[PATCH v7 04/10] scsi: ufs: introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk

[Alim Akhtar <alim.akhtar@samsung.com>]

Some UFS host controllers like Exynos uses granularities of PRDT length and
offset as bytes, whereas others uses actual segment count. This patch
adds a quirk to handle the same.

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Kiwoong Kim <kwmad.kim@samsung.com>
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
---
 drivers/scsi/ufs/ufshcd.c | 30 +++++++++++++++++++++++-------
 drivers/scsi/ufs/ufshcd.h |  6 ++++++
 2 files changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index ee30ed6cc805..ba093d0d0942 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2151,8 +2151,14 @@ static int ufshcd_map_sg(struct ufs_hba *hba, 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((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;
 
@@ -3500,11 +3506,21 @@ 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 =
-			cpu_to_le16(response_offset >> 2);
-		utrdlp[i].prd_table_offset = cpu_to_le16(prdt_offset >> 2);
-		utrdlp[i].response_upiu_length =
-			cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
+		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 =
+				cpu_to_le16(prdt_offset >> 2);
+			utrdlp[i].response_upiu_length =
+				cpu_to_le16(ALIGNED_UPIU_SIZE >> 2);
+		}
 
 		ufshcd_init_lrb(hba, &hba->lrb[i], i);
 	}
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index f8d08cb9caf7..a9b9ace9fc72 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -535,6 +535,12 @@ enum ufshcd_quirks {
 	 * enabled via HCE register.
 	 */
 	UFSHCI_QUIRK_BROKEN_HCE				= 1 << 8,
+
+	/*
+	 * This quirk needs to be enabled if the host controller regards
+	 * resolution of the values of PRDTO and PRDTL in UTRD as byte.
+	 */
+	UFSHCD_QUIRK_PRDT_BYTE_GRAN			= 1 << 9,
 };
 
 enum ufshcd_caps {
-- 
2.17.1