libutils: add atomic load, store and cas

* Adds atomic_load_uint() and atomic_load_u32()
* Adds atomic_store_uint() and atomic_store_u32()
* Adds atomic_cas_uint() and atomic_cas_u32(), compare and store

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

lib/libutils/ext/include/atomic.h

@@ -1,36 +1,48 @@
 /*
- * Copyright (c) 2016, Linaro Limited
+ * Copyright (c) 2016-2017, Linaro Limited
  * All rights reserved.
  *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
- * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
- * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
- * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
- * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
- * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
- * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
- * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
- * POSSIBILITY OF SUCH DAMAGE.
+ * SPDX-License-Identifier: BSD-2-Clause
  */
 
 #ifndef __ATOMIC_H
 #define __ATOMIC_H
 
+#include <compiler.h>
 #include <types_ext.h>
 
 uint32_t atomic_inc32(volatile uint32_t *v);
 uint32_t atomic_dec32(volatile uint32_t *v);
 
+static inline bool atomic_cas_uint(unsigned int *p, unsigned int *oval,
+				   unsigned int nval)
+{
+	return __compiler_compare_and_swap(p, oval, nval);
+}
+
+static inline bool atomic_cas_u32(uint32_t *p, uint32_t *oval, uint32_t nval)
+{
+	return __compiler_compare_and_swap(p, oval, nval);
+}
+
+static inline unsigned int atomic_load_uint(unsigned int *p)
+{
+	return __compiler_atomic_load(p);
+}
+
+static inline unsigned int atomic_load_u32(unsigned int *p)
+{
+	return __compiler_atomic_load(p);
+}
+
+static inline void atomic_store_uint(unsigned int *p, unsigned int val)
+{
+	__compiler_atomic_store(p, val);
+}
+
+static inline void atomic_store_u32(uint32_t *p, uint32_t val)
+{
+	__compiler_atomic_store(p, val);
+}
+
 #endif /*__ATOMIC_H*/

lib/libutils/ext/include/compiler.h

@@ -185,4 +185,12 @@
 
 #endif /*!__HAVE_BUILTIN_OVERFLOW*/
 
+#define __compiler_compare_and_swap(p, oval, nval) \
+	__atomic_compare_exchange_n((p), (oval), (nval), true, \
+				    __ATOMIC_ACQUIRE, __ATOMIC_RELAXED) \
+
+#define __compiler_atomic_load(p) __atomic_load_n((p), __ATOMIC_RELAXED)
+#define __compiler_atomic_store(p, val) \
+	__atomic_store_n((p), (val), __ATOMIC_RELAXED)
+
 #endif /*COMPILER_H*/