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_dr_template;
  48 static struct se_subsystem_api rd_mcp_template;
  49
  50 /* #define DEBUG_RAMDISK_MCP */
  51 /* #define DEBUG_RAMDISK_DR */
  52
  53 /*      rd_attach_hba(): (Part of se_subsystem_api_t template)
  54  *
  55  *
  56  */
  57 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
  58 {
  59         struct rd_host *rd_host;
  60
  61         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
  62         if (!(rd_host)) {
  63                 printk(KERN_ERR "Unable to allocate memory for struct rd_host\n");
  64                 return -ENOMEM;
  65         }
  66
  67         rd_host->rd_host_id = host_id;
  68
  69         hba->hba_ptr = (void *) rd_host;
  70
  71         printk(KERN_INFO "CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  72                 " Generic Target Core Stack %s\n", hba->hba_id,
  73                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
  74         printk(KERN_INFO "CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
  75                 " MaxSectors: %u\n", hba->hba_id,
  76                 rd_host->rd_host_id, RD_MAX_SECTORS);
  77
  78         return 0;
  79 }
  80
  81 static void rd_detach_hba(struct se_hba *hba)
  82 {
  83         struct rd_host *rd_host = hba->hba_ptr;
  84
  85         printk(KERN_INFO "CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  86                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  87
  88         kfree(rd_host);
  89         hba->hba_ptr = NULL;
  90 }
  91
  92 /*      rd_release_device_space():
  93  *
  94  *
  95  */
  96 static void rd_release_device_space(struct rd_dev *rd_dev)
  97 {
  98         u32 i, j, page_count = 0, sg_per_table;
  99         struct rd_dev_sg_table *sg_table;
 100         struct page *pg;
 101         struct scatterlist *sg;
 102
 103         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 104                 return;
 105
 106         sg_table = rd_dev->sg_table_array;
 107
 108         for (i = 0; i < rd_dev->sg_table_count; i++) {
 109                 sg = sg_table[i].sg_table;
 110                 sg_per_table = sg_table[i].rd_sg_count;
 111
 112                 for (j = 0; j < sg_per_table; j++) {
 113                         pg = sg_page(&sg[j]);
 114                         if ((pg)) {
 115                                 __free_page(pg);
 116                                 page_count++;
 117                         }
 118                 }
 119
 120                 kfree(sg);
 121         }
 122
 123         printk(KERN_INFO "CORE_RD[%u] - Released device space for Ramdisk"
 124                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 125                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 126                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 127
 128         kfree(sg_table);
 129         rd_dev->sg_table_array = NULL;
 130         rd_dev->sg_table_count = 0;
 131 }
 132
 133
 134 /*      rd_build_device_space():
 135  *
 136  *
 137  */
 138 static int rd_build_device_space(struct rd_dev *rd_dev)
 139 {
 140         u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
 141         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 142                                 sizeof(struct scatterlist));
 143         struct rd_dev_sg_table *sg_table;
 144         struct page *pg;
 145         struct scatterlist *sg;
 146
 147         if (rd_dev->rd_page_count <= 0) {
 148                 printk(KERN_ERR "Illegal page count: %u for Ramdisk device\n",
 149                         rd_dev->rd_page_count);
 150                 return -EINVAL;
 151         }
 152         total_sg_needed = rd_dev->rd_page_count;
 153
 154         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 155
 156         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 157         if (!(sg_table)) {
 158                 printk(KERN_ERR "Unable to allocate memory for Ramdisk"
 159                         " scatterlist tables\n");
 160                 return -ENOMEM;
 161         }
 162
 163         rd_dev->sg_table_array = sg_table;
 164         rd_dev->sg_table_count = sg_tables;
 165
 166         while (total_sg_needed) {
 167                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 168                         max_sg_per_table : total_sg_needed;
 169
 170                 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
 171                                 GFP_KERNEL);
 172                 if (!(sg)) {
 173                         printk(KERN_ERR "Unable to allocate scatterlist array"
 174                                 " for struct rd_dev\n");
 175                         return -ENOMEM;
 176                 }
 177
 178                 sg_init_table((struct scatterlist *)&sg[0], sg_per_table);
 179
 180                 sg_table[i].sg_table = sg;
 181                 sg_table[i].rd_sg_count = sg_per_table;
 182                 sg_table[i].page_start_offset = page_offset;
 183                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 184                                                 - 1;
 185
 186                 for (j = 0; j < sg_per_table; j++) {
 187                         pg = alloc_pages(GFP_KERNEL, 0);
 188                         if (!(pg)) {
 189                                 printk(KERN_ERR "Unable to allocate scatterlist"
 190                                         " pages for struct rd_dev_sg_table\n");
 191                                 return -ENOMEM;
 192                         }
 193                         sg_assign_page(&sg[j], pg);
 194                         sg[j].length = PAGE_SIZE;
 195                 }
 196
 197                 page_offset += sg_per_table;
 198                 total_sg_needed -= sg_per_table;
 199         }
 200
 201         printk(KERN_INFO "CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 202                 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 203                 rd_dev->rd_dev_id, rd_dev->rd_page_count,
 204                 rd_dev->sg_table_count);
 205
 206         return 0;
 207 }
 208
 209 static void *rd_allocate_virtdevice(
 210         struct se_hba *hba,
 211         const char *name,
 212         int rd_direct)
 213 {
 214         struct rd_dev *rd_dev;
 215         struct rd_host *rd_host = hba->hba_ptr;
 216
 217         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 218         if (!(rd_dev)) {
 219                 printk(KERN_ERR "Unable to allocate memory for struct rd_dev\n");
 220                 return NULL;
 221         }
 222
 223         rd_dev->rd_host = rd_host;
 224         rd_dev->rd_direct = rd_direct;
 225
 226         return rd_dev;
 227 }
 228
 229 static void *rd_DIRECT_allocate_virtdevice(struct se_hba *hba, const char *name)
 230 {
 231         return rd_allocate_virtdevice(hba, name, 1);
 232 }
 233
 234 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba *hba, const char *name)
 235 {
 236         return rd_allocate_virtdevice(hba, name, 0);
 237 }
 238
 239 /*      rd_create_virtdevice():
 240  *
 241  *
 242  */
 243 static struct se_device *rd_create_virtdevice(
 244         struct se_hba *hba,
 245         struct se_subsystem_dev *se_dev,
 246         void *p,
 247         int rd_direct)
 248 {
 249         struct se_device *dev;
 250         struct se_dev_limits dev_limits;
 251         struct rd_dev *rd_dev = p;
 252         struct rd_host *rd_host = hba->hba_ptr;
 253         int dev_flags = 0, ret;
 254         char prod[16], rev[4];
 255
 256         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 257
 258         ret = rd_build_device_space(rd_dev);
 259         if (ret < 0)
 260                 goto fail;
 261
 262         snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
 263         snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
 264                                                 RD_MCP_VERSION);
 265
 266         dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
 267         dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS;
 268         dev_limits.limits.max_sectors = RD_MAX_SECTORS;
 269         dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 270         dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
 271
 272         dev = transport_add_device_to_core_hba(hba,
 273                         (rd_dev->rd_direct) ? &rd_dr_template :
 274                         &rd_mcp_template, se_dev, dev_flags, (void *)rd_dev,
 275                         &dev_limits, prod, rev);
 276         if (!(dev))
 277                 goto fail;
 278
 279         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 280         rd_dev->rd_queue_depth = dev->queue_depth;
 281
 282         printk(KERN_INFO "CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
 283                 " %u pages in %u tables, %lu total bytes\n",
 284                 rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" :
 285                 "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count,
 286                 rd_dev->sg_table_count,
 287                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 288
 289         return dev;
 290
 291 fail:
 292         rd_release_device_space(rd_dev);
 293         return ERR_PTR(ret);
 294 }
 295
 296 static struct se_device *rd_DIRECT_create_virtdevice(
 297         struct se_hba *hba,
 298         struct se_subsystem_dev *se_dev,
 299         void *p)
 300 {
 301         return rd_create_virtdevice(hba, se_dev, p, 1);
 302 }
 303
 304 static struct se_device *rd_MEMCPY_create_virtdevice(
 305         struct se_hba *hba,
 306         struct se_subsystem_dev *se_dev,
 307         void *p)
 308 {
 309         return rd_create_virtdevice(hba, se_dev, p, 0);
 310 }
 311
 312 /*      rd_free_device(): (Part of se_subsystem_api_t template)
 313  *
 314  *
 315  */
 316 static void rd_free_device(void *p)
 317 {
 318         struct rd_dev *rd_dev = p;
 319
 320         rd_release_device_space(rd_dev);
 321         kfree(rd_dev);
 322 }
 323
 324 static inline struct rd_request *RD_REQ(struct se_task *task)
 325 {
 326         return container_of(task, struct rd_request, rd_task);
 327 }
 328
 329 static struct se_task *
 330 rd_alloc_task(struct se_cmd *cmd)
 331 {
 332         struct rd_request *rd_req;
 333
 334         rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL);
 335         if (!rd_req) {
 336                 printk(KERN_ERR "Unable to allocate struct rd_request\n");
 337                 return NULL;
 338         }
 339         rd_req->rd_dev = cmd->se_lun->lun_se_dev->dev_ptr;
 340
 341         return &rd_req->rd_task;
 342 }
 343
 344 /*      rd_get_sg_table():
 345  *
 346  *
 347  */
 348 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 349 {
 350         u32 i;
 351         struct rd_dev_sg_table *sg_table;
 352
 353         for (i = 0; i < rd_dev->sg_table_count; i++) {
 354                 sg_table = &rd_dev->sg_table_array[i];
 355                 if ((sg_table->page_start_offset <= page) &&
 356                     (sg_table->page_end_offset >= page))
 357                         return sg_table;
 358         }
 359
 360         printk(KERN_ERR "Unable to locate struct rd_dev_sg_table for page: %u\n",
 361                         page);
 362
 363         return NULL;
 364 }
 365
 366 /*      rd_MEMCPY_read():
 367  *
 368  *
 369  */
 370 static int rd_MEMCPY_read(struct rd_request *req)
 371 {
 372         struct se_task *task = &req->rd_task;
 373         struct rd_dev *dev = req->rd_dev;
 374         struct rd_dev_sg_table *table;
 375         struct scatterlist *sg_d, *sg_s;
 376         void *dst, *src;
 377         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 378         u32 length, page_end = 0, table_sg_end;
 379         u32 rd_offset = req->rd_offset;
 380
 381         table = rd_get_sg_table(dev, req->rd_page);
 382         if (!(table))
 383                 return -EINVAL;
 384
 385         table_sg_end = (table->page_end_offset - req->rd_page);
 386         sg_d = task->task_sg;
 387         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 388 #ifdef DEBUG_RAMDISK_MCP
 389         printk(KERN_INFO "RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:"
 390                 " %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 391                 req->rd_page, req->rd_offset);
 392 #endif
 393         src_offset = rd_offset;
 394
 395         while (req->rd_size) {
 396                 if ((sg_d[i].length - dst_offset) <
 397                     (sg_s[j].length - src_offset)) {
 398                         length = (sg_d[i].length - dst_offset);
 399 #ifdef DEBUG_RAMDISK_MCP
 400                         printk(KERN_INFO "Step 1 - sg_d[%d]: %p length: %d"
 401                                 " offset: %u sg_s[%d].length: %u\n", i,
 402                                 &sg_d[i], sg_d[i].length, sg_d[i].offset, j,
 403                                 sg_s[j].length);
 404                         printk(KERN_INFO "Step 1 - length: %u dst_offset: %u"
 405                                 " src_offset: %u\n", length, dst_offset,
 406                                 src_offset);
 407 #endif
 408                         if (length > req->rd_size)
 409                                 length = req->rd_size;
 410
 411                         dst = sg_virt(&sg_d[i++]) + dst_offset;
 412                         if (!dst)
 413                                 BUG();
 414
 415                         src = sg_virt(&sg_s[j]) + src_offset;
 416                         if (!src)
 417                                 BUG();
 418
 419                         dst_offset = 0;
 420                         src_offset = length;
 421                         page_end = 0;
 422                 } else {
 423                         length = (sg_s[j].length - src_offset);
 424 #ifdef DEBUG_RAMDISK_MCP
 425                         printk(KERN_INFO "Step 2 - sg_d[%d]: %p length: %d"
 426                                 " offset: %u sg_s[%d].length: %u\n", i,
 427                                 &sg_d[i], sg_d[i].length, sg_d[i].offset,
 428                                 j, sg_s[j].length);
 429                         printk(KERN_INFO "Step 2 - length: %u dst_offset: %u"
 430                                 " src_offset: %u\n", length, dst_offset,
 431                                 src_offset);
 432 #endif
 433                         if (length > req->rd_size)
 434                                 length = req->rd_size;
 435
 436                         dst = sg_virt(&sg_d[i]) + dst_offset;
 437                         if (!dst)
 438                                 BUG();
 439
 440                         if (sg_d[i].length == length) {
 441                                 i++;
 442                                 dst_offset = 0;
 443                         } else
 444                                 dst_offset = length;
 445
 446                         src = sg_virt(&sg_s[j++]) + src_offset;
 447                         if (!src)
 448                                 BUG();
 449
 450                         src_offset = 0;
 451                         page_end = 1;
 452                 }
 453
 454                 memcpy(dst, src, length);
 455
 456 #ifdef DEBUG_RAMDISK_MCP
 457                 printk(KERN_INFO "page: %u, remaining size: %u, length: %u,"
 458                         " i: %u, j: %u\n", req->rd_page,
 459                         (req->rd_size - length), length, i, j);
 460 #endif
 461                 req->rd_size -= length;
 462                 if (!(req->rd_size))
 463                         return 0;
 464
 465                 if (!page_end)
 466                         continue;
 467
 468                 if (++req->rd_page <= table->page_end_offset) {
 469 #ifdef DEBUG_RAMDISK_MCP
 470                         printk(KERN_INFO "page: %u in same page table\n",
 471                                 req->rd_page);
 472 #endif
 473                         continue;
 474                 }
 475 #ifdef DEBUG_RAMDISK_MCP
 476                 printk(KERN_INFO "getting new page table for page: %u\n",
 477                                 req->rd_page);
 478 #endif
 479                 table = rd_get_sg_table(dev, req->rd_page);
 480                 if (!(table))
 481                         return -EINVAL;
 482
 483                 sg_s = &table->sg_table[j = 0];
 484         }
 485
 486         return 0;
 487 }
 488
 489 /*      rd_MEMCPY_write():
 490  *
 491  *
 492  */
 493 static int rd_MEMCPY_write(struct rd_request *req)
 494 {
 495         struct se_task *task = &req->rd_task;
 496         struct rd_dev *dev = req->rd_dev;
 497         struct rd_dev_sg_table *table;
 498         struct scatterlist *sg_d, *sg_s;
 499         void *dst, *src;
 500         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 501         u32 length, page_end = 0, table_sg_end;
 502         u32 rd_offset = req->rd_offset;
 503
 504         table = rd_get_sg_table(dev, req->rd_page);
 505         if (!(table))
 506                 return -EINVAL;
 507
 508         table_sg_end = (table->page_end_offset - req->rd_page);
 509         sg_d = &table->sg_table[req->rd_page - table->page_start_offset];
 510         sg_s = task->task_sg;
 511 #ifdef DEBUG_RAMDISK_MCP
 512         printk(KERN_INFO "RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
 513                 " Offset: %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 514                 req->rd_page, req->rd_offset);
 515 #endif
 516         dst_offset = rd_offset;
 517
 518         while (req->rd_size) {
 519                 if ((sg_s[i].length - src_offset) <
 520                     (sg_d[j].length - dst_offset)) {
 521                         length = (sg_s[i].length - src_offset);
 522 #ifdef DEBUG_RAMDISK_MCP
 523                         printk(KERN_INFO "Step 1 - sg_s[%d]: %p length: %d"
 524                                 " offset: %d sg_d[%d].length: %u\n", i,
 525                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 526                                 j, sg_d[j].length);
 527                         printk(KERN_INFO "Step 1 - length: %u src_offset: %u"
 528                                 " dst_offset: %u\n", length, src_offset,
 529                                 dst_offset);
 530 #endif
 531                         if (length > req->rd_size)
 532                                 length = req->rd_size;
 533
 534                         src = sg_virt(&sg_s[i++]) + src_offset;
 535                         if (!src)
 536                                 BUG();
 537
 538                         dst = sg_virt(&sg_d[j]) + dst_offset;
 539                         if (!dst)
 540                                 BUG();
 541
 542                         src_offset = 0;
 543                         dst_offset = length;
 544                         page_end = 0;
 545                 } else {
 546                         length = (sg_d[j].length - dst_offset);
 547 #ifdef DEBUG_RAMDISK_MCP
 548                         printk(KERN_INFO "Step 2 - sg_s[%d]: %p length: %d"
 549                                 " offset: %d sg_d[%d].length: %u\n", i,
 550                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 551                                 j, sg_d[j].length);
 552                         printk(KERN_INFO "Step 2 - length: %u src_offset: %u"
 553                                 " dst_offset: %u\n", length, src_offset,
 554                                 dst_offset);
 555 #endif
 556                         if (length > req->rd_size)
 557                                 length = req->rd_size;
 558
 559                         src = sg_virt(&sg_s[i]) + src_offset;
 560                         if (!src)
 561                                 BUG();
 562
 563                         if (sg_s[i].length == length) {
 564                                 i++;
 565                                 src_offset = 0;
 566                         } else
 567                                 src_offset = length;
 568
 569                         dst = sg_virt(&sg_d[j++]) + dst_offset;
 570                         if (!dst)
 571                                 BUG();
 572
 573                         dst_offset = 0;
 574                         page_end = 1;
 575                 }
 576
 577                 memcpy(dst, src, length);
 578
 579 #ifdef DEBUG_RAMDISK_MCP
 580                 printk(KERN_INFO "page: %u, remaining size: %u, length: %u,"
 581                         " i: %u, j: %u\n", req->rd_page,
 582                         (req->rd_size - length), length, i, j);
 583 #endif
 584                 req->rd_size -= length;
 585                 if (!(req->rd_size))
 586                         return 0;
 587
 588                 if (!page_end)
 589                         continue;
 590
 591                 if (++req->rd_page <= table->page_end_offset) {
 592 #ifdef DEBUG_RAMDISK_MCP
 593                         printk(KERN_INFO "page: %u in same page table\n",
 594                                 req->rd_page);
 595 #endif
 596                         continue;
 597                 }
 598 #ifdef DEBUG_RAMDISK_MCP
 599                 printk(KERN_INFO "getting new page table for page: %u\n",
 600                                 req->rd_page);
 601 #endif
 602                 table = rd_get_sg_table(dev, req->rd_page);
 603                 if (!(table))
 604                         return -EINVAL;
 605
 606                 sg_d = &table->sg_table[j = 0];
 607         }
 608
 609         return 0;
 610 }
 611
 612 /*      rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
 613  *
 614  *
 615  */
 616 static int rd_MEMCPY_do_task(struct se_task *task)
 617 {
 618         struct se_device *dev = task->se_dev;
 619         struct rd_request *req = RD_REQ(task);
 620         unsigned long long lba;
 621         int ret;
 622
 623         req->rd_page = (task->task_lba * dev->se_sub_dev->se_dev_attrib.block_size) / PAGE_SIZE;
 624         lba = task->task_lba;
 625         req->rd_offset = (do_div(lba,
 626                           (PAGE_SIZE / dev->se_sub_dev->se_dev_attrib.block_size))) *
 627                            dev->se_sub_dev->se_dev_attrib.block_size;
 628         req->rd_size = task->task_size;
 629
 630         if (task->task_data_direction == DMA_FROM_DEVICE)
 631                 ret = rd_MEMCPY_read(req);
 632         else
 633                 ret = rd_MEMCPY_write(req);
 634
 635         if (ret != 0)
 636                 return ret;
 637
 638         task->task_scsi_status = GOOD;
 639         transport_complete_task(task, 1);
 640
 641         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 642 }
 643
 644 /*      rd_DIRECT_with_offset():
 645  *
 646  *
 647  */
 648 static int rd_DIRECT_with_offset(
 649         struct se_task *task,
 650         struct list_head *se_mem_list,
 651         u32 *se_mem_cnt,
 652         u32 *task_offset)
 653 {
 654         struct rd_request *req = RD_REQ(task);
 655         struct rd_dev *dev = req->rd_dev;
 656         struct rd_dev_sg_table *table;
 657         struct se_mem *se_mem;
 658         struct scatterlist *sg_s;
 659         u32 j = 0, set_offset = 1;
 660         u32 get_next_table = 0, offset_length, table_sg_end;
 661
 662         table = rd_get_sg_table(dev, req->rd_page);
 663         if (!(table))
 664                 return -EINVAL;
 665
 666         table_sg_end = (table->page_end_offset - req->rd_page);
 667         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 668 #ifdef DEBUG_RAMDISK_DR
 669         printk(KERN_INFO "%s DIRECT LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 670                 (task->task_data_direction == DMA_TO_DEVICE) ?
 671                         "Write" : "Read",
 672                 task->task_lba, req->rd_size, req->rd_page, req->rd_offset);
 673 #endif
 674         while (req->rd_size) {
 675                 se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
 676                 if (!(se_mem)) {
 677                         printk(KERN_ERR "Unable to allocate struct se_mem\n");
 678                         return -ENOMEM;
 679                 }
 680                 INIT_LIST_HEAD(&se_mem->se_list);
 681
 682                 if (set_offset) {
 683                         offset_length = sg_s[j].length - req->rd_offset;
 684                         if (offset_length > req->rd_size)
 685                                 offset_length = req->rd_size;
 686
 687                         se_mem->se_page = sg_page(&sg_s[j++]);
 688                         se_mem->se_off = req->rd_offset;
 689                         se_mem->se_len = offset_length;
 690
 691                         set_offset = 0;
 692                         get_next_table = (j > table_sg_end);
 693                         goto check_eot;
 694                 }
 695
 696                 offset_length = (req->rd_size < req->rd_offset) ?
 697                         req->rd_size : req->rd_offset;
 698
 699                 se_mem->se_page = sg_page(&sg_s[j]);
 700                 se_mem->se_len = offset_length;
 701
 702                 set_offset = 1;
 703
 704 check_eot:
 705 #ifdef DEBUG_RAMDISK_DR
 706                 printk(KERN_INFO "page: %u, size: %u, offset_length: %u, j: %u"
 707                         " se_mem: %p, se_page: %p se_off: %u se_len: %u\n",
 708                         req->rd_page, req->rd_size, offset_length, j, se_mem,
 709                         se_mem->se_page, se_mem->se_off, se_mem->se_len);
 710 #endif
 711                 list_add_tail(&se_mem->se_list, se_mem_list);
 712                 (*se_mem_cnt)++;
 713
 714                 req->rd_size -= offset_length;
 715                 if (!(req->rd_size))
 716                         goto out;
 717
 718                 if (!set_offset && !get_next_table)
 719                         continue;
 720
 721                 if (++req->rd_page <= table->page_end_offset) {
 722 #ifdef DEBUG_RAMDISK_DR
 723                         printk(KERN_INFO "page: %u in same page table\n",
 724                                         req->rd_page);
 725 #endif
 726                         continue;
 727                 }
 728 #ifdef DEBUG_RAMDISK_DR
 729                 printk(KERN_INFO "getting new page table for page: %u\n",
 730                                 req->rd_page);
 731 #endif
 732                 table = rd_get_sg_table(dev, req->rd_page);
 733                 if (!(table))
 734                         return -EINVAL;
 735
 736                 sg_s = &table->sg_table[j = 0];
 737         }
 738
 739 out:
 740         task->task_se_cmd->t_task->t_tasks_se_num += *se_mem_cnt;
 741 #ifdef DEBUG_RAMDISK_DR
 742         printk(KERN_INFO "RD_DR - Allocated %u struct se_mem segments for task\n",
 743                         *se_mem_cnt);
 744 #endif
 745         return 0;
 746 }
 747
 748 /*      rd_DIRECT_without_offset():
 749  *
 750  *
 751  */
 752 static int rd_DIRECT_without_offset(
 753         struct se_task *task,
 754         struct list_head *se_mem_list,
 755         u32 *se_mem_cnt,
 756         u32 *task_offset)
 757 {
 758         struct rd_request *req = RD_REQ(task);
 759         struct rd_dev *dev = req->rd_dev;
 760         struct rd_dev_sg_table *table;
 761         struct se_mem *se_mem;
 762         struct scatterlist *sg_s;
 763         u32 length, j = 0;
 764
 765         table = rd_get_sg_table(dev, req->rd_page);
 766         if (!(table))
 767                 return -EINVAL;
 768
 769         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 770 #ifdef DEBUG_RAMDISK_DR
 771         printk(KERN_INFO "%s DIRECT LBA: %llu, Size: %u, Page: %u\n",
 772                 (task->task_data_direction == DMA_TO_DEVICE) ?
 773                         "Write" : "Read",
 774                 task->task_lba, req->rd_size, req->rd_page);
 775 #endif
 776         while (req->rd_size) {
 777                 se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
 778                 if (!(se_mem)) {
 779                         printk(KERN_ERR "Unable to allocate struct se_mem\n");
 780                         return -ENOMEM;
 781                 }
 782                 INIT_LIST_HEAD(&se_mem->se_list);
 783
 784                 length = (req->rd_size < sg_s[j].length) ?
 785                         req->rd_size : sg_s[j].length;
 786
 787                 se_mem->se_page = sg_page(&sg_s[j++]);
 788                 se_mem->se_len = length;
 789
 790 #ifdef DEBUG_RAMDISK_DR
 791                 printk(KERN_INFO "page: %u, size: %u, j: %u se_mem: %p,"
 792                         " se_page: %p se_off: %u se_len: %u\n", req->rd_page,
 793                         req->rd_size, j, se_mem, se_mem->se_page,
 794                         se_mem->se_off, se_mem->se_len);
 795 #endif
 796                 list_add_tail(&se_mem->se_list, se_mem_list);
 797                 (*se_mem_cnt)++;
 798
 799                 req->rd_size -= length;
 800                 if (!(req->rd_size))
 801                         goto out;
 802
 803                 if (++req->rd_page <= table->page_end_offset) {
 804 #ifdef DEBUG_RAMDISK_DR
 805                         printk("page: %u in same page table\n",
 806                                 req->rd_page);
 807 #endif
 808                         continue;
 809                 }
 810 #ifdef DEBUG_RAMDISK_DR
 811                 printk(KERN_INFO "getting new page table for page: %u\n",
 812                                 req->rd_page);
 813 #endif
 814                 table = rd_get_sg_table(dev, req->rd_page);
 815                 if (!(table))
 816                         return -EINVAL;
 817
 818                 sg_s = &table->sg_table[j = 0];
 819         }
 820
 821 out:
 822         task->task_se_cmd->t_task->t_tasks_se_num += *se_mem_cnt;
 823 #ifdef DEBUG_RAMDISK_DR
 824         printk(KERN_INFO "RD_DR - Allocated %u struct se_mem segments for task\n",
 825                         *se_mem_cnt);
 826 #endif
 827         return 0;
 828 }
 829
 830 /*      rd_DIRECT_do_se_mem_map():
 831  *
 832  *
 833  */
 834 static int rd_DIRECT_do_se_mem_map(
 835         struct se_task *task,
 836         struct list_head *se_mem_list,
 837         void *in_mem,
 838         struct se_mem *in_se_mem,
 839         struct se_mem **out_se_mem,
 840         u32 *se_mem_cnt,
 841         u32 *task_offset_in)
 842 {
 843         struct se_cmd *cmd = task->task_se_cmd;
 844         struct rd_request *req = RD_REQ(task);
 845         u32 task_offset = *task_offset_in;
 846         unsigned long long lba;
 847         int ret;
 848         int block_size = task->se_dev->se_sub_dev->se_dev_attrib.block_size;
 849
 850         lba = task->task_lba;
 851         req->rd_page = ((task->task_lba * block_size) / PAGE_SIZE);
 852         req->rd_offset = (do_div(lba, (PAGE_SIZE / block_size))) * block_size;
 853         req->rd_size = task->task_size;
 854
 855         if (req->rd_offset)
 856                 ret = rd_DIRECT_with_offset(task, se_mem_list, se_mem_cnt,
 857                                 task_offset_in);
 858         else
 859                 ret = rd_DIRECT_without_offset(task, se_mem_list, se_mem_cnt,
 860                                 task_offset_in);
 861
 862         if (ret < 0)
 863                 return ret;
 864
 865         if (cmd->se_tfo->task_sg_chaining == 0)
 866                 return 0;
 867         /*
 868          * Currently prevent writers from multiple HW fabrics doing
 869          * pci_map_sg() to RD_DR's internal scatterlist memory.
 870          */
 871         if (cmd->data_direction == DMA_TO_DEVICE) {
 872                 printk(KERN_ERR "DMA_TO_DEVICE not supported for"
 873                                 " RAMDISK_DR with task_sg_chaining=1\n");
 874                 return -ENOSYS;
 875         }
 876         /*
 877          * Special case for if task_sg_chaining is enabled, then
 878          * we setup struct se_task->task_sg[], as it will be used by
 879          * transport_do_task_sg_chain() for creating chainged SGLs
 880          * across multiple struct se_task->task_sg[].
 881          */
 882         ret = transport_init_task_sg(task,
 883                         list_entry(cmd->t_task->t_mem_list->next,
 884                                    struct se_mem, se_list),
 885                         task_offset);
 886         if (ret <= 0)
 887                 return ret;
 888
 889         return transport_map_mem_to_sg(task, se_mem_list, task->task_sg,
 890                         list_entry(cmd->t_task->t_mem_list->next,
 891                                    struct se_mem, se_list),
 892                         out_se_mem, se_mem_cnt, task_offset_in);
 893 }
 894
 895 /*      rd_DIRECT_do_task(): (Part of se_subsystem_api_t template)
 896  *
 897  *
 898  */
 899 static int rd_DIRECT_do_task(struct se_task *task)
 900 {
 901         /*
 902          * At this point the locally allocated RD tables have been mapped
 903          * to struct se_mem elements in rd_DIRECT_do_se_mem_map().
 904          */
 905         task->task_scsi_status = GOOD;
 906         transport_complete_task(task, 1);
 907
 908         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 909 }
 910
 911 /*      rd_free_task(): (Part of se_subsystem_api_t template)
 912  *
 913  *
 914  */
 915 static void rd_free_task(struct se_task *task)
 916 {
 917         kfree(RD_REQ(task));
 918 }
 919
 920 enum {
 921         Opt_rd_pages, Opt_err
 922 };
 923
 924 static match_table_t tokens = {
 925         {Opt_rd_pages, "rd_pages=%d"},
 926         {Opt_err, NULL}
 927 };
 928
 929 static ssize_t rd_set_configfs_dev_params(
 930         struct se_hba *hba,
 931         struct se_subsystem_dev *se_dev,
 932         const char *page,
 933         ssize_t count)
 934 {
 935         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 936         char *orig, *ptr, *opts;
 937         substring_t args[MAX_OPT_ARGS];
 938         int ret = 0, arg, token;
 939
 940         opts = kstrdup(page, GFP_KERNEL);
 941         if (!opts)
 942                 return -ENOMEM;
 943
 944         orig = opts;
 945
 946         while ((ptr = strsep(&opts, ",")) != NULL) {
 947                 if (!*ptr)
 948                         continue;
 949
 950                 token = match_token(ptr, tokens, args);
 951                 switch (token) {
 952                 case Opt_rd_pages:
 953                         match_int(args, &arg);
 954                         rd_dev->rd_page_count = arg;
 955                         printk(KERN_INFO "RAMDISK: Referencing Page"
 956                                 " Count: %u\n", rd_dev->rd_page_count);
 957                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 958                         break;
 959                 default:
 960                         break;
 961                 }
 962         }
 963
 964         kfree(orig);
 965         return (!ret) ? count : ret;
 966 }
 967
 968 static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
 969 {
 970         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 971
 972         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 973                 printk(KERN_INFO "Missing rd_pages= parameter\n");
 974                 return -EINVAL;
 975         }
 976
 977         return 0;
 978 }
 979
 980 static ssize_t rd_show_configfs_dev_params(
 981         struct se_hba *hba,
 982         struct se_subsystem_dev *se_dev,
 983         char *b)
 984 {
 985         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 986         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: %s\n",
 987                         rd_dev->rd_dev_id, (rd_dev->rd_direct) ?
 988                         "rd_direct" : "rd_mcp");
 989         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 990                         "  SG_table_count: %u\n", rd_dev->rd_page_count,
 991                         PAGE_SIZE, rd_dev->sg_table_count);
 992         return bl;
 993 }
 994
 995 /*      rd_get_cdb(): (Part of se_subsystem_api_t template)
 996  *
 997  *
 998  */
 999 static unsigned char *rd_get_cdb(struct se_task *task)
1000 {
1001         struct rd_request *req = RD_REQ(task);
1002
1003         return req->rd_scsi_cdb;
1004 }
1005
1006 static u32 rd_get_device_rev(struct se_device *dev)
1007 {
1008         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
1009 }
1010
1011 static u32 rd_get_device_type(struct se_device *dev)
1012 {
1013         return TYPE_DISK;
1014 }
1015
1016 static sector_t rd_get_blocks(struct se_device *dev)
1017 {
1018         struct rd_dev *rd_dev = dev->dev_ptr;
1019         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
1020                         dev->se_sub_dev->se_dev_attrib.block_size) - 1;
1021
1022         return blocks_long;
1023 }
1024
1025 static struct se_subsystem_api rd_dr_template = {
1026         .name                   = "rd_dr",
1027         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
1028         .attach_hba             = rd_attach_hba,
1029         .detach_hba             = rd_detach_hba,
1030         .allocate_virtdevice    = rd_DIRECT_allocate_virtdevice,
1031         .create_virtdevice      = rd_DIRECT_create_virtdevice,
1032         .free_device            = rd_free_device,
1033         .alloc_task             = rd_alloc_task,
1034         .do_task                = rd_DIRECT_do_task,
1035         .free_task              = rd_free_task,
1036         .check_configfs_dev_params = rd_check_configfs_dev_params,
1037         .set_configfs_dev_params = rd_set_configfs_dev_params,
1038         .show_configfs_dev_params = rd_show_configfs_dev_params,
1039         .get_cdb                = rd_get_cdb,
1040         .get_device_rev         = rd_get_device_rev,
1041         .get_device_type        = rd_get_device_type,
1042         .get_blocks             = rd_get_blocks,
1043         .do_se_mem_map          = rd_DIRECT_do_se_mem_map,
1044 };
1045
1046 static struct se_subsystem_api rd_mcp_template = {
1047         .name                   = "rd_mcp",
1048         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
1049         .attach_hba             = rd_attach_hba,
1050         .detach_hba             = rd_detach_hba,
1051         .allocate_virtdevice    = rd_MEMCPY_allocate_virtdevice,
1052         .create_virtdevice      = rd_MEMCPY_create_virtdevice,
1053         .free_device            = rd_free_device,
1054         .alloc_task             = rd_alloc_task,
1055         .do_task                = rd_MEMCPY_do_task,
1056         .free_task              = rd_free_task,
1057         .check_configfs_dev_params = rd_check_configfs_dev_params,
1058         .set_configfs_dev_params = rd_set_configfs_dev_params,
1059         .show_configfs_dev_params = rd_show_configfs_dev_params,
1060         .get_cdb                = rd_get_cdb,
1061         .get_device_rev         = rd_get_device_rev,
1062         .get_device_type        = rd_get_device_type,
1063         .get_blocks             = rd_get_blocks,
1064 };
1065
1066 int __init rd_module_init(void)
1067 {
1068         int ret;
1069
1070         ret = transport_subsystem_register(&rd_dr_template);
1071         if (ret < 0)
1072                 return ret;
1073
1074         ret = transport_subsystem_register(&rd_mcp_template);
1075         if (ret < 0) {
1076                 transport_subsystem_release(&rd_dr_template);
1077                 return ret;
1078         }
1079
1080         return 0;
1081 }
1082
1083 void rd_module_exit(void)
1084 {
1085         transport_subsystem_release(&rd_dr_template);
1086         transport_subsystem_release(&rd_mcp_template);
1087 }