[PATCH v13 3/3] ufs: qcom: add support for wrapped keys

Eric Biggers
2025-04-04T23:16:31Z

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 flag 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.

Acked-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> # sm8650
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
drivers/ufs/host/ufs-qcom.c | 51 ++++++++++++++++++++++++++++++++-----
1 file changed, 45 insertions(+), 6 deletions(-)

diff --git a/drivers/ufs/host/ufs-qcom.c b/drivers/ufs/host/ufs-qcom.c
index 85040861ddc6e..46cca52aa6f11 100644
--- a/drivers/ufs/host/ufs-qcom.c
+++ b/drivers/ufs/host/ufs-qcom.c
@@ -154,15 +154,10 @@ 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_get_supported_key_type(ice) != BLK_CRYPTO_KEY_TYPE_RAW) {
- dev_warn(dev, "Wrapped keys not supported. 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));
@@ -172,11 +167,11 @@ 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;
+ profile->key_types_supported = qcom_ice_get_supported_key_type(ice);
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
@@ -240,13 +235,57 @@ 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)
--
2.49.0