irq_domain: Move irq_domain code from powerpc to kernel/irq
authorGrant Likely <grant.likely@secretlab.ca>
Thu, 16 Feb 2012 08:37:49 +0000 (01:37 -0700)
committerGrant Likely <grant.likely@secretlab.ca>
Thu, 16 Feb 2012 08:37:49 +0000 (01:37 -0700)
This patch only moves the code.  It doesn't make any changes, and the
code is still only compiled for powerpc.  Follow-on patches will generalize
the code for other architectures.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
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>
arch/powerpc/Kconfig
arch/powerpc/include/asm/irq.h
arch/powerpc/kernel/irq.c
include/linux/irqdomain.h
kernel/irq/irqdomain.c

index 1919634a9b32c261c6f989f7c87b7403a5c6c57e..303703d716feaf21308b53e5eb016ddd6ee74ecf 100644 (file)
@@ -135,6 +135,7 @@ config PPC
        select HAVE_GENERIC_HARDIRQS
        select HAVE_SPARSE_IRQ
        select IRQ_PER_CPU
+       select IRQ_DOMAIN
        select GENERIC_IRQ_SHOW
        select GENERIC_IRQ_SHOW_LEVEL
        select IRQ_FORCED_THREADING
index f80f262e05970a692fc458515422750a531c7620..728cc30d04ead6ac671f20b4b538d49a3e566878 100644 (file)
@@ -42,154 +42,10 @@ extern atomic_t ppc_n_lost_interrupts;
 /* Same thing, used by the generic IRQ code */
 #define NR_IRQS_LEGACY         NUM_ISA_INTERRUPTS
 
-/*
- * 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_data;
 extern irq_hw_number_t irqd_to_hwirq(struct irq_data *d);
 extern irq_hw_number_t virq_to_hw(unsigned int virq);
 
-/**
- * irq_alloc_host - 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 host callbacks
- * @inval_irq: provide a hw number in that host space that is always invalid
- *
- * 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).
- */
-extern 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);
-
-
-/**
- * irq_find_host - Locates a host for a given device node
- * @node: device-tree node of the interrupt controller
- */
-extern struct irq_domain *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_domain *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_domain *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_domain *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_domain *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_domain *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_domain *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_domain *host,
-                                     irq_hw_number_t hwirq);
-
-
 /**
  * irq_early_init - Init irq remapping subsystem
  */
index 269fbd5ac62f302b1be9248a169707e734b88778..e3673ff6b7a0f58f20880ab0700286b058ab4b72 100644 (file)
@@ -486,17 +486,6 @@ void do_softirq(void)
        local_irq_restore(flags);
 }
 
-
-/*
- * IRQ controller and virtual interrupts
- */
-
-static LIST_HEAD(irq_domain_list);
-static DEFINE_MUTEX(irq_domain_mutex);
-static DEFINE_MUTEX(revmap_trees_mutex);
-static unsigned int irq_virq_count = NR_IRQS;
-static struct irq_domain *irq_default_host;
-
 irq_hw_number_t irqd_to_hwirq(struct irq_data *d)
 {
        return d->hwirq;
@@ -510,362 +499,6 @@ irq_hw_number_t virq_to_hw(unsigned int virq)
 }
 EXPORT_SYMBOL_GPL(virq_to_hw);
 
-static int default_irq_host_match(struct irq_domain *h, struct device_node *np)
-{
-       return h->of_node != NULL && h->of_node == np;
-}
-
-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)
-{
-       struct irq_domain *host, *h;
-       unsigned int size = sizeof(struct irq_domain);
-       unsigned int i;
-       unsigned int *rmap;
-
-       /* Allocate structure and revmap table if using linear mapping */
-       if (revmap_type == IRQ_DOMAIN_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;
-
-       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(host->of_node);
-                               kfree(host);
-                               return NULL;
-                       }
-               }
-       }
-       list_add(&host->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 */
-               host->inval_irq = 0;
-               /* setup us as the host 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 = host;
-
-                       /* Legacy flags are left to default at this point,
-                        * one can then use irq_create_mapping() to
-                        * explicitly change them
-                        */
-                       ops->map(host, i, i);
-
-                       /* Clear norequest flags */
-                       irq_clear_status_flags(i, IRQ_NOREQUEST);
-               }
-               break;
-       case IRQ_DOMAIN_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;
-               host->revmap_data.linear.revmap = rmap;
-               break;
-       case IRQ_DOMAIN_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_domain *irq_find_host(struct device_node *node)
-{
-       struct irq_domain *h, *found = NULL;
-
-       /* 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...
-        */
-       mutex_lock(&irq_domain_mutex);
-       list_for_each_entry(h, &irq_domain_list, link)
-               if (h->ops->match(h, node)) {
-                       found = h;
-                       break;
-               }
-       mutex_unlock(&irq_domain_mutex);
-       return found;
-}
-EXPORT_SYMBOL_GPL(irq_find_host);
-
-void irq_set_default_host(struct irq_domain *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 < NUM_ISA_INTERRUPTS);
-       if (count < NR_IRQS)
-               irq_virq_count = count;
-}
-
-static int irq_setup_virq(struct irq_domain *host, unsigned int virq,
-                           irq_hw_number_t hwirq)
-{
-       struct irq_data *irq_data = irq_get_irq_data(virq);
-
-       irq_data->hwirq = hwirq;
-       irq_data->domain = host;
-       if (host->ops->map(host, virq, hwirq)) {
-               pr_debug("irq: -> mapping failed, freeing\n");
-               irq_data->domain = NULL;
-               irq_data->hwirq = 0;
-               return -1;
-       }
-
-       irq_clear_status_flags(virq, IRQ_NOREQUEST);
-
-       return 0;
-}
-
-unsigned int irq_create_direct_mapping(struct irq_domain *host)
-{
-       unsigned int virq;
-
-       if (host == NULL)
-               host = irq_default_host;
-
-       BUG_ON(host == NULL);
-       WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
-
-       virq = irq_alloc_desc_from(1, 0);
-       if (virq == NO_IRQ) {
-               pr_debug("irq: create_direct virq allocation failed\n");
-               return NO_IRQ;
-       }
-       if (virq >= irq_virq_count) {
-               pr_err("ERROR: no free irqs available below %i maximum\n",
-                       irq_virq_count);
-               irq_free_desc(virq);
-               return 0;
-       }
-
-       pr_debug("irq: create_direct obtained virq %d\n", virq);
-
-       if (irq_setup_virq(host, virq, virq)) {
-               irq_free_desc(virq);
-               return NO_IRQ;
-       }
-
-       return virq;
-}
-
-unsigned int irq_create_mapping(struct irq_domain *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;
-       }
-
-       /* Get a virtual interrupt number */
-       if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
-               /* Handle legacy */
-               virq = (unsigned int)hwirq;
-               if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
-                       return NO_IRQ;
-               return virq;
-       } else {
-               /* Allocate a virtual interrupt number */
-               hint = hwirq % irq_virq_count;
-               if (hint == 0)
-                       hint = 1;
-               virq = irq_alloc_desc_from(hint, 0);
-               if (!virq)
-                       virq = irq_alloc_desc_from(1, 0);
-               if (virq == NO_IRQ) {
-                       pr_debug("irq: -> virq allocation failed\n");
-                       return NO_IRQ;
-               }
-       }
-
-       if (irq_setup_virq(host, virq, hwirq)) {
-               if (host->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
-                       irq_free_desc(virq);
-               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_domain *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_data *irq_data = irq_get_irq_data(virq);
-       struct irq_domain *host;
-       irq_hw_number_t hwirq;
-
-       if (virq == NO_IRQ || !irq_data)
-               return;
-
-       host = irq_data->domain;
-       if (WARN_ON(host == NULL))
-               return;
-
-       /* Never unmap legacy interrupts */
-       if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
-               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_data->hwirq;
-       switch(host->revmap_type) {
-       case IRQ_DOMAIN_MAP_LINEAR:
-               if (hwirq < host->revmap_data.linear.size)
-                       host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
-               break;
-       case IRQ_DOMAIN_MAP_TREE:
-               mutex_lock(&revmap_trees_mutex);
-               radix_tree_delete(&host->revmap_data.tree, hwirq);
-               mutex_unlock(&revmap_trees_mutex);
-               break;
-       }
-
-       /* Destroy map */
-       irq_data->hwirq = host->inval_irq;
-
-       irq_free_desc(virq);
-}
-EXPORT_SYMBOL_GPL(irq_dispose_mapping);
-
-unsigned int irq_find_mapping(struct irq_domain *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;
-
-       /* legacy -> bail early */
-       if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
-               return hwirq;
-
-       /* Slow path does a linear search of the map */
-       if (hint == 0)
-               hint = 1;
-       i = hint;
-       do {
-               struct irq_data *data = irq_get_irq_data(i);
-               if (data && (data->domain == host) && (data->hwirq == hwirq))
-                       return i;
-               i++;
-               if (i >= irq_virq_count)
-                       i = 1;
-       } while(i != hint);
-       return NO_IRQ;
-}
-EXPORT_SYMBOL_GPL(irq_find_mapping);
-
 #ifdef CONFIG_SMP
 int irq_choose_cpu(const struct cpumask *mask)
 {
@@ -902,146 +535,11 @@ int irq_choose_cpu(const struct cpumask *mask)
 }
 #endif
 
-unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
-                                    irq_hw_number_t hwirq)
-{
-       struct irq_data *irq_data;
-
-       if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
-               return irq_find_mapping(host, hwirq);
-
-       /*
-        * Freeing an irq can delete nodes along the path to
-        * do the lookup via call_rcu.
-        */
-       rcu_read_lock();
-       irq_data = 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.
-        */
-       return irq_data ? irq_data->irq : irq_find_mapping(host, hwirq);
-}
-
-void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
-                            irq_hw_number_t hwirq)
-{
-       struct irq_data *irq_data = irq_get_irq_data(virq);
-
-       if (WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
-               return;
-
-       if (virq != NO_IRQ) {
-               mutex_lock(&revmap_trees_mutex);
-               radix_tree_insert(&host->revmap_data.tree, hwirq, irq_data);
-               mutex_unlock(&revmap_trees_mutex);
-       }
-}
-
-unsigned int irq_linear_revmap(struct irq_domain *host,
-                              irq_hw_number_t hwirq)
-{
-       unsigned int *revmap;
-
-       if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_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];
-}
-
 int arch_early_irq_init(void)
 {
        return 0;
 }
 
-#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  ", desc->irq_data.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 (desc->irq_data.domain->of_node)
-                               p = desc->irq_data.domain->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;
-}
-__initcall(irq_debugfs_init);
-#endif /* CONFIG_VIRQ_DEBUG */
-
 #ifdef CONFIG_PPC64
 static int __init setup_noirqdistrib(char *str)
 {
index 35b9ff382e45c8c96205e3d14772611c963feab7..18f4ab002d2e161ceeafd125b16f3a9b6e3d978c 100644 (file)
  * (though a domain can cover more than one PIC if they have a flat number
  * model). It's the domain 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 agnostic to whether or not
+ * 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 domain->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.
  */
 
 #ifndef _LINUX_IRQDOMAIN_H
@@ -108,6 +119,32 @@ struct irq_domain {
 };
 
 #ifdef CONFIG_IRQ_DOMAIN
+#ifdef CONFIG_PPC
+extern 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);
+extern struct irq_domain *irq_find_host(struct device_node *node);
+extern void irq_set_default_host(struct irq_domain *host);
+extern void irq_set_virq_count(unsigned 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);
+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);
+extern void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
+                                   irq_hw_number_t hwirq);
+extern unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
+                                           irq_hw_number_t hwirq);
+extern unsigned int irq_linear_revmap(struct irq_domain *host,
+                                     irq_hw_number_t hwirq);
+
+#else /* CONFIG_PPC */
+
 /**
  * irq_domain_to_irq() - Translate from a hardware irq to a linux irq number
  *
@@ -137,15 +174,16 @@ extern void irq_domain_add(struct irq_domain *domain);
 extern void irq_domain_del(struct irq_domain *domain);
 
 extern struct irq_domain_ops irq_domain_simple_ops;
-#endif /* CONFIG_IRQ_DOMAIN */
 
-#if defined(CONFIG_IRQ_DOMAIN) && defined(CONFIG_OF_IRQ)
+#if defined(CONFIG_OF_IRQ)
 extern void irq_domain_add_simple(struct device_node *controller, int irq_base);
 extern void irq_domain_generate_simple(const struct of_device_id *match,
                                        u64 phys_base, unsigned int irq_start);
-#else /* CONFIG_IRQ_DOMAIN && CONFIG_OF_IRQ */
+#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_IRQ_DOMAIN && CONFIG_OF_IRQ */
+#endif /* !CONFIG_OF_IRQ */
+#endif /* !CONFIG_PPC */
+#endif /* CONFIG_IRQ_DOMAIN */
 
 #endif /* _LINUX_IRQDOMAIN_H */
index 509adb8762d7d405fd826f5f508f0eb3eb671975..f551bc1d31678819e8f6645950f093da962020bc 100644 (file)
+#include <linux/debugfs.h>
+#include <linux/hardirq.h>
+#include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <linux/irqdesc.h>
 #include <linux/irqdomain.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
+#include <linux/smp.h>
+#include <linux/fs.h>
 
 static LIST_HEAD(irq_domain_list);
 static DEFINE_MUTEX(irq_domain_mutex);
 
+#ifdef CONFIG_PPC
+static DEFINE_MUTEX(revmap_trees_mutex);
+static unsigned int irq_virq_count = NR_IRQS;
+static struct irq_domain *irq_default_host;
+
+static int default_irq_host_match(struct irq_domain *h, struct device_node *np)
+{
+       return h->of_node != NULL && h->of_node == np;
+}
+
+/**
+ * irq_alloc_host() - 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 host callbacks
+ * @inval_irq: provide a hw number in that host space that is always invalid
+ *
+ * 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).
+ */
+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)
+{
+       struct irq_domain *host, *h;
+       unsigned int size = sizeof(struct irq_domain);
+       unsigned int i;
+       unsigned int *rmap;
+
+       /* Allocate structure and revmap table if using linear mapping */
+       if (revmap_type == IRQ_DOMAIN_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;
+
+       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(host->of_node);
+                               kfree(host);
+                               return NULL;
+                       }
+               }
+       }
+       list_add(&host->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 */
+               host->inval_irq = 0;
+               /* setup us as the host 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 = host;
+
+                       /* Legacy flags are left to default at this point,
+                        * one can then use irq_create_mapping() to
+                        * explicitly change them
+                        */
+                       ops->map(host, i, i);
+
+                       /* Clear norequest flags */
+                       irq_clear_status_flags(i, IRQ_NOREQUEST);
+               }
+               break;
+       case IRQ_DOMAIN_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;
+               host->revmap_data.linear.revmap = rmap;
+               break;
+       case IRQ_DOMAIN_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;
+}
+
+/**
+ * irq_find_host() - Locates a domain for a given device node
+ * @node: device-tree node of the interrupt controller
+ */
+struct irq_domain *irq_find_host(struct device_node *node)
+{
+       struct irq_domain *h, *found = NULL;
+
+       /* 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...
+        */
+       mutex_lock(&irq_domain_mutex);
+       list_for_each_entry(h, &irq_domain_list, link)
+               if (h->ops->match(h, node)) {
+                       found = h;
+                       break;
+               }
+       mutex_unlock(&irq_domain_mutex);
+       return found;
+}
+EXPORT_SYMBOL_GPL(irq_find_host);
+
+/**
+ * irq_set_default_host() - Set a "default" irq domain
+ * @host: default host pointer
+ *
+ * For convenience, it's possible to set a "default" domain 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.
+ */
+void irq_set_default_host(struct irq_domain *host)
+{
+       pr_debug("irq: Default host set to @0x%p\n", host);
+
+       irq_default_host = host;
+}
+
+/**
+ * irq_set_virq_count() - Set the maximum number of linux irqs
+ * @count: number of linux 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
+ */
+void irq_set_virq_count(unsigned int count)
+{
+       pr_debug("irq: Trying to set virq count to %d\n", count);
+
+       BUG_ON(count < NUM_ISA_INTERRUPTS);
+       if (count < NR_IRQS)
+               irq_virq_count = count;
+}
+
+static int irq_setup_virq(struct irq_domain *host, unsigned int virq,
+                           irq_hw_number_t hwirq)
+{
+       struct irq_data *irq_data = irq_get_irq_data(virq);
+
+       irq_data->hwirq = hwirq;
+       irq_data->domain = host;
+       if (host->ops->map(host, virq, hwirq)) {
+               pr_debug("irq: -> mapping failed, freeing\n");
+               irq_data->domain = NULL;
+               irq_data->hwirq = 0;
+               return -1;
+       }
+
+       irq_clear_status_flags(virq, IRQ_NOREQUEST);
+
+       return 0;
+}
+
+/**
+ * irq_create_direct_mapping() - Allocate an irq for direct mapping
+ * @host: domain to allocate the irq 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 irq as the hardware interrupt number.
+ */
+unsigned int irq_create_direct_mapping(struct irq_domain *host)
+{
+       unsigned int virq;
+
+       if (host == NULL)
+               host = irq_default_host;
+
+       BUG_ON(host == NULL);
+       WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_NOMAP);
+
+       virq = irq_alloc_desc_from(1, 0);
+       if (virq == NO_IRQ) {
+               pr_debug("irq: create_direct virq allocation failed\n");
+               return NO_IRQ;
+       }
+       if (virq >= irq_virq_count) {
+               pr_err("ERROR: no free irqs available below %i maximum\n",
+                       irq_virq_count);
+               irq_free_desc(virq);
+               return 0;
+       }
+
+       pr_debug("irq: create_direct obtained virq %d\n", virq);
+
+       if (irq_setup_virq(host, virq, virq)) {
+               irq_free_desc(virq);
+               return NO_IRQ;
+       }
+
+       return virq;
+}
+
+/**
+ * irq_create_mapping() - Map a hardware interrupt into linux irq 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
+ * irq number.
+ * If the sense/trigger is to be specified, set_irq_type() should be called
+ * on the number returned from that call.
+ */
+unsigned int irq_create_mapping(struct irq_domain *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;
+       }
+
+       /* Get a virtual interrupt number */
+       if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY) {
+               /* Handle legacy */
+               virq = (unsigned int)hwirq;
+               if (virq == 0 || virq >= NUM_ISA_INTERRUPTS)
+                       return NO_IRQ;
+               return virq;
+       } else {
+               /* Allocate a virtual interrupt number */
+               hint = hwirq % irq_virq_count;
+               if (hint == 0)
+                       hint++;
+               virq = irq_alloc_desc_from(hint, 0);
+               if (!virq)
+                       virq = irq_alloc_desc_from(1, 0);
+               if (virq == NO_IRQ) {
+                       pr_debug("irq: -> virq allocation failed\n");
+                       return NO_IRQ;
+               }
+       }
+
+       if (irq_setup_virq(host, virq, hwirq)) {
+               if (host->revmap_type != IRQ_DOMAIN_MAP_LEGACY)
+                       irq_free_desc(virq);
+               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_domain *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);
+
+/**
+ * irq_dispose_mapping() - Unmap an interrupt
+ * @virq: linux irq number of the interrupt to unmap
+ */
+void irq_dispose_mapping(unsigned int virq)
+{
+       struct irq_data *irq_data = irq_get_irq_data(virq);
+       struct irq_domain *host;
+       irq_hw_number_t hwirq;
+
+       if (virq == NO_IRQ || !irq_data)
+               return;
+
+       host = irq_data->domain;
+       if (WARN_ON(host == NULL))
+               return;
+
+       /* Never unmap legacy interrupts */
+       if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+               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_data->hwirq;
+       switch(host->revmap_type) {
+       case IRQ_DOMAIN_MAP_LINEAR:
+               if (hwirq < host->revmap_data.linear.size)
+                       host->revmap_data.linear.revmap[hwirq] = NO_IRQ;
+               break;
+       case IRQ_DOMAIN_MAP_TREE:
+               mutex_lock(&revmap_trees_mutex);
+               radix_tree_delete(&host->revmap_data.tree, hwirq);
+               mutex_unlock(&revmap_trees_mutex);
+               break;
+       }
+
+       /* Destroy map */
+       irq_data->hwirq = host->inval_irq;
+
+       irq_free_desc(virq);
+}
+EXPORT_SYMBOL_GPL(irq_dispose_mapping);
+
+/**
+ * irq_find_mapping() - Find a linux irq from an hw irq number.
+ * @host: domain 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.
+ */
+unsigned int irq_find_mapping(struct irq_domain *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;
+
+       /* legacy -> bail early */
+       if (host->revmap_type == IRQ_DOMAIN_MAP_LEGACY)
+               return hwirq;
+
+       /* Slow path does a linear search of the map */
+       if (hint == 0)
+               hint = 1;
+       i = hint;
+       do {
+               struct irq_data *data = irq_get_irq_data(i);
+               if (data && (data->domain == host) && (data->hwirq == hwirq))
+                       return i;
+               i++;
+               if (i >= irq_virq_count)
+                       i = 1;
+       } while(i != hint);
+       return NO_IRQ;
+}
+EXPORT_SYMBOL_GPL(irq_find_mapping);
+
+/**
+ * irq_radix_revmap_lookup() - Find a linux irq 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
+ */
+unsigned int irq_radix_revmap_lookup(struct irq_domain *host,
+                                    irq_hw_number_t hwirq)
+{
+       struct irq_data *irq_data;
+
+       if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
+               return irq_find_mapping(host, hwirq);
+
+       /*
+        * Freeing an irq can delete nodes along the path to
+        * do the lookup via call_rcu.
+        */
+       rcu_read_lock();
+       irq_data = 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.
+        */
+       return irq_data ? irq_data->irq : irq_find_mapping(host, hwirq);
+}
+
+/**
+ * irq_radix_revmap_insert() - Insert a hw irq to linux irq 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.
+ */
+void irq_radix_revmap_insert(struct irq_domain *host, unsigned int virq,
+                            irq_hw_number_t hwirq)
+{
+       struct irq_data *irq_data = irq_get_irq_data(virq);
+
+       if (WARN_ON(host->revmap_type != IRQ_DOMAIN_MAP_TREE))
+               return;
+
+       if (virq != NO_IRQ) {
+               mutex_lock(&revmap_trees_mutex);
+               radix_tree_insert(&host->revmap_data.tree, hwirq, irq_data);
+               mutex_unlock(&revmap_trees_mutex);
+       }
+}
+
+/**
+ * irq_linear_revmap() - Find a linux irq 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
+ */
+unsigned int irq_linear_revmap(struct irq_domain *host,
+                              irq_hw_number_t hwirq)
+{
+       unsigned int *revmap;
+
+       if (WARN_ON_ONCE(host->revmap_type != IRQ_DOMAIN_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];
+}
+
+#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  ", desc->irq_data.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 (desc->irq_data.domain->of_node)
+                               p = desc->irq_data.domain->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;
+}
+__initcall(irq_debugfs_init);
+#endif /* CONFIG_VIRQ_DEBUG */
+
+#else /* CONFIG_PPC */
+
 /**
  * irq_domain_add() - Register an irq_domain
  * @domain: ptr to initialized irq_domain structure
@@ -185,3 +783,5 @@ struct irq_domain_ops irq_domain_simple_ops = {
 #endif /* CONFIG_OF_IRQ */
 };
 EXPORT_SYMBOL_GPL(irq_domain_simple_ops);
+
+#endif /* !CONFIG_PPC */