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 #include <target/target_core_backend_configfs.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 /*      rd_attach_hba(): (Part of se_subsystem_api_t template)
  47  *
  48  *
  49  */
  50 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  51 {
  52         struct rd_host *rd_host;
  53
  54         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
  55         if (!rd_host) {
  56                 pr_err("Unable to allocate memory for struct rd_host\n");
  57                 return -ENOMEM;
  58         }
  59
  60         rd_host->rd_host_id = host_id;
  61
  62         hba->hba_ptr = rd_host;
  63
  64         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  65                 " Generic Target Core Stack %s\n", hba->hba_id,
  66                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
  67
  68         return 0;
  69 }
  70
  71 static void rd_detach_hba(struct se_hba *hba)
  72 {
  73         struct rd_host *rd_host = hba->hba_ptr;
  74
  75         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  76                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  77
  78         kfree(rd_host);
  79         hba->hba_ptr = NULL;
  80 }
  81
  82 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
  83                                  u32 sg_table_count)
  84 {
  85         struct page *pg;
  86         struct scatterlist *sg;
  87         u32 i, j, page_count = 0, sg_per_table;
  88
  89         for (i = 0; i < sg_table_count; i++) {
  90                 sg = sg_table[i].sg_table;
  91                 sg_per_table = sg_table[i].rd_sg_count;
  92
  93                 for (j = 0; j < sg_per_table; j++) {
  94                         pg = sg_page(&sg[j]);
  95                         if (pg) {
  96                                 __free_page(pg);
  97                                 page_count++;
  98                         }
  99                 }
 100                 kfree(sg);
 101         }
 102
 103         kfree(sg_table);
 104         return page_count;
 105 }
 106
 107 static void rd_release_device_space(struct rd_dev *rd_dev)
 108 {
 109         u32 page_count;
 110
 111         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 112                 return;
 113
 114         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
 115                                           rd_dev->sg_table_count);
 116
 117         pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
 118                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 119                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 120                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 121
 122         rd_dev->sg_table_array = NULL;
 123         rd_dev->sg_table_count = 0;
 124 }
 125
 126
 127 /*      rd_build_device_space():
 128  *
 129  *
 130  */
 131 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
 132                                  u32 total_sg_needed, unsigned char init_payload)
 133 {
 134         u32 i = 0, j, page_offset = 0, sg_per_table;
 135         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 136                                 sizeof(struct scatterlist));
 137         struct page *pg;
 138         struct scatterlist *sg;
 139         unsigned char *p;
 140
 141         while (total_sg_needed) {
 142                 unsigned int chain_entry = 0;
 143
 144                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 145                         max_sg_per_table : total_sg_needed;
 146
 147 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 148
 149                 /*
 150                  * Reserve extra element for chain entry
 151                  */
 152                 if (sg_per_table < total_sg_needed)
 153                         chain_entry = 1;
 154
 155 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 156
 157                 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 158                                 GFP_KERNEL);
 159                 if (!sg) {
 160                         pr_err("Unable to allocate scatterlist array"
 161                                 " for struct rd_dev\n");
 162                         return -ENOMEM;
 163                 }
 164
 165                 sg_init_table(sg, sg_per_table + chain_entry);
 166
 167 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 168
 169                 if (i > 0) {
 170                         sg_chain(sg_table[i - 1].sg_table,
 171                                  max_sg_per_table + 1, sg);
 172                 }
 173
 174 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 175
 176                 sg_table[i].sg_table = sg;
 177                 sg_table[i].rd_sg_count = sg_per_table;
 178                 sg_table[i].page_start_offset = page_offset;
 179                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 180                                                 - 1;
 181
 182                 for (j = 0; j < sg_per_table; j++) {
 183                         pg = alloc_pages(GFP_KERNEL, 0);
 184                         if (!pg) {
 185                                 pr_err("Unable to allocate scatterlist"
 186                                         " pages for struct rd_dev_sg_table\n");
 187                                 return -ENOMEM;
 188                         }
 189                         sg_assign_page(&sg[j], pg);
 190                         sg[j].length = PAGE_SIZE;
 191
 192                         p = kmap(pg);
 193                         memset(p, init_payload, PAGE_SIZE);
 194                         kunmap(pg);
 195                 }
 196
 197                 page_offset += sg_per_table;
 198                 total_sg_needed -= sg_per_table;
 199         }
 200
 201         return 0;
 202 }
 203
 204 static int rd_build_device_space(struct rd_dev *rd_dev)
 205 {
 206         struct rd_dev_sg_table *sg_table;
 207         u32 sg_tables, total_sg_needed;
 208         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 209                                 sizeof(struct scatterlist));
 210         int rc;
 211
 212         if (rd_dev->rd_page_count <= 0) {
 213                 pr_err("Illegal page count: %u for Ramdisk device\n",
 214                        rd_dev->rd_page_count);
 215                 return -EINVAL;
 216         }
 217
 218         /* Don't need backing pages for NULLIO */
 219         if (rd_dev->rd_flags & RDF_NULLIO)
 220                 return 0;
 221
 222         total_sg_needed = rd_dev->rd_page_count;
 223
 224         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 225
 226         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 227         if (!sg_table) {
 228                 pr_err("Unable to allocate memory for Ramdisk"
 229                        " scatterlist tables\n");
 230                 return -ENOMEM;
 231         }
 232
 233         rd_dev->sg_table_array = sg_table;
 234         rd_dev->sg_table_count = sg_tables;
 235
 236         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 237         if (rc)
 238                 return rc;
 239
 240         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 241                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 242                  rd_dev->rd_dev_id, rd_dev->rd_page_count,
 243                  rd_dev->sg_table_count);
 244
 245         return 0;
 246 }
 247
 248 static void rd_release_prot_space(struct rd_dev *rd_dev)
 249 {
 250         u32 page_count;
 251
 252         if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 253                 return;
 254
 255         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 256                                           rd_dev->sg_prot_count);
 257
 258         pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 259                  " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 260                  rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 261                  rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 262
 263         rd_dev->sg_prot_array = NULL;
 264         rd_dev->sg_prot_count = 0;
 265 }
 266
 267 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 268 {
 269         struct rd_dev_sg_table *sg_table;
 270         u32 total_sg_needed, sg_tables;
 271         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 272                                 sizeof(struct scatterlist));
 273         int rc;
 274
 275         if (rd_dev->rd_flags & RDF_NULLIO)
 276                 return 0;
 277         /*
 278          * prot_length=8byte dif data
 279          * tot sg needed = rd_page_count * (PGSZ/block_size) *
 280          *                 (prot_length/block_size) + pad
 281          * PGSZ canceled each other.
 282          */
 283         total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 284
 285         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 286
 287         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 288         if (!sg_table) {
 289                 pr_err("Unable to allocate memory for Ramdisk protection"
 290                        " scatterlist tables\n");
 291                 return -ENOMEM;
 292         }
 293
 294         rd_dev->sg_prot_array = sg_table;
 295         rd_dev->sg_prot_count = sg_tables;
 296
 297         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 298         if (rc)
 299                 return rc;
 300
 301         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 302                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 303                  rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 304
 305         return 0;
 306 }
 307
 308 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 309 {
 310         struct rd_dev *rd_dev;
 311         struct rd_host *rd_host = hba->hba_ptr;
 312
 313         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 314         if (!rd_dev) {
 315                 pr_err("Unable to allocate memory for struct rd_dev\n");
 316                 return NULL;
 317         }
 318
 319         rd_dev->rd_host = rd_host;
 320
 321         return &rd_dev->dev;
 322 }
 323
 324 static int rd_configure_device(struct se_device *dev)
 325 {
 326         struct rd_dev *rd_dev = RD_DEV(dev);
 327         struct rd_host *rd_host = dev->se_hba->hba_ptr;
 328         int ret;
 329
 330         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 331                 pr_debug("Missing rd_pages= parameter\n");
 332                 return -EINVAL;
 333         }
 334
 335         ret = rd_build_device_space(rd_dev);
 336         if (ret < 0)
 337                 goto fail;
 338
 339         dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 340         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 341         dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 342
 343         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 344
 345         pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 346                 " %u pages in %u tables, %lu total bytes\n",
 347                 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 348                 rd_dev->sg_table_count,
 349                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 350
 351         return 0;
 352
 353 fail:
 354         rd_release_device_space(rd_dev);
 355         return ret;
 356 }
 357
 358 static void rd_free_device(struct se_device *dev)
 359 {
 360         struct rd_dev *rd_dev = RD_DEV(dev);
 361
 362         rd_release_device_space(rd_dev);
 363         kfree(rd_dev);
 364 }
 365
 366 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 367 {
 368         struct rd_dev_sg_table *sg_table;
 369         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 370                                 sizeof(struct scatterlist));
 371
 372         i = page / sg_per_table;
 373         if (i < rd_dev->sg_table_count) {
 374                 sg_table = &rd_dev->sg_table_array[i];
 375                 if ((sg_table->page_start_offset <= page) &&
 376                     (sg_table->page_end_offset >= page))
 377                         return sg_table;
 378         }
 379
 380         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
 381                         page);
 382
 383         return NULL;
 384 }
 385
 386 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
 387 {
 388         struct rd_dev_sg_table *sg_table;
 389         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 390                                 sizeof(struct scatterlist));
 391
 392         i = page / sg_per_table;
 393         if (i < rd_dev->sg_prot_count) {
 394                 sg_table = &rd_dev->sg_prot_array[i];
 395                 if ((sg_table->page_start_offset <= page) &&
 396                      (sg_table->page_end_offset >= page))
 397                         return sg_table;
 398         }
 399
 400         pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
 401                         page);
 402
 403         return NULL;
 404 }
 405
 406 typedef sense_reason_t (*dif_verify)(struct se_cmd *, sector_t, unsigned int,
 407                                      unsigned int, struct scatterlist *, int);
 408
 409 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify)
 410 {
 411         struct se_device *se_dev = cmd->se_dev;
 412         struct rd_dev *dev = RD_DEV(se_dev);
 413         struct rd_dev_sg_table *prot_table;
 414         bool need_to_release = false;
 415         struct scatterlist *prot_sg;
 416         u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
 417         u32 prot_offset, prot_page;
 418         u32 prot_npages __maybe_unused;
 419         u64 tmp;
 420         sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 421
 422         tmp = cmd->t_task_lba * se_dev->prot_length;
 423         prot_offset = do_div(tmp, PAGE_SIZE);
 424         prot_page = tmp;
 425
 426         prot_table = rd_get_prot_table(dev, prot_page);
 427         if (!prot_table)
 428                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 429
 430         prot_sg = &prot_table->sg_table[prot_page -
 431                                         prot_table->page_start_offset];
 432
 433 #ifndef CONFIG_ARCH_HAS_SG_CHAIN
 434
 435         prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length,
 436                                    PAGE_SIZE);
 437
 438         /*
 439          * Allocate temporaly contiguous scatterlist entries if prot pages
 440          * straddles multiple scatterlist tables.
 441          */
 442         if (prot_table->page_end_offset < prot_page + prot_npages - 1) {
 443                 int i;
 444
 445                 prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL);
 446                 if (!prot_sg)
 447                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 448
 449                 need_to_release = true;
 450                 sg_init_table(prot_sg, prot_npages);
 451
 452                 for (i = 0; i < prot_npages; i++) {
 453                         if (prot_page + i > prot_table->page_end_offset) {
 454                                 prot_table = rd_get_prot_table(dev,
 455                                                                 prot_page + i);
 456                                 if (!prot_table) {
 457                                         kfree(prot_sg);
 458                                         return rc;
 459                                 }
 460                                 sg_unmark_end(&prot_sg[i - 1]);
 461                         }
 462                         prot_sg[i] = prot_table->sg_table[prot_page + i -
 463                                                 prot_table->page_start_offset];
 464                 }
 465         }
 466
 467 #endif /* !CONFIG_ARCH_HAS_SG_CHAIN */
 468
 469         rc = dif_verify(cmd, cmd->t_task_lba, sectors, 0, prot_sg, prot_offset);
 470         if (need_to_release)
 471                 kfree(prot_sg);
 472
 473         return rc;
 474 }
 475
 476 static sense_reason_t
 477 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 478               enum dma_data_direction data_direction)
 479 {
 480         struct se_device *se_dev = cmd->se_dev;
 481         struct rd_dev *dev = RD_DEV(se_dev);
 482         struct rd_dev_sg_table *table;
 483         struct scatterlist *rd_sg;
 484         struct sg_mapping_iter m;
 485         u32 rd_offset;
 486         u32 rd_size;
 487         u32 rd_page;
 488         u32 src_len;
 489         u64 tmp;
 490         sense_reason_t rc;
 491
 492         if (dev->rd_flags & RDF_NULLIO) {
 493                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 494                 return 0;
 495         }
 496
 497         tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 498         rd_offset = do_div(tmp, PAGE_SIZE);
 499         rd_page = tmp;
 500         rd_size = cmd->data_length;
 501
 502         table = rd_get_sg_table(dev, rd_page);
 503         if (!table)
 504                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 505
 506         rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 507
 508         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 509                         dev->rd_dev_id,
 510                         data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 511                         cmd->t_task_lba, rd_size, rd_page, rd_offset);
 512
 513         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 514             data_direction == DMA_TO_DEVICE) {
 515                 rc = rd_do_prot_rw(cmd, sbc_dif_verify_write);
 516                 if (rc)
 517                         return rc;
 518         }
 519
 520         src_len = PAGE_SIZE - rd_offset;
 521         sg_miter_start(&m, sgl, sgl_nents,
 522                         data_direction == DMA_FROM_DEVICE ?
 523                                 SG_MITER_TO_SG : SG_MITER_FROM_SG);
 524         while (rd_size) {
 525                 u32 len;
 526                 void *rd_addr;
 527
 528                 sg_miter_next(&m);
 529                 if (!(u32)m.length) {
 530                         pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 531                                  dev->rd_dev_id, m.addr, m.length);
 532                         sg_miter_stop(&m);
 533                         return TCM_INCORRECT_AMOUNT_OF_DATA;
 534                 }
 535                 len = min((u32)m.length, src_len);
 536                 if (len > rd_size) {
 537                         pr_debug("RD[%u]: size underrun page %d offset %d "
 538                                  "size %d\n", dev->rd_dev_id,
 539                                  rd_page, rd_offset, rd_size);
 540                         len = rd_size;
 541                 }
 542                 m.consumed = len;
 543
 544                 rd_addr = sg_virt(rd_sg) + rd_offset;
 545
 546                 if (data_direction == DMA_FROM_DEVICE)
 547                         memcpy(m.addr, rd_addr, len);
 548                 else
 549                         memcpy(rd_addr, m.addr, len);
 550
 551                 rd_size -= len;
 552                 if (!rd_size)
 553                         continue;
 554
 555                 src_len -= len;
 556                 if (src_len) {
 557                         rd_offset += len;
 558                         continue;
 559                 }
 560
 561                 /* rd page completed, next one please */
 562                 rd_page++;
 563                 rd_offset = 0;
 564                 src_len = PAGE_SIZE;
 565                 if (rd_page <= table->page_end_offset) {
 566                         rd_sg++;
 567                         continue;
 568                 }
 569
 570                 table = rd_get_sg_table(dev, rd_page);
 571                 if (!table) {
 572                         sg_miter_stop(&m);
 573                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 574                 }
 575
 576                 /* since we increment, the first sg entry is correct */
 577                 rd_sg = table->sg_table;
 578         }
 579         sg_miter_stop(&m);
 580
 581         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 582             data_direction == DMA_FROM_DEVICE) {
 583                 rc = rd_do_prot_rw(cmd, sbc_dif_verify_read);
 584                 if (rc)
 585                         return rc;
 586         }
 587
 588         target_complete_cmd(cmd, SAM_STAT_GOOD);
 589         return 0;
 590 }
 591
 592 enum {
 593         Opt_rd_pages, Opt_rd_nullio, Opt_err
 594 };
 595
 596 static match_table_t tokens = {
 597         {Opt_rd_pages, "rd_pages=%d"},
 598         {Opt_rd_nullio, "rd_nullio=%d"},
 599         {Opt_err, NULL}
 600 };
 601
 602 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 603                 const char *page, ssize_t count)
 604 {
 605         struct rd_dev *rd_dev = RD_DEV(dev);
 606         char *orig, *ptr, *opts;
 607         substring_t args[MAX_OPT_ARGS];
 608         int ret = 0, arg, token;
 609
 610         opts = kstrdup(page, GFP_KERNEL);
 611         if (!opts)
 612                 return -ENOMEM;
 613
 614         orig = opts;
 615
 616         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 617                 if (!*ptr)
 618                         continue;
 619
 620                 token = match_token(ptr, tokens, args);
 621                 switch (token) {
 622                 case Opt_rd_pages:
 623                         match_int(args, &arg);
 624                         rd_dev->rd_page_count = arg;
 625                         pr_debug("RAMDISK: Referencing Page"
 626                                 " Count: %u\n", rd_dev->rd_page_count);
 627                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 628                         break;
 629                 case Opt_rd_nullio:
 630                         match_int(args, &arg);
 631                         if (arg != 1)
 632                                 break;
 633
 634                         pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 635                         rd_dev->rd_flags |= RDF_NULLIO;
 636                         break;
 637                 default:
 638                         break;
 639                 }
 640         }
 641
 642         kfree(orig);
 643         return (!ret) ? count : ret;
 644 }
 645
 646 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 647 {
 648         struct rd_dev *rd_dev = RD_DEV(dev);
 649
 650         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 651                         rd_dev->rd_dev_id);
 652         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 653                         "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 654                         PAGE_SIZE, rd_dev->sg_table_count,
 655                         !!(rd_dev->rd_flags & RDF_NULLIO));
 656         return bl;
 657 }
 658
 659 static sector_t rd_get_blocks(struct se_device *dev)
 660 {
 661         struct rd_dev *rd_dev = RD_DEV(dev);
 662
 663         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 664                         dev->dev_attrib.block_size) - 1;
 665
 666         return blocks_long;
 667 }
 668
 669 static int rd_init_prot(struct se_device *dev)
 670 {
 671         struct rd_dev *rd_dev = RD_DEV(dev);
 672
 673         if (!dev->dev_attrib.pi_prot_type)
 674                 return 0;
 675
 676         return rd_build_prot_space(rd_dev, dev->prot_length,
 677                                    dev->dev_attrib.block_size);
 678 }
 679
 680 static void rd_free_prot(struct se_device *dev)
 681 {
 682         struct rd_dev *rd_dev = RD_DEV(dev);
 683
 684         rd_release_prot_space(rd_dev);
 685 }
 686
 687 static struct sbc_ops rd_sbc_ops = {
 688         .execute_rw             = rd_execute_rw,
 689 };
 690
 691 static sense_reason_t
 692 rd_parse_cdb(struct se_cmd *cmd)
 693 {
 694         return sbc_parse_cdb(cmd, &rd_sbc_ops);
 695 }
 696
 697 DEF_TB_DEFAULT_ATTRIBS(rd_mcp);
 698
 699 static struct configfs_attribute *rd_mcp_backend_dev_attrs[] = {
 700         &rd_mcp_dev_attrib_emulate_model_alias.attr,
 701         &rd_mcp_dev_attrib_emulate_dpo.attr,
 702         &rd_mcp_dev_attrib_emulate_fua_write.attr,
 703         &rd_mcp_dev_attrib_emulate_fua_read.attr,
 704         &rd_mcp_dev_attrib_emulate_write_cache.attr,
 705         &rd_mcp_dev_attrib_emulate_ua_intlck_ctrl.attr,
 706         &rd_mcp_dev_attrib_emulate_tas.attr,
 707         &rd_mcp_dev_attrib_emulate_tpu.attr,
 708         &rd_mcp_dev_attrib_emulate_tpws.attr,
 709         &rd_mcp_dev_attrib_emulate_caw.attr,
 710         &rd_mcp_dev_attrib_emulate_3pc.attr,
 711         &rd_mcp_dev_attrib_pi_prot_type.attr,
 712         &rd_mcp_dev_attrib_hw_pi_prot_type.attr,
 713         &rd_mcp_dev_attrib_pi_prot_format.attr,
 714         &rd_mcp_dev_attrib_enforce_pr_isids.attr,
 715         &rd_mcp_dev_attrib_is_nonrot.attr,
 716         &rd_mcp_dev_attrib_emulate_rest_reord.attr,
 717         &rd_mcp_dev_attrib_force_pr_aptpl.attr,
 718         &rd_mcp_dev_attrib_hw_block_size.attr,
 719         &rd_mcp_dev_attrib_block_size.attr,
 720         &rd_mcp_dev_attrib_hw_max_sectors.attr,
 721         &rd_mcp_dev_attrib_optimal_sectors.attr,
 722         &rd_mcp_dev_attrib_hw_queue_depth.attr,
 723         &rd_mcp_dev_attrib_queue_depth.attr,
 724         &rd_mcp_dev_attrib_max_unmap_lba_count.attr,
 725         &rd_mcp_dev_attrib_max_unmap_block_desc_count.attr,
 726         &rd_mcp_dev_attrib_unmap_granularity.attr,
 727         &rd_mcp_dev_attrib_unmap_granularity_alignment.attr,
 728         &rd_mcp_dev_attrib_max_write_same_len.attr,
 729         NULL,
 730 };
 731
 732 static struct se_subsystem_api rd_mcp_template = {
 733         .name                   = "rd_mcp",
 734         .inquiry_prod           = "RAMDISK-MCP",
 735         .inquiry_rev            = RD_MCP_VERSION,
 736         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
 737         .attach_hba             = rd_attach_hba,
 738         .detach_hba             = rd_detach_hba,
 739         .alloc_device           = rd_alloc_device,
 740         .configure_device       = rd_configure_device,
 741         .free_device            = rd_free_device,
 742         .parse_cdb              = rd_parse_cdb,
 743         .set_configfs_dev_params = rd_set_configfs_dev_params,
 744         .show_configfs_dev_params = rd_show_configfs_dev_params,
 745         .get_device_type        = sbc_get_device_type,
 746         .get_blocks             = rd_get_blocks,
 747         .init_prot              = rd_init_prot,
 748         .free_prot              = rd_free_prot,
 749 };
 750
 751 int __init rd_module_init(void)
 752 {
 753         struct target_backend_cits *tbc = &rd_mcp_template.tb_cits;
 754         int ret;
 755
 756         target_core_setup_sub_cits(&rd_mcp_template);
 757         tbc->tb_dev_attrib_cit.ct_attrs = rd_mcp_backend_dev_attrs;
 758
 759         ret = transport_subsystem_register(&rd_mcp_template);
 760         if (ret < 0) {
 761                 return ret;
 762         }
 763
 764         return 0;
 765 }
 766
 767 void rd_module_exit(void)
 768 {
 769         transport_subsystem_release(&rd_mcp_template);
 770 }