arch/x86/kernel/genapic_64.c

   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  */
  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
  19 #include <asm/smp.h>
  20 #include <asm/ipi.h>
  21 #include <asm/genapic.h>
  22
  23 #ifdef CONFIG_ACPI
  24 #include <acpi/acpi_bus.h>
  25 #endif
  26
  27 /* which logical CPU number maps to which CPU (physical APIC ID) */
  28 u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly
  29                                         = { [0 ... NR_CPUS-1] = BAD_APICID };
  30 EXPORT_SYMBOL(x86_cpu_to_apicid);
  31
  32 u8 x86_cpu_to_log_apicid[NR_CPUS]       = { [0 ... NR_CPUS-1] = BAD_APICID };
  33
  34 struct genapic __read_mostly *genapic = &apic_flat;
  35
  36 /*
  37  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  38  */
  39 void __init setup_apic_routing(void)
  40 {
  41 #ifdef CONFIG_ACPI
  42         /*
  43          * Quirk: some x86_64 machines can only use physical APIC mode
  44          * regardless of how many processors are present (x86_64 ES7000
  45          * is an example).
  46          */
  47         if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
  48                         (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
  49                 genapic = &apic_physflat;
  50         else
  51 #endif
  52
  53         if (cpus_weight(cpu_possible_map) <= 8)
  54                 genapic = &apic_flat;
  55         else
  56                 genapic = &apic_physflat;
  57
  58         printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
  59 }
  60
  61 /* Same for both flat and physical. */
  62
  63 void send_IPI_self(int vector)
  64 {
  65         __send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
  66 }