[PATCH] ufs: core: Improve the documentation of UFS data frames

[Bart Van Assche <bvanassche@acm.org>]

In source code comments, use terminology that comes from the JEDEC
UFS standard. This makes it easier to compare the UFS driver code with the
JEDEC UFS standard. Add static_assert() statements that verify the size
of data structures defined in the UFS standard.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 include/uapi/scsi/scsi_bsg_ufs.h | 17 ++++++++---------
 include/ufs/ufs.h                |  5 ++++-
 2 files changed, 12 insertions(+), 10 deletions(-)

diff --git a/include/uapi/scsi/scsi_bsg_ufs.h b/include/uapi/scsi/scsi_bsg_ufs.h
index 8c29e498ef98..06f88d1b1876 100644
--- a/include/uapi/scsi/scsi_bsg_ufs.h
+++ b/include/uapi/scsi/scsi_bsg_ufs.h
@@ -94,16 +94,15 @@ struct utp_upiu_header {
 };
 
 /**
- * struct utp_upiu_query - upiu request buffer structure for
- * query request.
- * @opcode: command to perform B-0
- * @idn: a value that indicates the particular type of data B-1
- * @index: Index to further identify data B-2
- * @selector: Index to further identify data B-3
+ * struct utp_upiu_query - QUERY REQUEST UPIU structure.
+ * @opcode: query function to perform B-0
+ * @idn: descriptor or attribute identification number B-1
+ * @index: Index that further identifies which data to access B-2
+ * @selector: Index that further identifies which data to access B-3
  * @reserved_osf: spec reserved field B-4,5
- * @length: number of descriptor bytes to read/write B-6,7
- * @value: Attribute value to be written DW-5
- * @reserved: spec reserved DW-6,7
+ * @length: number of descriptor bytes to read or write B-6,7
+ * @value: if @opcode == UPIU_QUERY_OPCODE_WRITE_ATTR, the value to be written B-6,7
+ * @reserved: reserved for future use DW-6,7
  */
 struct utp_upiu_query {
 	__u8 opcode;
diff --git a/include/ufs/ufs.h b/include/ufs/ufs.h
index ab8f6c07b5a2..602aa34c9822 100644
--- a/include/ufs/ufs.h
+++ b/include/ufs/ufs.h
@@ -21,6 +21,7 @@
  * in this header file of the size of struct utp_upiu_header.
  */
 static_assert(sizeof(struct utp_upiu_header) == 12);
+static_assert(sizeof(struct utp_upiu_query) == 20);
 
 #define GENERAL_UPIU_REQUEST_SIZE (sizeof(struct utp_upiu_req))
 #define QUERY_DESC_MAX_SIZE       255
@@ -561,7 +562,7 @@ enum ufs_dev_pwr_mode {
 #define UFS_WB_BUF_REMAIN_PERCENT(val) ((val) / 10)
 
 /**
- * struct utp_cmd_rsp - Response UPIU structure
+ * struct utp_cmd_rsp - RESPONSE UPIU structure
  * @residual_transfer_count: Residual transfer count DW-3
  * @reserved: Reserved double words DW-4 to DW-7
  * @sense_data_len: Sense data length DW-8 U16
@@ -574,6 +575,8 @@ struct utp_cmd_rsp {
 	u8 sense_data[UFS_SENSE_SIZE];
 };
 
+static_assert(sizeof(struct utp_cmd_rsp) == 40);
+
 /**
  * struct utp_upiu_rsp - general upiu response structure
  * @header: UPIU header structure DW-0 to DW-2