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  */
33 static 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 
57 static 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 
89 out_err:
90 	if (np) {
91 		of_node_put(np->parent);
92 		kfree(np->full_name);
93 		kfree(np);
94 	}
95 	return err;
96 }
97 
98 static 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 
124 static 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  */
148 static 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 
202 static 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 
221 cleanup:
222 	kfree(new->name);
223 	kfree(new->value);
224 	kfree(new);
225 	return NULL;
226 }
227 
228 static 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 
268 out:
269 	if (rv)
270 		release_prop_list(prop);
271 	return rv;
272 }
273 
274 static 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 
286 static 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 
306 static 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 
331 static 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 
353 static 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  */
395 static 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;
433 out:
434 	kfree(kbuf);
435 	return rv ? rv : count;
436 }
437 
438 static 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 */
444 static 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);
458