Add support for crypto keyslot remapping in the exynos UFS driver using
the device tree property 'ufs-keyslot-offset'.

This allows platforms to apply a fixed offset to the logical keyslot,
enabling secure inline encryption in virtualized or multi-domain
environments.

The implementation is generic and optional which only active if the DT
property is present.

Signed-off-by: zheng.gong <zheng.gong@samsung.com>
---
 drivers/ufs/host/ufs-exynos.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/ufs/host/ufs-exynos.c b/drivers/ufs/host/ufs-exynos.c
index 70d195179eba..dc63900ebbee 100644
--- a/drivers/ufs/host/ufs-exynos.c
+++ b/drivers/ufs/host/ufs-exynos.c
@@ -1437,6 +1437,19 @@ static int exynos_ufs_fmp_fill_prdt(struct ufs_hba *hba,
 	return 0;
 }
 
+static void exynos_ufs_fmp_crypto_keyslot_remap(struct ufs_hba *hba,
+				    struct ufshcd_lrb *lrbp)
+{
+	struct device_node *np = hba->dev->of_node;
+	u32 offset;
+
+	/* If dt property is not present, use identity mapping still.*/
+	if (of_property_read_u32(np, "ufs-keyslot-offset", &offset) == 0) {
+		if (lrbp->crypto_key_slot >= 0)
+			lrbp->crypto_key_slot += offset;
+	}
+}
+
 #else /* CONFIG_SCSI_UFS_CRYPTO */
 
 static void exynos_ufs_fmp_init(struct ufs_hba *hba, struct exynos_ufs *ufs)
@@ -1449,6 +1462,8 @@ static void exynos_ufs_fmp_resume(struct ufs_hba *hba)
 
 #define exynos_ufs_fmp_fill_prdt NULL
 
+#define exynos_ufs_fmp_crypto_keyslot_remap NULL
+
 #endif /* !CONFIG_SCSI_UFS_CRYPTO */
 
 static int exynos_ufs_init(struct ufs_hba *hba)
@@ -2013,6 +2028,7 @@ static const struct ufs_hba_variant_ops ufs_hba_exynos_ops = {
 	.suspend			= exynos_ufs_suspend,
 	.resume				= exynos_ufs_resume,
 	.fill_crypto_prdt		= exynos_ufs_fmp_fill_prdt,
+	.crypto_keyslot_remap = exynos_ufs_fmp_crypto_keyslot_remap,
 };
 
 static struct ufs_hba_variant_ops ufs_hba_exynosauto_vh_ops = {
-- 
2.50.1