Commit-ID: 8d80696060eedf49c080c0f2cf39a20ae7e787f9 Gitweb: http://git.kernel.org/tip/8d80696060eedf49c080c0f2cf39a20ae7e787f9 Author: Thomas Gleixner <[email protected]> AuthorDate: Thu, 15 Jan 2015 21:22:09 +0000 Committer: Thomas Gleixner <[email protected]> CommitDate: Thu, 22 Jan 2015 15:10:54 +0100
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 <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Jiang Liu <[email protected]> Cc: Joerg Roedel <[email protected]> Cc: Tony Luck <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/include/asm/apic.h | 19 ++++++++++--------- 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 465b309..1a8ba26 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 35e6d09..7ecfce1 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"); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
