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 (bounce_addr == 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 (bounce_addr == 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         unsigned int sg_count = 0;
 619
 620         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 621                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 622                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 623                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 624                    scmnd->device->tagged_supported);
 625
 626         /* If retrying, no need to prep the cmd */
 627         if (scmnd->host_scribble) {
 628                 /* ASSERT(scmnd->scsi_done != NULL); */
 629
 630                 cmd_request =
 631                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 632                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 633                             scmnd, cmd_request);
 634
 635                 goto retry_request;
 636         }
 637
 638         /* ASSERT(scmnd->scsi_done == NULL); */
 639         /* ASSERT(scmnd->host_scribble == NULL); */
 640
 641         scmnd->scsi_done = done;
 642
 643         request_size = sizeof(struct storvsc_cmd_request);
 644
 645         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 646                                        GFP_ATOMIC);
 647         if (!cmd_request) {
 648                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 649                            "storvsc_cmd_request...marking queue busy", scmnd);
 650                 scmnd->scsi_done = NULL;
 651                 return SCSI_MLQUEUE_DEVICE_BUSY;
 652         }
 653
 654         /* Setup the cmd request */
 655         cmd_request->bounce_sgl_count = 0;
 656         cmd_request->bounce_sgl = NULL;
 657         cmd_request->cmd = scmnd;
 658
 659         scmnd->host_scribble = (unsigned char *)cmd_request;
 660
 661         request = &cmd_request->request;
 662
 663         request->Extension =
 664                 (void *)((unsigned long)cmd_request + request_size);
 665         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 666                    storvsc_drv_obj->RequestExtSize);
 667
 668         /* Build the SRB */
 669         switch (scmnd->sc_data_direction) {
 670         case DMA_TO_DEVICE:
 671                 request->Type = WRITE_TYPE;
 672                 break;
 673         case DMA_FROM_DEVICE:
 674                 request->Type = READ_TYPE;
 675                 break;
 676         default:
 677                 request->Type = UNKNOWN_TYPE;
 678                 break;
 679         }
 680
 681         request->OnIOCompletion = storvsc_commmand_completion;
 682         request->Context = cmd_request;/* scmnd; */
 683
 684         /* request->PortId = scmnd->device->channel; */
 685         request->Host = host_device_ctx->port;
 686         request->Bus = scmnd->device->channel;
 687         request->TargetId = scmnd->device->id;
 688         request->LunId = scmnd->device->lun;
 689
 690         /* ASSERT(scmnd->cmd_len <= 16); */
 691         request->CdbLen = scmnd->cmd_len;
 692         request->Cdb = scmnd->cmnd;
 693
 694         request->SenseBuffer = scmnd->sense_buffer;
 695         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 696
 697
 698         request->DataBuffer.Length = scsi_bufflen(scmnd);
 699         if (scsi_sg_count(scmnd)) {
 700                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 701                 sg_count = scsi_sg_count(scmnd);
 702
 703                 /* check if we need to bounce the sgl */
 704                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 705                         DPRINT_INFO(STORVSC_DRV,
 706                                     "need to bounce buffer for this scmnd %p",
 707                                     scmnd);
 708                         cmd_request->bounce_sgl =
 709                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 710                                                      scsi_bufflen(scmnd));
 711                         if (!cmd_request->bounce_sgl) {
 712                                 DPRINT_ERR(STORVSC_DRV,
 713                                            "unable to create bounce buffer for "
 714                                            "this scmnd %p", scmnd);
 715
 716                                 scmnd->scsi_done = NULL;
 717                                 scmnd->host_scribble = NULL;
 718                                 kmem_cache_free(host_device_ctx->request_pool,
 719                                                 cmd_request);
 720
 721                                 return SCSI_MLQUEUE_HOST_BUSY;
 722                         }
 723
 724                         cmd_request->bounce_sgl_count =
 725                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 726                                         PAGE_SHIFT;
 727
 728                         /*
 729                          * FIXME: We can optimize on reads by just skipping
 730                          * this
 731                          */
 732                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 733                                               scsi_sg_count(scmnd));
 734
 735                         sgl = cmd_request->bounce_sgl;
 736                         sg_count = cmd_request->bounce_sgl_count;
 737                 }
 738
 739                 request->DataBuffer.Offset = sgl[0].offset;
 740
 741                 for (i = 0; i < sg_count; i++) {
 742                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d\n",
 743                                    i, sgl[i].length, sgl[i].offset);
 744                         request->DataBuffer.PfnArray[i] =
 745                                 page_to_pfn(sg_page((&sgl[i])));
 746                 }
 747         } else if (scsi_sglist(scmnd)) {
 748                 /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
 749                 request->DataBuffer.Offset =
 750                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 751                 request->DataBuffer.PfnArray[0] =
 752                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 753         }
 754
 755 retry_request:
 756         /* Invokes the vsc to start an IO */
 757         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj,
 758                                            &cmd_request->request);
 759         if (ret == -1) {
 760                 /* no more space */
 761                 DPRINT_ERR(STORVSC_DRV,
 762                            "scmnd (%p) - queue FULL...marking queue busy",
 763                            scmnd);
 764
 765                 if (cmd_request->bounce_sgl_count) {
 766                         /*
 767                          * FIXME: We can optimize on writes by just skipping
 768                          * this
 769                          */
 770                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 771                                                 cmd_request->bounce_sgl,
 772                                                 scsi_sg_count(scmnd));
 773                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 774                                               cmd_request->bounce_sgl_count);
 775                 }
 776
 777                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 778
 779                 scmnd->scsi_done = NULL;
 780                 scmnd->host_scribble = NULL;
 781
 782                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 783         }
 784
 785         return ret;
 786 }
 787
 788 static int storvsc_merge_bvec(struct request_queue *q,
 789                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 790 {
 791         /* checking done by caller. */
 792         return bvec->bv_len;
 793 }
 794
 795 /*
 796  * storvsc_device_configure - Configure the specified scsi device
 797  */
 798 static int storvsc_device_alloc(struct scsi_device *sdevice)
 799 {
 800         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d",
 801                    sdevice, BLIST_SPARSELUN);
 802         /*
 803          * This enables luns to be located sparsely. Otherwise, we may not
 804          * discovered them.
 805          */
 806         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 807         return 0;
 808 }
 809
 810 static int storvsc_device_configure(struct scsi_device *sdevice)
 811 {
 812         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - curr queue depth %d", sdevice,
 813                     sdevice->queue_depth);
 814
 815         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d",
 816                     sdevice, STORVSC_MAX_IO_REQUESTS);
 817         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 818                                 STORVSC_MAX_IO_REQUESTS);
 819
 820         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 821                     sdevice, PAGE_SIZE);
 822         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 823
 824         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 825                     sdevice);
 826         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 827
 828         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 829         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 830
 831         return 0;
 832 }
 833
 834 /*
 835  * storvsc_host_reset_handler - Reset the scsi HBA
 836  */
 837 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 838 {
 839         int ret;
 840         struct host_device_context *host_device_ctx =
 841                 (struct host_device_context *)scmnd->device->host->hostdata;
 842         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 843
 844         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 845                     scmnd->device, &device_ctx->device_obj);
 846
 847         /* Invokes the vsc to reset the host/bus */
 848         ret = StorVscOnHostReset(&device_ctx->device_obj);
 849         if (ret != 0)
 850                 return ret;
 851
 852         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 853                     scmnd->device, &device_ctx->device_obj);
 854
 855         return ret;
 856 }
 857
 858 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
 859                            sector_t capacity, int *info)
 860 {
 861         sector_t total_sectors = capacity;
 862         sector_t cylinder_times_heads = 0;
 863         sector_t temp = 0;
 864
 865         int sectors_per_track = 0;
 866         int heads = 0;
 867         int cylinders = 0;
 868         int rem = 0;
 869
 870         if (total_sectors > (65535 * 16 * 255))
 871                 total_sectors = (65535 * 16 * 255);
 872
 873         if (total_sectors >= (65535 * 16 * 63)) {
 874                 sectors_per_track = 255;
 875                 heads = 16;
 876
 877                 cylinder_times_heads = total_sectors;
 878                 /* sector_div stores the quotient in cylinder_times_heads */
 879                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 880         } else {
 881                 sectors_per_track = 17;
 882
 883                 cylinder_times_heads = total_sectors;
 884                 /* sector_div stores the quotient in cylinder_times_heads */
 885                 rem = sector_div(cylinder_times_heads, sectors_per_track);
 886
 887                 temp = cylinder_times_heads + 1023;
 888                 /* sector_div stores the quotient in temp */
 889                 rem = sector_div(temp, 1024);
 890
 891                 heads = temp;
 892
 893                 if (heads < 4)
 894                         heads = 4;
 895
 896                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
 897                         sectors_per_track = 31;
 898                         heads = 16;
 899
 900                         cylinder_times_heads = total_sectors;
 901                         /*
 902                          * sector_div stores the quotient in
 903                          * cylinder_times_heads
 904                          */
 905                         rem = sector_div(cylinder_times_heads,
 906                                          sectors_per_track);
 907                 }
 908
 909                 if (cylinder_times_heads >= (heads * 1024)) {
 910                         sectors_per_track = 63;
 911                         heads = 16;
 912
 913                         cylinder_times_heads = total_sectors;
 914                         /*
 915                          * sector_div stores the quotient in
 916                          * cylinder_times_heads
 917                          */
 918                         rem = sector_div(cylinder_times_heads,
 919                                          sectors_per_track);
 920                 }
 921         }
 922
 923         temp = cylinder_times_heads;
 924         /* sector_div stores the quotient in temp */
 925         rem = sector_div(temp, heads);
 926         cylinders = temp;
 927
 928         info[0] = heads;
 929         info[1] = sectors_per_track;
 930         info[2] = cylinders;
 931
 932         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
 933                     sectors_per_track);
 934
 935     return 0;
 936 }
 937
 938 static int __init storvsc_init(void)
 939 {
 940         int ret;
 941
 942         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
 943         ret = storvsc_drv_init(StorVscInitialize);
 944         return ret;
 945 }
 946
 947 static void __exit storvsc_exit(void)
 948 {
 949         storvsc_drv_exit();
 950 }
 951
 952 MODULE_LICENSE("GPL");
 953 MODULE_VERSION(HV_DRV_VERSION);
 954 MODULE_DESCRIPTION("Microsoft Hyper-V virtual storage driver");
 955 module_init(storvsc_init);
 956 module_exit(storvsc_exit);