diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c
index 9dc447db8a44..d9f3b6e7c7cb 100644
--- a/arch/sh/kernel/irq.c
+++ b/arch/sh/kernel/irq.c
@@ -273,12 +273,6 @@ void __init init_IRQ(void)
 {
 	plat_irq_setup();
 
-	/*
-	 * Pin any of the legacy IRQ vectors that haven't already been
-	 * grabbed by the platform
-	 */
-	reserve_irq_legacy();
-
 	/* Perform the machine specific initialisation */
 	if (sh_mv.mv_init_irq)
 		sh_mv.mv_init_irq();
diff --git a/drivers/sh/intc/core.c b/drivers/sh/intc/core.c
index 8f3c27e9f9e2..0801089828e7 100644
--- a/drivers/sh/intc/core.c
+++ b/drivers/sh/intc/core.c
@@ -78,7 +78,7 @@ static void __init intc_register_irq(struct intc_desc *desc,
 	 * Register the IRQ position with the global IRQ map, then insert
 	 * it in to the radix tree.
 	 */
-	reserve_irq_vector(irq);
+	irq_reserve_irqs(irq, 1);
 
 	raw_spin_lock_irqsave(&intc_big_lock, flags);
 	radix_tree_insert(&d->tree, enum_id, intc_irq_xlate_get(irq));
diff --git a/drivers/sh/intc/dynamic.c b/drivers/sh/intc/dynamic.c
index e994c7ed916e..4187cce20ffd 100644
--- a/drivers/sh/intc/dynamic.c
+++ b/drivers/sh/intc/dynamic.c
@@ -17,7 +17,7 @@
 #include "internals.h" /* only for activate_irq() damage.. */
 
 /*
- * The intc_irq_map provides a global map of bound IRQ vectors for a
+ * The IRQ bitmap provides a global map of bound IRQ vectors for a
  * given platform. Allocation of IRQs are either static through the CPU
  * vector map, or dynamic in the case of board mux vectors or MSI.
  *
@@ -27,104 +27,38 @@
  * when dynamically creating IRQs, as well as tying in to otherwise
  * unused irq_desc positions in the sparse array.
  */
-static DECLARE_BITMAP(intc_irq_map, NR_IRQS);
-static DEFINE_RAW_SPINLOCK(vector_lock);
 
 /*
  * Dynamic IRQ allocation and deallocation
  */
 unsigned int create_irq_nr(unsigned int irq_want, int node)
 {
-	unsigned int irq = 0, new;
-	unsigned long flags;
-
-	raw_spin_lock_irqsave(&vector_lock, flags);
-
-	/*
-	 * First try the wanted IRQ
-	 */
-	if (test_and_set_bit(irq_want, intc_irq_map) == 0) {
-		new = irq_want;
-	} else {
-		/* .. then fall back to scanning. */
-		new = find_first_zero_bit(intc_irq_map, nr_irqs);
-		if (unlikely(new == nr_irqs))
-			goto out_unlock;
-
-		__set_bit(new, intc_irq_map);
-	}
-
-	raw_spin_unlock_irqrestore(&vector_lock, flags);
-
-	irq = irq_alloc_desc_at(new, node);
-	if (unlikely(irq != new)) {
-		pr_err("can't get irq_desc for %d\n", new);
+	int irq = irq_alloc_desc_at(irq_want, node);
+	if (irq < 0)
 		return 0;
-	}
 
 	activate_irq(irq);
-	return 0;
-
-out_unlock:
-	raw_spin_unlock_irqrestore(&vector_lock, flags);
-	return 0;
+	return irq;
 }
 
 int create_irq(void)
 {
-	int nid = cpu_to_node(smp_processor_id());
-	int irq;
-
-	irq = create_irq_nr(NR_IRQS_LEGACY, nid);
-	if (irq == 0)
-		irq = -1;
+	int irq = irq_alloc_desc(numa_node_id());
+	if (irq >= 0)
+		activate_irq(irq);
 
 	return irq;
 }
 
 void destroy_irq(unsigned int irq)
 {
-	unsigned long flags;
-
 	irq_free_desc(irq);
-
-	raw_spin_lock_irqsave(&vector_lock, flags);
-	__clear_bit(irq, intc_irq_map);
-	raw_spin_unlock_irqrestore(&vector_lock, flags);
-}
-
-int reserve_irq_vector(unsigned int irq)
-{
-	unsigned long flags;
-	int ret = 0;
-
-	raw_spin_lock_irqsave(&vector_lock, flags);
-	if (test_and_set_bit(irq, intc_irq_map))
-		ret = -EBUSY;
-	raw_spin_unlock_irqrestore(&vector_lock, flags);
-
-	return ret;
 }
 
 void reserve_intc_vectors(struct intc_vect *vectors, unsigned int nr_vecs)
 {
-	unsigned long flags;
 	int i;
 
-	raw_spin_lock_irqsave(&vector_lock, flags);
 	for (i = 0; i < nr_vecs; i++)
-		__set_bit(evt2irq(vectors[i].vect), intc_irq_map);
-	raw_spin_unlock_irqrestore(&vector_lock, flags);
-}
-
-void reserve_irq_legacy(void)
-{
-	unsigned long flags;
-	int i, j;
-
-	raw_spin_lock_irqsave(&vector_lock, flags);
-	j = find_first_bit(intc_irq_map, nr_irqs);
-	for (i = 0; i < j; i++)
-		__set_bit(i, intc_irq_map);
-	raw_spin_unlock_irqrestore(&vector_lock, flags);
+		irq_reserve_irqs(evt2irq(vectors[i].vect), 1);
 }
diff --git a/include/linux/sh_intc.h b/include/linux/sh_intc.h
index b4f183a31f13..f656d1a43dc0 100644
--- a/include/linux/sh_intc.h
+++ b/include/linux/sh_intc.h
@@ -129,7 +129,4 @@ static inline int register_intc_userimask(unsigned long addr)
 }
 #endif
 
-int reserve_irq_vector(unsigned int irq);
-void reserve_irq_legacy(void);
-
 #endif /* __SH_INTC_H */