Changeset 6b781c0 in mainline for uspace/libc/arch/arm32/include/atomic.h

Timestamp:

2007-06-08T15:02:49Z (17 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

c03ee1c

Parents:

3ee8a075

Message:

Merge arm32 into trunk.

File:

• uspace/libc/arch/arm32/include/atomic.h (modified) (3 diffs)

uspace/libc/arch/arm32/include/atomic.h

@@ -1 +1 @@
 /*
- * Copyright (c) 2005 Jakub Jermar
+ * Copyright (c) 2007 Michal Kebrt
  * All rights reserved.
  *
@@ -31 +31 @@
  */
 /** @file
+ *  @brief Atomic operations.
  */
 
@@ -38 +39 @@
 /** Atomic addition.
  *
- * @param val Atomic value.
- * @param imm Value to add.
+ * @param val Where to add.
+ * @param i   Value to be added.
  *
  * @return Value after addition.
  */
-static inline long atomic_add(atomic_t *val, int imm)
+static inline long atomic_add(atomic_t *val, int i)
 {
-        /* TODO */
-        return (val->count += imm);
+        int ret;
+        volatile long * mem = &(val->count);
+
+        asm volatile (
+                "1:                 \n"
+                "ldr r2, [%1]       \n"
+                "add r3, r2, %2     \n"
+                "str r3, %0         \n"
+                "swp r3, r3, [%1]   \n"
+                "cmp r3, r2         \n"
+                "bne 1b             \n"
+
+                : "=m" (ret)
+                : "r" (mem), "r" (i)
+                : "r3", "r2"
+        );
+
+        return ret;
 }
 
+
+/** Atomic increment.
+ *
+ * @param val Variable to be incremented.
+ */
 static inline void atomic_inc(atomic_t *val) { atomic_add(val, 1); }
+
+
+/** Atomic decrement.
+ *
+ * @param val Variable to be decremented.
+ */
 static inline void atomic_dec(atomic_t *val) { atomic_add(val, -1); }
 
-static inline long atomic_preinc(atomic_t *val) { return atomic_add(val, 1) + 1; }
-static inline long atomic_predec(atomic_t *val) { return atomic_add(val, -1) - 1; }
 
-static inline long atomic_postinc(atomic_t *val) { return atomic_add(val, 1); }
-static inline long atomic_postdec(atomic_t *val) { return atomic_add(val, -1); }
+/** Atomic pre-increment.
+ *
+ * @param val Variable to be incremented.
+ * @return    Value after incrementation.
+ */
+static inline long atomic_preinc(atomic_t *val) { return atomic_add(val, 1); }
+
+
+/** Atomic pre-decrement.
+ *
+ * @param val Variable to be decremented.
+ * @return    Value after decrementation.
+ */
+static inline long atomic_predec(atomic_t *val) { return atomic_add(val, -1); }
+
+
+/** Atomic post-increment.
+ *
+ * @param val Variable to be incremented.
+ * @return    Value before incrementation.
+ */
+static inline long atomic_postinc(atomic_t *val) { return atomic_add(val, 1) - 1; }
+
+
+/** Atomic post-decrement.
+ *
+ * @param val Variable to be decremented.
+ * @return    Value before decrementation.
+ */
+static inline long atomic_postdec(atomic_t *val) { return atomic_add(val, -1) + 1; }
+
 
 #endif