LXR linux/include/linux/linkage.h

   1#ifndef _LINUX_LINKAGE_H
   2#define _LINUX_LINKAGE_H
   3
   4#include <linux/compiler.h>
   5#include <linux/stringify.h>
   6#include <linux/export.h>
   7#include <asm/linkage.h>
   8
   9#ifdef __cplusplus
  10#define CPP_ASMLINKAGE extern "C"
  11#else
  12#define CPP_ASMLINKAGE
  13#endif
  14
  15#ifndef asmlinkage
  16#define asmlinkage CPP_ASMLINKAGE
  17#endif
  18
  19#ifndef cond_syscall
  20#define cond_syscall(x) asm(                            \
  21        ".weak " VMLINUX_SYMBOL_STR(x) "\n\t"           \
  22        ".set  " VMLINUX_SYMBOL_STR(x) ","              \
  23                 VMLINUX_SYMBOL_STR(sys_ni_syscall))
  24#endif
  25
  26#ifndef SYSCALL_ALIAS
  27#define SYSCALL_ALIAS(alias, name) asm(                 \
  28        ".globl " VMLINUX_SYMBOL_STR(alias) "\n\t"      \
  29        ".set   " VMLINUX_SYMBOL_STR(alias) ","         \
  30                  VMLINUX_SYMBOL_STR(name))
  31#endif
  32
  33#define __page_aligned_data     __section(.data..page_aligned) __aligned(PAGE_SIZE)
  34#define __page_aligned_bss      __section(.bss..page_aligned) __aligned(PAGE_SIZE)
  35
  36/*
  37 * For assembly routines.
  38 *
  39 * Note when using these that you must specify the appropriate
  40 * alignment directives yourself
  41 */
  42#define __PAGE_ALIGNED_DATA     .section ".data..page_aligned", "aw"
  43#define __PAGE_ALIGNED_BSS      .section ".bss..page_aligned", "aw"
  44
  45/*
  46 * This is used by architectures to keep arguments on the stack
  47 * untouched by the compiler by keeping them live until the end.
  48 * The argument stack may be owned by the assembly-language
  49 * caller, not the callee, and gcc doesn't always understand
  50 * that.
  51 *
  52 * We have the return value, and a maximum of six arguments.
  53 *
  54 * This should always be followed by a "return ret" for the
  55 * protection to work (ie no more work that the compiler might
  56 * end up needing stack temporaries for).
  57 */
  58/* Assembly files may be compiled with -traditional .. */
  59#ifndef __ASSEMBLY__
  60#ifndef asmlinkage_protect
  61# define asmlinkage_protect(n, ret, args...)    do { } while (0)
  62#endif
  63#endif
  64
  65#ifndef __ALIGN
  66#define __ALIGN         .align 4,0x90
  67#define __ALIGN_STR     ".align 4,0x90"
  68#endif
  69
  70#ifdef __ASSEMBLY__
  71
  72#ifndef LINKER_SCRIPT
  73#define ALIGN __ALIGN
  74#define ALIGN_STR __ALIGN_STR
  75
  76#ifndef ENTRY
  77#define ENTRY(name) \
  78  .globl name; \
  79  ALIGN; \
  80  name:
  81#endif
  82#endif /* LINKER_SCRIPT */
  83
  84#ifndef WEAK
  85#define WEAK(name)         \
  86        .weak name;        \
  87        name:
  88#endif
  89
  90#ifndef END
  91#define END(name) \
  92  .size name, .-name
  93#endif
  94
  95/* If symbol 'name' is treated as a subroutine (gets called, and returns)
  96 * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of
  97 * static analysis tools such as stack depth analyzer.
  98 */
  99#ifndef ENDPROC
 100#define ENDPROC(name) \
 101  .type name, @function; \
 102  END(name)
 103#endif
 104
 105#endif
 106
 107#endif
 108