#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/module.h>
-#include <linux/dmi.h>
#include <asm/atomic.h>
#include <asm/smp.h>
* Knob to control our willingness to enable the local APIC.
*/
int enable_local_apic __initdata = 0; /* -1=force-disable, +1=force-enable */
-int prefer_apic __initdata = 0; /* when enable_local_apic == 0 prefer APIC but don't force against
- BIOS wishes */
-int apic_disabled_by_dmi __initdata;
/*
* Debug level
static int __init apic_set_verbosity(char *str)
{
- if (*str == '=')
- ++str;
- if (*str == 0)
- prefer_apic = 1;
if (strcmp("debug", str) == 0)
apic_verbosity = APIC_DEBUG;
else if (strcmp("verbose", str) == 0)
return 1;
}
-__setup("apic", apic_set_verbosity);
+__setup("apic=", apic_set_verbosity);
static int __init detect_init_APIC (void)
{
* APIC only if "lapic" specified.
*/
if (enable_local_apic <= 0) {
- if (!apic_disabled_by_dmi)
- printk("Local APIC disabled by BIOS -- "
- "you can enable it with \"lapic\"\n");
+ printk("Local APIC disabled by BIOS -- "
+ "you can enable it with \"lapic\"\n");
return -1;
}
/*
irq_exit();
}
-#ifdef CONFIG_X86_APIC_AUTO
-
-/* Some heuristics to decide when to enable the APICs */
-
-static __init int dmi_enable_apic(void)
-{
- int year;
- int apic;
- char *vendor;
-
- /* If the machine has more than one CPU try to use APIC because it'll
- be running the SMP kernel with APIC soon anyways.
- This won't cover dual core, but they are handled by the date check
- below. */
- if (dmi_cpus > 1)
- return 1;
-
- year = dmi_get_year(DMI_BIOS_DATE);
- vendor = dmi_get_system_info(DMI_BIOS_VENDOR);
- apic = 0;
-
- /* All Intel BIOS since 1998 assumed APIC on. Don't include 1998 itself
- because we're not sure for that. */
- if (vendor && !strncmp(vendor, "Intel", 5))
- apic = 1;
- /* Use APIC for anything since 2001 */
- else if (year >= 2001)
- apic = 1;
-
-#ifdef CONFIG_ACPI
- /* When ACPI is disabled also default to APIC off on very new systems (>= 2004)
- which typically don't have working mptables anymore */
- if (acpi_noirq && year >= 2004)
- apic = 0;
-#endif
-
- if (!apic)
- apic_disabled_by_dmi = 1;
-
- return apic;
-}
-
-void __init dmi_check_apic(void)
-{
- if (enable_local_apic != 0 || prefer_apic)
- return;
- if (!dmi_enable_apic()) {
- clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
- nr_ioapics = 0;
- enable_local_apic = -1;
- printk(KERN_INFO "IO/L-APIC disabled because your old system seems to be old\n");
- printk(KERN_INFO "overwrite with \"apic\"\n");
- return;
- }
- printk(KERN_INFO "IO/L-APIC allowed because system is MP or new enough\n");
-}
-#endif
-
/*
* This initializes the IO-APIC and APIC hardware if this is
* a UP kernel.