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