locking/atomic: h8300: use asm-generic exclusively

As h8300's implementation of the atomics isn't using any arch-specific
functionality, and its implementation of cmpxchg only uses assembly to
non-atomically swap two elements in memory, we may as well use the
asm-generic atomic.h and cmpxchg.h, and avoid the duplicate code.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-4-mark.rutland@arm.com

arch/h8300/include/asm/Kbuild

 # SPDX-License-Identifier: GPL-2.0
 generic-y += asm-offsets.h
+generic-y += cmpxchg.h
 generic-y += extable.h
 generic-y += kvm_para.h
 generic-y += mcs_spinlock.h

arch/h8300/include/asm/atomic.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ARCH_H8300_ATOMIC__
-#define __ARCH_H8300_ATOMIC__
-
-#include <linux/compiler.h>
-#include <linux/types.h>
-#include <asm/cmpxchg.h>
-#include <asm/irqflags.h>
-
-/*
- * Atomic operations that C can't guarantee us.  Useful for
- * resource counting etc..
- */
-
-#define atomic_read(v)		READ_ONCE((v)->counter)
-#define atomic_set(v, i)	WRITE_ONCE(((v)->counter), (i))
-
-#define ATOMIC_OP_RETURN(op, c_op)				\
-static inline int atomic_##op##_return(int i, atomic_t *v)	\
-{								\
-	h8300flags flags;					\
-	int ret;						\
-								\
-	flags = arch_local_irq_save();				\
-	ret = v->counter c_op i;				\
-	arch_local_irq_restore(flags);				\
-	return ret;						\
-}
-
-#define ATOMIC_FETCH_OP(op, c_op)				\
-static inline int atomic_fetch_##op(int i, atomic_t *v)		\
-{								\
-	h8300flags flags;					\
-	int ret;						\
-								\
-	flags = arch_local_irq_save();				\
-	ret = v->counter;					\
-	v->counter c_op i;					\
-	arch_local_irq_restore(flags);				\
-	return ret;						\
-}
-
-#define ATOMIC_OP(op, c_op)					\
-static inline void atomic_##op(int i, atomic_t *v)		\
-{								\
-	h8300flags flags;					\
-								\
-	flags = arch_local_irq_save();				\
-	v->counter c_op i;					\
-	arch_local_irq_restore(flags);				\
-}
-
-ATOMIC_OP_RETURN(add, +=)
-ATOMIC_OP_RETURN(sub, -=)
-
-#define ATOMIC_OPS(op, c_op)					\
-	ATOMIC_OP(op, c_op)					\
-	ATOMIC_FETCH_OP(op, c_op)
-
-ATOMIC_OPS(and, &=)
-ATOMIC_OPS(or,  |=)
-ATOMIC_OPS(xor, ^=)
-ATOMIC_OPS(add, +=)
-ATOMIC_OPS(sub, -=)
-
-#undef ATOMIC_OPS
-#undef ATOMIC_OP_RETURN
-#undef ATOMIC_OP
-
-static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
-{
-	int ret;
-	h8300flags flags;
-
-	flags = arch_local_irq_save();
-	ret = v->counter;
-	if (likely(ret == old))
-		v->counter = new;
-	arch_local_irq_restore(flags);
-	return ret;
-}
-
-static inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
-{
-	int ret;
-	h8300flags flags;
-
-	flags = arch_local_irq_save();
-	ret = v->counter;
-	if (ret != u)
-		v->counter += a;
-	arch_local_irq_restore(flags);
-	return ret;
-}
-#define atomic_fetch_add_unless		atomic_fetch_add_unless
-
-#endif /* __ARCH_H8300_ATOMIC __ */

arch/h8300/include/asm/cmpxchg.h

-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef __ARCH_H8300_CMPXCHG__
-#define __ARCH_H8300_CMPXCHG__
-
-#include <linux/irqflags.h>
-
-#define xchg(ptr, x) \
-	((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), \
-				    sizeof(*(ptr))))
-
-struct __xchg_dummy { unsigned long a[100]; };
-#define __xg(x) ((volatile struct __xchg_dummy *)(x))
-
-static inline unsigned long __xchg(unsigned long x,
-				   volatile void *ptr, int size)
-{
-	unsigned long tmp, flags;
-
-	local_irq_save(flags);
-
-	switch (size) {
-	case 1:
-		__asm__ __volatile__
-			("mov.b %2,%0\n\t"
-			 "mov.b %1,%2"
-			 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)));
-		break;
-	case 2:
-		__asm__ __volatile__
-			("mov.w %2,%0\n\t"
-			 "mov.w %1,%2"
-			 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)));
-		break;
-	case 4:
-		__asm__ __volatile__
-			("mov.l %2,%0\n\t"
-			 "mov.l %1,%2"
-			 : "=&r" (tmp) : "r" (x), "m" (*__xg(ptr)));
-		break;
-	default:
-		tmp = 0;
-	}
-	local_irq_restore(flags);
-	return tmp;
-}
-
-#include <asm-generic/cmpxchg-local.h>
-
-/*
- * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
- * them available.
- */
-#define cmpxchg_local(ptr, o, n)					 \
-	((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr),		 \
-						     (unsigned long)(o), \
-						     (unsigned long)(n), \
-						     sizeof(*(ptr))))
-#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
-
-#ifndef CONFIG_SMP
-#include <asm-generic/cmpxchg.h>
-#endif
-
-#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
-
-#endif /* __ARCH_H8300_CMPXCHG__ */