blob: 65d0b7adfcd4b2208521226aef8b84f6203205ea [file] [log] [blame]
Rob Herringaf6074f2017-12-27 12:55:14 -06001// SPDX-License-Identifier: GPL-2.0
Pantelis Antoniou7941b272014-07-04 19:59:20 +03002/*
3 * Functions for dealing with DT resolution
4 *
5 * Copyright (C) 2012 Pantelis Antoniou <panto@antoniou-consulting.com>
6 * Copyright (C) 2012 Texas Instruments Inc.
Pantelis Antoniou7941b272014-07-04 19:59:20 +03007 */
8
Rob Herring606ad422016-06-15 08:32:18 -05009#define pr_fmt(fmt) "OF: resolver: " fmt
10
Pantelis Antoniou7941b272014-07-04 19:59:20 +030011#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/of.h>
14#include <linux/of_device.h>
15#include <linux/string.h>
16#include <linux/ctype.h>
17#include <linux/errno.h>
Pantelis Antoniou7941b272014-07-04 19:59:20 +030018#include <linux/slab.h>
19
Rob Herring27497e12017-06-02 12:43:18 -050020#include "of_private.h"
21
Frank Rowandf94823f2016-10-28 23:26:24 -070022static phandle live_tree_max_phandle(void)
Pantelis Antoniou7941b272014-07-04 19:59:20 +030023{
24 struct device_node *node;
25 phandle phandle;
26 unsigned long flags;
27
Pantelis Antoniou7941b272014-07-04 19:59:20 +030028 raw_spin_lock_irqsave(&devtree_lock, flags);
29 phandle = 0;
30 for_each_of_allnodes(node) {
31 if (node->phandle != OF_PHANDLE_ILLEGAL &&
32 node->phandle > phandle)
33 phandle = node->phandle;
34 }
35 raw_spin_unlock_irqrestore(&devtree_lock, flags);
36
37 return phandle;
38}
39
Frank Rowand25e16872016-10-28 23:26:26 -070040static void adjust_overlay_phandles(struct device_node *overlay,
Pantelis Antoniou7941b272014-07-04 19:59:20 +030041 int phandle_delta)
42{
43 struct device_node *child;
44 struct property *prop;
45 phandle phandle;
46
Frank Rowand269f1a62016-10-28 23:26:29 -070047 /* adjust node's phandle in node */
Frank Rowand25e16872016-10-28 23:26:26 -070048 if (overlay->phandle != 0 && overlay->phandle != OF_PHANDLE_ILLEGAL)
49 overlay->phandle += phandle_delta;
Pantelis Antoniou7941b272014-07-04 19:59:20 +030050
Frank Rowand269f1a62016-10-28 23:26:29 -070051 /* copy adjusted phandle into *phandle properties */
Frank Rowand25e16872016-10-28 23:26:26 -070052 for_each_property_of_node(overlay, prop) {
Pantelis Antoniou7941b272014-07-04 19:59:20 +030053
Frank Rowand9f27ede2016-10-28 23:26:23 -070054 if (of_prop_cmp(prop->name, "phandle") &&
55 of_prop_cmp(prop->name, "linux,phandle"))
Pantelis Antoniou7941b272014-07-04 19:59:20 +030056 continue;
57
Pantelis Antoniou7941b272014-07-04 19:59:20 +030058 if (prop->length < 4)
59 continue;
60
Pantelis Antoniou7941b272014-07-04 19:59:20 +030061 phandle = be32_to_cpup(prop->value);
Frank Rowanda67976e2016-10-28 23:26:21 -070062 if (phandle == OF_PHANDLE_ILLEGAL)
Pantelis Antoniou7941b272014-07-04 19:59:20 +030063 continue;
64
Rob Herring17a70352017-05-04 12:56:12 -050065 *(__be32 *)prop->value = cpu_to_be32(overlay->phandle);
Pantelis Antoniou7941b272014-07-04 19:59:20 +030066 }
67
Frank Rowand25e16872016-10-28 23:26:26 -070068 for_each_child_of_node(overlay, child)
Frank Rowandf94823f2016-10-28 23:26:24 -070069 adjust_overlay_phandles(child, phandle_delta);
Pantelis Antoniou7941b272014-07-04 19:59:20 +030070}
71
Frank Rowand25e16872016-10-28 23:26:26 -070072static int update_usages_of_a_phandle_reference(struct device_node *overlay,
73 struct property *prop_fixup, phandle phandle)
Pantelis Antoniou7941b272014-07-04 19:59:20 +030074{
Pantelis Antoniou7941b272014-07-04 19:59:20 +030075 struct device_node *refnode;
Frank Rowand25e16872016-10-28 23:26:26 -070076 struct property *prop;
77 char *value, *cur, *end, *node_path, *prop_name, *s;
78 int offset, len;
Pantelis Antoniou7941b272014-07-04 19:59:20 +030079 int err = 0;
80
Stephen Boydeeb09502017-10-13 00:35:58 -070081 value = kmemdup(prop_fixup->value, prop_fixup->length, GFP_KERNEL);
Frank Rowand25e16872016-10-28 23:26:26 -070082 if (!value)
Pantelis Antoniou7941b272014-07-04 19:59:20 +030083 return -ENOMEM;
Pantelis Antoniou7941b272014-07-04 19:59:20 +030084
Frank Rowand269f1a62016-10-28 23:26:29 -070085 /* prop_fixup contains a list of tuples of path:property_name:offset */
Frank Rowand25e16872016-10-28 23:26:26 -070086 end = value + prop_fixup->length;
87 for (cur = value; cur < end; cur += len + 1) {
88 len = strlen(cur);
Pantelis Antoniou7941b272014-07-04 19:59:20 +030089
Frank Rowand25e16872016-10-28 23:26:26 -070090 node_path = cur;
91 s = strchr(cur, ':');
Pantelis Antoniou7941b272014-07-04 19:59:20 +030092 if (!s) {
Pantelis Antoniou7941b272014-07-04 19:59:20 +030093 err = -EINVAL;
94 goto err_fail;
95 }
96 *s++ = '\0';
97
Frank Rowand25e16872016-10-28 23:26:26 -070098 prop_name = s;
Pantelis Antoniou7941b272014-07-04 19:59:20 +030099 s = strchr(s, ':');
100 if (!s) {
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300101 err = -EINVAL;
102 goto err_fail;
103 }
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300104 *s++ = '\0';
Frank Rowand624ab2a2016-10-28 23:26:27 -0700105
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300106 err = kstrtoint(s, 10, &offset);
Frank Rowand9f27ede2016-10-28 23:26:23 -0700107 if (err)
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300108 goto err_fail;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300109
Rob Herring27497e12017-06-02 12:43:18 -0500110 refnode = __of_find_node_by_full_path(of_node_get(overlay), node_path);
Frank Rowand96d1c8e2016-10-28 23:26:22 -0700111 if (!refnode)
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300112 continue;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300113
Frank Rowand25e16872016-10-28 23:26:26 -0700114 for_each_property_of_node(refnode, prop) {
115 if (!of_prop_cmp(prop->name, prop_name))
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300116 break;
117 }
Amitoj Kaur Chawla82f68752016-02-03 23:39:01 +0530118 of_node_put(refnode);
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300119
Frank Rowand25e16872016-10-28 23:26:26 -0700120 if (!prop) {
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300121 err = -ENOENT;
122 goto err_fail;
123 }
124
Frank Rowand25e16872016-10-28 23:26:26 -0700125 *(__be32 *)(prop->value + offset) = cpu_to_be32(phandle);
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300126 }
127
128err_fail:
Frank Rowand25e16872016-10-28 23:26:26 -0700129 kfree(value);
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300130 return err;
131}
132
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200133/* compare nodes taking into account that 'name' strips out the @ part */
Frank Rowandfad556b2016-10-28 23:26:25 -0700134static int node_name_cmp(const struct device_node *dn1,
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200135 const struct device_node *dn2)
136{
Rob Herring95e6b1f2017-06-01 18:00:00 -0500137 const char *n1 = kbasename(dn1->full_name);
138 const char *n2 = kbasename(dn2->full_name);
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200139
140 return of_node_cmp(n1, n2);
141}
142
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300143/*
144 * Adjust the local phandle references by the given phandle delta.
Frank Rowand269f1a62016-10-28 23:26:29 -0700145 *
146 * Subtree @local_fixups, which is overlay node __local_fixups__,
147 * mirrors the fragment node structure at the root of the overlay.
148 *
149 * For each property in the fragments that contains a phandle reference,
150 * @local_fixups has a property of the same name that contains a list
151 * of offsets of the phandle reference(s) within the respective property
152 * value(s). The values at these offsets will be fixed up.
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300153 */
Frank Rowand25e16872016-10-28 23:26:26 -0700154static int adjust_local_phandle_references(struct device_node *local_fixups,
155 struct device_node *overlay, int phandle_delta)
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300156{
Frank Rowand25e16872016-10-28 23:26:26 -0700157 struct device_node *child, *overlay_child;
158 struct property *prop_fix, *prop;
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200159 int err, i, count;
160 unsigned int off;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300161
Frank Rowand25e16872016-10-28 23:26:26 -0700162 if (!local_fixups)
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300163 return 0;
164
Frank Rowand25e16872016-10-28 23:26:26 -0700165 for_each_property_of_node(local_fixups, prop_fix) {
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200166
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300167 /* skip properties added automatically */
Frank Rowand25e16872016-10-28 23:26:26 -0700168 if (!of_prop_cmp(prop_fix->name, "name") ||
169 !of_prop_cmp(prop_fix->name, "phandle") ||
170 !of_prop_cmp(prop_fix->name, "linux,phandle"))
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300171 continue;
172
Frank Rowand25e16872016-10-28 23:26:26 -0700173 if ((prop_fix->length % 4) != 0 || prop_fix->length == 0)
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200174 return -EINVAL;
Frank Rowand25e16872016-10-28 23:26:26 -0700175 count = prop_fix->length / sizeof(__be32);
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200176
Frank Rowand25e16872016-10-28 23:26:26 -0700177 for_each_property_of_node(overlay, prop) {
178 if (!of_prop_cmp(prop->name, prop_fix->name))
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200179 break;
180 }
181
Frank Rowand25e16872016-10-28 23:26:26 -0700182 if (!prop)
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200183 return -EINVAL;
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200184
185 for (i = 0; i < count; i++) {
Frank Rowand25e16872016-10-28 23:26:26 -0700186 off = be32_to_cpu(((__be32 *)prop_fix->value)[i]);
Frank Rowandea8229b2016-10-28 23:26:28 -0700187 if ((off + 4) > prop->length)
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200188 return -EINVAL;
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200189
Stephen Boydd35d6232017-10-13 00:35:57 -0700190 be32_add_cpu(prop->value + off, phandle_delta);
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200191 }
192 }
193
Frank Rowand269f1a62016-10-28 23:26:29 -0700194 /*
195 * These nested loops recurse down two subtrees in parallel, where the
196 * node names in the two subtrees match.
197 *
198 * The roots of the subtrees are the overlay's __local_fixups__ node
199 * and the overlay's root node.
200 */
Frank Rowand25e16872016-10-28 23:26:26 -0700201 for_each_child_of_node(local_fixups, child) {
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200202
Frank Rowand25e16872016-10-28 23:26:26 -0700203 for_each_child_of_node(overlay, overlay_child)
204 if (!node_name_cmp(child, overlay_child))
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200205 break;
206
Frank Rowand25e16872016-10-28 23:26:26 -0700207 if (!overlay_child)
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200208 return -EINVAL;
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200209
Frank Rowand25e16872016-10-28 23:26:26 -0700210 err = adjust_local_phandle_references(child, overlay_child,
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200211 phandle_delta);
Frank Rowand9f27ede2016-10-28 23:26:23 -0700212 if (err)
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300213 return err;
214 }
215
216 return 0;
217}
218
219/**
Frank Rowand269f1a62016-10-28 23:26:29 -0700220 * of_resolve_phandles - Relocate and resolve overlay against live tree
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300221 *
Frank Rowand269f1a62016-10-28 23:26:29 -0700222 * @overlay: Pointer to devicetree overlay to relocate and resolve
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300223 *
Frank Rowand269f1a62016-10-28 23:26:29 -0700224 * Modify (relocate) values of local phandles in @overlay to a range that
225 * does not conflict with the live expanded devicetree. Update references
226 * to the local phandles in @overlay. Update (resolve) phandle references
227 * in @overlay that refer to the live expanded devicetree.
228 *
229 * Phandle values in the live tree are in the range of
230 * 1 .. live_tree_max_phandle(). The range of phandle values in the overlay
231 * also begin with at 1. Adjust the phandle values in the overlay to begin
232 * at live_tree_max_phandle() + 1. Update references to the phandles to
233 * the adjusted phandle values.
234 *
235 * The name of each property in the "__fixups__" node in the overlay matches
236 * the name of a symbol (a label) in the live tree. The values of each
237 * property in the "__fixups__" node is a list of the property values in the
238 * overlay that need to be updated to contain the phandle reference
239 * corresponding to that symbol in the live tree. Update the references in
240 * the overlay with the phandle values in the live tree.
241 *
242 * @overlay must be detached.
243 *
244 * Resolving and applying @overlay to the live expanded devicetree must be
245 * protected by a mechanism to ensure that multiple overlays are processed
246 * in a single threaded manner so that multiple overlays will not relocate
247 * phandles to overlapping ranges. The mechanism to enforce this is not
248 * yet implemented.
249 *
250 * Return: %0 on success or a negative error value on error.
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300251 */
Frank Rowand25e16872016-10-28 23:26:26 -0700252int of_resolve_phandles(struct device_node *overlay)
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300253{
Frank Rowand25e16872016-10-28 23:26:26 -0700254 struct device_node *child, *local_fixups, *refnode;
Frank Rowand5581a952016-10-28 23:26:32 -0700255 struct device_node *tree_symbols, *overlay_fixups;
Frank Rowand25e16872016-10-28 23:26:26 -0700256 struct property *prop;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300257 const char *refpath;
258 phandle phandle, phandle_delta;
259 int err;
260
Frank Rowandd9181b22016-10-28 23:26:30 -0700261 tree_symbols = NULL;
262
Frank Rowand624ab2a2016-10-28 23:26:27 -0700263 if (!overlay) {
264 pr_err("null overlay\n");
Frank Rowandd9181b22016-10-28 23:26:30 -0700265 err = -EINVAL;
Moritz Fischer32bed312016-12-01 22:10:25 -0800266 goto out;
Frank Rowand624ab2a2016-10-28 23:26:27 -0700267 }
Frank Rowandf948d6d2017-10-17 16:36:29 -0700268
Frank Rowand624ab2a2016-10-28 23:26:27 -0700269 if (!of_node_check_flag(overlay, OF_DETACHED)) {
270 pr_err("overlay not detached\n");
Frank Rowandd9181b22016-10-28 23:26:30 -0700271 err = -EINVAL;
Moritz Fischer32bed312016-12-01 22:10:25 -0800272 goto out;
Frank Rowand624ab2a2016-10-28 23:26:27 -0700273 }
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300274
Frank Rowandf94823f2016-10-28 23:26:24 -0700275 phandle_delta = live_tree_max_phandle() + 1;
Frank Rowand25e16872016-10-28 23:26:26 -0700276 adjust_overlay_phandles(overlay, phandle_delta);
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200277
Frank Rowand25e16872016-10-28 23:26:26 -0700278 for_each_child_of_node(overlay, local_fixups)
279 if (!of_node_cmp(local_fixups->name, "__local_fixups__"))
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200280 break;
281
Frank Rowand624ab2a2016-10-28 23:26:27 -0700282 err = adjust_local_phandle_references(local_fixups, overlay, phandle_delta);
283 if (err)
Moritz Fischer32bed312016-12-01 22:10:25 -0800284 goto out;
Pantelis Antoniouda56d042014-10-28 22:33:49 +0200285
Frank Rowand25e16872016-10-28 23:26:26 -0700286 overlay_fixups = NULL;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300287
Frank Rowand25e16872016-10-28 23:26:26 -0700288 for_each_child_of_node(overlay, child) {
Frank Rowand624ab2a2016-10-28 23:26:27 -0700289 if (!of_node_cmp(child->name, "__fixups__"))
Frank Rowand25e16872016-10-28 23:26:26 -0700290 overlay_fixups = child;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300291 }
292
Frank Rowand25e16872016-10-28 23:26:26 -0700293 if (!overlay_fixups) {
Frank Rowanda67976e2016-10-28 23:26:21 -0700294 err = 0;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300295 goto out;
296 }
297
Frank Rowand4458db42016-10-28 23:26:31 -0700298 tree_symbols = of_find_node_by_path("/__symbols__");
Frank Rowand25e16872016-10-28 23:26:26 -0700299 if (!tree_symbols) {
Frank Rowand624ab2a2016-10-28 23:26:27 -0700300 pr_err("no symbols in root of device tree.\n");
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300301 err = -EINVAL;
Moritz Fischer32bed312016-12-01 22:10:25 -0800302 goto out;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300303 }
304
Frank Rowand25e16872016-10-28 23:26:26 -0700305 for_each_property_of_node(overlay_fixups, prop) {
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300306
307 /* skip properties added automatically */
Frank Rowand25e16872016-10-28 23:26:26 -0700308 if (!of_prop_cmp(prop->name, "name"))
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300309 continue;
310
Frank Rowand25e16872016-10-28 23:26:26 -0700311 err = of_property_read_string(tree_symbols,
312 prop->name, &refpath);
Frank Rowand9f27ede2016-10-28 23:26:23 -0700313 if (err)
Moritz Fischer32bed312016-12-01 22:10:25 -0800314 goto out;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300315
316 refnode = of_find_node_by_path(refpath);
317 if (!refnode) {
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300318 err = -ENOENT;
Moritz Fischer32bed312016-12-01 22:10:25 -0800319 goto out;
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300320 }
321
322 phandle = refnode->phandle;
323 of_node_put(refnode);
324
Frank Rowand25e16872016-10-28 23:26:26 -0700325 err = update_usages_of_a_phandle_reference(overlay, prop, phandle);
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300326 if (err)
327 break;
328 }
329
330out:
Moritz Fischer32bed312016-12-01 22:10:25 -0800331 if (err)
332 pr_err("overlay phandle fixup failed: %d\n", err);
Frank Rowand25e16872016-10-28 23:26:26 -0700333 of_node_put(tree_symbols);
Pantelis Antoniou7941b272014-07-04 19:59:20 +0300334
335 return err;
336}
337EXPORT_SYMBOL_GPL(of_resolve_phandles);