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1da177e4 LT |
1 | /* |
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 | */ | |
1da177e4 LT |
11 | #include <linux/threads.h> |
12 | #include <linux/cpumask.h> | |
13 | #include <linux/string.h> | |
14 | #include <linux/kernel.h> | |
15 | #include <linux/ctype.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/module.h> | |
18 | ||
19 | #include <asm/smp.h> | |
20 | #include <asm/ipi.h> | |
21 | ||
76f58584 | 22 | #if defined(CONFIG_ACPI) |
90660ec3 JD |
23 | #include <acpi/acpi_bus.h> |
24 | #endif | |
25 | ||
1da177e4 | 26 | /* which logical CPU number maps to which CPU (physical APIC ID) */ |
6c231b7b | 27 | u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID }; |
1da177e4 LT |
28 | EXPORT_SYMBOL(x86_cpu_to_apicid); |
29 | u8 x86_cpu_to_log_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID }; | |
30 | ||
31 | extern struct genapic apic_cluster; | |
32 | extern struct genapic apic_flat; | |
f8d31193 | 33 | extern struct genapic apic_physflat; |
1da177e4 | 34 | |
f18d397e | 35 | struct genapic __read_mostly *genapic = &apic_flat; |
1da177e4 LT |
36 | |
37 | /* | |
38 | * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode. | |
39 | */ | |
40 | void __init clustered_apic_check(void) | |
41 | { | |
f18d397e | 42 | int i; |
1da177e4 LT |
43 | u8 clusters, max_cluster; |
44 | u8 id; | |
45 | u8 cluster_cnt[NUM_APIC_CLUSTERS]; | |
70556463 | 46 | int max_apic = 0; |
1da177e4 | 47 | |
f18d397e | 48 | #ifdef CONFIG_ACPI |
90660ec3 JD |
49 | /* |
50 | * Some x86_64 machines use physical APIC mode regardless of how many | |
51 | * procs/clusters are present (x86_64 ES7000 is an example). | |
52 | */ | |
cee324b1 AS |
53 | if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID) |
54 | if (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) { | |
90660ec3 JD |
55 | genapic = &apic_cluster; |
56 | goto print; | |
57 | } | |
58 | #endif | |
59 | ||
1da177e4 | 60 | memset(cluster_cnt, 0, sizeof(cluster_cnt)); |
1da177e4 LT |
61 | for (i = 0; i < NR_CPUS; i++) { |
62 | id = bios_cpu_apicid[i]; | |
f8d31193 AK |
63 | if (id == BAD_APICID) |
64 | continue; | |
70556463 AK |
65 | if (id > max_apic) |
66 | max_apic = id; | |
f8d31193 | 67 | cluster_cnt[APIC_CLUSTERID(id)]++; |
1da177e4 LT |
68 | } |
69 | ||
f18d397e IM |
70 | /* |
71 | * Don't use clustered mode on AMD platforms, default | |
72 | * to flat logical mode. | |
73 | */ | |
f8d31193 | 74 | if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { |
f18d397e IM |
75 | /* |
76 | * Switch to physical flat mode if more than 8 APICs | |
77 | * (In the case of 8 CPUs APIC ID goes from 0 to 7): | |
78 | */ | |
79 | if (max_apic >= 8) | |
80 | genapic = &apic_physflat; | |
f8d31193 AK |
81 | goto print; |
82 | } | |
83 | ||
1da177e4 LT |
84 | clusters = 0; |
85 | max_cluster = 0; | |
f8d31193 | 86 | |
1da177e4 LT |
87 | for (i = 0; i < NUM_APIC_CLUSTERS; i++) { |
88 | if (cluster_cnt[i] > 0) { | |
89 | ++clusters; | |
90 | if (cluster_cnt[i] > max_cluster) | |
91 | max_cluster = cluster_cnt[i]; | |
92 | } | |
93 | } | |
94 | ||
95 | /* | |
96 | * If we have clusters <= 1 and CPUs <= 8 in cluster 0, then flat mode, | |
97 | * else if max_cluster <= 4 and cluster_cnt[15] == 0, clustered logical | |
98 | * else physical mode. | |
99 | * (We don't use lowest priority delivery + HW APIC IRQ steering, so | |
100 | * can ignore the clustered logical case and go straight to physical.) | |
101 | */ | |
f18d397e | 102 | if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster) |
1da177e4 | 103 | genapic = &apic_flat; |
f18d397e | 104 | else |
1da177e4 LT |
105 | genapic = &apic_cluster; |
106 | ||
107 | print: | |
108 | printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name); | |
109 | } | |
110 | ||
111 | /* Same for both flat and clustered. */ | |
112 | ||
113 | void send_IPI_self(int vector) | |
114 | { | |
115 | __send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL); | |
116 | } |