[SCSI] Support devices with protection information
Implement support for DMA of protection information for devices that
are data integrity capable.
- Add support for mapping an extra scatter-gather list containing
the protection information.
- Allocate protection scsi_data_buffer if host is DIX (integrity DMA)
capable.
- Accessor function for checking whether a device has protection
enabled.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 402c107..f9f6e79 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -90,6 +90,8 @@
/* These elements define the operation we ultimately want to perform */
struct scsi_data_buffer sdb;
+ struct scsi_data_buffer *prot_sdb;
+
unsigned underflow; /* Return error if less than
this amount is transferred */
@@ -274,4 +276,22 @@
return scmd->request->sector;
}
+static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)
+{
+ return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;
+}
+
+static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)
+{
+ return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;
+}
+
+static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)
+{
+ return cmd->prot_sdb;
+}
+
+#define scsi_for_each_prot_sg(cmd, sg, nseg, __i) \
+ for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)
+
#endif /* _SCSI_SCSI_CMND_H */