[PATCH v4 08/15] ufs: core: add support to derive software secret

[Gaurav Kashyap]

Block crypto allows storage controllers like UFS to
register an op derive a software secret from wrapped
keys added to the kernel.

Wrapped keys in most cases will have vendor specific
implementations, which means this op would need to have
a corresponding UFS variant op.
This change adds hooks in UFS core to support this variant
ops and tie them to the blk crypto op.

Signed-off-by: Gaurav Kashyap <quic_gaurkash@xxxxxxxxxxx>
Tested-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
---
 drivers/ufs/core/ufshcd-crypto.c | 15 +++++++++++++++
 include/ufs/ufshcd.h             |  4 ++++
 2 files changed, 19 insertions(+)

diff --git a/drivers/ufs/core/ufshcd-crypto.c b/drivers/ufs/core/ufshcd-crypto.c
index 399b55d67b3b..c14800eac1ff 100644
--- a/drivers/ufs/core/ufshcd-crypto.c
+++ b/drivers/ufs/core/ufshcd-crypto.c
@@ -119,6 +119,20 @@ static int ufshcd_crypto_keyslot_evict(struct blk_crypto_profile *profile,
 	return ufshcd_clear_keyslot(hba, 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;
+}
+
 bool ufshcd_crypto_enable(struct ufs_hba *hba)
 {
 	if (!(hba->caps & UFSHCD_CAP_CRYPTO))
@@ -132,6 +146,7 @@ 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 680c010a53d4..8a773434a329 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -321,6 +321,7 @@ struct ufs_pwr_mode_info {
  * @device_reset: called to issue a reset pulse on the UFS device
  * @config_scaling_param: called to configure clock scaling parameters
  * @program_key: program or evict an inline encryption key
+ * @derive_sw_secret: derive sw secret from a wrapped key
  * @event_notify: called to notify important events
  * @reinit_notify: called to notify reinit of UFSHCD during max gear switch
  * @mcq_config_resource: called to configure MCQ platform resources
@@ -365,6 +366,9 @@ 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]);
 	void	(*event_notify)(struct ufs_hba *hba,
 				enum ufs_event_type evt, void *data);
 	void	(*reinit_notify)(struct ufs_hba *);
-- 
2.43.0