[PATCH v2 0/9] crypto: x86 - stop using the SIMD helper

Eric Biggers
2025-04-02T00:24:43Z

Patches 2-9 are almost identical to
https://lore.kernel.org/r/20250220051325.340691-3-ebiggers@kernel.org/
but now split into multiple patches. Patch 1 is just a resend of
https://lore.kernel.org/r/20250320220648.121990-1-ebiggers@kernel.org/
which is needed for the series to apply cleanly but is otherwise
unrelated. Description of patches 2-9 follows:

Stop wrapping skcipher and aead algorithms with the crypto SIMD helper
(crypto/simd.c). The only purpose of doing so was to work around x86
not always supporting kernel-mode FPU in softirqs. Specifically, if a
hardirq interrupted a task context kernel-mode FPU section and then a
softirqs were run at the end of that hardirq, those softirqs could not
use kernel-mode FPU. This has now been fixed. In combination with the
fact that the skcipher and aead APIs only support task and softirq
contexts, these can now just use kernel-mode FPU unconditionally on x86.

This simplifies the code and improves performance.

En/decryption gets at least somewhat faster for everyone, since the
crypto API functions such as crypto_skcipher_encrypt() now go directly
to the underlying algorithm rather than taking a detour through
crypto/simd.c which involved an extra indirect call. For example, on a
Ryzen 9 9950X desktop processor, AES-256-XTS is now 23% faster for
512-byte messages and 7% faster for 4096-byte messages (when accessed
through crypto_skcipher_encrypt() or crypto_skcipher_decrypt()).

There's also a much larger performance improvement for crypto API users
that only support synchronous algorithms. These users will now actually
use the x86 SIMD (e.g. AES-NI or VAES) optimized en/decryption modes,
which they couldn't before because they were marked as asynchronous.

Eric Biggers (9):
crypto: x86/aes - drop the avx10_256 AES-XTS and AES-CTR code
crypto: x86/aegis - stop using the SIMD helper
crypto: x86/aes - stop using the SIMD helper
crypto: x86/aria - stop using the SIMD helper
crypto: x86/camellia - stop using the SIMD helper
crypto: x86/cast - stop using the SIMD helper
crypto: x86/serpent - stop using the SIMD helper
crypto: x86/sm4 - stop using the SIMD helper
crypto: x86/twofish - stop using the SIMD helper

arch/x86/crypto/Kconfig | 14 --
arch/x86/crypto/aegis128-aesni-glue.c | 13 +-
arch/x86/crypto/aes-ctr-avx-x86_64.S | 47 ++----
arch/x86/crypto/aes-xts-avx-x86_64.S | 118 ++++++--------
arch/x86/crypto/aesni-intel_glue.c | 174 ++++++++-------------
arch/x86/crypto/aria_aesni_avx2_glue.c | 22 +--
arch/x86/crypto/aria_aesni_avx_glue.c | 20 +--
arch/x86/crypto/aria_gfni_avx512_glue.c | 22 +--
arch/x86/crypto/camellia_aesni_avx2_glue.c | 21 +--
arch/x86/crypto/camellia_aesni_avx_glue.c | 21 +--
arch/x86/crypto/cast5_avx_glue.c | 21 +--
arch/x86/crypto/cast6_avx_glue.c | 20 +--
arch/x86/crypto/serpent_avx2_glue.c | 21 +--
arch/x86/crypto/serpent_avx_glue.c | 21 +--
arch/x86/crypto/serpent_sse2_glue.c | 21 +--
arch/x86/crypto/sm4_aesni_avx2_glue.c | 31 ++--
arch/x86/crypto/sm4_aesni_avx_glue.c | 31 ++--
arch/x86/crypto/twofish_avx_glue.c | 21 +--
18 files changed, 227 insertions(+), 432 deletions(-)

base-commit: 91e5bfe317d8f8471fbaa3e70cf66cae1314a516
--
2.49.0