kernel-ark/arch/i386/mach-generic/probe.c
Fernando Luis Vazquez Cao a36166c6ef Use the APIC to determine the hardware processor id - i386
hard_smp_processor_id used to be just a macro that hard-coded
hard_smp_processor_id to 0 in the non SMP case.  When booting non SMP kernels
on hardware where the boot ioapic id is not 0 this turns out to be a problem.
This is happens frequently in the case of kdump and once in a great while in
the case of real hardware.

Use the APIC to determine the hardware processor id in both UP and SMP kernels
to fix this issue.

Notice that hard_smp_processor_id is only used by SMP code or by code that
works with apics so we do not need to handle the case when apics are not
present and hard_smp_processor_id should never be called there.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: Andi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-09 12:30:48 -07:00

126 lines
2.8 KiB
C

/* Copyright 2003 Andi Kleen, SuSE Labs.
* Subject to the GNU Public License, v.2
*
* Generic x86 APIC driver probe layer.
*/
#include <linux/threads.h>
#include <linux/cpumask.h>
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <asm/fixmap.h>
#include <asm/mpspec.h>
#include <asm/apicdef.h>
#include <asm/genapic.h>
extern struct genapic apic_summit;
extern struct genapic apic_bigsmp;
extern struct genapic apic_es7000;
extern struct genapic apic_default;
struct genapic *genapic = &apic_default;
struct genapic *apic_probe[] __initdata = {
&apic_summit,
&apic_bigsmp,
&apic_es7000,
&apic_default, /* must be last */
NULL,
};
static int cmdline_apic __initdata;
static int __init parse_apic(char *arg)
{
int i;
if (!arg)
return -EINVAL;
for (i = 0; apic_probe[i]; i++) {
if (!strcmp(apic_probe[i]->name, arg)) {
genapic = apic_probe[i];
cmdline_apic = 1;
return 0;
}
}
/* Parsed again by __setup for debug/verbose */
return 0;
}
early_param("apic", parse_apic);
void __init generic_bigsmp_probe(void)
{
/*
* This routine is used to switch to bigsmp mode when
* - There is no apic= option specified by the user
* - generic_apic_probe() has choosen apic_default as the sub_arch
* - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
*/
if (!cmdline_apic && genapic == &apic_default)
if (apic_bigsmp.probe()) {
genapic = &apic_bigsmp;
printk(KERN_INFO "Overriding APIC driver with %s\n",
genapic->name);
}
}
void __init generic_apic_probe(void)
{
if (!cmdline_apic) {
int i;
for (i = 0; apic_probe[i]; i++) {
if (apic_probe[i]->probe()) {
genapic = apic_probe[i];
break;
}
}
/* Not visible without early console */
if (!apic_probe[i])
panic("Didn't find an APIC driver");
}
printk(KERN_INFO "Using APIC driver %s\n", genapic->name);
}
/* These functions can switch the APIC even after the initial ->probe() */
int __init mps_oem_check(struct mp_config_table *mpc, char *oem, char *productid)
{
int i;
for (i = 0; apic_probe[i]; ++i) {
if (apic_probe[i]->mps_oem_check(mpc,oem,productid)) {
if (!cmdline_apic) {
genapic = apic_probe[i];
printk(KERN_INFO "Switched to APIC driver `%s'.\n",
genapic->name);
}
return 1;
}
}
return 0;
}
int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
{
int i;
for (i = 0; apic_probe[i]; ++i) {
if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
if (!cmdline_apic) {
genapic = apic_probe[i];
printk(KERN_INFO "Switched to APIC driver `%s'.\n",
genapic->name);
}
return 1;
}
}
return 0;
}
int hard_smp_processor_id(void)
{
return genapic->get_apic_id(*(unsigned long *)(APIC_BASE+APIC_ID));
}