channel, int, S_IRUGO);
 397 MODULE_PARM_DESC(storvsc_vcpus_per_sub_channel, "Ratio of VCPUs to subchannels");
 398 /*
 399  * Timeout in seconds for all devices managed by this driver.
 400  */
 401 static int storvsc_timeout = 180;
 402
 403 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 404 static struct scsi_transport_template *fc_transport_template;
 405 #endif
 406
 407 static void storvsc_on_channel_callback(void *context);
 408
 409 #define STORVSC_MAX_LUNS_PER_TARGET                     255
 410 #define STORVSC_MAX_TARGETS                             2
 411 #define STORVSC_MAX_CHANNELS                            8
 412
 413 #define STORVSC_FC_MAX_LUNS_PER_TARGET                  255
 414 #define STORVSC_FC_MAX_TARGETS                          128
 415 #define STORVSC_FC_MAX_CHANNELS                         8
 416
 417 #define STORVSC_IDE_MAX_LUNS_PER_TARGET                 64
 418 #define STORVSC_IDE_MAX_TARGETS                         1
 419 #define STORVSC_IDE_MAX_CHANNELS                        1
 420
 421 struct storvsc_cmd_request {
 422         struct scsi_cmnd *cmd;
 423
 424         struct hv_device *device;
 425
 426         /* Synchronize the request/response if needed */
 427         struct completion wait_event;
 428
 429         struct vmbus_channel_packet_multipage_buffer mpb;
 430         struct vmbus_packet_mpb_array *payload;
 431         u32 payload_sz;
 432
 433         struct vstor_packet vstor_packet;
 434 };
 435
 436
 437 /* A storvsc device is a device object that contains a vmbus channel */
 438 struct storvsc_device {
 439         struct hv_device *device;
 440
 441         bool     destroy;
 442         bool     drain_notify;
 443         bool     open_sub_channel;
 444         atomic_t num_outstanding_req;
 445         struct Scsi_Host *host;
 446
 447         wait_queue_head_t waiting_to_drain;
 448
 449         /*
 450          * Each unique Port/Path/Target represents 1 channel ie scsi
 451          * controller. In reality, the pathid, targetid is always 0
 452          * and the port is set by us
 453          */
 454         unsigned int port_number;
 455         unsigned char path_id;
 456         unsigned char target_id;
 457
 458         /*
 459          * Max I/O, the device can support.
 460          */
 461         u32   max_transfer_bytes;
 462         /*
 463          * Number of sub-channels we will open.
 464          */
 465         u16 num_sc;
 466         struct vmbus_channel **stor_chns;
 467         /*
 468          * Mask of CPUs bound to subchannels.
 469          */
 470         struct cpumask alloced_cpus;
 471         /* Used for vsc/vsp channel reset process */
 472         struct storvsc_cmd_request init_request;
 473         struct storvsc_cmd_request reset_request;
 474         /*
 475          * Currently active port and node names for FC devices.
 476          */
 477         u64 node_name;
 478         u64 port_name;
 479 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
 480         struct fc_rport *rport;
 481 #endif
 482 };
 483
 484 struct hv_host_device {
 485         struct hv_device *dev;
 486         unsigned int port;
 487         unsigned char path;
 488         unsigned char target;
 489 };
 490
 491 struct storvsc_scan_work {
 492         struct work_struct work;
 493         struct Scsi_Host *host;
 494         u8 lun;
 495         u8 tgt_id;
 496 };
 497
 498 static void storvsc_device_scan(struct work_struct *work)
 499 {
 500         struct storvsc_scan_work *wrk;
 501         struct scsi_device *sdev;
 502
 503         wrk = container_of(work, struct storvsc_scan_work, work);
 504
 505         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 506         if (!sdev)
 507                 goto done;
 508         scsi_rescan_device(&sdev->sdev_gendev);
 509         scsi_device_put(sdev);
 510
 511 done:
 512         kfree(wrk);
 513 }
 514
 515 static void storvsc_host_scan(struct work_struct *work)
 516 {
 517         struct storvsc_scan_work *wrk;
 518         struct Scsi_Host *host;
 519         struct scsi_device *sdev;
 520
 521         wrk = container_of(work, struct storvsc_scan_work, work);
 522         host = wrk->host;
 523
 524         /*
 525          * Before scanning the host, first check to see if any of the
 526          * currrently known devices have been hot removed. We issue a
 527          * "unit ready" command against all currently known devices.
 528          * This I/O will result in an error for devices that have been
 529          * removed. As part of handling the I/O error, we remove the device.
 530          *
 531          * When a LUN is added or removed, the host sends us a signal to
 532          * scan the host. Thus we are forced to discover the LUNs that
 533          * may have been removed this way.
 534          */
 535         mutex_lock(&host->scan_mutex);
 536         shost_for_each_device(sdev, host)
 537                 scsi_test_unit_ready(sdev, 1, 1, NULL);
 538         mutex_unlock(&host->scan_mutex);
 539         /*
 540          * Now scan the host to discover LUNs that may have been added.
 541          */
 542         scsi_scan_host(host);
 543
 544         kfree(wrk);
 545 }
 546
 547 static void storvsc_remove_lun(struct work_struct *work)
 548 {
 549         struct storvsc_scan_work *wrk;
 550         struct scsi_device *sdev;
 551
 552         wrk = container_of(work, struct storvsc_scan_work, work);
 553         if (!scsi_host_get(wrk->host))
 554                 goto done;
 555
 556         sdev = scsi_device_lookup(wrk->host, 0, wrk->tgt_id, wrk->lun);
 557
 558         if (sdev) {
 559                 scsi_remove_device(sdev);
 560                 scsi_device_put(sdev);
 561         }
 562         scsi_host_put(wrk->host);
 563
 564 done:
 565         kfree(wrk);
 566 }
 567
 568
 569 /*
 570  * We can get incoming messages from the host that are not in response to
 571  * messages that we have sent out. An example of this would be messages
 572  * received by the guest to notify dynamic addition/removal of LUNs. To
 573  * deal with potential race conditions where the driver may be in the
 574  * midst of being unloaded when we might receive an unsolicited message
 575  * from the host, we have implemented a mechanism to gurantee sequential
 576  * consistency:
 577  *
 578  * 1) Once the device is marked as being destroyed, we will fail all
 579  *    outgoing messages.
 580  * 2) We permit incoming messages when the device is being destroyed,
 581  *    only to properly account for messages already sent out.
 582  */
 583
 584 static inline struct storvsc_device *get_out_stor_device(
 585                                         struct hv_device *device)
 586 {
 587         struct storvsc_device *stor_device;
 588
 589         stor_device = hv_get_drvdata(device);
 590
 591         if (stor_device && stor_device->destroy)
 592                 stor_device = NULL;
 593
 594         return stor_device;
 595 }
 596
 597
 598 static inline void storvsc_wait_to_drain(struct storvsc_device *dev)
 599 {
 600         dev->drain_notify = true;
 601         wait_event(dev->waiting_to_drain,
 602                    atomic_read(&dev->num_outstanding_req) == 0);
 603         dev->drain_notify = false;
 604 }
 605
 606 static inline struct storvsc_device *get_in_stor_device(
 607                                         struct hv_device *device)
 608 {
 609         struct storvsc_device *stor_device;
 610
 611         stor_device = hv_get_drvdata(device);
 612
 613         if (!stor_device)
 614                 goto get_in_err;
 615
 616         /*
 617          * If the device is being destroyed; allow incoming
 618          * traffic only to cleanup outstanding requests.
 619          */
 620
 621         if (stor_device->destroy  &&
 622                 (atomic_read(&stor_device->num_outstanding_req) == 0))
 623                 stor_device = NULL;
 624
 625 get_in_err:
 626         return stor_device;
 627
 628 }
 629
 630 static void handle_sc_creation(struct vmbus_channel *new_sc)
 631 {
 632         struct hv_device *device = new_sc->primary_channel->device_obj;
 633         struct storvsc_device *stor_device;
 634         struct vmstorage_channel_properties props;
 635
 636         stor_device = get_out_stor_device(device);
 637         if (!stor_device)
 638                 return;
 639
 640         if (stor_device->open_sub_channel == false)
 641                 return;
 642
 643         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
 644
 645         vmbus_open(new_sc,
 646                    storvsc_ringbuffer_size,
 647                    storvsc_ringbuffer_size,
 648                    (void *)&props,
 649                    sizeof(struct vmstorage_channel_properties),
 650                    storvsc_on_channel_callback, new_sc);
 651
 652         if (new_sc->state == CHANNEL_OPENED_STATE) {
 653                 stor_device->stor_chns[new_sc->target_cpu] = new_sc;
 654                 cpumask_set_cpu(new_sc->target_cpu, &stor_device->alloced_cpus);
 655         }
 656 }
 657
 658 static void  handle_multichannel_storage(struct hv_device *device, int max_chns)
 659 {
 660         struct storvsc_device *stor_device;
 661         int num_cpus = num_online_cpus();
 662         int num_sc;
 663         struct storvsc_cmd_request *request;
 664         struct vstor_packet *vstor_packet;
 665         int ret, t;
 666
 667         num_sc = ((max_chns > num_cpus) ? num_cpus : max_chns);
 668         stor_device = get_out_stor_device(device);
 669         if (!stor_device)
 670                 return;
 671
 672         stor_device->num_sc = num_sc;
 673         request = &stor_device->init_request;
 674         vstor_packet = &request->vstor_packet;
 675
 676         stor_device->open_sub_channel = true;
 677         /*
 678          * Establish a handler for dealing with subchannels.
 679          */
 680         vmbus_set_sc_create_callback(device->channel, handle_sc_creation);
 681
 682         /*
 683          * Check to see if sub-channels have already been created. This
 684          * can happen when this driver is re-loaded after unloading.
 685          */
 686
 687         if (vmbus_are_subchannels_present(device->channel))
 688                 return;
 689
 690         stor_device->open_sub_channel = false;
 691         /*
 692          * Request the host to create sub-channels.
 693          */
 694         memset(request, 0, sizeof(struct storvsc_cmd_request));
 695         init_completion(&request->wait_event);
 696         vstor_packet->operation = VSTOR_OPERATION_CREATE_SUB_CHANNELS;
 697         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 698         vstor_packet->sub_channel_count = num_sc;
 699
 700         ret = vmbus_sendpacket(device->channel, vstor_packet,
 701                                (sizeof(struct vstor_packet) -
 702                                vmscsi_size_delta),
 703                                (unsigned long)request,
 704                                VM_PKT_DATA_INBAND,
 705                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 706
 707         if (ret != 0)
 708                 return;
 709
 710         t = wait_for_completion_timeout(&request->wait_event, 10*HZ);
 711         if (t == 0)
 712                 return;
 713
 714         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 715             vstor_packet->status != 0)
 716                 return;
 717
 718         /*
 719          * Now that we created the sub-channels, invoke the check; this
 720          * may trigger the callback.
 721          */
 722         stor_device->open_sub_channel = true;
 723         vmbus_are_subchannels_present(device->channel);
 724 }
 725
 726 static void cache_wwn(struct storvsc_device *stor_device,
 727                       struct vstor_packet *vstor_packet)
 728 {
 729         /*
 730          * Cache the currently active port and node ww names.
 731          */
 732         if (vstor_packet->wwn_packet.primary_active) {
 733                 stor_device->node_name =
 734                         wwn_to_u64(vstor_packet->wwn_packet.primary_node_wwn);
 735                 stor_device->port_name =
 736                         wwn_to_u64(vstor_packet->wwn_packet.primary_port_wwn);
 737         } else {
 738                 stor_device->node_name =
 739                         wwn_to_u64(vstor_packet->wwn_packet.secondary_node_wwn);
 740                 stor_device->port_name =
 741                         wwn_to_u64(vstor_packet->wwn_packet.secondary_port_wwn);
 742         }
 743 }
 744
 745
 746 static int storvsc_execute_vstor_op(struct hv_device *device,
 747                                     struct storvsc_cmd_request *request,
 748                                     bool status_check)
 749 {
 750         struct vstor_packet *vstor_packet;
 751         int ret, t;
 752
 753         vstor_packet = &request->vstor_packet;
 754
 755         init_completion(&request->wait_event);
 756         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 757
 758         ret = vmbus_sendpacket(device->channel, vstor_packet,
 759                                (sizeof(struct vstor_packet) -
 760                                vmscsi_size_delta),
 761                                (unsigned long)request,
 762                                VM_PKT_DATA_INBAND,
 763                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 764         if (ret != 0)
 765                 return ret;
 766
 767         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
 768         if (t == 0)
 769                 return -ETIMEDOUT;
 770
 771         if (!status_check)
 772                 return ret;
 773
 774         if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO ||
 775             vstor_packet->status != 0)
 776                 return -EINVAL;
 777
 778         return ret;
 779 }
 780
 781 static int storvsc_channel_init(struct hv_device *device, bool is_fc)
 782 {
 783         struct storvsc_device *stor_device;
 784         struct storvsc_cmd_request *request;
 785         struct vstor_packet *vstor_packet;
 786         int ret, i;
 787         int max_chns;
 788         bool process_sub_channels = false;
 789
 790         stor_device = get_out_stor_device(device);
 791         if (!stor_device)
 792                 return -ENODEV;
 793
 794         request = &stor_device->init_request;
 795         vstor_packet = &request->vstor_packet;
 796
 797         /*
 798          * Now, initiate the vsc/vsp initialization protocol on the open
 799          * channel
 800          */
 801         memset(request, 0, sizeof(struct storvsc_cmd_request));
 802         vstor_packet->operation = VSTOR_OPERATION_BEGIN_INITIALIZATION;
 803         ret = storvsc_execute_vstor_op(device, request, true);
 804         if (ret)
 805                 return ret;
 806         /*
 807          * Query host supported protocol version.
 808          */
 809
 810         for (i = 0; i < ARRAY_SIZE(vmstor_protocols); i++) {
 811                 /* reuse the packet for version range supported */
 812                 memset(vstor_packet, 0, sizeof(struct vstor_packet));
 813                 vstor_packet->operation =
 814                         VSTOR_OPERATION_QUERY_PROTOCOL_VERSION;
 815
 816                 vstor_packet->version.major_minor =
 817                         vmstor_protocols[i].protocol_version;
 818
 819                 /*
 820                  * The revision number is only used in Windows; set it to 0.
 821                  */
 822                 vstor_packet->version.revision = 0;
 823                 ret = storvsc_execute_vstor_op(device, request, false);
 824                 if (ret != 0)
 825                         return ret;
 826
 827                 if (vstor_packet->operation != VSTOR_OPERATION_COMPLETE_IO)
 828                         return -EINVAL;
 829
 830                 if (vstor_packet->status == 0) {
 831                         vmstor_proto_version =
 832                                 vmstor_protocols[i].protocol_version;
 833
 834                         sense_buffer_size =
 835                                 vmstor_protocols[i].sense_buffer_size;
 836
 837                         vmscsi_size_delta =
 838                                 vmstor_protocols[i].vmscsi_size_delta;
 839
 840                         break;
 841                 }
 842         }
 843
 844         if (vstor_packet->status != 0)
 845                 return -EINVAL;
 846
 847
 848         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 849         vstor_packet->operation = VSTOR_OPERATION_QUERY_PROPERTIES;
 850         ret = storvsc_execute_vstor_op(device, request, true);
 851         if (ret != 0)
 852                 return ret;
 853
 854         /*
 855          * Check to see if multi-channel support is there.
 856          * Hosts that implement protocol version of 5.1 and above
 857          * support multi-channel.
 858          */
 859         max_chns = vstor_packet->storage_channel_properties.max_channel_cnt;
 860
 861         /*
 862          * Allocate state to manage the sub-channels.
 863          * We allocate an array based on the numbers of possible CPUs
 864          * (Hyper-V does not support cpu online/offline).
 865          * This Array will be sparseley populated with unique
 866          * channels - primary + sub-channels.
 867          * We will however populate all the slots to evenly distribute
 868          * the load.
 869          */
 870         stor_device->stor_chns = kcalloc(num_possible_cpus(), sizeof(void *),
 871                                          GFP_KERNEL);
 872         if (stor_device->stor_chns == NULL)
 873                 return -ENOMEM;
 874
 875         stor_device->stor_chns[device->channel->target_cpu] = device->channel;
 876         cpumask_set_cpu(device->channel->target_cpu,
 877                         &stor_device->alloced_cpus);
 878
 879         if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN8) {
 880                 if (vstor_packet->storage_channel_properties.flags &
 881                     STORAGE_CHANNEL_SUPPORTS_MULTI_CHANNEL)
 882                         process_sub_channels = true;
 883         }
 884         stor_device->max_transfer_bytes =
 885                 vstor_packet->storage_channel_properties.max_transfer_bytes;
 886
 887         if (!is_fc)
 888                 goto done;
 889
 890         /*
 891          * For FC devices retrieve FC HBA data.
 892          */
 893         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 894         vstor_packet->operation = VSTOR_OPERATION_FCHBA_DATA;
 895         ret = storvsc_execute_vstor_op(device, request, true);
 896         if (ret != 0)
 897                 return ret;
 898
 899         /*
 900          * Cache the currently active port and node ww names.
 901          */
 902         cache_wwn(stor_device, vstor_packet);
 903
 904 done:
 905
 906         memset(vstor_packet, 0, sizeof(struct vstor_packet));
 907         vstor_packet->operation = VSTOR_OPERATION_END_INITIALIZATION;
 908         ret = storvsc_execute_vstor_op(device, request, true);
 909         if (ret != 0)
 910                 return ret;
 911
 912         if (process_sub_channels)
 913                 handle_multichannel_storage(device, max_chns);
 914
 915         return ret;
 916 }
 917
 918 static void storvsc_handle_error(struct vmscsi_request *vm_srb,
 919                                 struct scsi_cmnd *scmnd,
 920                                 struct Scsi_Host *host,
 921                                 u8 asc, u8 ascq)
 922 {
 923         struct storvsc_scan_work *wrk;
 924         void (*process_err_fn)(struct work_struct *work);
 925         bool do_work = false;
 926
 927         switch (SRB_STATUS(vm_srb->srb_status)) {
 928         case SRB_STATUS_ERROR:
 929                 /*
 930                  * Let upper layer deal with error when
 931                  * sense message is present.
 932                  */
 933
 934                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID)
 935                         break;
 936                 /*
 937                  * If there is an error; offline the device since all
 938                  * error recovery strategies would have already been
 939                  * deployed on the host side. However, if the command
 940                  * were a pass-through command deal with it appropriately.
 941                  */
 942                 switch (scmnd->cmnd[0]) {
 943                 case ATA_16:
 944                 case ATA_12:
 945                         set_host_byte(scmnd, DID_PASSTHROUGH);
 946                         break;
 947                 /*
 948                  * On Some Windows hosts TEST_UNIT_READY command can return
 949                  * SRB_STATUS_ERROR, let the upper level code deal with it
 950                  * based on the sense information.
 951                  */
 952                 case TEST_UNIT_READY:
 953                         break;
 954                 default:
 955                         set_host_byte(scmnd, DID_TARGET_FAILURE);
 956                 }
 957                 break;
 958         case SRB_STATUS_INVALID_LUN:
 959                 do_work = true;
 960                 process_err_fn = storvsc_remove_lun;
 961                 break;
 962         case SRB_STATUS_ABORTED:
 963                 if (vm_srb->srb_status & SRB_STATUS_AUTOSENSE_VALID &&
 964                     (asc == 0x2a) && (ascq == 0x9)) {
 965                         do_work = true;
 966                         process_err_fn = storvsc_device_scan;
 967                         /*
 968                          * Retry the I/O that trigerred this.
 969                          */
 970                         set_host_byte(scmnd, DID_REQUEUE);
 971                 }
 972                 break;
 973         }
 974
 975         if (!do_work)
 976                 return;
 977
 978         /*
 979          * We need to schedule work to process this error; schedule it.
 980          */
 981         wrk = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
 982         if (!wrk) {
 983                 set_host_byte(scmnd, DID_TARGET_FAILURE);
 984                 return;
 985         }
 986
 987         wrk->host = host;
 988         wrk->lun = vm_srb->lun;
 989         wrk->tgt_id = vm_srb->target_id;
 990         INIT_WORK(&wrk->work, process_err_fn);
 991         schedule_work(&wrk->work);
 992 }
 993
 994
 995 static void storvsc_command_completion(struct storvsc_cmd_request *cmd_request,
 996                                        struct storvsc_device *stor_dev)
 997 {
 998         struct scsi_cmnd *scmnd = cmd_request->cmd;
 999         struct scsi_sense_hdr sense_hdr;
1000         struct vmscsi_request *vm_srb;
1001         u32 data_transfer_length;
1002         struct Scsi_Host *host;
1003         u32 payload_sz = cmd_request->payload_sz;
1004         void *payload = cmd_request->payload;
1005
1006         host = stor_dev->host;
1007
1008         vm_srb = &cmd_request->vstor_packet.vm_srb;
1009         data_transfer_length = vm_srb->data_transfer_length;
1010
1011         scmnd->result = vm_srb->scsi_status;
1012
1013         if (scmnd->result) {
1014                 if (scsi_normalize_sense(scmnd->sense_buffer,
1015                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr) &&
1016                     !(sense_hdr.sense_key == NOT_READY &&
1017                                  sense_hdr.asc == 0x03A) &&
1018                     do_logging(STORVSC_LOGGING_ERROR))
1019                         scsi_print_sense_hdr(scmnd->device, "storvsc",
1020                                              &sense_hdr);
1021         }
1022
1023         if (vm_srb->srb_status != SRB_STATUS_SUCCESS) {
1024                 storvsc_handle_error(vm_srb, scmnd, host, sense_hdr.asc,
1025                                          sense_hdr.ascq);
1026                 /*
1027                  * The Windows driver set data_transfer_length on
1028                  * SRB_STATUS_DATA_OVERRUN. On other errors, this value
1029                  * is untouched.  In these cases we set it to 0.
1030                  */
1031                 if (vm_srb->srb_status != SRB_STATUS_DATA_OVERRUN)
1032                         data_transfer_length = 0;
1033         }
1034
1035         scsi_set_resid(scmnd,
1036                 cmd_request->payload->range.len - data_transfer_length);
1037
1038         scmnd->scsi_done(scmnd);
1039
1040         if (payload_sz >
1041                 sizeof(struct vmbus_channel_packet_multipage_buffer))
1042                 kfree(payload);
1043 }
1044
1045 static void storvsc_on_io_completion(struct storvsc_device *stor_device,
1046                                   struct vstor_packet *vstor_packet,
1047                                   struct storvsc_cmd_request *request)
1048 {
1049         struct vstor_packet *stor_pkt;
1050         struct hv_device *device = stor_device->device;
1051
1052         stor_pkt = &request->vstor_packet;
1053
1054         /*
1055          * The current SCSI handling on the host side does
1056          * not correctly handle:
1057          * INQUIRY command with page code parameter set to 0x80
1058          * MODE_SENSE command with cmd[2] == 0x1c
1059          *
1060          * Setup srb and scsi status so this won't be fatal.
1061          * We do this so we can distinguish truly fatal failues
1062          * (srb status == 0x4) and off-line the device in that case.
1063          */
1064
1065         if ((stor_pkt->vm_srb.cdb[0] == INQUIRY) ||
1066            (stor_pkt->vm_srb.cdb[0] == MODE_SENSE)) {
1067                 vstor_packet->vm_srb.scsi_status = 0;
1068                 vstor_packet->vm_srb.srb_status = SRB_STATUS_SUCCESS;
1069         }
1070
1071
1072         /* Copy over the status...etc */
1073         stor_pkt->vm_srb.scsi_status = vstor_packet->vm_srb.scsi_status;
1074         stor_pkt->vm_srb.srb_status = vstor_packet->vm_srb.srb_status;
1075         stor_pkt->vm_srb.sense_info_length =
1076         vstor_packet->vm_srb.sense_info_length;
1077
1078         if (vstor_packet->vm_srb.scsi_status != 0 ||
1079             vstor_packet->vm_srb.srb_status != SRB_STATUS_SUCCESS)
1080                 storvsc_log(device, STORVSC_LOGGING_WARN,
1081                         "cmd 0x%x scsi status 0x%x srb status 0x%x\n",
1082                         stor_pkt->vm_srb.cdb[0],
1083                         vstor_packet->vm_srb.scsi_status,
1084                         vstor_packet->vm_srb.srb_status);
1085
1086         if ((vstor_packet->vm_srb.scsi_status & 0xFF) == 0x02) {
1087                 /* CHECK_CONDITION */
1088                 if (vstor_packet->vm_srb.srb_status &
1089                         SRB_STATUS_AUTOSENSE_VALID) {
1090                         /* autosense data available */
1091
1092                         storvsc_log(device, STORVSC_LOGGING_WARN,
1093                                 "stor pkt %p autosense data valid - len %d\n",
1094                                 request, vstor_packet->vm_srb.sense_info_length);
1095
1096                         memcpy(request->cmd->sense_buffer,
1097                                vstor_packet->vm_srb.sense_data,
1098                                vstor_packet->vm_srb.sense_info_length);
1099
1100                 }
1101         }
1102
1103         stor_pkt->vm_srb.data_transfer_length =
1104         vstor_packet->vm_srb.data_transfer_length;
1105
1106         storvsc_command_completion(request, stor_device);
1107
1108         if (atomic_dec_and_test(&stor_device->num_outstanding_req) &&
1109                 stor_device->drain_notify)
1110                 wake_up(&stor_device->waiting_to_drain);
1111
1112
1113 }
1114
1115 static void storvsc_on_receive(struct storvsc_device *stor_device,
1116                              struct vstor_packet *vstor_packet,
1117                              struct storvsc_cmd_request *request)
1118 {
1119         struct storvsc_scan_work *work;
1120
1121         switch (vstor_packet->operation) {
1122         case VSTOR_OPERATION_COMPLETE_IO:
1123                 storvsc_on_io_completion(stor_device, vstor_packet, request);
1124                 break;
1125
1126         case VSTOR_OPERATION_REMOVE_DEVICE:
1127         case VSTOR_OPERATION_ENUMERATE_BUS:
1128                 work = kmalloc(sizeof(struct storvsc_scan_work), GFP_ATOMIC);
1129                 if (!work)
1130                         return;
1131
1132                 INIT_WORK(&work->work, storvsc_host_scan);
1133                 work->host = stor_device->host;
1134                 schedule_work(&work->work);
1135                 break;
1136
1137         case VSTOR_OPERATION_FCHBA_DATA:
1138                 cache_wwn(stor_device, vstor_packet);
1139 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1140                 fc_host_node_name(stor_device->host) = stor_device->node_name;
1141                 fc_host_port_name(stor_device->host) = stor_device->port_name;
1142 #endif
1143                 break;
1144         default:
1145                 break;
1146         }
1147 }
1148
1149 static void storvsc_on_channel_callback(void *context)
1150 {
1151         struct vmbus_channel *channel = (struct vmbus_channel *)context;
1152         struct hv_device *device;
1153         struct storvsc_device *stor_device;
1154         u32 bytes_recvd;
1155         u64 request_id;
1156         unsigned char packet[ALIGN(sizeof(struct vstor_packet), 8)];
1157         struct storvsc_cmd_request *request;
1158         int ret;
1159
1160         if (channel->primary_channel != NULL)
1161                 device = channel->primary_channel->device_obj;
1162         else
1163                 device = channel->device_obj;
1164
1165         stor_device = get_in_stor_device(device);
1166         if (!stor_device)
1167                 return;
1168
1169         do {
1170                 ret = vmbus_recvpacket(channel, packet,
1171                                        ALIGN((sizeof(struct vstor_packet) -
1172                                              vmscsi_size_delta), 8),
1173                                        &bytes_recvd, &request_id);
1174                 if (ret == 0 && bytes_recvd > 0) {
1175
1176                         request = (struct storvsc_cmd_request *)
1177                                         (unsigned long)request_id;
1178
1179                         if ((request == &stor_device->init_request) ||
1180                             (request == &stor_device->reset_request)) {
1181
1182                                 memcpy(&request->vstor_packet, packet,
1183                                        (sizeof(struct vstor_packet) -
1184                                         vmscsi_size_delta));
1185                                 complete(&request->wait_event);
1186                         } else {
1187                                 storvsc_on_receive(stor_device,
1188                                                 (struct vstor_packet *)packet,
1189                                                 request);
1190                         }
1191                 } else {
1192                         break;
1193                 }
1194         } while (1);
1195 }
1196
1197 static int storvsc_connect_to_vsp(struct hv_device *device, u32 ring_size,
1198                                   bool is_fc)
1199 {
1200         struct vmstorage_channel_properties props;
1201         int ret;
1202
1203         memset(&props, 0, sizeof(struct vmstorage_channel_properties));
1204
1205         ret = vmbus_open(device->channel,
1206                          ring_size,
1207                          ring_size,
1208                          (void *)&props,
1209                          sizeof(struct vmstorage_channel_properties),
1210                          storvsc_on_channel_callback, device->channel);
1211
1212         if (ret != 0)
1213                 return ret;
1214
1215         ret = storvsc_channel_init(device, is_fc);
1216
1217         return ret;
1218 }
1219
1220 static int storvsc_dev_remove(struct hv_device *device)
1221 {
1222         struct storvsc_device *stor_device;
1223         unsigned long flags;
1224
1225         stor_device = hv_get_drvdata(device);
1226
1227         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1228         stor_device->destroy = true;
1229         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1230
1231         /*
1232          * At this point, all outbound traffic should be disable. We
1233          * only allow inbound traffic (responses) to proceed so that
1234          * outstanding requests can be completed.
1235          */
1236
1237         storvsc_wait_to_drain(stor_device);
1238
1239         /*
1240          * Since we have already drained, we don't need to busy wait
1241          * as was done in final_release_stor_device()
1242          * Note that we cannot set the ext pointer to NULL until
1243          * we have drained - to drain the outgoing packets, we need to
1244          * allow incoming packets.
1245          */
1246         spin_lock_irqsave(&device->channel->inbound_lock, flags);
1247         hv_set_drvdata(device, NULL);
1248         spin_unlock_irqrestore(&device->channel->inbound_lock, flags);
1249
1250         /* Close the channel */
1251         vmbus_close(device->channel);
1252
1253         kfree(stor_device->stor_chns);
1254         kfree(stor_device);
1255         return 0;
1256 }
1257
1258 static struct vmbus_channel *get_og_chn(struct storvsc_device *stor_device,
1259                                         u16 q_num)
1260 {
1261         u16 slot = 0;
1262         u16 hash_qnum;
1263         struct cpumask alloced_mask;
1264         int num_channels, tgt_cpu;
1265
1266         if (stor_device->num_sc == 0)
1267                 return stor_device->device->channel;
1268
1269         /*
1270          * Our channel array is sparsley populated and we
1271          * initiated I/O on a processor/hw-q that does not
1272          * currently have a designated channel. Fix this.
1273          * The strategy is simple:
1274          * I. Ensure NUMA locality
1275          * II. Distribute evenly (best effort)
1276          * III. Mapping is persistent.
1277          */
1278
1279         cpumask_and(&alloced_mask, &stor_device->alloced_cpus,
1280                     cpumask_of_node(cpu_to_node(q_num)));
1281
1282         num_channels = cpumask_weight(&alloced_mask);
1283         if (num_channels == 0)
1284                 return stor_device->device->channel;
1285
1286         hash_qnum = q_num;
1287         while (hash_qnum >= num_channels)
1288                 hash_qnum -= num_channels;
1289
1290         for_each_cpu(tgt_cpu, &alloced_mask) {
1291                 if (slot == hash_qnum)
1292                         break;
1293                 slot++;
1294         }
1295
1296         stor_device->stor_chns[q_num] = stor_device->stor_chns[tgt_cpu];
1297
1298         return stor_device->stor_chns[q_num];
1299 }
1300
1301
1302 static int storvsc_do_io(struct hv_device *device,
1303                          struct storvsc_cmd_request *request, u16 q_num)
1304 {
1305         struct storvsc_device *stor_device;
1306         struct vstor_packet *vstor_packet;
1307         struct vmbus_channel *outgoing_channel;
1308         int ret = 0;
1309         struct cpumask alloced_mask;
1310         int tgt_cpu;
1311
1312         vstor_packet = &request->vstor_packet;
1313         stor_device = get_out_stor_device(device);
1314
1315         if (!stor_device)
1316                 return -ENODEV;
1317
1318
1319         request->device  = device;
1320         /*
1321          * Select an an appropriate channel to send the request out.
1322          */
1323
1324         if (stor_device->stor_chns[q_num] != NULL) {
1325                 outgoing_channel = stor_device->stor_chns[q_num];
1326                 if (outgoing_channel->target_cpu == smp_processor_id()) {
1327                         /*
1328                          * Ideally, we want to pick a different channel if
1329                          * available on the same NUMA node.
1330                          */
1331                         cpumask_and(&alloced_mask, &stor_device->alloced_cpus,
1332                                     cpumask_of_node(cpu_to_node(q_num)));
1333                         for_each_cpu(tgt_cpu, &alloced_mask) {
1334                                 if (tgt_cpu != outgoing_channel->target_cpu) {
1335                                         outgoing_channel =
1336                                         stor_device->stor_chns[tgt_cpu];
1337                                         break;
1338                                 }
1339                         }
1340                 }
1341         } else {
1342                 outgoing_channel = get_og_chn(stor_device, q_num);
1343         }
1344
1345
1346         vstor_packet->flags |= REQUEST_COMPLETION_FLAG;
1347
1348         vstor_packet->vm_srb.length = (sizeof(struct vmscsi_request) -
1349                                         vmscsi_size_delta);
1350
1351
1352         vstor_packet->vm_srb.sense_info_length = sense_buffer_size;
1353
1354
1355         vstor_packet->vm_srb.data_transfer_length =
1356         request->payload->range.len;
1357
1358         vstor_packet->operation = VSTOR_OPERATION_EXECUTE_SRB;
1359
1360         if (request->payload->range.len) {
1361
1362                 ret = vmbus_sendpacket_mpb_desc(outgoing_channel,
1363                                 request->payload, request->payload_sz,
1364                                 vstor_packet,
1365                                 (sizeof(struct vstor_packet) -
1366                                 vmscsi_size_delta),
1367                                 (unsigned long)request);
1368         } else {
1369                 ret = vmbus_sendpacket(outgoing_channel, vstor_packet,
1370                                (sizeof(struct vstor_packet) -
1371                                 vmscsi_size_delta),
1372                                (unsigned long)request,
1373                                VM_PKT_DATA_INBAND,
1374                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1375         }
1376
1377         if (ret != 0)
1378                 return ret;
1379
1380         atomic_inc(&stor_device->num_outstanding_req);
1381
1382         return ret;
1383 }
1384
1385 static int storvsc_device_alloc(struct scsi_device *sdevice)
1386 {
1387         /*
1388          * Set blist flag to permit the reading of the VPD pages even when
1389          * the target may claim SPC-2 compliance. MSFT targets currently
1390          * claim SPC-2 compliance while they implement post SPC-2 features.
1391          * With this flag we can correctly handle WRITE_SAME_16 issues.
1392          *
1393          * Hypervisor reports SCSI_UNKNOWN type for DVD ROM device but
1394          * still supports REPORT LUN.
1395          */
1396         sdevice->sdev_bflags = BLIST_REPORTLUN2 | BLIST_TRY_VPD_PAGES;
1397
1398         return 0;
1399 }
1400
1401 static int storvsc_device_configure(struct scsi_device *sdevice)
1402 {
1403
1404         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
1405
1406         blk_queue_rq_timeout(sdevice->request_queue, (storvsc_timeout * HZ));
1407
1408         /* Ensure there are no gaps in presented sgls */
1409         blk_queue_virt_boundary(sdevice->request_queue, PAGE_SIZE - 1);
1410
1411         sdevice->no_write_same = 1;
1412
1413         /*
1414          * If the host is WIN8 or WIN8 R2, claim conformance to SPC-3
1415          * if the device is a MSFT virtual device.  If the host is
1416          * WIN10 or newer, allow write_same.
1417          */
1418         if (!strncmp(sdevice->vendor, "Msft", 4)) {
1419                 switch (vmstor_proto_version) {
1420                 case VMSTOR_PROTO_VERSION_WIN8:
1421                 case VMSTOR_PROTO_VERSION_WIN8_1:
1422                         sdevice->scsi_level = SCSI_SPC_3;
1423                         break;
1424                 }
1425
1426                 if (vmstor_proto_version >= VMSTOR_PROTO_VERSION_WIN10)
1427                         sdevice->no_write_same = 0;
1428         }
1429
1430         return 0;
1431 }
1432
1433 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1434                            sector_t capacity, int *info)
1435 {
1436         sector_t nsect = capacity;
1437         sector_t cylinders = nsect;
1438         int heads, sectors_pt;
1439
1440         /*
1441          * We are making up these values; let us keep it simple.
1442          */
1443         heads = 0xff;
1444         sectors_pt = 0x3f;      /* Sectors per track */
1445         sector_div(cylinders, heads * sectors_pt);
1446         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
1447                 cylinders = 0xffff;
1448
1449         info[0] = heads;
1450         info[1] = sectors_pt;
1451         info[2] = (int)cylinders;
1452
1453         return 0;
1454 }
1455
1456 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
1457 {
1458         struct hv_host_device *host_dev = shost_priv(scmnd->device->host);
1459         struct hv_device *device = host_dev->dev;
1460
1461         struct storvsc_device *stor_device;
1462         struct storvsc_cmd_request *request;
1463         struct vstor_packet *vstor_packet;
1464         int ret, t;
1465
1466
1467         stor_device = get_out_stor_device(device);
1468         if (!stor_device)
1469                 return FAILED;
1470
1471         request = &stor_device->reset_request;
1472         vstor_packet = &request->vstor_packet;
1473
1474         init_completion(&request->wait_event);
1475
1476         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
1477         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
1478         vstor_packet->vm_srb.path_id = stor_device->path_id;
1479
1480         ret = vmbus_sendpacket(device->channel, vstor_packet,
1481                                (sizeof(struct vstor_packet) -
1482                                 vmscsi_size_delta),
1483                                (unsigned long)&stor_device->reset_request,
1484                                VM_PKT_DATA_INBAND,
1485                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
1486         if (ret != 0)
1487                 return FAILED;
1488
1489         t = wait_for_completion_timeout(&request->wait_event, 5*HZ);
1490         if (t == 0)
1491                 return TIMEOUT_ERROR;
1492
1493
1494         /*
1495          * At this point, all outstanding requests in the adapter
1496          * should have been flushed out and return to us
1497          * There is a potential race here where the host may be in
1498          * the process of responding when we return from here.
1499          * Just wait for all in-transit packets to be accounted for
1500          * before we return from here.
1501          */
1502         storvsc_wait_to_drain(stor_device);
1503
1504         return SUCCESS;
1505 }
1506
1507 /*
1508  * The host guarantees to respond to each command, although I/O latencies might
1509  * be unbounded on Azure.  Reset the timer unconditionally to give the host a
1510  * chance to perform EH.
1511  */
1512 static enum blk_eh_timer_return storvsc_eh_timed_out(struct scsi_cmnd *scmnd)
1513 {
1514         return BLK_EH_RESET_TIMER;
1515 }
1516
1517 static bool storvsc_scsi_cmd_ok(struct scsi_cmnd *scmnd)
1518 {
1519         bool allowed = true;
1520         u8 scsi_op = scmnd->cmnd[0];
1521
1522         switch (scsi_op) {
1523         /* the host does not handle WRITE_SAME, log accident usage */
1524         case WRITE_SAME:
1525         /*
1526          * smartd sends this command and the host does not handle
1527          * this. So, don't send it.
1528          */
1529         case SET_WINDOW:
1530                 scmnd->result = ILLEGAL_REQUEST << 16;
1531                 allowed = false;
1532                 break;
1533         default:
1534                 break;
1535         }
1536         return allowed;
1537 }
1538
1539 static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
1540 {
1541         int ret;
1542         struct hv_host_device *host_dev = shost_priv(host);
1543         struct hv_device *dev = host_dev->dev;
1544         struct storvsc_cmd_request *cmd_request = scsi_cmd_priv(scmnd);
1545         int i;
1546         struct scatterlist *sgl;
1547         unsigned int sg_count = 0;
1548         struct vmscsi_request *vm_srb;
1549         struct scatterlist *cur_sgl;
1550         struct vmbus_packet_mpb_array  *payload;
1551         u32 payload_sz;
1552         u32 length;
1553
1554         if (vmstor_proto_version <= VMSTOR_PROTO_VERSION_WIN8) {
1555                 /*
1556                  * On legacy hosts filter unimplemented commands.
1557                  * Future hosts are expected to correctly handle
1558                  * unsupported commands. Furthermore, it is
1559                  * possible that some of the currently
1560                  * unsupported commands maybe supported in
1561                  * future versions of the host.
1562                  */
1563                 if (!storvsc_scsi_cmd_ok(scmnd)) {
1564                         scmnd->scsi_done(scmnd);
1565                         return 0;
1566                 }
1567         }
1568
1569         /* Setup the cmd request */
1570         cmd_request->cmd = scmnd;
1571
1572         vm_srb = &cmd_request->vstor_packet.vm_srb;
1573         vm_srb->win8_extension.time_out_value = 60;
1574
1575         vm_srb->win8_extension.srb_flags |=
1576                 SRB_FLAGS_DISABLE_SYNCH_TRANSFER;
1577
1578         if (scmnd->device->tagged_supported) {
1579                 vm_srb->win8_extension.srb_flags |=
1580                 (SRB_FLAGS_QUEUE_ACTION_ENABLE | SRB_FLAGS_NO_QUEUE_FREEZE);
1581                 vm_srb->win8_extension.queue_tag = SP_UNTAGGED;
1582                 vm_srb->win8_extension.queue_action = SRB_SIMPLE_TAG_REQUEST;
1583         }
1584
1585         /* Build the SRB */
1586         switch (scmnd->sc_data_direction) {
1587         case DMA_TO_DEVICE:
1588                 vm_srb->data_in = WRITE_TYPE;
1589                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_OUT;
1590                 break;
1591         case DMA_FROM_DEVICE:
1592                 vm_srb->data_in = READ_TYPE;
1593                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_DATA_IN;
1594                 break;
1595         case DMA_NONE:
1596                 vm_srb->data_in = UNKNOWN_TYPE;
1597                 vm_srb->win8_extension.srb_flags |= SRB_FLAGS_NO_DATA_TRANSFER;
1598                 break;
1599         default:
1600                 /*
1601                  * This is DMA_BIDIRECTIONAL or something else we are never
1602                  * supposed to see here.
1603                  */
1604                 WARN(1, "Unexpected data direction: %d\n",
1605                      scmnd->sc_data_direction);
1606                 return -EINVAL;
1607         }
1608
1609
1610         vm_srb->port_number = host_dev->port;
1611         vm_srb->path_id = scmnd->device->channel;
1612         vm_srb->target_id = scmnd->device->id;
1613         vm_srb->lun = scmnd->device->lun;
1614
1615         vm_srb->cdb_length = scmnd->cmd_len;
1616
1617         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
1618
1619         sgl = (struct scatterlist *)scsi_sglist(scmnd);
1620         sg_count = scsi_sg_count(scmnd);
1621
1622         length = scsi_bufflen(scmnd);
1623         payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
1624         payload_sz = sizeof(cmd_request->mpb);
1625
1626         if (sg_count) {
1627                 if (sg_count > MAX_PAGE_BUFFER_COUNT) {
1628
1629                         payload_sz = (sg_count * sizeof(u64) +
1630                                       sizeof(struct vmbus_packet_mpb_array));
1631                         payload = kzalloc(payload_sz, GFP_ATOMIC);
1632                         if (!payload)
1633                                 return SCSI_MLQUEUE_DEVICE_BUSY;
1634                 }
1635
1636                 payload->range.len = length;
1637                 payload->range.offset = sgl[0].offset;
1638
1639                 cur_sgl = sgl;
1640                 for (i = 0; i < sg_count; i++) {
1641                         payload->range.pfn_array[i] =
1642                                 page_to_pfn(sg_page((cur_sgl)));
1643                         cur_sgl = sg_next(cur_sgl);
1644                 }
1645         }
1646
1647         cmd_request->payload = payload;
1648         cmd_request->payload_sz = payload_sz;
1649
1650         /* Invokes the vsc to start an IO */
1651         ret = storvsc_do_io(dev, cmd_request, get_cpu());
1652         put_cpu();
1653
1654         if (ret == -EAGAIN) {
1655                 /* no more space */
1656                 return SCSI_MLQUEUE_DEVICE_BUSY;
1657         }
1658
1659         return 0;
1660 }
1661
1662 static struct scsi_host_template scsi_driver = {
1663         .module =               THIS_MODULE,
1664         .name =                 "storvsc_host_t",
1665         .cmd_size =             sizeof(struct storvsc_cmd_request),
1666         .bios_param =           storvsc_get_chs,
1667         .queuecommand =         storvsc_queuecommand,
1668         .eh_host_reset_handler =        storvsc_host_reset_handler,
1669         .proc_name =            "storvsc_host",
1670         .eh_timed_out =         storvsc_eh_timed_out,
1671         .slave_alloc =          storvsc_device_alloc,
1672         .slave_configure =      storvsc_device_configure,
1673         .cmd_per_lun =          255,
1674         .this_id =              -1,
1675         .use_clustering =       ENABLE_CLUSTERING,
1676         /* Make sure we dont get a sg segment crosses a page boundary */
1677         .dma_boundary =         PAGE_SIZE-1,
1678         .no_write_same =        1,
1679         .track_queue_depth =    1,
1680 };
1681
1682 enum {
1683         SCSI_GUID,
1684         IDE_GUID,
1685         SFC_GUID,
1686 };
1687
1688 static const struct hv_vmbus_device_id id_table[] = {
1689         /* SCSI guid */
1690         { HV_SCSI_GUID,
1691           .driver_data = SCSI_GUID
1692         },
1693         /* IDE guid */
1694         { HV_IDE_GUID,
1695           .driver_data = IDE_GUID
1696         },
1697         /* Fibre Channel GUID */
1698         {
1699           HV_SYNTHFC_GUID,
1700           .driver_data = SFC_GUID
1701         },
1702         { },
1703 };
1704
1705 MODULE_DEVICE_TABLE(vmbus, id_table);
1706
1707 static int storvsc_probe(struct hv_device *device,
1708                         const struct hv_vmbus_device_id *dev_id)
1709 {
1710         int ret;
1711         int num_cpus = num_online_cpus();
1712         struct Scsi_Host *host;
1713         struct hv_host_device *host_dev;
1714         bool dev_is_ide = ((dev_id->driver_data == IDE_GUID) ? true : false);
1715         bool is_fc = ((dev_id->driver_data == SFC_GUID) ? true : false);
1716         int target = 0;
1717         struct storvsc_device *stor_device;
1718         int max_luns_per_target;
1719         int max_targets;
1720         int max_channels;
1721         int max_sub_channels = 0;
1722
1723         /*
1724          * Based on the windows host we are running on,
1725          * set state to properly communicate with the host.
1726          */
1727
1728         if (vmbus_proto_version < VERSION_WIN8) {
1729                 max_luns_per_target = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1730                 max_targets = STORVSC_IDE_MAX_TARGETS;
1731                 max_channels = STORVSC_IDE_MAX_CHANNELS;
1732         } else {
1733                 max_luns_per_target = STORVSC_MAX_LUNS_PER_TARGET;
1734                 max_targets = STORVSC_MAX_TARGETS;
1735                 max_channels = STORVSC_MAX_CHANNELS;
1736                 /*
1737                  * On Windows8 and above, we support sub-channels for storage.
1738                  * The number of sub-channels offerred is based on the number of
1739                  * VCPUs in the guest.
1740                  */
1741                 max_sub_channels = (num_cpus / storvsc_vcpus_per_sub_channel);
1742         }
1743
1744         scsi_driver.can_queue = (max_outstanding_req_per_channel *
1745                                  (max_sub_channels + 1));
1746
1747         host = scsi_host_alloc(&scsi_driver,
1748                                sizeof(struct hv_host_device));
1749         if (!host)
1750                 return -ENOMEM;
1751
1752         host_dev = shost_priv(host);
1753         memset(host_dev, 0, sizeof(struct hv_host_device));
1754
1755         host_dev->port = host->host_no;
1756         host_dev->dev = device;
1757
1758
1759         stor_device = kzalloc(sizeof(struct storvsc_device), GFP_KERNEL);
1760         if (!stor_device) {
1761                 ret = -ENOMEM;
1762                 goto err_out0;
1763         }
1764
1765         stor_device->destroy = false;
1766         stor_device->open_sub_channel = false;
1767         init_waitqueue_head(&stor_device->waiting_to_drain);
1768         stor_device->device = device;
1769         stor_device->host = host;
1770         hv_set_drvdata(device, stor_device);
1771
1772         stor_device->port_number = host->host_no;
1773         ret = storvsc_connect_to_vsp(device, storvsc_ringbuffer_size, is_fc);
1774         if (ret)
1775                 goto err_out1;
1776
1777         host_dev->path = stor_device->path_id;
1778         host_dev->target = stor_device->target_id;
1779
1780         switch (dev_id->driver_data) {
1781         case SFC_GUID:
1782                 host->max_lun = STORVSC_FC_MAX_LUNS_PER_TARGET;
1783                 host->max_id = STORVSC_FC_MAX_TARGETS;
1784                 host->max_channel = STORVSC_FC_MAX_CHANNELS - 1;
1785 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1786                 host->transportt = fc_transport_template;
1787 #endif
1788                 break;
1789
1790         case SCSI_GUID:
1791                 host->max_lun = max_luns_per_target;
1792                 host->max_id = max_targets;
1793                 host->max_channel = max_channels - 1;
1794                 break;
1795
1796         default:
1797                 host->max_lun = STORVSC_IDE_MAX_LUNS_PER_TARGET;
1798                 host->max_id = STORVSC_IDE_MAX_TARGETS;
1799                 host->max_channel = STORVSC_IDE_MAX_CHANNELS - 1;
1800                 break;
1801         }
1802         /* max cmd length */
1803         host->max_cmd_len = STORVSC_MAX_CMD_LEN;
1804
1805         /*
1806          * set the table size based on the info we got
1807          * from the host.
1808          */
1809         host->sg_tablesize = (stor_device->max_transfer_bytes >> PAGE_SHIFT);
1810         /*
1811          * Set the number of HW queues we are supporting.
1812          */
1813         if (stor_device->num_sc != 0)
1814                 host->nr_hw_queues = stor_device->num_sc + 1;
1815
1816         /* Register the HBA and start the scsi bus scan */
1817         ret = scsi_add_host(host, &device->device);
1818         if (ret != 0)
1819                 goto err_out2;
1820
1821         if (!dev_is_ide) {
1822                 scsi_scan_host(host);
1823         } else {
1824                 target = (device->dev_instance.b[5] << 8 |
1825                          device->dev_instance.b[4]);
1826                 ret = scsi_add_device(host, 0, target, 0);
1827                 if (ret)
1828                         goto err_out3;
1829         }
1830 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1831         if (host->transportt == fc_transport_template) {
1832                 struct fc_rport_identifiers ids = {
1833                         .roles = FC_PORT_ROLE_FCP_DUMMY_INITIATOR,
1834                 };
1835
1836                 fc_host_node_name(host) = stor_device->node_name;
1837                 fc_host_port_name(host) = stor_device->port_name;
1838                 stor_device->rport = fc_remote_port_add(host, 0, &ids);
1839                 if (!stor_device->rport)
1840                         goto err_out3;
1841         }
1842 #endif
1843         return 0;
1844
1845 err_out3:
1846         scsi_remove_host(host);
1847
1848 err_out2:
1849         /*
1850          * Once we have connected with the host, we would need to
1851          * to invoke storvsc_dev_remove() to rollback this state and
1852          * this call also frees up the stor_device; hence the jump around
1853          * err_out1 label.
1854          */
1855         storvsc_dev_remove(device);
1856         goto err_out0;
1857
1858 err_out1:
1859         kfree(stor_device->stor_chns);
1860         kfree(stor_device);
1861
1862 err_out0:
1863         scsi_host_put(host);
1864         return ret;
1865 }
1866
1867 static int storvsc_remove(struct hv_device *dev)
1868 {
1869         struct storvsc_device *stor_device = hv_get_drvdata(dev);
1870         struct Scsi_Host *host = stor_device->host;
1871
1872 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1873         if (host->transportt == fc_transport_template) {
1874                 fc_remote_port_delete(stor_device->rport);
1875                 fc_remove_host(host);
1876         }
1877 #endif
1878         scsi_remove_host(host);
1879         storvsc_dev_remove(dev);
1880         scsi_host_put(host);
1881
1882         return 0;
1883 }
1884
1885 static struct hv_driver storvsc_drv = {
1886         .name = KBUILD_MODNAME,
1887         .id_table = id_table,
1888         .probe = storvsc_probe,
1889         .remove = storvsc_remove,
1890 };
1891
1892 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1893 static struct fc_function_template fc_transport_functions = {
1894         .show_host_node_name = 1,
1895         .show_host_port_name = 1,
1896 };
1897 #endif
1898
1899 static int __init storvsc_drv_init(void)
1900 {
1901         int ret;
1902
1903         /*
1904          * Divide the ring buffer data size (which is 1 page less
1905          * than the ring buffer size since that page is reserved for
1906          * the ring buffer indices) by the max request size (which is
1907          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
1908          */
1909         max_outstanding_req_per_channel =
1910                 ((storvsc_ringbuffer_size - PAGE_SIZE) /
1911                 ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
1912                 sizeof(struct vstor_packet) + sizeof(u64) -
1913                 vmscsi_size_delta,
1914                 sizeof(u64)));
1915
1916 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1917         fc_transport_template = fc_attach_transport(&fc_transport_functions);
1918         if (!fc_transport_template)
1919                 return -ENODEV;
1920 #endif
1921
1922         ret = vmbus_driver_register(&storvsc_drv);
1923
1924 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1925         if (ret)
1926                 fc_release_transport(fc_transport_template);
1927 #endif
1928
1929         return ret;
1930 }
1931
1932 static void __exit storvsc_drv_exit(void)
1933 {
1934         vmbus_driver_unregister(&storvsc_drv);
1935 #if IS_ENABLED(CONFIG_SCSI_FC_ATTRS)
1936         fc_release_transport(fc_transport_template);
1937 #endif
1938 }
1939
1940 MODULE_LICENSE("GPL");
1941 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
1942 module_init(storvsc_drv_init);
1943 module_exit(storvsc_drv_exit);