1 files changed, 19 insertions, 85 deletions

diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index 0b3603adf56d..47496a40e84f 100644
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -11,120 +11,54 @@
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/string.h>
+#include <linux/module.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>
+#include <asm/genapic.h>
 
-#if defined(CONFIG_ACPI)
+#ifdef 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] __read_mostly = { [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;
+u8 x86_cpu_to_log_apicid[NR_CPUS]       = { [0 ... NR_CPUS-1] = BAD_APICID };
 
-struct genapic *genapic = &apic_flat;
-struct genapic *genapic_force;
+struct genapic __read_mostly *genapic = &apic_flat;
 
 /*
  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  */
-void __init clustered_apic_check(void)
+void __init setup_apic_routing(void)
 {
-        long i;
-        u8 clusters, max_cluster;
-        u8 id;
-        u8 cluster_cnt[NUM_APIC_CLUSTERS];
-        int max_apic = 0;
-
-        /* genapic selection can be forced because of certain quirks.
-         */
-        if (genapic_force) {
-                genapic = genapic_force;
-                goto print;
-        }
-
-#if defined(CONFIG_ACPI)
+#ifdef CONFIG_ACPI
         /*
-         * Some x86_64 machines use physical APIC mode regardless of how many
-         * procs/clusters are present (x86_64 ES7000 is an example).
+         * Quirk: some x86_64 machines can only use physical APIC mode
+         * regardless of how many processors are present (x86_64 ES7000
+         * is an example).
          */
-        if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID)
-                if (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) {
-                        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)
-                        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) {
+        if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
+                        (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
                 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;
+        else
 #endif
-                goto print;
-        }
 
-        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) {
-#ifdef CONFIG_HOTPLUG_CPU
-                /* Don't use APIC shortcuts in CPU hotplug to avoid races */
-                genapic = &apic_physflat;
-#else
+        if (cpus_weight(cpu_possible_map) <= 8)
                 genapic = &apic_flat;
-#endif
-        } else
-                genapic = &apic_cluster;
+        else
+                genapic = &apic_physflat;
 
-print:
         printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
 }
 
-/* Same for both flat and clustered. */
+/* Same for both flat and physical. */
 
 void send_IPI_self(int vector)
 {