crypto: arm64/crc32 - merge CRC32 and PMULL instruction based drivers

The PMULL based CRC32 implementation already contains code based on the
separate, optional CRC32 instructions to fallback to when operating on
small quantities of data. We can expose these routines directly on systems
that lack the 64x64 PMULL instructions but do implement the CRC32 ones,
which makes the driver that is based solely on those CRC32 instructions
redundant. So remove it.

Note that this aligns arm64 with ARM, whose accelerated CRC32 driver
also combines the CRC32 extension based and the PMULL based versions.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Matthias Brugger <mbrugger@suse.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

arch/arm64/configs/defconfig

@@ -516,4 +516,3 @@ CONFIG_CRYPTO_GHASH_ARM64_CE=y
 CONFIG_CRYPTO_AES_ARM64_CE_CCM=y
 CONFIG_CRYPTO_AES_ARM64_CE_BLK=y
 # CONFIG_CRYPTO_AES_ARM64_NEON_BLK is not set
-CONFIG_CRYPTO_CRC32_ARM64=y

arch/arm64/crypto/Kconfig

@@ -37,8 +37,8 @@ config CRYPTO_CRCT10DIF_ARM64_CE
 	select CRYPTO_HASH
 
 config CRYPTO_CRC32_ARM64_CE
-	tristate "CRC32 and CRC32C digest algorithms using PMULL instructions"
-	depends on KERNEL_MODE_NEON && CRC32
+	tristate "CRC32 and CRC32C digest algorithms using ARMv8 extensions"
+	depends on CRC32
 	select CRYPTO_HASH
 
 config CRYPTO_AES_ARM64
@@ -71,11 +71,6 @@ config CRYPTO_AES_ARM64_NEON_BLK
 	select CRYPTO_AES
 	select CRYPTO_SIMD
 
-config CRYPTO_CRC32_ARM64
-	tristate "CRC32 and CRC32C using optional ARMv8 instructions"
-	depends on ARM64
-	select CRYPTO_HASH
-
 config CRYPTO_CHACHA20_NEON
 	tristate "NEON accelerated ChaCha20 symmetric cipher"
 	depends on KERNEL_MODE_NEON

arch/arm64/crypto/Makefile

@@ -55,10 +55,6 @@ AFLAGS_aes-neon.o	:= -DINTERLEAVE=4
 
 CFLAGS_aes-glue-ce.o	:= -DUSE_V8_CRYPTO_EXTENSIONS
 
-obj-$(CONFIG_CRYPTO_CRC32_ARM64) += crc32-arm64.o
-
-CFLAGS_crc32-arm64.o	:= -mcpu=generic+crc
-
 $(obj)/aes-glue-%.o: $(src)/aes-glue.c FORCE
 	$(call if_changed_rule,cc_o_c)