1 files changed, 66 insertions, 0 deletions
diff --git a/arch/h8300/include/asm/cmpxchg.h b/arch/h8300/include/asm/cmpxchg.h
new file mode 100644
index 000000000..c64bb38ce
--- /dev/null
+++ b/arch/h8300/include/asm/cmpxchg.h
@@ -0,0 +1,66 @@
+/* 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__ */