Re: [PATCH 6/7] crypto: qce: common: Add support for AEAD algorithms

[Thara Gopinath <thara.gopinath@linaro.org>]

On 4/5/21 6:18 PM, Bjorn Andersson wrote:
> On Thu 25 Feb 12:27 CST 2021, Thara Gopinath wrote:
> 
>> Add register programming sequence for enabling AEAD
>> algorithms on the Qualcomm crypto engine.
>>
>> Signed-off-by: Thara Gopinath <thara.gopinath@linaro.org>
>> ---
>>   drivers/crypto/qce/common.c | 155 +++++++++++++++++++++++++++++++++++-
>>   1 file changed, 153 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/crypto/qce/common.c b/drivers/crypto/qce/common.c
>> index 05a71c5ecf61..54d209cb0525 100644
>> --- a/drivers/crypto/qce/common.c
>> +++ b/drivers/crypto/qce/common.c
>> @@ -15,6 +15,16 @@
>>   #include "core.h"
>>   #include "regs-v5.h"
>>   #include "sha.h"
>> +#include "aead.h"
>> +
>> +static const u32 std_iv_sha1[SHA256_DIGEST_SIZE / sizeof(u32)] = {
>> +	SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4, 0, 0, 0
>> +};
>> +
>> +static const u32 std_iv_sha256[SHA256_DIGEST_SIZE / sizeof(u32)] = {
>> +	SHA256_H0, SHA256_H1, SHA256_H2, SHA256_H3,
>> +	SHA256_H4, SHA256_H5, SHA256_H6, SHA256_H7
>> +};
>>   
>>   static inline u32 qce_read(struct qce_device *qce, u32 offset)
>>   {
>> @@ -96,7 +106,7 @@ static inline void qce_crypto_go(struct qce_device *qce, bool result_dump)
>>   		qce_write(qce, REG_GOPROC, BIT(GO_SHIFT));
>>   }
>>   
>> -#ifdef CONFIG_CRYPTO_DEV_QCE_SHA
>> +#if defined(CONFIG_CRYPTO_DEV_QCE_SHA) || defined(CONFIG_CRYPTO_DEV_QCE_AEAD)
>>   static u32 qce_auth_cfg(unsigned long flags, u32 key_size, u32 auth_size)
>>   {
>>   	u32 cfg = 0;
>> @@ -139,7 +149,9 @@ static u32 qce_auth_cfg(unsigned long flags, u32 key_size, u32 auth_size)
>>   
>>   	return cfg;
>>   }
>> +#endif
>>   
>> +#ifdef CONFIG_CRYPTO_DEV_QCE_SHA
>>   static int qce_setup_regs_ahash(struct crypto_async_request *async_req)
>>   {
>>   	struct ahash_request *req = ahash_request_cast(async_req);
>> @@ -225,7 +237,7 @@ static int qce_setup_regs_ahash(struct crypto_async_request *async_req)
>>   }
>>   #endif
>>   
>> -#ifdef CONFIG_CRYPTO_DEV_QCE_SKCIPHER
>> +#if defined(CONFIG_CRYPTO_DEV_QCE_SKCIPHER) || defined(CONFIG_CRYPTO_DEV_QCE_AEAD)
>>   static u32 qce_encr_cfg(unsigned long flags, u32 aes_key_size)
>>   {
>>   	u32 cfg = 0;
>> @@ -271,7 +283,9 @@ static u32 qce_encr_cfg(unsigned long flags, u32 aes_key_size)
>>   
>>   	return cfg;
>>   }
>> +#endif
>>   
>> +#ifdef CONFIG_CRYPTO_DEV_QCE_SKCIPHER
>>   static void qce_xts_swapiv(__be32 *dst, const u8 *src, unsigned int ivsize)
>>   {
>>   	u8 swap[QCE_AES_IV_LENGTH];
>> @@ -386,6 +400,139 @@ static int qce_setup_regs_skcipher(struct crypto_async_request *async_req)
>>   }
>>   #endif
>>   
>> +#ifdef CONFIG_CRYPTO_DEV_QCE_AEAD
>> +static int qce_setup_regs_aead(struct crypto_async_request *async_req)
>> +{
>> +	struct aead_request *req = aead_request_cast(async_req);
>> +	struct qce_aead_reqctx *rctx = aead_request_ctx(req);
>> +	struct qce_aead_ctx *ctx = crypto_tfm_ctx(async_req->tfm);
>> +	struct qce_alg_template *tmpl = to_aead_tmpl(crypto_aead_reqtfm(req));
>> +	struct qce_device *qce = tmpl->qce;
>> +	__be32 enckey[QCE_MAX_CIPHER_KEY_SIZE / sizeof(__be32)] = {0};
>> +	__be32 enciv[QCE_MAX_IV_SIZE / sizeof(__be32)] = {0};
>> +	__be32 authkey[QCE_SHA_HMAC_KEY_SIZE / sizeof(__be32)] = {0};
>> +	__be32 authiv[SHA256_DIGEST_SIZE / sizeof(__be32)] = {0};
>> +	__be32 authnonce[QCE_MAX_NONCE / sizeof(__be32)] = {0};
>> +	unsigned int enc_keylen = ctx->enc_keylen;
>> +	unsigned int auth_keylen = ctx->auth_keylen;
>> +	unsigned int enc_ivsize = rctx->ivsize;
>> +	unsigned int auth_ivsize;
>> +	unsigned int enckey_words, enciv_words;
>> +	unsigned int authkey_words, authiv_words, authnonce_words;
>> +	unsigned long flags = rctx->flags;
>> +	u32 encr_cfg = 0, auth_cfg = 0, config, totallen;
> 
> I don't see any reason to initialize encr_cfg or auth_cfg.
> 
>> +	u32 *iv_last_word;
>> +
>> +	qce_setup_config(qce);
>> +
>> +	/* Write encryption key */
>> +	qce_cpu_to_be32p_array(enckey, ctx->enc_key, enc_keylen);
>> +	enckey_words = enc_keylen / sizeof(u32);
>> +	qce_write_array(qce, REG_ENCR_KEY0, (u32 *)enckey, enckey_words);
> 
> Afaict all "array registers" in this function are affected by the
> CRYPTO_SETUP little endian bit, but you set this bit before launching
> the operation dependent on IS_CCM(). So is this really working for the
> !IS_CCM() case?
> 
>> +
>> +	/* Write encryption iv */
>> +	qce_cpu_to_be32p_array(enciv, rctx->iv, enc_ivsize);
>> +	enciv_words = enc_ivsize / sizeof(u32);
>> +	qce_write_array(qce, REG_CNTR0_IV0, (u32 *)enciv, enciv_words);
> 
> It would be nice if this snippet was extracted to a helper function.

I kind of forgot to type this earlier. So yes I agree in principle.
It is more elegant to have something like qce_convert_be32_and_write
and in the function do the above three steps. This snippet is prevalent 
in this driver code across other alogs as well (skcipher and hash).
Take it up as a separate clean up activity  ?

-- 
Warm Regards
Thara