// 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 <linux/module.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); MODULE_LICENSE("GPL");