Some cleanups and tweaks to some of the atomic.h files in preparation for

further changes and fixes in the future:
- Use aliases via macros rather than duplicated inlines wherever possible.
- Move all the aliases to the bottom of these files and the inline
  functions to the top.
- Add various comments.
- On alpha, drop atomic_{load_acq,store_rel}_{8,char,16,short}().
- On i386 and amd64, don't duplicate the extern declarations for functions
  in the two non-inline cases (KLD_MODULE and compiler doesn't do inlines),
  instead, consolidate those two cases.
- Some whitespace fixes.

Approved by:	re (scottl)

3 files changed, 234 insertions, 253 deletions

diff --git a/sys/alpha/include/atomic.h b/sys/alpha/include/atomic.h
index cc2dbb4..ba384be 100644
--- a/sys/alpha/include/atomic.h
+++ b/sys/alpha/include/atomic.h
@@ -27,7 +27,7 @@
  */
 
 #ifndef _MACHINE_ATOMIC_H_
-#define _MACHINE_ATOMIC_H_
+#define	_MACHINE_ATOMIC_H_
 
 #ifndef _SYS_CDEFS_H_
 #error this file needs sys/cdefs.h as a prerequisite
@@ -216,29 +216,7 @@ static __inline u_int64_t atomic_readandclear_64(volatile u_int64_t *addr)
 	return result;
 }
 
-#define atomic_set_char		atomic_set_8
-#define atomic_clear_char	atomic_clear_8
-#define atomic_add_char		atomic_add_8
-#define atomic_subtract_char	atomic_subtract_8
-
-#define atomic_set_short	atomic_set_16
-#define atomic_clear_short	atomic_clear_16
-#define atomic_add_short	atomic_add_16
-#define atomic_subtract_short	atomic_subtract_16
-
-#define atomic_set_int		atomic_set_32
-#define atomic_clear_int	atomic_clear_32
-#define atomic_add_int		atomic_add_32
-#define atomic_subtract_int	atomic_subtract_32
-#define atomic_readandclear_int	atomic_readandclear_32
-
-#define atomic_set_long		atomic_set_64
-#define atomic_clear_long	atomic_clear_64
-#define atomic_add_long		atomic_add_64
-#define atomic_subtract_long	atomic_subtract_64
-#define atomic_readandclear_long	atomic_readandclear_64
-
-#define ATOMIC_ACQ_REL(NAME, WIDTH, TYPE)				\
+#define	ATOMIC_ACQ_REL(NAME, WIDTH)					\
 static __inline void							\
 atomic_##NAME##_acq_##WIDTH(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
 {									\
@@ -251,49 +229,36 @@ atomic_##NAME##_rel_##WIDTH(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
 {									\
 	alpha_mb();							\
 	atomic_##NAME##_##WIDTH(p, v);					\
-}									\
-									\
-static __inline void							\
-atomic_##NAME##_acq_##TYPE(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
-{									\
-	atomic_##NAME##_##WIDTH(p, v);					\
-	alpha_mb();							\
-}									\
-									\
-static __inline void							\
-atomic_##NAME##_rel_##TYPE(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
-{									\
-	alpha_mb();							\
-	atomic_##NAME##_##WIDTH(p, v);					\
 }
 
-ATOMIC_ACQ_REL(set, 8, char)
-ATOMIC_ACQ_REL(clear, 8, char)
-ATOMIC_ACQ_REL(add, 8, char)
-ATOMIC_ACQ_REL(subtract, 8, char)
-ATOMIC_ACQ_REL(set, 16, short)
-ATOMIC_ACQ_REL(clear, 16, short)
-ATOMIC_ACQ_REL(add, 16, short)
-ATOMIC_ACQ_REL(subtract, 16, short)
-ATOMIC_ACQ_REL(set, 32, int)
-ATOMIC_ACQ_REL(clear, 32, int)
-ATOMIC_ACQ_REL(add, 32, int)
-ATOMIC_ACQ_REL(subtract, 32, int)
-ATOMIC_ACQ_REL(set, 64, long)
-ATOMIC_ACQ_REL(clear, 64, long)
-ATOMIC_ACQ_REL(add, 64, long)
-ATOMIC_ACQ_REL(subtract, 64, long)
+/* Variants of simple arithmetic with memory barriers. */
+ATOMIC_ACQ_REL(set, 8)
+ATOMIC_ACQ_REL(clear, 8)
+ATOMIC_ACQ_REL(add, 8)
+ATOMIC_ACQ_REL(subtract, 8)
+ATOMIC_ACQ_REL(set, 16)
+ATOMIC_ACQ_REL(clear, 16)
+ATOMIC_ACQ_REL(add, 16)
+ATOMIC_ACQ_REL(subtract, 16)
+ATOMIC_ACQ_REL(set, 32)
+ATOMIC_ACQ_REL(clear, 32)
+ATOMIC_ACQ_REL(add, 32)
+ATOMIC_ACQ_REL(subtract, 32)
+ATOMIC_ACQ_REL(set, 64)
+ATOMIC_ACQ_REL(clear, 64)
+ATOMIC_ACQ_REL(add, 64)
+ATOMIC_ACQ_REL(subtract, 64)
 
 #undef ATOMIC_ACQ_REL
 
 /*
  * We assume that a = b will do atomic loads and stores.
  */
-#define ATOMIC_STORE_LOAD(TYPE, WIDTH)			\
-static __inline u_##TYPE				\
-atomic_load_acq_##WIDTH(volatile u_##TYPE *p)		\
+#define	ATOMIC_STORE_LOAD(WIDTH)			\
+static __inline u_int##WIDTH##_t			\
+atomic_load_acq_##WIDTH(volatile u_int##WIDTH##_t *p)	\
 {							\
-	u_##TYPE v;					\
+	u_int##WIDTH##_t v;				\
 							\
 	v = *p;						\
 	alpha_mb();					\
@@ -301,32 +266,14 @@ atomic_load_acq_##WIDTH(volatile u_##TYPE *p)		\
 }							\
 							\
 static __inline void					\
-atomic_store_rel_##WIDTH(volatile u_##TYPE *p, u_##TYPE v)\
-{							\
-	alpha_mb();					\
-	*p = v;						\
-}							\
-static __inline u_##TYPE				\
-atomic_load_acq_##TYPE(volatile u_##TYPE *p)		\
-{							\
-	u_##TYPE v;					\
-							\
-	v = *p;						\
-	alpha_mb();					\
-	return (v);					\
-}							\
-							\
-static __inline void					\
-atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
+atomic_store_rel_##WIDTH(volatile u_int##WIDTH##_t *p, u_int##WIDTH##_t v)\
 {							\
 	alpha_mb();					\
 	*p = v;						\
 }
 
-ATOMIC_STORE_LOAD(char,		8)
-ATOMIC_STORE_LOAD(short,	16)
-ATOMIC_STORE_LOAD(int,		32)
-ATOMIC_STORE_LOAD(long,		64)
+ATOMIC_STORE_LOAD(32)
+ATOMIC_STORE_LOAD(64)
 
 #undef ATOMIC_STORE_LOAD
 
@@ -384,17 +331,6 @@ atomic_cmpset_64(volatile u_int64_t* p, u_int64_t cmpval, u_int64_t newval)
 	return ret;
 }
 
-#define	atomic_cmpset_int	atomic_cmpset_32
-#define	atomic_cmpset_long	atomic_cmpset_64
-
-static __inline int
-atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
-{
-
-        return (atomic_cmpset_long((volatile u_long *)dst, (u_long)exp,
-            (u_long)src));
-}
-
 static __inline u_int32_t
 atomic_cmpset_acq_32(volatile u_int32_t *p, u_int32_t cmpval, u_int32_t newval)
 {
@@ -429,10 +365,82 @@ atomic_cmpset_rel_64(volatile u_int64_t *p, u_int64_t cmpval, u_int64_t newval)
 	return (atomic_cmpset_64(p, cmpval, newval));
 }
 
+/* Operations on chars. */
+#define	atomic_set_char		atomic_set_8
+#define	atomic_set_acq_char	atomic_set_acq_8
+#define	atomic_set_rel_char	atomic_set_rel_8
+#define	atomic_clear_char	atomic_clear_8
+#define	atomic_clear_acq_char	atomic_clear_acq_8
+#define	atomic_clear_rel_char	atomic_clear_rel_8
+#define	atomic_add_char		atomic_add_8
+#define	atomic_add_acq_char	atomic_add_acq_8
+#define	atomic_add_rel_char	atomic_add_rel_8
+#define	atomic_subtract_char	atomic_subtract_8
+#define	atomic_subtract_acq_char	atomic_subtract_acq_8
+#define	atomic_subtract_rel_char	atomic_subtract_rel_8
+
+/* Operations on shorts. */
+#define	atomic_set_short	atomic_set_16
+#define	atomic_set_acq_short	atomic_set_acq_16
+#define	atomic_set_rel_short	atomic_set_rel_16
+#define	atomic_clear_short	atomic_clear_16
+#define	atomic_clear_acq_short	atomic_clear_acq_16
+#define	atomic_clear_rel_short	atomic_clear_rel_16
+#define	atomic_add_short	atomic_add_16
+#define	atomic_add_acq_short	atomic_add_acq_16
+#define	atomic_add_rel_short	atomic_add_rel_16
+#define	atomic_subtract_short	atomic_subtract_16
+#define	atomic_subtract_acq_short	atomic_subtract_acq_16
+#define	atomic_subtract_rel_short	atomic_subtract_rel_16
+
+/* Operations on ints. */
+#define	atomic_set_int		atomic_set_32
+#define	atomic_set_acq_int	atomic_set_acq_32
+#define	atomic_set_rel_int	atomic_set_rel_32
+#define	atomic_clear_int	atomic_clear_32
+#define	atomic_clear_acq_int	atomic_clear_acq_32
+#define	atomic_clear_rel_int	atomic_clear_rel_32
+#define	atomic_add_int		atomic_add_32
+#define	atomic_add_acq_int	atomic_add_acq_32
+#define	atomic_add_rel_int	atomic_add_rel_32
+#define	atomic_subtract_int	atomic_subtract_32
+#define	atomic_subtract_acq_int	atomic_subtract_acq_32
+#define	atomic_subtract_rel_int	atomic_subtract_rel_32
+#define	atomic_cmpset_int	atomic_cmpset_32
 #define	atomic_cmpset_acq_int	atomic_cmpset_acq_32
 #define	atomic_cmpset_rel_int	atomic_cmpset_rel_32
+#define	atomic_load_acq_int	atomic_load_acq_32
+#define	atomic_store_rel_int	atomic_store_rel_32
+#define	atomic_readandclear_int	atomic_readandclear_32
+
+/* Operations on longs. */
+#define	atomic_set_long		atomic_set_64
+#define	atomic_set_acq_long	atomic_set_acq_64
+#define	atomic_set_rel_long	atomic_set_rel_64
+#define	atomic_clear_long	atomic_clear_64
+#define	atomic_clear_acq_long	atomic_clear_acq_64
+#define	atomic_clear_rel_long	atomic_clear_rel_64
+#define	atomic_add_long		atomic_add_64
+#define	atomic_add_acq_long	atomic_add_acq_64
+#define	atomic_add_rel_long	atomic_add_rel_64
+#define	atomic_subtract_long	atomic_subtract_64
+#define	atomic_subtract_acq_long	atomic_subtract_acq_64
+#define	atomic_subtract_rel_long	atomic_subtract_rel_64
+#define	atomic_cmpset_long	atomic_cmpset_64
 #define	atomic_cmpset_acq_long	atomic_cmpset_acq_64
 #define	atomic_cmpset_rel_long	atomic_cmpset_rel_64
+#define	atomic_load_acq_long	atomic_load_acq_64
+#define	atomic_store_rel_long	atomic_store_rel_64
+#define	atomic_readandclear_long	atomic_readandclear_64
+
+/* Operations on pointers. */
+static __inline int
+atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
+{
+
+        return (atomic_cmpset_long((volatile u_long *)dst, (u_long)exp,
+            (u_long)src));
+}
 
 static __inline int
 atomic_cmpset_acq_ptr(volatile void *dst, void *exp, void *src)
@@ -462,7 +470,7 @@ atomic_store_rel_ptr(volatile void *p, void *v)
 	atomic_store_rel_long((volatile u_long *)p, (u_long)v);
 }
 
-#define ATOMIC_PTR(NAME)				\
+#define	ATOMIC_PTR(NAME)				\
 static __inline void					\
 atomic_##NAME##_ptr(volatile void *p, uintptr_t v)	\
 {							\
diff --git a/sys/amd64/include/atomic.h b/sys/amd64/include/atomic.h
index eaf8068..296143a 100644
--- a/sys/amd64/include/atomic.h
+++ b/sys/amd64/include/atomic.h
@@ -26,7 +26,7 @@
  * $FreeBSD$
  */
 #ifndef _MACHINE_ATOMIC_H_
-#define _MACHINE_ATOMIC_H_
+#define	_MACHINE_ATOMIC_H_
 
 #ifndef _SYS_CDEFS_H_
 #error this file needs sys/cdefs.h as a prerequisite
@@ -67,8 +67,8 @@
  * Kernel modules call real functions which are built into the kernel.
  * This allows kernel modules to be portable between UP and SMP systems.
  */
-#if defined(KLD_MODULE)
-#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)			\
+#if defined(KLD_MODULE) || !(defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE))
+#define	ATOMIC_ASM(NAME, TYPE, OP, CONS, V)			\
 void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
 int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
@@ -78,25 +78,23 @@ int atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src);
 u_##TYPE	atomic_load_acq_##TYPE(volatile u_##TYPE *p);	\
 void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#else /* !KLD_MODULE */
-
-#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
+#else /* !KLD_MODULE && __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
 
 /*
  * For userland, assume the SMP case and use lock prefixes so that
  * the binaries will run on both types of systems.
  */
 #if defined(SMP) || !defined(_KERNEL)
-#define MPLOCKED	lock ;
+#define	MPLOCKED	lock ;
 #else
-#define MPLOCKED
+#define	MPLOCKED
 #endif
 
 /*
  * The assembly is volatilized to demark potential before-and-after side
  * effects if an interrupt or SMP collision were to occur.
  */
-#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)		\
+#define	ATOMIC_ASM(NAME, TYPE, OP, CONS, V)		\
 static __inline void					\
 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 {							\
@@ -106,13 +104,6 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
-
-#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)				\
-extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
-
-#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
-
 /*
  * Atomic compare and set, used by the mutex functions
  *
@@ -121,8 +112,6 @@ extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
  * Returns 0 on failure, non-zero on success
  */
 
-#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
-
 static __inline int
 atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
 {
@@ -162,11 +151,8 @@ atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
 
 	return (res);
 }
-#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
-
-#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
 
-#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
+#define	ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
 static __inline u_##TYPE				\
 atomic_load_acq_##TYPE(volatile u_##TYPE *p)		\
 {							\
@@ -193,18 +179,7 @@ atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
-
-extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
-extern int atomic_cmpset_long(volatile u_long *, u_long, u_long);
-
-#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)				\
-extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p);		\
-extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
-
-#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
-
-#endif /* KLD_MODULE */
+#endif /* KLD_MODULE || !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
 
 ATOMIC_ASM(set,	     char,  "orb %b1,%0",  "iq",  v);
 ATOMIC_ASM(clear,    char,  "andb %b1,%0", "iq", ~v);
@@ -234,6 +209,49 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgq %0,%1",  "xchgq %1,%0");
 #undef ATOMIC_ASM
 #undef ATOMIC_STORE_LOAD
 
+#if !defined(WANT_FUNCTIONS)
+
+/* Read the current value and store a zero in the destination. */
+#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
+
+static __inline u_int
+atomic_readandclear_int(volatile u_int *addr)
+{
+	u_int result;
+
+	__asm __volatile (
+	"	xorl	%0,%0 ;		"
+	"	xchgl	%1,%0 ;		"
+	"# atomic_readandclear_int"
+	: "=&r" (result)		/* 0 (result) */
+	: "m" (*addr));			/* 1 (addr) */
+
+	return (result);
+}
+
+static __inline u_long
+atomic_readandclear_long(volatile u_long *addr)
+{
+	u_long result;
+
+	__asm __volatile (
+	"	xorq	%0,%0 ;		"
+	"	xchgq	%1,%0 ;		"
+	"# atomic_readandclear_long"
+	: "=&r" (result)		/* 0 (result) */
+	: "m" (*addr));			/* 1 (addr) */
+
+	return (result);
+}
+
+#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
+
+u_int	atomic_readandclear_int(volatile u_int *);
+u_long	atomic_readandclear_long(volatile u_long *);
+
+#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
+
+/* Acquire and release variants are identical to the normal ones. */
 #define	atomic_set_acq_char		atomic_set_char
 #define	atomic_set_rel_char		atomic_set_char
 #define	atomic_clear_acq_char		atomic_clear_char
@@ -260,8 +278,8 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgq %0,%1",  "xchgq %1,%0");
 #define	atomic_add_rel_int		atomic_add_int
 #define	atomic_subtract_acq_int		atomic_subtract_int
 #define	atomic_subtract_rel_int		atomic_subtract_int
-#define atomic_cmpset_acq_int		atomic_cmpset_int
-#define atomic_cmpset_rel_int		atomic_cmpset_int
+#define	atomic_cmpset_acq_int		atomic_cmpset_int
+#define	atomic_cmpset_rel_int		atomic_cmpset_int
 
 #define	atomic_set_acq_long		atomic_set_long
 #define	atomic_set_rel_long		atomic_set_long
@@ -271,10 +289,13 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgq %0,%1",  "xchgq %1,%0");
 #define	atomic_add_rel_long		atomic_add_long
 #define	atomic_subtract_acq_long	atomic_subtract_long
 #define	atomic_subtract_rel_long	atomic_subtract_long
+#define	atomic_cmpset_acq_long		atomic_cmpset_long
+#define	atomic_cmpset_rel_long		atomic_cmpset_long
 
-#define atomic_cmpset_acq_ptr		atomic_cmpset_ptr
-#define atomic_cmpset_rel_ptr		atomic_cmpset_ptr
+#define	atomic_cmpset_acq_ptr		atomic_cmpset_ptr
+#define	atomic_cmpset_rel_ptr		atomic_cmpset_ptr
 
+/* Operations on 8-bit bytes. */
 #define	atomic_set_8		atomic_set_char
 #define	atomic_set_acq_8	atomic_set_acq_char
 #define	atomic_set_rel_8	atomic_set_rel_char
@@ -290,6 +311,7 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgq %0,%1",  "xchgq %1,%0");
 #define	atomic_load_acq_8	atomic_load_acq_char
 #define	atomic_store_rel_8	atomic_store_rel_char
 
+/* Operations on 16-bit words. */
 #define	atomic_set_16		atomic_set_short
 #define	atomic_set_acq_16	atomic_set_acq_short
 #define	atomic_set_rel_16	atomic_set_rel_short
@@ -305,6 +327,7 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgq %0,%1",  "xchgq %1,%0");
 #define	atomic_load_acq_16	atomic_load_acq_short
 #define	atomic_store_rel_16	atomic_store_rel_short
 
+/* Operations on 32-bit double words. */
 #define	atomic_set_32		atomic_set_int
 #define	atomic_set_acq_32	atomic_set_acq_int
 #define	atomic_set_rel_32	atomic_set_rel_int
@@ -324,7 +347,7 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgq %0,%1",  "xchgq %1,%0");
 #define	atomic_cmpset_rel_32	atomic_cmpset_rel_int
 #define	atomic_readandclear_32	atomic_readandclear_int
 
-#if !defined(WANT_FUNCTIONS)
+/* Operations on pointers. */
 static __inline int
 atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
 {
@@ -349,7 +372,7 @@ atomic_store_rel_ptr(volatile void *p, void *v)
 	atomic_store_rel_long((volatile u_long *)p, (u_long)v);
 }
 
-#define ATOMIC_PTR(NAME)				\
+#define	ATOMIC_PTR(NAME)				\
 static __inline void					\
 atomic_##NAME##_ptr(volatile void *p, uintptr_t v)	\
 {							\
@@ -375,44 +398,5 @@ ATOMIC_PTR(subtract)
 
 #undef ATOMIC_PTR
 
-#if defined(__GNUCLIKE_ASM) && defined(__CC_SUPPORTS___INLINE)
-
-static __inline u_int
-atomic_readandclear_int(volatile u_int *addr)
-{
-	u_int result;
-
-	__asm __volatile (
-	"	xorl	%0,%0 ;		"
-	"	xchgl	%1,%0 ;		"
-	"# atomic_readandclear_int"
-	: "=&r" (result)		/* 0 (result) */
-	: "m" (*addr));			/* 1 (addr) */
-
-	return (result);
-}
-
-static __inline u_long
-atomic_readandclear_long(volatile u_long *addr)
-{
-	u_long result;
-
-	__asm __volatile (
-	"	xorq	%0,%0 ;		"
-	"	xchgq	%1,%0 ;		"
-	"# atomic_readandclear_int"
-	: "=&r" (result)		/* 0 (result) */
-	: "m" (*addr));			/* 1 (addr) */
-
-	return (result);
-}
-
-#else /* !(__GNUCLIKE_ASM && __CC_SUPPORTS___INLINE) */
-
-extern u_long	atomic_readandclear_long(volatile u_long *);
-extern u_int	atomic_readandclear_int(volatile u_int *);
-
-#endif /* __GNUCLIKE_ASM && __CC_SUPPORTS___INLINE */
-
 #endif	/* !defined(WANT_FUNCTIONS) */
 #endif /* ! _MACHINE_ATOMIC_H_ */
diff --git a/sys/i386/include/atomic.h b/sys/i386/include/atomic.h
index 219a33b..4515ffb 100644
--- a/sys/i386/include/atomic.h
+++ b/sys/i386/include/atomic.h
@@ -26,7 +26,7 @@
  * $FreeBSD$
  */
 #ifndef _MACHINE_ATOMIC_H_
-#define _MACHINE_ATOMIC_H_
+#define	_MACHINE_ATOMIC_H_
 
 #ifndef _SYS_CDEFS_H_
 #error this file needs sys/cdefs.h as a prerequisite
@@ -67,8 +67,8 @@
  * Kernel modules call real functions which are built into the kernel.
  * This allows kernel modules to be portable between UP and SMP systems.
  */
-#if defined(KLD_MODULE)
-#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)			\
+#if defined(KLD_MODULE) || !defined(__GNUCLIKE_ASM)
+#define	ATOMIC_ASM(NAME, TYPE, OP, CONS, V)			\
 void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
 int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
@@ -77,25 +77,23 @@ int atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src);
 u_##TYPE	atomic_load_acq_##TYPE(volatile u_##TYPE *p);	\
 void		atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
 
-#else /* !KLD_MODULE */
-
-#ifdef __GNUCLIKE_ASM
+#else /* !KLD_MODULE && __GNUCLIKE_ASM */
 
 /*
  * For userland, assume the SMP case and use lock prefixes so that
  * the binaries will run on both types of systems.
  */
 #if defined(SMP) || !defined(_KERNEL)
-#define MPLOCKED	lock ;
+#define	MPLOCKED	lock ;
 #else
-#define MPLOCKED
+#define	MPLOCKED
 #endif
 
 /*
  * The assembly is volatilized to demark potential before-and-after side
  * effects if an interrupt or SMP collision were to occur.
  */
-#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)		\
+#define	ATOMIC_ASM(NAME, TYPE, OP, CONS, V)		\
 static __inline void					\
 atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 {							\
@@ -105,13 +103,6 @@ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\
 }							\
 struct __hack
 
-#else /* !__GNUCLIKE_ASM */
-
-#define ATOMIC_ASM(NAME, TYPE, OP, CONS, V)				\
-extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
-
-#endif /* __GNUCLIKE_ASM */
-
 /*
  * Atomic compare and set, used by the mutex functions
  *
@@ -120,8 +111,6 @@ extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
  * Returns 0 on failure, non-zero on success
  */
 
-#ifdef __GNUCLIKE_ASM
-
 #if defined(CPU_DISABLE_CMPXCHG)
 
 static __inline int
@@ -172,10 +161,6 @@ atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
 
 #endif /* defined(CPU_DISABLE_CMPXCHG) */
 
-#endif /* __GNUCLIKE_ASM */
-
-#ifdef __GNUCLIKE_ASM
-
 #if defined(_KERNEL) && !defined(SMP)
 
 /*
@@ -185,7 +170,7 @@ atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
  * SMP kernels.  For UP kernels, however, the cache of the single processor
  * is always consistent, so we don't need any memory barriers.
  */
-#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
+#define	ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
 static __inline u_##TYPE				\
 atomic_load_acq_##TYPE(volatile u_##TYPE *p)		\
 {							\
@@ -201,7 +186,7 @@ struct __hack
 
 #else /* defined(SMP) */
 
-#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
+#define	ATOMIC_STORE_LOAD(TYPE, LOP, SOP)		\
 static __inline u_##TYPE				\
 atomic_load_acq_##TYPE(volatile u_##TYPE *p)		\
 {							\
@@ -230,17 +215,7 @@ struct __hack
 
 #endif	/* !defined(SMP) */
 
-#else /* !__GNUCLIKE_ASM */
-
-extern int atomic_cmpset_int(volatile u_int *, u_int, u_int);
-
-#define ATOMIC_STORE_LOAD(TYPE, LOP, SOP)				\
-extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p);		\
-extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)
-
-#endif /* __GNUCLIKE_ASM */
-
-#endif /* KLD_MODULE */
+#endif /* KLD_MODULE || !__GNUCLIKE_ASM */
 
 ATOMIC_ASM(set,	     char,  "orb %b1,%0",  "iq",  v);
 ATOMIC_ASM(clear,    char,  "andb %b1,%0", "iq", ~v);
@@ -270,6 +245,57 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgl %0,%1",  "xchgl %1,%0");
 #undef ATOMIC_ASM
 #undef ATOMIC_STORE_LOAD
 
+#if !defined(WANT_FUNCTIONS)
+
+static __inline int
+atomic_cmpset_long(volatile u_long *dst, u_long exp, u_long src)
+{
+
+	return (atomic_cmpset_int((volatile u_int *)dst, (u_int)exp,
+	    (u_int)src));
+}
+
+/* Read the current value and store a zero in the destination. */
+#ifdef __GNUCLIKE_ASM
+
+static __inline u_int
+atomic_readandclear_int(volatile u_int *addr)
+{
+	u_int result;
+
+	__asm __volatile (
+	"	xorl	%0,%0 ;		"
+	"	xchgl	%1,%0 ;		"
+	"# atomic_readandclear_int"
+	: "=&r" (result)		/* 0 (result) */
+	: "m" (*addr));			/* 1 (addr) */
+
+	return (result);
+}
+
+static __inline u_long
+atomic_readandclear_long(volatile u_long *addr)
+{
+	u_long result;
+
+	__asm __volatile (
+	"	xorl	%0,%0 ;		"
+	"	xchgl	%1,%0 ;		"
+	"# atomic_readandclear_long"
+	: "=&r" (result)		/* 0 (result) */
+	: "m" (*addr));			/* 1 (addr) */
+
+	return (result);
+}
+
+#else /* !__GNUCLIKE_ASM */
+
+u_int	atomic_readandclear_int(volatile u_int *);
+u_long	atomic_readandclear_long(volatile u_long *);
+
+#endif /* __GNUCLIKE_ASM */
+
+/* Acquire and release variants are identical to the normal ones. */
 #define	atomic_set_acq_char		atomic_set_char
 #define	atomic_set_rel_char		atomic_set_char
 #define	atomic_clear_acq_char		atomic_clear_char
@@ -296,8 +322,8 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgl %0,%1",  "xchgl %1,%0");
 #define	atomic_add_rel_int		atomic_add_int
 #define	atomic_subtract_acq_int		atomic_subtract_int
 #define	atomic_subtract_rel_int		atomic_subtract_int
-#define atomic_cmpset_acq_int		atomic_cmpset_int
-#define atomic_cmpset_rel_int		atomic_cmpset_int
+#define	atomic_cmpset_acq_int		atomic_cmpset_int
+#define	atomic_cmpset_rel_int		atomic_cmpset_int
 
 #define	atomic_set_acq_long		atomic_set_long
 #define	atomic_set_rel_long		atomic_set_long
@@ -307,13 +333,13 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgl %0,%1",  "xchgl %1,%0");
 #define	atomic_add_rel_long		atomic_add_long
 #define	atomic_subtract_acq_long	atomic_subtract_long
 #define	atomic_subtract_rel_long	atomic_subtract_long
-#define	atomic_cmpset_long		atomic_cmpset_int
-#define	atomic_cmpset_acq_long		atomic_cmpset_acq_int
-#define	atomic_cmpset_rel_long		atomic_cmpset_rel_int
+#define	atomic_cmpset_acq_long		atomic_cmpset_long
+#define	atomic_cmpset_rel_long		atomic_cmpset_long
 
-#define atomic_cmpset_acq_ptr		atomic_cmpset_ptr
-#define atomic_cmpset_rel_ptr		atomic_cmpset_ptr
+#define	atomic_cmpset_acq_ptr		atomic_cmpset_ptr
+#define	atomic_cmpset_rel_ptr		atomic_cmpset_ptr
 
+/* Operations on 8-bit bytes. */
 #define	atomic_set_8		atomic_set_char
 #define	atomic_set_acq_8	atomic_set_acq_char
 #define	atomic_set_rel_8	atomic_set_rel_char
@@ -329,6 +355,7 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgl %0,%1",  "xchgl %1,%0");
 #define	atomic_load_acq_8	atomic_load_acq_char
 #define	atomic_store_rel_8	atomic_store_rel_char
 
+/* Operations on 16-bit words. */
 #define	atomic_set_16		atomic_set_short
 #define	atomic_set_acq_16	atomic_set_acq_short
 #define	atomic_set_rel_16	atomic_set_rel_short
@@ -344,6 +371,7 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgl %0,%1",  "xchgl %1,%0");
 #define	atomic_load_acq_16	atomic_load_acq_short
 #define	atomic_store_rel_16	atomic_store_rel_short
 
+/* Operations on 32-bit double words. */
 #define	atomic_set_32		atomic_set_int
 #define	atomic_set_acq_32	atomic_set_acq_int
 #define	atomic_set_rel_32	atomic_set_rel_int
@@ -363,7 +391,7 @@ ATOMIC_STORE_LOAD(long,	"cmpxchgl %0,%1",  "xchgl %1,%0");
 #define	atomic_cmpset_rel_32	atomic_cmpset_rel_int
 #define	atomic_readandclear_32	atomic_readandclear_int
 
-#if !defined(WANT_FUNCTIONS)
+/* Operations on pointers. */
 static __inline int
 atomic_cmpset_ptr(volatile void *dst, void *exp, void *src)
 {
@@ -388,7 +416,7 @@ atomic_store_rel_ptr(volatile void *p, void *v)
 	atomic_store_rel_int((volatile u_int *)p, (u_int)v);
 }
 
-#define ATOMIC_PTR(NAME)				\
+#define	ATOMIC_PTR(NAME)				\
 static __inline void					\
 atomic_##NAME##_ptr(volatile void *p, uintptr_t v)	\
 {							\
@@ -414,44 +442,5 @@ ATOMIC_PTR(subtract)
 
 #undef ATOMIC_PTR
 
-#ifdef __GNUCLIKE_ASM
-
-static __inline u_int
-atomic_readandclear_int(volatile u_int *addr)
-{
-	u_int result;
-
-	__asm __volatile (
-	"	xorl	%0,%0 ;		"
-	"	xchgl	%1,%0 ;		"
-	"# atomic_readandclear_int"
-	: "=&r" (result)		/* 0 (result) */
-	: "m" (*addr));			/* 1 (addr) */
-
-	return (result);
-}
-
-static __inline u_long
-atomic_readandclear_long(volatile u_long *addr)
-{
-	u_long result;
-
-	__asm __volatile (
-	"	xorl	%0,%0 ;		"
-	"	xchgl	%1,%0 ;		"
-	"# atomic_readandclear_int"
-	: "=&r" (result)		/* 0 (result) */
-	: "m" (*addr));			/* 1 (addr) */
-
-	return (result);
-}
-
-#else /* !__GNUCLIKE_ASM */
-
-extern u_long	atomic_readandclear_long(volatile u_long *);
-extern u_int	atomic_readandclear_int(volatile u_int *);
-
-#endif /* __GNUCLIKE_ASM */
-
 #endif	/* !defined(WANT_FUNCTIONS) */
 #endif /* ! _MACHINE_ATOMIC_H_ */