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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-07-24 13:28:17 +0300
committerHerbert Xu <herbert@gondor.apana.org.au>2017-08-04 04:27:24 +0300
commit3759ee057261a45da0505e79084de8b6ac31c4a5 (patch)
tree70af3d5db93464c2e4b18051241225ffdd4d7139 /arch/arm/crypto/Kconfig
parent537c1445ab0b1e33ca338b669e347652c45f4e8c (diff)
downloadlinux-3759ee057261a45da0505e79084de8b6ac31c4a5.tar.xz
crypto: arm/ghash - add NEON accelerated fallback for vmull.p64
Implement a NEON fallback for systems that do support NEON but have no support for the optional 64x64->128 polynomial multiplication instruction that is part of the ARMv8 Crypto Extensions. It is based on the paper "Fast Software Polynomial Multiplication on ARM Processors Using the NEON Engine" by Danilo Camara, Conrado Gouvea, Julio Lopez and Ricardo Dahab (https://hal.inria.fr/hal-01506572) On a 32-bit guest executing under KVM on a Cortex-A57, the new code is not only 4x faster than the generic table based GHASH driver, it is also time invariant. (Note that the existing vmull.p64 code is 16x faster on this core). Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm/crypto/Kconfig')
-rw-r--r--arch/arm/crypto/Kconfig5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm/crypto/Kconfig b/arch/arm/crypto/Kconfig
index b9adedcc5b2e..ec72752d5668 100644
--- a/arch/arm/crypto/Kconfig
+++ b/arch/arm/crypto/Kconfig
@@ -94,14 +94,15 @@ config CRYPTO_AES_ARM_CE
ARMv8 Crypto Extensions
config CRYPTO_GHASH_ARM_CE
- tristate "PMULL-accelerated GHASH using ARMv8 Crypto Extensions"
+ tristate "PMULL-accelerated GHASH using NEON/ARMv8 Crypto Extensions"
depends on KERNEL_MODE_NEON
select CRYPTO_HASH
select CRYPTO_CRYPTD
help
Use an implementation of GHASH (used by the GCM AEAD chaining mode)
that uses the 64x64 to 128 bit polynomial multiplication (vmull.p64)
- that is part of the ARMv8 Crypto Extensions
+ that is part of the ARMv8 Crypto Extensions, or a slower variant that
+ uses the vmull.p8 instruction that is part of the basic NEON ISA.
config CRYPTO_CRCT10DIF_ARM_CE
tristate "CRCT10DIF digest algorithm using PMULL instructions"