AGP_MODE_MODE_3
onoff("AGP 3.0 Mode", rval, AGP_MODE_MODE_3);
isagp3 = rval & AGP_MODE_MODE_3;
#define AGP_MODE_GET_MODE_3(x) __SHIFTOUT((x), AGP_MODE_MODE_3)
#define AGP_MODE_SET_MODE_3(x, v) (((x) & ~AGP_MODE_MODE_3) \
| __SHIFTIN((v), AGP_MODE_MODE_3))