fedora core 6 1.2949 + vserver 2.2.0

[linux-2.6.git] / arch / x86_64 / kernel / genapic.c

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index 9aa5cb6..b007433 100644 (file)
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -8,7 +8,6 @@
  * 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>
@@ -20,16 +19,21 @@
 #include <asm/smp.h>
 #include <asm/ipi.h>
 
+#if defined(CONFIG_ACPI)
+#include <acpi/acpi_bus.h>
+#endif
+
 /* which logical CPU number maps to which CPU (physical APIC ID) */
-u8 x86_cpu_to_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
+u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly = { [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;
+extern struct genapic apic_physflat;
 
 struct genapic *genapic = &apic_flat;
-
+struct genapic *genapic_force;
 
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
@@ -40,17 +44,57 @@ void __init clustered_apic_check(void)
        u8 clusters, max_cluster;
        u8 id;
        u8 cluster_cnt[NUM_APIC_CLUSTERS];
+       int max_apic = 0;
 
-       memset(cluster_cnt, 0, sizeof(cluster_cnt));
+       /* genapic selection can be forced because of certain quirks.
+        */
+       if (genapic_force) {
+               genapic = genapic_force;
+               goto print;
+       }
+
+#if defined(CONFIG_ACPI)
+       /*
+        * Some x86_64 machines use physical APIC mode regardless of how many
+        * procs/clusters are present (x86_64 ES7000 is an example).
+        */
+       if (acpi_fadt.revision > FADT2_REVISION_ID)
+               if (acpi_fadt.force_apic_physical_destination_mode) {
+                       genapic = &apic_cluster;
+                       goto print;
+               }
+#endif
 
+       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)]++;
+               if (id == BAD_APICID)
+                       continue;
+               if (id > max_apic)
+                       max_apic = id;
+               cluster_cnt[APIC_CLUSTERID(id)]++;
        }
 
+       /* Don't use clustered mode on AMD platforms. */
+       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
+               genapic = &apic_physflat;
+#ifndef CONFIG_HOTPLUG_CPU
+               /* In the CPU hotplug case we cannot use broadcast mode
+                  because that opens a race when a CPU is removed.
+                  Stay at physflat mode in this case.
+                  It is bad to do this unconditionally though. Once
+                  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 (max_apic <= 8)
+                       genapic = &apic_flat;
+#endif
+               goto print;
+       }
+
        clusters = 0;
        max_cluster = 0;
+
        for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
                if (cluster_cnt[i] > 0) {
                        ++clusters;
@@ -66,11 +110,17 @@ void __init clustered_apic_check(void)
         * (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)
+       if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster) {
+#ifdef CONFIG_HOTPLUG_CPU
+               /* Don't use APIC shortcuts in CPU hotplug to avoid races */
+               genapic = &apic_physflat;
+#else
                genapic = &apic_flat;
-       else
+#endif
+       } else
                genapic = &apic_cluster;
 
+print:
        printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
 }