ARMv8.0 has optional crc32 instruction for crc32 calculation. The instruction is mandatory since ARMv8.1. The crc32 calculation is faster using the dedicated instruction, e.g. 1.4 GHz iMX8MN gives:
=> time crc32 0x50000000 0x2000000 time: 0.126 seconds # crc32 instruction time: 0.213 seconds # software crc32
Add implementation using the compiler builtin wrapper for the crc32 instruction and enable it by default, since we don't support any platforms which do not implement this instruction.
Signed-off-by: Marek Vasut marex@denx.de Cc: Simon Glass sjg@chromium.org Cc: Tom Rini trini@konsulko.com --- arch/arm/Kconfig | 9 +++++++++ arch/arm/Makefile | 4 ++++ lib/crc32.c | 7 +++++++ 3 files changed, 20 insertions(+)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 2d59562665f..134d3c6563d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -10,6 +10,15 @@ config ARM64 select SYS_CACHE_SHIFT_6
if ARM64 +config ARM64_CRC32 + bool "Enable support for CRC32 instruction" + default y + help + ARMv8 implements dedicated crc32 instruction for crc32 calculation. + This is faster than software crc32 calculation. This instruction may + not be present on all ARMv8.0, but is always present on ARMv8.1 and + newer. + config POSITION_INDEPENDENT bool "Generate position-independent pre-relocation code" help diff --git a/arch/arm/Makefile b/arch/arm/Makefile index c68e598a675..ce977bf6323 100644 --- a/arch/arm/Makefile +++ b/arch/arm/Makefile @@ -18,7 +18,11 @@ arch-$(CONFIG_CPU_V7A) =$(call cc-option, -march=armv7-a, \ $(call cc-option, -march=armv7)) arch-$(CONFIG_CPU_V7M) =-march=armv7-m arch-$(CONFIG_CPU_V7R) =-march=armv7-r +ifeq ($(CONFIG_ARM64_CRC32),y) +arch-$(CONFIG_ARM64) =-march=armv8-a+crc +else arch-$(CONFIG_ARM64) =-march=armv8-a +endif
# On Tegra systems we must build SPL for the armv4 core on the device # but otherwise we can use the value in CONFIG_SYS_ARM_ARCH diff --git a/lib/crc32.c b/lib/crc32.c index f2acc107fe4..a207e3d2b40 100644 --- a/lib/crc32.c +++ b/lib/crc32.c @@ -184,6 +184,12 @@ const uint32_t * ZEXPORT get_crc_table() */ uint32_t __efi_runtime crc32_no_comp(uint32_t crc, const Bytef *buf, uInt len) { +#ifdef CONFIG_ARM64_CRC32 + crc = cpu_to_le32(crc); + while (len--) + crc = __builtin_aarch64_crc32b(crc, *buf++); + return le32_to_cpu(crc); +#else const uint32_t *tab = crc_table; const uint32_t *b =(const uint32_t *)buf; size_t rem_len; @@ -221,6 +227,7 @@ uint32_t __efi_runtime crc32_no_comp(uint32_t crc, const Bytef *buf, uInt len) }
return le32_to_cpu(crc); +#endif } #undef DO_CRC