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         DPRINT_ENTER(STORVSC_DRV);
 145
 146         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 147
 148         storvsc_drv_obj->RingBufferSize = storvsc_ringbuffer_size;
 149
 150         /* Callback to client driver to complete the initialization */
 151         drv_init(&storvsc_drv_obj->Base);
 152
 153         DPRINT_INFO(STORVSC_DRV,
 154                     "request extension size %u, max outstanding reqs %u",
 155                     storvsc_drv_obj->RequestExtSize,
 156                     storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 157
 158         if (storvsc_drv_obj->MaxOutstandingRequestsPerChannel <
 159             STORVSC_MAX_IO_REQUESTS) {
 160                 DPRINT_ERR(STORVSC_DRV,
 161                            "The number of outstanding io requests (%d) "
 162                            "is larger than that supported (%d) internally.",
 163                            STORVSC_MAX_IO_REQUESTS,
 164                            storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 165                 return -1;
 166         }
 167
 168         drv_ctx->driver.name = storvsc_drv_obj->Base.name;
 169         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->Base.deviceType,
 170                sizeof(struct hv_guid));
 171
 172         drv_ctx->probe = storvsc_probe;
 173         drv_ctx->remove = storvsc_remove;
 174
 175         /* The driver belongs to vmbus */
 176         ret = vmbus_child_driver_register(drv_ctx);
 177
 178         DPRINT_EXIT(STORVSC_DRV);
 179
 180         return ret;
 181 }
 182
 183 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 184 {
 185         struct device **curr = (struct device **)data;
 186         *curr = dev;
 187         return 1; /* stop iterating */
 188 }
 189
 190 static void storvsc_drv_exit(void)
 191 {
 192         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 193         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 194         struct device *current_dev = NULL;
 195         int ret;
 196
 197         DPRINT_ENTER(STORVSC_DRV);
 198
 199         while (1) {
 200                 current_dev = NULL;
 201
 202                 /* Get the device */
 203                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 204                                              (void *) &current_dev,
 205                                              storvsc_drv_exit_cb);
 206
 207                 if (ret)
 208                         DPRINT_WARN(STORVSC_DRV,
 209                                     "driver_for_each_device returned %d", ret);
 210
 211                 if (current_dev == NULL)
 212                         break;
 213
 214                 /* Initiate removal from the top-down */
 215                 device_unregister(current_dev);
 216         }
 217
 218         if (storvsc_drv_obj->Base.OnCleanup)
 219                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 220
 221         vmbus_child_driver_unregister(drv_ctx);
 222
 223         DPRINT_EXIT(STORVSC_DRV);
 224
 225         return;
 226 }
 227
 228 /*
 229  * storvsc_probe - Add a new device for this driver
 230  */
 231 static int storvsc_probe(struct device *device)
 232 {
 233         int ret;
 234         struct driver_context *driver_ctx =
 235                                 driver_to_driver_context(device->driver);
 236         struct storvsc_driver_context *storvsc_drv_ctx =
 237                                 (struct storvsc_driver_context *)driver_ctx;
 238         struct storvsc_driver_object *storvsc_drv_obj =
 239                                 &storvsc_drv_ctx->drv_obj;
 240         struct vm_device *device_ctx = device_to_vm_device(device);
 241         struct hv_device *device_obj = &device_ctx->device_obj;
 242         struct Scsi_Host *host;
 243         struct host_device_context *host_device_ctx;
 244         struct storvsc_device_info device_info;
 245
 246         DPRINT_ENTER(STORVSC_DRV);
 247
 248         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 249                 return -1;
 250
 251         host = scsi_host_alloc(&scsi_driver,
 252                                sizeof(struct host_device_context));
 253         if (!host) {
 254                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 255                 return -ENOMEM;
 256         }
 257
 258         dev_set_drvdata(device, host);
 259
 260         host_device_ctx = (struct host_device_context *)host->hostdata;
 261         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 262
 263         host_device_ctx->port = host->host_no;
 264         host_device_ctx->device_ctx = device_ctx;
 265
 266         host_device_ctx->request_pool =
 267                                 kmem_cache_create(dev_name(&device_ctx->device),
 268                                         sizeof(struct storvsc_cmd_request) +
 269                                         storvsc_drv_obj->RequestExtSize, 0,
 270                                         SLAB_HWCACHE_ALIGN, NULL);
 271
 272         if (!host_device_ctx->request_pool) {
 273                 scsi_host_put(host);
 274                 DPRINT_EXIT(STORVSC_DRV);
 275
 276                 return -ENOMEM;
 277         }
 278
 279         device_info.PortNumber = host->host_no;
 280         /* Call to the vsc driver to add the device */
 281         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj,
 282                                                 (void *)&device_info);
 283         if (ret != 0) {
 284                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 285                 kmem_cache_destroy(host_device_ctx->request_pool);
 286                 scsi_host_put(host);
 287                 DPRINT_EXIT(STORVSC_DRV);
 288
 289                 return -1;
 290         }
 291
 292         /* host_device_ctx->port = device_info.PortNumber; */
 293         host_device_ctx->path = device_info.PathId;
 294         host_device_ctx->target = device_info.TargetId;
 295
 296         /* max # of devices per target */
 297         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 298         /* max # of targets per channel */
 299         host->max_id = STORVSC_MAX_TARGETS;
 300         /* max # of channels */
 301         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 302
 303         /* Register the HBA and start the scsi bus scan */
 304         ret = scsi_add_host(host, device);
 305         if (ret != 0) {
 306                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 307
 308                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 309
 310                 kmem_cache_destroy(host_device_ctx->request_pool);
 311                 scsi_host_put(host);
 312                 DPRINT_EXIT(STORVSC_DRV);
 313
 314                 return -1;
 315         }
 316
 317         scsi_scan_host(host);
 318
 319         DPRINT_EXIT(STORVSC_DRV);
 320
 321         return ret;
 322 }
 323
 324 /*
 325  * storvsc_remove - Callback when our device is removed
 326  */
 327 static int storvsc_remove(struct device *device)
 328 {
 329         int ret;
 330         struct driver_context *driver_ctx =
 331                         driver_to_driver_context(device->driver);
 332         struct storvsc_driver_context *storvsc_drv_ctx =
 333                         (struct storvsc_driver_context *)driver_ctx;
 334         struct storvsc_driver_object *storvsc_drv_obj =
 335                         &storvsc_drv_ctx->drv_obj;
 336         struct vm_device *device_ctx = device_to_vm_device(device);
 337         struct hv_device *device_obj = &device_ctx->device_obj;
 338         struct Scsi_Host *host = dev_get_drvdata(device);
 339         struct host_device_context *host_device_ctx =
 340                         (struct host_device_context *)host->hostdata;
 341
 342
 343         DPRINT_ENTER(STORVSC_DRV);
 344
 345         if (!storvsc_drv_obj->Base.OnDeviceRemove) {
 346                 DPRINT_EXIT(STORVSC_DRV);
 347                 return -1;
 348         }
 349
 350         /*
 351          * Call to the vsc driver to let it know that the device is being
 352          * removed
 353          */
 354         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 355         if (ret != 0) {
 356                 /* TODO: */
 357                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 358                            ret);
 359         }
 360
 361         if (host_device_ctx->request_pool) {
 362                 kmem_cache_destroy(host_device_ctx->request_pool);
 363                 host_device_ctx->request_pool = NULL;
 364         }
 365
 366         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 367         scsi_remove_host(host);
 368
 369         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 370         scsi_host_put(host);
 371
 372         DPRINT_EXIT(STORVSC_DRV);
 373
 374         return ret;
 375 }
 376
 377 /*
 378  * storvsc_commmand_completion - Command completion processing
 379  */
 380 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 381 {
 382         struct storvsc_cmd_request *cmd_request =
 383                 (struct storvsc_cmd_request *)request->Context;
 384         struct scsi_cmnd *scmnd = cmd_request->cmd;
 385         struct host_device_context *host_device_ctx =
 386                 (struct host_device_context *)scmnd->device->host->hostdata;
 387         void (*scsi_done_fn)(struct scsi_cmnd *);
 388         struct scsi_sense_hdr sense_hdr;
 389
 390         /* ASSERT(request == &cmd_request->request); */
 391         /* ASSERT(scmnd); */
 392         /* ASSERT((unsigned long)scmnd->host_scribble == */
 393         /*        (unsigned long)cmd_request); */
 394         /* ASSERT(scmnd->scsi_done); */
 395
 396         DPRINT_ENTER(STORVSC_DRV);
 397
 398         if (cmd_request->bounce_sgl_count) {
 399                 /* using bounce buffer */
 400                 /* printk("copy_from_bounce_buffer\n"); */
 401
 402                 /* FIXME: We can optimize on writes by just skipping this */
 403                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 404                                         cmd_request->bounce_sgl,
 405                                         scsi_sg_count(scmnd));
 406                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 407                                       cmd_request->bounce_sgl_count);
 408         }
 409
 410         scmnd->result = request->Status;
 411
 412         if (scmnd->result) {
 413                 if (scsi_normalize_sense(scmnd->sense_buffer,
 414                                          request->SenseBufferSize, &sense_hdr))
 415                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 416         }
 417
 418         /* ASSERT(request->BytesXfer <= request->DataBuffer.Length); */
 419         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 420
 421         scsi_done_fn = scmnd->scsi_done;
 422
 423         scmnd->host_scribble = NULL;
 424         scmnd->scsi_done = NULL;
 425
 426         /* !!DO NOT MODIFY the scmnd after this call */
 427         scsi_done_fn(scmnd);
 428
 429         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 430
 431         DPRINT_EXIT(STORVSC_DRV);
 432 }
 433
 434 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 435 {
 436         int i;
 437
 438         /* No need to check */
 439         if (sg_count < 2)
 440                 return -1;
 441
 442         /* We have at least 2 sg entries */
 443         for (i = 0; i < sg_count; i++) {
 444                 if (i == 0) {
 445                         /* make sure 1st one does not have hole */
 446                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 447                                 return i;
 448                 } else if (i == sg_count - 1) {
 449                         /* make sure last one does not have hole */
 450                         if (sgl[i].offset != 0)
 451                                 return i;
 452                 } else {
 453                         /* make sure no hole in the middle */
 454                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 455                                 return i;
 456                 }
 457         }
 458         return -1;
 459 }
 460
 461 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 462                                                 unsigned int sg_count,
 463                                                 unsigned int len)
 464 {
 465         int i;
 466         int num_pages;
 467         struct scatterlist *bounce_sgl;
 468         struct page *page_buf;
 469
 470         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 471
 472         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 473         if (!bounce_sgl)
 474                 return NULL;
 475
 476         for (i = 0; i < num_pages; i++) {
 477                 page_buf = alloc_page(GFP_ATOMIC);
 478                 if (!page_buf)
 479                         goto cleanup;
 480                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 481         }
 482
 483         return bounce_sgl;
 484
 485 cleanup:
 486         destroy_bounce_buffer(bounce_sgl, num_pages);
 487         return NULL;
 488 }
 489
 490 static void destroy_bounce_buffer(struct scatterlist *sgl,
 491                                   unsigned int sg_count)
 492 {
 493         int i;
 494         struct page *page_buf;
 495
 496         for (i = 0; i < sg_count; i++) {
 497                 page_buf = sg_page((&sgl[i]));
 498                 if (page_buf != NULL)
 499                         __free_page(page_buf);
 500         }
 501
 502         kfree(sgl);
 503 }
 504
 505 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 506 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 507                                           struct scatterlist *bounce_sgl,
 508                                           unsigned int orig_sgl_count)
 509 {
 510         int i;
 511         int j = 0;
 512         unsigned long src, dest;
 513         unsigned int srclen, destlen, copylen;
 514         unsigned int total_copied = 0;
 515         unsigned long bounce_addr = 0;
 516         unsigned long src_addr = 0;
 517         unsigned long flags;
 518
 519         local_irq_save(flags);
 520
 521         for (i = 0; i < orig_sgl_count; i++) {
 522                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 523                                 KM_IRQ0) + orig_sgl[i].offset;
 524                 src = src_addr;
 525                 srclen = orig_sgl[i].length;
 526
 527                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 528
 529                 if (j == 0)
 530                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 531
 532                 while (srclen) {
 533                         /* assume bounce offset always == 0 */
 534                         dest = bounce_addr + bounce_sgl[j].length;
 535                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 536
 537                         copylen = min(srclen, destlen);
 538                         memcpy((void *)dest, (void *)src, copylen);
 539
 540                         total_copied += copylen;
 541                         bounce_sgl[j].length += copylen;
 542                         srclen -= copylen;
 543                         src += copylen;
 544
 545                         if (bounce_sgl[j].length == PAGE_SIZE) {
 546                                 /* full..move to next entry */
 547                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 548                                 j++;
 549
 550                                 /* if we need to use another bounce buffer */
 551                                 if (srclen || i != orig_sgl_count - 1)
 552                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 553                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 554                                 /* unmap the last bounce that is < PAGE_SIZE */
 555                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 556                         }
 557                 }
 558
 559                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 560         }
 561
 562         local_irq_restore(flags);
 563
 564         return total_copied;
 565 }
 566
 567 /* Assume the original sgl has enough room */
 568 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 569                                             struct scatterlist *bounce_sgl,
 570                                             unsigned int orig_sgl_count)
 571 {
 572         int i;
 573         int j = 0;
 574         unsigned long src, dest;
 575         unsigned int srclen, destlen, copylen;
 576         unsigned int total_copied = 0;
 577         unsigned long bounce_addr = 0;
 578         unsigned long dest_addr = 0;
 579         unsigned long flags;
 580
 581         local_irq_save(flags);
 582
 583         for (i = 0; i < orig_sgl_count; i++) {
 584                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 585                                         KM_IRQ0) + orig_sgl[i].offset;
 586                 dest = dest_addr;
 587                 destlen = orig_sgl[i].length;
 588                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 589
 590                 if (j == 0)
 591                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 592
 593                 while (destlen) {
 594                         src = bounce_addr + bounce_sgl[j].offset;
 595                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 596
 597                         copylen = min(srclen, destlen);
 598                         memcpy((void *)dest, (void *)src, copylen);
 599
 600                         total_copied += copylen;
 601                         bounce_sgl[j].offset += copylen;
 602                         destlen -= copylen;
 603                         dest += copylen;
 604
 605                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 606                                 /* full */
 607                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 608                                 j++;
 609
 610                                 /* if we need to use another bounce buffer */
 611                                 if (destlen || i != orig_sgl_count - 1)
 612                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 613                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 614                                 /* unmap the last bounce that is < PAGE_SIZE */
 615                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 616                         }
 617                 }
 618
 619                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 620                               KM_IRQ0);
 621         }
 622
 623         local_irq_restore(flags);
 624
 625         return total_copied;
 626 }
 627
 628 /*
 629  * storvsc_queuecommand - Initiate command processing
 630  */
 631 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
 632                                 void (*done)(struct scsi_cmnd *))
 633 {
 634         int ret;
 635         struct host_device_context *host_device_ctx =
 636                 (struct host_device_context *)scmnd->device->host->hostdata;
 637         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 638         struct driver_context *driver_ctx =
 639                 driver_to_driver_context(device_ctx->device.driver);
 640         struct storvsc_driver_context *storvsc_drv_ctx =
 641                 (struct storvsc_driver_context *)driver_ctx;
 642         struct storvsc_driver_object *storvsc_drv_obj =
 643                 &storvsc_drv_ctx->drv_obj;
 644         struct hv_storvsc_request *request;
 645         struct storvsc_cmd_request *cmd_request;
 646         unsigned int request_size = 0;
 647         int i;
 648         struct scatterlist *sgl;
 649
 650         DPRINT_ENTER(STORVSC_DRV);
 651
 652         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 653                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 654                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 655                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 656                    scmnd->device->tagged_supported);
 657
 658         /* If retrying, no need to prep the cmd */
 659         if (scmnd->host_scribble) {
 660                 /* ASSERT(scmnd->scsi_done != NULL); */
 661
 662                 cmd_request =
 663                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 664                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 665                             scmnd, cmd_request);
 666
 667                 goto retry_request;
 668         }
 669
 670         /* ASSERT(scmnd->scsi_done == NULL); */
 671         /* ASSERT(scmnd->host_scribble == NULL); */
 672
 673         scmnd->scsi_done = done;
 674
 675         request_size = sizeof(struct storvsc_cmd_request);
 676
 677         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 678                                        GFP_ATOMIC);
 679         if (!cmd_request) {
 680                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 681                            "storvsc_cmd_request...marking queue busy", scmnd);
 682                 scmnd->scsi_done = NULL;
 683                 return SCSI_MLQUEUE_DEVICE_BUSY;
 684         }
 685
 686         /* Setup the cmd request */
 687         cmd_request->bounce_sgl_count = 0;
 688         cmd_request->bounce_sgl = NULL;
 689         cmd_request->cmd = scmnd;
 690
 691         scmnd->host_scribble = (unsigned char *)cmd_request;
 692
 693         request = &cmd_request->request;
 694
 695         request->Extension =
 696                 (void *)((unsigned long)cmd_request + request_size);
 697         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 698                    storvsc_drv_obj->RequestExtSize);
 699
 700         /* Build the SRB */
 701         switch (scmnd->sc_data_direction) {
 702         case DMA_TO_DEVICE:
 703                 request->Type = WRITE_TYPE;
 704                 break;
 705         case DMA_FROM_DEVICE:
 706                 request->Type = READ_TYPE;
 707                 break;
 708         default:
 709                 request->Type = UNKNOWN_TYPE;
 710                 break;
 711         }
 712
 713         request->OnIOCompletion = storvsc_commmand_completion;
 714         request->Context = cmd_request;/* scmnd; */
 715
 716         /* request->PortId = scmnd->device->channel; */
 717         request->Host = host_device_ctx->port;
 718         request->Bus = scmnd->device->channel;
 719         request->TargetId = scmnd->device->id;
 720         request->LunId = scmnd->device->lun;
 721
 722         /* ASSERT(scmnd->cmd_len <= 16); */
 723         request->CdbLen = scmnd->cmd_len;
 724         request->Cdb = scmnd->cmnd;
 725
 726         request->SenseBuffer = scmnd->sense_buffer;
 727         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 728
 729
 730         request->DataBuffer.Length = scsi_bufflen(scmnd);
 731         if (scsi_sg_count(scmnd)) {
 732                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 733
 734                 /* check if we need to bounce the sgl */
 735                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 736                         DPRINT_INFO(STORVSC_DRV,
 737                                     "need to bounce buffer for this scmnd %p",
 738                                     scmnd);
 739                         cmd_request->bounce_sgl =
 740                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 741                                                      scsi_bufflen(scmnd));
 742                         if (!cmd_request->bounce_sgl) {
 743                                 DPRINT_ERR(STORVSC_DRV,
 744                                            "unable to create bounce buffer for "
 745                                            "this scmnd %p", scmnd);
 746
 747                                 scmnd->scsi_done = NULL;
 748                                 scmnd->host_scribble = NULL;
 749                                 kmem_cache_free(host_device_ctx->request_pool,
 750                                                 cmd_request);
 751
 752                                 return SCSI_MLQUEUE_HOST_BUSY;
 753                         }
 754
 755                         cmd_request->bounce_sgl_count =
 756                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 757                                         PAGE_SHIFT;
 758
 759                         /*
 760                          * FIXME: We can optimize on reads by just skipping
 761                          * this
 762                          */
 763                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 764                                               scsi_sg_count(scmnd));
 765
 766                         sgl = cmd_request->bounce_sgl;
 767                 }
 768
 769                 request->DataBuffer.Offset = sgl[0].offset;
 770
 771                 for (i = 0; i < scsi_sg_count(scmnd); i++) {
 772                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d\n",
 773                                    i, sgl[i].length, sgl[i].offset);
 774                         request->DataBuffer.PfnArray[i] =
 775                                         page_to_pfn(sg_page((&sgl[i])));
 776                 }
 777         } else if (scsi_sglist(scmnd)) {
 778                 /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
 779                 request->DataBuffer.Offset =
 780                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 781                 request->DataBuffer.PfnArray[0] =
 782                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 783         }
 784
 785 retry_request:
 786         /* Invokes the vsc to start an IO */
 787         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj,
 788                                            &cmd_request->request);
 789         if (ret == -1) {
 790                 /* no more space */
 791                 DPRINT_ERR(STORVSC_DRV,
 792                            "scmnd (%p) - queue FULL...marking queue busy",
 793                            scmnd);
 794
 795                 if (cmd_request->bounce_sgl_count) {
 796                         /*
 797                          * FIXME: We can optimize on writes by just skipping
 798                          * this
 799                          */
 800                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 801                                                 cmd_request->bounce_sgl,
 802                                                 scsi_sg_count(scmnd));
 803                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 804                                               cmd_request->bounce_sgl_count);
 805                 }
 806
 807                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 808
 809                 scmnd->scsi_done = NULL;
 810                 scmnd->host_scribble = NULL;
 811
 812                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 813         }
 814
 815         DPRINT_EXIT(STORVSC_DRV);
 816
 817         return ret;
 818 }
 819
 820 static int storvsc_merge_bvec(struct request_queue *q,
 821                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 822 {
 823         /* checking done by caller. */
 824         return bvec->bv_len;
 825 }
 826
 827 /*
 828  * storvsc_device_configure - Configure the specified scsi device
 829  */
 830 static int storvsc_device_alloc(struct scsi_device *sdevice)
 831 {
 832         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d",
 833                    sdevice, BLIST_SPARSELUN);
 834         /*
 835          * This enables luns to be located sparsely. Otherwise, we may not
 836          * discovered them.
 837          */
 838         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 839         return 0;
 840 }
 841
 842 static int storvsc_device_configure(struct scsi_device *sdevice)
 843 {
 844         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - curr queue depth %d", sdevice,
 845                     sdevice->queue_depth);
 846
 847         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d",
 848                     sdevice, STORVSC_MAX_IO_REQUESTS);
 849         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 850                                 STORVSC_MAX_IO_REQUESTS);
 851
 852         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 853                     sdevice, PAGE_SIZE);
 854         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 855
 856         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 857                     sdevice);
 858         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 859
 860         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 861         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 862
 863         return 0;
 864 }
 865
 866 /*
 867  * storvsc_host_reset_handler - Reset the scsi HBA
 868  */
 869 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 870 {
 871         int ret;
 872         struct host_device_context *host_device_ctx =
 873                 (struct host_device_context *)scmnd->device->host->hostdata;
 874         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 875
 876         DPRINT_ENTER(STORVSC_DRV);
 877
 878         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 879                     scmnd->device, &device_ctx->device_obj);
 880
 881         /* Invokes the vsc to reset the host/bus */
 882         ret = StorVscOnHostReset(&device_ctx->device_obj);
 883         if (ret != 0) {
 884                 DPRINT_EXIT(STORVSC_DRV);
 885                 return ret;
 886         }
 887
 888         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 889                     scmnd->device, &device_ctx->device_obj);
 890
 891         DPRINT_EXIT(STORVSC_DRV);
 892
 893         return ret;
 894 }
 895
 896 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 897                            sector_t capacity, int *info)
 898 {
 899         sector_t total_sectors = capacity;
 900         sector_t cylinder_times_heads = 0;
 901         sector_t temp = 0;
 902
 903         int sectors_per_track = 0;
 904         int heads = 0;
 905         int cylinders = 0;
 906         int rem = 0;
 907
 908         if (total_sectors > (65535 * 16 * 255))
 909                 total_sectors = (65535 * 16 * 255);
 910
 911         if (total_sectors >= (65535 * 16 * 63)) {
 912                 sectors_per_track = 255;
 913                 heads = 16;
 914
 915                 cylinder_times_heads = total_sectors;
 916                 /* sector_div stores the quotient in cylinder_times_heads */
 917                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 918         } else {
 919                 sectors_per_track = 17;
 920
 921                 cylinder_times_heads = total_sectors;
 922                 /* sector_div stores the quotient in cylinder_times_heads */
 923                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 924
 925                 temp = cylinder_times_heads + 1023;
 926                 /* sector_div stores the quotient in temp */
 927                 rem = sector_div(temp, 1024);
 928
 929                 heads = temp;
 930
 931                 if (heads < 4)
 932                         heads = 4;
 933
 934                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
 935                         sectors_per_track = 31;
 936                         heads = 16;
 937
 938                         cylinder_times_heads = total_sectors;
 939                         /*
 940                          * sector_div stores the quotient in
 941                          * cylinder_times_heads
 942                          */
 943                         rem = sector_div(cylinder_times_heads,
 944                                          sectors_per_track);
 945                 }
 946
 947                 if (cylinder_times_heads >= (heads * 1024)) {
 948                         sectors_per_track = 63;
 949                         heads = 16;
 950
 951                         cylinder_times_heads = total_sectors;
 952                         /*
 953                          * sector_div stores the quotient in
 954                          * cylinder_times_heads
 955                          */
 956                         rem = sector_div(cylinder_times_heads,
 957                                          sectors_per_track);
 958                 }
 959         }
 960
 961         temp = cylinder_times_heads;
 962         /* sector_div stores the quotient in temp */
 963         rem = sector_div(temp, heads);
 964         cylinders = temp;
 965
 966         info[0] = heads;
 967         info[1] = sectors_per_track;
 968         info[2] = cylinders;
 969
 970         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
 971                     sectors_per_track);
 972
 973     return 0;
 974 }
 975
 976 static int __init storvsc_init(void)
 977 {
 978         int ret;
 979
 980         DPRINT_ENTER(STORVSC_DRV);
 981         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 982         ret = storvsc_drv_init(StorVscInitialize);
 983         DPRINT_EXIT(STORVSC_DRV);
 984         return ret;
 985 }
 986
 987 static void __exit storvsc_exit(void)
 988 {
 989         DPRINT_ENTER(STORVSC_DRV);
 990         storvsc_drv_exit();
 991         DPRINT_ENTER(STORVSC_DRV);
 992 }
 993
 994 MODULE_LICENSE("GPL");
 995 MODULE_VERSION(HV_DRV_VERSION);
 996 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
 997 module_init(storvsc_init);
 998 module_exit(storvsc_exit);