Pileus Git - ~andy/linux/blob - drivers/staging/hv/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 #include <linux/init.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/device.h>
  26 #include <linux/blkdev.h>
  27 #include <scsi/scsi.h>
  28 #include <scsi/scsi_cmnd.h>
  29 #include <scsi/scsi_host.h>
  30 #include <scsi/scsi_device.h>
  31 #include <scsi/scsi_tcq.h>
  32 #include <scsi/scsi_eh.h>
  33 #include <scsi/scsi_devinfo.h>
  34 #include <scsi/scsi_dbg.h>
  35
  36 #include "hyperv.h"
  37 #include "hv_api.h"
  38 #include "logging.h"
  39 #include "vmbus.h"
  40 #include "storvsc_api.h"
  41 #include "vstorage.h"
  42
  43 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
  44
  45 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
  46 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
  47
  48 static const char *driver_name = "storvsc";
  49
  50 /* {ba6163d9-04a1-4d29-b605-72e2ffb1dc7f} */
  51 static const struct hv_guid gStorVscDeviceType = {
  52         .data = {
  53                 0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
  54                 0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f
  55         }
  56 };
  57
  58 struct hv_host_device {
  59         struct hv_device *dev;
  60         struct kmem_cache *request_pool;
  61         unsigned int port;
  62         unsigned char path;
  63         unsigned char target;
  64 };
  65
  66 struct storvsc_cmd_request {
  67         struct list_head entry;
  68         struct scsi_cmnd *cmd;
  69
  70         unsigned int bounce_sgl_count;
  71         struct scatterlist *bounce_sgl;
  72
  73         struct hv_storvsc_request request;
  74 };
  75
  76
  77 static int storvsc_device_alloc(struct scsi_device *sdevice)
  78 {
  79         /*
  80          * This enables luns to be located sparsely. Otherwise, we may not
  81          * discovered them.
  82          */
  83         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
  84         return 0;
  85 }
  86
  87 static int storvsc_merge_bvec(struct request_queue *q,
  88                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
  89 {
  90         /* checking done by caller. */
  91         return bvec->bv_len;
  92 }
  93
  94 static int storvsc_device_configure(struct scsi_device *sdevice)
  95 {
  96         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
  97                                 STORVSC_MAX_IO_REQUESTS);
  98
  99         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 100                     sdevice, PAGE_SIZE);
 101         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 102
 103         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 104                     sdevice);
 105         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 106
 107         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 108
 109         return 0;
 110 }
 111
 112 static void destroy_bounce_buffer(struct scatterlist *sgl,
 113                                   unsigned int sg_count)
 114 {
 115         int i;
 116         struct page *page_buf;
 117
 118         for (i = 0; i < sg_count; i++) {
 119                 page_buf = sg_page((&sgl[i]));
 120                 if (page_buf != NULL)
 121                         __free_page(page_buf);
 122         }
 123
 124         kfree(sgl);
 125 }
 126
 127 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 128 {
 129         int i;
 130
 131         /* No need to check */
 132         if (sg_count < 2)
 133                 return -1;
 134
 135         /* We have at least 2 sg entries */
 136         for (i = 0; i < sg_count; i++) {
 137                 if (i == 0) {
 138                         /* make sure 1st one does not have hole */
 139                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 140                                 return i;
 141                 } else if (i == sg_count - 1) {
 142                         /* make sure last one does not have hole */
 143                         if (sgl[i].offset != 0)
 144                                 return i;
 145                 } else {
 146                         /* make sure no hole in the middle */
 147                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 148                                 return i;
 149                 }
 150         }
 151         return -1;
 152 }
 153
 154 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 155                                                 unsigned int sg_count,
 156                                                 unsigned int len)
 157 {
 158         int i;
 159         int num_pages;
 160         struct scatterlist *bounce_sgl;
 161         struct page *page_buf;
 162
 163         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 164
 165         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 166         if (!bounce_sgl)
 167                 return NULL;
 168
 169         for (i = 0; i < num_pages; i++) {
 170                 page_buf = alloc_page(GFP_ATOMIC);
 171                 if (!page_buf)
 172                         goto cleanup;
 173                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 174         }
 175
 176         return bounce_sgl;
 177
 178 cleanup:
 179         destroy_bounce_buffer(bounce_sgl, num_pages);
 180         return NULL;
 181 }
 182
 183
 184 /* Assume the original sgl has enough room */
 185 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 186                                             struct scatterlist *bounce_sgl,
 187                                             unsigned int orig_sgl_count)
 188 {
 189         int i;
 190         int j = 0;
 191         unsigned long src, dest;
 192         unsigned int srclen, destlen, copylen;
 193         unsigned int total_copied = 0;
 194         unsigned long bounce_addr = 0;
 195         unsigned long dest_addr = 0;
 196         unsigned long flags;
 197
 198         local_irq_save(flags);
 199
 200         for (i = 0; i < orig_sgl_count; i++) {
 201                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 202                                         KM_IRQ0) + orig_sgl[i].offset;
 203                 dest = dest_addr;
 204                 destlen = orig_sgl[i].length;
 205
 206                 if (bounce_addr == 0)
 207                         bounce_addr =
 208                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 209                                                         KM_IRQ0);
 210
 211                 while (destlen) {
 212                         src = bounce_addr + bounce_sgl[j].offset;
 213                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 214
 215                         copylen = min(srclen, destlen);
 216                         memcpy((void *)dest, (void *)src, copylen);
 217
 218                         total_copied += copylen;
 219                         bounce_sgl[j].offset += copylen;
 220                         destlen -= copylen;
 221                         dest += copylen;
 222
 223                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 224                                 /* full */
 225                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 226                                 j++;
 227
 228                                 /* if we need to use another bounce buffer */
 229                                 if (destlen || i != orig_sgl_count - 1)
 230                                         bounce_addr =
 231                                         (unsigned long)kmap_atomic(
 232                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 233                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 234                                 /* unmap the last bounce that is < PAGE_SIZE */
 235                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 236                         }
 237                 }
 238
 239                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 240                               KM_IRQ0);
 241         }
 242
 243         local_irq_restore(flags);
 244
 245         return total_copied;
 246 }
 247
 248
 249 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 250 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 251                                           struct scatterlist *bounce_sgl,
 252                                           unsigned int orig_sgl_count)
 253 {
 254         int i;
 255         int j = 0;
 256         unsigned long src, dest;
 257         unsigned int srclen, destlen, copylen;
 258         unsigned int total_copied = 0;
 259         unsigned long bounce_addr = 0;
 260         unsigned long src_addr = 0;
 261         unsigned long flags;
 262
 263         local_irq_save(flags);
 264
 265         for (i = 0; i < orig_sgl_count; i++) {
 266                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 267                                 KM_IRQ0) + orig_sgl[i].offset;
 268                 src = src_addr;
 269                 srclen = orig_sgl[i].length;
 270
 271                 if (bounce_addr == 0)
 272                         bounce_addr =
 273                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 274                                                 KM_IRQ0);
 275
 276                 while (srclen) {
 277                         /* assume bounce offset always == 0 */
 278                         dest = bounce_addr + bounce_sgl[j].length;
 279                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 280
 281                         copylen = min(srclen, destlen);
 282                         memcpy((void *)dest, (void *)src, copylen);
 283
 284                         total_copied += copylen;
 285                         bounce_sgl[j].length += copylen;
 286                         srclen -= copylen;
 287                         src += copylen;
 288
 289                         if (bounce_sgl[j].length == PAGE_SIZE) {
 290                                 /* full..move to next entry */
 291                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 292                                 j++;
 293
 294                                 /* if we need to use another bounce buffer */
 295                                 if (srclen || i != orig_sgl_count - 1)
 296                                         bounce_addr =
 297                                         (unsigned long)kmap_atomic(
 298                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 299
 300                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 301                                 /* unmap the last bounce that is < PAGE_SIZE */
 302                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 303                         }
 304                 }
 305
 306                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 307         }
 308
 309         local_irq_restore(flags);
 310
 311         return total_copied;
 312 }
 313
 314
 315 /*
 316  * storvsc_remove - Callback when our device is removed
 317  */
 318 static int storvsc_remove(struct hv_device *dev)
 319 {
 320         struct Scsi_Host *host = dev_get_drvdata(&dev->device);
 321         struct hv_host_device *host_dev =
 322                         (struct hv_host_device *)host->hostdata;
 323
 324         /*
 325          * Call to the vsc driver to let it know that the device is being
 326          * removed
 327          */
 328         storvsc_dev_remove(dev);
 329
 330         if (host_dev->request_pool) {
 331                 kmem_cache_destroy(host_dev->request_pool);
 332                 host_dev->request_pool = NULL;
 333         }
 334
 335         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 336         scsi_remove_host(host);
 337
 338         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 339         scsi_host_put(host);
 340         return 0;
 341 }
 342
 343
 344 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 345                            sector_t capacity, int *info)
 346 {
 347         sector_t nsect = capacity;
 348         sector_t cylinders = nsect;
 349         int heads, sectors_pt;
 350
 351         /*
 352          * We are making up these values; let us keep it simple.
 353          */
 354         heads = 0xff;
 355         sectors_pt = 0x3f;      /* Sectors per track */
 356         sector_div(cylinders, heads * sectors_pt);
 357         if ((sector_t)(cylinders + 1) * heads * sectors_pt < nsect)
 358                 cylinders = 0xffff;
 359
 360         info[0] = heads;
 361         info[1] = sectors_pt;
 362         info[2] = (int)cylinders;
 363
 364         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", (int)cylinders, heads,
 365                         sectors_pt);
 366
 367         return 0;
 368 }
 369
 370 static int storvsc_host_reset(struct hv_device *device)
 371 {
 372         struct storvsc_device *stor_device;
 373         struct hv_storvsc_request *request;
 374         struct vstor_packet *vstor_packet;
 375         int ret, t;
 376
 377         DPRINT_INFO(STORVSC, "resetting host adapter...");
 378
 379         stor_device = get_stor_device(device);
 380         if (!stor_device)
 381                 return -1;
 382
 383         request = &stor_device->reset_request;
 384         vstor_packet = &request->vstor_packet;
 385
 386         init_completion(&request->wait_event);
 387
 388         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
 389         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 390         vstor_packet->vm_srb.path_id = stor_device->path_id;
 391
 392         ret = vmbus_sendpacket(device->channel, vstor_packet,
 393                                sizeof(struct vstor_packet),
 394                                (unsigned long)&stor_device->reset_request,
 395                                VM_PKT_DATA_INBAND,
 396                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 397         if (ret != 0)
 398                 goto cleanup;
 399
 400         t = wait_for_completion_timeout(&request->wait_event, HZ);
 401         if (t == 0) {
 402                 ret = -ETIMEDOUT;
 403                 goto cleanup;
 404         }
 405
 406         DPRINT_INFO(STORVSC, "host adapter reset completed");
 407
 408         /*
 409          * At this point, all outstanding requests in the adapter
 410          * should have been flushed out and return to us
 411          */
 412
 413 cleanup:
 414         put_stor_device(device);
 415         return ret;
 416 }
 417
 418
 419 /*
 420  * storvsc_host_reset_handler - Reset the scsi HBA
 421  */
 422 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 423 {
 424         int ret;
 425         struct hv_host_device *host_dev =
 426                 (struct hv_host_device *)scmnd->device->host->hostdata;
 427         struct hv_device *dev = host_dev->dev;
 428
 429         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 430                     scmnd->device, dev);
 431
 432         /* Invokes the vsc to reset the host/bus */
 433         ret = storvsc_host_reset(dev);
 434         if (ret != 0)
 435                 return ret;
 436
 437         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 438                     scmnd->device, dev);
 439
 440         return ret;
 441 }
 442
 443
 444 /*
 445  * storvsc_commmand_completion - Command completion processing
 446  */
 447 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 448 {
 449         struct storvsc_cmd_request *cmd_request =
 450                 (struct storvsc_cmd_request *)request->context;
 451         struct scsi_cmnd *scmnd = cmd_request->cmd;
 452         struct hv_host_device *host_dev =
 453                 (struct hv_host_device *)scmnd->device->host->hostdata;
 454         void (*scsi_done_fn)(struct scsi_cmnd *);
 455         struct scsi_sense_hdr sense_hdr;
 456         struct vmscsi_request *vm_srb;
 457
 458         if (cmd_request->bounce_sgl_count) {
 459
 460                 /* FIXME: We can optimize on writes by just skipping this */
 461                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 462                                         cmd_request->bounce_sgl,
 463                                         scsi_sg_count(scmnd));
 464                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 465                                       cmd_request->bounce_sgl_count);
 466         }
 467
 468         vm_srb = &request->vstor_packet.vm_srb;
 469         scmnd->result = vm_srb->scsi_status;
 470
 471         if (scmnd->result) {
 472                 if (scsi_normalize_sense(scmnd->sense_buffer,
 473                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 474                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 475         }
 476
 477         scsi_set_resid(scmnd,
 478                 request->data_buffer.len -
 479                 vm_srb->data_transfer_length);
 480
 481         scsi_done_fn = scmnd->scsi_done;
 482
 483         scmnd->host_scribble = NULL;
 484         scmnd->scsi_done = NULL;
 485
 486         /* !!DO NOT MODIFY the scmnd after this call */
 487         scsi_done_fn(scmnd);
 488
 489         kmem_cache_free(host_dev->request_pool, cmd_request);
 490 }
 491
 492
 493 /*
 494  * storvsc_queuecommand - Initiate command processing
 495  */
 496 static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 497                                 void (*done)(struct scsi_cmnd *))
 498 {
 499         int ret;
 500         struct hv_host_device *host_dev =
 501                 (struct hv_host_device *)scmnd->device->host->hostdata;
 502         struct hv_device *dev = host_dev->dev;
 503         struct hv_storvsc_request *request;
 504         struct storvsc_cmd_request *cmd_request;
 505         unsigned int request_size = 0;
 506         int i;
 507         struct scatterlist *sgl;
 508         unsigned int sg_count = 0;
 509         struct vmscsi_request *vm_srb;
 510
 511
 512         /* If retrying, no need to prep the cmd */
 513         if (scmnd->host_scribble) {
 514
 515                 cmd_request =
 516                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 517                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 518                             scmnd, cmd_request);
 519
 520                 goto retry_request;
 521         }
 522
 523         scmnd->scsi_done = done;
 524
 525         request_size = sizeof(struct storvsc_cmd_request);
 526
 527         cmd_request = kmem_cache_zalloc(host_dev->request_pool,
 528                                        GFP_ATOMIC);
 529         if (!cmd_request) {
 530                 scmnd->scsi_done = NULL;
 531                 return SCSI_MLQUEUE_DEVICE_BUSY;
 532         }
 533
 534         /* Setup the cmd request */
 535         cmd_request->bounce_sgl_count = 0;
 536         cmd_request->bounce_sgl = NULL;
 537         cmd_request->cmd = scmnd;
 538
 539         scmnd->host_scribble = (unsigned char *)cmd_request;
 540
 541         request = &cmd_request->request;
 542         vm_srb = &request->vstor_packet.vm_srb;
 543
 544
 545         /* Build the SRB */
 546         switch (scmnd->sc_data_direction) {
 547         case DMA_TO_DEVICE:
 548                 vm_srb->data_in = WRITE_TYPE;
 549                 break;
 550         case DMA_FROM_DEVICE:
 551                 vm_srb->data_in = READ_TYPE;
 552                 break;
 553         default:
 554                 vm_srb->data_in = UNKNOWN_TYPE;
 555                 break;
 556         }
 557
 558         request->on_io_completion = storvsc_commmand_completion;
 559         request->context = cmd_request;/* scmnd; */
 560
 561         vm_srb->port_number = host_dev->port;
 562         vm_srb->path_id = scmnd->device->channel;
 563         vm_srb->target_id = scmnd->device->id;
 564         vm_srb->lun = scmnd->device->lun;
 565
 566         vm_srb->cdb_length = scmnd->cmd_len;
 567
 568         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
 569
 570         request->sense_buffer = scmnd->sense_buffer;
 571
 572
 573         request->data_buffer.len = scsi_bufflen(scmnd);
 574         if (scsi_sg_count(scmnd)) {
 575                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 576                 sg_count = scsi_sg_count(scmnd);
 577
 578                 /* check if we need to bounce the sgl */
 579                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 580                         cmd_request->bounce_sgl =
 581                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 582                                                      scsi_bufflen(scmnd));
 583                         if (!cmd_request->bounce_sgl) {
 584                                 scmnd->scsi_done = NULL;
 585                                 scmnd->host_scribble = NULL;
 586                                 kmem_cache_free(host_dev->request_pool,
 587                                                 cmd_request);
 588
 589                                 return SCSI_MLQUEUE_HOST_BUSY;
 590                         }
 591
 592                         cmd_request->bounce_sgl_count =
 593                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
 594                                         PAGE_SHIFT;
 595
 596                         /*
 597                          * FIXME: We can optimize on reads by just skipping
 598                          * this
 599                          */
 600                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 601                                               scsi_sg_count(scmnd));
 602
 603                         sgl = cmd_request->bounce_sgl;
 604                         sg_count = cmd_request->bounce_sgl_count;
 605                 }
 606
 607                 request->data_buffer.offset = sgl[0].offset;
 608
 609                 for (i = 0; i < sg_count; i++)
 610                         request->data_buffer.pfn_array[i] =
 611                                 page_to_pfn(sg_page((&sgl[i])));
 612
 613         } else if (scsi_sglist(scmnd)) {
 614                 request->data_buffer.offset =
 615                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 616                 request->data_buffer.pfn_array[0] =
 617                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 618         }
 619
 620 retry_request:
 621         /* Invokes the vsc to start an IO */
 622         ret = storvsc_do_io(dev, &cmd_request->request);
 623
 624         if (ret == -1) {
 625                 /* no more space */
 626
 627                 if (cmd_request->bounce_sgl_count) {
 628                         /*
 629                          * FIXME: We can optimize on writes by just skipping
 630                          * this
 631                          */
 632                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 633                                                 cmd_request->bounce_sgl,
 634                                                 scsi_sg_count(scmnd));
 635                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 636                                               cmd_request->bounce_sgl_count);
 637                 }
 638
 639                 kmem_cache_free(host_dev->request_pool, cmd_request);
 640
 641                 scmnd->scsi_done = NULL;
 642                 scmnd->host_scribble = NULL;
 643
 644                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 645         }
 646
 647         return ret;
 648 }
 649
 650 static DEF_SCSI_QCMD(storvsc_queuecommand)
 651
 652
 653 /* Scsi driver */
 654 static struct scsi_host_template scsi_driver = {
 655         .module =               THIS_MODULE,
 656         .name =                 "storvsc_host_t",
 657         .bios_param =           storvsc_get_chs,
 658         .queuecommand =         storvsc_queuecommand,
 659         .eh_host_reset_handler =        storvsc_host_reset_handler,
 660         .slave_alloc =          storvsc_device_alloc,
 661         .slave_configure =      storvsc_device_configure,
 662         .cmd_per_lun =          1,
 663         /* 64 max_queue * 1 target */
 664         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 665         .this_id =              -1,
 666         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 667         /* currently 32 */
 668         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 669         /*
 670          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 671          * into 1 sg element. If set, we must limit the max_segment_size to
 672          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 673          * multiple
 674          */
 675         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 676         .use_clustering =       ENABLE_CLUSTERING,
 677         /* Make sure we dont get a sg segment crosses a page boundary */
 678         .dma_boundary =         PAGE_SIZE-1,
 679 };
 680
 681
 682 /*
 683  * storvsc_probe - Add a new device for this driver
 684  */
 685
 686 static int storvsc_probe(struct hv_device *device)
 687 {
 688         int ret;
 689         struct Scsi_Host *host;
 690         struct hv_host_device *host_dev;
 691         struct storvsc_device_info device_info;
 692
 693         host = scsi_host_alloc(&scsi_driver,
 694                                sizeof(struct hv_host_device));
 695         if (!host)
 696                 return -ENOMEM;
 697
 698         dev_set_drvdata(&device->device, host);
 699
 700         host_dev = (struct hv_host_device *)host->hostdata;
 701         memset(host_dev, 0, sizeof(struct hv_host_device));
 702
 703         host_dev->port = host->host_no;
 704         host_dev->dev = device;
 705
 706         host_dev->request_pool =
 707                                 kmem_cache_create(dev_name(&device->device),
 708                                         sizeof(struct storvsc_cmd_request), 0,
 709                                         SLAB_HWCACHE_ALIGN, NULL);
 710
 711         if (!host_dev->request_pool) {
 712                 scsi_host_put(host);
 713                 return -ENOMEM;
 714         }
 715
 716         device_info.port_number = host->host_no;
 717         device_info.ring_buffer_size  = storvsc_ringbuffer_size;
 718         /* Call to the vsc driver to add the device */
 719         ret = storvsc_dev_add(device, (void *)&device_info);
 720
 721         if (ret != 0) {
 722                 kmem_cache_destroy(host_dev->request_pool);
 723                 scsi_host_put(host);
 724                 return -1;
 725         }
 726
 727         host_dev->path = device_info.path_id;
 728         host_dev->target = device_info.target_id;
 729
 730         /* max # of devices per target */
 731         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 732         /* max # of targets per channel */
 733         host->max_id = STORVSC_MAX_TARGETS;
 734         /* max # of channels */
 735         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 736
 737         /* Register the HBA and start the scsi bus scan */
 738         ret = scsi_add_host(host, &device->device);
 739         if (ret != 0) {
 740
 741                 storvsc_dev_remove(device);
 742
 743                 kmem_cache_destroy(host_dev->request_pool);
 744                 scsi_host_put(host);
 745                 return -1;
 746         }
 747
 748         scsi_scan_host(host);
 749         return ret;
 750 }
 751
 752 /* The one and only one */
 753
 754 static struct hv_driver storvsc_drv = {
 755         .probe = storvsc_probe,
 756         .remove = storvsc_remove,
 757 };
 758
 759
 760 /*
 761  * storvsc_drv_init - StorVsc driver initialization.
 762  */
 763 static int storvsc_drv_init(void)
 764 {
 765         int ret;
 766         struct hv_driver *drv = &storvsc_drv;
 767         u32 max_outstanding_req_per_channel;
 768
 769         /*
 770          * Divide the ring buffer data size (which is 1 page less
 771          * than the ring buffer size since that page is reserved for
 772          * the ring buffer indices) by the max request size (which is
 773          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
 774          */
 775
 776         max_outstanding_req_per_channel =
 777         ((storvsc_ringbuffer_size - PAGE_SIZE) /
 778         ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
 779         sizeof(struct vstor_packet) + sizeof(u64),
 780         sizeof(u64)));
 781
 782         memcpy(&drv->dev_type, &gStorVscDeviceType,
 783                sizeof(struct hv_guid));
 784
 785         if (max_outstanding_req_per_channel <
 786             STORVSC_MAX_IO_REQUESTS)
 787                 return -1;
 788
 789         drv->name = driver_name;
 790         drv->driver.name = driver_name;
 791
 792
 793         /* The driver belongs to vmbus */
 794         ret = vmbus_child_driver_register(&drv->driver);
 795
 796         return ret;
 797 }
 798
 799 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 800 {
 801         struct device **curr = (struct device **)data;
 802         *curr = dev;
 803         return 1; /* stop iterating */
 804 }
 805
 806 static void storvsc_drv_exit(void)
 807 {
 808         struct hv_driver *drv = &storvsc_drv;
 809         struct device *current_dev = NULL;
 810         int ret;
 811
 812         while (1) {
 813                 current_dev = NULL;
 814
 815                 /* Get the device */
 816                 ret = driver_for_each_device(&drv->driver, NULL,
 817                                              (void *) &current_dev,
 818                                              storvsc_drv_exit_cb);
 819
 820
 821                 if (current_dev == NULL)
 822                         break;
 823
 824                 /* Initiate removal from the top-down */
 825                 device_unregister(current_dev);
 826         }
 827
 828         vmbus_child_driver_unregister(&drv->driver);
 829         return;
 830 }
 831
 832 static int __init storvsc_init(void)
 833 {
 834         int ret;
 835
 836         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 837         ret = storvsc_drv_init();
 838         return ret;
 839 }
 840
 841 static void __exit storvsc_exit(void)
 842 {
 843         storvsc_drv_exit();
 844 }
 845
 846 MODULE_LICENSE("GPL");
 847 MODULE_VERSION(HV_DRV_VERSION);
 848 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
 849 module_init(storvsc_init);
 850 module_exit(storvsc_exit);