From d524165cb8dbb2ce5916cd7682236b9324ae2644 Mon Sep 17 00:00:00 2001
From: Thomas Gleixner <tglx@linutronix.de>
Date: Thu, 15 Jan 2015 21:22:17 +0000
Subject: [PATCH] x86/apic: Check x2apic early
No point in delaying the x2apic detection for the CONFIG_X86_X2APIC=n
case to enable_IR_x2apic(). We rather detect that before we try to
setup anything there.
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/20150115211702.702479404@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/apic.h | 2 +-
arch/x86/kernel/apic/apic.c | 34 ++++++++++++++++++++--------------
2 files changed, 21 insertions(+), 15 deletions(-)
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 392bbcf35471..ca8deb484d03 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -178,7 +178,7 @@ static inline u64 native_x2apic_icr_read(void)
extern int x2apic_mode;
extern int x2apic_phys;
-extern void check_x2apic(void);
+extern void __init check_x2apic(void);
extern void enable_x2apic(void);
static inline int x2apic_enabled(void)
{
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index fdc6c60faa6b..d5c35346b556 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -1541,14 +1541,6 @@ static __init void disable_x2apic(void)
x2apic_disabled = 1;
}
-void check_x2apic(void)
-{
- if (x2apic_enabled()) {
- pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
- x2apic_mode = 1;
- }
-}
-
void enable_x2apic(void)
{
u64 msr;
@@ -1568,7 +1560,26 @@ void enable_x2apic(void)
wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE);
}
}
-#endif /* CONFIG_X86_X2APIC */
+
+void __init check_x2apic(void)
+{
+ if (x2apic_enabled()) {
+ pr_info("x2apic enabled by BIOS, switching to x2apic ops\n");
+ x2apic_mode = 1;
+ }
+}
+#else /* CONFIG_X86_X2APIC */
+static int __init validate_x2apic(void)
+{
+ if (!apic_is_x2apic_enabled())
+ return 0;
+ /*
+ * Checkme: Can we simply turn off x2apic here instead of panic?
+ */
+ panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
+}
+early_initcall(validate_x2apic);
+#endif /* !CONFIG_X86_X2APIC */
static int __init try_to_enable_IR(void)
{
@@ -1620,11 +1631,6 @@ void __init enable_IR_x2apic(void)
unsigned long flags;
int ret, ir_stat;
- if (!IS_ENABLED(CONFIG_X86_X2APIC)) {
- if (apic_is_x2apic_enabled())
- panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n");
- }
-
ir_stat = irq_remapping_prepare();
if (ir_stat < 0 && !x2apic_supported())
return;
--
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