diff options
Diffstat (limited to 'drivers/serial/serial_core.c')
| -rw-r--r-- | drivers/serial/serial_core.c | 54 |
1 files changed, 37 insertions, 17 deletions
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 977ce820ce30..1e2b9d826f69 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -422,6 +422,7 @@ uart_get_divisor(struct uart_port *port, unsigned int baud) EXPORT_SYMBOL(uart_get_divisor); +/* FIXME: Consistent locking policy */ static void uart_change_speed(struct uart_state *state, struct ktermios *old_termios) { @@ -454,27 +455,30 @@ uart_change_speed(struct uart_state *state, struct ktermios *old_termios) port->ops->set_termios(port, termios, old_termios); } -static inline void +static inline int __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c) { unsigned long flags; + int ret = 0; if (!circ->buf) - return; + return 0; spin_lock_irqsave(&port->lock, flags); if (uart_circ_chars_free(circ) != 0) { circ->buf[circ->head] = c; circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1); + ret = 1; } spin_unlock_irqrestore(&port->lock, flags); + return ret; } -static void uart_put_char(struct tty_struct *tty, unsigned char ch) +static int uart_put_char(struct tty_struct *tty, unsigned char ch) { struct uart_state *state = tty->driver_data; - __uart_put_char(state->port, &state->info->xmit, ch); + return __uart_put_char(state->port, &state->info->xmit, ch); } static void uart_flush_chars(struct tty_struct *tty) @@ -528,15 +532,25 @@ uart_write(struct tty_struct *tty, const unsigned char *buf, int count) static int uart_write_room(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; + unsigned long flags; + int ret; - return uart_circ_chars_free(&state->info->xmit); + spin_lock_irqsave(&state->port->lock, flags); + ret = uart_circ_chars_free(&state->info->xmit); + spin_unlock_irqrestore(&state->port->lock, flags); + return ret; } static int uart_chars_in_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; + unsigned long flags; + int ret; - return uart_circ_chars_pending(&state->info->xmit); + spin_lock_irqsave(&state->port->lock, flags); + ret = uart_circ_chars_pending(&state->info->xmit); + spin_unlock_irqrestore(&state->port->lock, flags); + return ret; } static void uart_flush_buffer(struct tty_struct *tty) @@ -618,6 +632,11 @@ static int uart_get_info(struct uart_state *state, struct serial_struct tmp; memset(&tmp, 0, sizeof(tmp)); + + /* Ensure the state we copy is consistent and no hardware changes + occur as we go */ + mutex_lock(&state->mutex); + tmp.type = port->type; tmp.line = port->line; tmp.port = port->iobase; @@ -637,6 +656,8 @@ static int uart_get_info(struct uart_state *state, tmp.iomem_reg_shift = port->regshift; tmp.iomem_base = (void *)(unsigned long)port->mapbase; + mutex_unlock(&state->mutex); + if (copy_to_user(retinfo, &tmp, sizeof(*retinfo))) return -EFAULT; return 0; @@ -914,8 +935,6 @@ static void uart_break_ctl(struct tty_struct *tty, int break_state) struct uart_state *state = tty->driver_data; struct uart_port *port = state->port; - BUG_ON(!kernel_locked()); - mutex_lock(&state->mutex); if (port->type != PORT_UNKNOWN) @@ -1059,7 +1078,7 @@ static int uart_get_count(struct uart_state *state, } /* - * Called via sys_ioctl under the BKL. We can use spin_lock_irq() here. + * Called via sys_ioctl. We can use spin_lock_irq() here. */ static int uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, @@ -1069,7 +1088,6 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, void __user *uarg = (void __user *)arg; int ret = -ENOIOCTLCMD; - BUG_ON(!kernel_locked()); /* * These ioctls don't rely on the hardware to be present. @@ -1140,9 +1158,9 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd, break; } } - out_up: +out_up: mutex_unlock(&state->mutex); - out: +out: return ret; } @@ -1153,7 +1171,6 @@ static void uart_set_termios(struct tty_struct *tty, unsigned long flags; unsigned int cflag = tty->termios->c_cflag; - BUG_ON(!kernel_locked()); /* * These are the bits that are used to setup various @@ -1165,8 +1182,9 @@ static void uart_set_termios(struct tty_struct *tty, if ((cflag ^ old_termios->c_cflag) == 0 && tty->termios->c_ospeed == old_termios->c_ospeed && tty->termios->c_ispeed == old_termios->c_ispeed && - RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) + RELEVANT_IFLAG(tty->termios->c_iflag ^ old_termios->c_iflag) == 0) { return; + } uart_change_speed(state, old_termios); @@ -1200,7 +1218,6 @@ static void uart_set_termios(struct tty_struct *tty, } spin_unlock_irqrestore(&state->port->lock, flags); } - #if 0 /* * No need to wake up processes in open wait, since they @@ -1316,11 +1333,11 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout) struct uart_port *port = state->port; unsigned long char_time, expire; - BUG_ON(!kernel_locked()); - if (port->type == PORT_UNKNOWN || port->fifosize == 0) return; + lock_kernel(); + /* * Set the check interval to be 1/5 of the estimated time to * send a single character, and make it at least 1. The check @@ -1366,6 +1383,7 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout) break; } set_current_state(TASK_RUNNING); /* might not be needed */ + unlock_kernel(); } /* @@ -2079,7 +2097,9 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port) int ret; uart_change_pm(state, 0); + spin_lock_irq(&port->lock); ops->set_mctrl(port, 0); + spin_unlock_irq(&port->lock); ret = ops->startup(port); if (ret == 0) { uart_change_speed(state, NULL); |