1 files changed, 4 insertions, 0 deletions

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 53898b65a6ae..94ddb69ae15e 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -307,6 +307,9 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
  *
  * Vector mappings are hard coded. On K8 only offset 0 (APIC500) and
  * MCE interrupts are supported. Thus MCE offset must be set to 0.
+ *
+ * If mask=1, the LVT entry does not generate interrupts while mask=0
+ * enables the vector. See also the BKDGs.
  */
 
 #define APIC_EILVT_LVTOFF_MCE 0
@@ -331,6 +334,7 @@ u8 setup_APIC_eilvt_ibs(u8 vector, u8 msg_type, u8 mask)
         setup_APIC_eilvt(APIC_EILVT_LVTOFF_IBS, vector, msg_type, mask);
         return APIC_EILVT_LVTOFF_IBS;
 }
+EXPORT_SYMBOL_GPL(setup_APIC_eilvt_ibs);
 
 /*
  * Program the next event, relative to now