path: root/arch/powerpc/atomic_arch.h
diff options
authorRich Felker <>2016-01-21 19:08:54 +0000
committerRich Felker <>2016-01-21 19:08:54 +0000
commit1315596b510189b5159e742110b504177bdd4932 (patch)
tree27159b7b95b944671454b11f36ee13308241f4b5 /arch/powerpc/atomic_arch.h
parentce3e24eaae91e7a90f87eb7f1edea8df5942de11 (diff)
refactor internal atomic.h
rather than having each arch provide its own atomic.h, there is a new shared atomic.h in src/internal which pulls arch-specific definitions from arc/$(ARCH)/atomic_arch.h. the latter can be extremely minimal, defining only a_cas or new ll/sc type primitives which the shared atomic.h will use to construct everything else. this commit avoids making heavy changes to the individual archs' atomic implementations. definitions which are identical or near-identical to what the new shared atomic.h would produce have been removed, but otherwise the changes made are just hooking up the arch-specific files to the new infrastructure. major changes to take advantage of the new system will come in subsequent commits.
Diffstat (limited to 'arch/powerpc/atomic_arch.h')
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/powerpc/atomic_arch.h b/arch/powerpc/atomic_arch.h
new file mode 100644
index 00000000..f014e3b8
--- /dev/null
+++ b/arch/powerpc/atomic_arch.h
@@ -0,0 +1,15 @@
+#define a_cas a_cas
+static inline int a_cas(volatile int *p, int t, int s)
+ __asm__("\n"
+ " sync\n"
+ "1: lwarx %0, 0, %4\n"
+ " cmpw %0, %2\n"
+ " bne 1f\n"
+ " stwcx. %3, 0, %4\n"
+ " bne- 1b\n"
+ " isync\n"
+ "1: \n"
+ : "=&r"(t), "+m"(*p) : "r"(t), "r"(s), "r"(p) : "cc", "memory" );
+ return t;