v4.19.13 snapshot.
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
new file mode 100644
index 0000000..7de0149
--- /dev/null
+++ b/arch/xtensa/include/asm/atomic.h
@@ -0,0 +1,205 @@
+/*
+ * include/asm-xtensa/atomic.h
+ *
+ * Atomic operations that C can't guarantee us. Useful for resource counting..
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2008 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_ATOMIC_H
+#define _XTENSA_ATOMIC_H
+
+#include <linux/stringify.h>
+#include <linux/types.h>
+
+#ifdef __KERNEL__
+#include <asm/processor.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+#define ATOMIC_INIT(i) { (i) }
+
+/*
+ * This Xtensa implementation assumes that the right mechanism
+ * for exclusion is for locking interrupts to level EXCM_LEVEL.
+ *
+ * Locking interrupts looks like this:
+ *
+ * rsil a15, TOPLEVEL
+ * <code>
+ * wsr a15, PS
+ * rsync
+ *
+ * Note that a15 is used here because the register allocation
+ * done by the compiler is not guaranteed and a window overflow
+ * may not occur between the rsil and wsr instructions. By using
+ * a15 in the rsil, the machine is guaranteed to be in a state
+ * where no register reference will cause an overflow.
+ */
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+#define atomic_read(v) READ_ONCE((v)->counter)
+
+/**
+ * atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+#define atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
+
+#if XCHAL_HAVE_S32C1I
+#define ATOMIC_OP(op) \
+static inline void atomic_##op(int i, atomic_t * v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32i %1, %3, 0\n" \
+ " wsr %1, scompare1\n" \
+ " " #op " %0, %1, %2\n" \
+ " s32c1i %0, %3, 0\n" \
+ " bne %0, %1, 1b\n" \
+ : "=&a" (result), "=&a" (tmp) \
+ : "a" (i), "a" (v) \
+ : "memory" \
+ ); \
+} \
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int atomic_##op##_return(int i, atomic_t * v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32i %1, %3, 0\n" \
+ " wsr %1, scompare1\n" \
+ " " #op " %0, %1, %2\n" \
+ " s32c1i %0, %3, 0\n" \
+ " bne %0, %1, 1b\n" \
+ " " #op " %0, %0, %2\n" \
+ : "=&a" (result), "=&a" (tmp) \
+ : "a" (i), "a" (v) \
+ : "memory" \
+ ); \
+ \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(op) \
+static inline int atomic_fetch_##op(int i, atomic_t * v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32i %1, %3, 0\n" \
+ " wsr %1, scompare1\n" \
+ " " #op " %0, %1, %2\n" \
+ " s32c1i %0, %3, 0\n" \
+ " bne %0, %1, 1b\n" \
+ : "=&a" (result), "=&a" (tmp) \
+ : "a" (i), "a" (v) \
+ : "memory" \
+ ); \
+ \
+ return result; \
+}
+
+#else /* XCHAL_HAVE_S32C1I */
+
+#define ATOMIC_OP(op) \
+static inline void atomic_##op(int i, atomic_t * v) \
+{ \
+ unsigned int vval; \
+ \
+ __asm__ __volatile__( \
+ " rsil a15, "__stringify(TOPLEVEL)"\n"\
+ " l32i %0, %2, 0\n" \
+ " " #op " %0, %0, %1\n" \
+ " s32i %0, %2, 0\n" \
+ " wsr a15, ps\n" \
+ " rsync\n" \
+ : "=&a" (vval) \
+ : "a" (i), "a" (v) \
+ : "a15", "memory" \
+ ); \
+} \
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int atomic_##op##_return(int i, atomic_t * v) \
+{ \
+ unsigned int vval; \
+ \
+ __asm__ __volatile__( \
+ " rsil a15,"__stringify(TOPLEVEL)"\n" \
+ " l32i %0, %2, 0\n" \
+ " " #op " %0, %0, %1\n" \
+ " s32i %0, %2, 0\n" \
+ " wsr a15, ps\n" \
+ " rsync\n" \
+ : "=&a" (vval) \
+ : "a" (i), "a" (v) \
+ : "a15", "memory" \
+ ); \
+ \
+ return vval; \
+}
+
+#define ATOMIC_FETCH_OP(op) \
+static inline int atomic_fetch_##op(int i, atomic_t * v) \
+{ \
+ unsigned int tmp, vval; \
+ \
+ __asm__ __volatile__( \
+ " rsil a15,"__stringify(TOPLEVEL)"\n" \
+ " l32i %0, %3, 0\n" \
+ " " #op " %1, %0, %2\n" \
+ " s32i %1, %3, 0\n" \
+ " wsr a15, ps\n" \
+ " rsync\n" \
+ : "=&a" (vval), "=&a" (tmp) \
+ : "a" (i), "a" (v) \
+ : "a15", "memory" \
+ ); \
+ \
+ return vval; \
+}
+
+#endif /* XCHAL_HAVE_S32C1I */
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op) ATOMIC_OP_RETURN(op)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
+
+ATOMIC_OPS(and)
+ATOMIC_OPS(or)
+ATOMIC_OPS(xor)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#define atomic_cmpxchg(v, o, n) ((int)cmpxchg(&((v)->counter), (o), (n)))
+#define atomic_xchg(v, new) (xchg(&((v)->counter), new))
+
+#endif /* __KERNEL__ */
+
+#endif /* _XTENSA_ATOMIC_H */