sh: add J2 atomics using the cas.l instruction

Signed-off-by: Rich Felker <dalias@libc.org>

1 files changed, 93 insertions, 0 deletions

diff --git a/arch/sh/include/asm/bitops-cas.h b/arch/sh/include/asm/bitops-cas.h
new file mode 100644
index 000000000000..88f793c04d3c
--- /dev/null
+++ b/arch/sh/include/asm/bitops-cas.h
@@ -0,0 +1,93 @@
+#ifndef __ASM_SH_BITOPS_CAS_H
+#define __ASM_SH_BITOPS_CAS_H
+
+static inline unsigned __bo_cas(volatile unsigned *p, unsigned old, unsigned new)
+{
+	__asm__ __volatile__("cas.l %1,%0,@r0"
+		: "+r"(new)
+		: "r"(old), "z"(p)
+		: "t", "memory" );
+	return new;
+}
+
+static inline void set_bit(int nr, volatile void *addr)
+{
+	unsigned mask, old;
+	volatile unsigned *a = addr;
+
+	a += nr >> 5;
+	mask = 1U << (nr & 0x1f);
+
+	do old = *a;
+	while (__bo_cas(a, old, old|mask) != old);
+}
+
+static inline void clear_bit(int nr, volatile void *addr)
+{
+	unsigned mask, old;
+	volatile unsigned *a = addr;
+
+	a += nr >> 5;
+	mask = 1U << (nr & 0x1f);
+
+	do old = *a;
+	while (__bo_cas(a, old, old&~mask) != old);
+}
+
+static inline void change_bit(int nr, volatile void *addr)
+{
+	unsigned mask, old;
+	volatile unsigned *a = addr;
+
+	a += nr >> 5;
+	mask = 1U << (nr & 0x1f);
+
+	do old = *a;
+	while (__bo_cas(a, old, old^mask) != old);
+}
+
+static inline int test_and_set_bit(int nr, volatile void *addr)
+{
+	unsigned mask, old;
+	volatile unsigned *a = addr;
+
+	a += nr >> 5;
+	mask = 1U << (nr & 0x1f);
+
+	do old = *a;
+	while (__bo_cas(a, old, old|mask) != old);
+
+	return !!(old & mask);
+}
+
+static inline int test_and_clear_bit(int nr, volatile void *addr)
+{
+	unsigned mask, old;
+	volatile unsigned *a = addr;
+
+	a += nr >> 5;
+	mask = 1U << (nr & 0x1f);
+
+	do old = *a;
+	while (__bo_cas(a, old, old&~mask) != old);
+
+	return !!(old & mask);
+}
+
+static inline int test_and_change_bit(int nr, volatile void *addr)
+{
+	unsigned mask, old;
+	volatile unsigned *a = addr;
+
+	a += nr >> 5;
+	mask = 1U << (nr & 0x1f);
+
+	do old = *a;
+	while (__bo_cas(a, old, old^mask) != old);
+
+	return !!(old & mask);
+}
+
+#include <asm-generic/bitops/non-atomic.h>
+
+#endif /* __ASM_SH_BITOPS_CAS_H */