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 "VersionInfo.h"
  37 #include "vmbus.h"
  38 #include "StorVscApi.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
 101 /* The one and only one */
 102 static struct storvsc_driver_context g_storvsc_drv;
 103
 104 /* Scsi driver */
 105 static struct scsi_host_template scsi_driver = {
 106         .module =               THIS_MODULE,
 107         .name =                 "storvsc_host_t",
 108         .bios_param =           storvsc_get_chs,
 109         .queuecommand =         storvsc_queuecommand,
 110         .eh_host_reset_handler =        storvsc_host_reset_handler,
 111         .slave_alloc =          storvsc_device_alloc,
 112         .slave_configure =      storvsc_device_configure,
 113         .cmd_per_lun =          1,
 114         /* 64 max_queue * 1 target */
 115         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 116         .this_id =              -1,
 117         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 118         /* currently 32 */
 119         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 120         /*
 121          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 122          * into 1 sg element. If set, we must limit the max_segment_size to
 123          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 124          * multiple
 125          */
 126         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 127         .use_clustering =       ENABLE_CLUSTERING,
 128         /* Make sure we dont get a sg segment crosses a page boundary */
 129         .dma_boundary =         PAGE_SIZE-1,
 130 };
 131
 132
 133 /**
 134  * storvsc_drv_init - StorVsc driver initialization.
 135  */
 136 static int storvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 137 {
 138         int ret;
 139         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 140         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 141
 142         DPRINT_ENTER(STORVSC_DRV);
 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         DPRINT_ENTER(STORVSC_DRV);
 196
 197         while (1) {
 198                 current_dev = NULL;
 199
 200                 /* Get the device */
 201                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 202                                              (void *) &current_dev,
 203                                              storvsc_drv_exit_cb);
 204
 205                 if (ret)
 206                         DPRINT_WARN(STORVSC_DRV,
 207                                     "driver_for_each_device returned %d", ret);
 208
 209                 if (current_dev == NULL)
 210                         break;
 211
 212                 /* Initiate removal from the top-down */
 213                 device_unregister(current_dev);
 214         }
 215
 216         if (storvsc_drv_obj->Base.OnCleanup)
 217                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 218
 219         vmbus_child_driver_unregister(drv_ctx);
 220
 221         DPRINT_EXIT(STORVSC_DRV);
 222
 223         return;
 224 }
 225
 226 /**
 227  * storvsc_probe - Add a new device for this driver
 228  */
 229 static int storvsc_probe(struct device *device)
 230 {
 231         int ret;
 232         struct driver_context *driver_ctx =
 233                                 driver_to_driver_context(device->driver);
 234         struct storvsc_driver_context *storvsc_drv_ctx =
 235                                 (struct storvsc_driver_context *)driver_ctx;
 236         struct storvsc_driver_object *storvsc_drv_obj =
 237                                 &storvsc_drv_ctx->drv_obj;
 238         struct vm_device *device_ctx = device_to_vm_device(device);
 239         struct hv_device *device_obj = &device_ctx->device_obj;
 240         struct Scsi_Host *host;
 241         struct host_device_context *host_device_ctx;
 242         struct storvsc_device_info device_info;
 243
 244         DPRINT_ENTER(STORVSC_DRV);
 245
 246         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 247                 return -1;
 248
 249         host = scsi_host_alloc(&scsi_driver,
 250                                sizeof(struct host_device_context));
 251         if (!host) {
 252                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 253                 return -ENOMEM;
 254         }
 255
 256         dev_set_drvdata(device, host);
 257
 258         host_device_ctx = (struct host_device_context *)host->hostdata;
 259         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 260
 261         host_device_ctx->port = host->host_no;
 262         host_device_ctx->device_ctx = device_ctx;
 263
 264         host_device_ctx->request_pool =
 265                                 kmem_cache_create(dev_name(&device_ctx->device),
 266                                         sizeof(struct storvsc_cmd_request) +
 267                                         storvsc_drv_obj->RequestExtSize, 0,
 268                                         SLAB_HWCACHE_ALIGN, NULL);
 269
 270         if (!host_device_ctx->request_pool) {
 271                 scsi_host_put(host);
 272                 DPRINT_EXIT(STORVSC_DRV);
 273
 274                 return -ENOMEM;
 275         }
 276
 277         device_info.PortNumber = host->host_no;
 278         /* Call to the vsc driver to add the device */
 279         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj,
 280                                                 (void *)&device_info);
 281         if (ret != 0) {
 282                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 283                 kmem_cache_destroy(host_device_ctx->request_pool);
 284                 scsi_host_put(host);
 285                 DPRINT_EXIT(STORVSC_DRV);
 286
 287                 return -1;
 288         }
 289
 290         /* host_device_ctx->port = device_info.PortNumber; */
 291         host_device_ctx->path = device_info.PathId;
 292         host_device_ctx->target = device_info.TargetId;
 293
 294         /* max # of devices per target */
 295         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 296         /* max # of targets per channel */
 297         host->max_id = STORVSC_MAX_TARGETS;
 298         /* max # of channels */
 299         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 300
 301         /* Register the HBA and start the scsi bus scan */
 302         ret = scsi_add_host(host, device);
 303         if (ret != 0) {
 304                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 305
 306                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 307
 308                 kmem_cache_destroy(host_device_ctx->request_pool);
 309                 scsi_host_put(host);
 310                 DPRINT_EXIT(STORVSC_DRV);
 311
 312                 return -1;
 313         }
 314
 315         scsi_scan_host(host);
 316
 317         DPRINT_EXIT(STORVSC_DRV);
 318
 319         return ret;
 320 }
 321
 322 /**
 323  * storvsc_remove - Callback when our device is removed
 324  */
 325 static int storvsc_remove(struct device *device)
 326 {
 327         int ret;
 328         struct driver_context *driver_ctx =
 329                         driver_to_driver_context(device->driver);
 330         struct storvsc_driver_context *storvsc_drv_ctx =
 331                         (struct storvsc_driver_context *)driver_ctx;
 332         struct storvsc_driver_object *storvsc_drv_obj =
 333                         &storvsc_drv_ctx->drv_obj;
 334         struct vm_device *device_ctx = device_to_vm_device(device);
 335         struct hv_device *device_obj = &device_ctx->device_obj;
 336         struct Scsi_Host *host = dev_get_drvdata(device);
 337         struct host_device_context *host_device_ctx =
 338                         (struct host_device_context *)host->hostdata;
 339
 340
 341         DPRINT_ENTER(STORVSC_DRV);
 342
 343         if (!storvsc_drv_obj->Base.OnDeviceRemove) {
 344                 DPRINT_EXIT(STORVSC_DRV);
 345                 return -1;
 346         }
 347
 348         /*
 349          * Call to the vsc driver to let it know that the device is being
 350          * removed
 351          */
 352         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 353         if (ret != 0) {
 354                 /* TODO: */
 355                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 356                            ret);
 357         }
 358
 359         if (host_device_ctx->request_pool) {
 360                 kmem_cache_destroy(host_device_ctx->request_pool);
 361                 host_device_ctx->request_pool = NULL;
 362         }
 363
 364         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 365         scsi_remove_host(host);
 366
 367         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 368         scsi_host_put(host);
 369
 370         DPRINT_EXIT(STORVSC_DRV);
 371
 372         return ret;
 373 }
 374
 375 /**
 376  * storvsc_commmand_completion - Command completion processing
 377  */
 378 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 379 {
 380         struct storvsc_cmd_request *cmd_request =
 381                 (struct storvsc_cmd_request *)request->Context;
 382         struct scsi_cmnd *scmnd = cmd_request->cmd;
 383         struct host_device_context *host_device_ctx =
 384                 (struct host_device_context *)scmnd->device->host->hostdata;
 385         void (*scsi_done_fn)(struct scsi_cmnd *);
 386         struct scsi_sense_hdr sense_hdr;
 387
 388         ASSERT(request == &cmd_request->request);
 389         ASSERT((unsigned long)scmnd->host_scribble ==
 390                 (unsigned long)cmd_request);
 391         ASSERT(scmnd);
 392         ASSERT(scmnd->scsi_done);
 393
 394         DPRINT_ENTER(STORVSC_DRV);
 395
 396         if (cmd_request->bounce_sgl_count) {
 397                 /* using bounce buffer */
 398                 /* printk("copy_from_bounce_buffer\n"); */
 399
 400                 /* FIXME: We can optimize on writes by just skipping this */
 401                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 402                                         cmd_request->bounce_sgl,
 403                                         scsi_sg_count(scmnd));
 404                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 405                                       cmd_request->bounce_sgl_count);
 406         }
 407
 408         scmnd->result = request->Status;
 409
 410         if (scmnd->result) {
 411                 if (scsi_normalize_sense(scmnd->sense_buffer,
 412                                          request->SenseBufferSize, &sense_hdr))
 413                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 414         }
 415
 416         ASSERT(request->BytesXfer <= request->DataBuffer.Length);
 417         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 418
 419         scsi_done_fn = scmnd->scsi_done;
 420
 421         scmnd->host_scribble = NULL;
 422         scmnd->scsi_done = NULL;
 423
 424         /* !!DO NOT MODIFY the scmnd after this call */
 425         scsi_done_fn(scmnd);
 426
 427         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 428
 429         DPRINT_EXIT(STORVSC_DRV);
 430 }
 431
 432 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 433 {
 434         int i;
 435
 436         /* No need to check */
 437         if (sg_count < 2)
 438                 return -1;
 439
 440         /* We have at least 2 sg entries */
 441         for (i = 0; i < sg_count; i++) {
 442                 if (i == 0) {
 443                         /* make sure 1st one does not have hole */
 444                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 445                                 return i;
 446                 } else if (i == sg_count - 1) {
 447                         /* make sure last one does not have hole */
 448                         if (sgl[i].offset != 0)
 449                                 return i;
 450                 } else {
 451                         /* make sure no hole in the middle */
 452                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 453                                 return i;
 454                 }
 455         }
 456         return -1;
 457 }
 458
 459 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 460                                                 unsigned int sg_count,
 461                                                 unsigned int len)
 462 {
 463         int i;
 464         int num_pages;
 465         struct scatterlist *bounce_sgl;
 466         struct page *page_buf;
 467
 468         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 469
 470         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 471         if (!bounce_sgl)
 472                 return NULL;
 473
 474         for (i = 0; i < num_pages; i++) {
 475                 page_buf = alloc_page(GFP_ATOMIC);
 476                 if (!page_buf)
 477                         goto cleanup;
 478                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 479         }
 480
 481         return bounce_sgl;
 482
 483 cleanup:
 484         destroy_bounce_buffer(bounce_sgl, num_pages);
 485         return NULL;
 486 }
 487
 488 static void destroy_bounce_buffer(struct scatterlist *sgl,
 489                                   unsigned int sg_count)
 490 {
 491         int i;
 492         struct page *page_buf;
 493
 494         for (i = 0; i < sg_count; i++) {
 495                 page_buf = sg_page((&sgl[i]));
 496                 if (page_buf != NULL)
 497                         __free_page(page_buf);
 498         }
 499
 500         kfree(sgl);
 501 }
 502
 503 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 504 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 505                                           struct scatterlist *bounce_sgl,
 506                                           unsigned int orig_sgl_count)
 507 {
 508         int i;
 509         int j = 0;
 510         unsigned long src, dest;
 511         unsigned int srclen, destlen, copylen;
 512         unsigned int total_copied = 0;
 513         unsigned long bounce_addr = 0;
 514         unsigned long src_addr = 0;
 515         unsigned long flags;
 516
 517         local_irq_save(flags);
 518
 519         for (i = 0; i < orig_sgl_count; i++) {
 520                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 521                                 KM_IRQ0) + orig_sgl[i].offset;
 522                 src = src_addr;
 523                 srclen = orig_sgl[i].length;
 524
 525                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 526
 527                 if (j == 0)
 528                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 529
 530                 while (srclen) {
 531                         /* assume bounce offset always == 0 */
 532                         dest = bounce_addr + bounce_sgl[j].length;
 533                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 534
 535                         copylen = min(srclen, destlen);
 536                         memcpy((void *)dest, (void *)src, copylen);
 537
 538                         total_copied += copylen;
 539                         bounce_sgl[j].length += copylen;
 540                         srclen -= copylen;
 541                         src += copylen;
 542
 543                         if (bounce_sgl[j].length == PAGE_SIZE) {
 544                                 /* full..move to next entry */
 545                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 546                                 j++;
 547
 548                                 /* if we need to use another bounce buffer */
 549                                 if (srclen || i != orig_sgl_count - 1)
 550                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 551                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 552                                 /* unmap the last bounce that is < PAGE_SIZE */
 553                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 554                         }
 555                 }
 556
 557                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 558         }
 559
 560         local_irq_restore(flags);
 561
 562         return total_copied;
 563 }
 564
 565 /* Assume the original sgl has enough room */
 566 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 567                                             struct scatterlist *bounce_sgl,
 568                                             unsigned int orig_sgl_count)
 569 {
 570         int i;
 571         int j = 0;
 572         unsigned long src, dest;
 573         unsigned int srclen, destlen, copylen;
 574         unsigned int total_copied = 0;
 575         unsigned long bounce_addr = 0;
 576         unsigned long dest_addr = 0;
 577         unsigned long flags;
 578
 579         local_irq_save(flags);
 580
 581         for (i = 0; i < orig_sgl_count; i++) {
 582                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 583                                         KM_IRQ0) + orig_sgl[i].offset;
 584                 dest = dest_addr;
 585                 destlen = orig_sgl[i].length;
 586                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 587
 588                 if (j == 0)
 589                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 590
 591                 while (destlen) {
 592                         src = bounce_addr + bounce_sgl[j].offset;
 593                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 594
 595                         copylen = min(srclen, destlen);
 596                         memcpy((void *)dest, (void *)src, copylen);
 597
 598                         total_copied += copylen;
 599                         bounce_sgl[j].offset += copylen;
 600                         destlen -= copylen;
 601                         dest += copylen;
 602
 603                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 604                                 /* full */
 605                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 606                                 j++;
 607
 608                                 /* if we need to use another bounce buffer */
 609                                 if (destlen || i != orig_sgl_count - 1)
 610                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 611                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 612                                 /* unmap the last bounce that is < PAGE_SIZE */
 613                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 614                         }
 615                 }
 616
 617                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 618                               KM_IRQ0);
 619         }
 620
 621         local_irq_restore(flags);
 622
 623         return total_copied;
 624 }
 625
 626 /**
 627  * storvsc_queuecommand - Initiate command processing
 628  */
 629 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
 630                                 void (*done)(struct scsi_cmnd *))
 631 {
 632         int ret;
 633         struct host_device_context *host_device_ctx =
 634                 (struct host_device_context *)scmnd->device->host->hostdata;
 635         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 636         struct driver_context *driver_ctx =
 637                 driver_to_driver_context(device_ctx->device.driver);
 638         struct storvsc_driver_context *storvsc_drv_ctx =
 639                 (struct storvsc_driver_context *)driver_ctx;
 640         struct storvsc_driver_object *storvsc_drv_obj =
 641                 &storvsc_drv_ctx->drv_obj;
 642         struct hv_storvsc_request *request;
 643         struct storvsc_cmd_request *cmd_request;
 644         unsigned int request_size = 0;
 645         int i;
 646         struct scatterlist *sgl;
 647
 648         DPRINT_ENTER(STORVSC_DRV);
 649
 650         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 651                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 652                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 653                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 654                    scmnd->device->tagged_supported);
 655
 656         /* If retrying, no need to prep the cmd */
 657         if (scmnd->host_scribble) {
 658                 ASSERT(scmnd->scsi_done != NULL);
 659
 660                 cmd_request =
 661                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 662                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 663                             scmnd, cmd_request);
 664
 665                 goto retry_request;
 666         }
 667
 668         ASSERT(scmnd->scsi_done == NULL);
 669         ASSERT(scmnd->host_scribble == NULL);
 670
 671         scmnd->scsi_done = done;
 672
 673         request_size = sizeof(struct storvsc_cmd_request);
 674
 675         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 676                                        GFP_ATOMIC);
 677         if (!cmd_request) {
 678                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 679                            "storvsc_cmd_request...marking queue busy", scmnd);
 680                 scmnd->scsi_done = NULL;
 681                 return SCSI_MLQUEUE_DEVICE_BUSY;
 682         }
 683
 684         /* Setup the cmd request */
 685         cmd_request->bounce_sgl_count = 0;
 686         cmd_request->bounce_sgl = NULL;
 687         cmd_request->cmd = scmnd;
 688
 689         scmnd->host_scribble = (unsigned char *)cmd_request;
 690
 691         request = &cmd_request->request;
 692
 693         request->Extension =
 694                 (void *)((unsigned long)cmd_request + request_size);
 695         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 696                    storvsc_drv_obj->RequestExtSize);
 697
 698         /* Build the SRB */
 699         switch (scmnd->sc_data_direction) {
 700         case DMA_TO_DEVICE:
 701                 request->Type = WRITE_TYPE;
 702                 break;
 703         case DMA_FROM_DEVICE:
 704                 request->Type = READ_TYPE;
 705                 break;
 706         default:
 707                 request->Type = UNKNOWN_TYPE;
 708                 break;
 709         }
 710
 711         request->OnIOCompletion = storvsc_commmand_completion;
 712         request->Context = cmd_request;/* scmnd; */
 713
 714         /* request->PortId = scmnd->device->channel; */
 715         request->Host = host_device_ctx->port;
 716         request->Bus = scmnd->device->channel;
 717         request->TargetId = scmnd->device->id;
 718         request->LunId = scmnd->device->lun;
 719
 720         ASSERT(scmnd->cmd_len <= 16);
 721         request->CdbLen = scmnd->cmd_len;
 722         request->Cdb = scmnd->cmnd;
 723
 724         request->SenseBuffer = scmnd->sense_buffer;
 725         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 726
 727
 728         request->DataBuffer.Length = scsi_bufflen(scmnd);
 729         if (scsi_sg_count(scmnd)) {
 730                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 731
 732                 /* check if we need to bounce the sgl */
 733                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 734                         DPRINT_INFO(STORVSC_DRV,
 735                                     "need to bounce buffer for this scmnd %p",
 736                                     scmnd);
 737                         cmd_request->bounce_sgl =
 738                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 739                                                      scsi_bufflen(scmnd));
 740                         if (!cmd_request->bounce_sgl) {
 741                                 DPRINT_ERR(STORVSC_DRV,
 742                                            "unable to create bounce buffer for "
 743                                            "this scmnd %p", scmnd);
 744
 745                                 scmnd->scsi_done = NULL;
 746                                 scmnd->host_scribble = NULL;
 747                                 kmem_cache_free(host_device_ctx->request_pool,
 748                                                 cmd_request);
 749
 750                                 return SCSI_MLQUEUE_HOST_BUSY;
 751                         }
 752
 753                         cmd_request->bounce_sgl_count =
 754                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 755                                         PAGE_SHIFT;
 756
 757                         /*
 758                          * FIXME: We can optimize on reads by just skipping
 759                          * this
 760                          */
 761                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 762                                               scsi_sg_count(scmnd));
 763
 764                         sgl = cmd_request->bounce_sgl;
 765                 }
 766
 767                 request->DataBuffer.Offset = sgl[0].offset;
 768
 769                 for (i = 0; i < scsi_sg_count(scmnd); i++) {
 770                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d \n",
 771                                    i, sgl[i].length, sgl[i].offset);
 772                         request->DataBuffer.PfnArray[i] =
 773                                         page_to_pfn(sg_page((&sgl[i])));
 774                 }
 775         } else if (scsi_sglist(scmnd)) {
 776                 ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE);
 777                 request->DataBuffer.Offset =
 778                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 779                 request->DataBuffer.PfnArray[0] =
 780                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 781         } else {
 782                 ASSERT(scsi_bufflen(scmnd) == 0);
 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_param(storvsc_ringbuffer_size, int, S_IRUGO);
 997 module_init(storvsc_init);
 998 module_exit(storvsc_exit);