[PATCH v6 13/17] ufs: core: add support for deriving the software secret

[Bartosz Golaszewski <brgl@bgdev.pl>]

From: Gaurav Kashyap <quic_gaurkash@quicinc.com>

Extend the UFS core to allow calling the block layer's callback for
deriving the software secret from a wrapped key. This is needed as in
most cases the wrapped key support will be vendor-specific and the
implementation will live in the specific UFS driver.

Tested-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Om Prakash Singh <quic_omprsing@quicinc.com>
Signed-off-by: Gaurav Kashyap <quic_gaurkash@quicinc.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
---
 drivers/ufs/core/ufshcd-crypto.c | 15 +++++++++++++++
 include/ufs/ufshcd.h             |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/drivers/ufs/core/ufshcd-crypto.c b/drivers/ufs/core/ufshcd-crypto.c
index 64389e876910..2530239d42af 100644
--- a/drivers/ufs/core/ufshcd-crypto.c
+++ b/drivers/ufs/core/ufshcd-crypto.c
@@ -113,6 +113,20 @@ static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
 	return ufshcd_program_key(hba, NULL, &cfg, slot);
 }
 
+static int ufshcd_crypto_derive_sw_secret(struct blk_crypto_profile *profile,
+					  const u8 wkey[], size_t wkey_size,
+					  u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE])
+{
+	struct ufs_hba *hba =
+		container_of(profile, struct ufs_hba, crypto_profile);
+
+	if (hba->vops && hba->vops->derive_sw_secret)
+		return hba->vops->derive_sw_secret(hba, wkey, wkey_size,
+						   sw_secret);
+
+	return -EOPNOTSUPP;
+}
+
 /*
  * Reprogram the keyslots if needed, and return true if CRYPTO_GENERAL_ENABLE
  * should be used in the host controller initialization sequence.
@@ -134,6 +148,7 @@ bool ufshcd_crypto_enable(struct ufs_hba *hba)
 static const struct blk_crypto_ll_ops ufshcd_crypto_ops = {
 	.keyslot_program	= ufshcd_crypto_keyslot_program,
 	.keyslot_evict		= ufshcd_crypto_keyslot_evict,
+	.derive_sw_secret	= ufshcd_crypto_derive_sw_secret,
 };
 
 static enum blk_crypto_mode_num
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index a2dad4f982c2..c11dd3baf53c 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -372,6 +372,9 @@ struct ufs_hba_variant_ops {
 	int	(*program_key)(struct ufs_hba *hba,
 			       const struct blk_crypto_key *bkey,
 			       const union ufs_crypto_cfg_entry *cfg, int slot);
+	int	(*derive_sw_secret)(struct ufs_hba *hba, const u8 wkey[],
+				    unsigned int wkey_size,
+				    u8 sw_secret[BLK_CRYPTO_SW_SECRET_SIZE]);
 	int	(*fill_crypto_prdt)(struct ufs_hba *hba,
 				    const struct bio_crypt_ctx *crypt_ctx,
 				    void *prdt, unsigned int num_segments);

-- 
2.43.0