From bc95f982cb0be4933f4648ba292d65db208b9b7c Mon Sep 17 00:00:00 2001 From: Rongwei Wang Date: Sun, 26 Apr 2020 04:48:19 +0800 Subject: [PATCH 0980/2944] arm64: cpufeature: add feature for CRC32 instructions to #26730415 commit 86d0dd34eafffbc76a81aba6ae2d71927d3835a8 upstream. Add a CRC32 feature bit and wire it up to the CPU id register so we will be able to use alternatives patching for CRC32 operations. Acked-by: Will Deacon Signed-off-by: Ard Biesheuvel Signed-off-by: Catalin Marinas [ Rongwei: fixed conflicts ] Signed-off-by: Rongwei Wang Acked-by: Zou Cao --- arch/arm64/include/asm/cpucaps.h | 3 ++- arch/arm64/kernel/cpufeature.c | 9 +++++++++ 2 files changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index c3de0bb..6a531e6 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -53,7 +53,8 @@ #define ARM64_HAS_STAGE2_FWB 32 #define ARM64_WORKAROUND_1463225 33 #define ARM64_SSBS 34 +#define ARM64_HAS_CRC32 35 -#define ARM64_NCAPS 35 +#define ARM64_NCAPS 36 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 220ebfa..8a4ede8 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1338,6 +1338,15 @@ static void cpu_enable_ssbs(const struct arm64_cpu_capabilities *__unused) .cpu_enable = cpu_enable_ssbs, }, #endif + { + .desc = "CRC32 instructions", + .capability = ARM64_HAS_CRC32, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + .sys_reg = SYS_ID_AA64ISAR0_EL1, + .field_pos = ID_AA64ISAR0_CRC32_SHIFT, + .min_field_value = 1, + }, {}, }; -- 1.8.3.1