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76db5a27 MH |
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 | ||
4ee1b4ca | 10 | #ifdef __KERNEL__ |
76db5a27 MH |
11 | #include <linux/kernel.h> |
12 | #include <linux/types.h> | |
4ee1b4ca MH |
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 | |
76db5a27 | 22 | |
85c46b78 MH |
23 | #define BOOTCONFIG_MAGIC "#BOOTCONFIG\n" |
24 | #define BOOTCONFIG_MAGIC_LEN 12 | |
e1cef2d4 MH |
25 | #define BOOTCONFIG_ALIGN_SHIFT 2 |
26 | #define BOOTCONFIG_ALIGN (1 << BOOTCONFIG_ALIGN_SHIFT) | |
27 | #define BOOTCONFIG_ALIGN_MASK (BOOTCONFIG_ALIGN - 1) | |
85c46b78 | 28 | |
99f4f5d6 MH |
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 | */ | |
4f292c48 | 38 | static inline __init uint32_t xbc_calc_checksum(void *data, uint32_t size) |
99f4f5d6 MH |
39 | { |
40 | unsigned char *p = data; | |
4f292c48 | 41 | uint32_t ret = 0; |
99f4f5d6 MH |
42 | |
43 | while (size--) | |
44 | ret += *p++; | |
45 | ||
46 | return ret; | |
47 | } | |
48 | ||
76db5a27 MH |
49 | /* XBC tree node */ |
50 | struct xbc_node { | |
4f292c48 MH |
51 | uint16_t next; |
52 | uint16_t child; | |
53 | uint16_t parent; | |
54 | uint16_t data; | |
76db5a27 MH |
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 | ||
6c406249 | 62 | #define XBC_NODE_MAX 8192 |
76db5a27 MH |
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 | { | |
ca24306d | 104 | return xbc_node_is_value(node) && node->child != 0; |
76db5a27 MH |
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. | |
e5efaeb8 MH |
113 | * Note that the leaf node can have subkey nodes in addition to the |
114 | * value node. | |
76db5a27 MH |
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(xbc_node_get_child(node))); | |
120 | } | |
121 | ||
122 | /* Tree-based key-value access APIs */ | |
5dfe50b0 | 123 | struct xbc_node * __init xbc_node_find_subkey(struct xbc_node *parent, |
76db5a27 MH |
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 | { | |
5dfe50b0 | 161 | return xbc_node_find_subkey(NULL, key); |
76db5a27 MH |
162 | } |
163 | ||
e5efaeb8 MH |
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(child)) | |
176 | return xbc_node_get_next(child); | |
177 | else | |
178 | return child; | |
179 | } | |
180 | ||
76db5a27 MH |
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 ; \ | |
ca24306d | 192 | anode = xbc_node_get_child(anode), \ |
76db5a27 MH |
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. | |
e5efaeb8 | 201 | * The @child can be mixture of a value node and subkey nodes. |
76db5a27 MH |
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 | ||
e5efaeb8 MH |
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 | ||
76db5a27 MH |
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 | |
c23c8082 | 227 | * is stored to @anode and @value. If the @node doesn't have @key node, |
76db5a27 MH |
228 | * it does nothing. |
229 | * Note that even if the found key node has only one value (not array) | |
c23c8082 | 230 | * this executes block once. However, if the found key node has no value |
76db5a27 MH |
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; \ | |
ca24306d | 236 | anode = xbc_node_get_child(anode), \ |
76db5a27 MH |
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 */ | |
bdac5c2b | 284 | int __init xbc_init(const char *buf, size_t size, const char **emsg, int *epos); |
89b74cac | 285 | |
e306220c MH |
286 | /* XBC node and size information */ |
287 | int __init xbc_get_info(int *node_size, size_t *data_size); | |
76db5a27 MH |
288 | |
289 | /* XBC cleanup data structures */ | |
115d4d08 | 290 | void __init xbc_exit(void); |
76db5a27 | 291 | |
a2a9d67a MH |
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 | ||
76db5a27 | 302 | #endif |