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-rw-r--r--include/cutils/atomic-arm.h269
1 files changed, 269 insertions, 0 deletions
diff --git a/include/cutils/atomic-arm.h b/include/cutils/atomic-arm.h
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+++ b/include/cutils/atomic-arm.h
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+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef ANDROID_CUTILS_ATOMIC_ARM_H
+#define ANDROID_CUTILS_ATOMIC_ARM_H
+
+#include <stdint.h>
+#include <machine/cpu-features.h>
+
+extern inline void android_compiler_barrier(void)
+{
+ __asm__ __volatile__ ("" : : : "memory");
+}
+
+#if ANDROID_SMP == 0
+extern inline void android_memory_barrier(void)
+{
+ android_compiler_barrier();
+}
+#elif defined(__ARM_HAVE_DMB)
+extern inline void android_memory_barrier(void)
+{
+ __asm__ __volatile__ ("dmb" : : : "memory");
+}
+#elif defined(__ARM_HAVE_LDREX_STREX)
+extern inline void android_memory_barrier(void)
+{
+ __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5"
+ : : "r" (0) : "memory");
+}
+#else
+extern inline void android_memory_barrier(void)
+{
+ typedef void (kuser_memory_barrier)(void);
+ (*(kuser_memory_barrier *)0xffff0fa0)();
+}
+#endif
+
+extern inline int32_t android_atomic_acquire_load(volatile int32_t *ptr)
+{
+ int32_t value = *ptr;
+ android_memory_barrier();
+ return value;
+}
+
+extern inline int32_t android_atomic_release_load(volatile int32_t *ptr)
+{
+ android_memory_barrier();
+ return *ptr;
+}
+
+extern inline void android_atomic_acquire_store(int32_t value,
+ volatile int32_t *ptr)
+{
+ *ptr = value;
+ android_memory_barrier();
+}
+
+extern inline void android_atomic_release_store(int32_t value,
+ volatile int32_t *ptr)
+{
+ android_memory_barrier();
+ *ptr = value;
+}
+
+#if defined(__thumb__)
+extern int android_atomic_cas(int32_t old_value, int32_t new_value,
+ volatile int32_t *ptr);
+#elif defined(__ARM_HAVE_LDREX_STREX)
+extern inline int android_atomic_cas(int32_t old_value, int32_t new_value,
+ volatile int32_t *ptr)
+{
+ int32_t prev, status;
+ do {
+ __asm__ __volatile__ ("ldrex %0, [%3]\n"
+ "mov %1, #0\n"
+ "teq %0, %4\n"
+ "strexeq %1, %5, [%3]"
+ : "=&r" (prev), "=&r" (status), "+m"(*ptr)
+ : "r" (ptr), "Ir" (old_value), "r" (new_value)
+ : "cc");
+ } while (__builtin_expect(status != 0, 0));
+ return prev != old_value;
+}
+#else
+extern inline int android_atomic_cas(int32_t old_value, int32_t new_value,
+ volatile int32_t *ptr)
+{
+ typedef int (kuser_cmpxchg)(int32_t, int32_t, volatile int32_t *);
+ int32_t prev, status;
+ prev = *ptr;
+ do {
+ status = (*(kuser_cmpxchg *)0xffff0fc0)(old_value, new_value, ptr);
+ if (__builtin_expect(status == 0, 1))
+ return 0;
+ prev = *ptr;
+ } while (prev == old_value);
+ return 1;
+}
+#endif
+
+extern 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 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);
+}
+
+
+#if defined(__thumb__)
+extern int32_t android_atomic_swap(int32_t new_value,
+ volatile int32_t *ptr);
+#elif defined(__ARM_HAVE_LDREX_STREX)
+extern inline int32_t android_atomic_swap(int32_t new_value,
+ volatile int32_t *ptr)
+{
+ int32_t prev, status;
+ do {
+ __asm__ __volatile__ ("ldrex %0, [%3]\n"
+ "strex %1, %4, [%3]"
+ : "=&r" (prev), "=&r" (status), "+m" (*ptr)
+ : "r" (ptr), "r" (new_value)
+ : "cc");
+ } while (__builtin_expect(status != 0, 0));
+ android_memory_barrier();
+ return prev;
+}
+#else
+extern inline int32_t android_atomic_swap(int32_t new_value,
+ volatile int32_t *ptr)
+{
+ int32_t prev;
+ __asm__ __volatile__ ("swp %0, %2, [%3]"
+ : "=&r" (prev), "+m" (*ptr)
+ : "r" (new_value), "r" (ptr)
+ : "cc");
+ android_memory_barrier();
+ return prev;
+}
+#endif
+
+#if defined(__thumb__)
+extern int32_t android_atomic_add(int32_t increment,
+ volatile int32_t *ptr);
+#elif defined(__ARM_HAVE_LDREX_STREX)
+extern inline int32_t android_atomic_add(int32_t increment,
+ volatile int32_t *ptr)
+{
+ int32_t prev, tmp, status;
+ android_memory_barrier();
+ do {
+ __asm__ __volatile__ ("ldrex %0, [%4]\n"
+ "add %1, %0, %5\n"
+ "strex %2, %1, [%4]"
+ : "=&r" (prev), "=&r" (tmp),
+ "=&r" (status), "+m" (*ptr)
+ : "r" (ptr), "Ir" (increment)
+ : "cc");
+ } while (__builtin_expect(status != 0, 0));
+ return prev;
+}
+#else
+extern 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;
+}
+#endif
+
+extern inline int32_t android_atomic_inc(volatile int32_t *addr) {
+ return android_atomic_add(1, addr);
+}
+
+extern inline int32_t android_atomic_dec(volatile int32_t *addr) {
+ return android_atomic_add(-1, addr);
+}
+
+#if defined(__thumb__)
+extern int32_t android_atomic_and(int32_t value, volatile int32_t *ptr);
+#elif defined(__ARM_HAVE_LDREX_STREX)
+extern inline int32_t android_atomic_and(int32_t value, volatile int32_t *ptr)
+{
+ int32_t prev, tmp, status;
+ android_memory_barrier();
+ do {
+ __asm__ __volatile__ ("ldrex %0, [%4]\n"
+ "and %1, %0, %5\n"
+ "strex %2, %1, [%4]"
+ : "=&r" (prev), "=&r" (tmp),
+ "=&r" (status), "+m" (*ptr)
+ : "r" (ptr), "Ir" (value)
+ : "cc");
+ } while (__builtin_expect(status != 0, 0));
+ return prev;
+}
+#else
+extern 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;
+}
+#endif
+
+#if defined(__thumb__)
+extern int32_t android_atomic_or(int32_t value, volatile int32_t *ptr);
+#elif defined(__ARM_HAVE_LDREX_STREX)
+extern inline int32_t android_atomic_or(int32_t value, volatile int32_t *ptr)
+{
+ int32_t prev, tmp, status;
+ android_memory_barrier();
+ do {
+ __asm__ __volatile__ ("ldrex %0, [%4]\n"
+ "orr %1, %0, %5\n"
+ "strex %2, %1, [%4]"
+ : "=&r" (prev), "=&r" (tmp),
+ "=&r" (status), "+m" (*ptr)
+ : "r" (ptr), "Ir" (value)
+ : "cc");
+ } while (__builtin_expect(status != 0, 0));
+ return prev;
+}
+#else
+extern 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
+
+#endif /* ANDROID_CUTILS_ATOMIC_ARM_H */
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