linux-kernel - [PATCH 12/15] x86, x2apic: Don't map lapic addr for preenabled x2apic

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Date:	Sat, 23 Oct 2010 18:02:26 -0700
From:	Yinghai Lu <yinghai@...nel.org>
To:	Ingo Molnar <mingo@...e.hu>, Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Len Brown <lenb@...nel.org>, linux-kernel@...r.kernel.org,
	Yinghai Lu <yinghai@...nel.org>
Subject: [PATCH 12/15] x86, x2apic: Don't map lapic addr for preenabled x2apic

If x2apic is reenabled, and used in kernel, We don't need to map that lapic
address. That mapping will never be used.

So just skip that in smp_register_lapic_address()

Signed-off-by: Yinghai Lu <yinghai@...nel.org>
---
 arch/x86/kernel/apic/apic.c |    8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 2cfa622..d286db1 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1687,9 +1687,11 @@ void __init smp_register_lapic_address(unsigned long address)
 
 	mp_lapic_addr = address;
 
-	set_fixmap_nocache(FIX_APIC_BASE, address);
-	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
-		    APIC_BASE, mp_lapic_addr);
+	if (!x2apic_mode) {
+		set_fixmap_nocache(FIX_APIC_BASE, address);
+		apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
+			    APIC_BASE, mp_lapic_addr);
+	}
 	if (boot_cpu_physical_apicid == -1U) {
 		boot_cpu_physical_apicid  = read_apic_id();
 		apic_version[boot_cpu_physical_apicid] =
-- 
1.7.1

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