irqdomain: Introduce irq_resolve_mapping()

Rework irq_find_mapping() to return an both an irq_desc pointer,
optionally the virtual irq number, and rename the result to
__irq_resolve_mapping(). a new helper called irq_resolve_mapping()
is provided for code that doesn't need the virtual irq number.

irq_find_mapping() is also rewritten in terms of __irq_resolve_mapping().

Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index 2b696c9..23e4ee5 100644 (file)
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -41,6 +41,7 @@ struct fwnode_handle;
 struct irq_domain;
 struct irq_chip;
 struct irq_data;
+struct irq_desc;
 struct cpumask;
 struct seq_file;
 struct irq_affinity_desc;
@@ -401,13 +402,31 @@ static inline unsigned int irq_create_mapping(struct irq_domain *host,
        return irq_create_mapping_affinity(host, hwirq, NULL);
 }
 
+extern struct irq_desc *__irq_resolve_mapping(struct irq_domain *domain,
+                                             irq_hw_number_t hwirq,
+                                             unsigned int *irq);
+
+static inline struct irq_desc *irq_resolve_mapping(struct irq_domain *domain,
+                                                  irq_hw_number_t hwirq)
+{
+       return __irq_resolve_mapping(domain, hwirq, NULL);
+}
+
 /**
  * irq_find_mapping() - Find a linux irq from a hw irq number.
  * @domain: domain owning this hardware interrupt
  * @hwirq: hardware irq number in that domain space
  */
-extern unsigned int irq_find_mapping(struct irq_domain *host,
-                                    irq_hw_number_t hwirq);
+static inline unsigned int irq_find_mapping(struct irq_domain *domain,
+                                           irq_hw_number_t hwirq)
+{
+       unsigned int irq;
+
+       if (__irq_resolve_mapping(domain, hwirq, &irq))
+               return irq;
+
+       return 0;
+}
 
 static inline unsigned int irq_linear_revmap(struct irq_domain *domain,
                                             irq_hw_number_t hwirq)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 8fbadee..51c483c 100644 (file)
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -884,29 +884,34 @@ void irq_dispose_mapping(unsigned int virq)
 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
 
 /**
- * irq_find_mapping() - Find a linux irq from a hw irq number.
+ * __irq_resolve_mapping() - Find a linux irq from a hw irq number.
  * @domain: domain owning this hardware interrupt
  * @hwirq: hardware irq number in that domain space
+ * @irq: optional pointer to return the Linux irq if required
+ *
+ * Returns the interrupt descriptor.
  */
-unsigned int irq_find_mapping(struct irq_domain *domain,
-                             irq_hw_number_t hwirq)
+struct irq_desc *__irq_resolve_mapping(struct irq_domain *domain,
+                                      irq_hw_number_t hwirq,
+                                      unsigned int *irq)
 {
+       struct irq_desc *desc = NULL;
        struct irq_data *data;
 
        /* Look for default domain if necessary */
        if (domain == NULL)
                domain = irq_default_domain;
        if (domain == NULL)
-               return 0;
+               return desc;
 
        if (irq_domain_is_nomap(domain)) {
                if (hwirq < domain->revmap_size) {
                        data = irq_domain_get_irq_data(domain, hwirq);
                        if (data && data->hwirq == hwirq)
-                               return hwirq;
+                               desc = irq_data_to_desc(data);
                }
 
-               return 0;
+               return desc;
        }
 
        rcu_read_lock();
@@ -915,10 +920,17 @@ unsigned int irq_find_mapping(struct irq_domain *domain,
                data = rcu_dereference(domain->revmap[hwirq]);
        else
                data = radix_tree_lookup(&domain->revmap_tree, hwirq);
+
+       if (likely(data)) {
+               desc = irq_data_to_desc(data);
+               if (irq)
+                       *irq = data->irq;
+       }
+
        rcu_read_unlock();
-       return data ? data->irq : 0;
+       return desc;
 }
-EXPORT_SYMBOL_GPL(irq_find_mapping);
+EXPORT_SYMBOL_GPL(__irq_resolve_mapping);
 
 /**
  * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings