#define pr_fmt(fmt)  "irq: " fmt

#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/of_irq.h>
#include <linux/topology.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);

static DEFINE_MUTEX(revmap_trees_mutex);
static struct irq_domain *irq_default_domain;

static int irq_domain_alloc_descs(int virq, unsigned int nr_irqs,
				  irq_hw_number_t hwirq, int node);
static void irq_domain_check_hierarchy(struct irq_domain *domain);

/**
 * __irq_domain_add() - Allocate a new irq_domain data structure
 * @of_node: optional device-tree node of the interrupt controller
 * @size: Size of linear map; 0 for radix mapping only
 * @hwirq_max: Maximum number of interrupts supported by controller
 * @direct_max: Maximum value of direct maps; Use ~0 for no limit; 0 for no
 *              direct mapping
 * @ops: domain callbacks
 * @host_data: Controller private data pointer
 *
 * Allocates and initialize and irq_domain structure.
 * Returns pointer to IRQ domain, or NULL on failure.
 */
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) + (sizeof(unsigned int) * size),
			      GFP_KERNEL, of_node_to_nid(of_node));
	if (WARN_ON(!domain))
		return NULL;

	/* Fill structure */
	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;
	irq_domain_check_hierarchy(domain);

	mutex_lock(&irq_domain_mutex);
	list_add(&domain->link, &irq_domain_list);
	mutex_unlock(&irq_domain_mutex);

	pr_debug("Added domain %s\n", domain->name);
	return domain;
}
EXPORT_SYMBOL_GPL(__irq_domain_add);

/**
 * irq_domain_remove() - Remove an irq domain.
 * @domain: domain to remove
 *
 * This routine is used to remove an irq domain. The caller must ensure
 * that all mappings within the domain have been disposed of prior to
 * use, depending on the revmap type.
 */
void irq_domain_remove(struct irq_domain *domain)
{
	mutex_lock(&irq_domain_mutex);

	/*
	 * 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);

	/*
	 * If the going away domain is the default one, reset it.
	 */
	if (unlikely(irq_default_domain == domain))
		irq_set_default_host(NULL);

	mutex_unlock(&irq_domain_mutex);

	pr_debug("Removed domain %s\n", domain->name);

	of_node_put(domain->of_node);
	kfree(domain);
}
EXPORT_SYMBOL_GPL(irq_domain_remove);

/**
 * 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. If first_irq is non-zero, then
 *	pre-map all of the irqs in the domain to virqs starting at first_irq.
 * @ops: domain callbacks
 * @host_data: Controller private data pointer
 *
 * 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. 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,
					 unsigned int first_irq,
					 const struct irq_domain_ops *ops,
					 void *host_data)
{
	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)) {
			/* 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_domain_associate_many(domain, first_irq, 0, size);
	}

	return domain;
}
EXPORT_SYMBOL_GPL(irq_domain_add_simple);

/**
 * irq_domain_add_legacy() - Allocate and register a legacy revmap irq_domain.
 * @of_node: pointer to interrupt controller's device tree node.
 * @size: total number of irqs in legacy mapping
 * @first_irq: first number of irq block assigned to the domain
 * @first_hwirq: first hwirq number to use for the translation. Should normally
 *               be '0', but a positive integer can be used if the effective
 *               hwirqs numbering does not begin at zero.
 * @ops: map/unmap domain callbacks
 * @host_data: Controller private data pointer
 *
 * Note: the map() callback will be called before this function returns
 * for all legacy interrupts except 0 (which is always the invalid irq for
 * a legacy controller).
 */
struct irq_domain *irq_domain_add_legacy(struct device_node *of_node,
					 unsigned int size,
					 unsigned int first_irq,
					 irq_hw_number_t first_hwirq,
					 const struct irq_domain_ops *ops,
					 void *host_data)
{
	struct irq_domain *domain;

	domain = __irq_domain_add(of_node, first_hwirq + size,
				  first_hwirq + size, 0, ops, host_data);
	if (domain)
		irq_domain_associate_many(domain, first_irq, first_hwirq, size);

	return domain;
}
EXPORT_SYMBOL_GPL(irq_domain_add_legacy);

/**
 * 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;
	int rc;

	/* 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)
			rc = h->ops->match(h, node);
		else
			rc = (h->of_node != NULL) && (h->of_node == node);

		if (rc) {
			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
 * @domain: default domain 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 *domain)
{
	pr_debug("Default domain set to @0x%p\n", domain);

	irq_default_domain = domain;
}
EXPORT_SYMBOL_GPL(irq_set_default_host);

void irq_domain_disassociate(struct irq_domain *domain, unsigned int irq)
{
	struct irq_data *irq_data = irq_get_irq_data(irq);
	irq_hw_number_t hwirq;

	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);

	/* remove chip and handler */
	irq_set_chip_and_handler(irq, NULL, NULL);

	/* Make sure it's completed */
	synchronize_irq(irq);

	/* Tell the PIC about it */
	if (domain->ops->unmap)
		domain->ops->unmap(domain, irq);
	smp_mb();

	irq_data->domain = NULL;
	irq_data->hwirq = 0;

	/* 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(struct irq_domain *domain, unsigned int virq,
			 irq_hw_number_t hwirq)
{
	struct irq_data *irq_data = irq_get_irq_data(virq);
	int ret;

	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;

	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;
		}

		/* If not already assigned, give the domain the chip's name */
		if (!domain->name && irq_data->chip)
			domain->name = irq_data->chip->name;
	}

	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);

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);

/**
 * irq_create_direct_mapping() - Allocate an irq for direct mapping
 * @domain: domain to allocate the irq for or NULL for default domain
 *
 * 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. 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)
{
	unsigned int virq;

	if (domain == NULL)
		domain = irq_default_domain;

	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_direct_max_irq) {
		pr_err("ERROR: no free irqs available below %i maximum\n",
			domain->revmap_direct_max_irq);
		irq_free_desc(virq);
		return 0;
	}
	pr_debug("create_direct obtained virq %d\n", virq);

	if (irq_domain_associate(domain, virq, virq)) {
		irq_free_desc(virq);
		return 0;
	}

	return virq;
}
EXPORT_SYMBOL_GPL(irq_create_direct_mapping);

/**
 * irq_create_mapping() - Map a hardware interrupt into linux irq space
 * @domain: domain owning this hardware interrupt or NULL for default domain
 * @hwirq: hardware irq number in that domain 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 *domain,
				irq_hw_number_t hwirq)
{
	int virq;

	pr_debug("irq_create_mapping(0x%p, 0x%lx)\n", domain, hwirq);

	/* Look for default domain if nececssary */
	if (domain == NULL)
		domain = irq_default_domain;
	if (domain == NULL) {
		WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
		return 0;
	}
	pr_debug("-> using domain @%p\n", domain);

	/* Check if mapping already exists */
	virq = irq_find_mapping(domain, hwirq);
	if (virq) {
		pr_debug("-> existing mapping on virq %d\n", virq);
		return virq;
	}

	/* Allocate a virtual interrupt number */
	virq = irq_domain_alloc_descs(-1, 1, hwirq,
				      of_node_to_nid(domain->of_node));
	if (virq <= 0) {
		pr_debug("-> virq allocation failed\n");
		return 0;
	}

	if (irq_domain_associate(domain, virq, hwirq)) {
		irq_free_desc(virq);
		return 0;
	}

	pr_debug("irq %lu on domain %s mapped to virtual irq %u\n",
		hwirq, of_node_full_name(domain->of_node), virq);

	return virq;
}
EXPORT_SYMBOL_GPL(irq_create_mapping);

/**
 * irq_create_strict_mappings() - Map a range of hw irqs to fixed linux irqs
 * @domain: domain owning the interrupt range
 * @irq_base: beginning of linux IRQ range
 * @hwirq_base: beginning of hardware IRQ range
 * @count: Number of interrupts to map
 *
 * This routine is used for allocating and mapping a range of hardware
 * irqs to linux irqs where the linux irq numbers are at pre-defined
 * locations. For use by controllers that already have static mappings
 * to insert in to the domain.
 *
 * Non-linear users can use irq_create_identity_mapping() for IRQ-at-a-time
 * domain insertion.
 *
 * 0 is returned upon success, while any failure to establish a static
 * mapping is treated as an error.
 */
int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base,
			       irq_hw_number_t hwirq_base, int count)
{
	int ret;

	ret = irq_alloc_descs(irq_base, irq_base, count,
			      of_node_to_nid(domain->of_node));
	if (unlikely(ret < 0))
		return ret;

	irq_domain_associate_many(domain, irq_base, hwirq_base, count);
	return 0;
}
EXPORT_SYMBOL_GPL(irq_create_strict_mappings);

unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
{
	struct irq_domain *domain;
	irq_hw_number_t hwirq;
	unsigned int type = IRQ_TYPE_NONE;
	int virq;

	domain = irq_data->np ? irq_find_host(irq_data->np) : irq_default_domain;
	if (!domain) {
		pr_warn("no irq domain found for %s !\n",
			of_node_full_name(irq_data->np));
		return 0;
	}

	/* If domain has no translation, then we assume interrupt line */
	if (domain->ops->xlate == NULL)
		hwirq = irq_data->args[0];
	else {
		if (domain->ops->xlate(domain, irq_data->np, irq_data->args,
					irq_data->args_count, &hwirq, &type))
			return 0;
	}

	if (irq_domain_is_hierarchy(domain)) {
		/*
		 * If we've already configured this interrupt,
		 * don't do it again, or hell will break loose.
		 */
		virq = irq_find_mapping(domain, hwirq);
		if (virq)
			return virq;

		virq = irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, irq_data);
		if (virq <= 0)
			return 0;
	} else {
		/* Create mapping */
		virq = irq_create_mapping(domain, hwirq);
		if (!virq)
			return virq;
	}

	/* Set type if specified and different than the current one */
	if (type != IRQ_TYPE_NONE &&
	    type != irq_get_trigger_type(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 *domain;

	if (!virq || !irq_data)
		return;

	domain = irq_data->domain;
	if (WARN_ON(domain == NULL))
		return;

	irq_domain_disassociate(domain, virq);
	irq_free_desc(virq);
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);

/**
 * irq_find_mapping() - Find a linux irq from an hw irq number.
 * @domain: domain owning this hardware interrupt
 * @hwirq: hardware irq number in that domain space
 */
unsigned int irq_find_mapping(struct irq_domain *domain,
			      irq_hw_number_t hwirq)
{
	struct irq_data *data;

	/* Look for default domain if nececssary */
	if (domain == NULL)
		domain = irq_default_domain;
	if (domain == NULL)
		return 0;

	if (hwirq < domain->revmap_direct_max_irq) {
		data = irq_domain_get_irq_data(domain, hwirq);
		if (data && data->hwirq == hwirq)
			return hwirq;
	}

	/* Check if the hwirq is in the linear revmap. */
	if (hwirq < domain->revmap_size)
		return domain->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_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;
	struct irq_domain *domain;
	struct radix_tree_iter iter;
	void *data, **slot;
	int i;

	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",
		      "active", "type", "domain");

	for (i = 1; i < nr_irqs; i++) {
		desc = irq_to_desc(i);
		if (!desc)
			continue;

		raw_spin_lock_irqsave(&desc->lock, flags);
		domain = desc->irq_data.domain;

		if (domain) {
			struct irq_chip *chip;
			int hwirq = desc->irq_data.hwirq;
			bool direct;

			seq_printf(m, "%5d  ", i);
			seq_printf(m, "0x%05x  ", hwirq);

			chip = irq_desc_get_chip(desc);
			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);

			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);
	}

	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("irq_domain_mapping", S_IRUGO, NULL,
				 NULL, &virq_debug_fops) == NULL)
		return -ENOMEM;

	return 0;
}
__initcall(irq_debugfs_init);
#endif /* CONFIG_IRQ_DOMAIN_DEBUG */

/**
 * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings
 *
 * Device Tree IRQ specifier translation function which works with one cell
 * bindings where the cell value maps directly to the hwirq number.
 */
int irq_domain_xlate_onecell(struct irq_domain *d, struct device_node *ctrlr,
			     const u32 *intspec, unsigned int intsize,
			     unsigned long *out_hwirq, unsigned int *out_type)
{
	if (WARN_ON(intsize < 1))
		return -EINVAL;
	*out_hwirq = intspec[0];
	*out_type = IRQ_TYPE_NONE;
	return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_onecell);

/**
 * irq_domain_xlate_twocell() - Generic xlate for direct two cell bindings
 *
 * Device Tree IRQ specifier translation function which works with two cell
 * bindings where the cell values map directly to the hwirq number
 * and linux irq flags.
 */
int irq_domain_xlate_twocell(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 (WARN_ON(intsize < 2))
		return -EINVAL;
	*out_hwirq = intspec[0];
	*out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
	return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);

/**
 * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
 *
 * Device Tree IRQ specifier translation function which works with either one
 * or two cell bindings where the cell values map directly to the hwirq number
 * and linux irq flags.
 *
 * Note: don't use this function unless your interrupt controller explicitly
 * supports both one and two cell bindings.  For the majority of controllers
 * the _onecell() or _twocell() variants above should be used.
 */
int irq_domain_xlate_onetwocell(struct irq_domain *d,
				struct device_node *ctrlr,
				const u32 *intspec, unsigned int intsize,
				unsigned long *out_hwirq, unsigned int *out_type)
{
	if (WARN_ON(intsize < 1))
		return -EINVAL;
	*out_hwirq = intspec[0];
	*out_type = (intsize > 1) ? intspec[1] : IRQ_TYPE_NONE;
	return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_onetwocell);

const struct irq_domain_ops irq_domain_simple_ops = {
	.xlate = irq_domain_xlate_onetwocell,
};
EXPORT_SYMBOL_GPL(irq_domain_simple_ops);

static int irq_domain_alloc_descs(int virq, unsigned int cnt,
				  irq_hw_number_t hwirq, int node)
{
	unsigned int hint;

	if (virq >= 0) {
		virq = irq_alloc_descs(virq, virq, cnt, node);
	} else {
		hint = hwirq % nr_irqs;
		if (hint == 0)
			hint++;
		virq = irq_alloc_descs_from(hint, cnt, node);
		if (virq <= 0 && hint > 1)
			virq = irq_alloc_descs_from(1, cnt, node);
	}

	return virq;
}

#ifdef	CONFIG_IRQ_DOMAIN_HIERARCHY
/**
 * irq_domain_add_hierarchy - Add a irqdomain into the hierarchy
 * @parent:	Parent irq domain to associate with the new domain
 * @flags:	Irq domain flags associated to the domain
 * @size:	Size of the domain. See below
 * @node:	Optional device-tree node of the interrupt controller
 * @ops:	Pointer to the interrupt domain callbacks
 * @host_data:	Controller private data pointer
 *
 * If @size is 0 a tree domain is created, otherwise a linear domain.
 *
 * If successful the parent is associated to the new domain and the
 * domain flags are set.
 * Returns pointer to IRQ domain, or NULL on failure.
 */
struct irq_domain *irq_domain_add_hierarchy(struct irq_domain *parent,
					    unsigned int flags,
					    unsigned int size,
					    struct device_node *node,
					    const struct irq_domain_ops *ops,
					    void *host_data)
{
	struct irq_domain *domain;

	if (size)
		domain = irq_domain_add_linear(node, size, ops, host_data);
	else
		domain = irq_domain_add_tree(node, ops, host_data);
	if (domain) {
		domain->parent = parent;
		domain->flags |= flags;
	}

	return domain;
}

static void irq_domain_insert_irq(int virq)
{
	struct irq_data *data;

	for (data = irq_get_irq_data(virq); data; data = data->parent_data) {
		struct irq_domain *domain = data->domain;
		irq_hw_number_t hwirq = data->hwirq;

		if (hwirq < domain->revmap_size) {
			domain->linear_revmap[hwirq] = virq;
		} else {
			mutex_lock(&revmap_trees_mutex);
			radix_tree_insert(&domain->revmap_tree, hwirq, data);
			mutex_unlock(&revmap_trees_mutex);
		}

		/* If not already assigned, give the domain the chip's name */
		if (!domain->name && data->chip)
			domain->name = data->chip->name;
	}

	irq_clear_status_flags(virq, IRQ_NOREQUEST);
}

static void irq_domain_remove_irq(int virq)
{
	struct irq_data *data;

	irq_set_status_flags(virq, IRQ_NOREQUEST);
	irq_set_chip_and_handler(virq, NULL, NULL);
	synchronize_irq(virq);
	smp_mb();

	for (data = irq_get_irq_data(virq); data; data = data->parent_data) {
		struct irq_domain *domain = data->domain;
		irq_hw_number_t hwirq = data->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);
		}
	}
}

static struct irq_data *irq_domain_insert_irq_data(struct irq_domain *domain,
						   struct irq_data *child)
{
	struct irq_data *irq_data;

	irq_data = kzalloc_node(sizeof(*irq_data), GFP_KERNEL, child->node);
	if (irq_data) {
		child->parent_data = irq_data;
		irq_data->irq = child->irq;
		irq_data->node = child->node;
		irq_data->domain = domain;
	}

	return irq_data;
}

static void irq_domain_free_irq_data(unsigned int virq, unsigned int nr_irqs)
{
	struct irq_data *irq_data, *tmp;
	int i;

	for (i = 0; i < nr_irqs; i++) {
		irq_data = irq_get_irq_data(virq + i);
		tmp = irq_data->parent_data;
		irq_data->parent_data = NULL;
		irq_data->domain = NULL;

		while (tmp) {
			irq_data = tmp;
			tmp = tmp->parent_data;
			kfree(irq_data);
		}
	}
}

static int irq_domain_alloc_irq_data(struct irq_domain *domain,
				     unsigned int virq, unsigned int nr_irqs)
{
	struct irq_data *irq_data;
	struct irq_domain *parent;
	int i;

	/* The outermost irq_data is embedded in struct irq_desc */
	for (i = 0; i < nr_irqs; i++) {
		irq_data = irq_get_irq_data(virq + i);
		irq_data->domain = domain;

		for (parent = domain->parent; parent; parent = parent->parent) {
			irq_data = irq_domain_insert_irq_data(parent, irq_data);
			if (!irq_data) {
				irq_domain_free_irq_data(virq, i + 1);
				return -ENOMEM;
			}
		}
	}

	return 0;
}

/**
 * irq_domain_get_irq_data - Get irq_data associated with @virq and @domain
 * @domain:	domain to match
 * @virq:	IRQ number to get irq_data
 */
struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain,
					 unsigned int virq)
{
	struct irq_data *irq_data;

	for (irq_data = irq_get_irq_data(virq); irq_data;
	     irq_data = irq_data->parent_data)
		if (irq_data->domain == domain)
			return irq_data;

	return NULL;
}

/**
 * irq_domain_set_hwirq_and_chip - Set hwirq and irqchip of @virq at @domain
 * @domain:	Interrupt domain to match
 * @virq:	IRQ number
 * @hwirq:	The hwirq number
 * @chip:	The associated interrupt chip
 * @chip_data:	The associated chip data
 */
int irq_domain_set_hwirq_and_chip(struct irq_domain *domain, unsigned int virq,
				  irq_hw_number_t hwirq, struct irq_chip *chip,
				  void *chip_data)
{
	struct irq_data *irq_data = irq_domain_get_irq_data(domain, virq);

	if (!irq_data)
		return -ENOENT;

	irq_data->hwirq = hwirq;
	irq_data->chip = chip ? chip : &no_irq_chip;
	irq_data->chip_data = chip_data;

	return 0;
}

/**
 * irq_domain_set_info - Set the complete data for a @virq in @domain
 * @domain:		Interrupt domain to match
 * @virq:		IRQ number
 * @hwirq:		The hardware interrupt number
 * @chip:		The associated interrupt chip
 * @chip_data:		The associated interrupt chip data
 * @handler:		The interrupt flow handler
 * @handler_data:	The interrupt flow handler data
 * @handler_name:	The interrupt handler name
 */
void irq_domain_set_info(struct irq_domain *domain, unsigned int virq,
			 irq_hw_number_t hwirq, struct irq_chip *chip,
			 void *chip_data, irq_flow_handler_t handler,
			 void *handler_data, const char *handler_name)
{
	irq_domain_set_hwirq_and_chip(domain, virq, hwirq, chip, chip_data);
	__irq_set_handler(virq, handler, 0, handler_name);
	irq_set_handler_data(virq, handler_data);
}

/**
 * irq_domain_reset_irq_data - Clear hwirq, chip and chip_data in @irq_data
 * @irq_data:	The pointer to irq_data
 */
void irq_domain_reset_irq_data(struct irq_data *irq_data)
{
	irq_data->hwirq = 0;
	irq_data->chip = &no_irq_chip;
	irq_data->chip_data = NULL;
}

/**
 * irq_domain_free_irqs_common - Clear irq_data and free the parent
 * @domain:	Interrupt domain to match
 * @virq:	IRQ number to start with
 * @nr_irqs:	The number of irqs to free
 */
void irq_domain_free_irqs_common(struct irq_domain *domain, unsigned int virq,
				 unsigned int nr_irqs)
{
	struct irq_data *irq_data;
	int i;

	for (i = 0; i < nr_irqs; i++) {
		irq_data = irq_domain_get_irq_data(domain, virq + i);
		if (irq_data)
			irq_domain_reset_irq_data(irq_data);
	}
	irq_domain_free_irqs_parent(domain, virq, nr_irqs);
}

/**
 * irq_domain_free_irqs_top - Clear handler and handler data, clear irqdata and free parent
 * @domain:	Interrupt domain to match
 * @virq:	IRQ number to start with
 * @nr_irqs:	The number of irqs to free
 */
void irq_domain_free_irqs_top(struct irq_domain *domain, unsigned int virq,
			      unsigned int nr_irqs)
{
	int i;

	for (i = 0; i < nr_irqs; i++) {
		irq_set_handler_data(virq + i, NULL);
		irq_set_handler(virq + i, NULL);
	}
	irq_domain_free_irqs_common(domain, virq, nr_irqs);
}

static bool irq_domain_is_auto_recursive(struct irq_domain *domain)
{
	return domain->flags & IRQ_DOMAIN_FLAG_AUTO_RECURSIVE;
}

static void irq_domain_free_irqs_recursive(struct irq_domain *domain,
					   unsigned int irq_base,
					   unsigned int nr_irqs)
{
	domain->ops->free(domain, irq_base, nr_irqs);
	if (irq_domain_is_auto_recursive(domain)) {
		BUG_ON(!domain->parent);
		irq_domain_free_irqs_recursive(domain->parent, irq_base,
					       nr_irqs);
	}
}

static int irq_domain_alloc_irqs_recursive(struct irq_domain *domain,
					   unsigned int irq_base,
					   unsigned int nr_irqs, void *arg)
{
	int ret = 0;
	struct irq_domain *parent = domain->parent;
	bool recursive = irq_domain_is_auto_recursive(domain);

	BUG_ON(recursive && !parent);
	if (recursive)
		ret = irq_domain_alloc_irqs_recursive(parent, irq_base,
						      nr_irqs, arg);
	if (ret >= 0)
		ret = domain->ops->alloc(domain, irq_base, nr_irqs, arg);
	if (ret < 0 && recursive)
		irq_domain_free_irqs_recursive(parent, irq_base, nr_irqs);

	return ret;
}

/**
 * __irq_domain_alloc_irqs - Allocate IRQs from domain
 * @domain:	domain to allocate from
 * @irq_base:	allocate specified IRQ nubmer if irq_base >= 0
 * @nr_irqs:	number of IRQs to allocate
 * @node:	NUMA node id for memory allocation
 * @arg:	domain specific argument
 * @realloc:	IRQ descriptors have already been allocated if true
 *
 * Allocate IRQ numbers and initialized all data structures to support
 * hierarchy IRQ domains.
 * Parameter @realloc is mainly to support legacy IRQs.
 * Returns error code or allocated IRQ number
 *
 * The whole process to setup an IRQ has been split into two steps.
 * The first step, __irq_domain_alloc_irqs(), is to allocate IRQ
 * descriptor and required hardware resources. The second step,
 * irq_domain_activate_irq(), is to program hardwares with preallocated
 * resources. In this way, it's easier to rollback when failing to
 * allocate resources.
 */
int __irq_domain_alloc_irqs(struct irq_domain *domain, int irq_base,
			    unsigned int nr_irqs, int node, void *arg,
			    bool realloc)
{
	int i, ret, virq;

	if (domain == NULL) {
		domain = irq_default_domain;
		if (WARN(!domain, "domain is NULL; cannot allocate IRQ\n"))
			return -EINVAL;
	}

	if (!domain->ops->alloc) {
		pr_debug("domain->ops->alloc() is NULL\n");
		return -ENOSYS;
	}

	if (realloc && irq_base >= 0) {
		virq = irq_base;
	} else {
		virq = irq_domain_alloc_descs(irq_base, nr_irqs, 0, node);
		if (virq < 0) {
			pr_debug("cannot allocate IRQ(base %d, count %d)\n",
				 irq_base, nr_irqs);
			return virq;
		}
	}

	if (irq_domain_alloc_irq_data(domain, virq, nr_irqs)) {
		pr_debug("cannot allocate memory for IRQ%d\n", virq);
		ret = -ENOMEM;
		goto out_free_desc;
	}

	mutex_lock(&irq_domain_mutex);
	ret = irq_domain_alloc_irqs_recursive(domain, virq, nr_irqs, arg);
	if (ret < 0) {
		mutex_unlock(&irq_domain_mutex);
		goto out_free_irq_data;
	}
	for (i = 0; i < nr_irqs; i++)
		irq_domain_insert_irq(virq + i);
	mutex_unlock(&irq_domain_mutex);

	return virq;

out_free_irq_data:
	irq_domain_free_irq_data(virq, nr_irqs);
out_free_desc:
	irq_free_descs(virq, nr_irqs);
	return ret;
}

/**
 * irq_domain_free_irqs - Free IRQ number and associated data structures
 * @virq:	base IRQ number
 * @nr_irqs:	number of IRQs to free
 */
void irq_domain_free_irqs(unsigned int virq, unsigned int nr_irqs)
{
	struct irq_data *data = irq_get_irq_data(virq);
	int i;

	if (WARN(!data || !data->domain || !data->domain->ops->free,
		 "NULL pointer, cannot free irq\n"))
		return;

	mutex_lock(&irq_domain_mutex);
	for (i = 0; i < nr_irqs; i++)
		irq_domain_remove_irq(virq + i);
	irq_domain_free_irqs_recursive(data->domain, virq, nr_irqs);
	mutex_unlock(&irq_domain_mutex);

	irq_domain_free_irq_data(virq, nr_irqs);
	irq_free_descs(virq, nr_irqs);
}

/**
 * irq_domain_alloc_irqs_parent - Allocate interrupts from parent domain
 * @irq_base:	Base IRQ number
 * @nr_irqs:	Number of IRQs to allocate
 * @arg:	Allocation data (arch/domain specific)
 *
 * Check whether the domain has been setup recursive. If not allocate
 * through the parent domain.
 */
int irq_domain_alloc_irqs_parent(struct irq_domain *domain,
				 unsigned int irq_base, unsigned int nr_irqs,
				 void *arg)
{
	/* irq_domain_alloc_irqs_recursive() has called parent's alloc() */
	if (irq_domain_is_auto_recursive(domain))
		return 0;

	domain = domain->parent;
	if (domain)
		return irq_domain_alloc_irqs_recursive(domain, irq_base,
						       nr_irqs, arg);
	return -ENOSYS;
}

/**
 * irq_domain_free_irqs_parent - Free interrupts from parent domain
 * @irq_base:	Base IRQ number
 * @nr_irqs:	Number of IRQs to free
 *
 * Check whether the domain has been setup recursive. If not free
 * through the parent domain.
 */
void irq_domain_free_irqs_parent(struct irq_domain *domain,
				 unsigned int irq_base, unsigned int nr_irqs)
{
	/* irq_domain_free_irqs_recursive() will call parent's free */
	if (!irq_domain_is_auto_recursive(domain) && domain->parent)
		irq_domain_free_irqs_recursive(domain->parent, irq_base,
					       nr_irqs);
}

/**
 * irq_domain_activate_irq - Call domain_ops->activate recursively to activate
 *			     interrupt
 * @irq_data:	outermost irq_data associated with interrupt
 *
 * This is the second step to call domain_ops->activate to program interrupt
 * controllers, so the interrupt could actually get delivered.
 */
void irq_domain_activate_irq(struct irq_data *irq_data)
{
	if (irq_data && irq_data->domain) {
		struct irq_domain *domain = irq_data->domain;

		if (irq_data->parent_data)
			irq_domain_activate_irq(irq_data->parent_data);
		if (domain->ops->activate)
			domain->ops->activate(domain, irq_data);
	}
}

/**
 * irq_domain_deactivate_irq - Call domain_ops->deactivate recursively to
 *			       deactivate interrupt
 * @irq_data: outermost irq_data associated with interrupt
 *
 * It calls domain_ops->deactivate to program interrupt controllers to disable
 * interrupt delivery.
 */
void irq_domain_deactivate_irq(struct irq_data *irq_data)
{
	if (irq_data && irq_data->domain) {
		struct irq_domain *domain = irq_data->domain;

		if (domain->ops->deactivate)
			domain->ops->deactivate(domain, irq_data);
		if (irq_data->parent_data)
			irq_domain_deactivate_irq(irq_data->parent_data);
	}
}

static void irq_domain_check_hierarchy(struct irq_domain *domain)
{
	/* Hierarchy irq_domains must implement callback alloc() */
	if (domain->ops->alloc)
		domain->flags |= IRQ_DOMAIN_FLAG_HIERARCHY;
}
#else	/* CONFIG_IRQ_DOMAIN_HIERARCHY */
/**
 * irq_domain_get_irq_data - Get irq_data associated with @virq and @domain
 * @domain:	domain to match
 * @virq:	IRQ number to get irq_data
 */
struct irq_data *irq_domain_get_irq_data(struct irq_domain *domain,
					 unsigned int virq)
{
	struct irq_data *irq_data = irq_get_irq_data(virq);

	return (irq_data && irq_data->domain == domain) ? irq_data : NULL;
}

static void irq_domain_check_hierarchy(struct irq_domain *domain)
{
}
#endif	/* CONFIG_IRQ_DOMAIN_HIERARCHY */