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  * Copyright (c) 2003, 2004, 2005 PyX Technologies, Inc.
   8  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
   9  * Copyright (c) 2007-2010 Rising Tide Systems
  10  * Copyright (c) 2008-2010 Linux-iSCSI.org
  11  *
  12  * Nicholas A. Bellinger <nab@kernel.org>
  13  *
  14  * This program is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  *
  28  ******************************************************************************/
  29
  30 #include <linux/version.h>
  31 #include <linux/string.h>
  32 #include <linux/parser.h>
  33 #include <linux/timer.h>
  34 #include <linux/blkdev.h>
  35 #include <linux/slab.h>
  36 #include <linux/spinlock.h>
  37 #include <scsi/scsi.h>
  38 #include <scsi/scsi_host.h>
  39
  40 #include <target/target_core_base.h>
  41 #include <target/target_core_device.h>
  42 #include <target/target_core_transport.h>
  43 #include <target/target_core_fabric_ops.h>
  44
  45 #include "target_core_rd.h"
  46
  47 static struct se_subsystem_api rd_mcp_template;
  48
  49 /*      rd_attach_hba(): (Part of se_subsystem_api_t template)
  50  *
  51  *
  52  */
  53 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  54 {
  55         struct rd_host *rd_host;
  56
  57         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
  58         if (!rd_host) {
  59                 pr_err("Unable to allocate memory for struct rd_host\n");
  60                 return -ENOMEM;
  61         }
  62
  63         rd_host->rd_host_id = host_id;
  64
  65         hba->hba_ptr = rd_host;
  66
  67         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  68                 " Generic Target Core Stack %s\n", hba->hba_id,
  69                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
  70         pr_debug("CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
  71                 " MaxSectors: %u\n", hba->hba_id,
  72                 rd_host->rd_host_id, RD_MAX_SECTORS);
  73
  74         return 0;
  75 }
  76
  77 static void rd_detach_hba(struct se_hba *hba)
  78 {
  79         struct rd_host *rd_host = hba->hba_ptr;
  80
  81         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  82                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  83
  84         kfree(rd_host);
  85         hba->hba_ptr = NULL;
  86 }
  87
  88 /*      rd_release_device_space():
  89  *
  90  *
  91  */
  92 static void rd_release_device_space(struct rd_dev *rd_dev)
  93 {
  94         u32 i, j, page_count = 0, sg_per_table;
  95         struct rd_dev_sg_table *sg_table;
  96         struct page *pg;
  97         struct scatterlist *sg;
  98
  99         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 100                 return;
 101
 102         sg_table = rd_dev->sg_table_array;
 103
 104         for (i = 0; i < rd_dev->sg_table_count; i++) {
 105                 sg = sg_table[i].sg_table;
 106                 sg_per_table = sg_table[i].rd_sg_count;
 107
 108                 for (j = 0; j < sg_per_table; j++) {
 109                         pg = sg_page(&sg[j]);
 110                         if (pg) {
 111                                 __free_page(pg);
 112                                 page_count++;
 113                         }
 114                 }
 115
 116                 kfree(sg);
 117         }
 118
 119         pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
 120                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 121                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 122                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 123
 124         kfree(sg_table);
 125         rd_dev->sg_table_array = NULL;
 126         rd_dev->sg_table_count = 0;
 127 }
 128
 129
 130 /*      rd_build_device_space():
 131  *
 132  *
 133  */
 134 static int rd_build_device_space(struct rd_dev *rd_dev)
 135 {
 136         u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
 137         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 138                                 sizeof(struct scatterlist));
 139         struct rd_dev_sg_table *sg_table;
 140         struct page *pg;
 141         struct scatterlist *sg;
 142
 143         if (rd_dev->rd_page_count <= 0) {
 144                 pr_err("Illegal page count: %u for Ramdisk device\n",
 145                         rd_dev->rd_page_count);
 146                 return -EINVAL;
 147         }
 148         total_sg_needed = rd_dev->rd_page_count;
 149
 150         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 151
 152         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 153         if (!sg_table) {
 154                 pr_err("Unable to allocate memory for Ramdisk"
 155                         " scatterlist tables\n");
 156                 return -ENOMEM;
 157         }
 158
 159         rd_dev->sg_table_array = sg_table;
 160         rd_dev->sg_table_count = sg_tables;
 161
 162         while (total_sg_needed) {
 163                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 164                         max_sg_per_table : total_sg_needed;
 165
 166                 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
 167                                 GFP_KERNEL);
 168                 if (!sg) {
 169                         pr_err("Unable to allocate scatterlist array"
 170                                 " for struct rd_dev\n");
 171                         return -ENOMEM;
 172                 }
 173
 174                 sg_init_table(sg, sg_per_table);
 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
 193                 page_offset += sg_per_table;
 194                 total_sg_needed -= sg_per_table;
 195         }
 196
 197         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 198                 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 199                 rd_dev->rd_dev_id, rd_dev->rd_page_count,
 200                 rd_dev->sg_table_count);
 201
 202         return 0;
 203 }
 204
 205 static void *rd_allocate_virtdevice(
 206         struct se_hba *hba,
 207         const char *name,
 208         int rd_direct)
 209 {
 210         struct rd_dev *rd_dev;
 211         struct rd_host *rd_host = hba->hba_ptr;
 212
 213         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 214         if (!rd_dev) {
 215                 pr_err("Unable to allocate memory for struct rd_dev\n");
 216                 return NULL;
 217         }
 218
 219         rd_dev->rd_host = rd_host;
 220         rd_dev->rd_direct = rd_direct;
 221
 222         return rd_dev;
 223 }
 224
 225 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba *hba, const char *name)
 226 {
 227         return rd_allocate_virtdevice(hba, name, 0);
 228 }
 229
 230 /*      rd_create_virtdevice():
 231  *
 232  *
 233  */
 234 static struct se_device *rd_create_virtdevice(
 235         struct se_hba *hba,
 236         struct se_subsystem_dev *se_dev,
 237         void *p,
 238         int rd_direct)
 239 {
 240         struct se_device *dev;
 241         struct se_dev_limits dev_limits;
 242         struct rd_dev *rd_dev = p;
 243         struct rd_host *rd_host = hba->hba_ptr;
 244         int dev_flags = 0, ret;
 245         char prod[16], rev[4];
 246
 247         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 248
 249         ret = rd_build_device_space(rd_dev);
 250         if (ret < 0)
 251                 goto fail;
 252
 253         snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
 254         snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
 255                                                 RD_MCP_VERSION);
 256
 257         dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
 258         dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS;
 259         dev_limits.limits.max_sectors = RD_MAX_SECTORS;
 260         dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 261         dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
 262
 263         dev = transport_add_device_to_core_hba(hba,
 264                         &rd_mcp_template, se_dev, dev_flags, rd_dev,
 265                         &dev_limits, prod, rev);
 266         if (!dev)
 267                 goto fail;
 268
 269         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 270         rd_dev->rd_queue_depth = dev->queue_depth;
 271
 272         pr_debug("CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
 273                 " %u pages in %u tables, %lu total bytes\n",
 274                 rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" :
 275                 "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count,
 276                 rd_dev->sg_table_count,
 277                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 278
 279         return dev;
 280
 281 fail:
 282         rd_release_device_space(rd_dev);
 283         return ERR_PTR(ret);
 284 }
 285
 286 static struct se_device *rd_MEMCPY_create_virtdevice(
 287         struct se_hba *hba,
 288         struct se_subsystem_dev *se_dev,
 289         void *p)
 290 {
 291         return rd_create_virtdevice(hba, se_dev, p, 0);
 292 }
 293
 294 /*      rd_free_device(): (Part of se_subsystem_api_t template)
 295  *
 296  *
 297  */
 298 static void rd_free_device(void *p)
 299 {
 300         struct rd_dev *rd_dev = p;
 301
 302         rd_release_device_space(rd_dev);
 303         kfree(rd_dev);
 304 }
 305
 306 static inline struct rd_request *RD_REQ(struct se_task *task)
 307 {
 308         return container_of(task, struct rd_request, rd_task);
 309 }
 310
 311 static struct se_task *
 312 rd_alloc_task(unsigned char *cdb)
 313 {
 314         struct rd_request *rd_req;
 315
 316         rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL);
 317         if (!rd_req) {
 318                 pr_err("Unable to allocate struct rd_request\n");
 319                 return NULL;
 320         }
 321
 322         return &rd_req->rd_task;
 323 }
 324
 325 /*      rd_get_sg_table():
 326  *
 327  *
 328  */
 329 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 330 {
 331         u32 i;
 332         struct rd_dev_sg_table *sg_table;
 333
 334         for (i = 0; i < rd_dev->sg_table_count; i++) {
 335                 sg_table = &rd_dev->sg_table_array[i];
 336                 if ((sg_table->page_start_offset <= page) &&
 337                     (sg_table->page_end_offset >= page))
 338                         return sg_table;
 339         }
 340
 341         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
 342                         page);
 343
 344         return NULL;
 345 }
 346
 347 /*      rd_MEMCPY_read():
 348  *
 349  *
 350  */
 351 static int rd_MEMCPY_read(struct rd_request *req)
 352 {
 353         struct se_task *task = &req->rd_task;
 354         struct rd_dev *dev = req->rd_task.se_dev->dev_ptr;
 355         struct rd_dev_sg_table *table;
 356         struct scatterlist *sg_d, *sg_s;
 357         void *dst, *src;
 358         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 359         u32 length, page_end = 0, table_sg_end;
 360         u32 rd_offset = req->rd_offset;
 361
 362         table = rd_get_sg_table(dev, req->rd_page);
 363         if (!table)
 364                 return -EINVAL;
 365
 366         table_sg_end = (table->page_end_offset - req->rd_page);
 367         sg_d = task->task_sg;
 368         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 369
 370         pr_debug("RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:"
 371                 " %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 372                 req->rd_page, req->rd_offset);
 373
 374         src_offset = rd_offset;
 375
 376         while (req->rd_size) {
 377                 if ((sg_d[i].length - dst_offset) <
 378                     (sg_s[j].length - src_offset)) {
 379                         length = (sg_d[i].length - dst_offset);
 380
 381                         pr_debug("Step 1 - sg_d[%d]: %p length: %d"
 382                                 " offset: %u sg_s[%d].length: %u\n", i,
 383                                 &sg_d[i], sg_d[i].length, sg_d[i].offset, j,
 384                                 sg_s[j].length);
 385                         pr_debug("Step 1 - length: %u dst_offset: %u"
 386                                 " src_offset: %u\n", length, dst_offset,
 387                                 src_offset);
 388
 389                         if (length > req->rd_size)
 390                                 length = req->rd_size;
 391
 392                         dst = sg_virt(&sg_d[i++]) + dst_offset;
 393                         BUG_ON(!dst);
 394
 395                         src = sg_virt(&sg_s[j]) + src_offset;
 396                         BUG_ON(!src);
 397
 398                         dst_offset = 0;
 399                         src_offset = length;
 400                         page_end = 0;
 401                 } else {
 402                         length = (sg_s[j].length - src_offset);
 403
 404                         pr_debug("Step 2 - sg_d[%d]: %p length: %d"
 405                                 " offset: %u sg_s[%d].length: %u\n", i,
 406                                 &sg_d[i], sg_d[i].length, sg_d[i].offset,
 407                                 j, sg_s[j].length);
 408                         pr_debug("Step 2 - length: %u dst_offset: %u"
 409                                 " src_offset: %u\n", length, dst_offset,
 410                                 src_offset);
 411
 412                         if (length > req->rd_size)
 413                                 length = req->rd_size;
 414
 415                         dst = sg_virt(&sg_d[i]) + dst_offset;
 416                         BUG_ON(!dst);
 417
 418                         if (sg_d[i].length == length) {
 419                                 i++;
 420                                 dst_offset = 0;
 421                         } else
 422                                 dst_offset = length;
 423
 424                         src = sg_virt(&sg_s[j++]) + src_offset;
 425                         BUG_ON(!src);
 426
 427                         src_offset = 0;
 428                         page_end = 1;
 429                 }
 430
 431                 memcpy(dst, src, length);
 432
 433                 pr_debug("page: %u, remaining size: %u, length: %u,"
 434                         " i: %u, j: %u\n", req->rd_page,
 435                         (req->rd_size - length), length, i, j);
 436
 437                 req->rd_size -= length;
 438                 if (!req->rd_size)
 439                         return 0;
 440
 441                 if (!page_end)
 442                         continue;
 443
 444                 if (++req->rd_page <= table->page_end_offset) {
 445                         pr_debug("page: %u in same page table\n",
 446                                 req->rd_page);
 447                         continue;
 448                 }
 449
 450                 pr_debug("getting new page table for page: %u\n",
 451                                 req->rd_page);
 452
 453                 table = rd_get_sg_table(dev, req->rd_page);
 454                 if (!table)
 455                         return -EINVAL;
 456
 457                 sg_s = &table->sg_table[j = 0];
 458         }
 459
 460         return 0;
 461 }
 462
 463 /*      rd_MEMCPY_write():
 464  *
 465  *
 466  */
 467 static int rd_MEMCPY_write(struct rd_request *req)
 468 {
 469         struct se_task *task = &req->rd_task;
 470         struct rd_dev *dev = req->rd_task.se_dev->dev_ptr;
 471         struct rd_dev_sg_table *table;
 472         struct scatterlist *sg_d, *sg_s;
 473         void *dst, *src;
 474         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 475         u32 length, page_end = 0, table_sg_end;
 476         u32 rd_offset = req->rd_offset;
 477
 478         table = rd_get_sg_table(dev, req->rd_page);
 479         if (!table)
 480                 return -EINVAL;
 481
 482         table_sg_end = (table->page_end_offset - req->rd_page);
 483         sg_d = &table->sg_table[req->rd_page - table->page_start_offset];
 484         sg_s = task->task_sg;
 485
 486         pr_debug("RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
 487                 " Offset: %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 488                 req->rd_page, req->rd_offset);
 489
 490         dst_offset = rd_offset;
 491
 492         while (req->rd_size) {
 493                 if ((sg_s[i].length - src_offset) <
 494                     (sg_d[j].length - dst_offset)) {
 495                         length = (sg_s[i].length - src_offset);
 496
 497                         pr_debug("Step 1 - sg_s[%d]: %p length: %d"
 498                                 " offset: %d sg_d[%d].length: %u\n", i,
 499                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 500                                 j, sg_d[j].length);
 501                         pr_debug("Step 1 - length: %u src_offset: %u"
 502                                 " dst_offset: %u\n", length, src_offset,
 503                                 dst_offset);
 504
 505                         if (length > req->rd_size)
 506                                 length = req->rd_size;
 507
 508                         src = sg_virt(&sg_s[i++]) + src_offset;
 509                         BUG_ON(!src);
 510
 511                         dst = sg_virt(&sg_d[j]) + dst_offset;
 512                         BUG_ON(!dst);
 513
 514                         src_offset = 0;
 515                         dst_offset = length;
 516                         page_end = 0;
 517                 } else {
 518                         length = (sg_d[j].length - dst_offset);
 519
 520                         pr_debug("Step 2 - sg_s[%d]: %p length: %d"
 521                                 " offset: %d sg_d[%d].length: %u\n", i,
 522                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 523                                 j, sg_d[j].length);
 524                         pr_debug("Step 2 - length: %u src_offset: %u"
 525                                 " dst_offset: %u\n", length, src_offset,
 526                                 dst_offset);
 527
 528                         if (length > req->rd_size)
 529                                 length = req->rd_size;
 530
 531                         src = sg_virt(&sg_s[i]) + src_offset;
 532                         BUG_ON(!src);
 533
 534                         if (sg_s[i].length == length) {
 535                                 i++;
 536                                 src_offset = 0;
 537                         } else
 538                                 src_offset = length;
 539
 540                         dst = sg_virt(&sg_d[j++]) + dst_offset;
 541                         BUG_ON(!dst);
 542
 543                         dst_offset = 0;
 544                         page_end = 1;
 545                 }
 546
 547                 memcpy(dst, src, length);
 548
 549                 pr_debug("page: %u, remaining size: %u, length: %u,"
 550                         " i: %u, j: %u\n", req->rd_page,
 551                         (req->rd_size - length), length, i, j);
 552
 553                 req->rd_size -= length;
 554                 if (!req->rd_size)
 555                         return 0;
 556
 557                 if (!page_end)
 558                         continue;
 559
 560                 if (++req->rd_page <= table->page_end_offset) {
 561                         pr_debug("page: %u in same page table\n",
 562                                 req->rd_page);
 563                         continue;
 564                 }
 565
 566                 pr_debug("getting new page table for page: %u\n",
 567                                 req->rd_page);
 568
 569                 table = rd_get_sg_table(dev, req->rd_page);
 570                 if (!table)
 571                         return -EINVAL;
 572
 573                 sg_d = &table->sg_table[j = 0];
 574         }
 575
 576         return 0;
 577 }
 578
 579 /*      rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
 580  *
 581  *
 582  */
 583 static int rd_MEMCPY_do_task(struct se_task *task)
 584 {
 585         struct se_device *dev = task->se_dev;
 586         struct rd_request *req = RD_REQ(task);
 587         unsigned long long lba;
 588         int ret;
 589
 590         req->rd_page = (task->task_lba * dev->se_sub_dev->se_dev_attrib.block_size) / PAGE_SIZE;
 591         lba = task->task_lba;
 592         req->rd_offset = (do_div(lba,
 593                           (PAGE_SIZE / dev->se_sub_dev->se_dev_attrib.block_size))) *
 594                            dev->se_sub_dev->se_dev_attrib.block_size;
 595         req->rd_size = task->task_size;
 596
 597         if (task->task_data_direction == DMA_FROM_DEVICE)
 598                 ret = rd_MEMCPY_read(req);
 599         else
 600                 ret = rd_MEMCPY_write(req);
 601
 602         if (ret != 0)
 603                 return ret;
 604
 605         task->task_scsi_status = GOOD;
 606         transport_complete_task(task, 1);
 607
 608         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 609 }
 610
 611 /*      rd_free_task(): (Part of se_subsystem_api_t template)
 612  *
 613  *
 614  */
 615 static void rd_free_task(struct se_task *task)
 616 {
 617         kfree(RD_REQ(task));
 618 }
 619
 620 enum {
 621         Opt_rd_pages, Opt_err
 622 };
 623
 624 static match_table_t tokens = {
 625         {Opt_rd_pages, "rd_pages=%d"},
 626         {Opt_err, NULL}
 627 };
 628
 629 static ssize_t rd_set_configfs_dev_params(
 630         struct se_hba *hba,
 631         struct se_subsystem_dev *se_dev,
 632         const char *page,
 633         ssize_t count)
 634 {
 635         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 636         char *orig, *ptr, *opts;
 637         substring_t args[MAX_OPT_ARGS];
 638         int ret = 0, arg, token;
 639
 640         opts = kstrdup(page, GFP_KERNEL);
 641         if (!opts)
 642                 return -ENOMEM;
 643
 644         orig = opts;
 645
 646         while ((ptr = strsep(&opts, ",")) != NULL) {
 647                 if (!*ptr)
 648                         continue;
 649
 650                 token = match_token(ptr, tokens, args);
 651                 switch (token) {
 652                 case Opt_rd_pages:
 653                         match_int(args, &arg);
 654                         rd_dev->rd_page_count = arg;
 655                         pr_debug("RAMDISK: Referencing Page"
 656                                 " Count: %u\n", rd_dev->rd_page_count);
 657                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 658                         break;
 659                 default:
 660                         break;
 661                 }
 662         }
 663
 664         kfree(orig);
 665         return (!ret) ? count : ret;
 666 }
 667
 668 static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
 669 {
 670         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 671
 672         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 673                 pr_debug("Missing rd_pages= parameter\n");
 674                 return -EINVAL;
 675         }
 676
 677         return 0;
 678 }
 679
 680 static ssize_t rd_show_configfs_dev_params(
 681         struct se_hba *hba,
 682         struct se_subsystem_dev *se_dev,
 683         char *b)
 684 {
 685         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 686         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: %s\n",
 687                         rd_dev->rd_dev_id, (rd_dev->rd_direct) ?
 688                         "rd_direct" : "rd_mcp");
 689         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 690                         "  SG_table_count: %u\n", rd_dev->rd_page_count,
 691                         PAGE_SIZE, rd_dev->sg_table_count);
 692         return bl;
 693 }
 694
 695 /*      rd_get_cdb(): (Part of se_subsystem_api_t template)
 696  *
 697  *
 698  */
 699 static unsigned char *rd_get_cdb(struct se_task *task)
 700 {
 701         struct rd_request *req = RD_REQ(task);
 702
 703         return req->rd_scsi_cdb;
 704 }
 705
 706 static u32 rd_get_device_rev(struct se_device *dev)
 707 {
 708         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
 709 }
 710
 711 static u32 rd_get_device_type(struct se_device *dev)
 712 {
 713         return TYPE_DISK;
 714 }
 715
 716 static sector_t rd_get_blocks(struct se_device *dev)
 717 {
 718         struct rd_dev *rd_dev = dev->dev_ptr;
 719         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
 720                         dev->se_sub_dev->se_dev_attrib.block_size) - 1;
 721
 722         return blocks_long;
 723 }
 724
 725 static struct se_subsystem_api rd_mcp_template = {
 726         .name                   = "rd_mcp",
 727         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
 728         .attach_hba             = rd_attach_hba,
 729         .detach_hba             = rd_detach_hba,
 730         .allocate_virtdevice    = rd_MEMCPY_allocate_virtdevice,
 731         .create_virtdevice      = rd_MEMCPY_create_virtdevice,
 732         .free_device            = rd_free_device,
 733         .alloc_task             = rd_alloc_task,
 734         .do_task                = rd_MEMCPY_do_task,
 735         .free_task              = rd_free_task,
 736         .check_configfs_dev_params = rd_check_configfs_dev_params,
 737         .set_configfs_dev_params = rd_set_configfs_dev_params,
 738         .show_configfs_dev_params = rd_show_configfs_dev_params,
 739         .get_cdb                = rd_get_cdb,
 740         .get_device_rev         = rd_get_device_rev,
 741         .get_device_type        = rd_get_device_type,
 742         .get_blocks             = rd_get_blocks,
 743 };
 744
 745 int __init rd_module_init(void)
 746 {
 747         int ret;
 748
 749         ret = transport_subsystem_register(&rd_mcp_template);
 750         if (ret < 0) {
 751                 return ret;
 752         }
 753
 754         return 0;
 755 }
 756
 757 void rd_module_exit(void)
 758 {
 759         transport_subsystem_release(&rd_mcp_template);
 760 }