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/config.h>
   7 #include <linux/threads.h>
   8 #include <linux/cpumask.h>
   9 #include <linux/string.h>
  10 #include <linux/kernel.h>
  11 #include <linux/ctype.h>
  12 #include <linux/init.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_default;
  21
  22 struct genapic *genapic = &apic_default;
  23
  24 struct genapic *apic_probe[] __initdata = {
  25         &apic_summit,
  26         &apic_bigsmp,
  27         &apic_default,  /* must be last */
  28         NULL,
  29 };
  30
  31 void __init generic_apic_probe(char *command_line)
  32 {
  33         char *s;
  34         int i;
  35         int changed = 0;
  36
  37         s = strstr(command_line, "apic=");
  38         if (s && (s == command_line || isspace(s[-1]))) {
  39                 char *p = strchr(s, ' '), old;
  40                 if (!p)
  41                         p = strchr(s, '\0');
  42                 old = *p;
  43                 *p = 0;
  44                 for (i = 0; !changed && apic_probe[i]; i++) {
  45                         if (!strcmp(apic_probe[i]->name, s+5)) {
  46                                 changed = 1;
  47                                 genapic = apic_probe[i];
  48                         }
  49                 }
  50                 if (!changed)
  51                         printk(KERN_ERR "Unknown genapic `%s' specified.\n", s);
  52                 *p = old;
  53         }
  54         for (i = 0; !changed && apic_probe[i]; i++) {
  55                 if (apic_probe[i]->probe()) {
  56                         changed = 1;
  57                         genapic = apic_probe[i];
  58                 }
  59         }
  60         /* Not visible without early console */
  61         if (!changed)
  62                 panic("Didn't find an APIC driver");
  63
  64         printk(KERN_INFO "Using APIC driver %s\n", genapic->name);
  65 }
  66
  67 /* These functions can switch the APIC even after the initial ->probe() */
  68
  69 int __init mps_oem_check(struct mp_config_table *mpc, char *oem, char *productid)
  70 {
  71         int i;
  72         for (i = 0; apic_probe[i]; ++i) {
  73                 if (apic_probe[i]->mps_oem_check(mpc,oem,productid)) {
  74                         genapic = apic_probe[i];
  75                         printk(KERN_INFO "Switched to APIC driver `%s'.\n",
  76                                genapic->name);
  77                         return 1;
  78                 }
  79         }
  80         return 0;
  81 }
  82
  83 int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
  84 {
  85         int i;
  86         for (i = 0; apic_probe[i]; ++i) {
  87                 if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
  88                         genapic = apic_probe[i];
  89                         printk(KERN_INFO "Switched to APIC driver `%s'.\n",
  90                                genapic->name);
  91                         return 1;
  92                 }
  93         }
  94         return 0;
  95 }
  96
  97 int hard_smp_processor_id(void)
  98 {
  99         return genapic->get_apic_id(*(unsigned long *)(APIC_BASE+APIC_ID));
 100 }