[PATCH v8 04/10] scsi: ufs: introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk

[Alim Akhtar]

Some UFS host controllers like Exynos uses granularities of PRDT length and
offset as bytes, whereas others uses actual segment count.

Reviewed-by: Avri Altman <avri.alt...@wdc.com>
Signed-off-by: Kiwoong Kim <kwmad....@samsung.com>
Signed-off-by: Alim Akhtar <alim.akh...@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