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 /* rd_release_device_space():
85 static void rd_release_device_space(struct rd_dev
*rd_dev
)
87 u32 i
, j
, page_count
= 0, sg_per_table
;
88 struct rd_dev_sg_table
*sg_table
;
90 struct scatterlist
*sg
;
92 if (!rd_dev
->sg_table_array
|| !rd_dev
->sg_table_count
)
95 sg_table
= rd_dev
->sg_table_array
;
97 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
98 sg
= sg_table
[i
].sg_table
;
99 sg_per_table
= sg_table
[i
].rd_sg_count
;
101 for (j
= 0; j
< sg_per_table
; j
++) {
102 pg
= sg_page(&sg
[j
]);
112 pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
113 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
114 rd_dev
->rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, page_count
,
115 rd_dev
->sg_table_count
, (unsigned long)page_count
* PAGE_SIZE
);
118 rd_dev
->sg_table_array
= NULL
;
119 rd_dev
->sg_table_count
= 0;
123 /* rd_build_device_space():
127 static int rd_build_device_space(struct rd_dev
*rd_dev
)
129 u32 i
= 0, j
, page_offset
= 0, sg_per_table
, sg_tables
, total_sg_needed
;
130 u32 max_sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
131 sizeof(struct scatterlist
));
132 struct rd_dev_sg_table
*sg_table
;
134 struct scatterlist
*sg
;
136 if (rd_dev
->rd_page_count
<= 0) {
137 pr_err("Illegal page count: %u for Ramdisk device\n",
138 rd_dev
->rd_page_count
);
142 /* Don't need backing pages for NULLIO */
143 if (rd_dev
->rd_flags
& RDF_NULLIO
)
146 total_sg_needed
= rd_dev
->rd_page_count
;
148 sg_tables
= (total_sg_needed
/ max_sg_per_table
) + 1;
150 sg_table
= kzalloc(sg_tables
* sizeof(struct rd_dev_sg_table
), GFP_KERNEL
);
152 pr_err("Unable to allocate memory for Ramdisk"
153 " scatterlist tables\n");
157 rd_dev
->sg_table_array
= sg_table
;
158 rd_dev
->sg_table_count
= sg_tables
;
160 while (total_sg_needed
) {
161 sg_per_table
= (total_sg_needed
> max_sg_per_table
) ?
162 max_sg_per_table
: total_sg_needed
;
164 sg
= kzalloc(sg_per_table
* sizeof(struct scatterlist
),
167 pr_err("Unable to allocate scatterlist array"
168 " for struct rd_dev\n");
172 sg_init_table(sg
, sg_per_table
);
174 sg_table
[i
].sg_table
= sg
;
175 sg_table
[i
].rd_sg_count
= sg_per_table
;
176 sg_table
[i
].page_start_offset
= page_offset
;
177 sg_table
[i
++].page_end_offset
= (page_offset
+ sg_per_table
)
180 for (j
= 0; j
< sg_per_table
; j
++) {
181 pg
= alloc_pages(GFP_KERNEL
, 0);
183 pr_err("Unable to allocate scatterlist"
184 " pages for struct rd_dev_sg_table\n");
187 sg_assign_page(&sg
[j
], pg
);
188 sg
[j
].length
= PAGE_SIZE
;
191 page_offset
+= sg_per_table
;
192 total_sg_needed
-= sg_per_table
;
195 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
196 " %u pages in %u tables\n", rd_dev
->rd_host
->rd_host_id
,
197 rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
198 rd_dev
->sg_table_count
);
203 static struct se_device
*rd_alloc_device(struct se_hba
*hba
, const char *name
)
205 struct rd_dev
*rd_dev
;
206 struct rd_host
*rd_host
= hba
->hba_ptr
;
208 rd_dev
= kzalloc(sizeof(struct rd_dev
), GFP_KERNEL
);
210 pr_err("Unable to allocate memory for struct rd_dev\n");
214 rd_dev
->rd_host
= rd_host
;
219 static int rd_configure_device(struct se_device
*dev
)
221 struct rd_dev
*rd_dev
= RD_DEV(dev
);
222 struct rd_host
*rd_host
= dev
->se_hba
->hba_ptr
;
225 if (!(rd_dev
->rd_flags
& RDF_HAS_PAGE_COUNT
)) {
226 pr_debug("Missing rd_pages= parameter\n");
230 ret
= rd_build_device_space(rd_dev
);
234 dev
->dev_attrib
.hw_block_size
= RD_BLOCKSIZE
;
235 dev
->dev_attrib
.hw_max_sectors
= UINT_MAX
;
236 dev
->dev_attrib
.hw_queue_depth
= RD_MAX_DEVICE_QUEUE_DEPTH
;
238 rd_dev
->rd_dev_id
= rd_host
->rd_host_dev_id_count
++;
240 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
241 " %u pages in %u tables, %lu total bytes\n",
242 rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
243 rd_dev
->sg_table_count
,
244 (unsigned long)(rd_dev
->rd_page_count
* PAGE_SIZE
));
249 rd_release_device_space(rd_dev
);
253 static void rd_free_device(struct se_device
*dev
)
255 struct rd_dev
*rd_dev
= RD_DEV(dev
);
257 rd_release_device_space(rd_dev
);
261 static struct rd_dev_sg_table
*rd_get_sg_table(struct rd_dev
*rd_dev
, u32 page
)
263 struct rd_dev_sg_table
*sg_table
;
264 u32 i
, sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
265 sizeof(struct scatterlist
));
267 i
= page
/ sg_per_table
;
268 if (i
< rd_dev
->sg_table_count
) {
269 sg_table
= &rd_dev
->sg_table_array
[i
];
270 if ((sg_table
->page_start_offset
<= page
) &&
271 (sg_table
->page_end_offset
>= page
))
275 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
281 static sense_reason_t
282 rd_execute_rw(struct se_cmd
*cmd
, struct scatterlist
*sgl
, u32 sgl_nents
,
283 enum dma_data_direction data_direction
)
285 struct se_device
*se_dev
= cmd
->se_dev
;
286 struct rd_dev
*dev
= RD_DEV(se_dev
);
287 struct rd_dev_sg_table
*table
;
288 struct scatterlist
*rd_sg
;
289 struct sg_mapping_iter m
;
296 if (dev
->rd_flags
& RDF_NULLIO
) {
297 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
301 tmp
= cmd
->t_task_lba
* se_dev
->dev_attrib
.block_size
;
302 rd_offset
= do_div(tmp
, PAGE_SIZE
);
304 rd_size
= cmd
->data_length
;
306 table
= rd_get_sg_table(dev
, rd_page
);
308 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
310 rd_sg
= &table
->sg_table
[rd_page
- table
->page_start_offset
];
312 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
314 data_direction
== DMA_FROM_DEVICE
? "Read" : "Write",
315 cmd
->t_task_lba
, rd_size
, rd_page
, rd_offset
);
317 src_len
= PAGE_SIZE
- rd_offset
;
318 sg_miter_start(&m
, sgl
, sgl_nents
,
319 data_direction
== DMA_FROM_DEVICE
?
320 SG_MITER_TO_SG
: SG_MITER_FROM_SG
);
326 if (!(u32
)m
.length
) {
327 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
328 dev
->rd_dev_id
, m
.addr
, m
.length
);
330 return TCM_INCORRECT_AMOUNT_OF_DATA
;
332 len
= min((u32
)m
.length
, src_len
);
334 pr_debug("RD[%u]: size underrun page %d offset %d "
335 "size %d\n", dev
->rd_dev_id
,
336 rd_page
, rd_offset
, rd_size
);
341 rd_addr
= sg_virt(rd_sg
) + rd_offset
;
343 if (data_direction
== DMA_FROM_DEVICE
)
344 memcpy(m
.addr
, rd_addr
, len
);
346 memcpy(rd_addr
, m
.addr
, len
);
358 /* rd page completed, next one please */
362 if (rd_page
<= table
->page_end_offset
) {
367 table
= rd_get_sg_table(dev
, rd_page
);
370 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
373 /* since we increment, the first sg entry is correct */
374 rd_sg
= table
->sg_table
;
378 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
383 Opt_rd_pages
, Opt_rd_nullio
, Opt_err
386 static match_table_t tokens
= {
387 {Opt_rd_pages
, "rd_pages=%d"},
388 {Opt_rd_nullio
, "rd_nullio=%d"},
392 static ssize_t
rd_set_configfs_dev_params(struct se_device
*dev
,
393 const char *page
, ssize_t count
)
395 struct rd_dev
*rd_dev
= RD_DEV(dev
);
396 char *orig
, *ptr
, *opts
;
397 substring_t args
[MAX_OPT_ARGS
];
398 int ret
= 0, arg
, token
;
400 opts
= kstrdup(page
, GFP_KERNEL
);
406 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
410 token
= match_token(ptr
, tokens
, args
);
413 match_int(args
, &arg
);
414 rd_dev
->rd_page_count
= arg
;
415 pr_debug("RAMDISK: Referencing Page"
416 " Count: %u\n", rd_dev
->rd_page_count
);
417 rd_dev
->rd_flags
|= RDF_HAS_PAGE_COUNT
;
420 match_int(args
, &arg
);
424 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg
);
425 rd_dev
->rd_flags
|= RDF_NULLIO
;
433 return (!ret
) ? count
: ret
;
436 static ssize_t
rd_show_configfs_dev_params(struct se_device
*dev
, char *b
)
438 struct rd_dev
*rd_dev
= RD_DEV(dev
);
440 ssize_t bl
= sprintf(b
, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
442 bl
+= sprintf(b
+ bl
, " PAGES/PAGE_SIZE: %u*%lu"
443 " SG_table_count: %u nullio: %d\n", rd_dev
->rd_page_count
,
444 PAGE_SIZE
, rd_dev
->sg_table_count
,
445 !!(rd_dev
->rd_flags
& RDF_NULLIO
));
449 static sector_t
rd_get_blocks(struct se_device
*dev
)
451 struct rd_dev
*rd_dev
= RD_DEV(dev
);
453 unsigned long long blocks_long
= ((rd_dev
->rd_page_count
* PAGE_SIZE
) /
454 dev
->dev_attrib
.block_size
) - 1;
459 static struct sbc_ops rd_sbc_ops
= {
460 .execute_rw
= rd_execute_rw
,
463 static sense_reason_t
464 rd_parse_cdb(struct se_cmd
*cmd
)
466 return sbc_parse_cdb(cmd
, &rd_sbc_ops
);
469 static struct se_subsystem_api rd_mcp_template
= {
471 .inquiry_prod
= "RAMDISK-MCP",
472 .inquiry_rev
= RD_MCP_VERSION
,
473 .transport_type
= TRANSPORT_PLUGIN_VHBA_VDEV
,
474 .attach_hba
= rd_attach_hba
,
475 .detach_hba
= rd_detach_hba
,
476 .alloc_device
= rd_alloc_device
,
477 .configure_device
= rd_configure_device
,
478 .free_device
= rd_free_device
,
479 .parse_cdb
= rd_parse_cdb
,
480 .set_configfs_dev_params
= rd_set_configfs_dev_params
,
481 .show_configfs_dev_params
= rd_show_configfs_dev_params
,
482 .get_device_type
= sbc_get_device_type
,
483 .get_blocks
= rd_get_blocks
,
486 int __init
rd_module_init(void)
490 ret
= transport_subsystem_register(&rd_mcp_template
);
498 void rd_module_exit(void)
500 transport_subsystem_release(&rd_mcp_template
);