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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/kernel/genapic.c
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!
Diffstat (limited to 'arch/x86_64/kernel/genapic.c')
-rw-r--r--arch/x86_64/kernel/genapic.c89
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
new file mode 100644
index 00000000000..d2c42fb99cb
--- /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);
+}