cdrom: Fix info leak/OOB read in cdrom_ioctl_drive_status

[mirror_ubuntu-bionic-kernel.git] / kernel / irq / irqdomain.c

#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 void irq_domain_check_hierarchy(struct irq_domain *domain);

struct irqchip_fwid {
        struct fwnode_handle    fwnode;
        unsigned int            type;
        char                    *name;
        void *data;
};

#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

const struct fwnode_operations irqchip_fwnode_ops;
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
 * @name:       Optional user provided domain name
 * @id:         Optional user provided id if name != NULL
 * @data:       Optional user-provided data
 *
 * Allocate a struct irqchip_fwid, and return a poiner 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, void *data)
{
        struct irqchip_fwid *fwid;
        char *n;

        fwid = kzalloc(sizeof(*fwid), GFP_KERNEL);

        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@%p", data);
                break;
        }

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

        fwid->type = type;
        fwid->name = n;
        fwid->data = data;
        fwid->fwnode.ops = &irqchip_fwnode_ops;
        return &fwid->fwnode;
}
EXPORT_SYMBOL_GPL(__irq_domain_alloc_fwnode);

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

        if (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);

/**
 * __irq_domain_add() - Allocate a new irq_domain data structure
 * @fwnode: firmware node for 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 fwnode_handle *fwnode, int size,
                                    irq_hw_number_t hwirq_max, int direct_max,
                                    const struct irq_domain_ops *ops,
                                    void *host_data)
{
        struct device_node *of_node = to_of_node(fwnode);
        struct irqchip_fwid *fwid;
        struct irq_domain *domain;

        static atomic_t unknown_domains;

        domain = kzalloc_node(sizeof(*domain) + (sizeof(unsigned int) * size),
                              GFP_KERNEL, of_node_to_nid(of_node));
        if (WARN_ON(!domain))
                return NULL;

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

                switch (fwid->type) {
                case IRQCHIP_FWNODE_NAMED:
                case IRQCHIP_FWNODE_NAMED_ID:
                        domain->name = kstrdup(fwid->name, GFP_KERNEL);
                        if (!domain->name) {
                                kfree(domain);
                                return NULL;
                        }
                        domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
                        break;
                default:
                        domain->fwnode = fwnode;
                        domain->name = fwid->name;
                        break;
                }
#ifdef CONFIG_ACPI
        } else if (is_acpi_device_node(fwnode)) {
                struct acpi_buffer buf = {
                        .length = ACPI_ALLOCATE_BUFFER,
                };
                acpi_handle handle;

                handle = acpi_device_handle(to_acpi_device_node(fwnode));
                if (acpi_get_name(handle, ACPI_FULL_PATHNAME, &buf) == AE_OK) {
                        domain->name = buf.pointer;
                        domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
                }

                domain->fwnode = fwnode;
#endif
        } else if (of_node) {
                char *name;

                /*
                 * DT paths contain '/', which debugfs is legitimately
                 * unhappy about. Replace them with ':', which does
                 * the trick and is not as offensive as '\'...
                 */
                name = kstrdup(of_node_full_name(of_node), GFP_KERNEL);
                if (!name) {
                        kfree(domain);
                        return NULL;
                }

                strreplace(name, '/', ':');

                domain->name = name;
                domain->fwnode = fwnode;
                domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
        }

        if (!domain->name) {
                if (fwnode)
                        pr_err("Invalid fwnode type for irqdomain\n");
                domain->name = kasprintf(GFP_KERNEL, "unknown-%d",
                                         atomic_inc_return(&unknown_domains));
                if (!domain->name) {
                        kfree(domain);
                        return NULL;
                }
                domain->flags |= IRQ_DOMAIN_NAME_ALLOCATED;
        }

        of_node_get(of_node);

        /* Fill structure */
        INIT_RADIX_TREE(&domain->revmap_tree, GFP_KERNEL);
        mutex_init(&domain->revmap_tree_mutex);
        domain->ops = ops;
        domain->host_data = host_data;
        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);
        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);
        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);
        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_host(NULL);

        mutex_unlock(&irq_domain_mutex);

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

        of_node_put(irq_domain_get_of_node(domain));
        if (domain->flags & IRQ_DOMAIN_NAME_ALLOCATED)
                kfree(domain->name);
        kfree(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);
}

/**
 * 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_to_fwnode(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_to_fwnode(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_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 && fwspec->param_count)
                        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_domain_check_msi_remap - Check whether all MSI irq domains implement
 * IRQ remapping
 *
 * Return: false if any MSI irq domain does not support IRQ remapping,
 * true otherwise (including if there is no MSI irq domain)
 */
bool irq_domain_check_msi_remap(void)
{
        struct irq_domain *h;
        bool ret = true;

        mutex_lock(&irq_domain_mutex);
        list_for_each_entry(h, &irq_domain_list, link) {
                if (irq_domain_is_msi(h) &&
                    !irq_domain_hierarchical_is_msi_remap(h)) {
                        ret = false;
                        break;
                }
        }
        mutex_unlock(&irq_domain_mutex);
        return ret;
}
EXPORT_SYMBOL_GPL(irq_domain_check_msi_remap);

/**
 * 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);

static void irq_domain_clear_mapping(struct irq_domain *domain,
                                     irq_hw_number_t hwirq)
{
        if (hwirq < domain->revmap_size) {
                domain->linear_revmap[hwirq] = 0;
        } else {
                mutex_lock(&domain->revmap_tree_mutex);
                radix_tree_delete(&domain->revmap_tree, hwirq);
                mutex_unlock(&domain->revmap_tree_mutex);
        }
}

static void irq_domain_set_mapping(struct irq_domain *domain,
                                   irq_hw_number_t hwirq,
                                   struct irq_data *irq_data)
{
        if (hwirq < domain->revmap_size) {
                domain->linear_revmap[hwirq] = irq_data->irq;
        } else {
                mutex_lock(&domain->revmap_tree_mutex);
                radix_tree_insert(&domain->revmap_tree, hwirq, irq_data);
                mutex_unlock(&domain->revmap_tree_mutex);
        }
}

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;
        domain->mapcount--;

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

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;
        }

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

/**
 * 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->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)
{
        struct device_node *of_node;
        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);

        of_node = irq_domain_get_of_node(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(of_node), NULL);
        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(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)
{
        struct device_node *of_node;
        int ret;

        of_node = irq_domain_get_of_node(domain);
        ret = irq_alloc_descs(irq_base, irq_base, count,
                              of_node_to_nid(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);

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;
}

static void of_phandle_args_to_fwspec(struct of_phandle_args *irq_data,
                                      struct irq_fwspec *fwspec)
{
        int i;

        fwspec->fwnode = irq_data->np ? &irq_data->np->fwnode : NULL;
        fwspec->param_count = irq_data->args_count;

        for (i = 0; i < irq_data->args_count; i++)
                fwspec->param[i] = irq_data->args[i];
}

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

        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;
        }

        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;

        /*
         * 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))
                        return virq;

                /*
                 * 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)
                                return 0;

                        irqd_set_trigger_type(irq_data, type);
                        return virq;
                }

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

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

        irq_data = irq_get_irq_data(virq);
        if (!irq_data) {
                if (irq_domain_is_hierarchy(domain))
                        irq_domain_free_irqs(virq, 1);
                else
                        irq_dispose_mapping(virq);
                return 0;
        }

        /* Store trigger type */
        irqd_set_trigger_type(irq_data, type);

        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, &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 = irq_get_irq_data(virq);
        struct irq_domain *domain;

        if (!virq || !irq_data)
                return;

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

        if (irq_domain_is_hierarchy(domain)) {
                irq_domain_free_irqs(virq, 1);
        } else {
                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 void virq_debug_show_one(struct seq_file *m, struct irq_desc *desc)
{
        struct irq_domain *domain;
        struct irq_data *data;

        domain = desc->irq_data.domain;
        data = &desc->irq_data;

        while (domain) {
                unsigned int irq = data->irq;
                unsigned long hwirq = data->hwirq;
                struct irq_chip *chip;
                bool direct;

                if (data == &desc->irq_data)
                        seq_printf(m, "%5d  ", irq);
                else
                        seq_printf(m, "%5d+ ", irq);
                seq_printf(m, "0x%05lx  ", hwirq);

                chip = irq_data_get_irq_chip(data);
                seq_printf(m, "%-15s  ", (chip && chip->name) ? chip->name : "none");

                seq_printf(m, "0x%p  ", irq_data_get_irq_chip_data(data));

                seq_printf(m, "   %c    ", (desc->action && desc->action->handler) ? '*' : ' ');
                direct = (irq == hwirq) && (irq < domain->revmap_direct_max_irq);
                seq_printf(m, "%6s%-8s  ",
                           (hwirq < domain->revmap_size) ? "LINEAR" : "RADIX",
                           direct ? "(DIRECT)" : "");
                seq_printf(m, "%s\n", domain->name);
#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY
                domain = domain->parent;
                data = data->parent_data;
#else
                domain = NULL;
#endif
        }
}

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 __rcu **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) {
                struct device_node *of_node;
                const char *name;

                int count = 0;

                of_node = irq_domain_get_of_node(domain);
                if (of_node)
                        name = of_node_full_name(of_node);
                else if (is_fwnode_irqchip(domain->fwnode))
                        name = container_of(domain->fwnode, struct irqchip_fwid,
                                            fwnode)->name;
                else
                        name = "";

                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,
                           name);
        }
        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);
                virq_debug_show_one(m, desc);
                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];
        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);

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

        if (virq >= 0) {
                virq = __irq_alloc_descs(virq, virq, cnt, node, THIS_MODULE,
                                         affinity);
        } else {
                hint = hwirq % 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;
}

#ifdef  CONFIG_IRQ_DOMAIN_HIERARCHY
/**
 * irq_domain_create_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
 * @fwnode:     Optional fwnode 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_create_hierarchy(struct irq_domain *parent,
                                            unsigned int flags,
                                            unsigned int size,
                                            struct fwnode_handle *fwnode,
                                            const struct irq_domain_ops *ops,
                                            void *host_data)
{
        struct irq_domain *domain;

        if (size)
                domain = irq_domain_create_linear(fwnode, size, ops, host_data);
        else
                domain = irq_domain_create_tree(fwnode, ops, host_data);
        if (domain) {
                domain->parent = parent;
                domain->flags |= flags;
        }

        return domain;
}
EXPORT_SYMBOL_GPL(irq_domain_create_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);

                /* 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;

                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_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;
}
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, 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;
}
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, 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_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);

/**
 * 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);
}

static void irq_domain_free_irqs_hierarchy(struct irq_domain *domain,
                                           unsigned int irq_base,
                                           unsigned int nr_irqs)
{
        if (domain->ops->free)
                domain->ops->free(domain, irq_base, nr_irqs);
}

int irq_domain_alloc_irqs_hierarchy(struct irq_domain *domain,
                                    unsigned int irq_base,
                                    unsigned int nr_irqs, void *arg)
{
        return domain->ops->alloc(domain, irq_base, nr_irqs, arg);
}

/**
 * __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
 * @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 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, const struct cpumask *affinity)
{
        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,
                                              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;
        }

        mutex_lock(&irq_domain_mutex);
        ret = irq_domain_alloc_irqs_hierarchy(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;
}

/* 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;

        if (d->hwirq < d->domain->revmap_size)
                return; /* Not using radix tree. */

        /* Fix up the revmap. */
        mutex_lock(&d->domain->revmap_tree_mutex);
        slot = radix_tree_lookup_slot(&d->domain->revmap_tree, d->hwirq);
        if (slot)
                radix_tree_replace_slot(&d->domain->revmap_tree, slot, d);
        mutex_unlock(&d->domain->revmap_tree_mutex);
}

/**
 * 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 *child_irq_data;
        struct irq_data *root_irq_data = irq_get_irq_data(virq);
        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 (!root_irq_data)
                return -EINVAL;

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

        child_irq_data = kzalloc_node(sizeof(*child_irq_data), GFP_KERNEL,
                                      irq_data_get_node(root_irq_data));
        if (!child_irq_data)
                return -ENOMEM;

        mutex_lock(&irq_domain_mutex);

        /* Copy the original irq_data. */
        *child_irq_data = *root_irq_data;

        /*
         * Overwrite the root_irq_data, which is embedded in struct
         * irq_desc, with values for this domain.
         */
        root_irq_data->parent_data = child_irq_data;
        root_irq_data->domain = domain;
        root_irq_data->mask = 0;
        root_irq_data->hwirq = 0;
        root_irq_data->chip = NULL;
        root_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. */
                *root_irq_data = *child_irq_data;
                goto error;
        }

        irq_domain_fix_revmap(child_irq_data);
        irq_domain_set_mapping(domain, root_irq_data->hwirq, root_irq_data);

error:
        mutex_unlock(&irq_domain_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 *root_irq_data = irq_get_irq_data(virq);
        struct irq_data *child_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 (!root_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(root_irq_data != tmp_irq_data))
                return -EINVAL;

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

        child_irq_data = root_irq_data->parent_data;
        if (WARN_ON(!child_irq_data))
                return -EINVAL;

        mutex_lock(&irq_domain_mutex);

        root_irq_data->parent_data = NULL;

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

        /* Restore the original irq_data. */
        *root_irq_data = *child_irq_data;

        irq_domain_fix_revmap(root_irq_data);

        mutex_unlock(&irq_domain_mutex);

        kfree(child_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);
        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_hierarchy(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)
{
        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
 * @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)
{
        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;
}

/**
 * irq_domain_hierarchical_is_msi_remap - Check if the domain or any
 * parent has MSI remapping support
 * @domain: domain pointer
 */
bool irq_domain_hierarchical_is_msi_remap(struct irq_domain *domain)
{
        for (; domain; domain = domain->parent) {
                if (irq_domain_is_msi_remap(domain))
                        return true;
        }
        return false;
}
#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, 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 void irq_domain_check_hierarchy(struct irq_domain *domain)
{
}
#endif  /* CONFIG_IRQ_DOMAIN_HIERARCHY */

#ifdef CONFIG_GENERIC_IRQ_DEBUGFS
static struct dentry *domain_dir;

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 + d->revmap_direct_max_irq);
        seq_printf(m, "%*smapped: %u\n", ind + 1, "", d->mapcount);
        seq_printf(m, "%*sflags:  0x%08x\n", ind +1 , "", d->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;
}

static int irq_domain_debug_open(struct inode *inode, struct file *file)
{
        return single_open(file, irq_domain_debug_show, inode->i_private);
}

static const struct file_operations dfs_domain_ops = {
        .open           = irq_domain_debug_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = single_release,
};

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

static void debugfs_remove_domain_dir(struct irq_domain *d)
{
        debugfs_remove(d->debugfs_file);
}

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

        domain_dir = debugfs_create_dir("domains", root);
        if (!domain_dir)
                return;

        debugfs_create_file("default", 0444, domain_dir, NULL, &dfs_domain_ops);
        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