source: mainline/boot/genarch/src/ofw_tree.c@ c77cfd8

ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since c77cfd8 was 84239b1, checked in by Jiri Svoboda <jiri@…>, 7 years ago

And there was much fixing.
  • Property mode set to 100644
File size: 7.3 KB
Line 
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 <genarch/ofw_tree.h>
30#include <genarch/ofw.h>
31#include <arch/ofw.h>
32#include <stddef.h>
33#include <str.h>
34#include <balloc.h>
35#include <memstr.h>
36
37static char path[OFW_TREE_PATH_MAX_LEN + 1];
38static char name[OFW_TREE_PROPERTY_MAX_NAMELEN];
39static char name2[OFW_TREE_PROPERTY_MAX_NAMELEN];
40
41static ofw_tree_node_t *ofw_tree_node_alloc(void)
42{
43 return balloc(sizeof(ofw_tree_node_t), sizeof(ofw_tree_node_t));
44}
45
46static ofw_tree_property_t *ofw_tree_properties_alloc(size_t count)
47{
48 return balloc(count * sizeof(ofw_tree_property_t),
49 sizeof(ofw_tree_property_t));
50}
51
52static void *ofw_tree_space_alloc(size_t size)
53{
54 /*
55 * What we do here is a nasty hack :-)
56 * Problem: string property values that are allocated via this
57 * function typically do not contain the trailing '\0'. This
58 * is very uncomfortable for kernel, which is supposed to deal
59 * with the properties.
60 * Solution: when allocating space via this function, we always
61 * allocate space for the extra '\0' character that we store
62 * behind the requested memory.
63 */
64 char *addr = balloc(size + 1, 4);
65 if (addr)
66 addr[size] = '\0';
67
68 return addr;
69}
70
71/** Transfer information from one OpenFirmware node into its memory
72 * representation.
73 *
74 * Transfer entire information from the OpenFirmware device tree 'current' node
75 * to its memory representation in 'current_node'. This function recursively
76 * processes all node's children. Node's peers are processed iteratively in
77 * order to prevent stack from overflowing.
78 *
79 * @param current_node Pointer to uninitialized ofw_tree_node structure that
80 * will become the memory represenation of 'current'.
81 * @param parent_node Parent ofw_tree_node structure or NULL in case of root
82 * node.
83 * @param current OpenFirmware phandle to the current device tree node.
84 *
85 */
86static void ofw_tree_node_process(ofw_tree_node_t *current_node,
87 ofw_tree_node_t *parent_node, phandle current)
88{
89 while (current_node) {
90 /*
91 * Initialize node.
92 */
93 current_node->parent = (ofw_tree_node_t *) balloc_rebase(parent_node);
94 current_node->peer = NULL;
95 current_node->child = NULL;
96 current_node->node_handle = current;
97 current_node->properties = 0;
98 current_node->property = NULL;
99 current_node->device = NULL;
100
101 /*
102 * Get the disambigued name.
103 */
104 size_t len = ofw_package_to_path(current, path, OFW_TREE_PATH_MAX_LEN);
105 if (len == (size_t) -1)
106 return;
107
108 path[len] = '\0';
109
110 /* Find last slash */
111 size_t i;
112 i = len;
113 while (i > 0 && path[i - 1] != '/')
114 i--;
115
116 /* Do not include the slash */
117 len -= i;
118
119 /* Add space for trailing '\0' */
120 char *da_name = ofw_tree_space_alloc(len + 1);
121 if (!da_name)
122 return;
123
124 memcpy(da_name, &path[i], len);
125 da_name[len] = '\0';
126 current_node->da_name = (char *) balloc_rebase(da_name);
127
128 /*
129 * Recursively process the potential child node.
130 */
131 phandle child = ofw_get_child_node(current);
132 if ((child != 0) && (child != (phandle) -1)) {
133 ofw_tree_node_t *child_node = ofw_tree_node_alloc();
134 if (child_node) {
135 ofw_tree_node_process(child_node, current_node,
136 child);
137 current_node->child =
138 (ofw_tree_node_t *) balloc_rebase(child_node);
139 }
140 }
141
142 /*
143 * Count properties.
144 */
145 name[0] = '\0';
146 while (ofw_next_property(current, name, name2) == 1) {
147 current_node->properties++;
148 memcpy(name, name2, OFW_TREE_PROPERTY_MAX_NAMELEN);
149 }
150
151 if (!current_node->properties)
152 return;
153
154 /*
155 * Copy properties.
156 */
157 ofw_tree_property_t *property =
158 ofw_tree_properties_alloc(current_node->properties);
159 if (!property)
160 return;
161
162 name[0] = '\0';
163 for (i = 0; ofw_next_property(current, name, name2) == 1; i++) {
164 if (i == current_node->properties)
165 break;
166
167 memcpy(name, name2, OFW_TREE_PROPERTY_MAX_NAMELEN);
168 memcpy(property[i].name, name, OFW_TREE_PROPERTY_MAX_NAMELEN);
169 property[i].name[OFW_TREE_PROPERTY_MAX_NAMELEN - 1] = '\0';
170
171 size_t size = ofw_get_proplen(current, name);
172 property[i].size = size;
173
174 if (size) {
175 void *buf = ofw_tree_space_alloc(size);
176 if (buf) {
177 /*
178 * Copy property value to memory node.
179 */
180 (void) ofw_get_property(current, name, buf, size);
181 property[i].value = balloc_rebase(buf);
182 }
183 } else
184 property[i].value = NULL;
185 }
186
187 /* Just in case we ran out of memory. */
188 current_node->properties = i;
189 current_node->property = (ofw_tree_property_t *) balloc_rebase(property);
190
191 /*
192 * Iteratively process the next peer node.
193 * Note that recursion is a bad idea here.
194 * Due to the topology of the OpenFirmware device tree,
195 * the nesting of peer nodes could be to wide and the
196 * risk of overflowing the stack is too real.
197 */
198 phandle peer = ofw_get_peer_node(current);
199 if ((peer != 0) && (peer != (phandle) -1)) {
200 ofw_tree_node_t *peer_node = ofw_tree_node_alloc();
201 if (peer_node) {
202 current_node->peer = (ofw_tree_node_t *) balloc_rebase(peer_node);
203 current_node = peer_node;
204 current = peer;
205 /*
206 * Process the peer in next iteration.
207 */
208 continue;
209 }
210 }
211
212 /*
213 * No more peers on this level.
214 */
215 break;
216 }
217}
218
219/** Construct memory representation of OpenFirmware device tree.
220 *
221 * @return NULL on failure or kernel pointer to the root node.
222 *
223 */
224ofw_tree_node_t *ofw_tree_build(void)
225{
226 ofw_tree_node_t *root = ofw_tree_node_alloc();
227 if (root)
228 ofw_tree_node_process(root, NULL, ofw_root);
229
230 /*
231 * The firmware client interface does not automatically include the
232 * "ssm" node in the list of children of "/". A nasty yet working
233 * solution is to explicitly stick "ssm" to the OFW tree.
234 */
235 phandle ssm_node = ofw_find_device("/ssm@0,0");
236 if (ssm_node != (phandle) -1) {
237 ofw_tree_node_t *ssm = ofw_tree_node_alloc();
238 if (ssm) {
239 ofw_tree_node_process(ssm, root,
240 ofw_find_device("/ssm@0,0"));
241 ssm->peer = root->child;
242 root->child = (ofw_tree_node_t *) balloc_rebase(ssm);
243 }
244 }
245
246 return (ofw_tree_node_t *) balloc_rebase(root);
247}
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