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 4558f0d0822dcbaf7e0c7b9504e5a2ccb05879c4..ce664f33ea8ee25ccda84095dd478aa1473f8ae3 100644 (file)
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -219,6 +219,8 @@ static int __init
 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_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
 
        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 @@ acpi_parse_x2apic(struct acpi_subtable_header *header, const unsigned long end)
         * 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 81dbfdeb080db2e42ff61cd16a3fb63de23085db..fd61b3fb73411f89b5a5d1b2805e133bcbd8be94 100644 (file)
--- a/arch/x86/mm/srat.c
+++ b/arch/x86/mm/srat.c
@@ -69,6 +69,12 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
        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 @@ acpi_numa_x2apic_affinity_init(struct acpi_srat_x2apic_cpu_affinity *pa)
                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;