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 #include <linux/slab.h>
19 
20 #include <asm/prom.h>
21 #include <asm/machdep.h>
22 #include <asm/uaccess.h>
23 #include <asm/pSeries_reconfig.h>
24 #include <asm/mmu.h>
25 
26 
27 
28 /*
29  * Routines for "runtime" addition and removal of device tree nodes.
30  */
31 #ifdef CONFIG_PROC_DEVICETREE
32 /*
33  * Add a node to /proc/device-tree.
34  */
35 static void add_node_proc_entries(struct device_node *np)
36 {
37 	struct proc_dir_entry *ent;
38 
39 	ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
40 	if (ent)
41 		proc_device_tree_add_node(np, ent);
42 }
43 
44 static void remove_node_proc_entries(struct device_node *np)
45 {
46 	struct property *pp = np->properties;
47 	struct device_node *parent = np->parent;
48 
49 	while (pp) {
50 		remove_proc_entry(pp->name, np->pde);
51 		pp = pp->next;
52 	}
53 	if (np->pde)
54 		remove_proc_entry(np->pde->name, parent->pde);
55 }
56 #else /* !CONFIG_PROC_DEVICETREE */
57 static void add_node_proc_entries(struct device_node *np)
58 {
59 	return;
60 }
61 
62 static void remove_node_proc_entries(struct device_node *np)
63 {
64 	return;
65 }
66 #endif /* CONFIG_PROC_DEVICETREE */
67 
68 /**
69  *	derive_parent - basically like dirname(1)
70  *	@path:  the full_name of a node to be added to the tree
71  *
72  *	Returns the node which should be the parent of the node
73  *	described by path.  E.g., for path = "/foo/bar", returns
74  *	the node with full_name = "/foo".
75  */
76 static struct device_node *derive_parent(const char *path)
77 {
78 	struct device_node *parent = NULL;
79 	char *parent_path = "/";
80 	size_t parent_path_len = strrchr(path, '/') - path + 1;
81 
82 	/* reject if path is "/" */
83 	if (!strcmp(path, "/"))
84 		return ERR_PTR(-EINVAL);
85 
86 	if (strrchr(path, '/') != path) {
87 		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
88 		if (!parent_path)
89 			return ERR_PTR(-ENOMEM);
90 		strlcpy(parent_path, path, parent_path_len);
91 	}
92 	parent = of_find_node_by_path(parent_path);
93 	if (!parent)
94 		return ERR_PTR(-EINVAL);
95 	if (strcmp(parent_path, "/"))
96 		kfree(parent_path);
97 	return parent;
98 }
99 
100 static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
101 
102 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
103 {
104 	return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
105 }
106 EXPORT_SYMBOL_GPL(pSeries_reconfig_notifier_register);
107 
108 void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
109 {
110 	blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
111 }
112 EXPORT_SYMBOL_GPL(pSeries_reconfig_notifier_unregister);
113 
114 int pSeries_reconfig_notify(unsigned long action, void *p)
115 {
116 	int err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
117 						action, p);
118 
119 	return notifier_to_errno(err);
120 }
121 
122 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
123 {
124 	struct device_node *np;
125 	int err = -ENOMEM;
126 
127 	np = kzalloc(sizeof(*np), GFP_KERNEL);
128 	if (!np)
129 		goto out_err;
130 
131 	np->full_name = kstrdup(path, GFP_KERNEL);
132 	if (!np->full_name)
133 		goto out_err;
134 
135 	np->properties = proplist;
136 	of_node_set_flag(np, OF_DYNAMIC);
137 	kref_init(&np->kref);
138 
139 	np->parent = derive_parent(path);
140 	if (IS_ERR(np->parent)) {
141 		err = PTR_ERR(np->parent);
142 		goto out_err;
143 	}
144 
145 	err = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, np);
146 	if (err) {
147 		printk(KERN_ERR "Failed to add device node %s\n", path);
148 		goto out_err;
149 	}
150 
151 	of_attach_node(np);
152 
153 	add_node_proc_entries(np);
154 
155 	of_node_put(np->parent);
156 
157 	return 0;
158 
159 out_err:
160 	if (np) {
161 		of_node_put(np->parent);
162 		kfree(np->full_name);
163 		kfree(np);
164 	}
165 	return err;
166 }
167 
168 static int pSeries_reconfig_remove_node(struct device_node *np)
169 {
170 	struct device_node *parent, *child;
171 
172 	parent = of_get_parent(np);
173 	if (!parent)
174 		return -EINVAL;
175 
176 	if ((child = of_get_next_child(np, NULL))) {
177 		of_node_put(child);
178 		of_node_put(parent);
179 		return -EBUSY;
180 	}
181 
182 	remove_node_proc_entries(np);
183 
184 	pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, np);
185 	of_detach_node(np);
186 
187 	of_node_put(parent);
188 	of_node_put(np); /* Must decrement the refcount */
189 	return 0;
190 }
191 
192 /*
193  * /proc/powerpc/ofdt - yucky binary interface for adding and removing
194  * OF device nodes.  Should be deprecated as soon as we get an
195  * in-kernel wrapper for the RTAS ibm,configure-connector call.
196  */
197 
198 static void release_prop_list(const struct property *prop)
199 {
200 	struct property *next;
201 	for (; prop; prop = next) {
202 		next = prop->next;
203 		kfree(prop->name);
204 		kfree(prop->value);
205 		kfree(prop);
206 	}
207 
208 }
209 
210 /**
211  * parse_next_property - process the next property from raw input buffer
212  * @buf: input buffer, must be nul-terminated
213  * @end: end of the input buffer + 1, for validation
214  * @name: return value; set to property name in buf
215  * @length: return value; set to length of value
216  * @value: return value; set to the property value in buf
217  *
218  * Note that the caller must make copies of the name and value returned,
219  * this function does no allocation or copying of the data.  Return value
220  * is set to the next name in buf, or NULL on error.
221  */
222 static char * parse_next_property(char *buf, char *end, char **name, int *length,
223 				  unsigned char **value)
224 {
225 	char *tmp;
226 
227 	*name = buf;
228 
229 	tmp = strchr(buf, ' ');
230 	if (!tmp) {
231 		printk(KERN_ERR "property parse failed in %s at line %d\n",
232 		       __func__, __LINE__);
233 		return NULL;
234 	}
235 	*tmp = '\0';
236 
237 	if (++tmp >= end) {
238 		printk(KERN_ERR "property parse failed in %s at line %d\n",
239 		       __func__, __LINE__);
240 		return NULL;
241 	}
242 
243 	/* now we're on the length */
244 	*length = -1;
245 	*length = simple_strtoul(tmp, &tmp, 10);
246 	if (*length == -1) {
247 		printk(KERN_ERR "property parse failed in %s at line %d\n",
248 		       __func__, __LINE__);
249 		return NULL;
250 	}
251 	if (*tmp != ' ' || ++tmp >= end) {
252 		printk(KERN_ERR "property parse failed in %s at line %d\n",
253 		       __func__, __LINE__);
254 		return NULL;
255 	}
256 
257 	/* now we're on the value */
258 	*value = tmp;
259 	tmp += *length;
260 	if (tmp > end) {
261 		printk(KERN_ERR "property parse failed in %s at line %d\n",
262 		       __func__, __LINE__);
263 		return NULL;
264 	}
265 	else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
266 		printk(KERN_ERR "property parse failed in %s at line %d\n",
267 		       __func__, __LINE__);
268 		return NULL;
269 	}
270 	tmp++;
271 
272 	/* and now we should be on the next name, or the end */
273 	return tmp;
274 }
275 
276 static struct property *new_property(const char *name, const int length,
277 				     const unsigned char *value, struct property *last)
278 {
279 	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
280 
281 	if (!new)
282 		return NULL;
283 
284 	if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
285 		goto cleanup;
286 	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
287 		goto cleanup;
288 
289 	strcpy(new->name, name);
290 	memcpy(new->value, value, length);
291 	*(((char *)new->value) + length) = 0;
292 	new->length = length;
293 	new->next = last;
294 	return new;
295 
296 cleanup:
297 	kfree(new->name);
298 	kfree(new->value);
299 	kfree(new);
300 	return NULL;
301 }
302 
303 static int do_add_node(char *buf, size_t bufsize)
304 {
305 	char *path, *end, *name;
306 	struct device_node *np;
307 	struct property *prop = NULL;
308 	unsigned char* value;
309 	int length, rv = 0;
310 
311 	end = buf + bufsize;
312 	path = buf;
313 	buf = strchr(buf, ' ');
314 	if (!buf)
315 		return -EINVAL;
316 	*buf = '\0';
317 	buf++;
318 
319 	if ((np = of_find_node_by_path(path))) {
320 		of_node_put(np);
321 		return -EINVAL;
322 	}
323 
324 	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
325 	while (buf < end &&
326 	       (buf = parse_next_property(buf, end, &name, &length, &value))) {
327 		struct property *last = prop;
328 
329 		prop = new_property(name, length, value, last);
330 		if (!prop) {
331 			rv = -ENOMEM;
332 			prop = last;
333 			goto out;
334 		}
335 	}
336 	if (!buf) {
337 		rv = -EINVAL;
338 		goto out;
339 	}
340 
341 	rv = pSeries_reconfig_add_node(path, prop);
342 
343 out:
344 	if (rv)
345 		release_prop_list(prop);
346 	return rv;
347 }
348 
349 static int do_remove_node(char *buf)
350 {
351 	struct device_node *node;
352 	int rv = -ENODEV;
353 
354 	if ((node = of_find_node_by_path(buf)))
355 		rv = pSeries_reconfig_remove_node(node);
356 
357 	of_node_put(node);
358 	return rv;
359 }
360 
361 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
362 {
363 	char *handle_str;
364 	phandle handle;
365 	*npp = NULL;
366 
367 	handle_str = buf;
368 
369 	buf = strchr(buf, ' ');
370 	if (!buf)
371 		return NULL;
372 	*buf = '\0';
373 	buf++;
374 
375 	handle = simple_strtoul(handle_str, NULL, 0);
376 
377 	*npp = of_find_node_by_phandle(handle);
378 	return buf;
379 }
380 
381 static int do_add_property(char *buf, size_t bufsize)
382 {
383 	struct property *prop = NULL;
384 	struct device_node *np;
385 	unsigned char *value;
386 	char *name, *end;
387 	int length;
388 	end = buf + bufsize;
389 	buf = parse_node(buf, bufsize, &np);
390 
391 	if (!np)
392 		return -ENODEV;
393 
394 	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
395 		return -EINVAL;
396 
397 	prop = new_property(name, length, value, NULL);
398 	if (!prop)
399 		return -ENOMEM;
400 
401 	prom_add_property(np, prop);
402 
403 	return 0;
404 }
405 
406 static int do_remove_property(char *buf, size_t bufsize)
407 {
408 	struct device_node *np;
409 	char *tmp;
410 	struct property *prop;
411 	buf = parse_node(buf, bufsize, &np);
412 
413 	if (!np)
414 		return -ENODEV;
415 
416 	tmp = strchr(buf,' ');
417 	if (tmp)
418 		*tmp = '\0';
419 
420 	if (strlen(buf) == 0)
421 		return -EINVAL;
422 
423 	prop = of_find_property(np, buf, NULL);
424 
425 	return prom_remove_property(np, prop);
426 }
427 
428 static int do_update_property(char *buf, size_t bufsize)
429 {
430 	struct device_node *np;
431 	struct pSeries_reconfig_prop_update upd_value;
432 	unsigned char *value;
433 	char *name, *end, *next_prop;
434 	int rc, length;
435 	struct property *newprop;
436 	buf = parse_node(buf, bufsize, &np);
437 	end = buf + bufsize;
438 
439 	if (!np)
440 		return -ENODEV;
441 
442 	next_prop = parse_next_property(buf, end, &name, &length, &value);
443 	if (!next_prop)
444 		return -EINVAL;
445 
446 	if (!strlen(name))
447 		return -ENODEV;
448 
449 	newprop = new_property(name, length, value, NULL);
450 	if (!newprop)
451 		return -ENOMEM;
452 
453 	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
454 		slb_set_size(*(int *)value);
455 
456 	upd_value.node = np;
457 	upd_value.property = newprop;
458 	pSeries_reconfig_notify(PSERIES_UPDATE_PROPERTY, &upd_value);
459 
460 	rc = prom_update_property(np, newprop);
461 	if (rc)
462 		return rc;
463 
464 	/* For memory under the ibm,dynamic-reconfiguration-memory node
465 	 * of the device tree, adding and removing memory is just an update
466 	 * to the ibm,dynamic-memory property instead of adding/removing a
467 	 * memory node in the device tree.  For these cases we still need to
468 	 * involve the notifier chain.
469 	 */
470 	if (!strcmp(name, "ibm,dynamic-memory")) {
471 		int action;
472 
473 		next_prop = parse_next_property(next_prop, end, &name,
474 						&length, &value);
475 		if (!next_prop)
476 			return -EINVAL;
477 
478 		if (!strcmp(name, "add"))
479 			action = PSERIES_DRCONF_MEM_ADD;
480 		else
481 			action = PSERIES_DRCONF_MEM_REMOVE;
482 
483 		rc = pSeries_reconfig_notify(action, value);
484 		if (rc) {
485 			prom_update_property(np, newprop);
486 			return rc;
487 		}
488 	}
489 
490 	return 0;
491 }
492 
493 /**
494  * ofdt_write - perform operations on the Open Firmware device tree
495  *
496  * @file: not used
497  * @buf: command and arguments
498  * @count: size of the command buffer
499  * @off: not used
500  *
501  * Operations supported at this time are addition and removal of
502  * whole nodes along with their properties.  Operations on individual
503  * properties are not implemented (yet).
504  */
505 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
506 			  loff_t *off)
507 {
508 	int rv = 0;
509 	char *kbuf;
510 	char *tmp;
511 
512 	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
513 		rv = -ENOMEM;
514 		goto out;
515 	}
516 	if (copy_from_user(kbuf, buf, count)) {
517 		rv = -EFAULT;
518 		goto out;
519 	}
520 
521 	kbuf[count] = '\0';
522 
523 	tmp = strchr(kbuf, ' ');
524 	if (!tmp) {
525 		rv = -EINVAL;
526 		goto out;
527 	}
528 	*tmp = '\0';
529 	tmp++;
530 
531 	if (!strcmp(kbuf, "add_node"))
532 		rv = do_add_node(tmp, count - (tmp - kbuf));
533 	else if (!strcmp(kbuf, "remove_node"))
534 		rv = do_remove_node(tmp);
535 	else if (!strcmp(kbuf, "add_property"))
536 		rv = do_add_property(tmp, count - (tmp - kbuf));
537 	else if (!strcmp(kbuf, "remove_property"))
538 		rv = do_remove_property(tmp, count - (tmp - kbuf));
539 	else if (!strcmp(kbuf, "update_property"))
540 		rv = do_update_property(tmp, count - (tmp - kbuf));
541 	else
542 		rv = -EINVAL;
543 out:
544 	kfree(kbuf);
545 	return rv ? rv : count;
546 }
547 
548 static const struct file_operations ofdt_fops = {
549 	.write = ofdt_write,
550 	.llseek = noop_llseek,
551 };
552 
553 /* create /proc/powerpc/ofdt write-only by root */
554 static int proc_ppc64_create_ofdt(void)
555 {
556 	struct proc_dir_entry *ent;
557 
558 	if (!machine_is(pseries))
559 		return 0;
560 
561 	ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
562 	if (ent)
563 		ent->size = 0;
564 
565 	return 0;
566 }
567 __initcall(proc_ppc64_create_ofdt);
568