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
, int block_size
)
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 * prot_length=8byte dif data
257 * tot sg needed = rd_page_count * (PGSZ/block_size) *
258 * (prot_length/block_size) + pad
259 * PGSZ canceled each other.
261 total_sg_needed
= (rd_dev
->rd_page_count
* prot_length
/ block_size
) + 1;
263 sg_tables
= (total_sg_needed
/ max_sg_per_table
) + 1;
265 sg_table
= kzalloc(sg_tables
* sizeof(struct rd_dev_sg_table
), GFP_KERNEL
);
267 pr_err("Unable to allocate memory for Ramdisk protection"
268 " scatterlist tables\n");
272 rd_dev
->sg_prot_array
= sg_table
;
273 rd_dev
->sg_prot_count
= sg_tables
;
275 rc
= rd_allocate_sgl_table(rd_dev
, sg_table
, total_sg_needed
, 0xff);
279 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
280 " %u pages in %u tables\n", rd_dev
->rd_host
->rd_host_id
,
281 rd_dev
->rd_dev_id
, total_sg_needed
, rd_dev
->sg_prot_count
);
286 static struct se_device
*rd_alloc_device(struct se_hba
*hba
, const char *name
)
288 struct rd_dev
*rd_dev
;
289 struct rd_host
*rd_host
= hba
->hba_ptr
;
291 rd_dev
= kzalloc(sizeof(struct rd_dev
), GFP_KERNEL
);
293 pr_err("Unable to allocate memory for struct rd_dev\n");
297 rd_dev
->rd_host
= rd_host
;
302 static int rd_configure_device(struct se_device
*dev
)
304 struct rd_dev
*rd_dev
= RD_DEV(dev
);
305 struct rd_host
*rd_host
= dev
->se_hba
->hba_ptr
;
308 if (!(rd_dev
->rd_flags
& RDF_HAS_PAGE_COUNT
)) {
309 pr_debug("Missing rd_pages= parameter\n");
313 ret
= rd_build_device_space(rd_dev
);
317 dev
->dev_attrib
.hw_block_size
= RD_BLOCKSIZE
;
318 dev
->dev_attrib
.hw_max_sectors
= UINT_MAX
;
319 dev
->dev_attrib
.hw_queue_depth
= RD_MAX_DEVICE_QUEUE_DEPTH
;
321 rd_dev
->rd_dev_id
= rd_host
->rd_host_dev_id_count
++;
323 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
324 " %u pages in %u tables, %lu total bytes\n",
325 rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
326 rd_dev
->sg_table_count
,
327 (unsigned long)(rd_dev
->rd_page_count
* PAGE_SIZE
));
332 rd_release_device_space(rd_dev
);
336 static void rd_free_device(struct se_device
*dev
)
338 struct rd_dev
*rd_dev
= RD_DEV(dev
);
340 rd_release_device_space(rd_dev
);
344 static struct rd_dev_sg_table
*rd_get_sg_table(struct rd_dev
*rd_dev
, u32 page
)
346 struct rd_dev_sg_table
*sg_table
;
347 u32 i
, sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
348 sizeof(struct scatterlist
));
350 i
= page
/ sg_per_table
;
351 if (i
< rd_dev
->sg_table_count
) {
352 sg_table
= &rd_dev
->sg_table_array
[i
];
353 if ((sg_table
->page_start_offset
<= page
) &&
354 (sg_table
->page_end_offset
>= page
))
358 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
364 static struct rd_dev_sg_table
*rd_get_prot_table(struct rd_dev
*rd_dev
, u32 page
)
366 struct rd_dev_sg_table
*sg_table
;
367 u32 i
, sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
368 sizeof(struct scatterlist
));
370 i
= page
/ sg_per_table
;
371 if (i
< rd_dev
->sg_prot_count
) {
372 sg_table
= &rd_dev
->sg_prot_array
[i
];
373 if ((sg_table
->page_start_offset
<= page
) &&
374 (sg_table
->page_end_offset
>= page
))
378 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
384 static sense_reason_t
385 rd_execute_rw(struct se_cmd
*cmd
, struct scatterlist
*sgl
, u32 sgl_nents
,
386 enum dma_data_direction data_direction
)
388 struct se_device
*se_dev
= cmd
->se_dev
;
389 struct rd_dev
*dev
= RD_DEV(se_dev
);
390 struct rd_dev_sg_table
*table
;
391 struct scatterlist
*rd_sg
;
392 struct sg_mapping_iter m
;
400 if (dev
->rd_flags
& RDF_NULLIO
) {
401 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
405 tmp
= cmd
->t_task_lba
* se_dev
->dev_attrib
.block_size
;
406 rd_offset
= do_div(tmp
, PAGE_SIZE
);
408 rd_size
= cmd
->data_length
;
410 table
= rd_get_sg_table(dev
, rd_page
);
412 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
414 rd_sg
= &table
->sg_table
[rd_page
- table
->page_start_offset
];
416 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
418 data_direction
== DMA_FROM_DEVICE
? "Read" : "Write",
419 cmd
->t_task_lba
, rd_size
, rd_page
, rd_offset
);
421 if (cmd
->prot_type
&& data_direction
== DMA_TO_DEVICE
) {
422 struct rd_dev_sg_table
*prot_table
;
423 struct scatterlist
*prot_sg
;
424 u32 sectors
= cmd
->data_length
/ se_dev
->dev_attrib
.block_size
;
425 u32 prot_offset
, prot_page
;
427 tmp
= cmd
->t_task_lba
* se_dev
->prot_length
;
428 prot_offset
= do_div(tmp
, PAGE_SIZE
);
431 prot_table
= rd_get_prot_table(dev
, prot_page
);
433 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
435 prot_sg
= &prot_table
->sg_table
[prot_page
- prot_table
->page_start_offset
];
437 rc
= sbc_dif_verify_write(cmd
, cmd
->t_task_lba
, sectors
, 0,
438 prot_sg
, prot_offset
);
443 src_len
= PAGE_SIZE
- rd_offset
;
444 sg_miter_start(&m
, sgl
, sgl_nents
,
445 data_direction
== DMA_FROM_DEVICE
?
446 SG_MITER_TO_SG
: SG_MITER_FROM_SG
);
452 if (!(u32
)m
.length
) {
453 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
454 dev
->rd_dev_id
, m
.addr
, m
.length
);
456 return TCM_INCORRECT_AMOUNT_OF_DATA
;
458 len
= min((u32
)m
.length
, src_len
);
460 pr_debug("RD[%u]: size underrun page %d offset %d "
461 "size %d\n", dev
->rd_dev_id
,
462 rd_page
, rd_offset
, rd_size
);
467 rd_addr
= sg_virt(rd_sg
) + rd_offset
;
469 if (data_direction
== DMA_FROM_DEVICE
)
470 memcpy(m
.addr
, rd_addr
, len
);
472 memcpy(rd_addr
, m
.addr
, len
);
484 /* rd page completed, next one please */
488 if (rd_page
<= table
->page_end_offset
) {
493 table
= rd_get_sg_table(dev
, rd_page
);
496 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
499 /* since we increment, the first sg entry is correct */
500 rd_sg
= table
->sg_table
;
504 if (cmd
->prot_type
&& data_direction
== DMA_FROM_DEVICE
) {
505 struct rd_dev_sg_table
*prot_table
;
506 struct scatterlist
*prot_sg
;
507 u32 sectors
= cmd
->data_length
/ se_dev
->dev_attrib
.block_size
;
508 u32 prot_offset
, prot_page
;
510 tmp
= cmd
->t_task_lba
* se_dev
->prot_length
;
511 prot_offset
= do_div(tmp
, PAGE_SIZE
);
514 prot_table
= rd_get_prot_table(dev
, prot_page
);
516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE
;
518 prot_sg
= &prot_table
->sg_table
[prot_page
- prot_table
->page_start_offset
];
520 rc
= sbc_dif_verify_read(cmd
, cmd
->t_task_lba
, sectors
, 0,
521 prot_sg
, prot_offset
);
526 target_complete_cmd(cmd
, SAM_STAT_GOOD
);
531 Opt_rd_pages
, Opt_rd_nullio
, Opt_err
534 static match_table_t tokens
= {
535 {Opt_rd_pages
, "rd_pages=%d"},
536 {Opt_rd_nullio
, "rd_nullio=%d"},
540 static ssize_t
rd_set_configfs_dev_params(struct se_device
*dev
,
541 const char *page
, ssize_t count
)
543 struct rd_dev
*rd_dev
= RD_DEV(dev
);
544 char *orig
, *ptr
, *opts
;
545 substring_t args
[MAX_OPT_ARGS
];
546 int ret
= 0, arg
, token
;
548 opts
= kstrdup(page
, GFP_KERNEL
);
554 while ((ptr
= strsep(&opts
, ",\n")) != NULL
) {
558 token
= match_token(ptr
, tokens
, args
);
561 match_int(args
, &arg
);
562 rd_dev
->rd_page_count
= arg
;
563 pr_debug("RAMDISK: Referencing Page"
564 " Count: %u\n", rd_dev
->rd_page_count
);
565 rd_dev
->rd_flags
|= RDF_HAS_PAGE_COUNT
;
568 match_int(args
, &arg
);
572 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg
);
573 rd_dev
->rd_flags
|= RDF_NULLIO
;
581 return (!ret
) ? count
: ret
;
584 static ssize_t
rd_show_configfs_dev_params(struct se_device
*dev
, char *b
)
586 struct rd_dev
*rd_dev
= RD_DEV(dev
);
588 ssize_t bl
= sprintf(b
, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
590 bl
+= sprintf(b
+ bl
, " PAGES/PAGE_SIZE: %u*%lu"
591 " SG_table_count: %u nullio: %d\n", rd_dev
->rd_page_count
,
592 PAGE_SIZE
, rd_dev
->sg_table_count
,
593 !!(rd_dev
->rd_flags
& RDF_NULLIO
));
597 static sector_t
rd_get_blocks(struct se_device
*dev
)
599 struct rd_dev
*rd_dev
= RD_DEV(dev
);
601 unsigned long long blocks_long
= ((rd_dev
->rd_page_count
* PAGE_SIZE
) /
602 dev
->dev_attrib
.block_size
) - 1;
607 static int rd_init_prot(struct se_device
*dev
)
609 struct rd_dev
*rd_dev
= RD_DEV(dev
);
611 if (!dev
->dev_attrib
.pi_prot_type
)
614 return rd_build_prot_space(rd_dev
, dev
->prot_length
,
615 dev
->dev_attrib
.block_size
);
618 static void rd_free_prot(struct se_device
*dev
)
620 struct rd_dev
*rd_dev
= RD_DEV(dev
);
622 rd_release_prot_space(rd_dev
);
625 static struct sbc_ops rd_sbc_ops
= {
626 .execute_rw
= rd_execute_rw
,
629 static sense_reason_t
630 rd_parse_cdb(struct se_cmd
*cmd
)
632 return sbc_parse_cdb(cmd
, &rd_sbc_ops
);
635 static struct se_subsystem_api rd_mcp_template
= {
637 .inquiry_prod
= "RAMDISK-MCP",
638 .inquiry_rev
= RD_MCP_VERSION
,
639 .transport_type
= TRANSPORT_PLUGIN_VHBA_VDEV
,
640 .attach_hba
= rd_attach_hba
,
641 .detach_hba
= rd_detach_hba
,
642 .alloc_device
= rd_alloc_device
,
643 .configure_device
= rd_configure_device
,
644 .free_device
= rd_free_device
,
645 .parse_cdb
= rd_parse_cdb
,
646 .set_configfs_dev_params
= rd_set_configfs_dev_params
,
647 .show_configfs_dev_params
= rd_show_configfs_dev_params
,
648 .get_device_type
= sbc_get_device_type
,
649 .get_blocks
= rd_get_blocks
,
650 .init_prot
= rd_init_prot
,
651 .free_prot
= rd_free_prot
,
654 int __init
rd_module_init(void)
658 ret
= transport_subsystem_register(&rd_mcp_template
);
666 void rd_module_exit(void)
668 transport_subsystem_release(&rd_mcp_template
);