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/module.h>
  23 #include <linux/device.h>
  24 #include <linux/blkdev.h>
  25 #include <scsi/scsi.h>
  26 #include <scsi/scsi_cmnd.h>
  27 #include <scsi/scsi_host.h>
  28 #include <scsi/scsi_device.h>
  29 #include <scsi/scsi_tcq.h>
  30 #include <scsi/scsi_eh.h>
  31 #include <scsi/scsi_devinfo.h>
  32 #include <scsi/scsi_dbg.h>
  33 #include "osd.h"
  34 #include "logging.h"
  35 #include "vmbus.h"
  36 #include "StorVscApi.h"
  37
  38
  39 struct host_device_context {
  40         /* must be 1st field
  41          * FIXME this is a bug */
  42         struct work_struct host_rescan_work;
  43
  44         /* point back to our device context */
  45         struct device_context *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 void storvsc_host_rescan_callback(struct work_struct *work);
  81 static void storvsc_host_rescan(struct hv_device *device_obj);
  82 static int storvsc_remove(struct device *dev);
  83
  84 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
  85                                                 unsigned int sg_count,
  86                                                 unsigned int len);
  87 static void destroy_bounce_buffer(struct scatterlist *sgl,
  88                                   unsigned int sg_count);
  89 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count);
  90 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
  91                                             struct scatterlist *bounce_sgl,
  92                                             unsigned int orig_sgl_count);
  93 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
  94                                           struct scatterlist *bounce_sgl,
  95                                           unsigned int orig_sgl_count);
  96
  97 static int storvsc_report_luns(struct scsi_device *sdev, unsigned int luns[],
  98                                unsigned int *lun_count);
  99 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device *bdev,
 100                            sector_t capacity, int *info);
 101
 102
 103 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
 104
 105 /* The one and only one */
 106 static struct storvsc_driver_context g_storvsc_drv;
 107
 108 /* Scsi driver */
 109 static struct scsi_host_template scsi_driver = {
 110         .module =               THIS_MODULE,
 111         .name =                 "storvsc_host_t",
 112         .bios_param =           storvsc_get_chs,
 113         .queuecommand =         storvsc_queuecommand,
 114         .eh_host_reset_handler =        storvsc_host_reset_handler,
 115         .slave_alloc =          storvsc_device_alloc,
 116         .slave_configure =      storvsc_device_configure,
 117         .cmd_per_lun =          1,
 118         /* 64 max_queue * 1 target */
 119         .can_queue =            STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS,
 120         .this_id =              -1,
 121         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 122         /* currently 32 */
 123         .sg_tablesize =         MAX_MULTIPAGE_BUFFER_COUNT,
 124         /*
 125          * ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge
 126          * into 1 sg element. If set, we must limit the max_segment_size to
 127          * PAGE_SIZE, otherwise we may get 1 sg element that represents
 128          * multiple
 129          */
 130         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 131         .use_clustering =       ENABLE_CLUSTERING,
 132         /* Make sure we dont get a sg segment crosses a page boundary */
 133         .dma_boundary =         PAGE_SIZE-1,
 134 };
 135
 136
 137 /**
 138  * storvsc_drv_init - StorVsc driver initialization.
 139  */
 140 static int storvsc_drv_init(int (*drv_init)(struct hv_driver *drv))
 141 {
 142         int ret;
 143         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 144         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 145
 146         DPRINT_ENTER(STORVSC_DRV);
 147
 148         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 149
 150         storvsc_drv_obj->RingBufferSize = storvsc_ringbuffer_size;
 151         storvsc_drv_obj->OnHostRescan = storvsc_host_rescan;
 152
 153         /* Callback to client driver to complete the initialization */
 154         drv_init(&storvsc_drv_obj->Base);
 155
 156         DPRINT_INFO(STORVSC_DRV,
 157                     "request extension size %u, max outstanding reqs %u",
 158                     storvsc_drv_obj->RequestExtSize,
 159                     storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 160
 161         if (storvsc_drv_obj->MaxOutstandingRequestsPerChannel <
 162             STORVSC_MAX_IO_REQUESTS) {
 163                 DPRINT_ERR(STORVSC_DRV,
 164                            "The number of outstanding io requests (%d) "
 165                            "is larger than that supported (%d) internally.",
 166                            STORVSC_MAX_IO_REQUESTS,
 167                            storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 168                 return -1;
 169         }
 170
 171         drv_ctx->driver.name = storvsc_drv_obj->Base.name;
 172         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->Base.deviceType,
 173                sizeof(struct hv_guid));
 174
 175         drv_ctx->probe = storvsc_probe;
 176         drv_ctx->remove = storvsc_remove;
 177
 178         /* The driver belongs to vmbus */
 179         ret = vmbus_child_driver_register(drv_ctx);
 180
 181         DPRINT_EXIT(STORVSC_DRV);
 182
 183         return ret;
 184 }
 185
 186 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 187 {
 188         struct device **curr = (struct device **)data;
 189         *curr = dev;
 190         return 1; /* stop iterating */
 191 }
 192
 193 static void storvsc_drv_exit(void)
 194 {
 195         struct storvsc_driver_object *storvsc_drv_obj = &g_storvsc_drv.drv_obj;
 196         struct driver_context *drv_ctx = &g_storvsc_drv.drv_ctx;
 197         struct device *current_dev = NULL;
 198         int ret;
 199
 200         DPRINT_ENTER(STORVSC_DRV);
 201
 202         while (1) {
 203                 current_dev = NULL;
 204
 205                 /* Get the device */
 206                 ret = driver_for_each_device(&drv_ctx->driver, NULL,
 207                                              (void *) &current_dev,
 208                                              storvsc_drv_exit_cb);
 209
 210                 if (ret)
 211                         DPRINT_WARN(STORVSC_DRV,
 212                                     "driver_for_each_device returned %d", ret);
 213
 214                 if (current_dev == NULL)
 215                         break;
 216
 217                 /* Initiate removal from the top-down */
 218                 device_unregister(current_dev);
 219         }
 220
 221         if (storvsc_drv_obj->Base.OnCleanup)
 222                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 223
 224         vmbus_child_driver_unregister(drv_ctx);
 225
 226         DPRINT_EXIT(STORVSC_DRV);
 227
 228         return;
 229 }
 230
 231 /**
 232  * storvsc_probe - Add a new device for this driver
 233  */
 234 static int storvsc_probe(struct device *device)
 235 {
 236         int ret;
 237         struct driver_context *driver_ctx =
 238                                 driver_to_driver_context(device->driver);
 239         struct storvsc_driver_context *storvsc_drv_ctx =
 240                                 (struct storvsc_driver_context *)driver_ctx;
 241         struct storvsc_driver_object *storvsc_drv_obj =
 242                                 &storvsc_drv_ctx->drv_obj;
 243         struct device_context *device_ctx = device_to_device_context(device);
 244         struct hv_device *device_obj = &device_ctx->device_obj;
 245         struct Scsi_Host *host;
 246         struct host_device_context *host_device_ctx;
 247         struct storvsc_device_info device_info;
 248
 249         DPRINT_ENTER(STORVSC_DRV);
 250
 251         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 252                 return -1;
 253
 254         host = scsi_host_alloc(&scsi_driver,
 255                                sizeof(struct host_device_context));
 256         if (!host) {
 257                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 258                 return -ENOMEM;
 259         }
 260
 261         dev_set_drvdata(device, host);
 262
 263         host_device_ctx = (struct host_device_context *)host->hostdata;
 264         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 265
 266         host_device_ctx->port = host->host_no;
 267         host_device_ctx->device_ctx = device_ctx;
 268
 269         INIT_WORK(&host_device_ctx->host_rescan_work,
 270                   storvsc_host_rescan_callback);
 271
 272         host_device_ctx->request_pool =
 273                                 kmem_cache_create(dev_name(&device_ctx->device),
 274                                         sizeof(struct storvsc_cmd_request) +
 275                                         storvsc_drv_obj->RequestExtSize, 0,
 276                                         SLAB_HWCACHE_ALIGN, NULL);
 277
 278         if (!host_device_ctx->request_pool) {
 279                 scsi_host_put(host);
 280                 DPRINT_EXIT(STORVSC_DRV);
 281
 282                 return -ENOMEM;
 283         }
 284
 285         device_info.PortNumber = host->host_no;
 286         /* Call to the vsc driver to add the device */
 287         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj,
 288                                                 (void *)&device_info);
 289         if (ret != 0) {
 290                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 291                 kmem_cache_destroy(host_device_ctx->request_pool);
 292                 scsi_host_put(host);
 293                 DPRINT_EXIT(STORVSC_DRV);
 294
 295                 return -1;
 296         }
 297
 298         /* host_device_ctx->port = device_info.PortNumber; */
 299         host_device_ctx->path = device_info.PathId;
 300         host_device_ctx->target = device_info.TargetId;
 301
 302         /* max # of devices per target */
 303         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;
 304         /* max # of targets per channel */
 305         host->max_id = STORVSC_MAX_TARGETS;
 306         /* max # of channels */
 307         host->max_channel = STORVSC_MAX_CHANNELS - 1;
 308
 309         /* Register the HBA and start the scsi bus scan */
 310         ret = scsi_add_host(host, device);
 311         if (ret != 0) {
 312                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 313
 314                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 315
 316                 kmem_cache_destroy(host_device_ctx->request_pool);
 317                 scsi_host_put(host);
 318                 DPRINT_EXIT(STORVSC_DRV);
 319
 320                 return -1;
 321         }
 322
 323         scsi_scan_host(host);
 324
 325         DPRINT_EXIT(STORVSC_DRV);
 326
 327         return ret;
 328 }
 329
 330 /**
 331  * storvsc_remove - Callback when our device is removed
 332  */
 333 static int storvsc_remove(struct device *device)
 334 {
 335         int ret;
 336         struct driver_context *driver_ctx =
 337                         driver_to_driver_context(device->driver);
 338         struct storvsc_driver_context *storvsc_drv_ctx =
 339                         (struct storvsc_driver_context *)driver_ctx;
 340         struct storvsc_driver_object *storvsc_drv_obj =
 341                         &storvsc_drv_ctx->drv_obj;
 342         struct device_context *device_ctx = device_to_device_context(device);
 343         struct hv_device *device_obj = &device_ctx->device_obj;
 344         struct Scsi_Host *host = dev_get_drvdata(device);
 345         struct host_device_context *host_device_ctx =
 346                         (struct host_device_context *)host->hostdata;
 347
 348
 349         DPRINT_ENTER(STORVSC_DRV);
 350
 351         if (!storvsc_drv_obj->Base.OnDeviceRemove) {
 352                 DPRINT_EXIT(STORVSC_DRV);
 353                 return -1;
 354         }
 355
 356         /*
 357          * Call to the vsc driver to let it know that the device is being
 358          * removed
 359          */
 360         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 361         if (ret != 0) {
 362                 /* TODO: */
 363                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)",
 364                            ret);
 365         }
 366
 367         if (host_device_ctx->request_pool) {
 368                 kmem_cache_destroy(host_device_ctx->request_pool);
 369                 host_device_ctx->request_pool = NULL;
 370         }
 371
 372         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 373         scsi_remove_host(host);
 374
 375         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 376         scsi_host_put(host);
 377
 378         DPRINT_EXIT(STORVSC_DRV);
 379
 380         return ret;
 381 }
 382
 383 /**
 384  * storvsc_commmand_completion - Command completion processing
 385  */
 386 static void storvsc_commmand_completion(struct hv_storvsc_request *request)
 387 {
 388         struct storvsc_cmd_request *cmd_request =
 389                 (struct storvsc_cmd_request *)request->Context;
 390         struct scsi_cmnd *scmnd = cmd_request->cmd;
 391         struct host_device_context *host_device_ctx =
 392                 (struct host_device_context *)scmnd->device->host->hostdata;
 393         void (*scsi_done_fn)(struct scsi_cmnd *);
 394         struct scsi_sense_hdr sense_hdr;
 395
 396         ASSERT(request == &cmd_request->request);
 397         ASSERT((unsigned long)scmnd->host_scribble ==
 398                 (unsigned long)cmd_request);
 399         ASSERT(scmnd);
 400         ASSERT(scmnd->scsi_done);
 401
 402         DPRINT_ENTER(STORVSC_DRV);
 403
 404         if (cmd_request->bounce_sgl_count) {
 405                 /* using bounce buffer */
 406                 /* printk("copy_from_bounce_buffer\n"); */
 407
 408                 /* FIXME: We can optimize on writes by just skipping this */
 409                 copy_from_bounce_buffer(scsi_sglist(scmnd),
 410                                         cmd_request->bounce_sgl,
 411                                         scsi_sg_count(scmnd));
 412                 destroy_bounce_buffer(cmd_request->bounce_sgl,
 413                                       cmd_request->bounce_sgl_count);
 414         }
 415
 416         scmnd->result = request->Status;
 417
 418         if (scmnd->result) {
 419                 if (scsi_normalize_sense(scmnd->sense_buffer,
 420                                          request->SenseBufferSize, &sense_hdr))
 421                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 422         }
 423
 424         ASSERT(request->BytesXfer <= request->DataBuffer.Length);
 425         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 426
 427         scsi_done_fn = scmnd->scsi_done;
 428
 429         scmnd->host_scribble = NULL;
 430         scmnd->scsi_done = NULL;
 431
 432         /* !!DO NOT MODIFY the scmnd after this call */
 433         scsi_done_fn(scmnd);
 434
 435         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 436
 437         DPRINT_EXIT(STORVSC_DRV);
 438 }
 439
 440 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 441 {
 442         int i;
 443
 444         /* No need to check */
 445         if (sg_count < 2)
 446                 return -1;
 447
 448         /* We have at least 2 sg entries */
 449         for (i = 0; i < sg_count; i++) {
 450                 if (i == 0) {
 451                         /* make sure 1st one does not have hole */
 452                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 453                                 return i;
 454                 } else if (i == sg_count - 1) {
 455                         /* make sure last one does not have hole */
 456                         if (sgl[i].offset != 0)
 457                                 return i;
 458                 } else {
 459                         /* make sure no hole in the middle */
 460                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 461                                 return i;
 462                 }
 463         }
 464         return -1;
 465 }
 466
 467 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl,
 468                                                 unsigned int sg_count,
 469                                                 unsigned int len)
 470 {
 471         int i;
 472         int num_pages;
 473         struct scatterlist *bounce_sgl;
 474         struct page *page_buf;
 475
 476         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 477
 478         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 479         if (!bounce_sgl)
 480                 return NULL;
 481
 482         for (i = 0; i < num_pages; i++) {
 483                 page_buf = alloc_page(GFP_ATOMIC);
 484                 if (!page_buf)
 485                         goto cleanup;
 486                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 487         }
 488
 489         return bounce_sgl;
 490
 491 cleanup:
 492         destroy_bounce_buffer(bounce_sgl, num_pages);
 493         return NULL;
 494 }
 495
 496 static void destroy_bounce_buffer(struct scatterlist *sgl,
 497                                   unsigned int sg_count)
 498 {
 499         int i;
 500         struct page *page_buf;
 501
 502         for (i = 0; i < sg_count; i++) {
 503                 page_buf = sg_page((&sgl[i]));
 504                 if (page_buf != NULL)
 505                         __free_page(page_buf);
 506         }
 507
 508         kfree(sgl);
 509 }
 510
 511 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 512 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl,
 513                                           struct scatterlist *bounce_sgl,
 514                                           unsigned int orig_sgl_count)
 515 {
 516         int i;
 517         int j = 0;
 518         unsigned long src, dest;
 519         unsigned int srclen, destlen, copylen;
 520         unsigned int total_copied = 0;
 521         unsigned long bounce_addr = 0;
 522         unsigned long src_addr = 0;
 523         unsigned long flags;
 524
 525         local_irq_save(flags);
 526
 527         for (i = 0; i < orig_sgl_count; i++) {
 528                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 529                                 KM_IRQ0) + orig_sgl[i].offset;
 530                 src = src_addr;
 531                 srclen = orig_sgl[i].length;
 532
 533                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 534
 535                 if (j == 0)
 536                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 537
 538                 while (srclen) {
 539                         /* assume bounce offset always == 0 */
 540                         dest = bounce_addr + bounce_sgl[j].length;
 541                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 542
 543                         copylen = min(srclen, destlen);
 544                         memcpy((void *)dest, (void *)src, copylen);
 545
 546                         total_copied += copylen;
 547                         bounce_sgl[j].length += copylen;
 548                         srclen -= copylen;
 549                         src += copylen;
 550
 551                         if (bounce_sgl[j].length == PAGE_SIZE) {
 552                                 /* full..move to next entry */
 553                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 554                                 j++;
 555
 556                                 /* if we need to use another bounce buffer */
 557                                 if (srclen || i != orig_sgl_count - 1)
 558                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 559                         } else if (srclen == 0 && i == orig_sgl_count - 1) {
 560                                 /* unmap the last bounce that is < PAGE_SIZE */
 561                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 562                         }
 563                 }
 564
 565                 kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 566         }
 567
 568         local_irq_restore(flags);
 569
 570         return total_copied;
 571 }
 572
 573 /* Assume the original sgl has enough room */
 574 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl,
 575                                             struct scatterlist *bounce_sgl,
 576                                             unsigned int orig_sgl_count)
 577 {
 578         int i;
 579         int j = 0;
 580         unsigned long src, dest;
 581         unsigned int srclen, destlen, copylen;
 582         unsigned int total_copied = 0;
 583         unsigned long bounce_addr = 0;
 584         unsigned long dest_addr = 0;
 585         unsigned long flags;
 586
 587         local_irq_save(flags);
 588
 589         for (i = 0; i < orig_sgl_count; i++) {
 590                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])),
 591                                         KM_IRQ0) + orig_sgl[i].offset;
 592                 dest = dest_addr;
 593                 destlen = orig_sgl[i].length;
 594                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 595
 596                 if (j == 0)
 597                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 598
 599                 while (destlen) {
 600                         src = bounce_addr + bounce_sgl[j].offset;
 601                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 602
 603                         copylen = min(srclen, destlen);
 604                         memcpy((void *)dest, (void *)src, copylen);
 605
 606                         total_copied += copylen;
 607                         bounce_sgl[j].offset += copylen;
 608                         destlen -= copylen;
 609                         dest += copylen;
 610
 611                         if (bounce_sgl[j].offset == bounce_sgl[j].length) {
 612                                 /* full */
 613                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 614                                 j++;
 615
 616                                 /* if we need to use another bounce buffer */
 617                                 if (destlen || i != orig_sgl_count - 1)
 618                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 619                         } else if (destlen == 0 && i == orig_sgl_count - 1) {
 620                                 /* unmap the last bounce that is < PAGE_SIZE */
 621                                 kunmap_atomic((void *)bounce_addr, KM_IRQ0);
 622                         }
 623                 }
 624
 625                 kunmap_atomic((void *)(dest_addr - orig_sgl[i].offset),
 626                               KM_IRQ0);
 627         }
 628
 629         local_irq_restore(flags);
 630
 631         return total_copied;
 632 }
 633
 634 /**
 635  * storvsc_queuecommand - Initiate command processing
 636  */
 637 static int storvsc_queuecommand(struct scsi_cmnd *scmnd,
 638                                 void (*done)(struct scsi_cmnd *))
 639 {
 640         int ret;
 641         struct host_device_context *host_device_ctx =
 642                 (struct host_device_context *)scmnd->device->host->hostdata;
 643         struct device_context *device_ctx = host_device_ctx->device_ctx;
 644         struct driver_context *driver_ctx =
 645                 driver_to_driver_context(device_ctx->device.driver);
 646         struct storvsc_driver_context *storvsc_drv_ctx =
 647                 (struct storvsc_driver_context *)driver_ctx;
 648         struct storvsc_driver_object *storvsc_drv_obj =
 649                 &storvsc_drv_ctx->drv_obj;
 650         struct hv_storvsc_request *request;
 651         struct storvsc_cmd_request *cmd_request;
 652         unsigned int request_size = 0;
 653         int i;
 654         struct scatterlist *sgl;
 655
 656         DPRINT_ENTER(STORVSC_DRV);
 657
 658         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d "
 659                    "queue depth %d tagged %d", scmnd, scmnd->sc_data_direction,
 660                    scsi_sg_count(scmnd), scsi_sglist(scmnd),
 661                    scsi_bufflen(scmnd), scmnd->device->queue_depth,
 662                    scmnd->device->tagged_supported);
 663
 664         /* If retrying, no need to prep the cmd */
 665         if (scmnd->host_scribble) {
 666                 ASSERT(scmnd->scsi_done != NULL);
 667
 668                 cmd_request =
 669                         (struct storvsc_cmd_request *)scmnd->host_scribble;
 670                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p",
 671                             scmnd, cmd_request);
 672
 673                 goto retry_request;
 674         }
 675
 676         ASSERT(scmnd->scsi_done == NULL);
 677         ASSERT(scmnd->host_scribble == NULL);
 678
 679         scmnd->scsi_done = done;
 680
 681         request_size = sizeof(struct storvsc_cmd_request);
 682
 683         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool,
 684                                        GFP_ATOMIC);
 685         if (!cmd_request) {
 686                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate "
 687                            "storvsc_cmd_request...marking queue busy", scmnd);
 688                 scmnd->scsi_done = NULL;
 689                 return SCSI_MLQUEUE_DEVICE_BUSY;
 690         }
 691
 692         /* Setup the cmd request */
 693         cmd_request->bounce_sgl_count = 0;
 694         cmd_request->bounce_sgl = NULL;
 695         cmd_request->cmd = scmnd;
 696
 697         scmnd->host_scribble = (unsigned char *)cmd_request;
 698
 699         request = &cmd_request->request;
 700
 701         request->Extension =
 702                 (void *)((unsigned long)cmd_request + request_size);
 703         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size,
 704                    storvsc_drv_obj->RequestExtSize);
 705
 706         /* Build the SRB */
 707         switch (scmnd->sc_data_direction) {
 708         case DMA_TO_DEVICE:
 709                 request->Type = WRITE_TYPE;
 710                 break;
 711         case DMA_FROM_DEVICE:
 712                 request->Type = READ_TYPE;
 713                 break;
 714         default:
 715                 request->Type = UNKNOWN_TYPE;
 716                 break;
 717         }
 718
 719         request->OnIOCompletion = storvsc_commmand_completion;
 720         request->Context = cmd_request;/* scmnd; */
 721
 722         /* request->PortId = scmnd->device->channel; */
 723         request->Host = host_device_ctx->port;
 724         request->Bus = scmnd->device->channel;
 725         request->TargetId = scmnd->device->id;
 726         request->LunId = scmnd->device->lun;
 727
 728         ASSERT(scmnd->cmd_len <= 16);
 729         request->CdbLen = scmnd->cmd_len;
 730         request->Cdb = scmnd->cmnd;
 731
 732         request->SenseBuffer = scmnd->sense_buffer;
 733         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 734
 735
 736         request->DataBuffer.Length = scsi_bufflen(scmnd);
 737         if (scsi_sg_count(scmnd)) {
 738                 sgl = (struct scatterlist *)scsi_sglist(scmnd);
 739
 740                 /* check if we need to bounce the sgl */
 741                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1) {
 742                         DPRINT_INFO(STORVSC_DRV,
 743                                     "need to bounce buffer for this scmnd %p",
 744                                     scmnd);
 745                         cmd_request->bounce_sgl =
 746                                 create_bounce_buffer(sgl, scsi_sg_count(scmnd),
 747                                                      scsi_bufflen(scmnd));
 748                         if (!cmd_request->bounce_sgl) {
 749                                 DPRINT_ERR(STORVSC_DRV,
 750                                            "unable to create bounce buffer for "
 751                                            "this scmnd %p", scmnd);
 752
 753                                 scmnd->scsi_done = NULL;
 754                                 scmnd->host_scribble = NULL;
 755                                 kmem_cache_free(host_device_ctx->request_pool,
 756                                                 cmd_request);
 757
 758                                 return SCSI_MLQUEUE_HOST_BUSY;
 759                         }
 760
 761                         cmd_request->bounce_sgl_count =
 762                                 ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >>
 763                                         PAGE_SHIFT;
 764
 765                         /*
 766                          * FIXME: We can optimize on reads by just skipping
 767                          * this
 768                          */
 769                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl,
 770                                               scsi_sg_count(scmnd));
 771
 772                         sgl = cmd_request->bounce_sgl;
 773                 }
 774
 775                 request->DataBuffer.Offset = sgl[0].offset;
 776
 777                 for (i = 0; i < scsi_sg_count(scmnd); i++) {
 778                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d \n",
 779                                    i, sgl[i].length, sgl[i].offset);
 780                         request->DataBuffer.PfnArray[i] =
 781                                         page_to_pfn(sg_page((&sgl[i])));
 782                 }
 783         } else if (scsi_sglist(scmnd)) {
 784                 ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE);
 785                 request->DataBuffer.Offset =
 786                         virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 787                 request->DataBuffer.PfnArray[0] =
 788                         virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 789         } else {
 790                 ASSERT(scsi_bufflen(scmnd) == 0);
 791         }
 792
 793 retry_request:
 794         /* Invokes the vsc to start an IO */
 795         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj,
 796                                            &cmd_request->request);
 797         if (ret == -1) {
 798                 /* no more space */
 799                 DPRINT_ERR(STORVSC_DRV,
 800                            "scmnd (%p) - queue FULL...marking queue busy",
 801                            scmnd);
 802
 803                 if (cmd_request->bounce_sgl_count) {
 804                         /*
 805                          * FIXME: We can optimize on writes by just skipping
 806                          * this
 807                          */
 808                         copy_from_bounce_buffer(scsi_sglist(scmnd),
 809                                                 cmd_request->bounce_sgl,
 810                                                 scsi_sg_count(scmnd));
 811                         destroy_bounce_buffer(cmd_request->bounce_sgl,
 812                                               cmd_request->bounce_sgl_count);
 813                 }
 814
 815                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 816
 817                 scmnd->scsi_done = NULL;
 818                 scmnd->host_scribble = NULL;
 819
 820                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 821         }
 822
 823         DPRINT_EXIT(STORVSC_DRV);
 824
 825         return ret;
 826 }
 827
 828 static int storvsc_merge_bvec(struct request_queue *q,
 829                               struct bvec_merge_data *bmd, struct bio_vec *bvec)
 830 {
 831         /* checking done by caller. */
 832         return bvec->bv_len;
 833 }
 834
 835 /**
 836  * storvsc_device_configure - Configure the specified scsi device
 837  */
 838 static int storvsc_device_alloc(struct scsi_device *sdevice)
 839 {
 840         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d",
 841                    sdevice, BLIST_SPARSELUN);
 842         /*
 843          * This enables luns to be located sparsely. Otherwise, we may not
 844          * discovered them.
 845          */
 846         sdevice->sdev_bflags |= BLIST_SPARSELUN | BLIST_LARGELUN;
 847         return 0;
 848 }
 849
 850 static int storvsc_device_configure(struct scsi_device *sdevice)
 851 {
 852         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - curr queue depth %d", sdevice,
 853                     sdevice->queue_depth);
 854
 855         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d",
 856                     sdevice, STORVSC_MAX_IO_REQUESTS);
 857         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG,
 858                                 STORVSC_MAX_IO_REQUESTS);
 859
 860         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld",
 861                     sdevice, PAGE_SIZE);
 862         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 863
 864         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine",
 865                     sdevice);
 866         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 867
 868         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 869         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 870
 871         return 0;
 872 }
 873
 874 /**
 875  * storvsc_host_reset_handler - Reset the scsi HBA
 876  */
 877 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 878 {
 879         int ret;
 880         struct host_device_context *host_device_ctx =
 881                 (struct host_device_context *)scmnd->device->host->hostdata;
 882         struct device_context *device_ctx = host_device_ctx->device_ctx;
 883         struct driver_context *driver_ctx =
 884                         driver_to_driver_context(device_ctx->device.driver);
 885         struct storvsc_driver_context *storvsc_drv_ctx =
 886                         (struct storvsc_driver_context *)driver_ctx;
 887
 888         struct storvsc_driver_object *storvsc_drv_obj =
 889                         &storvsc_drv_ctx->drv_obj;
 890
 891         DPRINT_ENTER(STORVSC_DRV);
 892
 893         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...",
 894                     scmnd->device, &device_ctx->device_obj);
 895
 896         /* Invokes the vsc to reset the host/bus */
 897         ASSERT(storvsc_drv_obj->OnHostReset);
 898         ret = storvsc_drv_obj->OnHostReset(&device_ctx->device_obj);
 899         if (ret != 0) {
 900                 DPRINT_EXIT(STORVSC_DRV);
 901                 return ret;
 902         }
 903
 904         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted",
 905                     scmnd->device, &device_ctx->device_obj);
 906
 907         DPRINT_EXIT(STORVSC_DRV);
 908
 909         return ret;
 910 }
 911
 912 /**
 913  * storvsc_host_rescan - Rescan the scsi HBA
 914  */
 915 static void storvsc_host_rescan_callback(struct work_struct *work)
 916 {
 917         struct hv_device *device_obj =
 918             &((struct host_device_context *)work)->device_ctx->device_obj;
 919         struct device_context *device_ctx = to_device_context(device_obj);
 920         struct Scsi_Host *host = dev_get_drvdata(&device_ctx->device);
 921         struct scsi_device *sdev;
 922         struct host_device_context *host_device_ctx;
 923         struct scsi_device **sdevs_remove_list;
 924         unsigned int sdevs_count = 0;
 925         unsigned int found;
 926         unsigned int i;
 927         unsigned int lun_count = 0;
 928         unsigned int *lun_list;
 929
 930         DPRINT_ENTER(STORVSC_DRV);
 931
 932         host_device_ctx = (struct host_device_context *)host->hostdata;
 933         lun_list = kcalloc(STORVSC_MAX_LUNS_PER_TARGET, sizeof(unsigned int),
 934                            GFP_ATOMIC);
 935         if (!lun_list) {
 936                 DPRINT_ERR(STORVSC_DRV, "unable to allocate lun list");
 937                 return;
 938         }
 939
 940         sdevs_remove_list = kcalloc(STORVSC_MAX_LUNS_PER_TARGET,
 941                                     sizeof(void *), GFP_ATOMIC);
 942         if (!sdevs_remove_list) {
 943                 kfree(lun_list);
 944                 DPRINT_ERR(STORVSC_DRV, "unable to allocate lun remove list");
 945                 return;
 946         }
 947
 948         DPRINT_INFO(STORVSC_DRV, "rescanning host for new scsi devices...");
 949
 950         /* Rescan for new device */
 951         scsi_scan_target(&host->shost_gendev, host_device_ctx->path,
 952                          host_device_ctx->target, SCAN_WILD_CARD, 1);
 953
 954         DPRINT_INFO(STORVSC_DRV, "rescanning host for removed scsi device...");
 955
 956         /* Use the 1st device to send the report luns cmd */
 957         shost_for_each_device(sdev, host) {
 958                 lun_count = STORVSC_MAX_LUNS_PER_TARGET;
 959                 storvsc_report_luns(sdev, lun_list, &lun_count);
 960
 961                 DPRINT_INFO(STORVSC_DRV,
 962                             "report luns on scsi device (%p) found %u luns ",
 963                             sdev, lun_count);
 964                 DPRINT_INFO(STORVSC_DRV,
 965                             "existing luns on scsi device (%p) host (%d)",
 966                             sdev, host->host_no);
 967
 968                 scsi_device_put(sdev);
 969                 break;
 970         }
 971
 972         for (i = 0; i < lun_count; i++)
 973                 DPRINT_INFO(STORVSC_DRV, "%d) lun %u", i, lun_list[i]);
 974
 975         /* Rescan for devices that may have been removed.
 976          * We do not have to worry that new devices may have been added since
 977          * this callback is serialized by the workqueue ie add/remove are done
 978          * here.
 979          */
 980         shost_for_each_device(sdev, host) {
 981                 /* See if this device is still here */
 982                 found = 0;
 983                 for (i = 0; i < lun_count; i++) {
 984                         if (sdev->lun == lun_list[i]) {
 985                                 found = 1;
 986                                 break;
 987                         }
 988                 }
 989                 if (!found) {
 990                         DPRINT_INFO(STORVSC_DRV, "lun (%u) does not exists",
 991                                     sdev->lun);
 992                         sdevs_remove_list[sdevs_count++] = sdev;
 993                 }
 994         }
 995
 996         /* Now remove the devices */
 997         for (i = 0; i < sdevs_count; i++) {
 998                 DPRINT_INFO(STORVSC_DRV,
 999                             "removing scsi device (%p) lun (%u)...",
1000                             sdevs_remove_list[i], sdevs_remove_list[i]->lun);
1001
1002                 /* make sure it is not removed from underneath us */
1003                 if (!scsi_device_get(sdevs_remove_list[i])) {
1004                         scsi_remove_device(sdevs_remove_list[i]);
1005                         scsi_device_put(sdevs_remove_list[i]);
1006                 }
1007         }
1008
1009         DPRINT_INFO(STORVSC_DRV, "rescan completed on dev obj (%p) "
1010                     "target (%u) bus (%u)", device_obj,
1011                     host_device_ctx->target, host_device_ctx->path);
1012
1013         kfree(lun_list);
1014         kfree(sdevs_remove_list);
1015
1016         DPRINT_EXIT(STORVSC_DRV);
1017 }
1018
1019 static int storvsc_report_luns(struct scsi_device *sdev, unsigned int luns[],
1020                                unsigned int *lun_count)
1021 {
1022         int i, j;
1023         unsigned int lun = 0;
1024         unsigned int num_luns;
1025         int result;
1026         unsigned char *data;
1027         struct scsi_sense_hdr sshdr;
1028         unsigned char cmd[16] = {0};
1029         /* Add 1 to cover the report_lun header */
1030         unsigned int report_len = 8 * (STORVSC_MAX_LUNS_PER_TARGET+1);
1031         unsigned long long *report_luns;
1032         const unsigned int in_lun_count = *lun_count;
1033
1034         *lun_count = 0;
1035
1036         report_luns = kzalloc(report_len, GFP_ATOMIC);
1037         if (!report_luns)
1038                 return -ENOMEM;
1039
1040         cmd[0] = REPORT_LUNS;
1041
1042         /* cmd length */
1043         *(unsigned int *)&cmd[6] = cpu_to_be32(report_len);
1044
1045         result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE,
1046                                   (unsigned char *)report_luns, report_len,
1047                                   &sshdr, 30 * HZ, 3, NULL);
1048         if (result != 0) {
1049                 kfree(report_luns);
1050                 return -EBUSY;
1051         }
1052
1053         /* get the length from the first four bytes */
1054         report_len = be32_to_cpu(*(unsigned int *)&report_luns[0]);
1055
1056         num_luns = (report_len / sizeof(unsigned long long));
1057         if (num_luns > in_lun_count) {
1058                 kfree(report_luns);
1059                 return -EINVAL;
1060         }
1061
1062         *lun_count = num_luns;
1063
1064         DPRINT_DBG(STORVSC_DRV,
1065                    "report luns on scsi device (%p) found %u luns ",
1066                    sdev, num_luns);
1067
1068         /* lun id starts at 1 */
1069         for (i = 1; i < num_luns + 1; i++) {
1070                 lun = 0;
1071                 data = (unsigned char *)&report_luns[i];
1072                 for (j = 0; j < sizeof(lun); j += 2) {
1073                         lun = lun | (((data[j] << 8) | data[j + 1]) <<
1074                                 (j * 8));
1075                 }
1076
1077                 luns[i-1] = lun;
1078         }
1079
1080         kfree(report_luns);
1081         return 0;
1082 }
1083
1084 static void storvsc_host_rescan(struct hv_device *device_obj)
1085 {
1086         struct device_context *device_ctx = to_device_context(device_obj);
1087         struct Scsi_Host *host = dev_get_drvdata(&device_ctx->device);
1088         struct host_device_context *host_device_ctx;
1089
1090         DPRINT_ENTER(STORVSC_DRV);
1091
1092         host_device_ctx = (struct host_device_context *)host->hostdata;
1093
1094         DPRINT_INFO(STORVSC_DRV, "initiating rescan on dev obj (%p) "
1095                     "target (%u) bus (%u)...", device_obj,
1096                     host_device_ctx->target, host_device_ctx->path);
1097
1098         /*
1099          * We need to queue this since the scanning may block and the caller
1100          * may be in an intr context
1101          */
1102         /* scsi_queue_work(host, &host_device_ctx->host_rescan_work); */
1103         schedule_work(&host_device_ctx->host_rescan_work);
1104         DPRINT_EXIT(STORVSC_DRV);
1105 }
1106
1107 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev,
1108                            sector_t capacity, int *info)
1109 {
1110         sector_t total_sectors = capacity;
1111         sector_t cylinder_times_heads = 0;
1112         sector_t temp = 0;
1113
1114         int sectors_per_track = 0;
1115         int heads = 0;
1116         int cylinders = 0;
1117         int rem = 0;
1118
1119         if (total_sectors > (65535 * 16 * 255))
1120                 total_sectors = (65535 * 16 * 255);
1121
1122         if (total_sectors >= (65535 * 16 * 63)) {
1123                 sectors_per_track = 255;
1124                 heads = 16;
1125
1126                 cylinder_times_heads = total_sectors;
1127                 /* sector_div stores the quotient in cylinder_times_heads */
1128                 rem = sector_div(cylinder_times_heads, sectors_per_track);
1129         } else {
1130                 sectors_per_track = 17;
1131
1132                 cylinder_times_heads = total_sectors;
1133                 /* sector_div stores the quotient in cylinder_times_heads */
1134                 rem = sector_div(cylinder_times_heads, sectors_per_track);
1135
1136                 temp = cylinder_times_heads + 1023;
1137                 /* sector_div stores the quotient in temp */
1138                 rem = sector_div(temp, 1024);
1139
1140                 heads = temp;
1141
1142                 if (heads < 4)
1143                         heads = 4;
1144
1145                 if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
1146                         sectors_per_track = 31;
1147                         heads = 16;
1148
1149                         cylinder_times_heads = total_sectors;
1150                         /*
1151                          * sector_div stores the quotient in
1152                          * cylinder_times_heads
1153                          */
1154                         rem = sector_div(cylinder_times_heads,
1155                                          sectors_per_track);
1156                 }
1157
1158                 if (cylinder_times_heads >= (heads * 1024)) {
1159                         sectors_per_track = 63;
1160                         heads = 16;
1161
1162                         cylinder_times_heads = total_sectors;
1163                         /*
1164                          * sector_div stores the quotient in
1165                          * cylinder_times_heads
1166                          */
1167                         rem = sector_div(cylinder_times_heads,
1168                                          sectors_per_track);
1169                 }
1170         }
1171
1172         temp = cylinder_times_heads;
1173         /* sector_div stores the quotient in temp */
1174         rem = sector_div(temp, heads);
1175         cylinders = temp;
1176
1177         info[0] = heads;
1178         info[1] = sectors_per_track;
1179         info[2] = cylinders;
1180
1181         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads,
1182                     sectors_per_track);
1183
1184     return 0;
1185 }
1186
1187 static int __init storvsc_init(void)
1188 {
1189         int ret;
1190
1191         DPRINT_ENTER(STORVSC_DRV);
1192         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
1193         ret = storvsc_drv_init(StorVscInitialize);
1194         DPRINT_EXIT(STORVSC_DRV);
1195         return ret;
1196 }
1197
1198 static void __exit storvsc_exit(void)
1199 {
1200         DPRINT_ENTER(STORVSC_DRV);
1201         storvsc_drv_exit();
1202         DPRINT_ENTER(STORVSC_DRV);
1203 }
1204
1205 MODULE_LICENSE("GPL");
1206 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
1207 module_init(storvsc_init);
1208 module_exit(storvsc_exit);