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clk: return probe defer when DT clock not yet ready
[linux-2.6/btrfs-unstable.git] / drivers / target / target_core_rd.c
blob66a5aba5a0d9c6a6708582a026b25b0f6a17075e
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)
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 total_sg_needed = rd_dev->rd_page_count / prot_length;
257
258 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
259
260 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
261 if (!sg_table) {
262 pr_err("Unable to allocate memory for Ramdisk protection"
263 " scatterlist tables\n");
264 return -ENOMEM;
265 }
266
267 rd_dev->sg_prot_array = sg_table;
268 rd_dev->sg_prot_count = sg_tables;
269
270 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
271 if (rc)
272 return rc;
273
274 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
275 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
276 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
277
278 return 0;
279 }
280
281 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
282 {
283 struct rd_dev *rd_dev;
284 struct rd_host *rd_host = hba->hba_ptr;
285
286 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
287 if (!rd_dev) {
288 pr_err("Unable to allocate memory for struct rd_dev\n");
289 return NULL;
290 }
291
292 rd_dev->rd_host = rd_host;
293
294 return &rd_dev->dev;
295 }
296
297 static int rd_configure_device(struct se_device *dev)
298 {
299 struct rd_dev *rd_dev = RD_DEV(dev);
300 struct rd_host *rd_host = dev->se_hba->hba_ptr;
301 int ret;
302
303 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
304 pr_debug("Missing rd_pages= parameter\n");
305 return -EINVAL;
306 }
307
308 ret = rd_build_device_space(rd_dev);
309 if (ret < 0)
310 goto fail;
311
312 dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
313 dev->dev_attrib.hw_max_sectors = UINT_MAX;
314 dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
315
316 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
317
318 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
319 " %u pages in %u tables, %lu total bytes\n",
320 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
321 rd_dev->sg_table_count,
322 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
323
324 return 0;
325
326 fail:
327 rd_release_device_space(rd_dev);
328 return ret;
329 }
330
331 static void rd_free_device(struct se_device *dev)
332 {
333 struct rd_dev *rd_dev = RD_DEV(dev);
334
335 rd_release_device_space(rd_dev);
336 kfree(rd_dev);
337 }
338
339 static 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
359 static 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
379 static sense_reason_t
380 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
381 enum dma_data_direction data_direction)
382 {
383 struct se_device *se_dev = cmd->se_dev;
384 struct rd_dev *dev = RD_DEV(se_dev);
385 struct rd_dev_sg_table *table;
386 struct scatterlist *rd_sg;
387 struct sg_mapping_iter m;
388 u32 rd_offset;
389 u32 rd_size;
390 u32 rd_page;
391 u32 src_len;
392 u64 tmp;
393 sense_reason_t rc;
394
395 if (dev->rd_flags & RDF_NULLIO) {
396 target_complete_cmd(cmd, SAM_STAT_GOOD);
397 return 0;
398 }
399
400 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
401 rd_offset = do_div(tmp, PAGE_SIZE);
402 rd_page = tmp;
403 rd_size = cmd->data_length;
404
405 table = rd_get_sg_table(dev, rd_page);
406 if (!table)
407 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
408
409 rd_sg = &table->sg_table[rd_page - table->page_start_offset];
410
411 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
412 dev->rd_dev_id,
413 data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
414 cmd->t_task_lba, rd_size, rd_page, rd_offset);
415
416 if (cmd->prot_type && data_direction == DMA_TO_DEVICE) {
417 struct rd_dev_sg_table *prot_table;
418 struct scatterlist *prot_sg;
419 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
420 u32 prot_offset, prot_page;
421
422 tmp = cmd->t_task_lba * se_dev->prot_length;
423 prot_offset = do_div(tmp, PAGE_SIZE);
424 prot_page = tmp;
425
426 prot_table = rd_get_prot_table(dev, prot_page);
427 if (!prot_table)
428 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
429
430 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
431
432 rc = sbc_dif_verify_write(cmd, cmd->t_task_lba, sectors, 0,
433 prot_sg, prot_offset);
434 if (rc)
435 return rc;
436 }
437
438 src_len = PAGE_SIZE - rd_offset;
439 sg_miter_start(&m, sgl, sgl_nents,
440 data_direction == DMA_FROM_DEVICE ?
441 SG_MITER_TO_SG : SG_MITER_FROM_SG);
442 while (rd_size) {
443 u32 len;
444 void *rd_addr;
445
446 sg_miter_next(&m);
447 if (!(u32)m.length) {
448 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
449 dev->rd_dev_id, m.addr, m.length);
450 sg_miter_stop(&m);
451 return TCM_INCORRECT_AMOUNT_OF_DATA;
452 }
453 len = min((u32)m.length, src_len);
454 if (len > rd_size) {
455 pr_debug("RD[%u]: size underrun page %d offset %d "
456 "size %d\n", dev->rd_dev_id,
457 rd_page, rd_offset, rd_size);
458 len = rd_size;
459 }
460 m.consumed = len;
461
462 rd_addr = sg_virt(rd_sg) + rd_offset;
463
464 if (data_direction == DMA_FROM_DEVICE)
465 memcpy(m.addr, rd_addr, len);
466 else
467 memcpy(rd_addr, m.addr, len);
468
469 rd_size -= len;
470 if (!rd_size)
471 continue;
472
473 src_len -= len;
474 if (src_len) {
475 rd_offset += len;
476 continue;
477 }
478
479 /* rd page completed, next one please */
480 rd_page++;
481 rd_offset = 0;
482 src_len = PAGE_SIZE;
483 if (rd_page <= table->page_end_offset) {
484 rd_sg++;
485 continue;
486 }
487
488 table = rd_get_sg_table(dev, rd_page);
489 if (!table) {
490 sg_miter_stop(&m);
491 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
492 }
493
494 /* since we increment, the first sg entry is correct */
495 rd_sg = table->sg_table;
496 }
497 sg_miter_stop(&m);
498
499 if (cmd->prot_type && data_direction == DMA_FROM_DEVICE) {
500 struct rd_dev_sg_table *prot_table;
501 struct scatterlist *prot_sg;
502 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
503 u32 prot_offset, prot_page;
504
505 tmp = cmd->t_task_lba * se_dev->prot_length;
506 prot_offset = do_div(tmp, PAGE_SIZE);
507 prot_page = tmp;
508
509 prot_table = rd_get_prot_table(dev, prot_page);
510 if (!prot_table)
511 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
512
513 prot_sg = &prot_table->sg_table[prot_page - prot_table->page_start_offset];
514
515 rc = sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
516 prot_sg, prot_offset);
517 if (rc)
518 return rc;
519 }
520
521 target_complete_cmd(cmd, SAM_STAT_GOOD);
522 return 0;
523 }
524
525 enum {
526 Opt_rd_pages, Opt_rd_nullio, Opt_err
527 };
528
529 static match_table_t tokens = {
530 {Opt_rd_pages, "rd_pages=%d"},
531 {Opt_rd_nullio, "rd_nullio=%d"},
532 {Opt_err, NULL}
533 };
534
535 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
536 const char *page, ssize_t count)
537 {
538 struct rd_dev *rd_dev = RD_DEV(dev);
539 char *orig, *ptr, *opts;
540 substring_t args[MAX_OPT_ARGS];
541 int ret = 0, arg, token;
542
543 opts = kstrdup(page, GFP_KERNEL);
544 if (!opts)
545 return -ENOMEM;
546
547 orig = opts;
548
549 while ((ptr = strsep(&opts, ",\n")) != NULL) {
550 if (!*ptr)
551 continue;
552
553 token = match_token(ptr, tokens, args);
554 switch (token) {
555 case Opt_rd_pages:
556 match_int(args, &arg);
557 rd_dev->rd_page_count = arg;
558 pr_debug("RAMDISK: Referencing Page"
559 " Count: %u\n", rd_dev->rd_page_count);
560 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
561 break;
562 case Opt_rd_nullio:
563 match_int(args, &arg);
564 if (arg != 1)
565 break;
566
567 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
568 rd_dev->rd_flags |= RDF_NULLIO;
569 break;
570 default:
571 break;
572 }
573 }
574
575 kfree(orig);
576 return (!ret) ? count : ret;
577 }
578
579 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
580 {
581 struct rd_dev *rd_dev = RD_DEV(dev);
582
583 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
584 rd_dev->rd_dev_id);
585 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
586 " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
587 PAGE_SIZE, rd_dev->sg_table_count,
588 !!(rd_dev->rd_flags & RDF_NULLIO));
589 return bl;
590 }
591
592 static sector_t rd_get_blocks(struct se_device *dev)
593 {
594 struct rd_dev *rd_dev = RD_DEV(dev);
595
596 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
597 dev->dev_attrib.block_size) - 1;
598
599 return blocks_long;
600 }
601
602 static int rd_init_prot(struct se_device *dev)
603 {
604 struct rd_dev *rd_dev = RD_DEV(dev);
605
606 if (!dev->dev_attrib.pi_prot_type)
607 return 0;
608
609 return rd_build_prot_space(rd_dev, dev->prot_length);
610 }
611
612 static void rd_free_prot(struct se_device *dev)
613 {
614 struct rd_dev *rd_dev = RD_DEV(dev);
615
616 rd_release_prot_space(rd_dev);
617 }
618
619 static struct sbc_ops rd_sbc_ops = {
620 .execute_rw = rd_execute_rw,
621 };
622
623 static sense_reason_t
624 rd_parse_cdb(struct se_cmd *cmd)
625 {
626 return sbc_parse_cdb(cmd, &rd_sbc_ops);
627 }
628
629 static struct se_subsystem_api rd_mcp_template = {
630 .name = "rd_mcp",
631 .inquiry_prod = "RAMDISK-MCP",
632 .inquiry_rev = RD_MCP_VERSION,
633 .transport_type = TRANSPORT_PLUGIN_VHBA_VDEV,
634 .attach_hba = rd_attach_hba,
635 .detach_hba = rd_detach_hba,
636 .alloc_device = rd_alloc_device,
637 .configure_device = rd_configure_device,
638 .free_device = rd_free_device,
639 .parse_cdb = rd_parse_cdb,
640 .set_configfs_dev_params = rd_set_configfs_dev_params,
641 .show_configfs_dev_params = rd_show_configfs_dev_params,
642 .get_device_type = sbc_get_device_type,
643 .get_blocks = rd_get_blocks,
644 .init_prot = rd_init_prot,
645 .free_prot = rd_free_prot,
646 };
647
648 int __init rd_module_init(void)
649 {
650 int ret;
651
652 ret = transport_subsystem_register(&rd_mcp_template);
653 if (ret < 0) {
654 return ret;
655 }
656
657 return 0;
658 }
659
660 void rd_module_exit(void)
661 {
662 transport_subsystem_release(&rd_mcp_template);
663 }
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