drivers/target/target_core_sbc.c

   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 static sense_reason_t
 274 sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags, struct sbc_ops *ops)
 275 {
 276         struct se_device *dev = cmd->se_dev;
 277         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 278         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 279         sense_reason_t ret;
 280
 281         if ((flags & 0x04) || (flags & 0x02)) {
 282                 pr_err("WRITE_SAME PBDATA and LBDATA"
 283                         " bits not supported for Block Discard"
 284                         " Emulation\n");
 285                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 286         }
 287         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 288                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 289                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 290                 return TCM_INVALID_CDB_FIELD;
 291         }
 292         /*
 293          * Sanity check for LBA wrap and request past end of device.
 294          */
 295         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 296             ((cmd->t_task_lba + sectors) > end_lba)) {
 297                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 298                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 299                 return TCM_ADDRESS_OUT_OF_RANGE;
 300         }
 301
 302         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 303         if (flags & 0x10) {
 304                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 305                 return TCM_INVALID_CDB_FIELD;
 306         }
 307
 308         if (flags & 0x01) {
 309                 pr_warn("WRITE SAME with NDOB not supported\n");
 310                 return TCM_INVALID_CDB_FIELD;
 311         }
 312
 313         /*
 314          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 315          * translated into block discard requests within backend code.
 316          */
 317         if (flags & 0x08) {
 318                 if (!ops->execute_unmap)
 319                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 320
 321                 if (!dev->dev_attrib.emulate_tpws) {
 322                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 323                                " has emulate_tpws disabled\n");
 324                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 325                 }
 326                 cmd->execute_cmd = sbc_execute_write_same_unmap;
 327                 return 0;
 328         }
 329         if (!ops->execute_write_same)
 330                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 331
 332         ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
 333         if (ret)
 334                 return ret;
 335
 336         cmd->execute_cmd = ops->execute_write_same;
 337         return 0;
 338 }
 339
 340 static sense_reason_t
 341 sbc_execute_rw(struct se_cmd *cmd)
 342 {
 343         struct sbc_ops *ops = cmd->protocol_data;
 344
 345         return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 346                                cmd->data_direction);
 347 }
 348
 349 static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 350                                              int *post_ret)
 351 {
 352         struct se_device *dev = cmd->se_dev;
 353         sense_reason_t ret = TCM_NO_SENSE;
 354
 355         spin_lock_irq(&cmd->t_state_lock);
 356         if (success) {
 357                 *post_ret = 1;
 358
 359                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 360                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 361         }
 362         spin_unlock_irq(&cmd->t_state_lock);
 363
 364         /*
 365          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 366          * before the original READ I/O submission.
 367          */
 368         up(&dev->caw_sem);
 369
 370         return ret;
 371 }
 372
 373 /*
 374  * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
 375  * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
 376  */
 377 static sense_reason_t
 378 compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
 379                          struct scatterlist *cmp_sgl, unsigned int cmp_nents,
 380                          unsigned int cmp_len, unsigned int *miscmp_off)
 381 {
 382         unsigned char *buf = NULL;
 383         struct scatterlist *sg;
 384         sense_reason_t ret;
 385         unsigned int offset;
 386         size_t rc;
 387         int sg_cnt;
 388
 389         buf = kzalloc(cmp_len, GFP_KERNEL);
 390         if (!buf) {
 391                 ret = TCM_OUT_OF_RESOURCES;
 392                 goto out;
 393         }
 394
 395         rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
 396         if (!rc) {
 397                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 398                 ret = TCM_OUT_OF_RESOURCES;
 399                 goto out;
 400         }
 401         /*
 402          * Compare SCSI READ payload against verify payload
 403          */
 404         offset = 0;
 405         ret = TCM_NO_SENSE;
 406         for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
 407                 unsigned int len = min(sg->length, cmp_len);
 408                 unsigned char *addr = kmap_atomic(sg_page(sg));
 409
 410                 if (memcmp(addr, buf + offset, len)) {
 411                         unsigned int i;
 412
 413                         for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
 414                                 ;
 415                         *miscmp_off = offset + i;
 416                         pr_warn("Detected MISCOMPARE at offset %u\n",
 417                                 *miscmp_off);
 418                         ret = TCM_MISCOMPARE_VERIFY;
 419                 }
 420                 kunmap_atomic(addr);
 421                 if (ret != TCM_NO_SENSE)
 422                         goto out;
 423
 424                 offset += len;
 425                 cmp_len -= len;
 426                 if (!cmp_len)
 427                         break;
 428         }
 429         pr_debug("COMPARE AND WRITE read data matches compare data\n");
 430 out:
 431         kfree(buf);
 432         return ret;
 433 }
 434
 435 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 436                                                  int *post_ret)
 437 {
 438         struct se_device *dev = cmd->se_dev;
 439         struct sg_table write_tbl = { };
 440         struct scatterlist *write_sg;
 441         struct sg_mapping_iter m;
 442         unsigned int len;
 443         unsigned int block_size = dev->dev_attrib.block_size;
 444         unsigned int compare_len = (cmd->t_task_nolb * block_size);
 445         unsigned int miscmp_off = 0;
 446         sense_reason_t ret = TCM_NO_SENSE;
 447         int i;
 448
 449         if (!success) {
 450                 /*
 451                  * Handle early failure in transport_generic_request_failure(),
 452                  * which will not have taken ->caw_sem yet..
 453                  */
 454                 if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 455                         return TCM_NO_SENSE;
 456
 457                 /*
 458                  * The command has been stopped or aborted so
 459                  * we don't have to perform the write operation.
 460                  */
 461                 WARN_ON(!(cmd->transport_state &
 462                         (CMD_T_ABORTED | CMD_T_STOP)));
 463                 goto out;
 464         }
 465         /*
 466          * Handle special case for zero-length COMPARE_AND_WRITE
 467          */
 468         if (!cmd->data_length)
 469                 goto out;
 470         /*
 471          * Immediately exit + release dev->caw_sem if command has already
 472          * been failed with a non-zero SCSI status.
 473          */
 474         if (cmd->scsi_status) {
 475                 pr_debug("compare_and_write_callback: non zero scsi_status:"
 476                         " 0x%02x\n", cmd->scsi_status);
 477                 *post_ret = 1;
 478                 if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 479                         ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 480                 goto out;
 481         }
 482
 483         ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
 484                                        cmd->t_bidi_data_nents,
 485                                        cmd->t_data_sg,
 486                                        cmd->t_data_nents,
 487                                        compare_len,
 488                                        &miscmp_off);
 489         if (ret == TCM_MISCOMPARE_VERIFY) {
 490                 /*
 491                  * SBC-4 r15: 5.3 COMPARE AND WRITE command
 492                  * In the sense data (see 4.18 and SPC-5) the offset from the
 493                  * start of the Data-Out Buffer to the first byte of data that
 494                  * was not equal shall be reported in the INFORMATION field.
 495                  */
 496                 cmd->sense_info = miscmp_off;
 497                 goto out;
 498         } else if (ret)
 499                 goto out;
 500
 501         if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
 502                 pr_err("Unable to allocate compare_and_write sg\n");
 503                 ret = TCM_OUT_OF_RESOURCES;
 504                 goto out;
 505         }
 506         write_sg = write_tbl.sgl;
 507
 508         i = 0;
 509         len = compare_len;
 510         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 511         /*
 512          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 513          */
 514         while (len) {
 515                 sg_miter_next(&m);
 516
 517                 if (block_size < PAGE_SIZE) {
 518                         sg_set_page(&write_sg[i], m.page, block_size,
 519                                     m.piter.sg->offset + block_size);
 520                 } else {
 521                         sg_miter_next(&m);
 522                         sg_set_page(&write_sg[i], m.page, block_size,
 523                                     m.piter.sg->offset);
 524                 }
 525                 len -= block_size;
 526                 i++;
 527         }
 528         sg_miter_stop(&m);
 529         /*
 530          * Save the original SGL + nents values before updating to new
 531          * assignments, to be released in transport_free_pages() ->
 532          * transport_reset_sgl_orig()
 533          */
 534         cmd->t_data_sg_orig = cmd->t_data_sg;
 535         cmd->t_data_sg = write_sg;
 536         cmd->t_data_nents_orig = cmd->t_data_nents;
 537         cmd->t_data_nents = 1;
 538
 539         cmd->sam_task_attr = TCM_HEAD_TAG;
 540         cmd->transport_complete_callback = compare_and_write_post;
 541         /*
 542          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 543          * for submitting the adjusted SGL to write instance user-data.
 544          */
 545         cmd->execute_cmd = sbc_execute_rw;
 546
 547         spin_lock_irq(&cmd->t_state_lock);
 548         cmd->t_state = TRANSPORT_PROCESSING;
 549         cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 550         spin_unlock_irq(&cmd->t_state_lock);
 551
 552         __target_execute_cmd(cmd, false);
 553
 554         return ret;
 555
 556 out:
 557         /*
 558          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 559          * sbc_compare_and_write() before the original READ I/O submission.
 560          */
 561         up(&dev->caw_sem);
 562         sg_free_table(&write_tbl);
 563         return ret;
 564 }
 565
 566 static sense_reason_t
 567 sbc_compare_and_write(struct se_cmd *cmd)
 568 {
 569         struct sbc_ops *ops = cmd->protocol_data;
 570         struct se_device *dev = cmd->se_dev;
 571         sense_reason_t ret;
 572         int rc;
 573         /*
 574          * Submit the READ first for COMPARE_AND_WRITE to perform the
 575          * comparision using SGLs at cmd->t_bidi_data_sg..
 576          */
 577         rc = down_interruptible(&dev->caw_sem);
 578         if (rc != 0) {
 579                 cmd->transport_complete_callback = NULL;
 580                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 581         }
 582         /*
 583          * Reset cmd->data_length to individual block_size in order to not
 584          * confuse backend drivers that depend on this value matching the
 585          * size of the I/O being submitted.
 586          */
 587         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 588
 589         ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 590                               DMA_FROM_DEVICE);
 591         if (ret) {
 592                 cmd->transport_complete_callback = NULL;
 593                 up(&dev->caw_sem);
 594                 return ret;
 595         }
 596         /*
 597          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 598          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 599          * of WRITE instance user-data.
 600          */
 601         return TCM_NO_SENSE;
 602 }
 603
 604 static int
 605 sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 606                        bool is_write, struct se_cmd *cmd)
 607 {
 608         if (is_write) {
 609                 cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 610                                protect ? TARGET_PROT_DOUT_PASS :
 611                                TARGET_PROT_DOUT_INSERT;
 612                 switch (protect) {
 613                 case 0x0:
 614                 case 0x3:
 615                         cmd->prot_checks = 0;
 616                         break;
 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 0x4:
 628                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 629                         break;
 630                 default:
 631                         pr_err("Unsupported protect field %d\n", protect);
 632                         return -EINVAL;
 633                 }
 634         } else {
 635                 cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 636                                protect ? TARGET_PROT_DIN_PASS :
 637                                TARGET_PROT_DIN_STRIP;
 638                 switch (protect) {
 639                 case 0x0:
 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 0x3:
 651                         cmd->prot_checks = 0;
 652                         break;
 653                 case 0x4:
 654                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 655                         break;
 656                 default:
 657                         pr_err("Unsupported protect field %d\n", protect);
 658                         return -EINVAL;
 659                 }
 660         }
 661
 662         return 0;
 663 }
 664
 665 static sense_reason_t
 666 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 667                u32 sectors, bool is_write)
 668 {
 669         int sp_ops = cmd->se_sess->sup_prot_ops;
 670         int pi_prot_type = dev->dev_attrib.pi_prot_type;
 671         bool fabric_prot = false;
 672
 673         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 674                 if (unlikely(protect &&
 675                     !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 676                         pr_err("CDB contains protect bit, but device + fabric does"
 677                                " not advertise PROTECT=1 feature bit\n");
 678                         return TCM_INVALID_CDB_FIELD;
 679                 }
 680                 if (cmd->prot_pto)
 681                         return TCM_NO_SENSE;
 682         }
 683
 684         switch (dev->dev_attrib.pi_prot_type) {
 685         case TARGET_DIF_TYPE3_PROT:
 686                 cmd->reftag_seed = 0xffffffff;
 687                 break;
 688         case TARGET_DIF_TYPE2_PROT:
 689                 if (protect)
 690                         return TCM_INVALID_CDB_FIELD;
 691
 692                 cmd->reftag_seed = cmd->t_task_lba;
 693                 break;
 694         case TARGET_DIF_TYPE1_PROT:
 695                 cmd->reftag_seed = cmd->t_task_lba;
 696                 break;
 697         case TARGET_DIF_TYPE0_PROT:
 698                 /*
 699                  * See if the fabric supports T10-PI, and the session has been
 700                  * configured to allow export PROTECT=1 feature bit with backend
 701                  * devices that don't support T10-PI.
 702                  */
 703                 fabric_prot = is_write ?
 704                               !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 705                               !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 706
 707                 if (fabric_prot && cmd->se_sess->sess_prot_type) {
 708                         pi_prot_type = cmd->se_sess->sess_prot_type;
 709                         break;
 710                 }
 711                 if (!protect)
 712                         return TCM_NO_SENSE;
 713                 fallthrough;
 714         default:
 715                 pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 716                        "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 717                 return TCM_INVALID_CDB_FIELD;
 718         }
 719
 720         if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 721                 return TCM_INVALID_CDB_FIELD;
 722
 723         cmd->prot_type = pi_prot_type;
 724         cmd->prot_length = dev->prot_length * sectors;
 725
 726         /**
 727          * In case protection information exists over the wire
 728          * we modify command data length to describe pure data.
 729          * The actual transfer length is data length + protection
 730          * length
 731          **/
 732         if (protect)
 733                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 734
 735         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 736                  "prot_op=%d prot_checks=%d\n",
 737                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 738                  cmd->prot_op, cmd->prot_checks);
 739
 740         return TCM_NO_SENSE;
 741 }
 742
 743 static int
 744 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 745 {
 746         if (cdb[1] & 0x10) {
 747                 /* see explanation in spc_emulate_modesense */
 748                 if (!target_check_fua(dev)) {
 749                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 750                                " does not advertise support for DPO\n", cdb[0]);
 751                         return -EINVAL;
 752                 }
 753         }
 754         if (cdb[1] & 0x8) {
 755                 if (!target_check_fua(dev)) {
 756                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 757                                " does not advertise support for FUA write\n",
 758                                cdb[0]);
 759                         return -EINVAL;
 760                 }
 761                 cmd->se_cmd_flags |= SCF_FUA;
 762         }
 763         return 0;
 764 }
 765
 766 sense_reason_t
 767 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 768 {
 769         struct se_device *dev = cmd->se_dev;
 770         unsigned char *cdb = cmd->t_task_cdb;
 771         unsigned int size;
 772         u32 sectors = 0;
 773         sense_reason_t ret;
 774
 775         cmd->protocol_data = ops;
 776
 777         switch (cdb[0]) {
 778         case READ_6:
 779                 sectors = transport_get_sectors_6(cdb);
 780                 cmd->t_task_lba = transport_lba_21(cdb);
 781                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 782                 cmd->execute_cmd = sbc_execute_rw;
 783                 break;
 784         case READ_10:
 785                 sectors = transport_get_sectors_10(cdb);
 786                 cmd->t_task_lba = transport_lba_32(cdb);
 787
 788                 if (sbc_check_dpofua(dev, cmd, cdb))
 789                         return TCM_INVALID_CDB_FIELD;
 790
 791                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 792                 if (ret)
 793                         return ret;
 794
 795                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 796                 cmd->execute_cmd = sbc_execute_rw;
 797                 break;
 798         case READ_12:
 799                 sectors = transport_get_sectors_12(cdb);
 800                 cmd->t_task_lba = transport_lba_32(cdb);
 801
 802                 if (sbc_check_dpofua(dev, cmd, cdb))
 803                         return TCM_INVALID_CDB_FIELD;
 804
 805                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 806                 if (ret)
 807                         return ret;
 808
 809                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 810                 cmd->execute_cmd = sbc_execute_rw;
 811                 break;
 812         case READ_16:
 813                 sectors = transport_get_sectors_16(cdb);
 814                 cmd->t_task_lba = transport_lba_64(cdb);
 815
 816                 if (sbc_check_dpofua(dev, cmd, cdb))
 817                         return TCM_INVALID_CDB_FIELD;
 818
 819                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 820                 if (ret)
 821                         return ret;
 822
 823                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 824                 cmd->execute_cmd = sbc_execute_rw;
 825                 break;
 826         case WRITE_6:
 827                 sectors = transport_get_sectors_6(cdb);
 828                 cmd->t_task_lba = transport_lba_21(cdb);
 829                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 830                 cmd->execute_cmd = sbc_execute_rw;
 831                 break;
 832         case WRITE_10:
 833         case WRITE_VERIFY:
 834                 sectors = transport_get_sectors_10(cdb);
 835                 cmd->t_task_lba = transport_lba_32(cdb);
 836
 837                 if (sbc_check_dpofua(dev, cmd, cdb))
 838                         return TCM_INVALID_CDB_FIELD;
 839
 840                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 841                 if (ret)
 842                         return ret;
 843
 844                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 845                 cmd->execute_cmd = sbc_execute_rw;
 846                 break;
 847         case WRITE_12:
 848                 sectors = transport_get_sectors_12(cdb);
 849                 cmd->t_task_lba = transport_lba_32(cdb);
 850
 851                 if (sbc_check_dpofua(dev, cmd, cdb))
 852                         return TCM_INVALID_CDB_FIELD;
 853
 854                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 855                 if (ret)
 856                         return ret;
 857
 858                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 859                 cmd->execute_cmd = sbc_execute_rw;
 860                 break;
 861         case WRITE_16:
 862         case WRITE_VERIFY_16:
 863                 sectors = transport_get_sectors_16(cdb);
 864                 cmd->t_task_lba = transport_lba_64(cdb);
 865
 866                 if (sbc_check_dpofua(dev, cmd, cdb))
 867                         return TCM_INVALID_CDB_FIELD;
 868
 869                 ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 870                 if (ret)
 871                         return ret;
 872
 873                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 874                 cmd->execute_cmd = sbc_execute_rw;
 875                 break;
 876         case VARIABLE_LENGTH_CMD:
 877         {
 878                 u16 service_action = get_unaligned_be16(&cdb[8]);
 879                 switch (service_action) {
 880                 case WRITE_SAME_32:
 881                         sectors = transport_get_sectors_32(cdb);
 882                         if (!sectors) {
 883                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 884                                        " supported\n");
 885                                 return TCM_INVALID_CDB_FIELD;
 886                         }
 887
 888                         size = sbc_get_size(cmd, 1);
 889                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 890
 891                         ret = sbc_setup_write_same(cmd, cdb[10], ops);
 892                         if (ret)
 893                                 return ret;
 894                         break;
 895                 default:
 896                         pr_err("VARIABLE_LENGTH_CMD service action"
 897                                 " 0x%04x not supported\n", service_action);
 898                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 899                 }
 900                 break;
 901         }
 902         case COMPARE_AND_WRITE:
 903                 if (!dev->dev_attrib.emulate_caw) {
 904                         pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
 905                                            dev->se_hba->backend->ops->name,
 906                                            config_item_name(&dev->dev_group.cg_item),
 907                                            dev->t10_wwn.unit_serial);
 908                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 909                 }
 910                 sectors = cdb[13];
 911                 /*
 912                  * Currently enforce COMPARE_AND_WRITE for a single sector
 913                  */
 914                 if (sectors > 1) {
 915                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 916                                " than 1\n", sectors);
 917                         return TCM_INVALID_CDB_FIELD;
 918                 }
 919                 if (sbc_check_dpofua(dev, cmd, cdb))
 920                         return TCM_INVALID_CDB_FIELD;
 921
 922                 /*
 923                  * Double size because we have two buffers, note that
 924                  * zero is not an error..
 925                  */
 926                 size = 2 * sbc_get_size(cmd, sectors);
 927                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 928                 cmd->t_task_nolb = sectors;
 929                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 930                 cmd->execute_cmd = sbc_compare_and_write;
 931                 cmd->transport_complete_callback = compare_and_write_callback;
 932                 break;
 933         case READ_CAPACITY:
 934                 size = READ_CAP_LEN;
 935                 cmd->execute_cmd = sbc_emulate_readcapacity;
 936                 break;
 937         case SERVICE_ACTION_IN_16:
 938                 switch (cmd->t_task_cdb[1] & 0x1f) {
 939                 case SAI_READ_CAPACITY_16:
 940                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 941                         break;
 942                 case SAI_REPORT_REFERRALS:
 943                         cmd->execute_cmd = target_emulate_report_referrals;
 944                         break;
 945                 default:
 946                         pr_err("Unsupported SA: 0x%02x\n",
 947                                 cmd->t_task_cdb[1] & 0x1f);
 948                         return TCM_INVALID_CDB_FIELD;
 949                 }
 950                 size = get_unaligned_be32(&cdb[10]);
 951                 break;
 952         case SYNCHRONIZE_CACHE:
 953         case SYNCHRONIZE_CACHE_16:
 954                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 955                         sectors = transport_get_sectors_10(cdb);
 956                         cmd->t_task_lba = transport_lba_32(cdb);
 957                 } else {
 958                         sectors = transport_get_sectors_16(cdb);
 959                         cmd->t_task_lba = transport_lba_64(cdb);
 960                 }
 961                 if (ops->execute_sync_cache) {
 962                         cmd->execute_cmd = ops->execute_sync_cache;
 963                         goto check_lba;
 964                 }
 965                 size = 0;
 966                 cmd->execute_cmd = sbc_emulate_noop;
 967                 break;
 968         case UNMAP:
 969                 if (!ops->execute_unmap)
 970                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 971
 972                 if (!dev->dev_attrib.emulate_tpu) {
 973                         pr_err("Got UNMAP, but backend device has"
 974                                " emulate_tpu disabled\n");
 975                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 976                 }
 977                 size = get_unaligned_be16(&cdb[7]);
 978                 cmd->execute_cmd = sbc_execute_unmap;
 979                 break;
 980         case WRITE_SAME_16:
 981                 sectors = transport_get_sectors_16(cdb);
 982                 if (!sectors) {
 983                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 984                         return TCM_INVALID_CDB_FIELD;
 985                 }
 986
 987                 size = sbc_get_size(cmd, 1);
 988                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 989
 990                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
 991                 if (ret)
 992                         return ret;
 993                 break;
 994         case WRITE_SAME:
 995                 sectors = transport_get_sectors_10(cdb);
 996                 if (!sectors) {
 997                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 998                         return TCM_INVALID_CDB_FIELD;
 999                 }
1000
1001                 size = sbc_get_size(cmd, 1);
1002                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1003
1004                 /*
1005                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1006                  * of byte 1 bit 3 UNMAP instead of original reserved field
1007                  */
1008                 ret = sbc_setup_write_same(cmd, cdb[1], ops);
1009                 if (ret)
1010                         return ret;
1011                 break;
1012         case VERIFY:
1013         case VERIFY_16:
1014                 size = 0;
1015                 if (cdb[0] == VERIFY) {
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                 cmd->execute_cmd = sbc_emulate_noop;
1023                 goto check_lba;
1024         case REZERO_UNIT:
1025         case SEEK_6:
1026         case SEEK_10:
1027                 /*
1028                  * There are still clients out there which use these old SCSI-2
1029                  * commands. This mainly happens when running VMs with legacy
1030                  * guest systems, connected via SCSI command pass-through to
1031                  * iSCSI targets. Make them happy and return status GOOD.
1032                  */
1033                 size = 0;
1034                 cmd->execute_cmd = sbc_emulate_noop;
1035                 break;
1036         case START_STOP:
1037                 size = 0;
1038                 cmd->execute_cmd = sbc_emulate_startstop;
1039                 break;
1040         default:
1041                 ret = spc_parse_cdb(cmd, &size);
1042                 if (ret)
1043                         return ret;
1044         }
1045
1046         /* reject any command that we don't have a handler for */
1047         if (!cmd->execute_cmd)
1048                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1049
1050         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1051                 unsigned long long end_lba;
1052 check_lba:
1053                 end_lba = dev->transport->get_blocks(dev) + 1;
1054                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1055                     ((cmd->t_task_lba + sectors) > end_lba)) {
1056                         pr_err("cmd exceeds last lba %llu "
1057                                 "(lba %llu, sectors %u)\n",
1058                                 end_lba, cmd->t_task_lba, sectors);
1059                         return TCM_ADDRESS_OUT_OF_RANGE;
1060                 }
1061
1062                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1063                         size = sbc_get_size(cmd, sectors);
1064         }
1065
1066         return target_cmd_size_check(cmd, size);
1067 }
1068 EXPORT_SYMBOL(sbc_parse_cdb);
1069
1070 u32 sbc_get_device_type(struct se_device *dev)
1071 {
1072         return TYPE_DISK;
1073 }
1074 EXPORT_SYMBOL(sbc_get_device_type);
1075
1076 static sense_reason_t
1077 sbc_execute_unmap(struct se_cmd *cmd)
1078 {
1079         struct sbc_ops *ops = cmd->protocol_data;
1080         struct se_device *dev = cmd->se_dev;
1081         unsigned char *buf, *ptr = NULL;
1082         sector_t lba;
1083         int size;
1084         u32 range;
1085         sense_reason_t ret = 0;
1086         int dl, bd_dl;
1087
1088         /* We never set ANC_SUP */
1089         if (cmd->t_task_cdb[1])
1090                 return TCM_INVALID_CDB_FIELD;
1091
1092         if (cmd->data_length == 0) {
1093                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1094                 return 0;
1095         }
1096
1097         if (cmd->data_length < 8) {
1098                 pr_warn("UNMAP parameter list length %u too small\n",
1099                         cmd->data_length);
1100                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1101         }
1102
1103         buf = transport_kmap_data_sg(cmd);
1104         if (!buf)
1105                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1106
1107         dl = get_unaligned_be16(&buf[0]);
1108         bd_dl = get_unaligned_be16(&buf[2]);
1109
1110         size = cmd->data_length - 8;
1111         if (bd_dl > size)
1112                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1113                         cmd->data_length, bd_dl);
1114         else
1115                 size = bd_dl;
1116
1117         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1118                 ret = TCM_INVALID_PARAMETER_LIST;
1119                 goto err;
1120         }
1121
1122         /* First UNMAP block descriptor starts at 8 byte offset */
1123         ptr = &buf[8];
1124         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1125                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1126
1127         while (size >= 16) {
1128                 lba = get_unaligned_be64(&ptr[0]);
1129                 range = get_unaligned_be32(&ptr[8]);
1130                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1131                                  (unsigned long long)lba, range);
1132
1133                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1134                         ret = TCM_INVALID_PARAMETER_LIST;
1135                         goto err;
1136                 }
1137
1138                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1139                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1140                         goto err;
1141                 }
1142
1143                 if (range) {
1144                         ret = ops->execute_unmap(cmd, lba, range);
1145                         if (ret)
1146                                 goto err;
1147                 }
1148
1149                 ptr += 16;
1150                 size -= 16;
1151         }
1152
1153 err:
1154         transport_kunmap_data_sg(cmd);
1155         if (!ret)
1156                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1157         return ret;
1158 }
1159
1160 void
1161 sbc_dif_generate(struct se_cmd *cmd)
1162 {
1163         struct se_device *dev = cmd->se_dev;
1164         struct t10_pi_tuple *sdt;
1165         struct scatterlist *dsg = cmd->t_data_sg, *psg;
1166         sector_t sector = cmd->t_task_lba;
1167         void *daddr, *paddr;
1168         int i, j, offset = 0;
1169         unsigned int block_size = dev->dev_attrib.block_size;
1170
1171         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1172                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1173                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1174
1175                 for (j = 0; j < psg->length;
1176                                 j += sizeof(*sdt)) {
1177                         __u16 crc;
1178                         unsigned int avail;
1179
1180                         if (offset >= dsg->length) {
1181                                 offset -= dsg->length;
1182                                 kunmap_atomic(daddr - dsg->offset);
1183                                 dsg = sg_next(dsg);
1184                                 if (!dsg) {
1185                                         kunmap_atomic(paddr - psg->offset);
1186                                         return;
1187                                 }
1188                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1189                         }
1190
1191                         sdt = paddr + j;
1192                         avail = min(block_size, dsg->length - offset);
1193                         crc = crc_t10dif(daddr + offset, avail);
1194                         if (avail < block_size) {
1195                                 kunmap_atomic(daddr - dsg->offset);
1196                                 dsg = sg_next(dsg);
1197                                 if (!dsg) {
1198                                         kunmap_atomic(paddr - psg->offset);
1199                                         return;
1200                                 }
1201                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1202                                 offset = block_size - avail;
1203                                 crc = crc_t10dif_update(crc, daddr, offset);
1204                         } else {
1205                                 offset += block_size;
1206                         }
1207
1208                         sdt->guard_tag = cpu_to_be16(crc);
1209                         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1210                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1211                         sdt->app_tag = 0;
1212
1213                         pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1214                                  " app_tag: 0x%04x ref_tag: %u\n",
1215                                  (cmd->data_direction == DMA_TO_DEVICE) ?
1216                                  "WRITE" : "READ", (unsigned long long)sector,
1217                                  sdt->guard_tag, sdt->app_tag,
1218                                  be32_to_cpu(sdt->ref_tag));
1219
1220                         sector++;
1221                 }
1222
1223                 kunmap_atomic(daddr - dsg->offset);
1224                 kunmap_atomic(paddr - psg->offset);
1225         }
1226 }
1227
1228 static sense_reason_t
1229 sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1230                   __u16 crc, sector_t sector, unsigned int ei_lba)
1231 {
1232         __be16 csum;
1233
1234         if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1235                 goto check_ref;
1236
1237         csum = cpu_to_be16(crc);
1238
1239         if (sdt->guard_tag != csum) {
1240                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1241                         " csum 0x%04x\n", (unsigned long long)sector,
1242                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1243                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1244         }
1245
1246 check_ref:
1247         if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1248                 return 0;
1249
1250         if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1251             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1252                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1253                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1254                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1255                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1256         }
1257
1258         if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1259             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1260                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1261                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1262                         be32_to_cpu(sdt->ref_tag), ei_lba);
1263                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1264         }
1265
1266         return 0;
1267 }
1268
1269 void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1270                        struct scatterlist *sg, int sg_off)
1271 {
1272         struct se_device *dev = cmd->se_dev;
1273         struct scatterlist *psg;
1274         void *paddr, *addr;
1275         unsigned int i, len, left;
1276         unsigned int offset = sg_off;
1277
1278         if (!sg)
1279                 return;
1280
1281         left = sectors * dev->prot_length;
1282
1283         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1284                 unsigned int psg_len, copied = 0;
1285
1286                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1287                 psg_len = min(left, psg->length);
1288                 while (psg_len) {
1289                         len = min(psg_len, sg->length - offset);
1290                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1291
1292                         if (read)
1293                                 memcpy(paddr + copied, addr, len);
1294                         else
1295                                 memcpy(addr, paddr + copied, len);
1296
1297                         left -= len;
1298                         offset += len;
1299                         copied += len;
1300                         psg_len -= len;
1301
1302                         kunmap_atomic(addr - sg->offset - offset);
1303
1304                         if (offset >= sg->length) {
1305                                 sg = sg_next(sg);
1306                                 offset = 0;
1307                         }
1308                 }
1309                 kunmap_atomic(paddr - psg->offset);
1310         }
1311 }
1312 EXPORT_SYMBOL(sbc_dif_copy_prot);
1313
1314 sense_reason_t
1315 sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1316                unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1317 {
1318         struct se_device *dev = cmd->se_dev;
1319         struct t10_pi_tuple *sdt;
1320         struct scatterlist *dsg = cmd->t_data_sg;
1321         sector_t sector = start;
1322         void *daddr, *paddr;
1323         int i;
1324         sense_reason_t rc;
1325         int dsg_off = 0;
1326         unsigned int block_size = dev->dev_attrib.block_size;
1327
1328         for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1329                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1330                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1331
1332                 for (i = psg_off; i < psg->length &&
1333                                 sector < start + sectors;
1334                                 i += sizeof(*sdt)) {
1335                         __u16 crc;
1336                         unsigned int avail;
1337
1338                         if (dsg_off >= dsg->length) {
1339                                 dsg_off -= dsg->length;
1340                                 kunmap_atomic(daddr - dsg->offset);
1341                                 dsg = sg_next(dsg);
1342                                 if (!dsg) {
1343                                         kunmap_atomic(paddr - psg->offset);
1344                                         return 0;
1345                                 }
1346                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1347                         }
1348
1349                         sdt = paddr + i;
1350
1351                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1352                                  " app_tag: 0x%04x ref_tag: %u\n",
1353                                  (unsigned long long)sector, sdt->guard_tag,
1354                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1355
1356                         if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1357                                 dsg_off += block_size;
1358                                 goto next;
1359                         }
1360
1361                         avail = min(block_size, dsg->length - dsg_off);
1362                         crc = crc_t10dif(daddr + dsg_off, avail);
1363                         if (avail < block_size) {
1364                                 kunmap_atomic(daddr - dsg->offset);
1365                                 dsg = sg_next(dsg);
1366                                 if (!dsg) {
1367                                         kunmap_atomic(paddr - psg->offset);
1368                                         return 0;
1369                                 }
1370                                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1371                                 dsg_off = block_size - avail;
1372                                 crc = crc_t10dif_update(crc, daddr, dsg_off);
1373                         } else {
1374                                 dsg_off += block_size;
1375                         }
1376
1377                         rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1378                         if (rc) {
1379                                 kunmap_atomic(daddr - dsg->offset);
1380                                 kunmap_atomic(paddr - psg->offset);
1381                                 cmd->sense_info = sector;
1382                                 return rc;
1383                         }
1384 next:
1385                         sector++;
1386                         ei_lba++;
1387                 }
1388
1389                 psg_off = 0;
1390                 kunmap_atomic(daddr - dsg->offset);
1391                 kunmap_atomic(paddr - psg->offset);
1392         }
1393
1394         return 0;
1395 }
1396 EXPORT_SYMBOL(sbc_dif_verify);