scsi: ufs: Introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk

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

Link: https://lore.kernel.org/r/20200528011658.71590-5-alim.akhtar@samsung.com
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>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 411d9a43282d6a21f061d53c904c7b56240e0360..52206d5c2ca20933034fc3476c8d8be2d5eed1d1 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2168,8 +2168,14 @@ 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;
 
@@ -3518,11 +3524,21 @@ 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 904bc620c2eda7d6050962a7f40a7aabc0c0a27e..519a9e82ab958cbf528844aecf3ec101327248ad 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -537,6 +537,12 @@ 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 {