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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*******************************************************************************
3 * Filename: target_core_rd.c
4 *
5 * This file contains the Storage Engine <-> Ramdisk transport
6 * specific functions.
7 *
8 * (c) Copyright 2003-2013 Datera, Inc.
9 *
10 * Nicholas A. Bellinger <nab@kernel.org>
11 *
12 ******************************************************************************/
13
14#include <linux/string.h>
15#include <linux/parser.h>
16#include <linux/highmem.h>
17#include <linux/timer.h>
18#include <linux/scatterlist.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21#include <scsi/scsi_proto.h>
22
23#include <target/target_core_base.h>
24#include <target/target_core_backend.h>
25
26#include "target_core_rd.h"
27
28static inline struct rd_dev *RD_DEV(struct se_device *dev)
29{
30 return container_of(dev, struct rd_dev, dev);
31}
32
33static int rd_attach_hba(struct se_hba *hba, u32 host_id)
34{
35 struct rd_host *rd_host;
36
37 rd_host = kzalloc(sizeof(*rd_host), GFP_KERNEL);
38 if (!rd_host)
39 return -ENOMEM;
40
41 rd_host->rd_host_id = host_id;
42
43 hba->hba_ptr = rd_host;
44
45 pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
46 " Generic Target Core Stack %s\n", hba->hba_id,
47 RD_HBA_VERSION, TARGET_CORE_VERSION);
48
49 return 0;
50}
51
52static void rd_detach_hba(struct se_hba *hba)
53{
54 struct rd_host *rd_host = hba->hba_ptr;
55
56 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
57 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
58
59 kfree(rd_host);
60 hba->hba_ptr = NULL;
61}
62
63static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
64 u32 sg_table_count)
65{
66 struct page *pg;
67 struct scatterlist *sg;
68 u32 i, j, page_count = 0, sg_per_table;
69
70 for (i = 0; i < sg_table_count; i++) {
71 sg = sg_table[i].sg_table;
72 sg_per_table = sg_table[i].rd_sg_count;
73
74 for (j = 0; j < sg_per_table; j++) {
75 pg = sg_page(&sg[j]);
76 if (pg) {
77 __free_page(pg);
78 page_count++;
79 }
80 }
81 kfree(sg);
82 }
83
84 kfree(sg_table);
85 return page_count;
86}
87
88static void rd_release_device_space(struct rd_dev *rd_dev)
89{
90 u32 page_count;
91
92 if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
93 return;
94
95 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
96 rd_dev->sg_table_count);
97
98 pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
99 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
100 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
101 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
102
103 rd_dev->sg_table_array = NULL;
104 rd_dev->sg_table_count = 0;
105}
106
107
108/* rd_build_device_space():
109 *
110 *
111 */
112static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
113 u32 total_sg_needed, unsigned char init_payload)
114{
115 u32 i = 0, j, page_offset = 0, sg_per_table;
116 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
117 sizeof(struct scatterlist));
118 struct page *pg;
119 struct scatterlist *sg;
120 unsigned char *p;
121
122 while (total_sg_needed) {
123 unsigned int chain_entry = 0;
124
125 sg_per_table = (total_sg_needed > max_sg_per_table) ?
126 max_sg_per_table : total_sg_needed;
127
128 /*
129 * Reserve extra element for chain entry
130 */
131 if (sg_per_table < total_sg_needed)
132 chain_entry = 1;
133
134 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
135 GFP_KERNEL);
136 if (!sg)
137 return -ENOMEM;
138
139 sg_init_table(sg, sg_per_table + chain_entry);
140
141 if (i > 0) {
142 sg_chain(sg_table[i - 1].sg_table,
143 max_sg_per_table + 1, sg);
144 }
145
146 sg_table[i].sg_table = sg;
147 sg_table[i].rd_sg_count = sg_per_table;
148 sg_table[i].page_start_offset = page_offset;
149 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
150 - 1;
151
152 for (j = 0; j < sg_per_table; j++) {
153 pg = alloc_pages(GFP_KERNEL, 0);
154 if (!pg) {
155 pr_err("Unable to allocate scatterlist"
156 " pages for struct rd_dev_sg_table\n");
157 return -ENOMEM;
158 }
159 sg_assign_page(&sg[j], pg);
160 sg[j].length = PAGE_SIZE;
161
162 p = kmap(pg);
163 memset(p, init_payload, PAGE_SIZE);
164 kunmap(pg);
165 }
166
167 page_offset += sg_per_table;
168 total_sg_needed -= sg_per_table;
169 }
170
171 return 0;
172}
173
174static int rd_build_device_space(struct rd_dev *rd_dev)
175{
176 struct rd_dev_sg_table *sg_table;
177 u32 sg_tables, total_sg_needed;
178 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
179 sizeof(struct scatterlist));
180 int rc;
181
182 if (rd_dev->rd_page_count <= 0) {
183 pr_err("Illegal page count: %u for Ramdisk device\n",
184 rd_dev->rd_page_count);
185 return -EINVAL;
186 }
187
188 /* Don't need backing pages for NULLIO */
189 if (rd_dev->rd_flags & RDF_NULLIO)
190 return 0;
191
192 total_sg_needed = rd_dev->rd_page_count;
193
194 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
195 sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
196 if (!sg_table)
197 return -ENOMEM;
198
199 rd_dev->sg_table_array = sg_table;
200 rd_dev->sg_table_count = sg_tables;
201
202 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
203 if (rc)
204 return rc;
205
206 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
207 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
208 rd_dev->rd_dev_id, rd_dev->rd_page_count,
209 rd_dev->sg_table_count);
210
211 return 0;
212}
213
214static void rd_release_prot_space(struct rd_dev *rd_dev)
215{
216 u32 page_count;
217
218 if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
219 return;
220
221 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
222 rd_dev->sg_prot_count);
223
224 pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
225 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
226 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
227 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
228
229 rd_dev->sg_prot_array = NULL;
230 rd_dev->sg_prot_count = 0;
231}
232
233static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
234{
235 struct rd_dev_sg_table *sg_table;
236 u32 total_sg_needed, sg_tables;
237 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
238 sizeof(struct scatterlist));
239 int rc;
240
241 if (rd_dev->rd_flags & RDF_NULLIO)
242 return 0;
243 /*
244 * prot_length=8byte dif data
245 * tot sg needed = rd_page_count * (PGSZ/block_size) *
246 * (prot_length/block_size) + pad
247 * PGSZ canceled each other.
248 */
249 total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
250
251 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
252 sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
253 if (!sg_table)
254 return -ENOMEM;
255
256 rd_dev->sg_prot_array = sg_table;
257 rd_dev->sg_prot_count = sg_tables;
258
259 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
260 if (rc)
261 return rc;
262
263 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
264 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
265 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
266
267 return 0;
268}
269
270static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
271{
272 struct rd_dev *rd_dev;
273 struct rd_host *rd_host = hba->hba_ptr;
274
275 rd_dev = kzalloc(sizeof(*rd_dev), GFP_KERNEL);
276 if (!rd_dev)
277 return NULL;
278
279 rd_dev->rd_host = rd_host;
280
281 return &rd_dev->dev;
282}
283
284static int rd_configure_device(struct se_device *dev)
285{
286 struct rd_dev *rd_dev = RD_DEV(dev);
287 struct rd_host *rd_host = dev->se_hba->hba_ptr;
288 int ret;
289
290 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
291 pr_debug("Missing rd_pages= parameter\n");
292 return -EINVAL;
293 }
294
295 ret = rd_build_device_space(rd_dev);
296 if (ret < 0)
297 goto fail;
298
299 dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
300 dev->dev_attrib.hw_max_sectors = UINT_MAX;
301 dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
302 dev->dev_attrib.is_nonrot = 1;
303
304 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
305
306 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
307 " %u pages in %u tables, %lu total bytes\n",
308 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
309 rd_dev->sg_table_count,
310 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
311
312 return 0;
313
314fail:
315 rd_release_device_space(rd_dev);
316 return ret;
317}
318
319static void rd_dev_call_rcu(struct rcu_head *p)
320{
321 struct se_device *dev = container_of(p, struct se_device, rcu_head);
322 struct rd_dev *rd_dev = RD_DEV(dev);
323
324 kfree(rd_dev);
325}
326
327static void rd_free_device(struct se_device *dev)
328{
329 call_rcu(&dev->rcu_head, rd_dev_call_rcu);
330}
331
332static void rd_destroy_device(struct se_device *dev)
333{
334 struct rd_dev *rd_dev = RD_DEV(dev);
335
336 rd_release_device_space(rd_dev);
337}
338
339static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
340{
341 struct rd_dev_sg_table *sg_table;
342 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
343 sizeof(struct scatterlist));
344
345 i = page / sg_per_table;
346 if (i < rd_dev->sg_table_count) {
347 sg_table = &rd_dev->sg_table_array[i];
348 if ((sg_table->page_start_offset <= page) &&
349 (sg_table->page_end_offset >= page))
350 return sg_table;
351 }
352
353 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
354 page);
355
356 return NULL;
357}
358
359static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
360{
361 struct rd_dev_sg_table *sg_table;
362 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
363 sizeof(struct scatterlist));
364
365 i = page / sg_per_table;
366 if (i < rd_dev->sg_prot_count) {
367 sg_table = &rd_dev->sg_prot_array[i];
368 if ((sg_table->page_start_offset <= page) &&
369 (sg_table->page_end_offset >= page))
370 return sg_table;
371 }
372
373 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
374 page);
375
376 return NULL;
377}
378
379static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
380{
381 struct se_device *se_dev = cmd->se_dev;
382 struct rd_dev *dev = RD_DEV(se_dev);
383 struct rd_dev_sg_table *prot_table;
384 struct scatterlist *prot_sg;
385 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
386 u32 prot_offset, prot_page;
387 u32 prot_npages __maybe_unused;
388 u64 tmp;
389 sense_reason_t rc = 0;
390
391 tmp = cmd->t_task_lba * se_dev->prot_length;
392 prot_offset = do_div(tmp, PAGE_SIZE);
393 prot_page = tmp;
394
395 prot_table = rd_get_prot_table(dev, prot_page);
396 if (!prot_table)
397 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
398
399 prot_sg = &prot_table->sg_table[prot_page -
400 prot_table->page_start_offset];
401
402 if (se_dev->dev_attrib.pi_prot_verify) {
403 if (is_read)
404 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
405 prot_sg, prot_offset);
406 else
407 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
408 cmd->t_prot_sg, 0);
409 }
410 if (!rc)
411 sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
412
413 return rc;
414}
415
416static sense_reason_t
417rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
418 enum dma_data_direction data_direction)
419{
420 struct se_device *se_dev = cmd->se_dev;
421 struct rd_dev *dev = RD_DEV(se_dev);
422 struct rd_dev_sg_table *table;
423 struct scatterlist *rd_sg;
424 struct sg_mapping_iter m;
425 u32 rd_offset;
426 u32 rd_size;
427 u32 rd_page;
428 u32 src_len;
429 u64 tmp;
430 sense_reason_t rc;
431
432 if (dev->rd_flags & RDF_NULLIO) {
433 target_complete_cmd(cmd, SAM_STAT_GOOD);
434 return 0;
435 }
436
437 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
438 rd_offset = do_div(tmp, PAGE_SIZE);
439 rd_page = tmp;
440 rd_size = cmd->data_length;
441
442 table = rd_get_sg_table(dev, rd_page);
443 if (!table)
444 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
445
446 rd_sg = &table->sg_table[rd_page - table->page_start_offset];
447
448 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
449 dev->rd_dev_id,
450 data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
451 cmd->t_task_lba, rd_size, rd_page, rd_offset);
452
453 if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
454 data_direction == DMA_TO_DEVICE) {
455 rc = rd_do_prot_rw(cmd, false);
456 if (rc)
457 return rc;
458 }
459
460 src_len = PAGE_SIZE - rd_offset;
461 sg_miter_start(&m, sgl, sgl_nents,
462 data_direction == DMA_FROM_DEVICE ?
463 SG_MITER_TO_SG : SG_MITER_FROM_SG);
464 while (rd_size) {
465 u32 len;
466 void *rd_addr;
467
468 sg_miter_next(&m);
469 if (!(u32)m.length) {
470 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
471 dev->rd_dev_id, m.addr, m.length);
472 sg_miter_stop(&m);
473 return TCM_INCORRECT_AMOUNT_OF_DATA;
474 }
475 len = min((u32)m.length, src_len);
476 if (len > rd_size) {
477 pr_debug("RD[%u]: size underrun page %d offset %d "
478 "size %d\n", dev->rd_dev_id,
479 rd_page, rd_offset, rd_size);
480 len = rd_size;
481 }
482 m.consumed = len;
483
484 rd_addr = sg_virt(rd_sg) + rd_offset;
485
486 if (data_direction == DMA_FROM_DEVICE)
487 memcpy(m.addr, rd_addr, len);
488 else
489 memcpy(rd_addr, m.addr, len);
490
491 rd_size -= len;
492 if (!rd_size)
493 continue;
494
495 src_len -= len;
496 if (src_len) {
497 rd_offset += len;
498 continue;
499 }
500
501 /* rd page completed, next one please */
502 rd_page++;
503 rd_offset = 0;
504 src_len = PAGE_SIZE;
505 if (rd_page <= table->page_end_offset) {
506 rd_sg++;
507 continue;
508 }
509
510 table = rd_get_sg_table(dev, rd_page);
511 if (!table) {
512 sg_miter_stop(&m);
513 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
514 }
515
516 /* since we increment, the first sg entry is correct */
517 rd_sg = table->sg_table;
518 }
519 sg_miter_stop(&m);
520
521 if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
522 data_direction == DMA_FROM_DEVICE) {
523 rc = rd_do_prot_rw(cmd, true);
524 if (rc)
525 return rc;
526 }
527
528 target_complete_cmd(cmd, SAM_STAT_GOOD);
529 return 0;
530}
531
532enum {
533 Opt_rd_pages, Opt_rd_nullio, Opt_err
534};
535
536static match_table_t tokens = {
537 {Opt_rd_pages, "rd_pages=%d"},
538 {Opt_rd_nullio, "rd_nullio=%d"},
539 {Opt_err, NULL}
540};
541
542static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
543 const char *page, ssize_t count)
544{
545 struct rd_dev *rd_dev = RD_DEV(dev);
546 char *orig, *ptr, *opts;
547 substring_t args[MAX_OPT_ARGS];
548 int arg, token;
549
550 opts = kstrdup(page, GFP_KERNEL);
551 if (!opts)
552 return -ENOMEM;
553
554 orig = opts;
555
556 while ((ptr = strsep(&opts, ",\n")) != NULL) {
557 if (!*ptr)
558 continue;
559
560 token = match_token(ptr, tokens, args);
561 switch (token) {
562 case Opt_rd_pages:
563 match_int(args, &arg);
564 rd_dev->rd_page_count = arg;
565 pr_debug("RAMDISK: Referencing Page"
566 " Count: %u\n", rd_dev->rd_page_count);
567 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
568 break;
569 case Opt_rd_nullio:
570 match_int(args, &arg);
571 if (arg != 1)
572 break;
573
574 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
575 rd_dev->rd_flags |= RDF_NULLIO;
576 break;
577 default:
578 break;
579 }
580 }
581
582 kfree(orig);
583 return count;
584}
585
586static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
587{
588 struct rd_dev *rd_dev = RD_DEV(dev);
589
590 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
591 rd_dev->rd_dev_id);
592 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
593 " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
594 PAGE_SIZE, rd_dev->sg_table_count,
595 !!(rd_dev->rd_flags & RDF_NULLIO));
596 return bl;
597}
598
599static sector_t rd_get_blocks(struct se_device *dev)
600{
601 struct rd_dev *rd_dev = RD_DEV(dev);
602
603 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
604 dev->dev_attrib.block_size) - 1;
605
606 return blocks_long;
607}
608
609static int rd_init_prot(struct se_device *dev)
610{
611 struct rd_dev *rd_dev = RD_DEV(dev);
612
613 if (!dev->dev_attrib.pi_prot_type)
614 return 0;
615
616 return rd_build_prot_space(rd_dev, dev->prot_length,
617 dev->dev_attrib.block_size);
618}
619
620static void rd_free_prot(struct se_device *dev)
621{
622 struct rd_dev *rd_dev = RD_DEV(dev);
623
624 rd_release_prot_space(rd_dev);
625}
626
627static struct sbc_ops rd_sbc_ops = {
628 .execute_rw = rd_execute_rw,
629};
630
631static sense_reason_t
632rd_parse_cdb(struct se_cmd *cmd)
633{
634 return sbc_parse_cdb(cmd, &rd_sbc_ops);
635}
636
637static const struct target_backend_ops rd_mcp_ops = {
638 .name = "rd_mcp",
639 .inquiry_prod = "RAMDISK-MCP",
640 .inquiry_rev = RD_MCP_VERSION,
641 .attach_hba = rd_attach_hba,
642 .detach_hba = rd_detach_hba,
643 .alloc_device = rd_alloc_device,
644 .configure_device = rd_configure_device,
645 .destroy_device = rd_destroy_device,
646 .free_device = rd_free_device,
647 .parse_cdb = rd_parse_cdb,
648 .set_configfs_dev_params = rd_set_configfs_dev_params,
649 .show_configfs_dev_params = rd_show_configfs_dev_params,
650 .get_device_type = sbc_get_device_type,
651 .get_blocks = rd_get_blocks,
652 .init_prot = rd_init_prot,
653 .free_prot = rd_free_prot,
654 .tb_dev_attrib_attrs = sbc_attrib_attrs,
655};
656
657int __init rd_module_init(void)
658{
659 return transport_backend_register(&rd_mcp_ops);
660}
661
662void rd_module_exit(void)
663{
664 target_backend_unregister(&rd_mcp_ops);
665}
1/*******************************************************************************
2 * Filename: target_core_rd.c
3 *
4 * This file contains the Storage Engine <-> Ramdisk transport
5 * specific functions.
6 *
7 * (c) Copyright 2003-2013 Datera, Inc.
8 *
9 * Nicholas A. Bellinger <nab@kernel.org>
10 *
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.
15 *
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.
20 *
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.
24 *
25 ******************************************************************************/
26
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>
34
35#include <target/target_core_base.h>
36#include <target/target_core_backend.h>
37
38#include "target_core_rd.h"
39
40static inline struct rd_dev *RD_DEV(struct se_device *dev)
41{
42 return container_of(dev, struct rd_dev, dev);
43}
44
45/* rd_attach_hba(): (Part of se_subsystem_api_t template)
46 *
47 *
48 */
49static int rd_attach_hba(struct se_hba *hba, u32 host_id)
50{
51 struct rd_host *rd_host;
52
53 rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
54 if (!rd_host) {
55 pr_err("Unable to allocate memory for struct rd_host\n");
56 return -ENOMEM;
57 }
58
59 rd_host->rd_host_id = host_id;
60
61 hba->hba_ptr = rd_host;
62
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);
66
67 return 0;
68}
69
70static void rd_detach_hba(struct se_hba *hba)
71{
72 struct rd_host *rd_host = hba->hba_ptr;
73
74 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
75 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
76
77 kfree(rd_host);
78 hba->hba_ptr = NULL;
79}
80
81static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
82 u32 sg_table_count)
83{
84 struct page *pg;
85 struct scatterlist *sg;
86 u32 i, j, page_count = 0, sg_per_table;
87
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;
91
92 for (j = 0; j < sg_per_table; j++) {
93 pg = sg_page(&sg[j]);
94 if (pg) {
95 __free_page(pg);
96 page_count++;
97 }
98 }
99 kfree(sg);
100 }
101
102 kfree(sg_table);
103 return page_count;
104}
105
106static void rd_release_device_space(struct rd_dev *rd_dev)
107{
108 u32 page_count;
109
110 if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
111 return;
112
113 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
114 rd_dev->sg_table_count);
115
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);
120
121 rd_dev->sg_table_array = NULL;
122 rd_dev->sg_table_count = 0;
123}
124
125
126/* rd_build_device_space():
127 *
128 *
129 */
130static 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)
132{
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));
136 struct page *pg;
137 struct scatterlist *sg;
138 unsigned char *p;
139
140 while (total_sg_needed) {
141 sg_per_table = (total_sg_needed > max_sg_per_table) ?
142 max_sg_per_table : total_sg_needed;
143
144 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
145 GFP_KERNEL);
146 if (!sg) {
147 pr_err("Unable to allocate scatterlist array"
148 " for struct rd_dev\n");
149 return -ENOMEM;
150 }
151
152 sg_init_table(sg, sg_per_table);
153
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)
158 - 1;
159
160 for (j = 0; j < sg_per_table; j++) {
161 pg = alloc_pages(GFP_KERNEL, 0);
162 if (!pg) {
163 pr_err("Unable to allocate scatterlist"
164 " pages for struct rd_dev_sg_table\n");
165 return -ENOMEM;
166 }
167 sg_assign_page(&sg[j], pg);
168 sg[j].length = PAGE_SIZE;
169
170 p = kmap(pg);
171 memset(p, init_payload, PAGE_SIZE);
172 kunmap(pg);
173 }
174
175 page_offset += sg_per_table;
176 total_sg_needed -= sg_per_table;
177 }
178
179 return 0;
180}
181
182static int rd_build_device_space(struct rd_dev *rd_dev)
183{
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));
188 int rc;
189
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);
193 return -EINVAL;
194 }
195
196 /* Don't need backing pages for NULLIO */
197 if (rd_dev->rd_flags & RDF_NULLIO)
198 return 0;
199
200 total_sg_needed = rd_dev->rd_page_count;
201
202 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
203
204 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
205 if (!sg_table) {
206 pr_err("Unable to allocate memory for Ramdisk"
207 " scatterlist tables\n");
208 return -ENOMEM;
209 }
210
211 rd_dev->sg_table_array = sg_table;
212 rd_dev->sg_table_count = sg_tables;
213
214 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
215 if (rc)
216 return rc;
217
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);
222
223 return 0;
224}
225
226static void rd_release_prot_space(struct rd_dev *rd_dev)
227{
228 u32 page_count;
229
230 if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
231 return;
232
233 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
234 rd_dev->sg_prot_count);
235
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);
240
241 rd_dev->sg_prot_array = NULL;
242 rd_dev->sg_prot_count = 0;
243}
244
245static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
246{
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));
251 int rc;
252
253 if (rd_dev->rd_flags & RDF_NULLIO)
254 return 0;
255 /*
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.
260 */
261 total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
262
263 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
264
265 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
266 if (!sg_table) {
267 pr_err("Unable to allocate memory for Ramdisk protection"
268 " scatterlist tables\n");
269 return -ENOMEM;
270 }
271
272 rd_dev->sg_prot_array = sg_table;
273 rd_dev->sg_prot_count = sg_tables;
274
275 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
276 if (rc)
277 return rc;
278
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);
282
283 return 0;
284}
285
286static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
287{
288 struct rd_dev *rd_dev;
289 struct rd_host *rd_host = hba->hba_ptr;
290
291 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
292 if (!rd_dev) {
293 pr_err("Unable to allocate memory for struct rd_dev\n");
294 return NULL;
295 }
296
297 rd_dev->rd_host = rd_host;
298
299 return &rd_dev->dev;
300}
301
302static int rd_configure_device(struct se_device *dev)
303{
304 struct rd_dev *rd_dev = RD_DEV(dev);
305 struct rd_host *rd_host = dev->se_hba->hba_ptr;
306 int ret;
307
308 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
309 pr_debug("Missing rd_pages= parameter\n");
310 return -EINVAL;
311 }
312
313 ret = rd_build_device_space(rd_dev);
314 if (ret < 0)
315 goto fail;
316
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;
320
321 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
322
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));
328
329 return 0;
330
331fail:
332 rd_release_device_space(rd_dev);
333 return ret;
334}
335
336static void rd_free_device(struct se_device *dev)
337{
338 struct rd_dev *rd_dev = RD_DEV(dev);
339
340 rd_release_device_space(rd_dev);
341 kfree(rd_dev);
342}
343
344static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
345{
346 struct rd_dev_sg_table *sg_table;
347 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
348 sizeof(struct scatterlist));
349
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))
355 return sg_table;
356 }
357
358 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
359 page);
360
361 return NULL;
362}
363
364static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
365{
366 struct rd_dev_sg_table *sg_table;
367 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
368 sizeof(struct scatterlist));
369
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))
375 return sg_table;
376 }
377
378 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
379 page);
380
381 return NULL;
382}
383
384static sense_reason_t
385rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
386 enum dma_data_direction data_direction)
387{
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;
393 u32 rd_offset;
394 u32 rd_size;
395 u32 rd_page;
396 u32 src_len;
397 u64 tmp;
398 sense_reason_t rc;
399
400 if (dev->rd_flags & RDF_NULLIO) {
401 target_complete_cmd(cmd, SAM_STAT_GOOD);
402 return 0;
403 }
404
405 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
406 rd_offset = do_div(tmp, PAGE_SIZE);
407 rd_page = tmp;
408 rd_size = cmd->data_length;
409
410 table = rd_get_sg_table(dev, rd_page);
411 if (!table)
412 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
413
414 rd_sg = &table->sg_table[rd_page - table->page_start_offset];
415
416 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
417 dev->rd_dev_id,
418 data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
419 cmd->t_task_lba, rd_size, rd_page, rd_offset);
420
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;
426
427 tmp = cmd->t_task_lba * se_dev->prot_length;
428 prot_offset = do_div(tmp, PAGE_SIZE);
429 prot_page = tmp;
430
431 prot_table = rd_get_prot_table(dev, prot_page);
432 if (!prot_table)
433 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
434
435 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
436
437 rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors, 0,
438 prot_sg, prot_offset);
439 if (rc)
440 return rc;
441 }
442
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);
447 while (rd_size) {
448 u32 len;
449 void *rd_addr;
450
451 sg_miter_next(&m);
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);
455 sg_miter_stop(&m);
456 return TCM_INCORRECT_AMOUNT_OF_DATA;
457 }
458 len = min((u32)m.length, src_len);
459 if (len > rd_size) {
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);
463 len = rd_size;
464 }
465 m.consumed = len;
466
467 rd_addr = sg_virt(rd_sg) + rd_offset;
468
469 if (data_direction == DMA_FROM_DEVICE)
470 memcpy(m.addr, rd_addr, len);
471 else
472 memcpy(rd_addr, m.addr, len);
473
474 rd_size -= len;
475 if (!rd_size)
476 continue;
477
478 src_len -= len;
479 if (src_len) {
480 rd_offset += len;
481 continue;
482 }
483
484 /* rd page completed, next one please */
485 rd_page++;
486 rd_offset = 0;
487 src_len = PAGE_SIZE;
488 if (rd_page <= table->page_end_offset) {
489 rd_sg++;
490 continue;
491 }
492
493 table = rd_get_sg_table(dev, rd_page);
494 if (!table) {
495 sg_miter_stop(&m);
496 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
497 }
498
499 /* since we increment, the first sg entry is correct */
500 rd_sg = table->sg_table;
501 }
502 sg_miter_stop(&m);
503
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;
509
510 tmp = cmd->t_task_lba * se_dev->prot_length;
511 prot_offset = do_div(tmp, PAGE_SIZE);
512 prot_page = tmp;
513
514 prot_table = rd_get_prot_table(dev, prot_page);
515 if (!prot_table)
516 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
517
518 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
519
520 rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
521 prot_sg, prot_offset);
522 if (rc)
523 return rc;
524 }
525
526 target_complete_cmd(cmd, SAM_STAT_GOOD);
527 return 0;
528}
529
530enum {
531 Opt_rd_pages, Opt_rd_nullio, Opt_err
532};
533
534static match_table_t tokens = {
535 {Opt_rd_pages, "rd_pages=%d"},
536 {Opt_rd_nullio, "rd_nullio=%d"},
537 {Opt_err, NULL}
538};
539
540static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
541 const char *page, ssize_t count)
542{
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;
547
548 opts = kstrdup(page, GFP_KERNEL);
549 if (!opts)
550 return -ENOMEM;
551
552 orig = opts;
553
554 while ((ptr = strsep(&opts, ",\n")) != NULL) {
555 if (!*ptr)
556 continue;
557
558 token = match_token(ptr, tokens, args);
559 switch (token) {
560 case Opt_rd_pages:
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;
566 break;
567 case Opt_rd_nullio:
568 match_int(args, &arg);
569 if (arg != 1)
570 break;
571
572 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
573 rd_dev->rd_flags |= RDF_NULLIO;
574 break;
575 default:
576 break;
577 }
578 }
579
580 kfree(orig);
581 return (!ret) ? count : ret;
582}
583
584static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
585{
586 struct rd_dev *rd_dev = RD_DEV(dev);
587
588 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
589 rd_dev->rd_dev_id);
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));
594 return bl;
595}
596
597static sector_t rd_get_blocks(struct se_device *dev)
598{
599 struct rd_dev *rd_dev = RD_DEV(dev);
600
601 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
602 dev->dev_attrib.block_size) - 1;
603
604 return blocks_long;
605}
606
607static int rd_init_prot(struct se_device *dev)
608{
609 struct rd_dev *rd_dev = RD_DEV(dev);
610
611 if (!dev->dev_attrib.pi_prot_type)
612 return 0;
613
614 return rd_build_prot_space(rd_dev, dev->prot_length,
615 dev->dev_attrib.block_size);
616}
617
618static void rd_free_prot(struct se_device *dev)
619{
620 struct rd_dev *rd_dev = RD_DEV(dev);
621
622 rd_release_prot_space(rd_dev);
623}
624
625static struct sbc_ops rd_sbc_ops = {
626 .execute_rw = rd_execute_rw,
627};
628
629static sense_reason_t
630rd_parse_cdb(struct se_cmd *cmd)
631{
632 return sbc_parse_cdb(cmd, &rd_sbc_ops);
633}
634
635static struct se_subsystem_api rd_mcp_template = {
636 .name = "rd_mcp",
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,
652};
653
654int __init rd_module_init(void)
655{
656 int ret;
657
658 ret = transport_subsystem_register(&rd_mcp_template);
659 if (ret < 0) {
660 return ret;
661 }
662
663 return 0;
664}
665
666void rd_module_exit(void)
667{
668 transport_subsystem_release(&rd_mcp_template);
669}