Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux

Pull irqdomain refactoring from Grant Likely:
 "This is the long awaited simplification of irqdomain.  It gets rid of
  the different types of irq domains and instead both linear and tree
  mappings can be supported in a single domain.  Doing this removes a
  lot of special case code and makes irq domains simpler to understand
  overall"

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux:
  irq: fix checkpatch error
  irqdomain: Include hwirq number in /proc/interrupts
  irqdomain: make irq_linear_revmap() a fast path again
  irqdomain: remove irq_domain_generate_simple()
  irqdomain: Refactor irq_domain_associate_many()
  irqdomain: Beef up debugfs output
  irqdomain: Clean up aftermath of irq_domain refactoring
  irqdomain: Eliminate revmap type
  irqdomain: merge linear and tree reverse mappings.
  irqdomain: Add a name field
  irqdomain: Replace LEGACY mapping with LINEAR
  irqdomain: Relax failure path on setting up mappings

7 files changed, 264 insertions, 473 deletions

diff --git a/arch/powerpc/platforms/cell/beat_interrupt.c b/arch/powerpc/platforms/cell/beat_interrupt.c
index 8c6dc42ecf65..9e5dfbcc00af 100644
--- a/arch/powerpc/platforms/cell/beat_interrupt.c
+++ b/arch/powerpc/platforms/cell/beat_interrupt.c
@@ -239,7 +239,7 @@ void __init beatic_init_IRQ(void)
 	ppc_md.get_irq = beatic_get_irq;
 
 	/* Allocate an irq host */
-	beatic_host = irq_domain_add_nomap(NULL, 0, &beatic_pic_host_ops, NULL);
+	beatic_host = irq_domain_add_nomap(NULL, ~0, &beatic_pic_host_ops, NULL);
 	BUG_ON(beatic_host == NULL);
 	irq_set_default_host(beatic_host);
 }
diff --git a/arch/powerpc/platforms/powermac/smp.c b/arch/powerpc/platforms/powermac/smp.c
index 49c9f9501c21..5cbd4d67d5c4 100644
--- a/arch/powerpc/platforms/powermac/smp.c
+++ b/arch/powerpc/platforms/powermac/smp.c
@@ -192,7 +192,7 @@ static int psurge_secondary_ipi_init(void)
 {
 	int rc = -ENOMEM;
 
-	psurge_host = irq_domain_add_nomap(NULL, 0, &psurge_host_ops, NULL);
+	psurge_host = irq_domain_add_nomap(NULL, ~0, &psurge_host_ops, NULL);
 
 	if (psurge_host)
 		psurge_secondary_virq = irq_create_direct_mapping(psurge_host);
diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c
index b1581527a236..4934890e4db2 100644
--- a/arch/x86/kernel/devicetree.c
+++ b/arch/x86/kernel/devicetree.c
@@ -364,9 +364,7 @@ static void dt_add_ioapic_domain(unsigned int ioapic_num,
 		 * and assigned so we can keep the 1:1 mapping which the ioapic
 		 * is having.
 		 */
-		ret = irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
-		if (ret)
-			pr_err("Error mapping legacy IRQs: %d\n", ret);
+		irq_domain_associate_many(id, 0, 0, NR_IRQS_LEGACY);
 
 		if (num > NR_IRQS_LEGACY) {
 			ret = irq_create_strict_mappings(id, NR_IRQS_LEGACY,
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index ba2c708adcff..c983ed18c332 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h
@@ -73,57 +73,48 @@ struct irq_domain_chip_generic;
 /**
  * struct irq_domain - Hardware interrupt number translation object
  * @link: Element in global irq_domain list.
- * @revmap_type: Method used for reverse mapping hwirq numbers to linux irq. This
- *               will be one of the IRQ_DOMAIN_MAP_* values.
- * @revmap_data: Revmap method specific data.
+ * @name: Name of interrupt domain
  * @ops: pointer to irq_domain methods
  * @host_data: private data pointer for use by owner.  Not touched by irq_domain
  *             core code.
- * @irq_base: Start of irq_desc range assigned to the irq_domain.  The creator
- *            of the irq_domain is responsible for allocating the array of
- *            irq_desc structures.
- * @nr_irq: Number of irqs managed by the irq domain
- * @hwirq_base: Starting number for hwirqs managed by the irq domain
- * @of_node: (optional) Pointer to device tree nodes associated with the
- *           irq_domain.  Used when decoding device tree interrupt specifiers.
+ *
+ * Optional elements
+ * @of_node: Pointer to device tree nodes associated with the irq_domain. Used
+ *           when decoding device tree interrupt specifiers.
+ * @gc: Pointer to a list of generic chips. There is a helper function for
+ *      setting up one or more generic chips for interrupt controllers
+ *      drivers using the generic chip library which uses this pointer.
+ *
+ * Revmap data, used internally by irq_domain
+ * @revmap_direct_max_irq: The largest hwirq that can be set for controllers that
+ *                         support direct mapping
+ * @revmap_size: Size of the linear map table @linear_revmap[]
+ * @revmap_tree: Radix map tree for hwirqs that don't fit in the linear map
+ * @linear_revmap: Linear table of hwirq->virq reverse mappings
  */
 struct irq_domain {
 	struct list_head link;
-
-	/* type of reverse mapping_technique */
-	unsigned int revmap_type;
-	union {
-		struct {
-			unsigned int size;
-			unsigned int first_irq;
-			irq_hw_number_t first_hwirq;
-		} legacy;
-		struct {
-			unsigned int size;
-			unsigned int *revmap;
-		} linear;
-		struct {
-			unsigned int max_irq;
-		} nomap;
-		struct radix_tree_root tree;
-	} revmap_data;
+	const char *name;
 	const struct irq_domain_ops *ops;
 	void *host_data;
-	irq_hw_number_t inval_irq;
 
-	/* Optional device node pointer */
+	/* Optional data */
 	struct device_node *of_node;
-	/* Optional pointer to generic interrupt chips */
 	struct irq_domain_chip_generic *gc;
-};
 
-#define IRQ_DOMAIN_MAP_LEGACY 0 /* driver allocated fixed range of irqs.
-				 * ie. 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 */
+	/* reverse map data. The linear map gets appended to the irq_domain */
+	irq_hw_number_t hwirq_max;
+	unsigned int revmap_direct_max_irq;
+	unsigned int revmap_size;
+	struct radix_tree_root revmap_tree;
+	unsigned int linear_revmap[];
+};
 
 #ifdef CONFIG_IRQ_DOMAIN
+struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
+				    irq_hw_number_t hwirq_max, int direct_max,
+				    const struct irq_domain_ops *ops,
+				    void *host_data);
 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
 					 unsigned int size,
 					 unsigned int first_irq,
@@ -135,21 +126,30 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
 					 irq_hw_number_t first_hwirq,
 					 const struct irq_domain_ops *ops,
 					 void *host_data);
-struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
+extern struct irq_domain *irq_find_host(struct device_node *node);
+extern void irq_set_default_host(struct irq_domain *host);
+
+/**
+ * irq_domain_add_linear() - Allocate and register a linear 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
+ */
+static inline struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
 					 unsigned int size,
 					 const struct irq_domain_ops *ops,
-					 void *host_data);
-struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
+					 void *host_data)
+{
+	return __irq_domain_add(of_node, size, size, 0, ops, host_data);
+}
+static inline struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
 					 unsigned int max_irq,
 					 const struct irq_domain_ops *ops,
-					 void *host_data);
-struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
-					 const struct irq_domain_ops *ops,
-					 void *host_data);
-
-extern struct irq_domain *irq_find_host(struct device_node *node);
-extern void irq_set_default_host(struct irq_domain *host);
-
+					 void *host_data)
+{
+	return __irq_domain_add(of_node, 0, max_irq, max_irq, ops, host_data);
+}
 static inline struct irq_domain *irq_domain_add_legacy_isa(
 				struct device_node *of_node,
 				const struct irq_domain_ops *ops,
@@ -158,21 +158,40 @@ 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);
 }
+static inline struct irq_domain *irq_domain_add_tree(struct device_node *of_node,
+					 const struct irq_domain_ops *ops,
+					 void *host_data)
+{
+	return __irq_domain_add(of_node, 0, ~0, 0, ops, host_data);
+}
 
 extern void irq_domain_remove(struct irq_domain *host);
 
-extern int irq_domain_associate_many(struct irq_domain *domain,
-				     unsigned int irq_base,
-				     irq_hw_number_t hwirq_base, int count);
-static inline int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
-					irq_hw_number_t hwirq)
-{
-	return irq_domain_associate_many(domain, irq, hwirq, 1);
-}
+extern int irq_domain_associate(struct irq_domain *domain, unsigned int irq,
+					irq_hw_number_t hwirq);
+extern void irq_domain_associate_many(struct irq_domain *domain,
+				      unsigned int irq_base,
+				      irq_hw_number_t hwirq_base, int count);
 
 extern unsigned int irq_create_mapping(struct irq_domain *host,
 				       irq_hw_number_t hwirq);
 extern void irq_dispose_mapping(unsigned int virq);
+
+/**
+ * irq_linear_revmap() - Find a linux irq from a hw irq number.
+ * @domain: domain owning this hardware interrupt
+ * @hwirq: hardware irq number in that domain space
+ *
+ * This is a fast path alternative to irq_find_mapping() that can be
+ * called directly by irq controller code to save a handful of
+ * instructions. It is always safe to call, but won't find irqs mapped
+ * using the radix tree.
+ */
+static inline unsigned int irq_linear_revmap(struct irq_domain *domain,
+					     irq_hw_number_t hwirq)
+{
+	return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0;
+}
 extern unsigned int irq_find_mapping(struct irq_domain *host,
 				     irq_hw_number_t hwirq);
 extern unsigned int irq_create_direct_mapping(struct irq_domain *host);
@@ -186,9 +205,6 @@ static inline int irq_create_identity_mapping(struct irq_domain *host,
 	return irq_create_strict_mappings(host, hwirq, hwirq, 1);
 }
 
-extern unsigned int irq_linear_revmap(struct irq_domain *host,
-				      irq_hw_number_t hwirq);
-
 extern const struct irq_domain_ops irq_domain_simple_ops;
 
 /* stock xlate functions */
@@ -202,14 +218,6 @@ int irq_domain_xlate_onetwocell(struct irq_domain *d, struct device_node *ctrlr,
 			const u32 *intspec, unsigned int intsize,
 			irq_hw_number_t *out_hwirq, unsigned int *out_type);
 
-#if defined(CONFIG_OF_IRQ)
-extern void irq_domain_generate_simple(const struct of_device_id *match,
-					u64 phys_base, unsigned int irq_start);
-#else /* CONFIG_OF_IRQ */
-static inline void irq_domain_generate_simple(const struct of_device_id *match,
-					u64 phys_base, unsigned int irq_start) { }
-#endif /* !CONFIG_OF_IRQ */
-
 #else /* CONFIG_IRQ_DOMAIN */
 static inline void irq_dispose_mapping(unsigned int virq) { }
 #endif /* !CONFIG_IRQ_DOMAIN */
diff --git a/kernel/irq/generic-chip.c b/kernel/irq/generic-chip.c
index e3544c19bdd2..10e663ab1f4a 100644
--- a/kernel/irq/generic-chip.c
+++ b/kernel/irq/generic-chip.c
@@ -275,10 +275,7 @@ int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
 	if (d->gc)
 		return -EBUSY;
 
-	if (d->revmap_type != IRQ_DOMAIN_MAP_LINEAR)
-		return -EINVAL;
-
-	numchips = d->revmap_data.linear.size / irqs_per_chip;
+	numchips = d->revmap_size / irqs_per_chip;
 	if (!numchips)
 		return -EINVAL;
 
@@ -310,6 +307,7 @@ int irq_alloc_domain_generic_chips(struct irq_domain *d, int irqs_per_chip,
 		/* Calc pointer to the next generic chip */
 		tmp += sizeof(*gc) + num_ct * sizeof(struct irq_chip_type);
 	}
+	d->name = name;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(irq_alloc_domain_generic_chips);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 1ed8dff17eb9..2d7cd3428365 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -23,9 +23,11 @@ static DEFINE_MUTEX(revmap_trees_mutex);
 static struct irq_domain *irq_default_domain;
 
 /**
- * irq_domain_alloc() - Allocate a new irq_domain data structure
+ * __irq_domain_add() - 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
+ * @size: Size of linear map; 0 for radix mapping only
+ * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
+ *              direct mapping
  * @ops: map/unmap domain callbacks
  * @host_data: Controller private data pointer
  *
@@ -33,41 +35,35 @@ static struct irq_domain *irq_default_domain;
  * register allocated irq_domain with irq_domain_register().  Returns pointer
  * to IRQ domain, or NULL on failure.
  */
-static struct irq_domain *irq_domain_alloc(struct device_node *of_node,
-					   unsigned int revmap_type,
-					   const struct irq_domain_ops *ops,
-					   void *host_data)
+struct irq_domain *__irq_domain_add(struct device_node *of_node, int size,
+				    irq_hw_number_t hwirq_max, int direct_max,
+				    const struct irq_domain_ops *ops,
+				    void *host_data)
 {
 	struct irq_domain *domain;
 
-	domain = kzalloc_node(sizeof(*domain), GFP_KERNEL,
-			      of_node_to_nid(of_node));
+	domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
+			      GFP_KERNEL, of_node_to_nid(of_node));
 	if (WARN_ON(!domain))
 		return NULL;
 
 	/* Fill structure */
-	domain->revmap_type = revmap_type;
+	INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
 	domain->ops = ops;
 	domain->host_data = host_data;
 	domain->of_node = of_node_get(of_node);
+	domain->hwirq_max = hwirq_max;
+	domain->revmap_size = size;
+	domain->revmap_direct_max_irq = direct_max;
 
-	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("Allocated domain of type %d @0x%p\n",
-		 domain->revmap_type, domain);
+
+	pr_debug("Added domain %s\n", domain->name);
+	return domain;
 }
+EXPORT_SYMBOL_GPL(__irq_domain_add);
 
 /**
  * irq_domain_remove() - Remove an irq domain.
@@ -81,29 +77,12 @@ 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;
-	}
+	/*
+	 * 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_tree.height);
 
 	list_del(&domain->link);
 
@@ -115,44 +94,30 @@ void irq_domain_remove(struct irq_domain *domain)
 
 	mutex_unlock(&irq_domain_mutex);
 
-	pr_debug("Removed domain of type %d @0x%p\n",
-		 domain->revmap_type, domain);
+	pr_debug("Removed domain %s\n", domain->name);
 
-	irq_domain_free(domain);
+	of_node_put(domain->of_node);
+	kfree(domain);
 }
 EXPORT_SYMBOL_GPL(irq_domain_remove);
 
-static unsigned int irq_domain_legacy_revmap(struct irq_domain *domain,
-					     irq_hw_number_t hwirq)
-{
-	irq_hw_number_t first_hwirq = domain->revmap_data.legacy.first_hwirq;
-	int size = domain->revmap_data.legacy.size;
-
-	if (WARN_ON(hwirq < first_hwirq || hwirq >= first_hwirq + size))
-		return 0;
-	return hwirq - first_hwirq + domain->revmap_data.legacy.first_irq;
-}
-
 /**
- * irq_domain_add_simple() - Allocate and register a simple irq_domain.
+ * irq_domain_add_simple() - Register an irq_domain and optionally map a range of irqs
  * @of_node: pointer to interrupt controller's device tree node.
  * @size: total number of irqs in mapping
  * @first_irq: first number of irq block assigned to the domain,
- *	pass zero to assign irqs on-the-fly. This will result in a
- *	linear IRQ domain so it is important to use irq_create_mapping()
- *	for each used IRQ, especially when SPARSE_IRQ is enabled.
+ *	pass zero to assign irqs on-the-fly. If first_irq is non-zero, then
+ *	pre-map all of the irqs in the domain to virqs starting at first_irq.
  * @ops: map/unmap domain callbacks
  * @host_data: Controller private data pointer
  *
- * Allocates a legacy irq_domain if irq_base is positive or a linear
- * domain otherwise. For the legacy domain, IRQ descriptors will also
- * be allocated.
+ * Allocates an irq_domain, and optionally if first_irq is positive then also
+ * allocate irq_descs and map all of the hwirqs to virqs starting at first_irq.
  *
  * This is intended to implement the expected behaviour for most
- * interrupt controllers which is that a linear mapping should
- * normally be used unless the system requires a legacy mapping in
- * order to support supplying interrupt numbers during non-DT
- * registration of devices.
+ * interrupt controllers. If device tree is used, then first_irq will be 0 and
+ * irqs get mapped dynamically on the fly. However, if the controller requires
+ * static virq assignments (non-DT boot) then it will set that up correctly.
  */
 struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
 					 unsigned int size,
@@ -160,33 +125,25 @@ struct irq_domain *irq_domain_add_simple(struct device_node *of_node,
 					 const struct irq_domain_ops *ops,
 					 void *host_data)
 {
-	if (first_irq > 0) {
-		int irq_base;
+	struct irq_domain *domain;
+
+	domain = __irq_domain_add(of_node, size, size, 0, ops, host_data);
+	if (!domain)
+		return NULL;
 
+	if (first_irq > 0) {
 		if (IS_ENABLED(CONFIG_SPARSE_IRQ)) {
-			/*
-			 * Set the descriptor allocator to search for a
-			 * 1-to-1 mapping, such as irq_alloc_desc_at().
-			 * Use of_node_to_nid() which is defined to
-			 * numa_node_id() on platforms that have no custom
-			 * implementation.
-			 */
-			irq_base = irq_alloc_descs(first_irq, first_irq, size,
-						   of_node_to_nid(of_node));
-			if (irq_base < 0) {
+			/* attempt to allocated irq_descs */
+			int rc = irq_alloc_descs(first_irq, first_irq, size,
+						 of_node_to_nid(of_node));
+			if (rc < 0)
 				pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
 					first_irq);
-				irq_base = first_irq;
-			}
-		} else
-			irq_base = first_irq;
-
-		return irq_domain_add_legacy(of_node, size, irq_base, 0,
-					     ops, host_data);
+		}
+		irq_domain_associate_many(domain, first_irq, 0, size);
 	}
 
-	/* A linear domain is the default */
-	return irq_domain_add_linear(of_node, size, ops, host_data);
+	return domain;
 }
 EXPORT_SYMBOL_GPL(irq_domain_add_simple);
 
@@ -213,131 +170,19 @@ struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
 					 void *host_data)
 {
 	struct irq_domain *domain;
-	unsigned int i;
 
-	domain = irq_domain_alloc(of_node, IRQ_DOMAIN_MAP_LEGACY, ops, host_data);
+	domain = __irq_domain_add(of_node, first_hwirq + size,
+				  first_hwirq + size, 0, ops, host_data);
 	if (!domain)
 		return NULL;
 
-	domain->revmap_data.legacy.first_irq = first_irq;
-	domain->revmap_data.legacy.first_hwirq = first_hwirq;
-	domain->revmap_data.legacy.size = size;
+	irq_domain_associate_many(domain, first_irq, first_hwirq, size);
 
-	mutex_lock(&irq_domain_mutex);
-	/* Verify that all the irqs are available */
-	for (i = 0; i < size; i++) {
-		int irq = first_irq + i;
-		struct irq_data *irq_data = irq_get_irq_data(irq);
-
-		if (WARN_ON(!irq_data || irq_data->domain)) {
-			mutex_unlock(&irq_domain_mutex);
-			irq_domain_free(domain);
-			return NULL;
-		}
-	}
-
-	/* Claim all of the irqs before registering a legacy domain */
-	for (i = 0; i < size; i++) {
-		struct irq_data *irq_data = irq_get_irq_data(first_irq + i);
-		irq_data->hwirq = first_hwirq + i;
-		irq_data->domain = domain;
-	}
-	mutex_unlock(&irq_domain_mutex);
-
-	for (i = 0; i < size; i++) {
-		int irq = first_irq + i;
-		int hwirq = first_hwirq + i;
-
-		/* IRQ0 gets ignored */
-		if (!irq)
-			continue;
-
-		/* Legacy flags are left to default at this point,
-		 * one can then use irq_create_mapping() to
-		 * explicitly change them
-		 */
-		if (ops->map)
-			ops->map(domain, irq, hwirq);
-
-		/* Clear norequest flags */
-		irq_clear_status_flags(irq, IRQ_NOREQUEST);
-	}
-
-	irq_domain_add(domain);
 	return domain;
 }
 EXPORT_SYMBOL_GPL(irq_domain_add_legacy);
 
 /**
- * irq_domain_add_linear() - Allocate and register a linear 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
- */
-struct irq_domain *irq_domain_add_linear(struct device_node *of_node,
-					 unsigned int size,
-					 const struct irq_domain_ops *ops,
-					 void *host_data)
-{
-	struct irq_domain *domain;
-	unsigned int *revmap;
-
-	revmap = kzalloc_node(sizeof(*revmap) * size, GFP_KERNEL,
-			      of_node_to_nid(of_node));
-	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;
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_linear);
-
-struct irq_domain *irq_domain_add_nomap(struct device_node *of_node,
-					 unsigned int max_irq,
-					 const 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) {
-		domain->revmap_data.nomap.max_irq = max_irq ? max_irq : ~0;
-		irq_domain_add(domain);
-	}
-	return domain;
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_nomap);
-
-/**
- * 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,
-					 const 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;
-}
-EXPORT_SYMBOL_GPL(irq_domain_add_tree);
-
-/**
  * irq_find_host() - Locates a domain for a given device node
  * @node: device-tree node of the interrupt controller
  */
@@ -385,125 +230,108 @@ void irq_set_default_host(struct irq_domain *domain)
 }
 EXPORT_SYMBOL_GPL(irq_set_default_host);
 
-static void irq_domain_disassociate_many(struct irq_domain *domain,
-					 unsigned int irq_base, int count)
+static void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
 {
-	/*
-	 * disassociate in reverse order;
-	 * not strictly necessary, but nice for unwinding
-	 */
-	while (count--) {
-		int irq = irq_base + count;
-		struct irq_data *irq_data = irq_get_irq_data(irq);
-		irq_hw_number_t hwirq;
+	struct irq_data *irq_data = irq_get_irq_data(irq);
+	irq_hw_number_t hwirq;
 
-		if (WARN_ON(!irq_data || irq_data->domain != domain))
-			continue;
+	if (WARN(!irq_data || irq_data->domain != domain,
+		 "virq%i doesn't exist; cannot disassociate\n", irq))
+		return;
 
-		hwirq = irq_data->hwirq;
-		irq_set_status_flags(irq, IRQ_NOREQUEST);
+	hwirq = irq_data->hwirq;
+	irq_set_status_flags(irq, IRQ_NOREQUEST);
 
-		/* remove chip and handler */
-		irq_set_chip_and_handler(irq, NULL, NULL);
+	/* remove chip and handler */
+	irq_set_chip_and_handler(irq, NULL, NULL);
 
-		/* Make sure it's completed */
-		synchronize_irq(irq);
+	/* Make sure it's completed */
+	synchronize_irq(irq);
 
-		/* Tell the PIC about it */
-		if (domain->ops->unmap)
-			domain->ops->unmap(domain, irq);
-		smp_mb();
+	/* Tell the PIC about it */
+	if (domain->ops->unmap)
+		domain->ops->unmap(domain, irq);
+	smp_mb();
 
-		irq_data->domain = NULL;
-		irq_data->hwirq = 0;
+	irq_data->domain = NULL;
+	irq_data->hwirq = 0;
 
-		/* Clear reverse map */
-		switch(domain->revmap_type) {
-		case IRQ_DOMAIN_MAP_LINEAR:
-			if (hwirq < domain->revmap_data.linear.size)
-				domain->revmap_data.linear.revmap[hwirq] = 0;
-			break;
-		case IRQ_DOMAIN_MAP_TREE:
-			mutex_lock(&revmap_trees_mutex);
-			radix_tree_delete(&domain->revmap_data.tree, hwirq);
-			mutex_unlock(&revmap_trees_mutex);
-			break;
-		}
+	/* Clear reverse map for this hwirq */
+	if (hwirq < domain->revmap_size) {
+		domain->linear_revmap[hwirq] = 0;
+	} else {
+		mutex_lock(&revmap_trees_mutex);
+		radix_tree_delete(&domain->revmap_tree, hwirq);
+		mutex_unlock(&revmap_trees_mutex);
 	}
 }
 
-int irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
-			      irq_hw_number_t hwirq_base, int count)
+int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
+			 irq_hw_number_t hwirq)
 {
-	unsigned int virq = irq_base;
-	irq_hw_number_t hwirq = hwirq_base;
-	int i, ret;
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	int ret;
 
-	pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
-		of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
+	if (WARN(hwirq >= domain->hwirq_max,
+		 "error: hwirq 0x%x is too large for %s\n", (int)hwirq, domain->name))
+		return -EINVAL;
+	if (WARN(!irq_data, "error: virq%i is not allocated", virq))
+		return -EINVAL;
+	if (WARN(irq_data->domain, "error: virq%i is already associated", virq))
+		return -EINVAL;
 
-	for (i = 0; i < count; i++) {
-		struct irq_data *irq_data = irq_get_irq_data(virq + i);
-
-		if (WARN(!irq_data, "error: irq_desc not allocated; "
-			 "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
-			return -EINVAL;
-		if (WARN(irq_data->domain, "error: irq_desc already associated; "
-			 "irq=%i hwirq=0x%x\n", virq + i, (int)hwirq + i))
-			return -EINVAL;
-	};
-
-	for (i = 0; i < count; i++, virq++, hwirq++) {
-		struct irq_data *irq_data = irq_get_irq_data(virq);
-
-		irq_data->hwirq = hwirq;
-		irq_data->domain = domain;
-		if (domain->ops->map) {
-			ret = domain->ops->map(domain, virq, hwirq);
-			if (ret != 0) {
-				/*
-				 * If map() returns -EPERM, this interrupt is protected
-				 * by the firmware or some other service and shall not
-				 * be mapped.
-				 *
-				 * Since on some platforms we blindly try to map everything
-				 * we end up with a log full of backtraces.
-				 *
-				 * So instead, we silently fail on -EPERM, it is the
-				 * responsibility of the PIC driver to display a relevant
-				 * message if needed.
-				 */
-				if (ret != -EPERM) {
-					pr_err("irq-%i==>hwirq-0x%lx mapping failed: %d\n",
-					       virq, hwirq, ret);
-					WARN_ON(1);
-				}
-				irq_data->domain = NULL;
-				irq_data->hwirq = 0;
-				goto err_unmap;
+	mutex_lock(&irq_domain_mutex);
+	irq_data->hwirq = hwirq;
+	irq_data->domain = domain;
+	if (domain->ops->map) {
+		ret = domain->ops->map(domain, virq, hwirq);
+		if (ret != 0) {
+			/*
+			 * If map() returns -EPERM, this interrupt is protected
+			 * by the firmware or some other service and shall not
+			 * be mapped. Don't bother telling the user about it.
+			 */
+			if (ret != -EPERM) {
+				pr_info("%s didn't like hwirq-0x%lx to VIRQ%i mapping (rc=%d)\n",
+				       domain->name, hwirq, virq, ret);
 			}
+			irq_data->domain = NULL;
+			irq_data->hwirq = 0;
+			mutex_unlock(&irq_domain_mutex);
+			return ret;
 		}
 
-		switch (domain->revmap_type) {
-		case IRQ_DOMAIN_MAP_LINEAR:
-			if (hwirq < domain->revmap_data.linear.size)
-				domain->revmap_data.linear.revmap[hwirq] = virq;
-			break;
-		case IRQ_DOMAIN_MAP_TREE:
-			mutex_lock(&revmap_trees_mutex);
-			radix_tree_insert(&domain->revmap_data.tree, hwirq, irq_data);
-			mutex_unlock(&revmap_trees_mutex);
-			break;
-		}
+		/* If not already assigned, give the domain the chip's name */
+		if (!domain->name && irq_data->chip)
+			domain->name = irq_data->chip->name;
+	}
 
-		irq_clear_status_flags(virq, IRQ_NOREQUEST);
+	if (hwirq < domain->revmap_size) {
+		domain->linear_revmap[hwirq] = virq;
+	} else {
+		mutex_lock(&revmap_trees_mutex);
+		radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
+		mutex_unlock(&revmap_trees_mutex);
 	}
+	mutex_unlock(&irq_domain_mutex);
+
+	irq_clear_status_flags(virq, IRQ_NOREQUEST);
 
 	return 0;
+}
+EXPORT_SYMBOL_GPL(irq_domain_associate);
 
- err_unmap:
-	irq_domain_disassociate_many(domain, irq_base, i);
-	return -EINVAL;
+void irq_domain_associate_many(struct irq_domain *domain, unsigned int irq_base,
+			       irq_hw_number_t hwirq_base, int count)
+{
+	int i;
+
+	pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
+		of_node_full_name(domain->of_node), irq_base, (int)hwirq_base, count);
+
+	for (i = 0; i < count; i++) {
+		irq_domain_associate(domain, irq_base + i, hwirq_base + i);
+	}
 }
 EXPORT_SYMBOL_GPL(irq_domain_associate_many);
 
@@ -513,7 +341,9 @@ EXPORT_SYMBOL_GPL(irq_domain_associate_many);
  *
  * This routine is used for irq controllers which can choose the hardware
  * interrupt numbers they generate. In such a case it's simplest to use
- * the linux irq as the hardware interrupt number.
+ * the linux irq as the hardware interrupt number. It still uses the linear
+ * or radix tree to store the mapping, but the irq controller can optimize
+ * the revmap path by using the hwirq directly.
  */
 unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 {
@@ -522,17 +352,14 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain)
 	if (domain == NULL)
 		domain = irq_default_domain;
 
-	if (WARN_ON(!domain || domain->revmap_type != IRQ_DOMAIN_MAP_NOMAP))
-		return 0;
-
 	virq = irq_alloc_desc_from(1, of_node_to_nid(domain->of_node));
 	if (!virq) {
 		pr_debug("create_direct virq allocation failed\n");
 		return 0;
 	}
-	if (virq >= domain->revmap_data.nomap.max_irq) {
+	if (virq >= domain->revmap_direct_max_irq) {
 		pr_err("ERROR: no free irqs available below %i maximum\n",
-			domain->revmap_data.nomap.max_irq);
+			domain->revmap_direct_max_irq);
 		irq_free_desc(virq);
 		return 0;
 	}
@@ -569,9 +396,7 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
 	if (domain == NULL)
 		domain = irq_default_domain;
 	if (domain == NULL) {
-		pr_warning("irq_create_mapping called for"
-			   " NULL domain, hwirq=%lx\n", hwirq);
-		WARN_ON(1);
+		WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
 		return 0;
 	}
 	pr_debug("-> using domain @%p\n", domain);
@@ -583,10 +408,6 @@ unsigned int irq_create_mapping(struct irq_domain *domain,
 		return virq;
 	}
 
-	/* Get a virtual interrupt number */
-	if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
-		return irq_domain_legacy_revmap(domain, hwirq);
-
 	/* Allocate a virtual interrupt number */
 	hint = hwirq % nr_irqs;
 	if (hint == 0)
@@ -639,12 +460,7 @@ int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
 	if (unlikely(ret < 0))
 		return ret;
 
-	ret = irq_domain_associate_many(domain, irq_base, hwirq_base, count);
-	if (unlikely(ret < 0)) {
-		irq_free_descs(irq_base, count);
-		return ret;
-	}
-
+	irq_domain_associate_many(domain, irq_base, hwirq_base, count);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(irq_create_strict_mappings);
@@ -671,8 +487,8 @@ unsigned int irq_create_of_mapping(struct device_node *controller,
 		if (intsize > 0)
 			return intspec[0];
 #endif
-		pr_warning("no irq domain found for %s !\n",
-			   of_node_full_name(controller));
+		pr_warn("no irq domain found for %s !\n",
+			of_node_full_name(controller));
 		return 0;
 	}
 
@@ -714,11 +530,7 @@ void irq_dispose_mapping(unsigned int virq)
 	if (WARN_ON(domain == NULL))
 		return;
 
-	/* Never unmap legacy interrupts */
-	if (domain->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
-		return;
-
-	irq_domain_disassociate_many(domain, virq, 1);
+	irq_domain_disassociate(domain, virq);
 	irq_free_desc(virq);
 }
 EXPORT_SYMBOL_GPL(irq_dispose_mapping);
@@ -739,63 +551,51 @@ unsigned int irq_find_mapping(struct irq_domain *domain,
 	if (domain == NULL)
 		return 0;
 
-	switch (domain->revmap_type) {
-	case IRQ_DOMAIN_MAP_LEGACY:
-		return irq_domain_legacy_revmap(domain, hwirq);
-	case IRQ_DOMAIN_MAP_LINEAR:
-		return irq_linear_revmap(domain, hwirq);
-	case IRQ_DOMAIN_MAP_TREE:
-		rcu_read_lock();
-		data = radix_tree_lookup(&domain->revmap_data.tree, hwirq);
-		rcu_read_unlock();
-		if (data)
-			return data->irq;
-		break;
-	case IRQ_DOMAIN_MAP_NOMAP:
+	if (hwirq < domain->revmap_direct_max_irq) {
 		data = irq_get_irq_data(hwirq);
 		if (data && (data->domain == domain) && (data->hwirq == hwirq))
 			return hwirq;
-		break;
 	}
 
-	return 0;
-}
-EXPORT_SYMBOL_GPL(irq_find_mapping);
+	/* Check if the hwirq is in the linear revmap. */
+	if (hwirq < domain->revmap_size)
+		return domain->linear_revmap[hwirq];
 
-/**
- * irq_linear_revmap() - Find a linux irq from a hw irq number.
- * @domain: domain owning this hardware interrupt
- * @hwirq: hardware irq number in that domain space
- *
- * This is a fast path that can be called directly by irq controller code to
- * save a handful of instructions.
- */
-unsigned int irq_linear_revmap(struct irq_domain *domain,
-			       irq_hw_number_t hwirq)
-{
-	BUG_ON(domain->revmap_type != IRQ_DOMAIN_MAP_LINEAR);
-
-	/* Check revmap bounds; complain if exceeded */
-	if (WARN_ON(hwirq >= domain->revmap_data.linear.size))
-		return 0;
-
-	return domain->revmap_data.linear.revmap[hwirq];
+	rcu_read_lock();
+	data = radix_tree_lookup(&domain->revmap_tree, hwirq);
+	rcu_read_unlock();
+	return data ? data->irq : 0;
 }
-EXPORT_SYMBOL_GPL(irq_linear_revmap);
+EXPORT_SYMBOL_GPL(irq_find_mapping);
 
 #ifdef CONFIG_IRQ_DOMAIN_DEBUG
 static int virq_debug_show(struct seq_file *m, void *private)
 {
 	unsigned long flags;
 	struct irq_desc *desc;
-	const char *p;
-	static const char none[] = "none";
-	void *data;
+	struct irq_domain *domain;
+	struct radix_tree_iter iter;
+	void *data, **slot;
 	int i;
 
-	seq_printf(m, "%-5s  %-7s  %-15s  %-*s  %s\n", "irq", "hwirq",
+	seq_printf(m, " %-16s  %-6s  %-10s  %-10s  %s\n",
+		   "name", "mapped", "linear-max", "direct-max", "devtree-node");
+	mutex_lock(&irq_domain_mutex);
+	list_for_each_entry(domain, &irq_domain_list, link) {
+		int count = 0;
+		radix_tree_for_each_slot(slot, &domain->revmap_tree, &iter, 0)
+			count++;
+		seq_printf(m, "%c%-16s  %6u  %10u  %10u  %s\n",
+			   domain == irq_default_domain ? '*' : ' ', domain->name,
+			   domain->revmap_size + count, domain->revmap_size,
+			   domain->revmap_direct_max_irq,
+			   domain->of_node ? of_node_full_name(domain->of_node) : "");
+	}
+	mutex_unlock(&irq_domain_mutex);
+
+	seq_printf(m, "%-5s  %-7s  %-15s  %-*s  %6s  %-14s  %s\n", "irq", "hwirq",
 		      "chip name", (int)(2 * sizeof(void *) + 2), "chip data",
-		      "domain name");
+		      "active", "type", "domain");
 
 	for (i = 1; i < nr_irqs; i++) {
 		desc = irq_to_desc(i);
@@ -803,28 +603,28 @@ static int virq_debug_show(struct seq_file *m, void *private)
 			continue;
 
 		raw_spin_lock_irqsave(&desc->lock, flags);
+		domain = desc->irq_data.domain;
 
-		if (desc->action && desc->action->handler) {
+		if (domain) {
 			struct irq_chip *chip;
+			int hwirq = desc->irq_data.hwirq;
+			bool direct;
 
 			seq_printf(m, "%5d  ", i);
-			seq_printf(m, "0x%05lx  ", desc->irq_data.hwirq);
+			seq_printf(m, "0x%05x  ", hwirq);
 
 			chip = irq_desc_get_chip(desc);
-			if (chip && chip->name)
-				p = chip->name;
-			else
-				p = none;
-			seq_printf(m, "%-15s  ", p);
+			seq_printf(m, "%-15s  ", (chip && chip->name) ? chip->name : "none");
 
 			data = irq_desc_get_chip_data(desc);
 			seq_printf(m, data ? "0x%p  " : "  %p  ", data);
 
-			if (desc->irq_data.domain)
-				p = of_node_full_name(desc->irq_data.domain->of_node);
-			else
-				p = none;
-			seq_printf(m, "%s\n", p);
+			seq_printf(m, "   %c    ", (desc->action && desc->action->handler) ? '*' : ' ');
+			direct = (i == hwirq) && (i < domain->revmap_direct_max_irq);
+			seq_printf(m, "%6s%-8s  ",
+				   (hwirq < domain->revmap_size) ? "LINEAR" : "RADIX",
+				   direct ? "(DIRECT)" : "");
+			seq_printf(m, "%s\n", desc->irq_data.domain->name);
 		}
 
 		raw_spin_unlock_irqrestore(&desc->lock, flags);
@@ -921,18 +721,3 @@ const struct irq_domain_ops irq_domain_simple_ops = {
 	.xlate = irq_domain_xlate_onetwocell,
 };
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
-
-#ifdef CONFIG_OF_IRQ
-void irq_domain_generate_simple(const struct of_device_id *match,
-				u64 phys_base, unsigned int irq_start)
-{
-	struct device_node *node;
-	pr_debug("looking for phys_base=%llx, irq_start=%i\n",
-		(unsigned long long) phys_base, (int) irq_start);
-	node = of_find_matching_node_by_address(NULL, match, phys_base);
-	if (node)
-		irq_domain_add_legacy(node, 32, irq_start, 0,
-				      &irq_domain_simple_ops, NULL);
-}
-EXPORT_SYMBOL_GPL(irq_domain_generate_simple);
-#endif
diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c
index 19ed5c425c3b..36f6ee181b0c 100644
--- a/kernel/irq/proc.c
+++ b/kernel/irq/proc.c
@@ -462,6 +462,8 @@ int show_interrupts(struct seq_file *p, void *v)
 	} else {
 		seq_printf(p, " %8s", "None");
 	}
+	if (desc->irq_data.domain)
+		seq_printf(p, " %*d", prec, (int) desc->irq_data.hwirq);
 #ifdef CONFIG_GENERIC_IRQ_SHOW_LEVEL
 	seq_printf(p, " %-8s", irqd_is_level_type(&desc->irq_data) ? "Level" : "Edge");
 #endif