diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/special_insns.h | 9 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/core.c | 14 |
3 files changed, 25 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/api.h b/arch/x86/include/asm/fpu/api.h index 6b0f31fb53f7..503a577814b2 100644 --- a/arch/x86/include/asm/fpu/api.h +++ b/arch/x86/include/asm/fpu/api.h @@ -164,4 +164,6 @@ static inline bool fpstate_is_confidential(struct fpu_guest *gfpu) /* prctl */ extern long fpu_xstate_prctl(int option, unsigned long arg2); +extern void fpu_idle_fpregs(void); + #endif /* _ASM_X86_FPU_API_H */ diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h index 45b18eb94fa1..35f709f619fb 100644 --- a/arch/x86/include/asm/special_insns.h +++ b/arch/x86/include/asm/special_insns.h @@ -295,6 +295,15 @@ static inline int enqcmds(void __iomem *dst, const void *src) return 0; } +static inline void tile_release(void) +{ + /* + * Instruction opcode for TILERELEASE; supported in binutils + * version >= 2.36. + */ + asm volatile(".byte 0xc4, 0xe2, 0x78, 0x49, 0xc0"); +} + #endif /* __KERNEL__ */ #endif /* _ASM_X86_SPECIAL_INSNS_H */ diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 0531d6a06df5..3b28c5b25e12 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -851,3 +851,17 @@ int fpu__exception_code(struct fpu *fpu, int trap_nr) */ return 0; } + +/* + * Initialize register state that may prevent from entering low-power idle. + * This function will be invoked from the cpuidle driver only when needed. + */ +void fpu_idle_fpregs(void) +{ + /* Note: AMX_TILE being enabled implies XGETBV1 support */ + if (cpu_feature_enabled(X86_FEATURE_AMX_TILE) && + (xfeatures_in_use() & XFEATURE_MASK_XTILE)) { + tile_release(); + fpregs_deactivate(¤t->thread.fpu); + } +} |