From 659006bf3ae37a08706907ce1a36ddf57c9131d2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 15 Jan 2015 21:22:26 +0000 Subject: [PATCH] x86/x2apic: Split enable and setup function enable_x2apic() is a convoluted unreadable mess because it is used for both enablement in early boot and for setup in cpu_init(). Split the code into x2apic_enable() for enablement and x2apic_setup() for setup of (secondary cpus). Make use of the new state tracking to simplify the logic. Signed-off-by: Thomas Gleixner Cc: Jiang Liu Cc: Joerg Roedel Cc: Tony Luck Cc: Borislav Petkov Link: http://lkml.kernel.org/r/20150115211703.129287153@linutronix.de Signed-off-by: Thomas Gleixner --- arch/x86/include/asm/apic.h | 4 +-- arch/x86/kernel/apic/apic.c | 63 ++++++++++++++++++++++-------------- arch/x86/kernel/cpu/common.c | 2 +- 3 files changed, 41 insertions(+), 28 deletions(-) diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 5d7488e9b66e..ac60c603f8dd 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -179,7 +179,7 @@ static inline u64 native_x2apic_icr_read(void) extern int x2apic_mode; extern int x2apic_phys; extern void __init check_x2apic(void); -extern void enable_x2apic(void); +extern void x2apic_setup(void); static inline int x2apic_enabled(void) { return cpu_has_x2apic && apic_is_x2apic_enabled(); @@ -188,7 +188,7 @@ static inline int x2apic_enabled(void) #define x2apic_supported() (cpu_has_x2apic) #else static inline void check_x2apic(void) { } -static inline void enable_x2apic(void) { } +static inline void x2apic_setup(void) { } static inline int x2apic_enabled(void) { return 0; } #define x2apic_mode (0) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 90b8ac5df250..0ee96b9fe4e6 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1488,6 +1488,9 @@ static inline void __x2apic_disable(void) { u64 msr; + if (cpu_has_apic) + return; + rdmsrl(MSR_IA32_APICBASE, msr); if (!(msr & X2APIC_ENABLE)) return; @@ -1497,6 +1500,17 @@ static inline void __x2apic_disable(void) printk_once(KERN_INFO "x2apic disabled\n"); } +static inline void __x2apic_enable(void) +{ + u64 msr; + + rdmsrl(MSR_IA32_APICBASE, msr); + if (msr & X2APIC_ENABLE) + return; + wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE); + printk_once(KERN_INFO "x2apic enabled\n"); +} + static int __init setup_nox2apic(char *str) { if (x2apic_enabled()) { @@ -1517,6 +1531,20 @@ static int __init setup_nox2apic(char *str) } early_param("nox2apic", setup_nox2apic); +/* Called from cpu_init() to enable x2apic on (secondary) cpus */ +void x2apic_setup(void) +{ + /* + * If x2apic is not in ON state, disable it if already enabled + * from BIOS. + */ + if (x2apic_state != X2APIC_ON) { + __x2apic_disable(); + return; + } + __x2apic_enable(); +} + static __init void x2apic_disable(void) { u64 msr; @@ -1541,30 +1569,19 @@ static __init void x2apic_disable(void) x2apic_state = X2APIC_DISABLED; } -void enable_x2apic(void) +static __init void x2apic_enable(void) { - u64 msr; - - if (x2apic_state == X2APIC_DISABLED) { - __x2apic_disable(); - x2apic_mode = 0; - return; - } - - if (!x2apic_mode) + if (x2apic_state != X2APIC_OFF) return; - rdmsrl(MSR_IA32_APICBASE, msr); - if (!(msr & X2APIC_ENABLE)) { - printk_once(KERN_INFO "Enabling x2apic\n"); - wrmsrl(MSR_IA32_APICBASE, msr | X2APIC_ENABLE); - } + x2apic_mode = 1; x2apic_state = X2APIC_ON; + __x2apic_enable(); } static __init void try_to_enable_x2apic(int remap_mode) { - if (!x2apic_supported()) + if (x2apic_state == X2APIC_DISABLED) return; if (remap_mode != IRQ_REMAP_X2APIC_MODE) { @@ -1585,12 +1602,7 @@ static __init void try_to_enable_x2apic(int remap_mode) */ x2apic_phys = 1; } - - if (!x2apic_mode) { - x2apic_mode = 1; - enable_x2apic(); - pr_info("Enabled x2apic\n"); - } + x2apic_enable(); } void __init check_x2apic(void) @@ -1616,6 +1628,7 @@ static int __init validate_x2apic(void) early_initcall(validate_x2apic); static inline void try_to_enable_x2apic(int remap_mode) { } +static inline void __x2apic_enable(void) { } #endif /* !CONFIG_X86_X2APIC */ static int __init try_to_enable_IR(void) @@ -2357,9 +2370,9 @@ static void lapic_resume(void) mask_ioapic_entries(); legacy_pic->mask_all(); - if (x2apic_mode) - enable_x2apic(); - else { + if (x2apic_mode) { + __x2apic_enable(); + } else { /* * Make sure the APICBASE points to the right address * diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c6049650c093..cb5692551b98 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1332,7 +1332,7 @@ void cpu_init(void) barrier(); x86_configure_nx(); - enable_x2apic(); + x2apic_setup(); /* * set up and load the per-CPU TSS -- 2.39.5