Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull irq_domain support for all architectures from Grant Likely:
 "Generialize powerpc's irq_host as irq_domain

  This branch takes the PowerPC irq_host infrastructure (reverse mapping
  from Linux IRQ numbers to hardware irq numbering), generalizes it,
  renames it to irq_domain, and makes it available to all architectures.

  Originally the plan has been to create an all-new irq_domain
  implementation which addresses some of the powerpc shortcomings such
  as not handling 1:1 mappings well, but doing that proved to be far
  more difficult and invasive than generalizing the working code and
  refactoring it in-place.  So, this branch rips out the 'new'
  irq_domain and replaces it with the modified powerpc version (in a
  fully bisectable way of course).  It converts all users over to the
  new API and makes irq_domain selectable on any architecture.

  No architecture is forced to enable irq_domain, but the infrastructure
  is required for doing OpenFirmware style irq translations.  It will
  even work on SPARC even though SPARC has it's own mechanism for
  translating irqs at boot time.  MIPS, microblaze, embedded x86 and c6x
  are converted too.

  The resulting irq_domain code is probably still too verbose and can be
  optimized more, but that can be done incrementally and is a task for
  follow-on patches."

* tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6: (31 commits)
  dt: fix twl4030 for non-dt compile on x86
  mfd: twl-core: Add IRQ_DOMAIN dependency
  devicetree: Add empty of_platform_populate() for !CONFIG_OF_ADDRESS (sparc)
  irq_domain: Centralize definition of irq_dispose_mapping()
  irq_domain/mips: Allow irq_domain on MIPS
  irq_domain/x86: Convert x86 (embedded) to use common irq_domain
  ppc-6xx: fix build failure in flipper-pic.c and hlwd-pic.c
  irq_domain/microblaze: Convert microblaze to use irq_domains
  irq_domain/powerpc: Replace custom xlate functions with library functions
  irq_domain/powerpc: constify irq_domain_ops
  irq_domain/c6x: Use library of xlate functions
  irq_domain/c6x: constify irq_domain structures
  irq_domain/c6x: Convert c6x to use generic irq_domain support.
  irq_domain: constify irq_domain_ops
  irq_domain: Create common xlate functions that device drivers can use
  irq_domain: Remove irq_domain_add_simple()
  irq_domain: Remove 'new' irq_domain in favour of the ppc one
  mfd: twl-core.c: Fix the number of interrupts managed by twl4030
  of/address: add empty static inlines for !CONFIG_OF
  irq_domain: Add support for base irq and hwirq in legacy mappings
  ...

4 files changed, 22 insertions, 861 deletions

diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index 26e67f0f0051..3c64b2894c13 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -12,6 +12,7 @@ config TMS320C6X
 	select HAVE_GENERIC_HARDIRQS
 	select HAVE_MEMBLOCK
 	select HAVE_SPARSE_IRQ
+	select IRQ_DOMAIN
 	select OF
 	select OF_EARLY_FLATTREE
 
diff --git a/arch/c6x/include/asm/irq.h b/arch/c6x/include/asm/irq.h
index a6ae3c9d9c40..f13b78d5e1ca 100644
--- a/arch/c6x/include/asm/irq.h
+++ b/arch/c6x/include/asm/irq.h
@@ -13,6 +13,7 @@
 #ifndef _ASM_C6X_IRQ_H
 #define _ASM_C6X_IRQ_H
 
+#include <linux/irqdomain.h>
 #include <linux/threads.h>
 #include <linux/list.h>
 #include <linux/radix-tree.h>
@@ -41,253 +42,9 @@
 /* This number is used when no interrupt has been assigned */
 #define NO_IRQ		0
 
-/* This type is the placeholder for a hardware interrupt number. It has to
- * be big enough to enclose whatever representation is used by a given
- * platform.
- */
-typedef unsigned long irq_hw_number_t;
-
-/* Interrupt controller "host" data structure. This could be defined as a
- * irq domain controller. That is, it handles the mapping between hardware
- * and virtual interrupt numbers for a given interrupt domain. The host
- * structure is generally created by the PIC code for a given PIC instance
- * (though a host can cover more than one PIC if they have a flat number
- * model). It's the host callbacks that are responsible for setting the
- * irq_chip on a given irq_desc after it's been mapped.
- *
- * The host code and data structures are fairly agnostic to the fact that
- * we use an open firmware device-tree. We do have references to struct
- * device_node in two places: in irq_find_host() to find the host matching
- * a given interrupt controller node, and of course as an argument to its
- * counterpart host->ops->match() callback. However, those are treated as
- * generic pointers by the core and the fact that it's actually a device-node
- * pointer is purely a convention between callers and implementation. This
- * code could thus be used on other architectures by replacing those two
- * by some sort of arch-specific void * "token" used to identify interrupt
- * controllers.
- */
-struct irq_host;
-struct radix_tree_root;
-struct device_node;
-
-/* Functions below are provided by the host and called whenever a new mapping
- * is created or an old mapping is disposed. The host can then proceed to
- * whatever internal data structures management is required. It also needs
- * to setup the irq_desc when returning from map().
- */
-struct irq_host_ops {
-	/* Match an interrupt controller device node to a host, returns
-	 * 1 on a match
-	 */
-	int (*match)(struct irq_host *h, struct device_node *node);
-
-	/* Create or update a mapping between a virtual irq number and a hw
-	 * irq number. This is called only once for a given mapping.
-	 */
-	int (*map)(struct irq_host *h, unsigned int virq, irq_hw_number_t hw);
-
-	/* Dispose of such a mapping */
-	void (*unmap)(struct irq_host *h, unsigned int virq);
-
-	/* Translate device-tree interrupt specifier from raw format coming
-	 * from the firmware to a irq_hw_number_t (interrupt line number) and
-	 * type (sense) that can be passed to set_irq_type(). In the absence
-	 * of this callback, irq_create_of_mapping() and irq_of_parse_and_map()
-	 * will return the hw number in the first cell and IRQ_TYPE_NONE for
-	 * the type (which amount to keeping whatever default value the
-	 * interrupt controller has for that line)
-	 */
-	int (*xlate)(struct irq_host *h, struct device_node *ctrler,
-		     const u32 *intspec, unsigned int intsize,
-		     irq_hw_number_t *out_hwirq, unsigned int *out_type);
-};
-
-struct irq_host {
-	struct list_head	link;
-
-	/* type of reverse mapping technique */
-	unsigned int		revmap_type;
-#define IRQ_HOST_MAP_PRIORITY   0 /* core priority irqs, get irqs 1..15 */
-#define IRQ_HOST_MAP_NOMAP	1 /* no fast reverse mapping */
-#define IRQ_HOST_MAP_LINEAR	2 /* linear map of interrupts */
-#define IRQ_HOST_MAP_TREE	3 /* radix tree */
-	union {
-		struct {
-			unsigned int size;
-			unsigned int *revmap;
-		} linear;
-		struct radix_tree_root tree;
-	} revmap_data;
-	struct irq_host_ops	*ops;
-	void			*host_data;
-	irq_hw_number_t		inval_irq;
-
-	/* Optional device node pointer */
-	struct device_node	*of_node;
-};
-
 struct irq_data;
 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 extern irq_hw_number_t virq_to_hw(unsigned int virq);
-extern bool virq_is_host(unsigned int virq, struct irq_host *host);
-
-/**
- * irq_alloc_host - Allocate a new irq_host data structure
- * @of_node: optional device-tree node of the interrupt controller
- * @revmap_type: type of reverse mapping to use
- * @revmap_arg: for IRQ_HOST_MAP_LINEAR linear only: size of the map
- * @ops: map/unmap host callbacks
- * @inval_irq: provide a hw number in that host space that is always invalid
- *
- * Allocates and initialize and irq_host structure. Note that in the case of
- * IRQ_HOST_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_HOST_MAP_LINEAR, the map is allocated by
- * this call as well. For a IRQ_HOST_MAP_TREE, the radix tree will be allocated
- * later during boot automatically (the reverse mapping will use the slow path
- * until that happens).
- */
-extern struct irq_host *irq_alloc_host(struct device_node *of_node,
-				       unsigned int revmap_type,
-				       unsigned int revmap_arg,
-				       struct irq_host_ops *ops,
-				       irq_hw_number_t inval_irq);
-
-
-/**
- * irq_find_host - Locates a host for a given device node
- * @node: device-tree node of the interrupt controller
- */
-extern struct irq_host *irq_find_host(struct device_node *node);
-
-
-/**
- * irq_set_default_host - Set a "default" host
- * @host: default host pointer
- *
- * For convenience, it's possible to set a "default" host that will be used
- * whenever NULL is passed to irq_create_mapping(). It makes life easier for
- * platforms that want to manipulate a few hard coded interrupt numbers that
- * aren't properly represented in the device-tree.
- */
-extern void irq_set_default_host(struct irq_host *host);
-
-
-/**
- * irq_set_virq_count - Set the maximum number of virt irqs
- * @count: number of linux virtual irqs, capped with NR_IRQS
- *
- * This is mainly for use by platforms like iSeries who want to program
- * the virtual irq number in the controller to avoid the reverse mapping
- */
-extern void irq_set_virq_count(unsigned int count);
-
-
-/**
- * irq_create_mapping - Map a hardware interrupt into linux virq space
- * @host: host owning this hardware interrupt or NULL for default host
- * @hwirq: hardware irq number in that host space
- *
- * Only one mapping per hardware interrupt is permitted. Returns a linux
- * virq number.
- * If the sense/trigger is to be specified, set_irq_type() should be called
- * on the number returned from that call.
- */
-extern unsigned int irq_create_mapping(struct irq_host *host,
-				       irq_hw_number_t hwirq);
-
-
-/**
- * irq_dispose_mapping - Unmap an interrupt
- * @virq: linux virq number of the interrupt to unmap
- */
-extern void irq_dispose_mapping(unsigned int virq);
-
-/**
- * irq_find_mapping - Find a linux virq from an hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a slow path, for use by generic code. It's expected that an
- * irq controller implementation directly calls the appropriate low level
- * mapping function.
- */
-extern unsigned int irq_find_mapping(struct irq_host *host,
-				     irq_hw_number_t hwirq);
-
-/**
- * irq_create_direct_mapping - Allocate a virq for direct mapping
- * @host: host to allocate the virq for or NULL for default host
- *
- * 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 virq as the hardware interrupt number.
- */
-extern unsigned int irq_create_direct_mapping(struct irq_host *host);
-
-/**
- * irq_radix_revmap_insert - Insert a hw irq to linux virq number mapping.
- * @host: host owning this hardware interrupt
- * @virq: linux irq number
- * @hwirq: hardware irq number in that host space
- *
- * This is for use by irq controllers that use a radix tree reverse
- * mapping for fast lookup.
- */
-extern void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
-				    irq_hw_number_t hwirq);
-
-/**
- * irq_radix_revmap_lookup - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses radix tree
- * revmaps
- */
-extern unsigned int irq_radix_revmap_lookup(struct irq_host *host,
-					    irq_hw_number_t hwirq);
-
-/**
- * irq_linear_revmap - Find a linux virq from a hw irq number.
- * @host: host owning this hardware interrupt
- * @hwirq: hardware irq number in that host space
- *
- * This is a fast path, for use by irq controller code that uses linear
- * revmaps. It does fallback to the slow path if the revmap doesn't exist
- * yet and will create the revmap entry with appropriate locking
- */
-
-extern unsigned int irq_linear_revmap(struct irq_host *host,
-				      irq_hw_number_t hwirq);
-
-
-
-/**
- * irq_alloc_virt - Allocate virtual irq numbers
- * @host: host owning these new virtual irqs
- * @count: number of consecutive numbers to allocate
- * @hint: pass a hint number, the allocator will try to use a 1:1 mapping
- *
- * This is a low level function that is used internally by irq_create_mapping()
- * and that can be used by some irq controllers implementations for things
- * like allocating ranges of numbers for MSIs. The revmaps are left untouched.
- */
-extern unsigned int irq_alloc_virt(struct irq_host *host,
-				   unsigned int count,
-				   unsigned int hint);
-
-/**
- * irq_free_virt - Free virtual irq numbers
- * @virq: virtual irq number of the first interrupt to free
- * @count: number of interrupts to free
- *
- * This function is the opposite of irq_alloc_virt. It will not clear reverse
- * maps, this should be done previously by unmap'ing the interrupt. In fact,
- * all interrupts covered by the range being freed should have been unmapped
- * prior to calling this.
- */
-extern void irq_free_virt(unsigned int virq, unsigned int count);
 
 extern void __init init_pic_c64xplus(void);
 
diff --git a/arch/c6x/kernel/irq.c b/arch/c6x/kernel/irq.c
index 0929e4b2b244..d77bcfdf0d8e 100644
--- a/arch/c6x/kernel/irq.c
+++ b/arch/c6x/kernel/irq.c
@@ -73,10 +73,10 @@ asmlinkage void c6x_do_IRQ(unsigned int prio, struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }
 
-static struct irq_host *core_host;
+static struct irq_domain *core_domain;
 
-static int core_host_map(struct irq_host *h, unsigned int virq,
-			 irq_hw_number_t hw)
+static int core_domain_map(struct irq_domain *h, unsigned int virq,
+			   irq_hw_number_t hw)
 {
 	if (hw < 4 || hw >= NR_PRIORITY_IRQS)
 		return -EINVAL;
@@ -86,8 +86,9 @@ static int core_host_map(struct irq_host *h, unsigned int virq,
 	return 0;
 }
 
-static struct irq_host_ops core_host_ops = {
-	.map = core_host_map,
+static const struct irq_domain_ops core_domain_ops = {
+	.map = core_domain_map,
+	.xlate = irq_domain_xlate_onecell,
 };
 
 void __init init_IRQ(void)
@@ -100,10 +101,11 @@ void __init init_IRQ(void)
 	np = of_find_compatible_node(NULL, NULL, "ti,c64x+core-pic");
 	if (np != NULL) {
 		/* create the core host */
-		core_host = irq_alloc_host(np, IRQ_HOST_MAP_PRIORITY, 0,
-					   &core_host_ops, 0);
-		if (core_host)
-			irq_set_default_host(core_host);
+		core_domain = irq_domain_add_legacy(np, NR_PRIORITY_IRQS,
+						    0, 0, &core_domain_ops,
+						    NULL);
+		if (core_domain)
+			irq_set_default_host(core_domain);
 		of_node_put(np);
 	}
 
@@ -128,601 +130,15 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 	return 0;
 }
 
-/*
- * IRQ controller and virtual interrupts
- */
-
-/* The main irq map itself is an array of NR_IRQ entries containing the
- * associate host and irq number. An entry with a host of NULL is free.
- * An entry can be allocated if it's free, the allocator always then sets
- * hwirq first to the host's invalid irq number and then fills ops.
- */
-struct irq_map_entry {
-	irq_hw_number_t	hwirq;
-	struct irq_host	*host;
-};
-
-static LIST_HEAD(irq_hosts);
-static DEFINE_RAW_SPINLOCK(irq_big_lock);
-static DEFINE_MUTEX(revmap_trees_mutex);
-static struct irq_map_entry irq_map[NR_IRQS];
-static unsigned int irq_virq_count = NR_IRQS;
-static struct irq_host *irq_default_host;
-
 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 {
-	return irq_map[d->irq].hwirq;
+	return d->hwirq;
 }
 EXPORT_SYMBOL_GPL(irqd_to_hwirq);
 
 irq_hw_number_t virq_to_hw(unsigned int virq)
 {
-	return irq_map[virq].hwirq;
+	struct irq_data *irq_data = irq_get_irq_data(virq);
+	return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
 }
 EXPORT_SYMBOL_GPL(virq_to_hw);
-
-bool virq_is_host(unsigned int virq, struct irq_host *host)
-{
-	return irq_map[virq].host == host;
-}
-EXPORT_SYMBOL_GPL(virq_is_host);
-
-static int default_irq_host_match(struct irq_host *h, struct device_node *np)
-{
-	return h->of_node != NULL && h->of_node == np;
-}
-
-struct irq_host *irq_alloc_host(struct device_node *of_node,
-				unsigned int revmap_type,
-				unsigned int revmap_arg,
-				struct irq_host_ops *ops,
-				irq_hw_number_t inval_irq)
-{
-	struct irq_host *host;
-	unsigned int size = sizeof(struct irq_host);
-	unsigned int i;
-	unsigned int *rmap;
-	unsigned long flags;
-
-	/* Allocate structure and revmap table if using linear mapping */
-	if (revmap_type == IRQ_HOST_MAP_LINEAR)
-		size += revmap_arg * sizeof(unsigned int);
-	host = kzalloc(size, GFP_KERNEL);
-	if (host == NULL)
-		return NULL;
-
-	/* Fill structure */
-	host->revmap_type = revmap_type;
-	host->inval_irq = inval_irq;
-	host->ops = ops;
-	host->of_node = of_node_get(of_node);
-
-	if (host->ops->match == NULL)
-		host->ops->match = default_irq_host_match;
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-
-	/* Check for the priority controller. */
-	if (revmap_type == IRQ_HOST_MAP_PRIORITY) {
-		if (irq_map[0].host != NULL) {
-			raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-			of_node_put(host->of_node);
-			kfree(host);
-			return NULL;
-		}
-		irq_map[0].host = host;
-	}
-
-	list_add(&host->link, &irq_hosts);
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-
-	/* Additional setups per revmap type */
-	switch (revmap_type) {
-	case IRQ_HOST_MAP_PRIORITY:
-		/* 0 is always the invalid number for priority */
-		host->inval_irq = 0;
-		/* setup us as the host for all priority interrupts */
-		for (i = 1; i < NR_PRIORITY_IRQS; i++) {
-			irq_map[i].hwirq = i;
-			smp_wmb();
-			irq_map[i].host = host;
-			smp_wmb();
-
-			ops->map(host, i, i);
-		}
-		break;
-	case IRQ_HOST_MAP_LINEAR:
-		rmap = (unsigned int *)(host + 1);
-		for (i = 0; i < revmap_arg; i++)
-			rmap[i] = NO_IRQ;
-		host->revmap_data.linear.size = revmap_arg;
-		smp_wmb();
-		host->revmap_data.linear.revmap = rmap;
-		break;
-	case IRQ_HOST_MAP_TREE:
-		INIT_RADIX_TREE(&host->revmap_data.tree, GFP_KERNEL);
-		break;
-	default:
-		break;
-	}
-
-	pr_debug("irq: Allocated host of type %d @0x%p\n", revmap_type, host);
-
-	return host;
-}
-
-struct irq_host *irq_find_host(struct device_node *node)
-{
-	struct irq_host *h, *found = NULL;
-	unsigned long flags;
-
-	/* We might want to match the legacy controller last since
-	 * it might potentially be set to match all interrupts in
-	 * the absence of a device node. This isn't a problem so far
-	 * yet though...
-	 */
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-	list_for_each_entry(h, &irq_hosts, link)
-		if (h->ops->match(h, node)) {
-			found = h;
-			break;
-		}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-	return found;
-}
-EXPORT_SYMBOL_GPL(irq_find_host);
-
-void irq_set_default_host(struct irq_host *host)
-{
-	pr_debug("irq: Default host set to @0x%p\n", host);
-
-	irq_default_host = host;
-}
-
-void irq_set_virq_count(unsigned int count)
-{
-	pr_debug("irq: Trying to set virq count to %d\n", count);
-
-	BUG_ON(count < NR_PRIORITY_IRQS);
-	if (count < NR_IRQS)
-		irq_virq_count = count;
-}
-
-static int irq_setup_virq(struct irq_host *host, unsigned int virq,
-			    irq_hw_number_t hwirq)
-{
-	int res;
-
-	res = irq_alloc_desc_at(virq, 0);
-	if (res != virq) {
-		pr_debug("irq: -> allocating desc failed\n");
-		goto error;
-	}
-
-	/* map it */
-	smp_wmb();
-	irq_map[virq].hwirq = hwirq;
-	smp_mb();
-
-	if (host->ops->map(host, virq, hwirq)) {
-		pr_debug("irq: -> mapping failed, freeing\n");
-		goto errdesc;
-	}
-
-	irq_clear_status_flags(virq, IRQ_NOREQUEST);
-
-	return 0;
-
-errdesc:
-	irq_free_descs(virq, 1);
-error:
-	irq_free_virt(virq, 1);
-	return -1;
-}
-
-unsigned int irq_create_direct_mapping(struct irq_host *host)
-{
-	unsigned int virq;
-
-	if (host == NULL)
-		host = irq_default_host;
-
-	BUG_ON(host == NULL);
-	WARN_ON(host->revmap_type != IRQ_HOST_MAP_NOMAP);
-
-	virq = irq_alloc_virt(host, 1, 0);
-	if (virq == NO_IRQ) {
-		pr_debug("irq: create_direct virq allocation failed\n");
-		return NO_IRQ;
-	}
-
-	pr_debug("irq: create_direct obtained virq %d\n", virq);
-
-	if (irq_setup_virq(host, virq, virq))
-		return NO_IRQ;
-
-	return virq;
-}
-
-unsigned int irq_create_mapping(struct irq_host *host,
-				irq_hw_number_t hwirq)
-{
-	unsigned int virq, hint;
-
-	pr_debug("irq: irq_create_mapping(0x%p, 0x%lx)\n", host, hwirq);
-
-	/* Look for default host if nececssary */
-	if (host == NULL)
-		host = irq_default_host;
-	if (host == NULL) {
-		printk(KERN_WARNING "irq_create_mapping called for"
-		       " NULL host, hwirq=%lx\n", hwirq);
-		WARN_ON(1);
-		return NO_IRQ;
-	}
-	pr_debug("irq: -> using host @%p\n", host);
-
-	/* Check if mapping already exists */
-	virq = irq_find_mapping(host, hwirq);
-	if (virq != NO_IRQ) {
-		pr_debug("irq: -> existing mapping on virq %d\n", virq);
-		return virq;
-	}
-
-	/* Allocate a virtual interrupt number */
-	hint = hwirq % irq_virq_count;
-	virq = irq_alloc_virt(host, 1, hint);
-	if (virq == NO_IRQ) {
-		pr_debug("irq: -> virq allocation failed\n");
-		return NO_IRQ;
-	}
-
-	if (irq_setup_virq(host, virq, hwirq))
-		return NO_IRQ;
-
-	pr_debug("irq: irq %lu on host %s mapped to virtual irq %u\n",
-		hwirq, host->of_node ? host->of_node->full_name : "null", virq);
-
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_mapping);
-
-unsigned int irq_create_of_mapping(struct device_node *controller,
-				   const u32 *intspec, unsigned int intsize)
-{
-	struct irq_host *host;
-	irq_hw_number_t hwirq;
-	unsigned int type = IRQ_TYPE_NONE;
-	unsigned int virq;
-
-	if (controller == NULL)
-		host = irq_default_host;
-	else
-		host = irq_find_host(controller);
-	if (host == NULL) {
-		printk(KERN_WARNING "irq: no irq host found for %s !\n",
-		       controller->full_name);
-		return NO_IRQ;
-	}
-
-	/* If host has no translation, then we assume interrupt line */
-	if (host->ops->xlate == NULL)
-		hwirq = intspec[0];
-	else {
-		if (host->ops->xlate(host, controller, intspec, intsize,
-				     &hwirq, &type))
-			return NO_IRQ;
-	}
-
-	/* Create mapping */
-	virq = irq_create_mapping(host, hwirq);
-	if (virq == NO_IRQ)
-		return virq;
-
-	/* Set type if specified and different than the current one */
-	if (type != IRQ_TYPE_NONE &&
-	    type != (irqd_get_trigger_type(irq_get_irq_data(virq))))
-		irq_set_irq_type(virq, type);
-	return virq;
-}
-EXPORT_SYMBOL_GPL(irq_create_of_mapping);
-
-void irq_dispose_mapping(unsigned int virq)
-{
-	struct irq_host *host;
-	irq_hw_number_t hwirq;
-
-	if (virq == NO_IRQ)
-		return;
-
-	/* Never unmap priority interrupts */
-	if (virq < NR_PRIORITY_IRQS)
-		return;
-
-	host = irq_map[virq].host;
-	if (WARN_ON(host == NULL))
-		return;
-
-	irq_set_status_flags(virq, IRQ_NOREQUEST);
-
-	/* remove chip and handler */
-	irq_set_chip_and_handler(virq, NULL, NULL);
-
-	/* Make sure it's completed */
-	synchronize_irq(virq);
-
-	/* Tell the PIC about it */
-	if (host->ops->unmap)
-		host->ops->unmap(host, virq);
-	smp_mb();
-
-	/* Clear reverse map */
-	hwirq = irq_map[virq].hwirq;
-	switch (host->revmap_type) {
-	case IRQ_HOST_MAP_LINEAR:
-		if (hwirq < host->revmap_data.linear.size)
-			host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
-		break;
-	case IRQ_HOST_MAP_TREE:
-		mutex_lock(&revmap_trees_mutex);
-		radix_tree_delete(&host->revmap_data.tree, hwirq);
-		mutex_unlock(&revmap_trees_mutex);
-		break;
-	}
-
-	/* Destroy map */
-	smp_mb();
-	irq_map[virq].hwirq = host->inval_irq;
-
-	irq_free_descs(virq, 1);
-	/* Free it */
-	irq_free_virt(virq, 1);
-}
-EXPORT_SYMBOL_GPL(irq_dispose_mapping);
-
-unsigned int irq_find_mapping(struct irq_host *host,
-			      irq_hw_number_t hwirq)
-{
-	unsigned int i;
-	unsigned int hint = hwirq % irq_virq_count;
-
-	/* Look for default host if nececssary */
-	if (host == NULL)
-		host = irq_default_host;
-	if (host == NULL)
-		return NO_IRQ;
-
-	/* Slow path does a linear search of the map */
-	i = hint;
-	do  {
-		if (irq_map[i].host == host &&
-		    irq_map[i].hwirq == hwirq)
-			return i;
-		i++;
-		if (i >= irq_virq_count)
-			i = 4;
-	} while (i != hint);
-	return NO_IRQ;
-}
-EXPORT_SYMBOL_GPL(irq_find_mapping);
-
-unsigned int irq_radix_revmap_lookup(struct irq_host *host,
-				     irq_hw_number_t hwirq)
-{
-	struct irq_map_entry *ptr;
-	unsigned int virq;
-
-	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_TREE))
-		return irq_find_mapping(host, hwirq);
-
-	/*
-	 * The ptr returned references the static global irq_map.
-	 * but freeing an irq can delete nodes along the path to
-	 * do the lookup via call_rcu.
-	 */
-	rcu_read_lock();
-	ptr = radix_tree_lookup(&host->revmap_data.tree, hwirq);
-	rcu_read_unlock();
-
-	/*
-	 * If found in radix tree, then fine.
-	 * Else fallback to linear lookup - this should not happen in practice
-	 * as it means that we failed to insert the node in the radix tree.
-	 */
-	if (ptr)
-		virq = ptr - irq_map;
-	else
-		virq = irq_find_mapping(host, hwirq);
-
-	return virq;
-}
-
-void irq_radix_revmap_insert(struct irq_host *host, unsigned int virq,
-			     irq_hw_number_t hwirq)
-{
-	if (WARN_ON(host->revmap_type != IRQ_HOST_MAP_TREE))
-		return;
-
-	if (virq != NO_IRQ) {
-		mutex_lock(&revmap_trees_mutex);
-		radix_tree_insert(&host->revmap_data.tree, hwirq,
-				  &irq_map[virq]);
-		mutex_unlock(&revmap_trees_mutex);
-	}
-}
-
-unsigned int irq_linear_revmap(struct irq_host *host,
-			       irq_hw_number_t hwirq)
-{
-	unsigned int *revmap;
-
-	if (WARN_ON_ONCE(host->revmap_type != IRQ_HOST_MAP_LINEAR))
-		return irq_find_mapping(host, hwirq);
-
-	/* Check revmap bounds */
-	if (unlikely(hwirq >= host->revmap_data.linear.size))
-		return irq_find_mapping(host, hwirq);
-
-	/* Check if revmap was allocated */
-	revmap = host->revmap_data.linear.revmap;
-	if (unlikely(revmap == NULL))
-		return irq_find_mapping(host, hwirq);
-
-	/* Fill up revmap with slow path if no mapping found */
-	if (unlikely(revmap[hwirq] == NO_IRQ))
-		revmap[hwirq] = irq_find_mapping(host, hwirq);
-
-	return revmap[hwirq];
-}
-
-unsigned int irq_alloc_virt(struct irq_host *host,
-			    unsigned int count,
-			    unsigned int hint)
-{
-	unsigned long flags;
-	unsigned int i, j, found = NO_IRQ;
-
-	if (count == 0 || count > (irq_virq_count - NR_PRIORITY_IRQS))
-		return NO_IRQ;
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-
-	/* Use hint for 1 interrupt if any */
-	if (count == 1 && hint >= NR_PRIORITY_IRQS &&
-	    hint < irq_virq_count && irq_map[hint].host == NULL) {
-		found = hint;
-		goto hint_found;
-	}
-
-	/* Look for count consecutive numbers in the allocatable
-	 * (non-legacy) space
-	 */
-	for (i = NR_PRIORITY_IRQS, j = 0; i < irq_virq_count; i++) {
-		if (irq_map[i].host != NULL)
-			j = 0;
-		else
-			j++;
-
-		if (j == count) {
-			found = i - count + 1;
-			break;
-		}
-	}
-	if (found == NO_IRQ) {
-		raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-		return NO_IRQ;
-	}
- hint_found:
-	for (i = found; i < (found + count); i++) {
-		irq_map[i].hwirq = host->inval_irq;
-		smp_wmb();
-		irq_map[i].host = host;
-	}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-	return found;
-}
-
-void irq_free_virt(unsigned int virq, unsigned int count)
-{
-	unsigned long flags;
-	unsigned int i;
-
-	WARN_ON(virq < NR_PRIORITY_IRQS);
-	WARN_ON(count == 0 || (virq + count) > irq_virq_count);
-
-	if (virq < NR_PRIORITY_IRQS) {
-		if (virq + count < NR_PRIORITY_IRQS)
-			return;
-		count  -= NR_PRIORITY_IRQS - virq;
-		virq = NR_PRIORITY_IRQS;
-	}
-
-	if (count > irq_virq_count || virq > irq_virq_count - count) {
-		if (virq > irq_virq_count)
-			return;
-		count = irq_virq_count - virq;
-	}
-
-	raw_spin_lock_irqsave(&irq_big_lock, flags);
-	for (i = virq; i < (virq + count); i++) {
-		struct irq_host *host;
-
-		host = irq_map[i].host;
-		irq_map[i].hwirq = host->inval_irq;
-		smp_wmb();
-		irq_map[i].host = NULL;
-	}
-	raw_spin_unlock_irqrestore(&irq_big_lock, flags);
-}
-
-#ifdef CONFIG_VIRQ_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;
-	int i;
-
-	seq_printf(m, "%-5s  %-7s  %-15s  %-18s  %s\n", "virq", "hwirq",
-		      "chip name", "chip data", "host name");
-
-	for (i = 1; i < nr_irqs; i++) {
-		desc = irq_to_desc(i);
-		if (!desc)
-			continue;
-
-		raw_spin_lock_irqsave(&desc->lock, flags);
-
-		if (desc->action && desc->action->handler) {
-			struct irq_chip *chip;
-
-			seq_printf(m, "%5d  ", i);
-			seq_printf(m, "0x%05lx  ", irq_map[i].hwirq);
-
-			chip = irq_desc_get_chip(desc);
-			if (chip && chip->name)
-				p = chip->name;
-			else
-				p = none;
-			seq_printf(m, "%-15s  ", p);
-
-			data = irq_desc_get_chip_data(desc);
-			seq_printf(m, "0x%16p  ", data);
-
-			if (irq_map[i].host && irq_map[i].host->of_node)
-				p = irq_map[i].host->of_node->full_name;
-			else
-				p = none;
-			seq_printf(m, "%s\n", p);
-		}
-
-		raw_spin_unlock_irqrestore(&desc->lock, flags);
-	}
-
-	return 0;
-}
-
-static int virq_debug_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, virq_debug_show, inode->i_private);
-}
-
-static const struct file_operations virq_debug_fops = {
-	.open = virq_debug_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
-
-static int __init irq_debugfs_init(void)
-{
-	if (debugfs_create_file("virq_mapping", S_IRUGO, powerpc_debugfs_root,
-				 NULL, &virq_debug_fops) == NULL)
-		return -ENOMEM;
-
-	return 0;
-}
-device_initcall(irq_debugfs_init);
-#endif /* CONFIG_VIRQ_DEBUG */
diff --git a/arch/c6x/platforms/megamod-pic.c b/arch/c6x/platforms/megamod-pic.c
index 7c37a947fb1c..c1c4e2ae3f85 100644
--- a/arch/c6x/platforms/megamod-pic.c
+++ b/arch/c6x/platforms/megamod-pic.c
@@ -48,7 +48,7 @@ struct megamod_regs {
 };
 
 struct megamod_pic {
-	struct irq_host	*irqhost;
+	struct irq_domain *irqhost;
 	struct megamod_regs __iomem *regs;
 	raw_spinlock_t lock;
 
@@ -116,7 +116,7 @@ static void megamod_irq_cascade(unsigned int irq, struct irq_desc *desc)
 	}
 }
 
-static int megamod_map(struct irq_host *h, unsigned int virq,
+static int megamod_map(struct irq_domain *h, unsigned int virq,
 		       irq_hw_number_t hw)
 {
 	struct megamod_pic *pic = h->host_data;
@@ -136,21 +136,9 @@ static int megamod_map(struct irq_host *h, unsigned int virq,
 	return 0;
 }
 
-static int megamod_xlate(struct irq_host *h, struct device_node *ct,
-			 const u32 *intspec, unsigned int intsize,
-			 irq_hw_number_t *out_hwirq, unsigned int *out_type)
-
-{
-	/* megamod intspecs must have 1 cell */
-	BUG_ON(intsize != 1);
-	*out_hwirq = intspec[0];
-	*out_type = IRQ_TYPE_NONE;
-	return 0;
-}
-
-static struct irq_host_ops megamod_host_ops = {
+static const struct irq_domain_ops megamod_domain_ops = {
 	.map	= megamod_map,
-	.xlate	= megamod_xlate,
+	.xlate	= irq_domain_xlate_onecell,
 };
 
 static void __init set_megamod_mux(struct megamod_pic *pic, int src, int output)
@@ -223,9 +211,8 @@ static struct megamod_pic * __init init_megamod_pic(struct device_node *np)
 		return NULL;
 	}
 
-	pic->irqhost = irq_alloc_host(np, IRQ_HOST_MAP_LINEAR,
-				      NR_COMBINERS * 32, &megamod_host_ops,
-				      IRQ_UNMAPPED);
+	pic->irqhost = irq_domain_add_linear(np, NR_COMBINERS * 32,
+					     &megamod_domain_ops, pic);
 	if (!pic->irqhost) {
 		pr_err("%s: Could not alloc host.\n", np->full_name);
 		goto error_free;