[PATCH v10 15/15] ufs: qcom: add support for wrapped keys

[Eric Biggers <ebiggers@kernel.org>]

From: Eric Biggers <ebiggers@google.com>

Wire up the wrapped key support for ufs-qcom by implementing the needed
methods in struct blk_crypto_ll_ops and setting the appropriate flags in
blk_crypto_profile::key_types_supported.

For more information about this feature and how to use it, refer to
the sections about hardware-wrapped keys in
Documentation/block/inline-encryption.rst and
Documentation/filesystems/fscrypt.rst.

Based on patches by Gaurav Kashyap <quic_gaurkash@quicinc.com>.
Reworked to use the custom crypto profile support.

Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # sm8650
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 drivers/ufs/host/ufs-qcom.c | 54 ++++++++++++++++++++++++++++++++-----
 1 file changed, 48 insertions(+), 6 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 9c700bbaa12c..c9cca4348dab 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -132,15 +132,10 @@ static int ufs_qcom_ice_init(struct ufs_qcom_host *host)
 	}
 
 	if (IS_ERR_OR_NULL(ice))
 		return PTR_ERR_OR_ZERO(ice);
 
-	if (qcom_ice_using_hwkm(ice)) {
-		dev_warn(dev, "HWKM mode unsupported; disabling inline encryption support\n");
-		return 0;
-	}
-
 	host->ice = ice;
 
 	/* Initialize the blk_crypto_profile */
 
 	caps.reg_val = cpu_to_le32(ufshcd_readl(hba, REG_UFS_CCAP));
@@ -150,11 +145,14 @@ static int ufs_qcom_ice_init(struct ufs_qcom_host *host)
 	if (err)
 		return err;
 
 	profile->ll_ops = ufs_qcom_crypto_ops;
 	profile->max_dun_bytes_supported = 8;
-	profile->key_types_supported = BLK_CRYPTO_KEY_TYPE_RAW;
+	if (qcom_ice_using_hwkm(ice))
+		profile->key_types_supported = BLK_CRYPTO_KEY_TYPE_HW_WRAPPED;
+	else
+		profile->key_types_supported = BLK_CRYPTO_KEY_TYPE_RAW;
 	profile->dev = dev;
 
 	/*
 	 * Currently this driver only supports AES-256-XTS.  All known versions
 	 * of ICE support it, but to be safe make sure it is really declared in
@@ -218,13 +216,57 @@ static int ufs_qcom_ice_keyslot_evict(struct blk_crypto_profile *profile,
 	err = qcom_ice_evict_key(host->ice, slot);
 	ufshcd_release(hba);
 	return err;
 }
 
+static int ufs_qcom_ice_derive_sw_secret(struct blk_crypto_profile *profile,
+					 const u8 *eph_key, size_t eph_key_size,
+					 u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE])
+{
+	struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	return qcom_ice_derive_sw_secret(host->ice, eph_key, eph_key_size,
+					 sw_secret);
+}
+
+static int ufs_qcom_ice_import_key(struct blk_crypto_profile *profile,
+				   const u8 *raw_key, size_t raw_key_size,
+				   u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+	struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	return qcom_ice_import_key(host->ice, raw_key, raw_key_size, lt_key);
+}
+
+static int ufs_qcom_ice_generate_key(struct blk_crypto_profile *profile,
+				     u8 lt_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+	struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	return qcom_ice_generate_key(host->ice, lt_key);
+}
+
+static int ufs_qcom_ice_prepare_key(struct blk_crypto_profile *profile,
+				    const u8 *lt_key, size_t lt_key_size,
+				    u8 eph_key[BLK_CRYPTO_MAX_HW_WRAPPED_KEY_SIZE])
+{
+	struct ufs_hba *hba = ufs_hba_from_crypto_profile(profile);
+	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
+
+	return qcom_ice_prepare_key(host->ice, lt_key, lt_key_size, eph_key);
+}
+
 static const struct blk_crypto_ll_ops ufs_qcom_crypto_ops = {
 	.keyslot_program	= ufs_qcom_ice_keyslot_program,
 	.keyslot_evict		= ufs_qcom_ice_keyslot_evict,
+	.derive_sw_secret	= ufs_qcom_ice_derive_sw_secret,
+	.import_key		= ufs_qcom_ice_import_key,
+	.generate_key		= ufs_qcom_ice_generate_key,
+	.prepare_key		= ufs_qcom_ice_prepare_key,
 };
 
 #else
 
 static inline void ufs_qcom_ice_enable(struct ufs_qcom_host *host)
-- 
2.47.1