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_Host *shost, struct scsi_cmnd *scmnd);
  76 static int storvsc_device_alloc(struct scsi_device *);
  77 static int storvsc_device_configure(struct scsi_device *);
  78 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd);
  79 static int storvsc_remove(struct device *dev);
  80
  81 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
  82                                                 unsigned int sg_count,
  83                                                 unsigned int len);
  84 static void destroy_bounce_buffer(struct scatterlist *sgl,
  85                                   unsigned int sg_count);
  86 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count);
  87 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
  88                                             struct scatterlist *bounce_sgl,
  89                                             unsigned int orig_sgl_count);
  90 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
  91                                           struct scatterlist *bounce_sgl,
  92                                           unsigned int orig_sgl_count);
  93
  94 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device *bdev,
  95                            sector_t capacity, int *info);
  96
  97
  98 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
  99 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
 100 MODULE_PARM_DESC(storvsc_ringbuffer_size, "Ring buffer size (bytes)");
 101
 102 /* The one and only one */
 103 static struct storvsc_driver_context g_storvsc_drv;
 104
 105 /* Scsi driver */
 106 static struct scsi_host_template scsi_driver = {
 107         .module =               THIS_MODULE,
 108         .name =                 "storvsc_host_t",
 109         .bios_param =           storvsc_get_chs,
 110         .queuecommand =         storvsc_queuecommand,
 111         .eh_host_reset_handler =        storvsc_host_reset_handler,
 112         .slave_alloc =          storvsc_device_alloc,
 113         .slave_configure =      storvsc_device_configure,
 114         .cmd_per_lun =          1,
 115         /* 64 max_queue * 1 target */
 116         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 117         .this_id =              -1,
 118         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 119         /* currently 32 */
 120         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 121         /*
 122          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 123          * into 1 sg element. If set, we must limit the max_segment_size to
 124          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 125          * multiple
 126          */
 127         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 128         .use_clustering =       ENABLE_CLUSTERING,
 129         /* Make sure we dont get a sg segment crosses a page boundary */
 130         .dma_boundary =         PAGE_SIZE-1,
 131 };
 132
 133
 134 /*
 135  * storvsc_drv_init - StorVsc driver initialization.
 136  */
 137 static int storvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 138 {
 139         int ret;
 140         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 141         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 142
 143         storvsc_drv_obj->ring_buffer_size = storvsc_ringbuffer_size;
 144
 145         /* Callback to client driver to complete the initialization */
 146         drv_init(&storvsc_drv_obj->base);
 147
 148         DPRINT_INFO(STORVSC_DRV,
 149                     "request extension size %u, max outstanding reqs %u",
 150                     storvsc_drv_obj->request_ext_size,
 151                     storvsc_drv_obj->max_outstanding_req_per_channel);
 152
 153         if (storvsc_drv_obj->max_outstanding_req_per_channel <
 154             STORVSC_MAX_IO_REQUESTS) {
 155                 DPRINT_ERR(STORVSC_DRV,
 156                            "The number of outstanding io requests (%d) "
 157                            "is larger than that supported (%d) internally.",
 158                            STORVSC_MAX_IO_REQUESTS,
 159                            storvsc_drv_obj->max_outstanding_req_per_channel);
 160                 return -1;
 161         }
 162
 163         drv_ctx->driver.name = storvsc_drv_obj->base.name;
 164         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->base.deviceType,
 165                sizeof(struct hv_guid));
 166
 167         drv_ctx->probe = storvsc_probe;
 168         drv_ctx->remove = storvsc_remove;
 169
 170         /* The driver belongs to vmbus */
 171         ret = vmbus_child_driver_register(drv_ctx);
 172
 173         return ret;
 174 }
 175
 176 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 177 {
 178         struct device **curr = (struct device **)data;
 179         *curr = dev;
 180         return 1; /* stop iterating */
 181 }
 182
 183 static void storvsc_drv_exit(void)
 184 {
 185         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 186         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 187         struct device *current_dev = NULL;
 188         int ret;
 189
 190         while (1) {
 191                 current_dev = NULL;
 192
 193                 /* Get the device */
 194                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 195                                              (void *) &current_dev,
 196                                              storvsc_drv_exit_cb);
 197
 198                 if (ret)
 199                         DPRINT_WARN(STORVSC_DRV,
 200                                     "driver_for_each_device returned %d", ret);
 201
 202                 if (current_dev == NULL)
 203                         break;
 204
 205                 /* Initiate removal from the top-down */
 206                 device_unregister(current_dev);
 207         }
 208
 209         if (storvsc_drv_obj->base.OnCleanup)
 210                 storvsc_drv_obj->base.OnCleanup(&storvsc_drv_obj->base);
 211
 212         vmbus_child_driver_unregister(drv_ctx);
 213         return;
 214 }
 215
 216 /*
 217  * storvsc_probe - Add a new device for this driver
 218  */
 219 static int storvsc_probe(struct device *device)
 220 {
 221         int ret;
 222         struct driver_context *driver_ctx =
 223                                 driver_to_driver_context(device->driver);
 224         struct storvsc_driver_context *storvsc_drv_ctx =
 225                                 (struct storvsc_driver_context *)driver_ctx;
 226         struct storvsc_driver_object *storvsc_drv_obj =
 227                                 &storvsc_drv_ctx->drv_obj;
 228         struct vm_device *device_ctx = device_to_vm_device(device);
 229         struct hv_device *device_obj = &device_ctx->device_obj;
 230         struct Scsi_Host *host;
 231         struct host_device_context *host_device_ctx;
 232         struct storvsc_device_info device_info;
 233
 234         if (!storvsc_drv_obj->base.OnDeviceAdd)
 235                 return -1;
 236
 237         host = scsi_host_alloc(&scsi_driver,
 238                                sizeof(struct host_device_context));
 239         if (!host) {
 240                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 241                 return -ENOMEM;
 242         }
 243
 244         dev_set_drvdata(device, host);
 245
 246         host_device_ctx = (struct host_device_context *)host->hostdata;
 247         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 248
 249         host_device_ctx->port = host->host_no;
 250         host_device_ctx->device_ctx = device_ctx;
 251
 252         host_device_ctx->request_pool =
 253                                 kmem_cache_create(dev_name(&device_ctx->device),
 254                                         sizeof(struct storvsc_cmd_request) +
 255                                         storvsc_drv_obj->request_ext_size, 0,
 256                                         SLAB_HWCACHE_ALIGN, NULL);
 257
 258         if (!host_device_ctx->request_pool) {
 259                 scsi_host_put(host);
 260                 return -ENOMEM;
 261         }
 262
 263         device_info.port_number = host->host_no;
 264         /* Call to the vsc driver to add the device */
 265         ret = storvsc_drv_obj->base.OnDeviceAdd(device_obj,
 266                                                 (void *)&device_info);
 267         if (ret != 0) {
 268                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 269                 kmem_cache_destroy(host_device_ctx->request_pool);
 270                 scsi_host_put(host);
 271                 return -1;
 272         }
 273
 274         /* host_device_ctx->port = device_info.PortNumber; */
 275         host_device_ctx->path = device_info.path_id;
 276         host_device_ctx->target = device_info.target_id;
 277
 278         /* max # of devices per target */
 279         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 280         /* max # of targets per channel */
 281         host->max_id = STORVSC_MAX_TARGETS;
 282         /* max # of channels */
 283         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 284
 285         /* Register the HBA and start the scsi bus scan */
 286         ret = scsi_add_host(host, device);
 287         if (ret != 0) {
 288                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 289
 290                 storvsc_drv_obj->base.OnDeviceRemove(device_obj);
 291
 292                 kmem_cache_destroy(host_device_ctx->request_pool);
 293                 scsi_host_put(host);
 294                 return -1;
 295         }
 296
 297         scsi_scan_host(host);
 298         return ret;
 299 }
 300
 301 /*
 302  * storvsc_remove - Callback when our device is removed
 303  */
 304 static int storvsc_remove(struct device *device)
 305 {
 306         int ret;
 307         struct driver_context *driver_ctx =
 308                         driver_to_driver_context(device->driver);
 309         struct storvsc_driver_context *storvsc_drv_ctx =
 310                         (struct storvsc_driver_context *)driver_ctx;
 311         struct storvsc_driver_object *storvsc_drv_obj =
 312                         &storvsc_drv_ctx->drv_obj;
 313         struct vm_device *device_ctx = device_to_vm_device(device);
 314         struct hv_device *device_obj = &device_ctx->device_obj;
 315         struct Scsi_Host *host = dev_get_drvdata(device);
 316         struct host_device_context *host_device_ctx =
 317                         (struct host_device_context *)host->hostdata;
 318
 319
 320         if (!storvsc_drv_obj->base.OnDeviceRemove)
 321                 return -1;
 322
 323         /*
 324          * Call to the vsc driver to let it know that the device is being
 325          * removed
 326          */
 327         ret = storvsc_drv_obj->base.OnDeviceRemove(device_obj);
 328         if (ret != 0) {
 329                 /* TODO: */
 330                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 331                            ret);
 332         }
 333
 334         if (host_device_ctx->request_pool) {
 335                 kmem_cache_destroy(host_device_ctx->request_pool);
 336                 host_device_ctx->request_pool = NULL;
 337         }
 338
 339         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 340         scsi_remove_host(host);
 341
 342         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 343         scsi_host_put(host);
 344         return ret;
 345 }
 346
 347 /*
 348  * storvsc_commmand_completion - Command completion processing
 349  */
 350 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 351 {
 352         struct storvsc_cmd_request *cmd_request =
 353                 (struct storvsc_cmd_request *)request->context;
 354         struct scsi_cmnd *scmnd = cmd_request->cmd;
 355         struct host_device_context *host_device_ctx =
 356                 (struct host_device_context *)scmnd->device->host->hostdata;
 357         void (*scsi_done_fn)(struct scsi_cmnd *);
 358         struct scsi_sense_hdr sense_hdr;
 359
 360         /* ASSERT(request == &cmd_request->request); */
 361         /* ASSERT(scmnd); */
 362         /* ASSERT((unsigned long)scmnd->host_scribble == */
 363         /*        (unsigned long)cmd_request); */
 364         /* ASSERT(scmnd->scsi_done); */
 365
 366         if (cmd_request->bounce_sgl_count) {
 367                 /* using bounce buffer */
 368                 /* printk("copy_from_bounce_buffer\n"); */
 369
 370                 /* FIXME: We can optimize on writes by just skipping this */
 371                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 372                                         cmd_request->bounce_sgl,
 373                                         scsi_sg_count(scmnd));
 374                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 375                                       cmd_request->bounce_sgl_count);
 376         }
 377
 378         scmnd->result = request->status;
 379
 380         if (scmnd->result) {
 381                 if (scsi_normalize_sense(scmnd->sense_buffer,
 382                                 request->sense_buffer_size, &sense_hdr))
 383                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 384         }
 385
 386         /* ASSERT(request->BytesXfer <= request->data_buffer.Length); */
 387         scsi_set_resid(scmnd,
 388                 request->data_buffer.Length - request->bytes_xfer);
 389
 390         scsi_done_fn = scmnd->scsi_done;
 391
 392         scmnd->host_scribble = NULL;
 393         scmnd->scsi_done = NULL;
 394
 395         /* !!DO NOT MODIFY the scmnd after this call */
 396         scsi_done_fn(scmnd);
 397
 398         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 399 }
 400
 401 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 402 {
 403         int i;
 404
 405         /* No need to check */
 406         if (sg_count < 2)
 407                 return -1;
 408
 409         /* We have at least 2 sg entries */
 410         for (i = 0; i < sg_count; i++) {
 411                 if (i == 0) {
 412                         /* make sure 1st one does not have hole */
 413                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 414                                 return i;
 415                 } else if (i == sg_count - 1) {
 416                         /* make sure last one does not have hole */
 417                         if (sgl[i].offset != 0)
 418                                 return i;
 419                 } else {
 420                         /* make sure no hole in the middle */
 421                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 422                                 return i;
 423                 }
 424         }
 425         return -1;
 426 }
 427
 428 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 429                                                 unsigned int sg_count,
 430                                                 unsigned int len)
 431 {
 432         int i;
 433         int num_pages;
 434         struct scatterlist *bounce_sgl;
 435         struct page *page_buf;
 436
 437         num_pages = ALIGN(len, PAGE_SIZE) >> PAGE_SHIFT;
 438
 439         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 440         if (!bounce_sgl)
 441                 return NULL;
 442
 443         for (i = 0; i < num_pages; i++) {
 444                 page_buf = alloc_page(GFP_ATOMIC);
 445                 if (!page_buf)
 446                         goto cleanup;
 447                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 448         }
 449
 450         return bounce_sgl;
 451
 452 cleanup:
 453         destroy_bounce_buffer(bounce_sgl, num_pages);
 454         return NULL;
 455 }
 456
 457 static void destroy_bounce_buffer(struct scatterlist *sgl,
 458                                   unsigned int sg_count)
 459 {
 460         int i;
 461         struct page *page_buf;
 462
 463         for (i = 0; i < sg_count; i++) {
 464                 page_buf = sg_page((&sgl[i]));
 465                 if (page_buf != NULL)
 466                         __free_page(page_buf);
 467         }
 468
 469         kfree(sgl);
 470 }
 471
 472 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 473 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 474                                           struct scatterlist *bounce_sgl,
 475                                           unsigned int orig_sgl_count)
 476 {
 477         int i;
 478         int j = 0;
 479         unsigned long src, dest;
 480         unsigned int srclen, destlen, copylen;
 481         unsigned int total_copied = 0;
 482         unsigned long bounce_addr = 0;
 483         unsigned long src_addr = 0;
 484         unsigned long flags;
 485
 486         local_irq_save(flags);
 487
 488         for (i = 0; i < orig_sgl_count; i++) {
 489                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 490                                 KM_IRQ0) + orig_sgl[i].offset;
 491                 src = src_addr;
 492                 srclen = orig_sgl[i].length;
 493
 494                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 495
 496                 if (bounce_addr == 0)
 497                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 498
 499                 while (srclen) {
 500                         /* assume bounce offset always == 0 */
 501                         dest = bounce_addr + bounce_sgl[j].length;
 502                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 503
 504                         copylen = min(srclen, destlen);
 505                         memcpy((void *)dest, (void *)src, copylen);
 506
 507                         total_copied += copylen;
 508                         bounce_sgl[j].length += copylen;
 509                         srclen -= copylen;
 510                         src += copylen;
 511
 512                         if (bounce_sgl[j].length == PAGE_SIZE) {
 513                                 /* full..move to next entry */
 514                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 515                                 j++;
 516
 517                                 /* if we need to use another bounce buffer */
 518                                 if (srclen || i != orig_sgl_count - 1)
 519                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 520                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 521                                 /* unmap the last bounce that is < PAGE_SIZE */
 522                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 523                         }
 524                 }
 525
 526                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 527         }
 528
 529         local_irq_restore(flags);
 530
 531         return total_copied;
 532 }
 533
 534 /* Assume the original sgl has enough room */
 535 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 536                                             struct scatterlist *bounce_sgl,
 537                                             unsigned int orig_sgl_count)
 538 {
 539         int i;
 540         int j = 0;
 541         unsigned long src, dest;
 542         unsigned int srclen, destlen, copylen;
 543         unsigned int total_copied = 0;
 544         unsigned long bounce_addr = 0;
 545         unsigned long dest_addr = 0;
 546         unsigned long flags;
 547
 548         local_irq_save(flags);
 549
 550         for (i = 0; i < orig_sgl_count; i++) {
 551                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 552                                         KM_IRQ0) + orig_sgl[i].offset;
 553                 dest = dest_addr;
 554                 destlen = orig_sgl[i].length;
 555                 /* ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE); */
 556
 557                 if (bounce_addr == 0)
 558                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 559
 560                 while (destlen) {
 561                         src = bounce_addr + bounce_sgl[j].offset;
 562                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 563
 564                         copylen = min(srclen, destlen);
 565                         memcpy((void *)dest, (void *)src, copylen);
 566
 567                         total_copied += copylen;
 568                         bounce_sgl[j].offset += copylen;
 569                         destlen -= copylen;
 570                         dest += copylen;
 571
 572                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 573                                 /* full */
 574                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 575                                 j++;
 576
 577                                 /* if we need to use another bounce buffer */
 578                                 if (destlen || i != orig_sgl_count - 1)
 579                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 580                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 581                                 /* unmap the last bounce that is < PAGE_SIZE */
 582                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 583                         }
 584                 }
 585
 586                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 587                               KM_IRQ0);
 588         }
 589
 590         local_irq_restore(flags);
 591
 592         return total_copied;
 593 }
 594
 595 /*
 596  * storvsc_queuecommand - Initiate command processing
 597  */
 598 static int storvsc_queuecommand_lck(struct scsi_cmnd *scmnd,
 599                                 void (*done)(struct scsi_cmnd *))
 600 {
 601         int ret;
 602         struct host_device_context *host_device_ctx =
 603                 (struct host_device_context *)scmnd->device->host->hostdata;
 604         struct vm_device *device_ctx = host_device_ctx->device_ctx;
 605         struct driver_context *driver_ctx =
 606                 driver_to_driver_context(device_ctx->device.driver);
 607         struct storvsc_driver_context *storvsc_drv_ctx =
 608                 (struct storvsc_driver_context *)driver_ctx;
 609         struct storvsc_driver_object *storvsc_drv_obj =
 610                 &storvsc_drv_ctx->drv_obj;
 611         struct hv_storvsc_request *request;
 612         struct storvsc_cmd_request *cmd_request;
 613         unsigned int request_size = 0;
 614         int i;
 615         struct scatterlist *sgl;
 616         unsigned int sg_count = 0;
 617
 618         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 619                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 620                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 621                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 622                    scmnd->device->tagged_supported);
 623
 624         /* If retrying, no need to prep the cmd */
 625         if (scmnd->host_scribble) {
 626                 /* ASSERT(scmnd->scsi_done != NULL); */
 627
 628                 cmd_request =
 629                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 630                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 631                             scmnd, cmd_request);
 632
 633                 goto retry_request;
 634         }
 635
 636         /* ASSERT(scmnd->scsi_done == NULL); */
 637         /* ASSERT(scmnd->host_scribble == NULL); */
 638
 639         scmnd->scsi_done = done;
 640
 641         request_size = sizeof(struct storvsc_cmd_request);
 642
 643         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 644                                        GFP_ATOMIC);
 645         if (!cmd_request) {
 646                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 647                            "storvsc_cmd_request...marking queue busy", scmnd);
 648                 scmnd->scsi_done = NULL;
 649                 return SCSI_MLQUEUE_DEVICE_BUSY;
 650         }
 651
 652         /* Setup the cmd request */
 653         cmd_request->bounce_sgl_count = 0;
 654         cmd_request->bounce_sgl = NULL;
 655         cmd_request->cmd = scmnd;
 656
 657         scmnd->host_scribble = (unsigned char *)cmd_request;
 658
 659         request = &cmd_request->request;
 660
 661         request->extension =
 662                 (void *)((unsigned long)cmd_request + request_size);
 663         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 664                    storvsc_drv_obj->request_ext_size);
 665
 666         /* Build the SRB */
 667         switch (scmnd->sc_data_direction) {
 668         case DMA_TO_DEVICE:
 669                 request->type = WRITE_TYPE;
 670                 break;
 671         case DMA_FROM_DEVICE:
 672                 request->type = READ_TYPE;
 673                 break;
 674         default:
 675                 request->type = UNKNOWN_TYPE;
 676                 break;
 677         }
 678
 679         request->on_io_completion = storvsc_commmand_completion;
 680         request->context = cmd_request;/* scmnd; */
 681
 682         /* request->PortId = scmnd->device->channel; */
 683         request->host = host_device_ctx->port;
 684         request->bus = scmnd->device->channel;
 685         request->target_id = scmnd->device->id;
 686         request->lun_id = scmnd->device->lun;
 687
 688         /* ASSERT(scmnd->cmd_len <= 16); */
 689         request->cdb_len = scmnd->cmd_len;
 690         request->cdb = scmnd->cmnd;
 691
 692         request->sense_buffer = scmnd->sense_buffer;
 693         request->sense_buffer_size = SCSI_SENSE_BUFFERSIZE;
 694
 695
 696         request->data_buffer.Length = scsi_bufflen(scmnd);
 697         if (scsi_sg_count(scmnd)) {
 698                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 699                 sg_count = scsi_sg_count(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(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                         sg_count = cmd_request->bounce_sgl_count;
 735                 }
 736
 737                 request->data_buffer.Offset = sgl[0].offset;
 738
 739                 for (i = 0; i < sg_count; i++) {
 740                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d\n",
 741                                    i, sgl[i].length, sgl[i].offset);
 742                         request->data_buffer.PfnArray[i] =
 743                                 page_to_pfn(sg_page((&sgl[i])));
 744                 }
 745         } else if (scsi_sglist(scmnd)) {
 746                 /* ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE); */
 747                 request->data_buffer.Offset =
 748                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 749                 request->data_buffer.PfnArray[0] =
 750                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 751         }
 752
 753 retry_request:
 754         /* Invokes the vsc to start an IO */
 755         ret = storvsc_drv_obj->on_io_request(&device_ctx->device_obj,
 756                                            &cmd_request->request);
 757         if (ret == -1) {
 758                 /* no more space */
 759                 DPRINT_ERR(STORVSC_DRV,
 760                            "scmnd (%p) - queue FULL...marking queue busy",
 761                            scmnd);
 762
 763                 if (cmd_request->bounce_sgl_count) {
 764                         /*
 765                          * FIXME: We can optimize on writes by just skipping
 766                          * this
 767                          */
 768                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 769                                                 cmd_request->bounce_sgl,
 770                                                 scsi_sg_count(scmnd));
 771                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 772                                               cmd_request->bounce_sgl_count);
 773                 }
 774
 775                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 776
 777                 scmnd->scsi_done = NULL;
 778                 scmnd->host_scribble = NULL;
 779
 780                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 781         }
 782
 783         return ret;
 784 }
 785
 786 static DEF_SCSI_QCMD(storvsc_queuecommand)
 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 = stor_vsc_on_host_reset(&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(stor_vsc_initialize);
 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);