[PATCH v4 05/40] scsi: prepare for using 16-bits defined sense codes

[Damien Le Moal <dlemoal@kernel.org>]

In preparation for handling sense codes and their qualifiers as a single
16-bits sense code field, with the values  defined as macros in
include/scsi/scsi_sense.h, modify the definition of the structures
scsi_failure and scsi_sense_hdr to introduce a 16-bits sense_code field
as a union with the existing 8-bits asc and ascq fields.

This temporary modification allows accessing either the asc and ascq
fields individually, or their combination as the 16-bits sense_code field.

The helper functions scsi_sense_asc(), scsi_sense_ascq() are defined to
allow accessing the 8-bits ASC and ASCQ values from the sense_code filed
of struct scsi_sense_hdr. The helper functions scsi_failure_asc() and
scsi_failure_ascq() provide the same for the sense code field of struct
scsi_failure.

The helper functions scsi_set_sense_buffer() and scsi_set_sense() are also
added to wrap calls to scsi_build_sense_buffer() and scsi_build_sense()
using a 16-bits sense code aregument instead of the 8-bits ASC and ASCQ
arguments.

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 include/scsi/scsi_cmnd.h   |  7 +++++++
 include/scsi/scsi_common.h | 31 +++++++++++++++++++++++++++++--
 include/scsi/scsi_device.h | 25 +++++++++++++++++++++++--
 3 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 8ecfb94049db..bf6d69f0249f 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -394,6 +394,13 @@ static inline unsigned scsi_transfer_length(struct scsi_cmnd *scmd)
 extern void scsi_build_sense(struct scsi_cmnd *scmd, int desc,
 			     u8 key, u8 asc, u8 ascq);
 
+static inline void scsi_set_sense(struct scsi_cmnd *scmd, int desc,
+				  u8 key, u16 code)
+{
+	scsi_build_sense(scmd, desc, key, scsi_sense_code_asc(code),
+			 scsi_sense_code_ascq(code));
+}
+
 struct request *scsi_alloc_request(struct request_queue *q, blk_opf_t opf,
 				   blk_mq_req_flags_t flags);
 
diff --git a/include/scsi/scsi_common.h b/include/scsi/scsi_common.h
index 00c8a16d3cd2..6fb2c290ba33 100644
--- a/include/scsi/scsi_common.h
+++ b/include/scsi/scsi_common.h
@@ -71,8 +71,18 @@ extern u64 scsilun_to_int(struct scsi_lun *);
 struct scsi_sense_hdr {		/* See SPC-3 section 4.5 */
 	u8 response_code;	/* permit: 0x0, 0x70, 0x71, 0x72, 0x73 */
 	u8 sense_key;
-	u8 asc;
-	u8 ascq;
+	union {
+		struct {
+#if defined(__BIG_ENDIAN)
+			u8 asc;
+			u8 ascq;
+#elif defined(__LITTLE_ENDIAN)
+			u8 ascq;
+			u8 asc;
+#endif
+		};
+		u16 sense_code;
+	};
 	u8 byte4;
 	u8 byte5;
 	u8 byte6;
@@ -87,10 +97,27 @@ static inline bool scsi_sense_valid(const struct scsi_sense_hdr *sshdr)
 	return (sshdr->response_code & 0x70) == 0x70;
 }
 
+static inline u8 scsi_sense_asc(const struct scsi_sense_hdr *sshdr)
+{
+	return scsi_sense_code_asc(sshdr->sense_code);
+}
+
+static inline u8 scsi_sense_ascq(const struct scsi_sense_hdr *sshdr)
+{
+	return scsi_sense_code_ascq(sshdr->sense_code);
+}
+
 extern bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
 				 struct scsi_sense_hdr *sshdr);
 
 extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
+
+static inline void scsi_set_sense_buffer(int desc, u8 *buf, u8 key, u16 code)
+{
+	scsi_build_sense_buffer(desc, buf, key, scsi_sense_code_asc(code),
+				scsi_sense_code_ascq(code));
+}
+
 int scsi_set_sense_information(u8 *buf, int buf_len, u64 info);
 int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd);
 extern const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index e321471e8ca2..11910142ac50 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -518,6 +518,7 @@ extern void scsi_sanitize_inquiry_string(unsigned char *s, int len);
  * to match any sense key, ASC, and ASCQ value.
  */
 #define SCMD_FAILURE_SENSE_KEY_ANY	0xff
+#define SCMD_FAILURE_SENSE_CODE_ANY	0xffff
 #define SCMD_FAILURE_ASC_ANY		0xff
 #define SCMD_FAILURE_ASCQ_ANY		0xff
 /* Always retry a matching failure. */
@@ -526,8 +527,18 @@ extern void scsi_sanitize_inquiry_string(unsigned char *s, int len);
 struct scsi_failure {
 	int result;
 	u8 sense_key;
-	u8 asc;
-	u8 ascq;
+	union {
+		struct {
+#if defined(__BIG_ENDIAN)
+			u8 asc;
+			u8 ascq;
+#elif defined(__LITTLE_ENDIAN)
+			u8 ascq;
+			u8 asc;
+#endif
+		};
+		u16 sense_code;
+	};
 	/*
 	 * Number of times scsi_execute_cmd will retry the failure. It does
 	 * not count for the total_allowed.
@@ -537,6 +548,16 @@ struct scsi_failure {
 	s8 retries;
 };
 
+static inline u8 scsi_failure_asc(const struct scsi_failure *failure)
+{
+	return scsi_sense_code_asc(failure->sense_code);
+}
+
+static inline u8 scsi_failure_ascq(const struct scsi_failure *failure)
+{
+	return scsi_sense_code_ascq(failure->sense_code);
+}
+
 struct scsi_failures {
 	/*
 	 * If a scsi_failure does not have a retry limit setup this limit will
-- 
2.55.0