+/**
+ * irq_find_mapping() - Find a linux irq from an hw irq number.
+ * @host: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that host space
+ *
+ * This is a slow path, for use by generic code. It's expected that an
+ * irq controller implementation directly calls the appropriate low level
+ * mapping function.
+ */
+unsigned int irq_find_mapping(struct irq_domain *host,
+ irq_hw_number_t hwirq)
+{
+ unsigned int i;
+ unsigned int hint = hwirq % irq_virq_count;
+
+ /* Look for default host if nececssary */
+ if (host == NULL)
+ host = irq_default_host;
+ if (host == NULL)
+ return NO_IRQ;
+
+ /* legacy -> bail early */
+ if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+ return hwirq;
+
+ /* Slow path does a linear search of the map */
+ if (hint == 0)
+ hint = 1;
+ i = hint;
+ do {
+ struct irq_data *data = irq_get_irq_data(i);
+ if (data&& (data->domain == host)&& (data->hwirq == hwirq))
+ return i;
+ i++;
+ if (i>= irq_virq_count)
+ i = 1