drivers/target/target_core_sbc.c

   1 /*
   2  * SCSI Block Commands (SBC) parsing and emulation.
   3  *
   4  * (c) Copyright 2002-2013 Datera, Inc.
   5  *
   6  * Nicholas A. Bellinger <nab@kernel.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/ratelimit.h>
  26 #include <linux/crc-t10dif.h>
  27 #include <asm/unaligned.h>
  28 #include <scsi/scsi.h>
  29 #include <scsi/scsi_tcq.h>
  30
  31 #include <target/target_core_base.h>
  32 #include <target/target_core_backend.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "target_core_internal.h"
  36 #include "target_core_ua.h"
  37 #include "target_core_alua.h"
  38
  39 static sense_reason_t
  40 sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
  41
  42 static sense_reason_t
  43 sbc_emulate_readcapacity(struct se_cmd *cmd)
  44 {
  45         struct se_device *dev = cmd->se_dev;
  46         unsigned char *cdb = cmd->t_task_cdb;
  47         unsigned long long blocks_long = dev->transport->get_blocks(dev);
  48         unsigned char *rbuf;
  49         unsigned char buf[8];
  50         u32 blocks;
  51
  52         /*
  53          * SBC-2 says:
  54          *   If the PMI bit is set to zero and the LOGICAL BLOCK
  55          *   ADDRESS field is not set to zero, the device server shall
  56          *   terminate the command with CHECK CONDITION status with
  57          *   the sense key set to ILLEGAL REQUEST and the additional
  58          *   sense code set to INVALID FIELD IN CDB.
  59          *
  60          * In SBC-3, these fields are obsolete, but some SCSI
  61          * compliance tests actually check this, so we might as well
  62          * follow SBC-2.
  63          */
  64         if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  65                 return TCM_INVALID_CDB_FIELD;
  66
  67         if (blocks_long >= 0x00000000ffffffff)
  68                 blocks = 0xffffffff;
  69         else
  70                 blocks = (u32)blocks_long;
  71
  72         buf[0] = (blocks >> 24) & 0xff;
  73         buf[1] = (blocks >> 16) & 0xff;
  74         buf[2] = (blocks >> 8) & 0xff;
  75         buf[3] = blocks & 0xff;
  76         buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  77         buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  78         buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  79         buf[7] = dev->dev_attrib.block_size & 0xff;
  80
  81         rbuf = transport_kmap_data_sg(cmd);
  82         if (rbuf) {
  83                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  84                 transport_kunmap_data_sg(cmd);
  85         }
  86
  87         target_complete_cmd_with_length(cmd, GOOD, 8);
  88         return 0;
  89 }
  90
  91 static sense_reason_t
  92 sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  93 {
  94         struct se_device *dev = cmd->se_dev;
  95         struct se_session *sess = cmd->se_sess;
  96         unsigned char *rbuf;
  97         unsigned char buf[32];
  98         unsigned long long blocks = dev->transport->get_blocks(dev);
  99
 100         memset(buf, 0, sizeof(buf));
 101         buf[0] = (blocks >> 56) & 0xff;
 102         buf[1] = (blocks >> 48) & 0xff;
 103         buf[2] = (blocks >> 40) & 0xff;
 104         buf[3] = (blocks >> 32) & 0xff;
 105         buf[4] = (blocks >> 24) & 0xff;
 106         buf[5] = (blocks >> 16) & 0xff;
 107         buf[6] = (blocks >> 8) & 0xff;
 108         buf[7] = blocks & 0xff;
 109         buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 110         buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 111         buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 112         buf[11] = dev->dev_attrib.block_size & 0xff;
 113         /*
 114          * Set P_TYPE and PROT_EN bits for DIF support
 115          */
 116         if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 117                 if (dev->dev_attrib.pi_prot_type)
 118                         buf[12] = (dev->dev_attrib.pi_prot_type - 1) << 1 | 0x1;
 119         }
 120
 121         if (dev->transport->get_lbppbe)
 122                 buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 123
 124         if (dev->transport->get_alignment_offset_lbas) {
 125                 u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 126                 buf[14] = (lalba >> 8) & 0x3f;
 127                 buf[15] = lalba & 0xff;
 128         }
 129
 130         /*
 131          * Set Thin Provisioning Enable bit following sbc3r22 in section
 132          * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 133          */
 134         if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
 135                 buf[14] |= 0x80;
 136
 137         rbuf = transport_kmap_data_sg(cmd);
 138         if (rbuf) {
 139                 memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 140                 transport_kunmap_data_sg(cmd);
 141         }
 142
 143         target_complete_cmd_with_length(cmd, GOOD, 32);
 144         return 0;
 145 }
 146
 147 sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 148 {
 149         u32 num_blocks;
 150
 151         if (cmd->t_task_cdb[0] == WRITE_SAME)
 152                 num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 153         else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 154                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 155         else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 156                 num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 157
 158         /*
 159          * Use the explicit range when non zero is supplied, otherwise calculate
 160          * the remaining range based on ->get_blocks() - starting LBA.
 161          */
 162         if (num_blocks)
 163                 return num_blocks;
 164
 165         return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 166                 cmd->t_task_lba + 1;
 167 }
 168 EXPORT_SYMBOL(sbc_get_write_same_sectors);
 169
 170 static sense_reason_t
 171 sbc_emulate_noop(struct se_cmd *cmd)
 172 {
 173         target_complete_cmd(cmd, GOOD);
 174         return 0;
 175 }
 176
 177 static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 178 {
 179         return cmd->se_dev->dev_attrib.block_size * sectors;
 180 }
 181
 182 static inline u32 transport_get_sectors_6(unsigned char *cdb)
 183 {
 184         /*
 185          * Use 8-bit sector value.  SBC-3 says:
 186          *
 187          *   A TRANSFER LENGTH field set to zero specifies that 256
 188          *   logical blocks shall be written.  Any other value
 189          *   specifies the number of logical blocks that shall be
 190          *   written.
 191          */
 192         return cdb[4] ? : 256;
 193 }
 194
 195 static inline u32 transport_get_sectors_10(unsigned char *cdb)
 196 {
 197         return (u32)(cdb[7] << 8) + cdb[8];
 198 }
 199
 200 static inline u32 transport_get_sectors_12(unsigned char *cdb)
 201 {
 202         return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 203 }
 204
 205 static inline u32 transport_get_sectors_16(unsigned char *cdb)
 206 {
 207         return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 208                     (cdb[12] << 8) + cdb[13];
 209 }
 210
 211 /*
 212  * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 213  */
 214 static inline u32 transport_get_sectors_32(unsigned char *cdb)
 215 {
 216         return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 217                     (cdb[30] << 8) + cdb[31];
 218
 219 }
 220
 221 static inline u32 transport_lba_21(unsigned char *cdb)
 222 {
 223         return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 224 }
 225
 226 static inline u32 transport_lba_32(unsigned char *cdb)
 227 {
 228         return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 229 }
 230
 231 static inline unsigned long long transport_lba_64(unsigned char *cdb)
 232 {
 233         unsigned int __v1, __v2;
 234
 235         __v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 236         __v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 237
 238         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 239 }
 240
 241 /*
 242  * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 243  */
 244 static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 245 {
 246         unsigned int __v1, __v2;
 247
 248         __v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 249         __v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 250
 251         return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 252 }
 253
 254 static sense_reason_t
 255 sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 256 {
 257         struct se_device *dev = cmd->se_dev;
 258         sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 259         unsigned int sectors = sbc_get_write_same_sectors(cmd);
 260         sense_reason_t ret;
 261
 262         if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 263                 pr_err("WRITE_SAME PBDATA and LBDATA"
 264                         " bits not supported for Block Discard"
 265                         " Emulation\n");
 266                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 267         }
 268         if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 269                 pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 270                         sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 271                 return TCM_INVALID_CDB_FIELD;
 272         }
 273         /*
 274          * Sanity check for LBA wrap and request past end of device.
 275          */
 276         if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 277             ((cmd->t_task_lba + sectors) > end_lba)) {
 278                 pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 279                        (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 280                 return TCM_ADDRESS_OUT_OF_RANGE;
 281         }
 282
 283         /* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 284         if (flags[0] & 0x10) {
 285                 pr_warn("WRITE SAME with ANCHOR not supported\n");
 286                 return TCM_INVALID_CDB_FIELD;
 287         }
 288         /*
 289          * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 290          * translated into block discard requests within backend code.
 291          */
 292         if (flags[0] & 0x08) {
 293                 if (!ops->execute_write_same_unmap)
 294                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 295
 296                 if (!dev->dev_attrib.emulate_tpws) {
 297                         pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 298                                " has emulate_tpws disabled\n");
 299                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 300                 }
 301                 cmd->execute_cmd = ops->execute_write_same_unmap;
 302                 return 0;
 303         }
 304         if (!ops->execute_write_same)
 305                 return TCM_UNSUPPORTED_SCSI_OPCODE;
 306
 307         ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 308         if (ret)
 309                 return ret;
 310
 311         cmd->execute_cmd = ops->execute_write_same;
 312         return 0;
 313 }
 314
 315 static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
 316 {
 317         unsigned char *buf, *addr;
 318         struct scatterlist *sg;
 319         unsigned int offset;
 320         sense_reason_t ret = TCM_NO_SENSE;
 321         int i, count;
 322         /*
 323          * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 324          *
 325          * 1) read the specified logical block(s);
 326          * 2) transfer logical blocks from the data-out buffer;
 327          * 3) XOR the logical blocks transferred from the data-out buffer with
 328          *    the logical blocks read, storing the resulting XOR data in a buffer;
 329          * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 330          *    blocks transferred from the data-out buffer; and
 331          * 5) transfer the resulting XOR data to the data-in buffer.
 332          */
 333         buf = kmalloc(cmd->data_length, GFP_KERNEL);
 334         if (!buf) {
 335                 pr_err("Unable to allocate xor_callback buf\n");
 336                 return TCM_OUT_OF_RESOURCES;
 337         }
 338         /*
 339          * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 340          * into the locally allocated *buf
 341          */
 342         sg_copy_to_buffer(cmd->t_data_sg,
 343                           cmd->t_data_nents,
 344                           buf,
 345                           cmd->data_length);
 346
 347         /*
 348          * Now perform the XOR against the BIDI read memory located at
 349          * cmd->t_mem_bidi_list
 350          */
 351
 352         offset = 0;
 353         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 354                 addr = kmap_atomic(sg_page(sg));
 355                 if (!addr) {
 356                         ret = TCM_OUT_OF_RESOURCES;
 357                         goto out;
 358                 }
 359
 360                 for (i = 0; i < sg->length; i++)
 361                         *(addr + sg->offset + i) ^= *(buf + offset + i);
 362
 363                 offset += sg->length;
 364                 kunmap_atomic(addr);
 365         }
 366
 367 out:
 368         kfree(buf);
 369         return ret;
 370 }
 371
 372 static sense_reason_t
 373 sbc_execute_rw(struct se_cmd *cmd)
 374 {
 375         return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 376                                cmd->data_direction);
 377 }
 378
 379 static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
 380 {
 381         struct se_device *dev = cmd->se_dev;
 382
 383         /*
 384          * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 385          * within target_complete_ok_work() if the command was successfully
 386          * sent to the backend driver.
 387          */
 388         spin_lock_irq(&cmd->t_state_lock);
 389         if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status)
 390                 cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 391         spin_unlock_irq(&cmd->t_state_lock);
 392
 393         /*
 394          * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 395          * before the original READ I/O submission.
 396          */
 397         up(&dev->caw_sem);
 398
 399         return TCM_NO_SENSE;
 400 }
 401
 402 static sense_reason_t compare_and_write_callback(struct se_cmd *cmd)
 403 {
 404         struct se_device *dev = cmd->se_dev;
 405         struct scatterlist *write_sg = NULL, *sg;
 406         unsigned char *buf = NULL, *addr;
 407         struct sg_mapping_iter m;
 408         unsigned int offset = 0, len;
 409         unsigned int nlbas = cmd->t_task_nolb;
 410         unsigned int block_size = dev->dev_attrib.block_size;
 411         unsigned int compare_len = (nlbas * block_size);
 412         sense_reason_t ret = TCM_NO_SENSE;
 413         int rc, i;
 414
 415         /*
 416          * Handle early failure in transport_generic_request_failure(),
 417          * which will not have taken ->caw_mutex yet..
 418          */
 419         if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 420                 return TCM_NO_SENSE;
 421         /*
 422          * Immediately exit + release dev->caw_sem if command has already
 423          * been failed with a non-zero SCSI status.
 424          */
 425         if (cmd->scsi_status) {
 426                 pr_err("compare_and_write_callback: non zero scsi_status:"
 427                         " 0x%02x\n", cmd->scsi_status);
 428                 goto out;
 429         }
 430
 431         buf = kzalloc(cmd->data_length, GFP_KERNEL);
 432         if (!buf) {
 433                 pr_err("Unable to allocate compare_and_write buf\n");
 434                 ret = TCM_OUT_OF_RESOURCES;
 435                 goto out;
 436         }
 437
 438         write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 439                            GFP_KERNEL);
 440         if (!write_sg) {
 441                 pr_err("Unable to allocate compare_and_write sg\n");
 442                 ret = TCM_OUT_OF_RESOURCES;
 443                 goto out;
 444         }
 445         sg_init_table(write_sg, cmd->t_data_nents);
 446         /*
 447          * Setup verify and write data payloads from total NumberLBAs.
 448          */
 449         rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 450                                cmd->data_length);
 451         if (!rc) {
 452                 pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 453                 ret = TCM_OUT_OF_RESOURCES;
 454                 goto out;
 455         }
 456         /*
 457          * Compare against SCSI READ payload against verify payload
 458          */
 459         for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 460                 addr = (unsigned char *)kmap_atomic(sg_page(sg));
 461                 if (!addr) {
 462                         ret = TCM_OUT_OF_RESOURCES;
 463                         goto out;
 464                 }
 465
 466                 len = min(sg->length, compare_len);
 467
 468                 if (memcmp(addr, buf + offset, len)) {
 469                         pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 470                                 addr, buf + offset);
 471                         kunmap_atomic(addr);
 472                         goto miscompare;
 473                 }
 474                 kunmap_atomic(addr);
 475
 476                 offset += len;
 477                 compare_len -= len;
 478                 if (!compare_len)
 479                         break;
 480         }
 481
 482         i = 0;
 483         len = cmd->t_task_nolb * block_size;
 484         sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 485         /*
 486          * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 487          */
 488         while (len) {
 489                 sg_miter_next(&m);
 490
 491                 if (block_size < PAGE_SIZE) {
 492                         sg_set_page(&write_sg[i], m.page, block_size,
 493                                     block_size);
 494                 } else {
 495                         sg_miter_next(&m);
 496                         sg_set_page(&write_sg[i], m.page, block_size,
 497                                     0);
 498                 }
 499                 len -= block_size;
 500                 i++;
 501         }
 502         sg_miter_stop(&m);
 503         /*
 504          * Save the original SGL + nents values before updating to new
 505          * assignments, to be released in transport_free_pages() ->
 506          * transport_reset_sgl_orig()
 507          */
 508         cmd->t_data_sg_orig = cmd->t_data_sg;
 509         cmd->t_data_sg = write_sg;
 510         cmd->t_data_nents_orig = cmd->t_data_nents;
 511         cmd->t_data_nents = 1;
 512
 513         cmd->sam_task_attr = TCM_HEAD_TAG;
 514         cmd->transport_complete_callback = compare_and_write_post;
 515         /*
 516          * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 517          * for submitting the adjusted SGL to write instance user-data.
 518          */
 519         cmd->execute_cmd = sbc_execute_rw;
 520
 521         spin_lock_irq(&cmd->t_state_lock);
 522         cmd->t_state = TRANSPORT_PROCESSING;
 523         cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 524         spin_unlock_irq(&cmd->t_state_lock);
 525
 526         __target_execute_cmd(cmd);
 527
 528         kfree(buf);
 529         return ret;
 530
 531 miscompare:
 532         pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 533                 dev->transport->name);
 534         ret = TCM_MISCOMPARE_VERIFY;
 535 out:
 536         /*
 537          * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 538          * sbc_compare_and_write() before the original READ I/O submission.
 539          */
 540         up(&dev->caw_sem);
 541         kfree(write_sg);
 542         kfree(buf);
 543         return ret;
 544 }
 545
 546 static sense_reason_t
 547 sbc_compare_and_write(struct se_cmd *cmd)
 548 {
 549         struct se_device *dev = cmd->se_dev;
 550         sense_reason_t ret;
 551         int rc;
 552         /*
 553          * Submit the READ first for COMPARE_AND_WRITE to perform the
 554          * comparision using SGLs at cmd->t_bidi_data_sg..
 555          */
 556         rc = down_interruptible(&dev->caw_sem);
 557         if ((rc != 0) || signal_pending(current)) {
 558                 cmd->transport_complete_callback = NULL;
 559                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 560         }
 561         /*
 562          * Reset cmd->data_length to individual block_size in order to not
 563          * confuse backend drivers that depend on this value matching the
 564          * size of the I/O being submitted.
 565          */
 566         cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 567
 568         ret = cmd->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 569                               DMA_FROM_DEVICE);
 570         if (ret) {
 571                 cmd->transport_complete_callback = NULL;
 572                 up(&dev->caw_sem);
 573                 return ret;
 574         }
 575         /*
 576          * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 577          * upon MISCOMPARE, or in compare_and_write_done() upon completion
 578          * of WRITE instance user-data.
 579          */
 580         return TCM_NO_SENSE;
 581 }
 582
 583 static int
 584 sbc_set_prot_op_checks(u8 protect, enum target_prot_type prot_type,
 585                        bool is_write, struct se_cmd *cmd)
 586 {
 587         if (is_write) {
 588                 cmd->prot_op = protect ? TARGET_PROT_DOUT_PASS :
 589                                          TARGET_PROT_DOUT_INSERT;
 590                 switch (protect) {
 591                 case 0x0:
 592                 case 0x3:
 593                         cmd->prot_checks = 0;
 594                         break;
 595                 case 0x1:
 596                 case 0x5:
 597                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 598                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 599                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 600                         break;
 601                 case 0x2:
 602                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 603                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 604                         break;
 605                 case 0x4:
 606                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 607                         break;
 608                 default:
 609                         pr_err("Unsupported protect field %d\n", protect);
 610                         return -EINVAL;
 611                 }
 612         } else {
 613                 cmd->prot_op = protect ? TARGET_PROT_DIN_PASS :
 614                                          TARGET_PROT_DIN_STRIP;
 615                 switch (protect) {
 616                 case 0x0:
 617                 case 0x1:
 618                 case 0x5:
 619                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 620                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 621                                 cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 622                         break;
 623                 case 0x2:
 624                         if (prot_type == TARGET_DIF_TYPE1_PROT)
 625                                 cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 626                         break;
 627                 case 0x3:
 628                         cmd->prot_checks = 0;
 629                         break;
 630                 case 0x4:
 631                         cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 632                         break;
 633                 default:
 634                         pr_err("Unsupported protect field %d\n", protect);
 635                         return -EINVAL;
 636                 }
 637         }
 638
 639         return 0;
 640 }
 641
 642 static sense_reason_t
 643 sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 644                u32 sectors, bool is_write)
 645 {
 646         u8 protect = cdb[1] >> 5;
 647
 648         if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 649                 if (protect && !dev->dev_attrib.pi_prot_type) {
 650                         pr_err("CDB contains protect bit, but device does not"
 651                                " advertise PROTECT=1 feature bit\n");
 652                         return TCM_INVALID_CDB_FIELD;
 653                 }
 654                 if (cmd->prot_pto)
 655                         return TCM_NO_SENSE;
 656         }
 657
 658         switch (dev->dev_attrib.pi_prot_type) {
 659         case TARGET_DIF_TYPE3_PROT:
 660                 cmd->reftag_seed = 0xffffffff;
 661                 break;
 662         case TARGET_DIF_TYPE2_PROT:
 663                 if (protect)
 664                         return TCM_INVALID_CDB_FIELD;
 665
 666                 cmd->reftag_seed = cmd->t_task_lba;
 667                 break;
 668         case TARGET_DIF_TYPE1_PROT:
 669                 cmd->reftag_seed = cmd->t_task_lba;
 670                 break;
 671         case TARGET_DIF_TYPE0_PROT:
 672         default:
 673                 return TCM_NO_SENSE;
 674         }
 675
 676         if (sbc_set_prot_op_checks(protect, dev->dev_attrib.pi_prot_type,
 677                                    is_write, cmd))
 678                 return TCM_INVALID_CDB_FIELD;
 679
 680         cmd->prot_type = dev->dev_attrib.pi_prot_type;
 681         cmd->prot_length = dev->prot_length * sectors;
 682
 683         /**
 684          * In case protection information exists over the wire
 685          * we modify command data length to describe pure data.
 686          * The actual transfer length is data length + protection
 687          * length
 688          **/
 689         if (protect)
 690                 cmd->data_length = sectors * dev->dev_attrib.block_size;
 691
 692         pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 693                  "prot_op=%d prot_checks=%d\n",
 694                  __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 695                  cmd->prot_op, cmd->prot_checks);
 696
 697         return TCM_NO_SENSE;
 698 }
 699
 700 static int
 701 sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 702 {
 703         if (cdb[1] & 0x10) {
 704                 if (!dev->dev_attrib.emulate_dpo) {
 705                         pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 706                                " does not advertise support for DPO\n", cdb[0]);
 707                         return -EINVAL;
 708                 }
 709         }
 710         if (cdb[1] & 0x8) {
 711                 if (!dev->dev_attrib.emulate_fua_write ||
 712                     !dev->dev_attrib.emulate_write_cache) {
 713                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 714                                " does not advertise support for FUA write\n",
 715                                cdb[0]);
 716                         return -EINVAL;
 717                 }
 718                 cmd->se_cmd_flags |= SCF_FUA;
 719         }
 720         return 0;
 721 }
 722
 723 sense_reason_t
 724 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 725 {
 726         struct se_device *dev = cmd->se_dev;
 727         unsigned char *cdb = cmd->t_task_cdb;
 728         unsigned int size;
 729         u32 sectors = 0;
 730         sense_reason_t ret;
 731
 732         switch (cdb[0]) {
 733         case READ_6:
 734                 sectors = transport_get_sectors_6(cdb);
 735                 cmd->t_task_lba = transport_lba_21(cdb);
 736                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 737                 cmd->execute_rw = ops->execute_rw;
 738                 cmd->execute_cmd = sbc_execute_rw;
 739                 break;
 740         case READ_10:
 741                 sectors = transport_get_sectors_10(cdb);
 742                 cmd->t_task_lba = transport_lba_32(cdb);
 743
 744                 if (sbc_check_dpofua(dev, cmd, cdb))
 745                         return TCM_INVALID_CDB_FIELD;
 746
 747                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 748                 if (ret)
 749                         return ret;
 750
 751                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 752                 cmd->execute_rw = ops->execute_rw;
 753                 cmd->execute_cmd = sbc_execute_rw;
 754                 break;
 755         case READ_12:
 756                 sectors = transport_get_sectors_12(cdb);
 757                 cmd->t_task_lba = transport_lba_32(cdb);
 758
 759                 if (sbc_check_dpofua(dev, cmd, cdb))
 760                         return TCM_INVALID_CDB_FIELD;
 761
 762                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 763                 if (ret)
 764                         return ret;
 765
 766                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 767                 cmd->execute_rw = ops->execute_rw;
 768                 cmd->execute_cmd = sbc_execute_rw;
 769                 break;
 770         case READ_16:
 771                 sectors = transport_get_sectors_16(cdb);
 772                 cmd->t_task_lba = transport_lba_64(cdb);
 773
 774                 if (sbc_check_dpofua(dev, cmd, cdb))
 775                         return TCM_INVALID_CDB_FIELD;
 776
 777                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 778                 if (ret)
 779                         return ret;
 780
 781                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 782                 cmd->execute_rw = ops->execute_rw;
 783                 cmd->execute_cmd = sbc_execute_rw;
 784                 break;
 785         case WRITE_6:
 786                 sectors = transport_get_sectors_6(cdb);
 787                 cmd->t_task_lba = transport_lba_21(cdb);
 788                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 789                 cmd->execute_rw = ops->execute_rw;
 790                 cmd->execute_cmd = sbc_execute_rw;
 791                 break;
 792         case WRITE_10:
 793         case WRITE_VERIFY:
 794                 sectors = transport_get_sectors_10(cdb);
 795                 cmd->t_task_lba = transport_lba_32(cdb);
 796
 797                 if (sbc_check_dpofua(dev, cmd, cdb))
 798                         return TCM_INVALID_CDB_FIELD;
 799
 800                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 801                 if (ret)
 802                         return ret;
 803
 804                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 805                 cmd->execute_rw = ops->execute_rw;
 806                 cmd->execute_cmd = sbc_execute_rw;
 807                 break;
 808         case WRITE_12:
 809                 sectors = transport_get_sectors_12(cdb);
 810                 cmd->t_task_lba = transport_lba_32(cdb);
 811
 812                 if (sbc_check_dpofua(dev, cmd, cdb))
 813                         return TCM_INVALID_CDB_FIELD;
 814
 815                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 816                 if (ret)
 817                         return ret;
 818
 819                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 820                 cmd->execute_rw = ops->execute_rw;
 821                 cmd->execute_cmd = sbc_execute_rw;
 822                 break;
 823         case WRITE_16:
 824                 sectors = transport_get_sectors_16(cdb);
 825                 cmd->t_task_lba = transport_lba_64(cdb);
 826
 827                 if (sbc_check_dpofua(dev, cmd, cdb))
 828                         return TCM_INVALID_CDB_FIELD;
 829
 830                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 831                 if (ret)
 832                         return ret;
 833
 834                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 835                 cmd->execute_rw = ops->execute_rw;
 836                 cmd->execute_cmd = sbc_execute_rw;
 837                 break;
 838         case XDWRITEREAD_10:
 839                 if (cmd->data_direction != DMA_TO_DEVICE ||
 840                     !(cmd->se_cmd_flags & SCF_BIDI))
 841                         return TCM_INVALID_CDB_FIELD;
 842                 sectors = transport_get_sectors_10(cdb);
 843
 844                 if (sbc_check_dpofua(dev, cmd, cdb))
 845                         return TCM_INVALID_CDB_FIELD;
 846
 847                 cmd->t_task_lba = transport_lba_32(cdb);
 848                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 849
 850                 /*
 851                  * Setup BIDI XOR callback to be run after I/O completion.
 852                  */
 853                 cmd->execute_rw = ops->execute_rw;
 854                 cmd->execute_cmd = sbc_execute_rw;
 855                 cmd->transport_complete_callback = &xdreadwrite_callback;
 856                 break;
 857         case VARIABLE_LENGTH_CMD:
 858         {
 859                 u16 service_action = get_unaligned_be16(&cdb[8]);
 860                 switch (service_action) {
 861                 case XDWRITEREAD_32:
 862                         sectors = transport_get_sectors_32(cdb);
 863
 864                         if (sbc_check_dpofua(dev, cmd, cdb))
 865                                 return TCM_INVALID_CDB_FIELD;
 866                         /*
 867                          * Use WRITE_32 and READ_32 opcodes for the emulated
 868                          * XDWRITE_READ_32 logic.
 869                          */
 870                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 871                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 872
 873                         /*
 874                          * Setup BIDI XOR callback to be run during after I/O
 875                          * completion.
 876                          */
 877                         cmd->execute_rw = ops->execute_rw;
 878                         cmd->execute_cmd = sbc_execute_rw;
 879                         cmd->transport_complete_callback = &xdreadwrite_callback;
 880                         break;
 881                 case WRITE_SAME_32:
 882                         sectors = transport_get_sectors_32(cdb);
 883                         if (!sectors) {
 884                                 pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 885                                        " supported\n");
 886                                 return TCM_INVALID_CDB_FIELD;
 887                         }
 888
 889                         size = sbc_get_size(cmd, 1);
 890                         cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 891
 892                         ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 893                         if (ret)
 894                                 return ret;
 895                         break;
 896                 default:
 897                         pr_err("VARIABLE_LENGTH_CMD service action"
 898                                 " 0x%04x not supported\n", service_action);
 899                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 900                 }
 901                 break;
 902         }
 903         case COMPARE_AND_WRITE:
 904                 sectors = cdb[13];
 905                 /*
 906                  * Currently enforce COMPARE_AND_WRITE for a single sector
 907                  */
 908                 if (sectors > 1) {
 909                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 910                                " than 1\n", sectors);
 911                         return TCM_INVALID_CDB_FIELD;
 912                 }
 913                 /*
 914                  * Double size because we have two buffers, note that
 915                  * zero is not an error..
 916                  */
 917                 size = 2 * sbc_get_size(cmd, sectors);
 918                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 919                 cmd->t_task_nolb = sectors;
 920                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 921                 cmd->execute_rw = ops->execute_rw;
 922                 cmd->execute_cmd = sbc_compare_and_write;
 923                 cmd->transport_complete_callback = compare_and_write_callback;
 924                 break;
 925         case READ_CAPACITY:
 926                 size = READ_CAP_LEN;
 927                 cmd->execute_cmd = sbc_emulate_readcapacity;
 928                 break;
 929         case SERVICE_ACTION_IN_16:
 930                 switch (cmd->t_task_cdb[1] & 0x1f) {
 931                 case SAI_READ_CAPACITY_16:
 932                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 933                         break;
 934                 case SAI_REPORT_REFERRALS:
 935                         cmd->execute_cmd = target_emulate_report_referrals;
 936                         break;
 937                 default:
 938                         pr_err("Unsupported SA: 0x%02x\n",
 939                                 cmd->t_task_cdb[1] & 0x1f);
 940                         return TCM_INVALID_CDB_FIELD;
 941                 }
 942                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 943                        (cdb[12] << 8) | cdb[13];
 944                 break;
 945         case SYNCHRONIZE_CACHE:
 946         case SYNCHRONIZE_CACHE_16:
 947                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 948                         sectors = transport_get_sectors_10(cdb);
 949                         cmd->t_task_lba = transport_lba_32(cdb);
 950                 } else {
 951                         sectors = transport_get_sectors_16(cdb);
 952                         cmd->t_task_lba = transport_lba_64(cdb);
 953                 }
 954                 if (ops->execute_sync_cache) {
 955                         cmd->execute_cmd = ops->execute_sync_cache;
 956                         goto check_lba;
 957                 }
 958                 size = 0;
 959                 cmd->execute_cmd = sbc_emulate_noop;
 960                 break;
 961         case UNMAP:
 962                 if (!ops->execute_unmap)
 963                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 964
 965                 if (!dev->dev_attrib.emulate_tpu) {
 966                         pr_err("Got UNMAP, but backend device has"
 967                                " emulate_tpu disabled\n");
 968                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 969                 }
 970                 size = get_unaligned_be16(&cdb[7]);
 971                 cmd->execute_cmd = ops->execute_unmap;
 972                 break;
 973         case WRITE_SAME_16:
 974                 sectors = transport_get_sectors_16(cdb);
 975                 if (!sectors) {
 976                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 977                         return TCM_INVALID_CDB_FIELD;
 978                 }
 979
 980                 size = sbc_get_size(cmd, 1);
 981                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 982
 983                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 984                 if (ret)
 985                         return ret;
 986                 break;
 987         case WRITE_SAME:
 988                 sectors = transport_get_sectors_10(cdb);
 989                 if (!sectors) {
 990                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 991                         return TCM_INVALID_CDB_FIELD;
 992                 }
 993
 994                 size = sbc_get_size(cmd, 1);
 995                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 996
 997                 /*
 998                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 999                  * of byte 1 bit 3 UNMAP instead of original reserved field
1000                  */
1001                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1002                 if (ret)
1003                         return ret;
1004                 break;
1005         case VERIFY:
1006                 size = 0;
1007                 sectors = transport_get_sectors_10(cdb);
1008                 cmd->t_task_lba = transport_lba_32(cdb);
1009                 cmd->execute_cmd = sbc_emulate_noop;
1010                 goto check_lba;
1011         case REZERO_UNIT:
1012         case SEEK_6:
1013         case SEEK_10:
1014                 /*
1015                  * There are still clients out there which use these old SCSI-2
1016                  * commands. This mainly happens when running VMs with legacy
1017                  * guest systems, connected via SCSI command pass-through to
1018                  * iSCSI targets. Make them happy and return status GOOD.
1019                  */
1020                 size = 0;
1021                 cmd->execute_cmd = sbc_emulate_noop;
1022                 break;
1023         default:
1024                 ret = spc_parse_cdb(cmd, &size);
1025                 if (ret)
1026                         return ret;
1027         }
1028
1029         /* reject any command that we don't have a handler for */
1030         if (!cmd->execute_cmd)
1031                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1032
1033         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1034                 unsigned long long end_lba;
1035
1036                 if (sectors > dev->dev_attrib.fabric_max_sectors) {
1037                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
1038                                 " big sectors %u exceeds fabric_max_sectors:"
1039                                 " %u\n", cdb[0], sectors,
1040                                 dev->dev_attrib.fabric_max_sectors);
1041                         return TCM_INVALID_CDB_FIELD;
1042                 }
1043                 if (sectors > dev->dev_attrib.hw_max_sectors) {
1044                         printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
1045                                 " big sectors %u exceeds backend hw_max_sectors:"
1046                                 " %u\n", cdb[0], sectors,
1047                                 dev->dev_attrib.hw_max_sectors);
1048                         return TCM_INVALID_CDB_FIELD;
1049                 }
1050 check_lba:
1051                 end_lba = dev->transport->get_blocks(dev) + 1;
1052                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1053                     ((cmd->t_task_lba + sectors) > end_lba)) {
1054                         pr_err("cmd exceeds last lba %llu "
1055                                 "(lba %llu, sectors %u)\n",
1056                                 end_lba, cmd->t_task_lba, sectors);
1057                         return TCM_ADDRESS_OUT_OF_RANGE;
1058                 }
1059
1060                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1061                         size = sbc_get_size(cmd, sectors);
1062         }
1063
1064         return target_cmd_size_check(cmd, size);
1065 }
1066 EXPORT_SYMBOL(sbc_parse_cdb);
1067
1068 u32 sbc_get_device_type(struct se_device *dev)
1069 {
1070         return TYPE_DISK;
1071 }
1072 EXPORT_SYMBOL(sbc_get_device_type);
1073
1074 sense_reason_t
1075 sbc_execute_unmap(struct se_cmd *cmd,
1076         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1077                                       sector_t, sector_t),
1078         void *priv)
1079 {
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                 ret = do_unmap_fn(cmd, priv, lba, range);
1144                 if (ret)
1145                         goto err;
1146
1147                 ptr += 16;
1148                 size -= 16;
1149         }
1150
1151 err:
1152         transport_kunmap_data_sg(cmd);
1153         if (!ret)
1154                 target_complete_cmd(cmd, GOOD);
1155         return ret;
1156 }
1157 EXPORT_SYMBOL(sbc_execute_unmap);
1158
1159 void
1160 sbc_dif_generate(struct se_cmd *cmd)
1161 {
1162         struct se_device *dev = cmd->se_dev;
1163         struct se_dif_v1_tuple *sdt;
1164         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1165         sector_t sector = cmd->t_task_lba;
1166         void *daddr, *paddr;
1167         int i, j, offset = 0;
1168
1169         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1170                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1171                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1172
1173                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1174
1175                         if (offset >= psg->length) {
1176                                 kunmap_atomic(paddr);
1177                                 psg = sg_next(psg);
1178                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1179                                 offset = 0;
1180                         }
1181
1182                         sdt = paddr + offset;
1183                         sdt->guard_tag = cpu_to_be16(crc_t10dif(daddr + j,
1184                                                 dev->dev_attrib.block_size));
1185                         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT)
1186                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1187                         sdt->app_tag = 0;
1188
1189                         pr_debug("DIF WRITE INSERT sector: %llu guard_tag: 0x%04x"
1190                                  " app_tag: 0x%04x ref_tag: %u\n",
1191                                  (unsigned long long)sector, sdt->guard_tag,
1192                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1193
1194                         sector++;
1195                         offset += sizeof(struct se_dif_v1_tuple);
1196                 }
1197
1198                 kunmap_atomic(paddr);
1199                 kunmap_atomic(daddr);
1200         }
1201 }
1202
1203 static sense_reason_t
1204 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1205                   const void *p, sector_t sector, unsigned int ei_lba)
1206 {
1207         int block_size = dev->dev_attrib.block_size;
1208         __be16 csum;
1209
1210         csum = cpu_to_be16(crc_t10dif(p, block_size));
1211
1212         if (sdt->guard_tag != csum) {
1213                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1214                         " csum 0x%04x\n", (unsigned long long)sector,
1215                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1216                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1217         }
1218
1219         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1220             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1221                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1222                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1223                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1224                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1225         }
1226
1227         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1228             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1229                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1230                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1231                         be32_to_cpu(sdt->ref_tag), ei_lba);
1232                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1233         }
1234
1235         return 0;
1236 }
1237
1238 static void
1239 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1240                   struct scatterlist *sg, int sg_off)
1241 {
1242         struct se_device *dev = cmd->se_dev;
1243         struct scatterlist *psg;
1244         void *paddr, *addr;
1245         unsigned int i, len, left;
1246         unsigned int offset = sg_off;
1247
1248         left = sectors * dev->prot_length;
1249
1250         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1251                 unsigned int psg_len, copied = 0;
1252
1253                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1254                 psg_len = min(left, psg->length);
1255                 while (psg_len) {
1256                         len = min(psg_len, sg->length - offset);
1257                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1258
1259                         if (read)
1260                                 memcpy(paddr + copied, addr, len);
1261                         else
1262                                 memcpy(addr, paddr + copied, len);
1263
1264                         left -= len;
1265                         offset += len;
1266                         copied += len;
1267                         psg_len -= len;
1268
1269                         if (offset >= sg->length) {
1270                                 sg = sg_next(sg);
1271                                 offset = 0;
1272                         }
1273                         kunmap_atomic(addr);
1274                 }
1275                 kunmap_atomic(paddr);
1276         }
1277 }
1278
1279 sense_reason_t
1280 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1281                      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1282 {
1283         struct se_device *dev = cmd->se_dev;
1284         struct se_dif_v1_tuple *sdt;
1285         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1286         sector_t sector = start;
1287         void *daddr, *paddr;
1288         int i, j, offset = 0;
1289         sense_reason_t rc;
1290
1291         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1292                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1293                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1294
1295                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1296
1297                         if (offset >= psg->length) {
1298                                 kunmap_atomic(paddr);
1299                                 psg = sg_next(psg);
1300                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1301                                 offset = 0;
1302                         }
1303
1304                         sdt = paddr + offset;
1305
1306                         pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1307                                  " app_tag: 0x%04x ref_tag: %u\n",
1308                                  (unsigned long long)sector, sdt->guard_tag,
1309                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1310
1311                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1312                                                ei_lba);
1313                         if (rc) {
1314                                 kunmap_atomic(paddr);
1315                                 kunmap_atomic(daddr);
1316                                 cmd->bad_sector = sector;
1317                                 return rc;
1318                         }
1319
1320                         sector++;
1321                         ei_lba++;
1322                         offset += sizeof(struct se_dif_v1_tuple);
1323                 }
1324
1325                 kunmap_atomic(paddr);
1326                 kunmap_atomic(daddr);
1327         }
1328         sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1329
1330         return 0;
1331 }
1332 EXPORT_SYMBOL(sbc_dif_verify_write);
1333
1334 static sense_reason_t
1335 __sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1336                       unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1337 {
1338         struct se_device *dev = cmd->se_dev;
1339         struct se_dif_v1_tuple *sdt;
1340         struct scatterlist *dsg, *psg = sg;
1341         sector_t sector = start;
1342         void *daddr, *paddr;
1343         int i, j, offset = sg_off;
1344         sense_reason_t rc;
1345
1346         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1347                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1348                 paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1349
1350                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1351
1352                         if (offset >= psg->length) {
1353                                 kunmap_atomic(paddr);
1354                                 psg = sg_next(psg);
1355                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1356                                 offset = 0;
1357                         }
1358
1359                         sdt = paddr + offset;
1360
1361                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1362                                  " app_tag: 0x%04x ref_tag: %u\n",
1363                                  (unsigned long long)sector, sdt->guard_tag,
1364                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1365
1366                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1367                                 sector++;
1368                                 offset += sizeof(struct se_dif_v1_tuple);
1369                                 continue;
1370                         }
1371
1372                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1373                                                ei_lba);
1374                         if (rc) {
1375                                 kunmap_atomic(paddr);
1376                                 kunmap_atomic(daddr);
1377                                 cmd->bad_sector = sector;
1378                                 return rc;
1379                         }
1380
1381                         sector++;
1382                         ei_lba++;
1383                         offset += sizeof(struct se_dif_v1_tuple);
1384                 }
1385
1386                 kunmap_atomic(paddr);
1387                 kunmap_atomic(daddr);
1388         }
1389
1390         return 0;
1391 }
1392
1393 sense_reason_t
1394 sbc_dif_read_strip(struct se_cmd *cmd)
1395 {
1396         struct se_device *dev = cmd->se_dev;
1397         u32 sectors = cmd->prot_length / dev->prot_length;
1398
1399         return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
1400                                      cmd->t_prot_sg, 0);
1401 }
1402
1403 sense_reason_t
1404 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1405                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1406 {
1407         sense_reason_t rc;
1408
1409         rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
1410         if (rc)
1411                 return rc;
1412
1413         sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1414         return 0;
1415 }
1416 EXPORT_SYMBOL(sbc_dif_verify_read);