From ea0dcf903e7d76aa5d483d876215fedcfdfe140f Mon Sep 17 00:00:00 2001 From: Greg Pearson Date: Tue, 24 Apr 2012 18:23:56 -0600 Subject: [PATCH] x86/apic: Use x2apic physical mode based on FADT setting Provide systems that do not support x2apic cluster mode a mechanism to select x2apic physical mode using the FADT FORCE_APIC_PHYSICAL_DESTINATION_MODE bit. Changes from v1: (based on Suresh's comments) - removed #ifdef CONFIG_ACPI - removed #include Signed-off-by: Greg Pearson Acked-by: Suresh Siddha Link: http://lkml.kernel.org/r/1335313436-32020-1-git-send-email-greg.pearson@hp.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/x2apic_phys.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/x86/kernel/apic/x2apic_phys.c b/arch/x86/kernel/apic/x2apic_phys.c index 8a778db45e3a..991e315f4227 100644 --- a/arch/x86/kernel/apic/x2apic_phys.c +++ b/arch/x86/kernel/apic/x2apic_phys.c @@ -24,6 +24,12 @@ static int x2apic_acpi_madt_oem_check(char *oem_id, char *oem_table_id) { if (x2apic_phys) return x2apic_enabled(); + else if ((acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) && + (acpi_gbl_FADT.flags & ACPI_FADT_APIC_PHYSICAL) && + x2apic_enabled()) { + printk(KERN_DEBUG "System requires x2apic physical mode\n"); + return 1; + } else return 0; }