From 9aa16365275a272283acbda665634ca3dc8b46fe Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 15 Jan 2015 21:22:16 +0000 Subject: [PATCH] x86/apic: Make disable x2apic work really If x2apic_preenabled is not enabled, then disable_x2apic() is not called from various places which results in x2apic_disabled not being set. So other code pathes can happily reenable the x2apic. Signed-off-by: Thomas Gleixner Cc: Jiang Liu Cc: Joerg Roedel Cc: Tony Luck Cc: Borislav Petkov Link: http://lkml.kernel.org/r/20150115211702.621431109@linutronix.de Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/apic.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 08144f5c1236..fdc6c60faa6b 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1479,8 +1479,6 @@ static bool nox2apic __initdata; #ifdef CONFIG_X86_X2APIC int x2apic_mode; -/* x2apic enabled before OS handover */ -static int x2apic_preenabled; static int x2apic_disabled; static int __init setup_nox2apic(char *str) { @@ -1535,18 +1533,19 @@ static __init void disable_x2apic(void) setup_clear_cpu_cap(X86_FEATURE_X2APIC); } - x2apic_disabled = 1; x2apic_mode = 0; register_lapic_address(mp_lapic_addr); } + + x2apic_disabled = 1; } void check_x2apic(void) { if (x2apic_enabled()) { pr_info("x2apic enabled by BIOS, switching to x2apic ops\n"); - x2apic_preenabled = x2apic_mode = 1; + x2apic_mode = 1; } } @@ -1569,8 +1568,6 @@ 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) @@ -1599,8 +1596,7 @@ static __init void try_to_enable_x2apic(int ir_stat) (IS_ENABLED(CONFIG_HYPERVISOR_GUEST) && !hypervisor_x2apic_available())) { pr_info("IRQ remapping doesn't support X2APIC mode, disable x2apic.\n"); - if (x2apic_preenabled) - disable_x2apic(); + disable_x2apic(); return; } @@ -1643,7 +1639,7 @@ void __init enable_IR_x2apic(void) legacy_pic->mask_all(); mask_ioapic_entries(); - if (x2apic_preenabled && nox2apic) + if (nox2apic) disable_x2apic(); /* If irq_remapping_prepare() succeded, try to enable it */ if (ir_stat >= 0) -- 2.39.5