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 		return -EBUSY;
171 	}
172 
173 	remove_node_proc_entries(np);
174 
175 	blocking_notifier_call_chain(&pSeries_reconfig_chain,
176 			    PSERIES_RECONFIG_REMOVE, np);
177 	of_detach_node(np);
178 
179 	of_node_put(parent);
180 	of_node_put(np); /* Must decrement the refcount */
181 	return 0;
182 }
183 
184 /*
185  * /proc/ppc64/ofdt - yucky binary interface for adding and removing
186  * OF device nodes.  Should be deprecated as soon as we get an
187  * in-kernel wrapper for the RTAS ibm,configure-connector call.
188  */
189 
190 static void release_prop_list(const struct property *prop)
191 {
192 	struct property *next;
193 	for (; prop; prop = next) {
194 		next = prop->next;
195 		kfree(prop->name);
196 		kfree(prop->value);
197 		kfree(prop);
198 	}
199 
200 }
201 
202 /**
203  * parse_next_property - process the next property from raw input buffer
204  * @buf: input buffer, must be nul-terminated
205  * @end: end of the input buffer + 1, for validation
206  * @name: return value; set to property name in buf
207  * @length: return value; set to length of value
208  * @value: return value; set to the property value in buf
209  *
210  * Note that the caller must make copies of the name and value returned,
211  * this function does no allocation or copying of the data.  Return value
212  * is set to the next name in buf, or NULL on error.
213  */
214 static char * parse_next_property(char *buf, char *end, char **name, int *length,
215 				  unsigned char **value)
216 {
217 	char *tmp;
218 
219 	*name = buf;
220 
221 	tmp = strchr(buf, ' ');
222 	if (!tmp) {
223 		printk(KERN_ERR "property parse failed in %s at line %d\n",
224 		       __FUNCTION__, __LINE__);
225 		return NULL;
226 	}
227 	*tmp = '\0';
228 
229 	if (++tmp >= end) {
230 		printk(KERN_ERR "property parse failed in %s at line %d\n",
231 		       __FUNCTION__, __LINE__);
232 		return NULL;
233 	}
234 
235 	/* now we're on the length */
236 	*length = -1;
237 	*length = simple_strtoul(tmp, &tmp, 10);
238 	if (*length == -1) {
239 		printk(KERN_ERR "property parse failed in %s at line %d\n",
240 		       __FUNCTION__, __LINE__);
241 		return NULL;
242 	}
243 	if (*tmp != ' ' || ++tmp >= end) {
244 		printk(KERN_ERR "property parse failed in %s at line %d\n",
245 		       __FUNCTION__, __LINE__);
246 		return NULL;
247 	}
248 
249 	/* now we're on the value */
250 	*value = tmp;
251 	tmp += *length;
252 	if (tmp > end) {
253 		printk(KERN_ERR "property parse failed in %s at line %d\n",
254 		       __FUNCTION__, __LINE__);
255 		return NULL;
256 	}
257 	else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
258 		printk(KERN_ERR "property parse failed in %s at line %d\n",
259 		       __FUNCTION__, __LINE__);
260 		return NULL;
261 	}
262 	tmp++;
263 
264 	/* and now we should be on the next name, or the end */
265 	return tmp;
266 }
267 
268 static struct property *new_property(const char *name, const int length,
269 				     const unsigned char *value, struct property *last)
270 {
271 	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
272 
273 	if (!new)
274 		return NULL;
275 
276 	if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
277 		goto cleanup;
278 	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
279 		goto cleanup;
280 
281 	strcpy(new->name, name);
282 	memcpy(new->value, value, length);
283 	*(((char *)new->value) + length) = 0;
284 	new->length = length;
285 	new->next = last;
286 	return new;
287 
288 cleanup:
289 	kfree(new->name);
290 	kfree(new->value);
291 	kfree(new);
292 	return NULL;
293 }
294 
295 static int do_add_node(char *buf, size_t bufsize)
296 {
297 	char *path, *end, *name;
298 	struct device_node *np;
299 	struct property *prop = NULL;
300 	unsigned char* value;
301 	int length, rv = 0;
302 
303 	end = buf + bufsize;
304 	path = buf;
305 	buf = strchr(buf, ' ');
306 	if (!buf)
307 		return -EINVAL;
308 	*buf = '\0';
309 	buf++;
310 
311 	if ((np = of_find_node_by_path(path))) {
312 		of_node_put(np);
313 		return -EINVAL;
314 	}
315 
316 	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
317 	while (buf < end &&
318 	       (buf = parse_next_property(buf, end, &name, &length, &value))) {
319 		struct property *last = prop;
320 
321 		prop = new_property(name, length, value, last);
322 		if (!prop) {
323 			rv = -ENOMEM;
324 			prop = last;
325 			goto out;
326 		}
327 	}
328 	if (!buf) {
329 		rv = -EINVAL;
330 		goto out;
331 	}
332 
333 	rv = pSeries_reconfig_add_node(path, prop);
334 
335 out:
336 	if (rv)
337 		release_prop_list(prop);
338 	return rv;
339 }
340 
341 static int do_remove_node(char *buf)
342 {
343 	struct device_node *node;
344 	int rv = -ENODEV;
345 
346 	if ((node = of_find_node_by_path(buf)))
347 		rv = pSeries_reconfig_remove_node(node);
348 
349 	of_node_put(node);
350 	return rv;
351 }
352 
353 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
354 {
355 	char *handle_str;
356 	phandle handle;
357 	*npp = NULL;
358 
359 	handle_str = buf;
360 
361 	buf = strchr(buf, ' ');
362 	if (!buf)
363 		return NULL;
364 	*buf = '\0';
365 	buf++;
366 
367 	handle = simple_strtoul(handle_str, NULL, 10);
368 
369 	*npp = of_find_node_by_phandle(handle);
370 	return buf;
371 }
372 
373 static int do_add_property(char *buf, size_t bufsize)
374 {
375 	struct property *prop = NULL;
376 	struct device_node *np;
377 	unsigned char *value;
378 	char *name, *end;
379 	int length;
380 	end = buf + bufsize;
381 	buf = parse_node(buf, bufsize, &np);
382 
383 	if (!np)
384 		return -ENODEV;
385 
386 	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
387 		return -EINVAL;
388 
389 	prop = new_property(name, length, value, NULL);
390 	if (!prop)
391 		return -ENOMEM;
392 
393 	prom_add_property(np, prop);
394 
395 	return 0;
396 }
397 
398 static int do_remove_property(char *buf, size_t bufsize)
399 {
400 	struct device_node *np;
401 	char *tmp;
402 	struct property *prop;
403 	buf = parse_node(buf, bufsize, &np);
404 
405 	if (!np)
406 		return -ENODEV;
407 
408 	tmp = strchr(buf,' ');
409 	if (tmp)
410 		*tmp = '\0';
411 
412 	if (strlen(buf) == 0)
413 		return -EINVAL;
414 
415 	prop = of_find_property(np, buf, NULL);
416 
417 	return prom_remove_property(np, prop);
418 }
419 
420 static int do_update_property(char *buf, size_t bufsize)
421 {
422 	struct device_node *np;
423 	unsigned char *value;
424 	char *name, *end;
425 	int length;
426 	struct property *newprop, *oldprop;
427 	buf = parse_node(buf, bufsize, &np);
428 	end = buf + bufsize;
429 
430 	if (!np)
431 		return -ENODEV;
432 
433 	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
434 		return -EINVAL;
435 
436 	newprop = new_property(name, length, value, NULL);
437 	if (!newprop)
438 		return -ENOMEM;
439 
440 	oldprop = of_find_property(np, name,NULL);
441 	if (!oldprop)
442 		return -ENODEV;
443 
444 	return prom_update_property(np, newprop, oldprop);
445 }
446 
447 /**
448  * ofdt_write - perform operations on the Open Firmware device tree
449  *
450  * @file: not used
451  * @buf: command and arguments
452  * @count: size of the command buffer
453  * @off: not used
454  *
455  * Operations supported at this time are addition and removal of
456  * whole nodes along with their properties.  Operations on individual
457  * properties are not implemented (yet).
458  */
459 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
460 			  loff_t *off)
461 {
462 	int rv = 0;
463 	char *kbuf;
464 	char *tmp;
465 
466 	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
467 		rv = -ENOMEM;
468 		goto out;
469 	}
470 	if (copy_from_user(kbuf, buf, count)) {
471 		rv = -EFAULT;
472 		goto out;
473 	}
474 
475 	kbuf[count] = '\0';
476 
477 	tmp = strchr(kbuf, ' ');
478 	if (!tmp) {
479 		rv = -EINVAL;
480 		goto out;
481 	}
482 	*tmp = '\0';
483 	tmp++;
484 
485 	if (!strcmp(kbuf, "add_node"))
486 		rv = do_add_node(tmp, count - (tmp - kbuf));
487 	else if (!strcmp(kbuf, "remove_node"))
488 		rv = do_remove_node(tmp);
489 	else if (!strcmp(kbuf, "add_property"))
490 		rv = do_add_property(tmp, count - (tmp - kbuf));
491 	else if (!strcmp(kbuf, "remove_property"))
492 		rv = do_remove_property(tmp, count - (tmp - kbuf));
493 	else if (!strcmp(kbuf, "update_property"))
494 		rv = do_update_property(tmp, count - (tmp - kbuf));
495 	else
496 		rv = -EINVAL;
497 out:
498 	kfree(kbuf);
499 	return rv ? rv : count;
500 }
501 
502 static const struct file_operations ofdt_fops = {
503 	.write = ofdt_write
504 };
505 
506 /* create /proc/ppc64/ofdt write-only by root */
507 static int proc_ppc64_create_ofdt(void)
508 {
509 	struct proc_dir_entry *ent;
510 
511 	if (!machine_is(pseries))
512 		return 0;
513 
514 	ent = create_proc_entry("ppc64/ofdt", S_IWUSR, NULL);
515 	if (ent) {
516 		ent->data = NULL;
517 		ent->size = 0;
518 		ent->proc_fops = &ofdt_fops;
519 	}
520 
521 	return 0;
522 }
523 __initcall(proc_ppc64_create_ofdt);
524