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.

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/or1k/atomic_arch.h b/arch/or1k/atomic_arch.h
new file mode 100644
index 00000000..11a54292
--- /dev/null
+++ b/arch/or1k/atomic_arch.h
@@ -0,0 +1,14 @@
+#define a_cas a_cas
+static inline int a_cas(volatile int *p, int t, int s)
+{
+	__asm__("1:	l.lwa %0, %1\n"
+		"	l.sfeq %0, %2\n"
+		"	l.bnf 1f\n"
+		"	 l.nop\n"
+		"	l.swa %1, %3\n"
+		"	l.bnf 1b\n"
+		"	 l.nop\n"
+		"1:	\n"
+		: "=&r"(t), "+m"(*p) : "r"(t), "r"(s) : "cc", "memory" );
+        return t;
+}