/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ARCH_M68K_CMPXCHG__
#define __ARCH_M68K_CMPXCHG__

#include <linux/irqflags.h>
#include <linux/minmax.h>

#define __xg(type, x) ((volatile type *)(x))

extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);

#ifndef CONFIG_RMW_INSNS
static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
{
        unsigned long flags;

        local_irq_save(flags);

        switch (size) {
        case 1:
                swap(*(u8 *)ptr, x);
                break;
        case 2:
                swap(*(u16 *)ptr, x);
                break;
        case 4:
                swap(*(u32 *)ptr, x);
                break;
        default:
                x = __invalid_xchg_size(x, ptr, size);
                break;
        }

        local_irq_restore(flags);
        return x;
}
#else
static inline unsigned long __arch_xchg(unsigned long x, volatile void * ptr, int size)
{
        switch (size) {
        case 1:
                __asm__ __volatile__
                        ("moveb %2,%0\n\t"
                         "1:\n\t"
                         "casb %0,%1,%2\n\t"
                         "jne 1b"
                         : "=&d" (x) : "d" (x), "m" (*__xg(u8, ptr)) : "memory");
                break;
        case 2:
                __asm__ __volatile__
                        ("movew %2,%0\n\t"
                         "1:\n\t"
                         "casw %0,%1,%2\n\t"
                         "jne 1b"
                         : "=&d" (x) : "d" (x), "m" (*__xg(u16, ptr)) : "memory");
                break;
        case 4:
                __asm__ __volatile__
                        ("movel %2,%0\n\t"
                         "1:\n\t"
                         "casl %0,%1,%2\n\t"
                         "jne 1b"
                         : "=&d" (x) : "d" (x), "m" (*__xg(u32, ptr)) : "memory");
                break;
        default:
                x = __invalid_xchg_size(x, ptr, size);
                break;
        }
        return x;
}
#endif

#define arch_xchg(ptr,x) ({(__typeof__(*(ptr)))__arch_xchg((unsigned long)(x),(ptr),sizeof(*(ptr)));})

#include <asm-generic/cmpxchg-local.h>

#define arch_cmpxchg64_local(ptr, o, n) __generic_cmpxchg64_local((ptr), (o), (n))

extern unsigned long __invalid_cmpxchg_size(volatile void *,
                                            unsigned long, unsigned long, int);

/*
 * Atomic compare and exchange.  Compare OLD with MEM, if identical,
 * store NEW in MEM.  Return the initial value in MEM.  Success is
 * indicated by comparing RETURN with OLD.
 */
#ifdef CONFIG_RMW_INSNS

static inline unsigned long __cmpxchg(volatile void *p, unsigned long old,
                                      unsigned long new, int size)
{
        switch (size) {
        case 1:
                __asm__ __volatile__ ("casb %0,%2,%1"
                                      : "=d" (old), "=m" (*(char *)p)
                                      : "d" (new), "0" (old), "m" (*(char *)p));
                break;
        case 2:
                __asm__ __volatile__ ("casw %0,%2,%1"
                                      : "=d" (old), "=m" (*(short *)p)
                                      : "d" (new), "0" (old), "m" (*(short *)p));
                break;
        case 4:
                __asm__ __volatile__ ("casl %0,%2,%1"
                                      : "=d" (old), "=m" (*(int *)p)
                                      : "d" (new), "0" (old), "m" (*(int *)p));
                break;
        default:
                old = __invalid_cmpxchg_size(p, old, new, size);
                break;
        }
        return old;
}

#define arch_cmpxchg(ptr, o, n)                                             \
        ({(__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),          \
                        (unsigned long)(n), sizeof(*(ptr)));})
#define arch_cmpxchg_local(ptr, o, n)                                       \
        ({(__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o),          \
                        (unsigned long)(n), sizeof(*(ptr)));})

#define arch_cmpxchg64(ptr, o, n)       arch_cmpxchg64_local((ptr), (o), (n))

#else

#include <asm-generic/cmpxchg.h>

#endif

#endif /* __ARCH_M68K_CMPXCHG__ */