[PATCH v10 04/10] scsi: ufs: introduce UFSHCD_QUIRK_PRDT_BYTE_GRAN quirk

From: Alim Akhtar
Date: Wed May 27 2020 - 21:33:16 EST


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.altman@xxxxxxx>
Signed-off-by: Kiwoong Kim <kwmad.kim@xxxxxxxxxxx>
Signed-off-by: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
---
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