irqchip/mips-gic: Use for_each_set_bit to iterate over local IRQs

paulburton · KAGA-KOKO · commit 0f4ed1580ce6 · 2016-09-20T23:21:55.000+02:00
The MIPS GIC driver has previously iterated over bits set in a bitmap representing pending local IRQs by calling find_first_bit, clearing that bit then calling find_first_bit again until all bits are clear. If multiple interrupts are pending then this is wasteful, as find_first_bit will have to loop over the whole bitmap from the start. Use the for_each_set_bit macro which performs exactly what we need here instead. It will use find_next_bit and thus only scan over the relevant part of the bitmap, and it makes the intent of the code clearer. This makes the same change for local interrupts that commit cae750b ("irqchip: mips-gic: Use for_each_set_bit to iterate over IRQs") made for shared interrupts. Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: linux-mips@linux-mips.org Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/20160913165427.31686-1-paul.burton@imgtec.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/drivers/irqchip/irq-mips-gic.c b/drivers/irqchip/irq-mips-gic.c
@@ -518,18 +518,13 @@ static void gic_handle_local_int(bool chained)
 
 	bitmap_and(&pending, &pending, &masked, GIC_NUM_LOCAL_INTRS);
 
-	intr = find_first_bit(&pending, GIC_NUM_LOCAL_INTRS);
-	while (intr != GIC_NUM_LOCAL_INTRS) {
+	for_each_set_bit(intr, &pending, GIC_NUM_LOCAL_INTRS) {
 		virq = irq_linear_revmap(gic_irq_domain,
 					 GIC_LOCAL_TO_HWIRQ(intr));
 		if (chained)
 			generic_handle_irq(virq);
 		else
 			do_IRQ(virq);
-
-		/* go to next pending bit */
-		bitmap_clear(&pending, intr, 1);
-		intr = find_first_bit(&pending, GIC_NUM_LOCAL_INTRS);
 	}
 }
 
