[SCSI] sd: Identify DIF protection type and application tag ownership

If a disk is formatted with protection information (Inquiry bit
PROTECT=1) it is required to support Read Capacity(16).  Force use of
the 16-bit command in this case and extract the P_TYPE field which
indicates whether the disk is formatted using DIF Type 1, 2 or 3.

The ATO (App Tag Own) bit in the Control Mode Page indicates whether
the storage device or the initiator own the contents of the
DIF application tag.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 03a3d45cfa42..86b18d4170fe 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -41,7 +41,9 @@ struct scsi_disk {
         u32             index;
         u8              media_present;
         u8              write_prot;
+        u8              protection_type;/* Data Integrity Field */
         unsigned        previous_state : 1;
+        unsigned        ATO : 1;        /* state of disk ATO bit */
         unsigned        WCE : 1;        /* state of disk WCE bit */
         unsigned        RCD : 1;        /* state of disk RCD bit, unused */
         unsigned        DPOFUA : 1;     /* state of disk DPOFUA bit */
@@ -59,4 +61,25 @@ static inline struct scsi_disk *scsi_disk(struct gendisk *disk)
                     (sdsk)->disk->disk_name, ##a) :                     \
         sdev_printk(prefix, (sdsk)->device, fmt, ##a)
 
+/*
+ * A DIF-capable target device can be formatted with different
+ * protection schemes.  Currently 0 through 3 are defined:
+ *
+ * Type 0 is regular (unprotected) I/O
+ *
+ * Type 1 defines the contents of the guard and reference tags
+ *
+ * Type 2 defines the contents of the guard and reference tags and
+ * uses 32-byte commands to seed the latter
+ *
+ * Type 3 defines the contents of the guard tag only
+ */
+
+enum sd_dif_target_protection_types {
+        SD_DIF_TYPE0_PROTECTION = 0x0,
+        SD_DIF_TYPE1_PROTECTION = 0x1,
+        SD_DIF_TYPE2_PROTECTION = 0x2,
+        SD_DIF_TYPE3_PROTECTION = 0x3,
+};
+
 #endif /* _SCSI_DISK_H */