x86: avoid redundant loop in io_apic_level_ack_pending()

If one can find an ack pending pin, there is no need to check
the rest of them.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/x86/kernel/io_apic_64.c b/arch/x86/kernel/io_apic_64.c
index 65b6840e1820..cd01f3aa17ba 100644
--- a/arch/x86/kernel/io_apic_64.c
+++ b/arch/x86/kernel/io_apic_64.c
@@ -167,11 +167,10 @@ static inline void io_apic_modify(unsigned int apic, unsigned int value)
         writel(value, &io_apic->data);
 }
 
-static int io_apic_level_ack_pending(unsigned int irq)
+static bool io_apic_level_ack_pending(unsigned int irq)
 {
         struct irq_pin_list *entry;
         unsigned long flags;
-        int pending = 0;
 
         spin_lock_irqsave(&ioapic_lock, flags);
         entry = irq_2_pin + irq;
@@ -184,13 +183,17 @@ static int io_apic_level_ack_pending(unsigned int irq)
                         break;
                 reg = io_apic_read(entry->apic, 0x10 + pin*2);
                 /* Is the remote IRR bit set? */
-                pending |= (reg >> 14) & 1;
+                if ((reg >> 14) & 1) {
+                        spin_unlock_irqrestore(&ioapic_lock, flags);
+                        return true;
+                }
                 if (!entry->next)
                         break;
                 entry = irq_2_pin + entry->next;
         }
         spin_unlock_irqrestore(&ioapic_lock, flags);
-        return pending;
+
+        return false;
 }
 
 /*