Changeset e4ddfa8 in mainline for arch/ppc32/include/atomic.h

Timestamp:

2006-03-14T19:06:16Z (19 years ago)

Author:

Martin Decky <martin@…>

Branches:

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

Children:

1065603e

Parents:

edc89bd

Message:

ppc32: initial stack, memory barriers, atomic operations, stack offset fix

File:

• arch/ppc32/include/atomic.h (modified) (1 diff)

arch/ppc32/include/atomic.h

@@ -34 +34 @@
 typedef struct { volatile __u32 count; } atomic_t;
 
-/*
- * TODO: these are just placeholders for real implementations of atomic_inc and atomic_dec.
- * WARNING: the following functions cause the code to be preemption-unsafe !!!
- */
+static inline void atomic_inc(atomic_t *val) {
+        __u32 tmp;
 
-static inline void atomic_inc(atomic_t *val) {
-        val->count++;
+        asm __volatile__ (
+                "1:\n"
+                "lwarx %0, 0, %2\n"
+                "addic %0, %0, 1\n"
+                "stwcx. %0, 0, %2\n"
+                "bne- 1b"
+                : "=&r" (tmp), "=m" (val->count)
+                : "r" (&val->count), "m" (val->count)
+                : "cc");
 }
 
 static inline void atomic_dec(atomic_t *val) {
-        val->count--;
+        __u32 tmp;
+
+        asm __volatile__(
+                "1:\n"
+                "lwarx %0, 0, %2\n"
+                "addic %0, %0, -1\n"
+                "stwcx. %0, 0, %2\n"
+                "bne- 1b"
+                : "=&r" (tmp), "=m" (val->count)
+                : "r" (&val->count), "m" (val->count)
+                : "cc");
 }