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, 96 insertions, 0 deletions

diff --git a/arch/sh/atomic_arch.h b/arch/sh/atomic_arch.h
new file mode 100644
index 00000000..2ac77246
--- /dev/null
+++ b/arch/sh/atomic_arch.h
@@ -0,0 +1,96 @@
+#define LLSC_CLOBBERS "r0", "t", "memory"
+#define LLSC_START(mem) "synco\n"  \
+	"0:	movli.l @" mem ", r0\n"
+#define LLSC_END(mem)              \
+	"1:	movco.l r0, @" mem "\n"    \
+	"	bf 0b\n"                   \
+	"	synco\n"
+
+static inline int __sh_cas_llsc(volatile int *p, int t, int s)
+{
+	int old;
+	__asm__ __volatile__(
+		LLSC_START("%1")
+		"	mov r0, %0\n"
+		"	cmp/eq %0, %2\n"
+		"	bf 1f\n"
+		"	mov %3, r0\n"
+		LLSC_END("%1")
+		: "=&r"(old) : "r"(p), "r"(t), "r"(s) : LLSC_CLOBBERS);
+	return old;
+}
+
+static inline int __sh_swap_llsc(volatile int *x, int v)
+{
+	int old;
+	__asm__ __volatile__(
+		LLSC_START("%1")
+		"	mov r0, %0\n"
+		"	mov %2, r0\n"
+		LLSC_END("%1")
+		: "=&r"(old) : "r"(x), "r"(v) : LLSC_CLOBBERS);
+	return old;
+}
+
+static inline int __sh_fetch_add_llsc(volatile int *x, int v)
+{
+	int old;
+	__asm__ __volatile__(
+		LLSC_START("%1")
+		"	mov r0, %0\n"
+		"	add %2, r0\n"
+		LLSC_END("%1")
+		: "=&r"(old) : "r"(x), "r"(v) : LLSC_CLOBBERS);
+	return old;
+}
+
+static inline void __sh_store_llsc(volatile int *p, int x)
+{
+	__asm__ __volatile__(
+		"	synco\n"
+		"	mov.l %1, @%0\n"
+		"	synco\n"
+		: : "r"(p), "r"(x) : "memory");
+}
+
+static inline void __sh_and_llsc(volatile int *x, int v)
+{
+	__asm__ __volatile__(
+		LLSC_START("%0")
+		"	and %1, r0\n"
+		LLSC_END("%0")
+		: : "r"(x), "r"(v) : LLSC_CLOBBERS);
+}
+
+static inline void __sh_or_llsc(volatile int *x, int v)
+{
+	__asm__ __volatile__(
+		LLSC_START("%0")
+		"	or %1, r0\n"
+		LLSC_END("%0")
+		: : "r"(x), "r"(v) : LLSC_CLOBBERS);
+}
+
+#ifdef __SH4A__
+#define a_cas(p,t,s)     __sh_cas_llsc(p,t,s)
+#define a_swap(x,v)      __sh_swap_llsc(x,v)
+#define a_fetch_add(x,v) __sh_fetch_add_llsc(x, v)
+#define a_store(x,v)     __sh_store_llsc(x, v)
+#define a_and(x,v)       __sh_and_llsc(x, v)
+#define a_or(x,v)        __sh_or_llsc(x, v)
+#else
+
+int  __sh_cas(volatile int *, int, int);
+int  __sh_swap(volatile int *, int);
+int  __sh_fetch_add(volatile int *, int);
+void __sh_store(volatile int *, int);
+void __sh_and(volatile int *, int);
+void __sh_or(volatile int *, int);
+
+#define a_cas(p,t,s)     __sh_cas(p,t,s)
+#define a_swap(x,v)      __sh_swap(x,v)
+#define a_fetch_add(x,v) __sh_fetch_add(x, v)
+#define a_store(x,v)     __sh_store(x, v)
+#define a_and(x,v)       __sh_and(x, v)
+#define a_or(x,v)        __sh_or(x, v)
+#endif