crypto: arm/poly1305 - incorporate OpenSSL/CRYPTOGAMS NEON implementa…

…tion

This is a straight import of the OpenSSL/CRYPTOGAMS Poly1305 implementation
for NEON authored by Andy Polyakov, and contributed by him to the OpenSSL
project. The file 'poly1305-armv4.pl' is taken straight from this upstream
GitHub repository [0] at commit ec55a08dc0244ce570c4fc7cade330c60798952f,
and already contains all the changes required to build it as part of a
Linux kernel module.

[0] https://github.com/dot-asm/cryptogams

Co-developed-by: Andy Polyakov <appro@cryptogams.org>
Signed-off-by: Andy Polyakov <appro@cryptogams.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm/crypto/Kconfig

@@ -132,6 +132,11 @@ config CRYPTO_CHACHA20_NEON
 	select CRYPTO_SKCIPHER
 	select CRYPTO_ARCH_HAVE_LIB_CHACHA
 
+config CRYPTO_POLY1305_ARM
+	tristate "Accelerated scalar and SIMD Poly1305 hash implementations"
+	select CRYPTO_HASH
+	select CRYPTO_ARCH_HAVE_LIB_POLY1305
+
 config CRYPTO_NHPOLY1305_NEON
 	tristate "NEON accelerated NHPoly1305 hash function (for Adiantum)"
 	depends on KERNEL_MODE_NEON

arch/arm/crypto/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_CRYPTO_SHA1_ARM_NEON) += sha1-arm-neon.o
 obj-$(CONFIG_CRYPTO_SHA256_ARM) += sha256-arm.o
 obj-$(CONFIG_CRYPTO_SHA512_ARM) += sha512-arm.o
 obj-$(CONFIG_CRYPTO_CHACHA20_NEON) += chacha-neon.o
+obj-$(CONFIG_CRYPTO_POLY1305_ARM) += poly1305-arm.o
 obj-$(CONFIG_CRYPTO_NHPOLY1305_NEON) += nhpoly1305-neon.o
 
 obj-$(CONFIG_CRYPTO_AES_ARM_CE) += aes-arm-ce.o
@@ -35,17 +36,26 @@ crct10dif-arm-ce-y	:= crct10dif-ce-core.o crct10dif-ce-glue.o
 crc32-arm-ce-y:= crc32-ce-core.o crc32-ce-glue.o
 chacha-neon-y := chacha-scalar-core.o chacha-glue.o
 chacha-neon-$(CONFIG_KERNEL_MODE_NEON) += chacha-neon-core.o
+poly1305-arm-y := poly1305-core.o poly1305-glue.o
 nhpoly1305-neon-y := nh-neon-core.o nhpoly1305-neon-glue.o
 
 ifdef REGENERATE_ARM_CRYPTO
 quiet_cmd_perl = PERL    $@
       cmd_perl = $(PERL) $(<) > $(@)
 
+$(src)/poly1305-core.S_shipped: $(src)/poly1305-armv4.pl
+	$(call cmd,perl)
+
 $(src)/sha256-core.S_shipped: $(src)/sha256-armv4.pl
 	$(call cmd,perl)
 
 $(src)/sha512-core.S_shipped: $(src)/sha512-armv4.pl
 	$(call cmd,perl)
 endif
 
-clean-files += sha256-core.S sha512-core.S
+clean-files += poly1305-core.S sha256-core.S sha512-core.S
+
+# massage the perlasm code a bit so we only get the NEON routine if we need it
+poly1305-aflags-$(CONFIG_CPU_V7) := -U__LINUX_ARM_ARCH__ -D__LINUX_ARM_ARCH__=5
+poly1305-aflags-$(CONFIG_KERNEL_MODE_NEON) := -U__LINUX_ARM_ARCH__ -D__LINUX_ARM_ARCH__=7
+AFLAGS_poly1305-core.o += $(poly1305-aflags-y)