linux-kernel - [PATCH v2 1/6] x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernels

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Date:   Thu,  1 Dec 2016 16:34:57 -0800
From:   Andy Lutomirski <luto@...nel.org>
To:     x86@...nel.org
Cc:     One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>,
        Borislav Petkov <bp@...en8.de>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Brian Gerst <brgerst@...il.com>,
        Matthew Whitehead <tedheadster@...il.com>,
        Henrique de Moraes Holschuh <hmh@....eng.br>,
        Peter Zijlstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>
Subject: [PATCH v2 1/6] x86/asm/32: Make sync_core() handle missing CPUID on all 32-bit kernels

We support various non-Intel CPUs that don't have the CPUID
instruction, so the M486 test was wrong.  For now, fix it with a big
hammer: handle missing CPUID on all 32-bit CPUs.

Reported-by: One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>
Signed-off-by: Andy Lutomirski <luto@...nel.org>
---
 arch/x86/include/asm/processor.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 984a7bf17f6a..64fbc937d586 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -595,7 +595,7 @@ static inline void sync_core(void)
 {
 	int tmp;
 
-#ifdef CONFIG_M486
+#ifdef CONFIG_X86_32
 	/*
 	 * Do a CPUID if available, otherwise do a jump.  The jump
 	 * can conveniently enough be the jump around CPUID.
-- 
2.9.3