When support for a crypto algorithm is enabled, the arch-optimized
implementation of that algorithm should be enabled too. We've learned
this the hard way many times over the years: people regularly forget to
enable the arch-optimized implementations of the crypto algorithms,
resulting in significant performance being left on the table.
Currently, BLAKE2s support is always enabled ('obj-y'), since random.c
uses it. Therefore, the arch-optimized BLAKE2s code, which exists for
ARM and x86_64, should be always enabled too. Let's do that.
Note that the effect on kernel image size is very small and should not
be a concern. On ARM, enabling CRYPTO_BLAKE2S_ARM actually *shrinks*
the kernel size by about 1200 bytes, since the ARM-optimized
blake2s_compress() completely replaces the generic blake2s_compress().
On x86_64, enabling CRYPTO_BLAKE2S_X86 increases the kernel size by
about 1400 bytes, as the generic blake2s_compress() is still included as
a fallback; however, for context, that is only about a quarter the size
of the generic blake2s_compress(). The x86_64 optimized BLAKE2s code
uses much less icache at runtime than the generic code.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
lib/crypto/arm/Kconfig | 2 +-
lib/crypto/x86/Kconfig | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/crypto/arm/Kconfig b/lib/crypto/arm/Kconfig
index 740341aa35d21..a5607ad079c4f 100644
--- a/lib/crypto/arm/Kconfig
+++ b/lib/crypto/arm/Kconfig
@@ -1,9 +1,9 @@
# SPDX-License-Identifier: GPL-2.0-only
config CRYPTO_BLAKE2S_ARM
- bool "Hash functions: BLAKE2s"
+ def_bool y
select CRYPTO_ARCH_HAVE_LIB_BLAKE2S
help
BLAKE2s cryptographic hash function (RFC 7693)
Architecture: arm
diff --git a/lib/crypto/x86/Kconfig b/lib/crypto/x86/Kconfig
index eb47da71aa6b6..ffa718321369f 100644
--- a/lib/crypto/x86/Kconfig
+++ b/lib/crypto/x86/Kconfig
@@ -1,9 +1,9 @@
# SPDX-License-Identifier: GPL-2.0-only
config CRYPTO_BLAKE2S_X86
- bool "Hash functions: BLAKE2s (SSSE3/AVX-512)"
+ def_bool y
depends on 64BIT
select CRYPTO_LIB_BLAKE2S_GENERIC
select CRYPTO_ARCH_HAVE_LIB_BLAKE2S
help
BLAKE2s cryptographic hash function (RFC 7693)
--
2.50.1
