3 files changed, 183 insertions, 0 deletions

diff --git a/drivers/target/Kconfig b/drivers/target/Kconfig
index 18303686eb58..50aad2eeed6e 100644
--- a/drivers/target/Kconfig
+++ b/drivers/target/Kconfig
@@ -3,6 +3,7 @@ menuconfig TARGET_CORE
         tristate "Generic Target Core Mod (TCM) and ConfigFS Infrastructure"
         depends on SCSI && BLOCK
         select CONFIGFS_FS
+        select CRC_T10DIF
         default n
         help
         Say Y or M here to enable the TCM Storage Engine and ConfigFS enabled
diff --git a/drivers/target/target_core_sbc.c b/drivers/target/target_core_sbc.c
index 91a92f354e9f..26e8bfb27787 100644
--- a/drivers/target/target_core_sbc.c
+++ b/drivers/target/target_core_sbc.c
@@ -23,6 +23,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/ratelimit.h>
+#include <linux/crc-t10dif.h>
 #include <asm/unaligned.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_tcq.h>
@@ -1024,3 +1025,180 @@ err:
         return ret;
 }
 EXPORT_SYMBOL(sbc_execute_unmap);
+
+static sense_reason_t
+sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,
+                  const void *p, sector_t sector, unsigned int ei_lba)
+{
+        int block_size = dev->dev_attrib.block_size;
+        __be16 csum;
+
+        csum = cpu_to_be16(crc_t10dif(p, block_size));
+
+        if (sdt->guard_tag != csum) {
+                pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
+                        " csum 0x%04x\n", (unsigned long long)sector,
+                        be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
+                return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
+        }
+
+        if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&
+            be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
+                pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
+                       " sector MSB: 0x%08x\n", (unsigned long long)sector,
+                       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
+                return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
+        }
+
+        if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&
+            be32_to_cpu(sdt->ref_tag) != ei_lba) {
+                pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
+                       " ei_lba: 0x%08x\n", (unsigned long long)sector,
+                        be32_to_cpu(sdt->ref_tag), ei_lba);
+                return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
+        }
+
+        return 0;
+}
+
+static void
+sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
+                  struct scatterlist *sg, int sg_off)
+{
+        struct se_device *dev = cmd->se_dev;
+        struct scatterlist *psg;
+        void *paddr, *addr;
+        unsigned int i, len, left;
+
+        left = sectors * dev->prot_length;
+
+        for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
+
+                len = min(psg->length, left);
+                paddr = kmap_atomic(sg_page(psg)) + psg->offset;
+                addr = kmap_atomic(sg_page(sg)) + sg_off;
+
+                if (read)
+                        memcpy(paddr, addr, len);
+                else
+                        memcpy(addr, paddr, len);
+
+                left -= len;
+                kunmap_atomic(paddr);
+                kunmap_atomic(addr);
+        }
+}
+
+sense_reason_t
+sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,
+                     unsigned int ei_lba, struct scatterlist *sg, int sg_off)
+{
+        struct se_device *dev = cmd->se_dev;
+        struct se_dif_v1_tuple *sdt;
+        struct scatterlist *dsg, *psg = cmd->t_prot_sg;
+        sector_t sector = start;
+        void *daddr, *paddr;
+        int i, j, offset = 0;
+        sense_reason_t rc;
+
+        for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
+                daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
+                paddr = kmap_atomic(sg_page(psg)) + psg->offset;
+
+                for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
+
+                        if (offset >= psg->length) {
+                                kunmap_atomic(paddr);
+                                psg = sg_next(psg);
+                                paddr = kmap_atomic(sg_page(psg)) + psg->offset;
+                                offset = 0;
+                        }
+
+                        sdt = paddr + offset;
+
+                        pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"
+                                 " app_tag: 0x%04x ref_tag: %u\n",
+                                 (unsigned long long)sector, sdt->guard_tag,
+                                 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
+
+                        rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
+                                               ei_lba);
+                        if (rc) {
+                                kunmap_atomic(paddr);
+                                kunmap_atomic(daddr);
+                                return rc;
+                        }
+
+                        sector++;
+                        ei_lba++;
+                        offset += sizeof(struct se_dif_v1_tuple);
+                }
+
+                kunmap_atomic(paddr);
+                kunmap_atomic(daddr);
+        }
+        sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);
+
+        return 0;
+}
+EXPORT_SYMBOL(sbc_dif_verify_write);
+
+sense_reason_t
+sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,
+                    unsigned int ei_lba, struct scatterlist *sg, int sg_off)
+{
+        struct se_device *dev = cmd->se_dev;
+        struct se_dif_v1_tuple *sdt;
+        struct scatterlist *dsg;
+        sector_t sector = start;
+        void *daddr, *paddr;
+        int i, j, offset = sg_off;
+        sense_reason_t rc;
+
+        for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {
+                daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
+                paddr = kmap_atomic(sg_page(sg)) + sg->offset;
+
+                for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {
+
+                        if (offset >= sg->length) {
+                                kunmap_atomic(paddr);
+                                sg = sg_next(sg);
+                                paddr = kmap_atomic(sg_page(sg)) + sg->offset;
+                                offset = 0;
+                        }
+
+                        sdt = paddr + offset;
+
+                        pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
+                                 " app_tag: 0x%04x ref_tag: %u\n",
+                                 (unsigned long long)sector, sdt->guard_tag,
+                                 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
+
+                        if (sdt->app_tag == cpu_to_be16(0xffff)) {
+                                sector++;
+                                offset += sizeof(struct se_dif_v1_tuple);
+                                continue;
+                        }
+
+                        rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,
+                                               ei_lba);
+                        if (rc) {
+                                kunmap_atomic(paddr);
+                                kunmap_atomic(daddr);
+                                return rc;
+                        }
+
+                        sector++;
+                        ei_lba++;
+                        offset += sizeof(struct se_dif_v1_tuple);
+                }
+
+                kunmap_atomic(paddr);
+                kunmap_atomic(daddr);
+        }
+        sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);
+
+        return 0;
+}
+EXPORT_SYMBOL(sbc_dif_verify_read);
diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 0dc2745b9b18..7020e33e742e 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -73,6 +73,10 @@ sense_reason_t sbc_execute_unmap(struct se_cmd *cmd,
         sense_reason_t (*do_unmap_fn)(struct se_cmd *cmd, void *priv,
                                       sector_t lba, sector_t nolb),
         void *priv);
+sense_reason_t  sbc_dif_verify_write(struct se_cmd *, sector_t, unsigned int,
+                                     unsigned int, struct scatterlist *, int);
+sense_reason_t  sbc_dif_verify_read(struct se_cmd *, sector_t, unsigned int,
+                                    unsigned int, struct scatterlist *, int);
 
 void    transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);
 int     transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);