Re: [PATCH v2 2/3] crypto: aria-avx: add AES-NI/AVX/x86_64 assembler implementation of aria cipher

[Taehee Yoo <ap420073@gmail.com>]

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