From: Prarit Bhargava <prarit@redhat.com>
Date: Tue, 9 Sep 2008 08:05:44 -0400
Subject: [x86_64] AMD 8-socket APICID patches
Message-id: 48C66698.1030805@redhat.com
O-Subject: Re: [RHEL5 PATCH]: AMD 8-socket APICID patches
Bugzilla: 459813
RH-Acked-by: Peter Martuccelli <peterm@redhat.com>

Backport of 322850af8d93735f67b8ebf84bb1350639be3f34 and f8fffa458368ed3d57385698f775880db629bd1a.

apic_is_clustered_box() should bail when an AMD or vsmp system is detected.

This functionality is required for new Sun and HP AMD hardware.

Compiled and regression tested on 4-way (8 cpu) Barcelona system.

Resolves BZ 459813.

diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index e2354f6..9798e8e 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -1009,6 +1009,15 @@ __cpuinit int apic_is_clustered_box(void)
 	unsigned id;
 	DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
 
+	/*
+	* there is not this kind of box with AMD CPU yet.
+	* Some AMD box with quadcore cpu and 8 sockets apicid
+	* will be [4, 0x23] or [8, 0x27] could be thought to
+	* have three apic_clusters. So go out early.
+	*/
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD && !is_vsmp_box())
+		return 0;
+
 	bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
 
 	for (i = 0; i < NR_CPUS; i++) {
diff --git a/arch/x86_64/kernel/vsmp.c b/arch/x86_64/kernel/vsmp.c
index 92f70c7..475c670 100644
--- a/arch/x86_64/kernel/vsmp.c
+++ b/arch/x86_64/kernel/vsmp.c
@@ -15,14 +15,30 @@
 #include <linux/pci_regs.h>
 #include <asm/pci-direct.h>
 
+static int vsmp = -1;
+
+int is_vsmp_box(void)
+{
+	if (vsmp != -1)
+		return vsmp;
+
+	vsmp = 0;
+
+	/* Check if we are running on a ScaleMP vSMP box */
+	if (read_pci_config(0, 0x1f, 0, PCI_VENDOR_ID) ==
+	     (PCI_VENDOR_ID_SCALEMP || (PCI_DEVICE_ID_SCALEMP_VSMP_CTL << 16)))
+		vsmp = 1;
+
+	return vsmp;
+}
+
 static int __init vsmp_init(void)
 {
 	void *address;
 	unsigned int cap, ctl;
 
-	/* Check if we are running on a ScaleMP vSMP box */
-	if ((read_pci_config_16(0, 0x1f, 0, PCI_VENDOR_ID) != PCI_VENDOR_ID_SCALEMP) ||
-	    (read_pci_config_16(0, 0x1f, 0, PCI_DEVICE_ID) != PCI_DEVICE_ID_SCALEMP_VSMP_CTL))
+
+	if (!is_vsmp_box())
 		return 0;
 
 	/* set vSMP magic bits to indicate vSMP capable kernel */
diff --git a/include/asm-x86_64/apic.h b/include/asm-x86_64/apic.h
index 12e8714..2a26391 100644
--- a/include/asm-x86_64/apic.h
+++ b/include/asm-x86_64/apic.h
@@ -103,8 +103,13 @@ extern int disable_timer_pin_1;
 void smp_send_timer_broadcast_ipi(void);
 void switch_APIC_timer_to_ipi(void *cpumask);
 void switch_ipi_to_APIC_timer(void *cpumask);
-
 #define ARCH_APICTIMER_STOPS_ON_C3	1
+static int inline is_vsmp_box(void)
+{
+	return 0;
+}
+#else
+extern int is_vsmp_box(void);
 #endif
 
 #endif /* CONFIG_X86_LOCAL_APIC */