From: Marc Zyngier maz@kernel.org
mainline inclusion from mainline-v5.16-rc1 commit fee29f008aa3 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4QCBG CVE: NA
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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 Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- Documentation/arm64/cpu-feature-registers.rst | 12 ++++++++++-- Documentation/arm64/elf_hwcaps.rst | 4 ++++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 1 + arch/arm64/kernel/cpufeature.c | 3 ++- 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 bbd9cf54db6c..95e66bd7dd17 100644 --- a/Documentation/arm64/elf_hwcaps.rst +++ b/Documentation/arm64/elf_hwcaps.rst @@ -245,6 +245,10 @@ 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 c9c6aa1c4b54..be9cb527b309 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 d267f00a9b71..3e6fe8befc63 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -259,7 +259,7 @@ 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), /* @@ -2361,6 +2361,7 @@ 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 1b5ee494488a..50bbce672a3c 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_AARCH32_EL0