Commit 280b68a3 authored by Pu Wen's avatar Pu Wen Committed by Borislav Petkov
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x86/cstate: Allow ACPI C1 FFH MWAIT use on Hygon systems 



Hygon systems support the MONITOR/MWAIT instructions and these can be
used for ACPI C1 in the same way as on AMD and Intel systems.

The BIOS declares a C1 state in _CST to use FFH and CPUID_Fn00000005_EDX
is non-zero on Hygon systems.

Allow ffh_cstate_init() to succeed on Hygon systems to default using FFH
MWAIT instead of HALT for ACPI C1.

Signed-off-by: default avatarPu Wen <puwen@hygon.cn>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20210528081417.31474-1-puwen@hygon.cn
parent 2ade8fc6

arch/x86/kernel/acpi/cstate.c

+2 −1
Original line number Diff line number Diff line
@@ -197,7 +197,8 @@ static int __init ffh_cstate_init(void) 
	struct cpuinfo_x86 *c = &boot_cpu_data;



	if (c->x86_vendor != X86_VENDOR_INTEL &&

	    c->x86_vendor != X86_VENDOR_AMD)

	    c->x86_vendor != X86_VENDOR_AMD &&

	    c->x86_vendor != X86_VENDOR_HYGON)

		return -1;



	cpu_cstate_entry = alloc_percpu(struct cstate_entry);