v4.19.13 snapshot.
diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
new file mode 100644
index 0000000..c452359
--- /dev/null
+++ b/arch/riscv/include/asm/atomic.h
@@ -0,0 +1,351 @@
+/*
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Copyright (C) 2012 Regents of the University of California
+ * Copyright (C) 2017 SiFive
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#ifndef _ASM_RISCV_ATOMIC_H
+#define _ASM_RISCV_ATOMIC_H
+
+#ifdef CONFIG_GENERIC_ATOMIC64
+# include <asm-generic/atomic64.h>
+#else
+# if (__riscv_xlen < 64)
+# error "64-bit atomics require XLEN to be at least 64"
+# endif
+#endif
+
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+#define ATOMIC_INIT(i) { (i) }
+
+#define __atomic_acquire_fence() \
+ __asm__ __volatile__(RISCV_ACQUIRE_BARRIER "" ::: "memory")
+
+#define __atomic_release_fence() \
+ __asm__ __volatile__(RISCV_RELEASE_BARRIER "" ::: "memory");
+
+static __always_inline int atomic_read(const atomic_t *v)
+{
+ return READ_ONCE(v->counter);
+}
+static __always_inline void atomic_set(atomic_t *v, int i)
+{
+ WRITE_ONCE(v->counter, i);
+}
+
+#ifndef CONFIG_GENERIC_ATOMIC64
+#define ATOMIC64_INIT(i) { (i) }
+static __always_inline long atomic64_read(const atomic64_t *v)
+{
+ return READ_ONCE(v->counter);
+}
+static __always_inline void atomic64_set(atomic64_t *v, long i)
+{
+ WRITE_ONCE(v->counter, i);
+}
+#endif
+
+/*
+ * First, the atomic ops that have no ordering constraints and therefor don't
+ * have the AQ or RL bits set. These don't return anything, so there's only
+ * one version to worry about.
+ */
+#define ATOMIC_OP(op, asm_op, I, asm_type, c_type, prefix) \
+static __always_inline \
+void atomic##prefix##_##op(c_type i, atomic##prefix##_t *v) \
+{ \
+ __asm__ __volatile__ ( \
+ " amo" #asm_op "." #asm_type " zero, %1, %0" \
+ : "+A" (v->counter) \
+ : "r" (I) \
+ : "memory"); \
+} \
+
+#ifdef CONFIG_GENERIC_ATOMIC64
+#define ATOMIC_OPS(op, asm_op, I) \
+ ATOMIC_OP (op, asm_op, I, w, int, )
+#else
+#define ATOMIC_OPS(op, asm_op, I) \
+ ATOMIC_OP (op, asm_op, I, w, int, ) \
+ ATOMIC_OP (op, asm_op, I, d, long, 64)
+#endif
+
+ATOMIC_OPS(add, add, i)
+ATOMIC_OPS(sub, add, -i)
+ATOMIC_OPS(and, and, i)
+ATOMIC_OPS( or, or, i)
+ATOMIC_OPS(xor, xor, i)
+
+#undef ATOMIC_OP
+#undef ATOMIC_OPS
+
+/*
+ * Atomic ops that have ordered, relaxed, acquire, and release variants.
+ * There's two flavors of these: the arithmatic ops have both fetch and return
+ * versions, while the logical ops only have fetch versions.
+ */
+#define ATOMIC_FETCH_OP(op, asm_op, I, asm_type, c_type, prefix) \
+static __always_inline \
+c_type atomic##prefix##_fetch_##op##_relaxed(c_type i, \
+ atomic##prefix##_t *v) \
+{ \
+ register c_type ret; \
+ __asm__ __volatile__ ( \
+ " amo" #asm_op "." #asm_type " %1, %2, %0" \
+ : "+A" (v->counter), "=r" (ret) \
+ : "r" (I) \
+ : "memory"); \
+ return ret; \
+} \
+static __always_inline \
+c_type atomic##prefix##_fetch_##op(c_type i, atomic##prefix##_t *v) \
+{ \
+ register c_type ret; \
+ __asm__ __volatile__ ( \
+ " amo" #asm_op "." #asm_type ".aqrl %1, %2, %0" \
+ : "+A" (v->counter), "=r" (ret) \
+ : "r" (I) \
+ : "memory"); \
+ return ret; \
+}
+
+#define ATOMIC_OP_RETURN(op, asm_op, c_op, I, asm_type, c_type, prefix) \
+static __always_inline \
+c_type atomic##prefix##_##op##_return_relaxed(c_type i, \
+ atomic##prefix##_t *v) \
+{ \
+ return atomic##prefix##_fetch_##op##_relaxed(i, v) c_op I; \
+} \
+static __always_inline \
+c_type atomic##prefix##_##op##_return(c_type i, atomic##prefix##_t *v) \
+{ \
+ return atomic##prefix##_fetch_##op(i, v) c_op I; \
+}
+
+#ifdef CONFIG_GENERIC_ATOMIC64
+#define ATOMIC_OPS(op, asm_op, c_op, I) \
+ ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
+ ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, )
+#else
+#define ATOMIC_OPS(op, asm_op, c_op, I) \
+ ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
+ ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, ) \
+ ATOMIC_FETCH_OP( op, asm_op, I, d, long, 64) \
+ ATOMIC_OP_RETURN(op, asm_op, c_op, I, d, long, 64)
+#endif
+
+ATOMIC_OPS(add, add, +, i)
+ATOMIC_OPS(sub, add, +, -i)
+
+#define atomic_add_return_relaxed atomic_add_return_relaxed
+#define atomic_sub_return_relaxed atomic_sub_return_relaxed
+#define atomic_add_return atomic_add_return
+#define atomic_sub_return atomic_sub_return
+
+#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
+#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
+#define atomic_fetch_add atomic_fetch_add
+#define atomic_fetch_sub atomic_fetch_sub
+
+#ifndef CONFIG_GENERIC_ATOMIC64
+#define atomic64_add_return_relaxed atomic64_add_return_relaxed
+#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
+#define atomic64_add_return atomic64_add_return
+#define atomic64_sub_return atomic64_sub_return
+
+#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
+#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
+#define atomic64_fetch_add atomic64_fetch_add
+#define atomic64_fetch_sub atomic64_fetch_sub
+#endif
+
+#undef ATOMIC_OPS
+
+#ifdef CONFIG_GENERIC_ATOMIC64
+#define ATOMIC_OPS(op, asm_op, I) \
+ ATOMIC_FETCH_OP(op, asm_op, I, w, int, )
+#else
+#define ATOMIC_OPS(op, asm_op, I) \
+ ATOMIC_FETCH_OP(op, asm_op, I, w, int, ) \
+ ATOMIC_FETCH_OP(op, asm_op, I, d, long, 64)
+#endif
+
+ATOMIC_OPS(and, and, i)
+ATOMIC_OPS( or, or, i)
+ATOMIC_OPS(xor, xor, i)
+
+#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
+#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
+#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
+#define atomic_fetch_and atomic_fetch_and
+#define atomic_fetch_or atomic_fetch_or
+#define atomic_fetch_xor atomic_fetch_xor
+
+#ifndef CONFIG_GENERIC_ATOMIC64
+#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
+#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
+#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
+#define atomic64_fetch_and atomic64_fetch_and
+#define atomic64_fetch_or atomic64_fetch_or
+#define atomic64_fetch_xor atomic64_fetch_xor
+#endif
+
+#undef ATOMIC_OPS
+
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+
+/* This is required to provide a full barrier on success. */
+static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+ int prev, rc;
+
+ __asm__ __volatile__ (
+ "0: lr.w %[p], %[c]\n"
+ " beq %[p], %[u], 1f\n"
+ " add %[rc], %[p], %[a]\n"
+ " sc.w.rl %[rc], %[rc], %[c]\n"
+ " bnez %[rc], 0b\n"
+ " fence rw, rw\n"
+ "1:\n"
+ : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
+ : [a]"r" (a), [u]"r" (u)
+ : "memory");
+ return prev;
+}
+#define atomic_fetch_add_unless atomic_fetch_add_unless
+
+#ifndef CONFIG_GENERIC_ATOMIC64
+static __always_inline long atomic64_fetch_add_unless(atomic64_t *v, long a, long u)
+{
+ long prev, rc;
+
+ __asm__ __volatile__ (
+ "0: lr.d %[p], %[c]\n"
+ " beq %[p], %[u], 1f\n"
+ " add %[rc], %[p], %[a]\n"
+ " sc.d.rl %[rc], %[rc], %[c]\n"
+ " bnez %[rc], 0b\n"
+ " fence rw, rw\n"
+ "1:\n"
+ : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
+ : [a]"r" (a), [u]"r" (u)
+ : "memory");
+ return prev;
+}
+#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+#endif
+
+/*
+ * atomic_{cmp,}xchg is required to have exactly the same ordering semantics as
+ * {cmp,}xchg and the operations that return, so they need a full barrier.
+ */
+#define ATOMIC_OP(c_t, prefix, size) \
+static __always_inline \
+c_t atomic##prefix##_xchg_relaxed(atomic##prefix##_t *v, c_t n) \
+{ \
+ return __xchg_relaxed(&(v->counter), n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_xchg_acquire(atomic##prefix##_t *v, c_t n) \
+{ \
+ return __xchg_acquire(&(v->counter), n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_xchg_release(atomic##prefix##_t *v, c_t n) \
+{ \
+ return __xchg_release(&(v->counter), n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_xchg(atomic##prefix##_t *v, c_t n) \
+{ \
+ return __xchg(&(v->counter), n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_cmpxchg_relaxed(atomic##prefix##_t *v, \
+ c_t o, c_t n) \
+{ \
+ return __cmpxchg_relaxed(&(v->counter), o, n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_cmpxchg_acquire(atomic##prefix##_t *v, \
+ c_t o, c_t n) \
+{ \
+ return __cmpxchg_acquire(&(v->counter), o, n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_cmpxchg_release(atomic##prefix##_t *v, \
+ c_t o, c_t n) \
+{ \
+ return __cmpxchg_release(&(v->counter), o, n, size); \
+} \
+static __always_inline \
+c_t atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \
+{ \
+ return __cmpxchg(&(v->counter), o, n, size); \
+}
+
+#ifdef CONFIG_GENERIC_ATOMIC64
+#define ATOMIC_OPS() \
+ ATOMIC_OP( int, , 4)
+#else
+#define ATOMIC_OPS() \
+ ATOMIC_OP( int, , 4) \
+ ATOMIC_OP(long, 64, 8)
+#endif
+
+ATOMIC_OPS()
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP
+
+static __always_inline int atomic_sub_if_positive(atomic_t *v, int offset)
+{
+ int prev, rc;
+
+ __asm__ __volatile__ (
+ "0: lr.w %[p], %[c]\n"
+ " sub %[rc], %[p], %[o]\n"
+ " bltz %[rc], 1f\n"
+ " sc.w.rl %[rc], %[rc], %[c]\n"
+ " bnez %[rc], 0b\n"
+ " fence rw, rw\n"
+ "1:\n"
+ : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
+ : [o]"r" (offset)
+ : "memory");
+ return prev - offset;
+}
+
+#define atomic_dec_if_positive(v) atomic_sub_if_positive(v, 1)
+
+#ifndef CONFIG_GENERIC_ATOMIC64
+static __always_inline long atomic64_sub_if_positive(atomic64_t *v, int offset)
+{
+ long prev, rc;
+
+ __asm__ __volatile__ (
+ "0: lr.d %[p], %[c]\n"
+ " sub %[rc], %[p], %[o]\n"
+ " bltz %[rc], 1f\n"
+ " sc.d.rl %[rc], %[rc], %[c]\n"
+ " bnez %[rc], 0b\n"
+ " fence rw, rw\n"
+ "1:\n"
+ : [p]"=&r" (prev), [rc]"=&r" (rc), [c]"+A" (v->counter)
+ : [o]"r" (offset)
+ : "memory");
+ return prev - offset;
+}
+
+#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(v, 1)
+#endif
+
+#endif /* _ASM_RISCV_ATOMIC_H */