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