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>

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index d2225fd..392bbcf 100644 (file)
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -178,7 +178,6 @@ static inline u64 native_x2apic_icr_read(void)
 
 extern int x2apic_mode;
 extern int x2apic_phys;
-extern int x2apic_preenabled;
 extern void check_x2apic(void);
 extern void enable_x2apic(void);
 static inline int x2apic_enabled(void)
@@ -210,7 +209,6 @@ static inline void x2apic_force_phys(void)
 }
 
 #define x2apic_mode            (0)
-#define        x2apic_preenabled       (0)
 #define        x2apic_supported()      (0)
 #endif
 

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index ff2a8b8..08144f5 100644 (file)
--- 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 3f5f604..e5e00f5 100644 (file)
--- 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");