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authorGrant Likely <grant.likely@linaro.org>2013-06-10 12:19:17 +0100
committerGrant Likely <grant.likely@linaro.org>2013-06-24 14:02:41 +0100
commitd3dcb436f61593843af178d4a520c8c43c04d3fc (patch)
tree1c2f64841936402a5d01ed923abd427f311a0e7a /include/linux/irqdomain.h
parent56a3d5ac774d054ece9373277a861338a468a294 (diff)
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>
Diffstat (limited to 'include/linux/irqdomain.h')
-rw-r--r--include/linux/irqdomain.h19
1 files changed, 16 insertions, 3 deletions
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 6efbeccac56c..c983ed18c332 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -176,6 +176,22 @@ extern void irq_domain_associate_many(struct irq_domain *domain,
extern unsigned int irq_create_mapping(struct irq_domain *host,
irq_hw_number_t hwirq);
extern void irq_dispose_mapping(unsigned int virq);
+
+/**
+ * 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 alternative to irq_find_mapping() that can be
+ * called directly by irq controller code to save a handful of
+ * instructions. It is always safe to call, but won't find irqs mapped
+ * using the radix tree.
+ */
+static inline unsigned int irq_linear_revmap(struct irq_domain *domain,
+ irq_hw_number_t hwirq)
+{
+ return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0;
+}
extern unsigned int irq_find_mapping(struct irq_domain *host,
irq_hw_number_t hwirq);
extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
@@ -189,9 +205,6 @@ static inline int irq_create_identity_mapping(struct irq_domain *host,
return irq_create_strict_mappings(host, hwirq, hwirq, 1);
}
-extern unsigned int irq_linear_revmap(struct irq_domain *host,
- irq_hw_number_t hwirq);
-
extern const struct irq_domain_ops irq_domain_simple_ops;
/* stock xlate functions */