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linux/arch/x86/kernel/genapic_64.c
Suresh Siddha 6e1cb38a2a x64, x2apic/intr-remap: add x2apic support, including enabling interrupt-remapping
x2apic support.  Interrupt-remapping must be enabled before enabling x2apic,
this is needed to ensure that IO interrupts continue to work properly after the
cpu mode is changed to x2apic(which uses 32bit extended physical/cluster
apic id).

On systems where apicid's are > 255, BIOS can handover the control to OS in
x2apic mode. Or if the OS handover was in legacy xapic mode, check
if it is capable of x2apic mode. And if we succeed in enabling
Interrupt-remapping, then we can enable x2apic mode in the CPU.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: akpm@linux-foundation.org
Cc: arjan@linux.intel.com
Cc: andi@firstfloor.org
Cc: ebiederm@xmission.com
Cc: jbarnes@virtuousgeek.org
Cc: steiner@sgi.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-12 08:45:06 +02:00

94 lines
2.1 KiB
C

/*
* 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/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/hardirq.h>
#include <linux/dmar.h>
#include <asm/smp.h>
#include <asm/ipi.h>
#include <asm/genapic.h>
#ifdef CONFIG_ACPI
#include <acpi/acpi_bus.h>
#endif
DEFINE_PER_CPU(int, x2apic_extra_bits);
struct genapic __read_mostly *genapic = &apic_flat;
static enum uv_system_type uv_system_type;
/*
* Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
*/
void __init setup_apic_routing(void)
{
if (uv_system_type == UV_NON_UNIQUE_APIC)
genapic = &apic_x2apic_uv_x;
else if (cpu_has_x2apic && intr_remapping_enabled)
genapic = &apic_x2apic_cluster;
else
#ifdef CONFIG_ACPI
/*
* 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 &&
(acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
genapic = &apic_physflat;
else
#endif
if (max_physical_apicid < 8)
genapic = &apic_flat;
else
genapic = &apic_physflat;
printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
}
/* Same for both flat and physical. */
void apic_send_IPI_self(int vector)
{
__send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
}
int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
if (!strcmp(oem_id, "SGI")) {
if (!strcmp(oem_table_id, "UVL"))
uv_system_type = UV_LEGACY_APIC;
else if (!strcmp(oem_table_id, "UVX"))
uv_system_type = UV_X2APIC;
else if (!strcmp(oem_table_id, "UVH"))
uv_system_type = UV_NON_UNIQUE_APIC;
}
return 0;
}
enum uv_system_type get_uv_system_type(void)
{
return uv_system_type;
}
int is_uv_system(void)
{
return uv_system_type != UV_NONE;
}