[PATCH v4 5/5] scsi: ufs: add compatibility with 3.1 UFS unit descriptor length

[Bean Huo <huobean@gmail.com>]

From: Bean Huo <beanhuo@micron.com>

For UFS 3.1, the normal unit descriptor is 10 bytes larger
than the RPMB unit, however, both descriptors share the same
desc_idn, to cover both unit descriptors with one length, we
choose the normal unit descriptor length by desc_index.

Signed-off-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/scsi/ufs/ufs.h    |  1 +
 drivers/scsi/ufs/ufshcd.c | 11 ++++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h
index 6548ef102eb9..332ae09e6238 100644
--- a/drivers/scsi/ufs/ufs.h
+++ b/drivers/scsi/ufs/ufs.h
@@ -63,6 +63,7 @@
 #define UFS_UPIU_MAX_UNIT_NUM_ID	0x7F
 #define UFS_MAX_LUNS		(SCSI_W_LUN_BASE + UFS_UPIU_MAX_UNIT_NUM_ID)
 #define UFS_UPIU_WLUN_ID	(1 << 7)
+#define UFS_RPMB_UNIT		0xC4
 
 /* WriteBooster buffer is available only for the logical unit from 0 to 7 */
 #define UFS_UPIU_MAX_WB_LUN_ID	8
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 45d1fef982a9..a64718bfe2bc 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3070,11 +3070,16 @@ void ufshcd_map_desc_id_to_length(struct ufs_hba *hba, enum desc_idn desc_id,
 EXPORT_SYMBOL(ufshcd_map_desc_id_to_length);
 
 static void ufshcd_update_desc_length(struct ufs_hba *hba,
-				      enum desc_idn desc_id,
+				      enum desc_idn desc_id, int desc_index,
 				      unsigned char desc_len)
 {
 	if (hba->desc_size[desc_id] == QUERY_DESC_MAX_SIZE &&
-	    desc_id != QUERY_DESC_IDN_STRING)
+	    desc_id != QUERY_DESC_IDN_STRING && desc_index != UFS_RPMB_UNIT)
+		/* For UFS 3.1, the normal unit descriptor is 10 bytes larger
+		 * than the RPMB unit, however, both descriptors share the same
+		 * desc_idn, to cover both unit descriptors with one length, we
+		 * choose the normal unit descriptor length by desc_index.
+		 */
 		hba->desc_size[desc_id] = desc_len;
 }
 
@@ -3143,7 +3148,7 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,
 
 	/* Update descriptor length */
 	buff_len = desc_buf[QUERY_DESC_LENGTH_OFFSET];
-	ufshcd_update_desc_length(hba, desc_id, buff_len);
+	ufshcd_update_desc_length(hba, desc_id, desc_index, buff_len);
 
 	/* Check wherher we will not copy more data, than available */
 	if (is_kmalloc && param_size > buff_len)
-- 
2.17.1