1 /*******************************************************************************
2 * Filename: target_core_rd.c
4 * This file contains the Storage Engine <-> Ramdisk transport
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
12 * Nicholas A. Bellinger <nab@kernel.org>
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.
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.
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.
28 ******************************************************************************/
30 #include <linux/string.h>
31 #include <linux/parser.h>
32 #include <linux/timer.h>
33 #include <linux/blkdev.h>
34 #include <linux/slab.h>
35 #include <linux/spinlock.h>
36 #include <scsi/scsi.h>
37 #include <scsi/scsi_host.h>
39 #include <target/target_core_base.h>
40 #include <target/target_core_backend.h>
42 #include "target_core_rd.h"
44 static struct se_subsystem_api rd_mcp_template;
46 /* rd_attach_hba(): (Part of se_subsystem_api_t template)
50 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
52 struct rd_host *rd_host;
54 rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
56 pr_err("Unable to allocate memory for struct rd_host\n");
60 rd_host->rd_host_id = host_id;
62 hba->hba_ptr = rd_host;
64 pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
65 " Generic Target Core Stack %s\n", hba->hba_id,
66 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
67 pr_debug("CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
68 " MaxSectors: %u\n", hba->hba_id,
69 rd_host->rd_host_id, RD_MAX_SECTORS);
74 static void rd_detach_hba(struct se_hba *hba)
76 struct rd_host *rd_host = hba->hba_ptr;
78 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
79 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
85 /* rd_release_device_space():
89 static void rd_release_device_space(struct rd_dev *rd_dev)
91 u32 i, j, page_count = 0, sg_per_table;
92 struct rd_dev_sg_table *sg_table;
94 struct scatterlist *sg;
96 if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
99 sg_table = rd_dev->sg_table_array;
101 for (i = 0; i < rd_dev->sg_table_count; i++) {
102 sg = sg_table[i].sg_table;
103 sg_per_table = sg_table[i].rd_sg_count;
105 for (j = 0; j < sg_per_table; j++) {
106 pg = sg_page(&sg[j]);
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);
122 rd_dev->sg_table_array = NULL;
123 rd_dev->sg_table_count = 0;
127 /* rd_build_device_space():
131 static int rd_build_device_space(struct rd_dev *rd_dev)
133 u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
134 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
135 sizeof(struct scatterlist));
136 struct rd_dev_sg_table *sg_table;
138 struct scatterlist *sg;
140 if (rd_dev->rd_page_count <= 0) {
141 pr_err("Illegal page count: %u for Ramdisk device\n",
142 rd_dev->rd_page_count);
145 total_sg_needed = rd_dev->rd_page_count;
147 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
149 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
151 pr_err("Unable to allocate memory for Ramdisk"
152 " scatterlist tables\n");
156 rd_dev->sg_table_array = sg_table;
157 rd_dev->sg_table_count = sg_tables;
159 while (total_sg_needed) {
160 sg_per_table = (total_sg_needed > max_sg_per_table) ?
161 max_sg_per_table : total_sg_needed;
163 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
166 pr_err("Unable to allocate scatterlist array"
167 " for struct rd_dev\n");
171 sg_init_table(sg, sg_per_table);
173 sg_table[i].sg_table = sg;
174 sg_table[i].rd_sg_count = sg_per_table;
175 sg_table[i].page_start_offset = page_offset;
176 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
179 for (j = 0; j < sg_per_table; j++) {
180 pg = alloc_pages(GFP_KERNEL, 0);
182 pr_err("Unable to allocate scatterlist"
183 " pages for struct rd_dev_sg_table\n");
186 sg_assign_page(&sg[j], pg);
187 sg[j].length = PAGE_SIZE;
190 page_offset += sg_per_table;
191 total_sg_needed -= sg_per_table;
194 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
195 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
196 rd_dev->rd_dev_id, rd_dev->rd_page_count,
197 rd_dev->sg_table_count);
202 static void *rd_allocate_virtdevice(
207 struct rd_dev *rd_dev;
208 struct rd_host *rd_host = hba->hba_ptr;
210 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
212 pr_err("Unable to allocate memory for struct rd_dev\n");
216 rd_dev->rd_host = rd_host;
217 rd_dev->rd_direct = rd_direct;
222 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba *hba, const char *name)
224 return rd_allocate_virtdevice(hba, name, 0);
227 /* rd_create_virtdevice():
231 static struct se_device *rd_create_virtdevice(
233 struct se_subsystem_dev *se_dev,
237 struct se_device *dev;
238 struct se_dev_limits dev_limits;
239 struct rd_dev *rd_dev = p;
240 struct rd_host *rd_host = hba->hba_ptr;
241 int dev_flags = 0, ret;
242 char prod[16], rev[4];
244 memset(&dev_limits, 0, sizeof(struct se_dev_limits));
246 ret = rd_build_device_space(rd_dev);
250 snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
251 snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
254 dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
255 dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS;
256 dev_limits.limits.max_sectors = RD_MAX_SECTORS;
257 dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
258 dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
260 dev = transport_add_device_to_core_hba(hba,
261 &rd_mcp_template, se_dev, dev_flags, rd_dev,
262 &dev_limits, prod, rev);
266 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
267 rd_dev->rd_queue_depth = dev->queue_depth;
269 pr_debug("CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
270 " %u pages in %u tables, %lu total bytes\n",
271 rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" :
272 "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count,
273 rd_dev->sg_table_count,
274 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
279 rd_release_device_space(rd_dev);
283 static struct se_device *rd_MEMCPY_create_virtdevice(
285 struct se_subsystem_dev *se_dev,
288 return rd_create_virtdevice(hba, se_dev, p, 0);
291 /* rd_free_device(): (Part of se_subsystem_api_t template)
295 static void rd_free_device(void *p)
297 struct rd_dev *rd_dev = p;
299 rd_release_device_space(rd_dev);
303 static inline struct rd_request *RD_REQ(struct se_task *task)
305 return container_of(task, struct rd_request, rd_task);
308 static struct se_task *
309 rd_alloc_task(unsigned char *cdb)
311 struct rd_request *rd_req;
313 rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL);
315 pr_err("Unable to allocate struct rd_request\n");
319 return &rd_req->rd_task;
322 /* rd_get_sg_table():
326 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
329 struct rd_dev_sg_table *sg_table;
331 for (i = 0; i < rd_dev->sg_table_count; i++) {
332 sg_table = &rd_dev->sg_table_array[i];
333 if ((sg_table->page_start_offset <= page) &&
334 (sg_table->page_end_offset >= page))
338 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
344 static int rd_MEMCPY(struct rd_request *req, u32 read_rd)
346 struct se_task *task = &req->rd_task;
347 struct rd_dev *dev = req->rd_task.task_se_cmd->se_dev->dev_ptr;
348 struct rd_dev_sg_table *table;
349 struct scatterlist *rd_sg;
350 struct sg_mapping_iter m;
351 u32 rd_offset = req->rd_offset;
354 table = rd_get_sg_table(dev, req->rd_page);
358 rd_sg = &table->sg_table[req->rd_page - table->page_start_offset];
360 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
361 dev->rd_dev_id, read_rd ? "Read" : "Write",
362 task->task_lba, req->rd_size, req->rd_page,
365 src_len = PAGE_SIZE - rd_offset;
366 sg_miter_start(&m, task->task_sg, task->task_sg_nents,
367 read_rd ? SG_MITER_TO_SG : SG_MITER_FROM_SG);
368 while (req->rd_size) {
373 len = min((u32)m.length, src_len);
376 rd_addr = sg_virt(rd_sg) + rd_offset;
379 memcpy(m.addr, rd_addr, len);
381 memcpy(rd_addr, m.addr, len);
393 /* rd page completed, next one please */
397 if (req->rd_page <= table->page_end_offset) {
402 table = rd_get_sg_table(dev, req->rd_page);
408 /* since we increment, the first sg entry is correct */
409 rd_sg = table->sg_table;
415 /* rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
419 static int rd_MEMCPY_do_task(struct se_task *task)
421 struct se_device *dev = task->task_se_cmd->se_dev;
422 struct rd_request *req = RD_REQ(task);
426 tmp = task->task_lba * dev->se_sub_dev->se_dev_attrib.block_size;
427 req->rd_offset = do_div(tmp, PAGE_SIZE);
429 req->rd_size = task->task_size;
431 ret = rd_MEMCPY(req, task->task_data_direction == DMA_FROM_DEVICE);
435 task->task_scsi_status = GOOD;
436 transport_complete_task(task, 1);
440 /* rd_free_task(): (Part of se_subsystem_api_t template)
444 static void rd_free_task(struct se_task *task)
450 Opt_rd_pages, Opt_err
453 static match_table_t tokens = {
454 {Opt_rd_pages, "rd_pages=%d"},
458 static ssize_t rd_set_configfs_dev_params(
460 struct se_subsystem_dev *se_dev,
464 struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
465 char *orig, *ptr, *opts;
466 substring_t args[MAX_OPT_ARGS];
467 int ret = 0, arg, token;
469 opts = kstrdup(page, GFP_KERNEL);
475 while ((ptr = strsep(&opts, ",\n")) != NULL) {
479 token = match_token(ptr, tokens, args);
482 match_int(args, &arg);
483 rd_dev->rd_page_count = arg;
484 pr_debug("RAMDISK: Referencing Page"
485 " Count: %u\n", rd_dev->rd_page_count);
486 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
494 return (!ret) ? count : ret;
497 static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
499 struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
501 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
502 pr_debug("Missing rd_pages= parameter\n");
509 static ssize_t rd_show_configfs_dev_params(
511 struct se_subsystem_dev *se_dev,
514 struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
515 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: %s\n",
516 rd_dev->rd_dev_id, (rd_dev->rd_direct) ?
517 "rd_direct" : "rd_mcp");
518 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
519 " SG_table_count: %u\n", rd_dev->rd_page_count,
520 PAGE_SIZE, rd_dev->sg_table_count);
524 static u32 rd_get_device_rev(struct se_device *dev)
526 return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
529 static u32 rd_get_device_type(struct se_device *dev)
534 static sector_t rd_get_blocks(struct se_device *dev)
536 struct rd_dev *rd_dev = dev->dev_ptr;
537 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
538 dev->se_sub_dev->se_dev_attrib.block_size) - 1;
543 static struct se_subsystem_api rd_mcp_template = {
545 .transport_type = TRANSPORT_PLUGIN_VHBA_VDEV,
546 .attach_hba = rd_attach_hba,
547 .detach_hba = rd_detach_hba,
548 .allocate_virtdevice = rd_MEMCPY_allocate_virtdevice,
549 .create_virtdevice = rd_MEMCPY_create_virtdevice,
550 .free_device = rd_free_device,
551 .alloc_task = rd_alloc_task,
552 .do_task = rd_MEMCPY_do_task,
553 .free_task = rd_free_task,
554 .check_configfs_dev_params = rd_check_configfs_dev_params,
555 .set_configfs_dev_params = rd_set_configfs_dev_params,
556 .show_configfs_dev_params = rd_show_configfs_dev_params,
557 .get_device_rev = rd_get_device_rev,
558 .get_device_type = rd_get_device_type,
559 .get_blocks = rd_get_blocks,
562 int __init rd_module_init(void)
566 ret = transport_subsystem_register(&rd_mcp_template);
574 void rd_module_exit(void)
576 transport_subsystem_release(&rd_mcp_template);