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Tom Rini83d290c2018-05-06 17:58:06 -04001/* SPDX-License-Identifier: GPL-2.0+ */
Marek Vasut42ebaae2012-10-12 10:27:02 +00002/*
3 * include/linker_lists.h
4 *
5 * Implementation of linker-generated arrays
6 *
7 * Copyright (C) 2012 Marek Vasut <marex@denx.de>
Marek Vasut42ebaae2012-10-12 10:27:02 +00008 */
Albert ARIBAUDef123c52013-02-25 00:59:00 +00009
Masahiro Yamadababb4442014-02-05 10:52:52 +090010#ifndef __LINKER_LISTS_H__
11#define __LINKER_LISTS_H__
12
Masahiro Yamadadc7cb462014-10-07 14:48:22 +090013#include <linux/compiler.h>
14
Albert ARIBAUDef123c52013-02-25 00:59:00 +000015/*
Heinrich Schuchardtd72fd7b2017-09-07 03:55:11 +020016 * There is no use in including this from ASM files.
Albert ARIBAUDef123c52013-02-25 00:59:00 +000017 * So just don't define anything when included from ASM.
18 */
19
20#if !defined(__ASSEMBLY__)
21
22/**
Bin Meng7e378b82015-07-19 00:20:02 +080023 * llsym() - Access a linker-generated array entry
Simon Glass72538f42015-03-25 12:21:49 -060024 * @_type: Data type of the entry
25 * @_name: Name of the entry
26 * @_list: name of the list. Should contain only characters allowed
27 * in a C variable name!
28 */
29#define llsym(_type, _name, _list) \
30 ((_type *)&_u_boot_list_2_##_list##_2_##_name)
31
32/**
Marek Vasut42ebaae2012-10-12 10:27:02 +000033 * ll_entry_declare() - Declare linker-generated array entry
34 * @_type: Data type of the entry
35 * @_name: Name of the entry
Albert ARIBAUDef123c52013-02-25 00:59:00 +000036 * @_list: name of the list. Should contain only characters allowed
37 * in a C variable name!
Marek Vasut42ebaae2012-10-12 10:27:02 +000038 *
39 * This macro declares a variable that is placed into a linker-generated
40 * array. This is a basic building block for more advanced use of linker-
41 * generated arrays. The user is expected to build their own macro wrapper
42 * around this one.
43 *
Albert ARIBAUDef123c52013-02-25 00:59:00 +000044 * A variable declared using this macro must be compile-time initialized.
Marek Vasut42ebaae2012-10-12 10:27:02 +000045 *
46 * Special precaution must be made when using this macro:
Marek Vasut42ebaae2012-10-12 10:27:02 +000047 *
Albert ARIBAUDef123c52013-02-25 00:59:00 +000048 * 1) The _type must not contain the "static" keyword, otherwise the
49 * entry is generated and can be iterated but is listed in the map
50 * file and cannot be retrieved by name.
Marek Vasut42ebaae2012-10-12 10:27:02 +000051 *
Albert ARIBAUDef123c52013-02-25 00:59:00 +000052 * 2) In case a section is declared that contains some array elements AND
53 * a subsection of this section is declared and contains some elements,
54 * it is imperative that the elements are of the same type.
Marek Vasut42ebaae2012-10-12 10:27:02 +000055 *
Mario Six78a88f72018-07-10 08:40:17 +020056 * 3) In case an outer section is declared that contains some array elements
Albert ARIBAUDef123c52013-02-25 00:59:00 +000057 * AND an inner subsection of this section is declared and contains some
Marek Vasut42ebaae2012-10-12 10:27:02 +000058 * elements, then when traversing the outer section, even the elements of
59 * the inner sections are present in the array.
60 *
61 * Example:
Mario Six78a88f72018-07-10 08:40:17 +020062 *
63 * ::
64 *
65 * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
66 * .x = 3,
67 * .y = 4,
68 * };
Marek Vasut42ebaae2012-10-12 10:27:02 +000069 */
Albert ARIBAUDef123c52013-02-25 00:59:00 +000070#define ll_entry_declare(_type, _name, _list) \
71 _type _u_boot_list_2_##_list##_2_##_name __aligned(4) \
72 __attribute__((unused, \
73 section(".u_boot_list_2_"#_list"_2_"#_name)))
74
75/**
Simon Glass3fcc3af2014-10-01 19:57:20 -060076 * ll_entry_declare_list() - Declare a list of link-generated array entries
77 * @_type: Data type of each entry
78 * @_name: Name of the entry
79 * @_list: name of the list. Should contain only characters allowed
80 * in a C variable name!
81 *
82 * This is like ll_entry_declare() but creates multiple entries. It should
83 * be assigned to an array.
84 *
Mario Six78a88f72018-07-10 08:40:17 +020085 * ::
86 *
87 * ll_entry_declare_list(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
88 * { .x = 3, .y = 4 },
89 * { .x = 8, .y = 2 },
90 * { .x = 1, .y = 7 }
91 * };
Simon Glass3fcc3af2014-10-01 19:57:20 -060092 */
93#define ll_entry_declare_list(_type, _name, _list) \
94 _type _u_boot_list_2_##_list##_2_##_name[] __aligned(4) \
95 __attribute__((unused, \
96 section(".u_boot_list_2_"#_list"_2_"#_name)))
97
Mario Six78a88f72018-07-10 08:40:17 +020098/*
Albert ARIBAUDef123c52013-02-25 00:59:00 +000099 * We need a 0-byte-size type for iterator symbols, and the compiler
100 * does not allow defining objects of C type 'void'. Using an empty
101 * struct is allowed by the compiler, but causes gcc versions 4.4 and
102 * below to complain about aliasing. Therefore we use the next best
103 * thing: zero-sized arrays, which are both 0-byte-size and exempt from
104 * aliasing warnings.
105 */
Marek Vasut42ebaae2012-10-12 10:27:02 +0000106
107/**
108 * ll_entry_start() - Point to first entry of linker-generated array
109 * @_type: Data type of the entry
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000110 * @_list: Name of the list in which this entry is placed
Marek Vasut42ebaae2012-10-12 10:27:02 +0000111 *
Mario Six78a88f72018-07-10 08:40:17 +0200112 * This function returns ``(_type *)`` pointer to the very first entry of a
Marek Vasut42ebaae2012-10-12 10:27:02 +0000113 * linker-generated array placed into subsection of .u_boot_list section
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000114 * specified by _list argument.
115 *
116 * Since this macro defines an array start symbol, its leftmost index
117 * must be 2 and its rightmost index must be 1.
Marek Vasut42ebaae2012-10-12 10:27:02 +0000118 *
119 * Example:
Mario Six78a88f72018-07-10 08:40:17 +0200120 *
121 * ::
122 *
123 * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
Marek Vasut42ebaae2012-10-12 10:27:02 +0000124 */
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000125#define ll_entry_start(_type, _list) \
126({ \
Simon Glass0b2fa982020-12-16 21:20:06 -0700127 static char start[0] __aligned(CONFIG_LINKER_LIST_ALIGN) \
128 __attribute__((unused, \
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000129 section(".u_boot_list_2_"#_list"_1"))); \
130 (_type *)&start; \
131})
Marek Vasut42ebaae2012-10-12 10:27:02 +0000132
133/**
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000134 * ll_entry_end() - Point after last entry of linker-generated array
135 * @_type: Data type of the entry
136 * @_list: Name of the list in which this entry is placed
137 * (with underscores instead of dots)
138 *
Mario Six78a88f72018-07-10 08:40:17 +0200139 * This function returns ``(_type *)`` pointer after the very last entry of
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000140 * a linker-generated array placed into subsection of .u_boot_list
141 * section specified by _list argument.
142 *
143 * Since this macro defines an array end symbol, its leftmost index
144 * must be 2 and its rightmost index must be 3.
145 *
146 * Example:
Mario Six78a88f72018-07-10 08:40:17 +0200147 *
148 * ::
149 *
150 * struct my_sub_cmd *msc = ll_entry_end(struct my_sub_cmd, cmd_sub);
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000151 */
152#define ll_entry_end(_type, _list) \
153({ \
Bin Meng7e378b82015-07-19 00:20:02 +0800154 static char end[0] __aligned(4) __attribute__((unused, \
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000155 section(".u_boot_list_2_"#_list"_3"))); \
156 (_type *)&end; \
157})
158/**
Marek Vasut42ebaae2012-10-12 10:27:02 +0000159 * ll_entry_count() - Return the number of elements in linker-generated array
160 * @_type: Data type of the entry
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000161 * @_list: Name of the list of which the number of elements is computed
Marek Vasut42ebaae2012-10-12 10:27:02 +0000162 *
163 * This function returns the number of elements of a linker-generated array
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000164 * placed into subsection of .u_boot_list section specified by _list
Marek Vasut42ebaae2012-10-12 10:27:02 +0000165 * argument. The result is of an unsigned int type.
166 *
167 * Example:
Mario Six78a88f72018-07-10 08:40:17 +0200168 *
169 * ::
170 *
171 * int i;
172 * const unsigned int count = ll_entry_count(struct my_sub_cmd, cmd_sub);
173 * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
174 * for (i = 0; i < count; i++, msc++)
175 * printf("Entry %i, x=%i y=%i\n", i, msc->x, msc->y);
Marek Vasut42ebaae2012-10-12 10:27:02 +0000176 */
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000177#define ll_entry_count(_type, _list) \
Marek Vasut42ebaae2012-10-12 10:27:02 +0000178 ({ \
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000179 _type *start = ll_entry_start(_type, _list); \
180 _type *end = ll_entry_end(_type, _list); \
181 unsigned int _ll_result = end - start; \
Marek Vasut42ebaae2012-10-12 10:27:02 +0000182 _ll_result; \
183 })
184
Marek Vasut42ebaae2012-10-12 10:27:02 +0000185/**
186 * ll_entry_get() - Retrieve entry from linker-generated array by name
187 * @_type: Data type of the entry
188 * @_name: Name of the entry
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000189 * @_list: Name of the list in which this entry is placed
Marek Vasut42ebaae2012-10-12 10:27:02 +0000190 *
Bin Meng7e378b82015-07-19 00:20:02 +0800191 * This function returns a pointer to a particular entry in linker-generated
192 * array identified by the subsection of u_boot_list where the entry resides
Marek Vasut42ebaae2012-10-12 10:27:02 +0000193 * and it's name.
194 *
195 * Example:
Mario Six78a88f72018-07-10 08:40:17 +0200196 *
197 * ::
198 *
199 * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
200 * .x = 3,
201 * .y = 4,
202 * };
203 * ...
204 * struct my_sub_cmd *c = ll_entry_get(struct my_sub_cmd, my_sub_cmd, cmd_sub);
Marek Vasut42ebaae2012-10-12 10:27:02 +0000205 */
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000206#define ll_entry_get(_type, _name, _list) \
Marek Vasut42ebaae2012-10-12 10:27:02 +0000207 ({ \
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000208 extern _type _u_boot_list_2_##_list##_2_##_name; \
209 _type *_ll_result = \
Bin Meng7e378b82015-07-19 00:20:02 +0800210 &_u_boot_list_2_##_list##_2_##_name; \
Marek Vasut42ebaae2012-10-12 10:27:02 +0000211 _ll_result; \
212 })
213
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000214/**
215 * ll_start() - Point to first entry of first linker-generated array
216 * @_type: Data type of the entry
217 *
Mario Six78a88f72018-07-10 08:40:17 +0200218 * This function returns ``(_type *)`` pointer to the very first entry of
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000219 * the very first linker-generated array.
220 *
221 * Since this macro defines the start of the linker-generated arrays,
222 * its leftmost index must be 1.
223 *
224 * Example:
Mario Six78a88f72018-07-10 08:40:17 +0200225 *
226 * ::
227 *
228 * struct my_sub_cmd *msc = ll_start(struct my_sub_cmd);
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000229 */
230#define ll_start(_type) \
231({ \
232 static char start[0] __aligned(4) __attribute__((unused, \
233 section(".u_boot_list_1"))); \
234 (_type *)&start; \
235})
236
237/**
Bin Meng7e378b82015-07-19 00:20:02 +0800238 * ll_end() - Point after last entry of last linker-generated array
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000239 * @_type: Data type of the entry
240 *
Mario Six78a88f72018-07-10 08:40:17 +0200241 * This function returns ``(_type *)`` pointer after the very last entry of
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000242 * the very last linker-generated array.
243 *
244 * Since this macro defines the end of the linker-generated arrays,
245 * its leftmost index must be 3.
246 *
247 * Example:
Mario Six78a88f72018-07-10 08:40:17 +0200248 *
249 * ::
250 *
251 * struct my_sub_cmd *msc = ll_end(struct my_sub_cmd);
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000252 */
253#define ll_end(_type) \
254({ \
Bin Meng7e378b82015-07-19 00:20:02 +0800255 static char end[0] __aligned(4) __attribute__((unused, \
Albert ARIBAUDef123c52013-02-25 00:59:00 +0000256 section(".u_boot_list_3"))); \
257 (_type *)&end; \
258})
259
260#endif /* __ASSEMBLY__ */
261
Marek Vasut42ebaae2012-10-12 10:27:02 +0000262#endif /* __LINKER_LISTS_H__ */