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 #include "hv_api.h"
  36 #include "logging.h"
  37 #include "version_info.h"
  38 #include "vmbus.h"
  39 #include "storvsc_api.h"
  40 #include "vstorage.h"
  41 #include "channel.h"
  42
  43
  44 static const char *driver_name = "storvsc";
  45
  46 /* {ba6163d9-04a1-4d29-b605-72e2ffb1dc7f} */
  47 static const struct hv_guid gStorVscDeviceType = {
  48         .data = {
  49                 0xd9, 0x63, 0x61, 0xba, 0xa1, 0x04, 0x29, 0x4d,
  50                 0xb6, 0x05, 0x72, 0xe2, 0xff, 0xb1, 0xdc, 0x7f
  51         }
  52 };
  53
  54 struct hv_host_device {
  55         struct hv_device *dev;
  56         struct kmem_cache *request_pool;
  57         unsigned int port;
  58         unsigned char path;
  59         unsigned char target;
  60 };
  61
  62 struct storvsc_cmd_request {
  63         struct list_head entry;
  64         struct scsi_cmnd *cmd;
  65
  66         unsigned int bounce_sgl_count;
  67         struct scatterlist *bounce_sgl;
  68
  69         struct hv_storvsc_request request;
  70 };
  71
  72
  73 /*
  74  * stor_vsc_initialize - Main entry point
  75  */
  76 static int stor_vsc_initialize(struct hv_driver *driver)
  77 {
  78         struct storvsc_driver *stor_driver;
  79
  80         stor_driver = hvdr_to_stordr(driver);
  81
  82
  83         /* Make sure we are at least 2 pages since 1 page is used for control */
  84
  85         driver->name = driver_name;
  86         memcpy(&driver->dev_type, &gStorVscDeviceType,
  87                sizeof(struct hv_guid));
  88
  89
  90         /*
  91          * Divide the ring buffer data size (which is 1 page less
  92          * than the ring buffer size since that page is reserved for
  93          * the ring buffer indices) by the max request size (which is
  94          * vmbus_channel_packet_multipage_buffer + struct vstor_packet + u64)
  95          */
  96         stor_driver->max_outstanding_req_per_channel =
  97                 ((stor_driver->ring_buffer_size - PAGE_SIZE) /
  98                   ALIGN(MAX_MULTIPAGE_BUFFER_PACKET +
  99                            sizeof(struct vstor_packet) + sizeof(u64),
 100                            sizeof(u64)));
 101
 102         DPRINT_INFO(STORVSC, "max io %u, currently %u\n",
 103                     stor_driver->max_outstanding_req_per_channel,
 104                     STORVSC_MAX_IO_REQUESTS);
 105
 106         /* Setup the dispatch table */
 107         stor_driver->base.dev_add       = storvsc_dev_add;
 108         stor_driver->base.dev_rm        = storvsc_dev_remove;
 109
 110         stor_driver->on_io_request      = storvsc_do_io;
 111
 112         return 0;
 113 }
 114
 115 static int storvsc_device_alloc(struct scsi_device *sdevice)
 116 {
 117         /*
 118          * This enables luns to be located sparsely. Otherwise, we may not
 119          * discovered them.
 120          */
 121         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 122         return 0;
 123 }
 124
 125 static int storvsc_merge_bvec(struct request_queue *q,
 126                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 127 {
 128         /* checking done by caller. */
 129         return bvec->bv_len;
 130 }
 131
 132 static int storvsc_device_configure(struct scsi_device *sdevice)
 133 {
 134         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 135                                 STORVSC_MAX_IO_REQUESTS);
 136
 137         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 138                     sdevice, PAGE_SIZE);
 139         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 140
 141         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 142                     sdevice);
 143         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 144
 145         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 146         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 147
 148         return 0;
 149 }
 150
 151 static void destroy_bounce_buffer(struct scatterlist *sgl,
 152                                   unsigned int sg_count)
 153 {
 154         int i;
 155         struct page *page_buf;
 156
 157         for (i = 0; i < sg_count; i++) {
 158                 page_buf = sg_page((&sgl[i]));
 159                 if (page_buf != NULL)
 160                         __free_page(page_buf);
 161         }
 162
 163         kfree(sgl);
 164 }
 165
 166 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 167 {
 168         int i;
 169
 170         /* No need to check */
 171         if (sg_count < 2)
 172                 return -1;
 173
 174         /* We have at least 2 sg entries */
 175         for (i = 0; i < sg_count; i++) {
 176                 if (i == 0) {
 177                         /* make sure 1st one does not have hole */
 178                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 179                                 return i;
 180                 } else if (i == sg_count - 1) {
 181                         /* make sure last one does not have hole */
 182                         if (sgl[i].offset != 0)
 183                                 return i;
 184                 } else {
 185                         /* make sure no hole in the middle */
 186                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 187                                 return i;
 188                 }
 189         }
 190         return -1;
 191 }
 192
 193 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 194                                                 unsigned int sg_count,
 195                                                 unsigned int len)
 196 {
 197         int i;
 198         int num_pages;
 199         struct scatterlist *bounce_sgl;
 200         struct page *page_buf;
 201
 202         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 203
 204         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 205         if (!bounce_sgl)
 206                 return NULL;
 207
 208         for (i = 0; i < num_pages; i++) {
 209                 page_buf = alloc_page(GFP_ATOMIC);
 210                 if (!page_buf)
 211                         goto cleanup;
 212                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 213         }
 214
 215         return bounce_sgl;
 216
 217 cleanup:
 218         destroy_bounce_buffer(bounce_sgl, num_pages);
 219         return NULL;
 220 }
 221
 222
 223 /* Assume the original sgl has enough room */
 224 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 225                                             struct scatterlist *bounce_sgl,
 226                                             unsigned int orig_sgl_count)
 227 {
 228         int i;
 229         int j = 0;
 230         unsigned long src, dest;
 231         unsigned int srclen, destlen, copylen;
 232         unsigned int total_copied = 0;
 233         unsigned long bounce_addr = 0;
 234         unsigned long dest_addr = 0;
 235         unsigned long flags;
 236
 237         local_irq_save(flags);
 238
 239         for (i = 0; i < orig_sgl_count; i++) {
 240                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 241                                         KM_IRQ0) + orig_sgl[i].offset;
 242                 dest = dest_addr;
 243                 destlen = orig_sgl[i].length;
 244
 245                 if (bounce_addr == 0)
 246                         bounce_addr =
 247                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 248                                                         KM_IRQ0);
 249
 250                 while (destlen) {
 251                         src = bounce_addr + bounce_sgl[j].offset;
 252                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 253
 254                         copylen = min(srclen, destlen);
 255                         memcpy((void *)dest, (void *)src, copylen);
 256
 257                         total_copied += copylen;
 258                         bounce_sgl[j].offset += copylen;
 259                         destlen -= copylen;
 260                         dest += copylen;
 261
 262                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 263                                 /* full */
 264                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 265                                 j++;
 266
 267                                 /* if we need to use another bounce buffer */
 268                                 if (destlen || i != orig_sgl_count - 1)
 269                                         bounce_addr =
 270                                         (unsigned long)kmap_atomic(
 271                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 272                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 273                                 /* unmap the last bounce that is < PAGE_SIZE */
 274                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 275                         }
 276                 }
 277
 278                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 279                               KM_IRQ0);
 280         }
 281
 282         local_irq_restore(flags);
 283
 284         return total_copied;
 285 }
 286
 287
 288 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 289 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 290                                           struct scatterlist *bounce_sgl,
 291                                           unsigned int orig_sgl_count)
 292 {
 293         int i;
 294         int j = 0;
 295         unsigned long src, dest;
 296         unsigned int srclen, destlen, copylen;
 297         unsigned int total_copied = 0;
 298         unsigned long bounce_addr = 0;
 299         unsigned long src_addr = 0;
 300         unsigned long flags;
 301
 302         local_irq_save(flags);
 303
 304         for (i = 0; i < orig_sgl_count; i++) {
 305                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 306                                 KM_IRQ0) + orig_sgl[i].offset;
 307                 src = src_addr;
 308                 srclen = orig_sgl[i].length;
 309
 310                 if (bounce_addr == 0)
 311                         bounce_addr =
 312                         (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])),
 313                                                 KM_IRQ0);
 314
 315                 while (srclen) {
 316                         /* assume bounce offset always == 0 */
 317                         dest = bounce_addr + bounce_sgl[j].length;
 318                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 319
 320                         copylen = min(srclen, destlen);
 321                         memcpy((void *)dest, (void *)src, copylen);
 322
 323                         total_copied += copylen;
 324                         bounce_sgl[j].length += copylen;
 325                         srclen -= copylen;
 326                         src += copylen;
 327
 328                         if (bounce_sgl[j].length == PAGE_SIZE) {
 329                                 /* full..move to next entry */
 330                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 331                                 j++;
 332
 333                                 /* if we need to use another bounce buffer */
 334                                 if (srclen || i != orig_sgl_count - 1)
 335                                         bounce_addr =
 336                                         (unsigned long)kmap_atomic(
 337                                         sg_page((&bounce_sgl[j])), KM_IRQ0);
 338
 339                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 340                                 /* unmap the last bounce that is < PAGE_SIZE */
 341                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 342                         }
 343                 }
 344
 345                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 346         }
 347
 348         local_irq_restore(flags);
 349
 350         return total_copied;
 351 }
 352
 353
 354 /*
 355  * storvsc_remove - Callback when our device is removed
 356  */
 357 static int storvsc_remove(struct hv_device *dev)
 358 {
 359         struct storvsc_driver *storvsc_drv_obj =
 360                          drv_to_stordrv(dev->device.driver);
 361         struct Scsi_Host *host = dev_get_drvdata(&dev->device);
 362         struct hv_host_device *host_dev =
 363                         (struct hv_host_device *)host->hostdata;
 364
 365         /*
 366          * Call to the vsc driver to let it know that the device is being
 367          * removed
 368          */
 369         storvsc_drv_obj->base.dev_rm(dev);
 370
 371         if (host_dev->request_pool) {
 372                 kmem_cache_destroy(host_dev->request_pool);
 373                 host_dev->request_pool = NULL;
 374         }
 375
 376         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 377         scsi_remove_host(host);
 378
 379         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 380         scsi_host_put(host);
 381         return 0;
 382 }
 383
 384 /* Static decl */
 385 static int storvsc_probe(struct hv_device *dev);
 386 static int storvsc_queuecommand(struct Scsi_Host *shost, struct scsi_cmnd *scmnd);
 387 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd);
 388
 389 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device *bdev,
 390                            sector_t capacity, int *info);
 391
 392
 393 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
 394 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 395 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 396
 397 /* The one and only one */
 398 static struct storvsc_driver g_storvsc_drv;
 399
 400 /* Scsi driver */
 401 static struct scsi_host_template scsi_driver = {
 402         .module =               THIS_MODULE,
 403         .name =                 "storvsc_host_t",
 404         .bios_param =           storvsc_get_chs,
 405         .queuecommand =         storvsc_queuecommand,
 406         .eh_host_reset_handler =        storvsc_host_reset_handler,
 407         .slave_alloc =          storvsc_device_alloc,
 408         .slave_configure =      storvsc_device_configure,
 409         .cmd_per_lun =          1,
 410         /* 64 max_queue * 1 target */
 411         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 412         .this_id =              -1,
 413         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 414         /* currently 32 */
 415         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 416         /*
 417          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 418          * into 1 sg element. If set, we must limit the max_segment_size to
 419          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 420          * multiple
 421          */
 422         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 423         .use_clustering =       ENABLE_CLUSTERING,
 424         /* Make sure we dont get a sg segment crosses a page boundary */
 425         .dma_boundary =         PAGE_SIZE-1,
 426 };
 427
 428
 429 /*
 430  * storvsc_drv_init - StorVsc driver initialization.
 431  */
 432 static int storvsc_drv_init(void)
 433 {
 434         int ret;
 435         struct storvsc_driver *storvsc_drv_obj = &g_storvsc_drv;
 436         struct hv_driver *drv = &g_storvsc_drv.base;
 437
 438         storvsc_drv_obj->ring_buffer_size = storvsc_ringbuffer_size;
 439
 440         /* Callback to client driver to complete the initialization */
 441         stor_vsc_initialize(&storvsc_drv_obj->base);
 442
 443         DPRINT_INFO(STORVSC_DRV,
 444                     "max outstanding reqs %u",
 445                     storvsc_drv_obj->max_outstanding_req_per_channel);
 446
 447         if (storvsc_drv_obj->max_outstanding_req_per_channel <
 448             STORVSC_MAX_IO_REQUESTS)
 449                 return -1;
 450
 451         drv->driver.name = storvsc_drv_obj->base.name;
 452
 453         drv->probe = storvsc_probe;
 454         drv->remove = storvsc_remove;
 455
 456         /* The driver belongs to vmbus */
 457         ret = vmbus_child_driver_register(&drv->driver);
 458
 459         return ret;
 460 }
 461
 462
 463 static int stor_vsc_on_host_reset(struct hv_device *device)
 464 {
 465         struct storvsc_device *stor_device;
 466         struct hv_storvsc_request *request;
 467         struct vstor_packet *vstor_packet;
 468         int ret, t;
 469
 470         DPRINT_INFO(STORVSC, "resetting host adapter...");
 471
 472         stor_device = get_stor_device(device);
 473         if (!stor_device)
 474                 return -1;
 475
 476         request = &stor_device->reset_request;
 477         vstor_packet = &request->vstor_packet;
 478
 479         init_completion(&request->wait_event);
 480
 481         vstor_packet->operation = VSTOR_OPERATION_RESET_BUS;
 482         vstor_packet->flags = REQUEST_COMPLETION_FLAG;
 483         vstor_packet->vm_srb.path_id = stor_device->path_id;
 484
 485         ret = vmbus_sendpacket(device->channel, vstor_packet,
 486                                sizeof(struct vstor_packet),
 487                                (unsigned long)&stor_device->reset_request,
 488                                VM_PKT_DATA_INBAND,
 489                                VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
 490         if (ret != 0)
 491                 goto cleanup;
 492
 493         t = wait_for_completion_timeout(&request->wait_event, HZ);
 494         if (t == 0) {
 495                 ret = -ETIMEDOUT;
 496                 goto cleanup;
 497         }
 498
 499         DPRINT_INFO(STORVSC, "host adapter reset completed");
 500
 501         /*
 502          * At this point, all outstanding requests in the adapter
 503          * should have been flushed out and return to us
 504          */
 505
 506 cleanup:
 507         put_stor_device(device);
 508         return ret;
 509 }
 510
 511 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 512 {
 513         struct device **curr = (struct device **)data;
 514         *curr = dev;
 515         return 1; /* stop iterating */
 516 }
 517
 518 static void storvsc_drv_exit(void)
 519 {
 520         struct storvsc_driver *storvsc_drv_obj = &g_storvsc_drv;
 521         struct hv_driver *drv = &g_storvsc_drv.base;
 522         struct device *current_dev = NULL;
 523         int ret;
 524
 525         while (1) {
 526                 current_dev = NULL;
 527
 528                 /* Get the device */
 529                 ret = driver_for_each_device(&drv->driver, NULL,
 530                                              (void *) &current_dev,
 531                                              storvsc_drv_exit_cb);
 532
 533
 534                 if (current_dev == NULL)
 535                         break;
 536
 537                 /* Initiate removal from the top-down */
 538                 device_unregister(current_dev);
 539         }
 540
 541         if (storvsc_drv_obj->base.cleanup)
 542                 storvsc_drv_obj->base.cleanup(&storvsc_drv_obj->base);
 543
 544         vmbus_child_driver_unregister(&drv->driver);
 545         return;
 546 }
 547
 548 /*
 549  * storvsc_probe - Add a new device for this driver
 550  */
 551 static int storvsc_probe(struct hv_device *device)
 552 {
 553         int ret;
 554         struct storvsc_driver *storvsc_drv_obj =
 555                  drv_to_stordrv(device->device.driver);
 556         struct Scsi_Host *host;
 557         struct hv_host_device *host_dev;
 558         struct storvsc_device_info device_info;
 559
 560         if (!storvsc_drv_obj->base.dev_add)
 561                 return -1;
 562
 563         host = scsi_host_alloc(&scsi_driver,
 564                                sizeof(struct hv_host_device));
 565         if (!host)
 566                 return -ENOMEM;
 567
 568         dev_set_drvdata(&device->device, host);
 569
 570         host_dev = (struct hv_host_device *)host->hostdata;
 571         memset(host_dev, 0, sizeof(struct hv_host_device));
 572
 573         host_dev->port = host->host_no;
 574         host_dev->dev = device;
 575
 576         host_dev->request_pool =
 577                                 kmem_cache_create(dev_name(&device->device),
 578                                         sizeof(struct storvsc_cmd_request), 0,
 579                                         SLAB_HWCACHE_ALIGN, NULL);
 580
 581         if (!host_dev->request_pool) {
 582                 scsi_host_put(host);
 583                 return -ENOMEM;
 584         }
 585
 586         device_info.port_number = host->host_no;
 587         /* Call to the vsc driver to add the device */
 588         ret = storvsc_drv_obj->base.dev_add(device, (void *)&device_info);
 589
 590         if (ret != 0) {
 591                 kmem_cache_destroy(host_dev->request_pool);
 592                 scsi_host_put(host);
 593                 return -1;
 594         }
 595
 596         host_dev->path = device_info.path_id;
 597         host_dev->target = device_info.target_id;
 598
 599         /* max # of devices per target */
 600         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 601         /* max # of targets per channel */
 602         host->max_id = STORVSC_MAX_TARGETS;
 603         /* max # of channels */
 604         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 605
 606         /* Register the HBA and start the scsi bus scan */
 607         ret = scsi_add_host(host, &device->device);
 608         if (ret != 0) {
 609
 610                 storvsc_drv_obj->base.dev_rm(device);
 611
 612                 kmem_cache_destroy(host_dev->request_pool);
 613                 scsi_host_put(host);
 614                 return -1;
 615         }
 616
 617         scsi_scan_host(host);
 618         return ret;
 619 }
 620
 621 /*
 622  * storvsc_commmand_completion - Command completion processing
 623  */
 624 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 625 {
 626         struct storvsc_cmd_request *cmd_request =
 627                 (struct storvsc_cmd_request *)request->context;
 628         struct scsi_cmnd *scmnd = cmd_request->cmd;
 629         struct hv_host_device *host_dev =
 630                 (struct hv_host_device *)scmnd->device->host->hostdata;
 631         void (*scsi_done_fn)(struct scsi_cmnd *);
 632         struct scsi_sense_hdr sense_hdr;
 633         struct vmscsi_request *vm_srb;
 634
 635         /* ASSERT(request == &cmd_request->request); */
 636         /* ASSERT(scmnd); */
 637         /* ASSERT((unsigned long)scmnd->host_scribble == */
 638         /*        (unsigned long)cmd_request); */
 639         /* ASSERT(scmnd->scsi_done); */
 640
 641         if (cmd_request->bounce_sgl_count) {
 642                 /* using bounce buffer */
 643                 /* printk("copy_from_bounce_buffer\n"); */
 644
 645                 /* FIXME: We can optimize on writes by just skipping this */
 646                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 647                                         cmd_request->bounce_sgl,
 648                                         scsi_sg_count(scmnd));
 649                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 650                                       cmd_request->bounce_sgl_count);
 651         }
 652
 653         vm_srb = &request->vstor_packet.vm_srb;
 654         scmnd->result = vm_srb->scsi_status;
 655
 656         if (scmnd->result) {
 657                 if (scsi_normalize_sense(scmnd->sense_buffer,
 658                                 SCSI_SENSE_BUFFERSIZE, &sense_hdr))
 659                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 660         }
 661
 662         /* ASSERT(request->BytesXfer <= request->data_buffer.Length); */
 663         scsi_set_resid(scmnd,
 664                 request->data_buffer.len -
 665                 vm_srb->data_transfer_length);
 666
 667         scsi_done_fn = scmnd->scsi_done;
 668
 669         scmnd->host_scribble = NULL;
 670         scmnd->scsi_done = NULL;
 671
 672         /* !!DO NOT MODIFY the scmnd after this call */
 673         scsi_done_fn(scmnd);
 674
 675         kmem_cache_free(host_dev->request_pool, cmd_request);
 676 }
 677
 678 /*
 679  * storvsc_queuecommand - Initiate command processing
 680  */
 681 static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 682                                 void (*done)(struct scsi_cmnd *))
 683 {
 684         int ret;
 685         struct hv_host_device *host_dev =
 686                 (struct hv_host_device *)scmnd->device->host->hostdata;
 687         struct hv_device *dev = host_dev->dev;
 688         struct storvsc_driver *storvsc_drv_obj =
 689                 drv_to_stordrv(dev->device.driver);
 690         struct hv_storvsc_request *request;
 691         struct storvsc_cmd_request *cmd_request;
 692         unsigned int request_size = 0;
 693         int i;
 694         struct scatterlist *sgl;
 695         unsigned int sg_count = 0;
 696         struct vmscsi_request *vm_srb;
 697
 698
 699         /* If retrying, no need to prep the cmd */
 700         if (scmnd->host_scribble) {
 701                 /* ASSERT(scmnd->scsi_done != NULL); */
 702
 703                 cmd_request =
 704                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 705                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 706                             scmnd, cmd_request);
 707
 708                 goto retry_request;
 709         }
 710
 711         /* ASSERT(scmnd->scsi_done == NULL); */
 712         /* ASSERT(scmnd->host_scribble == NULL); */
 713
 714         scmnd->scsi_done = done;
 715
 716         request_size = sizeof(struct storvsc_cmd_request);
 717
 718         cmd_request = kmem_cache_zalloc(host_dev->request_pool,
 719                                        GFP_ATOMIC);
 720         if (!cmd_request) {
 721                 scmnd->scsi_done = NULL;
 722                 return SCSI_MLQUEUE_DEVICE_BUSY;
 723         }
 724
 725         /* Setup the cmd request */
 726         cmd_request->bounce_sgl_count = 0;
 727         cmd_request->bounce_sgl = NULL;
 728         cmd_request->cmd = scmnd;
 729
 730         scmnd->host_scribble = (unsigned char *)cmd_request;
 731
 732         request = &cmd_request->request;
 733         vm_srb = &request->vstor_packet.vm_srb;
 734
 735
 736         /* Build the SRB */
 737         switch (scmnd->sc_data_direction) {
 738         case DMA_TO_DEVICE:
 739                 vm_srb->data_in = WRITE_TYPE;
 740                 break;
 741         case DMA_FROM_DEVICE:
 742                 vm_srb->data_in = READ_TYPE;
 743                 break;
 744         default:
 745                 vm_srb->data_in = UNKNOWN_TYPE;
 746                 break;
 747         }
 748
 749         request->on_io_completion = storvsc_commmand_completion;
 750         request->context = cmd_request;/* scmnd; */
 751
 752         /* request->PortId = scmnd->device->channel; */
 753         vm_srb->port_number = host_dev->port;
 754         vm_srb->path_id = scmnd->device->channel;
 755         vm_srb->target_id = scmnd->device->id;
 756         vm_srb->lun = scmnd->device->lun;
 757
 758         /* ASSERT(scmnd->cmd_len <= 16); */
 759         vm_srb->cdb_length = scmnd->cmd_len;
 760
 761         memcpy(vm_srb->cdb, scmnd->cmnd, vm_srb->cdb_length);
 762
 763         request->sense_buffer = scmnd->sense_buffer;
 764
 765
 766         request->data_buffer.len = scsi_bufflen(scmnd);
 767         if (scsi_sg_count(scmnd)) {
 768                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 769                 sg_count = scsi_sg_count(scmnd);
 770
 771                 /* check if we need to bounce the sgl */
 772                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 773                         cmd_request->bounce_sgl =
 774                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 775                                                      scsi_bufflen(scmnd));
 776                         if (!cmd_request->bounce_sgl) {
 777                                 scmnd->scsi_done = NULL;
 778                                 scmnd->host_scribble = NULL;
 779                                 kmem_cache_free(host_dev->request_pool,
 780                                                 cmd_request);
 781
 782                                 return SCSI_MLQUEUE_HOST_BUSY;
 783                         }
 784
 785                         cmd_request->bounce_sgl_count =
 786                                 ALIGN(scsi_bufflen(scmnd), PAGE_SIZE) >>
 787                                         PAGE_SHIFT;
 788
 789                         /*
 790                          * FIXME: We can optimize on reads by just skipping
 791                          * this
 792                          */
 793                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 794                                               scsi_sg_count(scmnd));
 795
 796                         sgl = cmd_request->bounce_sgl;
 797                         sg_count = cmd_request->bounce_sgl_count;
 798                 }
 799
 800                 request->data_buffer.offset = sgl[0].offset;
 801
 802                 for (i = 0; i < sg_count; i++)
 803                         request->data_buffer.pfn_array[i] =
 804                                 page_to_pfn(sg_page((&sgl[i])));
 805
 806         } else if (scsi_sglist(scmnd)) {
 807                 /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
 808                 request->data_buffer.offset =
 809                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 810                 request->data_buffer.pfn_array[0] =
 811                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 812         }
 813
 814 retry_request:
 815         /* Invokes the vsc to start an IO */
 816         ret = storvsc_drv_obj->on_io_request(dev,
 817                                            &cmd_request->request);
 818         if (ret == -1) {
 819                 /* no more space */
 820
 821                 if (cmd_request->bounce_sgl_count) {
 822                         /*
 823                          * FIXME: We can optimize on writes by just skipping
 824                          * this
 825                          */
 826                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 827                                                 cmd_request->bounce_sgl,
 828                                                 scsi_sg_count(scmnd));
 829                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 830                                               cmd_request->bounce_sgl_count);
 831                 }
 832
 833                 kmem_cache_free(host_dev->request_pool, cmd_request);
 834
 835                 scmnd->scsi_done = NULL;
 836                 scmnd->host_scribble = NULL;
 837
 838                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 839         }
 840
 841         return ret;
 842 }
 843
 844 static DEF_SCSI_QCMD(storvsc_queuecommand)
 845
 846 /*
 847  * storvsc_host_reset_handler - Reset the scsi HBA
 848  */
 849 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 850 {
 851         int ret;
 852         struct hv_host_device *host_dev =
 853                 (struct hv_host_device *)scmnd->device->host->hostdata;
 854         struct hv_device *dev = host_dev->dev;
 855
 856         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 857                     scmnd->device, dev);
 858
 859         /* Invokes the vsc to reset the host/bus */
 860         ret = stor_vsc_on_host_reset(dev);
 861         if (ret != 0)
 862                 return ret;
 863
 864         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 865                     scmnd->device, dev);
 866
 867         return ret;
 868 }
 869
 870 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 871                            sector_t capacity, int *info)
 872 {
 873         sector_t total_sectors = capacity;
 874         sector_t cylinder_times_heads = 0;
 875         sector_t temp = 0;
 876
 877         int sectors_per_track = 0;
 878         int heads = 0;
 879         int cylinders = 0;
 880         int rem = 0;
 881
 882         if (total_sectors > (65535 * 16 * 255))
 883                 total_sectors = (65535 * 16 * 255);
 884
 885         if (total_sectors >= (65535 * 16 * 63)) {
 886                 sectors_per_track = 255;
 887                 heads = 16;
 888
 889                 cylinder_times_heads = total_sectors;
 890                 /* sector_div stores the quotient in cylinder_times_heads */
 891                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 892         } else {
 893                 sectors_per_track = 17;
 894
 895                 cylinder_times_heads = total_sectors;
 896                 /* sector_div stores the quotient in cylinder_times_heads */
 897                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 898
 899                 temp = cylinder_times_heads + 1023;
 900                 /* sector_div stores the quotient in temp */
 901                 rem = sector_div(temp, 1024);
 902
 903                 heads = temp;
 904
 905                 if (heads < 4)
 906                         heads = 4;
 907
 908                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
 909                         sectors_per_track = 31;
 910                         heads = 16;
 911
 912                         cylinder_times_heads = total_sectors;
 913                         /*
 914                          * sector_div stores the quotient in
 915                          * cylinder_times_heads
 916                          */
 917                         rem = sector_div(cylinder_times_heads,
 918                                          sectors_per_track);
 919                 }
 920
 921                 if (cylinder_times_heads >= (heads * 1024)) {
 922                         sectors_per_track = 63;
 923                         heads = 16;
 924
 925                         cylinder_times_heads = total_sectors;
 926                         /*
 927                          * sector_div stores the quotient in
 928                          * cylinder_times_heads
 929                          */
 930                         rem = sector_div(cylinder_times_heads,
 931                                          sectors_per_track);
 932                 }
 933         }
 934
 935         temp = cylinder_times_heads;
 936         /* sector_div stores the quotient in temp */
 937         rem = sector_div(temp, heads);
 938         cylinders = temp;
 939
 940         info[0] = heads;
 941         info[1] = sectors_per_track;
 942         info[2] = cylinders;
 943
 944         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
 945                     sectors_per_track);
 946
 947     return 0;
 948 }
 949
 950 static int __init storvsc_init(void)
 951 {
 952         int ret;
 953
 954         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 955         ret = storvsc_drv_init();
 956         return ret;
 957 }
 958
 959 static void __exit storvsc_exit(void)
 960 {
 961         storvsc_drv_exit();
 962 }
 963
 964 MODULE_LICENSE("GPL");
 965 MODULE_VERSION(HV_DRV_VERSION);
 966 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
 967 module_init(storvsc_init);
 968 module_exit(storvsc_exit);