From: Andi Kleen <ak@suse.de>
Date: Mon, 12 Sep 2005 16:49:24 +0000 (+0200)
Subject: [PATCH] x86-64: Use largest APIC number, not number of CPUs to decide on physflat... 
X-Git-Tag: v2.6.14-rc1~81
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=70556463487f33bc6728a7596b97f86b811aad22;p=linux-2.6-omap-h63xx.git

[PATCH] x86-64: Use largest APIC number, not number of CPUs to decide on physflat mode

Handles case where BIOS gives CPUs very large APIC numbers correctly.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index b1c144f7314..f3159a496e3 100644
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -45,7 +45,7 @@ void __init clustered_apic_check(void)
 	u8 clusters, max_cluster;
 	u8 id;
 	u8 cluster_cnt[NUM_APIC_CLUSTERS];
-	int num_cpus = 0;
+	int max_apic = 0;
 
 #if defined(CONFIG_ACPI)
 	/*
@@ -64,7 +64,8 @@ void __init clustered_apic_check(void)
 		id = bios_cpu_apicid[i];
 		if (id == BAD_APICID)
 			continue;
-		num_cpus++;
+		if (id > max_apic)
+			max_apic = id;
 		cluster_cnt[APIC_CLUSTERID(id)]++;
 	}
 
@@ -79,7 +80,7 @@ void __init clustered_apic_check(void)
 		   we have ACPI platform support for CPU hotplug
 		   we should detect hotplug capablity from ACPI tables and
 		   only do this when really needed. -AK */
-		if (num_cpus <= 8)
+		if (max_apic <= 8)
 			genapic = &apic_flat;
 #endif
  		goto print;