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