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/*
* 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/config.h>
#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/module.h>
#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);
u8 x86_cpu_to_log_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
extern struct genapic apic_cluster;
extern struct genapic apic_flat;
struct genapic *genapic = &apic_flat;
/*
* Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
*/
void __init clustered_apic_check(void)
{
long i;
u8 clusters, max_cluster;
u8 id;
u8 cluster_cnt[NUM_APIC_CLUSTERS];
if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
/* AMD always uses flat mode right now */
genapic = &apic_flat;
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++) {
id = bios_cpu_apicid[i];
if (id != BAD_APICID)
cluster_cnt[APIC_CLUSTERID(id)]++;
}
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)
genapic = &apic_flat;
else
genapic = &apic_cluster;
print:
printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
}
/* Same for both flat and clustered. */
void send_IPI_self(int vector)
{
__send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
}
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