diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2015-01-16 00:22:09 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-01-22 17:10:54 +0300 |
| commit | 8d80696060eedf49c080c0f2cf39a20ae7e787f9 (patch) | |
| tree | 1b6282a1fc1305aec1ccba89515078b32914eb24 /arch/x86 | |
| parent | e901176046e6729e002839d7296f27f17599ccb8 (diff) | |
| download | linux-8d80696060eedf49c080c0f2cf39a20ae7e787f9.tar.xz | |
x86/apic: Avoid open coded x2apic detection
enable_IR_x2apic() grew a open coded x2apic detection. Implement a
proper helper function which shares the code with the already existing
x2apic_enabled().
Made it use rdmsrl_safe as suggested by Boris.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20150115211702.285038186@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/apic.h | 19 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 5 |
2 files changed, 11 insertions, 13 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 465b309af254..1a8ba26c2fbd 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -108,6 +108,15 @@ extern u64 native_apic_icr_read(void); extern int x2apic_mode; +static inline bool apic_is_x2apic_enabled(void) +{ + u64 msr; + + if (rdmsrl_safe(MSR_IA32_APICBASE, &msr)) + return false; + return msr & X2APIC_ENABLE; +} + #ifdef CONFIG_X86_X2APIC /* * Make previous memory operations globally visible before @@ -175,15 +184,7 @@ extern void check_x2apic(void); extern void enable_x2apic(void); static inline int x2apic_enabled(void) { - u64 msr; - - if (!cpu_has_x2apic) - return 0; - - rdmsrl(MSR_IA32_APICBASE, msr); - if (msr & X2APIC_ENABLE) - return 1; - return 0; + return cpu_has_x2apic && apic_is_x2apic_enabled(); } #define x2apic_supported() (cpu_has_x2apic) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 35e6d09294ed..7ecfce13be05 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1625,10 +1625,7 @@ void __init enable_IR_x2apic(void) int ret, ir_stat; if (!IS_ENABLED(CONFIG_X86_X2APIC)) { - u64 msr; - - rdmsrl(MSR_IA32_APICBASE, msr); - if (msr & X2APIC_ENABLE) + if (apic_is_x2apic_enabled()) panic("BIOS has enabled x2apic but kernel doesn't support x2apic, please disable x2apic in BIOS.\n"); } |