diff options
Diffstat (limited to 'arch/arm64/include/asm/cpufeature.h')
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 36 |
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 4ea3441a8fa7..9b27e8c10086 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -10,7 +10,9 @@ #define __ASM_CPUFEATURE_H #include <asm/cpucaps.h> +#include <asm/fpsimd.h> #include <asm/hwcap.h> +#include <asm/sigcontext.h> #include <asm/sysreg.h> /* @@ -223,6 +225,13 @@ static inline bool id_aa64pfr0_32bit_el0(u64 pfr0) return val == ID_AA64PFR0_EL0_32BIT_64BIT; } +static inline bool id_aa64pfr0_sve(u64 pfr0) +{ + u32 val = cpuid_feature_extract_unsigned_field(pfr0, ID_AA64PFR0_SVE_SHIFT); + + return val > 0; +} + void __init setup_cpu_features(void); void update_cpu_capabilities(const struct arm64_cpu_capabilities *caps, @@ -267,6 +276,33 @@ static inline bool system_supports_sve(void) return false; } +/* + * Read the pseudo-ZCR used by cpufeatures to identify the supported SVE + * vector length. + * + * Use only if SVE is present. + * This function clobbers the SVE vector length. + */ +static inline u64 read_zcr_features(void) +{ + u64 zcr; + unsigned int vq_max; + + /* + * Set the maximum possible VL, and write zeroes to all other + * bits to see if they stick. + */ + sve_kernel_enable(NULL); + write_sysreg_s(ZCR_ELx_LEN_MASK, SYS_ZCR_EL1); + + zcr = read_sysreg_s(SYS_ZCR_EL1); + zcr &= ~(u64)ZCR_ELx_LEN_MASK; /* find sticky 1s outside LEN field */ + vq_max = sve_vq_from_vl(sve_get_vl()); + zcr |= vq_max - 1; /* set LEN field to maximum effective value */ + + return zcr; +} + #endif /* __ASSEMBLY__ */ #endif |