atomic_and_8
#define PGR_CLEAR_FLAG(flg, val) (atomic_and_8(&(flg), ~(val)))
#define PGR_CLEAR_RSV_FLAG(flg) (atomic_and_8(&(flg), \
extern void atomic_and_8(volatile uint8_t *, uint8_t);
atomic_and_8(&pp->p_toxic, ~bits);
atomic_and_8(&vci->evtchn_upcall_pending, 0);
__ATOMIC_OPXX(atomic_and_8, uint8_t, uint8_t, "and" SUF_8, "q")
atomic_and_8(&vmp->vmp_flags, ~VPF_DEFER_DIRTY);