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