-
- DISABLE_PREEMPTION()
-
- li a6,1 // lock value
-
- lwz a7,0(a0) // Get lock word
- mr. a7,a7 // Is it held?
- bne-- 6f // Yup...
-
-9: lwarx a7,0,a0 // read the lock
- mr. a7,a7 // Is it held?
- bne-- 7f // yes, kill reservation
- stwcx. a6,0,a0 // try to get the lock
- bne-- 9b // failed, try again
- li a0,1 // return TRUE
- isync
- blr // got it, return
-
-7: li a7,-4 // Point to a spot in the red zone
- stwcx. a7,a7,r1 // Kill reservation
-
-6:
- ENABLE_PREEMPTION()
- li a0,0 // return FALSE
- blr
-
+ li a6,1 // lock value
+ DISABLE_PREEMPTION()
+ lwarx a7,0,a0 // CEMV10
+8:
+ sync
+ lwarx a7,0,a0 // read the lock
+ cmpwi cr0,a7,0 // is it busy?
+ bne- 9f // yes, give up
+ sync
+ stwcx. a6,0,a0 // try to get the lock
+ bne- 8b // failed, try again
+ li a0,1 // return TRUE
+ isync
+ blr
+9:
+ ENABLE_PREEMPTION()
+ li a0,0 // return FALSE
+ blr