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/highmem.h>
30 #include <linux/timer.h>
31 #include <linux/scatterlist.h>
32 #include <linux/slab.h>
33 #include <linux/spinlock.h>
34 #include <scsi/scsi_proto.h>
35 
36 #include <target/target_core_base.h>
37 #include <target/target_core_backend.h>
38 
39 #include "target_core_rd.h"
40 
41 static inline struct rd_dev *RD_DEV(struct se_device *dev)
42 {
43 	return container_of(dev, struct rd_dev, dev);
44 }
45 
46 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
47 {
48 	struct rd_host *rd_host;
49 
50 	rd_host = kzalloc(sizeof(*rd_host), GFP_KERNEL);
51 	if (!rd_host)
52 		return -ENOMEM;
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 
65 static 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 
76 static 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 
101 static 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 /*	rd_build_device_space():
122  *
123  *
124  */
125 static 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 		 * Reserve extra element for chain entry
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 			return -ENOMEM;
151 
152 		sg_init_table(sg, sg_per_table + chain_entry);
153 
154 		if (i > 0) {
155 			sg_chain(sg_table[i - 1].sg_table,
156 				 max_sg_per_table + 1, sg);
157 		}
158 
159 		sg_table[i].sg_table = sg;
160 		sg_table[i].rd_sg_count = sg_per_table;
161 		sg_table[i].page_start_offset = page_offset;
162 		sg_table[i++].page_end_offset = (page_offset + sg_per_table)
163 						- 1;
164 
165 		for (j = 0; j < sg_per_table; j++) {
166 			pg = alloc_pages(GFP_KERNEL, 0);
167 			if (!pg) {
168 				pr_err("Unable to allocate scatterlist"
169 					" pages for struct rd_dev_sg_table\n");
170 				return -ENOMEM;
171 			}
172 			sg_assign_page(&sg[j], pg);
173 			sg[j].length = PAGE_SIZE;
174 
175 			p = kmap(pg);
176 			memset(p, init_payload, PAGE_SIZE);
177 			kunmap(pg);
178 		}
179 
180 		page_offset += sg_per_table;
181 		total_sg_needed -= sg_per_table;
182 	}
183 
184 	return 0;
185 }
186 
187 static int rd_build_device_space(struct rd_dev *rd_dev)
188 {
189 	struct rd_dev_sg_table *sg_table;
190 	u32 sg_tables, total_sg_needed;
191 	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
192 				sizeof(struct scatterlist));
193 	int rc;
194 
195 	if (rd_dev->rd_page_count <= 0) {
196 		pr_err("Illegal page count: %u for Ramdisk device\n",
197 		       rd_dev->rd_page_count);
198 		return -EINVAL;
199 	}
200 
201 	/* Don't need backing pages for NULLIO */
202 	if (rd_dev->rd_flags & RDF_NULLIO)
203 		return 0;
204 
205 	total_sg_needed = rd_dev->rd_page_count;
206 
207 	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
208 	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
209 	if (!sg_table)
210 		return -ENOMEM;
211 
212 	rd_dev->sg_table_array = sg_table;
213 	rd_dev->sg_table_count = sg_tables;
214 
215 	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
216 	if (rc)
217 		return rc;
218 
219 	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
220 		 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
221 		 rd_dev->rd_dev_id, rd_dev->rd_page_count,
222 		 rd_dev->sg_table_count);
223 
224 	return 0;
225 }
226 
227 static void rd_release_prot_space(struct rd_dev *rd_dev)
228 {
229 	u32 page_count;
230 
231 	if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
232 		return;
233 
234 	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
235 					  rd_dev->sg_prot_count);
236 
237 	pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
238 		 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
239 		 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
240 		 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
241 
242 	rd_dev->sg_prot_array = NULL;
243 	rd_dev->sg_prot_count = 0;
244 }
245 
246 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
247 {
248 	struct rd_dev_sg_table *sg_table;
249 	u32 total_sg_needed, sg_tables;
250 	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
251 				sizeof(struct scatterlist));
252 	int rc;
253 
254 	if (rd_dev->rd_flags & RDF_NULLIO)
255 		return 0;
256 	/*
257 	 * prot_length=8byte dif data
258 	 * tot sg needed = rd_page_count * (PGSZ/block_size) *
259 	 * 		   (prot_length/block_size) + pad
260 	 * PGSZ canceled each other.
261 	 */
262 	total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
263 
264 	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
265 	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
266 	if (!sg_table)
267 		return -ENOMEM;
268 
269 	rd_dev->sg_prot_array = sg_table;
270 	rd_dev->sg_prot_count = sg_tables;
271 
272 	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
273 	if (rc)
274 		return rc;
275 
276 	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
277 		 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
278 		 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
279 
280 	return 0;
281 }
282 
283 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
284 {
285 	struct rd_dev *rd_dev;
286 	struct rd_host *rd_host = hba->hba_ptr;
287 
288 	rd_dev = kzalloc(sizeof(*rd_dev), GFP_KERNEL);
289 	if (!rd_dev)
290 		return NULL;
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 	dev->dev_attrib.is_nonrot = 1;
316 
317 	rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
318 
319 	pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
320 		" %u pages in %u tables, %lu total bytes\n",
321 		rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
322 		rd_dev->sg_table_count,
323 		(unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
324 
325 	return 0;
326 
327 fail:
328 	rd_release_device_space(rd_dev);
329 	return ret;
330 }
331 
332 static void rd_dev_call_rcu(struct rcu_head *p)
333 {
334 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
335 	struct rd_dev *rd_dev = RD_DEV(dev);
336 
337 	kfree(rd_dev);
338 }
339 
340 static void rd_free_device(struct se_device *dev)
341 {
342 	call_rcu(&dev->rcu_head, rd_dev_call_rcu);
343 }
344 
345 static void rd_destroy_device(struct se_device *dev)
346 {
347 	struct rd_dev *rd_dev = RD_DEV(dev);
348 
349 	rd_release_device_space(rd_dev);
350 }
351 
352 static struct rd_dev_sg_table *rd_get_sg_table(struct rd_dev *rd_dev, u32 page)
353 {
354 	struct rd_dev_sg_table *sg_table;
355 	u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
356 				sizeof(struct scatterlist));
357 
358 	i = page / sg_per_table;
359 	if (i < rd_dev->sg_table_count) {
360 		sg_table = &rd_dev->sg_table_array[i];
361 		if ((sg_table->page_start_offset <= page) &&
362 		    (sg_table->page_end_offset >= page))
363 			return sg_table;
364 	}
365 
366 	pr_err("Unable to locate struct rd_dev_sg_table for page: %u\n",
367 			page);
368 
369 	return NULL;
370 }
371 
372 static struct rd_dev_sg_table *rd_get_prot_table(struct rd_dev *rd_dev, u32 page)
373 {
374 	struct rd_dev_sg_table *sg_table;
375 	u32 i, sg_per_table = (RD_MAX_ALLOCATION_SIZE /
376 				sizeof(struct scatterlist));
377 
378 	i = page / sg_per_table;
379 	if (i < rd_dev->sg_prot_count) {
380 		sg_table = &rd_dev->sg_prot_array[i];
381 		if ((sg_table->page_start_offset <= page) &&
382 		     (sg_table->page_end_offset >= page))
383 			return sg_table;
384 	}
385 
386 	pr_err("Unable to locate struct prot rd_dev_sg_table for page: %u\n",
387 			page);
388 
389 	return NULL;
390 }
391 
392 static sense_reason_t rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
393 {
394 	struct se_device *se_dev = cmd->se_dev;
395 	struct rd_dev *dev = RD_DEV(se_dev);
396 	struct rd_dev_sg_table *prot_table;
397 	struct scatterlist *prot_sg;
398 	u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
399 	u32 prot_offset, prot_page;
400 	u32 prot_npages __maybe_unused;
401 	u64 tmp;
402 	sense_reason_t rc = 0;
403 
404 	tmp = cmd->t_task_lba * se_dev->prot_length;
405 	prot_offset = do_div(tmp, PAGE_SIZE);
406 	prot_page = tmp;
407 
408 	prot_table = rd_get_prot_table(dev, prot_page);
409 	if (!prot_table)
410 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
411 
412 	prot_sg = &prot_table->sg_table[prot_page -
413 					prot_table->page_start_offset];
414 
415 	if (se_dev->dev_attrib.pi_prot_verify) {
416 		if (is_read)
417 			rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
418 					    prot_sg, prot_offset);
419 		else
420 			rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
421 					    cmd->t_prot_sg, 0);
422 	}
423 	if (!rc)
424 		sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
425 
426 	return rc;
427 }
428 
429 static sense_reason_t
430 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
431 	      enum dma_data_direction data_direction)
432 {
433 	struct se_device *se_dev = cmd->se_dev;
434 	struct rd_dev *dev = RD_DEV(se_dev);
435 	struct rd_dev_sg_table *table;
436 	struct scatterlist *rd_sg;
437 	struct sg_mapping_iter m;
438 	u32 rd_offset;
439 	u32 rd_size;
440 	u32 rd_page;
441 	u32 src_len;
442 	u64 tmp;
443 	sense_reason_t rc;
444 
445 	if (dev->rd_flags & RDF_NULLIO) {
446 		target_complete_cmd(cmd, SAM_STAT_GOOD);
447 		return 0;
448 	}
449 
450 	tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
451 	rd_offset = do_div(tmp, PAGE_SIZE);
452 	rd_page = tmp;
453 	rd_size = cmd->data_length;
454 
455 	table = rd_get_sg_table(dev, rd_page);
456 	if (!table)
457 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
458 
459 	rd_sg = &table->sg_table[rd_page - table->page_start_offset];
460 
461 	pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
462 			dev->rd_dev_id,
463 			data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
464 			cmd->t_task_lba, rd_size, rd_page, rd_offset);
465 
466 	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
467 	    data_direction == DMA_TO_DEVICE) {
468 		rc = rd_do_prot_rw(cmd, false);
469 		if (rc)
470 			return rc;
471 	}
472 
473 	src_len = PAGE_SIZE - rd_offset;
474 	sg_miter_start(&m, sgl, sgl_nents,
475 			data_direction == DMA_FROM_DEVICE ?
476 				SG_MITER_TO_SG : SG_MITER_FROM_SG);
477 	while (rd_size) {
478 		u32 len;
479 		void *rd_addr;
480 
481 		sg_miter_next(&m);
482 		if (!(u32)m.length) {
483 			pr_debug("RD[%u]: invalid sgl %p len %zu\n",
484 				 dev->rd_dev_id, m.addr, m.length);
485 			sg_miter_stop(&m);
486 			return TCM_INCORRECT_AMOUNT_OF_DATA;
487 		}
488 		len = min((u32)m.length, src_len);
489 		if (len > rd_size) {
490 			pr_debug("RD[%u]: size underrun page %d offset %d "
491 				 "size %d\n", dev->rd_dev_id,
492 				 rd_page, rd_offset, rd_size);
493 			len = rd_size;
494 		}
495 		m.consumed = len;
496 
497 		rd_addr = sg_virt(rd_sg) + rd_offset;
498 
499 		if (data_direction == DMA_FROM_DEVICE)
500 			memcpy(m.addr, rd_addr, len);
501 		else
502 			memcpy(rd_addr, m.addr, len);
503 
504 		rd_size -= len;
505 		if (!rd_size)
506 			continue;
507 
508 		src_len -= len;
509 		if (src_len) {
510 			rd_offset += len;
511 			continue;
512 		}
513 
514 		/* rd page completed, next one please */
515 		rd_page++;
516 		rd_offset = 0;
517 		src_len = PAGE_SIZE;
518 		if (rd_page <= table->page_end_offset) {
519 			rd_sg++;
520 			continue;
521 		}
522 
523 		table = rd_get_sg_table(dev, rd_page);
524 		if (!table) {
525 			sg_miter_stop(&m);
526 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
527 		}
528 
529 		/* since we increment, the first sg entry is correct */
530 		rd_sg = table->sg_table;
531 	}
532 	sg_miter_stop(&m);
533 
534 	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
535 	    data_direction == DMA_FROM_DEVICE) {
536 		rc = rd_do_prot_rw(cmd, true);
537 		if (rc)
538 			return rc;
539 	}
540 
541 	target_complete_cmd(cmd, SAM_STAT_GOOD);
542 	return 0;
543 }
544 
545 enum {
546 	Opt_rd_pages, Opt_rd_nullio, Opt_err
547 };
548 
549 static match_table_t tokens = {
550 	{Opt_rd_pages, "rd_pages=%d"},
551 	{Opt_rd_nullio, "rd_nullio=%d"},
552 	{Opt_err, NULL}
553 };
554 
555 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
556 		const char *page, ssize_t count)
557 {
558 	struct rd_dev *rd_dev = RD_DEV(dev);
559 	char *orig, *ptr, *opts;
560 	substring_t args[MAX_OPT_ARGS];
561 	int arg, token;
562 
563 	opts = kstrdup(page, GFP_KERNEL);
564 	if (!opts)
565 		return -ENOMEM;
566 
567 	orig = opts;
568 
569 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
570 		if (!*ptr)
571 			continue;
572 
573 		token = match_token(ptr, tokens, args);
574 		switch (token) {
575 		case Opt_rd_pages:
576 			match_int(args, &arg);
577 			rd_dev->rd_page_count = arg;
578 			pr_debug("RAMDISK: Referencing Page"
579 				" Count: %u\n", rd_dev->rd_page_count);
580 			rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
581 			break;
582 		case Opt_rd_nullio:
583 			match_int(args, &arg);
584 			if (arg != 1)
585 				break;
586 
587 			pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
588 			rd_dev->rd_flags |= RDF_NULLIO;
589 			break;
590 		default:
591 			break;
592 		}
593 	}
594 
595 	kfree(orig);
596 	return count;
597 }
598 
599 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
600 {
601 	struct rd_dev *rd_dev = RD_DEV(dev);
602 
603 	ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
604 			rd_dev->rd_dev_id);
605 	bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
606 			"  SG_table_count: %u  nullio: %d\n", rd_dev->rd_page_count,
607 			PAGE_SIZE, rd_dev->sg_table_count,
608 			!!(rd_dev->rd_flags & RDF_NULLIO));
609 	return bl;
610 }
611 
612 static sector_t rd_get_blocks(struct se_device *dev)
613 {
614 	struct rd_dev *rd_dev = RD_DEV(dev);
615 
616 	unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
617 			dev->dev_attrib.block_size) - 1;
618 
619 	return blocks_long;
620 }
621 
622 static int rd_init_prot(struct se_device *dev)
623 {
624 	struct rd_dev *rd_dev = RD_DEV(dev);
625 
626         if (!dev->dev_attrib.pi_prot_type)
627 		return 0;
628 
629 	return rd_build_prot_space(rd_dev, dev->prot_length,
630 				   dev->dev_attrib.block_size);
631 }
632 
633 static void rd_free_prot(struct se_device *dev)
634 {
635 	struct rd_dev *rd_dev = RD_DEV(dev);
636 
637 	rd_release_prot_space(rd_dev);
638 }
639 
640 static struct sbc_ops rd_sbc_ops = {
641 	.execute_rw		= rd_execute_rw,
642 };
643 
644 static sense_reason_t
645 rd_parse_cdb(struct se_cmd *cmd)
646 {
647 	return sbc_parse_cdb(cmd, &rd_sbc_ops);
648 }
649 
650 static const struct target_backend_ops rd_mcp_ops = {
651 	.name			= "rd_mcp",
652 	.inquiry_prod		= "RAMDISK-MCP",
653 	.inquiry_rev		= RD_MCP_VERSION,
654 	.attach_hba		= rd_attach_hba,
655 	.detach_hba		= rd_detach_hba,
656 	.alloc_device		= rd_alloc_device,
657 	.configure_device	= rd_configure_device,
658 	.destroy_device		= rd_destroy_device,
659 	.free_device		= rd_free_device,
660 	.parse_cdb		= rd_parse_cdb,
661 	.set_configfs_dev_params = rd_set_configfs_dev_params,
662 	.show_configfs_dev_params = rd_show_configfs_dev_params,
663 	.get_device_type	= sbc_get_device_type,
664 	.get_blocks		= rd_get_blocks,
665 	.init_prot		= rd_init_prot,
666 	.free_prot		= rd_free_prot,
667 	.tb_dev_attrib_attrs	= sbc_attrib_attrs,
668 };
669 
670 int __init rd_module_init(void)
671 {
672 	return transport_backend_register(&rd_mcp_ops);
673 }
674 
675 void rd_module_exit(void)
676 {
677 	target_backend_unregister(&rd_mcp_ops);
678 }
679