linux-kernel - [PATCH 4.9 047/107] x86/CPU/AMD: Do not check CPUID max ext level before parsing SMP info

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Date:   Tue, 14 Aug 2018 19:17:10 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Borislav Petkov <bp@...e.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...nel.org>,
        David Woodhouse <dwmw@...zon.co.uk>
Subject: [PATCH 4.9 047/107] x86/CPU/AMD: Do not check CPUID max ext level before parsing SMP info

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Borislav Petkov <bp@...e.de>

commit 119bff8a9c9bb00116a844ec68be7bc4b1c768f5 upstream

Old code used to check whether CPUID ext max level is >= 0x80000008 because
that last leaf contains the number of cores of the physical CPU.  The three
functions called there now do not depend on that leaf anymore so the check
can go.

Signed-off-by: Borislav Petkov <bp@...e.de>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Acked-by: Ingo Molnar <mingo@...nel.org>
Signed-off-by: David Woodhouse <dwmw@...zon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 arch/x86/kernel/cpu/amd.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -799,11 +799,8 @@ static void init_amd(struct cpuinfo_x86
 
 	cpu_detect_cache_sizes(c);
 
-	/* Multi core CPU? */
-	if (c->extended_cpuid_level >= 0x80000008) {
-		amd_detect_cmp(c);
-		srat_detect_node(c);
-	}
+	amd_detect_cmp(c);
+	srat_detect_node(c);
 
 	init_amd_cacheinfo(c);