2 files changed, 89 insertions, 20 deletions

diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index c65740d76e66..5abb533eb8eb 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -141,9 +141,8 @@ static inline struct irq_domain *irq_domain_add_legacy_isa(
         return irq_domain_add_legacy(of_node, NUM_ISA_INTERRUPTS, 0, 0, ops,
                                      host_data);
 }
-extern struct irq_domain *irq_find_host(struct device_node *node);
-extern void irq_set_default_host(struct irq_domain *host);
 
+extern void irq_domain_remove(struct irq_domain *host);
 
 extern unsigned int irq_create_mapping(struct irq_domain *host,
                                        irq_hw_number_t hwirq);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 0e0ba5f840b2..41c1564103f1 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1,3 +1,5 @@
+#define pr_fmt(fmt)  "irq: " fmt
+
 #include <linux/debugfs.h>
 #include <linux/hardirq.h>
 #include <linux/interrupt.h>
@@ -56,14 +58,73 @@ static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
         return domain;
 }
 
+static void irq_domain_free(struct irq_domain *domain)
+{
+        of_node_put(domain->of_node);
+        kfree(domain);
+}
+
 static void irq_domain_add(struct irq_domain *domain)
 {
         mutex_lock(&irq_domain_mutex);
         list_add(&domain->link, &irq_domain_list);
         mutex_unlock(&irq_domain_mutex);
-        pr_debug("irq: Allocated domain of type %d @0x%p\n",
+        pr_debug("Allocated domain of type %d @0x%p\n",
+                 domain->revmap_type, domain);
+}
+
+/**
+ * irq_domain_remove() - Remove an irq domain.
+ * @domain: domain to remove
+ *
+ * This routine is used to remove an irq domain. The caller must ensure
+ * that all mappings within the domain have been disposed of prior to
+ * use, depending on the revmap type.
+ */
+void irq_domain_remove(struct irq_domain *domain)
+{
+        mutex_lock(&irq_domain_mutex);
+
+        switch (domain->revmap_type) {
+        case IRQ_DOMAIN_MAP_LEGACY:
+                /*
+                 * Legacy domains don't manage their own irq_desc
+                 * allocations, we expect the caller to handle irq_desc
+                 * freeing on their own.
+                 */
+                break;
+        case IRQ_DOMAIN_MAP_TREE:
+                /*
+                 * radix_tree_delete() takes care of destroying the root
+                 * node when all entries are removed. Shout if there are
+                 * any mappings left.
+                 */
+                WARN_ON(domain->revmap_data.tree.height);
+                break;
+        case IRQ_DOMAIN_MAP_LINEAR:
+                kfree(domain->revmap_data.linear.revmap);
+                domain->revmap_data.linear.size = 0;
+                break;
+        case IRQ_DOMAIN_MAP_NOMAP:
+                break;
+        }
+
+        list_del(&domain->link);
+
+        /*
+         * If the going away domain is the default one, reset it.
+         */
+        if (unlikely(irq_default_domain == domain))
+                irq_set_default_host(NULL);
+
+        mutex_unlock(&irq_domain_mutex);
+
+        pr_debug("Removed domain of type %d @0x%p\n",
                  domain->revmap_type, domain);
+
+        irq_domain_free(domain);
 }
+EXPORT_SYMBOL_GPL(irq_domain_remove);
 
 static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
                                              irq_hw_number_t hwirq)
@@ -117,8 +178,7 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
 
                 if (WARN_ON(!irq_data || irq_data->domain)) {
                         mutex_unlock(&irq_domain_mutex);
-                        of_node_put(domain->of_node);
-                        kfree(domain);
+                        irq_domain_free(domain);
                         return NULL;
                 }
         }
@@ -152,10 +212,12 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
         irq_domain_add(domain);
         return domain;
 }
+EXPORT_SYMBOL_GPL(irq_domain_add_legacy);
 
 /**
  * irq_domain_add_linear() - Allocate and register a legacy revmap irq_domain.
  * @of_node: pointer to interrupt controller's device tree node.
+ * @size: Number of interrupts in the domain.
  * @ops: map/unmap domain callbacks
  * @host_data: Controller private data pointer
  */
@@ -181,6 +243,7 @@ struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
         irq_domain_add(domain);
         return domain;
 }
+EXPORT_SYMBOL_GPL(irq_domain_add_linear);
 
 struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
                                          unsigned int max_irq,
@@ -195,6 +258,7 @@ struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
         }
         return domain;
 }
+EXPORT_SYMBOL_GPL(irq_domain_add_nomap);
 
 /**
  * irq_domain_add_tree()
@@ -216,6 +280,7 @@ struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
         }
         return domain;
 }
+EXPORT_SYMBOL_GPL(irq_domain_add_tree);
 
 /**
  * irq_find_host() - Locates a domain for a given device node
@@ -259,10 +324,11 @@ EXPORT_SYMBOL_GPL(irq_find_host);
  */
 void irq_set_default_host(struct irq_domain *domain)
 {
-        pr_debug("irq: Default domain set to @0x%p\n", domain);
+        pr_debug("Default domain set to @0x%p\n", domain);
 
         irq_default_domain = domain;
 }
+EXPORT_SYMBOL_GPL(irq_set_default_host);
 
 static int irq_setup_virq(struct irq_domain *domain, unsigned int virq,
                             irq_hw_number_t hwirq)
@@ -272,7 +338,7 @@ static int irq_setup_virq(struct irq_domain *domain, unsigned int virq,
         irq_data->hwirq = hwirq;
         irq_data->domain = domain;
         if (domain->ops->map(domain, virq, hwirq)) {
-                pr_debug("irq: -> mapping failed, freeing\n");
+                pr_debug("irq-%i==>hwirq-0x%lx mapping failed\n", virq, hwirq);
                 irq_data->domain = NULL;
                 irq_data->hwirq = 0;
                 return -1;
@@ -303,7 +369,7 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 
         virq = irq_alloc_desc_from(1, 0);
         if (!virq) {
-                pr_debug("irq: create_direct virq allocation failed\n");
+                pr_debug("create_direct virq allocation failed\n");
                 return 0;
         }
         if (virq >= domain->revmap_data.nomap.max_irq) {
@@ -312,7 +378,7 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
                 irq_free_desc(virq);
                 return 0;
         }
-        pr_debug("irq: create_direct obtained virq %d\n", virq);
+        pr_debug("create_direct obtained virq %d\n", virq);
 
         if (irq_setup_virq(domain, virq, virq)) {