xref: /openbmc/linux/drivers/target/target_core_sbc.c (revision a03a8dbe20eff6d57aae3147577bf84b52aba4e6)
1 /*
2  * SCSI Block Commands (SBC) parsing and emulation.
3  *
4  * (c) Copyright 2002-2013 Datera, Inc.
5  *
6  * Nicholas A. Bellinger <nab@kernel.org>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
21  */
22 
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/ratelimit.h>
26 #include <linux/crc-t10dif.h>
27 #include <asm/unaligned.h>
28 #include <scsi/scsi.h>
29 #include <scsi/scsi_tcq.h>
30 
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34 
35 #include "target_core_internal.h"
36 #include "target_core_ua.h"
37 #include "target_core_alua.h"
38 
39 static sense_reason_t
40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
41 
42 static sense_reason_t
43 sbc_emulate_readcapacity(struct se_cmd *cmd)
44 {
45 	struct se_device *dev = cmd->se_dev;
46 	unsigned char *cdb = cmd->t_task_cdb;
47 	unsigned long long blocks_long = dev->transport->get_blocks(dev);
48 	unsigned char *rbuf;
49 	unsigned char buf[8];
50 	u32 blocks;
51 
52 	/*
53 	 * SBC-2 says:
54 	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
55 	 *   ADDRESS field is not set to zero, the device server shall
56 	 *   terminate the command with CHECK CONDITION status with
57 	 *   the sense key set to ILLEGAL REQUEST and the additional
58 	 *   sense code set to INVALID FIELD IN CDB.
59 	 *
60 	 * In SBC-3, these fields are obsolete, but some SCSI
61 	 * compliance tests actually check this, so we might as well
62 	 * follow SBC-2.
63 	 */
64 	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
65 		return TCM_INVALID_CDB_FIELD;
66 
67 	if (blocks_long >= 0x00000000ffffffff)
68 		blocks = 0xffffffff;
69 	else
70 		blocks = (u32)blocks_long;
71 
72 	buf[0] = (blocks >> 24) & 0xff;
73 	buf[1] = (blocks >> 16) & 0xff;
74 	buf[2] = (blocks >> 8) & 0xff;
75 	buf[3] = blocks & 0xff;
76 	buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
77 	buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
78 	buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
79 	buf[7] = dev->dev_attrib.block_size & 0xff;
80 
81 	rbuf = transport_kmap_data_sg(cmd);
82 	if (rbuf) {
83 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
84 		transport_kunmap_data_sg(cmd);
85 	}
86 
87 	target_complete_cmd_with_length(cmd, GOOD, 8);
88 	return 0;
89 }
90 
91 static sense_reason_t
92 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
93 {
94 	struct se_device *dev = cmd->se_dev;
95 	struct se_session *sess = cmd->se_sess;
96 	unsigned char *rbuf;
97 	unsigned char buf[32];
98 	unsigned long long blocks = dev->transport->get_blocks(dev);
99 
100 	memset(buf, 0, sizeof(buf));
101 	buf[0] = (blocks >> 56) & 0xff;
102 	buf[1] = (blocks >> 48) & 0xff;
103 	buf[2] = (blocks >> 40) & 0xff;
104 	buf[3] = (blocks >> 32) & 0xff;
105 	buf[4] = (blocks >> 24) & 0xff;
106 	buf[5] = (blocks >> 16) & 0xff;
107 	buf[6] = (blocks >> 8) & 0xff;
108 	buf[7] = blocks & 0xff;
109 	buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
110 	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
111 	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
112 	buf[11] = dev->dev_attrib.block_size & 0xff;
113 	/*
114 	 * Set P_TYPE and PROT_EN bits for DIF support
115 	 */
116 	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
117 		if (dev->dev_attrib.pi_prot_type)
118 			buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
119 	}
120 
121 	if (dev->transport->get_lbppbe)
122 		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
123 
124 	if (dev->transport->get_alignment_offset_lbas) {
125 		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
126 		buf[14] = (lalba >> 8) & 0x3f;
127 		buf[15] = lalba & 0xff;
128 	}
129 
130 	/*
131 	 * Set Thin Provisioning Enable bit following sbc3r22 in section
132 	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
133 	 */
134 	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
135 		buf[14] |= 0x80;
136 
137 	rbuf = transport_kmap_data_sg(cmd);
138 	if (rbuf) {
139 		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
140 		transport_kunmap_data_sg(cmd);
141 	}
142 
143 	target_complete_cmd_with_length(cmd, GOOD, 32);
144 	return 0;
145 }
146 
147 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
148 {
149 	u32 num_blocks;
150 
151 	if (cmd->t_task_cdb[0] == WRITE_SAME)
152 		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
153 	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
154 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
155 	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
156 		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
157 
158 	/*
159 	 * Use the explicit range when non zero is supplied, otherwise calculate
160 	 * the remaining range based on ->get_blocks() - starting LBA.
161 	 */
162 	if (num_blocks)
163 		return num_blocks;
164 
165 	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
166 		cmd->t_task_lba + 1;
167 }
168 EXPORT_SYMBOL(sbc_get_write_same_sectors);
169 
170 static sense_reason_t
171 sbc_emulate_noop(struct se_cmd *cmd)
172 {
173 	target_complete_cmd(cmd, GOOD);
174 	return 0;
175 }
176 
177 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
178 {
179 	return cmd->se_dev->dev_attrib.block_size * sectors;
180 }
181 
182 static inline u32 transport_get_sectors_6(unsigned char *cdb)
183 {
184 	/*
185 	 * Use 8-bit sector value.  SBC-3 says:
186 	 *
187 	 *   A TRANSFER LENGTH field set to zero specifies that 256
188 	 *   logical blocks shall be written.  Any other value
189 	 *   specifies the number of logical blocks that shall be
190 	 *   written.
191 	 */
192 	return cdb[4] ? : 256;
193 }
194 
195 static inline u32 transport_get_sectors_10(unsigned char *cdb)
196 {
197 	return (u32)(cdb[7] << 8) + cdb[8];
198 }
199 
200 static inline u32 transport_get_sectors_12(unsigned char *cdb)
201 {
202 	return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
203 }
204 
205 static inline u32 transport_get_sectors_16(unsigned char *cdb)
206 {
207 	return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
208 		    (cdb[12] << 8) + cdb[13];
209 }
210 
211 /*
212  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
213  */
214 static inline u32 transport_get_sectors_32(unsigned char *cdb)
215 {
216 	return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
217 		    (cdb[30] << 8) + cdb[31];
218 
219 }
220 
221 static inline u32 transport_lba_21(unsigned char *cdb)
222 {
223 	return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
224 }
225 
226 static inline u32 transport_lba_32(unsigned char *cdb)
227 {
228 	return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
229 }
230 
231 static inline unsigned long long transport_lba_64(unsigned char *cdb)
232 {
233 	unsigned int __v1, __v2;
234 
235 	__v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
236 	__v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
237 
238 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
239 }
240 
241 /*
242  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
243  */
244 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
245 {
246 	unsigned int __v1, __v2;
247 
248 	__v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
249 	__v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
250 
251 	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
252 }
253 
254 static sense_reason_t
255 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
256 {
257 	struct se_device *dev = cmd->se_dev;
258 	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
259 	unsigned int sectors = sbc_get_write_same_sectors(cmd);
260 	sense_reason_t ret;
261 
262 	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
263 		pr_err("WRITE_SAME PBDATA and LBDATA"
264 			" bits not supported for Block Discard"
265 			" Emulation\n");
266 		return TCM_UNSUPPORTED_SCSI_OPCODE;
267 	}
268 	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
269 		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
270 			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
271 		return TCM_INVALID_CDB_FIELD;
272 	}
273 	/*
274 	 * Sanity check for LBA wrap and request past end of device.
275 	 */
276 	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
277 	    ((cmd->t_task_lba + sectors) > end_lba)) {
278 		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
279 		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
280 		return TCM_ADDRESS_OUT_OF_RANGE;
281 	}
282 
283 	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
284 	if (flags[0] & 0x10) {
285 		pr_warn("WRITE SAME with ANCHOR not supported\n");
286 		return TCM_INVALID_CDB_FIELD;
287 	}
288 	/*
289 	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
290 	 * translated into block discard requests within backend code.
291 	 */
292 	if (flags[0] & 0x08) {
293 		if (!ops->execute_write_same_unmap)
294 			return TCM_UNSUPPORTED_SCSI_OPCODE;
295 
296 		if (!dev->dev_attrib.emulate_tpws) {
297 			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
298 			       " has emulate_tpws disabled\n");
299 			return TCM_UNSUPPORTED_SCSI_OPCODE;
300 		}
301 		cmd->execute_cmd = ops->execute_write_same_unmap;
302 		return 0;
303 	}
304 	if (!ops->execute_write_same)
305 		return TCM_UNSUPPORTED_SCSI_OPCODE;
306 
307 	ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
308 	if (ret)
309 		return ret;
310 
311 	cmd->execute_cmd = ops->execute_write_same;
312 	return 0;
313 }
314 
315 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
316 {
317 	unsigned char *buf, *addr;
318 	struct scatterlist *sg;
319 	unsigned int offset;
320 	sense_reason_t ret = TCM_NO_SENSE;
321 	int i, count;
322 	/*
323 	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
324 	 *
325 	 * 1) read the specified logical block(s);
326 	 * 2) transfer logical blocks from the data-out buffer;
327 	 * 3) XOR the logical blocks transferred from the data-out buffer with
328 	 *    the logical blocks read, storing the resulting XOR data in a buffer;
329 	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
330 	 *    blocks transferred from the data-out buffer; and
331 	 * 5) transfer the resulting XOR data to the data-in buffer.
332 	 */
333 	buf = kmalloc(cmd->data_length, GFP_KERNEL);
334 	if (!buf) {
335 		pr_err("Unable to allocate xor_callback buf\n");
336 		return TCM_OUT_OF_RESOURCES;
337 	}
338 	/*
339 	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
340 	 * into the locally allocated *buf
341 	 */
342 	sg_copy_to_buffer(cmd->t_data_sg,
343 			  cmd->t_data_nents,
344 			  buf,
345 			  cmd->data_length);
346 
347 	/*
348 	 * Now perform the XOR against the BIDI read memory located at
349 	 * cmd->t_mem_bidi_list
350 	 */
351 
352 	offset = 0;
353 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
354 		addr = kmap_atomic(sg_page(sg));
355 		if (!addr) {
356 			ret = TCM_OUT_OF_RESOURCES;
357 			goto out;
358 		}
359 
360 		for (i = 0; i < sg->length; i++)
361 			*(addr + sg->offset + i) ^= *(buf + offset + i);
362 
363 		offset += sg->length;
364 		kunmap_atomic(addr);
365 	}
366 
367 out:
368 	kfree(buf);
369 	return ret;
370 }
371 
372 static sense_reason_t
373 sbc_execute_rw(struct se_cmd *cmd)
374 {
375 	return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
376 			       cmd->data_direction);
377 }
378 
379 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
380 {
381 	struct se_device *dev = cmd->se_dev;
382 
383 	/*
384 	 * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
385 	 * within target_complete_ok_work() if the command was successfully
386 	 * sent to the backend driver.
387 	 */
388 	spin_lock_irq(&cmd->t_state_lock);
389 	if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
390 		cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
391 	spin_unlock_irq(&cmd->t_state_lock);
392 
393 	/*
394 	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
395 	 * before the original READ I/O submission.
396 	 */
397 	up(&dev->caw_sem);
398 
399 	return TCM_NO_SENSE;
400 }
401 
402 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
403 {
404 	struct se_device *dev = cmd->se_dev;
405 	struct scatterlist *write_sg = NULL, *sg;
406 	unsigned char *buf = NULL, *addr;
407 	struct sg_mapping_iter m;
408 	unsigned int offset = 0, len;
409 	unsigned int nlbas = cmd->t_task_nolb;
410 	unsigned int block_size = dev->dev_attrib.block_size;
411 	unsigned int compare_len = (nlbas * block_size);
412 	sense_reason_t ret = TCM_NO_SENSE;
413 	int rc, i;
414 
415 	/*
416 	 * Handle early failure in transport_generic_request_failure(),
417 	 * which will not have taken ->caw_mutex yet..
418 	 */
419 	if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
420 		return TCM_NO_SENSE;
421 	/*
422 	 * Immediately exit + release dev->caw_sem if command has already
423 	 * been failed with a non-zero SCSI status.
424 	 */
425 	if (cmd->scsi_status) {
426 		pr_err("compare_and_write_callback: non zero scsi_status:"
427 			" 0x%02x\n", cmd->scsi_status);
428 		goto out;
429 	}
430 
431 	buf = kzalloc(cmd->data_length, GFP_KERNEL);
432 	if (!buf) {
433 		pr_err("Unable to allocate compare_and_write buf\n");
434 		ret = TCM_OUT_OF_RESOURCES;
435 		goto out;
436 	}
437 
438 	write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
439 			   GFP_KERNEL);
440 	if (!write_sg) {
441 		pr_err("Unable to allocate compare_and_write sg\n");
442 		ret = TCM_OUT_OF_RESOURCES;
443 		goto out;
444 	}
445 	sg_init_table(write_sg, cmd->t_data_nents);
446 	/*
447 	 * Setup verify and write data payloads from total NumberLBAs.
448 	 */
449 	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
450 			       cmd->data_length);
451 	if (!rc) {
452 		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
453 		ret = TCM_OUT_OF_RESOURCES;
454 		goto out;
455 	}
456 	/*
457 	 * Compare against SCSI READ payload against verify payload
458 	 */
459 	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
460 		addr = (unsigned char *)kmap_atomic(sg_page(sg));
461 		if (!addr) {
462 			ret = TCM_OUT_OF_RESOURCES;
463 			goto out;
464 		}
465 
466 		len = min(sg->length, compare_len);
467 
468 		if (memcmp(addr, buf + offset, len)) {
469 			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
470 				addr, buf + offset);
471 			kunmap_atomic(addr);
472 			goto miscompare;
473 		}
474 		kunmap_atomic(addr);
475 
476 		offset += len;
477 		compare_len -= len;
478 		if (!compare_len)
479 			break;
480 	}
481 
482 	i = 0;
483 	len = cmd->t_task_nolb * block_size;
484 	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
485 	/*
486 	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
487 	 */
488 	while (len) {
489 		sg_miter_next(&m);
490 
491 		if (block_size < PAGE_SIZE) {
492 			sg_set_page(&write_sg[i], m.page, block_size,
493 				    block_size);
494 		} else {
495 			sg_miter_next(&m);
496 			sg_set_page(&write_sg[i], m.page, block_size,
497 				    0);
498 		}
499 		len -= block_size;
500 		i++;
501 	}
502 	sg_miter_stop(&m);
503 	/*
504 	 * Save the original SGL + nents values before updating to new
505 	 * assignments, to be released in transport_free_pages() ->
506 	 * transport_reset_sgl_orig()
507 	 */
508 	cmd->t_data_sg_orig = cmd->t_data_sg;
509 	cmd->t_data_sg = write_sg;
510 	cmd->t_data_nents_orig = cmd->t_data_nents;
511 	cmd->t_data_nents = 1;
512 
513 	cmd->sam_task_attr = TCM_HEAD_TAG;
514 	cmd->transport_complete_callback = compare_and_write_post;
515 	/*
516 	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
517 	 * for submitting the adjusted SGL to write instance user-data.
518 	 */
519 	cmd->execute_cmd = sbc_execute_rw;
520 
521 	spin_lock_irq(&cmd->t_state_lock);
522 	cmd->t_state = TRANSPORT_PROCESSING;
523 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
524 	spin_unlock_irq(&cmd->t_state_lock);
525 
526 	__target_execute_cmd(cmd);
527 
528 	kfree(buf);
529 	return ret;
530 
531 miscompare:
532 	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
533 		dev->transport->name);
534 	ret = TCM_MISCOMPARE_VERIFY;
535 out:
536 	/*
537 	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
538 	 * sbc_compare_and_write() before the original READ I/O submission.
539 	 */
540 	up(&dev->caw_sem);
541 	kfree(write_sg);
542 	kfree(buf);
543 	return ret;
544 }
545 
546 static sense_reason_t
547 sbc_compare_and_write(struct se_cmd *cmd)
548 {
549 	struct se_device *dev = cmd->se_dev;
550 	sense_reason_t ret;
551 	int rc;
552 	/*
553 	 * Submit the READ first for COMPARE_AND_WRITE to perform the
554 	 * comparision using SGLs at cmd->t_bidi_data_sg..
555 	 */
556 	rc = down_interruptible(&dev->caw_sem);
557 	if ((rc != 0) || signal_pending(current)) {
558 		cmd->transport_complete_callback = NULL;
559 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
560 	}
561 	/*
562 	 * Reset cmd->data_length to individual block_size in order to not
563 	 * confuse backend drivers that depend on this value matching the
564 	 * size of the I/O being submitted.
565 	 */
566 	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
567 
568 	ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
569 			      DMA_FROM_DEVICE);
570 	if (ret) {
571 		cmd->transport_complete_callback = NULL;
572 		up(&dev->caw_sem);
573 		return ret;
574 	}
575 	/*
576 	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
577 	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
578 	 * of WRITE instance user-data.
579 	 */
580 	return TCM_NO_SENSE;
581 }
582 
583 static int
584 sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
585 		       bool is_write, struct se_cmd *cmd)
586 {
587 	if (is_write) {
588 		cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
589 					 TARGET_PROT_DOUT_INSERT;
590 		switch (protect) {
591 		case 0x0:
592 		case 0x3:
593 			cmd->prot_checks = 0;
594 			break;
595 		case 0x1:
596 		case 0x5:
597 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
598 			if (prot_type == TARGET_DIF_TYPE1_PROT)
599 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
600 			break;
601 		case 0x2:
602 			if (prot_type == TARGET_DIF_TYPE1_PROT)
603 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
604 			break;
605 		case 0x4:
606 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
607 			break;
608 		default:
609 			pr_err("Unsupported protect field %d\n", protect);
610 			return -EINVAL;
611 		}
612 	} else {
613 		cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
614 					 TARGET_PROT_DIN_STRIP;
615 		switch (protect) {
616 		case 0x0:
617 		case 0x1:
618 		case 0x5:
619 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
620 			if (prot_type == TARGET_DIF_TYPE1_PROT)
621 				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
622 			break;
623 		case 0x2:
624 			if (prot_type == TARGET_DIF_TYPE1_PROT)
625 				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
626 			break;
627 		case 0x3:
628 			cmd->prot_checks = 0;
629 			break;
630 		case 0x4:
631 			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
632 			break;
633 		default:
634 			pr_err("Unsupported protect field %d\n", protect);
635 			return -EINVAL;
636 		}
637 	}
638 
639 	return 0;
640 }
641 
642 static sense_reason_t
643 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
644 	       u32 sectors, bool is_write)
645 {
646 	u8 protect = cdb[1] >> 5;
647 
648 	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
649 		if (protect && !dev->dev_attrib.pi_prot_type) {
650 			pr_err("CDB contains protect bit, but device does not"
651 			       " advertise PROTECT=1 feature bit\n");
652 			return TCM_INVALID_CDB_FIELD;
653 		}
654 		if (cmd->prot_pto)
655 			return TCM_NO_SENSE;
656 	}
657 
658 	switch (dev->dev_attrib.pi_prot_type) {
659 	case TARGET_DIF_TYPE3_PROT:
660 		cmd->reftag_seed = 0xffffffff;
661 		break;
662 	case TARGET_DIF_TYPE2_PROT:
663 		if (protect)
664 			return TCM_INVALID_CDB_FIELD;
665 
666 		cmd->reftag_seed = cmd->t_task_lba;
667 		break;
668 	case TARGET_DIF_TYPE1_PROT:
669 		cmd->reftag_seed = cmd->t_task_lba;
670 		break;
671 	case TARGET_DIF_TYPE0_PROT:
672 	default:
673 		return TCM_NO_SENSE;
674 	}
675 
676 	if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
677 				   is_write, cmd))
678 		return TCM_INVALID_CDB_FIELD;
679 
680 	cmd->prot_type = dev->dev_attrib.pi_prot_type;
681 	cmd->prot_length = dev->prot_length * sectors;
682 
683 	/**
684 	 * In case protection information exists over the wire
685 	 * we modify command data length to describe pure data.
686 	 * The actual transfer length is data length + protection
687 	 * length
688 	 **/
689 	if (protect)
690 		cmd->data_length = sectors * dev->dev_attrib.block_size;
691 
692 	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
693 		 "prot_op=%d prot_checks=%d\n",
694 		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
695 		 cmd->prot_op, cmd->prot_checks);
696 
697 	return TCM_NO_SENSE;
698 }
699 
700 static int
701 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
702 {
703 	if (cdb[1] & 0x10) {
704 		if (!dev->dev_attrib.emulate_dpo) {
705 			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
706 			       " does not advertise support for DPO\n", cdb[0]);
707 			return -EINVAL;
708 		}
709 	}
710 	if (cdb[1] & 0x8) {
711 		if (!dev->dev_attrib.emulate_fua_write ||
712 		    !dev->dev_attrib.emulate_write_cache) {
713 			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
714 			       " does not advertise support for FUA write\n",
715 			       cdb[0]);
716 			return -EINVAL;
717 		}
718 		cmd->se_cmd_flags |= SCF_FUA;
719 	}
720 	return 0;
721 }
722 
723 sense_reason_t
724 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
725 {
726 	struct se_device *dev = cmd->se_dev;
727 	unsigned char *cdb = cmd->t_task_cdb;
728 	unsigned int size;
729 	u32 sectors = 0;
730 	sense_reason_t ret;
731 
732 	switch (cdb[0]) {
733 	case READ_6:
734 		sectors = transport_get_sectors_6(cdb);
735 		cmd->t_task_lba = transport_lba_21(cdb);
736 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
737 		cmd->execute_rw = ops->execute_rw;
738 		cmd->execute_cmd = sbc_execute_rw;
739 		break;
740 	case READ_10:
741 		sectors = transport_get_sectors_10(cdb);
742 		cmd->t_task_lba = transport_lba_32(cdb);
743 
744 		if (sbc_check_dpofua(dev, cmd, cdb))
745 			return TCM_INVALID_CDB_FIELD;
746 
747 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
748 		if (ret)
749 			return ret;
750 
751 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
752 		cmd->execute_rw = ops->execute_rw;
753 		cmd->execute_cmd = sbc_execute_rw;
754 		break;
755 	case READ_12:
756 		sectors = transport_get_sectors_12(cdb);
757 		cmd->t_task_lba = transport_lba_32(cdb);
758 
759 		if (sbc_check_dpofua(dev, cmd, cdb))
760 			return TCM_INVALID_CDB_FIELD;
761 
762 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
763 		if (ret)
764 			return ret;
765 
766 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
767 		cmd->execute_rw = ops->execute_rw;
768 		cmd->execute_cmd = sbc_execute_rw;
769 		break;
770 	case READ_16:
771 		sectors = transport_get_sectors_16(cdb);
772 		cmd->t_task_lba = transport_lba_64(cdb);
773 
774 		if (sbc_check_dpofua(dev, cmd, cdb))
775 			return TCM_INVALID_CDB_FIELD;
776 
777 		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
778 		if (ret)
779 			return ret;
780 
781 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
782 		cmd->execute_rw = ops->execute_rw;
783 		cmd->execute_cmd = sbc_execute_rw;
784 		break;
785 	case WRITE_6:
786 		sectors = transport_get_sectors_6(cdb);
787 		cmd->t_task_lba = transport_lba_21(cdb);
788 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
789 		cmd->execute_rw = ops->execute_rw;
790 		cmd->execute_cmd = sbc_execute_rw;
791 		break;
792 	case WRITE_10:
793 	case WRITE_VERIFY:
794 		sectors = transport_get_sectors_10(cdb);
795 		cmd->t_task_lba = transport_lba_32(cdb);
796 
797 		if (sbc_check_dpofua(dev, cmd, cdb))
798 			return TCM_INVALID_CDB_FIELD;
799 
800 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
801 		if (ret)
802 			return ret;
803 
804 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
805 		cmd->execute_rw = ops->execute_rw;
806 		cmd->execute_cmd = sbc_execute_rw;
807 		break;
808 	case WRITE_12:
809 		sectors = transport_get_sectors_12(cdb);
810 		cmd->t_task_lba = transport_lba_32(cdb);
811 
812 		if (sbc_check_dpofua(dev, cmd, cdb))
813 			return TCM_INVALID_CDB_FIELD;
814 
815 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
816 		if (ret)
817 			return ret;
818 
819 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
820 		cmd->execute_rw = ops->execute_rw;
821 		cmd->execute_cmd = sbc_execute_rw;
822 		break;
823 	case WRITE_16:
824 		sectors = transport_get_sectors_16(cdb);
825 		cmd->t_task_lba = transport_lba_64(cdb);
826 
827 		if (sbc_check_dpofua(dev, cmd, cdb))
828 			return TCM_INVALID_CDB_FIELD;
829 
830 		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
831 		if (ret)
832 			return ret;
833 
834 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
835 		cmd->execute_rw = ops->execute_rw;
836 		cmd->execute_cmd = sbc_execute_rw;
837 		break;
838 	case XDWRITEREAD_10:
839 		if (cmd->data_direction != DMA_TO_DEVICE ||
840 		    !(cmd->se_cmd_flags & SCF_BIDI))
841 			return TCM_INVALID_CDB_FIELD;
842 		sectors = transport_get_sectors_10(cdb);
843 
844 		if (sbc_check_dpofua(dev, cmd, cdb))
845 			return TCM_INVALID_CDB_FIELD;
846 
847 		cmd->t_task_lba = transport_lba_32(cdb);
848 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
849 
850 		/*
851 		 * Setup BIDI XOR callback to be run after I/O completion.
852 		 */
853 		cmd->execute_rw = ops->execute_rw;
854 		cmd->execute_cmd = sbc_execute_rw;
855 		cmd->transport_complete_callback = &xdreadwrite_callback;
856 		break;
857 	case VARIABLE_LENGTH_CMD:
858 	{
859 		u16 service_action = get_unaligned_be16(&cdb[8]);
860 		switch (service_action) {
861 		case XDWRITEREAD_32:
862 			sectors = transport_get_sectors_32(cdb);
863 
864 			if (sbc_check_dpofua(dev, cmd, cdb))
865 				return TCM_INVALID_CDB_FIELD;
866 			/*
867 			 * Use WRITE_32 and READ_32 opcodes for the emulated
868 			 * XDWRITE_READ_32 logic.
869 			 */
870 			cmd->t_task_lba = transport_lba_64_ext(cdb);
871 			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
872 
873 			/*
874 			 * Setup BIDI XOR callback to be run during after I/O
875 			 * completion.
876 			 */
877 			cmd->execute_rw = ops->execute_rw;
878 			cmd->execute_cmd = sbc_execute_rw;
879 			cmd->transport_complete_callback = &xdreadwrite_callback;
880 			break;
881 		case WRITE_SAME_32:
882 			sectors = transport_get_sectors_32(cdb);
883 			if (!sectors) {
884 				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
885 				       " supported\n");
886 				return TCM_INVALID_CDB_FIELD;
887 			}
888 
889 			size = sbc_get_size(cmd, 1);
890 			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
891 
892 			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
893 			if (ret)
894 				return ret;
895 			break;
896 		default:
897 			pr_err("VARIABLE_LENGTH_CMD service action"
898 				" 0x%04x not supported\n", service_action);
899 			return TCM_UNSUPPORTED_SCSI_OPCODE;
900 		}
901 		break;
902 	}
903 	case COMPARE_AND_WRITE:
904 		sectors = cdb[13];
905 		/*
906 		 * Currently enforce COMPARE_AND_WRITE for a single sector
907 		 */
908 		if (sectors > 1) {
909 			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
910 			       " than 1\n", sectors);
911 			return TCM_INVALID_CDB_FIELD;
912 		}
913 		/*
914 		 * Double size because we have two buffers, note that
915 		 * zero is not an error..
916 		 */
917 		size = 2 * sbc_get_size(cmd, sectors);
918 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
919 		cmd->t_task_nolb = sectors;
920 		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
921 		cmd->execute_rw = ops->execute_rw;
922 		cmd->execute_cmd = sbc_compare_and_write;
923 		cmd->transport_complete_callback = compare_and_write_callback;
924 		break;
925 	case READ_CAPACITY:
926 		size = READ_CAP_LEN;
927 		cmd->execute_cmd = sbc_emulate_readcapacity;
928 		break;
929 	case SERVICE_ACTION_IN_16:
930 		switch (cmd->t_task_cdb[1] & 0x1f) {
931 		case SAI_READ_CAPACITY_16:
932 			cmd->execute_cmd = sbc_emulate_readcapacity_16;
933 			break;
934 		case SAI_REPORT_REFERRALS:
935 			cmd->execute_cmd = target_emulate_report_referrals;
936 			break;
937 		default:
938 			pr_err("Unsupported SA: 0x%02x\n",
939 				cmd->t_task_cdb[1] & 0x1f);
940 			return TCM_INVALID_CDB_FIELD;
941 		}
942 		size = (cdb[10] << 24) | (cdb[11] << 16) |
943 		       (cdb[12] << 8) | cdb[13];
944 		break;
945 	case SYNCHRONIZE_CACHE:
946 	case SYNCHRONIZE_CACHE_16:
947 		if (cdb[0] == SYNCHRONIZE_CACHE) {
948 			sectors = transport_get_sectors_10(cdb);
949 			cmd->t_task_lba = transport_lba_32(cdb);
950 		} else {
951 			sectors = transport_get_sectors_16(cdb);
952 			cmd->t_task_lba = transport_lba_64(cdb);
953 		}
954 		if (ops->execute_sync_cache) {
955 			cmd->execute_cmd = ops->execute_sync_cache;
956 			goto check_lba;
957 		}
958 		size = 0;
959 		cmd->execute_cmd = sbc_emulate_noop;
960 		break;
961 	case UNMAP:
962 		if (!ops->execute_unmap)
963 			return TCM_UNSUPPORTED_SCSI_OPCODE;
964 
965 		if (!dev->dev_attrib.emulate_tpu) {
966 			pr_err("Got UNMAP, but backend device has"
967 			       " emulate_tpu disabled\n");
968 			return TCM_UNSUPPORTED_SCSI_OPCODE;
969 		}
970 		size = get_unaligned_be16(&cdb[7]);
971 		cmd->execute_cmd = ops->execute_unmap;
972 		break;
973 	case WRITE_SAME_16:
974 		sectors = transport_get_sectors_16(cdb);
975 		if (!sectors) {
976 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
977 			return TCM_INVALID_CDB_FIELD;
978 		}
979 
980 		size = sbc_get_size(cmd, 1);
981 		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
982 
983 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
984 		if (ret)
985 			return ret;
986 		break;
987 	case WRITE_SAME:
988 		sectors = transport_get_sectors_10(cdb);
989 		if (!sectors) {
990 			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
991 			return TCM_INVALID_CDB_FIELD;
992 		}
993 
994 		size = sbc_get_size(cmd, 1);
995 		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
996 
997 		/*
998 		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
999 		 * of byte 1 bit 3 UNMAP instead of original reserved field
1000 		 */
1001 		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1002 		if (ret)
1003 			return ret;
1004 		break;
1005 	case VERIFY:
1006 		size = 0;
1007 		sectors = transport_get_sectors_10(cdb);
1008 		cmd->t_task_lba = transport_lba_32(cdb);
1009 		cmd->execute_cmd = sbc_emulate_noop;
1010 		goto check_lba;
1011 	case REZERO_UNIT:
1012 	case SEEK_6:
1013 	case SEEK_10:
1014 		/*
1015 		 * There are still clients out there which use these old SCSI-2
1016 		 * commands. This mainly happens when running VMs with legacy
1017 		 * guest systems, connected via SCSI command pass-through to
1018 		 * iSCSI targets. Make them happy and return status GOOD.
1019 		 */
1020 		size = 0;
1021 		cmd->execute_cmd = sbc_emulate_noop;
1022 		break;
1023 	default:
1024 		ret = spc_parse_cdb(cmd, &size);
1025 		if (ret)
1026 			return ret;
1027 	}
1028 
1029 	/* reject any command that we don't have a handler for */
1030 	if (!cmd->execute_cmd)
1031 		return TCM_UNSUPPORTED_SCSI_OPCODE;
1032 
1033 	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1034 		unsigned long long end_lba;
1035 check_lba:
1036 		end_lba = dev->transport->get_blocks(dev) + 1;
1037 		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1038 		    ((cmd->t_task_lba + sectors) > end_lba)) {
1039 			pr_err("cmd exceeds last lba %llu "
1040 				"(lba %llu, sectors %u)\n",
1041 				end_lba, cmd->t_task_lba, sectors);
1042 			return TCM_ADDRESS_OUT_OF_RANGE;
1043 		}
1044 
1045 		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1046 			size = sbc_get_size(cmd, sectors);
1047 	}
1048 
1049 	return target_cmd_size_check(cmd, size);
1050 }
1051 EXPORT_SYMBOL(sbc_parse_cdb);
1052 
1053 u32 sbc_get_device_type(struct se_device *dev)
1054 {
1055 	return TYPE_DISK;
1056 }
1057 EXPORT_SYMBOL(sbc_get_device_type);
1058 
1059 sense_reason_t
1060 sbc_execute_unmap(struct se_cmd *cmd,
1061 	sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1062 				      sector_t, sector_t),
1063 	void *priv)
1064 {
1065 	struct se_device *dev = cmd->se_dev;
1066 	unsigned char *buf, *ptr = NULL;
1067 	sector_t lba;
1068 	int size;
1069 	u32 range;
1070 	sense_reason_t ret = 0;
1071 	int dl, bd_dl;
1072 
1073 	/* We never set ANC_SUP */
1074 	if (cmd->t_task_cdb[1])
1075 		return TCM_INVALID_CDB_FIELD;
1076 
1077 	if (cmd->data_length == 0) {
1078 		target_complete_cmd(cmd, SAM_STAT_GOOD);
1079 		return 0;
1080 	}
1081 
1082 	if (cmd->data_length < 8) {
1083 		pr_warn("UNMAP parameter list length %u too small\n",
1084 			cmd->data_length);
1085 		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1086 	}
1087 
1088 	buf = transport_kmap_data_sg(cmd);
1089 	if (!buf)
1090 		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1091 
1092 	dl = get_unaligned_be16(&buf[0]);
1093 	bd_dl = get_unaligned_be16(&buf[2]);
1094 
1095 	size = cmd->data_length - 8;
1096 	if (bd_dl > size)
1097 		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1098 			cmd->data_length, bd_dl);
1099 	else
1100 		size = bd_dl;
1101 
1102 	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1103 		ret = TCM_INVALID_PARAMETER_LIST;
1104 		goto err;
1105 	}
1106 
1107 	/* First UNMAP block descriptor starts at 8 byte offset */
1108 	ptr = &buf[8];
1109 	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1110 		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1111 
1112 	while (size >= 16) {
1113 		lba = get_unaligned_be64(&ptr[0]);
1114 		range = get_unaligned_be32(&ptr[8]);
1115 		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1116 				 (unsigned long long)lba, range);
1117 
1118 		if (range > dev->dev_attrib.max_unmap_lba_count) {
1119 			ret = TCM_INVALID_PARAMETER_LIST;
1120 			goto err;
1121 		}
1122 
1123 		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1124 			ret = TCM_ADDRESS_OUT_OF_RANGE;
1125 			goto err;
1126 		}
1127 
1128 		ret = do_unmap_fn(cmd, priv, lba, range);
1129 		if (ret)
1130 			goto err;
1131 
1132 		ptr += 16;
1133 		size -= 16;
1134 	}
1135 
1136 err:
1137 	transport_kunmap_data_sg(cmd);
1138 	if (!ret)
1139 		target_complete_cmd(cmd, GOOD);
1140 	return ret;
1141 }
1142 EXPORT_SYMBOL(sbc_execute_unmap);
1143 
1144 void
1145 sbc_dif_generate(struct se_cmd *cmd)
1146 {
1147 	struct se_device *dev = cmd->se_dev;
1148 	struct se_dif_v1_tuple *sdt;
1149 	struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1150 	sector_t sector = cmd->t_task_lba;
1151 	void *daddr, *paddr;
1152 	int i, j, offset = 0;
1153 
1154 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1155 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1156 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1157 
1158 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1159 
1160 			if (offset >= psg->length) {
1161 				kunmap_atomic(paddr);
1162 				psg = sg_next(psg);
1163 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1164 				offset = 0;
1165 			}
1166 
1167 			sdt = paddr + offset;
1168 			sdt->guard_tag = cpu_to_be16(crc_t10dif(daddr + j,
1169 						dev->dev_attrib.block_size));
1170 			if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT)
1171 				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1172 			sdt->app_tag = 0;
1173 
1174 			pr_debug("DIF WRITE INSERT sector: %llu guard_tag: 0x%04x"
1175 				 " app_tag: 0x%04x ref_tag: %u\n",
1176 				 (unsigned long long)sector, sdt->guard_tag,
1177 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1178 
1179 			sector++;
1180 			offset += sizeof(struct se_dif_v1_tuple);
1181 		}
1182 
1183 		kunmap_atomic(paddr);
1184 		kunmap_atomic(daddr);
1185 	}
1186 }
1187 
1188 static sense_reason_t
1189 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1190 		  const void *p, sector_t sector, unsigned int ei_lba)
1191 {
1192 	int block_size = dev->dev_attrib.block_size;
1193 	__be16 csum;
1194 
1195 	csum = cpu_to_be16(crc_t10dif(p, block_size));
1196 
1197 	if (sdt->guard_tag != csum) {
1198 		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1199 			" csum 0x%04x\n", (unsigned long long)sector,
1200 			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1201 		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1202 	}
1203 
1204 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1205 	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1206 		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1207 		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1208 		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1209 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1210 	}
1211 
1212 	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1213 	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1214 		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1215 		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1216 			be32_to_cpu(sdt->ref_tag), ei_lba);
1217 		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1218 	}
1219 
1220 	return 0;
1221 }
1222 
1223 static void
1224 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1225 		  struct scatterlist *sg, int sg_off)
1226 {
1227 	struct se_device *dev = cmd->se_dev;
1228 	struct scatterlist *psg;
1229 	void *paddr, *addr;
1230 	unsigned int i, len, left;
1231 	unsigned int offset = sg_off;
1232 
1233 	left = sectors * dev->prot_length;
1234 
1235 	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1236 		unsigned int psg_len, copied = 0;
1237 
1238 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1239 		psg_len = min(left, psg->length);
1240 		while (psg_len) {
1241 			len = min(psg_len, sg->length - offset);
1242 			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1243 
1244 			if (read)
1245 				memcpy(paddr + copied, addr, len);
1246 			else
1247 				memcpy(addr, paddr + copied, len);
1248 
1249 			left -= len;
1250 			offset += len;
1251 			copied += len;
1252 			psg_len -= len;
1253 
1254 			if (offset >= sg->length) {
1255 				sg = sg_next(sg);
1256 				offset = 0;
1257 			}
1258 			kunmap_atomic(addr);
1259 		}
1260 		kunmap_atomic(paddr);
1261 	}
1262 }
1263 
1264 sense_reason_t
1265 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1266 		     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1267 {
1268 	struct se_device *dev = cmd->se_dev;
1269 	struct se_dif_v1_tuple *sdt;
1270 	struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1271 	sector_t sector = start;
1272 	void *daddr, *paddr;
1273 	int i, j, offset = 0;
1274 	sense_reason_t rc;
1275 
1276 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1277 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1278 		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1279 
1280 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1281 
1282 			if (offset >= psg->length) {
1283 				kunmap_atomic(paddr);
1284 				psg = sg_next(psg);
1285 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1286 				offset = 0;
1287 			}
1288 
1289 			sdt = paddr + offset;
1290 
1291 			pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1292 				 " app_tag: 0x%04x ref_tag: %u\n",
1293 				 (unsigned long long)sector, sdt->guard_tag,
1294 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1295 
1296 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1297 					       ei_lba);
1298 			if (rc) {
1299 				kunmap_atomic(paddr);
1300 				kunmap_atomic(daddr);
1301 				cmd->bad_sector = sector;
1302 				return rc;
1303 			}
1304 
1305 			sector++;
1306 			ei_lba++;
1307 			offset += sizeof(struct se_dif_v1_tuple);
1308 		}
1309 
1310 		kunmap_atomic(paddr);
1311 		kunmap_atomic(daddr);
1312 	}
1313 	sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1314 
1315 	return 0;
1316 }
1317 EXPORT_SYMBOL(sbc_dif_verify_write);
1318 
1319 static sense_reason_t
1320 __sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1321 		      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1322 {
1323 	struct se_device *dev = cmd->se_dev;
1324 	struct se_dif_v1_tuple *sdt;
1325 	struct scatterlist *dsg, *psg = sg;
1326 	sector_t sector = start;
1327 	void *daddr, *paddr;
1328 	int i, j, offset = sg_off;
1329 	sense_reason_t rc;
1330 
1331 	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1332 		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1333 		paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1334 
1335 		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1336 
1337 			if (offset >= psg->length) {
1338 				kunmap_atomic(paddr);
1339 				psg = sg_next(psg);
1340 				paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1341 				offset = 0;
1342 			}
1343 
1344 			sdt = paddr + offset;
1345 
1346 			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1347 				 " app_tag: 0x%04x ref_tag: %u\n",
1348 				 (unsigned long long)sector, sdt->guard_tag,
1349 				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1350 
1351 			if (sdt->app_tag == cpu_to_be16(0xffff)) {
1352 				sector++;
1353 				offset += sizeof(struct se_dif_v1_tuple);
1354 				continue;
1355 			}
1356 
1357 			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1358 					       ei_lba);
1359 			if (rc) {
1360 				kunmap_atomic(paddr);
1361 				kunmap_atomic(daddr);
1362 				cmd->bad_sector = sector;
1363 				return rc;
1364 			}
1365 
1366 			sector++;
1367 			ei_lba++;
1368 			offset += sizeof(struct se_dif_v1_tuple);
1369 		}
1370 
1371 		kunmap_atomic(paddr);
1372 		kunmap_atomic(daddr);
1373 	}
1374 
1375 	return 0;
1376 }
1377 
1378 sense_reason_t
1379 sbc_dif_read_strip(struct se_cmd *cmd)
1380 {
1381 	struct se_device *dev = cmd->se_dev;
1382 	u32 sectors = cmd->prot_length / dev->prot_length;
1383 
1384 	return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
1385 				     cmd->t_prot_sg, 0);
1386 }
1387 
1388 sense_reason_t
1389 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1390 		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1391 {
1392 	sense_reason_t rc;
1393 
1394 	rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
1395 	if (rc)
1396 		return rc;
1397 
1398 	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1399 	return 0;
1400 }
1401 EXPORT_SYMBOL(sbc_dif_verify_read);
1402