1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_XBC_H |
3 | #define _LINUX_XBC_H |
4 | /* |
5 | * Extra Boot Config |
6 | * Copyright (C) 2019 Linaro Ltd. |
7 | * Author: Masami Hiramatsu <mhiramat@kernel.org> |
8 | */ |
9 | |
10 | #ifdef __KERNEL__ |
11 | #include <linux/kernel.h> |
12 | #include <linux/types.h> |
13 | #else /* !__KERNEL__ */ |
14 | /* |
15 | * NOTE: This is only for tools/bootconfig, because tools/bootconfig will |
16 | * run the parser sanity test. |
17 | * This does NOT mean linux/bootconfig.h is available in the user space. |
18 | * However, if you change this file, please make sure the tools/bootconfig |
19 | * has no issue on building and running. |
20 | */ |
21 | #endif |
22 | |
23 | #define BOOTCONFIG_MAGIC "#BOOTCONFIG\n" |
24 | #define BOOTCONFIG_MAGIC_LEN 12 |
25 | #define BOOTCONFIG_ALIGN_SHIFT 2 |
26 | #define BOOTCONFIG_ALIGN (1 << BOOTCONFIG_ALIGN_SHIFT) |
27 | #define BOOTCONFIG_ALIGN_MASK (BOOTCONFIG_ALIGN - 1) |
28 | |
29 | /** |
30 | * xbc_calc_checksum() - Calculate checksum of bootconfig |
31 | * @data: Bootconfig data. |
32 | * @size: The size of the bootconfig data. |
33 | * |
34 | * Calculate the checksum value of the bootconfig data. |
35 | * The checksum will be used with the BOOTCONFIG_MAGIC and the size for |
36 | * embedding the bootconfig in the initrd image. |
37 | */ |
38 | static inline __init uint32_t xbc_calc_checksum(void *data, uint32_t size) |
39 | { |
40 | unsigned char *p = data; |
41 | uint32_t ret = 0; |
42 | |
43 | while (size--) |
44 | ret += *p++; |
45 | |
46 | return ret; |
47 | } |
48 | |
49 | /* XBC tree node */ |
50 | struct xbc_node { |
51 | uint16_t next; |
52 | uint16_t child; |
53 | uint16_t parent; |
54 | uint16_t data; |
55 | } __attribute__ ((__packed__)); |
56 | |
57 | #define XBC_KEY 0 |
58 | #define XBC_VALUE (1 << 15) |
59 | /* Maximum size of boot config is 32KB - 1 */ |
60 | #define XBC_DATA_MAX (XBC_VALUE - 1) |
61 | |
62 | #define XBC_NODE_MAX 8192 |
63 | #define XBC_KEYLEN_MAX 256 |
64 | #define XBC_DEPTH_MAX 16 |
65 | |
66 | /* Node tree access raw APIs */ |
67 | struct xbc_node * __init xbc_root_node(void); |
68 | int __init xbc_node_index(struct xbc_node *node); |
69 | struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node); |
70 | struct xbc_node * __init xbc_node_get_child(struct xbc_node *node); |
71 | struct xbc_node * __init xbc_node_get_next(struct xbc_node *node); |
72 | const char * __init xbc_node_get_data(struct xbc_node *node); |
73 | |
74 | /** |
75 | * xbc_node_is_value() - Test the node is a value node |
76 | * @node: An XBC node. |
77 | * |
78 | * Test the @node is a value node and return true if a value node, false if not. |
79 | */ |
80 | static inline __init bool xbc_node_is_value(struct xbc_node *node) |
81 | { |
82 | return node->data & XBC_VALUE; |
83 | } |
84 | |
85 | /** |
86 | * xbc_node_is_key() - Test the node is a key node |
87 | * @node: An XBC node. |
88 | * |
89 | * Test the @node is a key node and return true if a key node, false if not. |
90 | */ |
91 | static inline __init bool xbc_node_is_key(struct xbc_node *node) |
92 | { |
93 | return !xbc_node_is_value(node); |
94 | } |
95 | |
96 | /** |
97 | * xbc_node_is_array() - Test the node is an arraied value node |
98 | * @node: An XBC node. |
99 | * |
100 | * Test the @node is an arraied value node. |
101 | */ |
102 | static inline __init bool xbc_node_is_array(struct xbc_node *node) |
103 | { |
104 | return xbc_node_is_value(node) && node->child != 0; |
105 | } |
106 | |
107 | /** |
108 | * xbc_node_is_leaf() - Test the node is a leaf key node |
109 | * @node: An XBC node. |
110 | * |
111 | * Test the @node is a leaf key node which is a key node and has a value node |
112 | * or no child. Returns true if it is a leaf node, or false if not. |
113 | * Note that the leaf node can have subkey nodes in addition to the |
114 | * value node. |
115 | */ |
116 | static inline __init bool xbc_node_is_leaf(struct xbc_node *node) |
117 | { |
118 | return xbc_node_is_key(node) && |
119 | (!node->child || xbc_node_is_value(node: xbc_node_get_child(node))); |
120 | } |
121 | |
122 | /* Tree-based key-value access APIs */ |
123 | struct xbc_node * __init xbc_node_find_subkey(struct xbc_node *parent, |
124 | const char *key); |
125 | |
126 | const char * __init xbc_node_find_value(struct xbc_node *parent, |
127 | const char *key, |
128 | struct xbc_node **vnode); |
129 | |
130 | struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root, |
131 | struct xbc_node *leaf); |
132 | |
133 | const char * __init xbc_node_find_next_key_value(struct xbc_node *root, |
134 | struct xbc_node **leaf); |
135 | |
136 | /** |
137 | * xbc_find_value() - Find a value which matches the key |
138 | * @key: Search key |
139 | * @vnode: A container pointer of XBC value node. |
140 | * |
141 | * Search a value whose key matches @key from whole of XBC tree and return |
142 | * the value if found. Found value node is stored in *@vnode. |
143 | * Note that this can return 0-length string and store NULL in *@vnode for |
144 | * key-only (non-value) entry. |
145 | */ |
146 | static inline const char * __init |
147 | xbc_find_value(const char *key, struct xbc_node **vnode) |
148 | { |
149 | return xbc_node_find_value(NULL, key, vnode); |
150 | } |
151 | |
152 | /** |
153 | * xbc_find_node() - Find a node which matches the key |
154 | * @key: Search key |
155 | * |
156 | * Search a (key) node whose key matches @key from whole of XBC tree and |
157 | * return the node if found. If not found, returns NULL. |
158 | */ |
159 | static inline struct xbc_node * __init xbc_find_node(const char *key) |
160 | { |
161 | return xbc_node_find_subkey(NULL, key); |
162 | } |
163 | |
164 | /** |
165 | * xbc_node_get_subkey() - Return the first subkey node if exists |
166 | * @node: Parent node |
167 | * |
168 | * Return the first subkey node of the @node. If the @node has no child |
169 | * or only value node, this will return NULL. |
170 | */ |
171 | static inline struct xbc_node * __init xbc_node_get_subkey(struct xbc_node *node) |
172 | { |
173 | struct xbc_node *child = xbc_node_get_child(node); |
174 | |
175 | if (child && xbc_node_is_value(node: child)) |
176 | return xbc_node_get_next(node: child); |
177 | else |
178 | return child; |
179 | } |
180 | |
181 | /** |
182 | * xbc_array_for_each_value() - Iterate value nodes on an array |
183 | * @anode: An XBC arraied value node |
184 | * @value: A value |
185 | * |
186 | * Iterate array value nodes and values starts from @anode. This is expected to |
187 | * be used with xbc_find_value() and xbc_node_find_value(), so that user can |
188 | * process each array entry node. |
189 | */ |
190 | #define xbc_array_for_each_value(anode, value) \ |
191 | for (value = xbc_node_get_data(anode); anode != NULL ; \ |
192 | anode = xbc_node_get_child(anode), \ |
193 | value = anode ? xbc_node_get_data(anode) : NULL) |
194 | |
195 | /** |
196 | * xbc_node_for_each_child() - Iterate child nodes |
197 | * @parent: An XBC node. |
198 | * @child: Iterated XBC node. |
199 | * |
200 | * Iterate child nodes of @parent. Each child nodes are stored to @child. |
201 | * The @child can be mixture of a value node and subkey nodes. |
202 | */ |
203 | #define xbc_node_for_each_child(parent, child) \ |
204 | for (child = xbc_node_get_child(parent); child != NULL ; \ |
205 | child = xbc_node_get_next(child)) |
206 | |
207 | /** |
208 | * xbc_node_for_each_subkey() - Iterate child subkey nodes |
209 | * @parent: An XBC node. |
210 | * @child: Iterated XBC node. |
211 | * |
212 | * Iterate subkey nodes of @parent. Each child nodes are stored to @child. |
213 | * The @child is only the subkey node. |
214 | */ |
215 | #define xbc_node_for_each_subkey(parent, child) \ |
216 | for (child = xbc_node_get_subkey(parent); child != NULL ; \ |
217 | child = xbc_node_get_next(child)) |
218 | |
219 | /** |
220 | * xbc_node_for_each_array_value() - Iterate array entries of geven key |
221 | * @node: An XBC node. |
222 | * @key: A key string searched under @node |
223 | * @anode: Iterated XBC node of array entry. |
224 | * @value: Iterated value of array entry. |
225 | * |
226 | * Iterate array entries of given @key under @node. Each array entry node |
227 | * is stored to @anode and @value. If the @node doesn't have @key node, |
228 | * it does nothing. |
229 | * Note that even if the found key node has only one value (not array) |
230 | * this executes block once. However, if the found key node has no value |
231 | * (key-only node), this does nothing. So don't use this for testing the |
232 | * key-value pair existence. |
233 | */ |
234 | #define xbc_node_for_each_array_value(node, key, anode, value) \ |
235 | for (value = xbc_node_find_value(node, key, &anode); value != NULL; \ |
236 | anode = xbc_node_get_child(anode), \ |
237 | value = anode ? xbc_node_get_data(anode) : NULL) |
238 | |
239 | /** |
240 | * xbc_node_for_each_key_value() - Iterate key-value pairs under a node |
241 | * @node: An XBC node. |
242 | * @knode: Iterated key node |
243 | * @value: Iterated value string |
244 | * |
245 | * Iterate key-value pairs under @node. Each key node and value string are |
246 | * stored in @knode and @value respectively. |
247 | */ |
248 | #define xbc_node_for_each_key_value(node, knode, value) \ |
249 | for (knode = NULL, value = xbc_node_find_next_key_value(node, &knode);\ |
250 | knode != NULL; value = xbc_node_find_next_key_value(node, &knode)) |
251 | |
252 | /** |
253 | * xbc_for_each_key_value() - Iterate key-value pairs |
254 | * @knode: Iterated key node |
255 | * @value: Iterated value string |
256 | * |
257 | * Iterate key-value pairs in whole XBC tree. Each key node and value string |
258 | * are stored in @knode and @value respectively. |
259 | */ |
260 | #define xbc_for_each_key_value(knode, value) \ |
261 | xbc_node_for_each_key_value(NULL, knode, value) |
262 | |
263 | /* Compose partial key */ |
264 | int __init xbc_node_compose_key_after(struct xbc_node *root, |
265 | struct xbc_node *node, char *buf, size_t size); |
266 | |
267 | /** |
268 | * xbc_node_compose_key() - Compose full key string of the XBC node |
269 | * @node: An XBC node. |
270 | * @buf: A buffer to store the key. |
271 | * @size: The size of the @buf. |
272 | * |
273 | * Compose the full-length key of the @node into @buf. Returns the total |
274 | * length of the key stored in @buf. Or returns -EINVAL if @node is NULL, |
275 | * and -ERANGE if the key depth is deeper than max depth. |
276 | */ |
277 | static inline int __init xbc_node_compose_key(struct xbc_node *node, |
278 | char *buf, size_t size) |
279 | { |
280 | return xbc_node_compose_key_after(NULL, node, buf, size); |
281 | } |
282 | |
283 | /* XBC node initializer */ |
284 | int __init xbc_init(const char *buf, size_t size, const char **emsg, int *epos); |
285 | |
286 | /* XBC node and size information */ |
287 | int __init xbc_get_info(int *node_size, size_t *data_size); |
288 | |
289 | /* XBC cleanup data structures */ |
290 | void __init xbc_exit(void); |
291 | |
292 | /* XBC embedded bootconfig data in kernel */ |
293 | #ifdef CONFIG_BOOT_CONFIG_EMBED |
294 | const char * __init xbc_get_embedded_bootconfig(size_t *size); |
295 | #else |
296 | static inline const char *xbc_get_embedded_bootconfig(size_t *size) |
297 | { |
298 | return NULL; |
299 | } |
300 | #endif |
301 | |
302 | #endif |
303 | |