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 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 142
 143                 /*
 144                  * Reserve extra element for chain entry
 145                  */
 146                 if (sg_per_table < total_sg_needed)
 147                         chain_entry = 1;
 148
 149 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 150
 151                 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 152                                 GFP_KERNEL);
 153                 if (!sg) {
 154                         pr_err("Unable to allocate scatterlist array"
 155                                 " for struct rd_dev\n");
 156                         return -ENOMEM;
 157                 }
 158
 159                 sg_init_table(sg, sg_per_table + chain_entry);
 160
 161 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 162
 163                 if (i > 0) {
 164                         sg_chain(sg_table[i - 1].sg_table,
 165                                  max_sg_per_table + 1, sg);
 166                 }
 167
 168 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 169
 170                 sg_table[i].sg_table = sg;
 171                 sg_table[i].rd_sg_count = sg_per_table;
 172                 sg_table[i].page_start_offset = page_offset;
 173                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 174                                                 - 1;
 175
 176                 for (j = 0; j < sg_per_table; j++) {
 177                         pg = alloc_pages(GFP_KERNEL, 0);
 178                         if (!pg) {
 179                                 pr_err("Unable to allocate scatterlist"
 180                                         " pages for struct rd_dev_sg_table\n");
 181                                 return -ENOMEM;
 182                         }
 183                         sg_assign_page(&sg[j], pg);
 184                         sg[j].length = PAGE_SIZE;
 185
 186                         p = kmap(pg);
 187                         memset(p, init_payload, PAGE_SIZE);
 188                         kunmap(pg);
 189                 }
 190
 191                 page_offset += sg_per_table;
 192                 total_sg_needed -= sg_per_table;
 193         }
 194
 195         return 0;
 196 }
 197
 198 static int rd_build_device_space(struct rd_dev *rd_dev)
 199 {
 200         struct rd_dev_sg_table *sg_table;
 201         u32 sg_tables, total_sg_needed;
 202         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 203                                 sizeof(struct scatterlist));
 204         int rc;
 205
 206         if (rd_dev->rd_page_count <= 0) {
 207                 pr_err("Illegal page count: %u for Ramdisk device\n",
 208                        rd_dev->rd_page_count);
 209                 return -EINVAL;
 210         }
 211
 212         /* Don't need backing pages for NULLIO */
 213         if (rd_dev->rd_flags & RDF_NULLIO)
 214                 return 0;
 215
 216         total_sg_needed = rd_dev->rd_page_count;
 217
 218         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 219
 220         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 221         if (!sg_table) {
 222                 pr_err("Unable to allocate memory for Ramdisk"
 223                        " scatterlist tables\n");
 224                 return -ENOMEM;
 225         }
 226
 227         rd_dev->sg_table_array = sg_table;
 228         rd_dev->sg_table_count = sg_tables;
 229
 230         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 231         if (rc)
 232                 return rc;
 233
 234         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 235                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 236                  rd_dev->rd_dev_id, rd_dev->rd_page_count,
 237                  rd_dev->sg_table_count);
 238
 239         return 0;
 240 }
 241
 242 static void rd_release_prot_space(struct rd_dev *rd_dev)
 243 {
 244         u32 page_count;
 245
 246         if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 247                 return;
 248
 249         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 250                                           rd_dev->sg_prot_count);
 251
 252         pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 253                  " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 254                  rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 255                  rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 256
 257         rd_dev->sg_prot_array = NULL;
 258         rd_dev->sg_prot_count = 0;
 259 }
 260
 261 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 262 {
 263         struct rd_dev_sg_table *sg_table;
 264         u32 total_sg_needed, sg_tables;
 265         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 266                                 sizeof(struct scatterlist));
 267         int rc;
 268
 269         if (rd_dev->rd_flags & RDF_NULLIO)
 270                 return 0;
 271         /*
 272          * prot_length=8byte dif data
 273          * tot sg needed = rd_page_count * (PGSZ/block_size) *
 274          *                 (prot_length/block_size) + pad
 275          * PGSZ canceled each other.
 276          */
 277         total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 278
 279         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 280
 281         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 282         if (!sg_table) {
 283                 pr_err("Unable to allocate memory for Ramdisk protection"
 284                        " scatterlist tables\n");
 285                 return -ENOMEM;
 286         }
 287
 288         rd_dev->sg_prot_array = sg_table;
 289         rd_dev->sg_prot_count = sg_tables;
 290
 291         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 292         if (rc)
 293                 return rc;
 294
 295         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 296                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 297                  rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 298
 299         return 0;
 300 }
 301
 302 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 303 {
 304         struct rd_dev *rd_dev;
 305         struct rd_host *rd_host = hba->hba_ptr;
 306
 307         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 308         if (!rd_dev) {
 309                 pr_err("Unable to allocate memory for struct rd_dev\n");
 310                 return NULL;
 311         }
 312
 313         rd_dev->rd_host = rd_host;
 314
 315         return &rd_dev->dev;
 316 }
 317
 318 static int rd_configure_device(struct se_device *dev)
 319 {
 320         struct rd_dev *rd_dev = RD_DEV(dev);
 321         struct rd_host *rd_host = dev->se_hba->hba_ptr;
 322         int ret;
 323
 324         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 325                 pr_debug("Missing rd_pages= parameter\n");
 326                 return -EINVAL;
 327         }
 328
 329         ret = rd_build_device_space(rd_dev);
 330         if (ret < 0)
 331                 goto fail;
 332
 333         dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 334         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 335         dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 336
 337         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 338
 339         pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 340                 " %u pages in %u tables, %lu total bytes\n",
 341                 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 342                 rd_dev->sg_table_count,
 343                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 344
 345         return 0;
 346
 347 fail:
 348         rd_release_device_space(rd_dev);
 349         return ret;
 350 }
 351
 352 static void rd_dev_call_rcu(struct rcu_head *p)
 353 {
 354         struct se_device *dev = container_of(p, struct se_device, rcu_head);
 355         struct rd_dev *rd_dev = RD_DEV(dev);
 356
 357         kfree(rd_dev);
 358 }
 359
 360 static void rd_free_device(struct se_device *dev)
 361 {
 362         struct rd_dev *rd_dev = RD_DEV(dev);
 363
 364         rd_release_device_space(rd_dev);
 365         call_rcu(&dev->rcu_head, rd_dev_call_rcu);
 366 }
 367
 368 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 369 {
 370         struct rd_dev_sg_table *sg_table;
 371         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 372                                 sizeof(struct scatterlist));
 373
 374         i = page / sg_per_table;
 375         if (i < rd_dev->sg_table_count) {
 376                 sg_table = &rd_dev->sg_table_array[i];
 377                 if ((sg_table->page_start_offset <= page) &&
 378                     (sg_table->page_end_offset >= page))
 379                         return sg_table;
 380         }
 381
 382         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
 383                         page);
 384
 385         return NULL;
 386 }
 387
 388 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
 389 {
 390         struct rd_dev_sg_table *sg_table;
 391         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 392                                 sizeof(struct scatterlist));
 393
 394         i = page / sg_per_table;
 395         if (i < rd_dev->sg_prot_count) {
 396                 sg_table = &rd_dev->sg_prot_array[i];
 397                 if ((sg_table->page_start_offset <= page) &&
 398                      (sg_table->page_end_offset >= page))
 399                         return sg_table;
 400         }
 401
 402         pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
 403                         page);
 404
 405         return NULL;
 406 }
 407
 408 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
 409 {
 410         struct se_device *se_dev = cmd->se_dev;
 411         struct rd_dev *dev = RD_DEV(se_dev);
 412         struct rd_dev_sg_table *prot_table;
 413         bool need_to_release = false;
 414         struct scatterlist *prot_sg;
 415         u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
 416         u32 prot_offset, prot_page;
 417         u32 prot_npages __maybe_unused;
 418         u64 tmp;
 419         sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 420
 421         tmp = cmd->t_task_lba * se_dev->prot_length;
 422         prot_offset = do_div(tmp, PAGE_SIZE);
 423         prot_page = tmp;
 424
 425         prot_table = rd_get_prot_table(dev, prot_page);
 426         if (!prot_table)
 427                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 428
 429         prot_sg = &prot_table->sg_table[prot_page -
 430                                         prot_table->page_start_offset];
 431
 432 #ifndef CONFIG_ARCH_HAS_SG_CHAIN
 433
 434         prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length,
 435                                    PAGE_SIZE);
 436
 437         /*
 438          * Allocate temporaly contiguous scatterlist entries if prot pages
 439          * straddles multiple scatterlist tables.
 440          */
 441         if (prot_table->page_end_offset < prot_page + prot_npages - 1) {
 442                 int i;
 443
 444                 prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL);
 445                 if (!prot_sg)
 446                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 447
 448                 need_to_release = true;
 449                 sg_init_table(prot_sg, prot_npages);
 450
 451                 for (i = 0; i < prot_npages; i++) {
 452                         if (prot_page + i > prot_table->page_end_offset) {
 453                                 prot_table = rd_get_prot_table(dev,
 454                                                                 prot_page + i);
 455                                 if (!prot_table) {
 456                                         kfree(prot_sg);
 457                                         return rc;
 458                                 }
 459                                 sg_unmark_end(&prot_sg[i - 1]);
 460                         }
 461                         prot_sg[i] = prot_table->sg_table[prot_page + i -
 462                                                 prot_table->page_start_offset];
 463                 }
 464         }
 465
 466 #endif /* !CONFIG_ARCH_HAS_SG_CHAIN */
 467
 468         if (is_read)
 469                 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 470                                     prot_sg, prot_offset);
 471         else
 472                 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 473                                     cmd->t_prot_sg, 0);
 474
 475         if (!rc)
 476                 sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
 477
 478         if (need_to_release)
 479                 kfree(prot_sg);
 480
 481         return rc;
 482 }
 483
 484 static sense_reason_t
 485 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 486               enum dma_data_direction data_direction)
 487 {
 488         struct se_device *se_dev = cmd->se_dev;
 489         struct rd_dev *dev = RD_DEV(se_dev);
 490         struct rd_dev_sg_table *table;
 491         struct scatterlist *rd_sg;
 492         struct sg_mapping_iter m;
 493         u32 rd_offset;
 494         u32 rd_size;
 495         u32 rd_page;
 496         u32 src_len;
 497         u64 tmp;
 498         sense_reason_t rc;
 499
 500         if (dev->rd_flags & RDF_NULLIO) {
 501                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 502                 return 0;
 503         }
 504
 505         tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 506         rd_offset = do_div(tmp, PAGE_SIZE);
 507         rd_page = tmp;
 508         rd_size = cmd->data_length;
 509
 510         table = rd_get_sg_table(dev, rd_page);
 511         if (!table)
 512                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 513
 514         rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 515
 516         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 517                         dev->rd_dev_id,
 518                         data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 519                         cmd->t_task_lba, rd_size, rd_page, rd_offset);
 520
 521         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 522             data_direction == DMA_TO_DEVICE) {
 523                 rc = rd_do_prot_rw(cmd, false);
 524                 if (rc)
 525                         return rc;
 526         }
 527
 528         src_len = PAGE_SIZE - rd_offset;
 529         sg_miter_start(&m, sgl, sgl_nents,
 530                         data_direction == DMA_FROM_DEVICE ?
 531                                 SG_MITER_TO_SG : SG_MITER_FROM_SG);
 532         while (rd_size) {
 533                 u32 len;
 534                 void *rd_addr;
 535
 536                 sg_miter_next(&m);
 537                 if (!(u32)m.length) {
 538                         pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 539                                  dev->rd_dev_id, m.addr, m.length);
 540                         sg_miter_stop(&m);
 541                         return TCM_INCORRECT_AMOUNT_OF_DATA;
 542                 }
 543                 len = min((u32)m.length, src_len);
 544                 if (len > rd_size) {
 545                         pr_debug("RD[%u]: size underrun page %d offset %d "
 546                                  "size %d\n", dev->rd_dev_id,
 547                                  rd_page, rd_offset, rd_size);
 548                         len = rd_size;
 549                 }
 550                 m.consumed = len;
 551
 552                 rd_addr = sg_virt(rd_sg) + rd_offset;
 553
 554                 if (data_direction == DMA_FROM_DEVICE)
 555                         memcpy(m.addr, rd_addr, len);
 556                 else
 557                         memcpy(rd_addr, m.addr, len);
 558
 559                 rd_size -= len;
 560                 if (!rd_size)
 561                         continue;
 562
 563                 src_len -= len;
 564                 if (src_len) {
 565                         rd_offset += len;
 566                         continue;
 567                 }
 568
 569                 /* rd page completed, next one please */
 570                 rd_page++;
 571                 rd_offset = 0;
 572                 src_len = PAGE_SIZE;
 573                 if (rd_page <= table->page_end_offset) {
 574                         rd_sg++;
 575                         continue;
 576                 }
 577
 578                 table = rd_get_sg_table(dev, rd_page);
 579                 if (!table) {
 580                         sg_miter_stop(&m);
 581                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 582                 }
 583
 584                 /* since we increment, the first sg entry is correct */
 585                 rd_sg = table->sg_table;
 586         }
 587         sg_miter_stop(&m);
 588
 589         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 590             data_direction == DMA_FROM_DEVICE) {
 591                 rc = rd_do_prot_rw(cmd, true);
 592                 if (rc)
 593                         return rc;
 594         }
 595
 596         target_complete_cmd(cmd, SAM_STAT_GOOD);
 597         return 0;
 598 }
 599
 600 enum {
 601         Opt_rd_pages, Opt_rd_nullio, Opt_err
 602 };
 603
 604 static match_table_t tokens = {
 605         {Opt_rd_pages, "rd_pages=%d"},
 606         {Opt_rd_nullio, "rd_nullio=%d"},
 607         {Opt_err, NULL}
 608 };
 609
 610 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 611                 const char *page, ssize_t count)
 612 {
 613         struct rd_dev *rd_dev = RD_DEV(dev);
 614         char *orig, *ptr, *opts;
 615         substring_t args[MAX_OPT_ARGS];
 616         int ret = 0, arg, token;
 617
 618         opts = kstrdup(page, GFP_KERNEL);
 619         if (!opts)
 620                 return -ENOMEM;
 621
 622         orig = opts;
 623
 624         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 625                 if (!*ptr)
 626                         continue;
 627
 628                 token = match_token(ptr, tokens, args);
 629                 switch (token) {
 630                 case Opt_rd_pages:
 631                         match_int(args, &arg);
 632                         rd_dev->rd_page_count = arg;
 633                         pr_debug("RAMDISK: Referencing Page"
 634                                 " Count: %u\n", rd_dev->rd_page_count);
 635                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 636                         break;
 637                 case Opt_rd_nullio:
 638                         match_int(args, &arg);
 639                         if (arg != 1)
 640                                 break;
 641
 642                         pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 643                         rd_dev->rd_flags |= RDF_NULLIO;
 644                         break;
 645                 default:
 646                         break;
 647                 }
 648         }
 649
 650         kfree(orig);
 651         return (!ret) ? count : ret;
 652 }
 653
 654 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 655 {
 656         struct rd_dev *rd_dev = RD_DEV(dev);
 657
 658         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 659                         rd_dev->rd_dev_id);
 660         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 661                         "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 662                         PAGE_SIZE, rd_dev->sg_table_count,
 663                         !!(rd_dev->rd_flags & RDF_NULLIO));
 664         return bl;
 665 }
 666
 667 static sector_t rd_get_blocks(struct se_device *dev)
 668 {
 669         struct rd_dev *rd_dev = RD_DEV(dev);
 670
 671         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 672                         dev->dev_attrib.block_size) - 1;
 673
 674         return blocks_long;
 675 }
 676
 677 static int rd_init_prot(struct se_device *dev)
 678 {
 679         struct rd_dev *rd_dev = RD_DEV(dev);
 680
 681         if (!dev->dev_attrib.pi_prot_type)
 682                 return 0;
 683
 684         return rd_build_prot_space(rd_dev, dev->prot_length,
 685                                    dev->dev_attrib.block_size);
 686 }
 687
 688 static void rd_free_prot(struct se_device *dev)
 689 {
 690         struct rd_dev *rd_dev = RD_DEV(dev);
 691
 692         rd_release_prot_space(rd_dev);
 693 }
 694
 695 static struct sbc_ops rd_sbc_ops = {
 696         .execute_rw             = rd_execute_rw,
 697 };
 698
 699 static sense_reason_t
 700 rd_parse_cdb(struct se_cmd *cmd)
 701 {
 702         return sbc_parse_cdb(cmd, &rd_sbc_ops);
 703 }
 704
 705 static const struct target_backend_ops rd_mcp_ops = {
 706         .name                   = "rd_mcp",
 707         .inquiry_prod           = "RAMDISK-MCP",
 708         .inquiry_rev            = RD_MCP_VERSION,
 709         .attach_hba             = rd_attach_hba,
 710         .detach_hba             = rd_detach_hba,
 711         .alloc_device           = rd_alloc_device,
 712         .configure_device       = rd_configure_device,
 713         .free_device            = rd_free_device,
 714         .parse_cdb              = rd_parse_cdb,
 715         .set_configfs_dev_params = rd_set_configfs_dev_params,
 716         .show_configfs_dev_params = rd_show_configfs_dev_params,
 717         .get_device_type        = sbc_get_device_type,
 718         .get_blocks             = rd_get_blocks,
 719         .init_prot              = rd_init_prot,
 720         .free_prot              = rd_free_prot,
 721         .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 722 };
 723
 724 int __init rd_module_init(void)
 725 {
 726         return transport_backend_register(&rd_mcp_ops);
 727 }
 728
 729 void rd_module_exit(void)
 730 {
 731         target_backend_unregister(&rd_mcp_ops);
 732 }