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 #include <linux/hardirq.h>
  19
  20 #include <asm/smp.h>
  21 #include <asm/ipi.h>
  22 #include <asm/genapic.h>
  23
  24 #ifdef CONFIG_ACPI
  25 #include <acpi/acpi_bus.h>
  26 #endif
  27
  28 DEFINE_PER_CPU(int, x2apic_extra_bits);
  29
  30 struct genapic __read_mostly *genapic = &apic_flat;
  31
  32 static enum uv_system_type uv_system_type;
  33
  34 /*
  35  * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode.
  36  */
  37 void __init setup_apic_routing(void)
  38 {
  39         if (uv_system_type == UV_NON_UNIQUE_APIC)
  40                 genapic = &apic_x2apic_uv_x;
  41         else
  42 #ifdef CONFIG_ACPI
  43         /*
  44          * Quirk: some x86_64 machines can only use physical APIC mode
  45          * regardless of how many processors are present (x86_64 ES7000
  46          * is an example).
  47          */
  48         if (acpi_gbl_FADT.header.revision > FADT2_REVISION_ID &&
  49                         (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL))
  50                 genapic = &apic_physflat;
  51         else
  52 #endif
  53
  54         if (num_possible_cpus() <= 8)
  55                 genapic = &apic_flat;
  56         else
  57                 genapic = &apic_physflat;
  58
  59         printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name);
  60 }
  61
  62 /* Same for both flat and physical. */
  63
  64 void send_IPI_self(int vector)
  65 {
  66         __send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL);
  67 }
  68
  69 int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
  70 {
  71         if (!strcmp(oem_id, "SGI")) {
  72                 if (!strcmp(oem_table_id, "UVL"))
  73                         uv_system_type = UV_LEGACY_APIC;
  74                 else if (!strcmp(oem_table_id, "UVX"))
  75                         uv_system_type = UV_X2APIC;
  76                 else if (!strcmp(oem_table_id, "UVH"))
  77                         uv_system_type = UV_NON_UNIQUE_APIC;
  78         }
  79         return 0;
  80 }
  81
  82 unsigned int read_apic_id(void)
  83 {
  84         unsigned int id;
  85
  86         WARN_ON(preemptible() && num_online_cpus() > 1);
  87         id = apic_read(APIC_ID);
  88         if (uv_system_type >= UV_X2APIC)
  89                 id  |= __get_cpu_var(x2apic_extra_bits);
  90         return id;
  91 }
  92
  93 enum uv_system_type get_uv_system_type(void)
  94 {
  95         return uv_system_type;
  96 }
  97
  98 int is_uv_system(void)
  99 {
 100         return uv_system_type != UV_NONE;
 101 }