1 /*******************************************************************************
2 * Filename: target_core_rd.c
4 * This file contains the Storage Engine <-> Ramdisk transport
7 * (c) Copyright 2003-2013 Datera, Inc.
9 * Nicholas A. Bellinger <nab@kernel.org>
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.
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.
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.
25 ******************************************************************************/
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_proto.h>
34 #include <target/target_core_base.h>
35 #include <target/target_core_backend.h>
36 #include <target/target_core_backend_configfs.h>
38 #include "target_core_rd.h"
40 static inline struct rd_dev *RD_DEV(struct se_device *dev)
42 return container_of(dev, struct rd_dev, dev);
45 /* rd_attach_hba(): (Part of se_subsystem_api_t template)
49 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
51 struct rd_host *rd_host;
53 rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
55 pr_err("Unable to allocate memory for struct rd_host\n");
59 rd_host->rd_host_id = host_id;
61 hba->hba_ptr = rd_host;
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);
70 static void rd_detach_hba(struct se_hba *hba)
72 struct rd_host *rd_host = hba->hba_ptr;
74 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
75 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
81 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
85 struct scatterlist *sg;
86 u32 i, j, page_count = 0, sg_per_table;
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;
92 for (j = 0; j < sg_per_table; j++) {
106 static void rd_release_device_space(struct rd_dev *rd_dev)
110 if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
113 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
114 rd_dev->sg_table_count);
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);
121 rd_dev->sg_table_array = NULL;
122 rd_dev->sg_table_count = 0;
126 /* rd_build_device_space():
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)
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));
137 struct scatterlist *sg;
140 while (total_sg_needed) {
141 unsigned int chain_entry = 0;
143 sg_per_table = (total_sg_needed > max_sg_per_table) ?
144 max_sg_per_table : total_sg_needed;
146 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
149 * Reserve extra element for chain entry
151 if (sg_per_table < total_sg_needed)
154 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
156 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
159 pr_err("Unable to allocate scatterlist array"
160 " for struct rd_dev\n");
164 sg_init_table(sg, sg_per_table + chain_entry);
166 #ifdef CONFIG_ARCH_HAS_SG_CHAIN
169 sg_chain(sg_table[i - 1].sg_table,
170 max_sg_per_table + 1, sg);
173 #endif /* CONFIG_ARCH_HAS_SG_CHAIN */
175 sg_table[i].sg_table = sg;
176 sg_table[i].rd_sg_count = sg_per_table;
177 sg_table[i].page_start_offset = page_offset;
178 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
181 for (j = 0; j < sg_per_table; j++) {
182 pg = alloc_pages(GFP_KERNEL, 0);
184 pr_err("Unable to allocate scatterlist"
185 " pages for struct rd_dev_sg_table\n");
188 sg_assign_page(&sg[j], pg);
189 sg[j].length = PAGE_SIZE;
192 memset(p, init_payload, PAGE_SIZE);
196 page_offset += sg_per_table;
197 total_sg_needed -= sg_per_table;
203 static int rd_build_device_space(struct rd_dev *rd_dev)
205 struct rd_dev_sg_table *sg_table;
206 u32 sg_tables, total_sg_needed;
207 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
208 sizeof(struct scatterlist));
211 if (rd_dev->rd_page_count <= 0) {
212 pr_err("Illegal page count: %u for Ramdisk device\n",
213 rd_dev->rd_page_count);
217 /* Don't need backing pages for NULLIO */
218 if (rd_dev->rd_flags & RDF_NULLIO)
221 total_sg_needed = rd_dev->rd_page_count;
223 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
225 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
227 pr_err("Unable to allocate memory for Ramdisk"
228 " scatterlist tables\n");
232 rd_dev->sg_table_array = sg_table;
233 rd_dev->sg_table_count = sg_tables;
235 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
239 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
240 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
241 rd_dev->rd_dev_id, rd_dev->rd_page_count,
242 rd_dev->sg_table_count);
247 static void rd_release_prot_space(struct rd_dev *rd_dev)
251 if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
254 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
255 rd_dev->sg_prot_count);
257 pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
258 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
259 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
260 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
262 rd_dev->sg_prot_array = NULL;
263 rd_dev->sg_prot_count = 0;
266 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
268 struct rd_dev_sg_table *sg_table;
269 u32 total_sg_needed, sg_tables;
270 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
271 sizeof(struct scatterlist));
274 if (rd_dev->rd_flags & RDF_NULLIO)
277 * prot_length=8byte dif data
278 * tot sg needed = rd_page_count * (PGSZ/block_size) *
279 * (prot_length/block_size) + pad
280 * PGSZ canceled each other.
282 total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
284 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
286 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
288 pr_err("Unable to allocate memory for Ramdisk protection"
289 " scatterlist tables\n");
293 rd_dev->sg_prot_array = sg_table;
294 rd_dev->sg_prot_count = sg_tables;
296 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
300 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
301 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
302 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
307 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
309 struct rd_dev *rd_dev;
310 struct rd_host *rd_host = hba->hba_ptr;
312 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
314 pr_err("Unable to allocate memory for struct rd_dev\n");
318 rd_dev->rd_host = rd_host;
323 static int rd_configure_device(struct se_device *dev)
325 struct rd_dev *rd_dev = RD_DEV(dev);
326 struct rd_host *rd_host = dev->se_hba->hba_ptr;
329 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
330 pr_debug("Missing rd_pages= parameter\n");
334 ret = rd_build_device_space(rd_dev);
338 dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
339 dev->dev_attrib.hw_max_sectors = UINT_MAX;
340 dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
342 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
344 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
345 " %u pages in %u tables, %lu total bytes\n",
346 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
347 rd_dev->sg_table_count,
348 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
353 rd_release_device_space(rd_dev);
357 static void rd_free_device(struct se_device *dev)
359 struct rd_dev *rd_dev = RD_DEV(dev);
361 rd_release_device_space(rd_dev);
365 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
367 struct rd_dev_sg_table *sg_table;
368 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
369 sizeof(struct scatterlist));
371 i = page / sg_per_table;
372 if (i < rd_dev->sg_table_count) {
373 sg_table = &rd_dev->sg_table_array[i];
374 if ((sg_table->page_start_offset <= page) &&
375 (sg_table->page_end_offset >= page))
379 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
385 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
387 struct rd_dev_sg_table *sg_table;
388 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
389 sizeof(struct scatterlist));
391 i = page / sg_per_table;
392 if (i < rd_dev->sg_prot_count) {
393 sg_table = &rd_dev->sg_prot_array[i];
394 if ((sg_table->page_start_offset <= page) &&
395 (sg_table->page_end_offset >= page))
399 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
405 typedef sense_reason_t (*dif_verify)(struct se_cmd *, sector_t, unsigned int,
406 unsigned int, struct scatterlist *, int);
408 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, dif_verify dif_verify)
410 struct se_device *se_dev = cmd->se_dev;
411 struct rd_dev *dev = RD_DEV(se_dev);
412 struct rd_dev_sg_table *prot_table;
413 bool need_to_release = false;
414 struct scatterlist *prot_sg;
415 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
416 u32 prot_offset, prot_page;
417 u32 prot_npages __maybe_unused;
419 sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
421 tmp = cmd->t_task_lba * se_dev->prot_length;
422 prot_offset = do_div(tmp, PAGE_SIZE);
425 prot_table = rd_get_prot_table(dev, prot_page);
427 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
429 prot_sg = &prot_table->sg_table[prot_page -
430 prot_table->page_start_offset];
432 #ifndef CONFIG_ARCH_HAS_SG_CHAIN
434 prot_npages = DIV_ROUND_UP(prot_offset + sectors * se_dev->prot_length,
438 * Allocate temporaly contiguous scatterlist entries if prot pages
439 * straddles multiple scatterlist tables.
441 if (prot_table->page_end_offset < prot_page + prot_npages - 1) {
444 prot_sg = kcalloc(prot_npages, sizeof(*prot_sg), GFP_KERNEL);
446 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
448 need_to_release = true;
449 sg_init_table(prot_sg, prot_npages);
451 for (i = 0; i < prot_npages; i++) {
452 if (prot_page + i > prot_table->page_end_offset) {
453 prot_table = rd_get_prot_table(dev,
459 sg_unmark_end(&prot_sg[i - 1]);
461 prot_sg[i] = prot_table->sg_table[prot_page + i -
462 prot_table->page_start_offset];
466 #endif /* !CONFIG_ARCH_HAS_SG_CHAIN */
468 rc = dif_verify(cmd, cmd->t_task_lba, sectors, 0, prot_sg, prot_offset);
475 static sense_reason_t
476 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
477 enum dma_data_direction data_direction)
479 struct se_device *se_dev = cmd->se_dev;
480 struct rd_dev *dev = RD_DEV(se_dev);
481 struct rd_dev_sg_table *table;
482 struct scatterlist *rd_sg;
483 struct sg_mapping_iter m;
491 if (dev->rd_flags & RDF_NULLIO) {
492 target_complete_cmd(cmd, SAM_STAT_GOOD);
496 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
497 rd_offset = do_div(tmp, PAGE_SIZE);
499 rd_size = cmd->data_length;
501 table = rd_get_sg_table(dev, rd_page);
503 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
505 rd_sg = &table->sg_table[rd_page - table->page_start_offset];
507 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
509 data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
510 cmd->t_task_lba, rd_size, rd_page, rd_offset);
512 if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
513 data_direction == DMA_TO_DEVICE) {
514 rc = rd_do_prot_rw(cmd, sbc_dif_verify_write);
519 src_len = PAGE_SIZE - rd_offset;
520 sg_miter_start(&m, sgl, sgl_nents,
521 data_direction == DMA_FROM_DEVICE ?
522 SG_MITER_TO_SG : SG_MITER_FROM_SG);
528 if (!(u32)m.length) {
529 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
530 dev->rd_dev_id, m.addr, m.length);
532 return TCM_INCORRECT_AMOUNT_OF_DATA;
534 len = min((u32)m.length, src_len);
536 pr_debug("RD[%u]: size underrun page %d offset %d "
537 "size %d\n", dev->rd_dev_id,
538 rd_page, rd_offset, rd_size);
543 rd_addr = sg_virt(rd_sg) + rd_offset;
545 if (data_direction == DMA_FROM_DEVICE)
546 memcpy(m.addr, rd_addr, len);
548 memcpy(rd_addr, m.addr, len);
560 /* rd page completed, next one please */
564 if (rd_page <= table->page_end_offset) {
569 table = rd_get_sg_table(dev, rd_page);
572 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
575 /* since we increment, the first sg entry is correct */
576 rd_sg = table->sg_table;
580 if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
581 data_direction == DMA_FROM_DEVICE) {
582 rc = rd_do_prot_rw(cmd, sbc_dif_verify_read);
587 target_complete_cmd(cmd, SAM_STAT_GOOD);
592 Opt_rd_pages, Opt_rd_nullio, Opt_err
595 static match_table_t tokens = {
596 {Opt_rd_pages, "rd_pages=%d"},
597 {Opt_rd_nullio, "rd_nullio=%d"},
601 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
602 const char *page, ssize_t count)
604 struct rd_dev *rd_dev = RD_DEV(dev);
605 char *orig, *ptr, *opts;
606 substring_t args[MAX_OPT_ARGS];
607 int ret = 0, arg, token;
609 opts = kstrdup(page, GFP_KERNEL);
615 while ((ptr = strsep(&opts, ",\n")) != NULL) {
619 token = match_token(ptr, tokens, args);
622 match_int(args, &arg);
623 rd_dev->rd_page_count = arg;
624 pr_debug("RAMDISK: Referencing Page"
625 " Count: %u\n", rd_dev->rd_page_count);
626 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
629 match_int(args, &arg);
633 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
634 rd_dev->rd_flags |= RDF_NULLIO;
642 return (!ret) ? count : ret;
645 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
647 struct rd_dev *rd_dev = RD_DEV(dev);
649 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
651 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
652 " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
653 PAGE_SIZE, rd_dev->sg_table_count,
654 !!(rd_dev->rd_flags & RDF_NULLIO));
658 static sector_t rd_get_blocks(struct se_device *dev)
660 struct rd_dev *rd_dev = RD_DEV(dev);
662 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
663 dev->dev_attrib.block_size) - 1;
668 static int rd_init_prot(struct se_device *dev)
670 struct rd_dev *rd_dev = RD_DEV(dev);
672 if (!dev->dev_attrib.pi_prot_type)
675 return rd_build_prot_space(rd_dev, dev->prot_length,
676 dev->dev_attrib.block_size);
679 static void rd_free_prot(struct se_device *dev)
681 struct rd_dev *rd_dev = RD_DEV(dev);
683 rd_release_prot_space(rd_dev);
686 static struct sbc_ops rd_sbc_ops = {
687 .execute_rw = rd_execute_rw,
690 static sense_reason_t
691 rd_parse_cdb(struct se_cmd *cmd)
693 return sbc_parse_cdb(cmd, &rd_sbc_ops);
696 DEF_TB_DEFAULT_ATTRIBS(rd_mcp);
698 static struct configfs_attribute *rd_mcp_backend_dev_attrs[] = {
699 &rd_mcp_dev_attrib_emulate_model_alias.attr,
700 &rd_mcp_dev_attrib_emulate_dpo.attr,
701 &rd_mcp_dev_attrib_emulate_fua_write.attr,
702 &rd_mcp_dev_attrib_emulate_fua_read.attr,
703 &rd_mcp_dev_attrib_emulate_write_cache.attr,
704 &rd_mcp_dev_attrib_emulate_ua_intlck_ctrl.attr,
705 &rd_mcp_dev_attrib_emulate_tas.attr,
706 &rd_mcp_dev_attrib_emulate_tpu.attr,
707 &rd_mcp_dev_attrib_emulate_tpws.attr,
708 &rd_mcp_dev_attrib_emulate_caw.attr,
709 &rd_mcp_dev_attrib_emulate_3pc.attr,
710 &rd_mcp_dev_attrib_pi_prot_type.attr,
711 &rd_mcp_dev_attrib_hw_pi_prot_type.attr,
712 &rd_mcp_dev_attrib_pi_prot_format.attr,
713 &rd_mcp_dev_attrib_enforce_pr_isids.attr,
714 &rd_mcp_dev_attrib_is_nonrot.attr,
715 &rd_mcp_dev_attrib_emulate_rest_reord.attr,
716 &rd_mcp_dev_attrib_force_pr_aptpl.attr,
717 &rd_mcp_dev_attrib_hw_block_size.attr,
718 &rd_mcp_dev_attrib_block_size.attr,
719 &rd_mcp_dev_attrib_hw_max_sectors.attr,
720 &rd_mcp_dev_attrib_optimal_sectors.attr,
721 &rd_mcp_dev_attrib_hw_queue_depth.attr,
722 &rd_mcp_dev_attrib_queue_depth.attr,
723 &rd_mcp_dev_attrib_max_unmap_lba_count.attr,
724 &rd_mcp_dev_attrib_max_unmap_block_desc_count.attr,
725 &rd_mcp_dev_attrib_unmap_granularity.attr,
726 &rd_mcp_dev_attrib_unmap_granularity_alignment.attr,
727 &rd_mcp_dev_attrib_max_write_same_len.attr,
731 static struct se_subsystem_api rd_mcp_template = {
733 .inquiry_prod = "RAMDISK-MCP",
734 .inquiry_rev = RD_MCP_VERSION,
735 .attach_hba = rd_attach_hba,
736 .detach_hba = rd_detach_hba,
737 .alloc_device = rd_alloc_device,
738 .configure_device = rd_configure_device,
739 .free_device = rd_free_device,
740 .parse_cdb = rd_parse_cdb,
741 .set_configfs_dev_params = rd_set_configfs_dev_params,
742 .show_configfs_dev_params = rd_show_configfs_dev_params,
743 .get_device_type = sbc_get_device_type,
744 .get_blocks = rd_get_blocks,
745 .init_prot = rd_init_prot,
746 .free_prot = rd_free_prot,
749 int __init rd_module_init(void)
751 struct target_backend_cits *tbc = &rd_mcp_template.tb_cits;
754 target_core_setup_sub_cits(&rd_mcp_template);
755 tbc->tb_dev_attrib_cit.ct_attrs = rd_mcp_backend_dev_attrs;
757 ret = transport_subsystem_register(&rd_mcp_template);
765 void rd_module_exit(void)
767 transport_subsystem_release(&rd_mcp_template);