LXR linux/arch/sh/include/asm/cmpxchg.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __ASM_SH_CMPXCHG_H
   3#define __ASM_SH_CMPXCHG_H
   4
   5/*
   6 * Atomic operations that C can't guarantee us.  Useful for
   7 * resource counting etc..
   8 */
   9
  10#include <linux/compiler.h>
  11#include <linux/types.h>
  12
  13#if defined(CONFIG_GUSA_RB)
  14#include <asm/cmpxchg-grb.h>
  15#elif defined(CONFIG_CPU_SH4A)
  16#include <asm/cmpxchg-llsc.h>
  17#elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
  18#include <asm/cmpxchg-cas.h>
  19#else
  20#include <asm/cmpxchg-irq.h>
  21#endif
  22
  23extern void __xchg_called_with_bad_pointer(void);
  24
  25#define __xchg(ptr, x, size)                            \
  26({                                                      \
  27        unsigned long __xchg__res;                      \
  28        volatile void *__xchg_ptr = (ptr);              \
  29        switch (size) {                                 \
  30        case 4:                                         \
  31                __xchg__res = xchg_u32(__xchg_ptr, x);  \
  32                break;                                  \
  33        case 2:                                         \
  34                __xchg__res = xchg_u16(__xchg_ptr, x);  \
  35                break;                                  \
  36        case 1:                                         \
  37                __xchg__res = xchg_u8(__xchg_ptr, x);   \
  38                break;                                  \
  39        default:                                        \
  40                __xchg_called_with_bad_pointer();       \
  41                __xchg__res = x;                        \
  42                break;                                  \
  43        }                                               \
  44                                                        \
  45        __xchg__res;                                    \
  46})
  47
  48#define xchg(ptr,x)     \
  49        ((__typeof__(*(ptr)))__xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
  50
  51/* This function doesn't exist, so you'll get a linker error
  52 * if something tries to do an invalid cmpxchg(). */
  53extern void __cmpxchg_called_with_bad_pointer(void);
  54
  55static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
  56                unsigned long new, int size)
  57{
  58        switch (size) {
  59        case 4:
  60                return __cmpxchg_u32(ptr, old, new);
  61        }
  62        __cmpxchg_called_with_bad_pointer();
  63        return old;
  64}
  65
  66#define cmpxchg(ptr,o,n)                                                 \
  67  ({                                                                     \
  68     __typeof__(*(ptr)) _o_ = (o);                                       \
  69     __typeof__(*(ptr)) _n_ = (n);                                       \
  70     (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
  71                                    (unsigned long)_n_, sizeof(*(ptr))); \
  72  })
  73
  74#endif /* __ASM_SH_CMPXCHG_H */
  75