linux/arch/x86/kernel/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
..
bugs.c x86/fpu: Replace the includes of fpu/internal.h 2021-10-20 15:27:29 +02:00
context.h x86/fpu: Update XFD state where required 2021-10-26 10:53:02 +02:00
core.c x86/fpu: Add a helper to prepare AMX state for low-power CPU idle 2022-07-19 18:46:15 +02:00
init.c x86/fpu: Add fpu_state_config::legacy_features 2021-10-26 10:18:09 +02:00
internal.h x86/fpu/signal: Prepare for variable sigframe length 2021-10-26 10:18:09 +02:00
legacy.h x86/fpu: Remove .fixup usage 2021-12-11 09:09:48 +01:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
regset.c x86/ptrace: Fix xfpregs_set()'s incorrect xmm clearing 2022-02-18 11:23:21 +01:00
signal.c x86/fpu/signal: Initialize sw_bytes in save_xstate_epilog() 2021-11-30 15:13:47 -08:00
xstate.c - Add support for XSAVEC - the Compacted XSTATE saving variant - and 2022-05-23 18:49:16 -07:00
xstate.h x86/fpu/xsave: Support XSAVEC in the kernel 2022-04-25 15:05:37 +02:00