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   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
  27static sense_reason_t
  28sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
  29static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  30
  31static sense_reason_t
  32sbc_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, GOOD, 8);
  71	return 0;
  72}
  73
  74static sense_reason_t
  75sbc_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, GOOD, 32);
 134	return 0;
 135}
 136
 137static sense_reason_t
 138sbc_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
 169sector_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}
 190EXPORT_SYMBOL(sbc_get_write_same_sectors);
 191
 192static sense_reason_t
 193sbc_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, GOOD);
 206	return 0;
 207}
 208
 209static sense_reason_t
 210sbc_emulate_noop(struct se_cmd *cmd)
 211{
 212	target_complete_cmd(cmd, GOOD);
 213	return 0;
 214}
 215
 216static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 217{
 218	return cmd->se_dev->dev_attrib.block_size * sectors;
 219}
 220
 221static 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
 234static inline u32 transport_get_sectors_10(unsigned char *cdb)
 235{
 236	return get_unaligned_be16(&cdb[7]);
 237}
 238
 239static inline u32 transport_get_sectors_12(unsigned char *cdb)
 240{
 241	return get_unaligned_be32(&cdb[6]);
 242}
 243
 244static 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 */
 252static inline u32 transport_get_sectors_32(unsigned char *cdb)
 253{
 254	return get_unaligned_be32(&cdb[28]);
 255
 256}
 257
 258static inline u32 transport_lba_21(unsigned char *cdb)
 259{
 260	return get_unaligned_be24(&cdb[1]) & 0x1fffff;
 261}
 262
 263static inline u32 transport_lba_32(unsigned char *cdb)
 264{
 265	return get_unaligned_be32(&cdb[2]);
 266}
 267
 268static 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 */
 276static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 277{
 278	return get_unaligned_be64(&cdb[12]);
 279}
 280
 281static sense_reason_t
 282sbc_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[0] & 0x04) || (flags[0] & 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[0] & 0x10) {
 312		pr_warn("WRITE SAME with ANCHOR not supported\n");
 313		return TCM_INVALID_CDB_FIELD;
 314	}
 315	/*
 316	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 317	 * translated into block discard requests within backend code.
 318	 */
 319	if (flags[0] & 0x08) {
 320		if (!ops->execute_unmap)
 321			return TCM_UNSUPPORTED_SCSI_OPCODE;
 322
 323		if (!dev->dev_attrib.emulate_tpws) {
 324			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 325			       " has emulate_tpws disabled\n");
 326			return TCM_UNSUPPORTED_SCSI_OPCODE;
 327		}
 328		cmd->execute_cmd = sbc_execute_write_same_unmap;
 329		return 0;
 330	}
 331	if (!ops->execute_write_same)
 332		return TCM_UNSUPPORTED_SCSI_OPCODE;
 333
 334	ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 335	if (ret)
 336		return ret;
 337
 338	cmd->execute_cmd = ops->execute_write_same;
 339	return 0;
 340}
 341
 342static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 343					   int *post_ret)
 344{
 345	unsigned char *buf, *addr;
 346	struct scatterlist *sg;
 347	unsigned int offset;
 348	sense_reason_t ret = TCM_NO_SENSE;
 349	int i, count;
 350
 351	if (!success)
 352		return 0;
 353
 354	/*
 355	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 356	 *
 357	 * 1) read the specified logical block(s);
 358	 * 2) transfer logical blocks from the data-out buffer;
 359	 * 3) XOR the logical blocks transferred from the data-out buffer with
 360	 *    the logical blocks read, storing the resulting XOR data in a buffer;
 361	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 362	 *    blocks transferred from the data-out buffer; and
 363	 * 5) transfer the resulting XOR data to the data-in buffer.
 364	 */
 365	buf = kmalloc(cmd->data_length, GFP_KERNEL);
 366	if (!buf) {
 367		pr_err("Unable to allocate xor_callback buf\n");
 368		return TCM_OUT_OF_RESOURCES;
 369	}
 370	/*
 371	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 372	 * into the locally allocated *buf
 373	 */
 374	sg_copy_to_buffer(cmd->t_data_sg,
 375			  cmd->t_data_nents,
 376			  buf,
 377			  cmd->data_length);
 378
 379	/*
 380	 * Now perform the XOR against the BIDI read memory located at
 381	 * cmd->t_mem_bidi_list
 382	 */
 383
 384	offset = 0;
 385	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 386		addr = kmap_atomic(sg_page(sg));
 387		if (!addr) {
 388			ret = TCM_OUT_OF_RESOURCES;
 389			goto out;
 390		}
 391
 392		for (i = 0; i < sg->length; i++)
 393			*(addr + sg->offset + i) ^= *(buf + offset + i);
 394
 395		offset += sg->length;
 396		kunmap_atomic(addr);
 397	}
 398
 399out:
 400	kfree(buf);
 401	return ret;
 402}
 403
 404static sense_reason_t
 405sbc_execute_rw(struct se_cmd *cmd)
 406{
 407	struct sbc_ops *ops = cmd->protocol_data;
 408
 409	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 410			       cmd->data_direction);
 411}
 412
 413static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 414					     int *post_ret)
 415{
 416	struct se_device *dev = cmd->se_dev;
 417	sense_reason_t ret = TCM_NO_SENSE;
 418
 419	spin_lock_irq(&cmd->t_state_lock);
 420	if (success) {
 421		*post_ret = 1;
 422
 423		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 424			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 425	}
 426	spin_unlock_irq(&cmd->t_state_lock);
 427
 428	/*
 429	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 430	 * before the original READ I/O submission.
 431	 */
 432	up(&dev->caw_sem);
 433
 434	return ret;
 435}
 436
 437static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 438						 int *post_ret)
 439{
 440	struct se_device *dev = cmd->se_dev;
 441	struct sg_table write_tbl = { };
 442	struct scatterlist *write_sg, *sg;
 443	unsigned char *buf = NULL, *addr;
 444	struct sg_mapping_iter m;
 445	unsigned int offset = 0, len;
 446	unsigned int nlbas = cmd->t_task_nolb;
 447	unsigned int block_size = dev->dev_attrib.block_size;
 448	unsigned int compare_len = (nlbas * block_size);
 449	sense_reason_t ret = TCM_NO_SENSE;
 450	int rc, i;
 451
 452	/*
 453	 * Handle early failure in transport_generic_request_failure(),
 454	 * which will not have taken ->caw_sem yet..
 455	 */
 456	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 457		return TCM_NO_SENSE;
 458	/*
 459	 * Handle special case for zero-length COMPARE_AND_WRITE
 460	 */
 461	if (!cmd->data_length)
 462		goto out;
 463	/*
 464	 * Immediately exit + release dev->caw_sem if command has already
 465	 * been failed with a non-zero SCSI status.
 466	 */
 467	if (cmd->scsi_status) {
 468		pr_debug("compare_and_write_callback: non zero scsi_status:"
 469			" 0x%02x\n", cmd->scsi_status);
 470		*post_ret = 1;
 471		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 472			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 473		goto out;
 474	}
 475
 476	buf = kzalloc(cmd->data_length, GFP_KERNEL);
 477	if (!buf) {
 478		pr_err("Unable to allocate compare_and_write buf\n");
 479		ret = TCM_OUT_OF_RESOURCES;
 480		goto out;
 481	}
 482
 483	if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
 484		pr_err("Unable to allocate compare_and_write sg\n");
 485		ret = TCM_OUT_OF_RESOURCES;
 486		goto out;
 487	}
 488	write_sg = write_tbl.sgl;
 489	/*
 490	 * Setup verify and write data payloads from total NumberLBAs.
 491	 */
 492	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 493			       cmd->data_length);
 494	if (!rc) {
 495		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 496		ret = TCM_OUT_OF_RESOURCES;
 497		goto out;
 498	}
 499	/*
 500	 * Compare against SCSI READ payload against verify payload
 501	 */
 502	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 503		addr = (unsigned char *)kmap_atomic(sg_page(sg));
 504		if (!addr) {
 505			ret = TCM_OUT_OF_RESOURCES;
 506			goto out;
 507		}
 508
 509		len = min(sg->length, compare_len);
 510
 511		if (memcmp(addr, buf + offset, len)) {
 512			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 513				addr, buf + offset);
 514			kunmap_atomic(addr);
 515			goto miscompare;
 516		}
 517		kunmap_atomic(addr);
 518
 519		offset += len;
 520		compare_len -= len;
 521		if (!compare_len)
 522			break;
 523	}
 524
 525	i = 0;
 526	len = cmd->t_task_nolb * block_size;
 527	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 528	/*
 529	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 530	 */
 531	while (len) {
 532		sg_miter_next(&m);
 533
 534		if (block_size < PAGE_SIZE) {
 535			sg_set_page(&write_sg[i], m.page, block_size,
 536				    m.piter.sg->offset + block_size);
 537		} else {
 538			sg_miter_next(&m);
 539			sg_set_page(&write_sg[i], m.page, block_size,
 540				    m.piter.sg->offset);
 541		}
 542		len -= block_size;
 543		i++;
 544	}
 545	sg_miter_stop(&m);
 546	/*
 547	 * Save the original SGL + nents values before updating to new
 548	 * assignments, to be released in transport_free_pages() ->
 549	 * transport_reset_sgl_orig()
 550	 */
 551	cmd->t_data_sg_orig = cmd->t_data_sg;
 552	cmd->t_data_sg = write_sg;
 553	cmd->t_data_nents_orig = cmd->t_data_nents;
 554	cmd->t_data_nents = 1;
 555
 556	cmd->sam_task_attr = TCM_HEAD_TAG;
 557	cmd->transport_complete_callback = compare_and_write_post;
 558	/*
 559	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 560	 * for submitting the adjusted SGL to write instance user-data.
 561	 */
 562	cmd->execute_cmd = sbc_execute_rw;
 563
 564	spin_lock_irq(&cmd->t_state_lock);
 565	cmd->t_state = TRANSPORT_PROCESSING;
 566	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 567	spin_unlock_irq(&cmd->t_state_lock);
 568
 569	__target_execute_cmd(cmd, false);
 570
 571	kfree(buf);
 572	return ret;
 573
 574miscompare:
 575	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 576		dev->transport->name);
 577	ret = TCM_MISCOMPARE_VERIFY;
 578out:
 579	/*
 580	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 581	 * sbc_compare_and_write() before the original READ I/O submission.
 582	 */
 583	up(&dev->caw_sem);
 584	sg_free_table(&write_tbl);
 585	kfree(buf);
 586	return ret;
 587}
 588
 589static sense_reason_t
 590sbc_compare_and_write(struct se_cmd *cmd)
 591{
 592	struct sbc_ops *ops = cmd->protocol_data;
 593	struct se_device *dev = cmd->se_dev;
 594	sense_reason_t ret;
 595	int rc;
 596	/*
 597	 * Submit the READ first for COMPARE_AND_WRITE to perform the
 598	 * comparision using SGLs at cmd->t_bidi_data_sg..
 599	 */
 600	rc = down_interruptible(&dev->caw_sem);
 601	if (rc != 0) {
 602		cmd->transport_complete_callback = NULL;
 603		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 604	}
 605	/*
 606	 * Reset cmd->data_length to individual block_size in order to not
 607	 * confuse backend drivers that depend on this value matching the
 608	 * size of the I/O being submitted.
 609	 */
 610	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 611
 612	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 613			      DMA_FROM_DEVICE);
 614	if (ret) {
 615		cmd->transport_complete_callback = NULL;
 616		up(&dev->caw_sem);
 617		return ret;
 618	}
 619	/*
 620	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 621	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
 622	 * of WRITE instance user-data.
 623	 */
 624	return TCM_NO_SENSE;
 625}
 626
 627static int
 628sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 629		       bool is_write, struct se_cmd *cmd)
 630{
 631	if (is_write) {
 632		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 633			       protect ? TARGET_PROT_DOUT_PASS :
 634			       TARGET_PROT_DOUT_INSERT;
 635		switch (protect) {
 636		case 0x0:
 637		case 0x3:
 638			cmd->prot_checks = 0;
 639			break;
 640		case 0x1:
 641		case 0x5:
 642			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 643			if (prot_type == TARGET_DIF_TYPE1_PROT)
 644				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 645			break;
 646		case 0x2:
 647			if (prot_type == TARGET_DIF_TYPE1_PROT)
 648				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 649			break;
 650		case 0x4:
 651			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 652			break;
 653		default:
 654			pr_err("Unsupported protect field %d\n", protect);
 655			return -EINVAL;
 656		}
 657	} else {
 658		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 659			       protect ? TARGET_PROT_DIN_PASS :
 660			       TARGET_PROT_DIN_STRIP;
 661		switch (protect) {
 662		case 0x0:
 663		case 0x1:
 664		case 0x5:
 665			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 666			if (prot_type == TARGET_DIF_TYPE1_PROT)
 667				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 668			break;
 669		case 0x2:
 670			if (prot_type == TARGET_DIF_TYPE1_PROT)
 671				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 672			break;
 673		case 0x3:
 674			cmd->prot_checks = 0;
 675			break;
 676		case 0x4:
 677			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 678			break;
 679		default:
 680			pr_err("Unsupported protect field %d\n", protect);
 681			return -EINVAL;
 682		}
 683	}
 684
 685	return 0;
 686}
 687
 688static sense_reason_t
 689sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 690	       u32 sectors, bool is_write)
 691{
 692	u8 protect = cdb[1] >> 5;
 693	int sp_ops = cmd->se_sess->sup_prot_ops;
 694	int pi_prot_type = dev->dev_attrib.pi_prot_type;
 695	bool fabric_prot = false;
 696
 697	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 698		if (unlikely(protect &&
 699		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 700			pr_err("CDB contains protect bit, but device + fabric does"
 701			       " not advertise PROTECT=1 feature bit\n");
 702			return TCM_INVALID_CDB_FIELD;
 703		}
 704		if (cmd->prot_pto)
 705			return TCM_NO_SENSE;
 706	}
 707
 708	switch (dev->dev_attrib.pi_prot_type) {
 709	case TARGET_DIF_TYPE3_PROT:
 710		cmd->reftag_seed = 0xffffffff;
 711		break;
 712	case TARGET_DIF_TYPE2_PROT:
 713		if (protect)
 714			return TCM_INVALID_CDB_FIELD;
 715
 716		cmd->reftag_seed = cmd->t_task_lba;
 717		break;
 718	case TARGET_DIF_TYPE1_PROT:
 719		cmd->reftag_seed = cmd->t_task_lba;
 720		break;
 721	case TARGET_DIF_TYPE0_PROT:
 722		/*
 723		 * See if the fabric supports T10-PI, and the session has been
 724		 * configured to allow export PROTECT=1 feature bit with backend
 725		 * devices that don't support T10-PI.
 726		 */
 727		fabric_prot = is_write ?
 728			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 729			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 730
 731		if (fabric_prot && cmd->se_sess->sess_prot_type) {
 732			pi_prot_type = cmd->se_sess->sess_prot_type;
 733			break;
 734		}
 735		if (!protect)
 736			return TCM_NO_SENSE;
 737		fallthrough;
 738	default:
 739		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 740		       "PROTECT: 0x%02x\n", cdb[0], protect);
 741		return TCM_INVALID_CDB_FIELD;
 742	}
 743
 744	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 745		return TCM_INVALID_CDB_FIELD;
 746
 747	cmd->prot_type = pi_prot_type;
 748	cmd->prot_length = dev->prot_length * sectors;
 749
 750	/**
 751	 * In case protection information exists over the wire
 752	 * we modify command data length to describe pure data.
 753	 * The actual transfer length is data length + protection
 754	 * length
 755	 **/
 756	if (protect)
 757		cmd->data_length = sectors * dev->dev_attrib.block_size;
 758
 759	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 760		 "prot_op=%d prot_checks=%d\n",
 761		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 762		 cmd->prot_op, cmd->prot_checks);
 763
 764	return TCM_NO_SENSE;
 765}
 766
 767static int
 768sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 769{
 770	if (cdb[1] & 0x10) {
 771		/* see explanation in spc_emulate_modesense */
 772		if (!target_check_fua(dev)) {
 773			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 774			       " does not advertise support for DPO\n", cdb[0]);
 775			return -EINVAL;
 776		}
 777	}
 778	if (cdb[1] & 0x8) {
 779		if (!target_check_fua(dev)) {
 780			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 781			       " does not advertise support for FUA write\n",
 782			       cdb[0]);
 783			return -EINVAL;
 784		}
 785		cmd->se_cmd_flags |= SCF_FUA;
 786	}
 787	return 0;
 788}
 789
 790sense_reason_t
 791sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 792{
 793	struct se_device *dev = cmd->se_dev;
 794	unsigned char *cdb = cmd->t_task_cdb;
 795	unsigned int size;
 796	u32 sectors = 0;
 797	sense_reason_t ret;
 798
 799	cmd->protocol_data = ops;
 800
 801	switch (cdb[0]) {
 802	case READ_6:
 803		sectors = transport_get_sectors_6(cdb);
 804		cmd->t_task_lba = transport_lba_21(cdb);
 805		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 806		cmd->execute_cmd = sbc_execute_rw;
 807		break;
 808	case READ_10:
 809		sectors = transport_get_sectors_10(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, false);
 816		if (ret)
 817			return ret;
 818
 819		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 820		cmd->execute_cmd = sbc_execute_rw;
 821		break;
 822	case READ_12:
 823		sectors = transport_get_sectors_12(cdb);
 824		cmd->t_task_lba = transport_lba_32(cdb);
 825
 826		if (sbc_check_dpofua(dev, cmd, cdb))
 827			return TCM_INVALID_CDB_FIELD;
 828
 829		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 830		if (ret)
 831			return ret;
 832
 833		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 834		cmd->execute_cmd = sbc_execute_rw;
 835		break;
 836	case READ_16:
 837		sectors = transport_get_sectors_16(cdb);
 838		cmd->t_task_lba = transport_lba_64(cdb);
 839
 840		if (sbc_check_dpofua(dev, cmd, cdb))
 841			return TCM_INVALID_CDB_FIELD;
 842
 843		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 844		if (ret)
 845			return ret;
 846
 847		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 848		cmd->execute_cmd = sbc_execute_rw;
 849		break;
 850	case WRITE_6:
 851		sectors = transport_get_sectors_6(cdb);
 852		cmd->t_task_lba = transport_lba_21(cdb);
 853		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 854		cmd->execute_cmd = sbc_execute_rw;
 855		break;
 856	case WRITE_10:
 857	case WRITE_VERIFY:
 858		sectors = transport_get_sectors_10(cdb);
 859		cmd->t_task_lba = transport_lba_32(cdb);
 860
 861		if (sbc_check_dpofua(dev, cmd, cdb))
 862			return TCM_INVALID_CDB_FIELD;
 863
 864		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 865		if (ret)
 866			return ret;
 867
 868		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 869		cmd->execute_cmd = sbc_execute_rw;
 870		break;
 871	case WRITE_12:
 872		sectors = transport_get_sectors_12(cdb);
 873		cmd->t_task_lba = transport_lba_32(cdb);
 874
 875		if (sbc_check_dpofua(dev, cmd, cdb))
 876			return TCM_INVALID_CDB_FIELD;
 877
 878		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 879		if (ret)
 880			return ret;
 881
 882		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 883		cmd->execute_cmd = sbc_execute_rw;
 884		break;
 885	case WRITE_16:
 886	case WRITE_VERIFY_16:
 887		sectors = transport_get_sectors_16(cdb);
 888		cmd->t_task_lba = transport_lba_64(cdb);
 889
 890		if (sbc_check_dpofua(dev, cmd, cdb))
 891			return TCM_INVALID_CDB_FIELD;
 892
 893		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 894		if (ret)
 895			return ret;
 896
 897		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 898		cmd->execute_cmd = sbc_execute_rw;
 899		break;
 900	case XDWRITEREAD_10:
 901		if (cmd->data_direction != DMA_TO_DEVICE ||
 902		    !(cmd->se_cmd_flags & SCF_BIDI))
 903			return TCM_INVALID_CDB_FIELD;
 904		sectors = transport_get_sectors_10(cdb);
 905
 906		if (sbc_check_dpofua(dev, cmd, cdb))
 907			return TCM_INVALID_CDB_FIELD;
 908
 909		cmd->t_task_lba = transport_lba_32(cdb);
 910		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 911
 912		/*
 913		 * Setup BIDI XOR callback to be run after I/O completion.
 914		 */
 915		cmd->execute_cmd = sbc_execute_rw;
 916		cmd->transport_complete_callback = &xdreadwrite_callback;
 917		break;
 918	case VARIABLE_LENGTH_CMD:
 919	{
 920		u16 service_action = get_unaligned_be16(&cdb[8]);
 921		switch (service_action) {
 922		case XDWRITEREAD_32:
 923			sectors = transport_get_sectors_32(cdb);
 924
 925			if (sbc_check_dpofua(dev, cmd, cdb))
 926				return TCM_INVALID_CDB_FIELD;
 927			/*
 928			 * Use WRITE_32 and READ_32 opcodes for the emulated
 929			 * XDWRITE_READ_32 logic.
 930			 */
 931			cmd->t_task_lba = transport_lba_64_ext(cdb);
 932			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 933
 934			/*
 935			 * Setup BIDI XOR callback to be run during after I/O
 936			 * completion.
 937			 */
 938			cmd->execute_cmd = sbc_execute_rw;
 939			cmd->transport_complete_callback = &xdreadwrite_callback;
 940			break;
 941		case WRITE_SAME_32:
 942			sectors = transport_get_sectors_32(cdb);
 943			if (!sectors) {
 944				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 945				       " supported\n");
 946				return TCM_INVALID_CDB_FIELD;
 947			}
 948
 949			size = sbc_get_size(cmd, 1);
 950			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 951
 952			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 953			if (ret)
 954				return ret;
 955			break;
 956		default:
 957			pr_err("VARIABLE_LENGTH_CMD service action"
 958				" 0x%04x not supported\n", service_action);
 959			return TCM_UNSUPPORTED_SCSI_OPCODE;
 960		}
 961		break;
 962	}
 963	case COMPARE_AND_WRITE:
 964		if (!dev->dev_attrib.emulate_caw) {
 965			pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
 966					   dev->se_hba->backend->ops->name,
 967					   config_item_name(&dev->dev_group.cg_item),
 968					   dev->t10_wwn.unit_serial);
 969			return TCM_UNSUPPORTED_SCSI_OPCODE;
 970		}
 971		sectors = cdb[13];
 972		/*
 973		 * Currently enforce COMPARE_AND_WRITE for a single sector
 974		 */
 975		if (sectors > 1) {
 976			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 977			       " than 1\n", sectors);
 978			return TCM_INVALID_CDB_FIELD;
 979		}
 980		if (sbc_check_dpofua(dev, cmd, cdb))
 981			return TCM_INVALID_CDB_FIELD;
 982
 983		/*
 984		 * Double size because we have two buffers, note that
 985		 * zero is not an error..
 986		 */
 987		size = 2 * sbc_get_size(cmd, sectors);
 988		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 989		cmd->t_task_nolb = sectors;
 990		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 991		cmd->execute_cmd = sbc_compare_and_write;
 992		cmd->transport_complete_callback = compare_and_write_callback;
 993		break;
 994	case READ_CAPACITY:
 995		size = READ_CAP_LEN;
 996		cmd->execute_cmd = sbc_emulate_readcapacity;
 997		break;
 998	case SERVICE_ACTION_IN_16:
 999		switch (cmd->t_task_cdb[1] & 0x1f) {
1000		case SAI_READ_CAPACITY_16:
1001			cmd->execute_cmd = sbc_emulate_readcapacity_16;
1002			break;
1003		case SAI_REPORT_REFERRALS:
1004			cmd->execute_cmd = target_emulate_report_referrals;
1005			break;
1006		default:
1007			pr_err("Unsupported SA: 0x%02x\n",
1008				cmd->t_task_cdb[1] & 0x1f);
1009			return TCM_INVALID_CDB_FIELD;
1010		}
1011		size = get_unaligned_be32(&cdb[10]);
1012		break;
1013	case SYNCHRONIZE_CACHE:
1014	case SYNCHRONIZE_CACHE_16:
1015		if (cdb[0] == SYNCHRONIZE_CACHE) {
1016			sectors = transport_get_sectors_10(cdb);
1017			cmd->t_task_lba = transport_lba_32(cdb);
1018		} else {
1019			sectors = transport_get_sectors_16(cdb);
1020			cmd->t_task_lba = transport_lba_64(cdb);
1021		}
1022		if (ops->execute_sync_cache) {
1023			cmd->execute_cmd = ops->execute_sync_cache;
1024			goto check_lba;
1025		}
1026		size = 0;
1027		cmd->execute_cmd = sbc_emulate_noop;
1028		break;
1029	case UNMAP:
1030		if (!ops->execute_unmap)
1031			return TCM_UNSUPPORTED_SCSI_OPCODE;
1032
1033		if (!dev->dev_attrib.emulate_tpu) {
1034			pr_err("Got UNMAP, but backend device has"
1035			       " emulate_tpu disabled\n");
1036			return TCM_UNSUPPORTED_SCSI_OPCODE;
1037		}
1038		size = get_unaligned_be16(&cdb[7]);
1039		cmd->execute_cmd = sbc_execute_unmap;
1040		break;
1041	case WRITE_SAME_16:
1042		sectors = transport_get_sectors_16(cdb);
1043		if (!sectors) {
1044			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1045			return TCM_INVALID_CDB_FIELD;
1046		}
1047
1048		size = sbc_get_size(cmd, 1);
1049		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1050
1051		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1052		if (ret)
1053			return ret;
1054		break;
1055	case WRITE_SAME:
1056		sectors = transport_get_sectors_10(cdb);
1057		if (!sectors) {
1058			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1059			return TCM_INVALID_CDB_FIELD;
1060		}
1061
1062		size = sbc_get_size(cmd, 1);
1063		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1064
1065		/*
1066		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1067		 * of byte 1 bit 3 UNMAP instead of original reserved field
1068		 */
1069		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1070		if (ret)
1071			return ret;
1072		break;
1073	case VERIFY:
1074	case VERIFY_16:
1075		size = 0;
1076		if (cdb[0] == VERIFY) {
1077			sectors = transport_get_sectors_10(cdb);
1078			cmd->t_task_lba = transport_lba_32(cdb);
1079		} else {
1080			sectors = transport_get_sectors_16(cdb);
1081			cmd->t_task_lba = transport_lba_64(cdb);
1082		}
1083		cmd->execute_cmd = sbc_emulate_noop;
1084		goto check_lba;
1085	case REZERO_UNIT:
1086	case SEEK_6:
1087	case SEEK_10:
1088		/*
1089		 * There are still clients out there which use these old SCSI-2
1090		 * commands. This mainly happens when running VMs with legacy
1091		 * guest systems, connected via SCSI command pass-through to
1092		 * iSCSI targets. Make them happy and return status GOOD.
1093		 */
1094		size = 0;
1095		cmd->execute_cmd = sbc_emulate_noop;
1096		break;
1097	case START_STOP:
1098		size = 0;
1099		cmd->execute_cmd = sbc_emulate_startstop;
1100		break;
1101	default:
1102		ret = spc_parse_cdb(cmd, &size);
1103		if (ret)
1104			return ret;
1105	}
1106
1107	/* reject any command that we don't have a handler for */
1108	if (!cmd->execute_cmd)
1109		return TCM_UNSUPPORTED_SCSI_OPCODE;
1110
1111	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1112		unsigned long long end_lba;
1113check_lba:
1114		end_lba = dev->transport->get_blocks(dev) + 1;
1115		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1116		    ((cmd->t_task_lba + sectors) > end_lba)) {
1117			pr_err("cmd exceeds last lba %llu "
1118				"(lba %llu, sectors %u)\n",
1119				end_lba, cmd->t_task_lba, sectors);
1120			return TCM_ADDRESS_OUT_OF_RANGE;
1121		}
1122
1123		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1124			size = sbc_get_size(cmd, sectors);
1125	}
1126
1127	return target_cmd_size_check(cmd, size);
1128}
1129EXPORT_SYMBOL(sbc_parse_cdb);
1130
1131u32 sbc_get_device_type(struct se_device *dev)
1132{
1133	return TYPE_DISK;
1134}
1135EXPORT_SYMBOL(sbc_get_device_type);
1136
1137static sense_reason_t
1138sbc_execute_unmap(struct se_cmd *cmd)
1139{
1140	struct sbc_ops *ops = cmd->protocol_data;
1141	struct se_device *dev = cmd->se_dev;
1142	unsigned char *buf, *ptr = NULL;
1143	sector_t lba;
1144	int size;
1145	u32 range;
1146	sense_reason_t ret = 0;
1147	int dl, bd_dl;
1148
1149	/* We never set ANC_SUP */
1150	if (cmd->t_task_cdb[1])
1151		return TCM_INVALID_CDB_FIELD;
1152
1153	if (cmd->data_length == 0) {
1154		target_complete_cmd(cmd, SAM_STAT_GOOD);
1155		return 0;
1156	}
1157
1158	if (cmd->data_length < 8) {
1159		pr_warn("UNMAP parameter list length %u too small\n",
1160			cmd->data_length);
1161		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1162	}
1163
1164	buf = transport_kmap_data_sg(cmd);
1165	if (!buf)
1166		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1167
1168	dl = get_unaligned_be16(&buf[0]);
1169	bd_dl = get_unaligned_be16(&buf[2]);
1170
1171	size = cmd->data_length - 8;
1172	if (bd_dl > size)
1173		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1174			cmd->data_length, bd_dl);
1175	else
1176		size = bd_dl;
1177
1178	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1179		ret = TCM_INVALID_PARAMETER_LIST;
1180		goto err;
1181	}
1182
1183	/* First UNMAP block descriptor starts at 8 byte offset */
1184	ptr = &buf[8];
1185	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1186		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1187
1188	while (size >= 16) {
1189		lba = get_unaligned_be64(&ptr[0]);
1190		range = get_unaligned_be32(&ptr[8]);
1191		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1192				 (unsigned long long)lba, range);
1193
1194		if (range > dev->dev_attrib.max_unmap_lba_count) {
1195			ret = TCM_INVALID_PARAMETER_LIST;
1196			goto err;
1197		}
1198
1199		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1200			ret = TCM_ADDRESS_OUT_OF_RANGE;
1201			goto err;
1202		}
1203
1204		if (range) {
1205			ret = ops->execute_unmap(cmd, lba, range);
1206			if (ret)
1207				goto err;
1208		}
1209
1210		ptr += 16;
1211		size -= 16;
1212	}
1213
1214err:
1215	transport_kunmap_data_sg(cmd);
1216	if (!ret)
1217		target_complete_cmd(cmd, GOOD);
1218	return ret;
1219}
1220
1221void
1222sbc_dif_generate(struct se_cmd *cmd)
1223{
1224	struct se_device *dev = cmd->se_dev;
1225	struct t10_pi_tuple *sdt;
1226	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1227	sector_t sector = cmd->t_task_lba;
1228	void *daddr, *paddr;
1229	int i, j, offset = 0;
1230	unsigned int block_size = dev->dev_attrib.block_size;
1231
1232	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1233		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1234		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1235
1236		for (j = 0; j < psg->length;
1237				j += sizeof(*sdt)) {
1238			__u16 crc;
1239			unsigned int avail;
1240
1241			if (offset >= dsg->length) {
1242				offset -= dsg->length;
1243				kunmap_atomic(daddr - dsg->offset);
1244				dsg = sg_next(dsg);
1245				if (!dsg) {
1246					kunmap_atomic(paddr - psg->offset);
1247					return;
1248				}
1249				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1250			}
1251
1252			sdt = paddr + j;
1253			avail = min(block_size, dsg->length - offset);
1254			crc = crc_t10dif(daddr + offset, avail);
1255			if (avail < block_size) {
1256				kunmap_atomic(daddr - dsg->offset);
1257				dsg = sg_next(dsg);
1258				if (!dsg) {
1259					kunmap_atomic(paddr - psg->offset);
1260					return;
1261				}
1262				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1263				offset = block_size - avail;
1264				crc = crc_t10dif_update(crc, daddr, offset);
1265			} else {
1266				offset += block_size;
1267			}
1268
1269			sdt->guard_tag = cpu_to_be16(crc);
1270			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1271				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1272			sdt->app_tag = 0;
1273
1274			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1275				 " app_tag: 0x%04x ref_tag: %u\n",
1276				 (cmd->data_direction == DMA_TO_DEVICE) ?
1277				 "WRITE" : "READ", (unsigned long long)sector,
1278				 sdt->guard_tag, sdt->app_tag,
1279				 be32_to_cpu(sdt->ref_tag));
1280
1281			sector++;
1282		}
1283
1284		kunmap_atomic(daddr - dsg->offset);
1285		kunmap_atomic(paddr - psg->offset);
1286	}
1287}
1288
1289static sense_reason_t
1290sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1291		  __u16 crc, sector_t sector, unsigned int ei_lba)
1292{
1293	__be16 csum;
1294
1295	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1296		goto check_ref;
1297
1298	csum = cpu_to_be16(crc);
1299
1300	if (sdt->guard_tag != csum) {
1301		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1302			" csum 0x%04x\n", (unsigned long long)sector,
1303			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1304		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1305	}
1306
1307check_ref:
1308	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1309		return 0;
1310
1311	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1312	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1313		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1314		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1315		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1316		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1317	}
1318
1319	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1320	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1321		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1322		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1323			be32_to_cpu(sdt->ref_tag), ei_lba);
1324		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1325	}
1326
1327	return 0;
1328}
1329
1330void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1331		       struct scatterlist *sg, int sg_off)
1332{
1333	struct se_device *dev = cmd->se_dev;
1334	struct scatterlist *psg;
1335	void *paddr, *addr;
1336	unsigned int i, len, left;
1337	unsigned int offset = sg_off;
1338
1339	if (!sg)
1340		return;
1341
1342	left = sectors * dev->prot_length;
1343
1344	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1345		unsigned int psg_len, copied = 0;
1346
1347		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1348		psg_len = min(left, psg->length);
1349		while (psg_len) {
1350			len = min(psg_len, sg->length - offset);
1351			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1352
1353			if (read)
1354				memcpy(paddr + copied, addr, len);
1355			else
1356				memcpy(addr, paddr + copied, len);
1357
1358			left -= len;
1359			offset += len;
1360			copied += len;
1361			psg_len -= len;
1362
1363			kunmap_atomic(addr - sg->offset - offset);
1364
1365			if (offset >= sg->length) {
1366				sg = sg_next(sg);
1367				offset = 0;
1368			}
1369		}
1370		kunmap_atomic(paddr - psg->offset);
1371	}
1372}
1373EXPORT_SYMBOL(sbc_dif_copy_prot);
1374
1375sense_reason_t
1376sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1377	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1378{
1379	struct se_device *dev = cmd->se_dev;
1380	struct t10_pi_tuple *sdt;
1381	struct scatterlist *dsg = cmd->t_data_sg;
1382	sector_t sector = start;
1383	void *daddr, *paddr;
1384	int i;
1385	sense_reason_t rc;
1386	int dsg_off = 0;
1387	unsigned int block_size = dev->dev_attrib.block_size;
1388
1389	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1390		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1391		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1392
1393		for (i = psg_off; i < psg->length &&
1394				sector < start + sectors;
1395				i += sizeof(*sdt)) {
1396			__u16 crc;
1397			unsigned int avail;
1398
1399			if (dsg_off >= dsg->length) {
1400				dsg_off -= dsg->length;
1401				kunmap_atomic(daddr - dsg->offset);
1402				dsg = sg_next(dsg);
1403				if (!dsg) {
1404					kunmap_atomic(paddr - psg->offset);
1405					return 0;
1406				}
1407				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1408			}
1409
1410			sdt = paddr + i;
1411
1412			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1413				 " app_tag: 0x%04x ref_tag: %u\n",
1414				 (unsigned long long)sector, sdt->guard_tag,
1415				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1416
1417			if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1418				dsg_off += block_size;
1419				goto next;
1420			}
1421
1422			avail = min(block_size, dsg->length - dsg_off);
1423			crc = crc_t10dif(daddr + dsg_off, avail);
1424			if (avail < block_size) {
1425				kunmap_atomic(daddr - dsg->offset);
1426				dsg = sg_next(dsg);
1427				if (!dsg) {
1428					kunmap_atomic(paddr - psg->offset);
1429					return 0;
1430				}
1431				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1432				dsg_off = block_size - avail;
1433				crc = crc_t10dif_update(crc, daddr, dsg_off);
1434			} else {
1435				dsg_off += block_size;
1436			}
1437
1438			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1439			if (rc) {
1440				kunmap_atomic(daddr - dsg->offset);
1441				kunmap_atomic(paddr - psg->offset);
1442				cmd->bad_sector = sector;
1443				return rc;
1444			}
1445next:
1446			sector++;
1447			ei_lba++;
1448		}
1449
1450		psg_off = 0;
1451		kunmap_atomic(daddr - dsg->offset);
1452		kunmap_atomic(paddr - psg->offset);
1453	}
1454
1455	return 0;
1456}
1457EXPORT_SYMBOL(sbc_dif_verify);