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 #include <linux/cmpxchg-emu.h>
  13
  14 #if defined(CONFIG_GUSA_RB)
  15 #include <asm/cmpxchg-grb.h>
  16 #elif defined(CONFIG_CPU_SH4A)
  17 #include <asm/cmpxchg-llsc.h>
  18 #elif defined(CONFIG_CPU_J2) && defined(CONFIG_SMP)
  19 #include <asm/cmpxchg-cas.h>
  20 #else
  21 #include <asm/cmpxchg-irq.h>
  22 #endif
  23
  24 extern void __xchg_called_with_bad_pointer(void);
  25
  26 #define __arch_xchg(ptr, x, size)                               \
  27 ({                                                      \
  28         unsigned long __xchg__res;                      \
  29         volatile void *__xchg_ptr = (ptr);              \
  30         switch (size) {                                 \
  31         case 4:                                         \
  32                 __xchg__res = xchg_u32(__xchg_ptr, x);  \
  33                 break;                                  \
  34         case 2:                                         \
  35                 __xchg__res = xchg_u16(__xchg_ptr, x);  \
  36                 break;                                  \
  37         case 1:                                         \
  38                 __xchg__res = xchg_u8(__xchg_ptr, x);   \
  39                 break;                                  \
  40         default:                                        \
  41                 __xchg_called_with_bad_pointer();       \
  42                 __xchg__res = x;                        \
  43                 break;                                  \
  44         }                                               \
  45                                                         \
  46         __xchg__res;                                    \
  47 })
  48
  49 #define arch_xchg(ptr,x)        \
  50         ((__typeof__(*(ptr)))__arch_xchg((ptr),(unsigned long)(x), sizeof(*(ptr))))
  51
  52 /* This function doesn't exist, so you'll get a linker error
  53  * if something tries to do an invalid cmpxchg(). */
  54 extern void __cmpxchg_called_with_bad_pointer(void);
  55
  56 static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
  57                 unsigned long new, int size)
  58 {
  59         switch (size) {
  60         case 1:
  61                 return cmpxchg_emu_u8(ptr, old, new);
  62         case 4:
  63                 return __cmpxchg_u32(ptr, old, new);
  64         }
  65         __cmpxchg_called_with_bad_pointer();
  66         return old;
  67 }
  68
  69 #define arch_cmpxchg(ptr,o,n)                                            \
  70   ({                                                                     \
  71      __typeof__(*(ptr)) _o_ = (o);                                       \
  72      __typeof__(*(ptr)) _n_ = (n);                                       \
  73      (__typeof__(*(ptr))) __cmpxchg((ptr), (unsigned long)_o_,           \
  74                                     (unsigned long)_n_, sizeof(*(ptr))); \
  75   })
  76
  77 #include <asm-generic/cmpxchg-local.h>
  78
  79 #define arch_cmpxchg_local(ptr, o, n) ({                                \
  80         (__typeof__(*ptr))__generic_cmpxchg_local((ptr),                \
  81                                                   (unsigned long)(o),   \
  82                                                   (unsigned long)(n),   \
  83                                                   sizeof(*(ptr)));      \
  84 })
  85
  86 #endif /* __ASM_SH_CMPXCHG_H */