[PATCH v4 11/15] ufs: host: implement derive sw secret vop in ufs qcom

[Gaurav Kashyap <quic_gaurkash@quicinc.com>]

UFS core defines a variant op to tie the corresponding
derive software secret blk crypto op to the vendor specific
implementation of wrapped keys. This patch implements
this variant op.

Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/ufs/host/ufs-qcom.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 5c9ba06438a9..e319176accd3 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -176,9 +176,23 @@ static int ufs_qcom_ice_program_key(struct ufs_hba *hba,
 		return qcom_ice_evict_key(host->ice, slot);
 }
 
+/*
+ * Derive a software secret from a hardware wrapped key. The key is unwrapped in
+ * hardware from trustzone and a software key/secret is then derived from it.
+ */
+static int ufs_qcom_ice_derive_sw_secret(struct ufs_hba *hba, const u8 wkey[],
+					 unsigned int wkey_size,
+					 u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE])
+{
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	return qcom_ice_derive_sw_secret(host->ice, wkey, wkey_size, sw_secret);
+}
+
 #else
 
 #define ufs_qcom_ice_program_key NULL
+#define ufs_qcom_ice_derive_sw_secret NULL
 
 static inline void ufs_qcom_ice_enable(struct ufs_qcom_host *host)
 {
@@ -1787,6 +1801,7 @@ static const struct ufs_hba_variant_ops ufs_hba_qcom_vops = {
 	.device_reset		= ufs_qcom_device_reset,
 	.config_scaling_param = ufs_qcom_config_scaling_param,
 	.program_key		= ufs_qcom_ice_program_key,
+	.derive_sw_secret	= ufs_qcom_ice_derive_sw_secret,
 	.reinit_notify		= ufs_qcom_reinit_notify,
 	.mcq_config_resource	= ufs_qcom_mcq_config_resource,
 	.get_hba_mac		= ufs_qcom_get_hba_mac,
-- 
2.43.0