// SPDX-License-Identifier: GPL-2.0+
/*
 *  Derived from arch/i386/kernel/irq.c
 *    Copyright (C) 1992 Linus Torvalds
 *  Adapted from arch/i386 by Gary Thomas
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
 *    Copyright (C) 1996-2001 Cort Dougan
 *  Adapted for Power Macintosh by Paul Mackerras
 *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
 *
 * This file contains the code used to make IRQ descriptions in the
 * device tree to actual irq numbers on an interrupt controller
 * driver.
 */

#define pr_fmt(fmt)     "OF: " fmt

#include <linux/cleanup.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/string.h>
#include <linux/slab.h>

#include "of_private.h"

/**
 * irq_of_parse_and_map - Parse and map an interrupt into linux virq space
 * @dev: Device node of the device whose interrupt is to be mapped
 * @index: Index of the interrupt to map
 *
 * This function is a wrapper that chains of_irq_parse_one() and
 * irq_create_of_mapping() to make things easier to callers
 */
unsigned int irq_of_parse_and_map(struct device_node *dev, int index)
{
        struct of_phandle_args oirq;
        unsigned int ret;

        if (of_irq_parse_one(dev, index, &oirq))
                return 0;

        ret = irq_create_of_mapping(&oirq);
        of_node_put(oirq.np);

        return ret;
}
EXPORT_SYMBOL_GPL(irq_of_parse_and_map);

/**
 * of_irq_find_parent - Given a device node, find its interrupt parent node
 * @child: pointer to device node
 *
 * Return: A pointer to the interrupt parent node with refcount increased
 * or NULL if the interrupt parent could not be determined.
 */
struct device_node *of_irq_find_parent(struct device_node *child)
{
        struct device_node *p;
        phandle parent;

        if (!of_node_get(child))
                return NULL;

        do {
                if (of_property_read_u32(child, "interrupt-parent", &parent)) {
                        p = of_get_parent(child);
                } else  {
                        if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
                                p = of_node_get(of_irq_dflt_pic);
                        else
                                p = of_find_node_by_phandle(parent);
                }
                of_node_put(child);
                child = p;
        } while (p && of_get_property(p, "#interrupt-cells", NULL) == NULL);

        return p;
}
EXPORT_SYMBOL_GPL(of_irq_find_parent);

/*
 * These interrupt controllers abuse interrupt-map for unspeakable
 * reasons and rely on the core code to *ignore* it (the drivers do
 * their own parsing of the property). The PAsemi entry covers a
 * non-sensical interrupt-map that is better left ignored.
 *
 * If you think of adding to the list for something *new*, think
 * again. There is a high chance that you will be sent back to the
 * drawing board.
 */
static const char * const of_irq_imap_abusers[] = {
        "CBEA,platform-spider-pic",
        "sti,platform-spider-pic",
        "realtek,rtl-intc",
        "fsl,ls1021a-extirq",
        "fsl,ls1043a-extirq",
        "fsl,ls1088a-extirq",
        "renesas,rza1-irqc",
        "pasemi,rootbus",
        NULL,
};

const __be32 *of_irq_parse_imap_parent(const __be32 *imap, int len, struct of_phandle_args *out_irq)
{
        u32 intsize, addrsize;
        struct device_node *np;

        /* Get the interrupt parent */
        if (of_irq_workarounds & OF_IMAP_NO_PHANDLE)
                np = of_node_get(of_irq_dflt_pic);
        else
                np = of_find_node_by_phandle(be32_to_cpup(imap));
        imap++;
        len--;

        /* Check if not found */
        if (!np) {
                pr_debug(" -> imap parent not found !\n");
                return NULL;
        }

        /* Get #interrupt-cells and #address-cells of new parent */
        if (of_property_read_u32(np, "#interrupt-cells",
                                        &intsize)) {
                pr_debug(" -> parent lacks #interrupt-cells!\n");
                of_node_put(np);
                return NULL;
        }
        if (of_property_read_u32(np, "#address-cells",
                                        &addrsize))
                addrsize = 0;

        pr_debug(" -> intsize=%d, addrsize=%d\n",
                intsize, addrsize);

        /* Check for malformed properties */
        if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)
                || (len < (addrsize + intsize))) {
                of_node_put(np);
                return NULL;
        }

        pr_debug(" -> imaplen=%d\n", len);

        imap += addrsize + intsize;

        out_irq->np = np;
        for (int i = 0; i < intsize; i++)
                out_irq->args[i] = be32_to_cpup(imap - intsize + i);
        out_irq->args_count = intsize;

        return imap;
}

int of_imap_parser_init(struct of_imap_parser *parser, struct device_node *node,
                        struct of_imap_item *item)
{
        int imaplen;
        u32 tmp;
        int ret;

        /*
         * parent_offset is the offset where the parent part is starting.
         * In other words, the offset where the parent interrupt controller
         * phandle is present.
         *
         * Compute this offset (child #interrupt-cells + child #address-cells)
         */
        parser->parent_offset = of_bus_n_addr_cells(node);

        ret = of_property_read_u32(node, "#interrupt-cells", &tmp);
        if (ret)
                return ret;

        parser->parent_offset += tmp;

        if (WARN(parser->parent_offset > ARRAY_SIZE(item->child_imap),
                 "child part size = %u, cannot fit in array of %zu items",
                 parser->parent_offset, ARRAY_SIZE(item->child_imap)))
                return -EINVAL;

        parser->imap = of_get_property(node, "interrupt-map", &imaplen);
        if (!parser->imap)
                return -ENOENT;

        imaplen /= sizeof(*parser->imap);
        parser->imap_end = parser->imap + imaplen;

        memset(item, 0, sizeof(*item));
        item->child_imap_count = parser->parent_offset;

        return 0;
}
EXPORT_SYMBOL_GPL(of_imap_parser_init);

struct of_imap_item *of_imap_parser_one(struct of_imap_parser *parser,
                                        struct of_imap_item *item)
{
        const __be32 *imap_parent, *imap_next;
        int i;

        /* Release previously get parent node */
        of_node_put(item->parent_args.np);

        if (parser->imap + parser->parent_offset + 1 >= parser->imap_end)
                return NULL;

        imap_parent = parser->imap + parser->parent_offset;

        imap_next = of_irq_parse_imap_parent(imap_parent,
                                             parser->imap_end - imap_parent,
                                             &item->parent_args);
        if (!imap_next)
                return NULL;

        for (i = 0; i < parser->parent_offset; i++)
                item->child_imap[i] = be32_to_cpu(*(parser->imap + i));

        parser->imap = imap_next;

        return item;
}
EXPORT_SYMBOL_GPL(of_imap_parser_one);

/**
 * of_irq_parse_raw - Low level interrupt tree parsing
 * @addr:       address specifier (start of "reg" property of the device) in be32 format
 * @out_irq:    structure of_phandle_args updated by this function
 *
 * This function is a low-level interrupt tree walking function. It
 * can be used to do a partial walk with synthesized reg and interrupts
 * properties, for example when resolving PCI interrupts when no device
 * node exist for the parent. It takes an interrupt specifier structure as
 * input, walks the tree looking for any interrupt-map properties, translates
 * the specifier for each map, and then returns the translated map.
 *
 * Return: 0 on success and a negative number on error
 *
 * Note: refcount of node @out_irq->np is increased by 1 on success.
 */
int of_irq_parse_raw(const __be32 *addr, struct of_phandle_args *out_irq)
{
        struct device_node *ipar, *tnode, *old = NULL;
        __be32 initial_match_array[MAX_PHANDLE_ARGS];
        const __be32 *match_array = initial_match_array;
        const __be32 *tmp, dummy_imask[] = { [0 ... (MAX_PHANDLE_ARGS - 1)] = cpu_to_be32(~0) };
        u32 intsize = 1, addrsize;
        int i, rc = -EINVAL;

#ifdef DEBUG
        of_print_phandle_args("of_irq_parse_raw: ", out_irq);
#endif

        ipar = of_node_get(out_irq->np);

        /* First get the #interrupt-cells property of the current cursor
         * that tells us how to interpret the passed-in intspec. If there
         * is none, we are nice and just walk up the tree
         */
        do {
                if (!of_property_read_u32(ipar, "#interrupt-cells", &intsize))
                        break;
                tnode = ipar;
                ipar = of_irq_find_parent(ipar);
                of_node_put(tnode);
        } while (ipar);
        if (ipar == NULL) {
                pr_debug(" -> no parent found !\n");
                goto fail;
        }

        pr_debug("of_irq_parse_raw: ipar=%pOF, size=%d\n", ipar, intsize);

        if (out_irq->args_count != intsize)
                goto fail;

        /* Look for this #address-cells. We have to implement the old linux
         * trick of looking for the parent here as some device-trees rely on it
         */
        old = of_node_get(ipar);
        do {
                tmp = of_get_property(old, "#address-cells", NULL);
                tnode = of_get_parent(old);
                of_node_put(old);
                old = tnode;
        } while (old && tmp == NULL);
        of_node_put(old);
        old = NULL;
        addrsize = (tmp == NULL) ? 2 : be32_to_cpu(*tmp);

        pr_debug(" -> addrsize=%d\n", addrsize);

        /* Range check so that the temporary buffer doesn't overflow */
        if (WARN_ON(addrsize + intsize > MAX_PHANDLE_ARGS)) {
                rc = -EFAULT;
                goto fail;
        }

        /* Precalculate the match array - this simplifies match loop */
        for (i = 0; i < addrsize; i++)
                initial_match_array[i] = addr ? addr[i] : 0;
        for (i = 0; i < intsize; i++)
                initial_match_array[addrsize + i] = cpu_to_be32(out_irq->args[i]);

        /* Now start the actual "proper" walk of the interrupt tree */
        while (ipar != NULL) {
                int imaplen, match;
                const __be32 *imap, *oldimap, *imask;
                struct device_node *newpar;
                /*
                 * Now check if cursor is an interrupt-controller and
                 * if it is then we are done, unless there is an
                 * interrupt-map which takes precedence except on one
                 * of these broken platforms that want to parse
                 * interrupt-map themselves for $reason.
                 */
                bool intc = of_property_read_bool(ipar, "interrupt-controller");

                imap = of_get_property(ipar, "interrupt-map", &imaplen);
                if (intc &&
                    (!imap || of_device_compatible_match(ipar, of_irq_imap_abusers))) {
                        pr_debug(" -> got it !\n");
                        return 0;
                }

                /*
                 * interrupt-map parsing does not work without a reg
                 * property when #address-cells != 0
                 */
                if (addrsize && !addr) {
                        pr_debug(" -> no reg passed in when needed !\n");
                        goto fail;
                }

                /* No interrupt map, check for an interrupt parent */
                if (imap == NULL) {
                        pr_debug(" -> no map, getting parent\n");
                        newpar = of_irq_find_parent(ipar);
                        goto skiplevel;
                }
                imaplen /= sizeof(u32);

                /* Look for a mask */
                imask = of_get_property(ipar, "interrupt-map-mask", NULL);
                if (!imask)
                        imask = dummy_imask;

                /* Parse interrupt-map */
                match = 0;
                while (imaplen > (addrsize + intsize + 1)) {
                        /* Compare specifiers */
                        match = 1;
                        for (i = 0; i < (addrsize + intsize); i++, imaplen--)
                                match &= !((match_array[i] ^ *imap++) & imask[i]);

                        pr_debug(" -> match=%d (imaplen=%d)\n", match, imaplen);

                        oldimap = imap;
                        imap = of_irq_parse_imap_parent(oldimap, imaplen, out_irq);
                        if (!imap)
                                goto fail;

                        match &= of_device_is_available(out_irq->np);
                        if (match)
                                break;

                        of_node_put(out_irq->np);
                        imaplen -= imap - oldimap;
                        pr_debug(" -> imaplen=%d\n", imaplen);
                }
                if (!match)
                        goto fail;

                /*
                 * Successfully parsed an interrupt-map translation; copy new
                 * interrupt specifier into the out_irq structure
                 */
                match_array = oldimap + 1;

                newpar = out_irq->np;
                intsize = out_irq->args_count;
                addrsize = (imap - match_array) - intsize;

                if (ipar == newpar) {
                        /*
                         * We got @ipar's refcount, but the refcount was
                         * gotten again by of_irq_parse_imap_parent() via its
                         * alias @newpar.
                         */
                        of_node_put(ipar);
                        pr_debug("%pOF interrupt-map entry to self\n", ipar);
                        return 0;
                }

        skiplevel:
                /* Iterate again with new parent */
                pr_debug(" -> new parent: %pOF\n", newpar);
                of_node_put(ipar);
                ipar = newpar;
                newpar = NULL;
        }
        rc = -ENOENT; /* No interrupt-map found */

 fail:
        of_node_put(ipar);

        return rc;
}
EXPORT_SYMBOL_GPL(of_irq_parse_raw);

/**
 * of_irq_parse_one - Resolve an interrupt for a device
 * @device: the device whose interrupt is to be resolved
 * @index: index of the interrupt to resolve
 * @out_irq: structure of_phandle_args filled by this function
 *
 * This function resolves an interrupt for a node by walking the interrupt tree,
 * finding which interrupt controller node it is attached to, and returning the
 * interrupt specifier that can be used to retrieve a Linux IRQ number.
 *
 * Note: refcount of node @out_irq->np is increased by 1 on success.
 */
int of_irq_parse_one(struct device_node *device, int index, struct of_phandle_args *out_irq)
{
        struct device_node __free(device_node) *p = NULL;
        const __be32 *addr;
        u32 intsize;
        int i, res, addr_len;
        __be32 addr_buf[3] = { 0 };

        pr_debug("of_irq_parse_one: dev=%pOF, index=%d\n", device, index);

        /* OldWorld mac stuff is "special", handle out of line */
        if (of_irq_workarounds & OF_IMAP_OLDWORLD_MAC)
                return of_irq_parse_oldworld(device, index, out_irq);

        /* Get the reg property (if any) */
        addr_len = 0;
        addr = of_get_property(device, "reg", &addr_len);

        /* Prevent out-of-bounds read in case of longer interrupt parent address size */
        if (addr_len > sizeof(addr_buf))
                addr_len = sizeof(addr_buf);
        if (addr)
                memcpy(addr_buf, addr, addr_len);

        /* Try the new-style interrupts-extended first */
        res = of_parse_phandle_with_args(device, "interrupts-extended",
                                        "#interrupt-cells", index, out_irq);
        if (!res) {
                p = out_irq->np;
        } else {
                /* Look for the interrupt parent. */
                p = of_irq_find_parent(device);
                /* Get size of interrupt specifier */
                if (!p || of_property_read_u32(p, "#interrupt-cells", &intsize))
                        return -EINVAL;

                pr_debug(" parent=%pOF, intsize=%d\n", p, intsize);

                /* Copy intspec into irq structure */
                out_irq->np = p;
                out_irq->args_count = intsize;
                for (i = 0; i < intsize; i++) {
                        res = of_property_read_u32_index(device, "interrupts",
                                                        (index * intsize) + i,
                                                        out_irq->args + i);
                        if (res)
                                return res;
                }

                pr_debug(" intspec=%d\n", *out_irq->args);
        }

        /* Check if there are any interrupt-map translations to process */
        return of_irq_parse_raw(addr_buf, out_irq);
}
EXPORT_SYMBOL_GPL(of_irq_parse_one);

/**
 * of_irq_to_resource - Decode a node's IRQ and return it as a resource
 * @dev: pointer to device tree node
 * @index: zero-based index of the irq
 * @r: pointer to resource structure to return result into.
 */
int of_irq_to_resource(struct device_node *dev, int index, struct resource *r)
{
        int irq = of_irq_get(dev, index);

        if (irq < 0)
                return irq;

        /* Only dereference the resource if both the
         * resource and the irq are valid. */
        if (r && irq) {
                const char *name = NULL;

                memset(r, 0, sizeof(*r));
                /*
                 * Get optional "interrupt-names" property to add a name
                 * to the resource.
                 */
                of_property_read_string_index(dev, "interrupt-names", index,
                                              &name);

                *r = DEFINE_RES_IRQ_NAMED(irq, name ?: of_node_full_name(dev));
                r->flags |= irq_get_trigger_type(irq);
        }

        return irq;
}
EXPORT_SYMBOL_GPL(of_irq_to_resource);

/**
 * of_irq_get - Decode a node's IRQ and return it as a Linux IRQ number
 * @dev: pointer to device tree node
 * @index: zero-based index of the IRQ
 *
 * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
 * of any other failure.
 */
int of_irq_get(struct device_node *dev, int index)
{
        int rc;
        struct of_phandle_args oirq;
        struct irq_domain *domain;

        rc = of_irq_parse_one(dev, index, &oirq);
        if (rc)
                return rc;

        domain = irq_find_host(oirq.np);
        if (!domain) {
                rc = -EPROBE_DEFER;
                goto out;
        }

        rc = irq_create_of_mapping(&oirq);
out:
        of_node_put(oirq.np);

        return rc;
}
EXPORT_SYMBOL_GPL(of_irq_get);

const struct cpumask *of_irq_get_affinity(struct device_node *dev, int index)
{
        struct of_phandle_args oirq;
        struct irq_fwspec_info info;
        struct irq_fwspec fwspec;
        int rc;

        rc = of_irq_parse_one(dev, index, &oirq);
        if (rc)
                return NULL;

        of_phandle_args_to_fwspec(oirq.np, oirq.args, oirq.args_count,
                                  &fwspec);

        if (irq_populate_fwspec_info(&fwspec, &info))
                return NULL;

        return info.affinity;
}

/**
 * of_irq_get_byname - Decode a node's IRQ and return it as a Linux IRQ number
 * @dev: pointer to device tree node
 * @name: IRQ name
 *
 * Return: Linux IRQ number on success, or 0 on the IRQ mapping failure, or
 * -EPROBE_DEFER if the IRQ domain is not yet created, or error code in case
 * of any other failure.
 */
int of_irq_get_byname(struct device_node *dev, const char *name)
{
        int index;

        if (unlikely(!name))
                return -EINVAL;

        index = of_property_match_string(dev, "interrupt-names", name);
        if (index < 0)
                return index;

        return of_irq_get(dev, index);
}
EXPORT_SYMBOL_GPL(of_irq_get_byname);

/**
 * of_irq_count - Count the number of IRQs a node uses
 * @dev: pointer to device tree node
 */
int of_irq_count(struct device_node *dev)
{
        struct of_phandle_args irq;
        int nr = 0;

        while (of_irq_parse_one(dev, nr, &irq) == 0) {
                of_node_put(irq.np);
                nr++;
        }

        return nr;
}
EXPORT_SYMBOL_GPL(of_irq_count);

/**
 * of_irq_to_resource_table - Fill in resource table with node's IRQ info
 * @dev: pointer to device tree node
 * @res: array of resources to fill in
 * @nr_irqs: the number of IRQs (and upper bound for num of @res elements)
 *
 * Return: The size of the filled in table (up to @nr_irqs).
 */
int of_irq_to_resource_table(struct device_node *dev, struct resource *res,
                int nr_irqs)
{
        int i;

        for (i = 0; i < nr_irqs; i++, res++)
                if (of_irq_to_resource(dev, i, res) <= 0)
                        break;

        return i;
}
EXPORT_SYMBOL_GPL(of_irq_to_resource_table);

struct of_intc_desc {
        struct list_head        list;
        of_irq_init_cb_t        irq_init_cb;
        struct device_node      *dev;
        struct device_node      *interrupt_parent;
};

/**
 * of_irq_init - Scan and init matching interrupt controllers in DT
 * @matches: 0 terminated array of nodes to match and init function to call
 *
 * This function scans the device tree for matching interrupt controller nodes,
 * and calls their initialization functions in order with parents first.
 */
void __init of_irq_init(const struct of_device_id *matches)
{
        const struct of_device_id *match;
        struct device_node *np, *parent = NULL;
        struct of_intc_desc *desc, *temp_desc;
        struct list_head intc_desc_list, intc_parent_list;

        INIT_LIST_HEAD(&intc_desc_list);
        INIT_LIST_HEAD(&intc_parent_list);

        for_each_matching_node_and_match(np, matches, &match) {
                if (!of_property_read_bool(np, "interrupt-controller") ||
                                !of_device_is_available(np))
                        continue;

                if (WARN(!match->data, "of_irq_init: no init function for %s\n",
                         match->compatible))
                        continue;

                /*
                 * Here, we allocate and populate an of_intc_desc with the node
                 * pointer, interrupt-parent device_node etc.
                 */
                desc = kzalloc_obj(*desc);
                if (!desc) {
                        of_node_put(np);
                        goto err;
                }

                desc->irq_init_cb = match->data;
                desc->dev = of_node_get(np);
                /*
                 * interrupts-extended can reference multiple parent domains.
                 * Arbitrarily pick the first one; assume any other parents
                 * are the same distance away from the root irq controller.
                 */
                desc->interrupt_parent = of_parse_phandle(np, "interrupts-extended", 0);
                if (!desc->interrupt_parent && of_property_present(np, "interrupts"))
                        desc->interrupt_parent = of_irq_find_parent(np);
                else if (!desc->interrupt_parent)
                        desc->interrupt_parent = of_parse_phandle(np, "interrupt-parent", 0);
                if (desc->interrupt_parent == np) {
                        of_node_put(desc->interrupt_parent);
                        desc->interrupt_parent = NULL;
                }
                list_add_tail(&desc->list, &intc_desc_list);
        }

        /*
         * The root irq controller is the one without an interrupt-parent.
         * That one goes first, followed by the controllers that reference it,
         * followed by the ones that reference the 2nd level controllers, etc.
         */
        while (!list_empty(&intc_desc_list)) {
                /*
                 * Process all controllers with the current 'parent'.
                 * First pass will be looking for NULL as the parent.
                 * The assumption is that NULL parent means a root controller.
                 */
                list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
                        int ret;

                        if (desc->interrupt_parent != parent)
                                continue;

                        list_del(&desc->list);

                        of_node_set_flag(desc->dev, OF_POPULATED);

                        pr_debug("of_irq_init: init %pOF (%p), parent %p\n",
                                 desc->dev,
                                 desc->dev, desc->interrupt_parent);
                        ret = desc->irq_init_cb(desc->dev,
                                                desc->interrupt_parent);
                        if (ret) {
                                pr_err("%s: Failed to init %pOF (%p), parent %p\n",
                                       __func__, desc->dev, desc->dev,
                                       desc->interrupt_parent);
                                of_node_clear_flag(desc->dev, OF_POPULATED);
                                of_node_put(desc->interrupt_parent);
                                of_node_put(desc->dev);
                                kfree(desc);
                                continue;
                        }

                        /*
                         * This one is now set up; add it to the parent list so
                         * its children can get processed in a subsequent pass.
                         */
                        list_add_tail(&desc->list, &intc_parent_list);
                }

                /* Get the next pending parent that might have children */
                desc = list_first_entry_or_null(&intc_parent_list,
                                                typeof(*desc), list);
                if (!desc) {
                        pr_err("of_irq_init: children remain, but no parents\n");
                        break;
                }
                list_del(&desc->list);
                parent = desc->dev;
                kfree(desc);
        }

        list_for_each_entry_safe(desc, temp_desc, &intc_parent_list, list) {
                list_del(&desc->list);
                kfree(desc);
        }
err:
        list_for_each_entry_safe(desc, temp_desc, &intc_desc_list, list) {
                list_del(&desc->list);
                of_node_put(desc->interrupt_parent);
                of_node_put(desc->dev);
                kfree(desc);
        }
}

static int of_check_msi_parent(struct device_node *dev_node, struct device_node **msi_node)
{
        struct of_phandle_args msi_spec;
        int ret;

        /*
         * An msi-parent phandle with a missing or == 0 #msi-cells
         * property identifies a 1:1 ID translation mapping.
         *
         * Set the msi controller node if the firmware matches this
         * condition.
         */
        ret = of_parse_phandle_with_optional_args(dev_node, "msi-parent", "#msi-cells",
                                                  0, &msi_spec);
        if (ret)
                return ret;

        if ((*msi_node && *msi_node != msi_spec.np) || msi_spec.args_count != 0)
                ret = -EINVAL;

        if (!ret) {
                /* Return with a node reference held */
                *msi_node = msi_spec.np;
                return 0;
        }
        of_node_put(msi_spec.np);

        return ret;
}

/**
 * of_msi_xlate - map a MSI ID and find relevant MSI controller node
 * @dev: device for which the mapping is to be done.
 * @msi_np: Pointer to target MSI controller node
 * @id_in: Device ID.
 *
 * Walk up the device hierarchy looking for devices with a "msi-map"
 * or "msi-parent" property. If found, apply the mapping to @id_in.
 * If @msi_np points to a non-NULL device node pointer, only entries targeting
 * that node will be matched; if it points to a NULL value, it will receive the
 * device node of the first matching target phandle, with a reference held.
 *
 * Returns: The mapped MSI id.
 */
u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
{
        struct device *parent_dev;
        u32 id_out = id_in;

        /*
         * Walk up the device parent links looking for one with a
         * "msi-map" or an "msi-parent" property.
         */
        for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
                if (!of_map_id(parent_dev->of_node, id_in, "msi-map",
                                "msi-map-mask", msi_np, &id_out))
                        break;
                if (!of_check_msi_parent(parent_dev->of_node, msi_np))
                        break;
        }
        return id_out;
}
EXPORT_SYMBOL_GPL(of_msi_xlate);

/**
 * of_msi_map_get_device_domain - Use msi-map to find the relevant MSI domain
 * @dev: device for which the mapping is to be done.
 * @id: Device ID.
 * @bus_token: Bus token
 *
 * Walk up the device hierarchy looking for devices with a "msi-map"
 * property.
 *
 * Returns: the MSI domain for this device (or NULL on failure)
 */
struct irq_domain *of_msi_map_get_device_domain(struct device *dev, u32 id,
                                                u32 bus_token)
{
        struct device_node *np = NULL;

        of_msi_xlate(dev, &np, id);
        return irq_find_matching_host(np, bus_token);
}

/**
 * of_msi_get_domain - Use msi-parent to find the relevant MSI domain
 * @dev: device for which the domain is requested
 * @np: device node for @dev
 * @token: bus type for this domain
 *
 * Parse the msi-parent property and returns the corresponding MSI domain.
 *
 * Returns: the MSI domain for this device (or NULL on failure).
 */
struct irq_domain *of_msi_get_domain(struct device *dev,
                                     const struct device_node *np,
                                     enum irq_domain_bus_token token)
{
        struct of_phandle_iterator it;
        struct irq_domain *d;
        int err;

        of_for_each_phandle(&it, err, np, "msi-parent", "#msi-cells", 0) {
                d = irq_find_matching_host(it.node, token);
                if (d) {
                        of_node_put(it.node);
                        return d;
                }
        }

        return NULL;
}
EXPORT_SYMBOL_GPL(of_msi_get_domain);

/**
 * of_msi_configure - Set the msi_domain field of a device
 * @dev: device structure to associate with an MSI irq domain
 * @np: device node for that device
 */
void of_msi_configure(struct device *dev, const struct device_node *np)
{
        dev_set_msi_domain(dev,
                           of_msi_get_domain(dev, np, DOMAIN_BUS_PLATFORM_MSI));
}
EXPORT_SYMBOL_GPL(of_msi_configure);