tx_lock            42 kernel/uart.c  static struct spinlock tx_lock;
tx_lock            74 kernel/uart.c    initlock(&tx_lock, "uart");
tx_lock            83 kernel/uart.c    acquire(&tx_lock);
tx_lock            90 kernel/uart.c        sleep(&tx_chan, &tx_lock);
tx_lock            98 kernel/uart.c    release(&tx_lock);
tx_lock           147 kernel/uart.c    acquire(&tx_lock);
tx_lock           153 kernel/uart.c    release(&tx_lock);