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(u16
, x86_cpu_to_apicid
) = BAD_APICID
;
35 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid
);
36 DEFINE_PER_CPU(int, x2apic_extra_bits
);
38 struct genapic __read_mostly
*genapic
= &apic_flat
;
40 static enum uv_system_type uv_system_type
;
43 * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
45 void __init
setup_apic_routing(void)
47 if (uv_system_type
== UV_NON_UNIQUE_APIC
)
48 genapic
= &apic_x2apic_uv_x
;
52 * Quirk: some x86_64 machines can only use physical APIC mode
53 * regardless of how many processors are present (x86_64 ES7000
56 if (acpi_gbl_FADT
.header
.revision
> FADT2_REVISION_ID
&&
57 (acpi_gbl_FADT
.flags
& ACPI_FADT_APIC_PHYSICAL
))
58 genapic
= &apic_physflat
;
62 if (cpus_weight(cpu_possible_map
) <= 8)
65 genapic
= &apic_physflat
;
67 printk(KERN_INFO
"Setting APIC routing to %s\n", genapic
->name
);
70 /* Same for both flat and physical. */
72 void send_IPI_self(int vector
)
74 __send_IPI_shortcut(APIC_DEST_SELF
, vector
, APIC_DEST_PHYSICAL
);
77 int __init
acpi_madt_oem_check(char *oem_id
, char *oem_table_id
)
79 if (!strcmp(oem_id
, "SGI")) {
80 if (!strcmp(oem_table_id
, "UVL"))
81 uv_system_type
= UV_LEGACY_APIC
;
82 else if (!strcmp(oem_table_id
, "UVX"))
83 uv_system_type
= UV_X2APIC
;
84 else if (!strcmp(oem_table_id
, "UVH"))
85 uv_system_type
= UV_NON_UNIQUE_APIC
;
90 unsigned int read_apic_id(void)
94 WARN_ON(preemptible());
95 id
= apic_read(APIC_ID
);
96 if (uv_system_type
>= UV_X2APIC
)
97 id
|= __get_cpu_var(x2apic_extra_bits
);
101 enum uv_system_type
get_uv_system_type(void)
103 return uv_system_type
;
106 int is_uv_system(void)
108 return uv_system_type
!= UV_NONE
;