static int __init intel_prepare_irq_remapping(void)
{
struct dmar_drhd_unit *drhd;
struct intel_iommu *iommu;
if (irq_remap_broken) {
printk(KERN_WARNING
"This system BIOS has enabled interrupt remapping\n"
"on a chipset that contains an erratum making that\n"
"feature unstable. To maintain system stability\n"
"interrupt remapping is being disabled. Please\n"
"contact your BIOS vendor for an update\n");
add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
return -ENODEV;
}
if (dmar_table_init() < 0)
return -ENODEV;
if (!dmar_ir_support())
return -ENODEV;
if (parse_ioapics_under_ir() != 1) {
printk(KERN_INFO "Not enabling interrupt remapping\n");
goto error;
}
/* First make sure all IOMMUs support IRQ remapping */
for_each_iommu(iommu, drhd)
if (!ecap_ir_support(iommu->ecap))
goto error;
/* Do the allocations early */
for_each_iommu(iommu, drhd)
if (intel_setup_irq_remapping(iommu))
goto error;
return 0;
error:
intel_cleanup_irq_remapping();
return -ENODEV;
}
static int __init intel_prepare_irq_remapping(void)
{
struct dmar_drhd_unit *drhd;
struct intel_iommu *iommu;
int eim = 0;
if (irq_remap_broken) {
pr_warn("This system BIOS has enabled interrupt remapping\n"
"on a chipset that contains an erratum making that\n"
"feature unstable. To maintain system stability\n"
"interrupt remapping is being disabled. Please\n"
"contact your BIOS vendor for an update\n");
add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
return -ENODEV;
}
if (dmar_table_init() < 0)
return -ENODEV;
if (!dmar_ir_support())
return -ENODEV;
if (parse_ioapics_under_ir()) {
pr_info("Not enabling interrupt remapping\n");
goto error;
}
/* First make sure all IOMMUs support IRQ remapping */
for_each_iommu(iommu, drhd)
if (!ecap_ir_support(iommu->ecap))
goto error;
/* Detect remapping mode: lapic or x2apic */
if (x2apic_supported()) {
eim = !dmar_x2apic_optout();
if (!eim) {
pr_info("x2apic is disabled because BIOS sets x2apic opt out bit.");
pr_info("Use 'intremap=no_x2apic_optout' to override the BIOS setting.\n");
}
}
for_each_iommu(iommu, drhd) {
if (eim && !ecap_eim_support(iommu->ecap)) {
pr_info("%s does not support EIM\n", iommu->name);
eim = 0;
}
}
eim_mode = eim;
if (eim)
pr_info("Queued invalidation will be enabled to support x2apic and Intr-remapping.\n");
/* Do the initializations early */
for_each_iommu(iommu, drhd) {
if (intel_setup_irq_remapping(iommu)) {
pr_err("Failed to setup irq remapping for %s\n",
iommu->name);
goto error;
}
}
return 0;
error:
intel_cleanup_irq_remapping();
return -ENODEV;
}
void __init enable_IR_x2apic(void)
{
unsigned long flags;
struct IO_APIC_route_entry **ioapic_entries = NULL;
int ret, x2apic_enabled = 0;
int dmar_table_init_ret = 0;
#ifdef CONFIG_INTR_REMAP
dmar_table_init_ret = dmar_table_init();
if (dmar_table_init_ret)
pr_debug("dmar_table_init() failed with %d:\n",
dmar_table_init_ret);
#endif
ioapic_entries = alloc_ioapic_entries();
if (!ioapic_entries) {
pr_err("Allocate ioapic_entries failed\n");
goto out;
}
ret = save_IO_APIC_setup(ioapic_entries);
if (ret) {
pr_info("Saving IO-APIC state failed: %d\n", ret);
goto out;
}
local_irq_save(flags);
mask_8259A();
mask_IO_APIC_setup(ioapic_entries);
if (dmar_table_init_ret)
ret = 0;
else
ret = enable_IR();
if (!ret) {
if (max_physical_apicid > 255 || !kvm_para_available())
goto nox2apic;
x2apic_force_phys();
}
x2apic_enabled = 1;
if (x2apic_supported() && !x2apic_mode) {
x2apic_mode = 1;
enable_x2apic();
pr_info("Enabled x2apic\n");
}
nox2apic:
if (!ret)
restore_IO_APIC_setup(ioapic_entries);
unmask_8259A();
local_irq_restore(flags);
out:
if (ioapic_entries)
free_ioapic_entries(ioapic_entries);
if (x2apic_enabled)
return;
if (x2apic_preenabled)
panic("x2apic: enabled by BIOS but kernel init failed.");
else if (cpu_has_x2apic)
pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
}
