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 <asm/fixmap.h>
  13 #include <asm/mpspec.h>
  14 #include <asm/apicdef.h>
  15 #include <asm/genapic.h>
  16
  17 extern struct genapic apic_summit;
  18 extern struct genapic apic_bigsmp;
  19 extern struct genapic apic_es7000;
  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_es7000,
  28         &apic_default,  /* must be last */
  29         NULL,
  30 };
  31
  32 static int cmdline_apic;
  33
  34 void __init generic_bigsmp_probe(void)
  35 {
  36         /*
  37          * This routine is used to switch to bigsmp mode when
  38          * - There is no apic= option specified by the user
  39          * - generic_apic_probe() has choosen apic_default as the sub_arch
  40          * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support
  41          */
  42
  43         if (!cmdline_apic && genapic == &apic_default)
  44                 if (apic_bigsmp.probe()) {
  45                         genapic = &apic_bigsmp;
  46                         printk(KERN_INFO "Overriding APIC driver with %s\n",
  47                                genapic->name);
  48                 }
  49 }
  50
  51 void __init generic_apic_probe(char *command_line)
  52 {
  53         char *s;
  54         int i;
  55         int changed = 0;
  56
  57         s = strstr(command_line, "apic=");
  58         if (s && (s == command_line || isspace(s[-1]))) {
  59                 char *p = strchr(s, ' '), old;
  60                 if (!p)
  61                         p = strchr(s, '\0');
  62                 old = *p;
  63                 *p = 0;
  64                 for (i = 0; !changed && apic_probe[i]; i++) {
  65                         if (!strcmp(apic_probe[i]->name, s+5)) {
  66                                 changed = 1;
  67                                 genapic = apic_probe[i];
  68                         }
  69                 }
  70                 if (!changed)
  71                         printk(KERN_ERR "Unknown genapic `%s' specified.\n", s);
  72                 *p = old;
  73                 cmdline_apic = changed;
  74         }
  75         for (i = 0; !changed && apic_probe[i]; i++) {
  76                 if (apic_probe[i]->probe()) {
  77                         changed = 1;
  78                         genapic = apic_probe[i];
  79                 }
  80         }
  81         /* Not visible without early console */
  82         if (!changed)
  83                 panic("Didn't find an APIC driver");
  84
  85         printk(KERN_INFO "Using APIC driver %s\n", genapic->name);
  86 }
  87
  88 /* These functions can switch the APIC even after the initial ->probe() */
  89
  90 int __init mps_oem_check(struct mp_config_table *mpc, char *oem, char *productid)
  91 {
  92         int i;
  93         for (i = 0; apic_probe[i]; ++i) {
  94                 if (apic_probe[i]->mps_oem_check(mpc,oem,productid)) {
  95                         if (!cmdline_apic) {
  96                                 genapic = apic_probe[i];
  97                                 printk(KERN_INFO "Switched to APIC driver `%s'.\n",
  98                                        genapic->name);
  99                         }
 100                         return 1;
 101                 }
 102         }
 103         return 0;
 104 }
 105
 106 int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id)
 107 {
 108         int i;
 109         for (i = 0; apic_probe[i]; ++i) {
 110                 if (apic_probe[i]->acpi_madt_oem_check(oem_id, oem_table_id)) {
 111                         if (!cmdline_apic) {
 112                                 genapic = apic_probe[i];
 113                                 printk(KERN_INFO "Switched to APIC driver `%s'.\n",
 114                                        genapic->name);
 115                         }
 116                         return 1;
 117                 }
 118         }
 119         return 0;
 120 }
 121
 122 int hard_smp_processor_id(void)
 123 {
 124         return genapic->get_apic_id(*(unsigned long *)(APIC_BASE+APIC_ID));
 125 }