// SPDX-License-Identifier: GPL-2.0+
/* pdt.c: OF PROM device tree support code.
 *
 * Paul Mackerras       August 1996.
 * Copyright (C) 1996-2005 Paul Mackerras.
 *
 *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
 *    {engebret|bergner}@us.ibm.com
 *
 *  Adapted for sparc by David S. Miller davem@davemloft.net
 *  Adapted for multiple architectures by Andres Salomon <dilinger@queued.net>
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_pdt.h>

#include "of_private.h"

static struct of_pdt_ops *of_pdt_prom_ops __initdata;

#if defined(CONFIG_SPARC)
unsigned int of_pdt_unique_id __initdata;

#define of_pdt_incr_unique_id(p) do { \
        (p)->unique_id = of_pdt_unique_id++; \
} while (0)

static char * __init of_pdt_build_full_name(struct device_node *dp)
{
        return build_path_component(dp);
}

#else /* CONFIG_SPARC */

static inline void of_pdt_incr_unique_id(void *p) { }
static inline void irq_trans_init(struct device_node *dp) { }

static char * __init of_pdt_build_full_name(struct device_node *dp)
{
        static int failsafe_id = 0; /* for generating unique names on failure */
        const char *name;
        char path[256];
        char *buf;
        int len;

        if (!of_pdt_prom_ops->pkg2path(dp->phandle, path, sizeof(path), &len)) {
                name = kbasename(path);
                buf = prom_early_alloc(strlen(name) + 1);
                strcpy(buf, name);
                return buf;
        }

        name = of_get_property(dp, "name", &len);
        buf = prom_early_alloc(len + 16);
        sprintf(buf, "%s@unknown%i", name, failsafe_id++);
        pr_err("%s: pkg2path failed; assigning %s\n", __func__, buf);
        return buf;
}

#endif /* !CONFIG_SPARC */

static struct property * __init of_pdt_build_one_prop(phandle node, char *prev,
                                               char *special_name,
                                               void *special_val,
                                               int special_len)
{
        static struct property *tmp = NULL;
        struct property *p;
        int err;

        if (tmp) {
                p = tmp;
                memset(p, 0, sizeof(*p) + 32);
                tmp = NULL;
        } else {
                p = prom_early_alloc(sizeof(struct property) + 32);
                of_pdt_incr_unique_id(p);
        }

        p->name = (char *) (p + 1);
        if (special_name) {
                strcpy(p->name, special_name);
                p->length = special_len;
                p->value = prom_early_alloc(special_len);
                memcpy(p->value, special_val, special_len);
        } else {
                err = of_pdt_prom_ops->nextprop(node, prev, p->name);
                if (err) {
                        tmp = p;
                        return NULL;
                }
                p->length = of_pdt_prom_ops->getproplen(node, p->name);
                if (p->length <= 0) {
                        p->length = 0;
                } else {
                        int len;

                        p->value = prom_early_alloc(p->length + 1);
                        len = of_pdt_prom_ops->getproperty(node, p->name,
                                        p->value, p->length);
                        if (len <= 0)
                                p->length = 0;
                        ((unsigned char *)p->value)[p->length] = '\0';
                }
        }
        return p;
}

static struct property * __init of_pdt_build_prop_list(phandle node)
{
        struct property *head, *tail;

        head = tail = of_pdt_build_one_prop(node, NULL,
                                     ".node", &node, sizeof(node));

        tail->next = of_pdt_build_one_prop(node, NULL, NULL, NULL, 0);
        tail = tail->next;
        while(tail) {
                tail->next = of_pdt_build_one_prop(node, tail->name,
                                            NULL, NULL, 0);
                tail = tail->next;
        }

        return head;
}

static char * __init of_pdt_get_one_property(phandle node, const char *name)
{
        char *buf = "<NULL>";
        int len;

        len = of_pdt_prom_ops->getproplen(node, name);
        if (len > 0) {
                buf = prom_early_alloc(len);
                len = of_pdt_prom_ops->getproperty(node, name, buf, len);
        }

        return buf;
}

static struct device_node * __init of_pdt_create_node(phandle node,
                                                    struct device_node *parent)
{
        struct device_node *dp;

        if (!node)
                return NULL;

        dp = prom_early_alloc(sizeof(*dp));
        of_node_init(dp);
        of_pdt_incr_unique_id(dp);
        dp->parent = parent;

        dp->name = of_pdt_get_one_property(node, "name");
        dp->phandle = node;

        dp->properties = of_pdt_build_prop_list(node);

        dp->full_name = of_pdt_build_full_name(dp);

        irq_trans_init(dp);

        return dp;
}

static struct device_node * __init of_pdt_build_tree(struct device_node *parent,
                                                   phandle node)
{
        struct device_node *ret = NULL, *prev_sibling = NULL;
        struct device_node *dp;

        while (1) {
                dp = of_pdt_create_node(node, parent);
                if (!dp)
                        break;

                if (prev_sibling)
                        prev_sibling->sibling = dp;

                if (!ret)
                        ret = dp;
                prev_sibling = dp;

                dp->child = of_pdt_build_tree(dp, of_pdt_prom_ops->getchild(node));

                node = of_pdt_prom_ops->getsibling(node);
        }

        return ret;
}

static void * __init kernel_tree_alloc(u64 size, u64 align)
{
        return prom_early_alloc(size);
}

void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
{
        BUG_ON(!ops);
        of_pdt_prom_ops = ops;

        of_root = of_pdt_create_node(root_node, NULL);
        of_root->full_name = "/";

        of_root->child = of_pdt_build_tree(of_root,
                                of_pdt_prom_ops->getchild(of_root->phandle));

        /* Get pointer to "/chosen" and "/aliases" nodes for use everywhere */
        of_alias_scan(kernel_tree_alloc);
}