[SCSI] sd: Support for SCSI disk (SBC) Data Integrity Field
Support for controllers and disks that implement DIF protection
information:
- During command preparation the RDPROTECT/WRPROTECT must be set
correctly if the target has DIF enabled.
- READ(6) and WRITE(6) are not supported when DIF is on.
- The controller must be told how to handle the I/O via the
protection operation field in scsi_cmnd.
- Refactor the I/O completion code that extracts failed LBA from the
returned sense data and handle DIF failures correctly.
- sd_dif.c implements the functions required to prepare and complete
requests with protection information attached.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 86b18d4..550b2f70 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -82,4 +82,29 @@
SD_DIF_TYPE3_PROTECTION = 0x3,
};
+/*
+ * Data Integrity Field tuple.
+ */
+struct sd_dif_tuple {
+ __be16 guard_tag; /* Checksum */
+ __be16 app_tag; /* Opaque storage */
+ __be32 ref_tag; /* Target LBA or indirect LBA */
+};
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+extern void sd_dif_op(struct scsi_cmnd *, unsigned int, unsigned int);
+extern void sd_dif_config_host(struct scsi_disk *);
+extern int sd_dif_prepare(struct request *rq, sector_t, unsigned int);
+extern void sd_dif_complete(struct scsi_cmnd *, unsigned int);
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+
+#define sd_dif_op(a, b, c) do { } while (0)
+#define sd_dif_config_host(a) do { } while (0)
+#define sd_dif_prepare(a, b, c) (0)
+#define sd_dif_complete(a, b) (0)
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
#endif /* _SCSI_DISK_H */