irqdomain: make irq_linear_revmap() a fast path again
Over the years, irq_linear_revmap() gained tests and checks to make sure
callers were using it safely, which while important, also make it less
of a fast path. After the irqdomain refactoring done recently, it is now
possible to make irq_linear_revmap() a fast path again. This patch moves
irq_linear_revmap() to the header file and makes it a static inline so
that interrupt controller drivers using a linear mapping can decode the
virq from a hwirq in just a couple of instructions.
Signed-off-by: Grant Likely <grant.likely@linaro.org>
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index e47b356..836a0f7 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -559,35 +559,17 @@
return hwirq;
}
- return irq_linear_revmap(domain, hwirq);
+ /* Check if the hwirq is in the linear revmap. */
+ if (hwirq < domain->revmap_size)
+ return domain->linear_revmap[hwirq];
+
+ rcu_read_lock();
+ data = radix_tree_lookup(&domain->revmap_tree, hwirq);
+ rcu_read_unlock();
+ return data ? data->irq : 0;
}
EXPORT_SYMBOL_GPL(irq_find_mapping);
-/**
- * irq_linear_revmap() - Find a linux irq from a hw irq number.
- * @domain: domain owning this hardware interrupt
- * @hwirq: hardware irq number in that domain space
- *
- * This is a fast path that can be called directly by irq controller code to
- * save a handful of instructions.
- */
-unsigned int irq_linear_revmap(struct irq_domain *domain,
- irq_hw_number_t hwirq)
-{
- struct irq_data *data;
-
- /* Check revmap bounds; complain if exceeded */
- if (hwirq >= domain->revmap_size) {
- rcu_read_lock();
- data = radix_tree_lookup(&domain->revmap_tree, hwirq);
- rcu_read_unlock();
- return data ? data->irq : 0;
- }
-
- return domain->linear_revmap[hwirq];
-}
-EXPORT_SYMBOL_GPL(irq_linear_revmap);
-
#ifdef CONFIG_IRQ_DOMAIN_DEBUG
static int virq_debug_show(struct seq_file *m, void *private)
{