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authorJoey Gouly <joey.gouly@arm.com>2024-08-22 17:10:54 +0200
committerWill Deacon <will@kernel.org>2024-09-04 13:52:40 +0200
commitbf83dae90fbc01d66477a3440eaad07da6657fdc (patch)
tree87f4088a1416d0121c55a928556b39a955e9f090 /arch/arm64/kernel
parentmm: use ARCH_PKEY_BITS to define VM_PKEY_BITN (diff)
downloadlinux-bf83dae90fbc01d66477a3440eaad07da6657fdc.tar.xz
linux-bf83dae90fbc01d66477a3440eaad07da6657fdc.zip
arm64: enable the Permission Overlay Extension for EL0
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> Link: https://lore.kernel.org/r/20240822151113.1479789-12-joey.gouly@arm.com Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r--arch/arm64/kernel/cpufeature.c14
-rw-r--r--arch/arm64/kernel/cpuinfo.c1
2 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 2daf5597cd65..718728a85430 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/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 a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 09eeaa24d456..b9db812082b3 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/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