MMC 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: Seshu Madhavi Puppala <quic_spuppala@quicinc.com>
---
 drivers/mmc/host/sdhci-msm.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
index f031a4dbc719..aba1d6e688b6 100644
--- a/drivers/mmc/host/sdhci-msm.c
+++ b/drivers/mmc/host/sdhci-msm.c
@@ -1897,6 +1897,21 @@ static int sdhci_msm_program_key(struct cqhci_host *cq_host,
 		return qcom_ice_evict_key(msm_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 sdhci_msm_ice_derive_sw_secret(struct cqhci_host *cq_host, const u8 wkey[],
+					  unsigned int wkey_size,
+					  u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE])
+{
+	struct sdhci_host *host = mmc_priv(cq_host->mmc);
+	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+	struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
+
+	return qcom_ice_derive_sw_secret(msm_host->ice, wkey, wkey_size, sw_secret);
+}
+
 #else /* CONFIG_MMC_CRYPTO */
 
 static inline int sdhci_msm_ice_init(struct sdhci_msm_host *msm_host,
@@ -2003,6 +2018,7 @@ static const struct cqhci_host_ops sdhci_msm_cqhci_ops = {
 	.disable	= sdhci_msm_cqe_disable,
 #ifdef CONFIG_MMC_CRYPTO
 	.program_key	= sdhci_msm_program_key,
+	.derive_sw_secret	= sdhci_msm_ice_derive_sw_secret,
 #endif
 };
 
-- 
2.17.1