drivers/staging/hv/storvsc_drv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  */
  21 #include <linux/init.h>
  22 #include <linux/slab.h>
  23 #include <linux/module.h>
  24 #include <linux/device.h>
  25 #include <linux/blkdev.h>
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_cmnd.h>
  28 #include <scsi/scsi_host.h>
  29 #include <scsi/scsi_device.h>
  30 #include <scsi/scsi_tcq.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_devinfo.h>
  33 #include <scsi/scsi_dbg.h>
  34 #include "osd.h"
  35 #include "logging.h"
  36 #include "version_info.h"
  37 #include "vmbus.h"
  38 #include "storvsc_api.h"
  39
  40
  41 struct host_device_context {
  42         /* must be 1st field
  43          * FIXME this is a bug */
  44         /* point back to our device context */
  45         struct vm_device *device_ctx;
  46         struct kmem_cache *request_pool;
  47         unsigned int port;
  48         unsigned char path;
  49         unsigned char target;
  50 };
  51
  52 struct storvsc_cmd_request {
  53         struct list_head entry;
  54         struct scsi_cmnd *cmd;
  55
  56         unsigned int bounce_sgl_count;
  57         struct scatterlist *bounce_sgl;
  58
  59         struct hv_storvsc_request request;
  60         /* !!!DO NOT ADD ANYTHING BELOW HERE!!! */
  61         /* The extension buffer falls right here and is pointed to by
  62          * request.Extension;
  63          * Which sounds like a very bad design... */
  64 };
  65
  66 struct storvsc_driver_context {
  67         /* !! These must be the first 2 fields !! */
  68         /* FIXME this is a bug... */
  69         struct driver_context drv_ctx;
  70         struct storvsc_driver_object drv_obj;
  71 };
  72
  73 /* Static decl */
  74 static int storvsc_probe(struct device *dev);
  75 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
  76                                 void (*done)(struct scsi_cmnd *));
  77 static int storvsc_device_alloc(struct scsi_device *);
  78 static int storvsc_device_configure(struct scsi_device *);
  79 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd);
  80 static int storvsc_remove(struct device *dev);
  81
  82 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
  83                                                 unsigned int sg_count,
  84                                                 unsigned int len);
  85 static void destroy_bounce_buffer(struct scatterlist *sgl,
  86                                   unsigned int sg_count);
  87 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count);
  88 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
  89                                             struct scatterlist *bounce_sgl,
  90                                             unsigned int orig_sgl_count);
  91 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
  92                                           struct scatterlist *bounce_sgl,
  93                                           unsigned int orig_sgl_count);
  94
  95 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device *bdev,
  96                            sector_t capacity, int *info);
  97
  98
  99 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
 100 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 101 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 102
 103 /* The one and only one */
 104 static struct storvsc_driver_context g_storvsc_drv;
 105
 106 /* Scsi driver */
 107 static struct scsi_host_template scsi_driver = {
 108         .module =               THIS_MODULE,
 109         .name =                 "storvsc_host_t",
 110         .bios_param =           storvsc_get_chs,
 111         .queuecommand =         storvsc_queuecommand,
 112         .eh_host_reset_handler =        storvsc_host_reset_handler,
 113         .slave_alloc =          storvsc_device_alloc,
 114         .slave_configure =      storvsc_device_configure,
 115         .cmd_per_lun =          1,
 116         /* 64 max_queue * 1 target */
 117         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 118         .this_id =              -1,
 119         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 120         /* currently 32 */
 121         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 122         /*
 123          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 124          * into 1 sg element. If set, we must limit the max_segment_size to
 125          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 126          * multiple
 127          */
 128         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 129         .use_clustering =       ENABLE_CLUSTERING,
 130         /* Make sure we dont get a sg segment crosses a page boundary */
 131         .dma_boundary =         PAGE_SIZE-1,
 132 };
 133
 134
 135 /*
 136  * storvsc_drv_init - StorVsc driver initialization.
 137  */
 138 static int storvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 139 {
 140         int ret;
 141         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 142         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 143
 144         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 145
 146         storvsc_drv_obj->RingBufferSize = storvsc_ringbuffer_size;
 147
 148         /* Callback to client driver to complete the initialization */
 149         drv_init(&storvsc_drv_obj->Base);
 150
 151         DPRINT_INFO(STORVSC_DRV,
 152                     "request extension size %u, max outstanding reqs %u",
 153                     storvsc_drv_obj->RequestExtSize,
 154                     storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 155
 156         if (storvsc_drv_obj->MaxOutstandingRequestsPerChannel <
 157             STORVSC_MAX_IO_REQUESTS) {
 158                 DPRINT_ERR(STORVSC_DRV,
 159                            "The number of outstanding io requests (%d) "
 160                            "is larger than that supported (%d) internally.",
 161                            STORVSC_MAX_IO_REQUESTS,
 162                            storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 163                 return -1;
 164         }
 165
 166         drv_ctx->driver.name = storvsc_drv_obj->Base.name;
 167         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->Base.deviceType,
 168                sizeof(struct hv_guid));
 169
 170         drv_ctx->probe = storvsc_probe;
 171         drv_ctx->remove = storvsc_remove;
 172
 173         /* The driver belongs to vmbus */
 174         ret = vmbus_child_driver_register(drv_ctx);
 175
 176         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         while (1) {
 194                 current_dev = NULL;
 195
 196                 /* Get the device */
 197                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 198                                              (void *) &current_dev,
 199                                              storvsc_drv_exit_cb);
 200
 201                 if (ret)
 202                         DPRINT_WARN(STORVSC_DRV,
 203                                     "driver_for_each_device returned %d", ret);
 204
 205                 if (current_dev == NULL)
 206                         break;
 207
 208                 /* Initiate removal from the top-down */
 209                 device_unregister(current_dev);
 210         }
 211
 212         if (storvsc_drv_obj->Base.OnCleanup)
 213                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 214
 215         vmbus_child_driver_unregister(drv_ctx);
 216         return;
 217 }
 218
 219 /*
 220  * storvsc_probe - Add a new device for this driver
 221  */
 222 static int storvsc_probe(struct device *device)
 223 {
 224         int ret;
 225         struct driver_context *driver_ctx =
 226                                 driver_to_driver_context(device->driver);
 227         struct storvsc_driver_context *storvsc_drv_ctx =
 228                                 (struct storvsc_driver_context *)driver_ctx;
 229         struct storvsc_driver_object *storvsc_drv_obj =
 230                                 &storvsc_drv_ctx->drv_obj;
 231         struct vm_device *device_ctx = device_to_vm_device(device);
 232         struct hv_device *device_obj = &device_ctx->device_obj;
 233         struct Scsi_Host *host;
 234         struct host_device_context *host_device_ctx;
 235         struct storvsc_device_info device_info;
 236
 237         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 238                 return -1;
 239
 240         host = scsi_host_alloc(&scsi_driver,
 241                                sizeof(struct host_device_context));
 242         if (!host) {
 243                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 244                 return -ENOMEM;
 245         }
 246
 247         dev_set_drvdata(device, host);
 248
 249         host_device_ctx = (struct host_device_context *)host->hostdata;
 250         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 251
 252         host_device_ctx->port = host->host_no;
 253         host_device_ctx->device_ctx = device_ctx;
 254
 255         host_device_ctx->request_pool =
 256                                 kmem_cache_create(dev_name(&device_ctx->device),
 257                                         sizeof(struct storvsc_cmd_request) +
 258                                         storvsc_drv_obj->RequestExtSize, 0,
 259                                         SLAB_HWCACHE_ALIGN, NULL);
 260
 261         if (!host_device_ctx->request_pool) {
 262                 scsi_host_put(host);
 263                 return -ENOMEM;
 264         }
 265
 266         device_info.PortNumber = host->host_no;
 267         /* Call to the vsc driver to add the device */
 268         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj,
 269                                                 (void *)&device_info);
 270         if (ret != 0) {
 271                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 272                 kmem_cache_destroy(host_device_ctx->request_pool);
 273                 scsi_host_put(host);
 274                 return -1;
 275         }
 276
 277         /* host_device_ctx->port = device_info.PortNumber; */
 278         host_device_ctx->path = device_info.PathId;
 279         host_device_ctx->target = device_info.TargetId;
 280
 281         /* max # of devices per target */
 282         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 283         /* max # of targets per channel */
 284         host->max_id = STORVSC_MAX_TARGETS;
 285         /* max # of channels */
 286         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 287
 288         /* Register the HBA and start the scsi bus scan */
 289         ret = scsi_add_host(host, device);
 290         if (ret != 0) {
 291                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 292
 293                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 294
 295                 kmem_cache_destroy(host_device_ctx->request_pool);
 296                 scsi_host_put(host);
 297                 return -1;
 298         }
 299
 300         scsi_scan_host(host);
 301         return ret;
 302 }
 303
 304 /*
 305  * storvsc_remove - Callback when our device is removed
 306  */
 307 static int storvsc_remove(struct device *device)
 308 {
 309         int ret;
 310         struct driver_context *driver_ctx =
 311                         driver_to_driver_context(device->driver);
 312         struct storvsc_driver_context *storvsc_drv_ctx =
 313                         (struct storvsc_driver_context *)driver_ctx;
 314         struct storvsc_driver_object *storvsc_drv_obj =
 315                         &storvsc_drv_ctx->drv_obj;
 316         struct vm_device *device_ctx = device_to_vm_device(device);
 317         struct hv_device *device_obj = &device_ctx->device_obj;
 318         struct Scsi_Host *host = dev_get_drvdata(device);
 319         struct host_device_context *host_device_ctx =
 320                         (struct host_device_context *)host->hostdata;
 321
 322
 323         if (!storvsc_drv_obj->Base.OnDeviceRemove)
 324                 return -1;
 325
 326         /*
 327          * Call to the vsc driver to let it know that the device is being
 328          * removed
 329          */
 330         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 331         if (ret != 0) {
 332                 /* TODO: */
 333                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 334                            ret);
 335         }
 336
 337         if (host_device_ctx->request_pool) {
 338                 kmem_cache_destroy(host_device_ctx->request_pool);
 339                 host_device_ctx->request_pool = NULL;
 340         }
 341
 342         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 343         scsi_remove_host(host);
 344
 345         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 346         scsi_host_put(host);
 347         return ret;
 348 }
 349
 350 /*
 351  * storvsc_commmand_completion - Command completion processing
 352  */
 353 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 354 {
 355         struct storvsc_cmd_request *cmd_request =
 356                 (struct storvsc_cmd_request *)request->Context;
 357         struct scsi_cmnd *scmnd = cmd_request->cmd;
 358         struct host_device_context *host_device_ctx =
 359                 (struct host_device_context *)scmnd->device->host->hostdata;
 360         void (*scsi_done_fn)(struct scsi_cmnd *);
 361         struct scsi_sense_hdr sense_hdr;
 362
 363         /* ASSERT(request == &cmd_request->request); */
 364         /* ASSERT(scmnd); */
 365         /* ASSERT((unsigned long)scmnd->host_scribble == */
 366         /*        (unsigned long)cmd_request); */
 367         /* ASSERT(scmnd->scsi_done); */
 368
 369         if (cmd_request->bounce_sgl_count) {
 370                 /* using bounce buffer */
 371                 /* printk("copy_from_bounce_buffer\n"); */
 372
 373                 /* FIXME: We can optimize on writes by just skipping this */
 374                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 375                                         cmd_request->bounce_sgl,
 376                                         scsi_sg_count(scmnd));
 377                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 378                                       cmd_request->bounce_sgl_count);
 379         }
 380
 381         scmnd->result = request->Status;
 382
 383         if (scmnd->result) {
 384                 if (scsi_normalize_sense(scmnd->sense_buffer,
 385                                          request->SenseBufferSize, &sense_hdr))
 386                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 387         }
 388
 389         /* ASSERT(request->BytesXfer <= request->DataBuffer.Length); */
 390         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 391
 392         scsi_done_fn = scmnd->scsi_done;
 393
 394         scmnd->host_scribble = NULL;
 395         scmnd->scsi_done = NULL;
 396
 397         /* !!DO NOT MODIFY the scmnd after this call */
 398         scsi_done_fn(scmnd);
 399
 400         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 401 }
 402
 403 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 404 {
 405         int i;
 406
 407         /* No need to check */
 408         if (sg_count < 2)
 409                 return -1;
 410
 411         /* We have at least 2 sg entries */
 412         for (i = 0; i < sg_count; i++) {
 413                 if (i == 0) {
 414                         /* make sure 1st one does not have hole */
 415                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 416                                 return i;
 417                 } else if (i == sg_count - 1) {
 418                         /* make sure last one does not have hole */
 419                         if (sgl[i].offset != 0)
 420                                 return i;
 421                 } else {
 422                         /* make sure no hole in the middle */
 423                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 424                                 return i;
 425                 }
 426         }
 427         return -1;
 428 }
 429
 430 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 431                                                 unsigned int sg_count,
 432                                                 unsigned int len)
 433 {
 434         int i;
 435         int num_pages;
 436         struct scatterlist *bounce_sgl;
 437         struct page *page_buf;
 438
 439         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 440
 441         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 442         if (!bounce_sgl)
 443                 return NULL;
 444
 445         for (i = 0; i < num_pages; i++) {
 446                 page_buf = alloc_page(GFP_ATOMIC);
 447                 if (!page_buf)
 448                         goto cleanup;
 449                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 450         }
 451
 452         return bounce_sgl;
 453
 454 cleanup:
 455         destroy_bounce_buffer(bounce_sgl, num_pages);
 456         return NULL;
 457 }
 458
 459 static void destroy_bounce_buffer(struct scatterlist *sgl,
 460                                   unsigned int sg_count)
 461 {
 462         int i;
 463         struct page *page_buf;
 464
 465         for (i = 0; i < sg_count; i++) {
 466                 page_buf = sg_page((&sgl[i]));
 467                 if (page_buf != NULL)
 468                         __free_page(page_buf);
 469         }
 470
 471         kfree(sgl);
 472 }
 473
 474 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 475 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 476                                           struct scatterlist *bounce_sgl,
 477                                           unsigned int orig_sgl_count)
 478 {
 479         int i;
 480         int j = 0;
 481         unsigned long src, dest;
 482         unsigned int srclen, destlen, copylen;
 483         unsigned int total_copied = 0;
 484         unsigned long bounce_addr = 0;
 485         unsigned long src_addr = 0;
 486         unsigned long flags;
 487
 488         local_irq_save(flags);
 489
 490         for (i = 0; i < orig_sgl_count; i++) {
 491                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 492                                 KM_IRQ0) + orig_sgl[i].offset;
 493                 src = src_addr;
 494                 srclen = orig_sgl[i].length;
 495
 496                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 497
 498                 if (j == 0)
 499                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 500
 501                 while (srclen) {
 502                         /* assume bounce offset always == 0 */
 503                         dest = bounce_addr + bounce_sgl[j].length;
 504                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 505
 506                         copylen = min(srclen, destlen);
 507                         memcpy((void *)dest, (void *)src, copylen);
 508
 509                         total_copied += copylen;
 510                         bounce_sgl[j].length += copylen;
 511                         srclen -= copylen;
 512                         src += copylen;
 513
 514                         if (bounce_sgl[j].length == PAGE_SIZE) {
 515                                 /* full..move to next entry */
 516                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 517                                 j++;
 518
 519                                 /* if we need to use another bounce buffer */
 520                                 if (srclen || i != orig_sgl_count - 1)
 521                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 522                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 523                                 /* unmap the last bounce that is < PAGE_SIZE */
 524                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 525                         }
 526                 }
 527
 528                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 529         }
 530
 531         local_irq_restore(flags);
 532
 533         return total_copied;
 534 }
 535
 536 /* Assume the original sgl has enough room */
 537 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 538                                             struct scatterlist *bounce_sgl,
 539                                             unsigned int orig_sgl_count)
 540 {
 541         int i;
 542         int j = 0;
 543         unsigned long src, dest;
 544         unsigned int srclen, destlen, copylen;
 545         unsigned int total_copied = 0;
 546         unsigned long bounce_addr = 0;
 547         unsigned long dest_addr = 0;
 548         unsigned long flags;
 549
 550         local_irq_save(flags);
 551
 552         for (i = 0; i < orig_sgl_count; i++) {
 553                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 554                                         KM_IRQ0) + orig_sgl[i].offset;
 555                 dest = dest_addr;
 556                 destlen = orig_sgl[i].length;
 557                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 558
 559                 if (j == 0)
 560                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 561
 562                 while (destlen) {
 563                         src = bounce_addr + bounce_sgl[j].offset;
 564                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 565
 566                         copylen = min(srclen, destlen);
 567                         memcpy((void *)dest, (void *)src, copylen);
 568
 569                         total_copied += copylen;
 570                         bounce_sgl[j].offset += copylen;
 571                         destlen -= copylen;
 572                         dest += copylen;
 573
 574                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 575                                 /* full */
 576                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 577                                 j++;
 578
 579                                 /* if we need to use another bounce buffer */
 580                                 if (destlen || i != orig_sgl_count - 1)
 581                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 582                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 583                                 /* unmap the last bounce that is < PAGE_SIZE */
 584                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 585                         }
 586                 }
 587
 588                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 589                               KM_IRQ0);
 590         }
 591
 592         local_irq_restore(flags);
 593
 594         return total_copied;
 595 }
 596
 597 /*
 598  * storvsc_queuecommand - Initiate command processing
 599  */
 600 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
 601                                 void (*done)(struct scsi_cmnd *))
 602 {
 603         int ret;
 604         struct host_device_context *host_device_ctx =
 605                 (struct host_device_context *)scmnd->device->host->hostdata;
 606         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 607         struct driver_context *driver_ctx =
 608                 driver_to_driver_context(device_ctx->device.driver);
 609         struct storvsc_driver_context *storvsc_drv_ctx =
 610                 (struct storvsc_driver_context *)driver_ctx;
 611         struct storvsc_driver_object *storvsc_drv_obj =
 612                 &storvsc_drv_ctx->drv_obj;
 613         struct hv_storvsc_request *request;
 614         struct storvsc_cmd_request *cmd_request;
 615         unsigned int request_size = 0;
 616         int i;
 617         struct scatterlist *sgl;
 618
 619         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 620                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 621                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 622                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 623                    scmnd->device->tagged_supported);
 624
 625         /* If retrying, no need to prep the cmd */
 626         if (scmnd->host_scribble) {
 627                 /* ASSERT(scmnd->scsi_done != NULL); */
 628
 629                 cmd_request =
 630                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 631                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 632                             scmnd, cmd_request);
 633
 634                 goto retry_request;
 635         }
 636
 637         /* ASSERT(scmnd->scsi_done == NULL); */
 638         /* ASSERT(scmnd->host_scribble == NULL); */
 639
 640         scmnd->scsi_done = done;
 641
 642         request_size = sizeof(struct storvsc_cmd_request);
 643
 644         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 645                                        GFP_ATOMIC);
 646         if (!cmd_request) {
 647                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 648                            "storvsc_cmd_request...marking queue busy", scmnd);
 649                 scmnd->scsi_done = NULL;
 650                 return SCSI_MLQUEUE_DEVICE_BUSY;
 651         }
 652
 653         /* Setup the cmd request */
 654         cmd_request->bounce_sgl_count = 0;
 655         cmd_request->bounce_sgl = NULL;
 656         cmd_request->cmd = scmnd;
 657
 658         scmnd->host_scribble = (unsigned char *)cmd_request;
 659
 660         request = &cmd_request->request;
 661
 662         request->Extension =
 663                 (void *)((unsigned long)cmd_request + request_size);
 664         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 665                    storvsc_drv_obj->RequestExtSize);
 666
 667         /* Build the SRB */
 668         switch (scmnd->sc_data_direction) {
 669         case DMA_TO_DEVICE:
 670                 request->Type = WRITE_TYPE;
 671                 break;
 672         case DMA_FROM_DEVICE:
 673                 request->Type = READ_TYPE;
 674                 break;
 675         default:
 676                 request->Type = UNKNOWN_TYPE;
 677                 break;
 678         }
 679
 680         request->OnIOCompletion = storvsc_commmand_completion;
 681         request->Context = cmd_request;/* scmnd; */
 682
 683         /* request->PortId = scmnd->device->channel; */
 684         request->Host = host_device_ctx->port;
 685         request->Bus = scmnd->device->channel;
 686         request->TargetId = scmnd->device->id;
 687         request->LunId = scmnd->device->lun;
 688
 689         /* ASSERT(scmnd->cmd_len <= 16); */
 690         request->CdbLen = scmnd->cmd_len;
 691         request->Cdb = scmnd->cmnd;
 692
 693         request->SenseBuffer = scmnd->sense_buffer;
 694         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 695
 696
 697         request->DataBuffer.Length = scsi_bufflen(scmnd);
 698         if (scsi_sg_count(scmnd)) {
 699                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 700
 701                 /* check if we need to bounce the sgl */
 702                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 703                         DPRINT_INFO(STORVSC_DRV,
 704                                     "need to bounce buffer for this scmnd %p",
 705                                     scmnd);
 706                         cmd_request->bounce_sgl =
 707                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 708                                                      scsi_bufflen(scmnd));
 709                         if (!cmd_request->bounce_sgl) {
 710                                 DPRINT_ERR(STORVSC_DRV,
 711                                            "unable to create bounce buffer for "
 712                                            "this scmnd %p", scmnd);
 713
 714                                 scmnd->scsi_done = NULL;
 715                                 scmnd->host_scribble = NULL;
 716                                 kmem_cache_free(host_device_ctx->request_pool,
 717                                                 cmd_request);
 718
 719                                 return SCSI_MLQUEUE_HOST_BUSY;
 720                         }
 721
 722                         cmd_request->bounce_sgl_count =
 723                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 724                                         PAGE_SHIFT;
 725
 726                         /*
 727                          * FIXME: We can optimize on reads by just skipping
 728                          * this
 729                          */
 730                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 731                                               scsi_sg_count(scmnd));
 732
 733                         sgl = cmd_request->bounce_sgl;
 734                 }
 735
 736                 request->DataBuffer.Offset = sgl[0].offset;
 737
 738                 for (i = 0; i < scsi_sg_count(scmnd); i++) {
 739                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d\n",
 740                                    i, sgl[i].length, sgl[i].offset);
 741                         request->DataBuffer.PfnArray[i] =
 742                                         page_to_pfn(sg_page((&sgl[i])));
 743                 }
 744         } else if (scsi_sglist(scmnd)) {
 745                 /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
 746                 request->DataBuffer.Offset =
 747                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 748                 request->DataBuffer.PfnArray[0] =
 749                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 750         }
 751
 752 retry_request:
 753         /* Invokes the vsc to start an IO */
 754         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj,
 755                                            &cmd_request->request);
 756         if (ret == -1) {
 757                 /* no more space */
 758                 DPRINT_ERR(STORVSC_DRV,
 759                            "scmnd (%p) - queue FULL...marking queue busy",
 760                            scmnd);
 761
 762                 if (cmd_request->bounce_sgl_count) {
 763                         /*
 764                          * FIXME: We can optimize on writes by just skipping
 765                          * this
 766                          */
 767                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 768                                                 cmd_request->bounce_sgl,
 769                                                 scsi_sg_count(scmnd));
 770                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 771                                               cmd_request->bounce_sgl_count);
 772                 }
 773
 774                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 775
 776                 scmnd->scsi_done = NULL;
 777                 scmnd->host_scribble = NULL;
 778
 779                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 780         }
 781
 782         return ret;
 783 }
 784
 785 static int storvsc_merge_bvec(struct request_queue *q,
 786                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 787 {
 788         /* checking done by caller. */
 789         return bvec->bv_len;
 790 }
 791
 792 /*
 793  * storvsc_device_configure - Configure the specified scsi device
 794  */
 795 static int storvsc_device_alloc(struct scsi_device *sdevice)
 796 {
 797         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d",
 798                    sdevice, BLIST_SPARSELUN);
 799         /*
 800          * This enables luns to be located sparsely. Otherwise, we may not
 801          * discovered them.
 802          */
 803         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 804         return 0;
 805 }
 806
 807 static int storvsc_device_configure(struct scsi_device *sdevice)
 808 {
 809         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - curr queue depth %d", sdevice,
 810                     sdevice->queue_depth);
 811
 812         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d",
 813                     sdevice, STORVSC_MAX_IO_REQUESTS);
 814         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 815                                 STORVSC_MAX_IO_REQUESTS);
 816
 817         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 818                     sdevice, PAGE_SIZE);
 819         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 820
 821         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 822                     sdevice);
 823         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 824
 825         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 826         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 827
 828         return 0;
 829 }
 830
 831 /*
 832  * storvsc_host_reset_handler - Reset the scsi HBA
 833  */
 834 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 835 {
 836         int ret;
 837         struct host_device_context *host_device_ctx =
 838                 (struct host_device_context *)scmnd->device->host->hostdata;
 839         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 840
 841         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 842                     scmnd->device, &device_ctx->device_obj);
 843
 844         /* Invokes the vsc to reset the host/bus */
 845         ret = StorVscOnHostReset(&device_ctx->device_obj);
 846         if (ret != 0)
 847                 return ret;
 848
 849         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 850                     scmnd->device, &device_ctx->device_obj);
 851
 852         return ret;
 853 }
 854
 855 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 856                            sector_t capacity, int *info)
 857 {
 858         sector_t total_sectors = capacity;
 859         sector_t cylinder_times_heads = 0;
 860         sector_t temp = 0;
 861
 862         int sectors_per_track = 0;
 863         int heads = 0;
 864         int cylinders = 0;
 865         int rem = 0;
 866
 867         if (total_sectors > (65535 * 16 * 255))
 868                 total_sectors = (65535 * 16 * 255);
 869
 870         if (total_sectors >= (65535 * 16 * 63)) {
 871                 sectors_per_track = 255;
 872                 heads = 16;
 873
 874                 cylinder_times_heads = total_sectors;
 875                 /* sector_div stores the quotient in cylinder_times_heads */
 876                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 877         } else {
 878                 sectors_per_track = 17;
 879
 880                 cylinder_times_heads = total_sectors;
 881                 /* sector_div stores the quotient in cylinder_times_heads */
 882                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 883
 884                 temp = cylinder_times_heads + 1023;
 885                 /* sector_div stores the quotient in temp */
 886                 rem = sector_div(temp, 1024);
 887
 888                 heads = temp;
 889
 890                 if (heads < 4)
 891                         heads = 4;
 892
 893                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
 894                         sectors_per_track = 31;
 895                         heads = 16;
 896
 897                         cylinder_times_heads = total_sectors;
 898                         /*
 899                          * sector_div stores the quotient in
 900                          * cylinder_times_heads
 901                          */
 902                         rem = sector_div(cylinder_times_heads,
 903                                          sectors_per_track);
 904                 }
 905
 906                 if (cylinder_times_heads >= (heads * 1024)) {
 907                         sectors_per_track = 63;
 908                         heads = 16;
 909
 910                         cylinder_times_heads = total_sectors;
 911                         /*
 912                          * sector_div stores the quotient in
 913                          * cylinder_times_heads
 914                          */
 915                         rem = sector_div(cylinder_times_heads,
 916                                          sectors_per_track);
 917                 }
 918         }
 919
 920         temp = cylinder_times_heads;
 921         /* sector_div stores the quotient in temp */
 922         rem = sector_div(temp, heads);
 923         cylinders = temp;
 924
 925         info[0] = heads;
 926         info[1] = sectors_per_track;
 927         info[2] = cylinders;
 928
 929         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
 930                     sectors_per_track);
 931
 932     return 0;
 933 }
 934
 935 static int __init storvsc_init(void)
 936 {
 937         int ret;
 938
 939         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 940         ret = storvsc_drv_init(StorVscInitialize);
 941         return ret;
 942 }
 943
 944 static void __exit storvsc_exit(void)
 945 {
 946         storvsc_drv_exit();
 947 }
 948
 949 MODULE_LICENSE("GPL");
 950 MODULE_VERSION(HV_DRV_VERSION);
 951 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
 952 module_init(storvsc_init);
 953 module_exit(storvsc_exit);