1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * pSeries_reconfig.c - support for dynamic reconfiguration (including PCI
4 * Hotplug and Dynamic Logical Partitioning on RPA platforms).
5 *
6 * Copyright (C) 2005 Nathan Lynch
7 * Copyright (C) 2005 IBM Corporation
8 */
9
10 #include <linux/kernel.h>
11 #include <linux/notifier.h>
12 #include <linux/proc_fs.h>
13 #include <linux/security.h>
14 #include <linux/slab.h>
15 #include <linux/of.h>
16
17 #include <asm/machdep.h>
18 #include <linux/uaccess.h>
19 #include <asm/mmu.h>
20
21 #include "of_helpers.h"
22
23 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
24 {
25 struct device_node *np;
26 int err = -ENOMEM;
27
28 np = kzalloc(sizeof(*np), GFP_KERNEL);
29 if (!np)
30 goto out_err;
31
32 np->full_name = kstrdup(kbasename(path), GFP_KERNEL);
33 if (!np->full_name)
34 goto out_err;
35
36 np->properties = proplist;
37 of_node_set_flag(np, OF_DYNAMIC);
38 of_node_init(np);
39
40 np->parent = pseries_of_derive_parent(path);
41 if (IS_ERR(np->parent)) {
42 err = PTR_ERR(np->parent);
43 goto out_err;
44 }
45
46 err = of_attach_node(np);
47 if (err) {
48 printk(KERN_ERR "Failed to add device node %s\n", path);
49 goto out_err;
50 }
51
52 of_node_put(np->parent);
53
54 return 0;
55
56 out_err:
57 if (np) {
58 of_node_put(np->parent);
59 kfree(np->full_name);
60 kfree(np);
61 }
62 return err;
63 }
64
65 static int pSeries_reconfig_remove_node(struct device_node *np)
66 {
67 struct device_node *parent, *child;
68
69 parent = of_get_parent(np);
70 if (!parent)
71 return -EINVAL;
72
73 if ((child = of_get_next_child(np, NULL))) {
74 of_node_put(child);
75 of_node_put(parent);
76 return -EBUSY;
77 }
78
79 of_detach_node(np);
80 of_node_put(parent);
81 return 0;
82 }
83
84 /*
85 * /proc/powerpc/ofdt - yucky binary interface for adding and removing
86 * OF device nodes. Should be deprecated as soon as we get an
87 * in-kernel wrapper for the RTAS ibm,configure-connector call.
88 */
89
90 static void release_prop_list(const struct property *prop)
91 {
92 struct property *next;
93 for (; prop; prop = next) {
94 next = prop->next;
95 kfree(prop->name);
96 kfree(prop->value);
97 kfree(prop);
98 }
99
100 }
101
102 /**
103 * parse_next_property - process the next property from raw input buffer
104 * @buf: input buffer, must be nul-terminated
105 * @end: end of the input buffer + 1, for validation
106 * @name: return value; set to property name in buf
107 * @length: return value; set to length of value
108 * @value: return value; set to the property value in buf
109 *
110 * Note that the caller must make copies of the name and value returned,
111 * this function does no allocation or copying of the data. Return value
112 * is set to the next name in buf, or NULL on error.
113 */
114 static char * parse_next_property(char *buf, char *end, char **name, int *length,
115 unsigned char **value)
116 {
117 char *tmp;
118
119 *name = buf;
120
121 tmp = strchr(buf, ' ');
122 if (!tmp) {
123 printk(KERN_ERR "property parse failed in %s at line %d\n",
124 __func__, __LINE__);
125 return NULL;
126 }
127 *tmp = '\0';
128
129 if (++tmp >= end) {
130 printk(KERN_ERR "property parse failed in %s at line %d\n",
131 __func__, __LINE__);
132 return NULL;
133 }
134
135 /* now we're on the length */
136 *length = -1;
137 *length = simple_strtoul(tmp, &tmp, 10);
138 if (*length == -1) {
139 printk(KERN_ERR "property parse failed in %s at line %d\n",
140 __func__, __LINE__);
141 return NULL;
142 }
143 if (*tmp != ' ' || ++tmp >= end) {
144 printk(KERN_ERR "property parse failed in %s at line %d\n",
145 __func__, __LINE__);
146 return NULL;
147 }
148
149 /* now we're on the value */
150 *value = tmp;
151 tmp += *length;
152 if (tmp > end) {
153 printk(KERN_ERR "property parse failed in %s at line %d\n",
154 __func__, __LINE__);
155 return NULL;
156 }
157 else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
158 printk(KERN_ERR "property parse failed in %s at line %d\n",
159 __func__, __LINE__);
160 return NULL;
161 }
162 tmp++;
163
164 /* and now we should be on the next name, or the end */
165 return tmp;
166 }
167
168 static struct property *new_property(const char *name, const int length,
169 const unsigned char *value, struct property *last)
170 {
171 struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
172
173 if (!new)
174 return NULL;
175
176 if (!(new->name = kstrdup(name, GFP_KERNEL)))
177 goto cleanup;
178 if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
179 goto cleanup;
180
181 memcpy(new->value, value, length);
182 *(((char *)new->value) + length) = 0;
183 new->length = length;
184 new->next = last;
185 return new;
186
187 cleanup:
188 kfree(new->name);
189 kfree(new->value);
190 kfree(new);
191 return NULL;
192 }
193
194 static int do_add_node(char *buf, size_t bufsize)
195 {
196 char *path, *end, *name;
197 struct device_node *np;
198 struct property *prop = NULL;
199 unsigned char* value;
200 int length, rv = 0;
201
202 end = buf + bufsize;
203 path = buf;
204 buf = strchr(buf, ' ');
205 if (!buf)
206 return -EINVAL;
207 *buf = '\0';
208 buf++;
209
210 if ((np = of_find_node_by_path(path))) {
211 of_node_put(np);
212 return -EINVAL;
213 }
214
215 /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
216 while (buf < end &&
217 (buf = parse_next_property(buf, end, &name, &length, &value))) {
218 struct property *last = prop;
219
220 prop = new_property(name, length, value, last);
221 if (!prop) {
222 rv = -ENOMEM;
223 prop = last;
224 goto out;
225 }
226 }
227 if (!buf) {
228 rv = -EINVAL;
229 goto out;
230 }
231
232 rv = pSeries_reconfig_add_node(path, prop);
233
234 out:
235 if (rv)
236 release_prop_list(prop);
237 return rv;
238 }
239
240 static int do_remove_node(char *buf)
241 {
242 struct device_node *node;
243 int rv = -ENODEV;
244
245 if ((node = of_find_node_by_path(buf)))
246 rv = pSeries_reconfig_remove_node(node);
247
248 of_node_put(node);
249 return rv;
250 }
251
252 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
253 {
254 char *handle_str;
255 phandle handle;
256 *npp = NULL;
257
258 handle_str = buf;
259
260 buf = strchr(buf, ' ');
261 if (!buf)
262 return NULL;
263 *buf = '\0';
264 buf++;
265
266 handle = simple_strtoul(handle_str, NULL, 0);
267
268 *npp = of_find_node_by_phandle(handle);
269 return buf;
270 }
271
272 static int do_add_property(char *buf, size_t bufsize)
273 {
274 struct property *prop = NULL;
275 struct device_node *np;
276 unsigned char *value;
277 char *name, *end;
278 int length;
279 end = buf + bufsize;
280 buf = parse_node(buf, bufsize, &np);
281
282 if (!np)
283 return -ENODEV;
284
285 if (parse_next_property(buf, end, &name, &length, &value) == NULL)
286 return -EINVAL;
287
288 prop = new_property(name, length, value, NULL);
289 if (!prop)
290 return -ENOMEM;
291
292 of_add_property(np, prop);
293
294 return 0;
295 }
296
297 static int do_remove_property(char *buf, size_t bufsize)
298 {
299 struct device_node *np;
300 char *tmp;
301 buf = parse_node(buf, bufsize, &np);
302
303 if (!np)
304 return -ENODEV;
305
306 tmp = strchr(buf,' ');
307 if (tmp)
308 *tmp = '\0';
309
310 if (strlen(buf) == 0)
311 return -EINVAL;
312
313 return of_remove_property(np, of_find_property(np, buf, NULL));
314 }
315
316 static int do_update_property(char *buf, size_t bufsize)
317 {
318 struct device_node *np;
319 unsigned char *value;
320 char *name, *end, *next_prop;
321 int length;
322 struct property *newprop;
323 buf = parse_node(buf, bufsize, &np);
324 end = buf + bufsize;
325
326 if (!np)
327 return -ENODEV;
328
329 next_prop = parse_next_property(buf, end, &name, &length, &value);
330 if (!next_prop)
331 return -EINVAL;
332
333 if (!strlen(name))
334 return -ENODEV;
335
336 newprop = new_property(name, length, value, NULL);
337 if (!newprop)
338 return -ENOMEM;
339
340 if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
341 slb_set_size(*(int *)value);
342
343 return of_update_property(np, newprop);
344 }
345
346 /**
347 * ofdt_write - perform operations on the Open Firmware device tree
348 *
349 * @file: not used
350 * @buf: command and arguments
351 * @count: size of the command buffer
352 * @off: not used
353 *
354 * Operations supported at this time are addition and removal of
355 * whole nodes along with their properties. Operations on individual
356 * properties are not implemented (yet).
357 */
358 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
359 loff_t *off)
360 {
361 int rv;
362 char *kbuf;
363 char *tmp;
364
365 rv = security_locked_down(LOCKDOWN_DEVICE_TREE);
366 if (rv)
367 return rv;
368
369 kbuf = memdup_user_nul(buf, count);
370 if (IS_ERR(kbuf))
371 return PTR_ERR(kbuf);
372
373 tmp = strchr(kbuf, ' ');
374 if (!tmp) {
375 rv = -EINVAL;
376 goto out;
377 }
378 *tmp = '\0';
379 tmp++;
380
381 if (!strcmp(kbuf, "add_node"))
382 rv = do_add_node(tmp, count - (tmp - kbuf));
383 else if (!strcmp(kbuf, "remove_node"))
384 rv = do_remove_node(tmp);
385 else if (!strcmp(kbuf, "add_property"))
386 rv = do_add_property(tmp, count - (tmp - kbuf));
387 else if (!strcmp(kbuf, "remove_property"))
388 rv = do_remove_property(tmp, count - (tmp - kbuf));
389 else if (!strcmp(kbuf, "update_property"))
390 rv = do_update_property(tmp, count - (tmp - kbuf));
391 else
392 rv = -EINVAL;
393 out:
394 kfree(kbuf);
395 return rv ? rv : count;
396 }
397
398 static const struct proc_ops ofdt_proc_ops = {
399 .proc_write = ofdt_write,
400 .proc_lseek = noop_llseek,
401 };
402
403 /* create /proc/powerpc/ofdt write-only by root */
404 static int proc_ppc64_create_ofdt(void)
405 {
406 struct proc_dir_entry *ent;
407
408 ent = proc_create("powerpc/ofdt", 0200, NULL, &ofdt_proc_ops);
409 if (ent)
410 proc_set_size(ent, 0);
411
412 return 0;
413 }
414 machine_device_initcall(pseries, proc_ppc64_create_ofdt);
415
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