drivers/staging/hv/storvsc_drv.c

   1 /*
   2  *
   3  * Copyright (c) 2009, Microsoft Corporation.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  *
  14  * You should have received a copy of the GNU General Public License along with
  15  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  16  * Place - Suite 330, Boston, MA 02111-1307 USA.
  17  *
  18  * Authors:
  19  *   Haiyang Zhang <haiyangz@microsoft.com>
  20  *   Hank Janssen  <hjanssen@microsoft.com>
  21  *
  22  */
  23
  24 #include <linux/init.h>
  25 #include <linux/module.h>
  26 #include <linux/device.h>
  27 #include <linux/blkdev.h>
  28
  29 #include <scsi/scsi.h>
  30 #include <scsi/scsi_cmnd.h>
  31 #include <scsi/scsi_host.h>
  32 #include <scsi/scsi_device.h>
  33 #include <scsi/scsi_tcq.h>
  34 #include <scsi/scsi_eh.h>
  35 #include <scsi/scsi_devinfo.h>
  36
  37 #include <scsi/scsi_dbg.h>
  38
  39 #include "include/logging.h"
  40 #include "include/vmbus.h"
  41
  42 #include "include/StorVscApi.h"
  43
  44
  45 /* #defines */
  46
  47
  48
  49 /* Data types */
  50
  51 struct host_device_context {
  52     struct work_struct          host_rescan_work;  /* must be 1st field */
  53     struct device_context       *device_ctx; /* point back to our device context */
  54     struct kmem_cache               *request_pool;
  55     unsigned int                        port;
  56     unsigned char                       path;
  57     unsigned char                       target;
  58 };
  59
  60 struct storvsc_cmd_request {
  61         struct list_head        entry;
  62         struct scsi_cmnd        *cmd;
  63
  64         unsigned int bounce_sgl_count;
  65         struct scatterlist      *bounce_sgl;
  66
  67         STORVSC_REQUEST         request;
  68         /* !!!DO NOT ADD ANYTHING BELOW HERE!!! */
  69         /* The extension buffer falls right here and is pointed to by request.Extension; */
  70 };
  71
  72 struct storvsc_driver_context {
  73         /* !! These must be the first 2 fields !! */
  74         struct driver_context   drv_ctx;
  75         STORVSC_DRIVER_OBJECT   drv_obj;
  76 };
  77
  78 /* Static decl */
  79 static int storvsc_probe(struct device *dev);
  80 static int storvsc_queuecommand(struct scsi_cmnd *scmnd, void (*done)(struct scsi_cmnd *));
  81 static int storvsc_device_alloc(struct scsi_device *);
  82 static int storvsc_device_configure(struct scsi_device *);
  83 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd);
  84 static void storvsc_host_rescan_callback(struct work_struct *work);
  85 static void storvsc_host_rescan(DEVICE_OBJECT* device_obj);
  86 static int storvsc_remove(struct device *dev);
  87
  88 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count, unsigned int len);
  89 static void destroy_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count);
  90 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count);
  91 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl, struct scatterlist *bounce_sgl, unsigned int orig_sgl_count);
  92 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl, struct scatterlist *bounce_sgl, unsigned int orig_sgl_count);
  93
  94 static int storvsc_report_luns(struct scsi_device *sdev, unsigned int luns[], unsigned int *lun_count);
  95 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev, sector_t capacity, int *info);
  96
  97
  98 static int storvsc_ringbuffer_size = STORVSC_RING_BUFFER_SIZE;
  99
 100 /* The one and only one */
 101 static struct storvsc_driver_context g_storvsc_drv;
 102
 103 /* Scsi driver */
 104 static struct scsi_host_template scsi_driver = {
 105         .module                                         = THIS_MODULE,
 106         .name                                           = "storvsc_host_t",
 107         .bios_param                                     = storvsc_get_chs,
 108         .queuecommand                           = storvsc_queuecommand,
 109         .eh_host_reset_handler          = storvsc_host_reset_handler,
 110         .slave_alloc                            = storvsc_device_alloc,
 111         .slave_configure                        = storvsc_device_configure,
 112         .cmd_per_lun                            = 1,
 113         .can_queue                                      = STORVSC_MAX_IO_REQUESTS*STORVSC_MAX_TARGETS, /* 64 max_queue * 1 target */
 114         .this_id                                        = -1,
 115         /* no use setting to 0 since ll_blk_rw reset it to 1 */
 116         .sg_tablesize                           = MAX_MULTIPAGE_BUFFER_COUNT,/* currently 32 */
 117         /* ENABLE_CLUSTERING allows mutiple physically contig bio_vecs to merge into 1 sg element. If set, we must */
 118         /* limit the max_segment_size to PAGE_SIZE, otherwise we may get 1 sg element that represents multiple */
 119         /* physically contig pfns (ie sg[x].length > PAGE_SIZE). */
 120         .use_clustering                         = ENABLE_CLUSTERING,
 121         /* Make sure we dont get a sg segment crosses a page boundary */
 122         .dma_boundary                           = PAGE_SIZE-1,
 123 };
 124
 125
 126 /*++
 127
 128 Name:   storvsc_drv_init()
 129
 130 Desc:   StorVsc driver initialization.
 131
 132 --*/
 133 int storvsc_drv_init(PFN_DRIVERINITIALIZE pfn_drv_init)
 134 {
 135         int ret=0;
 136         STORVSC_DRIVER_OBJECT *storvsc_drv_obj=&g_storvsc_drv.drv_obj;
 137         struct driver_context *drv_ctx=&g_storvsc_drv.drv_ctx;
 138
 139         DPRINT_ENTER(STORVSC_DRV);
 140
 141         vmbus_get_interface(&storvsc_drv_obj->Base.VmbusChannelInterface);
 142
 143         storvsc_drv_obj->RingBufferSize = storvsc_ringbuffer_size;
 144         storvsc_drv_obj->OnHostRescan = storvsc_host_rescan;
 145
 146         /* Callback to client driver to complete the initialization */
 147         pfn_drv_init(&storvsc_drv_obj->Base);
 148
 149         DPRINT_INFO(STORVSC_DRV, "request extension size %u, max outstanding reqs %u", storvsc_drv_obj->RequestExtSize, storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 150
 151         if (storvsc_drv_obj->MaxOutstandingRequestsPerChannel < STORVSC_MAX_IO_REQUESTS)
 152         {
 153                 DPRINT_ERR(STORVSC_DRV, "The number of outstanding io requests (%d) is larger than that supported (%d) internally.",
 154                         STORVSC_MAX_IO_REQUESTS, storvsc_drv_obj->MaxOutstandingRequestsPerChannel);
 155                 return -1;
 156         }
 157
 158         drv_ctx->driver.name = storvsc_drv_obj->Base.name;
 159         memcpy(&drv_ctx->class_id, &storvsc_drv_obj->Base.deviceType, sizeof(GUID));
 160
 161         drv_ctx->probe = storvsc_probe;
 162         drv_ctx->remove = storvsc_remove;
 163
 164         /* The driver belongs to vmbus */
 165         vmbus_child_driver_register(drv_ctx);
 166
 167         DPRINT_EXIT(STORVSC_DRV);
 168
 169         return ret;
 170 }
 171
 172
 173 static int storvsc_drv_exit_cb(struct device *dev, void *data)
 174 {
 175         struct device **curr = (struct device **)data;
 176         *curr = dev;
 177         return 1; /* stop iterating */
 178 }
 179
 180 /*++
 181
 182 Name:   storvsc_drv_exit()
 183
 184 Desc:
 185
 186 --*/
 187 void storvsc_drv_exit(void)
 188 {
 189         STORVSC_DRIVER_OBJECT *storvsc_drv_obj=&g_storvsc_drv.drv_obj;
 190         struct driver_context *drv_ctx=&g_storvsc_drv.drv_ctx;
 191
 192         struct device *current_dev=NULL;
 193
 194         DPRINT_ENTER(STORVSC_DRV);
 195
 196         while (1)
 197         {
 198                 current_dev = NULL;
 199
 200                 /* Get the device */
 201                 driver_for_each_device(&drv_ctx->driver, NULL, (void*)&current_dev, storvsc_drv_exit_cb);
 202
 203                 if (current_dev == NULL)
 204                         break;
 205
 206                 /* Initiate removal from the top-down */
 207                 device_unregister(current_dev);
 208         }
 209
 210         if (storvsc_drv_obj->Base.OnCleanup)
 211                 storvsc_drv_obj->Base.OnCleanup(&storvsc_drv_obj->Base);
 212
 213         vmbus_child_driver_unregister(drv_ctx);
 214
 215         DPRINT_EXIT(STORVSC_DRV);
 216
 217         return;
 218 }
 219
 220 /*++
 221
 222 Name:   storvsc_probe()
 223
 224 Desc:   Add a new device for this driver
 225
 226 --*/
 227 static int storvsc_probe(struct device *device)
 228 {
 229         int ret=0;
 230
 231         struct driver_context *driver_ctx = driver_to_driver_context(device->driver);
 232         struct storvsc_driver_context *storvsc_drv_ctx = (struct storvsc_driver_context*)driver_ctx;
 233         STORVSC_DRIVER_OBJECT* storvsc_drv_obj = &storvsc_drv_ctx->drv_obj;
 234
 235         struct device_context *device_ctx = device_to_device_context(device);
 236         DEVICE_OBJECT* device_obj = &device_ctx->device_obj;
 237
 238         struct Scsi_Host *host;
 239         struct host_device_context *host_device_ctx;
 240         STORVSC_DEVICE_INFO device_info;
 241
 242         DPRINT_ENTER(STORVSC_DRV);
 243
 244         if (!storvsc_drv_obj->Base.OnDeviceAdd)
 245                 return -1;
 246
 247         host = scsi_host_alloc(&scsi_driver, sizeof(struct host_device_context));
 248         if (!host)
 249         {
 250                 DPRINT_ERR(STORVSC_DRV, "unable to allocate scsi host object");
 251                 return -ENOMEM;
 252         }
 253
 254         dev_set_drvdata(device, host);
 255
 256         host_device_ctx = (struct host_device_context*)host->hostdata;
 257         memset(host_device_ctx, 0, sizeof(struct host_device_context));
 258
 259         host_device_ctx->port = host->host_no;
 260         host_device_ctx->device_ctx = device_ctx;
 261
 262         INIT_WORK(&host_device_ctx->host_rescan_work, storvsc_host_rescan_callback);
 263
 264         host_device_ctx->request_pool =
 265             kmem_cache_create
 266             (dev_name(&device_ctx->device),
 267              sizeof(struct storvsc_cmd_request) + storvsc_drv_obj->RequestExtSize,
 268              0,
 269              SLAB_HWCACHE_ALIGN, NULL);
 270
 271         if (!host_device_ctx->request_pool)
 272         {
 273                 scsi_host_put(host);
 274                 DPRINT_EXIT(STORVSC_DRV);
 275
 276                 return -ENOMEM;
 277         }
 278
 279         device_info.PortNumber = host->host_no;
 280         /* Call to the vsc driver to add the device */
 281         ret = storvsc_drv_obj->Base.OnDeviceAdd(device_obj, (void*)&device_info);
 282         if (ret != 0)
 283         {
 284                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi vsc device");
 285                 kmem_cache_destroy(host_device_ctx->request_pool);
 286                 scsi_host_put(host);
 287                 DPRINT_EXIT(STORVSC_DRV);
 288
 289                 return -1;
 290         }
 291
 292         /* host_device_ctx->port = device_info.PortNumber; */
 293         host_device_ctx->path = device_info.PathId;
 294         host_device_ctx->target = device_info.TargetId;
 295
 296         host->max_lun = STORVSC_MAX_LUNS_PER_TARGET;    /* max # of devices per target */
 297         host->max_id = STORVSC_MAX_TARGETS;                     /* max # of targets per channel */
 298         host->max_channel = STORVSC_MAX_CHANNELS -1;    /* max # of channels */
 299
 300         /* Register the HBA and start the scsi bus scan */
 301         ret = scsi_add_host(host, device);
 302         if (ret != 0)
 303         {
 304                 DPRINT_ERR(STORVSC_DRV, "unable to add scsi host device");
 305
 306                 storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 307
 308                 kmem_cache_destroy(host_device_ctx->request_pool);
 309                 scsi_host_put(host);
 310                 DPRINT_EXIT(STORVSC_DRV);
 311
 312                 return -1;
 313         }
 314
 315         scsi_scan_host(host);
 316
 317         DPRINT_EXIT(STORVSC_DRV);
 318
 319         return ret;
 320 }
 321
 322
 323 /*++
 324
 325 Name:   storvsc_remove()
 326
 327 Desc:   Callback when our device is removed
 328
 329 --*/
 330 static int storvsc_remove(struct device *device)
 331 {
 332         int ret=0;
 333
 334         struct driver_context *driver_ctx = driver_to_driver_context(device->driver);
 335         struct storvsc_driver_context *storvsc_drv_ctx = (struct storvsc_driver_context*)driver_ctx;
 336         STORVSC_DRIVER_OBJECT* storvsc_drv_obj = &storvsc_drv_ctx->drv_obj;
 337
 338         struct device_context *device_ctx = device_to_device_context(device);
 339         DEVICE_OBJECT* device_obj = &device_ctx->device_obj;
 340
 341         struct Scsi_Host *host = dev_get_drvdata(device);
 342         struct host_device_context *host_device_ctx=(struct host_device_context*)host->hostdata;
 343
 344
 345         DPRINT_ENTER(STORVSC_DRV);
 346
 347         if (!storvsc_drv_obj->Base.OnDeviceRemove)
 348         {
 349                 DPRINT_EXIT(STORVSC_DRV);
 350                 return -1;
 351         }
 352
 353         /* Call to the vsc driver to let it know that the device is being removed */
 354         ret = storvsc_drv_obj->Base.OnDeviceRemove(device_obj);
 355         if (ret != 0)
 356         {
 357                 /* TODO: */
 358                 DPRINT_ERR(STORVSC, "unable to remove vsc device (ret %d)", ret);
 359         }
 360
 361         if (host_device_ctx->request_pool)
 362         {
 363                 kmem_cache_destroy(host_device_ctx->request_pool);
 364                 host_device_ctx->request_pool = NULL;
 365         }
 366
 367         DPRINT_INFO(STORVSC, "removing host adapter (%p)...", host);
 368         scsi_remove_host(host);
 369
 370         DPRINT_INFO(STORVSC, "releasing host adapter (%p)...", host);
 371         scsi_host_put(host);
 372
 373         DPRINT_EXIT(STORVSC_DRV);
 374
 375         return ret;
 376 }
 377
 378 /*++
 379
 380 Name:   storvsc_commmand_completion()
 381
 382 Desc:   Command completion processing
 383
 384 --*/
 385 static void storvsc_commmand_completion(STORVSC_REQUEST* request)
 386 {
 387         struct storvsc_cmd_request *cmd_request = (struct storvsc_cmd_request*)request->Context;
 388         struct scsi_cmnd *scmnd = cmd_request->cmd;
 389         struct host_device_context *host_device_ctx = (struct host_device_context*)scmnd->device->host->hostdata;
 390         void (*scsi_done_fn)(struct scsi_cmnd *);
 391         struct scsi_sense_hdr sense_hdr;
 392
 393         ASSERT(request == &cmd_request->request);
 394         ASSERT((unsigned long)scmnd->host_scribble == (unsigned long)cmd_request);
 395         ASSERT(scmnd);
 396         ASSERT(scmnd->scsi_done);
 397
 398         DPRINT_ENTER(STORVSC_DRV);
 399
 400         if (cmd_request->bounce_sgl_count)/* using bounce buffer */
 401         {
 402                 /* printk("copy_from_bounce_buffer\n"); */
 403
 404                 /* FIXME: We can optimize on writes by just skipping this */
 405                 copy_from_bounce_buffer(scsi_sglist(scmnd), cmd_request->bounce_sgl, scsi_sg_count(scmnd));
 406                 destroy_bounce_buffer(cmd_request->bounce_sgl, cmd_request->bounce_sgl_count);
 407         }
 408
 409         scmnd->result = request->Status;
 410
 411         if (scmnd->result)
 412         {
 413                 if (scsi_normalize_sense(scmnd->sense_buffer, request->SenseBufferSize, &sense_hdr))
 414                 {
 415                         scsi_print_sense_hdr("storvsc", &sense_hdr);
 416                 }
 417         }
 418
 419         ASSERT(request->BytesXfer <= request->DataBuffer.Length);
 420         scsi_set_resid(scmnd, request->DataBuffer.Length - request->BytesXfer);
 421
 422         scsi_done_fn = scmnd->scsi_done;
 423
 424         scmnd->host_scribble = NULL;
 425         scmnd->scsi_done = NULL;
 426
 427         /* !!DO NOT MODIFY the scmnd after this call */
 428         scsi_done_fn(scmnd);
 429
 430         kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 431
 432         DPRINT_EXIT(STORVSC_DRV);
 433 }
 434
 435 static int do_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 436 {
 437         int i=0;
 438
 439         /* No need to check */
 440         if (sg_count < 2)
 441                 return -1;
 442
 443         /* We have at least 2 sg entries */
 444         for ( i=0; i<sg_count; i++ )
 445         {
 446                 if (i == 0) /* make sure 1st one does not have hole */
 447                 {
 448                         if (sgl[i].offset + sgl[i].length != PAGE_SIZE)
 449                                 return i;
 450                 }
 451                 else if (i == sg_count - 1) /* make sure last one does not have hole */
 452                 {
 453                         if (sgl[i].offset != 0)
 454                                 return i;
 455                 }
 456                 else /* make sure no hole in the middle */
 457                 {
 458                         if (sgl[i].length != PAGE_SIZE || sgl[i].offset != 0)
 459                         {
 460                                 return i;
 461                         }
 462                 }
 463         }
 464         return -1;
 465 }
 466
 467 static struct scatterlist *create_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count, unsigned int len)
 468 {
 469         int i;
 470         int num_pages=0;
 471         struct scatterlist* bounce_sgl;
 472         struct page *page_buf;
 473
 474         num_pages = ALIGN_UP(len, PAGE_SIZE) >> PAGE_SHIFT;
 475
 476         bounce_sgl = kcalloc(num_pages, sizeof(struct scatterlist), GFP_ATOMIC);
 477         if (!bounce_sgl)
 478         {
 479                 return NULL;
 480         }
 481
 482         for(i=0; i<num_pages; i++)
 483         {
 484                 page_buf = alloc_page(GFP_ATOMIC);
 485                 if (!page_buf)
 486                 {
 487                         goto cleanup;
 488                 }
 489                 sg_set_page(&bounce_sgl[i], page_buf, 0, 0);
 490         }
 491
 492         return bounce_sgl;
 493
 494 cleanup:
 495         destroy_bounce_buffer(bounce_sgl, num_pages);
 496         return NULL;
 497 }
 498
 499 static void destroy_bounce_buffer(struct scatterlist *sgl, unsigned int sg_count)
 500 {
 501         int i;
 502         struct page *page_buf;
 503
 504         for (i=0; i<sg_count; i++)
 505         {
 506                 if ((page_buf = sg_page((&sgl[i]))) != NULL)
 507
 508                 {
 509                         __free_page(page_buf);
 510                 }
 511         }
 512
 513         kfree(sgl);
 514 }
 515
 516 /* Assume the bounce_sgl has enough room ie using the create_bounce_buffer() */
 517 static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl, struct scatterlist *bounce_sgl, unsigned int orig_sgl_count)
 518 {
 519         int i=0,j=0;
 520         unsigned long src, dest;
 521         unsigned int srclen, destlen, copylen;
 522         unsigned int total_copied=0;
 523         unsigned long bounce_addr=0;
 524         unsigned long src_addr=0;
 525         unsigned long flags;
 526
 527         local_irq_save(flags);
 528
 529         for (i=0; i<orig_sgl_count; i++)
 530         {
 531                 src_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])), KM_IRQ0) + orig_sgl[i].offset;
 532                 src = src_addr;
 533                 srclen = orig_sgl[i].length;
 534
 535                 /* if (PageHighMem(orig_sgl[i].page)) */
 536                 /* printk("HighMem page detected - addr %p", (void*)src); */
 537
 538                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 539
 540                 if (j == 0)
 541                 {
 542                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 543                 }
 544
 545                 while (srclen)
 546                 {
 547                         /* assume bounce offset always == 0 */
 548                         dest = bounce_addr + bounce_sgl[j].length;
 549                         destlen = PAGE_SIZE - bounce_sgl[j].length;
 550
 551                         copylen = min(srclen, destlen);
 552                         memcpy((void*)dest, (void*)src, copylen);
 553
 554                         total_copied += copylen;
 555                         bounce_sgl[j].length += copylen;
 556                         srclen -= copylen;
 557                         src += copylen;
 558
 559                         if (bounce_sgl[j].length == PAGE_SIZE) /* full..move to next entry */
 560                         {
 561                                 kunmap_atomic((void*)bounce_addr, KM_IRQ0);
 562                                 j++;
 563
 564                                 /* if we need to use another bounce buffer */
 565                                 if (srclen || i != orig_sgl_count -1)
 566                                 {
 567                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 568                                 }
 569                         }
 570                         else if (srclen == 0 && i == orig_sgl_count -1) /* unmap the last bounce that is < PAGE_SIZE */
 571                         {
 572                                 kunmap_atomic((void*)bounce_addr, KM_IRQ0);
 573                         }
 574                 }
 575
 576                 kunmap_atomic((void*)(src_addr - orig_sgl[i].offset), KM_IRQ0);
 577         }
 578
 579         local_irq_restore(flags);
 580
 581         return total_copied;
 582 }
 583
 584 /* Assume the original sgl has enough room */
 585 static unsigned int copy_from_bounce_buffer(struct scatterlist *orig_sgl, struct scatterlist *bounce_sgl, unsigned int orig_sgl_count)
 586 {
 587         int i=0,j=0;
 588         unsigned long src, dest;
 589         unsigned int srclen, destlen, copylen;
 590         unsigned int total_copied=0;
 591         unsigned long bounce_addr=0;
 592         unsigned long dest_addr=0;
 593         unsigned long flags;
 594
 595         local_irq_save(flags);
 596
 597         for (i=0; i<orig_sgl_count; i++)
 598         {
 599                 dest_addr = (unsigned long)kmap_atomic(sg_page((&orig_sgl[i])), KM_IRQ0) + orig_sgl[i].offset;
 600                 dest = dest_addr;
 601                 destlen = orig_sgl[i].length;
 602                 ASSERT(orig_sgl[i].offset + orig_sgl[i].length <= PAGE_SIZE);
 603
 604                 if (j == 0)
 605                 {
 606                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 607                 }
 608
 609                 while (destlen)
 610                 {
 611                         src = bounce_addr + bounce_sgl[j].offset;
 612                         srclen = bounce_sgl[j].length - bounce_sgl[j].offset;
 613
 614                         copylen = min(srclen, destlen);
 615                         memcpy((void*)dest, (void*)src, copylen);
 616
 617                         total_copied += copylen;
 618                         bounce_sgl[j].offset += copylen;
 619                         destlen -= copylen;
 620                         dest += copylen;
 621
 622                         if (bounce_sgl[j].offset == bounce_sgl[j].length) /* full */
 623                         {
 624                                 kunmap_atomic((void*)bounce_addr, KM_IRQ0);
 625                                 j++;
 626
 627                                 /* if we need to use another bounce buffer */
 628                                 if (destlen || i != orig_sgl_count -1)
 629                                 {
 630                                         bounce_addr = (unsigned long)kmap_atomic(sg_page((&bounce_sgl[j])), KM_IRQ0);
 631                                 }
 632                         }
 633                         else if (destlen == 0 && i == orig_sgl_count -1) /* unmap the last bounce that is < PAGE_SIZE */
 634                         {
 635                                 kunmap_atomic((void*)bounce_addr, KM_IRQ0);
 636                         }
 637                 }
 638
 639                 kunmap_atomic((void*)(dest_addr - orig_sgl[i].offset), KM_IRQ0);
 640         }
 641
 642         local_irq_restore(flags);
 643
 644         return total_copied;
 645 }
 646
 647
 648 /*++
 649
 650 Name:   storvsc_queuecommand()
 651
 652 Desc:   Initiate command processing
 653
 654 --*/
 655 static int storvsc_queuecommand(struct scsi_cmnd *scmnd, void (*done)(struct scsi_cmnd *))
 656 {
 657         int ret=0;
 658         struct host_device_context *host_device_ctx = (struct host_device_context*)scmnd->device->host->hostdata;
 659         struct device_context *device_ctx=host_device_ctx->device_ctx;
 660         struct driver_context *driver_ctx = driver_to_driver_context(device_ctx->device.driver);
 661         struct storvsc_driver_context *storvsc_drv_ctx = (struct storvsc_driver_context*)driver_ctx;
 662         STORVSC_DRIVER_OBJECT* storvsc_drv_obj = &storvsc_drv_ctx->drv_obj;
 663
 664         STORVSC_REQUEST *request;
 665         struct storvsc_cmd_request *cmd_request;
 666         unsigned int request_size=0;
 667         int i;
 668         struct scatterlist *sgl;
 669
 670         DPRINT_ENTER(STORVSC_DRV);
 671
 672         DPRINT_DBG(STORVSC_DRV, "scmnd %p dir %d, use_sg %d buf %p len %d queue depth %d tagged %d",
 673                 scmnd,
 674                 scmnd->sc_data_direction,
 675                 scsi_sg_count(scmnd),
 676                 scsi_sglist(scmnd),
 677                 scsi_bufflen(scmnd),
 678                 scmnd->device->queue_depth,
 679                 scmnd->device->tagged_supported);
 680
 681         /* If retrying, no need to prep the cmd */
 682         if (scmnd->host_scribble)
 683         {
 684                 ASSERT(scmnd->scsi_done != NULL);
 685
 686                 cmd_request = (struct storvsc_cmd_request* )scmnd->host_scribble;
 687                 DPRINT_INFO(STORVSC_DRV, "retrying scmnd %p cmd_request %p", scmnd, cmd_request);
 688
 689                 goto retry_request;
 690         }
 691
 692         ASSERT(scmnd->scsi_done == NULL);
 693         ASSERT(scmnd->host_scribble == NULL);
 694
 695         scmnd->scsi_done = done;
 696
 697         request_size = sizeof(struct storvsc_cmd_request);
 698
 699         cmd_request = kmem_cache_alloc(host_device_ctx->request_pool, GFP_ATOMIC);
 700         if (!cmd_request)
 701         {
 702                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - unable to allocate storvsc_cmd_request...marking queue busy", scmnd);
 703
 704                 scmnd->scsi_done = NULL;
 705                 return SCSI_MLQUEUE_DEVICE_BUSY;
 706         }
 707
 708         /* Setup the cmd request */
 709         cmd_request->bounce_sgl_count = 0;
 710         cmd_request->bounce_sgl = NULL;
 711         cmd_request->cmd = scmnd;
 712
 713         scmnd->host_scribble = (unsigned char*)cmd_request;
 714
 715         request = &cmd_request->request;
 716
 717         request->Extension = (void*)((unsigned long)cmd_request + request_size);
 718         DPRINT_DBG(STORVSC_DRV, "req %p size %d ext %d", request, request_size, storvsc_drv_obj->RequestExtSize);
 719
 720         /* Build the SRB */
 721         switch(scmnd->sc_data_direction)
 722         {
 723         case DMA_TO_DEVICE:
 724                 request->Type = WRITE_TYPE;
 725                 break;
 726         case DMA_FROM_DEVICE:
 727                 request->Type = READ_TYPE;
 728                 break;
 729         default:
 730                 request->Type = UNKNOWN_TYPE;
 731                 break;
 732         }
 733
 734         request->OnIOCompletion = storvsc_commmand_completion;
 735         request->Context = cmd_request;/* scmnd; */
 736
 737         /* request->PortId = scmnd->device->channel; */
 738         request->Host = host_device_ctx->port;
 739         request->Bus = scmnd->device->channel;
 740         request->TargetId = scmnd->device->id;
 741         request->LunId = scmnd->device->lun;
 742
 743         ASSERT(scmnd->cmd_len <= 16);
 744         request->CdbLen = scmnd->cmd_len;
 745         request->Cdb = scmnd->cmnd;
 746
 747         request->SenseBuffer = scmnd->sense_buffer;
 748         request->SenseBufferSize = SCSI_SENSE_BUFFERSIZE;
 749
 750
 751         request->DataBuffer.Length = scsi_bufflen(scmnd);
 752         if (scsi_sg_count(scmnd))
 753         {
 754                 sgl = (struct scatterlist*)scsi_sglist(scmnd);
 755
 756                 /* check if we need to bounce the sgl */
 757                 if (do_bounce_buffer(sgl, scsi_sg_count(scmnd)) != -1)
 758                 {
 759                         DPRINT_INFO(STORVSC_DRV, "need to bounce buffer for this scmnd %p", scmnd);
 760                         cmd_request->bounce_sgl = create_bounce_buffer(sgl, scsi_sg_count(scmnd), scsi_bufflen(scmnd));
 761                         if (!cmd_request->bounce_sgl)
 762                         {
 763                                 DPRINT_ERR(STORVSC_DRV, "unable to create bounce buffer for this scmnd %p", scmnd);
 764
 765                                 scmnd->scsi_done = NULL;
 766                                 scmnd->host_scribble = NULL;
 767                                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 768
 769                                 return SCSI_MLQUEUE_HOST_BUSY;
 770                         }
 771
 772                         cmd_request->bounce_sgl_count = ALIGN_UP(scsi_bufflen(scmnd), PAGE_SIZE) >> PAGE_SHIFT;
 773
 774                         /* printk("bouncing buffer allocated %p original buffer %p\n", bounce_sgl, sgl); */
 775                         /* printk("copy_to_bounce_buffer\n"); */
 776                         /* FIXME: We can optimize on reads by just skipping this */
 777                         copy_to_bounce_buffer(sgl, cmd_request->bounce_sgl, scsi_sg_count(scmnd));
 778
 779                         sgl = cmd_request->bounce_sgl;
 780                 }
 781
 782                 request->DataBuffer.Offset = sgl[0].offset;
 783
 784                 for (i = 0; i < scsi_sg_count(scmnd); i++ )
 785                 {
 786                         DPRINT_DBG(STORVSC_DRV, "sgl[%d] len %d offset %d \n", i, sgl[i].length, sgl[i].offset);
 787                         request->DataBuffer.PfnArray[i] = page_to_pfn(sg_page((&sgl[i])));
 788                 }
 789         }
 790
 791         else if (scsi_sglist(scmnd))
 792         {
 793                 ASSERT(scsi_bufflen(scmnd) <= PAGE_SIZE);
 794                 request->DataBuffer.Offset = virt_to_phys(scsi_sglist(scmnd)) & (PAGE_SIZE-1);
 795                 request->DataBuffer.PfnArray[0] = virt_to_phys(scsi_sglist(scmnd)) >> PAGE_SHIFT;
 796         }
 797         else
 798         {
 799                 ASSERT(scsi_bufflen(scmnd) == 0);
 800         }
 801
 802 retry_request:
 803
 804         /* Invokes the vsc to start an IO */
 805         ret = storvsc_drv_obj->OnIORequest(&device_ctx->device_obj, &cmd_request->request);
 806         if (ret == -1) /* no more space */
 807         {
 808                 DPRINT_ERR(STORVSC_DRV, "scmnd (%p) - queue FULL...marking queue busy", scmnd);
 809
 810                 if (cmd_request->bounce_sgl_count)
 811                 {
 812                         /* FIXME: We can optimize on writes by just skipping this */
 813                         copy_from_bounce_buffer(scsi_sglist(scmnd), cmd_request->bounce_sgl, scsi_sg_count(scmnd));
 814                         destroy_bounce_buffer(cmd_request->bounce_sgl, cmd_request->bounce_sgl_count);
 815                 }
 816
 817                 kmem_cache_free(host_device_ctx->request_pool, cmd_request);
 818
 819                 scmnd->scsi_done = NULL;
 820                 scmnd->host_scribble = NULL;
 821
 822                 ret = SCSI_MLQUEUE_DEVICE_BUSY;
 823         }
 824
 825         DPRINT_EXIT(STORVSC_DRV);
 826
 827         return ret;
 828 }
 829
 830 static int storvsc_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd, struct bio_vec *bvec)
 831 {
 832         return bvec->bv_len; /* checking done by caller. */
 833 }
 834
 835 /*++
 836
 837 Name:   storvsc_device_configure()
 838
 839 Desc:   Configure the specified scsi device
 840
 841 --*/
 842 static int storvsc_device_alloc(struct scsi_device *sdevice)
 843 {
 844         DPRINT_DBG(STORVSC_DRV, "sdev (%p) - setting device flag to %d", sdevice, BLIST_SPARSELUN);
 845         /* This enables luns to be located sparsely. Otherwise, we may not discovered them. */
 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, sdevice->queue_depth);
 853
 854         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting queue depth to %d", sdevice, STORVSC_MAX_IO_REQUESTS);
 855         scsi_adjust_queue_depth(sdevice, MSG_SIMPLE_TAG, STORVSC_MAX_IO_REQUESTS);
 856
 857         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - setting max segment size to %ld", sdevice, PAGE_SIZE);
 858         blk_queue_max_segment_size(sdevice->request_queue, PAGE_SIZE);
 859
 860         DPRINT_INFO(STORVSC_DRV, "sdev (%p) - adding merge bio vec routine", sdevice);
 861         blk_queue_merge_bvec(sdevice->request_queue, storvsc_merge_bvec);
 862
 863         blk_queue_bounce_limit(sdevice->request_queue, BLK_BOUNCE_ANY);
 864         /* sdevice->timeout = (2000 * HZ);//(75 * HZ); */
 865
 866         return 0;
 867 }
 868
 869 /*++
 870
 871 Name:   storvsc_host_reset_handler()
 872
 873 Desc:   Reset the scsi HBA
 874
 875 --*/
 876 static int storvsc_host_reset_handler(struct scsi_cmnd *scmnd)
 877 {
 878         int ret=SUCCESS;
 879         struct host_device_context *host_device_ctx = (struct host_device_context*)scmnd->device->host->hostdata;
 880         struct device_context *device_ctx = host_device_ctx->device_ctx;
 881         struct driver_context *driver_ctx = driver_to_driver_context(device_ctx->device.driver);
 882         struct storvsc_driver_context *storvsc_drv_ctx = (struct storvsc_driver_context*)driver_ctx;
 883
 884         STORVSC_DRIVER_OBJECT *storvsc_drv_obj = &storvsc_drv_ctx->drv_obj;
 885
 886         DPRINT_ENTER(STORVSC_DRV);
 887
 888         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host resetting...", scmnd->device, &device_ctx->device_obj);
 889
 890         /* Invokes the vsc to reset the host/bus */
 891         ASSERT(storvsc_drv_obj->OnHostReset);
 892         ret = storvsc_drv_obj->OnHostReset(&device_ctx->device_obj);
 893         if (ret != 0)
 894         {
 895                 DPRINT_EXIT(STORVSC_DRV);
 896                 return ret;
 897         }
 898
 899         DPRINT_INFO(STORVSC_DRV, "sdev (%p) dev obj (%p) - host reseted", scmnd->device, &device_ctx->device_obj);
 900
 901         DPRINT_EXIT(STORVSC_DRV);
 902
 903         return ret;
 904 }
 905
 906 /*++
 907
 908 Name:   storvsc_host_rescan
 909
 910 Desc:   Rescan the scsi HBA
 911
 912 --*/
 913 static void storvsc_host_rescan_callback(struct work_struct *work)
 914 {
 915         DEVICE_OBJECT* device_obj =
 916             &((struct host_device_context*)work)->device_ctx->device_obj;
 917         struct device_context* device_ctx = to_device_context(device_obj);
 918         struct Scsi_Host *host = dev_get_drvdata(&device_ctx->device);
 919         struct scsi_device *sdev;
 920         struct host_device_context *host_device_ctx;
 921         struct scsi_device **sdevs_remove_list;
 922         unsigned int sdevs_count=0;
 923         unsigned int found;
 924         unsigned int i;
 925         unsigned int lun_count=0;
 926         unsigned int *lun_list;
 927
 928         DPRINT_ENTER(STORVSC_DRV);
 929
 930         host_device_ctx = (struct host_device_context*)host->hostdata;
 931         lun_list = kcalloc(STORVSC_MAX_LUNS_PER_TARGET, sizeof(unsigned int), GFP_ATOMIC);
 932         if (!lun_list)
 933         {
 934                 DPRINT_ERR(STORVSC_DRV, "unable to allocate lun list");
 935                 return;
 936         }
 937
 938         sdevs_remove_list = kcalloc(STORVSC_MAX_LUNS_PER_TARGET, sizeof(void *), GFP_ATOMIC);
 939         if (!sdevs_remove_list)
 940         {
 941                 kfree(lun_list);
 942                 DPRINT_ERR(STORVSC_DRV, "unable to allocate lun remove list");
 943                 return;
 944         }
 945
 946         DPRINT_INFO(STORVSC_DRV, "rescanning host for new scsi devices...", device_obj, host_device_ctx->target, host_device_ctx->path);
 947
 948         /* Rescan for new device */
 949         scsi_scan_target(&host->shost_gendev, host_device_ctx->path, host_device_ctx->target, SCAN_WILD_CARD, 1);
 950
 951         DPRINT_INFO(STORVSC_DRV, "rescanning host for removed scsi device...");
 952
 953         /* Use the 1st device to send the report luns cmd */
 954         shost_for_each_device(sdev, host)
 955         {
 956                 lun_count=STORVSC_MAX_LUNS_PER_TARGET;
 957                 storvsc_report_luns(sdev, lun_list, &lun_count);
 958
 959                 DPRINT_INFO(STORVSC_DRV, "report luns on scsi device (%p) found %u luns ", sdev, lun_count);
 960                 DPRINT_INFO(STORVSC_DRV, "existing luns on scsi device (%p) host (%d)", sdev, host->host_no);
 961
 962                 scsi_device_put(sdev);
 963                 break;
 964         }
 965
 966         for (i=0; i<lun_count; i++)
 967         {
 968                 DPRINT_INFO(STORVSC_DRV, "%d) lun %u", i, lun_list[i]);
 969         }
 970
 971         /* Rescan for devices that may have been removed. */
 972         /* We do not have to worry that new devices may have been added since */
 973         /* this callback is serialized by the workqueue ie add/remove are done here. */
 974         shost_for_each_device(sdev, host)
 975         {
 976                 /* See if this device is still here */
 977                 found = 0;
 978                 for (i=0; i<lun_count; i++)
 979                 {
 980                         if (sdev->lun == lun_list[i])
 981                         {
 982                                 found = 1;
 983                                 break;
 984                         }
 985                 }
 986                 if (!found)
 987                 {
 988                         DPRINT_INFO(STORVSC_DRV, "lun (%u) does not exists", sdev->lun);
 989                         sdevs_remove_list[sdevs_count++] = sdev;
 990                 }
 991         }
 992
 993         /* Now remove the devices */
 994         for (i=0; i< sdevs_count; i++)
 995         {
 996                 DPRINT_INFO(STORVSC_DRV, "removing scsi device (%p) lun (%u)...",
 997                                         sdevs_remove_list[i], sdevs_remove_list[i]->lun);
 998
 999                 /* make sure it is not removed from underneath us */
1000                 if (!scsi_device_get(sdevs_remove_list[i]))
1001                 {
1002                         scsi_remove_device(sdevs_remove_list[i]);
1003                         scsi_device_put(sdevs_remove_list[i]);
1004                 }
1005         }
1006
1007         DPRINT_INFO(STORVSC_DRV, "rescan completed on dev obj (%p) target (%u) bus (%u)", device_obj, host_device_ctx->target, host_device_ctx->path);
1008
1009         kfree(lun_list);
1010         kfree(sdevs_remove_list);
1011
1012         DPRINT_EXIT(STORVSC_DRV);
1013 }
1014
1015 static int storvsc_report_luns(struct scsi_device *sdev, unsigned int luns[], unsigned int *lun_count)
1016 {
1017         int i,j;
1018         unsigned int lun=0;
1019         unsigned int num_luns;
1020         int result;
1021         unsigned char *data;
1022         struct scsi_sense_hdr sshdr;
1023         unsigned char cmd[16]={0};
1024         unsigned int report_len = 8*(STORVSC_MAX_LUNS_PER_TARGET+1); /* Add 1 to cover the report_lun header */
1025         unsigned long long *report_luns;
1026         const unsigned int in_lun_count = *lun_count;
1027
1028         *lun_count = 0;
1029
1030         report_luns = kzalloc(report_len, GFP_ATOMIC);
1031         if (!report_luns)
1032         {
1033                 return -ENOMEM;
1034         }
1035
1036         cmd[0] = REPORT_LUNS;
1037
1038         /* cmd length */
1039         *(unsigned int*)&cmd[6] = cpu_to_be32(report_len);
1040
1041         result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, (unsigned char*)report_luns, report_len, &sshdr, 30*HZ, 3, NULL);
1042         if (result != 0)
1043         {
1044                 kfree(report_luns);
1045                 return -EBUSY;
1046         }
1047
1048         /* get the length from the first four bytes */
1049         report_len = be32_to_cpu(*(unsigned int*)&report_luns[0]);
1050
1051         num_luns = (report_len / sizeof(unsigned long long));
1052         if (num_luns > in_lun_count)
1053         {
1054                 kfree(report_luns);
1055                 return -EINVAL;
1056         }
1057
1058         *lun_count = num_luns;
1059
1060         DPRINT_DBG(STORVSC_DRV, "report luns on scsi device (%p) found %u luns ", sdev, num_luns);
1061
1062         /* lun id starts at 1 */
1063         for (i=1; i< num_luns+1; i++)
1064         {
1065                 lun = 0;
1066                 data = (unsigned char*)&report_luns[i];
1067                 for (j = 0; j < sizeof(lun); j += 2)
1068                  {
1069                          lun = lun | (((data[j] << 8) | data[j + 1]) << (j * 8));
1070                  }
1071
1072                 luns[i-1] = lun;
1073         }
1074
1075         kfree(report_luns);
1076         return 0;
1077 }
1078
1079 static void storvsc_host_rescan(DEVICE_OBJECT* device_obj)
1080 {
1081         struct device_context* device_ctx = to_device_context(device_obj);
1082         struct Scsi_Host *host = dev_get_drvdata(&device_ctx->device);
1083         struct host_device_context *host_device_ctx;
1084
1085         DPRINT_ENTER(STORVSC_DRV);
1086
1087         host_device_ctx = (struct host_device_context*)host->hostdata;
1088
1089         DPRINT_INFO(STORVSC_DRV, "initiating rescan on dev obj (%p) target (%u) bus (%u)...", device_obj, host_device_ctx->target, host_device_ctx->path);
1090
1091         /* We need to queue this since the scanning may block and the caller may be in an intr context */
1092         /* scsi_queue_work(host, &host_device_ctx->host_rescan_work); */
1093         schedule_work(&host_device_ctx->host_rescan_work);
1094         DPRINT_EXIT(STORVSC_DRV);
1095 }
1096
1097 static int storvsc_get_chs(struct scsi_device *sdev, struct block_device * bdev, sector_t capacity, int *info)
1098 {
1099         sector_t total_sectors = capacity;
1100         sector_t cylinder_times_heads=0;
1101         sector_t temp=0;
1102
1103         int sectors_per_track=0;
1104         int heads=0;
1105         int cylinders=0;
1106         int rem=0;
1107
1108     if (total_sectors > (65535 * 16 * 255)) {
1109         total_sectors = (65535 * 16 * 255);
1110     }
1111
1112     if (total_sectors >= (65535 * 16 * 63)) {
1113         sectors_per_track = 255;
1114         heads = 16;
1115
1116                 cylinder_times_heads = total_sectors;
1117                 rem = sector_div(cylinder_times_heads, sectors_per_track); /* sector_div stores the quotient in cylinder_times_heads */
1118     }
1119         else
1120         {
1121         sectors_per_track = 17;
1122
1123                 cylinder_times_heads = total_sectors;
1124         rem = sector_div(cylinder_times_heads, sectors_per_track);      /* sector_div stores the quotient in cylinder_times_heads */
1125
1126                 temp = cylinder_times_heads + 1023;
1127                 rem = sector_div(temp, 1024);   /* sector_div stores the quotient in temp */
1128
1129                 heads = temp;
1130
1131         if (heads < 4) {
1132             heads = 4;
1133         }
1134
1135         if (cylinder_times_heads >= (heads * 1024) || (heads > 16)) {
1136             sectors_per_track = 31;
1137             heads = 16;
1138
1139                         cylinder_times_heads = total_sectors;
1140             rem = sector_div(cylinder_times_heads, sectors_per_track); /* sector_div stores the quotient in cylinder_times_heads */
1141         }
1142
1143         if (cylinder_times_heads >= (heads * 1024)) {
1144             sectors_per_track = 63;
1145             heads = 16;
1146
1147                         cylinder_times_heads = total_sectors;
1148             rem = sector_div(cylinder_times_heads, sectors_per_track); /* sector_div stores the quotient in cylinder_times_heads */
1149         }
1150     }
1151
1152         temp = cylinder_times_heads;
1153     rem = sector_div(temp, heads); /* sector_div stores the quotient in temp */
1154         cylinders = temp;
1155
1156         info[0] = heads;
1157     info[1] = sectors_per_track;
1158     info[2] = cylinders;
1159
1160         DPRINT_INFO(STORVSC_DRV, "CHS (%d, %d, %d)", cylinders, heads, sectors_per_track);
1161
1162     return 0;
1163 }
1164
1165 MODULE_LICENSE("GPL");
1166
1167 static int __init storvsc_init(void)
1168 {
1169         int ret;
1170
1171         DPRINT_ENTER(STORVSC_DRV);
1172
1173         DPRINT_INFO(STORVSC_DRV, "Storvsc initializing....");
1174
1175         ret = storvsc_drv_init(StorVscInitialize);
1176
1177         DPRINT_EXIT(STORVSC_DRV);
1178
1179         return ret;
1180 }
1181
1182 static void __exit storvsc_exit(void)
1183 {
1184         DPRINT_ENTER(STORVSC_DRV);
1185
1186         storvsc_drv_exit();
1187
1188         DPRINT_ENTER(STORVSC_DRV);
1189 }
1190
1191 module_param(storvsc_ringbuffer_size, int, S_IRUGO);
1192
1193 module_init(storvsc_init);
1194 module_exit(storvsc_exit);
1195
1196 /* eof */