[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 <asm/prom.h>
#include <asm/machdep.h>
#include <asm/uaccess.h>
#include <asm/pSeries_reconfig.h>


/*
 * Routines for "runtime" addition and removal of device tree nodes.
 */
#ifdef CONFIG_PROC_DEVICETREE
/*
 * Add a node to /proc/device-tree.
 */
static void add_node_proc_entries(struct device_node *np)
{
	struct proc_dir_entry *ent;

	ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
	if (ent)
		proc_device_tree_add_node(np, ent);
}

static void remove_node_proc_entries(struct device_node *np)
{
	struct property *pp = np->properties;
	struct device_node *parent = np->parent;

	while (pp) {
		remove_proc_entry(pp->name, np->pde);
		pp = pp->next;
	}
	if (np->pde)
		remove_proc_entry(np->pde->name, parent->pde);
}
#else /* !CONFIG_PROC_DEVICETREE */
static void add_node_proc_entries(struct device_node *np)
{
	return;
}

static void remove_node_proc_entries(struct device_node *np)
{
	return;
}
#endif /* CONFIG_PROC_DEVICETREE */

/**
 *	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 BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);

int pSeries_reconfig_notifier_register(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
}

void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
{
	blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
}

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 = kmalloc(strlen(path) + 1, GFP_KERNEL);
	if (!np->full_name)
		goto out_err;

	strcpy(np->full_name, path);

	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 = blocking_notifier_call_chain(&pSeries_reconfig_chain,
				  PSERIES_RECONFIG_ADD, np);
	if (err == NOTIFY_BAD) {
		printk(KERN_ERR "Failed to add device node %s\n", path);
		err = -ENOMEM; /* For now, safe to assume kmalloc failure */
		goto out_err;
	}

	of_attach_node(np);

	add_node_proc_entries(np);

	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;
	}

	remove_node_proc_entries(np);

	blocking_notifier_call_chain(&pSeries_reconfig_chain,
			    PSERIES_RECONFIG_REMOVE, np);
	of_detach_node(np);

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

/*
 * /proc/ppc64/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 = kmalloc(strlen(name) + 1, GFP_KERNEL)))
		goto cleanup;
	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
		goto cleanup;

	strcpy(new->name, name);
	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, 10);

	*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;

	prom_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 prom_remove_property(np, prop);
}

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

	if (!np)
		return -ENODEV;

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

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

	oldprop = of_find_property(np, name,NULL);
	if (!oldprop)
		return -ENODEV;

	return prom_update_property(np, newprop, oldprop);
}

/**
 * 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
};

/* create /proc/ppc64/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("ppc64/ofdt", S_IWUSR, NULL, &ofdt_fops);
	if (ent)
		ent->size = 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>
	18
	19	#include <asm/prom.h>
e8222502	20	#include <asm/machdep.h>
1da177e4	21	#include <asm/uaccess.h>
e8222502	22	#include <asm/pSeries_reconfig.h>
1da177e4 LT	23
	24
	25
	26	/*
	27	* Routines for "runtime" addition and removal of device tree nodes.
	28	*/
	29	#ifdef CONFIG_PROC_DEVICETREE
	30	/*
	31	* Add a node to /proc/device-tree.
	32	*/
	33	static void add_node_proc_entries(struct device_node *np)
	34	{
	35	struct proc_dir_entry *ent;
	36
	37	ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
	38	if (ent)
	39	proc_device_tree_add_node(np, ent);
	40	}
	41
	42	static void remove_node_proc_entries(struct device_node *np)
	43	{
	44	struct property *pp = np->properties;
	45	struct device_node *parent = np->parent;
	46
	47	while (pp) {
	48	remove_proc_entry(pp->name, np->pde);
	49	pp = pp->next;
	50	}
1da177e4 LT	51	if (np->pde)
	52	remove_proc_entry(np->pde->name, parent->pde);
	53	}
	54	#else /* !CONFIG_PROC_DEVICETREE */
	55	static void add_node_proc_entries(struct device_node *np)
	56	{
	57	return;
	58	}
	59
	60	static void remove_node_proc_entries(struct device_node *np)
	61	{
	62	return;
	63	}
	64	#endif /* CONFIG_PROC_DEVICETREE */
	65
	66	/**
	67	* derive_parent - basically like dirname(1)
	68	* @path: the full_name of a node to be added to the tree
	69	*
	70	* Returns the node which should be the parent of the node
	71	* described by path. E.g., for path = "/foo/bar", returns
	72	* the node with full_name = "/foo".
	73	*/
	74	static struct device_node derive_parent(const char path)
	75	{
	76	struct device_node *parent = NULL;
	77	char *parent_path = "/";
	78	size_t parent_path_len = strrchr(path, '/') - path + 1;
	79
	80	/* reject if path is "/" */
	81	if (!strcmp(path, "/"))
	82	return ERR_PTR(-EINVAL);
	83
	84	if (strrchr(path, '/') != path) {
	85	parent_path = kmalloc(parent_path_len, GFP_KERNEL);
	86	if (!parent_path)
	87	return ERR_PTR(-ENOMEM);
	88	strlcpy(parent_path, path, parent_path_len);
	89	}
	90	parent = of_find_node_by_path(parent_path);
	91	if (!parent)
	92	return ERR_PTR(-EINVAL);
	93	if (strcmp(parent_path, "/"))
	94	kfree(parent_path);
	95	return parent;
	96	}
	97
e041c683	98	static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
1da177e4 LT	99
	100	int pSeries_reconfig_notifier_register(struct notifier_block *nb)
	101	{
e041c683	102	return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
1da177e4 LT	103	}
	104
	105	void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
	106	{
e041c683	107	blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
1da177e4 LT	108	}
	109
	110	static int pSeries_reconfig_add_node(const char path, struct property proplist)
	111	{
	112	struct device_node *np;
	113	int err = -ENOMEM;
	114
874ca6cd	115	np = kzalloc(sizeof(*np), GFP_KERNEL);
1da177e4 LT	116	if (!np)
	117	goto out_err;
	118
	119	np->full_name = kmalloc(strlen(path) + 1, GFP_KERNEL);
	120	if (!np->full_name)
	121	goto out_err;
	122
	123	strcpy(np->full_name, path);
	124
	125	np->properties = proplist;
d3b814bb	126	of_node_set_flag(np, OF_DYNAMIC);
1da177e4 LT	127	kref_init(&np->kref);
	128
	129	np->parent = derive_parent(path);
	130	if (IS_ERR(np->parent)) {
	131	err = PTR_ERR(np->parent);
	132	goto out_err;
	133	}
	134
e041c683	135	err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
1da177e4 LT	136	PSERIES_RECONFIG_ADD, np);
	137	if (err == NOTIFY_BAD) {
	138	printk(KERN_ERR "Failed to add device node %s\n", path);
	139	err = -ENOMEM; /* For now, safe to assume kmalloc failure */
	140	goto out_err;
	141	}
	142
	143	of_attach_node(np);
	144
	145	add_node_proc_entries(np);
	146
	147	of_node_put(np->parent);
	148
	149	return 0;
	150
	151	out_err:
	152	if (np) {
	153	of_node_put(np->parent);
	154	kfree(np->full_name);
	155	kfree(np);
	156	}
	157	return err;
	158	}
	159
	160	static int pSeries_reconfig_remove_node(struct device_node *np)
	161	{
	162	struct device_node parent, child;
	163
	164	parent = of_get_parent(np);
	165	if (!parent)
	166	return -EINVAL;
	167
	168	if ((child = of_get_next_child(np, NULL))) {
	169	of_node_put(child);
842decbd	170	of_node_put(parent);
1da177e4 LT	171	return -EBUSY;
	172	}
	173
	174	remove_node_proc_entries(np);
	175
e041c683	176	blocking_notifier_call_chain(&pSeries_reconfig_chain,
1da177e4 LT	177	PSERIES_RECONFIG_REMOVE, np);
	178	of_detach_node(np);
	179
	180	of_node_put(parent);
	181	of_node_put(np); /* Must decrement the refcount */
	182	return 0;
	183	}
	184
	185	/*
	186	* /proc/ppc64/ofdt - yucky binary interface for adding and removing
	187	* OF device nodes. Should be deprecated as soon as we get an
	188	* in-kernel wrapper for the RTAS ibm,configure-connector call.
	189	*/
	190
	191	static void release_prop_list(const struct property *prop)
	192	{
	193	struct property *next;
	194	for (; prop; prop = next) {
	195	next = prop->next;
	196	kfree(prop->name);
	197	kfree(prop->value);
	198	kfree(prop);
	199	}
	200
	201	}
	202
	203	/**
	204	* parse_next_property - process the next property from raw input buffer
	205	* @buf: input buffer, must be nul-terminated
	206	* @end: end of the input buffer + 1, for validation
	207	* @name: return value; set to property name in buf
	208	* @length: return value; set to length of value
	209	* @value: return value; set to the property value in buf
	210	*
	211	* Note that the caller must make copies of the name and value returned,
	212	* this function does no allocation or copying of the data. Return value
	213	* is set to the next name in buf, or NULL on error.
	214	*/
	215	static char * parse_next_property(char buf, char end, char *name, int length,
	216	unsigned char **value)
	217	{
	218	char *tmp;
	219
	220	*name = buf;
	221
	222	tmp = strchr(buf, ' ');
	223	if (!tmp) {
	224	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	225	__func__, __LINE__);
1da177e4 LT	226	return NULL;
	227	}
	228	*tmp = '\0';
	229
	230	if (++tmp >= end) {
	231	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	232	__func__, __LINE__);
1da177e4 LT	233	return NULL;
	234	}
	235
	236	/* now we're on the length */
	237	*length = -1;
	238	*length = simple_strtoul(tmp, &tmp, 10);
	239	if (*length == -1) {
	240	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	241	__func__, __LINE__);
1da177e4 LT	242	return NULL;
	243	}
	244	if (*tmp != ' ' \|\| ++tmp >= end) {
	245	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	246	__func__, __LINE__);
1da177e4 LT	247	return NULL;
	248	}
	249
	250	/* now we're on the value */
	251	*value = tmp;
	252	tmp += *length;
	253	if (tmp > end) {
	254	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	255	__func__, __LINE__);
1da177e4 LT	256	return NULL;
	257	}
	258	else if (tmp < end && tmp != ' ' && tmp != '\0') {
	259	printk(KERN_ERR "property parse failed in %s at line %d\n",
e48b1b45	260	__func__, __LINE__);
1da177e4 LT	261	return NULL;
	262	}
	263	tmp++;
	264
	265	/* and now we should be on the next name, or the end */
	266	return tmp;
	267	}
	268
	269	static struct property new_property(const char name, const int length,
	270	const unsigned char value, struct property last)
	271	{
f8485350	272	struct property new = kzalloc(sizeof(new), GFP_KERNEL);
1da177e4 LT	273
	274	if (!new)
	275	return NULL;
1da177e4 LT	276
	277	if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
	278	goto cleanup;
	279	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
	280	goto cleanup;
	281
	282	strcpy(new->name, name);
	283	memcpy(new->value, value, length);
	284	(((char )new->value) + length) = 0;
	285	new->length = length;
	286	new->next = last;
	287	return new;
	288
	289	cleanup:
b2325fe1 JJ	290	kfree(new->name);
b2325fe1 JJ	291	kfree(new->value);
1da177e4 LT	292	kfree(new);
	293	return NULL;
	294	}
	295
	296	static int do_add_node(char *buf, size_t bufsize)
	297	{
	298	char path, end, *name;
	299	struct device_node *np;
	300	struct property *prop = NULL;
	301	unsigned char* value;
	302	int length, rv = 0;
	303
	304	end = buf + bufsize;
	305	path = buf;
	306	buf = strchr(buf, ' ');
	307	if (!buf)
	308	return -EINVAL;
	309	*buf = '\0';
	310	buf++;
	311
	312	if ((np = of_find_node_by_path(path))) {
	313	of_node_put(np);
	314	return -EINVAL;
	315	}
	316
	317	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
	318	while (buf < end &&
	319	(buf = parse_next_property(buf, end, &name, &length, &value))) {
	320	struct property *last = prop;
	321
	322	prop = new_property(name, length, value, last);
	323	if (!prop) {
	324	rv = -ENOMEM;
	325	prop = last;
	326	goto out;
	327	}
	328	}
	329	if (!buf) {
	330	rv = -EINVAL;
	331	goto out;
	332	}
	333
	334	rv = pSeries_reconfig_add_node(path, prop);
	335
	336	out:
	337	if (rv)
	338	release_prop_list(prop);
	339	return rv;
	340	}
	341
	342	static int do_remove_node(char *buf)
	343	{
	344	struct device_node *node;
	345	int rv = -ENODEV;
	346
	347	if ((node = of_find_node_by_path(buf)))
	348	rv = pSeries_reconfig_remove_node(node);
	349
	350	of_node_put(node);
	351	return rv;
	352	}
	353
610d9151 DB	354	static char parse_node(char buf, size_t bufsize, struct device_node **npp)
	355	{
	356	char *handle_str;
	357	phandle handle;
	358	*npp = NULL;
	359
	360	handle_str = buf;
	361
	362	buf = strchr(buf, ' ');
	363	if (!buf)
	364	return NULL;
	365	*buf = '\0';
	366	buf++;
	367
	368	handle = simple_strtoul(handle_str, NULL, 10);
	369
	370	*npp = of_find_node_by_phandle(handle);
	371	return buf;
	372	}
	373
	374	static int do_add_property(char *buf, size_t bufsize)
	375	{
	376	struct property *prop = NULL;
	377	struct device_node *np;
	378	unsigned char *value;
	379	char name, end;
	380	int length;
	381	end = buf + bufsize;
	382	buf = parse_node(buf, bufsize, &np);
	383
	384	if (!np)
	385	return -ENODEV;
	386
	387	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
	388	return -EINVAL;
	389
	390	prop = new_property(name, length, value, NULL);
	391	if (!prop)
	392	return -ENOMEM;
	393
	394	prom_add_property(np, prop);
	395
	396	return 0;
	397	}
	398
	399	static int do_remove_property(char *buf, size_t bufsize)
	400	{
	401	struct device_node *np;
	402	char *tmp;
	403	struct property *prop;
	404	buf = parse_node(buf, bufsize, &np);
	405
	406	if (!np)
	407	return -ENODEV;
	408
	409	tmp = strchr(buf,' ');
	410	if (tmp)
	411	*tmp = '\0';
	412
	413	if (strlen(buf) == 0)
	414	return -EINVAL;
	415
	416	prop = of_find_property(np, buf, NULL);
	417
418	return prom_remove_property(np, prop);
419	}
420
421	static int do_update_property(char *buf, size_t bufsize)
422	{
423	struct device_node *np;
424	unsigned char *value;
425	char name, end;
426	int length;
427	struct property newprop, oldprop;
428	buf = parse_node(buf, bufsize, &np);
429	end = buf + bufsize;
430
431	if (!np)
432	return -ENODEV;
433
434	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
435	return -EINVAL;
436
437	newprop = new_property(name, length, value, NULL);
438	if (!newprop)
439	return -ENOMEM;
440
441	oldprop = of_find_property(np, name,NULL);
442	if (!oldprop)
443	return -ENODEV;
444
445	return prom_update_property(np, newprop, oldprop);
446	}
447
1da177e4 LT	448	/**
	449	* ofdt_write - perform operations on the Open Firmware device tree
	450	*
	451	* @file: not used
	452	* @buf: command and arguments
	453	* @count: size of the command buffer
	454	* @off: not used
	455	*
	456	* Operations supported at this time are addition and removal of
	457	* whole nodes along with their properties. Operations on individual
	458	* properties are not implemented (yet).
	459	*/
	460	static ssize_t ofdt_write(struct file file, const char __user buf, size_t count,
	461	loff_t *off)
	462	{
	463	int rv = 0;
	464	char *kbuf;
	465	char *tmp;
	466
	467	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
	468	rv = -ENOMEM;
	469	goto out;
	470	}
	471	if (copy_from_user(kbuf, buf, count)) {
	472	rv = -EFAULT;
	473	goto out;
	474	}
	475
	476	kbuf[count] = '\0';
	477
	478	tmp = strchr(kbuf, ' ');
	479	if (!tmp) {
	480	rv = -EINVAL;
	481	goto out;
	482	}
	483	*tmp = '\0';
	484	tmp++;
	485
	486	if (!strcmp(kbuf, "add_node"))
	487	rv = do_add_node(tmp, count - (tmp - kbuf));
	488	else if (!strcmp(kbuf, "remove_node"))
	489	rv = do_remove_node(tmp);
610d9151 DB	490	else if (!strcmp(kbuf, "add_property"))
	491	rv = do_add_property(tmp, count - (tmp - kbuf));
	492	else if (!strcmp(kbuf, "remove_property"))
	493	rv = do_remove_property(tmp, count - (tmp - kbuf));
	494	else if (!strcmp(kbuf, "update_property"))
	495	rv = do_update_property(tmp, count - (tmp - kbuf));
1da177e4 LT	496	else
	497	rv = -EINVAL;
	498	out:
	499	kfree(kbuf);
	500	return rv ? rv : count;
	501	}
	502
5dfe4c96	503	static const struct file_operations ofdt_fops = {
1da177e4 LT	504	.write = ofdt_write
	505	};
	506
	507	/* create /proc/ppc64/ofdt write-only by root */
	508	static int proc_ppc64_create_ofdt(void)
	509	{
	510	struct proc_dir_entry *ent;
	511
e8222502	512	if (!machine_is(pseries))
1da177e4 LT	513	return 0;
1da177e4 LT	514
66747138 DL	515	ent = proc_create("ppc64/ofdt", S_IWUSR, NULL, &ofdt_fops);
66747138 DL	516	if (ent)
1da177e4	517	ent->size = 0;
1da177e4 LT	518
	519	return 0;
	520	}
	521	__initcall(proc_ppc64_create_ofdt);