source: mainline/boot/genarch/ofw_tree.c@ 0b6d70d

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 0b6d70d was 8ea0308, checked in by Jakub Jermar <jakub@…>, 17 years ago

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1/*
2 * Copyright (c) 2006 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <ofw_tree.h>
30#include <ofw.h>
31#include <types.h>
32#include <string.h>
33#include <balloc.h>
34#include <asm.h>
35
36#define MAX_PATH_LEN 256
37
38static ofw_tree_node_t *ofw_tree_node_alloc(void)
39{
40 return balloc(sizeof(ofw_tree_node_t), sizeof(ofw_tree_node_t));
41}
42
43static ofw_tree_property_t *ofw_tree_properties_alloc(unsigned count)
44{
45 return balloc(count * sizeof(ofw_tree_property_t),
46 sizeof(ofw_tree_property_t));
47}
48
49static void *ofw_tree_space_alloc(size_t size)
50{
51 char *addr;
52
53 /*
54 * What we do here is a nasty hack :-)
55 * Problem: string property values that are allocated via this
56 * function typically do not contain the trailing '\0'. This
57 * is very uncomfortable for kernel, which is supposed to deal
58 * with the properties.
59 * Solution: when allocating space via this function, we always
60 * allocate space for the extra '\0' character that we store
61 * behind the requested memory.
62 */
63 addr = balloc(size + 1, size);
64 if (addr)
65 addr[size] = '\0';
66 return addr;
67}
68
69/** Transfer information from one OpenFirmware node into its memory
70 * representation.
71 *
72 * Transfer entire information from the OpenFirmware device tree 'current' node
73 * to its memory representation in 'current_node'. This function recursively
74 * processes all node's children. Node's peers are processed iteratively in
75 * order to prevent stack from overflowing.
76 *
77 * @param current_node Pointer to uninitialized ofw_tree_node structure that
78 * will become the memory represenation of 'current'.
79 * @param parent_node Parent ofw_tree_node structure or NULL in case of root
80 * node.
81 * @param current OpenFirmware phandle to the current device tree node.
82 */
83static void ofw_tree_node_process(ofw_tree_node_t *current_node,
84 ofw_tree_node_t *parent_node, phandle current)
85{
86 static char path[MAX_PATH_LEN + 1];
87 static char name[OFW_TREE_PROPERTY_MAX_NAMELEN];
88 static char name2[OFW_TREE_PROPERTY_MAX_NAMELEN];
89 phandle peer;
90 phandle child;
91 size_t len;
92 int i;
93
94 while (current_node) {
95 /*
96 * Initialize node.
97 */
98 current_node->parent = parent_node;
99 current_node->peer = NULL;
100 current_node->child = NULL;
101 current_node->node_handle = current;
102 current_node->properties = 0;
103 current_node->property = NULL;
104 current_node->device = NULL;
105
106 /*
107 * Get the disambigued name.
108 */
109 len = ofw_package_to_path(current, path, MAX_PATH_LEN);
110 if (len == -1)
111 return;
112
113 path[len] = '\0';
114 for (i = len - 1; i >= 0 && path[i] != '/'; i--)
115 ;
116 i++; /* do not include '/' */
117
118 len -= i;
119
120 /* add space for trailing '\0' */
121 current_node->da_name = ofw_tree_space_alloc(len + 1);
122 if (!current_node->da_name)
123 return;
124
125 memcpy(current_node->da_name, &path[i], len);
126 current_node->da_name[len] = '\0';
127
128 /*
129 * Recursively process the potential child node.
130 */
131 child = ofw_get_child_node(current);
132 if (child != 0 && child != -1) {
133 ofw_tree_node_t *child_node;
134
135 child_node = ofw_tree_node_alloc();
136 if (child_node) {
137 ofw_tree_node_process(child_node, current_node,
138 child);
139 current_node->child = child_node;
140 }
141 }
142
143 /*
144 * Count properties.
145 */
146 name[0] = '\0';
147 while (ofw_next_property(current, name, name2) == 1) {
148 current_node->properties++;
149 memcpy(name, name2, OFW_TREE_PROPERTY_MAX_NAMELEN);
150 }
151
152 if (!current_node->properties)
153 return;
154
155 /*
156 * Copy properties.
157 */
158 current_node->property =
159 ofw_tree_properties_alloc(current_node->properties);
160 if (!current_node->property)
161 return;
162
163 name[0] = '\0';
164 for (i = 0; ofw_next_property(current, name, name2) == 1; i++) {
165 size_t size;
166
167 if (i == current_node->properties)
168 break;
169
170 memcpy(name, name2, OFW_TREE_PROPERTY_MAX_NAMELEN);
171 memcpy(current_node->property[i].name, name,
172 OFW_TREE_PROPERTY_MAX_NAMELEN);
173 current_node->property[i].name[
174 OFW_TREE_PROPERTY_MAX_NAMELEN] = '\0';
175
176 size = ofw_get_proplen(current, name);
177 current_node->property[i].size = size;
178 if (size) {
179 void *buf;
180
181 buf = ofw_tree_space_alloc(size);
182 if (current_node->property[i].value = buf) {
183 /*
184 * Copy property value to memory node.
185 */
186 (void) ofw_get_property(current, name,
187 buf, size);
188 }
189 } else {
190 current_node->property[i].value = NULL;
191 }
192 }
193
194 /* Just in case we ran out of memory. */
195 current_node->properties = i;
196
197 /*
198 * Iteratively process the next peer node.
199 * Note that recursion is a bad idea here.
200 * Due to the topology of the OpenFirmware device tree,
201 * the nesting of peer nodes could be to wide and the
202 * risk of overflowing the stack is too real.
203 */
204 peer = ofw_get_peer_node(current);
205 if (peer != 0 && peer != -1) {
206 ofw_tree_node_t *peer_node;
207
208 peer_node = ofw_tree_node_alloc();
209 if (peer_node) {
210 current_node->peer = peer_node;
211 current_node = peer_node;
212 current = peer;
213 /*
214 * Process the peer in next iteration.
215 */
216 continue;
217 }
218 }
219 /*
220 * No more peers on this level.
221 */
222 break;
223 }
224}
225
226/** Construct memory representation of OpenFirmware device tree.
227 *
228 * @return NULL on failure or pointer to the root node.
229 */
230ofw_tree_node_t *ofw_tree_build(void)
231{
232 ofw_tree_node_t *root;
233 phandle ssm_node;
234 ofw_tree_node_t *ssm;
235
236 root = ofw_tree_node_alloc();
237 if (root)
238 ofw_tree_node_process(root, NULL, ofw_root);
239
240 /*
241 * The firmware client interface does not automatically include the
242 * "ssm" node in the list of children of "/". A nasty yet working
243 * solution is to explicitly stick "ssm" to the OFW tree.
244 */
245 ssm_node = ofw_find_device("/ssm@0,0");
246 if (ssm_node != -1) {
247 ssm = ofw_tree_node_alloc();
248 if (ssm) {
249 ofw_tree_node_process(ssm, root,
250 ofw_find_device("/ssm@0,0"));
251 ssm->peer = root->child;
252 root->child = ssm;
253 }
254 }
255
256 return root;
257}
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