arch/m68k/include/asm/cmpxchg.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __ARCH_M68K_CMPXCHG__
   3 #define __ARCH_M68K_CMPXCHG__
   4
   5 #include <linux/irqflags.h>
   6 #include <linux/minmax.h>
   7
   8 #define __xg(type, x) ((volatile type *)(x))
   9
  10 extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
  11
  12 #ifndef CONFIG_RMW_INSNS
  13 static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
  14 {
  15         unsigned long flags;
  16
  17         local_irq_save(flags);
  18
  19         switch (size) {
  20         case 1:
  21                 swap(*(u8 *)ptr, x);
  22                 break;
  23         case 2:
  24                 swap(*(u16 *)ptr, x);
  25                 break;
  26         case 4:
  27                 swap(*(u32 *)ptr, x);
  28                 break;
  29         default:
  30                 x = __invalid_xchg_size(x, ptr, size);
  31                 break;
  32         }
  33
  34         local_irq_restore(flags);
  35         return x;
  36 }
  37 #else
  38 static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
  39 {
  40         switch (size) {
  41         case 1:
  42                 __asm__ __volatile__
  43                         ("moveb %2,%0\n\t"
  44                          "1:\n\t"
  45                          "casb %0,%1,%2\n\t"
  46                          "jne 1b"
  47                          : "=&d" (x) : "d" (x), "m" (*__xg(u8, ptr)) : "memory");
  48                 break;
  49         case 2:
  50                 __asm__ __volatile__
  51                         ("movew %2,%0\n\t"
  52                          "1:\n\t"
  53                          "casw %0,%1,%2\n\t"
  54                          "jne 1b"
  55                          : "=&d" (x) : "d" (x), "m" (*__xg(u16, ptr)) : "memory");
  56                 break;
  57         case 4:
  58                 __asm__ __volatile__
  59                         ("movel %2,%0\n\t"
  60                          "1:\n\t"
  61                          "casl %0,%1,%2\n\t"
  62                          "jne 1b"
  63                          : "=&d" (x) : "d" (x), "m" (*__xg(u32, ptr)) : "memory");
  64                 break;
  65         default:
  66                 x = __invalid_xchg_size(x, ptr, size);
  67                 break;
  68         }
  69         return x;
  70 }
  71 #endif
  72
  73 #define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})
  74
  75 #include <asm-generic/cmpxchg-local.h>
  76
  77 #define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))
  78
  79 extern unsigned long __invalid_cmpxchg_size(volatile void *,
  80                                             unsigned long, unsigned long, int);
  81
  82 /*
  83  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
  84  * store NEW in MEM.  Return the initial value in MEM.  Success is
  85  * indicated by comparing RETURN with OLD.
  86  */
  87 #ifdef CONFIG_RMW_INSNS
  88
  89 static inline unsigned long __cmpxchg(volatile void *p, unsigned long old,
  90                                       unsigned long new, int size)
  91 {
  92         switch (size) {
  93         case 1:
  94                 __asm__ __volatile__ ("casb %0,%2,%1"
  95                                       : "=d" (old), "=m" (*(char *)p)
  96                                       : "d" (new), "0" (old), "m" (*(char *)p));
  97                 break;
  98         case 2:
  99                 __asm__ __volatile__ ("casw %0,%2,%1"
 100                                       : "=d" (old), "=m" (*(short *)p)
 101                                       : "d" (new), "0" (old), "m" (*(short *)p));
 102                 break;
 103         case 4:
 104                 __asm__ __volatile__ ("casl %0,%2,%1"
 105                                       : "=d" (old), "=m" (*(int *)p)
 106                                       : "d" (new), "0" (old), "m" (*(int *)p));
 107                 break;
 108         default:
 109                 old = __invalid_cmpxchg_size(p, old, new, size);
 110                 break;
 111         }
 112         return old;
 113 }
 114
 115 #define arch_cmpxchg(ptr, o, n)                                             \
 116         ({(__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),          \
 117                         (unsigned long)(n), sizeof(*(ptr)));})
 118 #define arch_cmpxchg_local(ptr, o, n)                                       \
 119         ({(__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),          \
 120                         (unsigned long)(n), sizeof(*(ptr)));})
 121
 122 #define arch_cmpxchg64(ptr, o, n)       arch_cmpxchg64_local((ptr), (o), (n))
 123
 124 #else
 125
 126 #include <asm-generic/cmpxchg.h>
 127
 128 #endif
 129
 130 #endif /* __ARCH_M68K_CMPXCHG__ */