MUTEX_ENTER
# define MUTEX_ENTER(x) spin_lock(&(x)->ipf_lk)
# define MUTEX_ENTER(x) simple_lock((x)->ipf_lk)
# define MUTEX_ENTER(x) eMmutex_enter(&(x)->ipf_emu, \
# define MUTEX_ENTER(x) ;
# define MUTEX_ENTER(x) mutex_enter(&(x)->ipf_lk)
# define MUTEX_ENTER(x) spinlock(&(x)->ipf_lk)
# undef MUTEX_ENTER
# define MUTEX_ENTER(x) mutex_lock(&(x)->ipf_lk, 0)
# define MUTEX_ENTER(x) (x)->ipf_lk.pl = LOCK((x)->ipf_lk.l, \
# define MUTEX_ENTER(x) simple_lock(&(x)->ipf_lk)
# define MUTEX_ENTER(x) mtx_lock(&(x)->ipf_lk)
#define MUTEX_ENTER(lock) mutex_enter(lock)
#define MUTEX_ENTER(lock) mutex_enter(lock)