arch/i386/mach-generic/probe.c

   1 /* Copyright 2003 Andi Kleen, SuSE Labs.
   2  * Subject to the GNU Public License, v.2
   3  *
   4  * Generic x86 APIC driver probe layer.
   5  */
   6 #include <linux/threads.h>
   7 #include <linux/cpumask.h>
   8 #include <linux/string.h>
   9 #include <linux/kernel.h>
  10 #include <linux/ctype.h>
  11 #include <linux/init.h>
  12 #include <linux/errno.h>
  13 #include <asm/fixmap.h>
  14 #include <asm/mpspec.h>
  15 #include <asm/apicdef.h>
  16 #include <asm/genapic.h>
  17
  18 extern struct genapic apic_summit;
  19 extern struct genapic apic_bigsmp;
  20 extern struct genapic apic_es7000;
  21 extern struct genapic apic_default;
  22
  23 struct genapic *genapic = &apic_default;
  24
  25 struct genapic *apic_probe[] __initdata = {
  26         &apic_summit,
  27         &apic_bigsmp,
  28         &apic_es7000,
  29         &apic_default,  /* must be last */
  30         NULL,
  31 };
  32
  33 static int cmdline_apic __initdata;
  34 static int __init parse_apic(char *arg)
  35 {
  36         int i;
  37
  38         if (!arg)
  39                 return -EINVAL;
  40
  41         for (i = 0; apic_probe[i]; i++) {
  42                 if (!strcmp(apic_probe[i]->name, arg)) {
  43                         genapic = apic_probe[i];
  44                         cmdline_apic = 1;
  45                         return 0;
  46                 }
  47         }
  48         return -ENOENT;
  49 }
  50 early_param("apic", parse_apic);
  51
  52 void __init generic_bigsmp_probe(void)
  53 {
  54         /*
  55          * This routine is used to switch to bigsmp mode when
  56          * - There is no apic= option specified by the user
  57          * - generic_apic_probe() has choosen apic_default as the sub_arch
  58          * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
  59          */
  60
  61         if (!cmdline_apic && genapic == &apic_default)
  62                 if (apic_bigsmp.probe()) {
  63                         genapic = &apic_bigsmp;
  64                         printk(KERN_INFO "Overriding APIC driver with %s\n",
  65                                genapic->name);
  66                 }
  67 }
  68
  69 void __init generic_apic_probe(void)
  70 {
  71         if (!cmdline_apic) {
  72                 int i;
  73                 for (i = 0; apic_probe[i]; i++) {
  74                         if (apic_probe[i]->probe()) {
  75                                 genapic = apic_probe[i];
  76                                 break;
  77                         }
  78                 }
  79                 /* Not visible without early console */
  80                 if (!apic_probe[i])
  81                         panic("Didn't find an APIC driver");
  82         }
  83         printk(KERN_INFO "Using APIC driver %s\n", genapic->name);
  84 }
  85
  86 /* These functions can switch the APIC even after the initial ->probe() */
  87
  88 int __init mps_oem_check(struct mp_config_table *mpc, char *oem, char *productid)
  89 {
  90         int i;
  91         for (i = 0; apic_probe[i]; ++i) {
  92                 if (apic_probe[i]->mps_oem_check(mpc,oem,productid)) {
  93                         if (!cmdline_apic) {
  94                                 genapic = apic_probe[i];
  95                                 printk(KERN_INFO "Switched to APIC driver `%s'.\n",
  96                                        genapic->name);
  97                         }
  98                         return 1;
  99                 }
 100         }
 101         return 0;
 102 }
 103
 104 int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 105 {
 106         int i;
 107         for (i = 0; apic_probe[i]; ++i) {
 108                 if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
 109                         if (!cmdline_apic) {
 110                                 genapic = apic_probe[i];
 111                                 printk(KERN_INFO "Switched to APIC driver `%s'.\n",
 112                                        genapic->name);
 113                         }
 114                         return 1;
 115                 }
 116         }
 117         return 0;
 118 }
 119
 120 #ifdef CONFIG_SMP
 121 int hard_smp_processor_id(void)
 122 {
 123         return genapic->get_apic_id(*(unsigned long *)(APIC_BASE+APIC_ID));
 124 }
 125 #endif