Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <258295d3-13af-db2c-d2c4-d571b6b44cd9@gmail.com>
Date:   Sat, 27 Aug 2022 15:18:19 +0900
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0)
 Gecko/20100101 Thunderbird/91.11.0
Subject: Re: [PATCH v2 2/3] crypto: aria-avx: add AES-NI/AVX/x86_64 assembler
 implementation of aria cipher
To:     "Elliott, Robert (Servers)" <elliott@hpe.com>,
        "linux-crypto@vger.kernel.org" <linux-crypto@vger.kernel.org>,
        "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
        "davem@davemloft.net" <davem@davemloft.net>,
        "tglx@linutronix.de" <tglx@linutronix.de>,
        "mingo@redhat.com" <mingo@redhat.com>,
        "bp@alien8.de" <bp@alien8.de>,
        "dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
        "x86@kernel.org" <x86@kernel.org>, "hpa@zytor.com" <hpa@zytor.com>
References: <20220826053131.24792-1-ap420073@gmail.com>
 <20220826053131.24792-3-ap420073@gmail.com>
 <MW5PR84MB1842DCF66CD8692D99545D98AB759@MW5PR84MB1842.NAMPRD84.PROD.OUTLOOK.COM>
From:   Taehee Yoo <ap420073@gmail.com>
In-Reply-To: <MW5PR84MB1842DCF66CD8692D99545D98AB759@MW5PR84MB1842.NAMPRD84.PROD.OUTLOOK.COM>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

Hi Elliott, Robert
Thanks for your review!

2022. 8. 27. 오전 12:12에 Elliott, Robert (Servers) 이(가) 쓴 글:
 >
 >
 >> -----Original Message-----
 >> From: Taehee Yoo <ap420073@gmail.com>
 >> Sent: Friday, August 26, 2022 12:32 AM
 >> Subject: [PATCH v2 2/3] crypto: aria-avx: add AES-NI/AVX/x86_64 
assembler
 >> implementation of aria cipher
 >>
 >> v2:
 >>   - Do not call non-FPU functions(aria_{encrypt | decrypt}() in the
 >>     FPU context.
 >>   - Do not acquire FPU context for too long.
 >
 > ...
 >> +static int ecb_do_encrypt(struct skcipher_request *req, const u32 
*rkey)
 >> +{
 > ...
 >> +	while ((nbytes = walk.nbytes) > 0) {
 >> +		const u8 *src = walk.src.virt.addr;
 >> +		u8 *dst = walk.dst.virt.addr;
 >> +
 >> +		kernel_fpu_begin();
 >> +		while (nbytes >= ARIA_AVX_BLOCK_SIZE) {
 >> +			aria_aesni_avx_crypt_16way(rkey, dst, src, ctx->rounds);
 >> +			dst += ARIA_AVX_BLOCK_SIZE;
 >> +			src += ARIA_AVX_BLOCK_SIZE;
 >> +			nbytes -= ARIA_AVX_BLOCK_SIZE;
 >> +		}
 >> +		kernel_fpu_end();
 >
 > Per Herbert's reply on the sha512-avx RCU stall issue, another nesting
 > level might be necessary limiting the amount of data processed between
 > each kernel_fpu_begin() to kernel_fpu_end() pair to 4 KiB.
 >
 > If you modify this driver to use the ECB_WALK_START, ECB_BLOCK, and
 > ECB_WALK_END macros from ecb_cbc_helpers.h and incorporate that fix,
 > then your fix would be easy to replicate into the other users (camellia,
 > cast5, cast6, serpent, and twofish).
 >

Now I understand why you suggested using ECB macro instead of open code.
I think your idea is nice for many users such as camellia, cast5, etc.

I will use ECB macro in the v3 patch.
Then, I will send a fixing the RCU stall issue patch separately instead 
of containing it.

Thanks a lot!
Taehee Yoo