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/module.h>
  23 #include <linux/device.h>
  24 #include <linux/blkdev.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/scsi_cmnd.h>
  27 #include <scsi/scsi_host.h>
  28 #include <scsi/scsi_device.h>
  29 #include <scsi/scsi_tcq.h>
  30 #include <scsi/scsi_eh.h>
  31 #include <scsi/scsi_devinfo.h>
  32 #include <scsi/scsi_dbg.h>
  33 #include "osd.h"
  34 #include "logging.h"
  35 #include "vmbus.h"
  36 #include "StorVscApi.h"
  37
  38
  39 struct host_device_context {
  40         /* must be 1st field
  41          * FIXME this is a bug */
  42         /* point back to our device context */
  43         struct device_context *device_ctx;
  44         struct kmem_cache *request_pool;
  45         unsigned int port;
  46         unsigned char path;
  47         unsigned char target;
  48 };
  49
  50 struct storvsc_cmd_request {
  51         struct list_head entry;
  52         struct scsi_cmnd *cmd;
  53
  54         unsigned int bounce_sgl_count;
  55         struct scatterlist *bounce_sgl;
  56
  57         struct hv_storvsc_request request;
  58         /* !!!DO NOT ADD ANYTHING BELOW HERE!!! */
  59         /* The extension buffer falls right here and is pointed to by
  60          * request.Extension;
  61          * Which sounds like a very bad design... */
  62 };
  63
  64 struct storvsc_driver_context {
  65         /* !! These must be the first 2 fields !! */
  66         /* FIXME this is a bug... */
  67         struct driver_context drv_ctx;
  68         struct storvsc_driver_object drv_obj;
  69 };
  70
  71 /* Static decl */
  72 static int storvsc_probe(struct device *dev);
  73 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
  74                                 void (*done)(struct scsi_cmnd *));
  75 static int storvsc_device_alloc(struct scsi_device *);
  76 static int storvsc_device_configure(struct scsi_device *);
  77 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd);
  78 static int storvsc_remove(struct device *dev);
  79
  80 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
  81                                                 unsigned int sg_count,
  82                                                 unsigned int len);
  83 static void destroy_bounce_buffer(struct scatterlist *sgl,
  84                                   unsigned int sg_count);
  85 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count);
  86 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
  87                                             struct scatterlist *bounce_sgl,
  88                                             unsigned int orig_sgl_count);
  89 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
  90                                           struct scatterlist *bounce_sgl,
  91                                           unsigned int orig_sgl_count);
  92
  93 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device *bdev,
  94                            sector_t capacity, int *info);
  95
  96
  97 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
  98
  99 /* The one and only one */
 100 static struct storvsc_driver_context g_storvsc_drv;
 101
 102 /* Scsi driver */
 103 static struct scsi_host_template scsi_driver = {
 104         .module =               THIS_MODULE,
 105         .name =                 "storvsc_host_t",
 106         .bios_param =           storvsc_get_chs,
 107         .queuecommand =         storvsc_queuecommand,
 108         .eh_host_reset_handler =        storvsc_host_reset_handler,
 109         .slave_alloc =          storvsc_device_alloc,
 110         .slave_configure =      storvsc_device_configure,
 111         .cmd_per_lun =          1,
 112         /* 64 max_queue * 1 target */
 113         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 114         .this_id =              -1,
 115         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 116         /* currently 32 */
 117         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 118         /*
 119          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 120          * into 1 sg element. If set, we must limit the max_segment_size to
 121          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 122          * multiple
 123          */
 124         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 125         .use_clustering =       ENABLE_CLUSTERING,
 126         /* Make sure we dont get a sg segment crosses a page boundary */
 127         .dma_boundary =         PAGE_SIZE-1,
 128 };
 129
 130
 131 /**
 132  * storvsc_drv_init - StorVsc driver initialization.
 133  */
 134 static int storvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 135 {
 136         int ret;
 137         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 138         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 139
 140         DPRINT_ENTER(STORVSC_DRV);
 141
 142         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 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         DPRINT_EXIT(STORVSC_DRV);
 175
 176         return ret;
 177 }
 178
 179 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 180 {
 181         struct device **curr = (struct device **)data;
 182         *curr = dev;
 183         return 1; /* stop iterating */
 184 }
 185
 186 static void storvsc_drv_exit(void)
 187 {
 188         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 189         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 190         struct device *current_dev = NULL;
 191         int ret;
 192
 193         DPRINT_ENTER(STORVSC_DRV);
 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 device_context *device_ctx = device_to_device_context(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         DPRINT_ENTER(STORVSC_DRV);
 243
 244         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 245                 return -1;
 246
 247         host = scsi_host_alloc(&scsi_driver,
 248                                sizeof(struct host_device_context));
 249         if (!host) {
 250                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 251                 return -ENOMEM;
 252         }
 253
 254         dev_set_drvdata(device, host);
 255
 256         host_device_ctx = (struct host_device_context *)host->hostdata;
 257         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 258
 259         host_device_ctx->port = host->host_no;
 260         host_device_ctx->device_ctx = device_ctx;
 261
 262         host_device_ctx->request_pool =
 263                                 kmem_cache_create(dev_name(&device_ctx->device),
 264                                         sizeof(struct storvsc_cmd_request) +
 265                                         storvsc_drv_obj->RequestExtSize, 0,
 266                                         SLAB_HWCACHE_ALIGN, NULL);
 267
 268         if (!host_device_ctx->request_pool) {
 269                 scsi_host_put(host);
 270                 DPRINT_EXIT(STORVSC_DRV);
 271
 272                 return -ENOMEM;
 273         }
 274
 275         device_info.PortNumber = host->host_no;
 276         /* Call to the vsc driver to add the device */
 277         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj,
 278                                                 (void *)&device_info);
 279         if (ret != 0) {
 280                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 281                 kmem_cache_destroy(host_device_ctx->request_pool);
 282                 scsi_host_put(host);
 283                 DPRINT_EXIT(STORVSC_DRV);
 284
 285                 return -1;
 286         }
 287
 288         /* host_device_ctx->port = device_info.PortNumber; */
 289         host_device_ctx->path = device_info.PathId;
 290         host_device_ctx->target = device_info.TargetId;
 291
 292         /* max # of devices per target */
 293         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 294         /* max # of targets per channel */
 295         host->max_id = STORVSC_MAX_TARGETS;
 296         /* max # of channels */
 297         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 298
 299         /* Register the HBA and start the scsi bus scan */
 300         ret = scsi_add_host(host, device);
 301         if (ret != 0) {
 302                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 303
 304                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 305
 306                 kmem_cache_destroy(host_device_ctx->request_pool);
 307                 scsi_host_put(host);
 308                 DPRINT_EXIT(STORVSC_DRV);
 309
 310                 return -1;
 311         }
 312
 313         scsi_scan_host(host);
 314
 315         DPRINT_EXIT(STORVSC_DRV);
 316
 317         return ret;
 318 }
 319
 320 /**
 321  * storvsc_remove - Callback when our device is removed
 322  */
 323 static int storvsc_remove(struct device *device)
 324 {
 325         int ret;
 326         struct driver_context *driver_ctx =
 327                         driver_to_driver_context(device->driver);
 328         struct storvsc_driver_context *storvsc_drv_ctx =
 329                         (struct storvsc_driver_context *)driver_ctx;
 330         struct storvsc_driver_object *storvsc_drv_obj =
 331                         &storvsc_drv_ctx->drv_obj;
 332         struct device_context *device_ctx = device_to_device_context(device);
 333         struct hv_device *device_obj = &device_ctx->device_obj;
 334         struct Scsi_Host *host = dev_get_drvdata(device);
 335         struct host_device_context *host_device_ctx =
 336                         (struct host_device_context *)host->hostdata;
 337
 338
 339         DPRINT_ENTER(STORVSC_DRV);
 340
 341         if (!storvsc_drv_obj->Base.OnDeviceRemove) {
 342                 DPRINT_EXIT(STORVSC_DRV);
 343                 return -1;
 344         }
 345
 346         /*
 347          * Call to the vsc driver to let it know that the device is being
 348          * removed
 349          */
 350         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 351         if (ret != 0) {
 352                 /* TODO: */
 353                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 354                            ret);
 355         }
 356
 357         if (host_device_ctx->request_pool) {
 358                 kmem_cache_destroy(host_device_ctx->request_pool);
 359                 host_device_ctx->request_pool = NULL;
 360         }
 361
 362         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 363         scsi_remove_host(host);
 364
 365         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 366         scsi_host_put(host);
 367
 368         DPRINT_EXIT(STORVSC_DRV);
 369
 370         return ret;
 371 }
 372
 373 /**
 374  * storvsc_commmand_completion - Command completion processing
 375  */
 376 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 377 {
 378         struct storvsc_cmd_request *cmd_request =
 379                 (struct storvsc_cmd_request *)request->Context;
 380         struct scsi_cmnd *scmnd = cmd_request->cmd;
 381         struct host_device_context *host_device_ctx =
 382                 (struct host_device_context *)scmnd->device->host->hostdata;
 383         void (*scsi_done_fn)(struct scsi_cmnd *);
 384         struct scsi_sense_hdr sense_hdr;
 385
 386         ASSERT(request == &cmd_request->request);
 387         ASSERT((unsigned long)scmnd->host_scribble ==
 388                 (unsigned long)cmd_request);
 389         ASSERT(scmnd);
 390         ASSERT(scmnd->scsi_done);
 391
 392         DPRINT_ENTER(STORVSC_DRV);
 393
 394         if (cmd_request->bounce_sgl_count) {
 395                 /* using bounce buffer */
 396                 /* printk("copy_from_bounce_buffer\n"); */
 397
 398                 /* FIXME: We can optimize on writes by just skipping this */
 399                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 400                                         cmd_request->bounce_sgl,
 401                                         scsi_sg_count(scmnd));
 402                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 403                                       cmd_request->bounce_sgl_count);
 404         }
 405
 406         scmnd->result = request->Status;
 407
 408         if (scmnd->result) {
 409                 if (scsi_normalize_sense(scmnd->sense_buffer,
 410                                          request->SenseBufferSize, &sense_hdr))
 411                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 412         }
 413
 414         ASSERT(request->BytesXfer <= request->DataBuffer.Length);
 415         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 416
 417         scsi_done_fn = scmnd->scsi_done;
 418
 419         scmnd->host_scribble = NULL;
 420         scmnd->scsi_done = NULL;
 421
 422         /* !!DO NOT MODIFY the scmnd after this call */
 423         scsi_done_fn(scmnd);
 424
 425         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 426
 427         DPRINT_EXIT(STORVSC_DRV);
 428 }
 429
 430 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 431 {
 432         int i;
 433
 434         /* No need to check */
 435         if (sg_count < 2)
 436                 return -1;
 437
 438         /* We have at least 2 sg entries */
 439         for (i = 0; i < sg_count; i++) {
 440                 if (i == 0) {
 441                         /* make sure 1st one does not have hole */
 442                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 443                                 return i;
 444                 } else if (i == sg_count - 1) {
 445                         /* make sure last one does not have hole */
 446                         if (sgl[i].offset != 0)
 447                                 return i;
 448                 } else {
 449                         /* make sure no hole in the middle */
 450                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 451                                 return i;
 452                 }
 453         }
 454         return -1;
 455 }
 456
 457 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 458                                                 unsigned int sg_count,
 459                                                 unsigned int len)
 460 {
 461         int i;
 462         int num_pages;
 463         struct scatterlist *bounce_sgl;
 464         struct page *page_buf;
 465
 466         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 467
 468         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 469         if (!bounce_sgl)
 470                 return NULL;
 471
 472         for (i = 0; i < num_pages; i++) {
 473                 page_buf = alloc_page(GFP_ATOMIC);
 474                 if (!page_buf)
 475                         goto cleanup;
 476                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 477         }
 478
 479         return bounce_sgl;
 480
 481 cleanup:
 482         destroy_bounce_buffer(bounce_sgl, num_pages);
 483         return NULL;
 484 }
 485
 486 static void destroy_bounce_buffer(struct scatterlist *sgl,
 487                                   unsigned int sg_count)
 488 {
 489         int i;
 490         struct page *page_buf;
 491
 492         for (i = 0; i < sg_count; i++) {
 493                 page_buf = sg_page((&sgl[i]));
 494                 if (page_buf != NULL)
 495                         __free_page(page_buf);
 496         }
 497
 498         kfree(sgl);
 499 }
 500
 501 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 502 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 503                                           struct scatterlist *bounce_sgl,
 504                                           unsigned int orig_sgl_count)
 505 {
 506         int i;
 507         int j = 0;
 508         unsigned long src, dest;
 509         unsigned int srclen, destlen, copylen;
 510         unsigned int total_copied = 0;
 511         unsigned long bounce_addr = 0;
 512         unsigned long src_addr = 0;
 513         unsigned long flags;
 514
 515         local_irq_save(flags);
 516
 517         for (i = 0; i < orig_sgl_count; i++) {
 518                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 519                                 KM_IRQ0) + orig_sgl[i].offset;
 520                 src = src_addr;
 521                 srclen = orig_sgl[i].length;
 522
 523                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 524
 525                 if (j == 0)
 526                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 527
 528                 while (srclen) {
 529                         /* assume bounce offset always == 0 */
 530                         dest = bounce_addr + bounce_sgl[j].length;
 531                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 532
 533                         copylen = min(srclen, destlen);
 534                         memcpy((void *)dest, (void *)src, copylen);
 535
 536                         total_copied += copylen;
 537                         bounce_sgl[j].length += copylen;
 538                         srclen -= copylen;
 539                         src += copylen;
 540
 541                         if (bounce_sgl[j].length == PAGE_SIZE) {
 542                                 /* full..move to next entry */
 543                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 544                                 j++;
 545
 546                                 /* if we need to use another bounce buffer */
 547                                 if (srclen || i != orig_sgl_count - 1)
 548                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 549                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 550                                 /* unmap the last bounce that is < PAGE_SIZE */
 551                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 552                         }
 553                 }
 554
 555                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 556         }
 557
 558         local_irq_restore(flags);
 559
 560         return total_copied;
 561 }
 562
 563 /* Assume the original sgl has enough room */
 564 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 565                                             struct scatterlist *bounce_sgl,
 566                                             unsigned int orig_sgl_count)
 567 {
 568         int i;
 569         int j = 0;
 570         unsigned long src, dest;
 571         unsigned int srclen, destlen, copylen;
 572         unsigned int total_copied = 0;
 573         unsigned long bounce_addr = 0;
 574         unsigned long dest_addr = 0;
 575         unsigned long flags;
 576
 577         local_irq_save(flags);
 578
 579         for (i = 0; i < orig_sgl_count; i++) {
 580                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 581                                         KM_IRQ0) + orig_sgl[i].offset;
 582                 dest = dest_addr;
 583                 destlen = orig_sgl[i].length;
 584                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 585
 586                 if (j == 0)
 587                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 588
 589                 while (destlen) {
 590                         src = bounce_addr + bounce_sgl[j].offset;
 591                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 592
 593                         copylen = min(srclen, destlen);
 594                         memcpy((void *)dest, (void *)src, copylen);
 595
 596                         total_copied += copylen;
 597                         bounce_sgl[j].offset += copylen;
 598                         destlen -= copylen;
 599                         dest += copylen;
 600
 601                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 602                                 /* full */
 603                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 604                                 j++;
 605
 606                                 /* if we need to use another bounce buffer */
 607                                 if (destlen || i != orig_sgl_count - 1)
 608                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 609                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 610                                 /* unmap the last bounce that is < PAGE_SIZE */
 611                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 612                         }
 613                 }
 614
 615                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 616                               KM_IRQ0);
 617         }
 618
 619         local_irq_restore(flags);
 620
 621         return total_copied;
 622 }
 623
 624 /**
 625  * storvsc_queuecommand - Initiate command processing
 626  */
 627 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
 628                                 void (*done)(struct scsi_cmnd *))
 629 {
 630         int ret;
 631         struct host_device_context *host_device_ctx =
 632                 (struct host_device_context *)scmnd->device->host->hostdata;
 633         struct device_context *device_ctx = host_device_ctx->device_ctx;
 634         struct driver_context *driver_ctx =
 635                 driver_to_driver_context(device_ctx->device.driver);
 636         struct storvsc_driver_context *storvsc_drv_ctx =
 637                 (struct storvsc_driver_context *)driver_ctx;
 638         struct storvsc_driver_object *storvsc_drv_obj =
 639                 &storvsc_drv_ctx->drv_obj;
 640         struct hv_storvsc_request *request;
 641         struct storvsc_cmd_request *cmd_request;
 642         unsigned int request_size = 0;
 643         int i;
 644         struct scatterlist *sgl;
 645
 646         DPRINT_ENTER(STORVSC_DRV);
 647
 648         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 649                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 650                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 651                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 652                    scmnd->device->tagged_supported);
 653
 654         /* If retrying, no need to prep the cmd */
 655         if (scmnd->host_scribble) {
 656                 ASSERT(scmnd->scsi_done != NULL);
 657
 658                 cmd_request =
 659                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 660                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 661                             scmnd, cmd_request);
 662
 663                 goto retry_request;
 664         }
 665
 666         ASSERT(scmnd->scsi_done == NULL);
 667         ASSERT(scmnd->host_scribble == NULL);
 668
 669         scmnd->scsi_done = done;
 670
 671         request_size = sizeof(struct storvsc_cmd_request);
 672
 673         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 674                                        GFP_ATOMIC);
 675         if (!cmd_request) {
 676                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 677                            "storvsc_cmd_request...marking queue busy", scmnd);
 678                 scmnd->scsi_done = NULL;
 679                 return SCSI_MLQUEUE_DEVICE_BUSY;
 680         }
 681
 682         /* Setup the cmd request */
 683         cmd_request->bounce_sgl_count = 0;
 684         cmd_request->bounce_sgl = NULL;
 685         cmd_request->cmd = scmnd;
 686
 687         scmnd->host_scribble = (unsigned char *)cmd_request;
 688
 689         request = &cmd_request->request;
 690
 691         request->Extension =
 692                 (void *)((unsigned long)cmd_request + request_size);
 693         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 694                    storvsc_drv_obj->RequestExtSize);
 695
 696         /* Build the SRB */
 697         switch (scmnd->sc_data_direction) {
 698         case DMA_TO_DEVICE:
 699                 request->Type = WRITE_TYPE;
 700                 break;
 701         case DMA_FROM_DEVICE:
 702                 request->Type = READ_TYPE;
 703                 break;
 704         default:
 705                 request->Type = UNKNOWN_TYPE;
 706                 break;
 707         }
 708
 709         request->OnIOCompletion = storvsc_commmand_completion;
 710         request->Context = cmd_request;/* scmnd; */
 711
 712         /* request->PortId = scmnd->device->channel; */
 713         request->Host = host_device_ctx->port;
 714         request->Bus = scmnd->device->channel;
 715         request->TargetId = scmnd->device->id;
 716         request->LunId = scmnd->device->lun;
 717
 718         ASSERT(scmnd->cmd_len <= 16);
 719         request->CdbLen = scmnd->cmd_len;
 720         request->Cdb = scmnd->cmnd;
 721
 722         request->SenseBuffer = scmnd->sense_buffer;
 723         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 724
 725
 726         request->DataBuffer.Length = scsi_bufflen(scmnd);
 727         if (scsi_sg_count(scmnd)) {
 728                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 729
 730                 /* check if we need to bounce the sgl */
 731                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 732                         DPRINT_INFO(STORVSC_DRV,
 733                                     "need to bounce buffer for this scmnd %p",
 734                                     scmnd);
 735                         cmd_request->bounce_sgl =
 736                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 737                                                      scsi_bufflen(scmnd));
 738                         if (!cmd_request->bounce_sgl) {
 739                                 DPRINT_ERR(STORVSC_DRV,
 740                                            "unable to create bounce buffer for "
 741                                            "this scmnd %p", scmnd);
 742
 743                                 scmnd->scsi_done = NULL;
 744                                 scmnd->host_scribble = NULL;
 745                                 kmem_cache_free(host_device_ctx->request_pool,
 746                                                 cmd_request);
 747
 748                                 return SCSI_MLQUEUE_HOST_BUSY;
 749                         }
 750
 751                         cmd_request->bounce_sgl_count =
 752                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 753                                         PAGE_SHIFT;
 754
 755                         /*
 756                          * FIXME: We can optimize on reads by just skipping
 757                          * this
 758                          */
 759                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 760                                               scsi_sg_count(scmnd));
 761
 762                         sgl = cmd_request->bounce_sgl;
 763                 }
 764
 765                 request->DataBuffer.Offset = sgl[0].offset;
 766
 767                 for (i = 0; i < scsi_sg_count(scmnd); i++) {
 768                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d \n",
 769                                    i, sgl[i].length, sgl[i].offset);
 770                         request->DataBuffer.PfnArray[i] =
 771                                         page_to_pfn(sg_page((&sgl[i])));
 772                 }
 773         } else if (scsi_sglist(scmnd)) {
 774                 ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE);
 775                 request->DataBuffer.Offset =
 776                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 777                 request->DataBuffer.PfnArray[0] =
 778                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 779         } else {
 780                 ASSERT(scsi_bufflen(scmnd) == 0);
 781         }
 782
 783 retry_request:
 784         /* Invokes the vsc to start an IO */
 785         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj,
 786                                            &cmd_request->request);
 787         if (ret == -1) {
 788                 /* no more space */
 789                 DPRINT_ERR(STORVSC_DRV,
 790                            "scmnd (%p) - queue FULL...marking queue busy",
 791                            scmnd);
 792
 793                 if (cmd_request->bounce_sgl_count) {
 794                         /*
 795                          * FIXME: We can optimize on writes by just skipping
 796                          * this
 797                          */
 798                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 799                                                 cmd_request->bounce_sgl,
 800                                                 scsi_sg_count(scmnd));
 801                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 802                                               cmd_request->bounce_sgl_count);
 803                 }
 804
 805                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 806
 807                 scmnd->scsi_done = NULL;
 808                 scmnd->host_scribble = NULL;
 809
 810                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 811         }
 812
 813         DPRINT_EXIT(STORVSC_DRV);
 814
 815         return ret;
 816 }
 817
 818 static int storvsc_merge_bvec(struct request_queue *q,
 819                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 820 {
 821         /* checking done by caller. */
 822         return bvec->bv_len;
 823 }
 824
 825 /**
 826  * storvsc_device_configure - Configure the specified scsi device
 827  */
 828 static int storvsc_device_alloc(struct scsi_device *sdevice)
 829 {
 830         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d",
 831                    sdevice, BLIST_SPARSELUN);
 832         /*
 833          * This enables luns to be located sparsely. Otherwise, we may not
 834          * discovered them.
 835          */
 836         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 837         return 0;
 838 }
 839
 840 static int storvsc_device_configure(struct scsi_device *sdevice)
 841 {
 842         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - curr queue depth %d", sdevice,
 843                     sdevice->queue_depth);
 844
 845         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d",
 846                     sdevice, STORVSC_MAX_IO_REQUESTS);
 847         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 848                                 STORVSC_MAX_IO_REQUESTS);
 849
 850         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 851                     sdevice, PAGE_SIZE);
 852         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 853
 854         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 855                     sdevice);
 856         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 857
 858         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 859         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 860
 861         return 0;
 862 }
 863
 864 /**
 865  * storvsc_host_reset_handler - Reset the scsi HBA
 866  */
 867 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 868 {
 869         int ret;
 870         struct host_device_context *host_device_ctx =
 871                 (struct host_device_context *)scmnd->device->host->hostdata;
 872         struct device_context *device_ctx = host_device_ctx->device_ctx;
 873
 874         DPRINT_ENTER(STORVSC_DRV);
 875
 876         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 877                     scmnd->device, &device_ctx->device_obj);
 878
 879         /* Invokes the vsc to reset the host/bus */
 880         ret = StorVscOnHostReset(&device_ctx->device_obj);
 881         if (ret != 0) {
 882                 DPRINT_EXIT(STORVSC_DRV);
 883                 return ret;
 884         }
 885
 886         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 887                     scmnd->device, &device_ctx->device_obj);
 888
 889         DPRINT_EXIT(STORVSC_DRV);
 890
 891         return ret;
 892 }
 893
 894 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 895                            sector_t capacity, int *info)
 896 {
 897         sector_t total_sectors = capacity;
 898         sector_t cylinder_times_heads = 0;
 899         sector_t temp = 0;
 900
 901         int sectors_per_track = 0;
 902         int heads = 0;
 903         int cylinders = 0;
 904         int rem = 0;
 905
 906         if (total_sectors > (65535 * 16 * 255))
 907                 total_sectors = (65535 * 16 * 255);
 908
 909         if (total_sectors >= (65535 * 16 * 63)) {
 910                 sectors_per_track = 255;
 911                 heads = 16;
 912
 913                 cylinder_times_heads = total_sectors;
 914                 /* sector_div stores the quotient in cylinder_times_heads */
 915                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 916         } else {
 917                 sectors_per_track = 17;
 918
 919                 cylinder_times_heads = total_sectors;
 920                 /* sector_div stores the quotient in cylinder_times_heads */
 921                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 922
 923                 temp = cylinder_times_heads + 1023;
 924                 /* sector_div stores the quotient in temp */
 925                 rem = sector_div(temp, 1024);
 926
 927                 heads = temp;
 928
 929                 if (heads < 4)
 930                         heads = 4;
 931
 932                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
 933                         sectors_per_track = 31;
 934                         heads = 16;
 935
 936                         cylinder_times_heads = total_sectors;
 937                         /*
 938                          * sector_div stores the quotient in
 939                          * cylinder_times_heads
 940                          */
 941                         rem = sector_div(cylinder_times_heads,
 942                                          sectors_per_track);
 943                 }
 944
 945                 if (cylinder_times_heads >= (heads * 1024)) {
 946                         sectors_per_track = 63;
 947                         heads = 16;
 948
 949                         cylinder_times_heads = total_sectors;
 950                         /*
 951                          * sector_div stores the quotient in
 952                          * cylinder_times_heads
 953                          */
 954                         rem = sector_div(cylinder_times_heads,
 955                                          sectors_per_track);
 956                 }
 957         }
 958
 959         temp = cylinder_times_heads;
 960         /* sector_div stores the quotient in temp */
 961         rem = sector_div(temp, heads);
 962         cylinders = temp;
 963
 964         info[0] = heads;
 965         info[1] = sectors_per_track;
 966         info[2] = cylinders;
 967
 968         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
 969                     sectors_per_track);
 970
 971     return 0;
 972 }
 973
 974 static int __init storvsc_init(void)
 975 {
 976         int ret;
 977
 978         DPRINT_ENTER(STORVSC_DRV);
 979         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 980         ret = storvsc_drv_init(StorVscInitialize);
 981         DPRINT_EXIT(STORVSC_DRV);
 982         return ret;
 983 }
 984
 985 static void __exit storvsc_exit(void)
 986 {
 987         DPRINT_ENTER(STORVSC_DRV);
 988         storvsc_drv_exit();
 989         DPRINT_ENTER(STORVSC_DRV);
 990 }
 991
 992 MODULE_LICENSE("GPL");
 993 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 994 module_init(storvsc_init);
 995 module_exit(storvsc_exit);