2 * Copyright 2004 James Cleverdon, IBM.
3 * Subject to the GNU Public License, v.2
5 * Generic APIC sub-arch probe layer.
7 * Hacked for x86-64 by James Cleverdon from i386 architecture code by
8 * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
11 #include <linux/threads.h>
12 #include <linux/cpumask.h>
13 #include <linux/string.h>
14 #include <linux/module.h>
15 #include <linux/kernel.h>
16 #include <linux/ctype.h>
17 #include <linux/init.h>
18 #include <linux/hardirq.h>
22 #include <asm/genapic.h>
25 #include <acpi/acpi_bus.h>
28 /* which logical CPU number maps to which CPU (physical APIC ID) */
30 u16 x86_cpu_to_apicid_init[NR_CPUS] __initdata
31 = { [0 ... NR_CPUS-1] = BAD_APICID };
32 void *x86_cpu_to_apicid_early_ptr;
34 DEFINE_PER_CPU(int, x2apic_extra_bits);
36 struct genapic __read_mostly *genapic = &apic_flat;
38 static enum uv_system_type uv_system_type;
41 * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
43 void __init setup_apic_routing(void)
45 if (uv_system_type == UV_NON_UNIQUE_APIC)
46 genapic = &apic_x2apic_uv_x;
50 * Quirk: some x86_64 machines can only use physical APIC mode
51 * regardless of how many processors are present (x86_64 ES7000
54 if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
55 (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
56 genapic = &apic_physflat;
60 if (cpus_weight(cpu_possible_map) <= 8)
63 genapic = &apic_physflat;
65 printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
68 /* Same for both flat and physical. */
70 void send_IPI_self(int vector)
72 __send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
75 int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
77 if (!strcmp(oem_id, "SGI")) {
78 if (!strcmp(oem_table_id, "UVL"))
79 uv_system_type = UV_LEGACY_APIC;
80 else if (!strcmp(oem_table_id, "UVX"))
81 uv_system_type = UV_X2APIC;
82 else if (!strcmp(oem_table_id, "UVH"))
83 uv_system_type = UV_NON_UNIQUE_APIC;
88 unsigned int read_apic_id(void)
92 WARN_ON(preemptible());
93 id = apic_read(APIC_ID);
94 if (uv_system_type >= UV_X2APIC)
95 id |= __get_cpu_var(x2apic_extra_bits);
99 enum uv_system_type get_uv_system_type(void)
101 return uv_system_type;
104 int is_uv_system(void)
106 return uv_system_type != UV_NONE;