// SPDX-License-Identifier: GPL-2.0

#define pr_fmt(fmt)  "irq: " fmt

#include <linux/acpi.h>
#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 struct irq_domain *irq_default_domain;

static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,
                                        unsigned int nr_irqs, int node, void *arg,
                                        bool realloc, const struct irq_affinity_desc *affinity);
static void irq_domain_check_hierarchy(struct irq_domain *domain);
static void irq_domain_free_one_irq(struct irq_domain *domain, unsigned int virq);

struct irqchip_fwid {
        struct fwnode_handle    fwnode;
        struct fwnode_handle    *parent;
        unsigned int            type;
        char                    *name;
        phys_addr_t             *pa;
};

#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
static void debugfs_add_domain_dir(struct irq_domain *d);
static void debugfs_remove_domain_dir(struct irq_domain *d);
#else
static inline void debugfs_add_domain_dir(struct irq_domain *d) { }
static inline void debugfs_remove_domain_dir(struct irq_domain *d) { }
#endif

static const char *irqchip_fwnode_get_name(const struct fwnode_handle *fwnode)
{
        struct irqchip_fwid *fwid = container_of(fwnode, struct irqchip_fwid, fwnode);

        return fwid->name;
}

static struct fwnode_handle *irqchip_fwnode_get_parent(const struct fwnode_handle *fwnode)
{
        struct irqchip_fwid *fwid = container_of(fwnode, struct irqchip_fwid, fwnode);

        return fwid->parent;
}

const struct fwnode_operations irqchip_fwnode_ops = {
        .get_name = irqchip_fwnode_get_name,
        .get_parent = irqchip_fwnode_get_parent,
};
EXPORT_SYMBOL_GPL(irqchip_fwnode_ops);

/**
 * __irq_domain_alloc_fwnode - Allocate a fwnode_handle suitable for
 *                           identifying an irq domain
 * @type:       Type of irqchip_fwnode. See linux/irqdomain.h
 * @id:         Optional user provided id if name != NULL
 * @name:       Optional user provided domain name
 * @pa:         Optional user-provided physical address
 * @parent:     Optional parent fwnode_handle
 *
 * Allocate a struct irqchip_fwid, and return a pointer to the embedded
 * fwnode_handle (or NULL on failure).
 *
 * Note: The types IRQCHIP_FWNODE_NAMED and IRQCHIP_FWNODE_NAMED_ID are
 * solely to transport name information to irqdomain creation code. The
 * node is not stored. For other types the pointer is kept in the irq
 * domain struct.
 */
struct fwnode_handle *__irq_domain_alloc_fwnode(unsigned int type, int id,
                                                const char *name,
                                                phys_addr_t *pa,
                                                struct fwnode_handle *parent)
{
        struct irqchip_fwid *fwid;
        char *n;

        fwid = kzalloc_obj(*fwid);

        switch (type) {
        case IRQCHIP_FWNODE_NAMED:
                n = kasprintf(GFP_KERNEL, "%s", name);
                break;
        case IRQCHIP_FWNODE_NAMED_ID:
                n = kasprintf(GFP_KERNEL, "%s-%d", name, id);
                break;
        default:
                n = kasprintf(GFP_KERNEL, "irqchip@%pa", pa);
                break;
        }

        if (!fwid || !n) {
                kfree(fwid);
                kfree(n);
                return NULL;
        }

        fwid->type = type;
        fwid->name = n;
        fwid->pa = pa;
        fwid->parent = parent;
        fwnode_init(&fwid->fwnode, &irqchip_fwnode_ops);
        return &fwid->fwnode;
}
EXPORT_SYMBOL_GPL(__irq_domain_alloc_fwnode);

/**
 * irq_domain_free_fwnode - Free a non-OF-backed fwnode_handle
 * @fwnode: fwnode_handle to free
 *
 * Free a fwnode_handle allocated with irq_domain_alloc_fwnode.
 */
void irq_domain_free_fwnode(struct fwnode_handle *fwnode)
{
        struct irqchip_fwid *fwid;

        if (!fwnode || WARN_ON(!is_fwnode_irqchip(fwnode)))
                return;

        fwid = container_of(fwnode, struct irqchip_fwid, fwnode);
        kfree(fwid->name);
        kfree(fwid);
}
EXPORT_SYMBOL_GPL(irq_domain_free_fwnode);

static int alloc_name(struct irq_domain *domain, char *base, enum irq_domain_bus_token bus_token)
{
        if (bus_token == DOMAIN_BUS_ANY)
                domain->name = kasprintf(GFP_KERNEL, "%s", base);
        else
                domain->name = kasprintf(GFP_KERNEL, "%s-%d", base, bus_token);
        if (!domain->name)
                return -ENOMEM;

        domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
        return 0;
}

static int alloc_fwnode_name(struct irq_domain *domain, const struct fwnode_handle *fwnode,
                             enum irq_domain_bus_token bus_token, const char *suffix)
{
        const char *sep = suffix ? "-" : "";
        const char *suf = suffix ? : "";
        char *name;

        if (bus_token == DOMAIN_BUS_ANY)
                name = kasprintf(GFP_KERNEL, "%pfw%s%s", fwnode, sep, suf);
        else
                name = kasprintf(GFP_KERNEL, "%pfw%s%s-%d", fwnode, sep, suf, bus_token);
        if (!name)
                return -ENOMEM;

        /*
         * fwnode paths contain '/', which debugfs is legitimately unhappy
         * about. Replace them with ':', which does the trick and is not as
         * offensive as '\'...
         */
        domain->name = strreplace(name, '/', ':');
        domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
        return 0;
}

static int alloc_unknown_name(struct irq_domain *domain, enum irq_domain_bus_token bus_token)
{
        static atomic_t unknown_domains;
        int id = atomic_inc_return(&unknown_domains);

        if (bus_token == DOMAIN_BUS_ANY)
                domain->name = kasprintf(GFP_KERNEL, "unknown-%d", id);
        else
                domain->name = kasprintf(GFP_KERNEL, "unknown-%d-%d", id, bus_token);
        if (!domain->name)
                return -ENOMEM;

        domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
        return 0;
}

static int irq_domain_set_name(struct irq_domain *domain, const struct irq_domain_info *info)
{
        enum irq_domain_bus_token bus_token = info->bus_token;
        const struct fwnode_handle *fwnode = info->fwnode;

        if (is_fwnode_irqchip(fwnode)) {
                const struct irqchip_fwid *fwid = container_of(fwnode, struct irqchip_fwid, fwnode);

                /*
                 * The name_suffix is only intended to be used to avoid a name
                 * collision when multiple domains are created for a single
                 * device and the name is picked using a real device node.
                 * (Typical use-case is regmap-IRQ controllers for devices
                 * providing more than one physical IRQ.) There should be no
                 * need to use name_suffix with irqchip-fwnode.
                 */
                if (info->name_suffix)
                        return -EINVAL;

                switch (fwid->type) {
                case IRQCHIP_FWNODE_NAMED:
                case IRQCHIP_FWNODE_NAMED_ID:
                        return alloc_name(domain, fwid->name, bus_token);
                default:
                        domain->name = fwid->name;
                        if (bus_token != DOMAIN_BUS_ANY)
                                return alloc_name(domain, fwid->name, bus_token);
                }

        } else if (is_of_node(fwnode) || is_acpi_device_node(fwnode) || is_software_node(fwnode)) {
                return alloc_fwnode_name(domain, fwnode, bus_token, info->name_suffix);
        }

        if (domain->name)
                return 0;

        if (fwnode)
                pr_err("Invalid fwnode type for irqdomain\n");
        return alloc_unknown_name(domain, bus_token);
}

static struct irq_domain *__irq_domain_create(const struct irq_domain_info *info)
{
        struct irq_domain *domain;
        int err;

        if (WARN_ON((info->size && info->direct_max) ||
                    (!IS_ENABLED(CONFIG_IRQ_DOMAIN_NOMAP) && info->direct_max) ||
                    (info->direct_max && info->direct_max != info->hwirq_max)))
                return ERR_PTR(-EINVAL);

        domain = kzalloc_node(struct_size(domain, revmap, info->size),
                              GFP_KERNEL, of_node_to_nid(to_of_node(info->fwnode)));
        if (!domain)
                return ERR_PTR(-ENOMEM);

        err = irq_domain_set_name(domain, info);
        if (err) {
                kfree(domain);
                return ERR_PTR(err);
        }

        domain->fwnode = fwnode_handle_get(info->fwnode);
        fwnode_dev_initialized(domain->fwnode, true);

        /* Fill structure */
        INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
        domain->ops = info->ops;
        domain->host_data = info->host_data;
        domain->bus_token = info->bus_token;
        domain->hwirq_max = info->hwirq_max;

        if (info->direct_max)
                domain->flags |= IRQ_DOMAIN_FLAG_NO_MAP;

        domain->revmap_size = info->size;

        /*
         * Hierarchical domains use the domain lock of the root domain
         * (innermost domain).
         *
         * For non-hierarchical domains (as for root domains), the root
         * pointer is set to the domain itself so that &domain->root->mutex
         * always points to the right lock.
         */
        mutex_init(&domain->mutex);
        domain->root = domain;

        irq_domain_check_hierarchy(domain);

        return domain;
}

static void __irq_domain_publish(struct irq_domain *domain)
{
        mutex_lock(&irq_domain_mutex);
        debugfs_add_domain_dir(domain);
        list_add(&domain->link, &irq_domain_list);
        mutex_unlock(&irq_domain_mutex);

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

static void irq_domain_free(struct irq_domain *domain)
{
        fwnode_dev_initialized(domain->fwnode, false);
        fwnode_handle_put(domain->fwnode);
        if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
                kfree(domain->name);
        kfree(domain);
}

static void irq_domain_instantiate_descs(const struct irq_domain_info *info)
{
        if (!IS_ENABLED(CONFIG_SPARSE_IRQ))
                return;

        if (irq_alloc_descs(info->virq_base, info->virq_base, info->size,
                            of_node_to_nid(to_of_node(info->fwnode))) < 0) {
                pr_info("Cannot allocate irq_descs @ IRQ%d, assuming pre-allocated\n",
                        info->virq_base);
        }
}

static struct irq_domain *__irq_domain_instantiate(const struct irq_domain_info *info,
                                                   bool cond_alloc_descs, bool force_associate)
{
        struct irq_domain *domain;
        int err;

        domain = __irq_domain_create(info);
        if (IS_ERR(domain))
                return domain;

        domain->flags |= info->domain_flags;
        domain->exit = info->exit;
        domain->dev = info->dev;

#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
        if (info->parent) {
                domain->root = info->parent->root;
                domain->parent = info->parent;
        }
#endif

        if (info->dgc_info) {
                err = irq_domain_alloc_generic_chips(domain, info->dgc_info);
                if (err)
                        goto err_domain_free;
        }

        if (info->init) {
                err = info->init(domain);
                if (err)
                        goto err_domain_gc_remove;
        }

        __irq_domain_publish(domain);

        if (cond_alloc_descs && info->virq_base > 0)
                irq_domain_instantiate_descs(info);

        /*
         * Legacy interrupt domains have a fixed Linux interrupt number
         * associated. Other interrupt domains can request association by
         * providing a Linux interrupt number > 0.
         */
        if (force_associate || info->virq_base > 0) {
                irq_domain_associate_many(domain, info->virq_base, info->hwirq_base,
                                          info->size - info->hwirq_base);
        }

        return domain;

err_domain_gc_remove:
        if (info->dgc_info)
                irq_domain_remove_generic_chips(domain);
err_domain_free:
        irq_domain_free(domain);
        return ERR_PTR(err);
}

/**
 * irq_domain_instantiate() - Instantiate a new irq domain data structure
 * @info: Domain information pointer pointing to the information for this domain
 *
 * Return: A pointer to the instantiated irq domain or an ERR_PTR value.
 */
struct irq_domain *irq_domain_instantiate(const struct irq_domain_info *info)
{
        return __irq_domain_instantiate(info, false, false);
}
EXPORT_SYMBOL_GPL(irq_domain_instantiate);

/**
 * 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)
{
        if (domain->exit)
                domain->exit(domain);

        mutex_lock(&irq_domain_mutex);
        debugfs_remove_domain_dir(domain);

        WARN_ON(!radix_tree_empty(&domain->revmap_tree));

        list_del(&domain->link);

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

        mutex_unlock(&irq_domain_mutex);

        if (domain->flags & IRQ_DOMAIN_FLAG_DESTROY_GC)
                irq_domain_remove_generic_chips(domain);

        pr_debug("Removed domain %s\n", domain->name);
        irq_domain_free(domain);
}
EXPORT_SYMBOL_GPL(irq_domain_remove);

void irq_domain_update_bus_token(struct irq_domain *domain,
                                 enum irq_domain_bus_token bus_token)
{
        char *name;

        if (domain->bus_token == bus_token)
                return;

        mutex_lock(&irq_domain_mutex);

        domain->bus_token = bus_token;

        name = kasprintf(GFP_KERNEL, "%s-%d", domain->name, bus_token);
        if (!name) {
                mutex_unlock(&irq_domain_mutex);
                return;
        }

        debugfs_remove_domain_dir(domain);

        if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
                kfree(domain->name);
        else
                domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;

        domain->name = name;
        debugfs_add_domain_dir(domain);

        mutex_unlock(&irq_domain_mutex);
}
EXPORT_SYMBOL_GPL(irq_domain_update_bus_token);

/**
 * irq_domain_create_simple() - Register an irq_domain and optionally map a range of irqs
 * @fwnode: firmware node for the interrupt controller
 * @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_create_simple(struct fwnode_handle *fwnode,
                                            unsigned int size,
                                            unsigned int first_irq,
                                            const struct irq_domain_ops *ops,
                                            void *host_data)
{
        struct irq_domain_info info = {
                .fwnode         = fwnode,
                .size           = size,
                .hwirq_max      = size,
                .virq_base      = first_irq,
                .ops            = ops,
                .host_data      = host_data,
        };
        struct irq_domain *domain = __irq_domain_instantiate(&info, true, false);

        return IS_ERR(domain) ? NULL : domain;
}
EXPORT_SYMBOL_GPL(irq_domain_create_simple);

struct irq_domain *irq_domain_create_legacy(struct fwnode_handle *fwnode,
                                         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_info info = {
                .fwnode         = fwnode,
                .size           = first_hwirq + size,
                .hwirq_max      = first_hwirq + size,
                .hwirq_base     = first_hwirq,
                .virq_base      = first_irq,
                .ops            = ops,
                .host_data      = host_data,
        };
        struct irq_domain *domain = __irq_domain_instantiate(&info, false, true);

        return IS_ERR(domain) ? NULL : domain;
}
EXPORT_SYMBOL_GPL(irq_domain_create_legacy);

/**
 * irq_find_matching_fwspec() - Locates a domain for a given fwspec
 * @fwspec: FW specifier for an interrupt
 * @bus_token: domain-specific data
 */
struct irq_domain *irq_find_matching_fwspec(struct irq_fwspec *fwspec,
                                            enum irq_domain_bus_token bus_token)
{
        struct irq_domain *h, *found = NULL;
        struct fwnode_handle *fwnode = fwspec->fwnode;
        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...
         *
         * bus_token == DOMAIN_BUS_ANY matches any domain, any other
         * values must generate an exact match for the domain to be
         * selected.
         */
        mutex_lock(&irq_domain_mutex);
        list_for_each_entry(h, &irq_domain_list, link) {
                if (h->ops->select && bus_token != DOMAIN_BUS_ANY)
                        rc = h->ops->select(h, fwspec, bus_token);
                else if (h->ops->match)
                        rc = h->ops->match(h, to_of_node(fwnode), bus_token);
                else
                        rc = ((fwnode != NULL) && (h->fwnode == fwnode) &&
                              ((bus_token == DOMAIN_BUS_ANY) ||
                               (h->bus_token == bus_token)));

                if (rc) {
                        found = h;
                        break;
                }
        }
        mutex_unlock(&irq_domain_mutex);
        return found;
}
EXPORT_SYMBOL_GPL(irq_find_matching_fwspec);

/**
 * irq_set_default_domain() - 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_domain(struct irq_domain *domain)
{
        pr_debug("Default domain set to @0x%p\n", domain);

        irq_default_domain = domain;
}
EXPORT_SYMBOL_GPL(irq_set_default_domain);

/**
 * irq_get_default_domain() - Retrieve the "default" irq domain
 *
 * Returns: the default domain, if any.
 *
 * Modern code should never use this. This should only be used on
 * systems that cannot implement a firmware->fwnode mapping (which
 * both DT and ACPI provide).
 */
struct irq_domain *irq_get_default_domain(void)
{
        return irq_default_domain;
}
EXPORT_SYMBOL_GPL(irq_get_default_domain);

static bool irq_domain_is_nomap(struct irq_domain *domain)
{
        return IS_ENABLED(CONFIG_IRQ_DOMAIN_NOMAP) &&
               (domain->flags & IRQ_DOMAIN_FLAG_NO_MAP);
}

static void irq_domain_clear_mapping(struct irq_domain *domain,
                                     irq_hw_number_t hwirq)
{
        lockdep_assert_held(&domain->root->mutex);

        if (irq_domain_is_nomap(domain))
                return;

        if (hwirq < domain->revmap_size)
                rcu_assign_pointer(domain->revmap[hwirq], NULL);
        else
                radix_tree_delete(&domain->revmap_tree, hwirq);
}

static void irq_domain_set_mapping(struct irq_domain *domain,
                                   irq_hw_number_t hwirq,
                                   struct irq_data *irq_data)
{
        /*
         * This also makes sure that all domains point to the same root when
         * called from irq_domain_insert_irq() for each domain in a hierarchy.
         */
        lockdep_assert_held(&domain->root->mutex);

        if (irq_domain_is_nomap(domain))
                return;

        if (hwirq < domain->revmap_size)
                rcu_assign_pointer(domain->revmap[hwirq], irq_data);
        else
                radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
}

static 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;

        mutex_lock(&domain->root->mutex);

        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;
        domain->mapcount--;

        /* Clear reverse map for this hwirq */
        irq_domain_clear_mapping(domain, hwirq);

        mutex_unlock(&domain->root->mutex);
}

static int irq_domain_associate_locked(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;

        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;
                        return ret;
                }
        }

        domain->mapcount++;
        irq_domain_set_mapping(domain, hwirq, irq_data);

        irq_clear_status_flags(virq, IRQ_NOREQUEST);

        return 0;
}

int irq_domain_associate(struct irq_domain *domain, unsigned int virq,
                         irq_hw_number_t hwirq)
{
        int ret;

        mutex_lock(&domain->root->mutex);
        ret = irq_domain_associate_locked(domain, virq, hwirq);
        mutex_unlock(&domain->root->mutex);

        return ret;
}
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)
{
        struct device_node *of_node;
        int i;

        of_node = irq_domain_get_of_node(domain);
        pr_debug("%s(%s, irqbase=%i, hwbase=%i, count=%i)\n", __func__,
                of_node_full_name(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);

#ifdef CONFIG_IRQ_DOMAIN_NOMAP
/**
 * 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)
{
        struct device_node *of_node;
        unsigned int virq;

        if (domain == NULL)
                domain = irq_default_domain;

        of_node = irq_domain_get_of_node(domain);
        virq = irq_alloc_desc_from(1, of_node_to_nid(of_node));
        if (!virq) {
                pr_debug("create_direct virq allocation failed\n");
                return 0;
        }
        if (virq >= domain->hwirq_max) {
                pr_err("ERROR: no free irqs available below %lu maximum\n",
                        domain->hwirq_max);
                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);
#endif

static unsigned int irq_create_mapping_affinity_locked(struct irq_domain *domain,
                                                       irq_hw_number_t hwirq,
                                                       const struct irq_affinity_desc *affinity)
{
        struct device_node *of_node = irq_domain_get_of_node(domain);
        int virq;

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

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

        if (irq_domain_associate_locked(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(of_node), virq);

        return virq;
}

/**
 * irq_create_mapping_affinity() - 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
 * @affinity: irq affinity
 *
 * 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_affinity(struct irq_domain *domain,
                                         irq_hw_number_t hwirq,
                                         const struct irq_affinity_desc *affinity)
{
        int virq;

        /* Look for default domain if necessary */
        if (domain == NULL)
                domain = irq_default_domain;
        if (domain == NULL) {
                WARN(1, "%s(, %lx) called with NULL domain\n", __func__, hwirq);
                return 0;
        }

        mutex_lock(&domain->root->mutex);

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

        virq = irq_create_mapping_affinity_locked(domain, hwirq, affinity);
out:
        mutex_unlock(&domain->root->mutex);

        return virq;
}
EXPORT_SYMBOL_GPL(irq_create_mapping_affinity);

static int irq_domain_translate(struct irq_domain *d,
                                struct irq_fwspec *fwspec,
                                irq_hw_number_t *hwirq, unsigned int *type)
{
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
        if (d->ops->translate)
                return d->ops->translate(d, fwspec, hwirq, type);
#endif
        if (d->ops->xlate)
                return d->ops->xlate(d, to_of_node(fwspec->fwnode),
                                     fwspec->param, fwspec->param_count,
                                     hwirq, type);

        /* If domain has no translation, then we assume interrupt line */
        *hwirq = fwspec->param[0];
        return 0;
}

void of_phandle_args_to_fwspec(struct device_node *np, const u32 *args,
                               unsigned int count, struct irq_fwspec *fwspec)
{
        int i;

        fwspec->fwnode = of_fwnode_handle(np);
        fwspec->param_count = count;

        for (i = 0; i < count; i++)
                fwspec->param[i] = args[i];
}
EXPORT_SYMBOL_GPL(of_phandle_args_to_fwspec);

static struct irq_domain *fwspec_to_domain(struct irq_fwspec *fwspec)
{
        struct irq_domain *domain;

        if (fwspec->fwnode) {
                domain = irq_find_matching_fwspec(fwspec, DOMAIN_BUS_WIRED);
                if (!domain)
                        domain = irq_find_matching_fwspec(fwspec, DOMAIN_BUS_ANY);
        } else {
                domain = irq_default_domain;
        }

        return domain;
}

#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
int irq_populate_fwspec_info(struct irq_fwspec *fwspec, struct irq_fwspec_info *info)
{
        struct irq_domain *domain = fwspec_to_domain(fwspec);

        memset(info, 0, sizeof(*info));

        if (!domain || !domain->ops->get_fwspec_info)
                return 0;

        return domain->ops->get_fwspec_info(fwspec, info);
}
#endif

unsigned int irq_create_fwspec_mapping(struct irq_fwspec *fwspec)
{
        unsigned int type = IRQ_TYPE_NONE;
        struct irq_domain *domain;
        struct irq_data *irq_data;
        irq_hw_number_t hwirq;
        int virq;

        domain = fwspec_to_domain(fwspec);
        if (!domain) {
                pr_warn("no irq domain found for %s !\n",
                        of_node_full_name(to_of_node(fwspec->fwnode)));
                return 0;
        }

        if (irq_domain_translate(domain, fwspec, &hwirq, &type))
                return 0;

        /*
         * WARN if the irqchip returns a type with bits
         * outside the sense mask set and clear these bits.
         */
        if (WARN_ON(type & ~IRQ_TYPE_SENSE_MASK))
                type &= IRQ_TYPE_SENSE_MASK;

        mutex_lock(&domain->root->mutex);

        /*
         * 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) {
                /*
                 * If the trigger type is not specified or matches the
                 * current trigger type then we are done so return the
                 * interrupt number.
                 */
                if (type == IRQ_TYPE_NONE || type == irq_get_trigger_type(virq))
                        goto out;

                /*
                 * If the trigger type has not been set yet, then set
                 * it now and return the interrupt number.
                 */
                if (irq_get_trigger_type(virq) == IRQ_TYPE_NONE) {
                        irq_data = irq_get_irq_data(virq);
                        if (!irq_data) {
                                virq = 0;
                                goto out;
                        }

                        irqd_set_trigger_type(irq_data, type);
                        goto out;
                }

                pr_warn("type mismatch, failed to map hwirq-%lu for %s!\n",
                        hwirq, of_node_full_name(to_of_node(fwspec->fwnode)));
                virq = 0;
                goto out;
        }

        if (irq_domain_is_hierarchy(domain)) {
                if (irq_domain_is_msi_device(domain)) {
                        mutex_unlock(&domain->root->mutex);
                        virq = msi_device_domain_alloc_wired(domain, hwirq, type);
                        mutex_lock(&domain->root->mutex);
                } else
                        virq = irq_domain_alloc_irqs_locked(domain, -1, 1, NUMA_NO_NODE,
                                                            fwspec, false, NULL);
                if (virq <= 0) {
                        virq = 0;
                        goto out;
                }
        } else {
                /* Create mapping */
                virq = irq_create_mapping_affinity_locked(domain, hwirq, NULL);
                if (!virq)
                        goto out;
        }

        irq_data = irq_get_irq_data(virq);
        if (WARN_ON(!irq_data)) {
                virq = 0;
                goto out;
        }

        /* Store trigger type */
        irqd_set_trigger_type(irq_data, type);
out:
        mutex_unlock(&domain->root->mutex);

        return virq;
}
EXPORT_SYMBOL_GPL(irq_create_fwspec_mapping);

unsigned int irq_create_of_mapping(struct of_phandle_args *irq_data)
{
        struct irq_fwspec fwspec;

        of_phandle_args_to_fwspec(irq_data->np, irq_data->args,
                                  irq_data->args_count, &fwspec);

        return irq_create_fwspec_mapping(&fwspec);
}
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;
        struct irq_domain *domain;

        irq_data = virq ? irq_get_irq_data(virq) : NULL;
        if (!irq_data)
                return;

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

        if (irq_domain_is_hierarchy(domain)) {
                irq_domain_free_one_irq(domain, virq);
        } else {
                irq_domain_disassociate(domain, virq);
                irq_free_desc(virq);
        }
}
EXPORT_SYMBOL_GPL(irq_dispose_mapping);

/**
 * __irq_resolve_mapping() - Find a linux irq from a hw irq number.
 * @domain: domain owning this hardware interrupt
 * @hwirq: hardware irq number in that domain space
 * @irq: optional pointer to return the Linux irq if required
 *
 * Returns the interrupt descriptor.
 */
struct irq_desc *__irq_resolve_mapping(struct irq_domain *domain,
                                       irq_hw_number_t hwirq,
                                       unsigned int *irq)
{
        struct irq_desc *desc = NULL;
        struct irq_data *data;

        /* Look for default domain if necessary */
        if (domain == NULL)
                domain = irq_default_domain;
        if (domain == NULL)
                return desc;

        if (irq_domain_is_nomap(domain)) {
                if (hwirq < domain->hwirq_max) {
                        data = irq_domain_get_irq_data(domain, hwirq);
                        if (data && data->hwirq == hwirq)
                                desc = irq_data_to_desc(data);
                        if (irq && desc)
                                *irq = hwirq;
                }

                return desc;
        }

        rcu_read_lock();
        /* Check if the hwirq is in the linear revmap. */
        if (hwirq < domain->revmap_size)
                data = rcu_dereference(domain->revmap[hwirq]);
        else
                data = radix_tree_lookup(&domain->revmap_tree, hwirq);

        if (likely(data)) {
                desc = irq_data_to_desc(data);
                if (irq)
                        *irq = data->irq;
        }

        rcu_read_unlock();
        return desc;
}
EXPORT_SYMBOL_GPL(__irq_resolve_mapping);

/**
 * irq_domain_xlate_onecell() - Generic xlate for direct one cell bindings
 * @d:          Interrupt domain involved in the translation
 * @ctrlr:      The device tree node for the device whose interrupt is translated
 * @intspec:    The interrupt specifier data from the device tree
 * @intsize:    The number of entries in @intspec
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 *
 * 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
 * @d:          Interrupt domain involved in the translation
 * @ctrlr:      The device tree node for the device whose interrupt is translated
 * @intspec:    The interrupt specifier data from the device tree
 * @intsize:    The number of entries in @intspec
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 *
 * 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)
{
        struct irq_fwspec fwspec;

        of_phandle_args_to_fwspec(ctrlr, intspec, intsize, &fwspec);
        return irq_domain_translate_twocell(d, &fwspec, out_hwirq, out_type);
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_twocell);

/**
 * irq_domain_xlate_twothreecell() - Generic xlate for direct two or three cell bindings
 * @d:          Interrupt domain involved in the translation
 * @ctrlr:      The device tree node for the device whose interrupt is translated
 * @intspec:    The interrupt specifier data from the device tree
 * @intsize:    The number of entries in @intspec
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 *
 * Device Tree interrupt specifier translation function for two or three
 * cell bindings, where the cell values map directly to the hardware
 * interrupt number and the type specifier.
 */
int irq_domain_xlate_twothreecell(struct irq_domain *d, struct device_node *ctrlr,
                                  const u32 *intspec, unsigned int intsize,
                                  irq_hw_number_t *out_hwirq, unsigned int *out_type)
{
        struct irq_fwspec fwspec;

        of_phandle_args_to_fwspec(ctrlr, intspec, intsize, &fwspec);

        return irq_domain_translate_twothreecell(d, &fwspec, out_hwirq, out_type);
}
EXPORT_SYMBOL_GPL(irq_domain_xlate_twothreecell);

/**
 * irq_domain_xlate_onetwocell() - Generic xlate for one or two cell bindings
 * @d:          Interrupt domain involved in the translation
 * @ctrlr:      The device tree node for the device whose interrupt is translated
 * @intspec:    The interrupt specifier data from the device tree
 * @intsize:    The number of entries in @intspec
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 *
 * 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];
        if (intsize > 1)
                *out_type = intspec[1] & IRQ_TYPE_SENSE_MASK;
        else
                *out_type = 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);

/**
 * irq_domain_translate_onecell() - Generic translate for direct one cell
 * bindings
 * @d:          Interrupt domain involved in the translation
 * @fwspec:     The firmware interrupt specifier to translate
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 */
int irq_domain_translate_onecell(struct irq_domain *d,
                                 struct irq_fwspec *fwspec,
                                 unsigned long *out_hwirq,
                                 unsigned int *out_type)
{
        if (WARN_ON(fwspec->param_count < 1))
                return -EINVAL;
        *out_hwirq = fwspec->param[0];
        *out_type = IRQ_TYPE_NONE;
        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_translate_onecell);

/**
 * irq_domain_translate_twocell() - Generic translate for direct two cell
 * bindings
 * @d:          Interrupt domain involved in the translation
 * @fwspec:     The firmware interrupt specifier to translate
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 *
 * 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_translate_twocell(struct irq_domain *d,
                                 struct irq_fwspec *fwspec,
                                 unsigned long *out_hwirq,
                                 unsigned int *out_type)
{
        if (WARN_ON(fwspec->param_count < 2))
                return -EINVAL;
        *out_hwirq = fwspec->param[0];
        *out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_translate_twocell);

/**
 * irq_domain_translate_twothreecell() - Generic translate for direct two or three cell
 * bindings
 * @d:          Interrupt domain involved in the translation
 * @fwspec:     The firmware interrupt specifier to translate
 * @out_hwirq:  Pointer to storage for the hardware interrupt number
 * @out_type:   Pointer to storage for the interrupt type
 *
 * Firmware interrupt specifier translation function for two or three cell
 * specifications, where the parameter values map directly to the hardware
 * interrupt number and the type specifier.
 */
int irq_domain_translate_twothreecell(struct irq_domain *d, struct irq_fwspec *fwspec,
                                      unsigned long *out_hwirq, unsigned int *out_type)
{
        if (fwspec->param_count == 2) {
                *out_hwirq = fwspec->param[0];
                *out_type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
                return 0;
        }

        if (fwspec->param_count == 3) {
                *out_hwirq = fwspec->param[1];
                *out_type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;
                return 0;
        }

        return -EINVAL;
}
EXPORT_SYMBOL_GPL(irq_domain_translate_twothreecell);

int irq_domain_alloc_descs(int virq, unsigned int cnt, irq_hw_number_t hwirq,
                           int node, const struct irq_affinity_desc *affinity)
{
        unsigned int hint;

        if (virq >= 0) {
                virq = __irq_alloc_descs(virq, virq, cnt, node, THIS_MODULE,
                                         affinity);
        } else {
                hint = hwirq % irq_get_nr_irqs();
                if (hint == 0)
                        hint++;
                virq = __irq_alloc_descs(-1, hint, cnt, node, THIS_MODULE,
                                         affinity);
                if (virq <= 0 && hint > 1) {
                        virq = __irq_alloc_descs(-1, 1, cnt, node, THIS_MODULE,
                                                 affinity);
                }
        }

        return virq;
}

/**
 * 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;
}
EXPORT_SYMBOL_GPL(irq_domain_reset_irq_data);

#ifdef  CONFIG_IRQ_DOMAIN_HIERARCHY
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;

                domain->mapcount++;
                irq_domain_set_mapping(domain, data->hwirq, data);
        }

        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;

                domain->mapcount--;
                irq_domain_clear_mapping(domain, hwirq);
        }
}

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,
                                irq_data_get_node(child));
        if (irq_data) {
                child->parent_data = irq_data;
                irq_data->irq = child->irq;
                irq_data->common = child->common;
                irq_data->domain = domain;
        }

        return irq_data;
}

static void __irq_domain_free_hierarchy(struct irq_data *irq_data)
{
        struct irq_data *tmp;

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

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;

                __irq_domain_free_hierarchy(tmp);
        }
}

/**
 * irq_domain_disconnect_hierarchy - Mark the first unused level of a hierarchy
 * @domain:     IRQ domain from which the hierarchy is to be disconnected
 * @virq:       IRQ number where the hierarchy is to be trimmed
 *
 * Marks the @virq level belonging to @domain as disconnected.
 * Returns -EINVAL if @virq doesn't have a valid irq_data pointing
 * to @domain.
 *
 * Its only use is to be able to trim levels of hierarchy that do not
 * have any real meaning for this interrupt, and that the driver marks
 * as such from its .alloc() callback.
 */
int irq_domain_disconnect_hierarchy(struct irq_domain *domain,
                                    unsigned int virq)
{
        struct irq_data *irqd;

        irqd = irq_domain_get_irq_data(domain, virq);
        if (!irqd)
                return -EINVAL;

        irqd->chip = ERR_PTR(-ENOTCONN);
        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_disconnect_hierarchy);

static int irq_domain_trim_hierarchy(unsigned int virq)
{
        struct irq_data *tail, *irqd, *irq_data;

        irq_data = irq_get_irq_data(virq);
        tail = NULL;

        /* The first entry must have a valid irqchip */
        if (IS_ERR_OR_NULL(irq_data->chip))
                return -EINVAL;

        /*
         * Validate that the irq_data chain is sane in the presence of
         * a hierarchy trimming marker.
         */
        for (irqd = irq_data->parent_data; irqd; irq_data = irqd, irqd = irqd->parent_data) {
                /* Can't have a valid irqchip after a trim marker */
                if (irqd->chip && tail)
                        return -EINVAL;

                /* Can't have an empty irqchip before a trim marker */
                if (!irqd->chip && !tail)
                        return -EINVAL;

                if (IS_ERR(irqd->chip)) {
                        /* Only -ENOTCONN is a valid trim marker */
                        if (PTR_ERR(irqd->chip) != -ENOTCONN)
                                return -EINVAL;

                        tail = irq_data;
                }
        }

        /* No trim marker, nothing to do */
        if (!tail)
                return 0;

        pr_info("IRQ%d: trimming hierarchy from %s\n",
                virq, tail->parent_data->domain->name);

        /* Sever the inner part of the hierarchy...  */
        irqd = tail;
        tail = tail->parent_data;
        irqd->parent_data = NULL;
        __irq_domain_free_hierarchy(tail);

        return 0;
}

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;
}
EXPORT_SYMBOL_GPL(irq_domain_get_irq_data);

/**
 * 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,
                                  const 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 = (struct irq_chip *)(chip ? chip : &no_irq_chip);
        irq_data->chip_data = chip_data;

        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_set_hwirq_and_chip);

/**
 * 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, const 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);
}
EXPORT_SYMBOL(irq_domain_set_info);

/**
 * 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);
}
EXPORT_SYMBOL_GPL(irq_domain_free_irqs_common);

/**
 * 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);
}
EXPORT_SYMBOL_GPL(irq_domain_free_irqs_top);

static void irq_domain_free_irqs_hierarchy(struct irq_domain *domain,
                                           unsigned int irq_base,
                                           unsigned int nr_irqs)
{
        unsigned int i;

        if (!domain->ops->free)
                return;

        for (i = 0; i < nr_irqs; i++) {
                if (irq_domain_get_irq_data(domain, irq_base + i))
                        domain->ops->free(domain, irq_base + i, 1);
        }
}

static int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain, unsigned int irq_base,
                                           unsigned int nr_irqs, void *arg)
{
        if (!domain->ops->alloc) {
                pr_debug("domain->ops->alloc() is NULL\n");
                return -ENOSYS;
        }

        return domain->ops->alloc(domain, irq_base, nr_irqs, arg);
}

static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,
                                        unsigned int nr_irqs, int node, void *arg,
                                        bool realloc, const struct irq_affinity_desc *affinity)
{
        int i, ret, virq;

        if (realloc && irq_base >= 0) {
                virq = irq_base;
        } else {
                virq = irq_domain_alloc_descs(irq_base, nr_irqs, 0, node,
                                              affinity);
                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;
        }

        ret = irq_domain_alloc_irqs_hierarchy(domain, virq, nr_irqs, arg);
        if (ret < 0)
                goto out_free_irq_data;

        for (i = 0; i < nr_irqs; i++) {
                ret = irq_domain_trim_hierarchy(virq + i);
                if (ret)
                        goto out_free_irq_data;
        }

        for (i = 0; i < nr_irqs; i++)
                irq_domain_insert_irq(virq + i);

        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_alloc_irqs - Allocate IRQs from domain
 * @domain:     domain to allocate from
 * @irq_base:   allocate specified IRQ number 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
 * @affinity:   Optional irq affinity mask for multiqueue devices
 *
 * 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 the hardware 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, const struct irq_affinity_desc *affinity)
{
        int ret;

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

        mutex_lock(&domain->root->mutex);
        ret = irq_domain_alloc_irqs_locked(domain, irq_base, nr_irqs, node, arg,
                                           realloc, affinity);
        mutex_unlock(&domain->root->mutex);

        return ret;
}
EXPORT_SYMBOL_GPL(__irq_domain_alloc_irqs);

/* The irq_data was moved, fix the revmap to refer to the new location */
static void irq_domain_fix_revmap(struct irq_data *d)
{
        void __rcu **slot;

        lockdep_assert_held(&d->domain->root->mutex);

        if (irq_domain_is_nomap(d->domain))
                return;

        /* Fix up the revmap. */
        if (d->hwirq < d->domain->revmap_size) {
                /* Not using radix tree */
                rcu_assign_pointer(d->domain->revmap[d->hwirq], d);
        } else {
                slot = radix_tree_lookup_slot(&d->domain->revmap_tree, d->hwirq);
                if (slot)
                        radix_tree_replace_slot(&d->domain->revmap_tree, slot, d);
        }
}

/**
 * irq_domain_push_irq() - Push a domain in to the top of a hierarchy.
 * @domain:     Domain to push.
 * @virq:       Irq to push the domain in to.
 * @arg:        Passed to the irq_domain_ops alloc() function.
 *
 * For an already existing irqdomain hierarchy, as might be obtained
 * via a call to pci_enable_msix(), add an additional domain to the
 * head of the processing chain.  Must be called before request_irq()
 * has been called.
 */
int irq_domain_push_irq(struct irq_domain *domain, int virq, void *arg)
{
        struct irq_data *irq_data = irq_get_irq_data(virq);
        struct irq_data *parent_irq_data;
        struct irq_desc *desc;
        int rv = 0;

        /*
         * Check that no action has been set, which indicates the virq
         * is in a state where this function doesn't have to deal with
         * races between interrupt handling and maintaining the
         * hierarchy.  This will catch gross misuse.  Attempting to
         * make the check race free would require holding locks across
         * calls to struct irq_domain_ops->alloc(), which could lead
         * to deadlock, so we just do a simple check before starting.
         */
        desc = irq_to_desc(virq);
        if (!desc)
                return -EINVAL;
        if (WARN_ON(desc->action))
                return -EBUSY;

        if (domain == NULL)
                return -EINVAL;

        if (WARN_ON(!irq_domain_is_hierarchy(domain)))
                return -EINVAL;

        if (!irq_data)
                return -EINVAL;

        if (domain->parent != irq_data->domain)
                return -EINVAL;

        parent_irq_data = kzalloc_node(sizeof(*parent_irq_data), GFP_KERNEL,
                                       irq_data_get_node(irq_data));
        if (!parent_irq_data)
                return -ENOMEM;

        mutex_lock(&domain->root->mutex);

        /* Copy the original irq_data. */
        *parent_irq_data = *irq_data;

        /*
         * Overwrite the irq_data, which is embedded in struct irq_desc, with
         * values for this domain.
         */
        irq_data->parent_data = parent_irq_data;
        irq_data->domain = domain;
        irq_data->mask = 0;
        irq_data->hwirq = 0;
        irq_data->chip = NULL;
        irq_data->chip_data = NULL;

        /* May (probably does) set hwirq, chip, etc. */
        rv = irq_domain_alloc_irqs_hierarchy(domain, virq, 1, arg);
        if (rv) {
                /* Restore the original irq_data. */
                *irq_data = *parent_irq_data;
                kfree(parent_irq_data);
                goto error;
        }

        irq_domain_fix_revmap(parent_irq_data);
        irq_domain_set_mapping(domain, irq_data->hwirq, irq_data);
error:
        mutex_unlock(&domain->root->mutex);

        return rv;
}
EXPORT_SYMBOL_GPL(irq_domain_push_irq);

/**
 * irq_domain_pop_irq() - Remove a domain from the top of a hierarchy.
 * @domain:     Domain to remove.
 * @virq:       Irq to remove the domain from.
 *
 * Undo the effects of a call to irq_domain_push_irq().  Must be
 * called either before request_irq() or after free_irq().
 */
int irq_domain_pop_irq(struct irq_domain *domain, int virq)
{
        struct irq_data *irq_data = irq_get_irq_data(virq);
        struct irq_data *parent_irq_data;
        struct irq_data *tmp_irq_data;
        struct irq_desc *desc;

        /*
         * Check that no action is set, which indicates the virq is in
         * a state where this function doesn't have to deal with races
         * between interrupt handling and maintaining the hierarchy.
         * This will catch gross misuse.  Attempting to make the check
         * race free would require holding locks across calls to
         * struct irq_domain_ops->free(), which could lead to
         * deadlock, so we just do a simple check before starting.
         */
        desc = irq_to_desc(virq);
        if (!desc)
                return -EINVAL;
        if (WARN_ON(desc->action))
                return -EBUSY;

        if (domain == NULL)
                return -EINVAL;

        if (!irq_data)
                return -EINVAL;

        tmp_irq_data = irq_domain_get_irq_data(domain, virq);

        /* We can only "pop" if this domain is at the top of the list */
        if (WARN_ON(irq_data != tmp_irq_data))
                return -EINVAL;

        if (WARN_ON(irq_data->domain != domain))
                return -EINVAL;

        parent_irq_data = irq_data->parent_data;
        if (WARN_ON(!parent_irq_data))
                return -EINVAL;

        mutex_lock(&domain->root->mutex);

        irq_data->parent_data = NULL;

        irq_domain_clear_mapping(domain, irq_data->hwirq);
        irq_domain_free_irqs_hierarchy(domain, virq, 1);

        /* Restore the original irq_data. */
        *irq_data = *parent_irq_data;

        irq_domain_fix_revmap(irq_data);

        mutex_unlock(&domain->root->mutex);

        kfree(parent_irq_data);

        return 0;
}
EXPORT_SYMBOL_GPL(irq_domain_pop_irq);

/**
 * 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);
        struct irq_domain *domain;
        int i;

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

        domain = data->domain;

        mutex_lock(&domain->root->mutex);
        for (i = 0; i < nr_irqs; i++)
                irq_domain_remove_irq(virq + i);
        irq_domain_free_irqs_hierarchy(domain, virq, nr_irqs);
        mutex_unlock(&domain->root->mutex);

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

static void irq_domain_free_one_irq(struct irq_domain *domain, unsigned int virq)
{
        if (irq_domain_is_msi_device(domain))
                msi_device_domain_free_wired(domain, virq);
        else
                irq_domain_free_irqs(virq, 1);
}

/**
 * irq_domain_alloc_irqs_parent - Allocate interrupts from parent domain
 * @domain:     Domain below which interrupts must be allocated
 * @irq_base:   Base IRQ number
 * @nr_irqs:    Number of IRQs to allocate
 * @arg:        Allocation data (arch/domain specific)
 */
int irq_domain_alloc_irqs_parent(struct irq_domain *domain,
                                 unsigned int irq_base, unsigned int nr_irqs,
                                 void *arg)
{
        if (!domain->parent)
                return -ENOSYS;

        return irq_domain_alloc_irqs_hierarchy(domain->parent, irq_base,
                                               nr_irqs, arg);
}
EXPORT_SYMBOL_GPL(irq_domain_alloc_irqs_parent);

/**
 * irq_domain_free_irqs_parent - Free interrupts from parent domain
 * @domain:     Domain below which interrupts must be freed
 * @irq_base:   Base IRQ number
 * @nr_irqs:    Number of IRQs to free
 */
void irq_domain_free_irqs_parent(struct irq_domain *domain,
                                 unsigned int irq_base, unsigned int nr_irqs)
{
        if (!domain->parent)
                return;

        irq_domain_free_irqs_hierarchy(domain->parent, irq_base, nr_irqs);
}
EXPORT_SYMBOL_GPL(irq_domain_free_irqs_parent);

static 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 int __irq_domain_activate_irq(struct irq_data *irqd, bool reserve)
{
        int ret = 0;

        if (irqd && irqd->domain) {
                struct irq_domain *domain = irqd->domain;

                if (irqd->parent_data)
                        ret = __irq_domain_activate_irq(irqd->parent_data,
                                                        reserve);
                if (!ret && domain->ops->activate) {
                        ret = domain->ops->activate(domain, irqd, reserve);
                        /* Rollback in case of error */
                        if (ret && irqd->parent_data)
                                __irq_domain_deactivate_irq(irqd->parent_data);
                }
        }
        return ret;
}

/**
 * irq_domain_activate_irq - Call domain_ops->activate recursively to activate
 *                           interrupt
 * @irq_data:   Outermost irq_data associated with interrupt
 * @reserve:    If set only reserve an interrupt vector instead of assigning one
 *
 * This is the second step to call domain_ops->activate to program interrupt
 * controllers, so the interrupt could actually get delivered.
 */
int irq_domain_activate_irq(struct irq_data *irq_data, bool reserve)
{
        int ret = 0;

        if (!irqd_is_activated(irq_data))
                ret = __irq_domain_activate_irq(irq_data, reserve);
        if (!ret)
                irqd_set_activated(irq_data);
        return ret;
}

/**
 * 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 (irqd_is_activated(irq_data)) {
                __irq_domain_deactivate_irq(irq_data);
                irqd_clr_activated(irq_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;
}
EXPORT_SYMBOL_GPL(irq_domain_get_irq_data);

/*
 * 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, const struct irq_chip *chip,
                         void *chip_data, irq_flow_handler_t handler,
                         void *handler_data, const char *handler_name)
{
        irq_set_chip_and_handler_name(virq, chip, handler, handler_name);
        irq_set_chip_data(virq, chip_data);
        irq_set_handler_data(virq, handler_data);
}

static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,
                                        unsigned int nr_irqs, int node, void *arg,
                                        bool realloc, const struct irq_affinity_desc *affinity)
{
        return -EINVAL;
}

static void irq_domain_check_hierarchy(struct irq_domain *domain) { }
static void irq_domain_free_one_irq(struct irq_domain *domain, unsigned int virq) { }

#endif  /* CONFIG_IRQ_DOMAIN_HIERARCHY */

#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
#include "internals.h"

static struct dentry *domain_dir;

static const struct irq_bit_descr irqdomain_flags[] = {
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_HIERARCHY),
        BIT_MASK_DESCR(IRQ_DOMAIN_NAME_ALLOCATED),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_IPI_PER_CPU),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_IPI_SINGLE),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_MSI),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_ISOLATED_MSI),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_NO_MAP),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_MSI_PARENT),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_MSI_DEVICE),
        BIT_MASK_DESCR(IRQ_DOMAIN_FLAG_NONCORE),
};

static void irq_domain_debug_show_one(struct seq_file *m, struct irq_domain *d, int ind)
{
        seq_printf(m, "%*sname:   %s\n", ind, "", d->name);
        seq_printf(m, "%*ssize:   %u\n", ind + 1, "", d->revmap_size);
        seq_printf(m, "%*smapped: %u\n", ind + 1, "", d->mapcount);
        seq_printf(m, "%*sflags:  0x%08x\n", ind +1 , "", d->flags);
        irq_debug_show_bits(m, ind, d->flags, irqdomain_flags, ARRAY_SIZE(irqdomain_flags));
        if (d->ops && d->ops->debug_show)
                d->ops->debug_show(m, d, NULL, ind + 1);
#ifdef  CONFIG_IRQ_DOMAIN_HIERARCHY
        if (!d->parent)
                return;
        seq_printf(m, "%*sparent: %s\n", ind + 1, "", d->parent->name);
        irq_domain_debug_show_one(m, d->parent, ind + 4);
#endif
}

static int irq_domain_debug_show(struct seq_file *m, void *p)
{
        struct irq_domain *d = m->private;

        /* Default domain? Might be NULL */
        if (!d) {
                if (!irq_default_domain)
                        return 0;
                d = irq_default_domain;
        }
        irq_domain_debug_show_one(m, d, 0);
        return 0;
}
DEFINE_SHOW_ATTRIBUTE(irq_domain_debug);

static void debugfs_add_domain_dir(struct irq_domain *d)
{
        if (!d->name || !domain_dir)
                return;
        debugfs_create_file(d->name, 0444, domain_dir, d,
                            &irq_domain_debug_fops);
}

static void debugfs_remove_domain_dir(struct irq_domain *d)
{
        debugfs_lookup_and_remove(d->name, domain_dir);
}

void __init irq_domain_debugfs_init(struct dentry *root)
{
        struct irq_domain *d;

        domain_dir = debugfs_create_dir("domains", root);

        debugfs_create_file("default", 0444, domain_dir, NULL,
                            &irq_domain_debug_fops);
        mutex_lock(&irq_domain_mutex);
        list_for_each_entry(d, &irq_domain_list, link)
                debugfs_add_domain_dir(d);
        mutex_unlock(&irq_domain_mutex);
}
#endif