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-rw-r--r--block/t10-pi.c285
1 files changed, 285 insertions, 0 deletions
diff --git a/block/t10-pi.c b/block/t10-pi.c
new file mode 100644
index 000000000..d910534b3
--- /dev/null
+++ b/block/t10-pi.c
@@ -0,0 +1,285 @@
+// 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");
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