[PATCH v2 09/10] soc: qcom: support for generate, import and prepare key

[Gaurav Kashyap <quic_gaurkash@quicinc.com>]

Implements the ICE apis for generate, prepare and import key
apis and hooks it up the scm calls defined for them.
Key management has to be done from Qualcomm Trustzone as only
it can interface with HWKM.

Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
---
 drivers/soc/qcom/ice.c | 72 ++++++++++++++++++++++++++++++++++++++++++
 include/soc/qcom/ice.h |  8 +++++
 2 files changed, 80 insertions(+)

diff --git a/drivers/soc/qcom/ice.c b/drivers/soc/qcom/ice.c
index 33f67fcfa1bc..16f7af74ddb0 100644
--- a/drivers/soc/qcom/ice.c
+++ b/drivers/soc/qcom/ice.c
@@ -19,6 +19,13 @@
 
 #define AES_256_XTS_KEY_SIZE			64
 
+/*
+ * Wrapped key sizes from HWKm is different for different versions of
+ * HW. It is not expected to change again in the future.
+ */
+#define QCOM_ICE_HWKM_WRAPPED_KEY_SIZE(v)	\
+	((v) == 1 ? 68 : 100)
+
 /* QCOM ICE registers */
 #define QCOM_ICE_REG_VERSION			0x0008
 #define QCOM_ICE_REG_FUSE_SETTING		0x0010
@@ -412,6 +419,71 @@ int qcom_ice_derive_sw_secret(struct qcom_ice *ice, const u8 wrapped_key[],
 }
 EXPORT_SYMBOL_GPL(qcom_ice_derive_sw_secret);
 
+/**
+ * qcom_ice_generate_key() - Generate a wrapped key for inline encryption
+ * @longterm_wrapped_key: wrapped key that is generated, which is
+ *                        BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE in size.
+ *
+ * Make a scm call into trustzone to generate a wrapped key for storage
+ * encryption using hwkm.
+ *
+ * Return: 0 on success; err on failure.
+ */
+int qcom_ice_generate_key(struct qcom_ice *ice,
+	u8 longterm_wrapped_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+	return qcom_scm_generate_ice_key(longterm_wrapped_key,
+				QCOM_ICE_HWKM_WRAPPED_KEY_SIZE(ice->hwkm_version));
+}
+EXPORT_SYMBOL_GPL(qcom_ice_generate_key);
+
+/**
+ * qcom_ice_prepare_key() - Prepare a longterm wrapped key for inline encryption
+ * @longterm_wrapped_key: wrapped key that is generated,
+ * @longterm_wrapped_key_size: size of the longterm wrapped_key
+ * @ephemerally_wrapped_key: wrapped key returned which has been wrapped with
+ *                           a per-boot ephemeral key, size of which is
+ *                           BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE in size.
+ *
+ * Make a scm call into trustzone to prepare a wrapped key for storage
+ * encryption by rewrapping the longterm wrapped key with a per boot ephemeral
+ * key using hwkm.
+ *
+ * Return: 0 on success; err on failure.
+ */
+int qcom_ice_prepare_key(struct qcom_ice *ice,
+	const u8 *longterm_wrapped_key, unsigned int longterm_wrapped_key_size,
+	u8 ephemerally_wrapped_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+	return qcom_scm_prepare_ice_key(longterm_wrapped_key,
+				longterm_wrapped_key_size,
+				ephemerally_wrapped_key,
+				QCOM_ICE_HWKM_WRAPPED_KEY_SIZE(ice->hwkm_version));
+}
+EXPORT_SYMBOL_GPL(qcom_ice_prepare_key);
+
+/**
+ * qcom_ice_import_key() - Import a raw key for inline encryption
+ * @imported_key: raw key that has to be imported
+ * @imported_key_size: size of the imported key
+ * @longterm_wrapped_key: wrapped key that is imported, which is
+ *                        BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE in size.
+ *
+ * Make a scm call into trustzone to import a raw key for storage encryption
+ * and generating a longterm wrapped key using hwkm.
+ *
+ * Return: 0 on success; err on failure.
+ */
+int qcom_ice_import_key(struct qcom_ice *ice,
+	const u8 *imported_key, unsigned int imported_key_size,
+	u8 longterm_wrapped_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+	return qcom_scm_import_ice_key(imported_key, imported_key_size,
+				longterm_wrapped_key,
+				QCOM_ICE_HWKM_WRAPPED_KEY_SIZE(ice->hwkm_version));
+}
+EXPORT_SYMBOL_GPL(qcom_ice_import_key);
+
 static struct qcom_ice *qcom_ice_create(struct device *dev,
 					void __iomem *base)
 {
diff --git a/include/soc/qcom/ice.h b/include/soc/qcom/ice.h
index 22ab8d1a56de..ce41ec442657 100644
--- a/include/soc/qcom/ice.h
+++ b/include/soc/qcom/ice.h
@@ -39,5 +39,13 @@ bool qcom_ice_hwkm_supported(struct qcom_ice *ice);
 int qcom_ice_derive_sw_secret(struct qcom_ice *ice, const u8 wrapped_key[],
 			      unsigned int wrapped_key_size,
 			      u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]);
+int qcom_ice_generate_key(struct qcom_ice *ice,
+	u8 longterm_wrapped_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]);
+int qcom_ice_prepare_key(struct qcom_ice *ice,
+	const u8 *longterm_wrapped_key, unsigned int longterm_wrapped_key_size,
+	u8 ephemerally_wrapped_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]);
+int qcom_ice_import_key(struct qcom_ice *ice,
+	const u8 *imported_key, unsigned int imported_key_size,
+	u8 longterm_wrapped_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE]);
 struct qcom_ice *of_qcom_ice_get(struct device *dev);
 #endif /* __QCOM_ICE_H__ */
-- 
2.25.1