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linux/arch/x86/include/asm/fpu
Chang S. Bae f17b168734 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
2022-07-19 18:46:15 +02:00
..
api.h x86/fpu: Add a helper to prepare AMX state for low-power CPU idle 2022-07-19 18:46:15 +02:00
regset.h x86: switch to ->regset_get() 2020-07-27 14:31:07 -04:00
sched.h fork: Generalize PF_IO_WORKER handling 2022-05-07 09:01:59 -05:00
signal.h x86/fpu: Remove duplicate copy_fpstate_to_sigframe() prototype 2021-12-10 19:13:06 +01:00
types.h x86/fpu: Add uabi_size to guest_fpu 2022-01-14 13:44:40 -05:00
xcr.h x86/fpu: Optimize out sigframe xfeatures when in init state 2021-11-03 22:42:35 +01:00
xstate.h x86/fpu: Optimize out sigframe xfeatures when in init state 2021-11-03 22:42:35 +01:00