target: Add DIF related base definitions

This patch adds DIF related definitions to target_core_base.h
that includes enums for target_prot_op + target_prot_type +
target_prot_version + target_guard_type + target_pi_error.

Also included is struct se_dif_v1_tuple, along with changes
to struct se_cmd, struct se_dev_attrib, and struct se_device.

Also, add new se_subsystem_api->[init,format,free]_prot() callers
used by target core code to setup backend specific protection
information after the device has been configured.

Enums taken from Sagi Grimberg's original patch.

v2 changes:
  - Drop guard_type related definitions
  - Update target_prot_op + target_prot_ho definitions (Sagi)
  - Drop SCF_PROT + pi_prot_version flag
  - Add se_subsystem_api->format_prot() (Sagi)
  - Add hw_pi_prot_type device attribute

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 47 insertions, 0 deletions

diff --git a/include/target/target_core_backend.h b/include/target/target_core_backend.h
index 39e0114d70c5..0dc2745b9b18 100644
--- a/include/target/target_core_backend.h
+++ b/include/target/target_core_backend.h
@@ -41,6 +41,9 @@ struct se_subsystem_api {
         unsigned int (*get_io_opt)(struct se_device *);
         unsigned char *(*get_sense_buffer)(struct se_cmd *);
         bool (*get_write_cache)(struct se_device *);
+        int (*init_prot)(struct se_device *);
+        int (*format_prot)(struct se_device *);
+        void (*free_prot)(struct se_device *);
 };
 
 struct sbc_ops {
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index dd87ab46ce21..d98048b97fe3 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -435,6 +435,34 @@ struct se_tmr_req {
         struct list_head        tmr_list;
 };
 
+enum target_prot_op {
+        TARGET_PROT_NORMAL = 0,
+        TARGET_PROT_DIN_INSERT,
+        TARGET_PROT_DOUT_INSERT,
+        TARGET_PROT_DIN_STRIP,
+        TARGET_PROT_DOUT_STRIP,
+        TARGET_PROT_DIN_PASS,
+        TARGET_PROT_DOUT_PASS,
+};
+
+enum target_prot_ho {
+        PROT_SEPERATED,
+        PROT_INTERLEAVED,
+};
+
+enum target_prot_type {
+        TARGET_DIF_TYPE0_PROT,
+        TARGET_DIF_TYPE1_PROT,
+        TARGET_DIF_TYPE2_PROT,
+        TARGET_DIF_TYPE3_PROT,
+};
+
+struct se_dif_v1_tuple {
+        __be16                  guard_tag;
+        __be16                  app_tag;
+        __be32                  ref_tag;
+};
+
 struct se_cmd {
         /* SAM response code being sent to initiator */
         u8                      scsi_status;
@@ -519,6 +547,17 @@ struct se_cmd {
 
         /* Used for lun->lun_ref counting */
         bool                    lun_ref_active;
+
+        /* DIF related members */
+        enum target_prot_op     prot_op;
+        enum target_prot_type   prot_type;
+        u32                     prot_length;
+        u32                     reftag_seed;
+        struct scatterlist      *t_prot_sg;
+        unsigned int            t_prot_nents;
+        enum target_prot_ho     prot_handover;
+        sense_reason_t          pi_err;
+        u32                     block_num;
 };
 
 struct se_ua {
@@ -629,6 +668,9 @@ struct se_dev_attrib {
         int             emulate_tpws;
         int             emulate_caw;
         int             emulate_3pc;
+        int             pi_prot_format;
+        enum target_prot_type pi_prot_type;
+        enum target_prot_type hw_pi_prot_type;
         int             enforce_pr_isids;
         int             is_nonrot;
         int             emulate_rest_reord;
@@ -759,6 +801,8 @@ struct se_device {
         /* Linked list for struct se_hba struct se_device list */
         struct list_head        dev_list;
         struct se_lun           xcopy_lun;
+        /* Protection Information */
+        int                     prot_length;
 };
 
 struct se_hba {