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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 | #include <linux/kernel.h> | |
11 | #include <linux/types.h> | |
12 | ||
85c46b78 MH |
13 | #define BOOTCONFIG_MAGIC "#BOOTCONFIG\n" |
14 | #define BOOTCONFIG_MAGIC_LEN 12 | |
e1cef2d4 MH |
15 | #define BOOTCONFIG_ALIGN_SHIFT 2 |
16 | #define BOOTCONFIG_ALIGN (1 << BOOTCONFIG_ALIGN_SHIFT) | |
17 | #define BOOTCONFIG_ALIGN_MASK (BOOTCONFIG_ALIGN - 1) | |
85c46b78 | 18 | |
99f4f5d6 MH |
19 | /** |
20 | * xbc_calc_checksum() - Calculate checksum of bootconfig | |
21 | * @data: Bootconfig data. | |
22 | * @size: The size of the bootconfig data. | |
23 | * | |
24 | * Calculate the checksum value of the bootconfig data. | |
25 | * The checksum will be used with the BOOTCONFIG_MAGIC and the size for | |
26 | * embedding the bootconfig in the initrd image. | |
27 | */ | |
28 | static inline __init u32 xbc_calc_checksum(void *data, u32 size) | |
29 | { | |
30 | unsigned char *p = data; | |
31 | u32 ret = 0; | |
32 | ||
33 | while (size--) | |
34 | ret += *p++; | |
35 | ||
36 | return ret; | |
37 | } | |
38 | ||
76db5a27 MH |
39 | /* XBC tree node */ |
40 | struct xbc_node { | |
41 | u16 next; | |
42 | u16 child; | |
43 | u16 parent; | |
44 | u16 data; | |
45 | } __attribute__ ((__packed__)); | |
46 | ||
47 | #define XBC_KEY 0 | |
48 | #define XBC_VALUE (1 << 15) | |
49 | /* Maximum size of boot config is 32KB - 1 */ | |
50 | #define XBC_DATA_MAX (XBC_VALUE - 1) | |
51 | ||
52 | #define XBC_NODE_MAX 1024 | |
53 | #define XBC_KEYLEN_MAX 256 | |
54 | #define XBC_DEPTH_MAX 16 | |
55 | ||
56 | /* Node tree access raw APIs */ | |
57 | struct xbc_node * __init xbc_root_node(void); | |
58 | int __init xbc_node_index(struct xbc_node *node); | |
59 | struct xbc_node * __init xbc_node_get_parent(struct xbc_node *node); | |
60 | struct xbc_node * __init xbc_node_get_child(struct xbc_node *node); | |
61 | struct xbc_node * __init xbc_node_get_next(struct xbc_node *node); | |
62 | const char * __init xbc_node_get_data(struct xbc_node *node); | |
63 | ||
64 | /** | |
65 | * xbc_node_is_value() - Test the node is a value node | |
66 | * @node: An XBC node. | |
67 | * | |
68 | * Test the @node is a value node and return true if a value node, false if not. | |
69 | */ | |
70 | static inline __init bool xbc_node_is_value(struct xbc_node *node) | |
71 | { | |
72 | return node->data & XBC_VALUE; | |
73 | } | |
74 | ||
75 | /** | |
76 | * xbc_node_is_key() - Test the node is a key node | |
77 | * @node: An XBC node. | |
78 | * | |
79 | * Test the @node is a key node and return true if a key node, false if not. | |
80 | */ | |
81 | static inline __init bool xbc_node_is_key(struct xbc_node *node) | |
82 | { | |
83 | return !xbc_node_is_value(node); | |
84 | } | |
85 | ||
86 | /** | |
87 | * xbc_node_is_array() - Test the node is an arraied value node | |
88 | * @node: An XBC node. | |
89 | * | |
90 | * Test the @node is an arraied value node. | |
91 | */ | |
92 | static inline __init bool xbc_node_is_array(struct xbc_node *node) | |
93 | { | |
ca24306d | 94 | return xbc_node_is_value(node) && node->child != 0; |
76db5a27 MH |
95 | } |
96 | ||
97 | /** | |
98 | * xbc_node_is_leaf() - Test the node is a leaf key node | |
99 | * @node: An XBC node. | |
100 | * | |
101 | * Test the @node is a leaf key node which is a key node and has a value node | |
102 | * or no child. Returns true if it is a leaf node, or false if not. | |
e5efaeb8 MH |
103 | * Note that the leaf node can have subkey nodes in addition to the |
104 | * value node. | |
76db5a27 MH |
105 | */ |
106 | static inline __init bool xbc_node_is_leaf(struct xbc_node *node) | |
107 | { | |
108 | return xbc_node_is_key(node) && | |
109 | (!node->child || xbc_node_is_value(xbc_node_get_child(node))); | |
110 | } | |
111 | ||
112 | /* Tree-based key-value access APIs */ | |
113 | struct xbc_node * __init xbc_node_find_child(struct xbc_node *parent, | |
114 | const char *key); | |
115 | ||
116 | const char * __init xbc_node_find_value(struct xbc_node *parent, | |
117 | const char *key, | |
118 | struct xbc_node **vnode); | |
119 | ||
120 | struct xbc_node * __init xbc_node_find_next_leaf(struct xbc_node *root, | |
121 | struct xbc_node *leaf); | |
122 | ||
123 | const char * __init xbc_node_find_next_key_value(struct xbc_node *root, | |
124 | struct xbc_node **leaf); | |
125 | ||
126 | /** | |
127 | * xbc_find_value() - Find a value which matches the key | |
128 | * @key: Search key | |
129 | * @vnode: A container pointer of XBC value node. | |
130 | * | |
131 | * Search a value whose key matches @key from whole of XBC tree and return | |
132 | * the value if found. Found value node is stored in *@vnode. | |
133 | * Note that this can return 0-length string and store NULL in *@vnode for | |
134 | * key-only (non-value) entry. | |
135 | */ | |
136 | static inline const char * __init | |
137 | xbc_find_value(const char *key, struct xbc_node **vnode) | |
138 | { | |
139 | return xbc_node_find_value(NULL, key, vnode); | |
140 | } | |
141 | ||
142 | /** | |
143 | * xbc_find_node() - Find a node which matches the key | |
144 | * @key: Search key | |
145 | * | |
146 | * Search a (key) node whose key matches @key from whole of XBC tree and | |
147 | * return the node if found. If not found, returns NULL. | |
148 | */ | |
149 | static inline struct xbc_node * __init xbc_find_node(const char *key) | |
150 | { | |
151 | return xbc_node_find_child(NULL, key); | |
152 | } | |
153 | ||
e5efaeb8 MH |
154 | /** |
155 | * xbc_node_get_subkey() - Return the first subkey node if exists | |
156 | * @node: Parent node | |
157 | * | |
158 | * Return the first subkey node of the @node. If the @node has no child | |
159 | * or only value node, this will return NULL. | |
160 | */ | |
161 | static inline struct xbc_node * __init xbc_node_get_subkey(struct xbc_node *node) | |
162 | { | |
163 | struct xbc_node *child = xbc_node_get_child(node); | |
164 | ||
165 | if (child && xbc_node_is_value(child)) | |
166 | return xbc_node_get_next(child); | |
167 | else | |
168 | return child; | |
169 | } | |
170 | ||
76db5a27 MH |
171 | /** |
172 | * xbc_array_for_each_value() - Iterate value nodes on an array | |
173 | * @anode: An XBC arraied value node | |
174 | * @value: A value | |
175 | * | |
176 | * Iterate array value nodes and values starts from @anode. This is expected to | |
177 | * be used with xbc_find_value() and xbc_node_find_value(), so that user can | |
178 | * process each array entry node. | |
179 | */ | |
180 | #define xbc_array_for_each_value(anode, value) \ | |
181 | for (value = xbc_node_get_data(anode); anode != NULL ; \ | |
ca24306d | 182 | anode = xbc_node_get_child(anode), \ |
76db5a27 MH |
183 | value = anode ? xbc_node_get_data(anode) : NULL) |
184 | ||
185 | /** | |
186 | * xbc_node_for_each_child() - Iterate child nodes | |
187 | * @parent: An XBC node. | |
188 | * @child: Iterated XBC node. | |
189 | * | |
190 | * Iterate child nodes of @parent. Each child nodes are stored to @child. | |
e5efaeb8 | 191 | * The @child can be mixture of a value node and subkey nodes. |
76db5a27 MH |
192 | */ |
193 | #define xbc_node_for_each_child(parent, child) \ | |
194 | for (child = xbc_node_get_child(parent); child != NULL ; \ | |
195 | child = xbc_node_get_next(child)) | |
196 | ||
e5efaeb8 MH |
197 | /** |
198 | * xbc_node_for_each_subkey() - Iterate child subkey nodes | |
199 | * @parent: An XBC node. | |
200 | * @child: Iterated XBC node. | |
201 | * | |
202 | * Iterate subkey nodes of @parent. Each child nodes are stored to @child. | |
203 | * The @child is only the subkey node. | |
204 | */ | |
205 | #define xbc_node_for_each_subkey(parent, child) \ | |
206 | for (child = xbc_node_get_subkey(parent); child != NULL ; \ | |
207 | child = xbc_node_get_next(child)) | |
208 | ||
76db5a27 MH |
209 | /** |
210 | * xbc_node_for_each_array_value() - Iterate array entries of geven key | |
211 | * @node: An XBC node. | |
212 | * @key: A key string searched under @node | |
213 | * @anode: Iterated XBC node of array entry. | |
214 | * @value: Iterated value of array entry. | |
215 | * | |
216 | * Iterate array entries of given @key under @node. Each array entry node | |
c23c8082 | 217 | * is stored to @anode and @value. If the @node doesn't have @key node, |
76db5a27 MH |
218 | * it does nothing. |
219 | * Note that even if the found key node has only one value (not array) | |
c23c8082 | 220 | * this executes block once. However, if the found key node has no value |
76db5a27 MH |
221 | * (key-only node), this does nothing. So don't use this for testing the |
222 | * key-value pair existence. | |
223 | */ | |
224 | #define xbc_node_for_each_array_value(node, key, anode, value) \ | |
225 | for (value = xbc_node_find_value(node, key, &anode); value != NULL; \ | |
ca24306d | 226 | anode = xbc_node_get_child(anode), \ |
76db5a27 MH |
227 | value = anode ? xbc_node_get_data(anode) : NULL) |
228 | ||
229 | /** | |
230 | * xbc_node_for_each_key_value() - Iterate key-value pairs under a node | |
231 | * @node: An XBC node. | |
232 | * @knode: Iterated key node | |
233 | * @value: Iterated value string | |
234 | * | |
235 | * Iterate key-value pairs under @node. Each key node and value string are | |
236 | * stored in @knode and @value respectively. | |
237 | */ | |
238 | #define xbc_node_for_each_key_value(node, knode, value) \ | |
239 | for (knode = NULL, value = xbc_node_find_next_key_value(node, &knode);\ | |
240 | knode != NULL; value = xbc_node_find_next_key_value(node, &knode)) | |
241 | ||
242 | /** | |
243 | * xbc_for_each_key_value() - Iterate key-value pairs | |
244 | * @knode: Iterated key node | |
245 | * @value: Iterated value string | |
246 | * | |
247 | * Iterate key-value pairs in whole XBC tree. Each key node and value string | |
248 | * are stored in @knode and @value respectively. | |
249 | */ | |
250 | #define xbc_for_each_key_value(knode, value) \ | |
251 | xbc_node_for_each_key_value(NULL, knode, value) | |
252 | ||
253 | /* Compose partial key */ | |
254 | int __init xbc_node_compose_key_after(struct xbc_node *root, | |
255 | struct xbc_node *node, char *buf, size_t size); | |
256 | ||
257 | /** | |
258 | * xbc_node_compose_key() - Compose full key string of the XBC node | |
259 | * @node: An XBC node. | |
260 | * @buf: A buffer to store the key. | |
261 | * @size: The size of the @buf. | |
262 | * | |
263 | * Compose the full-length key of the @node into @buf. Returns the total | |
264 | * length of the key stored in @buf. Or returns -EINVAL if @node is NULL, | |
265 | * and -ERANGE if the key depth is deeper than max depth. | |
266 | */ | |
267 | static inline int __init xbc_node_compose_key(struct xbc_node *node, | |
268 | char *buf, size_t size) | |
269 | { | |
270 | return xbc_node_compose_key_after(NULL, node, buf, size); | |
271 | } | |
272 | ||
273 | /* XBC node initializer */ | |
89b74cac MH |
274 | int __init xbc_init(char *buf, const char **emsg, int *epos); |
275 | ||
76db5a27 MH |
276 | |
277 | /* XBC cleanup data structures */ | |
278 | void __init xbc_destroy_all(void); | |
279 | ||
280 | /* Debug dump functions */ | |
281 | void __init xbc_debug_dump(void); | |
282 | ||
283 | #endif |