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.h>
  33 #include <scsi/scsi_host.h>
  34
  35 #include <target/target_core_base.h>
  36 #include <target/target_core_backend.h>
  37
  38 #include "target_core_rd.h"
  39
  40 static inline struct rd_dev *RD_DEV(struct se_device *dev)
  41 {
  42         return container_of(dev, struct rd_dev, dev);
  43 }
  44
  45 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  46 {
  47         struct rd_host *rd_host;
  48
  49         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
  50         if (!rd_host) {
  51                 pr_err("Unable to allocate memory for struct rd_host\n");
  52                 return -ENOMEM;
  53         }
  54
  55         rd_host->rd_host_id = host_id;
  56
  57         hba->hba_ptr = rd_host;
  58
  59         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  60                 " Generic Target Core Stack %s\n", hba->hba_id,
  61                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
  62
  63         return 0;
  64 }
  65
  66 static void rd_detach_hba(struct se_hba *hba)
  67 {
  68         struct rd_host *rd_host = hba->hba_ptr;
  69
  70         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  71                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  72
  73         kfree(rd_host);
  74         hba->hba_ptr = NULL;
  75 }
  76
  77 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
  78                                  u32 sg_table_count)
  79 {
  80         struct page *pg;
  81         struct scatterlist *sg;
  82         u32 i, j, page_count = 0, sg_per_table;
  83
  84         for (i = 0; i < sg_table_count; i++) {
  85                 sg = sg_table[i].sg_table;
  86                 sg_per_table = sg_table[i].rd_sg_count;
  87
  88                 for (j = 0; j < sg_per_table; j++) {
  89                         pg = sg_page(&sg[j]);
  90                         if (pg) {
  91                                 __free_page(pg);
  92                                 page_count++;
  93                         }
  94                 }
  95                 kfree(sg);
  96         }
  97
  98         kfree(sg_table);
  99         return page_count;
 100 }
 101
 102 static void rd_release_device_space(struct rd_dev *rd_dev)
 103 {
 104         u32 page_count;
 105
 106         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 107                 return;
 108
 109         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
 110                                           rd_dev->sg_table_count);
 111
 112         pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
 113                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 114                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 115                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 116
 117         rd_dev->sg_table_array = NULL;
 118         rd_dev->sg_table_count = 0;
 119 }
 120
 121
 122 /*      rd_build_device_space():
 123  *
 124  *
 125  */
 126 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
 127                                  u32 total_sg_needed, unsigned char init_payload)
 128 {
 129         u32 i = 0, j, page_offset = 0, sg_per_table;
 130         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 131                                 sizeof(struct scatterlist));
 132         struct page *pg;
 133         struct scatterlist *sg;
 134         unsigned char *p;
 135
 136         while (total_sg_needed) {
 137                 unsigned int chain_entry = 0;
 138
 139                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 140                         max_sg_per_table : total_sg_needed;
 141
 142 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 143
 144                 /*
 145                  * Reserve extra element for chain entry
 146                  */
 147                 if (sg_per_table < total_sg_needed)
 148                         chain_entry = 1;
 149
 150 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 151
 152                 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 153                                 GFP_KERNEL);
 154                 if (!sg) {
 155                         pr_err("Unable to allocate scatterlist array"
 156                                 " for struct rd_dev\n");
 157                         return -ENOMEM;
 158                 }
 159
 160                 sg_init_table(sg, sg_per_table + chain_entry);
 161
 162 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 163
 164                 if (i > 0) {
 165                         sg_chain(sg_table[i - 1].sg_table,
 166                                  max_sg_per_table + 1, sg);
 167                 }
 168
 169 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 170
 171                 sg_table[i].sg_table = sg;
 172                 sg_table[i].rd_sg_count = sg_per_table;
 173                 sg_table[i].page_start_offset = page_offset;
 174                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 175                                                 - 1;
 176
 177                 for (j = 0; j < sg_per_table; j++) {
 178                         pg = alloc_pages(GFP_KERNEL, 0);
 179                         if (!pg) {
 180                                 pr_err("Unable to allocate scatterlist"
 181                                         " pages for struct rd_dev_sg_table\n");
 182                                 return -ENOMEM;
 183                         }
 184                         sg_assign_page(&sg[j], pg);
 185                         sg[j].length = PAGE_SIZE;
 186
 187                         p = kmap(pg);
 188                         memset(p, init_payload, PAGE_SIZE);
 189                         kunmap(pg);
 190                 }
 191
 192                 page_offset += sg_per_table;
 193                 total_sg_needed -= sg_per_table;
 194         }
 195
 196         return 0;
 197 }
 198
 199 static int rd_build_device_space(struct rd_dev *rd_dev)
 200 {
 201         struct rd_dev_sg_table *sg_table;
 202         u32 sg_tables, total_sg_needed;
 203         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 204                                 sizeof(struct scatterlist));
 205         int rc;
 206
 207         if (rd_dev->rd_page_count <= 0) {
 208                 pr_err("Illegal page count: %u for Ramdisk device\n",
 209                        rd_dev->rd_page_count);
 210                 return -EINVAL;
 211         }
 212
 213         /* Don't need backing pages for NULLIO */
 214         if (rd_dev->rd_flags & RDF_NULLIO)
 215                 return 0;
 216
 217         total_sg_needed = rd_dev->rd_page_count;
 218
 219         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 220
 221         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 222         if (!sg_table) {
 223                 pr_err("Unable to allocate memory for Ramdisk"
 224                        " scatterlist tables\n");
 225                 return -ENOMEM;
 226         }
 227
 228         rd_dev->sg_table_array = sg_table;
 229         rd_dev->sg_table_count = sg_tables;
 230
 231         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 232         if (rc)
 233                 return rc;
 234
 235         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 236                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 237                  rd_dev->rd_dev_id, rd_dev->rd_page_count,
 238                  rd_dev->sg_table_count);
 239
 240         return 0;
 241 }
 242
 243 static void rd_release_prot_space(struct rd_dev *rd_dev)
 244 {
 245         u32 page_count;
 246
 247         if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 248                 return;
 249
 250         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 251                                           rd_dev->sg_prot_count);
 252
 253         pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 254                  " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 255                  rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 256                  rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 257
 258         rd_dev->sg_prot_array = NULL;
 259         rd_dev->sg_prot_count = 0;
 260 }
 261
 262 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 263 {
 264         struct rd_dev_sg_table *sg_table;
 265         u32 total_sg_needed, sg_tables;
 266         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 267                                 sizeof(struct scatterlist));
 268         int rc;
 269
 270         if (rd_dev->rd_flags & RDF_NULLIO)
 271                 return 0;
 272         /*
 273          * prot_length=8byte dif data
 274          * tot sg needed = rd_page_count * (PGSZ/block_size) *
 275          *                 (prot_length/block_size) + pad
 276          * PGSZ canceled each other.
 277          */
 278         total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 279
 280         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 281
 282         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 283         if (!sg_table) {
 284                 pr_err("Unable to allocate memory for Ramdisk protection"
 285                        " scatterlist tables\n");
 286                 return -ENOMEM;
 287         }
 288
 289         rd_dev->sg_prot_array = sg_table;
 290         rd_dev->sg_prot_count = sg_tables;
 291
 292         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 293         if (rc)
 294                 return rc;
 295
 296         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 297                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 298                  rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 299
 300         return 0;
 301 }
 302
 303 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 304 {
 305         struct rd_dev *rd_dev;
 306         struct rd_host *rd_host = hba->hba_ptr;
 307
 308         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 309         if (!rd_dev) {
 310                 pr_err("Unable to allocate memory for struct rd_dev\n");
 311                 return NULL;
 312         }
 313
 314         rd_dev->rd_host = rd_host;
 315
 316         return &rd_dev->dev;
 317 }
 318
 319 static int rd_configure_device(struct se_device *dev)
 320 {
 321         struct rd_dev *rd_dev = RD_DEV(dev);
 322         struct rd_host *rd_host = dev->se_hba->hba_ptr;
 323         int ret;
 324
 325         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 326                 pr_debug("Missing rd_pages= parameter\n");
 327                 return -EINVAL;
 328         }
 329
 330         ret = rd_build_device_space(rd_dev);
 331         if (ret < 0)
 332                 goto fail;
 333
 334         dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 335         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 336         dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 337
 338         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 339
 340         pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 341                 " %u pages in %u tables, %lu total bytes\n",
 342                 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 343                 rd_dev->sg_table_count,
 344                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 345
 346         return 0;
 347
 348 fail:
 349         rd_release_device_space(rd_dev);
 350         return ret;
 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         kfree(rd_dev);
 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         bool need_to_release = false;
 407         struct scatterlist *prot_sg;
 408         u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
 409         u32 prot_offset, prot_page;
 410         u32 prot_npages __maybe_unused;
 411         u64 tmp;
 412         sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 413
 414         tmp = cmd->t_task_lba * se_dev->prot_length;
 415         prot_offset = do_div(tmp, PAGE_SIZE);
 416         prot_page = tmp;
 417
 418         prot_table = rd_get_prot_table(dev, prot_page);
 419         if (!prot_table)
 420                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 421
 422         prot_sg = &prot_table->sg_table[prot_page -
 423                                         prot_table->page_start_offset];
 424
 425 #ifndef CONFIG_ARCH_HAS_SG_CHAIN
 426
 427         prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length,
 428                                    PAGE_SIZE);
 429
 430         /*
 431          * Allocate temporaly contiguous scatterlist entries if prot pages
 432          * straddles multiple scatterlist tables.
 433          */
 434         if (prot_table->page_end_offset < prot_page + prot_npages - 1) {
 435                 int i;
 436
 437                 prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL);
 438                 if (!prot_sg)
 439                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 440
 441                 need_to_release = true;
 442                 sg_init_table(prot_sg, prot_npages);
 443
 444                 for (i = 0; i < prot_npages; i++) {
 445                         if (prot_page + i > prot_table->page_end_offset) {
 446                                 prot_table = rd_get_prot_table(dev,
 447                                                                 prot_page + i);
 448                                 if (!prot_table) {
 449                                         kfree(prot_sg);
 450                                         return rc;
 451                                 }
 452                                 sg_unmark_end(&prot_sg[i - 1]);
 453                         }
 454                         prot_sg[i] = prot_table->sg_table[prot_page + i -
 455                                                 prot_table->page_start_offset];
 456                 }
 457         }
 458
 459 #endif /* !CONFIG_ARCH_HAS_SG_CHAIN */
 460
 461         if (is_read)
 462                 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 463                                     prot_sg, prot_offset);
 464         else
 465                 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 466                                     cmd->t_prot_sg, 0);
 467
 468         if (!rc)
 469                 sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
 470
 471         if (need_to_release)
 472                 kfree(prot_sg);
 473
 474         return rc;
 475 }
 476
 477 static sense_reason_t
 478 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 479               enum dma_data_direction data_direction)
 480 {
 481         struct se_device *se_dev = cmd->se_dev;
 482         struct rd_dev *dev = RD_DEV(se_dev);
 483         struct rd_dev_sg_table *table;
 484         struct scatterlist *rd_sg;
 485         struct sg_mapping_iter m;
 486         u32 rd_offset;
 487         u32 rd_size;
 488         u32 rd_page;
 489         u32 src_len;
 490         u64 tmp;
 491         sense_reason_t rc;
 492
 493         if (dev->rd_flags & RDF_NULLIO) {
 494                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 495                 return 0;
 496         }
 497
 498         tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 499         rd_offset = do_div(tmp, PAGE_SIZE);
 500         rd_page = tmp;
 501         rd_size = cmd->data_length;
 502
 503         table = rd_get_sg_table(dev, rd_page);
 504         if (!table)
 505                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 506
 507         rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 508
 509         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 510                         dev->rd_dev_id,
 511                         data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 512                         cmd->t_task_lba, rd_size, rd_page, rd_offset);
 513
 514         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 515             data_direction == DMA_TO_DEVICE) {
 516                 rc = rd_do_prot_rw(cmd, false);
 517                 if (rc)
 518                         return rc;
 519         }
 520
 521         src_len = PAGE_SIZE - rd_offset;
 522         sg_miter_start(&m, sgl, sgl_nents,
 523                         data_direction == DMA_FROM_DEVICE ?
 524                                 SG_MITER_TO_SG : SG_MITER_FROM_SG);
 525         while (rd_size) {
 526                 u32 len;
 527                 void *rd_addr;
 528
 529                 sg_miter_next(&m);
 530                 if (!(u32)m.length) {
 531                         pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 532                                  dev->rd_dev_id, m.addr, m.length);
 533                         sg_miter_stop(&m);
 534                         return TCM_INCORRECT_AMOUNT_OF_DATA;
 535                 }
 536                 len = min((u32)m.length, src_len);
 537                 if (len > rd_size) {
 538                         pr_debug("RD[%u]: size underrun page %d offset %d "
 539                                  "size %d\n", dev->rd_dev_id,
 540                                  rd_page, rd_offset, rd_size);
 541                         len = rd_size;
 542                 }
 543                 m.consumed = len;
 544
 545                 rd_addr = sg_virt(rd_sg) + rd_offset;
 546
 547                 if (data_direction == DMA_FROM_DEVICE)
 548                         memcpy(m.addr, rd_addr, len);
 549                 else
 550                         memcpy(rd_addr, m.addr, len);
 551
 552                 rd_size -= len;
 553                 if (!rd_size)
 554                         continue;
 555
 556                 src_len -= len;
 557                 if (src_len) {
 558                         rd_offset += len;
 559                         continue;
 560                 }
 561
 562                 /* rd page completed, next one please */
 563                 rd_page++;
 564                 rd_offset = 0;
 565                 src_len = PAGE_SIZE;
 566                 if (rd_page <= table->page_end_offset) {
 567                         rd_sg++;
 568                         continue;
 569                 }
 570
 571                 table = rd_get_sg_table(dev, rd_page);
 572                 if (!table) {
 573                         sg_miter_stop(&m);
 574                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 575                 }
 576
 577                 /* since we increment, the first sg entry is correct */
 578                 rd_sg = table->sg_table;
 579         }
 580         sg_miter_stop(&m);
 581
 582         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 583             data_direction == DMA_FROM_DEVICE) {
 584                 rc = rd_do_prot_rw(cmd, true);
 585                 if (rc)
 586                         return rc;
 587         }
 588
 589         target_complete_cmd(cmd, SAM_STAT_GOOD);
 590         return 0;
 591 }
 592
 593 enum {
 594         Opt_rd_pages, Opt_rd_nullio, Opt_err
 595 };
 596
 597 static match_table_t tokens = {
 598         {Opt_rd_pages, "rd_pages=%d"},
 599         {Opt_rd_nullio, "rd_nullio=%d"},
 600         {Opt_err, NULL}
 601 };
 602
 603 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 604                 const char *page, ssize_t count)
 605 {
 606         struct rd_dev *rd_dev = RD_DEV(dev);
 607         char *orig, *ptr, *opts;
 608         substring_t args[MAX_OPT_ARGS];
 609         int ret = 0, arg, token;
 610
 611         opts = kstrdup(page, GFP_KERNEL);
 612         if (!opts)
 613                 return -ENOMEM;
 614
 615         orig = opts;
 616
 617         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 618                 if (!*ptr)
 619                         continue;
 620
 621                 token = match_token(ptr, tokens, args);
 622                 switch (token) {
 623                 case Opt_rd_pages:
 624                         match_int(args, &arg);
 625                         rd_dev->rd_page_count = arg;
 626                         pr_debug("RAMDISK: Referencing Page"
 627                                 " Count: %u\n", rd_dev->rd_page_count);
 628                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 629                         break;
 630                 case Opt_rd_nullio:
 631                         match_int(args, &arg);
 632                         if (arg != 1)
 633                                 break;
 634
 635                         pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 636                         rd_dev->rd_flags |= RDF_NULLIO;
 637                         break;
 638                 default:
 639                         break;
 640                 }
 641         }
 642
 643         kfree(orig);
 644         return (!ret) ? count : ret;
 645 }
 646
 647 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 648 {
 649         struct rd_dev *rd_dev = RD_DEV(dev);
 650
 651         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 652                         rd_dev->rd_dev_id);
 653         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 654                         "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 655                         PAGE_SIZE, rd_dev->sg_table_count,
 656                         !!(rd_dev->rd_flags & RDF_NULLIO));
 657         return bl;
 658 }
 659
 660 static sector_t rd_get_blocks(struct se_device *dev)
 661 {
 662         struct rd_dev *rd_dev = RD_DEV(dev);
 663
 664         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 665                         dev->dev_attrib.block_size) - 1;
 666
 667         return blocks_long;
 668 }
 669
 670 static int rd_init_prot(struct se_device *dev)
 671 {
 672         struct rd_dev *rd_dev = RD_DEV(dev);
 673
 674         if (!dev->dev_attrib.pi_prot_type)
 675                 return 0;
 676
 677         return rd_build_prot_space(rd_dev, dev->prot_length,
 678                                    dev->dev_attrib.block_size);
 679 }
 680
 681 static void rd_free_prot(struct se_device *dev)
 682 {
 683         struct rd_dev *rd_dev = RD_DEV(dev);
 684
 685         rd_release_prot_space(rd_dev);
 686 }
 687
 688 static struct sbc_ops rd_sbc_ops = {
 689         .execute_rw             = rd_execute_rw,
 690 };
 691
 692 static sense_reason_t
 693 rd_parse_cdb(struct se_cmd *cmd)
 694 {
 695         return sbc_parse_cdb(cmd, &rd_sbc_ops);
 696 }
 697
 698 static const struct target_backend_ops rd_mcp_ops = {
 699         .name                   = "rd_mcp",
 700         .inquiry_prod           = "RAMDISK-MCP",
 701         .inquiry_rev            = RD_MCP_VERSION,
 702         .attach_hba             = rd_attach_hba,
 703         .detach_hba             = rd_detach_hba,
 704         .alloc_device           = rd_alloc_device,
 705         .configure_device       = rd_configure_device,
 706         .free_device            = rd_free_device,
 707         .parse_cdb              = rd_parse_cdb,
 708         .set_configfs_dev_params = rd_set_configfs_dev_params,
 709         .show_configfs_dev_params = rd_show_configfs_dev_params,
 710         .get_device_type        = sbc_get_device_type,
 711         .get_blocks             = rd_get_blocks,
 712         .init_prot              = rd_init_prot,
 713         .free_prot              = rd_free_prot,
 714         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 715 };
 716
 717 int __init rd_module_init(void)
 718 {
 719         return transport_backend_register(&rd_mcp_ops);
 720 }
 721
 722 void rd_module_exit(void)
 723 {
 724         target_backend_unregister(&rd_mcp_ops);
 725 }