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/notifier.h>
16 #include <linux/proc_fs.h>
17 #include <linux/slab.h>
18 #include <linux/of.h>
19 
20 #include <asm/prom.h>
21 #include <asm/machdep.h>
22 #include <asm/uaccess.h>
23 #include <asm/mmu.h>
24 
25 /**
26  *	derive_parent - basically like dirname(1)
27  *	@path:  the full_name of a node to be added to the tree
28  *
29  *	Returns the node which should be the parent of the node
30  *	described by path.  E.g., for path = "/foo/bar", returns
31  *	the node with full_name = "/foo".
32  */
33 static struct device_node *derive_parent(const char *path)
34 {
35 	struct device_node *parent = NULL;
36 	char *parent_path = "/";
37 	size_t parent_path_len = strrchr(path, '/') - path + 1;
38 
39 	/* reject if path is "/" */
40 	if (!strcmp(path, "/"))
41 		return ERR_PTR(-EINVAL);
42 
43 	if (strrchr(path, '/') != path) {
44 		parent_path = kmalloc(parent_path_len, GFP_KERNEL);
45 		if (!parent_path)
46 			return ERR_PTR(-ENOMEM);
47 		strlcpy(parent_path, path, parent_path_len);
48 	}
49 	parent = of_find_node_by_path(parent_path);
50 	if (!parent)
51 		return ERR_PTR(-EINVAL);
52 	if (strcmp(parent_path, "/"))
53 		kfree(parent_path);
54 	return parent;
55 }
56 
57 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
58 {
59 	struct device_node *np;
60 	int err = -ENOMEM;
61 
62 	np = kzalloc(sizeof(*np), GFP_KERNEL);
63 	if (!np)
64 		goto out_err;
65 
66 	np->full_name = kstrdup(path, GFP_KERNEL);
67 	if (!np->full_name)
68 		goto out_err;
69 
70 	np->properties = proplist;
71 	of_node_set_flag(np, OF_DYNAMIC);
72 	of_node_init(np);
73 
74 	np->parent = derive_parent(path);
75 	if (IS_ERR(np->parent)) {
76 		err = PTR_ERR(np->parent);
77 		goto out_err;
78 	}
79 
80 	err = of_attach_node(np);
81 	if (err) {
82 		printk(KERN_ERR "Failed to add device node %s\n", path);
83 		goto out_err;
84 	}
85 
86 	of_node_put(np->parent);
87 
88 	return 0;
89 
90 out_err:
91 	if (np) {
92 		of_node_put(np->parent);
93 		kfree(np->full_name);
94 		kfree(np);
95 	}
96 	return err;
97 }
98 
99 static int pSeries_reconfig_remove_node(struct device_node *np)
100 {
101 	struct device_node *parent, *child;
102 
103 	parent = of_get_parent(np);
104 	if (!parent)
105 		return -EINVAL;
106 
107 	if ((child = of_get_next_child(np, NULL))) {
108 		of_node_put(child);
109 		of_node_put(parent);
110 		return -EBUSY;
111 	}
112 
113 	of_detach_node(np);
114 	of_node_put(parent);
115 	of_node_put(np); /* Must decrement the refcount */
116 	return 0;
117 }
118 
119 /*
120  * /proc/powerpc/ofdt - yucky binary interface for adding and removing
121  * OF device nodes.  Should be deprecated as soon as we get an
122  * in-kernel wrapper for the RTAS ibm,configure-connector call.
123  */
124 
125 static void release_prop_list(const struct property *prop)
126 {
127 	struct property *next;
128 	for (; prop; prop = next) {
129 		next = prop->next;
130 		kfree(prop->name);
131 		kfree(prop->value);
132 		kfree(prop);
133 	}
134 
135 }
136 
137 /**
138  * parse_next_property - process the next property from raw input buffer
139  * @buf: input buffer, must be nul-terminated
140  * @end: end of the input buffer + 1, for validation
141  * @name: return value; set to property name in buf
142  * @length: return value; set to length of value
143  * @value: return value; set to the property value in buf
144  *
145  * Note that the caller must make copies of the name and value returned,
146  * this function does no allocation or copying of the data.  Return value
147  * is set to the next name in buf, or NULL on error.
148  */
149 static char * parse_next_property(char *buf, char *end, char **name, int *length,
150 				  unsigned char **value)
151 {
152 	char *tmp;
153 
154 	*name = buf;
155 
156 	tmp = strchr(buf, ' ');
157 	if (!tmp) {
158 		printk(KERN_ERR "property parse failed in %s at line %d\n",
159 		       __func__, __LINE__);
160 		return NULL;
161 	}
162 	*tmp = '\0';
163 
164 	if (++tmp >= end) {
165 		printk(KERN_ERR "property parse failed in %s at line %d\n",
166 		       __func__, __LINE__);
167 		return NULL;
168 	}
169 
170 	/* now we're on the length */
171 	*length = -1;
172 	*length = simple_strtoul(tmp, &tmp, 10);
173 	if (*length == -1) {
174 		printk(KERN_ERR "property parse failed in %s at line %d\n",
175 		       __func__, __LINE__);
176 		return NULL;
177 	}
178 	if (*tmp != ' ' || ++tmp >= end) {
179 		printk(KERN_ERR "property parse failed in %s at line %d\n",
180 		       __func__, __LINE__);
181 		return NULL;
182 	}
183 
184 	/* now we're on the value */
185 	*value = tmp;
186 	tmp += *length;
187 	if (tmp > end) {
188 		printk(KERN_ERR "property parse failed in %s at line %d\n",
189 		       __func__, __LINE__);
190 		return NULL;
191 	}
192 	else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
193 		printk(KERN_ERR "property parse failed in %s at line %d\n",
194 		       __func__, __LINE__);
195 		return NULL;
196 	}
197 	tmp++;
198 
199 	/* and now we should be on the next name, or the end */
200 	return tmp;
201 }
202 
203 static struct property *new_property(const char *name, const int length,
204 				     const unsigned char *value, struct property *last)
205 {
206 	struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
207 
208 	if (!new)
209 		return NULL;
210 
211 	if (!(new->name = kstrdup(name, GFP_KERNEL)))
212 		goto cleanup;
213 	if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
214 		goto cleanup;
215 
216 	memcpy(new->value, value, length);
217 	*(((char *)new->value) + length) = 0;
218 	new->length = length;
219 	new->next = last;
220 	return new;
221 
222 cleanup:
223 	kfree(new->name);
224 	kfree(new->value);
225 	kfree(new);
226 	return NULL;
227 }
228 
229 static int do_add_node(char *buf, size_t bufsize)
230 {
231 	char *path, *end, *name;
232 	struct device_node *np;
233 	struct property *prop = NULL;
234 	unsigned char* value;
235 	int length, rv = 0;
236 
237 	end = buf + bufsize;
238 	path = buf;
239 	buf = strchr(buf, ' ');
240 	if (!buf)
241 		return -EINVAL;
242 	*buf = '\0';
243 	buf++;
244 
245 	if ((np = of_find_node_by_path(path))) {
246 		of_node_put(np);
247 		return -EINVAL;
248 	}
249 
250 	/* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
251 	while (buf < end &&
252 	       (buf = parse_next_property(buf, end, &name, &length, &value))) {
253 		struct property *last = prop;
254 
255 		prop = new_property(name, length, value, last);
256 		if (!prop) {
257 			rv = -ENOMEM;
258 			prop = last;
259 			goto out;
260 		}
261 	}
262 	if (!buf) {
263 		rv = -EINVAL;
264 		goto out;
265 	}
266 
267 	rv = pSeries_reconfig_add_node(path, prop);
268 
269 out:
270 	if (rv)
271 		release_prop_list(prop);
272 	return rv;
273 }
274 
275 static int do_remove_node(char *buf)
276 {
277 	struct device_node *node;
278 	int rv = -ENODEV;
279 
280 	if ((node = of_find_node_by_path(buf)))
281 		rv = pSeries_reconfig_remove_node(node);
282 
283 	of_node_put(node);
284 	return rv;
285 }
286 
287 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
288 {
289 	char *handle_str;
290 	phandle handle;
291 	*npp = NULL;
292 
293 	handle_str = buf;
294 
295 	buf = strchr(buf, ' ');
296 	if (!buf)
297 		return NULL;
298 	*buf = '\0';
299 	buf++;
300 
301 	handle = simple_strtoul(handle_str, NULL, 0);
302 
303 	*npp = of_find_node_by_phandle(handle);
304 	return buf;
305 }
306 
307 static int do_add_property(char *buf, size_t bufsize)
308 {
309 	struct property *prop = NULL;
310 	struct device_node *np;
311 	unsigned char *value;
312 	char *name, *end;
313 	int length;
314 	end = buf + bufsize;
315 	buf = parse_node(buf, bufsize, &np);
316 
317 	if (!np)
318 		return -ENODEV;
319 
320 	if (parse_next_property(buf, end, &name, &length, &value) == NULL)
321 		return -EINVAL;
322 
323 	prop = new_property(name, length, value, NULL);
324 	if (!prop)
325 		return -ENOMEM;
326 
327 	of_add_property(np, prop);
328 
329 	return 0;
330 }
331 
332 static int do_remove_property(char *buf, size_t bufsize)
333 {
334 	struct device_node *np;
335 	char *tmp;
336 	struct property *prop;
337 	buf = parse_node(buf, bufsize, &np);
338 
339 	if (!np)
340 		return -ENODEV;
341 
342 	tmp = strchr(buf,' ');
343 	if (tmp)
344 		*tmp = '\0';
345 
346 	if (strlen(buf) == 0)
347 		return -EINVAL;
348 
349 	prop = of_find_property(np, buf, NULL);
350 
351 	return of_remove_property(np, prop);
352 }
353 
354 static int do_update_property(char *buf, size_t bufsize)
355 {
356 	struct device_node *np;
357 	unsigned char *value;
358 	char *name, *end, *next_prop;
359 	int length;
360 	struct property *newprop;
361 	buf = parse_node(buf, bufsize, &np);
362 	end = buf + bufsize;
363 
364 	if (!np)
365 		return -ENODEV;
366 
367 	next_prop = parse_next_property(buf, end, &name, &length, &value);
368 	if (!next_prop)
369 		return -EINVAL;
370 
371 	if (!strlen(name))
372 		return -ENODEV;
373 
374 	newprop = new_property(name, length, value, NULL);
375 	if (!newprop)
376 		return -ENOMEM;
377 
378 	if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
379 		slb_set_size(*(int *)value);
380 
381 	return of_update_property(np, newprop);
382 }
383 
384 /**
385  * ofdt_write - perform operations on the Open Firmware device tree
386  *
387  * @file: not used
388  * @buf: command and arguments
389  * @count: size of the command buffer
390  * @off: not used
391  *
392  * Operations supported at this time are addition and removal of
393  * whole nodes along with their properties.  Operations on individual
394  * properties are not implemented (yet).
395  */
396 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
397 			  loff_t *off)
398 {
399 	int rv = 0;
400 	char *kbuf;
401 	char *tmp;
402 
403 	if (!(kbuf = kmalloc(count + 1, GFP_KERNEL))) {
404 		rv = -ENOMEM;
405 		goto out;
406 	}
407 	if (copy_from_user(kbuf, buf, count)) {
408 		rv = -EFAULT;
409 		goto out;
410 	}
411 
412 	kbuf[count] = '\0';
413 
414 	tmp = strchr(kbuf, ' ');
415 	if (!tmp) {
416 		rv = -EINVAL;
417 		goto out;
418 	}
419 	*tmp = '\0';
420 	tmp++;
421 
422 	if (!strcmp(kbuf, "add_node"))
423 		rv = do_add_node(tmp, count - (tmp - kbuf));
424 	else if (!strcmp(kbuf, "remove_node"))
425 		rv = do_remove_node(tmp);
426 	else if (!strcmp(kbuf, "add_property"))
427 		rv = do_add_property(tmp, count - (tmp - kbuf));
428 	else if (!strcmp(kbuf, "remove_property"))
429 		rv = do_remove_property(tmp, count - (tmp - kbuf));
430 	else if (!strcmp(kbuf, "update_property"))
431 		rv = do_update_property(tmp, count - (tmp - kbuf));
432 	else
433 		rv = -EINVAL;
434 out:
435 	kfree(kbuf);
436 	return rv ? rv : count;
437 }
438 
439 static const struct file_operations ofdt_fops = {
440 	.write = ofdt_write,
441 	.llseek = noop_llseek,
442 };
443 
444 /* create /proc/powerpc/ofdt write-only by root */
445 static int proc_ppc64_create_ofdt(void)
446 {
447 	struct proc_dir_entry *ent;
448 
449 	ent = proc_create("powerpc/ofdt", S_IWUSR, NULL, &ofdt_fops);
450 	if (ent)
451 		proc_set_size(ent, 0);
452 
453 	return 0;
454 }
455 machine_device_initcall(pseries, proc_ppc64_create_ofdt);
456