sh: Provide movli.l/movco.l-based cmpxchg.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/include/asm/cmpxchg-llsc.h

@@ -0,0 +1,71 @@
+#ifndef __ASM_SH_CMPXCHG_LLSC_H
+#define __ASM_SH_CMPXCHG_LLSC_H
+
+static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
+{
+	unsigned long retval;
+	unsigned long tmp;
+
+	__asm__ __volatile__ (
+		"1:					\n\t"
+		"movli.l	@%1, %0	! xchg_u32	\n\t"
+		"mov		%0, %2			\n\t"
+		"mov		%4, %0			\n\t"
+		"movco.l	%0, @%1			\n\t"
+		"bf		1b			\n\t"
+		"synco					\n\t"
+		: "=&z"(tmp), "=r" (m), "=&r" (retval)
+		: "1" (m), "r" (val)
+		: "t", "memory"
+	);
+
+	return retval;
+}
+
+static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
+{
+	unsigned long retval;
+	unsigned long tmp;
+
+	__asm__ __volatile__ (
+		"1:					\n\t"
+		"movli.l	@%1, %0	! xchg_u8	\n\t"
+		"mov		%0, %2			\n\t"
+		"mov		%4, %0			\n\t"
+		"movco.l	%0, @%1			\n\t"
+		"bf		1b			\n\t"
+		"synco					\n\t"
+		: "=&z"(tmp), "=r" (m), "=&r" (retval)
+		: "1" (m), "r" (val & 0xff)
+		: "t", "memory"
+	);
+
+	return retval;
+}
+
+static inline unsigned long
+__cmpxchg_u32(volatile int *m, unsigned long old, unsigned long new)
+{
+	unsigned long retval;
+	unsigned long tmp;
+
+	__asm__ __volatile__ (
+		"1:						\n\t"
+		"movli.l	@%1, %0	! __cmpxchg_u32		\n\t"
+		"mov		%0, %2				\n\t"
+		"cmp/eq		%2, %4				\n\t"
+		"bf		2f				\n\t"
+		"mov		%5, %0				\n\t"
+		"2:						\n\t"
+		"movco.l	%0, @%1				\n\t"
+		"bf		1b				\n\t"
+		"synco						\n\t"
+		: "=&z" (tmp), "=r" (m), "=&r" (retval)
+		: "1" (m), "r" (old), "r" (new)
+		: "t", "memory"
+	);
+
+	return retval;
+}
+
+#endif /* __ASM_SH_CMPXCHG_LLSC_H */

arch/sh/include/asm/system.h

@@ -70,6 +70,8 @@
 
 #ifdef CONFIG_GUSA_RB
 #include <asm/cmpxchg-grb.h>
+#elif defined(CONFIG_CPU_SH4A)
+#include <asm/cmpxchg-llsc.h>
 #else
 #include <asm/cmpxchg-irq.h>
 #endif