1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_rd.c
4  *
5  * This file contains the Storage Engine <-> Ramdisk transport
6  * specific functions.
7  *
8  * (c) Copyright 2003-2013 Datera, Inc.
9  *
10  * Nicholas A. Bellinger <nab@kernel.org>
11  *
12  ******************************************************************************/
13 
14 #include <linux/string.h>
15 #include <linux/parser.h>
16 #include <linux/highmem.h>
17 #include <linux/timer.h>
18 #include <linux/scatterlist.h>
19 #include <linux/slab.h>
20 #include <linux/spinlock.h>
21 #include <scsi/scsi_proto.h>
22 
23 #include <target/target_core_base.h>
24 #include <target/target_core_backend.h>
25 
26 #include "target_core_rd.h"
27 
28 static inline struct rd_dev *RD_DEV(struct se_device *dev)
29 {
30 	return container_of(dev, struct rd_dev, dev);
31 }
32 
33 static int rd_attach_hba(struct se_hba *hba, u32 host_id)
34 {
35 	struct rd_host *rd_host;
36 
37 	rd_host = kzalloc(sizeof(*rd_host), GFP_KERNEL);
38 	if (!rd_host)
39 		return -ENOMEM;
40 
41 	rd_host->rd_host_id = host_id;
42 
43 	hba->hba_ptr = rd_host;
44 
45 	pr_debug("CORE_HBA[%d] - TCM Ramdisk HBA Driver %s on"
46 		" Generic Target Core Stack %s\n", hba->hba_id,
47 		RD_HBA_VERSION, TARGET_CORE_VERSION);
48 
49 	return 0;
50 }
51 
52 static void rd_detach_hba(struct se_hba *hba)
53 {
54 	struct rd_host *rd_host = hba->hba_ptr;
55 
56 	pr_debug("CORE_HBA[%d] - Detached Ramdisk HBA: %u from"
57 		" Generic Target Core\n", hba->hba_id, rd_host->rd_host_id);
58 
59 	kfree(rd_host);
60 	hba->hba_ptr = NULL;
61 }
62 
63 static u32 rd_release_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
64 				 u32 sg_table_count)
65 {
66 	struct page *pg;
67 	struct scatterlist *sg;
68 	u32 i, j, page_count = 0, sg_per_table;
69 
70 	for (i = 0; i < sg_table_count; i++) {
71 		sg = sg_table[i].sg_table;
72 		sg_per_table = sg_table[i].rd_sg_count;
73 
74 		for (j = 0; j < sg_per_table; j++) {
75 			pg = sg_page(&sg[j]);
76 			if (pg) {
77 				__free_page(pg);
78 				page_count++;
79 			}
80 		}
81 		kfree(sg);
82 	}
83 
84 	kfree(sg_table);
85 	return page_count;
86 }
87 
88 static void rd_release_device_space(struct rd_dev *rd_dev)
89 {
90 	u32 page_count;
91 
92 	if (!rd_dev->sg_table_array || !rd_dev->sg_table_count)
93 		return;
94 
95 	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_table_array,
96 					  rd_dev->sg_table_count);
97 
98 	pr_debug("CORE_RD[%u] - Released device space for Ramdisk"
99 		" Device ID: %u, pages %u in %u tables total bytes %lu\n",
100 		rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
101 		rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
102 
103 	rd_dev->sg_table_array = NULL;
104 	rd_dev->sg_table_count = 0;
105 }
106 
107 
108 /*	rd_build_device_space():
109  *
110  *
111  */
112 static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *sg_table,
113 				 u32 total_sg_needed, unsigned char init_payload)
114 {
115 	u32 i = 0, j, page_offset = 0, sg_per_table;
116 	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
117 				sizeof(struct scatterlist));
118 	struct page *pg;
119 	struct scatterlist *sg;
120 	unsigned char *p;
121 
122 	while (total_sg_needed) {
123 		unsigned int chain_entry = 0;
124 
125 		sg_per_table = (total_sg_needed > max_sg_per_table) ?
126 			max_sg_per_table : total_sg_needed;
127 
128 		/*
129 		 * Reserve extra element for chain entry
130 		 */
131 		if (sg_per_table < total_sg_needed)
132 			chain_entry = 1;
133 
134 		sg = kmalloc_array(sg_per_table + chain_entry, sizeof(*sg),
135 				GFP_KERNEL);
136 		if (!sg)
137 			return -ENOMEM;
138 
139 		sg_init_table(sg, sg_per_table + chain_entry);
140 
141 		if (i > 0) {
142 			sg_chain(sg_table[i - 1].sg_table,
143 				 max_sg_per_table + 1, sg);
144 		}
145 
146 		sg_table[i].sg_table = sg;
147 		sg_table[i].rd_sg_count = sg_per_table;
148 		sg_table[i].page_start_offset = page_offset;
149 		sg_table[i++].page_end_offset = (page_offset + sg_per_table)
150 						- 1;
151 
152 		for (j = 0; j < sg_per_table; j++) {
153 			pg = alloc_pages(GFP_KERNEL, 0);
154 			if (!pg) {
155 				pr_err("Unable to allocate scatterlist"
156 					" pages for struct rd_dev_sg_table\n");
157 				return -ENOMEM;
158 			}
159 			sg_assign_page(&sg[j], pg);
160 			sg[j].length = PAGE_SIZE;
161 
162 			p = kmap(pg);
163 			memset(p, init_payload, PAGE_SIZE);
164 			kunmap(pg);
165 		}
166 
167 		page_offset += sg_per_table;
168 		total_sg_needed -= sg_per_table;
169 	}
170 
171 	return 0;
172 }
173 
174 static int rd_build_device_space(struct rd_dev *rd_dev)
175 {
176 	struct rd_dev_sg_table *sg_table;
177 	u32 sg_tables, total_sg_needed;
178 	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
179 				sizeof(struct scatterlist));
180 	int rc;
181 
182 	if (rd_dev->rd_page_count <= 0) {
183 		pr_err("Illegal page count: %u for Ramdisk device\n",
184 		       rd_dev->rd_page_count);
185 		return -EINVAL;
186 	}
187 
188 	/* Don't need backing pages for NULLIO */
189 	if (rd_dev->rd_flags & RDF_NULLIO)
190 		return 0;
191 
192 	total_sg_needed = rd_dev->rd_page_count;
193 
194 	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
195 	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
196 	if (!sg_table)
197 		return -ENOMEM;
198 
199 	rd_dev->sg_table_array = sg_table;
200 	rd_dev->sg_table_count = sg_tables;
201 
202 	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0x00);
203 	if (rc)
204 		return rc;
205 
206 	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u space of"
207 		 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
208 		 rd_dev->rd_dev_id, rd_dev->rd_page_count,
209 		 rd_dev->sg_table_count);
210 
211 	return 0;
212 }
213 
214 static void rd_release_prot_space(struct rd_dev *rd_dev)
215 {
216 	u32 page_count;
217 
218 	if (!rd_dev->sg_prot_array || !rd_dev->sg_prot_count)
219 		return;
220 
221 	page_count = rd_release_sgl_table(rd_dev, rd_dev->sg_prot_array,
222 					  rd_dev->sg_prot_count);
223 
224 	pr_debug("CORE_RD[%u] - Released protection space for Ramdisk"
225 		 " Device ID: %u, pages %u in %u tables total bytes %lu\n",
226 		 rd_dev->rd_host->rd_host_id, rd_dev->rd_dev_id, page_count,
227 		 rd_dev->sg_table_count, (unsigned long)page_count * PAGE_SIZE);
228 
229 	rd_dev->sg_prot_array = NULL;
230 	rd_dev->sg_prot_count = 0;
231 }
232 
233 static int rd_build_prot_space(struct rd_dev *rd_dev, int prot_length, int block_size)
234 {
235 	struct rd_dev_sg_table *sg_table;
236 	u32 total_sg_needed, sg_tables;
237 	u32 max_sg_per_table = (RD_MAX_ALLOCATION_SIZE /
238 				sizeof(struct scatterlist));
239 	int rc;
240 
241 	if (rd_dev->rd_flags & RDF_NULLIO)
242 		return 0;
243 	/*
244 	 * prot_length=8byte dif data
245 	 * tot sg needed = rd_page_count * (PGSZ/block_size) *
246 	 * 		   (prot_length/block_size) + pad
247 	 * PGSZ canceled each other.
248 	 */
249 	total_sg_needed = (rd_dev->rd_page_count * prot_length / block_size) + 1;
250 
251 	sg_tables = (total_sg_needed / max_sg_per_table) + 1;
252 	sg_table = kcalloc(sg_tables, sizeof(*sg_table), GFP_KERNEL);
253 	if (!sg_table)
254 		return -ENOMEM;
255 
256 	rd_dev->sg_prot_array = sg_table;
257 	rd_dev->sg_prot_count = sg_tables;
258 
259 	rc = rd_allocate_sgl_table(rd_dev, sg_table, total_sg_needed, 0xff);
260 	if (rc)
261 		return rc;
262 
263 	pr_debug("CORE_RD[%u] - Built Ramdisk Device ID: %u prot space of"
264 		 " %u pages in %u tables\n", rd_dev->rd_host->rd_host_id,
265 		 rd_dev->rd_dev_id, total_sg_needed, rd_dev->sg_prot_count);
266 
267 	return 0;
268 }
269 
270 static struct se_device *rd_alloc_device(struct se_hba *hba, const char *name)
271 {
272 	struct rd_dev *rd_dev;
273 	struct rd_host *rd_host = hba->hba_ptr;
274 
275 	rd_dev = kzalloc(sizeof(*rd_dev), GFP_KERNEL);
276 	if (!rd_dev)
277 		return NULL;
278 
279 	rd_dev->rd_host = rd_host;
280 
281 	return &rd_dev->dev;
282 }
283 
284 static int rd_configure_device(struct se_device *dev)
285 {
286 	struct rd_dev *rd_dev = RD_DEV(dev);
287 	struct rd_host *rd_host = dev->se_hba->hba_ptr;
288 	int ret;
289 
290 	if (!(rd_dev->rd_flags & RDF_HAS_PAGE_COUNT)) {
291 		pr_debug("Missing rd_pages= parameter\n");
292 		return -EINVAL;
293 	}
294 
295 	ret = rd_build_device_space(rd_dev);
296 	if (ret < 0)
297 		goto fail;
298 
299 	dev->dev_attrib.hw_block_size = RD_BLOCKSIZE;
300 	dev->dev_attrib.hw_max_sectors = UINT_MAX;
301 	dev->dev_attrib.hw_queue_depth = RD_MAX_DEVICE_QUEUE_DEPTH;
302 	dev->dev_attrib.is_nonrot = 1;
303 
304 	rd_dev->rd_dev_id = rd_host->rd_host_dev_id_count++;
305 
306 	pr_debug("CORE_RD[%u] - Added TCM MEMCPY Ramdisk Device ID: %u of"
307 		" %u pages in %u tables, %lu total bytes\n",
308 		rd_host->rd_host_id, rd_dev->rd_dev_id, rd_dev->rd_page_count,
309 		rd_dev->sg_table_count,
310 		(unsigned long)(rd_dev->rd_page_count * PAGE_SIZE));
311 
312 	return 0;
313 
314 fail:
315 	rd_release_device_space(rd_dev);
316 	return ret;
317 }
318 
319 static void rd_dev_call_rcu(struct rcu_head *p)
320 {
321 	struct se_device *dev = container_of(p, struct se_device, rcu_head);
322 	struct rd_dev *rd_dev = RD_DEV(dev);
323 
324 	kfree(rd_dev);
325 }
326 
327 static void rd_free_device(struct se_device *dev)
328 {
329 	call_rcu(&dev->rcu_head, rd_dev_call_rcu);
330 }
331 
332 static void rd_destroy_device(struct se_device *dev)
333 {
334 	struct rd_dev *rd_dev = RD_DEV(dev);
335 
336 	rd_release_device_space(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 rd_do_prot_rw(struct se_cmd *cmd, bool is_read)
380 {
381 	struct se_device *se_dev = cmd->se_dev;
382 	struct rd_dev *dev = RD_DEV(se_dev);
383 	struct rd_dev_sg_table *prot_table;
384 	struct scatterlist *prot_sg;
385 	u32 sectors = cmd->data_length / se_dev->dev_attrib.block_size;
386 	u32 prot_offset, prot_page;
387 	u32 prot_npages __maybe_unused;
388 	u64 tmp;
389 	sense_reason_t rc = 0;
390 
391 	tmp = cmd->t_task_lba * se_dev->prot_length;
392 	prot_offset = do_div(tmp, PAGE_SIZE);
393 	prot_page = tmp;
394 
395 	prot_table = rd_get_prot_table(dev, prot_page);
396 	if (!prot_table)
397 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
398 
399 	prot_sg = &prot_table->sg_table[prot_page -
400 					prot_table->page_start_offset];
401 
402 	if (se_dev->dev_attrib.pi_prot_verify) {
403 		if (is_read)
404 			rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
405 					    prot_sg, prot_offset);
406 		else
407 			rc = sbc_dif_verify(cmd, cmd->t_task_lba, sectors, 0,
408 					    cmd->t_prot_sg, 0);
409 	}
410 	if (!rc)
411 		sbc_dif_copy_prot(cmd, sectors, is_read, prot_sg, prot_offset);
412 
413 	return rc;
414 }
415 
416 static sense_reason_t
417 rd_execute_rw(struct se_cmd *cmd, struct scatterlist *sgl, u32 sgl_nents,
418 	      enum dma_data_direction data_direction)
419 {
420 	struct se_device *se_dev = cmd->se_dev;
421 	struct rd_dev *dev = RD_DEV(se_dev);
422 	struct rd_dev_sg_table *table;
423 	struct scatterlist *rd_sg;
424 	struct sg_mapping_iter m;
425 	u32 rd_offset;
426 	u32 rd_size;
427 	u32 rd_page;
428 	u32 src_len;
429 	u64 tmp;
430 	sense_reason_t rc;
431 
432 	if (dev->rd_flags & RDF_NULLIO) {
433 		target_complete_cmd(cmd, SAM_STAT_GOOD);
434 		return 0;
435 	}
436 
437 	tmp = cmd->t_task_lba * se_dev->dev_attrib.block_size;
438 	rd_offset = do_div(tmp, PAGE_SIZE);
439 	rd_page = tmp;
440 	rd_size = cmd->data_length;
441 
442 	table = rd_get_sg_table(dev, rd_page);
443 	if (!table)
444 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
445 
446 	rd_sg = &table->sg_table[rd_page - table->page_start_offset];
447 
448 	pr_debug("RD[%u]: %s LBA: %llu, Size: %u Page: %u, Offset: %u\n",
449 			dev->rd_dev_id,
450 			data_direction == DMA_FROM_DEVICE ? "Read" : "Write",
451 			cmd->t_task_lba, rd_size, rd_page, rd_offset);
452 
453 	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
454 	    data_direction == DMA_TO_DEVICE) {
455 		rc = rd_do_prot_rw(cmd, false);
456 		if (rc)
457 			return rc;
458 	}
459 
460 	src_len = PAGE_SIZE - rd_offset;
461 	sg_miter_start(&m, sgl, sgl_nents,
462 			data_direction == DMA_FROM_DEVICE ?
463 				SG_MITER_TO_SG : SG_MITER_FROM_SG);
464 	while (rd_size) {
465 		u32 len;
466 		void *rd_addr;
467 
468 		sg_miter_next(&m);
469 		if (!(u32)m.length) {
470 			pr_debug("RD[%u]: invalid sgl %p len %zu\n",
471 				 dev->rd_dev_id, m.addr, m.length);
472 			sg_miter_stop(&m);
473 			return TCM_INCORRECT_AMOUNT_OF_DATA;
474 		}
475 		len = min((u32)m.length, src_len);
476 		if (len > rd_size) {
477 			pr_debug("RD[%u]: size underrun page %d offset %d "
478 				 "size %d\n", dev->rd_dev_id,
479 				 rd_page, rd_offset, rd_size);
480 			len = rd_size;
481 		}
482 		m.consumed = len;
483 
484 		rd_addr = sg_virt(rd_sg) + rd_offset;
485 
486 		if (data_direction == DMA_FROM_DEVICE)
487 			memcpy(m.addr, rd_addr, len);
488 		else
489 			memcpy(rd_addr, m.addr, len);
490 
491 		rd_size -= len;
492 		if (!rd_size)
493 			continue;
494 
495 		src_len -= len;
496 		if (src_len) {
497 			rd_offset += len;
498 			continue;
499 		}
500 
501 		/* rd page completed, next one please */
502 		rd_page++;
503 		rd_offset = 0;
504 		src_len = PAGE_SIZE;
505 		if (rd_page <= table->page_end_offset) {
506 			rd_sg++;
507 			continue;
508 		}
509 
510 		table = rd_get_sg_table(dev, rd_page);
511 		if (!table) {
512 			sg_miter_stop(&m);
513 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
514 		}
515 
516 		/* since we increment, the first sg entry is correct */
517 		rd_sg = table->sg_table;
518 	}
519 	sg_miter_stop(&m);
520 
521 	if (cmd->prot_type && se_dev->dev_attrib.pi_prot_type &&
522 	    data_direction == DMA_FROM_DEVICE) {
523 		rc = rd_do_prot_rw(cmd, true);
524 		if (rc)
525 			return rc;
526 	}
527 
528 	target_complete_cmd(cmd, SAM_STAT_GOOD);
529 	return 0;
530 }
531 
532 enum {
533 	Opt_rd_pages, Opt_rd_nullio, Opt_rd_dummy, Opt_err
534 };
535 
536 static match_table_t tokens = {
537 	{Opt_rd_pages, "rd_pages=%d"},
538 	{Opt_rd_nullio, "rd_nullio=%d"},
539 	{Opt_rd_dummy, "rd_dummy=%d"},
540 	{Opt_err, NULL}
541 };
542 
543 static ssize_t rd_set_configfs_dev_params(struct se_device *dev,
544 		const char *page, ssize_t count)
545 {
546 	struct rd_dev *rd_dev = RD_DEV(dev);
547 	char *orig, *ptr, *opts;
548 	substring_t args[MAX_OPT_ARGS];
549 	int arg, token;
550 
551 	opts = kstrdup(page, GFP_KERNEL);
552 	if (!opts)
553 		return -ENOMEM;
554 
555 	orig = opts;
556 
557 	while ((ptr = strsep(&opts, ",\n")) != NULL) {
558 		if (!*ptr)
559 			continue;
560 
561 		token = match_token(ptr, tokens, args);
562 		switch (token) {
563 		case Opt_rd_pages:
564 			match_int(args, &arg);
565 			rd_dev->rd_page_count = arg;
566 			pr_debug("RAMDISK: Referencing Page"
567 				" Count: %u\n", rd_dev->rd_page_count);
568 			rd_dev->rd_flags |= RDF_HAS_PAGE_COUNT;
569 			break;
570 		case Opt_rd_nullio:
571 			match_int(args, &arg);
572 			if (arg != 1)
573 				break;
574 
575 			pr_debug("RAMDISK: Setting NULLIO flag: %d\n", arg);
576 			rd_dev->rd_flags |= RDF_NULLIO;
577 			break;
578 		case Opt_rd_dummy:
579 			match_int(args, &arg);
580 			if (arg != 1)
581 				break;
582 
583 			pr_debug("RAMDISK: Setting DUMMY flag: %d\n", arg);
584 			rd_dev->rd_flags |= RDF_DUMMY;
585 			break;
586 		default:
587 			break;
588 		}
589 	}
590 
591 	kfree(orig);
592 	return count;
593 }
594 
595 static ssize_t rd_show_configfs_dev_params(struct se_device *dev, char *b)
596 {
597 	struct rd_dev *rd_dev = RD_DEV(dev);
598 
599 	ssize_t bl = sprintf(b, "TCM RamDisk ID: %u  RamDisk Makeup: rd_mcp\n",
600 			rd_dev->rd_dev_id);
601 	bl += sprintf(b + bl, "        PAGES/PAGE_SIZE: %u*%lu"
602 			"  SG_table_count: %u  nullio: %d dummy: %d\n",
603 			rd_dev->rd_page_count,
604 			PAGE_SIZE, rd_dev->sg_table_count,
605 			!!(rd_dev->rd_flags & RDF_NULLIO),
606 			!!(rd_dev->rd_flags & RDF_DUMMY));
607 	return bl;
608 }
609 
610 static u32 rd_get_device_type(struct se_device *dev)
611 {
612 	if (RD_DEV(dev)->rd_flags & RDF_DUMMY)
613 		return 0x3f; /* Unknown device type, not connected */
614 	else
615 		return sbc_get_device_type(dev);
616 }
617 
618 static sector_t rd_get_blocks(struct se_device *dev)
619 {
620 	struct rd_dev *rd_dev = RD_DEV(dev);
621 
622 	unsigned long long blocks_long = ((rd_dev->rd_page_count * PAGE_SIZE) /
623 			dev->dev_attrib.block_size) - 1;
624 
625 	return blocks_long;
626 }
627 
628 static int rd_init_prot(struct se_device *dev)
629 {
630 	struct rd_dev *rd_dev = RD_DEV(dev);
631 
632         if (!dev->dev_attrib.pi_prot_type)
633 		return 0;
634 
635 	return rd_build_prot_space(rd_dev, dev->prot_length,
636 				   dev->dev_attrib.block_size);
637 }
638 
639 static void rd_free_prot(struct se_device *dev)
640 {
641 	struct rd_dev *rd_dev = RD_DEV(dev);
642 
643 	rd_release_prot_space(rd_dev);
644 }
645 
646 static struct exec_cmd_ops rd_exec_cmd_ops = {
647 	.execute_rw		= rd_execute_rw,
648 };
649 
650 static sense_reason_t
651 rd_parse_cdb(struct se_cmd *cmd)
652 {
653 	return sbc_parse_cdb(cmd, &rd_exec_cmd_ops);
654 }
655 
656 static const struct target_backend_ops rd_mcp_ops = {
657 	.name			= "rd_mcp",
658 	.inquiry_prod		= "RAMDISK-MCP",
659 	.inquiry_rev		= RD_MCP_VERSION,
660 	.attach_hba		= rd_attach_hba,
661 	.detach_hba		= rd_detach_hba,
662 	.alloc_device		= rd_alloc_device,
663 	.configure_device	= rd_configure_device,
664 	.destroy_device		= rd_destroy_device,
665 	.free_device		= rd_free_device,
666 	.parse_cdb		= rd_parse_cdb,
667 	.set_configfs_dev_params = rd_set_configfs_dev_params,
668 	.show_configfs_dev_params = rd_show_configfs_dev_params,
669 	.get_device_type	= rd_get_device_type,
670 	.get_blocks		= rd_get_blocks,
671 	.init_prot		= rd_init_prot,
672 	.free_prot		= rd_free_prot,
673 	.tb_dev_attrib_attrs	= sbc_attrib_attrs,
674 };
675 
676 int __init rd_module_init(void)
677 {
678 	return transport_backend_register(&rd_mcp_ops);
679 }
680 
681 void rd_module_exit(void)
682 {
683 	target_backend_unregister(&rd_mcp_ops);
684 }
685