[PATCH v6 04/16] x86/smpboot: SMP init nodelay and not flush caches before sleep

From: Pu Wen
Date: Mon Sep 10 2018 - 09:16:39 EST


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

Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Pu Wen <puwen@xxxxxxxx>
---
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