From e60eb69bc029c04b39ef0de620002d5ba2433d04 Mon Sep 17 00:00:00 2001
From: Eric Anholt <anholt@freebsd.org>
Date: Sat, 26 Apr 2003 06:53:22 +0000
Subject: [PATCH] Replace the C atomic_cmpset_int compatibility function for
 -stable with the     real i386 atomic_cmpset_int from -current.
 FreeBSD-stable won't ever     have DRM support for non-i386.

---
 bsd-core/drm_os_freebsd.h | 25 ++++++++++++++++---------
 bsd/drm_os_freebsd.h      | 25 ++++++++++++++++---------
 2 files changed, 32 insertions(+), 18 deletions(-)

diff --git a/bsd-core/drm_os_freebsd.h b/bsd-core/drm_os_freebsd.h
index 461a26ce..acbd7cf3 100644
--- a/bsd-core/drm_os_freebsd.h
+++ b/bsd-core/drm_os_freebsd.h
@@ -249,16 +249,23 @@ typedef u_int8_t u8;
 #if __FreeBSD_version < 500000
 /* The extra atomic functions from 5.0 haven't been merged to 4.x */
 static __inline int
-atomic_cmpset_int(volatile int *dst, int old, int new)
+atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
 {
-	int s = splhigh();
-	if (*dst==old) {
-		*dst = new;
-		splx(s);
-		return 1;
-	}
-	splx(s);
-	return 0;
+	int res = exp;
+
+	__asm __volatile (
+	"	lock ;			"
+	"	cmpxchgl %1,%2 ;	"
+	"       setz	%%al ;		"
+	"	movzbl	%%al,%0 ;	"
+	"1:				"
+	"# atomic_cmpset_int"
+	: "+a" (res)			/* 0 (result) */
+	: "r" (src),			/* 1 */
+	  "m" (*(dst))			/* 2 */
+	: "memory");				 
+
+	return (res);
 }
 #endif
 
diff --git a/bsd/drm_os_freebsd.h b/bsd/drm_os_freebsd.h
index 461a26ce..acbd7cf3 100644
--- a/bsd/drm_os_freebsd.h
+++ b/bsd/drm_os_freebsd.h
@@ -249,16 +249,23 @@ typedef u_int8_t u8;
 #if __FreeBSD_version < 500000
 /* The extra atomic functions from 5.0 haven't been merged to 4.x */
 static __inline int
-atomic_cmpset_int(volatile int *dst, int old, int new)
+atomic_cmpset_int(volatile u_int *dst, u_int exp, u_int src)
 {
-	int s = splhigh();
-	if (*dst==old) {
-		*dst = new;
-		splx(s);
-		return 1;
-	}
-	splx(s);
-	return 0;
+	int res = exp;
+
+	__asm __volatile (
+	"	lock ;			"
+	"	cmpxchgl %1,%2 ;	"
+	"       setz	%%al ;		"
+	"	movzbl	%%al,%0 ;	"
+	"1:				"
+	"# atomic_cmpset_int"
+	: "+a" (res)			/* 0 (result) */
+	: "r" (src),			/* 1 */
+	  "m" (*(dst))			/* 2 */
+	: "memory");				 
+
+	return (res);
 }
 #endif