x86/irq: Seperate unused system vectors from spurious entry again

[platform/kernel/linux-rpi.git] / arch / x86 / kernel / apic / apic.c

diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 29fd508..a5241b2 100644 (file)
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -2068,21 +2068,32 @@ __visible void __irq_entry smp_spurious_interrupt(struct pt_regs *regs)
        entering_irq();
        trace_spurious_apic_entry(vector);
 
+       inc_irq_stat(irq_spurious_count);
+
+       /*
+        * If this is a spurious interrupt then do not acknowledge
+        */
+       if (vector == SPURIOUS_APIC_VECTOR) {
+               /* See SDM vol 3 */
+               pr_info("Spurious APIC interrupt (vector 0xFF) on CPU#%d, should never happen.\n",
+                       smp_processor_id());
+               goto out;
+       }
+
        /*
-        * Check if this really is a spurious interrupt and ACK it
-        * if it is a vectored one.  Just in case...
-        * Spurious interrupts should not be ACKed.
+        * If it is a vectored one, verify it's set in the ISR. If set,
+        * acknowledge it.
         */
        v = apic_read(APIC_ISR + ((vector & ~0x1f) >> 1));
-       if (v & (1 << (vector & 0x1f)))
+       if (v & (1 << (vector & 0x1f))) {
+               pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Acked\n",
+                       vector, smp_processor_id());
                ack_APIC_irq();
-
-       inc_irq_stat(irq_spurious_count);
-
-       /* see sw-dev-man vol 3, chapter 7.4.13.5 */
-       pr_info("spurious APIC interrupt through vector %02x on CPU#%d, "
-               "should never happen.\n", vector, smp_processor_id());
-
+       } else {
+               pr_info("Spurious interrupt (vector 0x%02x) on CPU#%d. Not pending!\n",
+                       vector, smp_processor_id());
+       }
+out:
        trace_spurious_apic_exit(vector);
        exiting_irq();
 }