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
 10extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
 11
 12#ifndef CONFIG_RMW_INSNS
 13static 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
 38static 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
 79extern 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
 89static 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__ */