From mboxrd@z Thu Jan 1 00:00:00 1970 From: suzuki.poulose@arm.com (Suzuki K. Poulose) Date: Mon, 5 Oct 2015 18:01:58 +0100 Subject: [PATCH v2 09/22] arm64: Read system wide CPUID value In-Reply-To: <1444064531-25607-1-git-send-email-suzuki.poulose@arm.com> References: <1444064531-25607-1-git-send-email-suzuki.poulose@arm.com> Message-ID: <1444064531-25607-10-git-send-email-suzuki.poulose@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Add an API for reading the safe CPUID value across the system from the new infrastructure. Signed-off-by: Suzuki K. Poulose --- arch/arm64/include/asm/cpufeature.h | 2 ++ arch/arm64/kernel/cpufeature.c | 9 +++++++++ 2 files changed, 11 insertions(+) diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 7ed92f2..2e17f9b 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -145,6 +145,8 @@ void check_local_cpu_features(void); bool cpu_supports_mixed_endian_el0(void); bool system_supports_mixed_endian_el0(void); +u64 read_system_reg(u32 id); + #endif /* __ASSEMBLY__ */ #endif diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index b5dd450..a4eff72 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -594,6 +594,15 @@ void update_cpu_features(int cpu, update_mixed_endian_el0_support(info); } +u64 read_system_reg(u32 id) +{ + struct arm64_ftr_reg *regp = get_arm64_sys_reg(id); + + /* We shouldn't get a request for an unsupported register */ + BUG_ON(!regp); + return regp->sys_val; +} + static bool feature_matches(u64 reg, const struct arm64_cpu_capabilities *entry) { -- 1.7.9.5