x86/ioapic: Check x2apic really

The x2apic_preenabled flag is just a horrible hack and if X2APIC
support is disabled it does not reflect the actual hardware
state. Check the hardware instead.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Link: http://lkml.kernel.org/r/20150115211702.541280622@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

2 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index ff2a8b8ffa0a..08144f5c1236 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1480,7 +1480,7 @@ static bool nox2apic __initdata;
 #ifdef CONFIG_X86_X2APIC
 int x2apic_mode;
 /* x2apic enabled before OS handover */
-int x2apic_preenabled;
+static int x2apic_preenabled;
 static int x2apic_disabled;
 static int __init setup_nox2apic(char *str)
 {
@@ -1569,6 +1569,8 @@ void enable_x2apic(void)
                 wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
         }
 }
+#else
+#define x2apic_preenabled       (0)
 #endif /* CONFIG_X86_X2APIC */
 
 static int __init try_to_enable_IR(void)
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 3f5f60406ab1..e5e00f509f03 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -2295,7 +2295,7 @@ static inline void __init check_timer(void)
         }
         local_irq_disable();
         apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");
-        if (x2apic_preenabled)
+        if (apic_is_x2apic_enabled())
                 apic_printk(APIC_QUIET, KERN_INFO
                             "Perhaps problem with the pre-enabled x2apic mode\n"
                             "Try booting with x2apic and interrupt-remapping disabled in the bios.\n");