Blame view

kernel/linux-rt-4.4.41/tools/arch/sh/include/asm/barrier.h 1 KB
5113f6f70   김현기   kernel add
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
  /*
   * Copied from the kernel sources:
   *
   * Copyright (C) 1999, 2000  Niibe Yutaka  &  Kaz Kojima
   * Copyright (C) 2002 Paul Mundt
   */
  #ifndef __TOOLS_LINUX_ASM_SH_BARRIER_H
  #define __TOOLS_LINUX_ASM_SH_BARRIER_H
  
  /*
   * A brief note on ctrl_barrier(), the control register write barrier.
   *
   * Legacy SH cores typically require a sequence of 8 nops after
   * modification of a control register in order for the changes to take
   * effect. On newer cores (like the sh4a and sh5) this is accomplished
   * with icbi.
   *
   * Also note that on sh4a in the icbi case we can forego a synco for the
   * write barrier, as it's not necessary for control registers.
   *
   * Historically we have only done this type of barrier for the MMUCR, but
   * it's also necessary for the CCR, so we make it generic here instead.
   */
  #if defined(__SH4A__) || defined(__SH5__)
  #define mb()		__asm__ __volatile__ ("synco": : :"memory")
  #define rmb()		mb()
  #define wmb()		mb()
  #endif
  
  #include <asm-generic/barrier.h>
  
  #endif /* __TOOLS_LINUX_ASM_SH_BARRIER_H */