1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_LINKAGE_H
3 #define _LINUX_LINKAGE_H
5 #include <linux/compiler_types.h>
6 #include <linux/stringify.h>
7 #include <linux/export.h>
8 #include <asm/linkage.h>
10 /* Some toolchains use other characters (e.g. '`') to mark new line in macro */
16 #define CPP_ASMLINKAGE extern "C"
18 #define CPP_ASMLINKAGE
22 #define asmlinkage CPP_ASMLINKAGE
26 #define cond_syscall(x) asm( \
27 ".weak " __stringify(x) "\n\t" \
28 ".set " __stringify(x) "," \
29 __stringify(sys_ni_syscall))
33 #define SYSCALL_ALIAS(alias, name) asm( \
34 ".globl " __stringify(alias) "\n\t" \
35 ".set " __stringify(alias) "," \
39 #define __page_aligned_data __section(".data..page_aligned") __aligned(PAGE_SIZE)
40 #define __page_aligned_bss __section(".bss..page_aligned") __aligned(PAGE_SIZE)
43 * For assembly routines.
45 * Note when using these that you must specify the appropriate
46 * alignment directives yourself
48 #define __PAGE_ALIGNED_DATA .section ".data..page_aligned", "aw"
49 #define __PAGE_ALIGNED_BSS .section ".bss..page_aligned", "aw"
52 * This is used by architectures to keep arguments on the stack
53 * untouched by the compiler by keeping them live until the end.
54 * The argument stack may be owned by the assembly-language
55 * caller, not the callee, and gcc doesn't always understand
58 * We have the return value, and a maximum of six arguments.
60 * This should always be followed by a "return ret" for the
61 * protection to work (ie no more work that the compiler might
62 * end up needing stack temporaries for).
64 /* Assembly files may be compiled with -traditional .. */
66 #ifndef asmlinkage_protect
67 # define asmlinkage_protect(n, ret, args...) do { } while (0)
72 #define __ALIGN .align 4,0x90
73 #define __ALIGN_STR ".align 4,0x90"
78 /* SYM_T_FUNC -- type used by assembler to mark functions */
80 #define SYM_T_FUNC STT_FUNC
83 /* SYM_T_OBJECT -- type used by assembler to mark data */
85 #define SYM_T_OBJECT STT_OBJECT
88 /* SYM_T_NONE -- type used by assembler to mark entries of unknown type */
90 #define SYM_T_NONE STT_NOTYPE
93 /* SYM_A_* -- align the symbol? */
94 #define SYM_A_ALIGN ALIGN
95 #define SYM_A_NONE /* nothing */
97 /* SYM_L_* -- linkage of symbols */
98 #define SYM_L_GLOBAL(name) .globl name
99 #define SYM_L_WEAK(name) .weak name
100 #define SYM_L_LOCAL(name) /* nothing */
102 #ifndef LINKER_SCRIPT
103 #define ALIGN __ALIGN
104 #define ALIGN_STR __ALIGN_STR
106 /* === DEPRECATED annotations === */
108 #ifndef CONFIG_ARCH_USE_SYM_ANNOTATIONS
110 /* deprecated, use SYM_DATA*, SYM_ENTRY, or similar */
111 #define GLOBAL(name) \
117 /* deprecated, use SYM_FUNC_START */
118 #define ENTRY(name) \
121 #endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */
122 #endif /* LINKER_SCRIPT */
124 #ifndef CONFIG_ARCH_USE_SYM_ANNOTATIONS
126 /* deprecated, use SYM_FUNC_START_WEAK* */
128 SYM_FUNC_START_WEAK(name)
132 /* deprecated, use SYM_FUNC_END, SYM_DATA_END, or SYM_END */
137 /* If symbol 'name' is treated as a subroutine (gets called, and returns)
138 * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of
139 * static analysis tools such as stack depth analyzer.
142 /* deprecated, use SYM_FUNC_END */
143 #define ENDPROC(name) \
146 #endif /* CONFIG_ARCH_USE_SYM_ANNOTATIONS */
148 /* === generic annotations === */
150 /* SYM_ENTRY -- use only if you have to for non-paired symbols */
152 #define SYM_ENTRY(name, linkage, align...) \
153 linkage(name) ASM_NL \
158 /* SYM_START -- use only if you have to */
160 #define SYM_START(name, linkage, align...) \
161 SYM_ENTRY(name, linkage, align)
164 /* SYM_END -- use only if you have to */
166 #define SYM_END(name, sym_type) \
167 .type name sym_type ASM_NL \
171 /* === code annotations === */
174 * FUNC -- C-like functions (proper stack frame etc.)
175 * CODE -- non-C code (e.g. irq handlers with different, special stack etc.)
177 * Objtool validates stack for FUNC, but not for CODE.
178 * Objtool generates debug info for both FUNC & CODE, but needs special
179 * annotations for each CODE's start (to describe the actual stack frame).
181 * Objtool requires that all code must be contained in an ELF symbol. Symbol
182 * names that have a .L prefix do not emit symbol table entries. .L
183 * prefixed symbols can be used within a code region, but should be avoided for
184 * denoting a range of code via ``SYM_*_START/END`` annotations.
186 * ALIAS -- does not generate debug info -- the aliased function will
189 /* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */
190 #ifndef SYM_INNER_LABEL_ALIGN
191 #define SYM_INNER_LABEL_ALIGN(name, linkage) \
192 .type name SYM_T_NONE ASM_NL \
193 SYM_ENTRY(name, linkage, SYM_A_ALIGN)
196 /* SYM_INNER_LABEL -- only for labels in the middle of code */
197 #ifndef SYM_INNER_LABEL
198 #define SYM_INNER_LABEL(name, linkage) \
199 .type name SYM_T_NONE ASM_NL \
200 SYM_ENTRY(name, linkage, SYM_A_NONE)
204 * SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for one
207 #ifndef SYM_FUNC_START_LOCAL_ALIAS
208 #define SYM_FUNC_START_LOCAL_ALIAS(name) \
209 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
213 * SYM_FUNC_START_ALIAS -- use where there are two global names for one
216 #ifndef SYM_FUNC_START_ALIAS
217 #define SYM_FUNC_START_ALIAS(name) \
218 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
221 /* SYM_FUNC_START -- use for global functions */
222 #ifndef SYM_FUNC_START
224 * The same as SYM_FUNC_START_ALIAS, but we will need to distinguish these two
227 #define SYM_FUNC_START(name) \
228 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
231 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */
232 #ifndef SYM_FUNC_START_NOALIGN
233 #define SYM_FUNC_START_NOALIGN(name) \
234 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
237 /* SYM_FUNC_START_LOCAL -- use for local functions */
238 #ifndef SYM_FUNC_START_LOCAL
239 /* the same as SYM_FUNC_START_LOCAL_ALIAS, see comment near SYM_FUNC_START */
240 #define SYM_FUNC_START_LOCAL(name) \
241 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
244 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */
245 #ifndef SYM_FUNC_START_LOCAL_NOALIGN
246 #define SYM_FUNC_START_LOCAL_NOALIGN(name) \
247 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
250 /* SYM_FUNC_START_WEAK -- use for weak functions */
251 #ifndef SYM_FUNC_START_WEAK
252 #define SYM_FUNC_START_WEAK(name) \
253 SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN)
256 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */
257 #ifndef SYM_FUNC_START_WEAK_NOALIGN
258 #define SYM_FUNC_START_WEAK_NOALIGN(name) \
259 SYM_START(name, SYM_L_WEAK, SYM_A_NONE)
262 /* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */
263 #ifndef SYM_FUNC_END_ALIAS
264 #define SYM_FUNC_END_ALIAS(name) \
265 SYM_END(name, SYM_T_FUNC)
269 * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START,
270 * SYM_FUNC_START_WEAK, ...
273 /* the same as SYM_FUNC_END_ALIAS, see comment near SYM_FUNC_START */
274 #define SYM_FUNC_END(name) \
275 SYM_END(name, SYM_T_FUNC)
278 /* SYM_CODE_START -- use for non-C (special) functions */
279 #ifndef SYM_CODE_START
280 #define SYM_CODE_START(name) \
281 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
284 /* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */
285 #ifndef SYM_CODE_START_NOALIGN
286 #define SYM_CODE_START_NOALIGN(name) \
287 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
290 /* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */
291 #ifndef SYM_CODE_START_LOCAL
292 #define SYM_CODE_START_LOCAL(name) \
293 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
297 * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions,
300 #ifndef SYM_CODE_START_LOCAL_NOALIGN
301 #define SYM_CODE_START_LOCAL_NOALIGN(name) \
302 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
305 /* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */
307 #define SYM_CODE_END(name) \
308 SYM_END(name, SYM_T_NONE)
311 /* === data annotations === */
313 /* SYM_DATA_START -- global data symbol */
314 #ifndef SYM_DATA_START
315 #define SYM_DATA_START(name) \
316 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
319 /* SYM_DATA_START -- local data symbol */
320 #ifndef SYM_DATA_START_LOCAL
321 #define SYM_DATA_START_LOCAL(name) \
322 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
325 /* SYM_DATA_END -- the end of SYM_DATA_START symbol */
327 #define SYM_DATA_END(name) \
328 SYM_END(name, SYM_T_OBJECT)
331 /* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */
332 #ifndef SYM_DATA_END_LABEL
333 #define SYM_DATA_END_LABEL(name, linkage, label) \
334 linkage(label) ASM_NL \
335 .type label SYM_T_OBJECT ASM_NL \
337 SYM_END(name, SYM_T_OBJECT)
340 /* SYM_DATA -- start+end wrapper around simple global data */
342 #define SYM_DATA(name, data...) \
343 SYM_DATA_START(name) ASM_NL \
348 /* SYM_DATA_LOCAL -- start+end wrapper around simple local data */
349 #ifndef SYM_DATA_LOCAL
350 #define SYM_DATA_LOCAL(name, data...) \
351 SYM_DATA_START_LOCAL(name) ASM_NL \
356 #endif /* __ASSEMBLY__ */
358 #endif /* _LINUX_LINKAGE_H */