drivers/target/target_core_rd.c

   1 /*******************************************************************************
   2  * Filename:  target_core_rd.c
   3  *
   4  * This file contains the Storage Engine <-> Ramdisk transport
   5  * specific functions.
   6  *
   7  * (c) Copyright 2003-2013 Datera, Inc.
   8  *
   9  * Nicholas A. Bellinger <nab@kernel.org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  *
  25  ******************************************************************************/
  26
  27 #include <linux/string.h>
  28 #include <linux/parser.h>
  29 #include <linux/highmem.h>
  30 #include <linux/timer.h>
  31 #include <linux/scatterlist.h>
  32 #include <linux/slab.h>
  33 #include <linux/spinlock.h>
  34 #include <scsi/scsi_proto.h>
  35
  36 #include <target/target_core_base.h>
  37 #include <target/target_core_backend.h>
  38
  39 #include "target_core_rd.h"
  40
  41 static inline struct rd_dev *RD_DEV(struct se_device *dev)
  42 {
  43         return container_of(dev, struct rd_dev, dev);
  44 }
  45
  46 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  47 {
  48         struct rd_host *rd_host;
  49
  50         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
  51         if (!rd_host) {
  52                 pr_err("Unable to allocate memory for struct rd_host\n");
  53                 return -ENOMEM;
  54         }
  55
  56         rd_host->rd_host_id = host_id;
  57
  58         hba->hba_ptr = rd_host;
  59
  60         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  61                 " Generic Target Core Stack %s\n", hba->hba_id,
  62                 RD_HBA_VERSION, TARGET_CORE_VERSION);
  63
  64         return 0;
  65 }
  66
  67 static void rd_detach_hba(struct se_hba *hba)
  68 {
  69         struct rd_host *rd_host = hba->hba_ptr;
  70
  71         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  72                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  73
  74         kfree(rd_host);
  75         hba->hba_ptr = NULL;
  76 }
  77
  78 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
  79                                  u32 sg_table_count)
  80 {
  81         struct page *pg;
  82         struct scatterlist *sg;
  83         u32 i, j, page_count = 0, sg_per_table;
  84
  85         for (i = 0; i < sg_table_count; i++) {
  86                 sg = sg_table[i].sg_table;
  87                 sg_per_table = sg_table[i].rd_sg_count;
  88
  89                 for (j = 0; j < sg_per_table; j++) {
  90                         pg = sg_page(&sg[j]);
  91                         if (pg) {
  92                                 __free_page(pg);
  93                                 page_count++;
  94                         }
  95                 }
  96                 kfree(sg);
  97         }
  98
  99         kfree(sg_table);
 100         return page_count;
 101 }
 102
 103 static void rd_release_device_space(struct rd_dev *rd_dev)
 104 {
 105         u32 page_count;
 106
 107         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 108                 return;
 109
 110         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
 111                                           rd_dev->sg_table_count);
 112
 113         pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
 114                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 115                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 116                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 117
 118         rd_dev->sg_table_array = NULL;
 119         rd_dev->sg_table_count = 0;
 120 }
 121
 122
 123 /*      rd_build_device_space():
 124  *
 125  *
 126  */
 127 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
 128                                  u32 total_sg_needed, unsigned char init_payload)
 129 {
 130         u32 i = 0, j, page_offset = 0, sg_per_table;
 131         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 132                                 sizeof(struct scatterlist));
 133         struct page *pg;
 134         struct scatterlist *sg;
 135         unsigned char *p;
 136
 137         while (total_sg_needed) {
 138                 unsigned int chain_entry = 0;
 139
 140                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 141                         max_sg_per_table : total_sg_needed;
 142
 143                 /*
 144                  * Reserve extra element for chain entry
 145                  */
 146                 if (sg_per_table < total_sg_needed)
 147                         chain_entry = 1;
 148
 149                 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 150                                 GFP_KERNEL);
 151                 if (!sg) {
 152                         pr_err("Unable to allocate scatterlist array"
 153                                 " for struct rd_dev\n");
 154                         return -ENOMEM;
 155                 }
 156
 157                 sg_init_table(sg, sg_per_table + chain_entry);
 158
 159                 if (i > 0) {
 160                         sg_chain(sg_table[i - 1].sg_table,
 161                                  max_sg_per_table + 1, sg);
 162                 }
 163
 164                 sg_table[i].sg_table = sg;
 165                 sg_table[i].rd_sg_count = sg_per_table;
 166                 sg_table[i].page_start_offset = page_offset;
 167                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 168                                                 - 1;
 169
 170                 for (j = 0; j < sg_per_table; j++) {
 171                         pg = alloc_pages(GFP_KERNEL, 0);
 172                         if (!pg) {
 173                                 pr_err("Unable to allocate scatterlist"
 174                                         " pages for struct rd_dev_sg_table\n");
 175                                 return -ENOMEM;
 176                         }
 177                         sg_assign_page(&sg[j], pg);
 178                         sg[j].length = PAGE_SIZE;
 179
 180                         p = kmap(pg);
 181                         memset(p, init_payload, PAGE_SIZE);
 182                         kunmap(pg);
 183                 }
 184
 185                 page_offset += sg_per_table;
 186                 total_sg_needed -= sg_per_table;
 187         }
 188
 189         return 0;
 190 }
 191
 192 static int rd_build_device_space(struct rd_dev *rd_dev)
 193 {
 194         struct rd_dev_sg_table *sg_table;
 195         u32 sg_tables, total_sg_needed;
 196         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 197                                 sizeof(struct scatterlist));
 198         int rc;
 199
 200         if (rd_dev->rd_page_count <= 0) {
 201                 pr_err("Illegal page count: %u for Ramdisk device\n",
 202                        rd_dev->rd_page_count);
 203                 return -EINVAL;
 204         }
 205
 206         /* Don't need backing pages for NULLIO */
 207         if (rd_dev->rd_flags & RDF_NULLIO)
 208                 return 0;
 209
 210         total_sg_needed = rd_dev->rd_page_count;
 211
 212         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 213
 214         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 215         if (!sg_table) {
 216                 pr_err("Unable to allocate memory for Ramdisk"
 217                        " scatterlist tables\n");
 218                 return -ENOMEM;
 219         }
 220
 221         rd_dev->sg_table_array = sg_table;
 222         rd_dev->sg_table_count = sg_tables;
 223
 224         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 225         if (rc)
 226                 return rc;
 227
 228         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 229                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 230                  rd_dev->rd_dev_id, rd_dev->rd_page_count,
 231                  rd_dev->sg_table_count);
 232
 233         return 0;
 234 }
 235
 236 static void rd_release_prot_space(struct rd_dev *rd_dev)
 237 {
 238         u32 page_count;
 239
 240         if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 241                 return;
 242
 243         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 244                                           rd_dev->sg_prot_count);
 245
 246         pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 247                  " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 248                  rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 249                  rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 250
 251         rd_dev->sg_prot_array = NULL;
 252         rd_dev->sg_prot_count = 0;
 253 }
 254
 255 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 256 {
 257         struct rd_dev_sg_table *sg_table;
 258         u32 total_sg_needed, sg_tables;
 259         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 260                                 sizeof(struct scatterlist));
 261         int rc;
 262
 263         if (rd_dev->rd_flags & RDF_NULLIO)
 264                 return 0;
 265         /*
 266          * prot_length=8byte dif data
 267          * tot sg needed = rd_page_count * (PGSZ/block_size) *
 268          *                 (prot_length/block_size) + pad
 269          * PGSZ canceled each other.
 270          */
 271         total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 272
 273         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 274
 275         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 276         if (!sg_table) {
 277                 pr_err("Unable to allocate memory for Ramdisk protection"
 278                        " scatterlist tables\n");
 279                 return -ENOMEM;
 280         }
 281
 282         rd_dev->sg_prot_array = sg_table;
 283         rd_dev->sg_prot_count = sg_tables;
 284
 285         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 286         if (rc)
 287                 return rc;
 288
 289         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 290                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 291                  rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 292
 293         return 0;
 294 }
 295
 296 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 297 {
 298         struct rd_dev *rd_dev;
 299         struct rd_host *rd_host = hba->hba_ptr;
 300
 301         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 302         if (!rd_dev) {
 303                 pr_err("Unable to allocate memory for struct rd_dev\n");
 304                 return NULL;
 305         }
 306
 307         rd_dev->rd_host = rd_host;
 308
 309         return &rd_dev->dev;
 310 }
 311
 312 static int rd_configure_device(struct se_device *dev)
 313 {
 314         struct rd_dev *rd_dev = RD_DEV(dev);
 315         struct rd_host *rd_host = dev->se_hba->hba_ptr;
 316         int ret;
 317
 318         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 319                 pr_debug("Missing rd_pages= parameter\n");
 320                 return -EINVAL;
 321         }
 322
 323         ret = rd_build_device_space(rd_dev);
 324         if (ret < 0)
 325                 goto fail;
 326
 327         dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 328         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 329         dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 330         dev->dev_attrib.is_nonrot = 1;
 331
 332         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 333
 334         pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 335                 " %u pages in %u tables, %lu total bytes\n",
 336                 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 337                 rd_dev->sg_table_count,
 338                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 339
 340         return 0;
 341
 342 fail:
 343         rd_release_device_space(rd_dev);
 344         return ret;
 345 }
 346
 347 static void rd_dev_call_rcu(struct rcu_head *p)
 348 {
 349         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 350         struct rd_dev *rd_dev = RD_DEV(dev);
 351
 352         kfree(rd_dev);
 353 }
 354
 355 static void rd_free_device(struct se_device *dev)
 356 {
 357         struct rd_dev *rd_dev = RD_DEV(dev);
 358
 359         rd_release_device_space(rd_dev);
 360         call_rcu(&dev->rcu_head, rd_dev_call_rcu);
 361 }
 362
 363 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 364 {
 365         struct rd_dev_sg_table *sg_table;
 366         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 367                                 sizeof(struct scatterlist));
 368
 369         i = page / sg_per_table;
 370         if (i < rd_dev->sg_table_count) {
 371                 sg_table = &rd_dev->sg_table_array[i];
 372                 if ((sg_table->page_start_offset <= page) &&
 373                     (sg_table->page_end_offset >= page))
 374                         return sg_table;
 375         }
 376
 377         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
 378                         page);
 379
 380         return NULL;
 381 }
 382
 383 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
 384 {
 385         struct rd_dev_sg_table *sg_table;
 386         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 387                                 sizeof(struct scatterlist));
 388
 389         i = page / sg_per_table;
 390         if (i < rd_dev->sg_prot_count) {
 391                 sg_table = &rd_dev->sg_prot_array[i];
 392                 if ((sg_table->page_start_offset <= page) &&
 393                      (sg_table->page_end_offset >= page))
 394                         return sg_table;
 395         }
 396
 397         pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
 398                         page);
 399
 400         return NULL;
 401 }
 402
 403 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
 404 {
 405         struct se_device *se_dev = cmd->se_dev;
 406         struct rd_dev *dev = RD_DEV(se_dev);
 407         struct rd_dev_sg_table *prot_table;
 408         struct scatterlist *prot_sg;
 409         u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
 410         u32 prot_offset, prot_page;
 411         u32 prot_npages __maybe_unused;
 412         u64 tmp;
 413         sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 414
 415         tmp = cmd->t_task_lba * se_dev->prot_length;
 416         prot_offset = do_div(tmp, PAGE_SIZE);
 417         prot_page = tmp;
 418
 419         prot_table = rd_get_prot_table(dev, prot_page);
 420         if (!prot_table)
 421                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 422
 423         prot_sg = &prot_table->sg_table[prot_page -
 424                                         prot_table->page_start_offset];
 425
 426         if (is_read)
 427                 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 428                                     prot_sg, prot_offset);
 429         else
 430                 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 431                                     cmd->t_prot_sg, 0);
 432
 433         if (!rc)
 434                 sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
 435
 436         return rc;
 437 }
 438
 439 static sense_reason_t
 440 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 441               enum dma_data_direction data_direction)
 442 {
 443         struct se_device *se_dev = cmd->se_dev;
 444         struct rd_dev *dev = RD_DEV(se_dev);
 445         struct rd_dev_sg_table *table;
 446         struct scatterlist *rd_sg;
 447         struct sg_mapping_iter m;
 448         u32 rd_offset;
 449         u32 rd_size;
 450         u32 rd_page;
 451         u32 src_len;
 452         u64 tmp;
 453         sense_reason_t rc;
 454
 455         if (dev->rd_flags & RDF_NULLIO) {
 456                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 457                 return 0;
 458         }
 459
 460         tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 461         rd_offset = do_div(tmp, PAGE_SIZE);
 462         rd_page = tmp;
 463         rd_size = cmd->data_length;
 464
 465         table = rd_get_sg_table(dev, rd_page);
 466         if (!table)
 467                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 468
 469         rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 470
 471         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 472                         dev->rd_dev_id,
 473                         data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 474                         cmd->t_task_lba, rd_size, rd_page, rd_offset);
 475
 476         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 477             data_direction == DMA_TO_DEVICE) {
 478                 rc = rd_do_prot_rw(cmd, false);
 479                 if (rc)
 480                         return rc;
 481         }
 482
 483         src_len = PAGE_SIZE - rd_offset;
 484         sg_miter_start(&m, sgl, sgl_nents,
 485                         data_direction == DMA_FROM_DEVICE ?
 486                                 SG_MITER_TO_SG : SG_MITER_FROM_SG);
 487         while (rd_size) {
 488                 u32 len;
 489                 void *rd_addr;
 490
 491                 sg_miter_next(&m);
 492                 if (!(u32)m.length) {
 493                         pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 494                                  dev->rd_dev_id, m.addr, m.length);
 495                         sg_miter_stop(&m);
 496                         return TCM_INCORRECT_AMOUNT_OF_DATA;
 497                 }
 498                 len = min((u32)m.length, src_len);
 499                 if (len > rd_size) {
 500                         pr_debug("RD[%u]: size underrun page %d offset %d "
 501                                  "size %d\n", dev->rd_dev_id,
 502                                  rd_page, rd_offset, rd_size);
 503                         len = rd_size;
 504                 }
 505                 m.consumed = len;
 506
 507                 rd_addr = sg_virt(rd_sg) + rd_offset;
 508
 509                 if (data_direction == DMA_FROM_DEVICE)
 510                         memcpy(m.addr, rd_addr, len);
 511                 else
 512                         memcpy(rd_addr, m.addr, len);
 513
 514                 rd_size -= len;
 515                 if (!rd_size)
 516                         continue;
 517
 518                 src_len -= len;
 519                 if (src_len) {
 520                         rd_offset += len;
 521                         continue;
 522                 }
 523
 524                 /* rd page completed, next one please */
 525                 rd_page++;
 526                 rd_offset = 0;
 527                 src_len = PAGE_SIZE;
 528                 if (rd_page <= table->page_end_offset) {
 529                         rd_sg++;
 530                         continue;
 531                 }
 532
 533                 table = rd_get_sg_table(dev, rd_page);
 534                 if (!table) {
 535                         sg_miter_stop(&m);
 536                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 537                 }
 538
 539                 /* since we increment, the first sg entry is correct */
 540                 rd_sg = table->sg_table;
 541         }
 542         sg_miter_stop(&m);
 543
 544         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 545             data_direction == DMA_FROM_DEVICE) {
 546                 rc = rd_do_prot_rw(cmd, true);
 547                 if (rc)
 548                         return rc;
 549         }
 550
 551         target_complete_cmd(cmd, SAM_STAT_GOOD);
 552         return 0;
 553 }
 554
 555 enum {
 556         Opt_rd_pages, Opt_rd_nullio, Opt_err
 557 };
 558
 559 static match_table_t tokens = {
 560         {Opt_rd_pages, "rd_pages=%d"},
 561         {Opt_rd_nullio, "rd_nullio=%d"},
 562         {Opt_err, NULL}
 563 };
 564
 565 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 566                 const char *page, ssize_t count)
 567 {
 568         struct rd_dev *rd_dev = RD_DEV(dev);
 569         char *orig, *ptr, *opts;
 570         substring_t args[MAX_OPT_ARGS];
 571         int ret = 0, arg, token;
 572
 573         opts = kstrdup(page, GFP_KERNEL);
 574         if (!opts)
 575                 return -ENOMEM;
 576
 577         orig = opts;
 578
 579         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 580                 if (!*ptr)
 581                         continue;
 582
 583                 token = match_token(ptr, tokens, args);
 584                 switch (token) {
 585                 case Opt_rd_pages:
 586                         match_int(args, &arg);
 587                         rd_dev->rd_page_count = arg;
 588                         pr_debug("RAMDISK: Referencing Page"
 589                                 " Count: %u\n", rd_dev->rd_page_count);
 590                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 591                         break;
 592                 case Opt_rd_nullio:
 593                         match_int(args, &arg);
 594                         if (arg != 1)
 595                                 break;
 596
 597                         pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 598                         rd_dev->rd_flags |= RDF_NULLIO;
 599                         break;
 600                 default:
 601                         break;
 602                 }
 603         }
 604
 605         kfree(orig);
 606         return (!ret) ? count : ret;
 607 }
 608
 609 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 610 {
 611         struct rd_dev *rd_dev = RD_DEV(dev);
 612
 613         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 614                         rd_dev->rd_dev_id);
 615         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 616                         "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 617                         PAGE_SIZE, rd_dev->sg_table_count,
 618                         !!(rd_dev->rd_flags & RDF_NULLIO));
 619         return bl;
 620 }
 621
 622 static sector_t rd_get_blocks(struct se_device *dev)
 623 {
 624         struct rd_dev *rd_dev = RD_DEV(dev);
 625
 626         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 627                         dev->dev_attrib.block_size) - 1;
 628
 629         return blocks_long;
 630 }
 631
 632 static int rd_init_prot(struct se_device *dev)
 633 {
 634         struct rd_dev *rd_dev = RD_DEV(dev);
 635
 636         if (!dev->dev_attrib.pi_prot_type)
 637                 return 0;
 638
 639         return rd_build_prot_space(rd_dev, dev->prot_length,
 640                                    dev->dev_attrib.block_size);
 641 }
 642
 643 static void rd_free_prot(struct se_device *dev)
 644 {
 645         struct rd_dev *rd_dev = RD_DEV(dev);
 646
 647         rd_release_prot_space(rd_dev);
 648 }
 649
 650 static struct sbc_ops rd_sbc_ops = {
 651         .execute_rw             = rd_execute_rw,
 652 };
 653
 654 static sense_reason_t
 655 rd_parse_cdb(struct se_cmd *cmd)
 656 {
 657         return sbc_parse_cdb(cmd, &rd_sbc_ops);
 658 }
 659
 660 static const struct target_backend_ops rd_mcp_ops = {
 661         .name                   = "rd_mcp",
 662         .inquiry_prod           = "RAMDISK-MCP",
 663         .inquiry_rev            = RD_MCP_VERSION,
 664         .attach_hba             = rd_attach_hba,
 665         .detach_hba             = rd_detach_hba,
 666         .alloc_device           = rd_alloc_device,
 667         .configure_device       = rd_configure_device,
 668         .free_device            = rd_free_device,
 669         .parse_cdb              = rd_parse_cdb,
 670         .set_configfs_dev_params = rd_set_configfs_dev_params,
 671         .show_configfs_dev_params = rd_show_configfs_dev_params,
 672         .get_device_type        = sbc_get_device_type,
 673         .get_blocks             = rd_get_blocks,
 674         .init_prot              = rd_init_prot,
 675         .free_prot              = rd_free_prot,
 676         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 677 };
 678
 679 int __init rd_module_init(void)
 680 {
 681         return transport_backend_register(&rd_mcp_ops);
 682 }
 683
 684 void rd_module_exit(void)
 685 {
 686         target_backend_unregister(&rd_mcp_ops);
 687 }