X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Fringbuffer%2Fvatomic.h;h=6fdc4d1bdee3c392eaa4c9d3b7f47f28762ce8c5;hb=refs%2Ftags%2Ffor-upstreaming-review-1;hp=a5e8c76ab2f861149df0a82e6c8b83a5a8f4a58e;hpb=369708f464bedc0682151df9308cebfa14dbdb2b;p=lttng-modules.git

diff --git a/include/ringbuffer/vatomic.h b/include/ringbuffer/vatomic.h
index a5e8c76a..6fdc4d1b 100644
--- a/include/ringbuffer/vatomic.h
+++ b/include/ringbuffer/vatomic.h
@@ -1,2 +1,84 @@
-/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only) */
-#include <lib/ringbuffer/vatomic.h>
+/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only)
+ *
+ * lib/ringbuffer/vatomic.h
+ *
+ * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#ifndef _LIB_RING_BUFFER_VATOMIC_H
+#define _LIB_RING_BUFFER_VATOMIC_H
+
+#include <asm/atomic.h>
+#include <asm/local.h>
+
+/*
+ * Same data type (long) accessed differently depending on configuration.
+ * v field is for non-atomic access (protected by mutual exclusion).
+ * In the fast-path, the ring_buffer_config structure is constant, so the
+ * compiler can statically select the appropriate branch.
+ * local_t is used for per-cpu and per-thread buffers.
+ * atomic_long_t is used for globally shared buffers.
+ */
+union v_atomic {
+	local_t l;
+	atomic_long_t a;
+	long v;
+};
+
+static inline
+long v_read(const struct lib_ring_buffer_config *config, union v_atomic *v_a)
+{
+	if (config->sync == RING_BUFFER_SYNC_PER_CPU)
+		return local_read(&v_a->l);
+	else
+		return atomic_long_read(&v_a->a);
+}
+
+static inline
+void v_set(const struct lib_ring_buffer_config *config, union v_atomic *v_a,
+	   long v)
+{
+	if (config->sync == RING_BUFFER_SYNC_PER_CPU)
+		local_set(&v_a->l, v);
+	else
+		atomic_long_set(&v_a->a, v);
+}
+
+static inline
+void v_add(const struct lib_ring_buffer_config *config, long v, union v_atomic *v_a)
+{
+	if (config->sync == RING_BUFFER_SYNC_PER_CPU)
+		local_add(v, &v_a->l);
+	else
+		atomic_long_add(v, &v_a->a);
+}
+
+static inline
+void v_inc(const struct lib_ring_buffer_config *config, union v_atomic *v_a)
+{
+	if (config->sync == RING_BUFFER_SYNC_PER_CPU)
+		local_inc(&v_a->l);
+	else
+		atomic_long_inc(&v_a->a);
+}
+
+/*
+ * Non-atomic decrement. Only used by reader, apply to reader-owned subbuffer.
+ */
+static inline
+void _v_dec(const struct lib_ring_buffer_config *config, union v_atomic *v_a)
+{
+	--v_a->v;
+}
+
+static inline
+long v_cmpxchg(const struct lib_ring_buffer_config *config, union v_atomic *v_a,
+	       long old, long _new)
+{
+	if (config->sync == RING_BUFFER_SYNC_PER_CPU)
+		return local_cmpxchg(&v_a->l, old, _new);
+	else
+		return atomic_long_cmpxchg(&v_a->a, old, _new);
+}
+
+#endif /* _LIB_RING_BUFFER_VATOMIC_H */