blob: 69b9c25a8fc4ee5399b76b4a5d0967fc9c520f33 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright 2004 James Cleverdon, IBM.
3 * Subject to the GNU Public License, v.2
4 *
5 * Generic APIC sub-arch probe layer.
6 *
7 * Hacked for x86-64 by James Cleverdon from i386 architecture code by
8 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
9 * James Cleverdon.
10 */
11#include <linux/config.h>
12#include <linux/threads.h>
13#include <linux/cpumask.h>
14#include <linux/string.h>
15#include <linux/kernel.h>
16#include <linux/ctype.h>
17#include <linux/init.h>
18#include <linux/module.h>
19
20#include <asm/smp.h>
21#include <asm/ipi.h>
22
Jason Davis90660ec2005-04-16 15:24:53 -070023#if defined(CONFIG_ACPI_BUS)
24#include <acpi/acpi_bus.h>
25#endif
26
Linus Torvalds1da177e2005-04-16 15:20:36 -070027/* which logical CPU number maps to which CPU (physical APIC ID) */
28u8 x86_cpu_to_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
29EXPORT_SYMBOL(x86_cpu_to_apicid);
30u8 x86_cpu_to_log_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
31
32extern struct genapic apic_cluster;
33extern struct genapic apic_flat;
34
35struct genapic *genapic = &apic_flat;
36
37
38/*
39 * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
40 */
41void __init clustered_apic_check(void)
42{
43 long i;
44 u8 clusters, max_cluster;
45 u8 id;
46 u8 cluster_cnt[NUM_APIC_CLUSTERS];
47
48 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
49 /* AMD always uses flat mode right now */
50 genapic = &apic_flat;
51 goto print;
52 }
53
Jason Davis90660ec2005-04-16 15:24:53 -070054#if defined(CONFIG_ACPI_BUS)
55 /*
56 * Some x86_64 machines use physical APIC mode regardless of how many
57 * procs/clusters are present (x86_64 ES7000 is an example).
58 */
59 if (acpi_fadt.revision > FADT2_REVISION_ID)
60 if (acpi_fadt.force_apic_physical_destination_mode) {
61 genapic = &apic_cluster;
62 goto print;
63 }
64#endif
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 memset(cluster_cnt, 0, sizeof(cluster_cnt));
67
68 for (i = 0; i < NR_CPUS; i++) {
69 id = bios_cpu_apicid[i];
70 if (id != BAD_APICID)
71 cluster_cnt[APIC_CLUSTERID(id)]++;
72 }
73
74 clusters = 0;
75 max_cluster = 0;
76 for (i = 0; i < NUM_APIC_CLUSTERS; i++) {
77 if (cluster_cnt[i] > 0) {
78 ++clusters;
79 if (cluster_cnt[i] > max_cluster)
80 max_cluster = cluster_cnt[i];
81 }
82 }
83
84 /*
85 * If we have clusters <= 1 and CPUs <= 8 in cluster 0, then flat mode,
86 * else if max_cluster <= 4 and cluster_cnt[15] == 0, clustered logical
87 * else physical mode.
88 * (We don't use lowest priority delivery + HW APIC IRQ steering, so
89 * can ignore the clustered logical case and go straight to physical.)
90 */
91 if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster)
92 genapic = &apic_flat;
93 else
94 genapic = &apic_cluster;
95
96print:
97 printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
98}
99
100/* Same for both flat and clustered. */
101
102void send_IPI_self(int vector)
103{
104 __send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
105}