xref: /linux/arch/powerpc/platforms/pseries/reconfig.c (revision 188917e183cf9ad0374b571006d0fc6d48a7f447)
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 #include <asm/mmu.h>
24 
25 
26 
27 /*
28  * Routines for "runtime" addition and removal of device tree nodes.
29  */
30 #ifdef CONFIG_PROC_DEVICETREE
31 /*
32  * Add a node to /proc/device-tree.
33  */
34 static void add_node_proc_entries(struct device_node *np)
35 {
36 	struct proc_dir_entry *ent;
37 
38 	ent = proc_mkdir(strrchr(np->full_name, '/') + 1, np->parent->pde);
39 	if (ent)
40 		proc_device_tree_add_node(np, ent);
41 }
42 
43 static void remove_node_proc_entries(struct device_node *np)
44 {
45 	struct property *pp = np->properties;
46 	struct device_node *parent = np->parent;
47 
48 	while (pp) {
49 		remove_proc_entry(pp->name, np->pde);
50 		pp = pp->next;
51 	}
52 	if (np->pde)
53 		remove_proc_entry(np->pde->name, parent->pde);
54 }
55 #else /* !CONFIG_PROC_DEVICETREE */
56 static void add_node_proc_entries(struct device_node *np)
57 {
58 	return;
59 }
60 
61 static void remove_node_proc_entries(struct device_node *np)
62 {
63 	return;
64 }
65 #endif /* CONFIG_PROC_DEVICETREE */
66 
67 /**
68  *	derive_parent - basically like dirname(1)
69  *	@path:  the full_name of a node to be added to the tree
70  *
71  *	Returns the node which should be the parent of the node
72  *	described by path.  E.g., for path = "/foo/bar", returns
73  *	the node with full_name = "/foo".
74  */
75 static struct device_node *derive_parent(const char *path)
76 {
77 	struct device_node *parent = NULL;
78 	char *parent_path = "/";
79 	size_t parent_path_len = strrchr(path, '/') - path + 1;
80 
81 	/* reject if path is "/" */
82 	if (!strcmp(path, "/"))
83 		return ERR_PTR(-EINVAL);
84 
85 	if (strrchr(path, '/') != path) {
86 		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
87 		if (!parent_path)
88 			return ERR_PTR(-ENOMEM);
89 		strlcpy(parent_path, path, parent_path_len);
90 	}
91 	parent = of_find_node_by_path(parent_path);
92 	if (!parent)
93 		return ERR_PTR(-EINVAL);
94 	if (strcmp(parent_path, "/"))
95 		kfree(parent_path);
96 	return parent;
97 }
98 
99 static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
100 
101 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
102 {
103 	return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
104 }
105 
106 void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
107 {
108 	blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
109 }
110 
111 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
112 {
113 	struct device_node *np;
114 	int err = -ENOMEM;
115 
116 	np = kzalloc(sizeof(*np), GFP_KERNEL);
117 	if (!np)
118 		goto out_err;
119 
120 	np->full_name = kmalloc(strlen(path) + 1, GFP_KERNEL);
121 	if (!np->full_name)
122 		goto out_err;
123 
124 	strcpy(np->full_name, path);
125 
126 	np->properties = proplist;
127 	of_node_set_flag(np, OF_DYNAMIC);
128 	kref_init(&np->kref);
129 
130 	np->parent = derive_parent(path);
131 	if (IS_ERR(np->parent)) {
132 		err = PTR_ERR(np->parent);
133 		goto out_err;
134 	}
135 
136 	err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
137 				  PSERIES_RECONFIG_ADD, np);
138 	if (err == NOTIFY_BAD) {
139 		printk(KERN_ERR "Failed to add device node %s\n", path);
140 		err = -ENOMEM; /* For now, safe to assume kmalloc failure */
141 		goto out_err;
142 	}
143 
144 	of_attach_node(np);
145 
146 	add_node_proc_entries(np);
147 
148 	of_node_put(np->parent);
149 
150 	return 0;
151 
152 out_err:
153 	if (np) {
154 		of_node_put(np->parent);
155 		kfree(np->full_name);
156 		kfree(np);
157 	}
158 	return err;
159 }
160 
161 static int pSeries_reconfig_remove_node(struct device_node *np)
162 {
163 	struct device_node *parent, *child;
164 
165 	parent = of_get_parent(np);
166 	if (!parent)
167 		return -EINVAL;
168 
169 	if ((child = of_get_next_child(np, NULL))) {
170 		of_node_put(child);
171 		of_node_put(parent);
172 		return -EBUSY;
173 	}
174 
175 	remove_node_proc_entries(np);
176 
177 	blocking_notifier_call_chain(&pSeries_reconfig_chain,
178 			    PSERIES_RECONFIG_REMOVE, np);
179 	of_detach_node(np);
180 
181 	of_node_put(parent);
182 	of_node_put(np); /* Must decrement the refcount */
183 	return 0;
184 }
185 
186 /*
187  * /proc/powerpc/ofdt - yucky binary interface for adding and removing
188  * OF device nodes.  Should be deprecated as soon as we get an
189  * in-kernel wrapper for the RTAS ibm,configure-connector call.
190  */
191 
192 static void release_prop_list(const struct property *prop)
193 {
194 	struct property *next;
195 	for (; prop; prop = next) {
196 		next = prop->next;
197 		kfree(prop->name);
198 		kfree(prop->value);
199 		kfree(prop);
200 	}
201 
202 }
203 
204 /**
205  * parse_next_property - process the next property from raw input buffer
206  * @buf: input buffer, must be nul-terminated
207  * @end: end of the input buffer + 1, for validation
208  * @name: return value; set to property name in buf
209  * @length: return value; set to length of value
210  * @value: return value; set to the property value in buf
211  *
212  * Note that the caller must make copies of the name and value returned,
213  * this function does no allocation or copying of the data.  Return value
214  * is set to the next name in buf, or NULL on error.
215  */
216 static char * parse_next_property(char *buf, char *end, char **name, int *length,
217 				  unsigned char **value)
218 {
219 	char *tmp;
220 
221 	*name = buf;
222 
223 	tmp = strchr(buf, ' ');
224 	if (!tmp) {
225 		printk(KERN_ERR "property parse failed in %s at line %d\n",
226 		       __func__, __LINE__);
227 		return NULL;
228 	}
229 	*tmp = '\0';
230 
231 	if (++tmp >= end) {
232 		printk(KERN_ERR "property parse failed in %s at line %d\n",
233 		       __func__, __LINE__);
234 		return NULL;
235 	}
236 
237 	/* now we're on the length */
238 	*length = -1;
239 	*length = simple_strtoul(tmp, &tmp, 10);
240 	if (*length == -1) {
241 		printk(KERN_ERR "property parse failed in %s at line %d\n",
242 		       __func__, __LINE__);
243 		return NULL;
244 	}
245 	if (*tmp != ' ' || ++tmp >= end) {
246 		printk(KERN_ERR "property parse failed in %s at line %d\n",
247 		       __func__, __LINE__);
248 		return NULL;
249 	}
250 
251 	/* now we're on the value */
252 	*value = tmp;
253 	tmp += *length;
254 	if (tmp > end) {
255 		printk(KERN_ERR "property parse failed in %s at line %d\n",
256 		       __func__, __LINE__);
257 		return NULL;
258 	}
259 	else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
260 		printk(KERN_ERR "property parse failed in %s at line %d\n",
261 		       __func__, __LINE__);
262 		return NULL;
263 	}
264 	tmp++;
265 
266 	/* and now we should be on the next name, or the end */
267 	return tmp;
268 }
269 
270 static struct property *new_property(const char *name, const int length,
271 				     const unsigned char *value, struct property *last)
272 {
273 	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
274 
275 	if (!new)
276 		return NULL;
277 
278 	if (!(new->name = kmalloc(strlen(name) + 1, GFP_KERNEL)))
279 		goto cleanup;
280 	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
281 		goto cleanup;
282 
283 	strcpy(new->name, name);
284 	memcpy(new->value, value, length);
285 	*(((char *)new->value) + length) = 0;
286 	new->length = length;
287 	new->next = last;
288 	return new;
289 
290 cleanup:
291 	kfree(new->name);
292 	kfree(new->value);
293 	kfree(new);
294 	return NULL;
295 }
296 
297 static int do_add_node(char *buf, size_t bufsize)
298 {
299 	char *path, *end, *name;
300 	struct device_node *np;
301 	struct property *prop = NULL;
302 	unsigned char* value;
303 	int length, rv = 0;
304 
305 	end = buf + bufsize;
306 	path = buf;
307 	buf = strchr(buf, ' ');
308 	if (!buf)
309 		return -EINVAL;
310 	*buf = '\0';
311 	buf++;
312 
313 	if ((np = of_find_node_by_path(path))) {
314 		of_node_put(np);
315 		return -EINVAL;
316 	}
317 
318 	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
319 	while (buf < end &&
320 	       (buf = parse_next_property(buf, end, &name, &length, &value))) {
321 		struct property *last = prop;
322 
323 		prop = new_property(name, length, value, last);
324 		if (!prop) {
325 			rv = -ENOMEM;
326 			prop = last;
327 			goto out;
328 		}
329 	}
330 	if (!buf) {
331 		rv = -EINVAL;
332 		goto out;
333 	}
334 
335 	rv = pSeries_reconfig_add_node(path, prop);
336 
337 out:
338 	if (rv)
339 		release_prop_list(prop);
340 	return rv;
341 }
342 
343 static int do_remove_node(char *buf)
344 {
345 	struct device_node *node;
346 	int rv = -ENODEV;
347 
348 	if ((node = of_find_node_by_path(buf)))
349 		rv = pSeries_reconfig_remove_node(node);
350 
351 	of_node_put(node);
352 	return rv;
353 }
354 
355 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
356 {
357 	char *handle_str;
358 	phandle handle;
359 	*npp = NULL;
360 
361 	handle_str = buf;
362 
363 	buf = strchr(buf, ' ');
364 	if (!buf)
365 		return NULL;
366 	*buf = '\0';
367 	buf++;
368 
369 	handle = simple_strtoul(handle_str, NULL, 0);
370 
371 	*npp = of_find_node_by_phandle(handle);
372 	return buf;
373 }
374 
375 static int do_add_property(char *buf, size_t bufsize)
376 {
377 	struct property *prop = NULL;
378 	struct device_node *np;
379 	unsigned char *value;
380 	char *name, *end;
381 	int length;
382 	end = buf + bufsize;
383 	buf = parse_node(buf, bufsize, &np);
384 
385 	if (!np)
386 		return -ENODEV;
387 
388 	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
389 		return -EINVAL;
390 
391 	prop = new_property(name, length, value, NULL);
392 	if (!prop)
393 		return -ENOMEM;
394 
395 	prom_add_property(np, prop);
396 
397 	return 0;
398 }
399 
400 static int do_remove_property(char *buf, size_t bufsize)
401 {
402 	struct device_node *np;
403 	char *tmp;
404 	struct property *prop;
405 	buf = parse_node(buf, bufsize, &np);
406 
407 	if (!np)
408 		return -ENODEV;
409 
410 	tmp = strchr(buf,' ');
411 	if (tmp)
412 		*tmp = '\0';
413 
414 	if (strlen(buf) == 0)
415 		return -EINVAL;
416 
417 	prop = of_find_property(np, buf, NULL);
418 
419 	return prom_remove_property(np, prop);
420 }
421 
422 static int do_update_property(char *buf, size_t bufsize)
423 {
424 	struct device_node *np;
425 	unsigned char *value;
426 	char *name, *end, *next_prop;
427 	int rc, length;
428 	struct property *newprop, *oldprop;
429 	buf = parse_node(buf, bufsize, &np);
430 	end = buf + bufsize;
431 
432 	if (!np)
433 		return -ENODEV;
434 
435 	next_prop = parse_next_property(buf, end, &name, &length, &value);
436 	if (!next_prop)
437 		return -EINVAL;
438 
439 	newprop = new_property(name, length, value, NULL);
440 	if (!newprop)
441 		return -ENOMEM;
442 
443 	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
444 		slb_set_size(*(int *)value);
445 
446 	oldprop = of_find_property(np, name,NULL);
447 	if (!oldprop) {
448 		if (strlen(name))
449 			return prom_add_property(np, newprop);
450 		return -ENODEV;
451 	}
452 
453 	rc = prom_update_property(np, newprop, oldprop);
454 	if (rc)
455 		return rc;
456 
457 	/* For memory under the ibm,dynamic-reconfiguration-memory node
458 	 * of the device tree, adding and removing memory is just an update
459 	 * to the ibm,dynamic-memory property instead of adding/removing a
460 	 * memory node in the device tree.  For these cases we still need to
461 	 * involve the notifier chain.
462 	 */
463 	if (!strcmp(name, "ibm,dynamic-memory")) {
464 		int action;
465 
466 		next_prop = parse_next_property(next_prop, end, &name,
467 						&length, &value);
468 		if (!next_prop)
469 			return -EINVAL;
470 
471 		if (!strcmp(name, "add"))
472 			action = PSERIES_DRCONF_MEM_ADD;
473 		else
474 			action = PSERIES_DRCONF_MEM_REMOVE;
475 
476 		rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
477 						  action, value);
478 		if (rc == NOTIFY_BAD) {
479 			rc = prom_update_property(np, oldprop, newprop);
480 			return -ENOMEM;
481 		}
482 	}
483 
484 	return 0;
485 }
486 
487 /**
488  * ofdt_write - perform operations on the Open Firmware device tree
489  *
490  * @file: not used
491  * @buf: command and arguments
492  * @count: size of the command buffer
493  * @off: not used
494  *
495  * Operations supported at this time are addition and removal of
496  * whole nodes along with their properties.  Operations on individual
497  * properties are not implemented (yet).
498  */
499 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
500 			  loff_t *off)
501 {
502 	int rv = 0;
503 	char *kbuf;
504 	char *tmp;
505 
506 	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
507 		rv = -ENOMEM;
508 		goto out;
509 	}
510 	if (copy_from_user(kbuf, buf, count)) {
511 		rv = -EFAULT;
512 		goto out;
513 	}
514 
515 	kbuf[count] = '\0';
516 
517 	tmp = strchr(kbuf, ' ');
518 	if (!tmp) {
519 		rv = -EINVAL;
520 		goto out;
521 	}
522 	*tmp = '\0';
523 	tmp++;
524 
525 	if (!strcmp(kbuf, "add_node"))
526 		rv = do_add_node(tmp, count - (tmp - kbuf));
527 	else if (!strcmp(kbuf, "remove_node"))
528 		rv = do_remove_node(tmp);
529 	else if (!strcmp(kbuf, "add_property"))
530 		rv = do_add_property(tmp, count - (tmp - kbuf));
531 	else if (!strcmp(kbuf, "remove_property"))
532 		rv = do_remove_property(tmp, count - (tmp - kbuf));
533 	else if (!strcmp(kbuf, "update_property"))
534 		rv = do_update_property(tmp, count - (tmp - kbuf));
535 	else
536 		rv = -EINVAL;
537 out:
538 	kfree(kbuf);
539 	return rv ? rv : count;
540 }
541 
542 static const struct file_operations ofdt_fops = {
543 	.write = ofdt_write
544 };
545 
546 /* create /proc/powerpc/ofdt write-only by root */
547 static int proc_ppc64_create_ofdt(void)
548 {
549 	struct proc_dir_entry *ent;
550 
551 	if (!machine_is(pseries))
552 		return 0;
553 
554 	ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
555 	if (ent)
556 		ent->size = 0;
557 
558 	return 0;
559 }
560 __initcall(proc_ppc64_create_ofdt);
561