1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SCSI Block Commands (SBC) parsing and emulation.
4  *
5  * (c) Copyright 2002-2013 Datera, Inc.
6  *
7  * Nicholas A. Bellinger <nab@kernel.org>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/ratelimit.h>
13 #include <linux/crc-t10dif.h>
14 #include <linux/t10-pi.h>
15 #include <asm/unaligned.h>
16 #include <scsi/scsi_proto.h>
17 #include <scsi/scsi_tcq.h>
18 
19 #include <target/target_core_base.h>
20 #include <target/target_core_backend.h>
21 #include <target/target_core_fabric.h>
22 
23 #include "target_core_internal.h"
24 #include "target_core_ua.h"
25 #include "target_core_alua.h"
26 
27 static sense_reason_t
28 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool);
29 static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
30 
31 static sense_reason_t
32 sbc_emulate_readcapacity(struct se_cmd *cmd)
33 {
34 	struct se_device *dev = cmd->se_dev;
35 	unsigned char *cdb = cmd->t_task_cdb;
36 	unsigned long long blocks_long = dev->transport->get_blocks(dev);
37 	unsigned char *rbuf;
38 	unsigned char buf[8];
39 	u32 blocks;
40 
41 	/*
42 	 * SBC-2 says:
43 	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
44 	 *   ADDRESS field is not set to zero, the device server shall
45 	 *   terminate the command with CHECK CONDITION status with
46 	 *   the sense key set to ILLEGAL REQUEST and the additional
47 	 *   sense code set to INVALID FIELD IN CDB.
48 	 *
49 	 * In SBC-3, these fields are obsolete, but some SCSI
50 	 * compliance tests actually check this, so we might as well
51 	 * follow SBC-2.
52 	 */
53 	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
54 		return TCM_INVALID_CDB_FIELD;
55 
56 	if (blocks_long >= 0x00000000ffffffff)
57 		blocks = 0xffffffff;
58 	else
59 		blocks = (u32)blocks_long;
60 
61 	put_unaligned_be32(blocks, &buf[0]);
62 	put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
63 
64 	rbuf = transport_kmap_data_sg(cmd);
65 	if (rbuf) {
66 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
67 		transport_kunmap_data_sg(cmd);
68 	}
69 
70 	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 8);
71 	return 0;
72 }
73 
74 static sense_reason_t
75 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
76 {
77 	struct se_device *dev = cmd->se_dev;
78 	struct se_session *sess = cmd->se_sess;
79 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
80 
81 	unsigned char *rbuf;
82 	unsigned char buf[32];
83 	unsigned long long blocks = dev->transport->get_blocks(dev);
84 
85 	memset(buf, 0, sizeof(buf));
86 	put_unaligned_be64(blocks, &buf[0]);
87 	put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
88 	/*
89 	 * Set P_TYPE and PROT_EN bits for DIF support
90 	 */
91 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
92 		/*
93 		 * Only override a device's pi_prot_type if no T10-PI is
94 		 * available, and sess_prot_type has been explicitly enabled.
95 		 */
96 		if (!pi_prot_type)
97 			pi_prot_type = sess->sess_prot_type;
98 
99 		if (pi_prot_type)
100 			buf[12] = (pi_prot_type - 1) << 1 | 0x1;
101 	}
102 
103 	if (dev->transport->get_lbppbe)
104 		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
105 
106 	if (dev->transport->get_alignment_offset_lbas) {
107 		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
108 
109 		put_unaligned_be16(lalba, &buf[14]);
110 	}
111 
112 	/*
113 	 * Set Thin Provisioning Enable bit following sbc3r22 in section
114 	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
115 	 */
116 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
117 		buf[14] |= 0x80;
118 
119 		/*
120 		 * LBPRZ signifies that zeroes will be read back from an LBA after
121 		 * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
122 		 */
123 		if (dev->dev_attrib.unmap_zeroes_data)
124 			buf[14] |= 0x40;
125 	}
126 
127 	rbuf = transport_kmap_data_sg(cmd);
128 	if (rbuf) {
129 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
130 		transport_kunmap_data_sg(cmd);
131 	}
132 
133 	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 32);
134 	return 0;
135 }
136 
137 static sense_reason_t
138 sbc_emulate_startstop(struct se_cmd *cmd)
139 {
140 	unsigned char *cdb = cmd->t_task_cdb;
141 
142 	/*
143 	 * See sbc3r36 section 5.25
144 	 * Immediate bit should be set since there is nothing to complete
145 	 * POWER CONDITION MODIFIER 0h
146 	 */
147 	if (!(cdb[1] & 1) || cdb[2] || cdb[3])
148 		return TCM_INVALID_CDB_FIELD;
149 
150 	/*
151 	 * See sbc3r36 section 5.25
152 	 * POWER CONDITION 0h START_VALID - process START and LOEJ
153 	 */
154 	if (cdb[4] >> 4 & 0xf)
155 		return TCM_INVALID_CDB_FIELD;
156 
157 	/*
158 	 * See sbc3r36 section 5.25
159 	 * LOEJ 0h - nothing to load or unload
160 	 * START 1h - we are ready
161 	 */
162 	if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
163 		return TCM_INVALID_CDB_FIELD;
164 
165 	target_complete_cmd(cmd, SAM_STAT_GOOD);
166 	return 0;
167 }
168 
169 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
170 {
171 	u32 num_blocks;
172 
173 	if (cmd->t_task_cdb[0] == WRITE_SAME)
174 		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
175 	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
176 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
177 	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
178 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
179 
180 	/*
181 	 * Use the explicit range when non zero is supplied, otherwise calculate
182 	 * the remaining range based on ->get_blocks() - starting LBA.
183 	 */
184 	if (num_blocks)
185 		return num_blocks;
186 
187 	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
188 		cmd->t_task_lba + 1;
189 }
190 EXPORT_SYMBOL(sbc_get_write_same_sectors);
191 
192 static sense_reason_t
193 sbc_execute_write_same_unmap(struct se_cmd *cmd)
194 {
195 	struct sbc_ops *ops = cmd->protocol_data;
196 	sector_t nolb = sbc_get_write_same_sectors(cmd);
197 	sense_reason_t ret;
198 
199 	if (nolb) {
200 		ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
201 		if (ret)
202 			return ret;
203 	}
204 
205 	target_complete_cmd(cmd, SAM_STAT_GOOD);
206 	return 0;
207 }
208 
209 static sense_reason_t
210 sbc_emulate_noop(struct se_cmd *cmd)
211 {
212 	target_complete_cmd(cmd, SAM_STAT_GOOD);
213 	return 0;
214 }
215 
216 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
217 {
218 	return cmd->se_dev->dev_attrib.block_size * sectors;
219 }
220 
221 static inline u32 transport_get_sectors_6(unsigned char *cdb)
222 {
223 	/*
224 	 * Use 8-bit sector value.  SBC-3 says:
225 	 *
226 	 *   A TRANSFER LENGTH field set to zero specifies that 256
227 	 *   logical blocks shall be written.  Any other value
228 	 *   specifies the number of logical blocks that shall be
229 	 *   written.
230 	 */
231 	return cdb[4] ? : 256;
232 }
233 
234 static inline u32 transport_get_sectors_10(unsigned char *cdb)
235 {
236 	return get_unaligned_be16(&cdb[7]);
237 }
238 
239 static inline u32 transport_get_sectors_12(unsigned char *cdb)
240 {
241 	return get_unaligned_be32(&cdb[6]);
242 }
243 
244 static inline u32 transport_get_sectors_16(unsigned char *cdb)
245 {
246 	return get_unaligned_be32(&cdb[10]);
247 }
248 
249 /*
250  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
251  */
252 static inline u32 transport_get_sectors_32(unsigned char *cdb)
253 {
254 	return get_unaligned_be32(&cdb[28]);
255 
256 }
257 
258 static inline u32 transport_lba_21(unsigned char *cdb)
259 {
260 	return get_unaligned_be24(&cdb[1]) & 0x1fffff;
261 }
262 
263 static inline u32 transport_lba_32(unsigned char *cdb)
264 {
265 	return get_unaligned_be32(&cdb[2]);
266 }
267 
268 static inline unsigned long long transport_lba_64(unsigned char *cdb)
269 {
270 	return get_unaligned_be64(&cdb[2]);
271 }
272 
273 /*
274  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
275  */
276 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
277 {
278 	return get_unaligned_be64(&cdb[12]);
279 }
280 
281 static sense_reason_t
282 sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
283 {
284 	struct se_device *dev = cmd->se_dev;
285 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
286 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
287 	sense_reason_t ret;
288 
289 	if ((flags & 0x04) || (flags & 0x02)) {
290 		pr_err("WRITE_SAME PBDATA and LBDATA"
291 			" bits not supported for Block Discard"
292 			" Emulation\n");
293 		return TCM_UNSUPPORTED_SCSI_OPCODE;
294 	}
295 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
296 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
297 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
298 		return TCM_INVALID_CDB_FIELD;
299 	}
300 	/*
301 	 * Sanity check for LBA wrap and request past end of device.
302 	 */
303 	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
304 	    ((cmd->t_task_lba + sectors) > end_lba)) {
305 		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
306 		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
307 		return TCM_ADDRESS_OUT_OF_RANGE;
308 	}
309 
310 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
311 	if (flags & 0x10) {
312 		pr_warn("WRITE SAME with ANCHOR not supported\n");
313 		return TCM_INVALID_CDB_FIELD;
314 	}
315 
316 	if (flags & 0x01) {
317 		pr_warn("WRITE SAME with NDOB not supported\n");
318 		return TCM_INVALID_CDB_FIELD;
319 	}
320 
321 	/*
322 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
323 	 * translated into block discard requests within backend code.
324 	 */
325 	if (flags & 0x08) {
326 		if (!ops->execute_unmap)
327 			return TCM_UNSUPPORTED_SCSI_OPCODE;
328 
329 		if (!dev->dev_attrib.emulate_tpws) {
330 			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
331 			       " has emulate_tpws disabled\n");
332 			return TCM_UNSUPPORTED_SCSI_OPCODE;
333 		}
334 		cmd->execute_cmd = sbc_execute_write_same_unmap;
335 		return 0;
336 	}
337 	if (!ops->execute_write_same)
338 		return TCM_UNSUPPORTED_SCSI_OPCODE;
339 
340 	ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
341 	if (ret)
342 		return ret;
343 
344 	cmd->execute_cmd = ops->execute_write_same;
345 	return 0;
346 }
347 
348 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
349 					   int *post_ret)
350 {
351 	unsigned char *buf, *addr;
352 	struct scatterlist *sg;
353 	unsigned int offset;
354 	sense_reason_t ret = TCM_NO_SENSE;
355 	int i, count;
356 
357 	if (!success)
358 		return 0;
359 
360 	/*
361 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
362 	 *
363 	 * 1) read the specified logical block(s);
364 	 * 2) transfer logical blocks from the data-out buffer;
365 	 * 3) XOR the logical blocks transferred from the data-out buffer with
366 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
367 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
368 	 *    blocks transferred from the data-out buffer; and
369 	 * 5) transfer the resulting XOR data to the data-in buffer.
370 	 */
371 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
372 	if (!buf) {
373 		pr_err("Unable to allocate xor_callback buf\n");
374 		return TCM_OUT_OF_RESOURCES;
375 	}
376 	/*
377 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
378 	 * into the locally allocated *buf
379 	 */
380 	sg_copy_to_buffer(cmd->t_data_sg,
381 			  cmd->t_data_nents,
382 			  buf,
383 			  cmd->data_length);
384 
385 	/*
386 	 * Now perform the XOR against the BIDI read memory located at
387 	 * cmd->t_mem_bidi_list
388 	 */
389 
390 	offset = 0;
391 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
392 		addr = kmap_atomic(sg_page(sg));
393 		if (!addr) {
394 			ret = TCM_OUT_OF_RESOURCES;
395 			goto out;
396 		}
397 
398 		for (i = 0; i < sg->length; i++)
399 			*(addr + sg->offset + i) ^= *(buf + offset + i);
400 
401 		offset += sg->length;
402 		kunmap_atomic(addr);
403 	}
404 
405 out:
406 	kfree(buf);
407 	return ret;
408 }
409 
410 static sense_reason_t
411 sbc_execute_rw(struct se_cmd *cmd)
412 {
413 	struct sbc_ops *ops = cmd->protocol_data;
414 
415 	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
416 			       cmd->data_direction);
417 }
418 
419 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
420 					     int *post_ret)
421 {
422 	struct se_device *dev = cmd->se_dev;
423 	sense_reason_t ret = TCM_NO_SENSE;
424 
425 	spin_lock_irq(&cmd->t_state_lock);
426 	if (success) {
427 		*post_ret = 1;
428 
429 		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
430 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
431 	}
432 	spin_unlock_irq(&cmd->t_state_lock);
433 
434 	/*
435 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
436 	 * before the original READ I/O submission.
437 	 */
438 	up(&dev->caw_sem);
439 
440 	return ret;
441 }
442 
443 /*
444  * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
445  * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
446  */
447 static sense_reason_t
448 compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
449 			 struct scatterlist *cmp_sgl, unsigned int cmp_nents,
450 			 unsigned int cmp_len, unsigned int *miscmp_off)
451 {
452 	unsigned char *buf = NULL;
453 	struct scatterlist *sg;
454 	sense_reason_t ret;
455 	unsigned int offset;
456 	size_t rc;
457 	int sg_cnt;
458 
459 	buf = kzalloc(cmp_len, GFP_KERNEL);
460 	if (!buf) {
461 		ret = TCM_OUT_OF_RESOURCES;
462 		goto out;
463 	}
464 
465 	rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
466 	if (!rc) {
467 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
468 		ret = TCM_OUT_OF_RESOURCES;
469 		goto out;
470 	}
471 	/*
472 	 * Compare SCSI READ payload against verify payload
473 	 */
474 	offset = 0;
475 	ret = TCM_NO_SENSE;
476 	for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
477 		unsigned int len = min(sg->length, cmp_len);
478 		unsigned char *addr = kmap_atomic(sg_page(sg));
479 
480 		if (memcmp(addr, buf + offset, len)) {
481 			unsigned int i;
482 
483 			for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
484 				;
485 			*miscmp_off = offset + i;
486 			pr_warn("Detected MISCOMPARE at offset %u\n",
487 				*miscmp_off);
488 			ret = TCM_MISCOMPARE_VERIFY;
489 		}
490 		kunmap_atomic(addr);
491 		if (ret != TCM_NO_SENSE)
492 			goto out;
493 
494 		offset += len;
495 		cmp_len -= len;
496 		if (!cmp_len)
497 			break;
498 	}
499 	pr_debug("COMPARE AND WRITE read data matches compare data\n");
500 out:
501 	kfree(buf);
502 	return ret;
503 }
504 
505 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
506 						 int *post_ret)
507 {
508 	struct se_device *dev = cmd->se_dev;
509 	struct sg_table write_tbl = { };
510 	struct scatterlist *write_sg;
511 	struct sg_mapping_iter m;
512 	unsigned int len;
513 	unsigned int block_size = dev->dev_attrib.block_size;
514 	unsigned int compare_len = (cmd->t_task_nolb * block_size);
515 	unsigned int miscmp_off = 0;
516 	sense_reason_t ret = TCM_NO_SENSE;
517 	int i;
518 
519 	/*
520 	 * Handle early failure in transport_generic_request_failure(),
521 	 * which will not have taken ->caw_sem yet..
522 	 */
523 	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
524 		return TCM_NO_SENSE;
525 	/*
526 	 * Handle special case for zero-length COMPARE_AND_WRITE
527 	 */
528 	if (!cmd->data_length)
529 		goto out;
530 	/*
531 	 * Immediately exit + release dev->caw_sem if command has already
532 	 * been failed with a non-zero SCSI status.
533 	 */
534 	if (cmd->scsi_status) {
535 		pr_debug("compare_and_write_callback: non zero scsi_status:"
536 			" 0x%02x\n", cmd->scsi_status);
537 		*post_ret = 1;
538 		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
539 			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
540 		goto out;
541 	}
542 
543 	ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
544 				       cmd->t_bidi_data_nents,
545 				       cmd->t_data_sg,
546 				       cmd->t_data_nents,
547 				       compare_len,
548 				       &miscmp_off);
549 	if (ret == TCM_MISCOMPARE_VERIFY) {
550 		/*
551 		 * SBC-4 r15: 5.3 COMPARE AND WRITE command
552 		 * In the sense data (see 4.18 and SPC-5) the offset from the
553 		 * start of the Data-Out Buffer to the first byte of data that
554 		 * was not equal shall be reported in the INFORMATION field.
555 		 */
556 		cmd->sense_info = miscmp_off;
557 		goto out;
558 	} else if (ret)
559 		goto out;
560 
561 	if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
562 		pr_err("Unable to allocate compare_and_write sg\n");
563 		ret = TCM_OUT_OF_RESOURCES;
564 		goto out;
565 	}
566 	write_sg = write_tbl.sgl;
567 
568 	i = 0;
569 	len = compare_len;
570 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
571 	/*
572 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
573 	 */
574 	while (len) {
575 		sg_miter_next(&m);
576 
577 		if (block_size < PAGE_SIZE) {
578 			sg_set_page(&write_sg[i], m.page, block_size,
579 				    m.piter.sg->offset + block_size);
580 		} else {
581 			sg_miter_next(&m);
582 			sg_set_page(&write_sg[i], m.page, block_size,
583 				    m.piter.sg->offset);
584 		}
585 		len -= block_size;
586 		i++;
587 	}
588 	sg_miter_stop(&m);
589 	/*
590 	 * Save the original SGL + nents values before updating to new
591 	 * assignments, to be released in transport_free_pages() ->
592 	 * transport_reset_sgl_orig()
593 	 */
594 	cmd->t_data_sg_orig = cmd->t_data_sg;
595 	cmd->t_data_sg = write_sg;
596 	cmd->t_data_nents_orig = cmd->t_data_nents;
597 	cmd->t_data_nents = 1;
598 
599 	cmd->sam_task_attr = TCM_HEAD_TAG;
600 	cmd->transport_complete_callback = compare_and_write_post;
601 	/*
602 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
603 	 * for submitting the adjusted SGL to write instance user-data.
604 	 */
605 	cmd->execute_cmd = sbc_execute_rw;
606 
607 	spin_lock_irq(&cmd->t_state_lock);
608 	cmd->t_state = TRANSPORT_PROCESSING;
609 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
610 	spin_unlock_irq(&cmd->t_state_lock);
611 
612 	__target_execute_cmd(cmd, false);
613 
614 	return ret;
615 
616 out:
617 	/*
618 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
619 	 * sbc_compare_and_write() before the original READ I/O submission.
620 	 */
621 	up(&dev->caw_sem);
622 	sg_free_table(&write_tbl);
623 	return ret;
624 }
625 
626 static sense_reason_t
627 sbc_compare_and_write(struct se_cmd *cmd)
628 {
629 	struct sbc_ops *ops = cmd->protocol_data;
630 	struct se_device *dev = cmd->se_dev;
631 	sense_reason_t ret;
632 	int rc;
633 	/*
634 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
635 	 * comparision using SGLs at cmd->t_bidi_data_sg..
636 	 */
637 	rc = down_interruptible(&dev->caw_sem);
638 	if (rc != 0) {
639 		cmd->transport_complete_callback = NULL;
640 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
641 	}
642 	/*
643 	 * Reset cmd->data_length to individual block_size in order to not
644 	 * confuse backend drivers that depend on this value matching the
645 	 * size of the I/O being submitted.
646 	 */
647 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
648 
649 	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
650 			      DMA_FROM_DEVICE);
651 	if (ret) {
652 		cmd->transport_complete_callback = NULL;
653 		up(&dev->caw_sem);
654 		return ret;
655 	}
656 	/*
657 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
658 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
659 	 * of WRITE instance user-data.
660 	 */
661 	return TCM_NO_SENSE;
662 }
663 
664 static int
665 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
666 		       bool is_write, struct se_cmd *cmd)
667 {
668 	if (is_write) {
669 		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
670 			       protect ? TARGET_PROT_DOUT_PASS :
671 			       TARGET_PROT_DOUT_INSERT;
672 		switch (protect) {
673 		case 0x0:
674 		case 0x3:
675 			cmd->prot_checks = 0;
676 			break;
677 		case 0x1:
678 		case 0x5:
679 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
680 			if (prot_type == TARGET_DIF_TYPE1_PROT)
681 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
682 			break;
683 		case 0x2:
684 			if (prot_type == TARGET_DIF_TYPE1_PROT)
685 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
686 			break;
687 		case 0x4:
688 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
689 			break;
690 		default:
691 			pr_err("Unsupported protect field %d\n", protect);
692 			return -EINVAL;
693 		}
694 	} else {
695 		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
696 			       protect ? TARGET_PROT_DIN_PASS :
697 			       TARGET_PROT_DIN_STRIP;
698 		switch (protect) {
699 		case 0x0:
700 		case 0x1:
701 		case 0x5:
702 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
703 			if (prot_type == TARGET_DIF_TYPE1_PROT)
704 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
705 			break;
706 		case 0x2:
707 			if (prot_type == TARGET_DIF_TYPE1_PROT)
708 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
709 			break;
710 		case 0x3:
711 			cmd->prot_checks = 0;
712 			break;
713 		case 0x4:
714 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
715 			break;
716 		default:
717 			pr_err("Unsupported protect field %d\n", protect);
718 			return -EINVAL;
719 		}
720 	}
721 
722 	return 0;
723 }
724 
725 static sense_reason_t
726 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
727 	       u32 sectors, bool is_write)
728 {
729 	int sp_ops = cmd->se_sess->sup_prot_ops;
730 	int pi_prot_type = dev->dev_attrib.pi_prot_type;
731 	bool fabric_prot = false;
732 
733 	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
734 		if (unlikely(protect &&
735 		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
736 			pr_err("CDB contains protect bit, but device + fabric does"
737 			       " not advertise PROTECT=1 feature bit\n");
738 			return TCM_INVALID_CDB_FIELD;
739 		}
740 		if (cmd->prot_pto)
741 			return TCM_NO_SENSE;
742 	}
743 
744 	switch (dev->dev_attrib.pi_prot_type) {
745 	case TARGET_DIF_TYPE3_PROT:
746 		cmd->reftag_seed = 0xffffffff;
747 		break;
748 	case TARGET_DIF_TYPE2_PROT:
749 		if (protect)
750 			return TCM_INVALID_CDB_FIELD;
751 
752 		cmd->reftag_seed = cmd->t_task_lba;
753 		break;
754 	case TARGET_DIF_TYPE1_PROT:
755 		cmd->reftag_seed = cmd->t_task_lba;
756 		break;
757 	case TARGET_DIF_TYPE0_PROT:
758 		/*
759 		 * See if the fabric supports T10-PI, and the session has been
760 		 * configured to allow export PROTECT=1 feature bit with backend
761 		 * devices that don't support T10-PI.
762 		 */
763 		fabric_prot = is_write ?
764 			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
765 			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
766 
767 		if (fabric_prot && cmd->se_sess->sess_prot_type) {
768 			pi_prot_type = cmd->se_sess->sess_prot_type;
769 			break;
770 		}
771 		if (!protect)
772 			return TCM_NO_SENSE;
773 		fallthrough;
774 	default:
775 		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
776 		       "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
777 		return TCM_INVALID_CDB_FIELD;
778 	}
779 
780 	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
781 		return TCM_INVALID_CDB_FIELD;
782 
783 	cmd->prot_type = pi_prot_type;
784 	cmd->prot_length = dev->prot_length * sectors;
785 
786 	/**
787 	 * In case protection information exists over the wire
788 	 * we modify command data length to describe pure data.
789 	 * The actual transfer length is data length + protection
790 	 * length
791 	 **/
792 	if (protect)
793 		cmd->data_length = sectors * dev->dev_attrib.block_size;
794 
795 	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
796 		 "prot_op=%d prot_checks=%d\n",
797 		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
798 		 cmd->prot_op, cmd->prot_checks);
799 
800 	return TCM_NO_SENSE;
801 }
802 
803 static int
804 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
805 {
806 	if (cdb[1] & 0x10) {
807 		/* see explanation in spc_emulate_modesense */
808 		if (!target_check_fua(dev)) {
809 			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
810 			       " does not advertise support for DPO\n", cdb[0]);
811 			return -EINVAL;
812 		}
813 	}
814 	if (cdb[1] & 0x8) {
815 		if (!target_check_fua(dev)) {
816 			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
817 			       " does not advertise support for FUA write\n",
818 			       cdb[0]);
819 			return -EINVAL;
820 		}
821 		cmd->se_cmd_flags |= SCF_FUA;
822 	}
823 	return 0;
824 }
825 
826 sense_reason_t
827 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
828 {
829 	struct se_device *dev = cmd->se_dev;
830 	unsigned char *cdb = cmd->t_task_cdb;
831 	unsigned int size;
832 	u32 sectors = 0;
833 	sense_reason_t ret;
834 
835 	cmd->protocol_data = ops;
836 
837 	switch (cdb[0]) {
838 	case READ_6:
839 		sectors = transport_get_sectors_6(cdb);
840 		cmd->t_task_lba = transport_lba_21(cdb);
841 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
842 		cmd->execute_cmd = sbc_execute_rw;
843 		break;
844 	case READ_10:
845 		sectors = transport_get_sectors_10(cdb);
846 		cmd->t_task_lba = transport_lba_32(cdb);
847 
848 		if (sbc_check_dpofua(dev, cmd, cdb))
849 			return TCM_INVALID_CDB_FIELD;
850 
851 		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
852 		if (ret)
853 			return ret;
854 
855 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
856 		cmd->execute_cmd = sbc_execute_rw;
857 		break;
858 	case READ_12:
859 		sectors = transport_get_sectors_12(cdb);
860 		cmd->t_task_lba = transport_lba_32(cdb);
861 
862 		if (sbc_check_dpofua(dev, cmd, cdb))
863 			return TCM_INVALID_CDB_FIELD;
864 
865 		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
866 		if (ret)
867 			return ret;
868 
869 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
870 		cmd->execute_cmd = sbc_execute_rw;
871 		break;
872 	case READ_16:
873 		sectors = transport_get_sectors_16(cdb);
874 		cmd->t_task_lba = transport_lba_64(cdb);
875 
876 		if (sbc_check_dpofua(dev, cmd, cdb))
877 			return TCM_INVALID_CDB_FIELD;
878 
879 		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
880 		if (ret)
881 			return ret;
882 
883 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
884 		cmd->execute_cmd = sbc_execute_rw;
885 		break;
886 	case WRITE_6:
887 		sectors = transport_get_sectors_6(cdb);
888 		cmd->t_task_lba = transport_lba_21(cdb);
889 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
890 		cmd->execute_cmd = sbc_execute_rw;
891 		break;
892 	case WRITE_10:
893 	case WRITE_VERIFY:
894 		sectors = transport_get_sectors_10(cdb);
895 		cmd->t_task_lba = transport_lba_32(cdb);
896 
897 		if (sbc_check_dpofua(dev, cmd, cdb))
898 			return TCM_INVALID_CDB_FIELD;
899 
900 		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
901 		if (ret)
902 			return ret;
903 
904 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
905 		cmd->execute_cmd = sbc_execute_rw;
906 		break;
907 	case WRITE_12:
908 		sectors = transport_get_sectors_12(cdb);
909 		cmd->t_task_lba = transport_lba_32(cdb);
910 
911 		if (sbc_check_dpofua(dev, cmd, cdb))
912 			return TCM_INVALID_CDB_FIELD;
913 
914 		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
915 		if (ret)
916 			return ret;
917 
918 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
919 		cmd->execute_cmd = sbc_execute_rw;
920 		break;
921 	case WRITE_16:
922 	case WRITE_VERIFY_16:
923 		sectors = transport_get_sectors_16(cdb);
924 		cmd->t_task_lba = transport_lba_64(cdb);
925 
926 		if (sbc_check_dpofua(dev, cmd, cdb))
927 			return TCM_INVALID_CDB_FIELD;
928 
929 		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
930 		if (ret)
931 			return ret;
932 
933 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
934 		cmd->execute_cmd = sbc_execute_rw;
935 		break;
936 	case XDWRITEREAD_10:
937 		if (cmd->data_direction != DMA_TO_DEVICE ||
938 		    !(cmd->se_cmd_flags & SCF_BIDI))
939 			return TCM_INVALID_CDB_FIELD;
940 		sectors = transport_get_sectors_10(cdb);
941 
942 		if (sbc_check_dpofua(dev, cmd, cdb))
943 			return TCM_INVALID_CDB_FIELD;
944 
945 		cmd->t_task_lba = transport_lba_32(cdb);
946 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
947 
948 		/*
949 		 * Setup BIDI XOR callback to be run after I/O completion.
950 		 */
951 		cmd->execute_cmd = sbc_execute_rw;
952 		cmd->transport_complete_callback = &xdreadwrite_callback;
953 		break;
954 	case VARIABLE_LENGTH_CMD:
955 	{
956 		u16 service_action = get_unaligned_be16(&cdb[8]);
957 		switch (service_action) {
958 		case XDWRITEREAD_32:
959 			sectors = transport_get_sectors_32(cdb);
960 
961 			if (sbc_check_dpofua(dev, cmd, cdb))
962 				return TCM_INVALID_CDB_FIELD;
963 			/*
964 			 * Use WRITE_32 and READ_32 opcodes for the emulated
965 			 * XDWRITE_READ_32 logic.
966 			 */
967 			cmd->t_task_lba = transport_lba_64_ext(cdb);
968 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
969 
970 			/*
971 			 * Setup BIDI XOR callback to be run during after I/O
972 			 * completion.
973 			 */
974 			cmd->execute_cmd = sbc_execute_rw;
975 			cmd->transport_complete_callback = &xdreadwrite_callback;
976 			break;
977 		case WRITE_SAME_32:
978 			sectors = transport_get_sectors_32(cdb);
979 			if (!sectors) {
980 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
981 				       " supported\n");
982 				return TCM_INVALID_CDB_FIELD;
983 			}
984 
985 			size = sbc_get_size(cmd, 1);
986 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
987 
988 			ret = sbc_setup_write_same(cmd, cdb[10], ops);
989 			if (ret)
990 				return ret;
991 			break;
992 		default:
993 			pr_err("VARIABLE_LENGTH_CMD service action"
994 				" 0x%04x not supported\n", service_action);
995 			return TCM_UNSUPPORTED_SCSI_OPCODE;
996 		}
997 		break;
998 	}
999 	case COMPARE_AND_WRITE:
1000 		if (!dev->dev_attrib.emulate_caw) {
1001 			pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
1002 					   dev->se_hba->backend->ops->name,
1003 					   config_item_name(&dev->dev_group.cg_item),
1004 					   dev->t10_wwn.unit_serial);
1005 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1006 		}
1007 		sectors = cdb[13];
1008 		/*
1009 		 * Currently enforce COMPARE_AND_WRITE for a single sector
1010 		 */
1011 		if (sectors > 1) {
1012 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1013 			       " than 1\n", sectors);
1014 			return TCM_INVALID_CDB_FIELD;
1015 		}
1016 		if (sbc_check_dpofua(dev, cmd, cdb))
1017 			return TCM_INVALID_CDB_FIELD;
1018 
1019 		/*
1020 		 * Double size because we have two buffers, note that
1021 		 * zero is not an error..
1022 		 */
1023 		size = 2 * sbc_get_size(cmd, sectors);
1024 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1025 		cmd->t_task_nolb = sectors;
1026 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1027 		cmd->execute_cmd = sbc_compare_and_write;
1028 		cmd->transport_complete_callback = compare_and_write_callback;
1029 		break;
1030 	case READ_CAPACITY:
1031 		size = READ_CAP_LEN;
1032 		cmd->execute_cmd = sbc_emulate_readcapacity;
1033 		break;
1034 	case SERVICE_ACTION_IN_16:
1035 		switch (cmd->t_task_cdb[1] & 0x1f) {
1036 		case SAI_READ_CAPACITY_16:
1037 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
1038 			break;
1039 		case SAI_REPORT_REFERRALS:
1040 			cmd->execute_cmd = target_emulate_report_referrals;
1041 			break;
1042 		default:
1043 			pr_err("Unsupported SA: 0x%02x\n",
1044 				cmd->t_task_cdb[1] & 0x1f);
1045 			return TCM_INVALID_CDB_FIELD;
1046 		}
1047 		size = get_unaligned_be32(&cdb[10]);
1048 		break;
1049 	case SYNCHRONIZE_CACHE:
1050 	case SYNCHRONIZE_CACHE_16:
1051 		if (cdb[0] == SYNCHRONIZE_CACHE) {
1052 			sectors = transport_get_sectors_10(cdb);
1053 			cmd->t_task_lba = transport_lba_32(cdb);
1054 		} else {
1055 			sectors = transport_get_sectors_16(cdb);
1056 			cmd->t_task_lba = transport_lba_64(cdb);
1057 		}
1058 		if (ops->execute_sync_cache) {
1059 			cmd->execute_cmd = ops->execute_sync_cache;
1060 			goto check_lba;
1061 		}
1062 		size = 0;
1063 		cmd->execute_cmd = sbc_emulate_noop;
1064 		break;
1065 	case UNMAP:
1066 		if (!ops->execute_unmap)
1067 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1068 
1069 		if (!dev->dev_attrib.emulate_tpu) {
1070 			pr_err("Got UNMAP, but backend device has"
1071 			       " emulate_tpu disabled\n");
1072 			return TCM_UNSUPPORTED_SCSI_OPCODE;
1073 		}
1074 		size = get_unaligned_be16(&cdb[7]);
1075 		cmd->execute_cmd = sbc_execute_unmap;
1076 		break;
1077 	case WRITE_SAME_16:
1078 		sectors = transport_get_sectors_16(cdb);
1079 		if (!sectors) {
1080 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1081 			return TCM_INVALID_CDB_FIELD;
1082 		}
1083 
1084 		size = sbc_get_size(cmd, 1);
1085 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1086 
1087 		ret = sbc_setup_write_same(cmd, cdb[1], ops);
1088 		if (ret)
1089 			return ret;
1090 		break;
1091 	case WRITE_SAME:
1092 		sectors = transport_get_sectors_10(cdb);
1093 		if (!sectors) {
1094 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1095 			return TCM_INVALID_CDB_FIELD;
1096 		}
1097 
1098 		size = sbc_get_size(cmd, 1);
1099 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1100 
1101 		/*
1102 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1103 		 * of byte 1 bit 3 UNMAP instead of original reserved field
1104 		 */
1105 		ret = sbc_setup_write_same(cmd, cdb[1], ops);
1106 		if (ret)
1107 			return ret;
1108 		break;
1109 	case VERIFY:
1110 	case VERIFY_16:
1111 		size = 0;
1112 		if (cdb[0] == VERIFY) {
1113 			sectors = transport_get_sectors_10(cdb);
1114 			cmd->t_task_lba = transport_lba_32(cdb);
1115 		} else {
1116 			sectors = transport_get_sectors_16(cdb);
1117 			cmd->t_task_lba = transport_lba_64(cdb);
1118 		}
1119 		cmd->execute_cmd = sbc_emulate_noop;
1120 		goto check_lba;
1121 	case REZERO_UNIT:
1122 	case SEEK_6:
1123 	case SEEK_10:
1124 		/*
1125 		 * There are still clients out there which use these old SCSI-2
1126 		 * commands. This mainly happens when running VMs with legacy
1127 		 * guest systems, connected via SCSI command pass-through to
1128 		 * iSCSI targets. Make them happy and return status GOOD.
1129 		 */
1130 		size = 0;
1131 		cmd->execute_cmd = sbc_emulate_noop;
1132 		break;
1133 	case START_STOP:
1134 		size = 0;
1135 		cmd->execute_cmd = sbc_emulate_startstop;
1136 		break;
1137 	default:
1138 		ret = spc_parse_cdb(cmd, &size);
1139 		if (ret)
1140 			return ret;
1141 	}
1142 
1143 	/* reject any command that we don't have a handler for */
1144 	if (!cmd->execute_cmd)
1145 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1146 
1147 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1148 		unsigned long long end_lba;
1149 check_lba:
1150 		end_lba = dev->transport->get_blocks(dev) + 1;
1151 		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1152 		    ((cmd->t_task_lba + sectors) > end_lba)) {
1153 			pr_err("cmd exceeds last lba %llu "
1154 				"(lba %llu, sectors %u)\n",
1155 				end_lba, cmd->t_task_lba, sectors);
1156 			return TCM_ADDRESS_OUT_OF_RANGE;
1157 		}
1158 
1159 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1160 			size = sbc_get_size(cmd, sectors);
1161 	}
1162 
1163 	return target_cmd_size_check(cmd, size);
1164 }
1165 EXPORT_SYMBOL(sbc_parse_cdb);
1166 
1167 u32 sbc_get_device_type(struct se_device *dev)
1168 {
1169 	return TYPE_DISK;
1170 }
1171 EXPORT_SYMBOL(sbc_get_device_type);
1172 
1173 static sense_reason_t
1174 sbc_execute_unmap(struct se_cmd *cmd)
1175 {
1176 	struct sbc_ops *ops = cmd->protocol_data;
1177 	struct se_device *dev = cmd->se_dev;
1178 	unsigned char *buf, *ptr = NULL;
1179 	sector_t lba;
1180 	int size;
1181 	u32 range;
1182 	sense_reason_t ret = 0;
1183 	int dl, bd_dl;
1184 
1185 	/* We never set ANC_SUP */
1186 	if (cmd->t_task_cdb[1])
1187 		return TCM_INVALID_CDB_FIELD;
1188 
1189 	if (cmd->data_length == 0) {
1190 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1191 		return 0;
1192 	}
1193 
1194 	if (cmd->data_length < 8) {
1195 		pr_warn("UNMAP parameter list length %u too small\n",
1196 			cmd->data_length);
1197 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1198 	}
1199 
1200 	buf = transport_kmap_data_sg(cmd);
1201 	if (!buf)
1202 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1203 
1204 	dl = get_unaligned_be16(&buf[0]);
1205 	bd_dl = get_unaligned_be16(&buf[2]);
1206 
1207 	size = cmd->data_length - 8;
1208 	if (bd_dl > size)
1209 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1210 			cmd->data_length, bd_dl);
1211 	else
1212 		size = bd_dl;
1213 
1214 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1215 		ret = TCM_INVALID_PARAMETER_LIST;
1216 		goto err;
1217 	}
1218 
1219 	/* First UNMAP block descriptor starts at 8 byte offset */
1220 	ptr = &buf[8];
1221 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1222 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1223 
1224 	while (size >= 16) {
1225 		lba = get_unaligned_be64(&ptr[0]);
1226 		range = get_unaligned_be32(&ptr[8]);
1227 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1228 				 (unsigned long long)lba, range);
1229 
1230 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1231 			ret = TCM_INVALID_PARAMETER_LIST;
1232 			goto err;
1233 		}
1234 
1235 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1236 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1237 			goto err;
1238 		}
1239 
1240 		if (range) {
1241 			ret = ops->execute_unmap(cmd, lba, range);
1242 			if (ret)
1243 				goto err;
1244 		}
1245 
1246 		ptr += 16;
1247 		size -= 16;
1248 	}
1249 
1250 err:
1251 	transport_kunmap_data_sg(cmd);
1252 	if (!ret)
1253 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1254 	return ret;
1255 }
1256 
1257 void
1258 sbc_dif_generate(struct se_cmd *cmd)
1259 {
1260 	struct se_device *dev = cmd->se_dev;
1261 	struct t10_pi_tuple *sdt;
1262 	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1263 	sector_t sector = cmd->t_task_lba;
1264 	void *daddr, *paddr;
1265 	int i, j, offset = 0;
1266 	unsigned int block_size = dev->dev_attrib.block_size;
1267 
1268 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1269 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1270 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1271 
1272 		for (j = 0; j < psg->length;
1273 				j += sizeof(*sdt)) {
1274 			__u16 crc;
1275 			unsigned int avail;
1276 
1277 			if (offset >= dsg->length) {
1278 				offset -= dsg->length;
1279 				kunmap_atomic(daddr - dsg->offset);
1280 				dsg = sg_next(dsg);
1281 				if (!dsg) {
1282 					kunmap_atomic(paddr - psg->offset);
1283 					return;
1284 				}
1285 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1286 			}
1287 
1288 			sdt = paddr + j;
1289 			avail = min(block_size, dsg->length - offset);
1290 			crc = crc_t10dif(daddr + offset, avail);
1291 			if (avail < block_size) {
1292 				kunmap_atomic(daddr - dsg->offset);
1293 				dsg = sg_next(dsg);
1294 				if (!dsg) {
1295 					kunmap_atomic(paddr - psg->offset);
1296 					return;
1297 				}
1298 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1299 				offset = block_size - avail;
1300 				crc = crc_t10dif_update(crc, daddr, offset);
1301 			} else {
1302 				offset += block_size;
1303 			}
1304 
1305 			sdt->guard_tag = cpu_to_be16(crc);
1306 			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1307 				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1308 			sdt->app_tag = 0;
1309 
1310 			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1311 				 " app_tag: 0x%04x ref_tag: %u\n",
1312 				 (cmd->data_direction == DMA_TO_DEVICE) ?
1313 				 "WRITE" : "READ", (unsigned long long)sector,
1314 				 sdt->guard_tag, sdt->app_tag,
1315 				 be32_to_cpu(sdt->ref_tag));
1316 
1317 			sector++;
1318 		}
1319 
1320 		kunmap_atomic(daddr - dsg->offset);
1321 		kunmap_atomic(paddr - psg->offset);
1322 	}
1323 }
1324 
1325 static sense_reason_t
1326 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1327 		  __u16 crc, sector_t sector, unsigned int ei_lba)
1328 {
1329 	__be16 csum;
1330 
1331 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1332 		goto check_ref;
1333 
1334 	csum = cpu_to_be16(crc);
1335 
1336 	if (sdt->guard_tag != csum) {
1337 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1338 			" csum 0x%04x\n", (unsigned long long)sector,
1339 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1340 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1341 	}
1342 
1343 check_ref:
1344 	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1345 		return 0;
1346 
1347 	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1348 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1349 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1350 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1351 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1352 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1353 	}
1354 
1355 	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1356 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1357 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1358 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1359 			be32_to_cpu(sdt->ref_tag), ei_lba);
1360 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1361 	}
1362 
1363 	return 0;
1364 }
1365 
1366 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1367 		       struct scatterlist *sg, int sg_off)
1368 {
1369 	struct se_device *dev = cmd->se_dev;
1370 	struct scatterlist *psg;
1371 	void *paddr, *addr;
1372 	unsigned int i, len, left;
1373 	unsigned int offset = sg_off;
1374 
1375 	if (!sg)
1376 		return;
1377 
1378 	left = sectors * dev->prot_length;
1379 
1380 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1381 		unsigned int psg_len, copied = 0;
1382 
1383 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1384 		psg_len = min(left, psg->length);
1385 		while (psg_len) {
1386 			len = min(psg_len, sg->length - offset);
1387 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1388 
1389 			if (read)
1390 				memcpy(paddr + copied, addr, len);
1391 			else
1392 				memcpy(addr, paddr + copied, len);
1393 
1394 			left -= len;
1395 			offset += len;
1396 			copied += len;
1397 			psg_len -= len;
1398 
1399 			kunmap_atomic(addr - sg->offset - offset);
1400 
1401 			if (offset >= sg->length) {
1402 				sg = sg_next(sg);
1403 				offset = 0;
1404 			}
1405 		}
1406 		kunmap_atomic(paddr - psg->offset);
1407 	}
1408 }
1409 EXPORT_SYMBOL(sbc_dif_copy_prot);
1410 
1411 sense_reason_t
1412 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1413 	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1414 {
1415 	struct se_device *dev = cmd->se_dev;
1416 	struct t10_pi_tuple *sdt;
1417 	struct scatterlist *dsg = cmd->t_data_sg;
1418 	sector_t sector = start;
1419 	void *daddr, *paddr;
1420 	int i;
1421 	sense_reason_t rc;
1422 	int dsg_off = 0;
1423 	unsigned int block_size = dev->dev_attrib.block_size;
1424 
1425 	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1426 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1427 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1428 
1429 		for (i = psg_off; i < psg->length &&
1430 				sector < start + sectors;
1431 				i += sizeof(*sdt)) {
1432 			__u16 crc;
1433 			unsigned int avail;
1434 
1435 			if (dsg_off >= dsg->length) {
1436 				dsg_off -= dsg->length;
1437 				kunmap_atomic(daddr - dsg->offset);
1438 				dsg = sg_next(dsg);
1439 				if (!dsg) {
1440 					kunmap_atomic(paddr - psg->offset);
1441 					return 0;
1442 				}
1443 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1444 			}
1445 
1446 			sdt = paddr + i;
1447 
1448 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1449 				 " app_tag: 0x%04x ref_tag: %u\n",
1450 				 (unsigned long long)sector, sdt->guard_tag,
1451 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1452 
1453 			if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1454 				dsg_off += block_size;
1455 				goto next;
1456 			}
1457 
1458 			avail = min(block_size, dsg->length - dsg_off);
1459 			crc = crc_t10dif(daddr + dsg_off, avail);
1460 			if (avail < block_size) {
1461 				kunmap_atomic(daddr - dsg->offset);
1462 				dsg = sg_next(dsg);
1463 				if (!dsg) {
1464 					kunmap_atomic(paddr - psg->offset);
1465 					return 0;
1466 				}
1467 				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1468 				dsg_off = block_size - avail;
1469 				crc = crc_t10dif_update(crc, daddr, dsg_off);
1470 			} else {
1471 				dsg_off += block_size;
1472 			}
1473 
1474 			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1475 			if (rc) {
1476 				kunmap_atomic(daddr - dsg->offset);
1477 				kunmap_atomic(paddr - psg->offset);
1478 				cmd->sense_info = sector;
1479 				return rc;
1480 			}
1481 next:
1482 			sector++;
1483 			ei_lba++;
1484 		}
1485 
1486 		psg_off = 0;
1487 		kunmap_atomic(daddr - dsg->offset);
1488 		kunmap_atomic(paddr - psg->offset);
1489 	}
1490 
1491 	return 0;
1492 }
1493 EXPORT_SYMBOL(sbc_dif_verify);
1494