AArch64: Add atomic functions

This patch adds atomic functions for AArch64. The functions
will be revisited later for potential optimizations using
assembly or otherwise.

This patch also introduces new 64-bit atomic functions for
LP64 platforms.

Change-Id: Id2127dd01cea65025f939e955d73d27e95d8687e
Signed-off-by: Marcus Oakland <marcus.oakland@arm.com>
Signed-off-by: Ashok Bhat <ashok.bhat@arm.com>

3 files changed, 247 insertions, 1 deletions

diff --git a/include/cutils/atomic-aarch64.h b/include/cutils/atomic-aarch64.h
new file mode 100644
index 0000000..927379f
--- /dev/null
+++ b/include/cutils/atomic-aarch64.h
@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * 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 OWNER 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.
+ */
+
+#ifndef ANDROID_CUTILS_ATOMIC_AARCH64_H
+#define ANDROID_CUTILS_ATOMIC_AARCH64_H
+
+#include <stdint.h>
+
+#ifndef ANDROID_ATOMIC_INLINE
+#define ANDROID_ATOMIC_INLINE inline __attribute__((always_inline))
+#endif
+
+/*
+   TODOAArch64: Revisit the below functions and check for potential
+   optimizations using assembly code or otherwise.
+*/
+
+extern ANDROID_ATOMIC_INLINE
+void android_compiler_barrier(void)
+{
+    __asm__ __volatile__ ("" : : : "memory");
+}
+
+#if ANDROID_SMP == 0
+extern ANDROID_ATOMIC_INLINE
+void android_memory_barrier(void)
+{
+    android_compiler_barrier();
+}
+extern ANDROID_ATOMIC_INLINE
+void android_memory_store_barrier(void)
+{
+    android_compiler_barrier();
+}
+#else
+extern ANDROID_ATOMIC_INLINE
+void android_memory_barrier(void)
+{
+    __asm__ __volatile__ ("dmb ish" : : : "memory");
+}
+extern ANDROID_ATOMIC_INLINE
+void android_memory_store_barrier(void)
+{
+    __asm__ __volatile__ ("dmb isht" : : : "memory");
+}
+#endif
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_acquire_load(volatile const int32_t *ptr)
+{
+    int32_t value = *ptr;
+    android_memory_barrier();
+    return value;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int64_t android_atomic_acquire_load64(volatile const int64_t *ptr)
+{
+    int64_t value = *ptr;
+    android_memory_barrier();
+    return value;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_release_load(volatile const int32_t *ptr)
+{
+    android_memory_barrier();
+    return *ptr;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int64_t android_atomic_release_load64(volatile const int64_t *ptr)
+{
+    android_memory_barrier();
+    return *ptr;
+}
+
+extern ANDROID_ATOMIC_INLINE
+void android_atomic_acquire_store(int32_t value, volatile int32_t *ptr)
+{
+    *ptr = value;
+    android_memory_barrier();
+}
+
+extern ANDROID_ATOMIC_INLINE
+void android_atomic_acquire_store64(int64_t value, volatile int64_t *ptr)
+{
+    *ptr = value;
+    android_memory_barrier();
+}
+
+extern ANDROID_ATOMIC_INLINE
+void android_atomic_release_store(int32_t value, volatile int32_t *ptr)
+{
+    android_memory_barrier();
+    *ptr = value;
+}
+
+extern ANDROID_ATOMIC_INLINE
+void android_atomic_release_store64(int64_t value, volatile int64_t *ptr)
+{
+    android_memory_barrier();
+    *ptr = value;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int android_atomic_cas(int32_t old_value, int32_t new_value,
+                       volatile int32_t *ptr)
+{
+    return __sync_val_compare_and_swap(ptr, old_value, new_value) != old_value;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int64_t android_atomic_cas64(int64_t old_value, int64_t new_value,
+                             volatile int64_t *ptr)
+{
+    return __sync_val_compare_and_swap(ptr, old_value, new_value) != old_value;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int android_atomic_acquire_cas(int32_t old_value, int32_t new_value,
+                               volatile int32_t *ptr)
+{
+    int status = android_atomic_cas(old_value, new_value, ptr);
+    android_memory_barrier();
+    return status;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int64_t android_atomic_acquire_cas64(int64_t old_value, int64_t new_value,
+                                     volatile int64_t *ptr)
+{
+    int status = android_atomic_cas64(old_value, new_value, ptr);
+    android_memory_barrier();
+    return status;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int android_atomic_release_cas(int32_t old_value, int32_t new_value,
+                               volatile int32_t *ptr)
+{
+    android_memory_barrier();
+    return android_atomic_cas(old_value, new_value, ptr);
+}
+
+extern ANDROID_ATOMIC_INLINE
+int64_t android_atomic_release_cas64(int64_t old_value, int64_t new_value,
+                                     volatile int64_t *ptr)
+{
+    android_memory_barrier();
+    return android_atomic_cas64(old_value, new_value, ptr);
+}
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_add(int32_t increment, volatile int32_t *ptr)
+{
+    int32_t prev, status;
+    android_memory_barrier();
+    do {
+        prev = *ptr;
+        status = android_atomic_cas(prev, prev + increment, ptr);
+    } while (__builtin_expect(status != 0, 0));
+    return prev;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_inc(volatile int32_t *addr)
+{
+    return android_atomic_add(1, addr);
+}
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_dec(volatile int32_t *addr)
+{
+    return android_atomic_add(-1, addr);
+}
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_and(int32_t value, volatile int32_t *ptr)
+{
+    int32_t prev, status;
+    android_memory_barrier();
+    do {
+        prev = *ptr;
+        status = android_atomic_cas(prev, prev & value, ptr);
+    } while (__builtin_expect(status != 0, 0));
+    return prev;
+}
+
+extern ANDROID_ATOMIC_INLINE
+int32_t android_atomic_or(int32_t value, volatile int32_t *ptr)
+{
+    int32_t prev, status;
+    android_memory_barrier();
+    do {
+        prev = *ptr;
+        status = android_atomic_cas(prev, prev | value, ptr);
+    } while (__builtin_expect(status != 0, 0));
+    return prev;
+}
+
+#endif /* ANDROID_CUTILS_ATOMIC_AARCH64_H */
diff --git a/include/cutils/atomic-inline.h b/include/cutils/atomic-inline.h
index 0b13138..29a28d5 100644
--- a/include/cutils/atomic-inline.h
+++ b/include/cutils/atomic-inline.h
@@ -43,7 +43,9 @@ extern "C" {
 # error "Must define ANDROID_SMP before including atomic-inline.h"
 #endif
 
-#if defined(__arm__)
+#if defined(__aarch64__)
+#include <cutils/atomic-aarch64.h>
+#elif defined(__arm__)
 #include <cutils/atomic-arm.h>
 #elif defined(__i386__) || defined(__x86_64__)
 #include <cutils/atomic-x86.h>
diff --git a/include/cutils/atomic.h b/include/cutils/atomic.h
index ae42eb8..1787e34 100644
--- a/include/cutils/atomic.h
+++ b/include/cutils/atomic.h
@@ -80,6 +80,11 @@ int32_t android_atomic_or(int32_t value, volatile int32_t* addr);
 int32_t android_atomic_acquire_load(volatile const int32_t* addr);
 int32_t android_atomic_release_load(volatile const int32_t* addr);
 
+#if defined (__LP64__)
+int64_t android_atomic_acquire_load64(volatile const int64_t* addr);
+int64_t android_atomic_release_load64(volatile const int64_t* addr);
+#endif
+
 /*
  * Perform an atomic store with "acquire" or "release" ordering.
  *
@@ -89,6 +94,11 @@ int32_t android_atomic_release_load(volatile const int32_t* addr);
 void android_atomic_acquire_store(int32_t value, volatile int32_t* addr);
 void android_atomic_release_store(int32_t value, volatile int32_t* addr);
 
+#if defined (__LP64__)
+void android_atomic_acquire_store64(int64_t value, volatile int64_t* addr);
+void android_atomic_release_store64(int64_t value, volatile int64_t* addr);
+#endif
+
 /*
  * Compare-and-set operation with "acquire" or "release" ordering.
  *
@@ -106,6 +116,13 @@ int android_atomic_acquire_cas(int32_t oldvalue, int32_t newvalue,
 int android_atomic_release_cas(int32_t oldvalue, int32_t newvalue,
         volatile int32_t* addr);
 
+#if defined (__LP64__)
+int64_t android_atomic_acquire_cas64(int64_t old_value, int64_t new_value,
+        volatile int64_t *ptr);
+int64_t android_atomic_release_cas64(int64_t old_value, int64_t new_value,
+        volatile int64_t *ptr);
+#endif
+
 /*
  * Aliases for code using an older version of this header.  These are now
  * deprecated and should not be used.  The definitions will be removed