linux/drivers/target/target_core_rd.c
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   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
  39static inline struct rd_dev *RD_DEV(struct se_device *dev)
  40{
  41        return container_of(dev, struct rd_dev, dev);
  42}
  43
  44static 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
  65static 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
  76static 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
 101static 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 */
 125static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
 126                                 u32 total_sg_needed, unsigned char init_payload)
 127{
 128        u32 i = 0, j, page_offset = 0, sg_per_table;
 129        u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 130                                sizeof(struct scatterlist));
 131        struct page *pg;
 132        struct scatterlist *sg;
 133        unsigned char *p;
 134
 135        while (total_sg_needed) {
 136                unsigned int chain_entry = 0;
 137
 138                sg_per_table = (total_sg_needed > max_sg_per_table) ?
 139                        max_sg_per_table : total_sg_needed;
 140
 141                /*
 142                 * Reserve extra element for chain entry
 143                 */
 144                if (sg_per_table < total_sg_needed)
 145                        chain_entry = 1;
 146
 147                sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
 148                                GFP_KERNEL);
 149                if (!sg) {
 150                        pr_err("Unable to allocate scatterlist array"
 151                                " for struct rd_dev\n");
 152                        return -ENOMEM;
 153                }
 154
 155                sg_init_table(sg, sg_per_table + chain_entry);
 156
 157                if (i > 0) {
 158                        sg_chain(sg_table[i - 1].sg_table,
 159                                 max_sg_per_table + 1, sg);
 160                }
 161
 162                sg_table[i].sg_table = sg;
 163                sg_table[i].rd_sg_count = sg_per_table;
 164                sg_table[i].page_start_offset = page_offset;
 165                sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 166                                                - 1;
 167
 168                for (j = 0; j < sg_per_table; j++) {
 169                        pg = alloc_pages(GFP_KERNEL, 0);
 170                        if (!pg) {
 171                                pr_err("Unable to allocate scatterlist"
 172                                        " pages for struct rd_dev_sg_table\n");
 173                                return -ENOMEM;
 174                        }
 175                        sg_assign_page(&sg[j], pg);
 176                        sg[j].length = PAGE_SIZE;
 177
 178                        p = kmap(pg);
 179                        memset(p, init_payload, PAGE_SIZE);
 180                        kunmap(pg);
 181                }
 182
 183                page_offset += sg_per_table;
 184                total_sg_needed -= sg_per_table;
 185        }
 186
 187        return 0;
 188}
 189
 190static int rd_build_device_space(struct rd_dev *rd_dev)
 191{
 192        struct rd_dev_sg_table *sg_table;
 193        u32 sg_tables, total_sg_needed;
 194        u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 195                                sizeof(struct scatterlist));
 196        int rc;
 197
 198        if (rd_dev->rd_page_count <= 0) {
 199                pr_err("Illegal page count: %u for Ramdisk device\n",
 200                       rd_dev->rd_page_count);
 201                return -EINVAL;
 202        }
 203
 204        /* Don't need backing pages for NULLIO */
 205        if (rd_dev->rd_flags & RDF_NULLIO)
 206                return 0;
 207
 208        total_sg_needed = rd_dev->rd_page_count;
 209
 210        sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 211
 212        sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 213        if (!sg_table) {
 214                pr_err("Unable to allocate memory for Ramdisk"
 215                       " scatterlist tables\n");
 216                return -ENOMEM;
 217        }
 218
 219        rd_dev->sg_table_array = sg_table;
 220        rd_dev->sg_table_count = sg_tables;
 221
 222        rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
 223        if (rc)
 224                return rc;
 225
 226        pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 227                 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 228                 rd_dev->rd_dev_id, rd_dev->rd_page_count,
 229                 rd_dev->sg_table_count);
 230
 231        return 0;
 232}
 233
 234static void rd_release_prot_space(struct rd_dev *rd_dev)
 235{
 236        u32 page_count;
 237
 238        if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
 239                return;
 240
 241        page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
 242                                          rd_dev->sg_prot_count);
 243
 244        pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
 245                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 246                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 247                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 248
 249        rd_dev->sg_prot_array = NULL;
 250        rd_dev->sg_prot_count = 0;
 251}
 252
 253static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
 254{
 255        struct rd_dev_sg_table *sg_table;
 256        u32 total_sg_needed, sg_tables;
 257        u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 258                                sizeof(struct scatterlist));
 259        int rc;
 260
 261        if (rd_dev->rd_flags & RDF_NULLIO)
 262                return 0;
 263        /*
 264         * prot_length=8byte dif data
 265         * tot sg needed = rd_page_count * (PGSZ/block_size) *
 266         *                 (prot_length/block_size) + pad
 267         * PGSZ canceled each other.
 268         */
 269        total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
 270
 271        sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 272
 273        sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 274        if (!sg_table) {
 275                pr_err("Unable to allocate memory for Ramdisk protection"
 276                       " scatterlist tables\n");
 277                return -ENOMEM;
 278        }
 279
 280        rd_dev->sg_prot_array = sg_table;
 281        rd_dev->sg_prot_count = sg_tables;
 282
 283        rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
 284        if (rc)
 285                return rc;
 286
 287        pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
 288                 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 289                 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
 290
 291        return 0;
 292}
 293
 294static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
 295{
 296        struct rd_dev *rd_dev;
 297        struct rd_host *rd_host = hba->hba_ptr;
 298
 299        rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 300        if (!rd_dev) {
 301                pr_err("Unable to allocate memory for struct rd_dev\n");
 302                return NULL;
 303        }
 304
 305        rd_dev->rd_host = rd_host;
 306
 307        return &rd_dev->dev;
 308}
 309
 310static int rd_configure_device(struct se_device *dev)
 311{
 312        struct rd_dev *rd_dev = RD_DEV(dev);
 313        struct rd_host *rd_host = dev->se_hba->hba_ptr;
 314        int ret;
 315
 316        if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 317                pr_debug("Missing rd_pages= parameter\n");
 318                return -EINVAL;
 319        }
 320
 321        ret = rd_build_device_space(rd_dev);
 322        if (ret < 0)
 323                goto fail;
 324
 325        dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
 326        dev->dev_attrib.hw_max_sectors = UINT_MAX;
 327        dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 328        dev->dev_attrib.is_nonrot = 1;
 329
 330        rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 331
 332        pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
 333                " %u pages in %u tables, %lu total bytes\n",
 334                rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
 335                rd_dev->sg_table_count,
 336                (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 337
 338        return 0;
 339
 340fail:
 341        rd_release_device_space(rd_dev);
 342        return ret;
 343}
 344
 345static void rd_dev_call_rcu(struct rcu_head *p)
 346{
 347        struct se_device *dev = container_of(p, struct se_device, rcu_head);
 348        struct rd_dev *rd_dev = RD_DEV(dev);
 349
 350        kfree(rd_dev);
 351}
 352
 353static void rd_free_device(struct se_device *dev)
 354{
 355        struct rd_dev *rd_dev = RD_DEV(dev);
 356
 357        rd_release_device_space(rd_dev);
 358        call_rcu(&dev->rcu_head, rd_dev_call_rcu);
 359}
 360
 361static 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
 381static 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
 401static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
 402{
 403        struct se_device *se_dev = cmd->se_dev;
 404        struct rd_dev *dev = RD_DEV(se_dev);
 405        struct rd_dev_sg_table *prot_table;
 406        struct scatterlist *prot_sg;
 407        u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
 408        u32 prot_offset, prot_page;
 409        u32 prot_npages __maybe_unused;
 410        u64 tmp;
 411        sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 412
 413        tmp = cmd->t_task_lba * se_dev->prot_length;
 414        prot_offset = do_div(tmp, PAGE_SIZE);
 415        prot_page = tmp;
 416
 417        prot_table = rd_get_prot_table(dev, prot_page);
 418        if (!prot_table)
 419                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 420
 421        prot_sg = &prot_table->sg_table[prot_page -
 422                                        prot_table->page_start_offset];
 423
 424        if (is_read)
 425                rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 426                                    prot_sg, prot_offset);
 427        else
 428                rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
 429                                    cmd->t_prot_sg, 0);
 430
 431        if (!rc)
 432                sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
 433
 434        return rc;
 435}
 436
 437static sense_reason_t
 438rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
 439              enum dma_data_direction data_direction)
 440{
 441        struct se_device *se_dev = cmd->se_dev;
 442        struct rd_dev *dev = RD_DEV(se_dev);
 443        struct rd_dev_sg_table *table;
 444        struct scatterlist *rd_sg;
 445        struct sg_mapping_iter m;
 446        u32 rd_offset;
 447        u32 rd_size;
 448        u32 rd_page;
 449        u32 src_len;
 450        u64 tmp;
 451        sense_reason_t rc;
 452
 453        if (dev->rd_flags & RDF_NULLIO) {
 454                target_complete_cmd(cmd, SAM_STAT_GOOD);
 455                return 0;
 456        }
 457
 458        tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
 459        rd_offset = do_div(tmp, PAGE_SIZE);
 460        rd_page = tmp;
 461        rd_size = cmd->data_length;
 462
 463        table = rd_get_sg_table(dev, rd_page);
 464        if (!table)
 465                return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 466
 467        rd_sg = &table->sg_table[rd_page - table->page_start_offset];
 468
 469        pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 470                        dev->rd_dev_id,
 471                        data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
 472                        cmd->t_task_lba, rd_size, rd_page, rd_offset);
 473
 474        if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 475            data_direction == DMA_TO_DEVICE) {
 476                rc = rd_do_prot_rw(cmd, false);
 477                if (rc)
 478                        return rc;
 479        }
 480
 481        src_len = PAGE_SIZE - rd_offset;
 482        sg_miter_start(&m, sgl, sgl_nents,
 483                        data_direction == DMA_FROM_DEVICE ?
 484                                SG_MITER_TO_SG : SG_MITER_FROM_SG);
 485        while (rd_size) {
 486                u32 len;
 487                void *rd_addr;
 488
 489                sg_miter_next(&m);
 490                if (!(u32)m.length) {
 491                        pr_debug("RD[%u]: invalid sgl %p len %zu\n",
 492                                 dev->rd_dev_id, m.addr, m.length);
 493                        sg_miter_stop(&m);
 494                        return TCM_INCORRECT_AMOUNT_OF_DATA;
 495                }
 496                len = min((u32)m.length, src_len);
 497                if (len > rd_size) {
 498                        pr_debug("RD[%u]: size underrun page %d offset %d "
 499                                 "size %d\n", dev->rd_dev_id,
 500                                 rd_page, rd_offset, rd_size);
 501                        len = rd_size;
 502                }
 503                m.consumed = len;
 504
 505                rd_addr = sg_virt(rd_sg) + rd_offset;
 506
 507                if (data_direction == DMA_FROM_DEVICE)
 508                        memcpy(m.addr, rd_addr, len);
 509                else
 510                        memcpy(rd_addr, m.addr, len);
 511
 512                rd_size -= len;
 513                if (!rd_size)
 514                        continue;
 515
 516                src_len -= len;
 517                if (src_len) {
 518                        rd_offset += len;
 519                        continue;
 520                }
 521
 522                /* rd page completed, next one please */
 523                rd_page++;
 524                rd_offset = 0;
 525                src_len = PAGE_SIZE;
 526                if (rd_page <= table->page_end_offset) {
 527                        rd_sg++;
 528                        continue;
 529                }
 530
 531                table = rd_get_sg_table(dev, rd_page);
 532                if (!table) {
 533                        sg_miter_stop(&m);
 534                        return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 535                }
 536
 537                /* since we increment, the first sg entry is correct */
 538                rd_sg = table->sg_table;
 539        }
 540        sg_miter_stop(&m);
 541
 542        if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
 543            data_direction == DMA_FROM_DEVICE) {
 544                rc = rd_do_prot_rw(cmd, true);
 545                if (rc)
 546                        return rc;
 547        }
 548
 549        target_complete_cmd(cmd, SAM_STAT_GOOD);
 550        return 0;
 551}
 552
 553enum {
 554        Opt_rd_pages, Opt_rd_nullio, Opt_err
 555};
 556
 557static match_table_t tokens = {
 558        {Opt_rd_pages, "rd_pages=%d"},
 559        {Opt_rd_nullio, "rd_nullio=%d"},
 560        {Opt_err, NULL}
 561};
 562
 563static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
 564                const char *page, ssize_t count)
 565{
 566        struct rd_dev *rd_dev = RD_DEV(dev);
 567        char *orig, *ptr, *opts;
 568        substring_t args[MAX_OPT_ARGS];
 569        int ret = 0, arg, token;
 570
 571        opts = kstrdup(page, GFP_KERNEL);
 572        if (!opts)
 573                return -ENOMEM;
 574
 575        orig = opts;
 576
 577        while ((ptr = strsep(&opts, ",\n")) != NULL) {
 578                if (!*ptr)
 579                        continue;
 580
 581                token = match_token(ptr, tokens, args);
 582                switch (token) {
 583                case Opt_rd_pages:
 584                        match_int(args, &arg);
 585                        rd_dev->rd_page_count = arg;
 586                        pr_debug("RAMDISK: Referencing Page"
 587                                " Count: %u\n", rd_dev->rd_page_count);
 588                        rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 589                        break;
 590                case Opt_rd_nullio:
 591                        match_int(args, &arg);
 592                        if (arg != 1)
 593                                break;
 594
 595                        pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
 596                        rd_dev->rd_flags |= RDF_NULLIO;
 597                        break;
 598                default:
 599                        break;
 600                }
 601        }
 602
 603        kfree(orig);
 604        return (!ret) ? count : ret;
 605}
 606
 607static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
 608{
 609        struct rd_dev *rd_dev = RD_DEV(dev);
 610
 611        ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
 612                        rd_dev->rd_dev_id);
 613        bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 614                        "  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
 615                        PAGE_SIZE, rd_dev->sg_table_count,
 616                        !!(rd_dev->rd_flags & RDF_NULLIO));
 617        return bl;
 618}
 619
 620static sector_t rd_get_blocks(struct se_device *dev)
 621{
 622        struct rd_dev *rd_dev = RD_DEV(dev);
 623
 624        unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 625                        dev->dev_attrib.block_size) - 1;
 626
 627        return blocks_long;
 628}
 629
 630static int rd_init_prot(struct se_device *dev)
 631{
 632        struct rd_dev *rd_dev = RD_DEV(dev);
 633
 634        if (!dev->dev_attrib.pi_prot_type)
 635                return 0;
 636
 637        return rd_build_prot_space(rd_dev, dev->prot_length,
 638                                   dev->dev_attrib.block_size);
 639}
 640
 641static void rd_free_prot(struct se_device *dev)
 642{
 643        struct rd_dev *rd_dev = RD_DEV(dev);
 644
 645        rd_release_prot_space(rd_dev);
 646}
 647
 648static struct sbc_ops rd_sbc_ops = {
 649        .execute_rw             = rd_execute_rw,
 650};
 651
 652static sense_reason_t
 653rd_parse_cdb(struct se_cmd *cmd)
 654{
 655        return sbc_parse_cdb(cmd, &rd_sbc_ops);
 656}
 657
 658static const struct target_backend_ops rd_mcp_ops = {
 659        .name                   = "rd_mcp",
 660        .inquiry_prod           = "RAMDISK-MCP",
 661        .inquiry_rev            = RD_MCP_VERSION,
 662        .attach_hba             = rd_attach_hba,
 663        .detach_hba             = rd_detach_hba,
 664        .alloc_device           = rd_alloc_device,
 665        .configure_device       = rd_configure_device,
 666        .free_device            = rd_free_device,
 667        .parse_cdb              = rd_parse_cdb,
 668        .set_configfs_dev_params = rd_set_configfs_dev_params,
 669        .show_configfs_dev_params = rd_show_configfs_dev_params,
 670        .get_device_type        = sbc_get_device_type,
 671        .get_blocks             = rd_get_blocks,
 672        .init_prot              = rd_init_prot,
 673        .free_prot              = rd_free_prot,
 674        .tb_dev_attrib_attrs    = sbc_attrib_attrs,
 675};
 676
 677int __init rd_module_init(void)
 678{
 679        return transport_backend_register(&rd_mcp_ops);
 680}
 681
 682void rd_module_exit(void)
 683{
 684        target_backend_unregister(&rd_mcp_ops);
 685}
 686