[PATCH] crypto: ccree - avoid implicit enum conversion

[Nathan Chancellor]

Clang warns when one enumerated type is implicitly converted to another
and this happens in several locations in this driver, ultimately related
to the set_cipher_{mode,config0} functions. set_cipher_mode expects a mode
of type drv_cipher_mode and set_cipher_config0 expects a mode of type
drv_crypto_direction.

drivers/crypto/ccree/cc_ivgen.c:58:35: warning: implicit conversion from
enumeration type 'enum cc_desc_direction' to different enumeration type
'enum drv_crypto_direction' [-Wenum-conversion]
        set_cipher_config0(&iv_seq[idx], DESC_DIRECTION_ENCRYPT_ENCRYPT);

drivers/crypto/ccree/cc_hash.c:99:28: warning: implicit conversion from
enumeration type 'enum cc_hash_conf_pad' to different enumeration type
'enum drv_crypto_direction' [-Wenum-conversion]
                set_cipher_config0(desc, HASH_DIGEST_RESULT_LITTLE_ENDIAN);

drivers/crypto/ccree/cc_aead.c:1643:30: warning: implicit conversion
from enumeration type 'enum drv_hash_hw_mode' to different enumeration
type 'enum drv_cipher_mode' [-Wenum-conversion]
        set_cipher_mode(&desc[idx], DRV_HASH_HW_GHASH);

Since this fundamentally isn't a problem because these values just
represent simple integers for a shift operation, make it clear to Clang
that this is okay by making the mode parameter in both functions an int.

Link: https://github.com/ClangBuiltLinux/linux/issues/46
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---

Alternatively:

1. The uses of DESC_DIRECTION_ENCRYPT_ENCRYPT could be replaced with
   DRV_CRYPTO_DIRECTION_ENCRYPT since they are the same value.

2. An enum of value 2 could be added to drv_crypto_direction which is
   what HASH_DIGEST_RESULT_LITTLE_ENDIAN is equal to (not sure what that
   should be named).

3. DRV_HASH_HW_GHASH could be removed and replaced with DRV_CIPHER_OFB
   since they are the same value.

This patch seems to make the most sense to me given that the enums are
just functioning as integers but I'm willing to fix this however the
maintainers want.

 drivers/crypto/ccree/cc_hw_queue_defs.h | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/ccree/cc_hw_queue_defs.h b/drivers/crypto/ccree/cc_hw_queue_defs.h
index a091ae57f902..45985b955d2c 100644
--- a/drivers/crypto/ccree/cc_hw_queue_defs.h
+++ b/drivers/crypto/ccree/cc_hw_queue_defs.h
@@ -449,8 +449,7 @@ static inline void set_flow_mode(struct cc_hw_desc *pdesc,
  * @pdesc: pointer HW descriptor struct
  * @mode:  Any one of the modes defined in [CC7x-DESC]
  */
-static inline void set_cipher_mode(struct cc_hw_desc *pdesc,
-				   enum drv_cipher_mode mode)
+static inline void set_cipher_mode(struct cc_hw_desc *pdesc, int mode)
 {
 	pdesc->word[4] |= FIELD_PREP(WORD4_CIPHER_MODE, mode);
 }
@@ -461,8 +460,7 @@ static inline void set_cipher_mode(struct cc_hw_desc *pdesc,
  * @pdesc: pointer HW descriptor struct
  * @mode: Any one of the modes defined in [CC7x-DESC]
  */
-static inline void set_cipher_config0(struct cc_hw_desc *pdesc,
-				      enum drv_crypto_direction mode)
+static inline void set_cipher_config0(struct cc_hw_desc *pdesc, int mode)
 {
 	pdesc->word[4] |= FIELD_PREP(WORD4_CIPHER_CONF0, mode);
 }
-- 
2.19.1