linux-kernel - [tip: x86/cpu] x86/cstate: Allow ACPI C1 FFH MWAIT use on Hygon systems

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Message-ID: <162245134873.29796.1219713411989119535.tip-bot2@tip-bot2>
Date:   Mon, 31 May 2021 08:55:48 -0000
From:   "tip-bot2 for Pu Wen" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Pu Wen <puwen@...on.cn>, Borislav Petkov <bp@...e.de>,
        x86@...nel.org, linux-kernel@...r.kernel.org
Subject: [tip: x86/cpu] x86/cstate: Allow ACPI C1 FFH MWAIT use on Hygon systems

The following commit has been merged into the x86/cpu branch of tip:

Commit-ID:     280b68a3b3b96b027fcdeb5a3916a8e2aaf84d03
Gitweb:        https://git.kernel.org/tip/280b68a3b3b96b027fcdeb5a3916a8e2aaf84d03
Author:        Pu Wen <puwen@...on.cn>
AuthorDate:    Fri, 28 May 2021 16:14:17 +08:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Mon, 31 May 2021 10:47:04 +02:00

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: Pu Wen <puwen@...on.cn>
Signed-off-by: Borislav Petkov <bp@...e.de>
Link: https://lkml.kernel.org/r/20210528081417.31474-1-puwen@hygon.cn
---
 arch/x86/kernel/acpi/cstate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/acpi/cstate.c b/arch/x86/kernel/acpi/cstate.c
index 49ae4e1..7de599e 100644
--- a/arch/x86/kernel/acpi/cstate.c
+++ b/arch/x86/kernel/acpi/cstate.c
@@ -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);