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 --- Documentation/arch/arm64/elf_hwcaps.rst | 3 +++ 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, 20 insertions(+)
diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst index ced7b335e2e0..fe7350a66cea 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -317,6 +317,9 @@ HWCAP2_LRCPC3 HWCAP2_LSE128 Functionality implied by ID_AA64ISAR0_EL1.Atomic == 0b0011.
+HWCAP2_POE + Functionality implied by ID_AA64MMFR3_EL1.S1POE == 0b0001. + 4. Unused AT_HWCAP bits -----------------------
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index cd71e09ea14d..9a1aa1e5e25c 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -142,6 +142,7 @@ #define KERNEL_HWCAP_SVE_B16B16 __khwcap2_feature(SVE_B16B16) #define KERNEL_HWCAP_LRCPC3 __khwcap2_feature(LRCPC3) #define KERNEL_HWCAP_LSE128 __khwcap2_feature(LSE128) +#define KERNEL_HWCAP_POE __khwcap2_feature(POE)
/* * This yields a mask that user programs can use to figure out what diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 5023599fa278..69f09521b553 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -107,5 +107,6 @@ #define HWCAP2_SVE_B16B16 (1UL << 45) #define HWCAP2_LRCPC3 (1UL << 46) #define HWCAP2_LSE128 (1UL << 47) +#define HWCAP2_POE (1UL << 48)
#endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 00b6d516ed3f..02169cb3b84b 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -402,6 +402,8 @@ 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, @@ -2242,6 +2244,14 @@ 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) @@ -2737,6 +2747,7 @@ 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 @@ -2889,6 +2900,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64SMFR0_EL1, BI32I32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_BI32I32), HWCAP_CAP(ID_AA64SMFR0_EL1, F32F32, IMP, CAP_HWCAP, KERNEL_HWCAP_SME_F32F32), #endif /* CONFIG_ARM64_SME */ +#ifdef CONFIG_ARM64_POE + HWCAP_CAP(ID_AA64MMFR3_EL1, S1POE, IMP, CAP_HWCAP, KERNEL_HWCAP_POE), +#endif {}, };
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index a257da7b56fe..5515c50f5219 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -130,6 +130,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SVE_B16B16] = "sveb16b16", [KERNEL_HWCAP_LRCPC3] = "lrcpc3", [KERNEL_HWCAP_LSE128] = "lse128", + [KERNEL_HWCAP_POE] = "poe", };
#ifdef CONFIG_COMPAT