Provide a hwcap to enable userspace to detect support for GCS.
Signed-off-by: Mark Brown broonie@kernel.org --- Documentation/arch/arm64/elf_hwcaps.rst | 4 ++++ arch/arm64/include/asm/hwcap.h | 1 + arch/arm64/include/uapi/asm/hwcap.h | 3 ++- arch/arm64/kernel/cpufeature.c | 3 +++ arch/arm64/kernel/cpuinfo.c | 1 + 5 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/Documentation/arch/arm64/elf_hwcaps.rst b/Documentation/arch/arm64/elf_hwcaps.rst index 694f67fa07d1..25b41ff74fa0 100644 --- a/Documentation/arch/arm64/elf_hwcaps.rst +++ b/Documentation/arch/arm64/elf_hwcaps.rst @@ -170,6 +170,10 @@ HWCAP_PACG ID_AA64ISAR1_EL1.GPI == 0b0001, as described by Documentation/arch/arm64/pointer-authentication.rst.
+HWCAP_GCS + Functionality implied by ID_AA64PFR1_EL1.GCS == 0b1, as + described by Documentation/arch/arm64/gcs.rst. + HWCAP2_DCPODP Functionality implied by ID_AA64ISAR1_EL1.DPB == 0b0010.
diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index a775adddecf2..7bcf1347ca0b 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -92,6 +92,7 @@ #define KERNEL_HWCAP_SB __khwcap_feature(SB) #define KERNEL_HWCAP_PACA __khwcap_feature(PACA) #define KERNEL_HWCAP_PACG __khwcap_feature(PACG) +#define KERNEL_HWCAP_GCS __khwcap_feature(GCS)
#define __khwcap2_feature(x) (const_ilog2(HWCAP2_ ## x) + 64) #define KERNEL_HWCAP_DCPODP __khwcap2_feature(DCPODP) diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 055381b2c615..675642ec4d91 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -21,7 +21,7 @@ * HWCAP flags - for AT_HWCAP * * Bits 62 and 63 are reserved for use by libc. - * Bits 32-61 are unallocated for potential use by libc. + * Bits 33-61 are unallocated for potential use by libc. */ #define HWCAP_FP (1 << 0) #define HWCAP_ASIMD (1 << 1) @@ -55,6 +55,7 @@ #define HWCAP_SB (1 << 29) #define HWCAP_PACA (1 << 30) #define HWCAP_PACG (1UL << 31) +#define HWCAP_GCS (1UL << 32)
/* * HWCAP2 flags - for AT_HWCAP2 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index d1e758e99e0a..b8655d55f318 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -3025,6 +3025,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(ID_AA64ZFR0_EL1, I8MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEI8MM), HWCAP_CAP(ID_AA64ZFR0_EL1, F32MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEF32MM), HWCAP_CAP(ID_AA64ZFR0_EL1, F64MM, IMP, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM), +#endif +#ifdef CONFIG_ARM64_GCS + HWCAP_CAP(ID_AA64PFR1_EL1, GCS, IMP, CAP_HWCAP, KERNEL_HWCAP_GCS), #endif HWCAP_CAP(ID_AA64PFR1_EL1, SSBS, SSBS2, CAP_HWCAP, KERNEL_HWCAP_SSBS), #ifdef CONFIG_ARM64_BTI diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 44718d0482b3..f2f92c6b1c85 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -80,6 +80,7 @@ static const char *const hwcap_str[] = { [KERNEL_HWCAP_SB] = "sb", [KERNEL_HWCAP_PACA] = "paca", [KERNEL_HWCAP_PACG] = "pacg", + [KERNEL_HWCAP_GCS] = "gcs", [KERNEL_HWCAP_DCPODP] = "dcpodp", [KERNEL_HWCAP_SVE2] = "sve2", [KERNEL_HWCAP_SVEAES] = "sveaes",