[patch 04/23] x86/ioapic: Check x2apic really

From: Thomas Gleixner
Date: Thu Jan 15 2015 - 16:28:11 EST


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@xxxxxxxxxxxxx>
---
arch/x86/include/asm/apic.h | 2 --
arch/x86/kernel/apic/apic.c | 4 +++-
arch/x86/kernel/apic/io_apic.c | 2 +-
3 files changed, 4 insertions(+), 4 deletions(-)

Index: tip/arch/x86/include/asm/apic.h
===================================================================
--- tip.orig/arch/x86/include/asm/apic.h
+++ tip/arch/x86/include/asm/apic.h
@@ -177,7 +177,6 @@ static inline u64 native_x2apic_icr_read

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)
@@ -209,7 +208,6 @@ static inline void x2apic_force_phys(voi
}

#define x2apic_mode (0)
-#define x2apic_preenabled (0)
#define x2apic_supported() (0)
#endif

Index: tip/arch/x86/kernel/apic/apic.c
===================================================================
--- tip.orig/arch/x86/kernel/apic/apic.c
+++ tip/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)
Index: tip/arch/x86/kernel/apic/io_apic.c
===================================================================
--- tip.orig/arch/x86/kernel/apic/io_apic.c
+++ tip/arch/x86/kernel/apic/io_apic.c
@@ -2295,7 +2295,7 @@ static inline void __init check_timer(vo
}
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");


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