/** * reset_buffer_flags - reset buffer state * @tty: terminal to reset * * Reset the read buffer counters, clear the flags, * and make sure the driver is unthrottled. Called * from n_tty_open() and n_tty_flush_buffer(). */ static void reset_buffer_flags(struct tty_struct *tty) { unsigned long flags; spin_lock_irqsave(&tty->read_lock, flags); tty->read_head = tty->read_tail = tty->read_cnt = 0; spin_unlock_irqrestore(&tty->read_lock, flags); tty->canon_head = tty->canon_data = tty->erasing = 0; memset(&tty->read_flags, 0, sizeof tty->read_flags); n_tty_set_room(tty); check_unthrottle(tty); }
static void reset_buffer_flags(struct tty_struct *tty) { unsigned long flags; spin_lock_irqsave(&tty->read_lock, flags); tty->read_head = tty->read_tail = tty->read_cnt = 0; spin_unlock_irqrestore(&tty->read_lock, flags); mutex_lock(&tty->echo_lock); tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0; mutex_unlock(&tty->echo_lock); tty->canon_head = tty->canon_data = tty->erasing = 0; memset(&tty->read_flags, 0, sizeof tty->read_flags); n_tty_set_room(tty); }
static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { const unsigned char *p; char *f, flags = TTY_NORMAL; int i; char buf[64]; unsigned long cpuflags; if (!tty->read_buf) return; if (tty->real_raw) { spin_lock_irqsave(&tty->read_lock, cpuflags); i = min(N_TTY_BUF_SIZE - tty->read_cnt, N_TTY_BUF_SIZE - tty->read_head); i = min(count, i); memcpy(tty->read_buf + tty->read_head, cp, i); tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); tty->read_cnt += i; cp += i; count -= i; i = min(N_TTY_BUF_SIZE - tty->read_cnt, N_TTY_BUF_SIZE - tty->read_head); i = min(count, i); memcpy(tty->read_buf + tty->read_head, cp, i); tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); tty->read_cnt += i; spin_unlock_irqrestore(&tty->read_lock, cpuflags); } else { for (i = count, p = cp, f = fp; i; i--, p++) { if (f) flags = *f++; switch (flags) { case TTY_NORMAL: n_tty_receive_char(tty, *p); break; case TTY_BREAK: n_tty_receive_break(tty); break; case TTY_PARITY: case TTY_FRAME: n_tty_receive_parity_error(tty, *p); break; case TTY_OVERRUN: n_tty_receive_overrun(tty); break; default: printk(KERN_ERR "%s: unknown flag %d\n", tty_name(tty, buf), flags); break; } } if (tty->ops->flush_chars) tty->ops->flush_chars(tty); } n_tty_set_room(tty); if ((!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) || L_EXTPROC(tty)) { kill_fasync(&tty->fasync, SIGIO, POLL_IN); if (waitqueue_active(&tty->read_wait)) wake_up_interruptible(&tty->read_wait); } if (tty->receive_room < TTY_THRESHOLD_THROTTLE) tty_throttle(tty); }
static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, unsigned char __user *buf, size_t nr) { unsigned char __user *b = buf; DECLARE_WAITQUEUE(wait, current); int c; int minimum, time; ssize_t retval = 0; ssize_t size; long timeout; unsigned long flags; int packet; do_it_again: BUG_ON(!tty->read_buf); c = job_control(tty, file); if (c < 0) return c; minimum = time = 0; timeout = MAX_SCHEDULE_TIMEOUT; if (!tty->icanon) { time = (HZ / 10) * TIME_CHAR(tty); minimum = MIN_CHAR(tty); if (minimum) { if (time) tty->minimum_to_wake = 1; else if (!waitqueue_active(&tty->read_wait) || (tty->minimum_to_wake > minimum)) tty->minimum_to_wake = minimum; } else { timeout = 0; if (time) { timeout = time; time = 0; } tty->minimum_to_wake = minimum = 1; } } if (file->f_flags & O_NONBLOCK) { if (!mutex_trylock(&tty->atomic_read_lock)) return -EAGAIN; } else { if (mutex_lock_interruptible(&tty->atomic_read_lock)) return -ERESTARTSYS; } packet = tty->packet; add_wait_queue(&tty->read_wait, &wait); while (nr) { if (packet && tty->link->ctrl_status) { unsigned char cs; if (b != buf) break; spin_lock_irqsave(&tty->link->ctrl_lock, flags); cs = tty->link->ctrl_status; tty->link->ctrl_status = 0; spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); if (tty_put_user(tty, cs, b++)) { retval = -EFAULT; b--; break; } nr--; break; } set_current_state(TASK_INTERRUPTIBLE); if (((minimum - (b - buf)) < tty->minimum_to_wake) && ((minimum - (b - buf)) >= 1)) tty->minimum_to_wake = (minimum - (b - buf)); if (!input_available_p(tty, 0)) { if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { retval = -EIO; break; } if (tty_hung_up_p(file)) break; if (!timeout) break; if (file->f_flags & O_NONBLOCK) { retval = -EAGAIN; break; } if (signal_pending(current)) { retval = -ERESTARTSYS; break; } n_tty_set_room(tty); timeout = schedule_timeout(timeout); BUG_ON(!tty->read_buf); continue; } __set_current_state(TASK_RUNNING); if (packet && b == buf) { if (tty_put_user(tty, TIOCPKT_DATA, b++)) { retval = -EFAULT; b--; break; } nr--; } if (tty->icanon && !L_EXTPROC(tty)) { while (nr && tty->read_cnt) { int eol; eol = test_and_clear_bit(tty->read_tail, tty->read_flags); c = tty->read_buf[tty->read_tail]; spin_lock_irqsave(&tty->read_lock, flags); tty->read_tail = ((tty->read_tail+1) & (N_TTY_BUF_SIZE-1)); tty->read_cnt--; if (eol) { if (--tty->canon_data < 0) tty->canon_data = 0; } spin_unlock_irqrestore(&tty->read_lock, flags); if (!eol || (c != __DISABLED_CHAR)) { if (tty_put_user(tty, c, b++)) { retval = -EFAULT; b--; break; } nr--; } if (eol) { tty_audit_push(tty); break; } } if (retval) break; } else { int uncopied; uncopied = copy_from_read_buf(tty, &b, &nr); uncopied += copy_from_read_buf(tty, &b, &nr); if (uncopied) { retval = -EFAULT; break; } } if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) { n_tty_set_room(tty); check_unthrottle(tty); } if (b - buf >= minimum) break; if (time) timeout = time; } mutex_unlock(&tty->atomic_read_lock); remove_wait_queue(&tty->read_wait, &wait); if (!waitqueue_active(&tty->read_wait)) tty->minimum_to_wake = minimum; __set_current_state(TASK_RUNNING); size = b - buf; if (size) { retval = size; if (nr) clear_bit(TTY_PUSH, &tty->flags); } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) goto do_it_again; n_tty_set_room(tty); return retval; }
static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) { int canon_change = 1; BUG_ON(!tty); if (old) canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON; if (canon_change) { memset(&tty->read_flags, 0, sizeof tty->read_flags); tty->canon_head = tty->read_tail; tty->canon_data = 0; tty->erasing = 0; } if (canon_change && !L_ICANON(tty) && tty->read_cnt) wake_up_interruptible(&tty->read_wait); tty->icanon = (L_ICANON(tty) != 0); if (test_bit(TTY_HW_COOK_IN, &tty->flags)) { tty->raw = 1; tty->real_raw = 1; n_tty_set_room(tty); return; } if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || I_PARMRK(tty)) { memset(tty->process_char_map, 0, 256/8); if (I_IGNCR(tty) || I_ICRNL(tty)) set_bit('\r', tty->process_char_map); if (I_INLCR(tty)) set_bit('\n', tty->process_char_map); if (L_ICANON(tty)) { set_bit(ERASE_CHAR(tty), tty->process_char_map); set_bit(KILL_CHAR(tty), tty->process_char_map); set_bit(EOF_CHAR(tty), tty->process_char_map); set_bit('\n', tty->process_char_map); set_bit(EOL_CHAR(tty), tty->process_char_map); if (L_IEXTEN(tty)) { set_bit(WERASE_CHAR(tty), tty->process_char_map); set_bit(LNEXT_CHAR(tty), tty->process_char_map); set_bit(EOL2_CHAR(tty), tty->process_char_map); if (L_ECHO(tty)) set_bit(REPRINT_CHAR(tty), tty->process_char_map); } } if (I_IXON(tty)) { set_bit(START_CHAR(tty), tty->process_char_map); set_bit(STOP_CHAR(tty), tty->process_char_map); } if (L_ISIG(tty)) { set_bit(INTR_CHAR(tty), tty->process_char_map); set_bit(QUIT_CHAR(tty), tty->process_char_map); set_bit(SUSP_CHAR(tty), tty->process_char_map); } clear_bit(__DISABLED_CHAR, tty->process_char_map); tty->raw = 0; tty->real_raw = 0; } else { tty->raw = 1; if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && (I_IGNPAR(tty) || !I_INPCK(tty)) && (tty->driver->flags & TTY_DRIVER_REAL_RAW)) tty->real_raw = 1; else tty->real_raw = 0; } n_tty_set_room(tty); wake_up_interruptible(&tty->write_wait); wake_up_interruptible(&tty->read_wait); }
static void n_tty_set_termios(struct tty_struct *tty, struct ktermios * old) { if (!tty) return; tty->icanon = (L_ICANON(tty) != 0); if (test_bit(TTY_HW_COOK_IN, &tty->flags)) { tty->raw = 1; tty->real_raw = 1; n_tty_set_room(tty); return; } if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || I_PARMRK(tty)) { memset(tty->process_char_map, 0, 256/8); if (I_IGNCR(tty) || I_ICRNL(tty)) set_bit('\r', tty->process_char_map); if (I_INLCR(tty)) set_bit('\n', tty->process_char_map); if (L_ICANON(tty)) { set_bit(ERASE_CHAR(tty), tty->process_char_map); set_bit(KILL_CHAR(tty), tty->process_char_map); set_bit(EOF_CHAR(tty), tty->process_char_map); set_bit('\n', tty->process_char_map); set_bit(EOL_CHAR(tty), tty->process_char_map); if (L_IEXTEN(tty)) { set_bit(WERASE_CHAR(tty), tty->process_char_map); set_bit(LNEXT_CHAR(tty), tty->process_char_map); set_bit(EOL2_CHAR(tty), tty->process_char_map); if (L_ECHO(tty)) set_bit(REPRINT_CHAR(tty), tty->process_char_map); } } if (I_IXON(tty)) { set_bit(START_CHAR(tty), tty->process_char_map); set_bit(STOP_CHAR(tty), tty->process_char_map); } if (L_ISIG(tty)) { set_bit(INTR_CHAR(tty), tty->process_char_map); set_bit(QUIT_CHAR(tty), tty->process_char_map); set_bit(SUSP_CHAR(tty), tty->process_char_map); } clear_bit(__DISABLED_CHAR, tty->process_char_map); tty->raw = 0; tty->real_raw = 0; } else { tty->raw = 1; if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && (I_IGNPAR(tty) || !I_INPCK(tty)) && (tty->driver->flags & TTY_DRIVER_REAL_RAW)) tty->real_raw = 1; else tty->real_raw = 0; } n_tty_set_room(tty); }
static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, char *fp, int count) { const unsigned char *p; char *f, flags = TTY_NORMAL; int i; char buf[64]; unsigned long cpuflags; if (!tty->read_buf) return; if (tty->real_raw) { spin_lock_irqsave(&tty->read_lock, cpuflags); i = min(N_TTY_BUF_SIZE - tty->read_cnt, N_TTY_BUF_SIZE - tty->read_head); i = min(count, i); memcpy(tty->read_buf + tty->read_head, cp, i); tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); tty->read_cnt += i; cp += i; count -= i; i = min(N_TTY_BUF_SIZE - tty->read_cnt, N_TTY_BUF_SIZE - tty->read_head); i = min(count, i); memcpy(tty->read_buf + tty->read_head, cp, i); tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); tty->read_cnt += i; spin_unlock_irqrestore(&tty->read_lock, cpuflags); } else { for (i=count, p = cp, f = fp; i; i--, p++) { if (f) flags = *f++; switch (flags) { case TTY_NORMAL: n_tty_receive_char(tty, *p); break; case TTY_BREAK: n_tty_receive_break(tty); break; case TTY_PARITY: case TTY_FRAME: n_tty_receive_parity_error(tty, *p); break; case TTY_OVERRUN: n_tty_receive_overrun(tty); break; default: printk("%s: unknown flag %d\n", tty_name(tty, buf), flags); break; } } if (tty->driver->flush_chars) tty->driver->flush_chars(tty); } n_tty_set_room(tty); if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) { kill_fasync(&tty->fasync, SIGIO, POLL_IN); if (waitqueue_active(&tty->read_wait)) wake_up_interruptible(&tty->read_wait); } /* * Check the remaining room for the input canonicalization * mode. We don't want to throttle the driver if we're in * canonical mode and don't have a newline yet! */ if (tty->receive_room < TTY_THRESHOLD_THROTTLE) { /* check TTY_THROTTLED first so it indicates our state */ if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) && tty->driver->throttle) tty->driver->throttle(tty); } }
static ssize_t read_chan(struct tty_struct *tty, struct file *file, unsigned char __user *buf, size_t nr) { unsigned char __user *b = buf; DECLARE_WAITQUEUE(wait, current); int c; int minimum, time; ssize_t retval = 0; ssize_t size; long timeout; unsigned long flags; do_it_again: if (!tty->read_buf) { printk("n_tty_read_chan: called with read_buf == NULL?!?\n"); return -EIO; } c = job_control(tty, file); if(c < 0) return c; minimum = time = 0; timeout = MAX_SCHEDULE_TIMEOUT; if (!tty->icanon) { time = (HZ / 10) * TIME_CHAR(tty); minimum = MIN_CHAR(tty); if (minimum) { if (time) tty->minimum_to_wake = 1; else if (!waitqueue_active(&tty->read_wait) || (tty->minimum_to_wake > minimum)) tty->minimum_to_wake = minimum; } else { timeout = 0; if (time) { timeout = time; time = 0; } tty->minimum_to_wake = minimum = 1; } } /* * Internal serialization of reads. */ if (tx_cache_get_file_ro(file)->f_flags & O_NONBLOCK) { if (!mutex_trylock(&tty->atomic_read_lock)) return -EAGAIN; } else { if (mutex_lock_interruptible(&tty->atomic_read_lock)) return -ERESTARTSYS; } add_wait_queue(&tty->read_wait, &wait); while (nr) { /* First test for status change. */ if (tty->packet && tty->link->ctrl_status) { unsigned char cs; if (b != buf) break; cs = tty->link->ctrl_status; tty->link->ctrl_status = 0; if (put_user(cs, b++)) { retval = -EFAULT; b--; break; } nr--; break; } /* This statement must be first before checking for input so that any interrupt will set the state back to TASK_RUNNING. */ set_current_state(TASK_INTERRUPTIBLE); if (((minimum - (b - buf)) < tty->minimum_to_wake) && ((minimum - (b - buf)) >= 1)) tty->minimum_to_wake = (minimum - (b - buf)); if (!input_available_p(tty, 0)) { if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { retval = -EIO; break; } if (tty_hung_up_p(file)) break; if (!timeout) break; if (tx_cache_get_file_ro(file)->f_flags & O_NONBLOCK) { retval = -EAGAIN; break; } if (signal_pending(current)) { retval = -ERESTARTSYS; break; } n_tty_set_room(tty); timeout = schedule_timeout(timeout); continue; } __set_current_state(TASK_RUNNING); /* Deal with packet mode. */ if (tty->packet && b == buf) { if (put_user(TIOCPKT_DATA, b++)) { retval = -EFAULT; b--; break; } nr--; } if (tty->icanon) { /* N.B. avoid overrun if nr == 0 */ while (nr && tty->read_cnt) { int eol; eol = test_and_clear_bit(tty->read_tail, tty->read_flags); c = tty->read_buf[tty->read_tail]; spin_lock_irqsave(&tty->read_lock, flags); tty->read_tail = ((tty->read_tail+1) & (N_TTY_BUF_SIZE-1)); tty->read_cnt--; if (eol) { /* this test should be redundant: * we shouldn't be reading data if * canon_data is 0 */ if (--tty->canon_data < 0) tty->canon_data = 0; } spin_unlock_irqrestore(&tty->read_lock, flags); if (!eol || (c != __DISABLED_CHAR)) { if (put_user(c, b++)) { retval = -EFAULT; b--; break; } nr--; } if (eol) break; } if (retval) break; } else { int uncopied; uncopied = copy_from_read_buf(tty, &b, &nr); uncopied += copy_from_read_buf(tty, &b, &nr); if (uncopied) { retval = -EFAULT; break; } } /* If there is enough space in the read buffer now, let the * low-level driver know. We use n_tty_chars_in_buffer() to * check the buffer, as it now knows about canonical mode. * Otherwise, if the driver is throttled and the line is * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, * we won't get any more characters. */ if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) { n_tty_set_room(tty); check_unthrottle(tty); } if (b - buf >= minimum) break; if (time) timeout = time; } mutex_unlock(&tty->atomic_read_lock); remove_wait_queue(&tty->read_wait, &wait); if (!waitqueue_active(&tty->read_wait)) tty->minimum_to_wake = minimum; __set_current_state(TASK_RUNNING); size = b - buf; if (size) { retval = size; if (nr) clear_bit(TTY_PUSH, &tty->flags); } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) goto do_it_again; n_tty_set_room(tty); return retval; }