irq_domain: Replace irq_alloc_host() with revmap-specific initializers

Each revmap type has different arguments for setting up the revmap.
This patch splits up the generator functions so that each revmap type
can do its own setup and the user doesn't need to keep track of how
each revmap type handles the arguments.

This patch also adds a host_data argument to the generators.  There are
cases where the host_data pointer will be needed before the function returns.
ie. the legacy map calls the .map callback for each irq before returning.

v2: - Add void *host_data argument to irq_domain_add_*() functions
    - fixed failure to compile
    - Moved IRQ_DOMAIN_MAP_* defines into irqdomain.c

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

1 files changed, 130 insertions, 70 deletions

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 432d292b33f8..acedba1a2651 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -13,6 +13,11 @@
 #include <linux/smp.h>
 #include <linux/fs.h>
 
+#define IRQ_DOMAIN_MAP_LEGACY 0 /* legacy 8259, gets irqs 1..15 */
+#define IRQ_DOMAIN_MAP_NOMAP 1 /* no fast reverse mapping */
+#define IRQ_DOMAIN_MAP_LINEAR 2 /* linear map of interrupts */
+#define IRQ_DOMAIN_MAP_TREE 3 /* radix tree */
+
 static LIST_HEAD(irq_domain_list);
 static DEFINE_MUTEX(irq_domain_mutex);
 
@@ -27,100 +32,158 @@ static int default_irq_domain_match(struct irq_domain *d, struct device_node *np
 }
 
 /**
- * irq_alloc_host() - Allocate a new irq_domain data structure
+ * irq_domain_alloc() - Allocate a new irq_domain data structure
  * @of_node: optional device-tree node of the interrupt controller
  * @revmap_type: type of reverse mapping to use
- * @revmap_arg: for IRQ_DOMAIN_MAP_LINEAR linear only: size of the map
  * @ops: map/unmap domain callbacks
- * @inval_irq: provide a hw number in that domain space that is always invalid
+ * @host_data: Controller private data pointer
  *
- * Allocates and initialize and irq_domain structure. Note that in the case of
- * IRQ_DOMAIN_MAP_LEGACY, the map() callback will be called before this returns
- * for all legacy interrupts except 0 (which is always the invalid irq for
- * a legacy controller). For a IRQ_DOMAIN_MAP_LINEAR, the map is allocated by
- * this call as well. For a IRQ_DOMAIN_MAP_TREE, the radix tree will be
- * allocated later during boot automatically (the reverse mapping will use the
- * slow path until that happens).
+ * Allocates and initialize and irq_domain structure.  Caller is expected to
+ * register allocated irq_domain with irq_domain_register().  Returns pointer
+ * to IRQ domain, or NULL on failure.
  */
-struct irq_domain *irq_alloc_host(struct device_node *of_node,
-				unsigned int revmap_type,
-				unsigned int revmap_arg,
-				struct irq_domain_ops *ops,
-				irq_hw_number_t inval_irq)
+static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
+					   unsigned int revmap_type,
+					   struct irq_domain_ops *ops,
+					   void *host_data)
 {
-	struct irq_domain *domain, *h;
-	unsigned int size = sizeof(struct irq_domain);
-	unsigned int i;
-	unsigned int *rmap;
+	struct irq_domain *domain;
 
-	/* Allocate structure and revmap table if using linear mapping */
-	if (revmap_type == IRQ_DOMAIN_MAP_LINEAR)
-		size += revmap_arg * sizeof(unsigned int);
-	domain = kzalloc(size, GFP_KERNEL);
-	if (domain == NULL)
+	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
+	if (WARN_ON(!domain))
 		return NULL;
 
 	/* Fill structure */
 	domain->revmap_type = revmap_type;
-	domain->inval_irq = inval_irq;
 	domain->ops = ops;
+	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;
+}
+
+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",
+		 domain->revmap_type, domain);
+}
+
+/**
+ * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ *
+ * Note: the map() callback will be called before this function returns
+ * for all legacy interrupts except 0 (which is always the invalid irq for
+ * a legacy controller).
+ */
+struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain, *h;
+	unsigned int i;
+
+	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
+	if (!domain)
+		return NULL;
+
 	mutex_lock(&irq_domain_mutex);
 	/* Make sure only one legacy controller can be created */
-	if (revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
-		list_for_each_entry(h, &irq_domain_list, link) {
-			if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) {
-				mutex_unlock(&irq_domain_mutex);
-				of_node_put(domain->of_node);
-				kfree(domain);
-				return NULL;
-			}
+	list_for_each_entry(h, &irq_domain_list, link) {
+		if (WARN_ON(h->revmap_type == IRQ_DOMAIN_MAP_LEGACY)) {
+			mutex_unlock(&irq_domain_mutex);
+			of_node_put(domain->of_node);
+			kfree(domain);
+			return NULL;
 		}
 	}
 	list_add(&domain->link, &irq_domain_list);
 	mutex_unlock(&irq_domain_mutex);
 
-	/* Additional setups per revmap type */
-	switch(revmap_type) {
-	case IRQ_DOMAIN_MAP_LEGACY:
-		/* 0 is always the invalid number for legacy */
-		domain->inval_irq = 0;
-		/* setup us as the domain for all legacy interrupts */
-		for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
-			struct irq_data *irq_data = irq_get_irq_data(i);
-			irq_data->hwirq = i;
-			irq_data->domain = domain;
-
-			/* Legacy flags are left to default at this point,
-			 * one can then use irq_create_mapping() to
-			 * explicitly change them
-			 */
-			ops->map(domain, i, i);
-
-			/* Clear norequest flags */
-			irq_clear_status_flags(i, IRQ_NOREQUEST);
-		}
-		break;
-	case IRQ_DOMAIN_MAP_LINEAR:
-		rmap = (unsigned int *)(domain + 1);
-		for (i = 0; i < revmap_arg; i++)
-			rmap[i] = 0;
-		domain->revmap_data.linear.size = revmap_arg;
-		domain->revmap_data.linear.revmap = rmap;
-		break;
-	case IRQ_DOMAIN_MAP_TREE:
-		INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
-		break;
-	default:
-		break;
+	/* setup us as the domain for all legacy interrupts */
+	for (i = 1; i < NUM_ISA_INTERRUPTS; i++) {
+		struct irq_data *irq_data = irq_get_irq_data(i);
+		irq_data->hwirq = i;
+		irq_data->domain = domain;
+
+		/* Legacy flags are left to default at this point,
+		 * one can then use irq_create_mapping() to
+		 * explicitly change them
+		 */
+		ops->map(domain, i, i);
+
+		/* Clear norequest flags */
+		irq_clear_status_flags(i, IRQ_NOREQUEST);
 	}
+	return domain;
+}
 
-	pr_debug("irq: Allocated domain of type %d @0x%p\n", revmap_type, domain);
+/**
+ * irq_domain_add_linear() - Allocate and register a legacy revmap irq_domain.
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ * @host_data: Controller private data pointer
+ */
+struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+					 unsigned int size,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain;
+	unsigned int *revmap;
+
+	revmap = kzalloc(sizeof(*revmap) * size, GFP_KERNEL);
+	if (WARN_ON(!revmap))
+		return NULL;
 
+	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LINEAR, ops, host_data);
+	if (!domain) {
+		kfree(revmap);
+		return NULL;
+	}
+	domain->revmap_data.linear.size = size;
+	domain->revmap_data.linear.revmap = revmap;
+	irq_domain_add(domain);
+	return domain;
+}
+
+struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+					 struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	struct irq_domain *domain = irq_domain_alloc(of_node,
+					IRQ_DOMAIN_MAP_NOMAP, ops, host_data);
+	if (domain)
+		irq_domain_add(domain);
+	return domain;
+}
+
+/**
+ * irq_domain_add_tree()
+ * @of_node: pointer to interrupt controller's device tree node.
+ * @ops: map/unmap domain callbacks
+ *
+ * Note: The radix tree will be allocated later during boot automatically
+ * (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,
+					 void *host_data)
+{
+	struct irq_domain *domain = irq_domain_alloc(of_node,
+					IRQ_DOMAIN_MAP_TREE, ops, host_data);
+	if (domain) {
+		INIT_RADIX_TREE(&domain->revmap_data.tree, GFP_KERNEL);
+		irq_domain_add(domain);
+	}
 	return domain;
 }
 
@@ -393,9 +456,6 @@ void irq_dispose_mapping(unsigned int virq)
 		break;
 	}
 
-	/* Destroy map */
-	irq_data->hwirq = domain->inval_irq;
-
 	irq_free_desc(virq);
 }
 EXPORT_SYMBOL_GPL(irq_dispose_mapping);