Expose a HWCAP and ID_AA64MMFR3_EL1_S1POE to userspace, so they can be used to check if the CPU supports the feature.
Signed-off-by: Joey Gouly joey.gouly@arm.com Cc: Catalin Marinas catalin.marinas@arm.com Cc: Will Deacon will@kernel.org Reviewed-by: Catalin Marinas catalin.marinas@arm.com Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com --- Documentation/arch/arm64/elf_hwcaps.rst | 2 ++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 14 ++++++++++++++ arch/arm64/kernel/cpuinfo.c | 1 + 5 files changed, 19 insertions(+)
diff --git Documentation/arch/arm64/elf_hwcaps.rst Documentation/arch/arm64/elf_hwcaps.rst index 448c1664879b..694f67fa07d1 100644 --- Documentation/arch/arm64/elf_hwcaps.rst +++ Documentation/arch/arm64/elf_hwcaps.rst @@ -365,6 +365,8 @@ HWCAP2_SME_SF8DP2 HWCAP2_SME_SF8DP4 Functionality implied by ID_AA64SMFR0_EL1.SF8DP4 == 0b1.
+HWCAP2_POE + Functionality implied by ID_AA64MMFR3_EL1.S1POE == 0b0001.
4. Unused AT_HWCAP bits ----------------------- diff --git arch/arm64/include/asm/hwcap.h arch/arm64/include/asm/hwcap.h index 4edd3b61df11..a775adddecf2 100644 --- arch/arm64/include/asm/hwcap.h +++ arch/arm64/include/asm/hwcap.h @@ -157,6 +157,7 @@ #define KERNEL_HWCAP_SME_SF8FMA __khwcap2_feature(SME_SF8FMA) #define KERNEL_HWCAP_SME_SF8DP4 __khwcap2_feature(SME_SF8DP4) #define KERNEL_HWCAP_SME_SF8DP2 __khwcap2_feature(SME_SF8DP2) +#define KERNEL_HWCAP_POE __khwcap2_feature(POE)
/* * This yields a mask that user programs can use to figure out what diff --git arch/arm64/include/uapi/asm/hwcap.h arch/arm64/include/uapi/asm/hwcap.h index 285610e626f5..055381b2c615 100644 --- arch/arm64/include/uapi/asm/hwcap.h +++ arch/arm64/include/uapi/asm/hwcap.h @@ -122,5 +122,6 @@ #define HWCAP2_SME_SF8FMA (1UL << 60) #define HWCAP2_SME_SF8DP4 (1UL << 61) #define HWCAP2_SME_SF8DP2 (1UL << 62) +#define HWCAP2_POE (1UL << 63)
#endif /* _UAPI__ASM_HWCAP_H */ diff --git arch/arm64/kernel/cpufeature.c arch/arm64/kernel/cpufeature.c index 2daf5597cd65..718728a85430 100644 --- arch/arm64/kernel/cpufeature.c +++ arch/arm64/kernel/cpufeature.c @@ -466,6 +466,8 @@ static const struct arm64_ftr_bits ftr_id_aa64mmfr2[] = { };
static const struct arm64_ftr_bits ftr_id_aa64mmfr3[] = { + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_POE), + FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR3_EL1_S1POE_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR3_EL1_S1PIE_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64MMFR3_EL1_TCRX_SHIFT, 4, 0), ARM64_FTR_END, @@ -2348,6 +2350,14 @@ static void cpu_enable_mops(const struct arm64_cpu_capabilities *__unused) sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_MSCEn); }
+#ifdef CONFIG_ARM64_POE +static void cpu_enable_poe(const struct arm64_cpu_capabilities *__unused) +{ + sysreg_clear_set(REG_TCR2_EL1, 0, TCR2_EL1x_E0POE); + sysreg_clear_set(CPACR_EL1, 0, CPACR_ELx_E0POE); +} +#endif + /* Internal helper functions to match cpu capability type */ static bool cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap) @@ -2876,6 +2886,7 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .capability = ARM64_HAS_S1POE, .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, .matches = has_cpuid_feature, + .cpu_enable = cpu_enable_poe, ARM64_CPUID_FIELDS(ID_AA64MMFR3_EL1, S1POE, IMP) }, #endif @@ -3043,6 +3054,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64FPFR0_EL1, F8DP2, IMP, CAP_HWCAP, KERNEL_HWCAP_F8DP2), HWCAP_CAP(ID_AA64FPFR0_EL1, F8E4M3, IMP, CAP_HWCAP, KERNEL_HWCAP_F8E4M3), HWCAP_CAP(ID_AA64FPFR0_EL1, F8E5M2, IMP, CAP_HWCAP, KERNEL_HWCAP_F8E5M2), +#ifdef CONFIG_ARM64_POE + HWCAP_CAP(ID_AA64MMFR3_EL1, S1POE, IMP, CAP_HWCAP, KERNEL_HWCAP_POE), +#endif {}, };
diff --git arch/arm64/kernel/cpuinfo.c arch/arm64/kernel/cpuinfo.c index 09eeaa24d456..b9db812082b3 100644 --- arch/arm64/kernel/cpuinfo.c +++ arch/arm64/kernel/cpuinfo.c @@ -143,6 +143,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SME_SF8FMA] = "smesf8fma", [KERNEL_HWCAP_SME_SF8DP4] = "smesf8dp4", [KERNEL_HWCAP_SME_SF8DP2] = "smesf8dp2", + [KERNEL_HWCAP_POE] = "poe", };
#ifdef CONFIG_COMPAT