target/tcm_fc: fix the lockdep warning due to inconsistent lock state
[linux-2.6.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  * 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
11  *
12  * Nicholas A. Bellinger <nab@kernel.org>
13  *
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.
18  *
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.
23  *
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.
27  *
28  ******************************************************************************/
29
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>
38
39 #include <target/target_core_base.h>
40 #include <target/target_core_backend.h>
41
42 #include "target_core_rd.h"
43
44 static struct se_subsystem_api rd_mcp_template;
45
46 /*      rd_attach_hba(): (Part of se_subsystem_api_t template)
47  *
48  *
49  */
50 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
51 {
52         struct rd_host *rd_host;
53
54         rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
55         if (!rd_host) {
56                 pr_err("Unable to allocate memory for struct rd_host\n");
57                 return -ENOMEM;
58         }
59
60         rd_host->rd_host_id = host_id;
61
62         hba->hba_ptr = rd_host;
63
64         pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
65                 " Generic Target Core Stack %s\n", hba->hba_id,
66                 RD_HBA_VERSION, TARGET_CORE_MOD_VERSION);
67         pr_debug("CORE_HBA[%d] - Attached Ramdisk HBA: %u to Generic"
68                 " MaxSectors: %u\n", hba->hba_id,
69                 rd_host->rd_host_id, RD_MAX_SECTORS);
70
71         return 0;
72 }
73
74 static void rd_detach_hba(struct se_hba *hba)
75 {
76         struct rd_host *rd_host = hba->hba_ptr;
77
78         pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
79                 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
80
81         kfree(rd_host);
82         hba->hba_ptr = NULL;
83 }
84
85 /*      rd_release_device_space():
86  *
87  *
88  */
89 static void rd_release_device_space(struct rd_dev *rd_dev)
90 {
91         u32 i, j, page_count = 0, sg_per_table;
92         struct rd_dev_sg_table *sg_table;
93         struct page *pg;
94         struct scatterlist *sg;
95
96         if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
97                 return;
98
99         sg_table = rd_dev->sg_table_array;
100
101         for (i = 0; i < rd_dev->sg_table_count; i++) {
102                 sg = sg_table[i].sg_table;
103                 sg_per_table = sg_table[i].rd_sg_count;
104
105                 for (j = 0; j < sg_per_table; j++) {
106                         pg = sg_page(&sg[j]);
107                         if (pg) {
108                                 __free_page(pg);
109                                 page_count++;
110                         }
111                 }
112
113                 kfree(sg);
114         }
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         kfree(sg_table);
122         rd_dev->sg_table_array = NULL;
123         rd_dev->sg_table_count = 0;
124 }
125
126
127 /*      rd_build_device_space():
128  *
129  *
130  */
131 static int rd_build_device_space(struct rd_dev *rd_dev)
132 {
133         u32 i = 0, j, page_offset = 0, sg_per_table, sg_tables, total_sg_needed;
134         u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
135                                 sizeof(struct scatterlist));
136         struct rd_dev_sg_table *sg_table;
137         struct page *pg;
138         struct scatterlist *sg;
139
140         if (rd_dev->rd_page_count <= 0) {
141                 pr_err("Illegal page count: %u for Ramdisk device\n",
142                         rd_dev->rd_page_count);
143                 return -EINVAL;
144         }
145         total_sg_needed = rd_dev->rd_page_count;
146
147         sg_tables = (total_sg_needed / max_sg_per_table) + 1;
148
149         sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
150         if (!sg_table) {
151                 pr_err("Unable to allocate memory for Ramdisk"
152                         " scatterlist tables\n");
153                 return -ENOMEM;
154         }
155
156         rd_dev->sg_table_array = sg_table;
157         rd_dev->sg_table_count = sg_tables;
158
159         while (total_sg_needed) {
160                 sg_per_table = (total_sg_needed > max_sg_per_table) ?
161                         max_sg_per_table : total_sg_needed;
162
163                 sg = kzalloc(sg_per_table * sizeof(struct scatterlist),
164                                 GFP_KERNEL);
165                 if (!sg) {
166                         pr_err("Unable to allocate scatterlist array"
167                                 " for struct rd_dev\n");
168                         return -ENOMEM;
169                 }
170
171                 sg_init_table(sg, sg_per_table);
172
173                 sg_table[i].sg_table = sg;
174                 sg_table[i].rd_sg_count = sg_per_table;
175                 sg_table[i].page_start_offset = page_offset;
176                 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
177                                                 - 1;
178
179                 for (j = 0; j < sg_per_table; j++) {
180                         pg = alloc_pages(GFP_KERNEL, 0);
181                         if (!pg) {
182                                 pr_err("Unable to allocate scatterlist"
183                                         " pages for struct rd_dev_sg_table\n");
184                                 return -ENOMEM;
185                         }
186                         sg_assign_page(&sg[j], pg);
187                         sg[j].length = PAGE_SIZE;
188                 }
189
190                 page_offset += sg_per_table;
191                 total_sg_needed -= sg_per_table;
192         }
193
194         pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
195                 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
196                 rd_dev->rd_dev_id, rd_dev->rd_page_count,
197                 rd_dev->sg_table_count);
198
199         return 0;
200 }
201
202 static void *rd_allocate_virtdevice(
203         struct se_hba *hba,
204         const char *name,
205         int rd_direct)
206 {
207         struct rd_dev *rd_dev;
208         struct rd_host *rd_host = hba->hba_ptr;
209
210         rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
211         if (!rd_dev) {
212                 pr_err("Unable to allocate memory for struct rd_dev\n");
213                 return NULL;
214         }
215
216         rd_dev->rd_host = rd_host;
217         rd_dev->rd_direct = rd_direct;
218
219         return rd_dev;
220 }
221
222 static void *rd_MEMCPY_allocate_virtdevice(struct se_hba *hba, const char *name)
223 {
224         return rd_allocate_virtdevice(hba, name, 0);
225 }
226
227 /*      rd_create_virtdevice():
228  *
229  *
230  */
231 static struct se_device *rd_create_virtdevice(
232         struct se_hba *hba,
233         struct se_subsystem_dev *se_dev,
234         void *p,
235         int rd_direct)
236 {
237         struct se_device *dev;
238         struct se_dev_limits dev_limits;
239         struct rd_dev *rd_dev = p;
240         struct rd_host *rd_host = hba->hba_ptr;
241         int dev_flags = 0, ret;
242         char prod[16], rev[4];
243
244         memset(&dev_limits, 0, sizeof(struct se_dev_limits));
245
246         ret = rd_build_device_space(rd_dev);
247         if (ret < 0)
248                 goto fail;
249
250         snprintf(prod, 16, "RAMDISK-%s", (rd_dev->rd_direct) ? "DR" : "MCP");
251         snprintf(rev, 4, "%s", (rd_dev->rd_direct) ? RD_DR_VERSION :
252                                                 RD_MCP_VERSION);
253
254         dev_limits.limits.logical_block_size = RD_BLOCKSIZE;
255         dev_limits.limits.max_hw_sectors = RD_MAX_SECTORS;
256         dev_limits.limits.max_sectors = RD_MAX_SECTORS;
257         dev_limits.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
258         dev_limits.queue_depth = RD_DEVICE_QUEUE_DEPTH;
259
260         dev = transport_add_device_to_core_hba(hba,
261                         &rd_mcp_template, se_dev, dev_flags, rd_dev,
262                         &dev_limits, prod, rev);
263         if (!dev)
264                 goto fail;
265
266         rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
267         rd_dev->rd_queue_depth = dev->queue_depth;
268
269         pr_debug("CORE_RD[%u] - Added TCM %s Ramdisk Device ID: %u of"
270                 " %u pages in %u tables, %lu total bytes\n",
271                 rd_host->rd_host_id, (!rd_dev->rd_direct) ? "MEMCPY" :
272                 "DIRECT", rd_dev->rd_dev_id, rd_dev->rd_page_count,
273                 rd_dev->sg_table_count,
274                 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
275
276         return dev;
277
278 fail:
279         rd_release_device_space(rd_dev);
280         return ERR_PTR(ret);
281 }
282
283 static struct se_device *rd_MEMCPY_create_virtdevice(
284         struct se_hba *hba,
285         struct se_subsystem_dev *se_dev,
286         void *p)
287 {
288         return rd_create_virtdevice(hba, se_dev, p, 0);
289 }
290
291 /*      rd_free_device(): (Part of se_subsystem_api_t template)
292  *
293  *
294  */
295 static void rd_free_device(void *p)
296 {
297         struct rd_dev *rd_dev = p;
298
299         rd_release_device_space(rd_dev);
300         kfree(rd_dev);
301 }
302
303 static inline struct rd_request *RD_REQ(struct se_task *task)
304 {
305         return container_of(task, struct rd_request, rd_task);
306 }
307
308 static struct se_task *
309 rd_alloc_task(unsigned char *cdb)
310 {
311         struct rd_request *rd_req;
312
313         rd_req = kzalloc(sizeof(struct rd_request), GFP_KERNEL);
314         if (!rd_req) {
315                 pr_err("Unable to allocate struct rd_request\n");
316                 return NULL;
317         }
318
319         return &rd_req->rd_task;
320 }
321
322 /*      rd_get_sg_table():
323  *
324  *
325  */
326 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
327 {
328         u32 i;
329         struct rd_dev_sg_table *sg_table;
330
331         for (i = 0; i < rd_dev->sg_table_count; i++) {
332                 sg_table = &rd_dev->sg_table_array[i];
333                 if ((sg_table->page_start_offset <= page) &&
334                     (sg_table->page_end_offset >= page))
335                         return sg_table;
336         }
337
338         pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
339                         page);
340
341         return NULL;
342 }
343
344 static int rd_MEMCPY(struct rd_request *req, u32 read_rd)
345 {
346         struct se_task *task = &req->rd_task;
347         struct rd_dev *dev = req->rd_task.task_se_cmd->se_dev->dev_ptr;
348         struct rd_dev_sg_table *table;
349         struct scatterlist *rd_sg;
350         struct sg_mapping_iter m;
351         u32 rd_offset = req->rd_offset;
352         u32 src_len;
353
354         table = rd_get_sg_table(dev, req->rd_page);
355         if (!table)
356                 return -EINVAL;
357
358         rd_sg = &table->sg_table[req->rd_page - table->page_start_offset];
359
360         pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
361                         dev->rd_dev_id, read_rd ? "Read" : "Write",
362                         task->task_lba, req->rd_size, req->rd_page,
363                         rd_offset);
364
365         src_len = PAGE_SIZE - rd_offset;
366         sg_miter_start(&m, task->task_sg, task->task_sg_nents,
367                         read_rd ? SG_MITER_TO_SG : SG_MITER_FROM_SG);
368         while (req->rd_size) {
369                 u32 len;
370                 void *rd_addr;
371
372                 sg_miter_next(&m);
373                 len = min((u32)m.length, src_len);
374                 m.consumed = len;
375
376                 rd_addr = sg_virt(rd_sg) + rd_offset;
377
378                 if (read_rd)
379                         memcpy(m.addr, rd_addr, len);
380                 else
381                         memcpy(rd_addr, m.addr, len);
382
383                 req->rd_size -= len;
384                 if (!req->rd_size)
385                         continue;
386
387                 src_len -= len;
388                 if (src_len) {
389                         rd_offset += len;
390                         continue;
391                 }
392
393                 /* rd page completed, next one please */
394                 req->rd_page++;
395                 rd_offset = 0;
396                 src_len = PAGE_SIZE;
397                 if (req->rd_page <= table->page_end_offset) {
398                         rd_sg++;
399                         continue;
400                 }
401
402                 table = rd_get_sg_table(dev, req->rd_page);
403                 if (!table) {
404                         sg_miter_stop(&m);
405                         return -EINVAL;
406                 }
407
408                 /* since we increment, the first sg entry is correct */
409                 rd_sg = table->sg_table;
410         }
411         sg_miter_stop(&m);
412         return 0;
413 }
414
415 /*      rd_MEMCPY_do_task(): (Part of se_subsystem_api_t template)
416  *
417  *
418  */
419 static int rd_MEMCPY_do_task(struct se_task *task)
420 {
421         struct se_device *dev = task->task_se_cmd->se_dev;
422         struct rd_request *req = RD_REQ(task);
423         u64 tmp;
424         int ret;
425
426         tmp = task->task_lba * dev->se_sub_dev->se_dev_attrib.block_size;
427         req->rd_offset = do_div(tmp, PAGE_SIZE);
428         req->rd_page = tmp;
429         req->rd_size = task->task_size;
430
431         ret = rd_MEMCPY(req, task->task_data_direction == DMA_FROM_DEVICE);
432         if (ret != 0)
433                 return ret;
434
435         task->task_scsi_status = GOOD;
436         transport_complete_task(task, 1);
437         return 0;
438 }
439
440 /*      rd_free_task(): (Part of se_subsystem_api_t template)
441  *
442  *
443  */
444 static void rd_free_task(struct se_task *task)
445 {
446         kfree(RD_REQ(task));
447 }
448
449 enum {
450         Opt_rd_pages, Opt_err
451 };
452
453 static match_table_t tokens = {
454         {Opt_rd_pages, "rd_pages=%d"},
455         {Opt_err, NULL}
456 };
457
458 static ssize_t rd_set_configfs_dev_params(
459         struct se_hba *hba,
460         struct se_subsystem_dev *se_dev,
461         const char *page,
462         ssize_t count)
463 {
464         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
465         char *orig, *ptr, *opts;
466         substring_t args[MAX_OPT_ARGS];
467         int ret = 0, arg, token;
468
469         opts = kstrdup(page, GFP_KERNEL);
470         if (!opts)
471                 return -ENOMEM;
472
473         orig = opts;
474
475         while ((ptr = strsep(&opts, ",\n")) != NULL) {
476                 if (!*ptr)
477                         continue;
478
479                 token = match_token(ptr, tokens, args);
480                 switch (token) {
481                 case Opt_rd_pages:
482                         match_int(args, &arg);
483                         rd_dev->rd_page_count = arg;
484                         pr_debug("RAMDISK: Referencing Page"
485                                 " Count: %u\n", rd_dev->rd_page_count);
486                         rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
487                         break;
488                 default:
489                         break;
490                 }
491         }
492
493         kfree(orig);
494         return (!ret) ? count : ret;
495 }
496
497 static ssize_t rd_check_configfs_dev_params(struct se_hba *hba, struct se_subsystem_dev *se_dev)
498 {
499         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
500
501         if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
502                 pr_debug("Missing rd_pages= parameter\n");
503                 return -EINVAL;
504         }
505
506         return 0;
507 }
508
509 static ssize_t rd_show_configfs_dev_params(
510         struct se_hba *hba,
511         struct se_subsystem_dev *se_dev,
512         char *b)
513 {
514         struct rd_dev *rd_dev = se_dev->se_dev_su_ptr;
515         ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: %s\n",
516                         rd_dev->rd_dev_id, (rd_dev->rd_direct) ?
517                         "rd_direct" : "rd_mcp");
518         bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
519                         "  SG_table_count: %u\n", rd_dev->rd_page_count,
520                         PAGE_SIZE, rd_dev->sg_table_count);
521         return bl;
522 }
523
524 static u32 rd_get_device_rev(struct se_device *dev)
525 {
526         return SCSI_SPC_2; /* Returns SPC-3 in Initiator Data */
527 }
528
529 static u32 rd_get_device_type(struct se_device *dev)
530 {
531         return TYPE_DISK;
532 }
533
534 static sector_t rd_get_blocks(struct se_device *dev)
535 {
536         struct rd_dev *rd_dev = dev->dev_ptr;
537         unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
538                         dev->se_sub_dev->se_dev_attrib.block_size) - 1;
539
540         return blocks_long;
541 }
542
543 static struct se_subsystem_api rd_mcp_template = {
544         .name                   = "rd_mcp",
545         .transport_type         = TRANSPORT_PLUGIN_VHBA_VDEV,
546         .attach_hba             = rd_attach_hba,
547         .detach_hba             = rd_detach_hba,
548         .allocate_virtdevice    = rd_MEMCPY_allocate_virtdevice,
549         .create_virtdevice      = rd_MEMCPY_create_virtdevice,
550         .free_device            = rd_free_device,
551         .alloc_task             = rd_alloc_task,
552         .do_task                = rd_MEMCPY_do_task,
553         .free_task              = rd_free_task,
554         .check_configfs_dev_params = rd_check_configfs_dev_params,
555         .set_configfs_dev_params = rd_set_configfs_dev_params,
556         .show_configfs_dev_params = rd_show_configfs_dev_params,
557         .get_device_rev         = rd_get_device_rev,
558         .get_device_type        = rd_get_device_type,
559         .get_blocks             = rd_get_blocks,
560 };
561
562 int __init rd_module_init(void)
563 {
564         int ret;
565
566         ret = transport_subsystem_register(&rd_mcp_template);
567         if (ret < 0) {
568                 return ret;
569         }
570
571         return 0;
572 }
573
574 void rd_module_exit(void)
575 {
576         transport_subsystem_release(&rd_mcp_template);
577 }