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.h>
33 #include <scsi/scsi_host.h>
35 #include <target/target_core_base.h>
36 #include <target/target_core_backend.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 sg_per_table = (total_sg_needed > max_sg_per_table) ?
142 max_sg_per_table : total_sg_needed;
144 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
147 pr_err("Unable to allocate scatterlist array"
148 " for struct rd_dev\n");
152 sg_init_table(sg, sg_per_table);
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)
160 for (j = 0; j < sg_per_table; j++) {
161 pg = alloc_pages(GFP_KERNEL, 0);
163 pr_err("Unable to allocate scatterlist"
164 " pages for struct rd_dev_sg_table\n");
167 sg_assign_page(&sg[j], pg);
168 sg[j].length = PAGE_SIZE;
171 memset(p, init_payload, PAGE_SIZE);
175 page_offset += sg_per_table;
176 total_sg_needed -= sg_per_table;
182 static int rd_build_device_space(struct rd_dev *rd_dev)
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));
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);
196 /* Don't need backing pages for NULLIO */
197 if (rd_dev->rd_flags & RDF_NULLIO)
200 total_sg_needed = rd_dev->rd_page_count;
202 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
204 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
206 pr_err("Unable to allocate memory for Ramdisk"
207 " scatterlist tables\n");
211 rd_dev->sg_table_array = sg_table;
212 rd_dev->sg_table_count = sg_tables;
214 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
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);
226 static void rd_release_prot_space(struct rd_dev *rd_dev)
230 if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
233 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
234 rd_dev->sg_prot_count);
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);
241 rd_dev->sg_prot_array = NULL;
242 rd_dev->sg_prot_count = 0;
245 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length)
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));
253 if (rd_dev->rd_flags & RDF_NULLIO)
256 total_sg_needed = rd_dev->rd_page_count / prot_length;
258 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
260 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
262 pr_err("Unable to allocate memory for Ramdisk protection"
263 " scatterlist tables\n");
267 rd_dev->sg_prot_array = sg_table;
268 rd_dev->sg_prot_count = sg_tables;
270 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
274 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
275 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
276 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
281 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
283 struct rd_dev *rd_dev;
284 struct rd_host *rd_host = hba->hba_ptr;
286 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
288 pr_err("Unable to allocate memory for struct rd_dev\n");
292 rd_dev->rd_host = rd_host;
297 static int rd_configure_device(struct se_device *dev)
299 struct rd_dev *rd_dev = RD_DEV(dev);
300 struct rd_host *rd_host = dev->se_hba->hba_ptr;
303 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
304 pr_debug("Missing rd_pages= parameter\n");
308 ret = rd_build_device_space(rd_dev);
312 dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
313 dev->dev_attrib.hw_max_sectors = UINT_MAX;
314 dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
316 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
318 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
319 " %u pages in %u tables, %lu total bytes\n",
320 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
321 rd_dev->sg_table_count,
322 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
327 rd_release_device_space(rd_dev);
331 static void rd_free_device(struct se_device *dev)
333 struct rd_dev *rd_dev = RD_DEV(dev);
335 rd_release_device_space(rd_dev);
339 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
341 struct rd_dev_sg_table *sg_table;
342 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
343 sizeof(struct scatterlist));
345 i = page / sg_per_table;
346 if (i < rd_dev->sg_table_count) {
347 sg_table = &rd_dev->sg_table_array[i];
348 if ((sg_table->page_start_offset <= page) &&
349 (sg_table->page_end_offset >= page))
353 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
359 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
361 struct rd_dev_sg_table *sg_table;
362 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
363 sizeof(struct scatterlist));
365 i = page / sg_per_table;
366 if (i < rd_dev->sg_prot_count) {
367 sg_table = &rd_dev->sg_prot_array[i];
368 if ((sg_table->page_start_offset <= page) &&
369 (sg_table->page_end_offset >= page))
373 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
379 static sense_reason_t
380 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
381 enum dma_data_direction data_direction)
383 struct se_device *se_dev = cmd->se_dev;
384 struct rd_dev *dev = RD_DEV(se_dev);
385 struct rd_dev_sg_table *table;
386 struct scatterlist *rd_sg;
387 struct sg_mapping_iter m;
395 if (dev->rd_flags & RDF_NULLIO) {
396 target_complete_cmd(cmd, SAM_STAT_GOOD);
400 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
401 rd_offset = do_div(tmp, PAGE_SIZE);
403 rd_size = cmd->data_length;
405 table = rd_get_sg_table(dev, rd_page);
407 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
409 rd_sg = &table->sg_table[rd_page - table->page_start_offset];
411 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
413 data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
414 cmd->t_task_lba, rd_size, rd_page, rd_offset);
416 if (cmd->prot_type && data_direction == DMA_TO_DEVICE) {
417 struct rd_dev_sg_table *prot_table;
418 struct scatterlist *prot_sg;
419 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
420 u32 prot_offset, prot_page;
422 tmp = cmd->t_task_lba * se_dev->prot_length;
423 prot_offset = do_div(tmp, PAGE_SIZE);
426 prot_table = rd_get_prot_table(dev, prot_page);
428 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
430 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
432 rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors, 0,
433 prot_sg, prot_offset);
438 src_len = PAGE_SIZE - rd_offset;
439 sg_miter_start(&m, sgl, sgl_nents,
440 data_direction == DMA_FROM_DEVICE ?
441 SG_MITER_TO_SG : SG_MITER_FROM_SG);
447 if (!(u32)m.length) {
448 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
449 dev->rd_dev_id, m.addr, m.length);
451 return TCM_INCORRECT_AMOUNT_OF_DATA;
453 len = min((u32)m.length, src_len);
455 pr_debug("RD[%u]: size underrun page %d offset %d "
456 "size %d\n", dev->rd_dev_id,
457 rd_page, rd_offset, rd_size);
462 rd_addr = sg_virt(rd_sg) + rd_offset;
464 if (data_direction == DMA_FROM_DEVICE)
465 memcpy(m.addr, rd_addr, len);
467 memcpy(rd_addr, m.addr, len);
479 /* rd page completed, next one please */
483 if (rd_page <= table->page_end_offset) {
488 table = rd_get_sg_table(dev, rd_page);
491 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
494 /* since we increment, the first sg entry is correct */
495 rd_sg = table->sg_table;
499 if (cmd->prot_type && data_direction == DMA_FROM_DEVICE) {
500 struct rd_dev_sg_table *prot_table;
501 struct scatterlist *prot_sg;
502 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
503 u32 prot_offset, prot_page;
505 tmp = cmd->t_task_lba * se_dev->prot_length;
506 prot_offset = do_div(tmp, PAGE_SIZE);
509 prot_table = rd_get_prot_table(dev, prot_page);
511 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
513 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
515 rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
516 prot_sg, prot_offset);
521 target_complete_cmd(cmd, SAM_STAT_GOOD);
526 Opt_rd_pages, Opt_rd_nullio, Opt_err
529 static match_table_t tokens = {
530 {Opt_rd_pages, "rd_pages=%d"},
531 {Opt_rd_nullio, "rd_nullio=%d"},
535 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
536 const char *page, ssize_t count)
538 struct rd_dev *rd_dev = RD_DEV(dev);
539 char *orig, *ptr, *opts;
540 substring_t args[MAX_OPT_ARGS];
541 int ret = 0, arg, token;
543 opts = kstrdup(page, GFP_KERNEL);
549 while ((ptr = strsep(&opts, ",\n")) != NULL) {
553 token = match_token(ptr, tokens, args);
556 match_int(args, &arg);
557 rd_dev->rd_page_count = arg;
558 pr_debug("RAMDISK: Referencing Page"
559 " Count: %u\n", rd_dev->rd_page_count);
560 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
563 match_int(args, &arg);
567 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
568 rd_dev->rd_flags |= RDF_NULLIO;
576 return (!ret) ? count : ret;
579 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
581 struct rd_dev *rd_dev = RD_DEV(dev);
583 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
585 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
586 " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
587 PAGE_SIZE, rd_dev->sg_table_count,
588 !!(rd_dev->rd_flags & RDF_NULLIO));
592 static sector_t rd_get_blocks(struct se_device *dev)
594 struct rd_dev *rd_dev = RD_DEV(dev);
596 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
597 dev->dev_attrib.block_size) - 1;
602 static int rd_init_prot(struct se_device *dev)
604 struct rd_dev *rd_dev = RD_DEV(dev);
606 if (!dev->dev_attrib.pi_prot_type)
609 return rd_build_prot_space(rd_dev, dev->prot_length);
612 static void rd_free_prot(struct se_device *dev)
614 struct rd_dev *rd_dev = RD_DEV(dev);
616 rd_release_prot_space(rd_dev);
619 static struct sbc_ops rd_sbc_ops = {
620 .execute_rw = rd_execute_rw,
623 static sense_reason_t
624 rd_parse_cdb(struct se_cmd *cmd)
626 return sbc_parse_cdb(cmd, &rd_sbc_ops);
629 static struct se_subsystem_api rd_mcp_template = {
631 .inquiry_prod = "RAMDISK-MCP",
632 .inquiry_rev = RD_MCP_VERSION,
633 .transport_type = TRANSPORT_PLUGIN_VHBA_VDEV,
634 .attach_hba = rd_attach_hba,
635 .detach_hba = rd_detach_hba,
636 .alloc_device = rd_alloc_device,
637 .configure_device = rd_configure_device,
638 .free_device = rd_free_device,
639 .parse_cdb = rd_parse_cdb,
640 .set_configfs_dev_params = rd_set_configfs_dev_params,
641 .show_configfs_dev_params = rd_show_configfs_dev_params,
642 .get_device_type = sbc_get_device_type,
643 .get_blocks = rd_get_blocks,
644 .init_prot = rd_init_prot,
645 .free_prot = rd_free_prot,
648 int __init rd_module_init(void)
652 ret = transport_subsystem_register(&rd_mcp_template);
660 void rd_module_exit(void)
662 transport_subsystem_release(&rd_mcp_template);