Merge tag 'pm+acpi-3.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[deliverable/linux.git] / drivers / target / target_core_rd.c
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
40 static 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 */
49 static 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
70 static 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
81 static 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
106 static 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 */
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)
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
182 static 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
226 static 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
245 static 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
286 static 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
302 static 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
331 fail:
332 rd_release_device_space(rd_dev);
333 return ret;
334 }
335
336 static 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
344 static 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
364 static 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
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)
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
530 enum {
531 Opt_rd_pages, Opt_rd_nullio, Opt_err
532 };
533
534 static match_table_t tokens = {
535 {Opt_rd_pages, "rd_pages=%d"},
536 {Opt_rd_nullio, "rd_nullio=%d"},
537 {Opt_err, NULL}
538 };
539
540 static 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
584 static 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
597 static 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
607 static 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
618 static 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
625 static struct sbc_ops rd_sbc_ops = {
626 .execute_rw = rd_execute_rw,
627 };
628
629 static sense_reason_t
630 rd_parse_cdb(struct se_cmd *cmd)
631 {
632 return sbc_parse_cdb(cmd, &rd_sbc_ops);
633 }
634
635 static 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
654 int __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
666 void rd_module_exit(void)
667 {
668 transport_subsystem_release(&rd_mcp_template);
669 }
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