[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / powerpc / platforms / pseries / reconfig.c

/*
 * pSeries_reconfig.c - support for dynamic reconfiguration (including PCI
 * Hotplug and Dynamic Logical Partitioning on RPA platforms).
 *
 * Copyright (C) 2005 Nathan Lynch
 * Copyright (C) 2005 IBM Corporation
 *
 *
 *	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.
 */

#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
#include <linux/of.h>

#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/uaccess.h>
#include <asm/mmu.h>

/**
 *	derive_parent - basically like dirname(1)
 *	@path:  the full_name of a node to be added to the tree
 *
 *	Returns the node which should be the parent of the node
 *	described by path.  E.g., for path = "/foo/bar", returns
 *	the node with full_name = "/foo".
 */
static struct device_node *derive_parent(const char *path)
{
	struct device_node *parent = NULL;
	char *parent_path = "/";
	size_t parent_path_len = strrchr(path, '/') - path + 1;

	/* reject if path is "/" */
	if (!strcmp(path, "/"))
		return ERR_PTR(-EINVAL);

	if (strrchr(path, '/') != path) {
		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
		if (!parent_path)
			return ERR_PTR(-ENOMEM);
		strlcpy(parent_path, path, parent_path_len);
	}
	parent = of_find_node_by_path(parent_path);
	if (!parent)
		return ERR_PTR(-EINVAL);
	if (strcmp(parent_path, "/"))
		kfree(parent_path);
	return parent;
}

static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
{
	struct device_node *np;
	int err = -ENOMEM;

	np = kzalloc(sizeof(*np), GFP_KERNEL);
	if (!np)
		goto out_err;

	np->full_name = kstrdup(path, GFP_KERNEL);
	if (!np->full_name)
		goto out_err;

	np->properties = proplist;
	of_node_set_flag(np, OF_DYNAMIC);
	kref_init(&np->kref);

	np->parent = derive_parent(path);
	if (IS_ERR(np->parent)) {
		err = PTR_ERR(np->parent);
		goto out_err;
	}

	err = of_attach_node(np);
	if (err) {
		printk(KERN_ERR "Failed to add device node %s\n", path);
		goto out_err;
	}

	of_node_put(np->parent);

	return 0;

out_err:
	if (np) {
		of_node_put(np->parent);
		kfree(np->full_name);
		kfree(np);
	}
	return err;
}

static int pSeries_reconfig_remove_node(struct device_node *np)
{
	struct device_node *parent, *child;

	parent = of_get_parent(np);
	if (!parent)
		return -EINVAL;

	if ((child = of_get_next_child(np, NULL))) {
		of_node_put(child);
		of_node_put(parent);
		return -EBUSY;
	}

	of_detach_node(np);
	of_node_put(parent);
	of_node_put(np); /* Must decrement the refcount */
	return 0;
}

/*
 * /proc/powerpc/ofdt - yucky binary interface for adding and removing
 * OF device nodes.  Should be deprecated as soon as we get an
 * in-kernel wrapper for the RTAS ibm,configure-connector call.
 */

static void release_prop_list(const struct property *prop)
{
	struct property *next;
	for (; prop; prop = next) {
		next = prop->next;
		kfree(prop->name);
		kfree(prop->value);
		kfree(prop);
	}

}

/**
 * parse_next_property - process the next property from raw input buffer
 * @buf: input buffer, must be nul-terminated
 * @end: end of the input buffer + 1, for validation
 * @name: return value; set to property name in buf
 * @length: return value; set to length of value
 * @value: return value; set to the property value in buf
 *
 * Note that the caller must make copies of the name and value returned,
 * this function does no allocation or copying of the data.  Return value
 * is set to the next name in buf, or NULL on error.
 */
static char * parse_next_property(char *buf, char *end, char **name, int *length,
				  unsigned char **value)
{
	char *tmp;

	*name = buf;

	tmp = strchr(buf, ' ');
	if (!tmp) {
		printk(KERN_ERR "property parse failed in %s at line %d\n",
		       __func__, __LINE__);
		return NULL;
	}
	*tmp = '\0';

	if (++tmp >= end) {
		printk(KERN_ERR "property parse failed in %s at line %d\n",
		       __func__, __LINE__);
		return NULL;
	}

	/* now we're on the length */
	*length = -1;
	*length = simple_strtoul(tmp, &tmp, 10);
	if (*length == -1) {
		printk(KERN_ERR "property parse failed in %s at line %d\n",
		       __func__, __LINE__);
		return NULL;
	}
	if (*tmp != ' ' || ++tmp >= end) {
		printk(KERN_ERR "property parse failed in %s at line %d\n",
		       __func__, __LINE__);
		return NULL;
	}

	/* now we're on the value */
	*value = tmp;
	tmp += *length;
	if (tmp > end) {
		printk(KERN_ERR "property parse failed in %s at line %d\n",
		       __func__, __LINE__);
		return NULL;
	}
	else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
		printk(KERN_ERR "property parse failed in %s at line %d\n",
		       __func__, __LINE__);
		return NULL;
	}
	tmp++;

	/* and now we should be on the next name, or the end */
	return tmp;
}

static struct property *new_property(const char *name, const int length,
				     const unsigned char *value, struct property *last)
{
	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);

	if (!new)
		return NULL;

	if (!(new->name = kstrdup(name, GFP_KERNEL)))
		goto cleanup;
	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
		goto cleanup;

	memcpy(new->value, value, length);
	*(((char *)new->value) + length) = 0;
	new->length = length;
	new->next = last;
	return new;

cleanup:
	kfree(new->name);
	kfree(new->value);
	kfree(new);
	return NULL;
}

static int do_add_node(char *buf, size_t bufsize)
{
	char *path, *end, *name;
	struct device_node *np;
	struct property *prop = NULL;
	unsigned char* value;
	int length, rv = 0;

	end = buf + bufsize;
	path = buf;
	buf = strchr(buf, ' ');
	if (!buf)
		return -EINVAL;
	*buf = '\0';
	buf++;

	if ((np = of_find_node_by_path(path))) {
		of_node_put(np);
		return -EINVAL;
	}

	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
	while (buf < end &&
	       (buf = parse_next_property(buf, end, &name, &length, &value))) {
		struct property *last = prop;

		prop = new_property(name, length, value, last);
		if (!prop) {
			rv = -ENOMEM;
			prop = last;
			goto out;
		}
	}
	if (!buf) {
		rv = -EINVAL;
		goto out;
	}

	rv = pSeries_reconfig_add_node(path, prop);

out:
	if (rv)
		release_prop_list(prop);
	return rv;
}

static int do_remove_node(char *buf)
{
	struct device_node *node;
	int rv = -ENODEV;

	if ((node = of_find_node_by_path(buf)))
		rv = pSeries_reconfig_remove_node(node);

	of_node_put(node);
	return rv;
}

static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
{
	char *handle_str;
	phandle handle;
	*npp = NULL;

	handle_str = buf;

	buf = strchr(buf, ' ');
	if (!buf)
		return NULL;
	*buf = '\0';
	buf++;

	handle = simple_strtoul(handle_str, NULL, 0);

	*npp = of_find_node_by_phandle(handle);
	return buf;
}

static int do_add_property(char *buf, size_t bufsize)
{
	struct property *prop = NULL;
	struct device_node *np;
	unsigned char *value;
	char *name, *end;
	int length;
	end = buf + bufsize;
	buf = parse_node(buf, bufsize, &np);

	if (!np)
		return -ENODEV;

	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
		return -EINVAL;

	prop = new_property(name, length, value, NULL);
	if (!prop)
		return -ENOMEM;

	of_add_property(np, prop);

	return 0;
}

static int do_remove_property(char *buf, size_t bufsize)
{
	struct device_node *np;
	char *tmp;
	struct property *prop;
	buf = parse_node(buf, bufsize, &np);

	if (!np)
		return -ENODEV;

	tmp = strchr(buf,' ');
	if (tmp)
		*tmp = '\0';

	if (strlen(buf) == 0)
		return -EINVAL;

	prop = of_find_property(np, buf, NULL);

	return of_remove_property(np, prop);
}

static int do_update_property(char *buf, size_t bufsize)
{
	struct device_node *np;
	unsigned char *value;
	char *name, *end, *next_prop;
	int length;
	struct property *newprop;
	buf = parse_node(buf, bufsize, &np);
	end = buf + bufsize;

	if (!np)
		return -ENODEV;

	next_prop = parse_next_property(buf, end, &name, &length, &value);
	if (!next_prop)
		return -EINVAL;

	if (!strlen(name))
		return -ENODEV;

	newprop = new_property(name, length, value, NULL);
	if (!newprop)
		return -ENOMEM;

	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
		slb_set_size(*(int *)value);

	return of_update_property(np, newprop);
}

/**
 * ofdt_write - perform operations on the Open Firmware device tree
 *
 * @file: not used
 * @buf: command and arguments
 * @count: size of the command buffer
 * @off: not used
 *
 * Operations supported at this time are addition and removal of
 * whole nodes along with their properties.  Operations on individual
 * properties are not implemented (yet).
 */
static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
			  loff_t *off)
{
	int rv = 0;
	char *kbuf;
	char *tmp;

	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
		rv = -ENOMEM;
		goto out;
	}
	if (copy_from_user(kbuf, buf, count)) {
		rv = -EFAULT;
		goto out;
	}

	kbuf[count] = '\0';

	tmp = strchr(kbuf, ' ');
	if (!tmp) {
		rv = -EINVAL;
		goto out;
	}
	*tmp = '\0';
	tmp++;

	if (!strcmp(kbuf, "add_node"))
		rv = do_add_node(tmp, count - (tmp - kbuf));
	else if (!strcmp(kbuf, "remove_node"))
		rv = do_remove_node(tmp);
	else if (!strcmp(kbuf, "add_property"))
		rv = do_add_property(tmp, count - (tmp - kbuf));
	else if (!strcmp(kbuf, "remove_property"))
		rv = do_remove_property(tmp, count - (tmp - kbuf));
	else if (!strcmp(kbuf, "update_property"))
		rv = do_update_property(tmp, count - (tmp - kbuf));
	else
		rv = -EINVAL;
out:
	kfree(kbuf);
	return rv ? rv : count;
}

static const struct file_operations ofdt_fops = {
	.write = ofdt_write,
	.llseek = noop_llseek,
};

/* create /proc/powerpc/ofdt write-only by root */
static int proc_ppc64_create_ofdt(void)
{
	struct proc_dir_entry *ent;

	if (!machine_is(pseries))
		return 0;

	ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
	if (ent)
		proc_set_size(ent, 0);

	return 0;
}
__initcall(proc_ppc64_create_ofdt);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* pSeries_reconfig.c - support for dynamic reconfiguration (including PCI
	3	* Hotplug and Dynamic Logical Partitioning on RPA platforms).
	4	*
	5	* Copyright (C) 2005 Nathan Lynch
	6	* Copyright (C) 2005 IBM Corporation
	7	*
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License version
	11	* 2 as published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/kref.h>
	16	#include <linux/notifier.h>
	17	#include <linux/proc_fs.h>
5a0e3ad6	18	#include <linux/slab.h>
1cf3d8b3	19	#include <linux/of.h>
1da177e4 LT	20
1da177e4 LT	21	#include <asm/prom.h>
e8222502	22	#include <asm/machdep.h>
1da177e4	23	#include <asm/uaccess.h>
46db2f86	24	#include <asm/mmu.h>
1da177e4	25
1da177e4 LT	26	/**
	27	* derive_parent - basically like dirname(1)
	28	* @path: the full_name of a node to be added to the tree
	29	*
	30	* Returns the node which should be the parent of the node
	31	* described by path. E.g., for path = "/foo/bar", returns
	32	* the node with full_name = "/foo".
	33	*/
	34	static struct device_node derive_parent(const char path)
	35	{
	36	struct device_node *parent = NULL;
	37	char *parent_path = "/";
	38	size_t parent_path_len = strrchr(path, '/') - path + 1;
	39
	40	/* reject if path is "/" */
	41	if (!strcmp(path, "/"))
	42	return ERR_PTR(-EINVAL);
	43
	44	if (strrchr(path, '/') != path) {
	45	parent_path = kmalloc(parent_path_len, GFP_KERNEL);
	46	if (!parent_path)
	47	return ERR_PTR(-ENOMEM);
	48	strlcpy(parent_path, path, parent_path_len);
	49	}
	50	parent = of_find_node_by_path(parent_path);
	51	if (!parent)
	52	return ERR_PTR(-EINVAL);
	53	if (strcmp(parent_path, "/"))
	54	kfree(parent_path);
	55	return parent;
	56	}
	57
1da177e4 LT	58	static int pSeries_reconfig_add_node(const char path, struct property proplist)
	59	{
	60	struct device_node *np;
	61	int err = -ENOMEM;
	62
874ca6cd	63	np = kzalloc(sizeof(*np), GFP_KERNEL);
1da177e4 LT	64	if (!np)
	65	goto out_err;
	66
74052173	67	np->full_name = kstrdup(path, GFP_KERNEL);
1da177e4 LT	68	if (!np->full_name)
	69	goto out_err;
	70
1da177e4	71	np->properties = proplist;
d3b814bb	72	of_node_set_flag(np, OF_DYNAMIC);
1da177e4 LT	73	kref_init(&np->kref);
	74
	75	np->parent = derive_parent(path);
	76	if (IS_ERR(np->parent)) {
	77	err = PTR_ERR(np->parent);
	78	goto out_err;
	79	}
	80
1cf3d8b3	81	err = of_attach_node(np);
3aef19f0	82	if (err) {
1da177e4	83	printk(KERN_ERR "Failed to add device node %s\n", path);
1da177e4 LT	84	goto out_err;
	85	}
	86
1da177e4 LT	87	of_node_put(np->parent);
	88
	89	return 0;
	90
	91	out_err:
	92	if (np) {
	93	of_node_put(np->parent);
	94	kfree(np->full_name);
	95	kfree(np);
	96	}
	97	return err;
	98	}
	99
	100	static int pSeries_reconfig_remove_node(struct device_node *np)
	101	{
	102	struct device_node parent, child;
	103
	104	parent = of_get_parent(np);
	105	if (!parent)
	106	return -EINVAL;
	107
	108	if ((child = of_get_next_child(np, NULL))) {
	109	of_node_put(child);
842decbd	110	of_node_put(parent);
1da177e4 LT	111	return -EBUSY;
	112	}
	113
1da177e4	114	of_detach_node(np);
1da177e4 LT	115	of_node_put(parent);
	116	of_node_put(np); /* Must decrement the refcount */
	117	return 0;
	118	}
	119
	120	/*
188917e1	121	* /proc/powerpc/ofdt - yucky binary interface for adding and removing
1da177e4 LT	122	* OF device nodes. Should be deprecated as soon as we get an
	123	* in-kernel wrapper for the RTAS ibm,configure-connector call.
	124	*/
	125
	126	static void release_prop_list(const struct property *prop)
	127	{
	128	struct property *next;
	129	for (; prop; prop = next) {
	130	next = prop->next;
	131	kfree(prop->name);
	132	kfree(prop->value);
	133	kfree(prop);
	134	}
	135
	136	}
	137
	138	/**
	139	* parse_next_property - process the next property from raw input buffer
	140	* @buf: input buffer, must be nul-terminated
	141	* @end: end of the input buffer + 1, for validation
	142	* @name: return value; set to property name in buf
	143	* @length: return value; set to length of value
	144	* @value: return value; set to the property value in buf
	145	*
	146	* Note that the caller must make copies of the name and value returned,
	147	* this function does no allocation or copying of the data. Return value
	148	* is set to the next name in buf, or NULL on error.
	149	*/
	150	static char * parse_next_property(char buf, char end, char *name, int length,
	151	unsigned char **value)
	152	{
	153	char *tmp;
	154
	155	*name = buf;
	156
	157	tmp = strchr(buf, ' ');
	158	if (!tmp) {
	159	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	160	__func__, __LINE__);
1da177e4 LT	161	return NULL;
	162	}
	163	*tmp = '\0';
	164
	165	if (++tmp >= end) {
	166	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	167	__func__, __LINE__);
1da177e4 LT	168	return NULL;
	169	}
	170
	171	/* now we're on the length */
	172	*length = -1;
	173	*length = simple_strtoul(tmp, &tmp, 10);
	174	if (*length == -1) {
	175	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	176	__func__, __LINE__);
1da177e4 LT	177	return NULL;
	178	}
	179	if (*tmp != ' ' \|\| ++tmp >= end) {
	180	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	181	__func__, __LINE__);
1da177e4 LT	182	return NULL;
	183	}
	184
	185	/* now we're on the value */
	186	*value = tmp;
	187	tmp += *length;
	188	if (tmp > end) {
	189	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	190	__func__, __LINE__);
1da177e4 LT	191	return NULL;
	192	}
	193	else if (tmp < end && tmp != ' ' && tmp != '\0') {
	194	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	195	__func__, __LINE__);
1da177e4 LT	196	return NULL;
	197	}
	198	tmp++;
	199
	200	/* and now we should be on the next name, or the end */
	201	return tmp;
	202	}
	203
	204	static struct property new_property(const char name, const int length,
	205	const unsigned char value, struct property last)
	206	{
f8485350	207	struct property new = kzalloc(sizeof(new), GFP_KERNEL);
1da177e4 LT	208
	209	if (!new)
	210	return NULL;
1da177e4	211
c22618a1	212	if (!(new->name = kstrdup(name, GFP_KERNEL)))
1da177e4 LT	213	goto cleanup;
	214	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
	215	goto cleanup;
	216
1da177e4 LT	217	memcpy(new->value, value, length);
	218	(((char )new->value) + length) = 0;
	219	new->length = length;
	220	new->next = last;
	221	return new;
	222
	223	cleanup:
b2325fe1 JJ	224	kfree(new->name);
b2325fe1 JJ	225	kfree(new->value);
1da177e4 LT	226	kfree(new);
	227	return NULL;
	228	}
	229
	230	static int do_add_node(char *buf, size_t bufsize)
	231	{
	232	char path, end, *name;
	233	struct device_node *np;
	234	struct property *prop = NULL;
	235	unsigned char* value;
	236	int length, rv = 0;
	237
	238	end = buf + bufsize;
	239	path = buf;
	240	buf = strchr(buf, ' ');
	241	if (!buf)
	242	return -EINVAL;
	243	*buf = '\0';
	244	buf++;
	245
	246	if ((np = of_find_node_by_path(path))) {
	247	of_node_put(np);
	248	return -EINVAL;
	249	}
	250
	251	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
	252	while (buf < end &&
	253	(buf = parse_next_property(buf, end, &name, &length, &value))) {
	254	struct property *last = prop;
	255
	256	prop = new_property(name, length, value, last);
	257	if (!prop) {
	258	rv = -ENOMEM;
	259	prop = last;
	260	goto out;
	261	}
	262	}
	263	if (!buf) {
	264	rv = -EINVAL;
	265	goto out;
	266	}
	267
	268	rv = pSeries_reconfig_add_node(path, prop);
	269
	270	out:
	271	if (rv)
	272	release_prop_list(prop);
	273	return rv;
	274	}
	275
	276	static int do_remove_node(char *buf)
	277	{
	278	struct device_node *node;
	279	int rv = -ENODEV;
	280
	281	if ((node = of_find_node_by_path(buf)))
	282	rv = pSeries_reconfig_remove_node(node);
	283
	284	of_node_put(node);
	285	return rv;
	286	}
	287
610d9151 DB	288	static char parse_node(char buf, size_t bufsize, struct device_node **npp)
	289	{
	290	char *handle_str;
	291	phandle handle;
	292	*npp = NULL;
	293
	294	handle_str = buf;
	295
	296	buf = strchr(buf, ' ');
	297	if (!buf)
	298	return NULL;
	299	*buf = '\0';
	300	buf++;
	301
4b6e805e	302	handle = simple_strtoul(handle_str, NULL, 0);
610d9151 DB	303
	304	*npp = of_find_node_by_phandle(handle);
	305	return buf;
	306	}
	307
	308	static int do_add_property(char *buf, size_t bufsize)
	309	{
	310	struct property *prop = NULL;
	311	struct device_node *np;
	312	unsigned char *value;
	313	char name, end;
	314	int length;
	315	end = buf + bufsize;
	316	buf = parse_node(buf, bufsize, &np);
	317
	318	if (!np)
	319	return -ENODEV;
	320
	321	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
	322	return -EINVAL;
	323
	324	prop = new_property(name, length, value, NULL);
	325	if (!prop)
	326	return -ENOMEM;
	327
79d1c712	328	of_add_property(np, prop);
610d9151 DB	329
	330	return 0;
	331	}
	332
	333	static int do_remove_property(char *buf, size_t bufsize)
	334	{
	335	struct device_node *np;
	336	char *tmp;
	337	struct property *prop;
	338	buf = parse_node(buf, bufsize, &np);
	339
	340	if (!np)
	341	return -ENODEV;
	342
	343	tmp = strchr(buf,' ');
	344	if (tmp)
	345	*tmp = '\0';
	346
	347	if (strlen(buf) == 0)
	348	return -EINVAL;
	349
	350	prop = of_find_property(np, buf, NULL);
	351
79d1c712	352	return of_remove_property(np, prop);
610d9151 DB	353	}
	354
	355	static int do_update_property(char *buf, size_t bufsize)
	356	{
	357	struct device_node *np;
	358	unsigned char *value;
3c3f67ea	359	char name, end, *next_prop;
1cf3d8b3	360	int length;
475d0094	361	struct property *newprop;
610d9151 DB	362	buf = parse_node(buf, bufsize, &np);
	363	end = buf + bufsize;
	364
	365	if (!np)
	366	return -ENODEV;
	367
3c3f67ea NF	368	next_prop = parse_next_property(buf, end, &name, &length, &value);
3c3f67ea NF	369	if (!next_prop)
610d9151 DB	370	return -EINVAL;
610d9151 DB	371
475d0094 DA	372	if (!strlen(name))
	373	return -ENODEV;
	374
610d9151 DB	375	newprop = new_property(name, length, value, NULL);
	376	if (!newprop)
	377	return -ENOMEM;
	378
46db2f86 BK	379	if (!strcmp(name, "slb-size") \|\| !strcmp(name, "ibm,slb-size"))
	380	slb_set_size((int )value);
	381
79d1c712	382	return of_update_property(np, newprop);
610d9151 DB	383	}
610d9151 DB	384
1da177e4 LT	385	/**
	386	* ofdt_write - perform operations on the Open Firmware device tree
	387	*
	388	* @file: not used
	389	* @buf: command and arguments
	390	* @count: size of the command buffer
	391	* @off: not used
	392	*
	393	* Operations supported at this time are addition and removal of
	394	* whole nodes along with their properties. Operations on individual
	395	* properties are not implemented (yet).
	396	*/
	397	static ssize_t ofdt_write(struct file file, const char __user buf, size_t count,
	398	loff_t *off)
	399	{
	400	int rv = 0;
	401	char *kbuf;
	402	char *tmp;
	403
	404	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
	405	rv = -ENOMEM;
	406	goto out;
	407	}
	408	if (copy_from_user(kbuf, buf, count)) {
	409	rv = -EFAULT;
	410	goto out;
	411	}
	412
	413	kbuf[count] = '\0';
	414
	415	tmp = strchr(kbuf, ' ');
	416	if (!tmp) {
	417	rv = -EINVAL;
	418	goto out;
	419	}
	420	*tmp = '\0';
	421	tmp++;
	422
	423	if (!strcmp(kbuf, "add_node"))
	424	rv = do_add_node(tmp, count - (tmp - kbuf));
	425	else if (!strcmp(kbuf, "remove_node"))
	426	rv = do_remove_node(tmp);
610d9151 DB	427	else if (!strcmp(kbuf, "add_property"))
	428	rv = do_add_property(tmp, count - (tmp - kbuf));
	429	else if (!strcmp(kbuf, "remove_property"))
	430	rv = do_remove_property(tmp, count - (tmp - kbuf));
	431	else if (!strcmp(kbuf, "update_property"))
	432	rv = do_update_property(tmp, count - (tmp - kbuf));
1da177e4 LT	433	else
	434	rv = -EINVAL;
	435	out:
	436	kfree(kbuf);
	437	return rv ? rv : count;
	438	}
	439
5dfe4c96	440	static const struct file_operations ofdt_fops = {
6038f373 AB	441	.write = ofdt_write,
6038f373 AB	442	.llseek = noop_llseek,
1da177e4 LT	443	};
1da177e4 LT	444
188917e1	445	/* create /proc/powerpc/ofdt write-only by root */
1da177e4 LT	446	static int proc_ppc64_create_ofdt(void)
	447	{
	448	struct proc_dir_entry *ent;
	449
e8222502	450	if (!machine_is(pseries))
1da177e4 LT	451	return 0;
1da177e4 LT	452
188917e1	453	ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
66747138	454	if (ent)
271a15ea	455	proc_set_size(ent, 0);
1da177e4 LT	456
	457	return 0;
	458	}
	459	__initcall(proc_ppc64_create_ofdt);