diff options
| author | Chang S. Bae <chang.seok.bae@intel.com> | 2022-06-08 09:47:47 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2022-07-19 18:46:15 +0200 |
| commit | f17b168734c0fe47343a7502d012266a051f9942 (patch) | |
| tree | 3ddb9d53f6afa31304c60ae68808664472800038 /arch/x86/include/asm/fpu/api.h | |
| parent | ff6992735ade75aae3e35d16b17da1008d753d28 (diff) | |
| download | linux-f17b168734c0fe47343a7502d012266a051f9942.tar.bz2 | |
x86/fpu: Add a helper to prepare AMX state for low-power CPU idle
When a CPU enters an idle state, a non-initialized AMX register state may
be the cause of preventing a deeper low-power state. Other extended
register states whether initialized or not do not impact the CPU idle
state.
The new helper can ensure the AMX state is initialized before the CPU is
idle, and it will be used by the intel idle driver.
Check the AMX_TILE feature bit before using XGETBV1 as a chain of
dependencies was established via cpuid_deps[]: AMX->XFD->XGETBV1.
Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20220608164748.11864-2-chang.seok.bae@intel.com
Diffstat (limited to 'arch/x86/include/asm/fpu/api.h')
| -rw-r--r-- | arch/x86/include/asm/fpu/api.h | 2 |
1 files changed, 2 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 */ |