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 || !se_dev_check_wce(dev)) {
 712                         pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 713                                " does not advertise support for FUA write\n",
 714                                cdb[0]);
 715                         return -EINVAL;
 716                 }
 717                 cmd->se_cmd_flags |= SCF_FUA;
 718         }
 719         return 0;
 720 }
 721
 722 sense_reason_t
 723 sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 724 {
 725         struct se_device *dev = cmd->se_dev;
 726         unsigned char *cdb = cmd->t_task_cdb;
 727         unsigned int size;
 728         u32 sectors = 0;
 729         sense_reason_t ret;
 730
 731         switch (cdb[0]) {
 732         case READ_6:
 733                 sectors = transport_get_sectors_6(cdb);
 734                 cmd->t_task_lba = transport_lba_21(cdb);
 735                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 736                 cmd->execute_rw = ops->execute_rw;
 737                 cmd->execute_cmd = sbc_execute_rw;
 738                 break;
 739         case READ_10:
 740                 sectors = transport_get_sectors_10(cdb);
 741                 cmd->t_task_lba = transport_lba_32(cdb);
 742
 743                 if (sbc_check_dpofua(dev, cmd, cdb))
 744                         return TCM_INVALID_CDB_FIELD;
 745
 746                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 747                 if (ret)
 748                         return ret;
 749
 750                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 751                 cmd->execute_rw = ops->execute_rw;
 752                 cmd->execute_cmd = sbc_execute_rw;
 753                 break;
 754         case READ_12:
 755                 sectors = transport_get_sectors_12(cdb);
 756                 cmd->t_task_lba = transport_lba_32(cdb);
 757
 758                 if (sbc_check_dpofua(dev, cmd, cdb))
 759                         return TCM_INVALID_CDB_FIELD;
 760
 761                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 762                 if (ret)
 763                         return ret;
 764
 765                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 766                 cmd->execute_rw = ops->execute_rw;
 767                 cmd->execute_cmd = sbc_execute_rw;
 768                 break;
 769         case READ_16:
 770                 sectors = transport_get_sectors_16(cdb);
 771                 cmd->t_task_lba = transport_lba_64(cdb);
 772
 773                 if (sbc_check_dpofua(dev, cmd, cdb))
 774                         return TCM_INVALID_CDB_FIELD;
 775
 776                 ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 777                 if (ret)
 778                         return ret;
 779
 780                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 781                 cmd->execute_rw = ops->execute_rw;
 782                 cmd->execute_cmd = sbc_execute_rw;
 783                 break;
 784         case WRITE_6:
 785                 sectors = transport_get_sectors_6(cdb);
 786                 cmd->t_task_lba = transport_lba_21(cdb);
 787                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 788                 cmd->execute_rw = ops->execute_rw;
 789                 cmd->execute_cmd = sbc_execute_rw;
 790                 break;
 791         case WRITE_10:
 792         case WRITE_VERIFY:
 793                 sectors = transport_get_sectors_10(cdb);
 794                 cmd->t_task_lba = transport_lba_32(cdb);
 795
 796                 if (sbc_check_dpofua(dev, cmd, cdb))
 797                         return TCM_INVALID_CDB_FIELD;
 798
 799                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 800                 if (ret)
 801                         return ret;
 802
 803                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 804                 cmd->execute_rw = ops->execute_rw;
 805                 cmd->execute_cmd = sbc_execute_rw;
 806                 break;
 807         case WRITE_12:
 808                 sectors = transport_get_sectors_12(cdb);
 809                 cmd->t_task_lba = transport_lba_32(cdb);
 810
 811                 if (sbc_check_dpofua(dev, cmd, cdb))
 812                         return TCM_INVALID_CDB_FIELD;
 813
 814                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 815                 if (ret)
 816                         return ret;
 817
 818                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 819                 cmd->execute_rw = ops->execute_rw;
 820                 cmd->execute_cmd = sbc_execute_rw;
 821                 break;
 822         case WRITE_16:
 823                 sectors = transport_get_sectors_16(cdb);
 824                 cmd->t_task_lba = transport_lba_64(cdb);
 825
 826                 if (sbc_check_dpofua(dev, cmd, cdb))
 827                         return TCM_INVALID_CDB_FIELD;
 828
 829                 ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 830                 if (ret)
 831                         return ret;
 832
 833                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 834                 cmd->execute_rw = ops->execute_rw;
 835                 cmd->execute_cmd = sbc_execute_rw;
 836                 break;
 837         case XDWRITEREAD_10:
 838                 if (cmd->data_direction != DMA_TO_DEVICE ||
 839                     !(cmd->se_cmd_flags & SCF_BIDI))
 840                         return TCM_INVALID_CDB_FIELD;
 841                 sectors = transport_get_sectors_10(cdb);
 842
 843                 if (sbc_check_dpofua(dev, cmd, cdb))
 844                         return TCM_INVALID_CDB_FIELD;
 845
 846                 cmd->t_task_lba = transport_lba_32(cdb);
 847                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 848
 849                 /*
 850                  * Setup BIDI XOR callback to be run after I/O completion.
 851                  */
 852                 cmd->execute_rw = ops->execute_rw;
 853                 cmd->execute_cmd = sbc_execute_rw;
 854                 cmd->transport_complete_callback = &xdreadwrite_callback;
 855                 break;
 856         case VARIABLE_LENGTH_CMD:
 857         {
 858                 u16 service_action = get_unaligned_be16(&cdb[8]);
 859                 switch (service_action) {
 860                 case XDWRITEREAD_32:
 861                         sectors = transport_get_sectors_32(cdb);
 862
 863                         if (sbc_check_dpofua(dev, cmd, cdb))
 864                                 return TCM_INVALID_CDB_FIELD;
 865                         /*
 866                          * Use WRITE_32 and READ_32 opcodes for the emulated
 867                          * XDWRITE_READ_32 logic.
 868                          */
 869                         cmd->t_task_lba = transport_lba_64_ext(cdb);
 870                         cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 871
 872                         /*
 873                          * Setup BIDI XOR callback to be run during after I/O
 874                          * completion.
 875                          */
 876                         cmd->execute_rw = ops->execute_rw;
 877                         cmd->execute_cmd = sbc_execute_rw;
 878                         cmd->transport_complete_callback = &xdreadwrite_callback;
 879                         break;
 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                 sectors = cdb[13];
 904                 /*
 905                  * Currently enforce COMPARE_AND_WRITE for a single sector
 906                  */
 907                 if (sectors > 1) {
 908                         pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 909                                " than 1\n", sectors);
 910                         return TCM_INVALID_CDB_FIELD;
 911                 }
 912                 /*
 913                  * Double size because we have two buffers, note that
 914                  * zero is not an error..
 915                  */
 916                 size = 2 * sbc_get_size(cmd, sectors);
 917                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 918                 cmd->t_task_nolb = sectors;
 919                 cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 920                 cmd->execute_rw = ops->execute_rw;
 921                 cmd->execute_cmd = sbc_compare_and_write;
 922                 cmd->transport_complete_callback = compare_and_write_callback;
 923                 break;
 924         case READ_CAPACITY:
 925                 size = READ_CAP_LEN;
 926                 cmd->execute_cmd = sbc_emulate_readcapacity;
 927                 break;
 928         case SERVICE_ACTION_IN_16:
 929                 switch (cmd->t_task_cdb[1] & 0x1f) {
 930                 case SAI_READ_CAPACITY_16:
 931                         cmd->execute_cmd = sbc_emulate_readcapacity_16;
 932                         break;
 933                 case SAI_REPORT_REFERRALS:
 934                         cmd->execute_cmd = target_emulate_report_referrals;
 935                         break;
 936                 default:
 937                         pr_err("Unsupported SA: 0x%02x\n",
 938                                 cmd->t_task_cdb[1] & 0x1f);
 939                         return TCM_INVALID_CDB_FIELD;
 940                 }
 941                 size = (cdb[10] << 24) | (cdb[11] << 16) |
 942                        (cdb[12] << 8) | cdb[13];
 943                 break;
 944         case SYNCHRONIZE_CACHE:
 945         case SYNCHRONIZE_CACHE_16:
 946                 if (cdb[0] == SYNCHRONIZE_CACHE) {
 947                         sectors = transport_get_sectors_10(cdb);
 948                         cmd->t_task_lba = transport_lba_32(cdb);
 949                 } else {
 950                         sectors = transport_get_sectors_16(cdb);
 951                         cmd->t_task_lba = transport_lba_64(cdb);
 952                 }
 953                 if (ops->execute_sync_cache) {
 954                         cmd->execute_cmd = ops->execute_sync_cache;
 955                         goto check_lba;
 956                 }
 957                 size = 0;
 958                 cmd->execute_cmd = sbc_emulate_noop;
 959                 break;
 960         case UNMAP:
 961                 if (!ops->execute_unmap)
 962                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 963
 964                 if (!dev->dev_attrib.emulate_tpu) {
 965                         pr_err("Got UNMAP, but backend device has"
 966                                " emulate_tpu disabled\n");
 967                         return TCM_UNSUPPORTED_SCSI_OPCODE;
 968                 }
 969                 size = get_unaligned_be16(&cdb[7]);
 970                 cmd->execute_cmd = ops->execute_unmap;
 971                 break;
 972         case WRITE_SAME_16:
 973                 sectors = transport_get_sectors_16(cdb);
 974                 if (!sectors) {
 975                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 976                         return TCM_INVALID_CDB_FIELD;
 977                 }
 978
 979                 size = sbc_get_size(cmd, 1);
 980                 cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 981
 982                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
 983                 if (ret)
 984                         return ret;
 985                 break;
 986         case WRITE_SAME:
 987                 sectors = transport_get_sectors_10(cdb);
 988                 if (!sectors) {
 989                         pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
 990                         return TCM_INVALID_CDB_FIELD;
 991                 }
 992
 993                 size = sbc_get_size(cmd, 1);
 994                 cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
 995
 996                 /*
 997                  * Follow sbcr26 with WRITE_SAME (10) and check for the existence
 998                  * of byte 1 bit 3 UNMAP instead of original reserved field
 999                  */
1000                 ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1001                 if (ret)
1002                         return ret;
1003                 break;
1004         case VERIFY:
1005                 size = 0;
1006                 sectors = transport_get_sectors_10(cdb);
1007                 cmd->t_task_lba = transport_lba_32(cdb);
1008                 cmd->execute_cmd = sbc_emulate_noop;
1009                 goto check_lba;
1010         case REZERO_UNIT:
1011         case SEEK_6:
1012         case SEEK_10:
1013                 /*
1014                  * There are still clients out there which use these old SCSI-2
1015                  * commands. This mainly happens when running VMs with legacy
1016                  * guest systems, connected via SCSI command pass-through to
1017                  * iSCSI targets. Make them happy and return status GOOD.
1018                  */
1019                 size = 0;
1020                 cmd->execute_cmd = sbc_emulate_noop;
1021                 break;
1022         default:
1023                 ret = spc_parse_cdb(cmd, &size);
1024                 if (ret)
1025                         return ret;
1026         }
1027
1028         /* reject any command that we don't have a handler for */
1029         if (!cmd->execute_cmd)
1030                 return TCM_UNSUPPORTED_SCSI_OPCODE;
1031
1032         if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1033                 unsigned long long end_lba;
1034 check_lba:
1035                 end_lba = dev->transport->get_blocks(dev) + 1;
1036                 if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1037                     ((cmd->t_task_lba + sectors) > end_lba)) {
1038                         pr_err("cmd exceeds last lba %llu "
1039                                 "(lba %llu, sectors %u)\n",
1040                                 end_lba, cmd->t_task_lba, sectors);
1041                         return TCM_ADDRESS_OUT_OF_RANGE;
1042                 }
1043
1044                 if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1045                         size = sbc_get_size(cmd, sectors);
1046         }
1047
1048         return target_cmd_size_check(cmd, size);
1049 }
1050 EXPORT_SYMBOL(sbc_parse_cdb);
1051
1052 u32 sbc_get_device_type(struct se_device *dev)
1053 {
1054         return TYPE_DISK;
1055 }
1056 EXPORT_SYMBOL(sbc_get_device_type);
1057
1058 sense_reason_t
1059 sbc_execute_unmap(struct se_cmd *cmd,
1060         sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
1061                                       sector_t, sector_t),
1062         void *priv)
1063 {
1064         struct se_device *dev = cmd->se_dev;
1065         unsigned char *buf, *ptr = NULL;
1066         sector_t lba;
1067         int size;
1068         u32 range;
1069         sense_reason_t ret = 0;
1070         int dl, bd_dl;
1071
1072         /* We never set ANC_SUP */
1073         if (cmd->t_task_cdb[1])
1074                 return TCM_INVALID_CDB_FIELD;
1075
1076         if (cmd->data_length == 0) {
1077                 target_complete_cmd(cmd, SAM_STAT_GOOD);
1078                 return 0;
1079         }
1080
1081         if (cmd->data_length < 8) {
1082                 pr_warn("UNMAP parameter list length %u too small\n",
1083                         cmd->data_length);
1084                 return TCM_PARAMETER_LIST_LENGTH_ERROR;
1085         }
1086
1087         buf = transport_kmap_data_sg(cmd);
1088         if (!buf)
1089                 return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1090
1091         dl = get_unaligned_be16(&buf[0]);
1092         bd_dl = get_unaligned_be16(&buf[2]);
1093
1094         size = cmd->data_length - 8;
1095         if (bd_dl > size)
1096                 pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1097                         cmd->data_length, bd_dl);
1098         else
1099                 size = bd_dl;
1100
1101         if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1102                 ret = TCM_INVALID_PARAMETER_LIST;
1103                 goto err;
1104         }
1105
1106         /* First UNMAP block descriptor starts at 8 byte offset */
1107         ptr = &buf[8];
1108         pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1109                 " ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1110
1111         while (size >= 16) {
1112                 lba = get_unaligned_be64(&ptr[0]);
1113                 range = get_unaligned_be32(&ptr[8]);
1114                 pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1115                                  (unsigned long long)lba, range);
1116
1117                 if (range > dev->dev_attrib.max_unmap_lba_count) {
1118                         ret = TCM_INVALID_PARAMETER_LIST;
1119                         goto err;
1120                 }
1121
1122                 if (lba + range > dev->transport->get_blocks(dev) + 1) {
1123                         ret = TCM_ADDRESS_OUT_OF_RANGE;
1124                         goto err;
1125                 }
1126
1127                 ret = do_unmap_fn(cmd, priv, lba, range);
1128                 if (ret)
1129                         goto err;
1130
1131                 ptr += 16;
1132                 size -= 16;
1133         }
1134
1135 err:
1136         transport_kunmap_data_sg(cmd);
1137         if (!ret)
1138                 target_complete_cmd(cmd, GOOD);
1139         return ret;
1140 }
1141 EXPORT_SYMBOL(sbc_execute_unmap);
1142
1143 void
1144 sbc_dif_generate(struct se_cmd *cmd)
1145 {
1146         struct se_device *dev = cmd->se_dev;
1147         struct se_dif_v1_tuple *sdt;
1148         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1149         sector_t sector = cmd->t_task_lba;
1150         void *daddr, *paddr;
1151         int i, j, offset = 0;
1152
1153         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1154                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1155                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1156
1157                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1158
1159                         if (offset >= psg->length) {
1160                                 kunmap_atomic(paddr);
1161                                 psg = sg_next(psg);
1162                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1163                                 offset = 0;
1164                         }
1165
1166                         sdt = paddr + offset;
1167                         sdt->guard_tag = cpu_to_be16(crc_t10dif(daddr + j,
1168                                                 dev->dev_attrib.block_size));
1169                         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT)
1170                                 sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1171                         sdt->app_tag = 0;
1172
1173                         pr_debug("DIF WRITE INSERT sector: %llu guard_tag: 0x%04x"
1174                                  " app_tag: 0x%04x ref_tag: %u\n",
1175                                  (unsigned long long)sector, sdt->guard_tag,
1176                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1177
1178                         sector++;
1179                         offset += sizeof(struct se_dif_v1_tuple);
1180                 }
1181
1182                 kunmap_atomic(paddr);
1183                 kunmap_atomic(daddr);
1184         }
1185 }
1186
1187 static sense_reason_t
1188 sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
1189                   const void *p, sector_t sector, unsigned int ei_lba)
1190 {
1191         int block_size = dev->dev_attrib.block_size;
1192         __be16 csum;
1193
1194         csum = cpu_to_be16(crc_t10dif(p, block_size));
1195
1196         if (sdt->guard_tag != csum) {
1197                 pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1198                         " csum 0x%04x\n", (unsigned long long)sector,
1199                         be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1200                 return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1201         }
1202
1203         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
1204             be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1205                 pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1206                        " sector MSB: 0x%08x\n", (unsigned long long)sector,
1207                        be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1208                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1209         }
1210
1211         if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
1212             be32_to_cpu(sdt->ref_tag) != ei_lba) {
1213                 pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1214                        " ei_lba: 0x%08x\n", (unsigned long long)sector,
1215                         be32_to_cpu(sdt->ref_tag), ei_lba);
1216                 return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1217         }
1218
1219         return 0;
1220 }
1221
1222 static void
1223 sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1224                   struct scatterlist *sg, int sg_off)
1225 {
1226         struct se_device *dev = cmd->se_dev;
1227         struct scatterlist *psg;
1228         void *paddr, *addr;
1229         unsigned int i, len, left;
1230         unsigned int offset = sg_off;
1231
1232         left = sectors * dev->prot_length;
1233
1234         for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1235                 unsigned int psg_len, copied = 0;
1236
1237                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1238                 psg_len = min(left, psg->length);
1239                 while (psg_len) {
1240                         len = min(psg_len, sg->length - offset);
1241                         addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1242
1243                         if (read)
1244                                 memcpy(paddr + copied, addr, len);
1245                         else
1246                                 memcpy(addr, paddr + copied, len);
1247
1248                         left -= len;
1249                         offset += len;
1250                         copied += len;
1251                         psg_len -= len;
1252
1253                         if (offset >= sg->length) {
1254                                 sg = sg_next(sg);
1255                                 offset = 0;
1256                         }
1257                         kunmap_atomic(addr);
1258                 }
1259                 kunmap_atomic(paddr);
1260         }
1261 }
1262
1263 sense_reason_t
1264 sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1265                      unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1266 {
1267         struct se_device *dev = cmd->se_dev;
1268         struct se_dif_v1_tuple *sdt;
1269         struct scatterlist *dsg, *psg = cmd->t_prot_sg;
1270         sector_t sector = start;
1271         void *daddr, *paddr;
1272         int i, j, offset = 0;
1273         sense_reason_t rc;
1274
1275         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1276                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1277                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1278
1279                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1280
1281                         if (offset >= psg->length) {
1282                                 kunmap_atomic(paddr);
1283                                 psg = sg_next(psg);
1284                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1285                                 offset = 0;
1286                         }
1287
1288                         sdt = paddr + offset;
1289
1290                         pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
1291                                  " app_tag: 0x%04x ref_tag: %u\n",
1292                                  (unsigned long long)sector, sdt->guard_tag,
1293                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1294
1295                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1296                                                ei_lba);
1297                         if (rc) {
1298                                 kunmap_atomic(paddr);
1299                                 kunmap_atomic(daddr);
1300                                 cmd->bad_sector = sector;
1301                                 return rc;
1302                         }
1303
1304                         sector++;
1305                         ei_lba++;
1306                         offset += sizeof(struct se_dif_v1_tuple);
1307                 }
1308
1309                 kunmap_atomic(paddr);
1310                 kunmap_atomic(daddr);
1311         }
1312         sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
1313
1314         return 0;
1315 }
1316 EXPORT_SYMBOL(sbc_dif_verify_write);
1317
1318 static sense_reason_t
1319 __sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1320                       unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1321 {
1322         struct se_device *dev = cmd->se_dev;
1323         struct se_dif_v1_tuple *sdt;
1324         struct scatterlist *dsg, *psg = sg;
1325         sector_t sector = start;
1326         void *daddr, *paddr;
1327         int i, j, offset = sg_off;
1328         sense_reason_t rc;
1329
1330         for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
1331                 daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1332                 paddr = kmap_atomic(sg_page(psg)) + sg->offset;
1333
1334                 for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
1335
1336                         if (offset >= psg->length) {
1337                                 kunmap_atomic(paddr);
1338                                 psg = sg_next(psg);
1339                                 paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1340                                 offset = 0;
1341                         }
1342
1343                         sdt = paddr + offset;
1344
1345                         pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1346                                  " app_tag: 0x%04x ref_tag: %u\n",
1347                                  (unsigned long long)sector, sdt->guard_tag,
1348                                  sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1349
1350                         if (sdt->app_tag == cpu_to_be16(0xffff)) {
1351                                 sector++;
1352                                 offset += sizeof(struct se_dif_v1_tuple);
1353                                 continue;
1354                         }
1355
1356                         rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
1357                                                ei_lba);
1358                         if (rc) {
1359                                 kunmap_atomic(paddr);
1360                                 kunmap_atomic(daddr);
1361                                 cmd->bad_sector = sector;
1362                                 return rc;
1363                         }
1364
1365                         sector++;
1366                         ei_lba++;
1367                         offset += sizeof(struct se_dif_v1_tuple);
1368                 }
1369
1370                 kunmap_atomic(paddr);
1371                 kunmap_atomic(daddr);
1372         }
1373
1374         return 0;
1375 }
1376
1377 sense_reason_t
1378 sbc_dif_read_strip(struct se_cmd *cmd)
1379 {
1380         struct se_device *dev = cmd->se_dev;
1381         u32 sectors = cmd->prot_length / dev->prot_length;
1382
1383         return __sbc_dif_verify_read(cmd, cmd->t_task_lba, sectors, 0,
1384                                      cmd->t_prot_sg, 0);
1385 }
1386
1387 sense_reason_t
1388 sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1389                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
1390 {
1391         sense_reason_t rc;
1392
1393         rc = __sbc_dif_verify_read(cmd, start, sectors, ei_lba, sg, sg_off);
1394         if (rc)
1395                 return rc;
1396
1397         sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
1398         return 0;
1399 }
1400 EXPORT_SYMBOL(sbc_dif_verify_read);