[PATCH v2] ufs: introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk

[Kiwoong Kim <kwmad.kim@samsung.com>]

Some UFS host controllers may think
granularitys of PRDT length and offset as bytes, not double words.

Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
---
 drivers/scsi/ufs/ufshcd.c | 28 +++++++++++++++++++++-------
 drivers/scsi/ufs/ufshcd.h |  6 ++++++
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index e75fbb3..d6e3112 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -1128,7 +1128,7 @@ ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
  *
  * Returns 0 in case of success, non-zero value in case of failure
  */
-static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
+static int ufshcd_map_sg(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 {
 	struct ufshcd_sg_entry *prd_table;
 	struct scatterlist *sg;
@@ -1142,8 +1142,13 @@ static int ufshcd_map_sg(struct ufshcd_lrb *lrbp)
 		return sg_segments;
 
 	if (sg_segments) {
-		lrbp->utr_descriptor_ptr->prd_table_length =
-					cpu_to_le16((u16) (sg_segments));
+		if (hba->quirks & UFSHCD_QUIRK_PRDT_BYTE_GRAN)
+			lrbp->utr_descriptor_ptr->prd_table_length =
+				cpu_to_le16((u16)(sg_segments *
+					sizeof(struct ufshcd_sg_entry)));
+		else
+			lrbp->utr_descriptor_ptr->prd_table_length =
+				cpu_to_le16((u16) (sg_segments));
 
 		prd_table = (struct ufshcd_sg_entry *)lrbp->ucd_prdt_ptr;
 
@@ -1505,7 +1510,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 
 	ufshcd_comp_scsi_upiu(hba, lrbp);
 
-	err = ufshcd_map_sg(lrbp);
+	err = ufshcd_map_sg(hba, lrbp);
 	if (err) {
 		lrbp->cmd = NULL;
 		clear_bit_unlock(tag, &hba->lrb_in_use);
@@ -2366,12 +2371,21 @@ static void ufshcd_host_memory_configure(struct ufs_hba *hba)
 				cpu_to_le32(upper_32_bits(cmd_desc_element_addr));
 
 		/* Response upiu and prdt offset should be in double words */
-		utrdlp[i].response_upiu_offset =
+		if (hba->quirks & UFSHCD_QUIRK_PRDT_BYTE_GRAN) {
+			utrdlp[i].response_upiu_offset =
+				cpu_to_le16(response_offset);
+			utrdlp[i].prd_table_offset =
+				cpu_to_le16(prdt_offset);
+			utrdlp[i].response_upiu_length =
+				cpu_to_le16(ALIGNED_UPIU_SIZE);
+		} else {
+			utrdlp[i].response_upiu_offset =
 				cpu_to_le16((response_offset >> 2));
-		utrdlp[i].prd_table_offset =
+			utrdlp[i].prd_table_offset =
 				cpu_to_le16((prdt_offset >> 2));
-		utrdlp[i].response_upiu_length =
+			utrdlp[i].response_upiu_length =
 				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
+		}
 
 		hba->lrb[i].utr_descriptor_ptr = (utrdlp + i);
 		hba->lrb[i].ucd_req_ptr =
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8e76501..7d9ff22 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -485,6 +485,12 @@ struct ufs_hba {
 	 */
 	#define UFSHCD_QUIRK_BROKEN_UFS_HCI_VERSION		UFS_BIT(5)
 
+	/*
+	 * This quirk needs to be enabled if the host contoller regards
+	 * resolution of the values of PRDTO and PRDTL in UTRD as byte.
+	 */
+	#define UFSHCD_QUIRK_PRDT_BYTE_GRAN			UFS_BIT(7)
+
 	unsigned int quirks;	/* Deviations from standard UFSHCI spec. */
 
 	/* Device deviations from standard UFS device spec. */
-- 
2.1.4