| 1 | /* |
| 2 | * sd_dif.c - SCSI Data Integrity Field |
| 3 | * |
| 4 | * Copyright (C) 2007, 2008 Oracle Corporation |
| 5 | * Written by: Martin K. Petersen <martin.petersen@oracle.com> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public License version |
| 9 | * 2 as published by the Free Software Foundation. |
| 10 | * |
| 11 | * This program is distributed in the hope that it will be useful, but |
| 12 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 14 | * General Public License for more details. |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License |
| 17 | * along with this program; see the file COPYING. If not, write to |
| 18 | * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, |
| 19 | * USA. |
| 20 | * |
| 21 | */ |
| 22 | |
| 23 | #include <linux/blkdev.h> |
| 24 | #include <linux/crc-t10dif.h> |
| 25 | |
| 26 | #include <scsi/scsi.h> |
| 27 | #include <scsi/scsi_cmnd.h> |
| 28 | #include <scsi/scsi_dbg.h> |
| 29 | #include <scsi/scsi_device.h> |
| 30 | #include <scsi/scsi_driver.h> |
| 31 | #include <scsi/scsi_eh.h> |
| 32 | #include <scsi/scsi_host.h> |
| 33 | #include <scsi/scsi_ioctl.h> |
| 34 | #include <scsi/scsicam.h> |
| 35 | |
| 36 | #include <net/checksum.h> |
| 37 | |
| 38 | #include "sd.h" |
| 39 | |
| 40 | typedef __u16 (csum_fn) (void *, unsigned int); |
| 41 | |
| 42 | static __u16 sd_dif_crc_fn(void *data, unsigned int len) |
| 43 | { |
| 44 | return cpu_to_be16(crc_t10dif(data, len)); |
| 45 | } |
| 46 | |
| 47 | static __u16 sd_dif_ip_fn(void *data, unsigned int len) |
| 48 | { |
| 49 | return ip_compute_csum(data, len); |
| 50 | } |
| 51 | |
| 52 | /* |
| 53 | * Type 1 and Type 2 protection use the same format: 16 bit guard tag, |
| 54 | * 16 bit app tag, 32 bit reference tag. |
| 55 | */ |
| 56 | static void sd_dif_type1_generate(struct blk_integrity_exchg *bix, csum_fn *fn) |
| 57 | { |
| 58 | void *buf = bix->data_buf; |
| 59 | struct sd_dif_tuple *sdt = bix->prot_buf; |
| 60 | sector_t sector = bix->sector; |
| 61 | unsigned int i; |
| 62 | |
| 63 | for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) { |
| 64 | sdt->guard_tag = fn(buf, bix->sector_size); |
| 65 | sdt->ref_tag = cpu_to_be32(sector & 0xffffffff); |
| 66 | sdt->app_tag = 0; |
| 67 | |
| 68 | buf += bix->sector_size; |
| 69 | sector++; |
| 70 | } |
| 71 | } |
| 72 | |
| 73 | static void sd_dif_type1_generate_crc(struct blk_integrity_exchg *bix) |
| 74 | { |
| 75 | sd_dif_type1_generate(bix, sd_dif_crc_fn); |
| 76 | } |
| 77 | |
| 78 | static void sd_dif_type1_generate_ip(struct blk_integrity_exchg *bix) |
| 79 | { |
| 80 | sd_dif_type1_generate(bix, sd_dif_ip_fn); |
| 81 | } |
| 82 | |
| 83 | static int sd_dif_type1_verify(struct blk_integrity_exchg *bix, csum_fn *fn) |
| 84 | { |
| 85 | void *buf = bix->data_buf; |
| 86 | struct sd_dif_tuple *sdt = bix->prot_buf; |
| 87 | sector_t sector = bix->sector; |
| 88 | unsigned int i; |
| 89 | __u16 csum; |
| 90 | |
| 91 | for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) { |
| 92 | /* Unwritten sectors */ |
| 93 | if (sdt->app_tag == 0xffff) |
| 94 | return 0; |
| 95 | |
| 96 | if (be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) { |
| 97 | printk(KERN_ERR |
| 98 | "%s: ref tag error on sector %lu (rcvd %u)\n", |
| 99 | bix->disk_name, (unsigned long)sector, |
| 100 | be32_to_cpu(sdt->ref_tag)); |
| 101 | return -EIO; |
| 102 | } |
| 103 | |
| 104 | csum = fn(buf, bix->sector_size); |
| 105 | |
| 106 | if (sdt->guard_tag != csum) { |
| 107 | printk(KERN_ERR "%s: guard tag error on sector %lu " \ |
| 108 | "(rcvd %04x, data %04x)\n", bix->disk_name, |
| 109 | (unsigned long)sector, |
| 110 | be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum)); |
| 111 | return -EIO; |
| 112 | } |
| 113 | |
| 114 | buf += bix->sector_size; |
| 115 | sector++; |
| 116 | } |
| 117 | |
| 118 | return 0; |
| 119 | } |
| 120 | |
| 121 | static int sd_dif_type1_verify_crc(struct blk_integrity_exchg *bix) |
| 122 | { |
| 123 | return sd_dif_type1_verify(bix, sd_dif_crc_fn); |
| 124 | } |
| 125 | |
| 126 | static int sd_dif_type1_verify_ip(struct blk_integrity_exchg *bix) |
| 127 | { |
| 128 | return sd_dif_type1_verify(bix, sd_dif_ip_fn); |
| 129 | } |
| 130 | |
| 131 | /* |
| 132 | * Functions for interleaving and deinterleaving application tags |
| 133 | */ |
| 134 | static void sd_dif_type1_set_tag(void *prot, void *tag_buf, unsigned int sectors) |
| 135 | { |
| 136 | struct sd_dif_tuple *sdt = prot; |
| 137 | u8 *tag = tag_buf; |
| 138 | unsigned int i, j; |
| 139 | |
| 140 | for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) { |
| 141 | sdt->app_tag = tag[j] << 8 | tag[j+1]; |
| 142 | BUG_ON(sdt->app_tag == 0xffff); |
| 143 | } |
| 144 | } |
| 145 | |
| 146 | static void sd_dif_type1_get_tag(void *prot, void *tag_buf, unsigned int sectors) |
| 147 | { |
| 148 | struct sd_dif_tuple *sdt = prot; |
| 149 | u8 *tag = tag_buf; |
| 150 | unsigned int i, j; |
| 151 | |
| 152 | for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) { |
| 153 | tag[j] = (sdt->app_tag & 0xff00) >> 8; |
| 154 | tag[j+1] = sdt->app_tag & 0xff; |
| 155 | } |
| 156 | } |
| 157 | |
| 158 | static struct blk_integrity dif_type1_integrity_crc = { |
| 159 | .name = "T10-DIF-TYPE1-CRC", |
| 160 | .generate_fn = sd_dif_type1_generate_crc, |
| 161 | .verify_fn = sd_dif_type1_verify_crc, |
| 162 | .get_tag_fn = sd_dif_type1_get_tag, |
| 163 | .set_tag_fn = sd_dif_type1_set_tag, |
| 164 | .tuple_size = sizeof(struct sd_dif_tuple), |
| 165 | .tag_size = 0, |
| 166 | }; |
| 167 | |
| 168 | static struct blk_integrity dif_type1_integrity_ip = { |
| 169 | .name = "T10-DIF-TYPE1-IP", |
| 170 | .generate_fn = sd_dif_type1_generate_ip, |
| 171 | .verify_fn = sd_dif_type1_verify_ip, |
| 172 | .get_tag_fn = sd_dif_type1_get_tag, |
| 173 | .set_tag_fn = sd_dif_type1_set_tag, |
| 174 | .tuple_size = sizeof(struct sd_dif_tuple), |
| 175 | .tag_size = 0, |
| 176 | }; |
| 177 | |
| 178 | |
| 179 | /* |
| 180 | * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque |
| 181 | * tag space. |
| 182 | */ |
| 183 | static void sd_dif_type3_generate(struct blk_integrity_exchg *bix, csum_fn *fn) |
| 184 | { |
| 185 | void *buf = bix->data_buf; |
| 186 | struct sd_dif_tuple *sdt = bix->prot_buf; |
| 187 | unsigned int i; |
| 188 | |
| 189 | for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) { |
| 190 | sdt->guard_tag = fn(buf, bix->sector_size); |
| 191 | sdt->ref_tag = 0; |
| 192 | sdt->app_tag = 0; |
| 193 | |
| 194 | buf += bix->sector_size; |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | static void sd_dif_type3_generate_crc(struct blk_integrity_exchg *bix) |
| 199 | { |
| 200 | sd_dif_type3_generate(bix, sd_dif_crc_fn); |
| 201 | } |
| 202 | |
| 203 | static void sd_dif_type3_generate_ip(struct blk_integrity_exchg *bix) |
| 204 | { |
| 205 | sd_dif_type3_generate(bix, sd_dif_ip_fn); |
| 206 | } |
| 207 | |
| 208 | static int sd_dif_type3_verify(struct blk_integrity_exchg *bix, csum_fn *fn) |
| 209 | { |
| 210 | void *buf = bix->data_buf; |
| 211 | struct sd_dif_tuple *sdt = bix->prot_buf; |
| 212 | sector_t sector = bix->sector; |
| 213 | unsigned int i; |
| 214 | __u16 csum; |
| 215 | |
| 216 | for (i = 0 ; i < bix->data_size ; i += bix->sector_size, sdt++) { |
| 217 | /* Unwritten sectors */ |
| 218 | if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff) |
| 219 | return 0; |
| 220 | |
| 221 | csum = fn(buf, bix->sector_size); |
| 222 | |
| 223 | if (sdt->guard_tag != csum) { |
| 224 | printk(KERN_ERR "%s: guard tag error on sector %lu " \ |
| 225 | "(rcvd %04x, data %04x)\n", bix->disk_name, |
| 226 | (unsigned long)sector, |
| 227 | be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum)); |
| 228 | return -EIO; |
| 229 | } |
| 230 | |
| 231 | buf += bix->sector_size; |
| 232 | sector++; |
| 233 | } |
| 234 | |
| 235 | return 0; |
| 236 | } |
| 237 | |
| 238 | static int sd_dif_type3_verify_crc(struct blk_integrity_exchg *bix) |
| 239 | { |
| 240 | return sd_dif_type3_verify(bix, sd_dif_crc_fn); |
| 241 | } |
| 242 | |
| 243 | static int sd_dif_type3_verify_ip(struct blk_integrity_exchg *bix) |
| 244 | { |
| 245 | return sd_dif_type3_verify(bix, sd_dif_ip_fn); |
| 246 | } |
| 247 | |
| 248 | static void sd_dif_type3_set_tag(void *prot, void *tag_buf, unsigned int sectors) |
| 249 | { |
| 250 | struct sd_dif_tuple *sdt = prot; |
| 251 | u8 *tag = tag_buf; |
| 252 | unsigned int i, j; |
| 253 | |
| 254 | for (i = 0, j = 0 ; i < sectors ; i++, j += 6, sdt++) { |
| 255 | sdt->app_tag = tag[j] << 8 | tag[j+1]; |
| 256 | sdt->ref_tag = tag[j+2] << 24 | tag[j+3] << 16 | |
| 257 | tag[j+4] << 8 | tag[j+5]; |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | static void sd_dif_type3_get_tag(void *prot, void *tag_buf, unsigned int sectors) |
| 262 | { |
| 263 | struct sd_dif_tuple *sdt = prot; |
| 264 | u8 *tag = tag_buf; |
| 265 | unsigned int i, j; |
| 266 | |
| 267 | for (i = 0, j = 0 ; i < sectors ; i++, j += 2, sdt++) { |
| 268 | tag[j] = (sdt->app_tag & 0xff00) >> 8; |
| 269 | tag[j+1] = sdt->app_tag & 0xff; |
| 270 | tag[j+2] = (sdt->ref_tag & 0xff000000) >> 24; |
| 271 | tag[j+3] = (sdt->ref_tag & 0xff0000) >> 16; |
| 272 | tag[j+4] = (sdt->ref_tag & 0xff00) >> 8; |
| 273 | tag[j+5] = sdt->ref_tag & 0xff; |
| 274 | BUG_ON(sdt->app_tag == 0xffff || sdt->ref_tag == 0xffffffff); |
| 275 | } |
| 276 | } |
| 277 | |
| 278 | static struct blk_integrity dif_type3_integrity_crc = { |
| 279 | .name = "T10-DIF-TYPE3-CRC", |
| 280 | .generate_fn = sd_dif_type3_generate_crc, |
| 281 | .verify_fn = sd_dif_type3_verify_crc, |
| 282 | .get_tag_fn = sd_dif_type3_get_tag, |
| 283 | .set_tag_fn = sd_dif_type3_set_tag, |
| 284 | .tuple_size = sizeof(struct sd_dif_tuple), |
| 285 | .tag_size = 0, |
| 286 | }; |
| 287 | |
| 288 | static struct blk_integrity dif_type3_integrity_ip = { |
| 289 | .name = "T10-DIF-TYPE3-IP", |
| 290 | .generate_fn = sd_dif_type3_generate_ip, |
| 291 | .verify_fn = sd_dif_type3_verify_ip, |
| 292 | .get_tag_fn = sd_dif_type3_get_tag, |
| 293 | .set_tag_fn = sd_dif_type3_set_tag, |
| 294 | .tuple_size = sizeof(struct sd_dif_tuple), |
| 295 | .tag_size = 0, |
| 296 | }; |
| 297 | |
| 298 | /* |
| 299 | * Configure exchange of protection information between OS and HBA. |
| 300 | */ |
| 301 | void sd_dif_config_host(struct scsi_disk *sdkp) |
| 302 | { |
| 303 | struct scsi_device *sdp = sdkp->device; |
| 304 | struct gendisk *disk = sdkp->disk; |
| 305 | u8 type = sdkp->protection_type; |
| 306 | int dif, dix; |
| 307 | |
| 308 | dif = scsi_host_dif_capable(sdp->host, type); |
| 309 | dix = scsi_host_dix_capable(sdp->host, type); |
| 310 | |
| 311 | if (!dix && scsi_host_dix_capable(sdp->host, 0)) { |
| 312 | dif = 0; dix = 1; |
| 313 | } |
| 314 | |
| 315 | if (!dix) |
| 316 | return; |
| 317 | |
| 318 | /* Enable DMA of protection information */ |
| 319 | if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) |
| 320 | if (type == SD_DIF_TYPE3_PROTECTION) |
| 321 | blk_integrity_register(disk, &dif_type3_integrity_ip); |
| 322 | else |
| 323 | blk_integrity_register(disk, &dif_type1_integrity_ip); |
| 324 | else |
| 325 | if (type == SD_DIF_TYPE3_PROTECTION) |
| 326 | blk_integrity_register(disk, &dif_type3_integrity_crc); |
| 327 | else |
| 328 | blk_integrity_register(disk, &dif_type1_integrity_crc); |
| 329 | |
| 330 | sd_printk(KERN_NOTICE, sdkp, |
| 331 | "Enabling DIX %s protection\n", disk->integrity->name); |
| 332 | |
| 333 | /* Signal to block layer that we support sector tagging */ |
| 334 | if (dif && type && sdkp->ATO) { |
| 335 | if (type == SD_DIF_TYPE3_PROTECTION) |
| 336 | disk->integrity->tag_size = sizeof(u16) + sizeof(u32); |
| 337 | else |
| 338 | disk->integrity->tag_size = sizeof(u16); |
| 339 | |
| 340 | sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n", |
| 341 | disk->integrity->tag_size); |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * The virtual start sector is the one that was originally submitted |
| 347 | * by the block layer. Due to partitioning, MD/DM cloning, etc. the |
| 348 | * actual physical start sector is likely to be different. Remap |
| 349 | * protection information to match the physical LBA. |
| 350 | * |
| 351 | * From a protocol perspective there's a slight difference between |
| 352 | * Type 1 and 2. The latter uses 32-byte CDBs exclusively, and the |
| 353 | * reference tag is seeded in the CDB. This gives us the potential to |
| 354 | * avoid virt->phys remapping during write. However, at read time we |
| 355 | * don't know whether the virt sector is the same as when we wrote it |
| 356 | * (we could be reading from real disk as opposed to MD/DM device. So |
| 357 | * we always remap Type 2 making it identical to Type 1. |
| 358 | * |
| 359 | * Type 3 does not have a reference tag so no remapping is required. |
| 360 | */ |
| 361 | void sd_dif_prepare(struct request *rq, sector_t hw_sector, |
| 362 | unsigned int sector_sz) |
| 363 | { |
| 364 | const int tuple_sz = sizeof(struct sd_dif_tuple); |
| 365 | struct bio *bio; |
| 366 | struct scsi_disk *sdkp; |
| 367 | struct sd_dif_tuple *sdt; |
| 368 | unsigned int i, j; |
| 369 | u32 phys, virt; |
| 370 | |
| 371 | sdkp = rq->bio->bi_bdev->bd_disk->private_data; |
| 372 | |
| 373 | if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION) |
| 374 | return; |
| 375 | |
| 376 | phys = hw_sector & 0xffffffff; |
| 377 | |
| 378 | __rq_for_each_bio(bio, rq) { |
| 379 | struct bio_vec *iv; |
| 380 | |
| 381 | /* Already remapped? */ |
| 382 | if (bio_flagged(bio, BIO_MAPPED_INTEGRITY)) |
| 383 | break; |
| 384 | |
| 385 | virt = bio->bi_integrity->bip_sector & 0xffffffff; |
| 386 | |
| 387 | bip_for_each_vec(iv, bio->bi_integrity, i) { |
| 388 | sdt = kmap_atomic(iv->bv_page) |
| 389 | + iv->bv_offset; |
| 390 | |
| 391 | for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) { |
| 392 | |
| 393 | if (be32_to_cpu(sdt->ref_tag) == virt) |
| 394 | sdt->ref_tag = cpu_to_be32(phys); |
| 395 | |
| 396 | virt++; |
| 397 | phys++; |
| 398 | } |
| 399 | |
| 400 | kunmap_atomic(sdt); |
| 401 | } |
| 402 | |
| 403 | bio->bi_flags |= (1 << BIO_MAPPED_INTEGRITY); |
| 404 | } |
| 405 | } |
| 406 | |
| 407 | /* |
| 408 | * Remap physical sector values in the reference tag to the virtual |
| 409 | * values expected by the block layer. |
| 410 | */ |
| 411 | void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes) |
| 412 | { |
| 413 | const int tuple_sz = sizeof(struct sd_dif_tuple); |
| 414 | struct scsi_disk *sdkp; |
| 415 | struct bio *bio; |
| 416 | struct sd_dif_tuple *sdt; |
| 417 | unsigned int i, j, sectors, sector_sz; |
| 418 | u32 phys, virt; |
| 419 | |
| 420 | sdkp = scsi_disk(scmd->request->rq_disk); |
| 421 | |
| 422 | if (sdkp->protection_type == SD_DIF_TYPE3_PROTECTION || good_bytes == 0) |
| 423 | return; |
| 424 | |
| 425 | sector_sz = scmd->device->sector_size; |
| 426 | sectors = good_bytes / sector_sz; |
| 427 | |
| 428 | phys = blk_rq_pos(scmd->request) & 0xffffffff; |
| 429 | if (sector_sz == 4096) |
| 430 | phys >>= 3; |
| 431 | |
| 432 | __rq_for_each_bio(bio, scmd->request) { |
| 433 | struct bio_vec *iv; |
| 434 | |
| 435 | virt = bio->bi_integrity->bip_sector & 0xffffffff; |
| 436 | |
| 437 | bip_for_each_vec(iv, bio->bi_integrity, i) { |
| 438 | sdt = kmap_atomic(iv->bv_page) |
| 439 | + iv->bv_offset; |
| 440 | |
| 441 | for (j = 0 ; j < iv->bv_len ; j += tuple_sz, sdt++) { |
| 442 | |
| 443 | if (sectors == 0) { |
| 444 | kunmap_atomic(sdt); |
| 445 | return; |
| 446 | } |
| 447 | |
| 448 | if (be32_to_cpu(sdt->ref_tag) == phys) |
| 449 | sdt->ref_tag = cpu_to_be32(virt); |
| 450 | |
| 451 | virt++; |
| 452 | phys++; |
| 453 | sectors--; |
| 454 | } |
| 455 | |
| 456 | kunmap_atomic(sdt); |
| 457 | } |
| 458 | } |
| 459 | } |
| 460 | |