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 -EINVAL;
 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 -ENOMEM;
 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 -ENOMEM;
 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 -ENOMEM;
 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, ret;
 257         char prod[16], rev[4];
 258
 259         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
 260
 261         ret = rd_build_device_space(rd_dev);
 262         if (ret < 0)
 263                 goto fail;
 264
 265         snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
 266         snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
 267                                                 RD_MCP_VERSION);
 268
 269         dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
 270         dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS;
 271         dev_limits.limits.max_sectors = RD_MAX_SECTORS;
 272         dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
 273         dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
 274
 275         dev = transport_add_device_to_core_hba(hba,
 276                         (rd_dev->rd_direct) ? &rd_dr_template :
 277                         &rd_mcp_template, se_dev, dev_flags, (void *)rd_dev,
 278                         &dev_limits, prod, rev);
 279         if (!(dev))
 280                 goto fail;
 281
 282         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
 283         rd_dev->rd_queue_depth = dev->queue_depth;
 284
 285         printk(KERN_INFO "CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
 286                 " %u pages in %u tables, %lu total bytes\n",
 287                 rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" :
 288                 "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count,
 289                 rd_dev->sg_table_count,
 290                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
 291
 292         return dev;
 293
 294 fail:
 295         rd_release_device_space(rd_dev);
 296         return ERR_PTR(ret);
 297 }
 298
 299 static struct se_device *rd_DIRECT_create_virtdevice(
 300         struct se_hba *hba,
 301         struct se_subsystem_dev *se_dev,
 302         void *p)
 303 {
 304         return rd_create_virtdevice(hba, se_dev, p, 1);
 305 }
 306
 307 static struct se_device *rd_MEMCPY_create_virtdevice(
 308         struct se_hba *hba,
 309         struct se_subsystem_dev *se_dev,
 310         void *p)
 311 {
 312         return rd_create_virtdevice(hba, se_dev, p, 0);
 313 }
 314
 315 /*      rd_free_device(): (Part of se_subsystem_api_t template)
 316  *
 317  *
 318  */
 319 static void rd_free_device(void *p)
 320 {
 321         struct rd_dev *rd_dev = p;
 322
 323         rd_release_device_space(rd_dev);
 324         kfree(rd_dev);
 325 }
 326
 327 static inline struct rd_request *RD_REQ(struct se_task *task)
 328 {
 329         return container_of(task, struct rd_request, rd_task);
 330 }
 331
 332 static struct se_task *
 333 rd_alloc_task(struct se_cmd *cmd)
 334 {
 335         struct rd_request *rd_req;
 336
 337         rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL);
 338         if (!rd_req) {
 339                 printk(KERN_ERR "Unable to allocate struct rd_request\n");
 340                 return NULL;
 341         }
 342         rd_req->rd_dev = SE_DEV(cmd)->dev_ptr;
 343
 344         return &rd_req->rd_task;
 345 }
 346
 347 /*      rd_get_sg_table():
 348  *
 349  *
 350  */
 351 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
 352 {
 353         u32 i;
 354         struct rd_dev_sg_table *sg_table;
 355
 356         for (i = 0; i < rd_dev->sg_table_count; i++) {
 357                 sg_table = &rd_dev->sg_table_array[i];
 358                 if ((sg_table->page_start_offset <= page) &&
 359                     (sg_table->page_end_offset >= page))
 360                         return sg_table;
 361         }
 362
 363         printk(KERN_ERR "Unable to locate struct rd_dev_sg_table for page: %u\n",
 364                         page);
 365
 366         return NULL;
 367 }
 368
 369 /*      rd_MEMCPY_read():
 370  *
 371  *
 372  */
 373 static int rd_MEMCPY_read(struct rd_request *req)
 374 {
 375         struct se_task *task = &req->rd_task;
 376         struct rd_dev *dev = req->rd_dev;
 377         struct rd_dev_sg_table *table;
 378         struct scatterlist *sg_d, *sg_s;
 379         void *dst, *src;
 380         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 381         u32 length, page_end = 0, table_sg_end;
 382         u32 rd_offset = req->rd_offset;
 383
 384         table = rd_get_sg_table(dev, req->rd_page);
 385         if (!(table))
 386                 return -1;
 387
 388         table_sg_end = (table->page_end_offset - req->rd_page);
 389         sg_d = task->task_sg;
 390         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 391 #ifdef DEBUG_RAMDISK_MCP
 392         printk(KERN_INFO "RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:"
 393                 " %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 394                 req->rd_page, req->rd_offset);
 395 #endif
 396         src_offset = rd_offset;
 397
 398         while (req->rd_size) {
 399                 if ((sg_d[i].length - dst_offset) <
 400                     (sg_s[j].length - src_offset)) {
 401                         length = (sg_d[i].length - dst_offset);
 402 #ifdef DEBUG_RAMDISK_MCP
 403                         printk(KERN_INFO "Step 1 - sg_d[%d]: %p length: %d"
 404                                 " offset: %u sg_s[%d].length: %u\n", i,
 405                                 &sg_d[i], sg_d[i].length, sg_d[i].offset, j,
 406                                 sg_s[j].length);
 407                         printk(KERN_INFO "Step 1 - length: %u dst_offset: %u"
 408                                 " src_offset: %u\n", length, dst_offset,
 409                                 src_offset);
 410 #endif
 411                         if (length > req->rd_size)
 412                                 length = req->rd_size;
 413
 414                         dst = sg_virt(&sg_d[i++]) + dst_offset;
 415                         if (!dst)
 416                                 BUG();
 417
 418                         src = sg_virt(&sg_s[j]) + src_offset;
 419                         if (!src)
 420                                 BUG();
 421
 422                         dst_offset = 0;
 423                         src_offset = length;
 424                         page_end = 0;
 425                 } else {
 426                         length = (sg_s[j].length - src_offset);
 427 #ifdef DEBUG_RAMDISK_MCP
 428                         printk(KERN_INFO "Step 2 - sg_d[%d]: %p length: %d"
 429                                 " offset: %u sg_s[%d].length: %u\n", i,
 430                                 &sg_d[i], sg_d[i].length, sg_d[i].offset,
 431                                 j, sg_s[j].length);
 432                         printk(KERN_INFO "Step 2 - length: %u dst_offset: %u"
 433                                 " src_offset: %u\n", length, dst_offset,
 434                                 src_offset);
 435 #endif
 436                         if (length > req->rd_size)
 437                                 length = req->rd_size;
 438
 439                         dst = sg_virt(&sg_d[i]) + dst_offset;
 440                         if (!dst)
 441                                 BUG();
 442
 443                         if (sg_d[i].length == length) {
 444                                 i++;
 445                                 dst_offset = 0;
 446                         } else
 447                                 dst_offset = length;
 448
 449                         src = sg_virt(&sg_s[j++]) + src_offset;
 450                         if (!src)
 451                                 BUG();
 452
 453                         src_offset = 0;
 454                         page_end = 1;
 455                 }
 456
 457                 memcpy(dst, src, length);
 458
 459 #ifdef DEBUG_RAMDISK_MCP
 460                 printk(KERN_INFO "page: %u, remaining size: %u, length: %u,"
 461                         " i: %u, j: %u\n", req->rd_page,
 462                         (req->rd_size - length), length, i, j);
 463 #endif
 464                 req->rd_size -= length;
 465                 if (!(req->rd_size))
 466                         return 0;
 467
 468                 if (!page_end)
 469                         continue;
 470
 471                 if (++req->rd_page <= table->page_end_offset) {
 472 #ifdef DEBUG_RAMDISK_MCP
 473                         printk(KERN_INFO "page: %u in same page table\n",
 474                                 req->rd_page);
 475 #endif
 476                         continue;
 477                 }
 478 #ifdef DEBUG_RAMDISK_MCP
 479                 printk(KERN_INFO "getting new page table for page: %u\n",
 480                                 req->rd_page);
 481 #endif
 482                 table = rd_get_sg_table(dev, req->rd_page);
 483                 if (!(table))
 484                         return -1;
 485
 486                 sg_s = &table->sg_table[j = 0];
 487         }
 488
 489         return 0;
 490 }
 491
 492 /*      rd_MEMCPY_write():
 493  *
 494  *
 495  */
 496 static int rd_MEMCPY_write(struct rd_request *req)
 497 {
 498         struct se_task *task = &req->rd_task;
 499         struct rd_dev *dev = req->rd_dev;
 500         struct rd_dev_sg_table *table;
 501         struct scatterlist *sg_d, *sg_s;
 502         void *dst, *src;
 503         u32 i = 0, j = 0, dst_offset = 0, src_offset = 0;
 504         u32 length, page_end = 0, table_sg_end;
 505         u32 rd_offset = req->rd_offset;
 506
 507         table = rd_get_sg_table(dev, req->rd_page);
 508         if (!(table))
 509                 return -1;
 510
 511         table_sg_end = (table->page_end_offset - req->rd_page);
 512         sg_d = &table->sg_table[req->rd_page - table->page_start_offset];
 513         sg_s = task->task_sg;
 514 #ifdef DEBUG_RAMDISK_MCP
 515         printk(KERN_INFO "RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
 516                 " Offset: %u\n", dev->rd_dev_id, task->task_lba, req->rd_size,
 517                 req->rd_page, req->rd_offset);
 518 #endif
 519         dst_offset = rd_offset;
 520
 521         while (req->rd_size) {
 522                 if ((sg_s[i].length - src_offset) <
 523                     (sg_d[j].length - dst_offset)) {
 524                         length = (sg_s[i].length - src_offset);
 525 #ifdef DEBUG_RAMDISK_MCP
 526                         printk(KERN_INFO "Step 1 - sg_s[%d]: %p length: %d"
 527                                 " offset: %d sg_d[%d].length: %u\n", i,
 528                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 529                                 j, sg_d[j].length);
 530                         printk(KERN_INFO "Step 1 - length: %u src_offset: %u"
 531                                 " dst_offset: %u\n", length, src_offset,
 532                                 dst_offset);
 533 #endif
 534                         if (length > req->rd_size)
 535                                 length = req->rd_size;
 536
 537                         src = sg_virt(&sg_s[i++]) + src_offset;
 538                         if (!src)
 539                                 BUG();
 540
 541                         dst = sg_virt(&sg_d[j]) + dst_offset;
 542                         if (!dst)
 543                                 BUG();
 544
 545                         src_offset = 0;
 546                         dst_offset = length;
 547                         page_end = 0;
 548                 } else {
 549                         length = (sg_d[j].length - dst_offset);
 550 #ifdef DEBUG_RAMDISK_MCP
 551                         printk(KERN_INFO "Step 2 - sg_s[%d]: %p length: %d"
 552                                 " offset: %d sg_d[%d].length: %u\n", i,
 553                                 &sg_s[i], sg_s[i].length, sg_s[i].offset,
 554                                 j, sg_d[j].length);
 555                         printk(KERN_INFO "Step 2 - length: %u src_offset: %u"
 556                                 " dst_offset: %u\n", length, src_offset,
 557                                 dst_offset);
 558 #endif
 559                         if (length > req->rd_size)
 560                                 length = req->rd_size;
 561
 562                         src = sg_virt(&sg_s[i]) + src_offset;
 563                         if (!src)
 564                                 BUG();
 565
 566                         if (sg_s[i].length == length) {
 567                                 i++;
 568                                 src_offset = 0;
 569                         } else
 570                                 src_offset = length;
 571
 572                         dst = sg_virt(&sg_d[j++]) + dst_offset;
 573                         if (!dst)
 574                                 BUG();
 575
 576                         dst_offset = 0;
 577                         page_end = 1;
 578                 }
 579
 580                 memcpy(dst, src, length);
 581
 582 #ifdef DEBUG_RAMDISK_MCP
 583                 printk(KERN_INFO "page: %u, remaining size: %u, length: %u,"
 584                         " i: %u, j: %u\n", req->rd_page,
 585                         (req->rd_size - length), length, i, j);
 586 #endif
 587                 req->rd_size -= length;
 588                 if (!(req->rd_size))
 589                         return 0;
 590
 591                 if (!page_end)
 592                         continue;
 593
 594                 if (++req->rd_page <= table->page_end_offset) {
 595 #ifdef DEBUG_RAMDISK_MCP
 596                         printk(KERN_INFO "page: %u in same page table\n",
 597                                 req->rd_page);
 598 #endif
 599                         continue;
 600                 }
 601 #ifdef DEBUG_RAMDISK_MCP
 602                 printk(KERN_INFO "getting new page table for page: %u\n",
 603                                 req->rd_page);
 604 #endif
 605                 table = rd_get_sg_table(dev, req->rd_page);
 606                 if (!(table))
 607                         return -1;
 608
 609                 sg_d = &table->sg_table[j = 0];
 610         }
 611
 612         return 0;
 613 }
 614
 615 /*      rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
 616  *
 617  *
 618  */
 619 static int rd_MEMCPY_do_task(struct se_task *task)
 620 {
 621         struct se_device *dev = task->se_dev;
 622         struct rd_request *req = RD_REQ(task);
 623         unsigned long long lba;
 624         int ret;
 625
 626         req->rd_page = (task->task_lba * DEV_ATTRIB(dev)->block_size) / PAGE_SIZE;
 627         lba = task->task_lba;
 628         req->rd_offset = (do_div(lba,
 629                           (PAGE_SIZE / DEV_ATTRIB(dev)->block_size))) *
 630                            DEV_ATTRIB(dev)->block_size;
 631         req->rd_size = task->task_size;
 632
 633         if (task->task_data_direction == DMA_FROM_DEVICE)
 634                 ret = rd_MEMCPY_read(req);
 635         else
 636                 ret = rd_MEMCPY_write(req);
 637
 638         if (ret != 0)
 639                 return ret;
 640
 641         task->task_scsi_status = GOOD;
 642         transport_complete_task(task, 1);
 643
 644         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 645 }
 646
 647 /*      rd_DIRECT_with_offset():
 648  *
 649  *
 650  */
 651 static int rd_DIRECT_with_offset(
 652         struct se_task *task,
 653         struct list_head *se_mem_list,
 654         u32 *se_mem_cnt,
 655         u32 *task_offset)
 656 {
 657         struct rd_request *req = RD_REQ(task);
 658         struct rd_dev *dev = req->rd_dev;
 659         struct rd_dev_sg_table *table;
 660         struct se_mem *se_mem;
 661         struct scatterlist *sg_s;
 662         u32 j = 0, set_offset = 1;
 663         u32 get_next_table = 0, offset_length, table_sg_end;
 664
 665         table = rd_get_sg_table(dev, req->rd_page);
 666         if (!(table))
 667                 return -1;
 668
 669         table_sg_end = (table->page_end_offset - req->rd_page);
 670         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 671 #ifdef DEBUG_RAMDISK_DR
 672         printk(KERN_INFO "%s DIRECT LBA: %llu, Size: %u Page: %u, Offset: %u\n",
 673                 (task->task_data_direction == DMA_TO_DEVICE) ?
 674                         "Write" : "Read",
 675                 task->task_lba, req->rd_size, req->rd_page, req->rd_offset);
 676 #endif
 677         while (req->rd_size) {
 678                 se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
 679                 if (!(se_mem)) {
 680                         printk(KERN_ERR "Unable to allocate struct se_mem\n");
 681                         return -1;
 682                 }
 683                 INIT_LIST_HEAD(&se_mem->se_list);
 684
 685                 if (set_offset) {
 686                         offset_length = sg_s[j].length - req->rd_offset;
 687                         if (offset_length > req->rd_size)
 688                                 offset_length = req->rd_size;
 689
 690                         se_mem->se_page = sg_page(&sg_s[j++]);
 691                         se_mem->se_off = req->rd_offset;
 692                         se_mem->se_len = offset_length;
 693
 694                         set_offset = 0;
 695                         get_next_table = (j > table_sg_end);
 696                         goto check_eot;
 697                 }
 698
 699                 offset_length = (req->rd_size < req->rd_offset) ?
 700                         req->rd_size : req->rd_offset;
 701
 702                 se_mem->se_page = sg_page(&sg_s[j]);
 703                 se_mem->se_len = offset_length;
 704
 705                 set_offset = 1;
 706
 707 check_eot:
 708 #ifdef DEBUG_RAMDISK_DR
 709                 printk(KERN_INFO "page: %u, size: %u, offset_length: %u, j: %u"
 710                         " se_mem: %p, se_page: %p se_off: %u se_len: %u\n",
 711                         req->rd_page, req->rd_size, offset_length, j, se_mem,
 712                         se_mem->se_page, se_mem->se_off, se_mem->se_len);
 713 #endif
 714                 list_add_tail(&se_mem->se_list, se_mem_list);
 715                 (*se_mem_cnt)++;
 716
 717                 req->rd_size -= offset_length;
 718                 if (!(req->rd_size))
 719                         goto out;
 720
 721                 if (!set_offset && !get_next_table)
 722                         continue;
 723
 724                 if (++req->rd_page <= table->page_end_offset) {
 725 #ifdef DEBUG_RAMDISK_DR
 726                         printk(KERN_INFO "page: %u in same page table\n",
 727                                         req->rd_page);
 728 #endif
 729                         continue;
 730                 }
 731 #ifdef DEBUG_RAMDISK_DR
 732                 printk(KERN_INFO "getting new page table for page: %u\n",
 733                                 req->rd_page);
 734 #endif
 735                 table = rd_get_sg_table(dev, req->rd_page);
 736                 if (!(table))
 737                         return -1;
 738
 739                 sg_s = &table->sg_table[j = 0];
 740         }
 741
 742 out:
 743         T_TASK(task->task_se_cmd)->t_tasks_se_num += *se_mem_cnt;
 744 #ifdef DEBUG_RAMDISK_DR
 745         printk(KERN_INFO "RD_DR - Allocated %u struct se_mem segments for task\n",
 746                         *se_mem_cnt);
 747 #endif
 748         return 0;
 749 }
 750
 751 /*      rd_DIRECT_without_offset():
 752  *
 753  *
 754  */
 755 static int rd_DIRECT_without_offset(
 756         struct se_task *task,
 757         struct list_head *se_mem_list,
 758         u32 *se_mem_cnt,
 759         u32 *task_offset)
 760 {
 761         struct rd_request *req = RD_REQ(task);
 762         struct rd_dev *dev = req->rd_dev;
 763         struct rd_dev_sg_table *table;
 764         struct se_mem *se_mem;
 765         struct scatterlist *sg_s;
 766         u32 length, j = 0;
 767
 768         table = rd_get_sg_table(dev, req->rd_page);
 769         if (!(table))
 770                 return -1;
 771
 772         sg_s = &table->sg_table[req->rd_page - table->page_start_offset];
 773 #ifdef DEBUG_RAMDISK_DR
 774         printk(KERN_INFO "%s DIRECT LBA: %llu, Size: %u, Page: %u\n",
 775                 (task->task_data_direction == DMA_TO_DEVICE) ?
 776                         "Write" : "Read",
 777                 task->task_lba, req->rd_size, req->rd_page);
 778 #endif
 779         while (req->rd_size) {
 780                 se_mem = kmem_cache_zalloc(se_mem_cache, GFP_KERNEL);
 781                 if (!(se_mem)) {
 782                         printk(KERN_ERR "Unable to allocate struct se_mem\n");
 783                         return -1;
 784                 }
 785                 INIT_LIST_HEAD(&se_mem->se_list);
 786
 787                 length = (req->rd_size < sg_s[j].length) ?
 788                         req->rd_size : sg_s[j].length;
 789
 790                 se_mem->se_page = sg_page(&sg_s[j++]);
 791                 se_mem->se_len = length;
 792
 793 #ifdef DEBUG_RAMDISK_DR
 794                 printk(KERN_INFO "page: %u, size: %u, j: %u se_mem: %p,"
 795                         " se_page: %p se_off: %u se_len: %u\n", req->rd_page,
 796                         req->rd_size, j, se_mem, se_mem->se_page,
 797                         se_mem->se_off, se_mem->se_len);
 798 #endif
 799                 list_add_tail(&se_mem->se_list, se_mem_list);
 800                 (*se_mem_cnt)++;
 801
 802                 req->rd_size -= length;
 803                 if (!(req->rd_size))
 804                         goto out;
 805
 806                 if (++req->rd_page <= table->page_end_offset) {
 807 #ifdef DEBUG_RAMDISK_DR
 808                         printk("page: %u in same page table\n",
 809                                 req->rd_page);
 810 #endif
 811                         continue;
 812                 }
 813 #ifdef DEBUG_RAMDISK_DR
 814                 printk(KERN_INFO "getting new page table for page: %u\n",
 815                                 req->rd_page);
 816 #endif
 817                 table = rd_get_sg_table(dev, req->rd_page);
 818                 if (!(table))
 819                         return -1;
 820
 821                 sg_s = &table->sg_table[j = 0];
 822         }
 823
 824 out:
 825         T_TASK(task->task_se_cmd)->t_tasks_se_num += *se_mem_cnt;
 826 #ifdef DEBUG_RAMDISK_DR
 827         printk(KERN_INFO "RD_DR - Allocated %u struct se_mem segments for task\n",
 828                         *se_mem_cnt);
 829 #endif
 830         return 0;
 831 }
 832
 833 /*      rd_DIRECT_do_se_mem_map():
 834  *
 835  *
 836  */
 837 static int rd_DIRECT_do_se_mem_map(
 838         struct se_task *task,
 839         struct list_head *se_mem_list,
 840         void *in_mem,
 841         struct se_mem *in_se_mem,
 842         struct se_mem **out_se_mem,
 843         u32 *se_mem_cnt,
 844         u32 *task_offset_in)
 845 {
 846         struct se_cmd *cmd = task->task_se_cmd;
 847         struct rd_request *req = RD_REQ(task);
 848         u32 task_offset = *task_offset_in;
 849         unsigned long long lba;
 850         int ret;
 851
 852         req->rd_page = ((task->task_lba * DEV_ATTRIB(task->se_dev)->block_size) /
 853                         PAGE_SIZE);
 854         lba = task->task_lba;
 855         req->rd_offset = (do_div(lba,
 856                           (PAGE_SIZE / DEV_ATTRIB(task->se_dev)->block_size))) *
 857                            DEV_ATTRIB(task->se_dev)->block_size;
 858         req->rd_size = task->task_size;
 859
 860         if (req->rd_offset)
 861                 ret = rd_DIRECT_with_offset(task, se_mem_list, se_mem_cnt,
 862                                 task_offset_in);
 863         else
 864                 ret = rd_DIRECT_without_offset(task, se_mem_list, se_mem_cnt,
 865                                 task_offset_in);
 866
 867         if (ret < 0)
 868                 return ret;
 869
 870         if (CMD_TFO(cmd)->task_sg_chaining == 0)
 871                 return 0;
 872         /*
 873          * Currently prevent writers from multiple HW fabrics doing
 874          * pci_map_sg() to RD_DR's internal scatterlist memory.
 875          */
 876         if (cmd->data_direction == DMA_TO_DEVICE) {
 877                 printk(KERN_ERR "DMA_TO_DEVICE not supported for"
 878                                 " RAMDISK_DR with task_sg_chaining=1\n");
 879                 return -1;
 880         }
 881         /*
 882          * Special case for if task_sg_chaining is enabled, then
 883          * we setup struct se_task->task_sg[], as it will be used by
 884          * transport_do_task_sg_chain() for creating chainged SGLs
 885          * across multiple struct se_task->task_sg[].
 886          */
 887         if (!(transport_calc_sg_num(task,
 888                         list_entry(T_TASK(cmd)->t_mem_list->next,
 889                                    struct se_mem, se_list),
 890                         task_offset)))
 891                 return -1;
 892
 893         return transport_map_mem_to_sg(task, se_mem_list, task->task_sg,
 894                         list_entry(T_TASK(cmd)->t_mem_list->next,
 895                                    struct se_mem, se_list),
 896                         out_se_mem, se_mem_cnt, task_offset_in);
 897 }
 898
 899 /*      rd_DIRECT_do_task(): (Part of se_subsystem_api_t template)
 900  *
 901  *
 902  */
 903 static int rd_DIRECT_do_task(struct se_task *task)
 904 {
 905         /*
 906          * At this point the locally allocated RD tables have been mapped
 907          * to struct se_mem elements in rd_DIRECT_do_se_mem_map().
 908          */
 909         task->task_scsi_status = GOOD;
 910         transport_complete_task(task, 1);
 911
 912         return PYX_TRANSPORT_SENT_TO_TRANSPORT;
 913 }
 914
 915 /*      rd_free_task(): (Part of se_subsystem_api_t template)
 916  *
 917  *
 918  */
 919 static void rd_free_task(struct se_task *task)
 920 {
 921         kfree(RD_REQ(task));
 922 }
 923
 924 enum {
 925         Opt_rd_pages, Opt_err
 926 };
 927
 928 static match_table_t tokens = {
 929         {Opt_rd_pages, "rd_pages=%d"},
 930         {Opt_err, NULL}
 931 };
 932
 933 static ssize_t rd_set_configfs_dev_params(
 934         struct se_hba *hba,
 935         struct se_subsystem_dev *se_dev,
 936         const char *page,
 937         ssize_t count)
 938 {
 939         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 940         char *orig, *ptr, *opts;
 941         substring_t args[MAX_OPT_ARGS];
 942         int ret = 0, arg, token;
 943
 944         opts = kstrdup(page, GFP_KERNEL);
 945         if (!opts)
 946                 return -ENOMEM;
 947
 948         orig = opts;
 949
 950         while ((ptr = strsep(&opts, ",")) != NULL) {
 951                 if (!*ptr)
 952                         continue;
 953
 954                 token = match_token(ptr, tokens, args);
 955                 switch (token) {
 956                 case Opt_rd_pages:
 957                         match_int(args, &arg);
 958                         rd_dev->rd_page_count = arg;
 959                         printk(KERN_INFO "RAMDISK: Referencing Page"
 960                                 " Count: %u\n", rd_dev->rd_page_count);
 961                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
 962                         break;
 963                 default:
 964                         break;
 965                 }
 966         }
 967
 968         kfree(orig);
 969         return (!ret) ? count : ret;
 970 }
 971
 972 static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
 973 {
 974         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 975
 976         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
 977                 printk(KERN_INFO "Missing rd_pages= parameter\n");
 978                 return -1;
 979         }
 980
 981         return 0;
 982 }
 983
 984 static ssize_t rd_show_configfs_dev_params(
 985         struct se_hba *hba,
 986         struct se_subsystem_dev *se_dev,
 987         char *b)
 988 {
 989         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
 990         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: %s\n",
 991                         rd_dev->rd_dev_id, (rd_dev->rd_direct) ?
 992                         "rd_direct" : "rd_mcp");
 993         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
 994                         "  SG_table_count: %u\n", rd_dev->rd_page_count,
 995                         PAGE_SIZE, rd_dev->sg_table_count);
 996         return bl;
 997 }
 998
 999 /*      rd_get_cdb(): (Part of se_subsystem_api_t template)
1000  *
1001  *
1002  */
1003 static unsigned char *rd_get_cdb(struct se_task *task)
1004 {
1005         struct rd_request *req = RD_REQ(task);
1006
1007         return req->rd_scsi_cdb;
1008 }
1009
1010 static u32 rd_get_device_rev(struct se_device *dev)
1011 {
1012         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
1013 }
1014
1015 static u32 rd_get_device_type(struct se_device *dev)
1016 {
1017         return TYPE_DISK;
1018 }
1019
1020 static sector_t rd_get_blocks(struct se_device *dev)
1021 {
1022         struct rd_dev *rd_dev = dev->dev_ptr;
1023         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
1024                         DEV_ATTRIB(dev)->block_size) - 1;
1025
1026         return blocks_long;
1027 }
1028
1029 static struct se_subsystem_api rd_dr_template = {
1030         .name                   = "rd_dr",
1031         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
1032         .attach_hba             = rd_attach_hba,
1033         .detach_hba             = rd_detach_hba,
1034         .allocate_virtdevice    = rd_DIRECT_allocate_virtdevice,
1035         .create_virtdevice      = rd_DIRECT_create_virtdevice,
1036         .free_device            = rd_free_device,
1037         .alloc_task             = rd_alloc_task,
1038         .do_task                = rd_DIRECT_do_task,
1039         .free_task              = rd_free_task,
1040         .check_configfs_dev_params = rd_check_configfs_dev_params,
1041         .set_configfs_dev_params = rd_set_configfs_dev_params,
1042         .show_configfs_dev_params = rd_show_configfs_dev_params,
1043         .get_cdb                = rd_get_cdb,
1044         .get_device_rev         = rd_get_device_rev,
1045         .get_device_type        = rd_get_device_type,
1046         .get_blocks             = rd_get_blocks,
1047         .do_se_mem_map          = rd_DIRECT_do_se_mem_map,
1048 };
1049
1050 static struct se_subsystem_api rd_mcp_template = {
1051         .name                   = "rd_mcp",
1052         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
1053         .attach_hba             = rd_attach_hba,
1054         .detach_hba             = rd_detach_hba,
1055         .allocate_virtdevice    = rd_MEMCPY_allocate_virtdevice,
1056         .create_virtdevice      = rd_MEMCPY_create_virtdevice,
1057         .free_device            = rd_free_device,
1058         .alloc_task             = rd_alloc_task,
1059         .do_task                = rd_MEMCPY_do_task,
1060         .free_task              = rd_free_task,
1061         .check_configfs_dev_params = rd_check_configfs_dev_params,
1062         .set_configfs_dev_params = rd_set_configfs_dev_params,
1063         .show_configfs_dev_params = rd_show_configfs_dev_params,
1064         .get_cdb                = rd_get_cdb,
1065         .get_device_rev         = rd_get_device_rev,
1066         .get_device_type        = rd_get_device_type,
1067         .get_blocks             = rd_get_blocks,
1068 };
1069
1070 int __init rd_module_init(void)
1071 {
1072         int ret;
1073
1074         ret = transport_subsystem_register(&rd_dr_template);
1075         if (ret < 0)
1076                 return ret;
1077
1078         ret = transport_subsystem_register(&rd_mcp_template);
1079         if (ret < 0) {
1080                 transport_subsystem_release(&rd_dr_template);
1081                 return ret;
1082         }
1083
1084         return 0;
1085 }
1086
1087 void rd_module_exit(void)
1088 {
1089         transport_subsystem_release(&rd_dr_template);
1090         transport_subsystem_release(&rd_mcp_template);
1091 }