irq: replace loop with nr_irqs with for_each_irq_desc
There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.
Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.
v2: make sure arch without GENERIC_HARDIRQS work too
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/linux/irq.h b/include/linux/irq.h
index c9ffef7..9de16ca 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -202,9 +202,16 @@
extern struct irq_desc *irq_desc;
#endif
+#ifdef CONFIG_GENERIC_HARDIRQS
+#define for_each_irq_desc(irq, desc) \
+ for (irq = 0, desc = irq_desc; irq < nr_irqs; irq++, desc = &irq_desc[irq])
+#endif
+
#else
extern struct irq_desc *sparse_irqs;
+#define for_each_irq_desc(irqX, desc) \
+ for (desc = sparse_irqs, irqX = desc->irq; desc && irqX != -1U; desc = desc->next, irqX = desc ? desc->irq : -1U)
#endif