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
 73	np->parent = derive_parent(path);
 74	if (IS_ERR(np->parent)) {
 75		err = PTR_ERR(np->parent);
 76		goto out_err;
 77	}
 78
 79	err = of_attach_node(np);
 80	if (err) {
 81		printk(KERN_ERR "Failed to add device node %s\n", path);
 82		goto out_err;
 83	}
 84
 85	of_node_put(np->parent);
 86
 87	return 0;
 88
 89out_err:
 90	if (np) {
 91		of_node_put(np->parent);
 92		kfree(np->full_name);
 93		kfree(np);
 94	}
 95	return err;
 96}
 97
 98static int pSeries_reconfig_remove_node(struct device_node *np)
 99{
100	struct device_node *parent, *child;
101
102	parent = of_get_parent(np);
103	if (!parent)
104		return -EINVAL;
105
106	if ((child = of_get_next_child(np, NULL))) {
107		of_node_put(child);
108		of_node_put(parent);
109		return -EBUSY;
110	}
111
112	of_detach_node(np);
113	of_node_put(parent);
114	of_node_put(np); /* Must decrement the refcount */
115	return 0;
116}
117
118/*
119 * /proc/powerpc/ofdt - yucky binary interface for adding and removing
120 * OF device nodes.  Should be deprecated as soon as we get an
121 * in-kernel wrapper for the RTAS ibm,configure-connector call.
122 */
123
124static void release_prop_list(const struct property *prop)
125{
126	struct property *next;
127	for (; prop; prop = next) {
128		next = prop->next;
129		kfree(prop->name);
130		kfree(prop->value);
131		kfree(prop);
132	}
133
134}
135
136/**
137 * parse_next_property - process the next property from raw input buffer
138 * @buf: input buffer, must be nul-terminated
139 * @end: end of the input buffer + 1, for validation
140 * @name: return value; set to property name in buf
141 * @length: return value; set to length of value
142 * @value: return value; set to the property value in buf
143 *
144 * Note that the caller must make copies of the name and value returned,
145 * this function does no allocation or copying of the data.  Return value
146 * is set to the next name in buf, or NULL on error.
147 */
148static char * parse_next_property(char *buf, char *end, char **name, int *length,
149				  unsigned char **value)
150{
151	char *tmp;
152
153	*name = buf;
154
155	tmp = strchr(buf, ' ');
156	if (!tmp) {
157		printk(KERN_ERR "property parse failed in %s at line %d\n",
158		       __func__, __LINE__);
159		return NULL;
160	}
161	*tmp = '\0';
162
163	if (++tmp >= end) {
164		printk(KERN_ERR "property parse failed in %s at line %d\n",
165		       __func__, __LINE__);
166		return NULL;
167	}
168
169	/* now we're on the length */
170	*length = -1;
171	*length = simple_strtoul(tmp, &tmp, 10);
172	if (*length == -1) {
173		printk(KERN_ERR "property parse failed in %s at line %d\n",
174		       __func__, __LINE__);
175		return NULL;
176	}
177	if (*tmp != ' ' || ++tmp >= end) {
178		printk(KERN_ERR "property parse failed in %s at line %d\n",
179		       __func__, __LINE__);
180		return NULL;
181	}
182
183	/* now we're on the value */
184	*value = tmp;
185	tmp += *length;
186	if (tmp > end) {
187		printk(KERN_ERR "property parse failed in %s at line %d\n",
188		       __func__, __LINE__);
189		return NULL;
190	}
191	else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
192		printk(KERN_ERR "property parse failed in %s at line %d\n",
193		       __func__, __LINE__);
194		return NULL;
195	}
196	tmp++;
197
198	/* and now we should be on the next name, or the end */
199	return tmp;
200}
201
202static struct property *new_property(const char *name, const int length,
203				     const unsigned char *value, struct property *last)
204{
205	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
206
207	if (!new)
208		return NULL;
209
210	if (!(new->name = kstrdup(name, GFP_KERNEL)))
211		goto cleanup;
212	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
213		goto cleanup;
214
215	memcpy(new->value, value, length);
216	*(((char *)new->value) + length) = 0;
217	new->length = length;
218	new->next = last;
219	return new;
220
221cleanup:
222	kfree(new->name);
223	kfree(new->value);
224	kfree(new);
225	return NULL;
226}
227
228static int do_add_node(char *buf, size_t bufsize)
229{
230	char *path, *end, *name;
231	struct device_node *np;
232	struct property *prop = NULL;
233	unsigned char* value;
234	int length, rv = 0;
235
236	end = buf + bufsize;
237	path = buf;
238	buf = strchr(buf, ' ');
239	if (!buf)
240		return -EINVAL;
241	*buf = '\0';
242	buf++;
243
244	if ((np = of_find_node_by_path(path))) {
245		of_node_put(np);
246		return -EINVAL;
247	}
248
249	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
250	while (buf < end &&
251	       (buf = parse_next_property(buf, end, &name, &length, &value))) {
252		struct property *last = prop;
253
254		prop = new_property(name, length, value, last);
255		if (!prop) {
256			rv = -ENOMEM;
257			prop = last;
258			goto out;
259		}
260	}
261	if (!buf) {
262		rv = -EINVAL;
263		goto out;
264	}
265
266	rv = pSeries_reconfig_add_node(path, prop);
267
268out:
269	if (rv)
270		release_prop_list(prop);
271	return rv;
272}
273
274static int do_remove_node(char *buf)
275{
276	struct device_node *node;
277	int rv = -ENODEV;
278
279	if ((node = of_find_node_by_path(buf)))
280		rv = pSeries_reconfig_remove_node(node);
281
282	of_node_put(node);
283	return rv;
284}
285
286static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
287{
288	char *handle_str;
289	phandle handle;
290	*npp = NULL;
291
292	handle_str = buf;
293
294	buf = strchr(buf, ' ');
295	if (!buf)
296		return NULL;
297	*buf = '\0';
298	buf++;
299
300	handle = simple_strtoul(handle_str, NULL, 0);
301
302	*npp = of_find_node_by_phandle(handle);
303	return buf;
304}
305
306static int do_add_property(char *buf, size_t bufsize)
307{
308	struct property *prop = NULL;
309	struct device_node *np;
310	unsigned char *value;
311	char *name, *end;
312	int length;
313	end = buf + bufsize;
314	buf = parse_node(buf, bufsize, &np);
315
316	if (!np)
317		return -ENODEV;
318
319	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
320		return -EINVAL;
321
322	prop = new_property(name, length, value, NULL);
323	if (!prop)
324		return -ENOMEM;
325
326	of_add_property(np, prop);
327
328	return 0;
329}
330
331static int do_remove_property(char *buf, size_t bufsize)
332{
333	struct device_node *np;
334	char *tmp;
335	struct property *prop;
336	buf = parse_node(buf, bufsize, &np);
337
338	if (!np)
339		return -ENODEV;
340
341	tmp = strchr(buf,' ');
342	if (tmp)
343		*tmp = '\0';
344
345	if (strlen(buf) == 0)
346		return -EINVAL;
347
348	prop = of_find_property(np, buf, NULL);
349
350	return of_remove_property(np, prop);
351}
352
353static int do_update_property(char *buf, size_t bufsize)
354{
355	struct device_node *np;
356	unsigned char *value;
357	char *name, *end, *next_prop;
358	int length;
359	struct property *newprop;
360	buf = parse_node(buf, bufsize, &np);
361	end = buf + bufsize;
362
363	if (!np)
364		return -ENODEV;
365
366	next_prop = parse_next_property(buf, end, &name, &length, &value);
367	if (!next_prop)
368		return -EINVAL;
369
370	if (!strlen(name))
371		return -ENODEV;
372
373	newprop = new_property(name, length, value, NULL);
374	if (!newprop)
375		return -ENOMEM;
376
377	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
378		slb_set_size(*(int *)value);
379
380	return of_update_property(np, newprop);
381}
382
383/**
384 * ofdt_write - perform operations on the Open Firmware device tree
385 *
386 * @file: not used
387 * @buf: command and arguments
388 * @count: size of the command buffer
389 * @off: not used
390 *
391 * Operations supported at this time are addition and removal of
392 * whole nodes along with their properties.  Operations on individual
393 * properties are not implemented (yet).
394 */
395static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
396			  loff_t *off)
397{
398	int rv = 0;
399	char *kbuf;
400	char *tmp;
401
402	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
403		rv = -ENOMEM;
404		goto out;
405	}
406	if (copy_from_user(kbuf, buf, count)) {
407		rv = -EFAULT;
408		goto out;
409	}
410
411	kbuf[count] = '\0';
412
413	tmp = strchr(kbuf, ' ');
414	if (!tmp) {
415		rv = -EINVAL;
416		goto out;
417	}
418	*tmp = '\0';
419	tmp++;
420
421	if (!strcmp(kbuf, "add_node"))
422		rv = do_add_node(tmp, count - (tmp - kbuf));
423	else if (!strcmp(kbuf, "remove_node"))
424		rv = do_remove_node(tmp);
425	else if (!strcmp(kbuf, "add_property"))
426		rv = do_add_property(tmp, count - (tmp - kbuf));
427	else if (!strcmp(kbuf, "remove_property"))
428		rv = do_remove_property(tmp, count - (tmp - kbuf));
429	else if (!strcmp(kbuf, "update_property"))
430		rv = do_update_property(tmp, count - (tmp - kbuf));
431	else
432		rv = -EINVAL;
433out:
434	kfree(kbuf);
435	return rv ? rv : count;
436}
437
438static const struct file_operations ofdt_fops = {
439	.write = ofdt_write,
440	.llseek = noop_llseek,
441};
442
443/* create /proc/powerpc/ofdt write-only by root */
444static int proc_ppc64_create_ofdt(void)
445{
446	struct proc_dir_entry *ent;
447
448	if (!machine_is(pseries))
449		return 0;
450
451	ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
452	if (ent)
453		proc_set_size(ent, 0);
454
455	return 0;
456}
457__initcall(proc_ppc64_create_ofdt);