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/version.h>
31 #include <linux/string.h>
32 #include <linux/parser.h>
33 #include <linux/timer.h>
34 #include <linux/blkdev.h>
35 #include <linux/slab.h>
36 #include <linux/spinlock.h>
37 #include <scsi/scsi.h>
38 #include <scsi/scsi_host.h>
40 #include <target/target_core_base.h>
41 #include <target/target_core_device.h>
42 #include <target/target_core_transport.h>
43 #include <target/target_core_fabric_ops.h>
45 #include "target_core_rd.h"
47 static struct se_subsystem_api rd_mcp_template
;
49 /* rd_attach_hba(): (Part of se_subsystem_api_t template)
53 static int rd_attach_hba(struct se_hba
*hba
, u32 host_id
)
55 struct rd_host
*rd_host
;
57 rd_host
= kzalloc(sizeof(struct rd_host
), GFP_KERNEL
);
59 pr_err("Unable to allocate memory for struct rd_host\n");
63 rd_host
->rd_host_id
= host_id
;
65 hba
->hba_ptr
= rd_host
;
67 pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
68 " Generic Target Core Stack %s\n", hba
->hba_id
,
69 RD_HBA_VERSION
, TARGET_CORE_MOD_VERSION
);
70 pr_debug("CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
71 " MaxSectors: %u\n", hba
->hba_id
,
72 rd_host
->rd_host_id
, RD_MAX_SECTORS
);
77 static void rd_detach_hba(struct se_hba
*hba
)
79 struct rd_host
*rd_host
= hba
->hba_ptr
;
81 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
82 " Generic Target Core\n", hba
->hba_id
, rd_host
->rd_host_id
);
88 /* rd_release_device_space():
92 static void rd_release_device_space(struct rd_dev
*rd_dev
)
94 u32 i
, j
, page_count
= 0, sg_per_table
;
95 struct rd_dev_sg_table
*sg_table
;
97 struct scatterlist
*sg
;
99 if (!rd_dev
->sg_table_array
|| !rd_dev
->sg_table_count
)
102 sg_table
= rd_dev
->sg_table_array
;
104 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
105 sg
= sg_table
[i
].sg_table
;
106 sg_per_table
= sg_table
[i
].rd_sg_count
;
108 for (j
= 0; j
< sg_per_table
; j
++) {
109 pg
= sg_page(&sg
[j
]);
119 pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
120 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
121 rd_dev
->rd_host
->rd_host_id
, rd_dev
->rd_dev_id
, page_count
,
122 rd_dev
->sg_table_count
, (unsigned long)page_count
* PAGE_SIZE
);
125 rd_dev
->sg_table_array
= NULL
;
126 rd_dev
->sg_table_count
= 0;
130 /* rd_build_device_space():
134 static int rd_build_device_space(struct rd_dev
*rd_dev
)
136 u32 i
= 0, j
, page_offset
= 0, sg_per_table
, sg_tables
, total_sg_needed
;
137 u32 max_sg_per_table
= (RD_MAX_ALLOCATION_SIZE
/
138 sizeof(struct scatterlist
));
139 struct rd_dev_sg_table
*sg_table
;
141 struct scatterlist
*sg
;
143 if (rd_dev
->rd_page_count
<= 0) {
144 pr_err("Illegal page count: %u for Ramdisk device\n",
145 rd_dev
->rd_page_count
);
148 total_sg_needed
= rd_dev
->rd_page_count
;
150 sg_tables
= (total_sg_needed
/ max_sg_per_table
) + 1;
152 sg_table
= kzalloc(sg_tables
* sizeof(struct rd_dev_sg_table
), GFP_KERNEL
);
154 pr_err("Unable to allocate memory for Ramdisk"
155 " scatterlist tables\n");
159 rd_dev
->sg_table_array
= sg_table
;
160 rd_dev
->sg_table_count
= sg_tables
;
162 while (total_sg_needed
) {
163 sg_per_table
= (total_sg_needed
> max_sg_per_table
) ?
164 max_sg_per_table
: total_sg_needed
;
166 sg
= kzalloc(sg_per_table
* sizeof(struct scatterlist
),
169 pr_err("Unable to allocate scatterlist array"
170 " for struct rd_dev\n");
174 sg_init_table(sg
, sg_per_table
);
176 sg_table
[i
].sg_table
= sg
;
177 sg_table
[i
].rd_sg_count
= sg_per_table
;
178 sg_table
[i
].page_start_offset
= page_offset
;
179 sg_table
[i
++].page_end_offset
= (page_offset
+ sg_per_table
)
182 for (j
= 0; j
< sg_per_table
; j
++) {
183 pg
= alloc_pages(GFP_KERNEL
, 0);
185 pr_err("Unable to allocate scatterlist"
186 " pages for struct rd_dev_sg_table\n");
189 sg_assign_page(&sg
[j
], pg
);
190 sg
[j
].length
= PAGE_SIZE
;
193 page_offset
+= sg_per_table
;
194 total_sg_needed
-= sg_per_table
;
197 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
198 " %u pages in %u tables\n", rd_dev
->rd_host
->rd_host_id
,
199 rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
200 rd_dev
->sg_table_count
);
205 static void *rd_allocate_virtdevice(
210 struct rd_dev
*rd_dev
;
211 struct rd_host
*rd_host
= hba
->hba_ptr
;
213 rd_dev
= kzalloc(sizeof(struct rd_dev
), GFP_KERNEL
);
215 pr_err("Unable to allocate memory for struct rd_dev\n");
219 rd_dev
->rd_host
= rd_host
;
220 rd_dev
->rd_direct
= rd_direct
;
225 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba
*hba
, const char *name
)
227 return rd_allocate_virtdevice(hba
, name
, 0);
230 /* rd_create_virtdevice():
234 static struct se_device
*rd_create_virtdevice(
236 struct se_subsystem_dev
*se_dev
,
240 struct se_device
*dev
;
241 struct se_dev_limits dev_limits
;
242 struct rd_dev
*rd_dev
= p
;
243 struct rd_host
*rd_host
= hba
->hba_ptr
;
244 int dev_flags
= 0, ret
;
245 char prod
[16], rev
[4];
247 memset(&dev_limits
, 0, sizeof(struct se_dev_limits
));
249 ret
= rd_build_device_space(rd_dev
);
253 snprintf(prod
, 16, "RAMDISK-%s", (rd_dev
->rd_direct
) ? "DR" : "MCP");
254 snprintf(rev
, 4, "%s", (rd_dev
->rd_direct
) ? RD_DR_VERSION
:
257 dev_limits
.limits
.logical_block_size
= RD_BLOCKSIZE
;
258 dev_limits
.limits
.max_hw_sectors
= RD_MAX_SECTORS
;
259 dev_limits
.limits
.max_sectors
= RD_MAX_SECTORS
;
260 dev_limits
.hw_queue_depth
= RD_MAX_DEVICE_QUEUE_DEPTH
;
261 dev_limits
.queue_depth
= RD_DEVICE_QUEUE_DEPTH
;
263 dev
= transport_add_device_to_core_hba(hba
,
264 &rd_mcp_template
, se_dev
, dev_flags
, rd_dev
,
265 &dev_limits
, prod
, rev
);
269 rd_dev
->rd_dev_id
= rd_host
->rd_host_dev_id_count
++;
270 rd_dev
->rd_queue_depth
= dev
->queue_depth
;
272 pr_debug("CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
273 " %u pages in %u tables, %lu total bytes\n",
274 rd_host
->rd_host_id
, (!rd_dev
->rd_direct
) ? "MEMCPY" :
275 "DIRECT", rd_dev
->rd_dev_id
, rd_dev
->rd_page_count
,
276 rd_dev
->sg_table_count
,
277 (unsigned long)(rd_dev
->rd_page_count
* PAGE_SIZE
));
282 rd_release_device_space(rd_dev
);
286 static struct se_device
*rd_MEMCPY_create_virtdevice(
288 struct se_subsystem_dev
*se_dev
,
291 return rd_create_virtdevice(hba
, se_dev
, p
, 0);
294 /* rd_free_device(): (Part of se_subsystem_api_t template)
298 static void rd_free_device(void *p
)
300 struct rd_dev
*rd_dev
= p
;
302 rd_release_device_space(rd_dev
);
306 static inline struct rd_request
*RD_REQ(struct se_task
*task
)
308 return container_of(task
, struct rd_request
, rd_task
);
311 static struct se_task
*
312 rd_alloc_task(unsigned char *cdb
)
314 struct rd_request
*rd_req
;
316 rd_req
= kzalloc(sizeof(struct rd_request
), GFP_KERNEL
);
318 pr_err("Unable to allocate struct rd_request\n");
322 return &rd_req
->rd_task
;
325 /* rd_get_sg_table():
329 static struct rd_dev_sg_table
*rd_get_sg_table(struct rd_dev
*rd_dev
, u32 page
)
332 struct rd_dev_sg_table
*sg_table
;
334 for (i
= 0; i
< rd_dev
->sg_table_count
; i
++) {
335 sg_table
= &rd_dev
->sg_table_array
[i
];
336 if ((sg_table
->page_start_offset
<= page
) &&
337 (sg_table
->page_end_offset
>= page
))
341 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
351 static int rd_MEMCPY_read(struct rd_request
*req
)
353 struct se_task
*task
= &req
->rd_task
;
354 struct rd_dev
*dev
= req
->rd_task
.se_dev
->dev_ptr
;
355 struct rd_dev_sg_table
*table
;
356 struct scatterlist
*sg_d
, *sg_s
;
358 u32 i
= 0, j
= 0, dst_offset
= 0, src_offset
= 0;
359 u32 length
, page_end
= 0, table_sg_end
;
360 u32 rd_offset
= req
->rd_offset
;
362 table
= rd_get_sg_table(dev
, req
->rd_page
);
366 table_sg_end
= (table
->page_end_offset
- req
->rd_page
);
367 sg_d
= task
->task_sg
;
368 sg_s
= &table
->sg_table
[req
->rd_page
- table
->page_start_offset
];
370 pr_debug("RD[%u]: Read LBA: %llu, Size: %u Page: %u, Offset:"
371 " %u\n", dev
->rd_dev_id
, task
->task_lba
, req
->rd_size
,
372 req
->rd_page
, req
->rd_offset
);
374 src_offset
= rd_offset
;
376 while (req
->rd_size
) {
377 if ((sg_d
[i
].length
- dst_offset
) <
378 (sg_s
[j
].length
- src_offset
)) {
379 length
= (sg_d
[i
].length
- dst_offset
);
381 pr_debug("Step 1 - sg_d[%d]: %p length: %d"
382 " offset: %u sg_s[%d].length: %u\n", i
,
383 &sg_d
[i
], sg_d
[i
].length
, sg_d
[i
].offset
, j
,
385 pr_debug("Step 1 - length: %u dst_offset: %u"
386 " src_offset: %u\n", length
, dst_offset
,
389 if (length
> req
->rd_size
)
390 length
= req
->rd_size
;
392 dst
= sg_virt(&sg_d
[i
++]) + dst_offset
;
396 src
= sg_virt(&sg_s
[j
]) + src_offset
;
404 length
= (sg_s
[j
].length
- src_offset
);
406 pr_debug("Step 2 - sg_d[%d]: %p length: %d"
407 " offset: %u sg_s[%d].length: %u\n", i
,
408 &sg_d
[i
], sg_d
[i
].length
, sg_d
[i
].offset
,
410 pr_debug("Step 2 - length: %u dst_offset: %u"
411 " src_offset: %u\n", length
, dst_offset
,
414 if (length
> req
->rd_size
)
415 length
= req
->rd_size
;
417 dst
= sg_virt(&sg_d
[i
]) + dst_offset
;
421 if (sg_d
[i
].length
== length
) {
427 src
= sg_virt(&sg_s
[j
++]) + src_offset
;
435 memcpy(dst
, src
, length
);
437 pr_debug("page: %u, remaining size: %u, length: %u,"
438 " i: %u, j: %u\n", req
->rd_page
,
439 (req
->rd_size
- length
), length
, i
, j
);
441 req
->rd_size
-= length
;
448 if (++req
->rd_page
<= table
->page_end_offset
) {
449 pr_debug("page: %u in same page table\n",
454 pr_debug("getting new page table for page: %u\n",
457 table
= rd_get_sg_table(dev
, req
->rd_page
);
461 sg_s
= &table
->sg_table
[j
= 0];
467 /* rd_MEMCPY_write():
471 static int rd_MEMCPY_write(struct rd_request
*req
)
473 struct se_task
*task
= &req
->rd_task
;
474 struct rd_dev
*dev
= req
->rd_task
.se_dev
->dev_ptr
;
475 struct rd_dev_sg_table
*table
;
476 struct scatterlist
*sg_d
, *sg_s
;
478 u32 i
= 0, j
= 0, dst_offset
= 0, src_offset
= 0;
479 u32 length
, page_end
= 0, table_sg_end
;
480 u32 rd_offset
= req
->rd_offset
;
482 table
= rd_get_sg_table(dev
, req
->rd_page
);
486 table_sg_end
= (table
->page_end_offset
- req
->rd_page
);
487 sg_d
= &table
->sg_table
[req
->rd_page
- table
->page_start_offset
];
488 sg_s
= task
->task_sg
;
490 pr_debug("RD[%d] Write LBA: %llu, Size: %u, Page: %u,"
491 " Offset: %u\n", dev
->rd_dev_id
, task
->task_lba
, req
->rd_size
,
492 req
->rd_page
, req
->rd_offset
);
494 dst_offset
= rd_offset
;
496 while (req
->rd_size
) {
497 if ((sg_s
[i
].length
- src_offset
) <
498 (sg_d
[j
].length
- dst_offset
)) {
499 length
= (sg_s
[i
].length
- src_offset
);
501 pr_debug("Step 1 - sg_s[%d]: %p length: %d"
502 " offset: %d sg_d[%d].length: %u\n", i
,
503 &sg_s
[i
], sg_s
[i
].length
, sg_s
[i
].offset
,
505 pr_debug("Step 1 - length: %u src_offset: %u"
506 " dst_offset: %u\n", length
, src_offset
,
509 if (length
> req
->rd_size
)
510 length
= req
->rd_size
;
512 src
= sg_virt(&sg_s
[i
++]) + src_offset
;
516 dst
= sg_virt(&sg_d
[j
]) + dst_offset
;
524 length
= (sg_d
[j
].length
- dst_offset
);
526 pr_debug("Step 2 - sg_s[%d]: %p length: %d"
527 " offset: %d sg_d[%d].length: %u\n", i
,
528 &sg_s
[i
], sg_s
[i
].length
, sg_s
[i
].offset
,
530 pr_debug("Step 2 - length: %u src_offset: %u"
531 " dst_offset: %u\n", length
, src_offset
,
534 if (length
> req
->rd_size
)
535 length
= req
->rd_size
;
537 src
= sg_virt(&sg_s
[i
]) + src_offset
;
541 if (sg_s
[i
].length
== length
) {
547 dst
= sg_virt(&sg_d
[j
++]) + dst_offset
;
555 memcpy(dst
, src
, length
);
557 pr_debug("page: %u, remaining size: %u, length: %u,"
558 " i: %u, j: %u\n", req
->rd_page
,
559 (req
->rd_size
- length
), length
, i
, j
);
561 req
->rd_size
-= length
;
568 if (++req
->rd_page
<= table
->page_end_offset
) {
569 pr_debug("page: %u in same page table\n",
574 pr_debug("getting new page table for page: %u\n",
577 table
= rd_get_sg_table(dev
, req
->rd_page
);
581 sg_d
= &table
->sg_table
[j
= 0];
587 /* rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
591 static int rd_MEMCPY_do_task(struct se_task
*task
)
593 struct se_device
*dev
= task
->se_dev
;
594 struct rd_request
*req
= RD_REQ(task
);
595 unsigned long long lba
;
598 req
->rd_page
= (task
->task_lba
* dev
->se_sub_dev
->se_dev_attrib
.block_size
) / PAGE_SIZE
;
599 lba
= task
->task_lba
;
600 req
->rd_offset
= (do_div(lba
,
601 (PAGE_SIZE
/ dev
->se_sub_dev
->se_dev_attrib
.block_size
))) *
602 dev
->se_sub_dev
->se_dev_attrib
.block_size
;
603 req
->rd_size
= task
->task_size
;
605 if (task
->task_data_direction
== DMA_FROM_DEVICE
)
606 ret
= rd_MEMCPY_read(req
);
608 ret
= rd_MEMCPY_write(req
);
613 task
->task_scsi_status
= GOOD
;
614 transport_complete_task(task
, 1);
616 return PYX_TRANSPORT_SENT_TO_TRANSPORT
;
619 /* rd_free_task(): (Part of se_subsystem_api_t template)
623 static void rd_free_task(struct se_task
*task
)
629 Opt_rd_pages
, Opt_err
632 static match_table_t tokens
= {
633 {Opt_rd_pages
, "rd_pages=%d"},
637 static ssize_t
rd_set_configfs_dev_params(
639 struct se_subsystem_dev
*se_dev
,
643 struct rd_dev
*rd_dev
= se_dev
->se_dev_su_ptr
;
644 char *orig
, *ptr
, *opts
;
645 substring_t args
[MAX_OPT_ARGS
];
646 int ret
= 0, arg
, token
;
648 opts
= kstrdup(page
, GFP_KERNEL
);
654 while ((ptr
= strsep(&opts
, ",")) != NULL
) {
658 token
= match_token(ptr
, tokens
, args
);
661 match_int(args
, &arg
);
662 rd_dev
->rd_page_count
= arg
;
663 pr_debug("RAMDISK: Referencing Page"
664 " Count: %u\n", rd_dev
->rd_page_count
);
665 rd_dev
->rd_flags
|= RDF_HAS_PAGE_COUNT
;
673 return (!ret
) ? count
: ret
;
676 static ssize_t
rd_check_configfs_dev_params(struct se_hba
*hba
, struct se_subsystem_dev
*se_dev
)
678 struct rd_dev
*rd_dev
= se_dev
->se_dev_su_ptr
;
680 if (!(rd_dev
->rd_flags
& RDF_HAS_PAGE_COUNT
)) {
681 pr_debug("Missing rd_pages= parameter\n");
688 static ssize_t
rd_show_configfs_dev_params(
690 struct se_subsystem_dev
*se_dev
,
693 struct rd_dev
*rd_dev
= se_dev
->se_dev_su_ptr
;
694 ssize_t bl
= sprintf(b
, "TCM RamDisk ID: %u RamDisk Makeup: %s\n",
695 rd_dev
->rd_dev_id
, (rd_dev
->rd_direct
) ?
696 "rd_direct" : "rd_mcp");
697 bl
+= sprintf(b
+ bl
, " PAGES/PAGE_SIZE: %u*%lu"
698 " SG_table_count: %u\n", rd_dev
->rd_page_count
,
699 PAGE_SIZE
, rd_dev
->sg_table_count
);
703 /* rd_get_cdb(): (Part of se_subsystem_api_t template)
707 static unsigned char *rd_get_cdb(struct se_task
*task
)
709 struct rd_request
*req
= RD_REQ(task
);
711 return req
->rd_scsi_cdb
;
714 static u32
rd_get_device_rev(struct se_device
*dev
)
716 return SCSI_SPC_2
; /* Returns SPC-3 in Initiator Data */
719 static u32
rd_get_device_type(struct se_device
*dev
)
724 static sector_t
rd_get_blocks(struct se_device
*dev
)
726 struct rd_dev
*rd_dev
= dev
->dev_ptr
;
727 unsigned long long blocks_long
= ((rd_dev
->rd_page_count
* PAGE_SIZE
) /
728 dev
->se_sub_dev
->se_dev_attrib
.block_size
) - 1;
733 static struct se_subsystem_api rd_mcp_template
= {
735 .transport_type
= TRANSPORT_PLUGIN_VHBA_VDEV
,
736 .attach_hba
= rd_attach_hba
,
737 .detach_hba
= rd_detach_hba
,
738 .allocate_virtdevice
= rd_MEMCPY_allocate_virtdevice
,
739 .create_virtdevice
= rd_MEMCPY_create_virtdevice
,
740 .free_device
= rd_free_device
,
741 .alloc_task
= rd_alloc_task
,
742 .do_task
= rd_MEMCPY_do_task
,
743 .free_task
= rd_free_task
,
744 .check_configfs_dev_params
= rd_check_configfs_dev_params
,
745 .set_configfs_dev_params
= rd_set_configfs_dev_params
,
746 .show_configfs_dev_params
= rd_show_configfs_dev_params
,
747 .get_cdb
= rd_get_cdb
,
748 .get_device_rev
= rd_get_device_rev
,
749 .get_device_type
= rd_get_device_type
,
750 .get_blocks
= rd_get_blocks
,
753 int __init
rd_module_init(void)
757 ret
= transport_subsystem_register(&rd_mcp_template
);
765 void rd_module_exit(void)
767 transport_subsystem_release(&rd_mcp_template
);