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authorJason Davis <jason@rightthere.net>2005-04-16 15:24:53 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:24:53 -0700
commit90660ec3c3e3f463a3cc7005213345b6c9ecfab9 (patch)
tree1b9d29d6db925d41e282f2f3dcff189b4c185f90 /arch/x86_64/kernel/genapic.c
parent107ce721abddbd876aa6203ac982821e405400e9 (diff)
[PATCH] x86_64 genapic update
x86_64 genapic mechanism should be aware of machines that use physical APIC mode regardless of how many clusters/processors are detected. ACPI 3.0 FADT makes this determination very simple by providing a feature flag "force_apic_physical_destination_mode" to state whether the machine unconditionally uses physical APIC mode. Unisys' next generation x86_64 ES7000 will need to utilize this FADT feature flag in order to boot the x86_64 kernel in the correct APIC mode. This patch has been tested on both x86_64 commodity and ES7000 boxes. Signed-off-by: Jason Davis <jason.davis@unisys.com> Acked-by: Andi Kleen <ak@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/x86_64/kernel/genapic.c')
-rw-r--r--arch/x86_64/kernel/genapic.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c
index d2c42fb99cb..69b9c25a8fc 100644
--- a/arch/x86_64/kernel/genapic.c
+++ b/arch/x86_64/kernel/genapic.c
@@ -20,6 +20,10 @@
#include <asm/smp.h>
#include <asm/ipi.h>
+#if defined(CONFIG_ACPI_BUS)
+#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 };
EXPORT_SYMBOL(x86_cpu_to_apicid);
@@ -47,6 +51,18 @@ void __init clustered_apic_check(void)
goto print;
}
+#if defined(CONFIG_ACPI_BUS)
+ /*
+ * 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++) {