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 #include <target/target_core_backend_configfs.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 /*      rd_attach_hba(): (Part of se_subsystem_api_t template)
  46  *
  47  *
  48  */
  49 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  50 {
  51         struct rd_host *rd_host;
  52
  53         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
  54         if (!rd_host) {
  55                 pr_err("Unable to allocate memory for struct rd_host\n");
  56                 return -ENOMEM;
  57         }
  58
  59         rd_host->rd_host_id = host_id;
  60
  61         hba->hba_ptr = rd_host;
  62
  63         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  64                 " Generic Target Core Stack %s\n", hba->hba_id,
  65                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
  66
  67         return 0;
  68 }
  69
  70 static void rd_detach_hba(struct se_hba *hba)
  71 {
  72         struct rd_host *rd_host = hba->hba_ptr;
  73
  74         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  75                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  76
  77         kfree(rd_host);
  78         hba->hba_ptr = NULL;
  79 }
  80
  81 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
  82                                  u32 sg_table_count)
  83 {
  84         struct page *pg;
  85         struct scatterlist *sg;
  86         u32 i, j, page_count = 0, sg_per_table;
  87
  88         for (i = 0; i < sg_table_count; i++) {
  89                 sg = sg_table[i].sg_table;
  90                 sg_per_table = sg_table[i].rd_sg_count;
  91
  92                 for (j = 0; j < sg_per_table; j++) {
  93                         pg = sg_page(&sg[j]);
  94                         if (pg) {
  95                                 __free_page(pg);
  96                                 page_count++;
  97                         }
  98                 }
  99                 kfree(sg);
 100         }
 101
 102         kfree(sg_table);
 103         return page_count;
 104 }
 105
 106 static void rd_release_device_space(struct rd_dev *rd_dev)
 107 {
 108         u32 page_count;
 109
 110         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 111                 return;
 112
 113         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
 114                                           rd_dev->sg_table_count);
 115
 116         pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
 117                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 118                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 119                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 120
 121         rd_dev->sg_table_array = NULL;
 122         rd_dev->sg_table_count = 0;
 123 }
 124
 125
 126 /*      rd_build_device_space():
 127  *
 128  *
 129  */
 130 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
 131                                  u32 total_sg_needed, unsigned char init_payload)
 132 {
 133         u32 i = 0, j, page_offset = 0, sg_per_table;
 134         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 135                                 sizeof(struct scatterlist));
 136         struct page *pg;
 137         struct scatterlist *sg;
 138         unsigned char *p;
 139
 140         while (total_sg_needed) {
 141                 unsigned int chain_entry = 0;
 142
 143                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 144                         max_sg_per_table : total_sg_needed;
 145
 146 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 147
 148                 /*
 149                  * Reserve extra element for chain entry
 150                  */
 151                 if (sg_per_table < total_sg_needed)
 152                         chain_entry = 1;
 153
 154 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 155
 156                 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 157                                 GFP_KERNEL);
 158                 if (!sg) {
 159                         pr_err("Unable to allocate scatterlist array"
 160                                 " for struct rd_dev\n");
 161                         return -ENOMEM;
 162                 }
 163
 164                 sg_init_table(sg, sg_per_table + chain_entry);
 165
 166 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
 167
 168                 if (i > 0) {
 169                         sg_chain(sg_table[i - 1].sg_table,
 170                                  max_sg_per_table + 1, sg);
 171                 }
 172
 173 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
 174
 175                 sg_table[i].sg_table = sg;
 176                 sg_table[i].rd_sg_count = sg_per_table;
 177                 sg_table[i].page_start_offset = page_offset;
 178                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 179                                                 - 1;
 180
 181                 for (j = 0; j < sg_per_table; j++) {
 182                         pg = alloc_pages(GFP_KERNEL, 0);
 183                         if (!pg) {
 184                                 pr_err("Unable to allocate scatterlist"
 185                                         " pages for struct rd_dev_sg_table\n");
 186                                 return -ENOMEM;
 187                         }
 188                         sg_assign_page(&sg[j], pg);
 189                         sg[j].length = PAGE_SIZE;
 190
 191                         p = kmap(pg);
 192                         memset(p, init_payload, PAGE_SIZE);
 193                         kunmap(pg);
 194                 }
 195
 196                 page_offset += sg_per_table;
 197                 total_sg_needed -= sg_per_table;
 198         }
 199
 200         return 0;
 201 }
 202
 203 static int rd_build_device_space(struct rd_dev *rd_dev)
 204 {
 205         struct rd_dev_sg_table *sg_table;
 206         u32 sg_tables, total_sg_needed;
 207         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 208                                 sizeof(struct scatterlist));
 209         int rc;
 210
 211         if (rd_dev->rd_page_count <= 0) {
 212                 pr_err("Illegal page count: %u for Ramdisk device\n",
 213                        rd_dev->rd_page_count);
 214                 return -EINVAL;
 215         }
 216
 217         /* Don't need backing pages for NULLIO */
 218         if (rd_dev->rd_flags & RDF_NULLIO)
 219                 return 0;
 220
 221         total_sg_needed = rd_dev->rd_page_count;
 222
 223         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 224
 225         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 226         if (!sg_table) {
 227                 pr_err("Unable to allocate memory for Ramdisk"
 228                        " scatterlist tables\n");
 229                 return -ENOMEM;
 230         }
 231
 232         rd_dev->sg_table_array = sg_table;
 233         rd_dev->sg_table_count = sg_tables;
 234
 235         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 236         if (rc)
 237                 return rc;
 238
 239         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 240                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 241                  rd_dev->rd_dev_id, rd_dev->rd_page_count,
 242                  rd_dev->sg_table_count);
 243
 244         return 0;
 245 }
 246
 247 static void rd_release_prot_space(struct rd_dev *rd_dev)
 248 {
 249         u32 page_count;
 250
 251         if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 252                 return;
 253
 254         page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 255                                           rd_dev->sg_prot_count);
 256
 257         pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 258                  " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 259                  rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 260                  rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 261
 262         rd_dev->sg_prot_array = NULL;
 263         rd_dev->sg_prot_count = 0;
 264 }
 265
 266 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 267 {
 268         struct rd_dev_sg_table *sg_table;
 269         u32 total_sg_needed, sg_tables;
 270         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 271                                 sizeof(struct scatterlist));
 272         int rc;
 273
 274         if (rd_dev->rd_flags & RDF_NULLIO)
 275                 return 0;
 276         /*
 277          * prot_length=8byte dif data
 278          * tot sg needed = rd_page_count * (PGSZ/block_size) *
 279          *                 (prot_length/block_size) + pad
 280          * PGSZ canceled each other.
 281          */
 282         total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 283
 284         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 285
 286         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 287         if (!sg_table) {
 288                 pr_err("Unable to allocate memory for Ramdisk protection"
 289                        " scatterlist tables\n");
 290                 return -ENOMEM;
 291         }
 292
 293         rd_dev->sg_prot_array = sg_table;
 294         rd_dev->sg_prot_count = sg_tables;
 295
 296         rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 297         if (rc)
 298                 return rc;
 299
 300         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 301                  " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 302                  rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 303
 304         return 0;
 305 }
 306
 307 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 308 {
 309         struct rd_dev *rd_dev;
 310         struct rd_host *rd_host = hba->hba_ptr;
 311
 312         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 313         if (!rd_dev) {
 314                 pr_err("Unable to allocate memory for struct rd_dev\n");
 315                 return NULL;
 316         }
 317
 318         rd_dev->rd_host = rd_host;
 319
 320         return &rd_dev->dev;
 321 }
 322
 323 static int rd_configure_device(struct se_device *dev)
 324 {
 325         struct rd_dev *rd_dev = RD_DEV(dev);
 326         struct rd_host *rd_host = dev->se_hba->hba_ptr;
 327         int ret;
 328
 329         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 330                 pr_debug("Missing rd_pages= parameter\n");
 331                 return -EINVAL;
 332         }
 333
 334         ret = rd_build_device_space(rd_dev);
 335         if (ret < 0)
 336                 goto fail;
 337
 338         dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 339         dev->dev_attrib.hw_max_sectors = UINT_MAX;
 340         dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 341
 342         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 343
 344         pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 345                 " %u pages in %u tables, %lu total bytes\n",
 346                 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 347                 rd_dev->sg_table_count,
 348                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 349
 350         return 0;
 351
 352 fail:
 353         rd_release_device_space(rd_dev);
 354         return ret;
 355 }
 356
 357 static void rd_free_device(struct se_device *dev)
 358 {
 359         struct rd_dev *rd_dev = RD_DEV(dev);
 360
 361         rd_release_device_space(rd_dev);
 362         kfree(rd_dev);
 363 }
 364
 365 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 366 {
 367         struct rd_dev_sg_table *sg_table;
 368         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 369                                 sizeof(struct scatterlist));
 370
 371         i = page / sg_per_table;
 372         if (i < rd_dev->sg_table_count) {
 373                 sg_table = &rd_dev->sg_table_array[i];
 374                 if ((sg_table->page_start_offset <= page) &&
 375                     (sg_table->page_end_offset >= page))
 376                         return sg_table;
 377         }
 378
 379         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
 380                         page);
 381
 382         return NULL;
 383 }
 384
 385 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
 386 {
 387         struct rd_dev_sg_table *sg_table;
 388         u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 389                                 sizeof(struct scatterlist));
 390
 391         i = page / sg_per_table;
 392         if (i < rd_dev->sg_prot_count) {
 393                 sg_table = &rd_dev->sg_prot_array[i];
 394                 if ((sg_table->page_start_offset <= page) &&
 395                      (sg_table->page_end_offset >= page))
 396                         return sg_table;
 397         }
 398
 399         pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
 400                         page);
 401
 402         return NULL;
 403 }
 404
 405 typedef sense_reason_t (*dif_verify)(struct se_cmd *, sector_t, unsigned int,
 406                                      unsigned int, struct scatterlist *, int);
 407
 408 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify)
 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         rc = dif_verify(cmd, cmd->t_task_lba, sectors, 0, prot_sg, prot_offset);
 469         if (need_to_release)
 470                 kfree(prot_sg);
 471
 472         return rc;
 473 }
 474
 475 static sense_reason_t
 476 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 477               enum dma_data_direction data_direction)
 478 {
 479         struct se_device *se_dev = cmd->se_dev;
 480         struct rd_dev *dev = RD_DEV(se_dev);
 481         struct rd_dev_sg_table *table;
 482         struct scatterlist *rd_sg;
 483         struct sg_mapping_iter m;
 484         u32 rd_offset;
 485         u32 rd_size;
 486         u32 rd_page;
 487         u32 src_len;
 488         u64 tmp;
 489         sense_reason_t rc;
 490
 491         if (dev->rd_flags & RDF_NULLIO) {
 492                 target_complete_cmd(cmd, SAM_STAT_GOOD);
 493                 return 0;
 494         }
 495
 496         tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 497         rd_offset = do_div(tmp, PAGE_SIZE);
 498         rd_page = tmp;
 499         rd_size = cmd->data_length;
 500
 501         table = rd_get_sg_table(dev, rd_page);
 502         if (!table)
 503                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 504
 505         rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 506
 507         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 508                         dev->rd_dev_id,
 509                         data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 510                         cmd->t_task_lba, rd_size, rd_page, rd_offset);
 511
 512         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 513             data_direction == DMA_TO_DEVICE) {
 514                 rc = rd_do_prot_rw(cmd, sbc_dif_verify_write);
 515                 if (rc)
 516                         return rc;
 517         }
 518
 519         src_len = PAGE_SIZE - rd_offset;
 520         sg_miter_start(&m, sgl, sgl_nents,
 521                         data_direction == DMA_FROM_DEVICE ?
 522                                 SG_MITER_TO_SG : SG_MITER_FROM_SG);
 523         while (rd_size) {
 524                 u32 len;
 525                 void *rd_addr;
 526
 527                 sg_miter_next(&m);
 528                 if (!(u32)m.length) {
 529                         pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 530                                  dev->rd_dev_id, m.addr, m.length);
 531                         sg_miter_stop(&m);
 532                         return TCM_INCORRECT_AMOUNT_OF_DATA;
 533                 }
 534                 len = min((u32)m.length, src_len);
 535                 if (len > rd_size) {
 536                         pr_debug("RD[%u]: size underrun page %d offset %d "
 537                                  "size %d\n", dev->rd_dev_id,
 538                                  rd_page, rd_offset, rd_size);
 539                         len = rd_size;
 540                 }
 541                 m.consumed = len;
 542
 543                 rd_addr = sg_virt(rd_sg) + rd_offset;
 544
 545                 if (data_direction == DMA_FROM_DEVICE)
 546                         memcpy(m.addr, rd_addr, len);
 547                 else
 548                         memcpy(rd_addr, m.addr, len);
 549
 550                 rd_size -= len;
 551                 if (!rd_size)
 552                         continue;
 553
 554                 src_len -= len;
 555                 if (src_len) {
 556                         rd_offset += len;
 557                         continue;
 558                 }
 559
 560                 /* rd page completed, next one please */
 561                 rd_page++;
 562                 rd_offset = 0;
 563                 src_len = PAGE_SIZE;
 564                 if (rd_page <= table->page_end_offset) {
 565                         rd_sg++;
 566                         continue;
 567                 }
 568
 569                 table = rd_get_sg_table(dev, rd_page);
 570                 if (!table) {
 571                         sg_miter_stop(&m);
 572                         return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 573                 }
 574
 575                 /* since we increment, the first sg entry is correct */
 576                 rd_sg = table->sg_table;
 577         }
 578         sg_miter_stop(&m);
 579
 580         if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 581             data_direction == DMA_FROM_DEVICE) {
 582                 rc = rd_do_prot_rw(cmd, sbc_dif_verify_read);
 583                 if (rc)
 584                         return rc;
 585         }
 586
 587         target_complete_cmd(cmd, SAM_STAT_GOOD);
 588         return 0;
 589 }
 590
 591 enum {
 592         Opt_rd_pages, Opt_rd_nullio, Opt_err
 593 };
 594
 595 static match_table_t tokens = {
 596         {Opt_rd_pages, "rd_pages=%d"},
 597         {Opt_rd_nullio, "rd_nullio=%d"},
 598         {Opt_err, NULL}
 599 };
 600
 601 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 602                 const char *page, ssize_t count)
 603 {
 604         struct rd_dev *rd_dev = RD_DEV(dev);
 605         char *orig, *ptr, *opts;
 606         substring_t args[MAX_OPT_ARGS];
 607         int ret = 0, arg, token;
 608
 609         opts = kstrdup(page, GFP_KERNEL);
 610         if (!opts)
 611                 return -ENOMEM;
 612
 613         orig = opts;
 614
 615         while ((ptr = strsep(&opts, ",\n")) != NULL) {
 616                 if (!*ptr)
 617                         continue;
 618
 619                 token = match_token(ptr, tokens, args);
 620                 switch (token) {
 621                 case Opt_rd_pages:
 622                         match_int(args, &arg);
 623                         rd_dev->rd_page_count = arg;
 624                         pr_debug("RAMDISK: Referencing Page"
 625                                 " Count: %u\n", rd_dev->rd_page_count);
 626                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 627                         break;
 628                 case Opt_rd_nullio:
 629                         match_int(args, &arg);
 630                         if (arg != 1)
 631                                 break;
 632
 633                         pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 634                         rd_dev->rd_flags |= RDF_NULLIO;
 635                         break;
 636                 default:
 637                         break;
 638                 }
 639         }
 640
 641         kfree(orig);
 642         return (!ret) ? count : ret;
 643 }
 644
 645 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 646 {
 647         struct rd_dev *rd_dev = RD_DEV(dev);
 648
 649         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 650                         rd_dev->rd_dev_id);
 651         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 652                         "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 653                         PAGE_SIZE, rd_dev->sg_table_count,
 654                         !!(rd_dev->rd_flags & RDF_NULLIO));
 655         return bl;
 656 }
 657
 658 static sector_t rd_get_blocks(struct se_device *dev)
 659 {
 660         struct rd_dev *rd_dev = RD_DEV(dev);
 661
 662         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 663                         dev->dev_attrib.block_size) - 1;
 664
 665         return blocks_long;
 666 }
 667
 668 static int rd_init_prot(struct se_device *dev)
 669 {
 670         struct rd_dev *rd_dev = RD_DEV(dev);
 671
 672         if (!dev->dev_attrib.pi_prot_type)
 673                 return 0;
 674
 675         return rd_build_prot_space(rd_dev, dev->prot_length,
 676                                    dev->dev_attrib.block_size);
 677 }
 678
 679 static void rd_free_prot(struct se_device *dev)
 680 {
 681         struct rd_dev *rd_dev = RD_DEV(dev);
 682
 683         rd_release_prot_space(rd_dev);
 684 }
 685
 686 static struct sbc_ops rd_sbc_ops = {
 687         .execute_rw             = rd_execute_rw,
 688 };
 689
 690 static sense_reason_t
 691 rd_parse_cdb(struct se_cmd *cmd)
 692 {
 693         return sbc_parse_cdb(cmd, &rd_sbc_ops);
 694 }
 695
 696 DEF_TB_DEFAULT_ATTRIBS(rd_mcp);
 697
 698 static struct configfs_attribute *rd_mcp_backend_dev_attrs[] = {
 699         &rd_mcp_dev_attrib_emulate_model_alias.attr,
 700         &rd_mcp_dev_attrib_emulate_dpo.attr,
 701         &rd_mcp_dev_attrib_emulate_fua_write.attr,
 702         &rd_mcp_dev_attrib_emulate_fua_read.attr,
 703         &rd_mcp_dev_attrib_emulate_write_cache.attr,
 704         &rd_mcp_dev_attrib_emulate_ua_intlck_ctrl.attr,
 705         &rd_mcp_dev_attrib_emulate_tas.attr,
 706         &rd_mcp_dev_attrib_emulate_tpu.attr,
 707         &rd_mcp_dev_attrib_emulate_tpws.attr,
 708         &rd_mcp_dev_attrib_emulate_caw.attr,
 709         &rd_mcp_dev_attrib_emulate_3pc.attr,
 710         &rd_mcp_dev_attrib_pi_prot_type.attr,
 711         &rd_mcp_dev_attrib_hw_pi_prot_type.attr,
 712         &rd_mcp_dev_attrib_pi_prot_format.attr,
 713         &rd_mcp_dev_attrib_enforce_pr_isids.attr,
 714         &rd_mcp_dev_attrib_is_nonrot.attr,
 715         &rd_mcp_dev_attrib_emulate_rest_reord.attr,
 716         &rd_mcp_dev_attrib_force_pr_aptpl.attr,
 717         &rd_mcp_dev_attrib_hw_block_size.attr,
 718         &rd_mcp_dev_attrib_block_size.attr,
 719         &rd_mcp_dev_attrib_hw_max_sectors.attr,
 720         &rd_mcp_dev_attrib_optimal_sectors.attr,
 721         &rd_mcp_dev_attrib_hw_queue_depth.attr,
 722         &rd_mcp_dev_attrib_queue_depth.attr,
 723         &rd_mcp_dev_attrib_max_unmap_lba_count.attr,
 724         &rd_mcp_dev_attrib_max_unmap_block_desc_count.attr,
 725         &rd_mcp_dev_attrib_unmap_granularity.attr,
 726         &rd_mcp_dev_attrib_unmap_granularity_alignment.attr,
 727         &rd_mcp_dev_attrib_max_write_same_len.attr,
 728         NULL,
 729 };
 730
 731 static struct se_subsystem_api rd_mcp_template = {
 732         .name                   = "rd_mcp",
 733         .inquiry_prod           = "RAMDISK-MCP",
 734         .inquiry_rev            = RD_MCP_VERSION,
 735         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
 736         .attach_hba             = rd_attach_hba,
 737         .detach_hba             = rd_detach_hba,
 738         .alloc_device           = rd_alloc_device,
 739         .configure_device       = rd_configure_device,
 740         .free_device            = rd_free_device,
 741         .parse_cdb              = rd_parse_cdb,
 742         .set_configfs_dev_params = rd_set_configfs_dev_params,
 743         .show_configfs_dev_params = rd_show_configfs_dev_params,
 744         .get_device_type        = sbc_get_device_type,
 745         .get_blocks             = rd_get_blocks,
 746         .init_prot              = rd_init_prot,
 747         .free_prot              = rd_free_prot,
 748 };
 749
 750 int __init rd_module_init(void)
 751 {
 752         struct target_backend_cits *tbc = &rd_mcp_template.tb_cits;
 753         int ret;
 754
 755         target_core_setup_sub_cits(&rd_mcp_template);
 756         tbc->tb_dev_attrib_cit.ct_attrs = rd_mcp_backend_dev_attrs;
 757
 758         ret = transport_subsystem_register(&rd_mcp_template);
 759         if (ret < 0) {
 760                 return ret;
 761         }
 762
 763         return 0;
 764 }
 765
 766 void rd_module_exit(void)
 767 {
 768         transport_subsystem_release(&rd_mcp_template);
 769 }