[mirror_ubuntu-artful-kernel.git] / drivers / of / resolver.c

/*
 * Functions for dealing with DT resolution
 *
 * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
 * Copyright (C) 2012 Texas Instruments Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * version 2 as published by the Free Software Foundation.
 */

#define pr_fmt(fmt)	"OF: resolver: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/slab.h>

/* illegal phandle value (set when unresolved) */
#define OF_PHANDLE_ILLEGAL	0xdeadbeef

/**
 * Find a node with the give full name by recursively following any of
 * the child node links.
 */
static struct device_node *__of_find_node_by_full_name(struct device_node *node,
		const char *full_name)
{
	struct device_node *child, *found;

	if (node == NULL)
		return NULL;

	if (of_node_cmp(node->full_name, full_name) == 0)
		return of_node_get(node);

	for_each_child_of_node(node, child) {
		found = __of_find_node_by_full_name(child, full_name);
		if (found != NULL) {
			of_node_put(child);
			return found;
		}
	}

	return NULL;
}

/*
 * Find live tree's maximum phandle value.
 */
static phandle of_get_tree_max_phandle(void)
{
	struct device_node *node;
	phandle phandle;
	unsigned long flags;

	raw_spin_lock_irqsave(&devtree_lock, flags);
	phandle = 0;
	for_each_of_allnodes(node) {
		if (node->phandle != OF_PHANDLE_ILLEGAL &&
				node->phandle > phandle)
			phandle = node->phandle;
	}
	raw_spin_unlock_irqrestore(&devtree_lock, flags);

	return phandle;
}

/*
 * Adjust a subtree's phandle values by a given delta.
 */
static void __of_adjust_tree_phandles(struct device_node *node,
		int phandle_delta)
{
	struct device_node *child;
	struct property *prop;
	phandle phandle;

	if (node->phandle != 0 && node->phandle != OF_PHANDLE_ILLEGAL)
		node->phandle += phandle_delta;

	for_each_property_of_node(node, prop) {

		if (of_prop_cmp(prop->name, "phandle") != 0 &&
		    of_prop_cmp(prop->name, "linux,phandle") != 0)
			continue;

		if (prop->length < 4)
			continue;

		phandle = be32_to_cpup(prop->value);
		if (phandle == OF_PHANDLE_ILLEGAL)
			continue;

		*(uint32_t *)prop->value = cpu_to_be32(node->phandle);
	}

	for_each_child_of_node(node, child)
		__of_adjust_tree_phandles(child, phandle_delta);
}

static int __of_adjust_phandle_ref(struct device_node *node,
		struct property *rprop, int value)
{
	phandle phandle;
	struct device_node *refnode;
	struct property *sprop;
	char *propval, *propcur, *propend, *nodestr, *propstr, *s;
	int offset, propcurlen;
	int err = 0;

	propval = kmalloc(rprop->length, GFP_KERNEL);
	if (!propval)
		return -ENOMEM;
	memcpy(propval, rprop->value, rprop->length);

	propend = propval + rprop->length;
	for (propcur = propval; propcur < propend; propcur += propcurlen + 1) {
		propcurlen = strlen(propcur);

		nodestr = propcur;
		s = strchr(propcur, ':');
		if (!s) {
			err = -EINVAL;
			goto err_fail;
		}
		*s++ = '\0';

		propstr = s;
		s = strchr(s, ':');
		if (!s) {
			err = -EINVAL;
			goto err_fail;
		}

		*s++ = '\0';
		err = kstrtoint(s, 10, &offset);
		if (err != 0)
			goto err_fail;

		refnode = __of_find_node_by_full_name(node, nodestr);
		if (!refnode)
			continue;

		for_each_property_of_node(refnode, sprop) {
			if (of_prop_cmp(sprop->name, propstr) == 0)
				break;
		}
		of_node_put(refnode);

		if (!sprop) {
			err = -ENOENT;
			goto err_fail;
		}

		phandle = value;
		*(__be32 *)(sprop->value + offset) = cpu_to_be32(phandle);
	}

err_fail:
	kfree(propval);
	return err;
}

/* compare nodes taking into account that 'name' strips out the @ part */
static int __of_node_name_cmp(const struct device_node *dn1,
		const struct device_node *dn2)
{
	const char *n1 = strrchr(dn1->full_name, '/') ? : "/";
	const char *n2 = strrchr(dn2->full_name, '/') ? : "/";

	return of_node_cmp(n1, n2);
}

/*
 * Adjust the local phandle references by the given phandle delta.
 * Assumes the existances of a __local_fixups__ node at the root.
 * Assumes that __of_verify_tree_phandle_references has been called.
 * Does not take any devtree locks so make sure you call this on a tree
 * which is at the detached state.
 */
static int __of_adjust_tree_phandle_references(struct device_node *node,
		struct device_node *target, int phandle_delta)
{
	struct device_node *child, *childtarget;
	struct property *rprop, *sprop;
	int err, i, count;
	unsigned int off;
	phandle phandle;

	if (node == NULL)
		return 0;

	for_each_property_of_node(node, rprop) {

		/* skip properties added automatically */
		if (of_prop_cmp(rprop->name, "name") == 0 ||
		    of_prop_cmp(rprop->name, "phandle") == 0 ||
		    of_prop_cmp(rprop->name, "linux,phandle") == 0)
			continue;

		if ((rprop->length % 4) != 0 || rprop->length == 0)
			return -EINVAL;
		count = rprop->length / sizeof(__be32);

		for_each_property_of_node(target, sprop) {
			if (of_prop_cmp(sprop->name, rprop->name) == 0)
				break;
		}

		if (sprop == NULL)
			return -EINVAL;

		for (i = 0; i < count; i++) {
			off = be32_to_cpu(((__be32 *)rprop->value)[i]);
			if (off >= sprop->length || (off + 4) > sprop->length)
				return -EINVAL;

			if (phandle_delta) {
				phandle = be32_to_cpu(*(__be32 *)(sprop->value + off));
				phandle += phandle_delta;
				*(__be32 *)(sprop->value + off) = cpu_to_be32(phandle);
			}
		}
	}

	for_each_child_of_node(node, child) {

		for_each_child_of_node(target, childtarget)
			if (__of_node_name_cmp(child, childtarget) == 0)
				break;

		if (!childtarget)
			return -EINVAL;

		err = __of_adjust_tree_phandle_references(child, childtarget,
				phandle_delta);
		if (err != 0)
			return err;
	}

	return 0;
}

/**
 * of_resolve	- Resolve the given node against the live tree.
 *
 * @resolve:	Node to resolve
 *
 * Perform dynamic Device Tree resolution against the live tree
 * to the given node to resolve. This depends on the live tree
 * having a __symbols__ node, and the resolve node the __fixups__ &
 * __local_fixups__ nodes (if needed).
 * The result of the operation is a resolve node that it's contents
 * are fit to be inserted or operate upon the live tree.
 * Returns 0 on success or a negative error value on error.
 */
int of_resolve_phandles(struct device_node *resolve)
{
	struct device_node *child, *childroot, *refnode;
	struct device_node *root_sym, *resolve_sym, *resolve_fix;
	struct property *rprop;
	const char *refpath;
	phandle phandle, phandle_delta;
	int err;

	if (!resolve)
		pr_err("%s: null node\n", __func__);
	if (resolve && !of_node_check_flag(resolve, OF_DETACHED))
		pr_err("%s: node %s not detached\n", __func__,
			 resolve->full_name);
	if (!resolve || !of_node_check_flag(resolve, OF_DETACHED))
		return -EINVAL;

	phandle_delta = of_get_tree_max_phandle() + 1;
	__of_adjust_tree_phandles(resolve, phandle_delta);

	childroot = NULL;
	for_each_child_of_node(resolve, childroot)
		if (of_node_cmp(childroot->name, "__local_fixups__") == 0)
			break;

	if (childroot != NULL) {
		err = __of_adjust_tree_phandle_references(childroot,
				resolve, 0);
		if (err != 0)
			return err;

		BUG_ON(__of_adjust_tree_phandle_references(childroot,
				resolve, phandle_delta));
	}

	root_sym = NULL;
	resolve_sym = NULL;
	resolve_fix = NULL;

	root_sym = of_find_node_by_path("/__symbols__");

	for_each_child_of_node(resolve, child) {

		if (!resolve_sym &&
				of_node_cmp(child->name, "__symbols__") == 0)
			resolve_sym = child;

		if (!resolve_fix &&
				of_node_cmp(child->name, "__fixups__") == 0)
			resolve_fix = child;

		if (resolve_sym && resolve_fix)
			break;
	}

	if (!resolve_fix) {
		err = 0;
		goto out;
	}

	if (!root_sym) {
		pr_err("%s: no symbols in root of device tree.\n", __func__);
		err = -EINVAL;
		goto out;
	}

	for_each_property_of_node(resolve_fix, rprop) {

		/* skip properties added automatically */
		if (of_prop_cmp(rprop->name, "name") == 0)
			continue;

		err = of_property_read_string(root_sym,
				rprop->name, &refpath);
		if (err != 0)
			goto out;

		refnode = of_find_node_by_path(refpath);
		if (!refnode) {
			err = -ENOENT;
			goto out;
		}

		phandle = refnode->phandle;
		of_node_put(refnode);

		err = __of_adjust_phandle_ref(resolve, rprop, phandle);
		if (err)
			break;
	}

out:
	of_node_put(root_sym);

	return err;
}
EXPORT_SYMBOL_GPL(of_resolve_phandles);
Commit	Line	Data
7941b27b PA	1	/*
	2	* Functions for dealing with DT resolution
	3	*
	4	* Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
	5	* Copyright (C) 2012 Texas Instruments Inc.
	6	*
	7	* This program is free software; you can redistribute it and/or
	8	* modify it under the terms of the GNU General Public License
	9	* version 2 as published by the Free Software Foundation.
	10	*/
	11
606ad42a RH	12	#define pr_fmt(fmt) "OF: resolver: " fmt
606ad42a RH	13
7941b27b PA	14	#include <linux/kernel.h>
	15	#include <linux/module.h>
	16	#include <linux/of.h>
	17	#include <linux/of_device.h>
	18	#include <linux/string.h>
	19	#include <linux/ctype.h>
	20	#include <linux/errno.h>
	21	#include <linux/string.h>
	22	#include <linux/slab.h>
	23
	24	/* illegal phandle value (set when unresolved) */
	25	#define OF_PHANDLE_ILLEGAL 0xdeadbeef
	26
	27	/**
	28	* Find a node with the give full name by recursively following any of
	29	* the child node links.
	30	*/
	31	static struct device_node __of_find_node_by_full_name(struct device_node node,
	32	const char *full_name)
	33	{
	34	struct device_node child, found;
	35
	36	if (node == NULL)
	37	return NULL;
	38
7941b27b	39	if (of_node_cmp(node->full_name, full_name) == 0)
82f68756	40	return of_node_get(node);
7941b27b PA	41
	42	for_each_child_of_node(node, child) {
	43	found = __of_find_node_by_full_name(child, full_name);
82f68756 AKC	44	if (found != NULL) {
82f68756 AKC	45	of_node_put(child);
7941b27b	46	return found;
82f68756	47	}
7941b27b PA	48	}
	49
	50	return NULL;
	51	}
	52
	53	/*
	54	* Find live tree's maximum phandle value.
	55	*/
	56	static phandle of_get_tree_max_phandle(void)
	57	{
	58	struct device_node *node;
	59	phandle phandle;
	60	unsigned long flags;
	61
7941b27b PA	62	raw_spin_lock_irqsave(&devtree_lock, flags);
	63	phandle = 0;
	64	for_each_of_allnodes(node) {
	65	if (node->phandle != OF_PHANDLE_ILLEGAL &&
	66	node->phandle > phandle)
	67	phandle = node->phandle;
	68	}
	69	raw_spin_unlock_irqrestore(&devtree_lock, flags);
	70
	71	return phandle;
	72	}
	73
	74	/*
	75	* Adjust a subtree's phandle values by a given delta.
7941b27b PA	76	*/
	77	static void __of_adjust_tree_phandles(struct device_node *node,
	78	int phandle_delta)
	79	{
	80	struct device_node *child;
	81	struct property *prop;
	82	phandle phandle;
	83
7941b27b PA	84	if (node->phandle != 0 && node->phandle != OF_PHANDLE_ILLEGAL)
	85	node->phandle += phandle_delta;
	86
7941b27b PA	87	for_each_property_of_node(node, prop) {
7941b27b PA	88
7941b27b PA	89	if (of_prop_cmp(prop->name, "phandle") != 0 &&
	90	of_prop_cmp(prop->name, "linux,phandle") != 0)
	91	continue;
	92
7941b27b PA	93	if (prop->length < 4)
	94	continue;
	95
7941b27b	96	phandle = be32_to_cpup(prop->value);
a67976ec	97	if (phandle == OF_PHANDLE_ILLEGAL)
7941b27b PA	98	continue;
7941b27b PA	99
7941b27b PA	100	(uint32_t )prop->value = cpu_to_be32(node->phandle);
	101	}
	102
7941b27b PA	103	for_each_child_of_node(node, child)
	104	__of_adjust_tree_phandles(child, phandle_delta);
	105	}
	106
da56d04c PA	107	static int __of_adjust_phandle_ref(struct device_node *node,
da56d04c PA	108	struct property *rprop, int value)
7941b27b PA	109	{
	110	phandle phandle;
	111	struct device_node *refnode;
	112	struct property *sprop;
	113	char propval, propcur, propend, nodestr, propstr, s;
	114	int offset, propcurlen;
	115	int err = 0;
	116
7941b27b	117	propval = kmalloc(rprop->length, GFP_KERNEL);
96d1c8e8	118	if (!propval)
7941b27b	119	return -ENOMEM;
7941b27b PA	120	memcpy(propval, rprop->value, rprop->length);
	121
	122	propend = propval + rprop->length;
	123	for (propcur = propval; propcur < propend; propcur += propcurlen + 1) {
	124	propcurlen = strlen(propcur);
	125
	126	nodestr = propcur;
	127	s = strchr(propcur, ':');
	128	if (!s) {
7941b27b PA	129	err = -EINVAL;
	130	goto err_fail;
	131	}
	132	*s++ = '\0';
	133
	134	propstr = s;
	135	s = strchr(s, ':');
	136	if (!s) {
7941b27b PA	137	err = -EINVAL;
	138	goto err_fail;
	139	}
	140
	141	*s++ = '\0';
	142	err = kstrtoint(s, 10, &offset);
96d1c8e8	143	if (err != 0)
7941b27b	144	goto err_fail;
7941b27b	145
7941b27b	146	refnode = __of_find_node_by_full_name(node, nodestr);
96d1c8e8	147	if (!refnode)
7941b27b	148	continue;
7941b27b	149
7941b27b PA	150	for_each_property_of_node(refnode, sprop) {
	151	if (of_prop_cmp(sprop->name, propstr) == 0)
	152	break;
	153	}
82f68756	154	of_node_put(refnode);
7941b27b PA	155
7941b27b PA	156	if (!sprop) {
7941b27b PA	157	err = -ENOENT;
	158	goto err_fail;
	159	}
	160
da56d04c	161	phandle = value;
7941b27b PA	162	(__be32 )(sprop->value + offset) = cpu_to_be32(phandle);
	163	}
	164
	165	err_fail:
	166	kfree(propval);
	167	return err;
	168	}
	169
da56d04c PA	170	/* compare nodes taking into account that 'name' strips out the @ part */
	171	static int __of_node_name_cmp(const struct device_node *dn1,
	172	const struct device_node *dn2)
	173	{
	174	const char *n1 = strrchr(dn1->full_name, '/') ? : "/";
	175	const char *n2 = strrchr(dn2->full_name, '/') ? : "/";
	176
	177	return of_node_cmp(n1, n2);
	178	}
	179
7941b27b PA	180	/*
7941b27b PA	181	* Adjust the local phandle references by the given phandle delta.
da56d04c PA	182	* Assumes the existances of a __local_fixups__ node at the root.
	183	* Assumes that __of_verify_tree_phandle_references has been called.
	184	* Does not take any devtree locks so make sure you call this on a tree
	185	* which is at the detached state.
7941b27b PA	186	*/
7941b27b PA	187	static int __of_adjust_tree_phandle_references(struct device_node *node,
da56d04c	188	struct device_node *target, int phandle_delta)
7941b27b	189	{
da56d04c PA	190	struct device_node child, childtarget;
	191	struct property rprop, sprop;
	192	int err, i, count;
	193	unsigned int off;
	194	phandle phandle;
7941b27b	195
da56d04c	196	if (node == NULL)
7941b27b PA	197	return 0;
7941b27b PA	198
da56d04c PA	199	for_each_property_of_node(node, rprop) {
da56d04c PA	200
7941b27b	201	/* skip properties added automatically */
da56d04c PA	202	if (of_prop_cmp(rprop->name, "name") == 0 \|\|
	203	of_prop_cmp(rprop->name, "phandle") == 0 \|\|
	204	of_prop_cmp(rprop->name, "linux,phandle") == 0)
7941b27b PA	205	continue;
7941b27b PA	206
96d1c8e8	207	if ((rprop->length % 4) != 0 \|\| rprop->length == 0)
da56d04c	208	return -EINVAL;
da56d04c PA	209	count = rprop->length / sizeof(__be32);
da56d04c PA	210
da56d04c PA	211	for_each_property_of_node(target, sprop) {
	212	if (of_prop_cmp(sprop->name, rprop->name) == 0)
	213	break;
	214	}
	215
96d1c8e8	216	if (sprop == NULL)
da56d04c	217	return -EINVAL;
da56d04c PA	218
	219	for (i = 0; i < count; i++) {
	220	off = be32_to_cpu(((__be32 *)rprop->value)[i]);
96d1c8e8	221	if (off >= sprop->length \|\| (off + 4) > sprop->length)
da56d04c	222	return -EINVAL;
da56d04c PA	223
da56d04c PA	224	if (phandle_delta) {
da56d04c PA	225	phandle = be32_to_cpu((__be32 )(sprop->value + off));
	226	phandle += phandle_delta;
	227	(__be32 )(sprop->value + off) = cpu_to_be32(phandle);
	228	}
	229	}
	230	}
	231
	232	for_each_child_of_node(node, child) {
	233
	234	for_each_child_of_node(target, childtarget)
	235	if (__of_node_name_cmp(child, childtarget) == 0)
	236	break;
	237
96d1c8e8	238	if (!childtarget)
da56d04c	239	return -EINVAL;
da56d04c PA	240
	241	err = __of_adjust_tree_phandle_references(child, childtarget,
	242	phandle_delta);
	243	if (err != 0)
7941b27b PA	244	return err;
	245	}
	246
	247	return 0;
	248	}
	249
	250	/**
	251	* of_resolve - Resolve the given node against the live tree.
	252	*
	253	* @resolve: Node to resolve
	254	*
	255	* Perform dynamic Device Tree resolution against the live tree
	256	* to the given node to resolve. This depends on the live tree
	257	* having a __symbols__ node, and the resolve node the __fixups__ &
	258	* __local_fixups__ nodes (if needed).
	259	* The result of the operation is a resolve node that it's contents
	260	* are fit to be inserted or operate upon the live tree.
	261	* Returns 0 on success or a negative error value on error.
	262	*/
	263	int of_resolve_phandles(struct device_node *resolve)
	264	{
da56d04c	265	struct device_node child, childroot, *refnode;
7941b27b PA	266	struct device_node root_sym, resolve_sym, *resolve_fix;
	267	struct property *rprop;
	268	const char *refpath;
	269	phandle phandle, phandle_delta;
	270	int err;
	271
5de3bbc8 MS	272	if (!resolve)
	273	pr_err("%s: null node\n", __func__);
	274	if (resolve && !of_node_check_flag(resolve, OF_DETACHED))
	275	pr_err("%s: node %s not detached\n", __func__,
	276	resolve->full_name);
7941b27b PA	277	if (!resolve \|\| !of_node_check_flag(resolve, OF_DETACHED))
	278	return -EINVAL;
	279
7941b27b PA	280	phandle_delta = of_get_tree_max_phandle() + 1;
7941b27b PA	281	__of_adjust_tree_phandles(resolve, phandle_delta);
da56d04c	282
da56d04c PA	283	childroot = NULL;
	284	for_each_child_of_node(resolve, childroot)
	285	if (of_node_cmp(childroot->name, "__local_fixups__") == 0)
	286	break;
	287
	288	if (childroot != NULL) {
da56d04c PA	289	err = __of_adjust_tree_phandle_references(childroot,
	290	resolve, 0);
	291	if (err != 0)
	292	return err;
	293
	294	BUG_ON(__of_adjust_tree_phandle_references(childroot,
	295	resolve, phandle_delta));
	296	}
7941b27b PA	297
	298	root_sym = NULL;
	299	resolve_sym = NULL;
	300	resolve_fix = NULL;
	301
7941b27b PA	302	root_sym = of_find_node_by_path("/__symbols__");
7941b27b PA	303
7941b27b PA	304	for_each_child_of_node(resolve, child) {
	305
	306	if (!resolve_sym &&
	307	of_node_cmp(child->name, "__symbols__") == 0)
	308	resolve_sym = child;
	309
	310	if (!resolve_fix &&
	311	of_node_cmp(child->name, "__fixups__") == 0)
	312	resolve_fix = child;
	313
7941b27b PA	314	if (resolve_sym && resolve_fix)
	315	break;
	316	}
	317
7941b27b	318	if (!resolve_fix) {
a67976ec	319	err = 0;
7941b27b PA	320	goto out;
	321	}
	322
7941b27b	323	if (!root_sym) {
5de3bbc8	324	pr_err("%s: no symbols in root of device tree.\n", __func__);
7941b27b PA	325	err = -EINVAL;
	326	goto out;
	327	}
	328
	329	for_each_property_of_node(resolve_fix, rprop) {
	330
	331	/* skip properties added automatically */
	332	if (of_prop_cmp(rprop->name, "name") == 0)
	333	continue;
	334
	335	err = of_property_read_string(root_sym,
	336	rprop->name, &refpath);
96d1c8e8	337	if (err != 0)
7941b27b	338	goto out;
7941b27b PA	339
	340	refnode = of_find_node_by_path(refpath);
	341	if (!refnode) {
7941b27b PA	342	err = -ENOENT;
	343	goto out;
	344	}
	345
	346	phandle = refnode->phandle;
	347	of_node_put(refnode);
	348
da56d04c	349	err = __of_adjust_phandle_ref(resolve, rprop, phandle);
7941b27b PA	350	if (err)
	351	break;
	352	}
	353
	354	out:
7941b27b PA	355	of_node_put(root_sym);
	356
	357	return err;
	358	}
	359	EXPORT_SYMBOL_GPL(of_resolve_phandles);