1 /******************************************************************************* 2 * Filename: target_core_rd.c 3 * 4 * This file contains the Storage Engine <-> Ramdisk transport 5 * specific functions. 6 * 7 * (c) Copyright 2003-2013 Datera, Inc. 8 * 9 * Nicholas A. Bellinger <nab@kernel.org> 10 * 11 * This program is free software; you can redistribute it and/or modify 12 * it under the terms of the GNU General Public License as published by 13 * the Free Software Foundation; either version 2 of the License, or 14 * (at your option) any later version. 15 * 16 * This program is distributed in the hope that it will be useful, 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19 * GNU General Public License for more details. 20 * 21 * You should have received a copy of the GNU General Public License 22 * along with this program; if not, write to the Free Software 23 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 24 * 25 ******************************************************************************/ 26 27 #include <linux/string.h> 28 #include <linux/parser.h> 29 #include <linux/timer.h> 30 #include <linux/slab.h> 31 #include <linux/spinlock.h> 32 #include <scsi/scsi.h> 33 #include <scsi/scsi_host.h> 34 35 #include <target/target_core_base.h> 36 #include <target/target_core_backend.h> 37 38 #include "target_core_rd.h" 39 40 static inline struct rd_dev *RD_DEV(struct se_device *dev) 41 { 42 return container_of(dev, struct rd_dev, dev); 43 } 44 45 /* rd_attach_hba(): (Part of se_subsystem_api_t template) 46 * 47 * 48 */ 49 static int rd_attach_hba(struct se_hba *hba, u32 host_id) 50 { 51 struct rd_host *rd_host; 52 53 rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL); 54 if (!rd_host) { 55 pr_err("Unable to allocate memory for struct rd_host\n"); 56 return -ENOMEM; 57 } 58 59 rd_host->rd_host_id = host_id; 60 61 hba->hba_ptr = rd_host; 62 63 pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on" 64 " Generic Target Core Stack %s\n", hba->hba_id, 65 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION); 66 67 return 0; 68 } 69 70 static void rd_detach_hba(struct se_hba *hba) 71 { 72 struct rd_host *rd_host = hba->hba_ptr; 73 74 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from" 75 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id); 76 77 kfree(rd_host); 78 hba->hba_ptr = NULL; 79 } 80 81 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table, 82 u32 sg_table_count) 83 { 84 struct page *pg; 85 struct scatterlist *sg; 86 u32 i, j, page_count = 0, sg_per_table; 87 88 for (i = 0; i < sg_table_count; i++) { 89 sg = sg_table[i].sg_table; 90 sg_per_table = sg_table[i].rd_sg_count; 91 92 for (j = 0; j < sg_per_table; j++) { 93 pg = sg_page(&sg[j]); 94 if (pg) { 95 __free_page(pg); 96 page_count++; 97 } 98 } 99 kfree(sg); 100 } 101 102 kfree(sg_table); 103 return page_count; 104 } 105 106 static void rd_release_device_space(struct rd_dev *rd_dev) 107 { 108 u32 page_count; 109 110 if (!rd_dev->sg_table_array || !rd_dev->sg_table_count) 111 return; 112 113 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array, 114 rd_dev->sg_table_count); 115 116 pr_debug("CORE_RD[%u] - Released device space for Ramdisk" 117 " Device ID: %u, pages %u in %u tables total bytes %lu\n", 118 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count, 119 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE); 120 121 rd_dev->sg_table_array = NULL; 122 rd_dev->sg_table_count = 0; 123 } 124 125 126 /* rd_build_device_space(): 127 * 128 * 129 */ 130 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table, 131 u32 total_sg_needed, unsigned char init_payload) 132 { 133 u32 i = 0, j, page_offset = 0, sg_per_table; 134 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE / 135 sizeof(struct scatterlist)); 136 struct page *pg; 137 struct scatterlist *sg; 138 unsigned char *p; 139 140 while (total_sg_needed) { 141 sg_per_table = (total_sg_needed > max_sg_per_table) ? 142 max_sg_per_table : total_sg_needed; 143 144 sg = kzalloc(sg_per_table * sizeof(struct scatterlist), 145 GFP_KERNEL); 146 if (!sg) { 147 pr_err("Unable to allocate scatterlist array" 148 " for struct rd_dev\n"); 149 return -ENOMEM; 150 } 151 152 sg_init_table(sg, sg_per_table); 153 154 sg_table[i].sg_table = sg; 155 sg_table[i].rd_sg_count = sg_per_table; 156 sg_table[i].page_start_offset = page_offset; 157 sg_table[i++].page_end_offset = (page_offset + sg_per_table) 158 - 1; 159 160 for (j = 0; j < sg_per_table; j++) { 161 pg = alloc_pages(GFP_KERNEL, 0); 162 if (!pg) { 163 pr_err("Unable to allocate scatterlist" 164 " pages for struct rd_dev_sg_table\n"); 165 return -ENOMEM; 166 } 167 sg_assign_page(&sg[j], pg); 168 sg[j].length = PAGE_SIZE; 169 170 p = kmap(pg); 171 memset(p, init_payload, PAGE_SIZE); 172 kunmap(pg); 173 } 174 175 page_offset += sg_per_table; 176 total_sg_needed -= sg_per_table; 177 } 178 179 return 0; 180 } 181 182 static int rd_build_device_space(struct rd_dev *rd_dev) 183 { 184 struct rd_dev_sg_table *sg_table; 185 u32 sg_tables, total_sg_needed; 186 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE / 187 sizeof(struct scatterlist)); 188 int rc; 189 190 if (rd_dev->rd_page_count <= 0) { 191 pr_err("Illegal page count: %u for Ramdisk device\n", 192 rd_dev->rd_page_count); 193 return -EINVAL; 194 } 195 196 /* Don't need backing pages for NULLIO */ 197 if (rd_dev->rd_flags & RDF_NULLIO) 198 return 0; 199 200 total_sg_needed = rd_dev->rd_page_count; 201 202 sg_tables = (total_sg_needed / max_sg_per_table) + 1; 203 204 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL); 205 if (!sg_table) { 206 pr_err("Unable to allocate memory for Ramdisk" 207 " scatterlist tables\n"); 208 return -ENOMEM; 209 } 210 211 rd_dev->sg_table_array = sg_table; 212 rd_dev->sg_table_count = sg_tables; 213 214 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00); 215 if (rc) 216 return rc; 217 218 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of" 219 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id, 220 rd_dev->rd_dev_id, rd_dev->rd_page_count, 221 rd_dev->sg_table_count); 222 223 return 0; 224 } 225 226 static void rd_release_prot_space(struct rd_dev *rd_dev) 227 { 228 u32 page_count; 229 230 if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count) 231 return; 232 233 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array, 234 rd_dev->sg_prot_count); 235 236 pr_debug("CORE_RD[%u] - Released protection space for Ramdisk" 237 " Device ID: %u, pages %u in %u tables total bytes %lu\n", 238 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count, 239 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE); 240 241 rd_dev->sg_prot_array = NULL; 242 rd_dev->sg_prot_count = 0; 243 } 244 245 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size) 246 { 247 struct rd_dev_sg_table *sg_table; 248 u32 total_sg_needed, sg_tables; 249 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE / 250 sizeof(struct scatterlist)); 251 int rc; 252 253 if (rd_dev->rd_flags & RDF_NULLIO) 254 return 0; 255 /* 256 * prot_length=8byte dif data 257 * tot sg needed = rd_page_count * (PGSZ/block_size) * 258 * (prot_length/block_size) + pad 259 * PGSZ canceled each other. 260 */ 261 total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1; 262 263 sg_tables = (total_sg_needed / max_sg_per_table) + 1; 264 265 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL); 266 if (!sg_table) { 267 pr_err("Unable to allocate memory for Ramdisk protection" 268 " scatterlist tables\n"); 269 return -ENOMEM; 270 } 271 272 rd_dev->sg_prot_array = sg_table; 273 rd_dev->sg_prot_count = sg_tables; 274 275 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff); 276 if (rc) 277 return rc; 278 279 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of" 280 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id, 281 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count); 282 283 return 0; 284 } 285 286 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name) 287 { 288 struct rd_dev *rd_dev; 289 struct rd_host *rd_host = hba->hba_ptr; 290 291 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL); 292 if (!rd_dev) { 293 pr_err("Unable to allocate memory for struct rd_dev\n"); 294 return NULL; 295 } 296 297 rd_dev->rd_host = rd_host; 298 299 return &rd_dev->dev; 300 } 301 302 static int rd_configure_device(struct se_device *dev) 303 { 304 struct rd_dev *rd_dev = RD_DEV(dev); 305 struct rd_host *rd_host = dev->se_hba->hba_ptr; 306 int ret; 307 308 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) { 309 pr_debug("Missing rd_pages= parameter\n"); 310 return -EINVAL; 311 } 312 313 ret = rd_build_device_space(rd_dev); 314 if (ret < 0) 315 goto fail; 316 317 dev->dev_attrib.hw_block_size = RD_BLOCKSIZE; 318 dev->dev_attrib.hw_max_sectors = UINT_MAX; 319 dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH; 320 321 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++; 322 323 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of" 324 " %u pages in %u tables, %lu total bytes\n", 325 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count, 326 rd_dev->sg_table_count, 327 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE)); 328 329 return 0; 330 331 fail: 332 rd_release_device_space(rd_dev); 333 return ret; 334 } 335 336 static void rd_free_device(struct se_device *dev) 337 { 338 struct rd_dev *rd_dev = RD_DEV(dev); 339 340 rd_release_device_space(rd_dev); 341 kfree(rd_dev); 342 } 343 344 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page) 345 { 346 struct rd_dev_sg_table *sg_table; 347 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE / 348 sizeof(struct scatterlist)); 349 350 i = page / sg_per_table; 351 if (i < rd_dev->sg_table_count) { 352 sg_table = &rd_dev->sg_table_array[i]; 353 if ((sg_table->page_start_offset <= page) && 354 (sg_table->page_end_offset >= page)) 355 return sg_table; 356 } 357 358 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n", 359 page); 360 361 return NULL; 362 } 363 364 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page) 365 { 366 struct rd_dev_sg_table *sg_table; 367 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE / 368 sizeof(struct scatterlist)); 369 370 i = page / sg_per_table; 371 if (i < rd_dev->sg_prot_count) { 372 sg_table = &rd_dev->sg_prot_array[i]; 373 if ((sg_table->page_start_offset <= page) && 374 (sg_table->page_end_offset >= page)) 375 return sg_table; 376 } 377 378 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n", 379 page); 380 381 return NULL; 382 } 383 384 static sense_reason_t 385 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents, 386 enum dma_data_direction data_direction) 387 { 388 struct se_device *se_dev = cmd->se_dev; 389 struct rd_dev *dev = RD_DEV(se_dev); 390 struct rd_dev_sg_table *table; 391 struct scatterlist *rd_sg; 392 struct sg_mapping_iter m; 393 u32 rd_offset; 394 u32 rd_size; 395 u32 rd_page; 396 u32 src_len; 397 u64 tmp; 398 sense_reason_t rc; 399 400 if (dev->rd_flags & RDF_NULLIO) { 401 target_complete_cmd(cmd, SAM_STAT_GOOD); 402 return 0; 403 } 404 405 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size; 406 rd_offset = do_div(tmp, PAGE_SIZE); 407 rd_page = tmp; 408 rd_size = cmd->data_length; 409 410 table = rd_get_sg_table(dev, rd_page); 411 if (!table) 412 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 413 414 rd_sg = &table->sg_table[rd_page - table->page_start_offset]; 415 416 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n", 417 dev->rd_dev_id, 418 data_direction == DMA_FROM_DEVICE ? "Read" : "Write", 419 cmd->t_task_lba, rd_size, rd_page, rd_offset); 420 421 if (cmd->prot_type && data_direction == DMA_TO_DEVICE) { 422 struct rd_dev_sg_table *prot_table; 423 struct scatterlist *prot_sg; 424 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; 425 u32 prot_offset, prot_page; 426 427 tmp = cmd->t_task_lba * se_dev->prot_length; 428 prot_offset = do_div(tmp, PAGE_SIZE); 429 prot_page = tmp; 430 431 prot_table = rd_get_prot_table(dev, prot_page); 432 if (!prot_table) 433 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 434 435 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset]; 436 437 rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors, 0, 438 prot_sg, prot_offset); 439 if (rc) 440 return rc; 441 } 442 443 src_len = PAGE_SIZE - rd_offset; 444 sg_miter_start(&m, sgl, sgl_nents, 445 data_direction == DMA_FROM_DEVICE ? 446 SG_MITER_TO_SG : SG_MITER_FROM_SG); 447 while (rd_size) { 448 u32 len; 449 void *rd_addr; 450 451 sg_miter_next(&m); 452 if (!(u32)m.length) { 453 pr_debug("RD[%u]: invalid sgl %p len %zu\n", 454 dev->rd_dev_id, m.addr, m.length); 455 sg_miter_stop(&m); 456 return TCM_INCORRECT_AMOUNT_OF_DATA; 457 } 458 len = min((u32)m.length, src_len); 459 if (len > rd_size) { 460 pr_debug("RD[%u]: size underrun page %d offset %d " 461 "size %d\n", dev->rd_dev_id, 462 rd_page, rd_offset, rd_size); 463 len = rd_size; 464 } 465 m.consumed = len; 466 467 rd_addr = sg_virt(rd_sg) + rd_offset; 468 469 if (data_direction == DMA_FROM_DEVICE) 470 memcpy(m.addr, rd_addr, len); 471 else 472 memcpy(rd_addr, m.addr, len); 473 474 rd_size -= len; 475 if (!rd_size) 476 continue; 477 478 src_len -= len; 479 if (src_len) { 480 rd_offset += len; 481 continue; 482 } 483 484 /* rd page completed, next one please */ 485 rd_page++; 486 rd_offset = 0; 487 src_len = PAGE_SIZE; 488 if (rd_page <= table->page_end_offset) { 489 rd_sg++; 490 continue; 491 } 492 493 table = rd_get_sg_table(dev, rd_page); 494 if (!table) { 495 sg_miter_stop(&m); 496 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 497 } 498 499 /* since we increment, the first sg entry is correct */ 500 rd_sg = table->sg_table; 501 } 502 sg_miter_stop(&m); 503 504 if (cmd->prot_type && data_direction == DMA_FROM_DEVICE) { 505 struct rd_dev_sg_table *prot_table; 506 struct scatterlist *prot_sg; 507 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size; 508 u32 prot_offset, prot_page; 509 510 tmp = cmd->t_task_lba * se_dev->prot_length; 511 prot_offset = do_div(tmp, PAGE_SIZE); 512 prot_page = tmp; 513 514 prot_table = rd_get_prot_table(dev, prot_page); 515 if (!prot_table) 516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE; 517 518 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset]; 519 520 rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0, 521 prot_sg, prot_offset); 522 if (rc) 523 return rc; 524 } 525 526 target_complete_cmd(cmd, SAM_STAT_GOOD); 527 return 0; 528 } 529 530 enum { 531 Opt_rd_pages, Opt_rd_nullio, Opt_err 532 }; 533 534 static match_table_t tokens = { 535 {Opt_rd_pages, "rd_pages=%d"}, 536 {Opt_rd_nullio, "rd_nullio=%d"}, 537 {Opt_err, NULL} 538 }; 539 540 static ssize_t rd_set_configfs_dev_params(struct se_device *dev, 541 const char *page, ssize_t count) 542 { 543 struct rd_dev *rd_dev = RD_DEV(dev); 544 char *orig, *ptr, *opts; 545 substring_t args[MAX_OPT_ARGS]; 546 int ret = 0, arg, token; 547 548 opts = kstrdup(page, GFP_KERNEL); 549 if (!opts) 550 return -ENOMEM; 551 552 orig = opts; 553 554 while ((ptr = strsep(&opts, ",\n")) != NULL) { 555 if (!*ptr) 556 continue; 557 558 token = match_token(ptr, tokens, args); 559 switch (token) { 560 case Opt_rd_pages: 561 match_int(args, &arg); 562 rd_dev->rd_page_count = arg; 563 pr_debug("RAMDISK: Referencing Page" 564 " Count: %u\n", rd_dev->rd_page_count); 565 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT; 566 break; 567 case Opt_rd_nullio: 568 match_int(args, &arg); 569 if (arg != 1) 570 break; 571 572 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg); 573 rd_dev->rd_flags |= RDF_NULLIO; 574 break; 575 default: 576 break; 577 } 578 } 579 580 kfree(orig); 581 return (!ret) ? count : ret; 582 } 583 584 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b) 585 { 586 struct rd_dev *rd_dev = RD_DEV(dev); 587 588 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n", 589 rd_dev->rd_dev_id); 590 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu" 591 " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count, 592 PAGE_SIZE, rd_dev->sg_table_count, 593 !!(rd_dev->rd_flags & RDF_NULLIO)); 594 return bl; 595 } 596 597 static sector_t rd_get_blocks(struct se_device *dev) 598 { 599 struct rd_dev *rd_dev = RD_DEV(dev); 600 601 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) / 602 dev->dev_attrib.block_size) - 1; 603 604 return blocks_long; 605 } 606 607 static int rd_init_prot(struct se_device *dev) 608 { 609 struct rd_dev *rd_dev = RD_DEV(dev); 610 611 if (!dev->dev_attrib.pi_prot_type) 612 return 0; 613 614 return rd_build_prot_space(rd_dev, dev->prot_length, 615 dev->dev_attrib.block_size); 616 } 617 618 static void rd_free_prot(struct se_device *dev) 619 { 620 struct rd_dev *rd_dev = RD_DEV(dev); 621 622 rd_release_prot_space(rd_dev); 623 } 624 625 static struct sbc_ops rd_sbc_ops = { 626 .execute_rw = rd_execute_rw, 627 }; 628 629 static sense_reason_t 630 rd_parse_cdb(struct se_cmd *cmd) 631 { 632 return sbc_parse_cdb(cmd, &rd_sbc_ops); 633 } 634 635 static struct se_subsystem_api rd_mcp_template = { 636 .name = "rd_mcp", 637 .inquiry_prod = "RAMDISK-MCP", 638 .inquiry_rev = RD_MCP_VERSION, 639 .transport_type = TRANSPORT_PLUGIN_VHBA_VDEV, 640 .attach_hba = rd_attach_hba, 641 .detach_hba = rd_detach_hba, 642 .alloc_device = rd_alloc_device, 643 .configure_device = rd_configure_device, 644 .free_device = rd_free_device, 645 .parse_cdb = rd_parse_cdb, 646 .set_configfs_dev_params = rd_set_configfs_dev_params, 647 .show_configfs_dev_params = rd_show_configfs_dev_params, 648 .get_device_type = sbc_get_device_type, 649 .get_blocks = rd_get_blocks, 650 .init_prot = rd_init_prot, 651 .free_prot = rd_free_prot, 652 }; 653 654 int __init rd_module_init(void) 655 { 656 int ret; 657 658 ret = transport_subsystem_register(&rd_mcp_template); 659 if (ret < 0) { 660 return ret; 661 } 662 663 return 0; 664 } 665 666 void rd_module_exit(void) 667 { 668 transport_subsystem_release(&rd_mcp_template); 669 } 670