1 // SPDX-License-Identifier: GPL-2.0-only
3 * pSeries_reconfig.c - support for dynamic reconfiguration (including PCI
4 * Hotplug and Dynamic Logical Partitioning on RPA platforms).
6 * Copyright (C) 2005 Nathan Lynch
7 * Copyright (C) 2005 IBM Corporation
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>
17 #include <asm/machdep.h>
18 #include <linux/uaccess.h>
21 #include "of_helpers.h"
23 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
25 struct device_node *np;
28 np = kzalloc(sizeof(*np), GFP_KERNEL);
32 np->full_name = kstrdup(kbasename(path), GFP_KERNEL);
36 np->properties = proplist;
37 of_node_set_flag(np, OF_DYNAMIC);
40 np->parent = pseries_of_derive_parent(path);
41 if (IS_ERR(np->parent)) {
42 err = PTR_ERR(np->parent);
46 err = of_attach_node(np);
48 printk(KERN_ERR "Failed to add device node %s\n", path);
52 of_node_put(np->parent);
58 of_node_put(np->parent);
65 static int pSeries_reconfig_remove_node(struct device_node *np)
67 struct device_node *parent, *child;
69 parent = of_get_parent(np);
73 if ((child = of_get_next_child(np, NULL))) {
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.
90 static void release_prop_list(const struct property *prop)
92 struct property *next;
93 for (; prop; prop = next) {
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
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.
114 static char * parse_next_property(char *buf, char *end, char **name, int *length,
115 unsigned char **value)
121 tmp = strchr(buf, ' ');
123 printk(KERN_ERR "property parse failed in %s at line %d\n",
130 printk(KERN_ERR "property parse failed in %s at line %d\n",
135 /* now we're on the length */
137 *length = simple_strtoul(tmp, &tmp, 10);
139 printk(KERN_ERR "property parse failed in %s at line %d\n",
143 if (*tmp != ' ' || ++tmp >= end) {
144 printk(KERN_ERR "property parse failed in %s at line %d\n",
149 /* now we're on the value */
153 printk(KERN_ERR "property parse failed in %s at line %d\n",
157 else if (tmp < end && *tmp != ' ' && *tmp != '\0') {
158 printk(KERN_ERR "property parse failed in %s at line %d\n",
164 /* and now we should be on the next name, or the end */
168 static struct property *new_property(const char *name, const int length,
169 const unsigned char *value, struct property *last)
171 struct property *new = kzalloc(sizeof(*new), GFP_KERNEL);
176 if (!(new->name = kstrdup(name, GFP_KERNEL)))
178 if (!(new->value = kmalloc(length + 1, GFP_KERNEL)))
181 memcpy(new->value, value, length);
182 *(((char *)new->value) + length) = 0;
183 new->length = length;
194 static int do_add_node(char *buf, size_t bufsize)
196 char *path, *end, *name;
197 struct device_node *np;
198 struct property *prop = NULL;
199 unsigned char* value;
204 buf = strchr(buf, ' ');
210 if ((np = of_find_node_by_path(path))) {
215 /* rv = build_prop_list(tmp, bufsize - (tmp - buf), &proplist); */
217 (buf = parse_next_property(buf, end, &name, &length, &value))) {
218 struct property *last = prop;
220 prop = new_property(name, length, value, last);
232 rv = pSeries_reconfig_add_node(path, prop);
236 release_prop_list(prop);
240 static int do_remove_node(char *buf)
242 struct device_node *node;
245 if ((node = of_find_node_by_path(buf)))
246 rv = pSeries_reconfig_remove_node(node);
252 static char *parse_node(char *buf, size_t bufsize, struct device_node **npp)
260 buf = strchr(buf, ' ');
266 handle = simple_strtoul(handle_str, NULL, 0);
268 *npp = of_find_node_by_phandle(handle);
272 static int do_add_property(char *buf, size_t bufsize)
274 struct property *prop = NULL;
275 struct device_node *np;
276 unsigned char *value;
280 buf = parse_node(buf, bufsize, &np);
285 if (parse_next_property(buf, end, &name, &length, &value) == NULL)
288 prop = new_property(name, length, value, NULL);
292 of_add_property(np, prop);
297 static int do_remove_property(char *buf, size_t bufsize)
299 struct device_node *np;
301 buf = parse_node(buf, bufsize, &np);
306 tmp = strchr(buf,' ');
310 if (strlen(buf) == 0)
313 return of_remove_property(np, of_find_property(np, buf, NULL));
316 static int do_update_property(char *buf, size_t bufsize)
318 struct device_node *np;
319 unsigned char *value;
320 char *name, *end, *next_prop;
322 struct property *newprop;
323 buf = parse_node(buf, bufsize, &np);
329 next_prop = parse_next_property(buf, end, &name, &length, &value);
336 newprop = new_property(name, length, value, NULL);
340 if (!strcmp(name, "slb-size") || !strcmp(name, "ibm,slb-size"))
341 slb_set_size(*(int *)value);
343 return of_update_property(np, newprop);
347 * ofdt_write - perform operations on the Open Firmware device tree
350 * @buf: command and arguments
351 * @count: size of the command buffer
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).
358 static ssize_t ofdt_write(struct file *file, const char __user *buf, size_t count,
365 rv = security_locked_down(LOCKDOWN_DEVICE_TREE);
369 kbuf = memdup_user_nul(buf, count);
371 return PTR_ERR(kbuf);
373 tmp = strchr(kbuf, ' ');
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));
395 return rv ? rv : count;
398 static const struct proc_ops ofdt_proc_ops = {
399 .proc_write = ofdt_write,
400 .proc_lseek = noop_llseek,
403 /* create /proc/powerpc/ofdt write-only by root */
404 static int proc_ppc64_create_ofdt(void)
406 struct proc_dir_entry *ent;
408 ent = proc_create("powerpc/ofdt", 0200, NULL, &ofdt_proc_ops);
410 proc_set_size(ent, 0);
414 machine_device_initcall(pseries, proc_ppc64_create_ofdt);