atomic.h: atomic_add_unless as inline. Remove system.h atomic.h circular dependency

atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
I agree (with Andi Kleen) this typeof is not needed and more error
prone. All the original atomic.h code that uses cmpxchg (which includes
the atomic_add_unless) uses defines instead of inline functions,
probably to circumvent a circular dependency between system.h and
atomic.h on powerpc (which my patch addresses). Therefore, it makes
sense to use inline functions that will provide type checking.

atomic_add_unless as inline. Remove system.h atomic.h circular dependency.
Digging into the FRV architecture shows me that it is also affected by
such a circular dependency. Here is the diff applying this against the
rest of my atomic.h patches.

It applies over the atomic.h standardization patches.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 69 insertions, 1 deletions

diff --git a/include/asm-frv/system.h b/include/asm-frv/system.h
index 1166899317d7..be303b3eef40 100644
--- a/include/asm-frv/system.h
+++ b/include/asm-frv/system.h
@@ -13,7 +13,6 @@
 #define _ASM_SYSTEM_H
 
 #include <linux/linkage.h>
-#include <asm/atomic.h>
 
 struct thread_struct;
 
@@ -197,4 +196,73 @@ extern void free_initmem(void);
 
 #define arch_align_stack(x) (x)
 
+/*****************************************************************************/
+/*
+ * compare and conditionally exchange value with memory
+ * - if (*ptr == test) then orig = *ptr; *ptr = test;
+ * - if (*ptr != test) then orig = *ptr;
+ */
+#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
+
+#define cmpxchg(ptr, test, new)							\
+({										\
+	__typeof__(ptr) __xg_ptr = (ptr);					\
+	__typeof__(*(ptr)) __xg_orig, __xg_tmp;					\
+	__typeof__(*(ptr)) __xg_test = (test);					\
+	__typeof__(*(ptr)) __xg_new = (new);					\
+										\
+	switch (sizeof(__xg_orig)) {						\
+	case 4:									\
+		asm volatile(							\
+			"0:						\n"	\
+			"	orcc		gr0,gr0,gr0,icc3	\n"	\
+			"	ckeq		icc3,cc7		\n"	\
+			"	ld.p		%M0,%1			\n"	\
+			"	orcr		cc7,cc7,cc3		\n"	\
+			"	sub%I4cc	%1,%4,%2,icc0		\n"	\
+			"	bne		icc0,#0,1f		\n"	\
+			"	cst.p		%3,%M0		,cc3,#1	\n"	\
+			"	corcc		gr29,gr29,gr0	,cc3,#1	\n"	\
+			"	beq		icc3,#0,0b		\n"	\
+			"1:						\n"	\
+			: "+U"(*__xg_ptr), "=&r"(__xg_orig), "=&r"(__xg_tmp)	\
+			: "r"(__xg_new), "NPr"(__xg_test)			\
+			: "memory", "cc7", "cc3", "icc3", "icc0"		\
+			);							\
+		break;								\
+										\
+	default:								\
+		__xg_orig = 0;							\
+		asm volatile("break");						\
+		break;								\
+	}									\
+										\
+	__xg_orig;								\
+})
+
+#else
+
+extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);
+
+#define cmpxchg(ptr, test, new)							\
+({										\
+	__typeof__(ptr) __xg_ptr = (ptr);					\
+	__typeof__(*(ptr)) __xg_orig;						\
+	__typeof__(*(ptr)) __xg_test = (test);					\
+	__typeof__(*(ptr)) __xg_new = (new);					\
+										\
+	switch (sizeof(__xg_orig)) {						\
+	case 4: __xg_orig = __cmpxchg_32(__xg_ptr, __xg_test, __xg_new); break;	\
+	default:								\
+		__xg_orig = 0;							\
+		asm volatile("break");						\
+		break;								\
+	}									\
+										\
+	__xg_orig;								\
+})
+
+#endif
+
+
 #endif /* _ASM_SYSTEM_H */