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 /* Some toolchains use other characters (e.g. '`') to mark new line in macro */
  10 #ifndef ASM_NL
  11 #define ASM_NL           ;
  12 #endif
  13
  14 #ifdef __cplusplus
  15 #define CPP_ASMLINKAGE extern "C"
  16 #else
  17 #define CPP_ASMLINKAGE
  18 #endif
  19
  20 #ifndef asmlinkage
  21 #define asmlinkage CPP_ASMLINKAGE
  22 #endif
  23
  24 #ifndef cond_syscall
  25 #define cond_syscall(x) asm(                            \
  26         ".weak " VMLINUX_SYMBOL_STR(x) "\n\t"           \
  27         ".set  " VMLINUX_SYMBOL_STR(x) ","              \
  28                  VMLINUX_SYMBOL_STR(sys_ni_syscall))
  29 #endif
  30
  31 #ifndef SYSCALL_ALIAS
  32 #define SYSCALL_ALIAS(alias, name) asm(                 \
  33         ".globl " VMLINUX_SYMBOL_STR(alias) "\n\t"      \
  34         ".set   " VMLINUX_SYMBOL_STR(alias) ","         \
  35                   VMLINUX_SYMBOL_STR(name))
  36 #endif
  37
  38 #define __page_aligned_data     __section(.data..page_aligned) __aligned(PAGE_SIZE)
  39 #define __page_aligned_bss      __section(.bss..page_aligned) __aligned(PAGE_SIZE)
  40
  41 /*
  42  * For assembly routines.
  43  *
  44  * Note when using these that you must specify the appropriate
  45  * alignment directives yourself
  46  */
  47 #define __PAGE_ALIGNED_DATA     .section ".data..page_aligned", "aw"
  48 #define __PAGE_ALIGNED_BSS      .section ".bss..page_aligned", "aw"
  49
  50 /*
  51  * This is used by architectures to keep arguments on the stack
  52  * untouched by the compiler by keeping them live until the end.
  53  * The argument stack may be owned by the assembly-language
  54  * caller, not the callee, and gcc doesn't always understand
  55  * that.
  56  *
  57  * We have the return value, and a maximum of six arguments.
  58  *
  59  * This should always be followed by a "return ret" for the
  60  * protection to work (ie no more work that the compiler might
  61  * end up needing stack temporaries for).
  62  */
  63 /* Assembly files may be compiled with -traditional .. */
  64 #ifndef __ASSEMBLY__
  65 #ifndef asmlinkage_protect
  66 # define asmlinkage_protect(n, ret, args...)    do { } while (0)
  67 #endif
  68 #endif
  69
  70 #ifndef __ALIGN
  71 #define __ALIGN         .align 4,0x90
  72 #define __ALIGN_STR     ".align 4,0x90"
  73 #endif
  74
  75 #ifdef __ASSEMBLY__
  76
  77 #ifndef LINKER_SCRIPT
  78 #define ALIGN __ALIGN
  79 #define ALIGN_STR __ALIGN_STR
  80
  81 #ifndef ENTRY
  82 #define ENTRY(name) \
  83         .globl name ASM_NL \
  84         ALIGN ASM_NL \
  85         name:
  86 #endif
  87 #endif /* LINKER_SCRIPT */
  88
  89 #ifndef WEAK
  90 #define WEAK(name)         \
  91         .weak name ASM_NL   \
  92         name:
  93 #endif
  94
  95 #ifndef END
  96 #define END(name) \
  97         .size name, .-name
  98 #endif
  99
 100 /* If symbol 'name' is treated as a subroutine (gets called, and returns)
 101  * then please use ENDPROC to mark 'name' as STT_FUNC for the benefit of
 102  * static analysis tools such as stack depth analyzer.
 103  */
 104 #ifndef ENDPROC
 105 #define ENDPROC(name) \
 106         .type name, @function ASM_NL \
 107         END(name)
 108 #endif
 109
 110 #endif
 111
 112 #endif