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Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
-rw-r--r--arch/x86/kernel/apic/apic.c23
1 files changed, 18 insertions, 5 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 28446fa6bf18..4b0f9117e1cd 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");

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