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         atomic_set(&hba->left_queue_depth, RD_HBA_QUEUE_DEPTH);
  70         atomic_set(&hba->max_queue_depth, RD_HBA_QUEUE_DEPTH);
  71         hba->hba_ptr = (void *) rd_host;
  72
  73         printk(KERN_INFO "CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
  74                 " Generic Target Core Stack %s\n", hba->hba_id,
  75                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
  76         printk(KERN_INFO "CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
  77                 " Target Core TCQ Depth: %d MaxSectors: %u\n", hba->hba_id,
  78                 rd_host->rd_host_id, atomic_read(&hba->max_queue_depth),
  79                 RD_MAX_SECTORS);
  80
  81         return 0;
  82 }
  83
  84 static void rd_detach_hba(struct se_hba *hba)
  85 {
  86         struct rd_host *rd_host = hba->hba_ptr;
  87
  88         printk(KERN_INFO "CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
  89                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
  90
  91         kfree(rd_host);
  92         hba->hba_ptr = NULL;
  93 }
  94
  95 /*      rd_release_device_space():
  96  *
  97  *
  98  */
  99 static void rd_release_device_space(struct rd_dev *rd_dev)
 100 {
 101         u32 i, j, page_count = 0, sg_per_table;
 102         struct rd_dev_sg_table *sg_table;
 103         struct page *pg;
 104         struct scatterlist *sg;
 105
 106         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
 107                 return;
 108
 109         sg_table = rd_dev->sg_table_array;
 110
 111         for (i = 0; i < rd_dev->sg_table_count; i++) {
 112                 sg = sg_table[i].sg_table;
 113                 sg_per_table = sg_table[i].rd_sg_count;
 114
 115                 for (j = 0; j < sg_per_table; j++) {
 116                         pg = sg_page(&sg[j]);
 117                         if ((pg)) {
 118                                 __free_page(pg);
 119                                 page_count++;
 120                         }
 121                 }
 122
 123                 kfree(sg);
 124         }
 125
 126         printk(KERN_INFO "CORE_RD[%u] - Released device space for Ramdisk"
 127                 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
 128                 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
 129                 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
 130
 131         kfree(sg_table);
 132         rd_dev->sg_table_array = NULL;
 133         rd_dev->sg_table_count = 0;
 134 }
 135
 136
 137 /*      rd_build_device_space():
 138  *
 139  *
 140  */
 141 static int rd_build_device_space(struct rd_dev *rd_dev)
 142 {
 143         u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
 144         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
 145                                 sizeof(struct scatterlist));
 146         struct rd_dev_sg_table *sg_table;
 147         struct page *pg;
 148         struct scatterlist *sg;
 149
 150         if (rd_dev->rd_page_count <= 0) {
 151                 printk(KERN_ERR "Illegal page count: %u for Ramdisk device\n",
 152                         rd_dev->rd_page_count);
 153                 return -1;
 154         }
 155         total_sg_needed = rd_dev->rd_page_count;
 156
 157         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
 158
 159         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
 160         if (!(sg_table)) {
 161                 printk(KERN_ERR "Unable to allocate memory for Ramdisk"
 162                         " scatterlist tables\n");
 163                 return -1;
 164         }
 165
 166         rd_dev->sg_table_array = sg_table;
 167         rd_dev->sg_table_count = sg_tables;
 168
 169         while (total_sg_needed) {
 170                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
 171                         max_sg_per_table : total_sg_needed;
 172
 173                 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
 174                                 GFP_KERNEL);
 175                 if (!(sg)) {
 176                         printk(KERN_ERR "Unable to allocate scatterlist array"
 177                                 " for struct rd_dev\n");
 178                         return -1;
 179                 }
 180
 181                 sg_init_table((struct scatterlist *)&sg[0], sg_per_table);
 182
 183                 sg_table[i].sg_table = sg;
 184                 sg_table[i].rd_sg_count = sg_per_table;
 185                 sg_table[i].page_start_offset = page_offset;
 186                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
 187                                                 - 1;
 188
 189                 for (j = 0; j < sg_per_table; j++) {
 190                         pg = alloc_pages(GFP_KERNEL, 0);
 191                         if (!(pg)) {
 192                                 printk(KERN_ERR "Unable to allocate scatterlist"
 193                                         " pages for struct rd_dev_sg_table\n");
 194                                 return -1;
 195                         }
 196                         sg_assign_page(&sg[j], pg);
 197                         sg[j].length = PAGE_SIZE;
 198                 }
 199
 200                 page_offset += sg_per_table;
 201                 total_sg_needed -= sg_per_table;
 202         }
 203
 204         printk(KERN_INFO "CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
 205                 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
 206                 rd_dev->rd_dev_id, rd_dev->rd_page_count,
 207                 rd_dev->sg_table_count);
 208
 209         return 0;
 210 }
 211
 212 static void *rd_allocate_virtdevice(
 213         struct se_hba *hba,
 214         const char *name,
 215         int rd_direct)
 216 {
 217         struct rd_dev *rd_dev;
 218         struct rd_host *rd_host = hba->hba_ptr;
 219
 220         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
 221         if (!(rd_dev)) {
 222                 printk(KERN_ERR "Unable to allocate memory for struct rd_dev\n");
 223                 return NULL;
 224         }
 225
 226         rd_dev->rd_host = rd_host;
 227         rd_dev->rd_direct = rd_direct;
 228
 229         return rd_dev;
 230 }
 231
 232 static void *rd_DIRECT_allocate_virtdevice(struct se_hba *hba, const char *name)
 233 {
 234         return rd_allocate_virtdevice(hba, name, 1);
 235 }
 236
 237 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba *hba, const char *name)
 238 {
 239         return rd_allocate_virtdevice(hba, name, 0);
 240 }
 241
 242 /*      rd_create_virtdevice():
 243  *
 244  *
 245  */
 246 static struct se_device *rd_create_virtdevice(
 247         struct se_hba *hba,
 248         struct se_subsystem_dev *se_dev,
 249         void *p,
 250         int rd_direct)
 251 {
 252         struct se_device *dev;
 253         struct se_dev_limits dev_limits;
 254         struct rd_dev *rd_dev = p;
 255         struct rd_host *rd_host = hba->hba_ptr;
 256         int dev_flags = 0;
 257         char prod[16], rev[4];
 258
 259         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 260
 261         if (rd_build_device_space(rd_dev) < 0)
 262                 goto fail;
 263
 264         snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
 265         snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
 266                                                 RD_MCP_VERSION);
 267
 268         dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
 269         dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS;
 270         dev_limits.limits.max_sectors = RD_MAX_SECTORS;
 271         dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 272         dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
 273
 274         dev = transport_add_device_to_core_hba(hba,
 275                         (rd_dev->rd_direct) ? &rd_dr_template :
 276                         &rd_mcp_template, se_dev, dev_flags, (void *)rd_dev,
 277                         &dev_limits, prod, rev);
 278         if (!(dev))
 279                 goto fail;
 280
 281         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 282         rd_dev->rd_queue_depth = dev->queue_depth;
 283
 284         printk(KERN_INFO "CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
 285                 " %u pages in %u tables, %lu total bytes\n",
 286                 rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" :
 287                 "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count,
 288                 rd_dev->sg_table_count,
 289                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 290
 291         return dev;
 292
 293 fail:
 294         rd_release_device_space(rd_dev);
 295         return NULL;
 296 }
 297
 298 static struct se_device *rd_DIRECT_create_virtdevice(
 299         struct se_hba *hba,
 300         struct se_subsystem_dev *se_dev,
 301         void *p)
 302 {
 303         return rd_create_virtdevice(hba, se_dev, p, 1);
 304 }
 305
 306 static struct se_device *rd_MEMCPY_create_virtdevice(
 307         struct se_hba *hba,
 308         struct se_subsystem_dev *se_dev,
 309         void *p)
 310 {
 311         return rd_create_virtdevice(hba, se_dev, p, 0);
 312 }
 313
 314 /*      rd_free_device(): (Part of se_subsystem_api_t template)
 315  *
 316  *
 317  */
 318 static void rd_free_device(void *p)
 319 {
 320         struct rd_dev *rd_dev = p;
 321
 322         rd_release_device_space(rd_dev);
 323         kfree(rd_dev);
 324 }
 325
 326 static inline struct rd_request *RD_REQ(struct se_task *task)
 327 {
 328         return container_of(task, struct rd_request, rd_task);
 329 }
 330
 331 static struct se_task *
 332 rd_alloc_task(struct se_cmd *cmd)
 333 {
 334         struct rd_request *rd_req;
 335
 336         rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL);
 337         if (!rd_req) {
 338                 printk(KERN_ERR "Unable to allocate struct rd_request\n");
 339                 return NULL;
 340         }
 341         rd_req->rd_dev = SE_DEV(cmd)->dev_ptr;
 342
 343         return &rd_req->rd_task;
 344 }
 345
 346 /*      rd_get_sg_table():
 347  *
 348  *
 349  */
 350 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 351 {
 352         u32 i;
 353         struct rd_dev_sg_table *sg_table;
 354
 355         for (i = 0; i < rd_dev->sg_table_count; i++) {
 356                 sg_table = &rd_dev->sg_table_array[i];
 357                 if ((sg_table->page_start_offset <= page) &&
 358                     (sg_table->page_end_offset >= page))
 359                         return sg_table;
 360         }
 361
 362         printk(KERN_ERR "Unable to locate struct rd_dev_sg_table for page: %u\n",
 363                         page);
 364
 365         return NULL;
 366 }
 367
 368 /*      rd_MEMCPY_read():
 369  *
 370  *
 371  */
 372 static int rd_MEMCPY_read(struct rd_request *req)
 373 {
 374         struct se_task *task = &req->rd_task;
 375         struct rd_dev *dev = req->rd_dev;
 376         struct rd_dev_sg_table *table;
 377         struct scatterlist *sg_d, *sg_s;
 378         void *dst, *src;
 379         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 380         u32 length, page_end = 0, table_sg_end;
 381         u32 rd_offset = req->rd_offset;
 382
 383         table = rd_get_sg_table(dev, req->rd_page);
 384         if (!(table))
 385                 return -1;
 386
 387         table_sg_end = (table->page_end_offset - req->rd_page);
 388         sg_d = task->task_sg;
 389         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 390 #ifdef DEBUG_RAMDISK_MCP
 391         printk(KERN_INFO "RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:"
 392                 " %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 393                 req->rd_page, req->rd_offset);
 394 #endif
 395         src_offset = rd_offset;
 396
 397         while (req->rd_size) {
 398                 if ((sg_d[i].length - dst_offset) <
 399                     (sg_s[j].length - src_offset)) {
 400                         length = (sg_d[i].length - dst_offset);
 401 #ifdef DEBUG_RAMDISK_MCP
 402                         printk(KERN_INFO "Step 1 - sg_d[%d]: %p length: %d"
 403                                 " offset: %u sg_s[%d].length: %u\n", i,
 404                                 &sg_d[i], sg_d[i].length, sg_d[i].offset, j,
 405                                 sg_s[j].length);
 406                         printk(KERN_INFO "Step 1 - length: %u dst_offset: %u"
 407                                 " src_offset: %u\n", length, dst_offset,
 408                                 src_offset);
 409 #endif
 410                         if (length > req->rd_size)
 411                                 length = req->rd_size;
 412
 413                         dst = sg_virt(&sg_d[i++]) + dst_offset;
 414                         if (!dst)
 415                                 BUG();
 416
 417                         src = sg_virt(&sg_s[j]) + src_offset;
 418                         if (!src)
 419                                 BUG();
 420
 421                         dst_offset = 0;
 422                         src_offset = length;
 423                         page_end = 0;
 424                 } else {
 425                         length = (sg_s[j].length - src_offset);
 426 #ifdef DEBUG_RAMDISK_MCP
 427                         printk(KERN_INFO "Step 2 - sg_d[%d]: %p length: %d"
 428                                 " offset: %u sg_s[%d].length: %u\n", i,
 429                                 &sg_d[i], sg_d[i].length, sg_d[i].offset,
 430                                 j, sg_s[j].length);
 431                         printk(KERN_INFO "Step 2 - length: %u dst_offset: %u"
 432                                 " src_offset: %u\n", length, dst_offset,
 433                                 src_offset);
 434 #endif
 435                         if (length > req->rd_size)
 436                                 length = req->rd_size;
 437
 438                         dst = sg_virt(&sg_d[i]) + dst_offset;
 439                         if (!dst)
 440                                 BUG();
 441
 442                         if (sg_d[i].length == length) {
 443                                 i++;
 444                                 dst_offset = 0;
 445                         } else
 446                                 dst_offset = length;
 447
 448                         src = sg_virt(&sg_s[j++]) + src_offset;
 449                         if (!src)
 450                                 BUG();
 451
 452                         src_offset = 0;
 453                         page_end = 1;
 454                 }
 455
 456                 memcpy(dst, src, length);
 457
 458 #ifdef DEBUG_RAMDISK_MCP
 459                 printk(KERN_INFO "page: %u, remaining size: %u, length: %u,"
 460                         " i: %u, j: %u\n", req->rd_page,
 461                         (req->rd_size - length), length, i, j);
 462 #endif
 463                 req->rd_size -= length;
 464                 if (!(req->rd_size))
 465                         return 0;
 466
 467                 if (!page_end)
 468                         continue;
 469
 470                 if (++req->rd_page <= table->page_end_offset) {
 471 #ifdef DEBUG_RAMDISK_MCP
 472                         printk(KERN_INFO "page: %u in same page table\n",
 473                                 req->rd_page);
 474 #endif
 475                         continue;
 476                 }
 477 #ifdef DEBUG_RAMDISK_MCP
 478                 printk(KERN_INFO "getting new page table for page: %u\n",
 479                                 req->rd_page);
 480 #endif
 481                 table = rd_get_sg_table(dev, req->rd_page);
 482                 if (!(table))
 483                         return -1;
 484
 485                 sg_s = &table->sg_table[j = 0];
 486         }
 487
 488         return 0;
 489 }
 490
 491 /*      rd_MEMCPY_write():
 492  *
 493  *
 494  */
 495 static int rd_MEMCPY_write(struct rd_request *req)
 496 {
 497         struct se_task *task = &req->rd_task;
 498         struct rd_dev *dev = req->rd_dev;
 499         struct rd_dev_sg_table *table;
 500         struct scatterlist *sg_d, *sg_s;
 501         void *dst, *src;
 502         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 503         u32 length, page_end = 0, table_sg_end;
 504         u32 rd_offset = req->rd_offset;
 505
 506         table = rd_get_sg_table(dev, req->rd_page);
 507         if (!(table))
 508                 return -1;
 509
 510         table_sg_end = (table->page_end_offset - req->rd_page);
 511         sg_d = &table->sg_table[req->rd_page - table->page_start_offset];
 512         sg_s = task->task_sg;
 513 #ifdef DEBUG_RAMDISK_MCP
 514         printk(KERN_INFO "RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
 515                 " Offset: %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 516                 req->rd_page, req->rd_offset);
 517 #endif
 518         dst_offset = rd_offset;
 519
 520         while (req->rd_size) {
 521                 if ((sg_s[i].length - src_offset) <
 522                     (sg_d[j].length - dst_offset)) {
 523                         length = (sg_s[i].length - src_offset);
 524 #ifdef DEBUG_RAMDISK_MCP
 525                         printk(KERN_INFO "Step 1 - sg_s[%d]: %p length: %d"
 526                                 " offset: %d sg_d[%d].length: %u\n", i,
 527                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 528                                 j, sg_d[j].length);
 529                         printk(KERN_INFO "Step 1 - length: %u src_offset: %u"
 530                                 " dst_offset: %u\n", length, src_offset,
 531                                 dst_offset);
 532 #endif
 533                         if (length > req->rd_size)
 534                                 length = req->rd_size;
 535
 536                         src = sg_virt(&sg_s[i++]) + src_offset;
 537                         if (!src)
 538                                 BUG();
 539
 540                         dst = sg_virt(&sg_d[j]) + dst_offset;
 541                         if (!dst)
 542                                 BUG();
 543
 544                         src_offset = 0;
 545                         dst_offset = length;
 546                         page_end = 0;
 547                 } else {
 548                         length = (sg_d[j].length - dst_offset);
 549 #ifdef DEBUG_RAMDISK_MCP
 550                         printk(KERN_INFO "Step 2 - sg_s[%d]: %p length: %d"
 551                                 " offset: %d sg_d[%d].length: %u\n", i,
 552                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 553                                 j, sg_d[j].length);
 554                         printk(KERN_INFO "Step 2 - length: %u src_offset: %u"
 555                                 " dst_offset: %u\n", length, src_offset,
 556                                 dst_offset);
 557 #endif
 558                         if (length > req->rd_size)
 559                                 length = req->rd_size;
 560
 561                         src = sg_virt(&sg_s[i]) + src_offset;
 562                         if (!src)
 563                                 BUG();
 564
 565                         if (sg_s[i].length == length) {
 566                                 i++;
 567                                 src_offset = 0;
 568                         } else
 569                                 src_offset = length;
 570
 571                         dst = sg_virt(&sg_d[j++]) + dst_offset;
 572                         if (!dst)
 573                                 BUG();
 574
 575                         dst_offset = 0;
 576                         page_end = 1;
 577                 }
 578
 579                 memcpy(dst, src, length);
 580
 581 #ifdef DEBUG_RAMDISK_MCP
 582                 printk(KERN_INFO "page: %u, remaining size: %u, length: %u,"
 583                         " i: %u, j: %u\n", req->rd_page,
 584                         (req->rd_size - length), length, i, j);
 585 #endif
 586                 req->rd_size -= length;
 587                 if (!(req->rd_size))
 588                         return 0;
 589
 590                 if (!page_end)
 591                         continue;
 592
 593                 if (++req->rd_page <= table->page_end_offset) {
 594 #ifdef DEBUG_RAMDISK_MCP
 595                         printk(KERN_INFO "page: %u in same page table\n",
 596                                 req->rd_page);
 597 #endif
 598                         continue;
 599                 }
 600 #ifdef DEBUG_RAMDISK_MCP
 601                 printk(KERN_INFO "getting new page table for page: %u\n",
 602                                 req->rd_page);
 603 #endif
 604                 table = rd_get_sg_table(dev, req->rd_page);
 605                 if (!(table))
 606                         return -1;
 607
 608                 sg_d = &table->sg_table[j = 0];
 609         }
 610
 611         return 0;
 612 }
 613
 614 /*      rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
 615  *
 616  *
 617  */
 618 static int rd_MEMCPY_do_task(struct se_task *task)
 619 {
 620         struct se_device *dev = task->se_dev;
 621         struct rd_request *req = RD_REQ(task);
 622         unsigned long long lba;
 623         int ret;
 624
 625         req->rd_page = (task->task_lba * DEV_ATTRIB(dev)->block_size) / PAGE_SIZE;
 626         lba = task->task_lba;
 627         req->rd_offset = (do_div(lba,
 628                           (PAGE_SIZE / DEV_ATTRIB(dev)->block_size))) *
 629                            DEV_ATTRIB(dev)->block_size;
 630         req->rd_size = task->task_size;
 631
 632         if (task->task_data_direction == DMA_FROM_DEVICE)
 633                 ret = rd_MEMCPY_read(req);
 634         else
 635                 ret = rd_MEMCPY_write(req);
 636
 637         if (ret != 0)
 638                 return ret;
 639
 640         task->task_scsi_status = GOOD;
 641         transport_complete_task(task, 1);
 642
 643         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 644 }
 645
 646 /*      rd_DIRECT_with_offset():
 647  *
 648  *
 649  */
 650 static int rd_DIRECT_with_offset(
 651         struct se_task *task,
 652         struct list_head *se_mem_list,
 653         u32 *se_mem_cnt,
 654         u32 *task_offset)
 655 {
 656         struct rd_request *req = RD_REQ(task);
 657         struct rd_dev *dev = req->rd_dev;
 658         struct rd_dev_sg_table *table;
 659         struct se_mem *se_mem;
 660         struct scatterlist *sg_s;
 661         u32 j = 0, set_offset = 1;
 662         u32 get_next_table = 0, offset_length, table_sg_end;
 663
 664         table = rd_get_sg_table(dev, req->rd_page);
 665         if (!(table))
 666                 return -1;
 667
 668         table_sg_end = (table->page_end_offset - req->rd_page);
 669         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 670 #ifdef DEBUG_RAMDISK_DR
 671         printk(KERN_INFO "%s DIRECT LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 672                 (task->task_data_direction == DMA_TO_DEVICE) ?
 673                         "Write" : "Read",
 674                 task->task_lba, req->rd_size, req->rd_page, req->rd_offset);
 675 #endif
 676         while (req->rd_size) {
 677                 se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
 678                 if (!(se_mem)) {
 679                         printk(KERN_ERR "Unable to allocate struct se_mem\n");
 680                         return -1;
 681                 }
 682                 INIT_LIST_HEAD(&se_mem->se_list);
 683
 684                 if (set_offset) {
 685                         offset_length = sg_s[j].length - req->rd_offset;
 686                         if (offset_length > req->rd_size)
 687                                 offset_length = req->rd_size;
 688
 689                         se_mem->se_page = sg_page(&sg_s[j++]);
 690                         se_mem->se_off = req->rd_offset;
 691                         se_mem->se_len = offset_length;
 692
 693                         set_offset = 0;
 694                         get_next_table = (j > table_sg_end);
 695                         goto check_eot;
 696                 }
 697
 698                 offset_length = (req->rd_size < req->rd_offset) ?
 699                         req->rd_size : req->rd_offset;
 700
 701                 se_mem->se_page = sg_page(&sg_s[j]);
 702                 se_mem->se_len = offset_length;
 703
 704                 set_offset = 1;
 705
 706 check_eot:
 707 #ifdef DEBUG_RAMDISK_DR
 708                 printk(KERN_INFO "page: %u, size: %u, offset_length: %u, j: %u"
 709                         " se_mem: %p, se_page: %p se_off: %u se_len: %u\n",
 710                         req->rd_page, req->rd_size, offset_length, j, se_mem,
 711                         se_mem->se_page, se_mem->se_off, se_mem->se_len);
 712 #endif
 713                 list_add_tail(&se_mem->se_list, se_mem_list);
 714                 (*se_mem_cnt)++;
 715
 716                 req->rd_size -= offset_length;
 717                 if (!(req->rd_size))
 718                         goto out;
 719
 720                 if (!set_offset && !get_next_table)
 721                         continue;
 722
 723                 if (++req->rd_page <= table->page_end_offset) {
 724 #ifdef DEBUG_RAMDISK_DR
 725                         printk(KERN_INFO "page: %u in same page table\n",
 726                                         req->rd_page);
 727 #endif
 728                         continue;
 729                 }
 730 #ifdef DEBUG_RAMDISK_DR
 731                 printk(KERN_INFO "getting new page table for page: %u\n",
 732                                 req->rd_page);
 733 #endif
 734                 table = rd_get_sg_table(dev, req->rd_page);
 735                 if (!(table))
 736                         return -1;
 737
 738                 sg_s = &table->sg_table[j = 0];
 739         }
 740
 741 out:
 742         T_TASK(task->task_se_cmd)->t_tasks_se_num += *se_mem_cnt;
 743 #ifdef DEBUG_RAMDISK_DR
 744         printk(KERN_INFO "RD_DR - Allocated %u struct se_mem segments for task\n",
 745                         *se_mem_cnt);
 746 #endif
 747         return 0;
 748 }
 749
 750 /*      rd_DIRECT_without_offset():
 751  *
 752  *
 753  */
 754 static int rd_DIRECT_without_offset(
 755         struct se_task *task,
 756         struct list_head *se_mem_list,
 757         u32 *se_mem_cnt,
 758         u32 *task_offset)
 759 {
 760         struct rd_request *req = RD_REQ(task);
 761         struct rd_dev *dev = req->rd_dev;
 762         struct rd_dev_sg_table *table;
 763         struct se_mem *se_mem;
 764         struct scatterlist *sg_s;
 765         u32 length, j = 0;
 766
 767         table = rd_get_sg_table(dev, req->rd_page);
 768         if (!(table))
 769                 return -1;
 770
 771         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 772 #ifdef DEBUG_RAMDISK_DR
 773         printk(KERN_INFO "%s DIRECT LBA: %llu, Size: %u, Page: %u\n",
 774                 (task->task_data_direction == DMA_TO_DEVICE) ?
 775                         "Write" : "Read",
 776                 task->task_lba, req->rd_size, req->rd_page);
 777 #endif
 778         while (req->rd_size) {
 779                 se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
 780                 if (!(se_mem)) {
 781                         printk(KERN_ERR "Unable to allocate struct se_mem\n");
 782                         return -1;
 783                 }
 784                 INIT_LIST_HEAD(&se_mem->se_list);
 785
 786                 length = (req->rd_size < sg_s[j].length) ?
 787                         req->rd_size : sg_s[j].length;
 788
 789                 se_mem->se_page = sg_page(&sg_s[j++]);
 790                 se_mem->se_len = length;
 791
 792 #ifdef DEBUG_RAMDISK_DR
 793                 printk(KERN_INFO "page: %u, size: %u, j: %u se_mem: %p,"
 794                         " se_page: %p se_off: %u se_len: %u\n", req->rd_page,
 795                         req->rd_size, j, se_mem, se_mem->se_page,
 796                         se_mem->se_off, se_mem->se_len);
 797 #endif
 798                 list_add_tail(&se_mem->se_list, se_mem_list);
 799                 (*se_mem_cnt)++;
 800
 801                 req->rd_size -= length;
 802                 if (!(req->rd_size))
 803                         goto out;
 804
 805                 if (++req->rd_page <= table->page_end_offset) {
 806 #ifdef DEBUG_RAMDISK_DR
 807                         printk("page: %u in same page table\n",
 808                                 req->rd_page);
 809 #endif
 810                         continue;
 811                 }
 812 #ifdef DEBUG_RAMDISK_DR
 813                 printk(KERN_INFO "getting new page table for page: %u\n",
 814                                 req->rd_page);
 815 #endif
 816                 table = rd_get_sg_table(dev, req->rd_page);
 817                 if (!(table))
 818                         return -1;
 819
 820                 sg_s = &table->sg_table[j = 0];
 821         }
 822
 823 out:
 824         T_TASK(task->task_se_cmd)->t_tasks_se_num += *se_mem_cnt;
 825 #ifdef DEBUG_RAMDISK_DR
 826         printk(KERN_INFO "RD_DR - Allocated %u struct se_mem segments for task\n",
 827                         *se_mem_cnt);
 828 #endif
 829         return 0;
 830 }
 831
 832 /*      rd_DIRECT_do_se_mem_map():
 833  *
 834  *
 835  */
 836 static int rd_DIRECT_do_se_mem_map(
 837         struct se_task *task,
 838         struct list_head *se_mem_list,
 839         void *in_mem,
 840         struct se_mem *in_se_mem,
 841         struct se_mem **out_se_mem,
 842         u32 *se_mem_cnt,
 843         u32 *task_offset_in)
 844 {
 845         struct se_cmd *cmd = task->task_se_cmd;
 846         struct rd_request *req = RD_REQ(task);
 847         u32 task_offset = *task_offset_in;
 848         unsigned long long lba;
 849         int ret;
 850
 851         req->rd_page = ((task->task_lba * DEV_ATTRIB(task->se_dev)->block_size) /
 852                         PAGE_SIZE);
 853         lba = task->task_lba;
 854         req->rd_offset = (do_div(lba,
 855                           (PAGE_SIZE / DEV_ATTRIB(task->se_dev)->block_size))) *
 856                            DEV_ATTRIB(task->se_dev)->block_size;
 857         req->rd_size = task->task_size;
 858
 859         if (req->rd_offset)
 860                 ret = rd_DIRECT_with_offset(task, se_mem_list, se_mem_cnt,
 861                                 task_offset_in);
 862         else
 863                 ret = rd_DIRECT_without_offset(task, se_mem_list, se_mem_cnt,
 864                                 task_offset_in);
 865
 866         if (ret < 0)
 867                 return ret;
 868
 869         if (CMD_TFO(cmd)->task_sg_chaining == 0)
 870                 return 0;
 871         /*
 872          * Currently prevent writers from multiple HW fabrics doing
 873          * pci_map_sg() to RD_DR's internal scatterlist memory.
 874          */
 875         if (cmd->data_direction == DMA_TO_DEVICE) {
 876                 printk(KERN_ERR "DMA_TO_DEVICE not supported for"
 877                                 " RAMDISK_DR with task_sg_chaining=1\n");
 878                 return -1;
 879         }
 880         /*
 881          * Special case for if task_sg_chaining is enabled, then
 882          * we setup struct se_task->task_sg[], as it will be used by
 883          * transport_do_task_sg_chain() for creating chainged SGLs
 884          * across multiple struct se_task->task_sg[].
 885          */
 886         if (!(transport_calc_sg_num(task,
 887                         list_entry(T_TASK(cmd)->t_mem_list->next,
 888                                    struct se_mem, se_list),
 889                         task_offset)))
 890                 return -1;
 891
 892         return transport_map_mem_to_sg(task, se_mem_list, task->task_sg,
 893                         list_entry(T_TASK(cmd)->t_mem_list->next,
 894                                    struct se_mem, se_list),
 895                         out_se_mem, se_mem_cnt, task_offset_in);
 896 }
 897
 898 /*      rd_DIRECT_do_task(): (Part of se_subsystem_api_t template)
 899  *
 900  *
 901  */
 902 static int rd_DIRECT_do_task(struct se_task *task)
 903 {
 904         /*
 905          * At this point the locally allocated RD tables have been mapped
 906          * to struct se_mem elements in rd_DIRECT_do_se_mem_map().
 907          */
 908         task->task_scsi_status = GOOD;
 909         transport_complete_task(task, 1);
 910
 911         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 912 }
 913
 914 /*      rd_free_task(): (Part of se_subsystem_api_t template)
 915  *
 916  *
 917  */
 918 static void rd_free_task(struct se_task *task)
 919 {
 920         kfree(RD_REQ(task));
 921 }
 922
 923 enum {
 924         Opt_rd_pages, Opt_err
 925 };
 926
 927 static match_table_t tokens = {
 928         {Opt_rd_pages, "rd_pages=%d"},
 929         {Opt_err, NULL}
 930 };
 931
 932 static ssize_t rd_set_configfs_dev_params(
 933         struct se_hba *hba,
 934         struct se_subsystem_dev *se_dev,
 935         const char *page,
 936         ssize_t count)
 937 {
 938         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 939         char *orig, *ptr, *opts;
 940         substring_t args[MAX_OPT_ARGS];
 941         int ret = 0, arg, token;
 942
 943         opts = kstrdup(page, GFP_KERNEL);
 944         if (!opts)
 945                 return -ENOMEM;
 946
 947         orig = opts;
 948
 949         while ((ptr = strsep(&opts, ",")) != NULL) {
 950                 if (!*ptr)
 951                         continue;
 952
 953                 token = match_token(ptr, tokens, args);
 954                 switch (token) {
 955                 case Opt_rd_pages:
 956                         match_int(args, &arg);
 957                         rd_dev->rd_page_count = arg;
 958                         printk(KERN_INFO "RAMDISK: Referencing Page"
 959                                 " Count: %u\n", rd_dev->rd_page_count);
 960                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 961                         break;
 962                 default:
 963                         break;
 964                 }
 965         }
 966
 967         kfree(orig);
 968         return (!ret) ? count : ret;
 969 }
 970
 971 static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
 972 {
 973         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 974
 975         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 976                 printk(KERN_INFO "Missing rd_pages= parameter\n");
 977                 return -1;
 978         }
 979
 980         return 0;
 981 }
 982
 983 static ssize_t rd_show_configfs_dev_params(
 984         struct se_hba *hba,
 985         struct se_subsystem_dev *se_dev,
 986         char *b)
 987 {
 988         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 989         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: %s\n",
 990                         rd_dev->rd_dev_id, (rd_dev->rd_direct) ?
 991                         "rd_direct" : "rd_mcp");
 992         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 993                         "  SG_table_count: %u\n", rd_dev->rd_page_count,
 994                         PAGE_SIZE, rd_dev->sg_table_count);
 995         return bl;
 996 }
 997
 998 /*      rd_get_cdb(): (Part of se_subsystem_api_t template)
 999  *
1000  *
1001  */
1002 static unsigned char *rd_get_cdb(struct se_task *task)
1003 {
1004         struct rd_request *req = RD_REQ(task);
1005
1006         return req->rd_scsi_cdb;
1007 }
1008
1009 static u32 rd_get_device_rev(struct se_device *dev)
1010 {
1011         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
1012 }
1013
1014 static u32 rd_get_device_type(struct se_device *dev)
1015 {
1016         return TYPE_DISK;
1017 }
1018
1019 static sector_t rd_get_blocks(struct se_device *dev)
1020 {
1021         struct rd_dev *rd_dev = dev->dev_ptr;
1022         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
1023                         DEV_ATTRIB(dev)->block_size) - 1;
1024
1025         return blocks_long;
1026 }
1027
1028 static struct se_subsystem_api rd_dr_template = {
1029         .name                   = "rd_dr",
1030         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
1031         .attach_hba             = rd_attach_hba,
1032         .detach_hba             = rd_detach_hba,
1033         .allocate_virtdevice    = rd_DIRECT_allocate_virtdevice,
1034         .create_virtdevice      = rd_DIRECT_create_virtdevice,
1035         .free_device            = rd_free_device,
1036         .alloc_task             = rd_alloc_task,
1037         .do_task                = rd_DIRECT_do_task,
1038         .free_task              = rd_free_task,
1039         .check_configfs_dev_params = rd_check_configfs_dev_params,
1040         .set_configfs_dev_params = rd_set_configfs_dev_params,
1041         .show_configfs_dev_params = rd_show_configfs_dev_params,
1042         .get_cdb                = rd_get_cdb,
1043         .get_device_rev         = rd_get_device_rev,
1044         .get_device_type        = rd_get_device_type,
1045         .get_blocks             = rd_get_blocks,
1046         .do_se_mem_map          = rd_DIRECT_do_se_mem_map,
1047 };
1048
1049 static struct se_subsystem_api rd_mcp_template = {
1050         .name                   = "rd_mcp",
1051         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
1052         .attach_hba             = rd_attach_hba,
1053         .detach_hba             = rd_detach_hba,
1054         .allocate_virtdevice    = rd_MEMCPY_allocate_virtdevice,
1055         .create_virtdevice      = rd_MEMCPY_create_virtdevice,
1056         .free_device            = rd_free_device,
1057         .alloc_task             = rd_alloc_task,
1058         .do_task                = rd_MEMCPY_do_task,
1059         .free_task              = rd_free_task,
1060         .check_configfs_dev_params = rd_check_configfs_dev_params,
1061         .set_configfs_dev_params = rd_set_configfs_dev_params,
1062         .show_configfs_dev_params = rd_show_configfs_dev_params,
1063         .get_cdb                = rd_get_cdb,
1064         .get_device_rev         = rd_get_device_rev,
1065         .get_device_type        = rd_get_device_type,
1066         .get_blocks             = rd_get_blocks,
1067 };
1068
1069 int __init rd_module_init(void)
1070 {
1071         int ret;
1072
1073         ret = transport_subsystem_register(&rd_dr_template);
1074         if (ret < 0)
1075                 return ret;
1076
1077         ret = transport_subsystem_register(&rd_mcp_template);
1078         if (ret < 0) {
1079                 transport_subsystem_release(&rd_dr_template);
1080                 return ret;
1081         }
1082
1083         return 0;
1084 }
1085
1086 void rd_module_exit(void)
1087 {
1088         transport_subsystem_release(&rd_dr_template);
1089         transport_subsystem_release(&rd_mcp_template);
1090 }