void __init check_x2apic_preenabled(void)
{
u32 lo, hi;
if ( !cpu_has_x2apic )
return;
/* Check whether x2apic mode was already enabled by the BIOS. */
rdmsr(MSR_IA32_APICBASE, lo, hi);
if ( lo & MSR_IA32_APICBASE_EXTD )
{
printk("x2APIC mode is already enabled by BIOS.\n");
#ifndef __i386__
x2apic_enabled = 1;
genapic = apic_x2apic_probe();
#else
lo &= ~(MSR_IA32_APICBASE_ENABLE | MSR_IA32_APICBASE_EXTD);
wrmsr(MSR_IA32_APICBASE, lo, hi);
lo |= MSR_IA32_APICBASE_ENABLE;
wrmsr(MSR_IA32_APICBASE, lo, hi);
printk("x2APIC disabled permanently on x86_32.\n");
#endif
}
#ifdef __i386__
clear_bit(X86_FEATURE_X2APIC, boot_cpu_data.x86_capability);
#endif
}
void __init check_x2apic_preenabled(void)
{
u32 lo, hi;
if ( !cpu_has_x2apic )
return;
/* Check whether x2apic mode was already enabled by the BIOS. */
rdmsr(MSR_IA32_APICBASE, lo, hi);
if ( lo & MSR_IA32_APICBASE_EXTD )
{
printk("x2APIC mode is already enabled by BIOS.\n");
x2apic_enabled = 1;
genapic = apic_x2apic_probe();
}
}
void __init x2apic_bsp_setup(void)
{
struct IO_APIC_route_entry **ioapic_entries = NULL;
if ( !cpu_has_x2apic )
return;
if ( !opt_x2apic )
{
if ( !x2apic_enabled )
{
printk("Not enabling x2APIC: disabled by cmdline.\n");
return;
}
printk("x2APIC: Already enabled by BIOS: Ignoring cmdline disable.\n");
}
if ( !iommu_supports_eim() )
{
if ( !x2apic_enabled )
{
printk("Not enabling x2APIC: depends on iommu_supports_eim.\n");
return;
}
panic("x2APIC: already enabled by BIOS, but "
"iommu_supports_eim failed!\n");
}
if ( (ioapic_entries = alloc_ioapic_entries()) == NULL )
{
printk("Allocate ioapic_entries failed\n");
goto out;
}
if ( save_IO_APIC_setup(ioapic_entries) )
{
printk("Saving IO-APIC state failed\n");
goto out;
}
mask_8259A();
mask_IO_APIC_setup(ioapic_entries);
if ( iommu_enable_x2apic_IR() )
{
if ( x2apic_enabled )
panic("Interrupt remapping could not be enabled while "
"x2APIC is already enabled by BIOS!\n");
printk(XENLOG_ERR
"Failed to enable Interrupt Remapping: Will not enable x2APIC.\n");
goto restore_out;
}
force_iommu = 1;
genapic = apic_x2apic_probe();
printk("Switched to APIC driver %s.\n", genapic->name);
if ( !x2apic_enabled )
{
x2apic_enabled = 1;
__enable_x2apic();
}
restore_out:
restore_IO_APIC_setup(ioapic_entries);
unmask_8259A();
out:
if ( ioapic_entries )
free_ioapic_entries(ioapic_entries);
}
