linux-kernel - [PATCH v7 04/16] x86/smpboot: SMP init no delay and not flush caches before sleep

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Message-Id: <87000fa82e273f5967c908448414228faf61e077.1537182523.git.puwen@hygon.cn>
Date:   Mon, 17 Sep 2018 21:30:11 +0800
From:   Pu Wen <puwen@...on.cn>
To:     bp@...en8.de, tglx@...utronix.de, mingo@...hat.com, hpa@...or.com,
        x86@...nel.org, thomas.lendacky@....com
Cc:     linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
        Pu Wen <puwen@...on.cn>
Subject: [PATCH v7 04/16] x86/smpboot: SMP init no delay and not flush caches before sleep

The Hygon Dhyana CPU uses no delay in smp_quirk_init_udelay(),
and returns in mwait_play_dead() as AMD does.

Signed-off-by: Pu Wen <puwen@...on.cn>
Reviewed-by: Borislav Petkov <bp@...e.de>
---
 arch/x86/kernel/smpboot.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index f02ecaf..5369d7f 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -676,6 +676,7 @@ static void __init smp_quirk_init_udelay(void)
 
 	/* if modern processor, use no delay */
 	if (((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && (boot_cpu_data.x86 == 6)) ||
+	    ((boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) && (boot_cpu_data.x86 >= 0x18)) ||
 	    ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD) && (boot_cpu_data.x86 >= 0xF))) {
 		init_udelay = 0;
 		return;
@@ -1592,7 +1593,8 @@ static inline void mwait_play_dead(void)
 	void *mwait_ptr;
 	int i;
 
-	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
+	    boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
 		return;
 	if (!this_cpu_has(X86_FEATURE_MWAIT))
 		return;
-- 
2.7.4