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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_proto.h>
33
34#include <target/target_core_base.h>
35#include <target/target_core_backend.h>
36
37#include "target_core_rd.h"
38
39static inline struct rd_dev *RD_DEV(struct se_device *dev)
40{
41 return container_of(dev, struct rd_dev, dev);
42}
43
44static int rd_attach_hba(struct se_hba *hba, u32 host_id)
45{
46 struct rd_host *rd_host;
47
48 rd_host = kzalloc(sizeof(struct rd_host), GFP_KERNEL);
49 if (!rd_host) {
50 pr_err("Unable to allocate memory for struct rd_host\n");
51 return -ENOMEM;
52 }
53
54 rd_host->rd_host_id = host_id;
55
56 hba->hba_ptr = rd_host;
57
58 pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
59 " Generic Target Core Stack %s\n", hba->hba_id,
60 RD_HBA_VERSION, TARGET_CORE_VERSION);
61
62 return 0;
63}
64
65static void rd_detach_hba(struct se_hba *hba)
66{
67 struct rd_host *rd_host = hba->hba_ptr;
68
69 pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
70 " Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
71
72 kfree(rd_host);
73 hba->hba_ptr = NULL;
74}
75
76static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
77 u32 sg_table_count)
78{
79 struct page *pg;
80 struct scatterlist *sg;
81 u32 i, j, page_count = 0, sg_per_table;
82
83 for (i = 0; i < sg_table_count; i++) {
84 sg = sg_table[i].sg_table;
85 sg_per_table = sg_table[i].rd_sg_count;
86
87 for (j = 0; j < sg_per_table; j++) {
88 pg = sg_page(&sg[j]);
89 if (pg) {
90 __free_page(pg);
91 page_count++;
92 }
93 }
94 kfree(sg);
95 }
96
97 kfree(sg_table);
98 return page_count;
99}
100
101static void rd_release_device_space(struct rd_dev *rd_dev)
102{
103 u32 page_count;
104
105 if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
106 return;
107
108 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
109 rd_dev->sg_table_count);
110
111 pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
112 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
113 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
114 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
115
116 rd_dev->sg_table_array = NULL;
117 rd_dev->sg_table_count = 0;
118}
119
120
121
122
123
124
125static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
126 u32 total_sg_needed, unsigned char init_payload)
127{
128 u32 i = 0, j, page_offset = 0, sg_per_table;
129 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
130 sizeof(struct scatterlist));
131 struct page *pg;
132 struct scatterlist *sg;
133 unsigned char *p;
134
135 while (total_sg_needed) {
136 unsigned int chain_entry = 0;
137
138 sg_per_table = (total_sg_needed > max_sg_per_table) ?
139 max_sg_per_table : total_sg_needed;
140
141
142
143
144 if (sg_per_table < total_sg_needed)
145 chain_entry = 1;
146
147 sg = kcalloc(sg_per_table + chain_entry, sizeof(*sg),
148 GFP_KERNEL);
149 if (!sg) {
150 pr_err("Unable to allocate scatterlist array"
151 " for struct rd_dev\n");
152 return -ENOMEM;
153 }
154
155 sg_init_table(sg, sg_per_table + chain_entry);
156
157 if (i > 0) {
158 sg_chain(sg_table[i - 1].sg_table,
159 max_sg_per_table + 1, sg);
160 }
161
162 sg_table[i].sg_table = sg;
163 sg_table[i].rd_sg_count = sg_per_table;
164 sg_table[i].page_start_offset = page_offset;
165 sg_table[i++].page_end_offset = (page_offset + sg_per_table)
166 - 1;
167
168 for (j = 0; j < sg_per_table; j++) {
169 pg = alloc_pages(GFP_KERNEL, 0);
170 if (!pg) {
171 pr_err("Unable to allocate scatterlist"
172 " pages for struct rd_dev_sg_table\n");
173 return -ENOMEM;
174 }
175 sg_assign_page(&sg[j], pg);
176 sg[j].length = PAGE_SIZE;
177
178 p = kmap(pg);
179 memset(p, init_payload, PAGE_SIZE);
180 kunmap(pg);
181 }
182
183 page_offset += sg_per_table;
184 total_sg_needed -= sg_per_table;
185 }
186
187 return 0;
188}
189
190static int rd_build_device_space(struct rd_dev *rd_dev)
191{
192 struct rd_dev_sg_table *sg_table;
193 u32 sg_tables, total_sg_needed;
194 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
195 sizeof(struct scatterlist));
196 int rc;
197
198 if (rd_dev->rd_page_count <= 0) {
199 pr_err("Illegal page count: %u for Ramdisk device\n",
200 rd_dev->rd_page_count);
201 return -EINVAL;
202 }
203
204
205 if (rd_dev->rd_flags & RDF_NULLIO)
206 return 0;
207
208 total_sg_needed = rd_dev->rd_page_count;
209
210 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
211
212 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
213 if (!sg_table) {
214 pr_err("Unable to allocate memory for Ramdisk"
215 " scatterlist tables\n");
216 return -ENOMEM;
217 }
218
219 rd_dev->sg_table_array = sg_table;
220 rd_dev->sg_table_count = sg_tables;
221
222 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
223 if (rc)
224 return rc;
225
226 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
227 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
228 rd_dev->rd_dev_id, rd_dev->rd_page_count,
229 rd_dev->sg_table_count);
230
231 return 0;
232}
233
234static void rd_release_prot_space(struct rd_dev *rd_dev)
235{
236 u32 page_count;
237
238 if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
239 return;
240
241 page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
242 rd_dev->sg_prot_count);
243
244 pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
245 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
246 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
247 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
248
249 rd_dev->sg_prot_array = NULL;
250 rd_dev->sg_prot_count = 0;
251}
252
253static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
254{
255 struct rd_dev_sg_table *sg_table;
256 u32 total_sg_needed, sg_tables;
257 u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
258 sizeof(struct scatterlist));
259 int rc;
260
261 if (rd_dev->rd_flags & RDF_NULLIO)
262 return 0;
263
264
265
266
267
268
269 total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
270
271 sg_tables = (total_sg_needed / max_sg_per_table) + 1;
272
273 sg_table = kzalloc(sg_tables * sizeof(struct rd_dev_sg_table), GFP_KERNEL);
274 if (!sg_table) {
275 pr_err("Unable to allocate memory for Ramdisk protection"
276 " scatterlist tables\n");
277 return -ENOMEM;
278 }
279
280 rd_dev->sg_prot_array = sg_table;
281 rd_dev->sg_prot_count = sg_tables;
282
283 rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
284 if (rc)
285 return rc;
286
287 pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
288 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
289 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
290
291 return 0;
292}
293
294static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
295{
296 struct rd_dev *rd_dev;
297 struct rd_host *rd_host = hba->hba_ptr;
298
299 rd_dev = kzalloc(sizeof(struct rd_dev), GFP_KERNEL);
300 if (!rd_dev) {
301 pr_err("Unable to allocate memory for struct rd_dev\n");
302 return NULL;
303 }
304
305 rd_dev->rd_host = rd_host;
306
307 return &rd_dev->dev;
308}
309
310static int rd_configure_device(struct se_device *dev)
311{
312 struct rd_dev *rd_dev = RD_DEV(dev);
313 struct rd_host *rd_host = dev->se_hba->hba_ptr;
314 int ret;
315
316 if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
317 pr_debug("Missing rd_pages= parameter\n");
318 return -EINVAL;
319 }
320
321 ret = rd_build_device_space(rd_dev);
322 if (ret < 0)
323 goto fail;
324
325 dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
326 dev->dev_attrib.hw_max_sectors = UINT_MAX;
327 dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
328 dev->dev_attrib.is_nonrot = 1;
329
330 rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
331
332 pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
333 " %u pages in %u tables, %lu total bytes\n",
334 rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
335 rd_dev->sg_table_count,
336 (unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
337
338 return 0;
339
340fail:
341 rd_release_device_space(rd_dev);
342 return ret;
343}
344
345static void rd_dev_call_rcu(struct rcu_head *p)
346{
347 struct se_device *dev = container_of(p, struct se_device, rcu_head);
348 struct rd_dev *rd_dev = RD_DEV(dev);
349
350 kfree(rd_dev);
351}
352
353static void rd_free_device(struct se_device *dev)
354{
355 struct rd_dev *rd_dev = RD_DEV(dev);
356
357 rd_release_device_space(rd_dev);
358 call_rcu(&dev->rcu_head, rd_dev_call_rcu);
359}
360
361static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
362{
363 struct rd_dev_sg_table *sg_table;
364 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
365 sizeof(struct scatterlist));
366
367 i = page / sg_per_table;
368 if (i < rd_dev->sg_table_count) {
369 sg_table = &rd_dev->sg_table_array[i];
370 if ((sg_table->page_start_offset <= page) &&
371 (sg_table->page_end_offset >= page))
372 return sg_table;
373 }
374
375 pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
376 page);
377
378 return NULL;
379}
380
381static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
382{
383 struct rd_dev_sg_table *sg_table;
384 u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
385 sizeof(struct scatterlist));
386
387 i = page / sg_per_table;
388 if (i < rd_dev->sg_prot_count) {
389 sg_table = &rd_dev->sg_prot_array[i];
390 if ((sg_table->page_start_offset <= page) &&
391 (sg_table->page_end_offset >= page))
392 return sg_table;
393 }
394
395 pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
396 page);
397
398 return NULL;
399}
400
401static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
402{
403 struct se_device *se_dev = cmd->se_dev;
404 struct rd_dev *dev = RD_DEV(se_dev);
405 struct rd_dev_sg_table *prot_table;
406 struct scatterlist *prot_sg;
407 u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
408 u32 prot_offset, prot_page;
409 u32 prot_npages __maybe_unused;
410 u64 tmp;
411 sense_reason_t rc = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
412
413 tmp = cmd->t_task_lba * se_dev->prot_length;
414 prot_offset = do_div(tmp, PAGE_SIZE);
415 prot_page = tmp;
416
417 prot_table = rd_get_prot_table(dev, prot_page);
418 if (!prot_table)
419 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
420
421 prot_sg = &prot_table->sg_table[prot_page -
422 prot_table->page_start_offset];
423
424 if (is_read)
425 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
426 prot_sg, prot_offset);
427 else
428 rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
429 cmd->t_prot_sg, 0);
430
431 if (!rc)
432 sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
433
434 return rc;
435}
436
437static sense_reason_t
438rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
439 enum dma_data_direction data_direction)
440{
441 struct se_device *se_dev = cmd->se_dev;
442 struct rd_dev *dev = RD_DEV(se_dev);
443 struct rd_dev_sg_table *table;
444 struct scatterlist *rd_sg;
445 struct sg_mapping_iter m;
446 u32 rd_offset;
447 u32 rd_size;
448 u32 rd_page;
449 u32 src_len;
450 u64 tmp;
451 sense_reason_t rc;
452
453 if (dev->rd_flags & RDF_NULLIO) {
454 target_complete_cmd(cmd, SAM_STAT_GOOD);
455 return 0;
456 }
457
458 tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
459 rd_offset = do_div(tmp, PAGE_SIZE);
460 rd_page = tmp;
461 rd_size = cmd->data_length;
462
463 table = rd_get_sg_table(dev, rd_page);
464 if (!table)
465 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
466
467 rd_sg = &table->sg_table[rd_page - table->page_start_offset];
468
469 pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
470 dev->rd_dev_id,
471 data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
472 cmd->t_task_lba, rd_size, rd_page, rd_offset);
473
474 if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
475 data_direction == DMA_TO_DEVICE) {
476 rc = rd_do_prot_rw(cmd, false);
477 if (rc)
478 return rc;
479 }
480
481 src_len = PAGE_SIZE - rd_offset;
482 sg_miter_start(&m, sgl, sgl_nents,
483 data_direction == DMA_FROM_DEVICE ?
484 SG_MITER_TO_SG : SG_MITER_FROM_SG);
485 while (rd_size) {
486 u32 len;
487 void *rd_addr;
488
489 sg_miter_next(&m);
490 if (!(u32)m.length) {
491 pr_debug("RD[%u]: invalid sgl %p len %zu\n",
492 dev->rd_dev_id, m.addr, m.length);
493 sg_miter_stop(&m);
494 return TCM_INCORRECT_AMOUNT_OF_DATA;
495 }
496 len = min((u32)m.length, src_len);
497 if (len > rd_size) {
498 pr_debug("RD[%u]: size underrun page %d offset %d "
499 "size %d\n", dev->rd_dev_id,
500 rd_page, rd_offset, rd_size);
501 len = rd_size;
502 }
503 m.consumed = len;
504
505 rd_addr = sg_virt(rd_sg) + rd_offset;
506
507 if (data_direction == DMA_FROM_DEVICE)
508 memcpy(m.addr, rd_addr, len);
509 else
510 memcpy(rd_addr, m.addr, len);
511
512 rd_size -= len;
513 if (!rd_size)
514 continue;
515
516 src_len -= len;
517 if (src_len) {
518 rd_offset += len;
519 continue;
520 }
521
522
523 rd_page++;
524 rd_offset = 0;
525 src_len = PAGE_SIZE;
526 if (rd_page <= table->page_end_offset) {
527 rd_sg++;
528 continue;
529 }
530
531 table = rd_get_sg_table(dev, rd_page);
532 if (!table) {
533 sg_miter_stop(&m);
534 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
535 }
536
537
538 rd_sg = table->sg_table;
539 }
540 sg_miter_stop(&m);
541
542 if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
543 data_direction == DMA_FROM_DEVICE) {
544 rc = rd_do_prot_rw(cmd, true);
545 if (rc)
546 return rc;
547 }
548
549 target_complete_cmd(cmd, SAM_STAT_GOOD);
550 return 0;
551}
552
553enum {
554 Opt_rd_pages, Opt_rd_nullio, Opt_err
555};
556
557static match_table_t tokens = {
558 {Opt_rd_pages, "rd_pages=%d"},
559 {Opt_rd_nullio, "rd_nullio=%d"},
560 {Opt_err, NULL}
561};
562
563static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
564 const char *page, ssize_t count)
565{
566 struct rd_dev *rd_dev = RD_DEV(dev);
567 char *orig, *ptr, *opts;
568 substring_t args[MAX_OPT_ARGS];
569 int ret = 0, arg, token;
570
571 opts = kstrdup(page, GFP_KERNEL);
572 if (!opts)
573 return -ENOMEM;
574
575 orig = opts;
576
577 while ((ptr = strsep(&opts, ",\n")) != NULL) {
578 if (!*ptr)
579 continue;
580
581 token = match_token(ptr, tokens, args);
582 switch (token) {
583 case Opt_rd_pages:
584 match_int(args, &arg);
585 rd_dev->rd_page_count = arg;
586 pr_debug("RAMDISK: Referencing Page"
587 " Count: %u\n", rd_dev->rd_page_count);
588 rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
589 break;
590 case Opt_rd_nullio:
591 match_int(args, &arg);
592 if (arg != 1)
593 break;
594
595 pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
596 rd_dev->rd_flags |= RDF_NULLIO;
597 break;
598 default:
599 break;
600 }
601 }
602
603 kfree(orig);
604 return (!ret) ? count : ret;
605}
606
607static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
608{
609 struct rd_dev *rd_dev = RD_DEV(dev);
610
611 ssize_t bl = sprintf(b, "TCM RamDisk ID: %u RamDisk Makeup: rd_mcp\n",
612 rd_dev->rd_dev_id);
613 bl += sprintf(b + bl, " PAGES/PAGE_SIZE: %u*%lu"
614 " SG_table_count: %u nullio: %d\n", rd_dev->rd_page_count,
615 PAGE_SIZE, rd_dev->sg_table_count,
616 !!(rd_dev->rd_flags & RDF_NULLIO));
617 return bl;
618}
619
620static sector_t rd_get_blocks(struct se_device *dev)
621{
622 struct rd_dev *rd_dev = RD_DEV(dev);
623
624 unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
625 dev->dev_attrib.block_size) - 1;
626
627 return blocks_long;
628}
629
630static int rd_init_prot(struct se_device *dev)
631{
632 struct rd_dev *rd_dev = RD_DEV(dev);
633
634 if (!dev->dev_attrib.pi_prot_type)
635 return 0;
636
637 return rd_build_prot_space(rd_dev, dev->prot_length,
638 dev->dev_attrib.block_size);
639}
640
641static void rd_free_prot(struct se_device *dev)
642{
643 struct rd_dev *rd_dev = RD_DEV(dev);
644
645 rd_release_prot_space(rd_dev);
646}
647
648static struct sbc_ops rd_sbc_ops = {
649 .execute_rw = rd_execute_rw,
650};
651
652static sense_reason_t
653rd_parse_cdb(struct se_cmd *cmd)
654{
655 return sbc_parse_cdb(cmd, &rd_sbc_ops);
656}
657
658static const struct target_backend_ops rd_mcp_ops = {
659 .name = "rd_mcp",
660 .inquiry_prod = "RAMDISK-MCP",
661 .inquiry_rev = RD_MCP_VERSION,
662 .attach_hba = rd_attach_hba,
663 .detach_hba = rd_detach_hba,
664 .alloc_device = rd_alloc_device,
665 .configure_device = rd_configure_device,
666 .free_device = rd_free_device,
667 .parse_cdb = rd_parse_cdb,
668 .set_configfs_dev_params = rd_set_configfs_dev_params,
669 .show_configfs_dev_params = rd_show_configfs_dev_params,
670 .get_device_type = sbc_get_device_type,
671 .get_blocks = rd_get_blocks,
672 .init_prot = rd_init_prot,
673 .free_prot = rd_free_prot,
674 .tb_dev_attrib_attrs = sbc_attrib_attrs,
675};
676
677int __init rd_module_init(void)
678{
679 return transport_backend_register(&rd_mcp_ops);
680}
681
682void rd_module_exit(void)
683{
684 target_backend_unregister(&rd_mcp_ops);
685}
686
