1 files changed, 99 insertions, 0 deletions
diff --git a/arch/microblaze/include/asm/futex.h b/arch/microblaze/include/asm/futex.h
new file mode 100644
index 0000000000..86131ed84c
--- /dev/null
+++ b/arch/microblaze/include/asm/futex.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_MICROBLAZE_FUTEX_H
+#define _ASM_MICROBLAZE_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+#include <asm/errno.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+({									\
+	__asm__ __volatile__ (						\
+			"1:	lwx	%0, %2, r0; "			\
+				insn					\
+			"2:	swx	%1, %2, r0;			\
+				addic	%1, r0, 0;			\
+				bnei	%1, 1b;				\
+			3:						\
+			.section .fixup,\"ax\";				\
+			4:	brid	3b;				\
+				addik	%1, r0, %3;			\
+			.previous;					\
+			.section __ex_table,\"a\";			\
+			.word	1b,4b,2b,4b;				\
+			.previous;"					\
+	: "=&r" (oldval), "=&r" (ret)					\
+	: "r" (uaddr), "i" (-EFAULT), "r" (oparg)			\
+	);								\
+})
+
+static inline int
+arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
+{
+	int oldval = 0, ret;
+
+	if (!access_ok(uaddr, sizeof(u32)))
+		return -EFAULT;
+
+	switch (op) {
+	case FUTEX_OP_SET:
+		__futex_atomic_op("or %1,%4,%4;", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ADD:
+		__futex_atomic_op("add %1,%0,%4;", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_OR:
+		__futex_atomic_op("or %1,%0,%4;", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_ANDN:
+		__futex_atomic_op("andn %1,%0,%4;", ret, oldval, uaddr, oparg);
+		break;
+	case FUTEX_OP_XOR:
+		__futex_atomic_op("xor %1,%0,%4;", ret, oldval, uaddr, oparg);
+		break;
+	default:
+		ret = -ENOSYS;
+	}
+
+	if (!ret)
+		*oval = oldval;
+
+	return ret;
+}
+
+static inline int
+futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+			      u32 oldval, u32 newval)
+{
+	int ret = 0, cmp;
+	u32 prev;
+
+	if (!access_ok(uaddr, sizeof(u32)))
+		return -EFAULT;
+
+	__asm__ __volatile__ ("1:	lwx	%1, %3, r0;		\
+					cmp	%2, %1, %4;		\
+					bnei	%2, 3f;			\
+				2:	swx	%5, %3, r0;		\
+					addic	%2, r0, 0;		\
+					bnei	%2, 1b;			\
+				3:					\
+				.section .fixup,\"ax\";			\
+				4:	brid	3b;			\
+					addik	%0, r0, %6;		\
+				.previous;				\
+				.section __ex_table,\"a\";		\
+				.word	1b,4b,2b,4b;			\
+				.previous;"				\
+		: "+r" (ret), "=&r" (prev), "=&r"(cmp)	\
+		: "r" (uaddr), "r" (oldval), "r" (newval), "i" (-EFAULT));
+
+	*uval = prev;
+	return ret;
+}
+
+#endif /* __KERNEL__ */
+
+#endif