Instead of calling ia32_pause() conditionally on __i386__ or __amd64__

being defined, define and use a new MD macro, cpu_spinwait().  It only
expands to something on i386 and amd64, so the compiled code should be
identical.

Name of the macro found by:	jhb
Reviewed by:	jhb

8 files changed, 16 insertions, 19 deletions

diff --git a/sys/alpha/include/cpu.h b/sys/alpha/include/cpu.h
index 9db2b9a..64dc773b2 100644
--- a/sys/alpha/include/cpu.h
+++ b/sys/alpha/include/cpu.h
@@ -93,6 +93,7 @@ struct clockframe {
 #ifdef _KERNEL
 
 #define	cpu_getstack(td)	(alpha_pal_rdusp())
+#define	cpu_spinwait()		/* nothing */
 #define	get_cyclecount		alpha_rpcc
 
 void	cpu_halt(void);
diff --git a/sys/amd64/include/cpu.h b/sys/amd64/include/cpu.h
index f8a2ee3..f069d2e 100644
--- a/sys/amd64/include/cpu.h
+++ b/sys/amd64/include/cpu.h
@@ -50,9 +50,10 @@
 #undef	COPY_SIGCODE		/* don't copy sigcode above user stack in exec */
 
 #define	cpu_exec(p)	/* nothing */
-#define cpu_swapin(p)	/* nothing */
+#define	cpu_swapin(p)	/* nothing */
 #define	cpu_getstack(td)		((td)->td_frame->tf_rsp)
-#define cpu_setstack(td, ap)		((td)->td_frame->tf_rsp = (ap))
+#define	cpu_setstack(td, ap)		((td)->td_frame->tf_rsp = (ap))
+#define	cpu_spinwait()			ia32_pause()
 
 #define	TRAPF_USERMODE(framep) \
 	(ISPL((framep)->tf_cs) == SEL_UPL)
diff --git a/sys/arm/include/cpu.h b/sys/arm/include/cpu.h
index 2130618..417a2fe 100644
--- a/sys/arm/include/cpu.h
+++ b/sys/arm/include/cpu.h
@@ -32,6 +32,7 @@ get_cyclecount(void)
 
 #define cpu_getstack(td)        ((td)->td_frame->tf_usr_sp)
 #define cpu_setstack(td, sp)    ((td)->td_frame->tf_usr_sp = (sp))
+#define cpu_spinwait()		/* nothing */
 
 #define ARM_NVEC		8
 #define ARM_VEC_ALL		0xffffffff
diff --git a/sys/i386/include/cpu.h b/sys/i386/include/cpu.h
index ad5665b..fb1017f 100644
--- a/sys/i386/include/cpu.h
+++ b/sys/i386/include/cpu.h
@@ -50,9 +50,10 @@
 #undef	COPY_SIGCODE		/* don't copy sigcode above user stack in exec */
 
 #define	cpu_exec(p)	/* nothing */
-#define cpu_swapin(p)	/* nothing */
+#define	cpu_swapin(p)	/* nothing */
 #define	cpu_getstack(td)		((td)->td_frame->tf_esp)
-#define cpu_setstack(td, ap)		((td)->td_frame->tf_esp = (ap))
+#define	cpu_setstack(td, ap)		((td)->td_frame->tf_esp = (ap))
+#define	cpu_spinwait()			ia32_pause()
 
 #define	TRAPF_USERMODE(framep) \
 	((ISPL((framep)->tf_cs) == SEL_UPL) || ((framep)->tf_eflags & PSL_VM))
diff --git a/sys/ia64/include/cpu.h b/sys/ia64/include/cpu.h
index f6f6b5c..c7a4603 100644
--- a/sys/ia64/include/cpu.h
+++ b/sys/ia64/include/cpu.h
@@ -86,6 +86,7 @@ struct clockframe {
 
 /* Used by signaling code. */
 #define	cpu_getstack(td)	((td)->td_frame->tf_special.sp)
+#define	cpu_spinwait()		/* nothing */
 
 void	cpu_halt(void);
 void	cpu_reset(void);
diff --git a/sys/kern/kern_mutex.c b/sys/kern/kern_mutex.c
index 507df8a..7b66186 100644
--- a/sys/kern/kern_mutex.c
+++ b/sys/kern/kern_mutex.c
@@ -465,9 +465,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
 		 */
 		if (v == MTX_UNOWNED) {
 			turnstile_release(&m->mtx_object);
-#if defined(__i386__) || defined(__amd64__)
-			ia32_pause();
-#endif
+			cpu_spinwait();
 			continue;
 		}
 
@@ -497,9 +495,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
 		    !atomic_cmpset_ptr(&m->mtx_lock, (void *)v,
 			(void *)(v | MTX_CONTESTED))) {
 			turnstile_release(&m->mtx_object);
-#if defined(__i386__) || defined(__amd64__)
-			ia32_pause();
-#endif
+			cpu_spinwait();
 			continue;
 		}
 
@@ -516,9 +512,7 @@ _mtx_lock_sleep(struct mtx *m, int opts, const char *file, int line)
 #endif
 			turnstile_release(&m->mtx_object);
 			while (mtx_owner(m) == owner && TD_IS_RUNNING(owner)) {
-#if defined(__i386__) || defined(__amd64__)
-				ia32_pause();
-#endif
+				cpu_spinwait();
 			}
 			continue;
 		}
@@ -583,9 +577,7 @@ _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line)
 		critical_exit();
 		while (m->mtx_lock != MTX_UNOWNED) {
 			if (i++ < 10000000) {
-#if defined(__i386__) || defined(__amd64__)
-				ia32_pause();
-#endif
+				cpu_spinwait();
 				continue;
 			}
 			if (i < 60000000)
@@ -599,9 +591,7 @@ _mtx_lock_spin(struct mtx *m, int opts, const char *file, int line)
 #endif
 				panic("spin lock held too long");
 			}
-#if defined(__i386__) || defined(__amd64__)
-			ia32_pause();
-#endif
+			cpu_spinwait();
 		}
 		critical_enter();
 	}
diff --git a/sys/powerpc/include/cpu.h b/sys/powerpc/include/cpu.h
index 4e4119c..abe7ef4 100644
--- a/sys/powerpc/include/cpu.h
+++ b/sys/powerpc/include/cpu.h
@@ -89,6 +89,7 @@ get_cyclecount(void)
 }
 
 #define	cpu_getstack(td)	((td)->td_frame->fixreg[1])
+#define	cpu_spinwait()		/* nothing */
 
 void	cpu_halt(void);
 void	cpu_reset(void);
diff --git a/sys/sparc64/include/cpu.h b/sys/sparc64/include/cpu.h
index b00280d..4dfe1e9 100644
--- a/sys/sparc64/include/cpu.h
+++ b/sys/sparc64/include/cpu.h
@@ -48,6 +48,7 @@
 
 #define	cpu_getstack(td)	((td)->td_frame->tf_sp)
 #define	cpu_setstack(td, sp)	((td)->td_frame->tf_sp = (sp))
+#define	cpu_spinwait()		/* nothing */
 
 /*
  * CTL_MACHDEP definitions.