diff options
| author | Marc Zyngier <maz@kernel.org> | 2021-10-17 13:42:25 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2021-10-19 10:56:20 +0100 |
| commit | fee29f008aa3f2aff01117f28b57b1145d92cb9b (patch) | |
| tree | c8e8ea36d8cb73ced0b6557d7e862cf9571408bb | |
| parent | ae976f063b605dd558571eff40c8229ffbc39e24 (diff) | |
| download | linux-fee29f008aa3f2aff01117f28b57b1145d92cb9b.tar.bz2 | |
arm64: Add HWCAP for self-synchronising virtual counter
Since userspace can make use of the CNTVSS_EL0 instruction, expose
it via a HWCAP.
Suggested-by: Will Deacon <will@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20211017124225.3018098-18-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
| -rw-r--r-- | Documentation/arm64/cpu-feature-registers.rst | 12 | ||||
| -rw-r--r-- | Documentation/arm64/elf_hwcaps.rst | 4 | ||||
| -rw-r--r-- | arch/arm64/include/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 3 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpuinfo.c | 1 |
6 files changed, 19 insertions, 3 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst index 328e0c454fbd..9f9b8fd06089 100644 --- a/Documentation/arm64/cpu-feature-registers.rst +++ b/Documentation/arm64/cpu-feature-registers.rst @@ -235,7 +235,15 @@ infrastructure: | DPB | [3-0] | y | +------------------------------+---------+---------+ - 6) ID_AA64MMFR2_EL1 - Memory model feature register 2 + 6) ID_AA64MMFR0_EL1 - Memory model feature register 0 + + +------------------------------+---------+---------+ + | Name | bits | visible | + +------------------------------+---------+---------+ + | ECV | [63-60] | y | + +------------------------------+---------+---------+ + + 7) ID_AA64MMFR2_EL1 - Memory model feature register 2 +------------------------------+---------+---------+ | Name | bits | visible | @@ -243,7 +251,7 @@ infrastructure: | AT | [35-32] | y | +------------------------------+---------+---------+ - 7) ID_AA64ZFR0_EL1 - SVE feature ID register 0 + 8) ID_AA64ZFR0_EL1 - SVE feature ID register 0 +------------------------------+---------+---------+ | Name | bits | visible | diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst index ec1a5a63c1d0..af106af8e1c0 100644 --- a/Documentation/arm64/elf_hwcaps.rst +++ b/Documentation/arm64/elf_hwcaps.rst @@ -247,6 +247,10 @@ HWCAP2_MTE Functionality implied by ID_AA64PFR1_EL1.MTE == 0b0010, as described by Documentation/arm64/memory-tagging-extension.rst. +HWCAP2_ECV + + Functionality implied by ID_AA64MMFR0_EL1.ECV == 0b0001. + 4. Unused AT_HWCAP bits ----------------------- diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 8c129db8232a..b100e0055eab 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -105,6 +105,7 @@ #define KERNEL_HWCAP_RNG __khwcap2_feature(RNG) #define KERNEL_HWCAP_BTI __khwcap2_feature(BTI) #define KERNEL_HWCAP_MTE __khwcap2_feature(MTE) +#define KERNEL_HWCAP_ECV __khwcap2_feature(ECV) /* * 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 b8f41aa234ee..7b23b16f21ce 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -75,5 +75,6 @@ #define HWCAP2_RNG (1 << 16) #define HWCAP2_BTI (1 << 17) #define HWCAP2_MTE (1 << 18) +#define HWCAP2_ECV (1 << 19) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 6fc33365cffe..de4cf6cfd806 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -279,7 +279,7 @@ static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = { }; static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = { - ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0), + ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_FGT_SHIFT, 4, 0), ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_EXS_SHIFT, 4, 0), /* @@ -2461,6 +2461,7 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { #ifdef CONFIG_ARM64_MTE HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_MTE_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_MTE, CAP_HWCAP, KERNEL_HWCAP_MTE), #endif /* CONFIG_ARM64_MTE */ + HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_ECV_SHIFT, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV), {}, }; diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 87731fea5e41..6e27b759056a 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -94,6 +94,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_RNG] = "rng", [KERNEL_HWCAP_BTI] = "bti", [KERNEL_HWCAP_MTE] = "mte", + [KERNEL_HWCAP_ECV] = "ecv", }; #ifdef CONFIG_COMPAT |