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