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Date:   Tue, 13 Apr 2021 17:33:16 -0500
From:   Bjorn Andersson <bjorn.andersson@linaro.org>
To:     Thara Gopinath <thara.gopinath@linaro.org>
Cc:     herbert@gondor.apana.org.au, davem@davemloft.net,
        ebiggers@google.com, ardb@kernel.org, sivaprak@codeaurora.org,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/7] crypto: qce: common: Add support for AEAD algorithms
Message-ID: <20210413223316.GT1538589@yoga>
References: <20210225182716.1402449-1-thara.gopinath@linaro.org>
 <20210225182716.1402449-7-thara.gopinath@linaro.org>
 <20210405221848.GA904837@yoga>
 <64543792-7237-8622-9619-7020ed0b3fa1@linaro.org>
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In-Reply-To: <64543792-7237-8622-9619-7020ed0b3fa1@linaro.org>
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On Tue 13 Apr 17:27 CDT 2021, Thara Gopinath wrote:

> 
> 
> 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).

Perhaps make qce_cpu_to_be32p_array() (or qce_be32_to_cpu() per the
other reply), could return the number of words written - that way you
remove the ugly middle line at least - and can still poke at the data
when needed.

> Take it up as a separate clean up activity  ?
> 

Yes, that seems like a good idea.

Regards,
Bjorn