1 /*******************************************************************************
2 * Filename: target_core_rd.c
4 * This file contains the Storage Engine <-> Ramdisk transport
7 * (c) Copyright 2003-2012 RisingTide Systems LLC.
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/blkdev.h>
31 #include <linux/slab.h>
32 #include <linux/spinlock.h>
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_host.h>
36 #include <target/target_core_base.h>
37 #include <target/target_core_backend.h>
39 #include "target_core_rd.h"
41 static inline struct rd_dev
*RD_DEV(struct se_device
*dev
)
43 return container_of(dev
, struct rd_dev
, dev
);
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
);
71 static void rd_detach_hba(struct se_hba
*hba
)
73 struct rd_host
*rd_host
= hba
->hba_ptr
;
75 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
76 " Generic Target Core\n", hba
->hba_id
, rd_host
->rd_host_id
);
82 /* rd_release_device_space():
86 static void rd_release_device_space(struct rd_dev
*rd_dev
)
88 u32 i
, j
, page_count
= 0, sg_per_table
;
89 struct rd_dev_sg_table
*sg_table
;
91 struct scatterlist
*sg
;
93 if (!rd_dev
->sg_table_array
|| !rd_dev
->sg_table_count
)
96 sg_table
= rd_dev
->sg_table_array
;
98 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
99 sg
= sg_table
[i
].sg_table
;
100 sg_per_table
= sg_table
[i
].rd_sg_count
;
102 for (j
= 0; j
< sg_per_table
; j
++) {
103 pg
= sg_page(&sg
[j
]);
113 pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
114 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
115 rd_dev
->rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, page_count
,
116 rd_dev
->sg_table_count
, (unsigned long)page_count
* PAGE_SIZE
);
119 rd_dev
->sg_table_array
= NULL
;
120 rd_dev
->sg_table_count
= 0;
124 /* rd_build_device_space():
128 static int rd_build_device_space(struct rd_dev
*rd_dev
)
130 u32 i
= 0, j
, page_offset
= 0, sg_per_table
, sg_tables
, total_sg_needed
;
131 u32 max_sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
132 sizeof(struct scatterlist
));
133 struct rd_dev_sg_table
*sg_table
;
135 struct scatterlist
*sg
;
137 if (rd_dev
->rd_page_count
<= 0) {
138 pr_err("Illegal page count: %u for Ramdisk device\n",
139 rd_dev
->rd_page_count
);
142 total_sg_needed
= rd_dev
->rd_page_count
;
144 sg_tables
= (total_sg_needed
/ max_sg_per_table
) + 1;
146 sg_table
= kzalloc(sg_tables
* sizeof(struct rd_dev_sg_table
), GFP_KERNEL
);
148 pr_err("Unable to allocate memory for Ramdisk"
149 " scatterlist tables\n");
153 rd_dev
->sg_table_array
= sg_table
;
154 rd_dev
->sg_table_count
= sg_tables
;
156 while (total_sg_needed
) {
157 sg_per_table
= (total_sg_needed
> max_sg_per_table
) ?
158 max_sg_per_table
: total_sg_needed
;
160 sg
= kzalloc(sg_per_table
* sizeof(struct scatterlist
),
163 pr_err("Unable to allocate scatterlist array"
164 " for struct rd_dev\n");
168 sg_init_table(sg
, sg_per_table
);
170 sg_table
[i
].sg_table
= sg
;
171 sg_table
[i
].rd_sg_count
= sg_per_table
;
172 sg_table
[i
].page_start_offset
= page_offset
;
173 sg_table
[i
++].page_end_offset
= (page_offset
+ sg_per_table
)
176 for (j
= 0; j
< sg_per_table
; j
++) {
177 pg
= alloc_pages(GFP_KERNEL
, 0);
179 pr_err("Unable to allocate scatterlist"
180 " pages for struct rd_dev_sg_table\n");
183 sg_assign_page(&sg
[j
], pg
);
184 sg
[j
].length
= PAGE_SIZE
;
187 page_offset
+= sg_per_table
;
188 total_sg_needed
-= sg_per_table
;
191 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
192 " %u pages in %u tables\n", rd_dev
->rd_host
->rd_host_id
,
193 rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
194 rd_dev
->sg_table_count
);
199 static struct se_device
*rd_alloc_device(struct se_hba
*hba
, const char *name
)
201 struct rd_dev
*rd_dev
;
202 struct rd_host
*rd_host
= hba
->hba_ptr
;
204 rd_dev
= kzalloc(sizeof(struct rd_dev
), GFP_KERNEL
);
206 pr_err("Unable to allocate memory for struct rd_dev\n");
210 rd_dev
->rd_host
= rd_host
;
215 static int rd_configure_device(struct se_device
*dev
)
217 struct rd_dev
*rd_dev
= RD_DEV(dev
);
218 struct rd_host
*rd_host
= dev
->se_hba
->hba_ptr
;
221 if (!(rd_dev
->rd_flags
& RDF_HAS_PAGE_COUNT
)) {
222 pr_debug("Missing rd_pages= parameter\n");
226 ret
= rd_build_device_space(rd_dev
);
230 dev
->dev_attrib
.hw_block_size
= RD_BLOCKSIZE
;
231 dev
->dev_attrib
.hw_max_sectors
= UINT_MAX
;
232 dev
->dev_attrib
.hw_queue_depth
= RD_MAX_DEVICE_QUEUE_DEPTH
;
234 rd_dev
->rd_dev_id
= rd_host
->rd_host_dev_id_count
++;
236 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
237 " %u pages in %u tables, %lu total bytes\n",
238 rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
239 rd_dev
->sg_table_count
,
240 (unsigned long)(rd_dev
->rd_page_count
* PAGE_SIZE
));
245 rd_release_device_space(rd_dev
);
249 static void rd_free_device(struct se_device
*dev
)
251 struct rd_dev
*rd_dev
= RD_DEV(dev
);
253 rd_release_device_space(rd_dev
);
257 static struct rd_dev_sg_table
*rd_get_sg_table(struct rd_dev
*rd_dev
, u32 page
)
260 struct rd_dev_sg_table
*sg_table
;
262 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
263 sg_table
= &rd_dev
->sg_table_array
[i
];
264 if ((sg_table
->page_start_offset
<= page
) &&
265 (sg_table
->page_end_offset
>= page
))
269 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
275 static sense_reason_t
276 rd_execute_rw(struct se_cmd
*cmd
)
278 struct scatterlist
*sgl
= cmd
->t_data_sg
;
279 u32 sgl_nents
= cmd
->t_data_nents
;
280 enum dma_data_direction data_direction
= cmd
->data_direction
;
281 struct se_device
*se_dev
= cmd
->se_dev
;
282 struct rd_dev
*dev
= RD_DEV(se_dev
);
283 struct rd_dev_sg_table
*table
;
284 struct scatterlist
*rd_sg
;
285 struct sg_mapping_iter m
;
292 tmp
= cmd
->t_task_lba
* se_dev
->dev_attrib
.block_size
;
293 rd_offset
= do_div(tmp
, PAGE_SIZE
);
295 rd_size
= cmd
->data_length
;
297 table
= rd_get_sg_table(dev
, rd_page
);
299 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
301 rd_sg
= &table
->sg_table
[rd_page
- table
->page_start_offset
];
303 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
305 data_direction
== DMA_FROM_DEVICE
? "Read" : "Write",
306 cmd
->t_task_lba
, rd_size
, rd_page
, rd_offset
);
308 src_len
= PAGE_SIZE
- rd_offset
;
309 sg_miter_start(&m
, sgl
, sgl_nents
,
310 data_direction
== DMA_FROM_DEVICE
?
311 SG_MITER_TO_SG
: SG_MITER_FROM_SG
);
317 len
= min((u32
)m
.length
, src_len
);
320 rd_addr
= sg_virt(rd_sg
) + rd_offset
;
322 if (data_direction
== DMA_FROM_DEVICE
)
323 memcpy(m
.addr
, rd_addr
, len
);
325 memcpy(rd_addr
, m
.addr
, len
);
337 /* rd page completed, next one please */
341 if (rd_page
<= table
->page_end_offset
) {
346 table
= rd_get_sg_table(dev
, rd_page
);
349 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
352 /* since we increment, the first sg entry is correct */
353 rd_sg
= table
->sg_table
;
357 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
362 Opt_rd_pages
, Opt_err
365 static match_table_t tokens
= {
366 {Opt_rd_pages
, "rd_pages=%d"},
370 static ssize_t
rd_set_configfs_dev_params(struct se_device
*dev
,
371 const char *page
, ssize_t count
)
373 struct rd_dev
*rd_dev
= RD_DEV(dev
);
374 char *orig
, *ptr
, *opts
;
375 substring_t args
[MAX_OPT_ARGS
];
376 int ret
= 0, arg
, token
;
378 opts
= kstrdup(page
, GFP_KERNEL
);
384 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
388 token
= match_token(ptr
, tokens
, args
);
391 match_int(args
, &arg
);
392 rd_dev
->rd_page_count
= arg
;
393 pr_debug("RAMDISK: Referencing Page"
394 " Count: %u\n", rd_dev
->rd_page_count
);
395 rd_dev
->rd_flags
|= RDF_HAS_PAGE_COUNT
;
403 return (!ret
) ? count
: ret
;
406 static ssize_t
rd_show_configfs_dev_params(struct se_device
*dev
, char *b
)
408 struct rd_dev
*rd_dev
= RD_DEV(dev
);
410 ssize_t bl
= sprintf(b
, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
412 bl
+= sprintf(b
+ bl
, " PAGES/PAGE_SIZE: %u*%lu"
413 " SG_table_count: %u\n", rd_dev
->rd_page_count
,
414 PAGE_SIZE
, rd_dev
->sg_table_count
);
418 static sector_t
rd_get_blocks(struct se_device
*dev
)
420 struct rd_dev
*rd_dev
= RD_DEV(dev
);
422 unsigned long long blocks_long
= ((rd_dev
->rd_page_count
* PAGE_SIZE
) /
423 dev
->dev_attrib
.block_size
) - 1;
428 static struct sbc_ops rd_sbc_ops
= {
429 .execute_rw
= rd_execute_rw
,
432 static sense_reason_t
433 rd_parse_cdb(struct se_cmd
*cmd
)
435 return sbc_parse_cdb(cmd
, &rd_sbc_ops
);
438 static struct se_subsystem_api rd_mcp_template
= {
440 .inquiry_prod
= "RAMDISK-MCP",
441 .inquiry_rev
= RD_MCP_VERSION
,
442 .transport_type
= TRANSPORT_PLUGIN_VHBA_VDEV
,
443 .attach_hba
= rd_attach_hba
,
444 .detach_hba
= rd_detach_hba
,
445 .alloc_device
= rd_alloc_device
,
446 .configure_device
= rd_configure_device
,
447 .free_device
= rd_free_device
,
448 .parse_cdb
= rd_parse_cdb
,
449 .set_configfs_dev_params
= rd_set_configfs_dev_params
,
450 .show_configfs_dev_params
= rd_show_configfs_dev_params
,
451 .get_device_type
= sbc_get_device_type
,
452 .get_blocks
= rd_get_blocks
,
455 int __init
rd_module_init(void)
459 ret
= transport_subsystem_register(&rd_mcp_template
);
467 void rd_module_exit(void)
469 transport_subsystem_release(&rd_mcp_template
);