1 files changed, 112 insertions, 0 deletions
diff --git a/arch/arm/atomic.h b/arch/arm/atomic.h
new file mode 100644
index 00000000..8dc31b2e
--- /dev/null
+++ b/arch/arm/atomic.h
@@ -0,0 +1,112 @@
+#ifndef _INTERNAL_ATOMIC_H
+#define _INTERNAL_ATOMIC_H
+
+#include <stdint.h>
+
+static inline int a_ctz_l(unsigned long x)
+{
+	static const char debruijn32[32] = {
+		0, 1, 23, 2, 29, 24, 19, 3, 30, 27, 25, 11, 20, 8, 4, 13,
+		31, 22, 28, 18, 26, 10, 7, 12, 21, 17, 9, 6, 16, 5, 15, 14
+	};
+	return debruijn32[(x&-x)*0x076be629 >> 27];
+}
+
+static inline int a_ctz_64(uint64_t x)
+{
+	uint32_t y = x;
+	if (!y) {
+		y = x>>32;
+		return 32 + a_ctz_l(y);
+	}
+	return a_ctz_l(y);
+}
+
+static inline int a_cas(volatile int *p, int t, int s)
+{
+	int old;
+	for (;;) {
+		if (!((int (*)(int, int, volatile int *))0xffff0fc0)(t, s, p))
+			return t;
+		if ((old=*p) != t)
+			return old;
+	}
+}
+
+static inline void *a_cas_p(volatile void *p, void *t, void *s)
+{
+	return (void *)a_cas(p, (int)t, (int)s);
+}
+
+static inline long a_cas_l(volatile void *p, long t, long s)
+{
+	return a_cas(p, t, s);
+}
+
+static inline int a_swap(volatile int *x, int v)
+{
+	int old;
+	do old = *x;
+	while (a_cas(x, old, v) != old);
+	return old;
+}
+
+static inline int a_fetch_add(volatile int *x, int v)
+{
+	int old;
+	do old = *x;
+	while (a_cas(x, old, old+v) != old);
+	return old;
+}
+
+static inline void a_inc(volatile int *x)
+{
+	a_fetch_add(x, 1);
+}
+
+static inline void a_dec(volatile int *x)
+{
+	a_fetch_add(x, -1);
+}
+
+static inline void a_store(volatile int *p, int x)
+{
+	*p=x;
+}
+
+static inline void a_spin()
+{
+}
+
+static inline void a_crash()
+{
+	*(volatile char *)0=0;
+}
+
+static inline void a_and(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, old&v) != old);
+}
+
+static inline void a_or(volatile int *p, int v)
+{
+	int old;
+	do old = *p;
+	while (a_cas(p, old, old|v) != old);
+}
+
+static inline void a_and_64(volatile uint64_t *p, uint64_t v)
+{
+	a_and((int *)p, v);
+	a_and((int *)p+1, v>>32);
+}
+
+static inline void a_or_64(volatile uint64_t *p, uint64_t v)
+{
+	a_or((int *)p, v);
+	a_or((int *)p+1, v>>32);
+}
+
+#endif