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