x86/smpboot: Do not use BSP INIT delay and MWAIT to idle on Dhyana
authorPu Wen <puwen@hygon.cn>
Sun, 23 Sep 2018 09:34:32 +0000 (17:34 +0800)
committerBorislav Petkov <bp@suse.de>
Thu, 27 Sep 2018 16:28:57 +0000 (18:28 +0200)
The Hygon Dhyana CPU uses no delay in smp_quirk_init_udelay(), and does
HLT on idle just like AMD does.

Signed-off-by: Pu Wen <puwen@hygon.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: bp@alien8.de
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: x86@kernel.org
Cc: thomas.lendacky@amd.com
Link: https://lkml.kernel.org/r/87000fa82e273f5967c908448414228faf61e077.1537533369.git.puwen@hygon.cn
arch/x86/kernel/smpboot.c

index f02ecaf..5369d7f 100644 (file)
@@ -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;