apic: use symbolic APIC_EOI_ACK

Use the symbol instead of hard-coded numbers,
now that the reason for the value is documented
where the constant is defined we don't need to
duplicate this explanation in code.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index d854101712608655a67e10a46ff7b964245798c7..a09e9ab0bbdfb19fe465bcdf736c10631ed4a08f 100644 (file)
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -463,9 +463,7 @@ static inline void ack_APIC_irq(void)
         * ack_APIC_irq() actually gets compiled as a single instruction
         * ... yummie.
         */
-
-       /* Docs say use 0 for future compatibility */
-       apic_write(APIC_EOI, 0);
+       apic_write(APIC_EOI, APIC_EOI_ACK);
 }
 
 static inline unsigned default_get_apic_id(unsigned long x)