478 lines
10 KiB
C
478 lines
10 KiB
C
/*
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* Procedures for creating, accessing and interpreting the device tree.
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*
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* Paul Mackerras August 1996.
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* Copyright (C) 1996-2005 Paul Mackerras.
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*
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* Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
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* {engebret|bergner}@us.ibm.com
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*
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* Adapted for sparc64 by David S. Miller davem@davemloft.net
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*
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* Adapter for i386/OLPC by Andres Salomon <dilinger@debian.org>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/kernel.h>
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#include <linux/types.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/bootmem.h>
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#include <linux/module.h>
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#include <asm/prom.h>
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#include <asm/ofw.h>
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/*
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* XXX: This is very much a stub; right now we're keeping 2 device trees
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* in memory (one for promfs, and one here). That will not remain
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* for long!
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*/
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static struct device_node *allnodes;
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/* use when traversing tree through the allnext, child, sibling,
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* or parent members of struct device_node.
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*/
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static DEFINE_RWLOCK(devtree_lock);
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int of_device_is_compatible(const struct device_node *device,
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const char *compat)
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{
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const char* cp;
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int cplen, l;
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cp = of_get_property(device, "compatible", &cplen);
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if (cp == NULL)
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return 0;
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while (cplen > 0) {
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if (strncmp(cp, compat, strlen(compat)) == 0)
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return 1;
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l = strlen(cp) + 1;
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cp += l;
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cplen -= l;
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}
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return 0;
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}
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EXPORT_SYMBOL(of_device_is_compatible);
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struct device_node *of_get_parent(const struct device_node *node)
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{
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struct device_node *np;
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if (!node)
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return NULL;
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np = node->parent;
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return np;
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}
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EXPORT_SYMBOL(of_get_parent);
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struct device_node *of_get_next_child(const struct device_node *node,
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struct device_node *prev)
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{
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struct device_node *next;
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next = prev ? prev->sibling : node->child;
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for (; next != 0; next = next->sibling) {
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break;
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}
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return next;
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}
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EXPORT_SYMBOL(of_get_next_child);
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struct device_node *of_find_node_by_path(const char *path)
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{
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struct device_node *np = allnodes;
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for (; np != 0; np = np->allnext) {
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if (np->full_name != 0 && strcmp(np->full_name, path) == 0)
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break;
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}
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return np;
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}
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EXPORT_SYMBOL(of_find_node_by_path);
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struct device_node *of_find_node_by_phandle(phandle handle)
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{
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struct device_node *np;
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for (np = allnodes; np != 0; np = np->allnext)
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if (np->node == handle)
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break;
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return np;
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}
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EXPORT_SYMBOL(of_find_node_by_phandle);
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struct device_node *of_find_node_by_name(struct device_node *from,
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const char *name)
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{
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struct device_node *np;
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np = from ? from->allnext : allnodes;
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for (; np != NULL; np = np->allnext)
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if (np->name != NULL && strcmp(np->name, name) == 0)
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break;
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return np;
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}
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EXPORT_SYMBOL(of_find_node_by_name);
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struct device_node *of_find_node_by_type(struct device_node *from,
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const char *type)
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{
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struct device_node *np;
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np = from ? from->allnext : allnodes;
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for (; np != 0; np = np->allnext)
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if (np->type != 0 && strcmp(np->type, type) == 0)
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break;
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return np;
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}
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EXPORT_SYMBOL(of_find_node_by_type);
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struct device_node *of_find_compatible_node(struct device_node *from,
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const char *type, const char *compatible)
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{
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struct device_node *np;
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np = from ? from->allnext : allnodes;
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for (; np != 0; np = np->allnext) {
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if (type != NULL
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&& !(np->type != 0 && strcmp(np->type, type) == 0))
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continue;
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if (of_device_is_compatible(np, compatible))
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break;
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}
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return np;
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}
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EXPORT_SYMBOL(of_find_compatible_node);
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struct property *of_find_property(const struct device_node *np,
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const char *name,
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int *lenp)
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{
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struct property *pp;
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for (pp = np->properties; pp != 0; pp = pp->next) {
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if (strcasecmp(pp->name, name) == 0) {
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if (lenp != 0)
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*lenp = pp->length;
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break;
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}
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}
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return pp;
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}
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EXPORT_SYMBOL(of_find_property);
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/*
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* Find a property with a given name for a given node
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* and return the value.
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*/
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const void *of_get_property(const struct device_node *np, const char *name,
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int *lenp)
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{
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struct property *pp = of_find_property(np,name,lenp);
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return pp ? pp->value : NULL;
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}
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EXPORT_SYMBOL(of_get_property);
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int of_getintprop_default(struct device_node *np, const char *name, int def)
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{
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struct property *prop;
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int len;
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prop = of_find_property(np, name, &len);
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if (!prop || len != 4)
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return def;
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return *(int *) prop->value;
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}
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EXPORT_SYMBOL(of_getintprop_default);
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int of_n_addr_cells(struct device_node *np)
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{
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const int* ip;
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do {
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if (np->parent)
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np = np->parent;
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ip = of_get_property(np, "#address-cells", NULL);
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if (ip != NULL)
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return *ip;
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} while (np->parent);
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/* No #address-cells property for the root node, default to 2 */
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return 2;
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}
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EXPORT_SYMBOL(of_n_addr_cells);
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int of_n_size_cells(struct device_node *np)
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{
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const int* ip;
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do {
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if (np->parent)
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np = np->parent;
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ip = of_get_property(np, "#size-cells", NULL);
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if (ip != NULL)
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return *ip;
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} while (np->parent);
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/* No #size-cells property for the root node, default to 1 */
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return 1;
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}
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EXPORT_SYMBOL(of_n_size_cells);
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int of_set_property(struct device_node *dp, const char *name, void *val, int len)
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{
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return -EIO;
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}
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EXPORT_SYMBOL(of_set_property);
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static unsigned int prom_early_allocated;
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static void * __init prom_early_alloc(unsigned long size)
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{
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void *ret;
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ret = kmalloc(size, GFP_KERNEL);
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if (ret != NULL)
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memset(ret, 0, size);
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else
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printk(KERN_ERR "ACK! couldn't allocate prom memory!\n");
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prom_early_allocated += size;
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return ret;
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}
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static int is_root_node(const struct device_node *dp)
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{
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if (!dp)
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return 0;
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return (dp->parent == NULL);
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}
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static char * __init build_path_component(struct device_node *dp)
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{
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int pathlen;
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char *n, *i;
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if (ofw("package-to-path", 3, 1, dp->node, NULL, 0, &pathlen)) {
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printk(KERN_ERR "PROM: unable to get path name from OFW!\n");
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return "ERROR";
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}
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n = prom_early_alloc(pathlen + 1);
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if (ofw("package-to-path", 3, 1, dp->node, n, pathlen+1, &pathlen))
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printk(KERN_ERR "PROM: unable to get path name from OFW\n");
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if ((i = strrchr(n, '/')))
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n = ++i; /* we only want the file name */
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return n;
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}
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static char * __init build_full_name(struct device_node *dp)
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{
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int len, ourlen, plen;
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char *n;
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plen = strlen(dp->parent->full_name);
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ourlen = strlen(dp->path_component_name);
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len = ourlen + plen + 2;
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n = prom_early_alloc(len);
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strcpy(n, dp->parent->full_name);
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if (!is_root_node(dp->parent)) {
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strcpy(n + plen, "/");
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plen++;
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}
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strcpy(n + plen, dp->path_component_name);
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return n;
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}
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static struct property * __init build_one_prop(phandle node, char *prev, char *special_name, void *special_val, int special_len)
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{
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static struct property *tmp = NULL;
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struct property *p;
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if (tmp) {
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p = tmp;
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memset(p, 0, sizeof(*p) + 32);
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tmp = NULL;
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} else {
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p = prom_early_alloc(sizeof(struct property) + 32);
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}
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p->name = (char *) (p + 1);
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if (special_name) {
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strcpy(p->name, special_name);
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p->length = special_len;
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p->value = prom_early_alloc(special_len);
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memcpy(p->value, special_val, special_len);
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} else {
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int fl;
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if (prev == NULL) {
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if (ofw("nextprop", 3, 1, node, "", p->name, &fl)) {
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printk(KERN_ERR "PROM: %s: nextprop failed!\n", __func__);
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return NULL;
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}
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} else {
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if (ofw("nextprop", 3, 1, node, prev, p->name, &fl)) {
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printk(KERN_ERR "PROM: %s: nextprop failed!\n", __func__);
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return NULL;
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}
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}
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if (strlen(p->name) == 0 || fl != 1) {
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tmp = p;
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return NULL;
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}
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if (ofw("getproplen", 2, 1, node, p->name, &p->length)) {
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printk(KERN_ERR "PROM: %s: getproplen failed!\n", __func__);
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return NULL;
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}
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if (p->length <= 0) {
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p->length = 0;
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} else {
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p->value = prom_early_alloc(p->length + 1);
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if (ofw("getprop", 4, 1, node, p->name, p->value, p->length, &p->length)) {
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printk(KERN_ERR "PROM: %s: getprop failed!\n", __func__);
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return NULL;
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}
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((unsigned char *)p->value)[p->length] = '\0';
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}
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}
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return p;
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}
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static struct property * __init build_prop_list(phandle node)
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{
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struct property *head, *tail;
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head = tail = build_one_prop(node, NULL,
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".node", &node, sizeof(node));
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tail->next = build_one_prop(node, NULL, NULL, NULL, 0);
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tail = tail->next;
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while(tail) {
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tail->next = build_one_prop(node, tail->name,
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NULL, NULL, 0);
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tail = tail->next;
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}
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return head;
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}
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static char * __init get_one_property(phandle node, const char *name)
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{
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char *buf = "<NULL>";
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int len;
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if (ofw("getproplen", 2, 1, node, name, &len)) {
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printk(KERN_ERR "PROM: %s: getproplen failed!\n", __func__);
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return NULL;
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}
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if (len > 0) {
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buf = prom_early_alloc(len);
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if (ofw("getprop", 4, 1, node, name, buf, len, &len)) {
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printk(KERN_ERR "PROM: %s: getprop failed!\n", __func__);
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return NULL;
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}
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}
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return buf;
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}
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static struct device_node * __init create_node(phandle node, struct device_node *parent)
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{
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struct device_node *dp;
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if (!node)
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return NULL;
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dp = prom_early_alloc(sizeof(*dp));
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dp->parent = parent;
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kref_init(&dp->kref);
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dp->name = get_one_property(node, "name");
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dp->type = get_one_property(node, "device_type");
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dp->node = node;
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dp->properties = build_prop_list(node);
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return dp;
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}
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static struct device_node * __init build_tree(struct device_node *parent, phandle node, struct device_node ***nextp)
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{
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struct device_node *ret = NULL, *prev_sibling = NULL;
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struct device_node *dp;
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u32 child;
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while (1) {
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dp = create_node(node, parent);
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if (!dp)
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break;
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if (prev_sibling)
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prev_sibling->sibling = dp;
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if (!ret)
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ret = dp;
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prev_sibling = dp;
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*(*nextp) = dp;
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*nextp = &dp->allnext;
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dp->path_component_name = build_path_component(dp);
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dp->full_name = build_full_name(dp);
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if (ofw("child", 1, 1, node, &child)) {
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printk(KERN_ERR "PROM: %s: fetching child failed!\n", __func__);
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return NULL;
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}
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dp->child = build_tree(dp, child, nextp);
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if (ofw("peer", 1, 1, node, &node)) {
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printk(KERN_ERR "PROM: %s: fetching peer failed!\n", __func__);
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return NULL;
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}
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}
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return ret;
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}
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static phandle root_node;
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void __init prom_build_devicetree(void)
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{
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struct device_node **nextp;
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u32 child;
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if (ofw("peer", 1, 1, 0, &root_node)) {
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printk(KERN_ERR "PROM: unable to get root node from OFW!\n");
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return;
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}
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allnodes = create_node(root_node, NULL);
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allnodes->path_component_name = "";
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allnodes->full_name = "/";
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nextp = &allnodes->allnext;
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if (ofw("child", 1, 1, allnodes->node, &child)) {
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printk(KERN_ERR "PROM: unable to get child node from OFW!\n");
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return;
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}
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allnodes->child = build_tree(allnodes, child, &nextp);
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printk("PROM: Built device tree with %u bytes of memory.\n",
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prom_early_allocated);
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}
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