diff options
Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 30 |
1 files changed, 25 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 28446fa6bf18..5f973fed3c9f 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -830,8 +830,17 @@ bool __init apic_needs_pit(void) if (!tsc_khz || !cpu_khz) return true; - /* Is there an APIC at all? */ - if (!boot_cpu_has(X86_FEATURE_APIC)) + /* Is there an APIC at all or is it disabled? */ + if (!boot_cpu_has(X86_FEATURE_APIC) || disable_apic) + return true; + + /* + * If interrupt delivery mode is legacy PIC or virtual wire without + * configuration, the local APIC timer wont be set up. Make sure + * that the PIT is initialized. + */ + if (apic_intr_mode == APIC_PIC || + apic_intr_mode == APIC_VIRTUAL_WIRE_NO_CONFIG) return true; /* Virt guests may lack ARAT, but still have DEADLINE */ @@ -1322,7 +1331,7 @@ void __init sync_Arb_IDs(void) enum apic_intr_mode_id apic_intr_mode __ro_after_init; -static int __init apic_intr_mode_select(void) +static int __init __apic_intr_mode_select(void) { /* Check kernel option */ if (disable_apic) { @@ -1384,6 +1393,12 @@ static int __init apic_intr_mode_select(void) return APIC_SYMMETRIC_IO; } +/* Select the interrupt delivery mode for the BSP */ +void __init apic_intr_mode_select(void) +{ + apic_intr_mode = __apic_intr_mode_select(); +} + /* * An initial setup of the virtual wire mode. */ @@ -1440,8 +1455,6 @@ void __init apic_intr_mode_init(void) { bool upmode = IS_ENABLED(CONFIG_UP_LATE_INIT); - apic_intr_mode = apic_intr_mode_select(); - switch (apic_intr_mode) { case APIC_PIC: pr_info("APIC: Keep in PIC mode(8259)\n"); @@ -2626,6 +2639,13 @@ static int lapic_suspend(void) #endif local_irq_save(flags); + + /* + * Mask IOAPIC before disabling the local APIC to prevent stale IRR + * entries on some implementations. + */ + mask_ioapic_entries(); + disable_local_APIC(); irq_remapping_disable(); |