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/*

 * proc_devtree.c - handles /proc/device-tree

 *

 * Copyright 1997 Paul Mackerras

 */

#include <linux/errno.h>

#include <linux/sched.h>

#include <linux/proc_fs.h>

#include <linux/stat.h>

#include <linux/string.h>

#include <asm/prom.h>

#include <asm/uaccess.h>

static struct proc_dir_entry *proc_device_tree;

/*

 * Supply data on a read from /proc/device-tree/node/property.

 */

static int property_read_proc(char *page, char **start, off_t off,

                              int count, int *eof, void *data)

{

        struct property *pp = data;

        int n;

        if (off >= pp->length) {

                *eof = 1;

                return 0;

        }

        n = pp->length - off;

        if (n > count)

                n = count;

        else

                *eof = 1;

        memcpy(page, pp->value + off, n);

        *start = page;

        return n;

}

/*

 * For a node with a name like "gc@10", we make symlinks called "gc"

 * and "@10" to it.

 */

/*

 * Process a node, adding entries for its children and its properties.

 */

static void add_node(struct device_node *np, struct proc_dir_entry *de)

{

        struct property *pp;

        struct proc_dir_entry *ent;

        struct device_node *child, *sib;

        const char *p, *at;

        int l;

        struct proc_dir_entry *list, **lastp, *al;

        lastp = &list;

        for (pp = np->properties; pp != 0; pp = pp->next) {

                /*

                 * Unfortunately proc_register puts each new entry

                 * at the beginning of the list.  So we rearrange them.

                 */

                ent = create_proc_read_entry(pp->name, strncmp(pp->name, "security-", 9) ?

                                             S_IRUGO : S_IRUSR, de, property_read_proc, pp);

                if (ent == 0)

                        break;

                if (!strncmp(pp->name, "security-", 9))

                     ent->size = 0; /* don't leak number of password chars */

                else

                     ent->size = pp->length;

                *lastp = ent;

                lastp = &ent->next;

        }

        for (child = np->child; child != 0; child = child->sibling) {

                p = strrchr(child->full_name, '/');

                if (p == 0)

                        p = child->full_name;

                else

                        ++p;

                /* chop off '@0' if the name ends with that */

                l = strlen(p);

                if (l > 2 && p[l-2] == '@' && p[l-1] == '0')

                        l -= 2;

                ent = proc_mkdir(p, de);

                if (ent == 0)

                        break;

                *lastp = ent;

                lastp = &ent->next;

                add_node(child, ent);

                /*

                 * If we left the address part on the name, consider

                 * adding symlinks from the name and address parts.

                 */

                if (p[l] != 0 || (at = strchr(p, '@')) == 0)

                        continue;

                /*

                 * If this is the first node with a given name property,

                 * add a symlink with the name property as its name.

                 */

                for (sib = np->child; sib != child; sib = sib->sibling)

                        if (sib->name && strcmp(sib->name, child->name) == 0)

                                break;

                if (sib == child && strncmp(p, child->name, l) != 0) {

                        al = proc_symlink(child->name, de, ent->name);

                        if (al == 0)

                                break;

                        *lastp = al;

                        lastp = &al->next;

                }

                /*

                 * Add another directory with the @address part as its name.

                 */

                al = proc_symlink(at, de, ent->name);

                if (al == 0)

                        break;

                *lastp = al;

                lastp = &al->next;

        }

        *lastp = 0;

        de->subdir = list;

}

/*

 * Called on initialization to set up the /proc/device-tree subtree

 */

void proc_device_tree_init(void)

{

        struct device_node *root;

        if ( !have_of )

                return;

        proc_device_tree = proc_mkdir("device-tree", 0);

        if (proc_device_tree == 0)

                return;

        root = find_path_device("/");

        if (root == 0) {

                printk(KERN_ERR "/proc/device-tree: can't find root\n");

                return;

        }

        add_node(root, proc_device_tree);

}