From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001
From: Linus Torvalds <torvalds@ppc970.osdl.org>
Date: Sat, 16 Apr 2005 15:20:36 -0700
Subject: Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
---
 arch/x86_64/kernel/genapic.c | 89 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 arch/x86_64/kernel/genapic.c

(limited to 'arch/x86_64/kernel/genapic.c')

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
new file mode 100644
index 000000000000..d2c42fb99cb3
--- /dev/null
+++ b/arch/x86_64/kernel/genapic.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2004 James Cleverdon, IBM.
+ * Subject to the GNU Public License, v.2
+ *
+ * Generic APIC sub-arch probe layer.
+ *
+ * Hacked for x86-64 by James Cleverdon from i386 architecture code by
+ * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
+ * James Cleverdon.
+ */
+#include <linux/config.h>
+#include <linux/threads.h>
+#include <linux/cpumask.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include <asm/smp.h>
+#include <asm/ipi.h>
+
+/* which logical CPU number maps to which CPU (physical APIC ID) */
+u8 x86_cpu_to_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
+EXPORT_SYMBOL(x86_cpu_to_apicid);
+u8 x86_cpu_to_log_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
+
+extern struct genapic apic_cluster;
+extern struct genapic apic_flat;
+
+struct genapic *genapic = &apic_flat;
+
+
+/*
+ * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
+ */
+void __init clustered_apic_check(void)
+{
+	long i;
+	u8 clusters, max_cluster;
+	u8 id;
+	u8 cluster_cnt[NUM_APIC_CLUSTERS];
+
+	if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+		/* AMD always uses flat mode right now */
+		genapic = &apic_flat;
+		goto print;
+	}
+
+	memset(cluster_cnt, 0, sizeof(cluster_cnt));
+
+	for (i = 0; i < NR_CPUS; i++) {
+		id = bios_cpu_apicid[i];
+		if (id != BAD_APICID)
+			cluster_cnt[APIC_CLUSTERID(id)]++;
+	}
+
+	clusters = 0;
+	max_cluster = 0;
+	for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
+		if (cluster_cnt[i] > 0) {
+			++clusters;
+			if (cluster_cnt[i] > max_cluster)
+				max_cluster = cluster_cnt[i];
+		}
+	}
+
+	/*
+	 * If we have clusters <= 1 and CPUs <= 8 in cluster 0, then flat mode,
+	 * else if max_cluster <= 4 and cluster_cnt[15] == 0, clustered logical
+	 * else physical mode.
+	 * (We don't use lowest priority delivery + HW APIC IRQ steering, so
+	 * can ignore the clustered logical case and go straight to physical.)
+	 */
+	if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster)
+		genapic = &apic_flat;
+	else
+		genapic = &apic_cluster;
+
+print:
+	printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
+}
+
+/* Same for both flat and clustered. */
+
+void send_IPI_self(int vector)
+{
+	__send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
+}
-- 
cgit v1.2.1