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

1 files changed, 5 insertions, 15 deletions

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();
 	}