| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * t10_pi.c - Functions for generating and verifying T10 Protection |
| * Information. |
| */ |
| |
| #include <linux/t10-pi.h> |
| #include <linux/blkdev.h> |
| #include <linux/crc-t10dif.h> |
| #include <net/checksum.h> |
| |
| typedef __be16 (csum_fn) (void *, unsigned int); |
| |
| static __be16 t10_pi_crc_fn(void *data, unsigned int len) |
| { |
| return cpu_to_be16(crc_t10dif(data, len)); |
| } |
| |
| static __be16 t10_pi_ip_fn(void *data, unsigned int len) |
| { |
| return (__force __be16)ip_compute_csum(data, len); |
| } |
| |
| /* |
| * Type 1 and Type 2 protection use the same format: 16 bit guard tag, |
| * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref |
| * tag. |
| */ |
| static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter, |
| csum_fn *fn, enum t10_dif_type type) |
| { |
| unsigned int i; |
| |
| for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
| struct t10_pi_tuple *pi = iter->prot_buf; |
| |
| pi->guard_tag = fn(iter->data_buf, iter->interval); |
| pi->app_tag = 0; |
| |
| if (type == T10_PI_TYPE1_PROTECTION) |
| pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed)); |
| else |
| pi->ref_tag = 0; |
| |
| iter->data_buf += iter->interval; |
| iter->prot_buf += sizeof(struct t10_pi_tuple); |
| iter->seed++; |
| } |
| |
| return BLK_STS_OK; |
| } |
| |
| static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter, |
| csum_fn *fn, enum t10_dif_type type) |
| { |
| unsigned int i; |
| |
| BUG_ON(type == T10_PI_TYPE0_PROTECTION); |
| |
| for (i = 0 ; i < iter->data_size ; i += iter->interval) { |
| struct t10_pi_tuple *pi = iter->prot_buf; |
| __be16 csum; |
| |
| if (type == T10_PI_TYPE1_PROTECTION || |
| type == T10_PI_TYPE2_PROTECTION) { |
| if (pi->app_tag == T10_PI_APP_ESCAPE) |
| goto next; |
| |
| if (be32_to_cpu(pi->ref_tag) != |
| lower_32_bits(iter->seed)) { |
| pr_err("%s: ref tag error at location %llu " \ |
| "(rcvd %u)\n", iter->disk_name, |
| (unsigned long long) |
| iter->seed, be32_to_cpu(pi->ref_tag)); |
| return BLK_STS_PROTECTION; |
| } |
| } else if (type == T10_PI_TYPE3_PROTECTION) { |
| if (pi->app_tag == T10_PI_APP_ESCAPE && |
| pi->ref_tag == T10_PI_REF_ESCAPE) |
| goto next; |
| } |
| |
| csum = fn(iter->data_buf, iter->interval); |
| |
| if (pi->guard_tag != csum) { |
| pr_err("%s: guard tag error at sector %llu " \ |
| "(rcvd %04x, want %04x)\n", iter->disk_name, |
| (unsigned long long)iter->seed, |
| be16_to_cpu(pi->guard_tag), be16_to_cpu(csum)); |
| return BLK_STS_PROTECTION; |
| } |
| |
| next: |
| iter->data_buf += iter->interval; |
| iter->prot_buf += sizeof(struct t10_pi_tuple); |
| iter->seed++; |
| } |
| |
| return BLK_STS_OK; |
| } |
| |
| static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_generate(iter, t10_pi_crc_fn, T10_PI_TYPE1_PROTECTION); |
| } |
| |
| static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_generate(iter, t10_pi_ip_fn, T10_PI_TYPE1_PROTECTION); |
| } |
| |
| static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_verify(iter, t10_pi_crc_fn, T10_PI_TYPE1_PROTECTION); |
| } |
| |
| static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_verify(iter, t10_pi_ip_fn, T10_PI_TYPE1_PROTECTION); |
| } |
| |
| /** |
| * t10_pi_type1_prepare - prepare PI prior submitting request to device |
| * @rq: request with PI that should be prepared |
| * |
| * For Type 1/Type 2, the virtual start sector is the one that was |
| * originally submitted by the block layer for the ref_tag usage. Due to |
| * partitioning, MD/DM cloning, etc. the actual physical start sector is |
| * likely to be different. Remap protection information to match the |
| * physical LBA. |
| */ |
| static void t10_pi_type1_prepare(struct request *rq) |
| { |
| const int tuple_sz = rq->q->integrity.tuple_size; |
| u32 ref_tag = t10_pi_ref_tag(rq); |
| struct bio *bio; |
| |
| __rq_for_each_bio(bio, rq) { |
| struct bio_integrity_payload *bip = bio_integrity(bio); |
| u32 virt = bip_get_seed(bip) & 0xffffffff; |
| struct bio_vec iv; |
| struct bvec_iter iter; |
| |
| /* Already remapped? */ |
| if (bip->bip_flags & BIP_MAPPED_INTEGRITY) |
| break; |
| |
| bip_for_each_vec(iv, bip, iter) { |
| void *p, *pmap; |
| unsigned int j; |
| |
| pmap = kmap_atomic(iv.bv_page); |
| p = pmap + iv.bv_offset; |
| for (j = 0; j < iv.bv_len; j += tuple_sz) { |
| struct t10_pi_tuple *pi = p; |
| |
| if (be32_to_cpu(pi->ref_tag) == virt) |
| pi->ref_tag = cpu_to_be32(ref_tag); |
| virt++; |
| ref_tag++; |
| p += tuple_sz; |
| } |
| |
| kunmap_atomic(pmap); |
| } |
| |
| bip->bip_flags |= BIP_MAPPED_INTEGRITY; |
| } |
| } |
| |
| /** |
| * t10_pi_type1_complete - prepare PI prior returning request to the blk layer |
| * @rq: request with PI that should be prepared |
| * @nr_bytes: total bytes to prepare |
| * |
| * For Type 1/Type 2, the virtual start sector is the one that was |
| * originally submitted by the block layer for the ref_tag usage. Due to |
| * partitioning, MD/DM cloning, etc. the actual physical start sector is |
| * likely to be different. Since the physical start sector was submitted |
| * to the device, we should remap it back to virtual values expected by the |
| * block layer. |
| */ |
| static void t10_pi_type1_complete(struct request *rq, unsigned int nr_bytes) |
| { |
| unsigned intervals = nr_bytes >> rq->q->integrity.interval_exp; |
| const int tuple_sz = rq->q->integrity.tuple_size; |
| u32 ref_tag = t10_pi_ref_tag(rq); |
| struct bio *bio; |
| |
| __rq_for_each_bio(bio, rq) { |
| struct bio_integrity_payload *bip = bio_integrity(bio); |
| u32 virt = bip_get_seed(bip) & 0xffffffff; |
| struct bio_vec iv; |
| struct bvec_iter iter; |
| |
| bip_for_each_vec(iv, bip, iter) { |
| void *p, *pmap; |
| unsigned int j; |
| |
| pmap = kmap_atomic(iv.bv_page); |
| p = pmap + iv.bv_offset; |
| for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) { |
| struct t10_pi_tuple *pi = p; |
| |
| if (be32_to_cpu(pi->ref_tag) == ref_tag) |
| pi->ref_tag = cpu_to_be32(virt); |
| virt++; |
| ref_tag++; |
| intervals--; |
| p += tuple_sz; |
| } |
| |
| kunmap_atomic(pmap); |
| } |
| } |
| } |
| |
| static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_generate(iter, t10_pi_crc_fn, T10_PI_TYPE3_PROTECTION); |
| } |
| |
| static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_generate(iter, t10_pi_ip_fn, T10_PI_TYPE3_PROTECTION); |
| } |
| |
| static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_verify(iter, t10_pi_crc_fn, T10_PI_TYPE3_PROTECTION); |
| } |
| |
| static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter) |
| { |
| return t10_pi_verify(iter, t10_pi_ip_fn, T10_PI_TYPE3_PROTECTION); |
| } |
| |
| /** |
| * Type 3 does not have a reference tag so no remapping is required. |
| */ |
| static void t10_pi_type3_prepare(struct request *rq) |
| { |
| } |
| |
| /** |
| * Type 3 does not have a reference tag so no remapping is required. |
| */ |
| static void t10_pi_type3_complete(struct request *rq, unsigned int nr_bytes) |
| { |
| } |
| |
| const struct blk_integrity_profile t10_pi_type1_crc = { |
| .name = "T10-DIF-TYPE1-CRC", |
| .generate_fn = t10_pi_type1_generate_crc, |
| .verify_fn = t10_pi_type1_verify_crc, |
| .prepare_fn = t10_pi_type1_prepare, |
| .complete_fn = t10_pi_type1_complete, |
| }; |
| EXPORT_SYMBOL(t10_pi_type1_crc); |
| |
| const struct blk_integrity_profile t10_pi_type1_ip = { |
| .name = "T10-DIF-TYPE1-IP", |
| .generate_fn = t10_pi_type1_generate_ip, |
| .verify_fn = t10_pi_type1_verify_ip, |
| .prepare_fn = t10_pi_type1_prepare, |
| .complete_fn = t10_pi_type1_complete, |
| }; |
| EXPORT_SYMBOL(t10_pi_type1_ip); |
| |
| const struct blk_integrity_profile t10_pi_type3_crc = { |
| .name = "T10-DIF-TYPE3-CRC", |
| .generate_fn = t10_pi_type3_generate_crc, |
| .verify_fn = t10_pi_type3_verify_crc, |
| .prepare_fn = t10_pi_type3_prepare, |
| .complete_fn = t10_pi_type3_complete, |
| }; |
| EXPORT_SYMBOL(t10_pi_type3_crc); |
| |
| const struct blk_integrity_profile t10_pi_type3_ip = { |
| .name = "T10-DIF-TYPE3-IP", |
| .generate_fn = t10_pi_type3_generate_ip, |
| .verify_fn = t10_pi_type3_verify_ip, |
| .prepare_fn = t10_pi_type3_prepare, |
| .complete_fn = t10_pi_type3_complete, |
| }; |
| EXPORT_SYMBOL(t10_pi_type3_ip); |