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 === */
109 /* deprecated, use SYM_DATA*, SYM_ENTRY, or similar */
110 #define GLOBAL(name) \
116 /* deprecated, use SYM_FUNC_START */
117 #define ENTRY(name) \
120 #endif /* LINKER_SCRIPT */
123 /* deprecated, use SYM_FUNC_START_WEAK* */
125 SYM_FUNC_START_WEAK(name)
129 /* deprecated, use SYM_FUNC_END, SYM_DATA_END, or SYM_END */
134 /* If symbol 'name' is treated as a subroutine (gets called, and returns)
135 * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of
136 * static analysis tools such as stack depth analyzer.
139 /* deprecated, use SYM_FUNC_END */
140 #define ENDPROC(name) \
144 /* === generic annotations === */
146 /* SYM_ENTRY -- use only if you have to for non-paired symbols */
148 #define SYM_ENTRY(name, linkage, align...) \
149 linkage(name) ASM_NL \
154 /* SYM_START -- use only if you have to */
156 #define SYM_START(name, linkage, align...) \
157 SYM_ENTRY(name, linkage, align)
160 /* SYM_END -- use only if you have to */
162 #define SYM_END(name, sym_type) \
163 .type name sym_type ASM_NL \
167 /* === code annotations === */
170 * FUNC -- C-like functions (proper stack frame etc.)
171 * CODE -- non-C code (e.g. irq handlers with different, special stack etc.)
173 * Objtool validates stack for FUNC, but not for CODE.
174 * Objtool generates debug info for both FUNC & CODE, but needs special
175 * annotations for each CODE's start (to describe the actual stack frame).
177 * ALIAS -- does not generate debug info -- the aliased function will
180 /* SYM_INNER_LABEL_ALIGN -- only for labels in the middle of code */
181 #ifndef SYM_INNER_LABEL_ALIGN
182 #define SYM_INNER_LABEL_ALIGN(name, linkage) \
183 .type name SYM_T_NONE ASM_NL \
184 SYM_ENTRY(name, linkage, SYM_A_ALIGN)
187 /* SYM_INNER_LABEL -- only for labels in the middle of code */
188 #ifndef SYM_INNER_LABEL
189 #define SYM_INNER_LABEL(name, linkage) \
190 .type name SYM_T_NONE ASM_NL \
191 SYM_ENTRY(name, linkage, SYM_A_NONE)
195 * SYM_FUNC_START_LOCAL_ALIAS -- use where there are two local names for one
198 #ifndef SYM_FUNC_START_LOCAL_ALIAS
199 #define SYM_FUNC_START_LOCAL_ALIAS(name) \
200 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
204 * SYM_FUNC_START_ALIAS -- use where there are two global names for one
207 #ifndef SYM_FUNC_START_ALIAS
208 #define SYM_FUNC_START_ALIAS(name) \
209 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
212 /* SYM_FUNC_START -- use for global functions */
213 #ifndef SYM_FUNC_START
215 * The same as SYM_FUNC_START_ALIAS, but we will need to distinguish these two
218 #define SYM_FUNC_START(name) \
219 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
222 /* SYM_FUNC_START_NOALIGN -- use for global functions, w/o alignment */
223 #ifndef SYM_FUNC_START_NOALIGN
224 #define SYM_FUNC_START_NOALIGN(name) \
225 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
228 /* SYM_FUNC_START_LOCAL -- use for local functions */
229 #ifndef SYM_FUNC_START_LOCAL
230 /* the same as SYM_FUNC_START_LOCAL_ALIAS, see comment near SYM_FUNC_START */
231 #define SYM_FUNC_START_LOCAL(name) \
232 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
235 /* SYM_FUNC_START_LOCAL_NOALIGN -- use for local functions, w/o alignment */
236 #ifndef SYM_FUNC_START_LOCAL_NOALIGN
237 #define SYM_FUNC_START_LOCAL_NOALIGN(name) \
238 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
241 /* SYM_FUNC_START_WEAK -- use for weak functions */
242 #ifndef SYM_FUNC_START_WEAK
243 #define SYM_FUNC_START_WEAK(name) \
244 SYM_START(name, SYM_L_WEAK, SYM_A_ALIGN)
247 /* SYM_FUNC_START_WEAK_NOALIGN -- use for weak functions, w/o alignment */
248 #ifndef SYM_FUNC_START_WEAK_NOALIGN
249 #define SYM_FUNC_START_WEAK_NOALIGN(name) \
250 SYM_START(name, SYM_L_WEAK, SYM_A_NONE)
253 /* SYM_FUNC_END_ALIAS -- the end of LOCAL_ALIASed or ALIASed function */
254 #ifndef SYM_FUNC_END_ALIAS
255 #define SYM_FUNC_END_ALIAS(name) \
256 SYM_END(name, SYM_T_FUNC)
260 * SYM_FUNC_END -- the end of SYM_FUNC_START_LOCAL, SYM_FUNC_START,
261 * SYM_FUNC_START_WEAK, ...
264 /* the same as SYM_FUNC_END_ALIAS, see comment near SYM_FUNC_START */
265 #define SYM_FUNC_END(name) \
266 SYM_END(name, SYM_T_FUNC)
269 /* SYM_CODE_START -- use for non-C (special) functions */
270 #ifndef SYM_CODE_START
271 #define SYM_CODE_START(name) \
272 SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
275 /* SYM_CODE_START_NOALIGN -- use for non-C (special) functions, w/o alignment */
276 #ifndef SYM_CODE_START_NOALIGN
277 #define SYM_CODE_START_NOALIGN(name) \
278 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
281 /* SYM_CODE_START_LOCAL -- use for local non-C (special) functions */
282 #ifndef SYM_CODE_START_LOCAL
283 #define SYM_CODE_START_LOCAL(name) \
284 SYM_START(name, SYM_L_LOCAL, SYM_A_ALIGN)
288 * SYM_CODE_START_LOCAL_NOALIGN -- use for local non-C (special) functions,
291 #ifndef SYM_CODE_START_LOCAL_NOALIGN
292 #define SYM_CODE_START_LOCAL_NOALIGN(name) \
293 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
296 /* SYM_CODE_END -- the end of SYM_CODE_START_LOCAL, SYM_CODE_START, ... */
298 #define SYM_CODE_END(name) \
299 SYM_END(name, SYM_T_NONE)
302 /* === data annotations === */
304 /* SYM_DATA_START -- global data symbol */
305 #ifndef SYM_DATA_START
306 #define SYM_DATA_START(name) \
307 SYM_START(name, SYM_L_GLOBAL, SYM_A_NONE)
310 /* SYM_DATA_START -- local data symbol */
311 #ifndef SYM_DATA_START_LOCAL
312 #define SYM_DATA_START_LOCAL(name) \
313 SYM_START(name, SYM_L_LOCAL, SYM_A_NONE)
316 /* SYM_DATA_END -- the end of SYM_DATA_START symbol */
318 #define SYM_DATA_END(name) \
319 SYM_END(name, SYM_T_OBJECT)
322 /* SYM_DATA_END_LABEL -- the labeled end of SYM_DATA_START symbol */
323 #ifndef SYM_DATA_END_LABEL
324 #define SYM_DATA_END_LABEL(name, linkage, label) \
325 linkage(label) ASM_NL \
326 .type label SYM_T_OBJECT ASM_NL \
328 SYM_END(name, SYM_T_OBJECT)
331 /* SYM_DATA -- start+end wrapper around simple global data */
333 #define SYM_DATA(name, data...) \
334 SYM_DATA_START(name) ASM_NL \
339 /* SYM_DATA_LOCAL -- start+end wrapper around simple local data */
340 #ifndef SYM_DATA_LOCAL
341 #define SYM_DATA_LOCAL(name, data...) \
342 SYM_DATA_START_LOCAL(name) ASM_NL \
347 #endif /* __ASSEMBLY__ */
349 #endif /* _LINUX_LINKAGE_H */