Commit 90660ec3 authored by Jason Davis's avatar Jason Davis Committed by Linus Torvalds
Browse files

[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: default avatarJason Davis <jason.davis@unisys.com>
Acked-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 107ce721

arch/i386/kernel/acpi/boot.c

+4 −0
Original line number Diff line number Diff line
@@ -608,6 +608,10 @@ static int __init acpi_parse_fadt(unsigned long phys, unsigned long size) 
	acpi_fadt.sci_int = fadt->sci_int;

#endif



	/* initialize rev and apic_phys_dest_mode for x86_64 genapic */

	acpi_fadt.revision = fadt->revision;

	acpi_fadt.force_apic_physical_destination_mode = fadt->force_apic_physical_destination_mode;



#ifdef CONFIG_X86_PM_TIMER

	/* detect the location of the ACPI PM Timer */

	if (fadt->revision >= FADT2_REVISION_ID) {

arch/x86_64/kernel/genapic.c

+16 −0
Original line number Diff line number Diff line
@@ -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++) {

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