Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 351 insertions, 0 deletions

diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
new file mode 100644
index 000000000..c452359c9
--- /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 */