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