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         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 145
 146         storvsc_drv_obj->RingBufferSize = storvsc_ringbuffer_size;
 147
 148         /* Callback to client driver to complete the initialization */
 149         drv_init(&storvsc_drv_obj->Base);
 150
 151         DPRINT_INFO(STORVSC_DRV,
 152                     "request extension size %u, max outstanding reqs %u",
 153                     storvsc_drv_obj->RequestExtSize,
 154                     storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 155
 156         if (storvsc_drv_obj->MaxOutstandingRequestsPerChannel <
 157             STORVSC_MAX_IO_REQUESTS) {
 158                 DPRINT_ERR(STORVSC_DRV,
 159                            "The number of outstanding io requests (%d) "
 160                            "is larger than that supported (%d) internally.",
 161                            STORVSC_MAX_IO_REQUESTS,
 162                            storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 163                 return -1;
 164         }
 165
 166         drv_ctx->driver.name = storvsc_drv_obj->Base.name;
 167         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->Base.deviceType,
 168                sizeof(struct hv_guid));
 169
 170         drv_ctx->probe = storvsc_probe;
 171         drv_ctx->remove = storvsc_remove;
 172
 173         /* The driver belongs to vmbus */
 174         ret = vmbus_child_driver_register(drv_ctx);
 175
 176         DPRINT_EXIT(STORVSC_DRV);
 177
 178         return ret;
 179 }
 180
 181 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 182 {
 183         struct device **curr = (struct device **)data;
 184         *curr = dev;
 185         return 1; /* stop iterating */
 186 }
 187
 188 static void storvsc_drv_exit(void)
 189 {
 190         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 191         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 192         struct device *current_dev = NULL;
 193         int ret;
 194
 195         while (1) {
 196                 current_dev = NULL;
 197
 198                 /* Get the device */
 199                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 200                                              (void *) &current_dev,
 201                                              storvsc_drv_exit_cb);
 202
 203                 if (ret)
 204                         DPRINT_WARN(STORVSC_DRV,
 205                                     "driver_for_each_device returned %d", ret);
 206
 207                 if (current_dev == NULL)
 208                         break;
 209
 210                 /* Initiate removal from the top-down */
 211                 device_unregister(current_dev);
 212         }
 213
 214         if (storvsc_drv_obj->Base.OnCleanup)
 215                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 216
 217         vmbus_child_driver_unregister(drv_ctx);
 218
 219         DPRINT_EXIT(STORVSC_DRV);
 220
 221         return;
 222 }
 223
 224 /*
 225  * storvsc_probe - Add a new device for this driver
 226  */
 227 static int storvsc_probe(struct device *device)
 228 {
 229         int ret;
 230         struct driver_context *driver_ctx =
 231                                 driver_to_driver_context(device->driver);
 232         struct storvsc_driver_context *storvsc_drv_ctx =
 233                                 (struct storvsc_driver_context *)driver_ctx;
 234         struct storvsc_driver_object *storvsc_drv_obj =
 235                                 &storvsc_drv_ctx->drv_obj;
 236         struct vm_device *device_ctx = device_to_vm_device(device);
 237         struct hv_device *device_obj = &device_ctx->device_obj;
 238         struct Scsi_Host *host;
 239         struct host_device_context *host_device_ctx;
 240         struct storvsc_device_info device_info;
 241
 242         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 243                 return -1;
 244
 245         host = scsi_host_alloc(&scsi_driver,
 246                                sizeof(struct host_device_context));
 247         if (!host) {
 248                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 249                 return -ENOMEM;
 250         }
 251
 252         dev_set_drvdata(device, host);
 253
 254         host_device_ctx = (struct host_device_context *)host->hostdata;
 255         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 256
 257         host_device_ctx->port = host->host_no;
 258         host_device_ctx->device_ctx = device_ctx;
 259
 260         host_device_ctx->request_pool =
 261                                 kmem_cache_create(dev_name(&device_ctx->device),
 262                                         sizeof(struct storvsc_cmd_request) +
 263                                         storvsc_drv_obj->RequestExtSize, 0,
 264                                         SLAB_HWCACHE_ALIGN, NULL);
 265
 266         if (!host_device_ctx->request_pool) {
 267                 scsi_host_put(host);
 268                 DPRINT_EXIT(STORVSC_DRV);
 269
 270                 return -ENOMEM;
 271         }
 272
 273         device_info.PortNumber = host->host_no;
 274         /* Call to the vsc driver to add the device */
 275         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj,
 276                                                 (void *)&device_info);
 277         if (ret != 0) {
 278                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 279                 kmem_cache_destroy(host_device_ctx->request_pool);
 280                 scsi_host_put(host);
 281                 DPRINT_EXIT(STORVSC_DRV);
 282
 283                 return -1;
 284         }
 285
 286         /* host_device_ctx->port = device_info.PortNumber; */
 287         host_device_ctx->path = device_info.PathId;
 288         host_device_ctx->target = device_info.TargetId;
 289
 290         /* max # of devices per target */
 291         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 292         /* max # of targets per channel */
 293         host->max_id = STORVSC_MAX_TARGETS;
 294         /* max # of channels */
 295         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 296
 297         /* Register the HBA and start the scsi bus scan */
 298         ret = scsi_add_host(host, device);
 299         if (ret != 0) {
 300                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 301
 302                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 303
 304                 kmem_cache_destroy(host_device_ctx->request_pool);
 305                 scsi_host_put(host);
 306                 DPRINT_EXIT(STORVSC_DRV);
 307
 308                 return -1;
 309         }
 310
 311         scsi_scan_host(host);
 312
 313         DPRINT_EXIT(STORVSC_DRV);
 314
 315         return ret;
 316 }
 317
 318 /*
 319  * storvsc_remove - Callback when our device is removed
 320  */
 321 static int storvsc_remove(struct device *device)
 322 {
 323         int ret;
 324         struct driver_context *driver_ctx =
 325                         driver_to_driver_context(device->driver);
 326         struct storvsc_driver_context *storvsc_drv_ctx =
 327                         (struct storvsc_driver_context *)driver_ctx;
 328         struct storvsc_driver_object *storvsc_drv_obj =
 329                         &storvsc_drv_ctx->drv_obj;
 330         struct vm_device *device_ctx = device_to_vm_device(device);
 331         struct hv_device *device_obj = &device_ctx->device_obj;
 332         struct Scsi_Host *host = dev_get_drvdata(device);
 333         struct host_device_context *host_device_ctx =
 334                         (struct host_device_context *)host->hostdata;
 335
 336
 337         if (!storvsc_drv_obj->Base.OnDeviceRemove) {
 338                 DPRINT_EXIT(STORVSC_DRV);
 339                 return -1;
 340         }
 341
 342         /*
 343          * Call to the vsc driver to let it know that the device is being
 344          * removed
 345          */
 346         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 347         if (ret != 0) {
 348                 /* TODO: */
 349                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 350                            ret);
 351         }
 352
 353         if (host_device_ctx->request_pool) {
 354                 kmem_cache_destroy(host_device_ctx->request_pool);
 355                 host_device_ctx->request_pool = NULL;
 356         }
 357
 358         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 359         scsi_remove_host(host);
 360
 361         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 362         scsi_host_put(host);
 363
 364         DPRINT_EXIT(STORVSC_DRV);
 365
 366         return ret;
 367 }
 368
 369 /*
 370  * storvsc_commmand_completion - Command completion processing
 371  */
 372 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 373 {
 374         struct storvsc_cmd_request *cmd_request =
 375                 (struct storvsc_cmd_request *)request->Context;
 376         struct scsi_cmnd *scmnd = cmd_request->cmd;
 377         struct host_device_context *host_device_ctx =
 378                 (struct host_device_context *)scmnd->device->host->hostdata;
 379         void (*scsi_done_fn)(struct scsi_cmnd *);
 380         struct scsi_sense_hdr sense_hdr;
 381
 382         /* ASSERT(request == &cmd_request->request); */
 383         /* ASSERT(scmnd); */
 384         /* ASSERT((unsigned long)scmnd->host_scribble == */
 385         /*        (unsigned long)cmd_request); */
 386         /* ASSERT(scmnd->scsi_done); */
 387
 388         if (cmd_request->bounce_sgl_count) {
 389                 /* using bounce buffer */
 390                 /* printk("copy_from_bounce_buffer\n"); */
 391
 392                 /* FIXME: We can optimize on writes by just skipping this */
 393                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 394                                         cmd_request->bounce_sgl,
 395                                         scsi_sg_count(scmnd));
 396                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 397                                       cmd_request->bounce_sgl_count);
 398         }
 399
 400         scmnd->result = request->Status;
 401
 402         if (scmnd->result) {
 403                 if (scsi_normalize_sense(scmnd->sense_buffer,
 404                                          request->SenseBufferSize, &sense_hdr))
 405                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 406         }
 407
 408         /* ASSERT(request->BytesXfer <= request->DataBuffer.Length); */
 409         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 410
 411         scsi_done_fn = scmnd->scsi_done;
 412
 413         scmnd->host_scribble = NULL;
 414         scmnd->scsi_done = NULL;
 415
 416         /* !!DO NOT MODIFY the scmnd after this call */
 417         scsi_done_fn(scmnd);
 418
 419         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 420
 421         DPRINT_EXIT(STORVSC_DRV);
 422 }
 423
 424 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 425 {
 426         int i;
 427
 428         /* No need to check */
 429         if (sg_count < 2)
 430                 return -1;
 431
 432         /* We have at least 2 sg entries */
 433         for (i = 0; i < sg_count; i++) {
 434                 if (i == 0) {
 435                         /* make sure 1st one does not have hole */
 436                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 437                                 return i;
 438                 } else if (i == sg_count - 1) {
 439                         /* make sure last one does not have hole */
 440                         if (sgl[i].offset != 0)
 441                                 return i;
 442                 } else {
 443                         /* make sure no hole in the middle */
 444                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 445                                 return i;
 446                 }
 447         }
 448         return -1;
 449 }
 450
 451 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 452                                                 unsigned int sg_count,
 453                                                 unsigned int len)
 454 {
 455         int i;
 456         int num_pages;
 457         struct scatterlist *bounce_sgl;
 458         struct page *page_buf;
 459
 460         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 461
 462         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 463         if (!bounce_sgl)
 464                 return NULL;
 465
 466         for (i = 0; i < num_pages; i++) {
 467                 page_buf = alloc_page(GFP_ATOMIC);
 468                 if (!page_buf)
 469                         goto cleanup;
 470                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 471         }
 472
 473         return bounce_sgl;
 474
 475 cleanup:
 476         destroy_bounce_buffer(bounce_sgl, num_pages);
 477         return NULL;
 478 }
 479
 480 static void destroy_bounce_buffer(struct scatterlist *sgl,
 481                                   unsigned int sg_count)
 482 {
 483         int i;
 484         struct page *page_buf;
 485
 486         for (i = 0; i < sg_count; i++) {
 487                 page_buf = sg_page((&sgl[i]));
 488                 if (page_buf != NULL)
 489                         __free_page(page_buf);
 490         }
 491
 492         kfree(sgl);
 493 }
 494
 495 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 496 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 497                                           struct scatterlist *bounce_sgl,
 498                                           unsigned int orig_sgl_count)
 499 {
 500         int i;
 501         int j = 0;
 502         unsigned long src, dest;
 503         unsigned int srclen, destlen, copylen;
 504         unsigned int total_copied = 0;
 505         unsigned long bounce_addr = 0;
 506         unsigned long src_addr = 0;
 507         unsigned long flags;
 508
 509         local_irq_save(flags);
 510
 511         for (i = 0; i < orig_sgl_count; i++) {
 512                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 513                                 KM_IRQ0) + orig_sgl[i].offset;
 514                 src = src_addr;
 515                 srclen = orig_sgl[i].length;
 516
 517                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 518
 519                 if (j == 0)
 520                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 521
 522                 while (srclen) {
 523                         /* assume bounce offset always == 0 */
 524                         dest = bounce_addr + bounce_sgl[j].length;
 525                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 526
 527                         copylen = min(srclen, destlen);
 528                         memcpy((void *)dest, (void *)src, copylen);
 529
 530                         total_copied += copylen;
 531                         bounce_sgl[j].length += copylen;
 532                         srclen -= copylen;
 533                         src += copylen;
 534
 535                         if (bounce_sgl[j].length == PAGE_SIZE) {
 536                                 /* full..move to next entry */
 537                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 538                                 j++;
 539
 540                                 /* if we need to use another bounce buffer */
 541                                 if (srclen || i != orig_sgl_count - 1)
 542                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 543                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 544                                 /* unmap the last bounce that is < PAGE_SIZE */
 545                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 546                         }
 547                 }
 548
 549                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 550         }
 551
 552         local_irq_restore(flags);
 553
 554         return total_copied;
 555 }
 556
 557 /* Assume the original sgl has enough room */
 558 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 559                                             struct scatterlist *bounce_sgl,
 560                                             unsigned int orig_sgl_count)
 561 {
 562         int i;
 563         int j = 0;
 564         unsigned long src, dest;
 565         unsigned int srclen, destlen, copylen;
 566         unsigned int total_copied = 0;
 567         unsigned long bounce_addr = 0;
 568         unsigned long dest_addr = 0;
 569         unsigned long flags;
 570
 571         local_irq_save(flags);
 572
 573         for (i = 0; i < orig_sgl_count; i++) {
 574                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 575                                         KM_IRQ0) + orig_sgl[i].offset;
 576                 dest = dest_addr;
 577                 destlen = orig_sgl[i].length;
 578                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 579
 580                 if (j == 0)
 581                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 582
 583                 while (destlen) {
 584                         src = bounce_addr + bounce_sgl[j].offset;
 585                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 586
 587                         copylen = min(srclen, destlen);
 588                         memcpy((void *)dest, (void *)src, copylen);
 589
 590                         total_copied += copylen;
 591                         bounce_sgl[j].offset += copylen;
 592                         destlen -= copylen;
 593                         dest += copylen;
 594
 595                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 596                                 /* full */
 597                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 598                                 j++;
 599
 600                                 /* if we need to use another bounce buffer */
 601                                 if (destlen || i != orig_sgl_count - 1)
 602                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 603                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 604                                 /* unmap the last bounce that is < PAGE_SIZE */
 605                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 606                         }
 607                 }
 608
 609                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 610                               KM_IRQ0);
 611         }
 612
 613         local_irq_restore(flags);
 614
 615         return total_copied;
 616 }
 617
 618 /*
 619  * storvsc_queuecommand - Initiate command processing
 620  */
 621 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
 622                                 void (*done)(struct scsi_cmnd *))
 623 {
 624         int ret;
 625         struct host_device_context *host_device_ctx =
 626                 (struct host_device_context *)scmnd->device->host->hostdata;
 627         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 628         struct driver_context *driver_ctx =
 629                 driver_to_driver_context(device_ctx->device.driver);
 630         struct storvsc_driver_context *storvsc_drv_ctx =
 631                 (struct storvsc_driver_context *)driver_ctx;
 632         struct storvsc_driver_object *storvsc_drv_obj =
 633                 &storvsc_drv_ctx->drv_obj;
 634         struct hv_storvsc_request *request;
 635         struct storvsc_cmd_request *cmd_request;
 636         unsigned int request_size = 0;
 637         int i;
 638         struct scatterlist *sgl;
 639
 640         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 641                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 642                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 643                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 644                    scmnd->device->tagged_supported);
 645
 646         /* If retrying, no need to prep the cmd */
 647         if (scmnd->host_scribble) {
 648                 /* ASSERT(scmnd->scsi_done != NULL); */
 649
 650                 cmd_request =
 651                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 652                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 653                             scmnd, cmd_request);
 654
 655                 goto retry_request;
 656         }
 657
 658         /* ASSERT(scmnd->scsi_done == NULL); */
 659         /* ASSERT(scmnd->host_scribble == NULL); */
 660
 661         scmnd->scsi_done = done;
 662
 663         request_size = sizeof(struct storvsc_cmd_request);
 664
 665         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 666                                        GFP_ATOMIC);
 667         if (!cmd_request) {
 668                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 669                            "storvsc_cmd_request...marking queue busy", scmnd);
 670                 scmnd->scsi_done = NULL;
 671                 return SCSI_MLQUEUE_DEVICE_BUSY;
 672         }
 673
 674         /* Setup the cmd request */
 675         cmd_request->bounce_sgl_count = 0;
 676         cmd_request->bounce_sgl = NULL;
 677         cmd_request->cmd = scmnd;
 678
 679         scmnd->host_scribble = (unsigned char *)cmd_request;
 680
 681         request = &cmd_request->request;
 682
 683         request->Extension =
 684                 (void *)((unsigned long)cmd_request + request_size);
 685         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 686                    storvsc_drv_obj->RequestExtSize);
 687
 688         /* Build the SRB */
 689         switch (scmnd->sc_data_direction) {
 690         case DMA_TO_DEVICE:
 691                 request->Type = WRITE_TYPE;
 692                 break;
 693         case DMA_FROM_DEVICE:
 694                 request->Type = READ_TYPE;
 695                 break;
 696         default:
 697                 request->Type = UNKNOWN_TYPE;
 698                 break;
 699         }
 700
 701         request->OnIOCompletion = storvsc_commmand_completion;
 702         request->Context = cmd_request;/* scmnd; */
 703
 704         /* request->PortId = scmnd->device->channel; */
 705         request->Host = host_device_ctx->port;
 706         request->Bus = scmnd->device->channel;
 707         request->TargetId = scmnd->device->id;
 708         request->LunId = scmnd->device->lun;
 709
 710         /* ASSERT(scmnd->cmd_len <= 16); */
 711         request->CdbLen = scmnd->cmd_len;
 712         request->Cdb = scmnd->cmnd;
 713
 714         request->SenseBuffer = scmnd->sense_buffer;
 715         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 716
 717
 718         request->DataBuffer.Length = scsi_bufflen(scmnd);
 719         if (scsi_sg_count(scmnd)) {
 720                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 721
 722                 /* check if we need to bounce the sgl */
 723                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 724                         DPRINT_INFO(STORVSC_DRV,
 725                                     "need to bounce buffer for this scmnd %p",
 726                                     scmnd);
 727                         cmd_request->bounce_sgl =
 728                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 729                                                      scsi_bufflen(scmnd));
 730                         if (!cmd_request->bounce_sgl) {
 731                                 DPRINT_ERR(STORVSC_DRV,
 732                                            "unable to create bounce buffer for "
 733                                            "this scmnd %p", scmnd);
 734
 735                                 scmnd->scsi_done = NULL;
 736                                 scmnd->host_scribble = NULL;
 737                                 kmem_cache_free(host_device_ctx->request_pool,
 738                                                 cmd_request);
 739
 740                                 return SCSI_MLQUEUE_HOST_BUSY;
 741                         }
 742
 743                         cmd_request->bounce_sgl_count =
 744                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 745                                         PAGE_SHIFT;
 746
 747                         /*
 748                          * FIXME: We can optimize on reads by just skipping
 749                          * this
 750                          */
 751                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 752                                               scsi_sg_count(scmnd));
 753
 754                         sgl = cmd_request->bounce_sgl;
 755                 }
 756
 757                 request->DataBuffer.Offset = sgl[0].offset;
 758
 759                 for (i = 0; i < scsi_sg_count(scmnd); i++) {
 760                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d\n",
 761                                    i, sgl[i].length, sgl[i].offset);
 762                         request->DataBuffer.PfnArray[i] =
 763                                         page_to_pfn(sg_page((&sgl[i])));
 764                 }
 765         } else if (scsi_sglist(scmnd)) {
 766                 /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
 767                 request->DataBuffer.Offset =
 768                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 769                 request->DataBuffer.PfnArray[0] =
 770                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 771         }
 772
 773 retry_request:
 774         /* Invokes the vsc to start an IO */
 775         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj,
 776                                            &cmd_request->request);
 777         if (ret == -1) {
 778                 /* no more space */
 779                 DPRINT_ERR(STORVSC_DRV,
 780                            "scmnd (%p) - queue FULL...marking queue busy",
 781                            scmnd);
 782
 783                 if (cmd_request->bounce_sgl_count) {
 784                         /*
 785                          * FIXME: We can optimize on writes by just skipping
 786                          * this
 787                          */
 788                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 789                                                 cmd_request->bounce_sgl,
 790                                                 scsi_sg_count(scmnd));
 791                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 792                                               cmd_request->bounce_sgl_count);
 793                 }
 794
 795                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 796
 797                 scmnd->scsi_done = NULL;
 798                 scmnd->host_scribble = NULL;
 799
 800                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 801         }
 802
 803         DPRINT_EXIT(STORVSC_DRV);
 804
 805         return ret;
 806 }
 807
 808 static int storvsc_merge_bvec(struct request_queue *q,
 809                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 810 {
 811         /* checking done by caller. */
 812         return bvec->bv_len;
 813 }
 814
 815 /*
 816  * storvsc_device_configure - Configure the specified scsi device
 817  */
 818 static int storvsc_device_alloc(struct scsi_device *sdevice)
 819 {
 820         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d",
 821                    sdevice, BLIST_SPARSELUN);
 822         /*
 823          * This enables luns to be located sparsely. Otherwise, we may not
 824          * discovered them.
 825          */
 826         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 827         return 0;
 828 }
 829
 830 static int storvsc_device_configure(struct scsi_device *sdevice)
 831 {
 832         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - curr queue depth %d", sdevice,
 833                     sdevice->queue_depth);
 834
 835         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d",
 836                     sdevice, STORVSC_MAX_IO_REQUESTS);
 837         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 838                                 STORVSC_MAX_IO_REQUESTS);
 839
 840         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 841                     sdevice, PAGE_SIZE);
 842         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 843
 844         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 845                     sdevice);
 846         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 847
 848         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 849         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 850
 851         return 0;
 852 }
 853
 854 /*
 855  * storvsc_host_reset_handler - Reset the scsi HBA
 856  */
 857 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 858 {
 859         int ret;
 860         struct host_device_context *host_device_ctx =
 861                 (struct host_device_context *)scmnd->device->host->hostdata;
 862         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 863
 864         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 865                     scmnd->device, &device_ctx->device_obj);
 866
 867         /* Invokes the vsc to reset the host/bus */
 868         ret = StorVscOnHostReset(&device_ctx->device_obj);
 869         if (ret != 0) {
 870                 DPRINT_EXIT(STORVSC_DRV);
 871                 return ret;
 872         }
 873
 874         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 875                     scmnd->device, &device_ctx->device_obj);
 876
 877         DPRINT_EXIT(STORVSC_DRV);
 878
 879         return ret;
 880 }
 881
 882 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 883                            sector_t capacity, int *info)
 884 {
 885         sector_t total_sectors = capacity;
 886         sector_t cylinder_times_heads = 0;
 887         sector_t temp = 0;
 888
 889         int sectors_per_track = 0;
 890         int heads = 0;
 891         int cylinders = 0;
 892         int rem = 0;
 893
 894         if (total_sectors > (65535 * 16 * 255))
 895                 total_sectors = (65535 * 16 * 255);
 896
 897         if (total_sectors >= (65535 * 16 * 63)) {
 898                 sectors_per_track = 255;
 899                 heads = 16;
 900
 901                 cylinder_times_heads = total_sectors;
 902                 /* sector_div stores the quotient in cylinder_times_heads */
 903                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 904         } else {
 905                 sectors_per_track = 17;
 906
 907                 cylinder_times_heads = total_sectors;
 908                 /* sector_div stores the quotient in cylinder_times_heads */
 909                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 910
 911                 temp = cylinder_times_heads + 1023;
 912                 /* sector_div stores the quotient in temp */
 913                 rem = sector_div(temp, 1024);
 914
 915                 heads = temp;
 916
 917                 if (heads < 4)
 918                         heads = 4;
 919
 920                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
 921                         sectors_per_track = 31;
 922                         heads = 16;
 923
 924                         cylinder_times_heads = total_sectors;
 925                         /*
 926                          * sector_div stores the quotient in
 927                          * cylinder_times_heads
 928                          */
 929                         rem = sector_div(cylinder_times_heads,
 930                                          sectors_per_track);
 931                 }
 932
 933                 if (cylinder_times_heads >= (heads * 1024)) {
 934                         sectors_per_track = 63;
 935                         heads = 16;
 936
 937                         cylinder_times_heads = total_sectors;
 938                         /*
 939                          * sector_div stores the quotient in
 940                          * cylinder_times_heads
 941                          */
 942                         rem = sector_div(cylinder_times_heads,
 943                                          sectors_per_track);
 944                 }
 945         }
 946
 947         temp = cylinder_times_heads;
 948         /* sector_div stores the quotient in temp */
 949         rem = sector_div(temp, heads);
 950         cylinders = temp;
 951
 952         info[0] = heads;
 953         info[1] = sectors_per_track;
 954         info[2] = cylinders;
 955
 956         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
 957                     sectors_per_track);
 958
 959     return 0;
 960 }
 961
 962 static int __init storvsc_init(void)
 963 {
 964         int ret;
 965
 966         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 967         ret = storvsc_drv_init(StorVscInitialize);
 968         DPRINT_EXIT(STORVSC_DRV);
 969         return ret;
 970 }
 971
 972 static void __exit storvsc_exit(void)
 973 {
 974         storvsc_drv_exit();
 975 }
 976
 977 MODULE_LICENSE("GPL");
 978 MODULE_VERSION(HV_DRV_VERSION);
 979 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
 980 module_init(storvsc_init);
 981 module_exit(storvsc_exit);