x86, acpi: Skip acpi x2apic entries if the x2apic feature is not present
If the x2apic feature is not present (either the cpu is not capable of it
or the user has disabled the feature using boot-parameter etc), ignore the
x2apic MADT and SRAT entries provided by the ACPI tables.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20111222014632.540896503@sbsiddha-desk.sc.intel.com
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 4558f0d..ce664f3 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -219,6 +219,8 @@
acpi_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
{
struct acpi_madt_local_x2apic *processor = NULL;
+ int apic_id;
+ u8 enabled;
processor = (struct acpi_madt_local_x2apic *)header;
@@ -227,6 +229,8 @@
acpi_table_print_madt_entry(header);
+ apic_id = processor->local_apic_id;
+ enabled = processor->lapic_flags & ACPI_MADT_ENABLED;
#ifdef CONFIG_X86_X2APIC
/*
* We need to register disabled CPU as well to permit
@@ -235,8 +239,10 @@
* to not preallocating memory for all NR_CPUS
* when we use CPU hotplug.
*/
- acpi_register_lapic(processor->local_apic_id, /* APIC ID */
- processor->lapic_flags & ACPI_MADT_ENABLED);
+ if (!cpu_has_x2apic && (apic_id >= 0xff) && enabled)
+ printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
+ else
+ acpi_register_lapic(apic_id, enabled);
#else
printk(KERN_WARNING PREFIX "x2apic entry ignored\n");
#endif
diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c
index 81dbfde..fd61b3f 100644
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -69,6 +69,12 @@
if ((pa->flags & ACPI_SRAT_CPU_ENABLED) == 0)
return;
pxm = pa->proximity_domain;
+ apic_id = pa->apic_id;
+ if (!cpu_has_x2apic && (apic_id >= 0xff)) {
+ printk(KERN_INFO "SRAT: PXM %u -> X2APIC 0x%04x ignored\n",
+ pxm, apic_id);
+ return;
+ }
node = setup_node(pxm);
if (node < 0) {
printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
@@ -76,7 +82,6 @@
return;
}
- apic_id = pa->apic_id;
if (apic_id >= MAX_LOCAL_APIC) {
printk(KERN_INFO "SRAT: PXM %u -> APIC 0x%04x -> Node %u skipped apicid that is too big\n", pxm, apic_id, node);
return;