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_device.h>
41 #include <target/target_core_transport.h>
42 #include <target/target_core_fabric_ops.h>
44 #include "target_core_rd.h"
46 static struct se_subsystem_api rd_mcp_template
;
48 /* rd_attach_hba(): (Part of se_subsystem_api_t template)
52 static int rd_attach_hba(struct se_hba
*hba
, u32 host_id
)
54 struct rd_host
*rd_host
;
56 rd_host
= kzalloc(sizeof(struct rd_host
), GFP_KERNEL
);
58 pr_err("Unable to allocate memory for struct rd_host\n");
62 rd_host
->rd_host_id
= host_id
;
64 hba
->hba_ptr
= rd_host
;
66 pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
67 " Generic Target Core Stack %s\n", hba
->hba_id
,
68 RD_HBA_VERSION
, TARGET_CORE_MOD_VERSION
);
69 pr_debug("CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
70 " MaxSectors: %u\n", hba
->hba_id
,
71 rd_host
->rd_host_id
, RD_MAX_SECTORS
);
76 static void rd_detach_hba(struct se_hba
*hba
)
78 struct rd_host
*rd_host
= hba
->hba_ptr
;
80 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
81 " Generic Target Core\n", hba
->hba_id
, rd_host
->rd_host_id
);
87 /* rd_release_device_space():
91 static void rd_release_device_space(struct rd_dev
*rd_dev
)
93 u32 i
, j
, page_count
= 0, sg_per_table
;
94 struct rd_dev_sg_table
*sg_table
;
96 struct scatterlist
*sg
;
98 if (!rd_dev
->sg_table_array
|| !rd_dev
->sg_table_count
)
101 sg_table
= rd_dev
->sg_table_array
;
103 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
104 sg
= sg_table
[i
].sg_table
;
105 sg_per_table
= sg_table
[i
].rd_sg_count
;
107 for (j
= 0; j
< sg_per_table
; j
++) {
108 pg
= sg_page(&sg
[j
]);
118 pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
119 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
120 rd_dev
->rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, page_count
,
121 rd_dev
->sg_table_count
, (unsigned long)page_count
* PAGE_SIZE
);
124 rd_dev
->sg_table_array
= NULL
;
125 rd_dev
->sg_table_count
= 0;
129 /* rd_build_device_space():
133 static int rd_build_device_space(struct rd_dev
*rd_dev
)
135 u32 i
= 0, j
, page_offset
= 0, sg_per_table
, sg_tables
, total_sg_needed
;
136 u32 max_sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
137 sizeof(struct scatterlist
));
138 struct rd_dev_sg_table
*sg_table
;
140 struct scatterlist
*sg
;
142 if (rd_dev
->rd_page_count
<= 0) {
143 pr_err("Illegal page count: %u for Ramdisk device\n",
144 rd_dev
->rd_page_count
);
147 total_sg_needed
= rd_dev
->rd_page_count
;
149 sg_tables
= (total_sg_needed
/ max_sg_per_table
) + 1;
151 sg_table
= kzalloc(sg_tables
* sizeof(struct rd_dev_sg_table
), GFP_KERNEL
);
153 pr_err("Unable to allocate memory for Ramdisk"
154 " scatterlist tables\n");
158 rd_dev
->sg_table_array
= sg_table
;
159 rd_dev
->sg_table_count
= sg_tables
;
161 while (total_sg_needed
) {
162 sg_per_table
= (total_sg_needed
> max_sg_per_table
) ?
163 max_sg_per_table
: total_sg_needed
;
165 sg
= kzalloc(sg_per_table
* sizeof(struct scatterlist
),
168 pr_err("Unable to allocate scatterlist array"
169 " for struct rd_dev\n");
173 sg_init_table(sg
, sg_per_table
);
175 sg_table
[i
].sg_table
= sg
;
176 sg_table
[i
].rd_sg_count
= sg_per_table
;
177 sg_table
[i
].page_start_offset
= page_offset
;
178 sg_table
[i
++].page_end_offset
= (page_offset
+ sg_per_table
)
181 for (j
= 0; j
< sg_per_table
; j
++) {
182 pg
= alloc_pages(GFP_KERNEL
, 0);
184 pr_err("Unable to allocate scatterlist"
185 " pages for struct rd_dev_sg_table\n");
188 sg_assign_page(&sg
[j
], pg
);
189 sg
[j
].length
= PAGE_SIZE
;
192 page_offset
+= sg_per_table
;
193 total_sg_needed
-= sg_per_table
;
196 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
197 " %u pages in %u tables\n", rd_dev
->rd_host
->rd_host_id
,
198 rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
199 rd_dev
->sg_table_count
);
204 static void *rd_allocate_virtdevice(
209 struct rd_dev
*rd_dev
;
210 struct rd_host
*rd_host
= hba
->hba_ptr
;
212 rd_dev
= kzalloc(sizeof(struct rd_dev
), GFP_KERNEL
);
214 pr_err("Unable to allocate memory for struct rd_dev\n");
218 rd_dev
->rd_host
= rd_host
;
219 rd_dev
->rd_direct
= rd_direct
;
224 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba
*hba
, const char *name
)
226 return rd_allocate_virtdevice(hba
, name
, 0);
229 /* rd_create_virtdevice():
233 static struct se_device
*rd_create_virtdevice(
235 struct se_subsystem_dev
*se_dev
,
239 struct se_device
*dev
;
240 struct se_dev_limits dev_limits
;
241 struct rd_dev
*rd_dev
= p
;
242 struct rd_host
*rd_host
= hba
->hba_ptr
;
243 int dev_flags
= 0, ret
;
244 char prod
[16], rev
[4];
246 memset(&dev_limits
, 0, sizeof(struct se_dev_limits
));
248 ret
= rd_build_device_space(rd_dev
);
252 snprintf(prod
, 16, "RAMDISK-%s", (rd_dev
->rd_direct
) ? "DR" : "MCP");
253 snprintf(rev
, 4, "%s", (rd_dev
->rd_direct
) ? RD_DR_VERSION
:
256 dev_limits
.limits
.logical_block_size
= RD_BLOCKSIZE
;
257 dev_limits
.limits
.max_hw_sectors
= RD_MAX_SECTORS
;
258 dev_limits
.limits
.max_sectors
= RD_MAX_SECTORS
;
259 dev_limits
.hw_queue_depth
= RD_MAX_DEVICE_QUEUE_DEPTH
;
260 dev_limits
.queue_depth
= RD_DEVICE_QUEUE_DEPTH
;
262 dev
= transport_add_device_to_core_hba(hba
,
263 &rd_mcp_template
, se_dev
, dev_flags
, rd_dev
,
264 &dev_limits
, prod
, rev
);
268 rd_dev
->rd_dev_id
= rd_host
->rd_host_dev_id_count
++;
269 rd_dev
->rd_queue_depth
= dev
->queue_depth
;
271 pr_debug("CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
272 " %u pages in %u tables, %lu total bytes\n",
273 rd_host
->rd_host_id
, (!rd_dev
->rd_direct
) ? "MEMCPY" :
274 "DIRECT", rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
275 rd_dev
->sg_table_count
,
276 (unsigned long)(rd_dev
->rd_page_count
* PAGE_SIZE
));
281 rd_release_device_space(rd_dev
);
285 static struct se_device
*rd_MEMCPY_create_virtdevice(
287 struct se_subsystem_dev
*se_dev
,
290 return rd_create_virtdevice(hba
, se_dev
, p
, 0);
293 /* rd_free_device(): (Part of se_subsystem_api_t template)
297 static void rd_free_device(void *p
)
299 struct rd_dev
*rd_dev
= p
;
301 rd_release_device_space(rd_dev
);
305 static inline struct rd_request
*RD_REQ(struct se_task
*task
)
307 return container_of(task
, struct rd_request
, rd_task
);
310 static struct se_task
*
311 rd_alloc_task(unsigned char *cdb
)
313 struct rd_request
*rd_req
;
315 rd_req
= kzalloc(sizeof(struct rd_request
), GFP_KERNEL
);
317 pr_err("Unable to allocate struct rd_request\n");
321 return &rd_req
->rd_task
;
324 /* rd_get_sg_table():
328 static struct rd_dev_sg_table
*rd_get_sg_table(struct rd_dev
*rd_dev
, u32 page
)
331 struct rd_dev_sg_table
*sg_table
;
333 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
334 sg_table
= &rd_dev
->sg_table_array
[i
];
335 if ((sg_table
->page_start_offset
<= page
) &&
336 (sg_table
->page_end_offset
>= page
))
340 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
350 static int rd_MEMCPY_read(struct rd_request
*req
)
352 struct se_task
*task
= &req
->rd_task
;
353 struct rd_dev
*dev
= req
->rd_task
.task_se_cmd
->se_dev
->dev_ptr
;
354 struct rd_dev_sg_table
*table
;
355 struct scatterlist
*sg_d
, *sg_s
;
357 u32 i
= 0, j
= 0, dst_offset
= 0, src_offset
= 0;
358 u32 length
, page_end
= 0, table_sg_end
;
359 u32 rd_offset
= req
->rd_offset
;
361 table
= rd_get_sg_table(dev
, req
->rd_page
);
365 table_sg_end
= (table
->page_end_offset
- req
->rd_page
);
366 sg_d
= task
->task_sg
;
367 sg_s
= &table
->sg_table
[req
->rd_page
- table
->page_start_offset
];
369 pr_debug("RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:"
370 " %u\n", dev
->rd_dev_id
, task
->task_lba
, req
->rd_size
,
371 req
->rd_page
, req
->rd_offset
);
373 src_offset
= rd_offset
;
375 while (req
->rd_size
) {
376 if ((sg_d
[i
].length
- dst_offset
) <
377 (sg_s
[j
].length
- src_offset
)) {
378 length
= (sg_d
[i
].length
- dst_offset
);
380 pr_debug("Step 1 - sg_d[%d]: %p length: %d"
381 " offset: %u sg_s[%d].length: %u\n", i
,
382 &sg_d
[i
], sg_d
[i
].length
, sg_d
[i
].offset
, j
,
384 pr_debug("Step 1 - length: %u dst_offset: %u"
385 " src_offset: %u\n", length
, dst_offset
,
388 if (length
> req
->rd_size
)
389 length
= req
->rd_size
;
391 dst
= sg_virt(&sg_d
[i
++]) + dst_offset
;
394 src
= sg_virt(&sg_s
[j
]) + src_offset
;
401 length
= (sg_s
[j
].length
- src_offset
);
403 pr_debug("Step 2 - sg_d[%d]: %p length: %d"
404 " offset: %u sg_s[%d].length: %u\n", i
,
405 &sg_d
[i
], sg_d
[i
].length
, sg_d
[i
].offset
,
407 pr_debug("Step 2 - length: %u dst_offset: %u"
408 " src_offset: %u\n", length
, dst_offset
,
411 if (length
> req
->rd_size
)
412 length
= req
->rd_size
;
414 dst
= sg_virt(&sg_d
[i
]) + dst_offset
;
417 if (sg_d
[i
].length
== length
) {
423 src
= sg_virt(&sg_s
[j
++]) + src_offset
;
430 memcpy(dst
, src
, length
);
432 pr_debug("page: %u, remaining size: %u, length: %u,"
433 " i: %u, j: %u\n", req
->rd_page
,
434 (req
->rd_size
- length
), length
, i
, j
);
436 req
->rd_size
-= length
;
443 if (++req
->rd_page
<= table
->page_end_offset
) {
444 pr_debug("page: %u in same page table\n",
449 pr_debug("getting new page table for page: %u\n",
452 table
= rd_get_sg_table(dev
, req
->rd_page
);
456 sg_s
= &table
->sg_table
[j
= 0];
462 /* rd_MEMCPY_write():
466 static int rd_MEMCPY_write(struct rd_request
*req
)
468 struct se_task
*task
= &req
->rd_task
;
469 struct rd_dev
*dev
= req
->rd_task
.task_se_cmd
->se_dev
->dev_ptr
;
470 struct rd_dev_sg_table
*table
;
471 struct scatterlist
*sg_d
, *sg_s
;
473 u32 i
= 0, j
= 0, dst_offset
= 0, src_offset
= 0;
474 u32 length
, page_end
= 0, table_sg_end
;
475 u32 rd_offset
= req
->rd_offset
;
477 table
= rd_get_sg_table(dev
, req
->rd_page
);
481 table_sg_end
= (table
->page_end_offset
- req
->rd_page
);
482 sg_d
= &table
->sg_table
[req
->rd_page
- table
->page_start_offset
];
483 sg_s
= task
->task_sg
;
485 pr_debug("RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
486 " Offset: %u\n", dev
->rd_dev_id
, task
->task_lba
, req
->rd_size
,
487 req
->rd_page
, req
->rd_offset
);
489 dst_offset
= rd_offset
;
491 while (req
->rd_size
) {
492 if ((sg_s
[i
].length
- src_offset
) <
493 (sg_d
[j
].length
- dst_offset
)) {
494 length
= (sg_s
[i
].length
- src_offset
);
496 pr_debug("Step 1 - sg_s[%d]: %p length: %d"
497 " offset: %d sg_d[%d].length: %u\n", i
,
498 &sg_s
[i
], sg_s
[i
].length
, sg_s
[i
].offset
,
500 pr_debug("Step 1 - length: %u src_offset: %u"
501 " dst_offset: %u\n", length
, src_offset
,
504 if (length
> req
->rd_size
)
505 length
= req
->rd_size
;
507 src
= sg_virt(&sg_s
[i
++]) + src_offset
;
510 dst
= sg_virt(&sg_d
[j
]) + dst_offset
;
517 length
= (sg_d
[j
].length
- dst_offset
);
519 pr_debug("Step 2 - sg_s[%d]: %p length: %d"
520 " offset: %d sg_d[%d].length: %u\n", i
,
521 &sg_s
[i
], sg_s
[i
].length
, sg_s
[i
].offset
,
523 pr_debug("Step 2 - length: %u src_offset: %u"
524 " dst_offset: %u\n", length
, src_offset
,
527 if (length
> req
->rd_size
)
528 length
= req
->rd_size
;
530 src
= sg_virt(&sg_s
[i
]) + src_offset
;
533 if (sg_s
[i
].length
== length
) {
539 dst
= sg_virt(&sg_d
[j
++]) + dst_offset
;
546 memcpy(dst
, src
, length
);
548 pr_debug("page: %u, remaining size: %u, length: %u,"
549 " i: %u, j: %u\n", req
->rd_page
,
550 (req
->rd_size
- length
), length
, i
, j
);
552 req
->rd_size
-= length
;
559 if (++req
->rd_page
<= table
->page_end_offset
) {
560 pr_debug("page: %u in same page table\n",
565 pr_debug("getting new page table for page: %u\n",
568 table
= rd_get_sg_table(dev
, req
->rd_page
);
572 sg_d
= &table
->sg_table
[j
= 0];
578 /* rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
582 static int rd_MEMCPY_do_task(struct se_task
*task
)
584 struct se_device
*dev
= task
->task_se_cmd
->se_dev
;
585 struct rd_request
*req
= RD_REQ(task
);
586 unsigned long long lba
;
589 req
->rd_page
= (task
->task_lba
* dev
->se_sub_dev
->se_dev_attrib
.block_size
) / PAGE_SIZE
;
590 lba
= task
->task_lba
;
591 req
->rd_offset
= (do_div(lba
,
592 (PAGE_SIZE
/ dev
->se_sub_dev
->se_dev_attrib
.block_size
))) *
593 dev
->se_sub_dev
->se_dev_attrib
.block_size
;
594 req
->rd_size
= task
->task_size
;
596 if (task
->task_data_direction
== DMA_FROM_DEVICE
)
597 ret
= rd_MEMCPY_read(req
);
599 ret
= rd_MEMCPY_write(req
);
604 task
->task_scsi_status
= GOOD
;
605 transport_complete_task(task
, 1);
607 return PYX_TRANSPORT_SENT_TO_TRANSPORT
;
610 /* rd_free_task(): (Part of se_subsystem_api_t template)
614 static void rd_free_task(struct se_task
*task
)
620 Opt_rd_pages
, Opt_err
623 static match_table_t tokens
= {
624 {Opt_rd_pages
, "rd_pages=%d"},
628 static ssize_t
rd_set_configfs_dev_params(
630 struct se_subsystem_dev
*se_dev
,
634 struct rd_dev
*rd_dev
= se_dev
->se_dev_su_ptr
;
635 char *orig
, *ptr
, *opts
;
636 substring_t args
[MAX_OPT_ARGS
];
637 int ret
= 0, arg
, token
;
639 opts
= kstrdup(page
, GFP_KERNEL
);
645 while ((ptr
= strsep(&opts
, ",")) != NULL
) {
649 token
= match_token(ptr
, tokens
, args
);
652 match_int(args
, &arg
);
653 rd_dev
->rd_page_count
= arg
;
654 pr_debug("RAMDISK: Referencing Page"
655 " Count: %u\n", rd_dev
->rd_page_count
);
656 rd_dev
->rd_flags
|= RDF_HAS_PAGE_COUNT
;
664 return (!ret
) ? count
: ret
;
667 static ssize_t
rd_check_configfs_dev_params(struct se_hba
*hba
, struct se_subsystem_dev
*se_dev
)
669 struct rd_dev
*rd_dev
= se_dev
->se_dev_su_ptr
;
671 if (!(rd_dev
->rd_flags
& RDF_HAS_PAGE_COUNT
)) {
672 pr_debug("Missing rd_pages= parameter\n");
679 static ssize_t
rd_show_configfs_dev_params(
681 struct se_subsystem_dev
*se_dev
,
684 struct rd_dev
*rd_dev
= se_dev
->se_dev_su_ptr
;
685 ssize_t bl
= sprintf(b
, "TCM RamDisk ID: %u RamDisk Makeup: %s\n",
686 rd_dev
->rd_dev_id
, (rd_dev
->rd_direct
) ?
687 "rd_direct" : "rd_mcp");
688 bl
+= sprintf(b
+ bl
, " PAGES/PAGE_SIZE: %u*%lu"
689 " SG_table_count: %u\n", rd_dev
->rd_page_count
,
690 PAGE_SIZE
, rd_dev
->sg_table_count
);
694 static u32
rd_get_device_rev(struct se_device
*dev
)
696 return SCSI_SPC_2
; /* Returns SPC-3 in Initiator Data */
699 static u32
rd_get_device_type(struct se_device
*dev
)
704 static sector_t
rd_get_blocks(struct se_device
*dev
)
706 struct rd_dev
*rd_dev
= dev
->dev_ptr
;
707 unsigned long long blocks_long
= ((rd_dev
->rd_page_count
* PAGE_SIZE
) /
708 dev
->se_sub_dev
->se_dev_attrib
.block_size
) - 1;
713 static struct se_subsystem_api rd_mcp_template
= {
715 .transport_type
= TRANSPORT_PLUGIN_VHBA_VDEV
,
716 .attach_hba
= rd_attach_hba
,
717 .detach_hba
= rd_detach_hba
,
718 .allocate_virtdevice
= rd_MEMCPY_allocate_virtdevice
,
719 .create_virtdevice
= rd_MEMCPY_create_virtdevice
,
720 .free_device
= rd_free_device
,
721 .alloc_task
= rd_alloc_task
,
722 .do_task
= rd_MEMCPY_do_task
,
723 .free_task
= rd_free_task
,
724 .check_configfs_dev_params
= rd_check_configfs_dev_params
,
725 .set_configfs_dev_params
= rd_set_configfs_dev_params
,
726 .show_configfs_dev_params
= rd_show_configfs_dev_params
,
727 .get_device_rev
= rd_get_device_rev
,
728 .get_device_type
= rd_get_device_type
,
729 .get_blocks
= rd_get_blocks
,
732 int __init
rd_module_init(void)
736 ret
= transport_subsystem_register(&rd_mcp_template
);
744 void rd_module_exit(void)
746 transport_subsystem_release(&rd_mcp_template
);