irq_domain: constify irq_domain_ops

Make irq_domain_ops pointer a constant to make it safer for multiple
instances to share the same ops pointer and change the irq_domain code
so that it does not modify the ops.

v4: Fix mismatched type reference in powerpc code

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Milton Miller <miltonm@bga.com>
Tested-by: Olof Johansson <olof@lixom.net>

diff --git a/arch/powerpc/sysdev/mpic_msi.c b/arch/powerpc/sysdev/mpic_msi.c
index 00395f40fb5d8e9532ada1062f1afdfee07b104e..0622aa91b18a3bd569558eb60efd619d334425b0 100644 (file)
--- a/arch/powerpc/sysdev/mpic_msi.c
+++ b/arch/powerpc/sysdev/mpic_msi.c
@@ -32,7 +32,7 @@ void mpic_msi_reserve_hwirq(struct mpic *mpic, irq_hw_number_t hwirq)
 static int mpic_msi_reserve_u3_hwirqs(struct mpic *mpic)
 {
        irq_hw_number_t hwirq;
-       struct irq_domain_ops *ops = mpic->irqhost->ops;
+       const struct irq_domain_ops *ops = mpic->irqhost->ops;
        struct device_node *np;
        int flags, index, i;
        struct of_irq oirq;

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index ea58f36688a0274ab3b9ddeedc6ddcb9b6907d06..52454881938a5af9662214c775eb110d2c36fe41 100644 (file)
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -106,7 +106,7 @@ struct irq_domain {
                } linear;
                struct radix_tree_root tree;
        } revmap_data;
-       struct irq_domain_ops *ops;
+       const struct irq_domain_ops *ops;
        void *host_data;
        irq_hw_number_t inval_irq;
 
@@ -119,17 +119,17 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
                                         unsigned int size,
                                         unsigned int first_irq,
                                         irq_hw_number_t first_hwirq,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data);
 struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
                                         unsigned int size,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data);
 struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data);
 struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data);
 
 extern struct irq_domain *irq_find_host(struct device_node *node);
@@ -138,7 +138,7 @@ extern void irq_set_virq_count(unsigned int count);
 
 static inline struct irq_domain *irq_domain_add_legacy_isa(
                                struct device_node *of_node,
-                               struct irq_domain_ops *ops,
+                               const struct irq_domain_ops *ops,
                                void *host_data)
 {
        return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops,
@@ -162,7 +162,7 @@ extern unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
 extern unsigned int irq_linear_revmap(struct irq_domain *host,
                                      irq_hw_number_t hwirq);
 
-extern struct irq_domain_ops irq_domain_simple_ops;
+extern const struct irq_domain_ops irq_domain_simple_ops;
 
 /* stock xlate functions */
 int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 456e3fc8387fe4ec84e49bfbe6f4a92ce63a8069..25a498eb98a3ef21e303f43149de10a8bf97c176 100644 (file)
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -26,11 +26,6 @@ static DEFINE_MUTEX(revmap_trees_mutex);
 static unsigned int irq_virq_count = NR_IRQS;
 static struct irq_domain *irq_default_domain;
 
-static int default_irq_domain_match(struct irq_domain *d, struct device_node *np)
-{
-       return d->of_node != NULL && d->of_node == np;
-}
-
 /**
  * irq_domain_alloc() - Allocate a new irq_domain data structure
  * @of_node: optional device-tree node of the interrupt controller
@@ -44,7 +39,7 @@ static int default_irq_domain_match(struct irq_domain *d, struct device_node *np
  */
 static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
                                           unsigned int revmap_type,
-                                          struct irq_domain_ops *ops,
+                                          const struct irq_domain_ops *ops,
                                           void *host_data)
 {
        struct irq_domain *domain;
@@ -59,9 +54,6 @@ static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
        domain->host_data = host_data;
        domain->of_node = of_node_get(of_node);
 
-       if (domain->ops->match == NULL)
-               domain->ops->match = default_irq_domain_match;
-
        return domain;
 }
 
@@ -104,7 +96,7 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
                                         unsigned int size,
                                         unsigned int first_irq,
                                         irq_hw_number_t first_hwirq,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data)
 {
        struct irq_domain *domain;
@@ -170,7 +162,7 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
  */
 struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
                                         unsigned int size,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data)
 {
        struct irq_domain *domain;
@@ -192,7 +184,7 @@ struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
 }
 
 struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data)
 {
        struct irq_domain *domain = irq_domain_alloc(of_node,
@@ -211,7 +203,7 @@ struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
  * (the reverse mapping will use the slow path until that happens).
  */
 struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
-                                        struct irq_domain_ops *ops,
+                                        const struct irq_domain_ops *ops,
                                         void *host_data)
 {
        struct irq_domain *domain = irq_domain_alloc(of_node,
@@ -230,6 +222,7 @@ struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
 struct irq_domain *irq_find_host(struct device_node *node)
 {
        struct irq_domain *h, *found = NULL;
+       int rc;
 
        /* We might want to match the legacy controller last since
         * it might potentially be set to match all interrupts in
@@ -237,11 +230,17 @@ struct irq_domain *irq_find_host(struct device_node *node)
         * yet though...
         */
        mutex_lock(&irq_domain_mutex);
-       list_for_each_entry(h, &irq_domain_list, link)
-               if (h->ops->match(h, node)) {
+       list_for_each_entry(h, &irq_domain_list, link) {
+               if (h->ops->match)
+                       rc = h->ops->match(h, node);
+               else
+                       rc = (h->of_node != NULL) && (h->of_node == node);
+
+               if (rc) {
                        found = h;
                        break;
                }
+       }
        mutex_unlock(&irq_domain_mutex);
        return found;
 }
@@ -760,7 +759,7 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d,
 }
 EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);
 
-struct irq_domain_ops irq_domain_simple_ops = {
+const struct irq_domain_ops irq_domain_simple_ops = {
        .map = irq_domain_simple_map,
        .xlate = irq_domain_xlate_onetwocell,
 };