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>
20 #include <asm/machdep.h>
21 #include <asm/uaccess.h>
22 #include <asm/pSeries_reconfig.h>
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 	}
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 
98 static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
99 
100 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
101 {
102 	return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
103 }
104 
105 void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
106 {
107 	blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
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 
115 	np = kzalloc(sizeof(*np), GFP_KERNEL);
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;
126 	of_node_set_flag(np, OF_DYNAMIC);
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 
135 	err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
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);
170 		of_node_put(parent);
171 		return -EBUSY;
172 	}
173 
174 	remove_node_proc_entries(np);
175 
176 	blocking_notifier_call_chain(&pSeries_reconfig_chain,
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",
225 		       __FUNCTION__, __LINE__);
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",
232 		       __FUNCTION__, __LINE__);
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",
241 		       __FUNCTION__, __LINE__);
242 		return NULL;
243 	}
244 	if (*tmp != ' ' || ++tmp >= end) {
245 		printk(KERN_ERR "property parse failed in %s at line %d\n",
246 		       __FUNCTION__, __LINE__);
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",
255 		       __FUNCTION__, __LINE__);
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",
260 		       __FUNCTION__, __LINE__);
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 {
272 	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
273 
274 	if (!new)
275 		return NULL;
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:
290 	kfree(new->name);
291 	kfree(new->value);
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 
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 
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);
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));
496 	else
497 		rv = -EINVAL;
498 out:
499 	kfree(kbuf);
500 	return rv ? rv : count;
501 }
502 
503 static const struct file_operations ofdt_fops = {
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 
512 	if (!machine_is(pseries))
513 		return 0;
514 
515 	ent = create_proc_entry("ppc64/ofdt", S_IWUSR, NULL);
516 	if (ent) {
517 		ent->data = NULL;
518 		ent->size = 0;
519 		ent->proc_fops = &ofdt_fops;
520 	}
521 
522 	return 0;
523 }
524 __initcall(proc_ppc64_create_ofdt);
525