real i386 atomic_cmpset_int from -current. FreeBSD-stable won't ever
have DRM support for non-i386.
#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
#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