[PATCH v6 16/17] ufs: host: add a callback for deriving software secrets and use it

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Gaurav Kashyap <quic_gaurkash@quicinc.com>

Add a new UFS core callback for deriving software secrets from hardware
wrapped keys and implement it in QCom UFS.

Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/ufs/host/ufs-qcom.c | 15 +++++++++++++++
 include/ufs/ufshcd.h        |  1 +
 2 files changed, 16 insertions(+)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 366fd62a951f..77fb5e66e4be 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -182,9 +182,23 @@ 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)
 {
@@ -1815,6 +1829,7 @@ 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,
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index c11dd3baf53c..b8b1763df022 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -323,6 +323,7 @@ struct ufs_pwr_mode_info {
  * @device_reset: called to issue a reset pulse on the UFS device
  * @config_scaling_param: called to configure clock scaling parameters
  * @program_key: program or evict an inline encryption key
+ * @derive_sw_secret: derive sw secret from a wrapped key
  * @fill_crypto_prdt: initialize crypto-related fields in the PRDT
  * @event_notify: called to notify important events
  * @reinit_notify: called to notify reinit of UFSHCD during max gear switch

-- 
2.43.0