tty: We want the port object to be persistent (f751928e) · Commits · 戴 / test

drivers/serial/jsm/jsm_tty.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -272,7 +272,7 @@ static void jsm_tty_close(struct uart_port *port)
		jsm_printk(CLOSE, INFO, &channel->ch_bd->pci_dev, "start\n");

		bd = channel->ch_bd;
		ts = channel->uart_port.info->port.tty->termios;
		ts = port->info->port.tty->termios;

		channel->ch_flags &= ~(CH_STOPI);

drivers/serial/serial_core.c

+61 −83

Original line number	Diff line number	Diff line
		@@ -50,7 +50,7 @@ static struct lock_class_key port_lock_key;

		#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)

		#define uart_users(state) ((state)->count + ((state)->info ? (state)->info->port.blocked_open : 0))
		#define uart_users(state) ((state)->count + (state)->info.port.blocked_open)

		#ifdef CONFIG_SERIAL_CORE_CONSOLE
		#define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line)
		@@ -94,7 +94,7 @@ static void __uart_start(struct tty_struct *tty)
		struct uart_state *state = tty->driver_data;
		struct uart_port *port = state->port;

		if (!uart_circ_empty(&state->info->xmit) && state->info->xmit.buf &&
		if (!uart_circ_empty(&state->info.xmit) && state->info.xmit.buf &&
		!tty->stopped && !tty->hw_stopped)
		port->ops->start_tx(port);
		}
		@@ -113,7 +113,7 @@ static void uart_start(struct tty_struct *tty)
		static void uart_tasklet_action(unsigned long data)
		{
		struct uart_state state = (struct uart_state )data;
		tty_wakeup(state->info->port.tty);
		tty_wakeup(state->info.port.tty);
		}

		static inline void
		@@ -139,7 +139,7 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear)
		*/
		static int uart_startup(struct uart_state *state, int init_hw)
		{
		struct uart_info *info = state->info;
		struct uart_info *info = &state->info;
		struct uart_port *port = state->port;
		unsigned long page;
		int retval = 0;
		@@ -212,14 +212,15 @@ static int uart_startup(struct uart_state *state, int init_hw)
		*/
		static void uart_shutdown(struct uart_state *state)
		{
		struct uart_info *info = state->info;
		struct uart_info *info = &state->info;
		struct uart_port *port = state->port;
		struct tty_struct *tty = info->port.tty;

		/*
		* Set the TTY IO error marker
		*/
		if (info->port.tty)
		set_bit(TTY_IO_ERROR, &info->port.tty->flags);
		if (tty)
		set_bit(TTY_IO_ERROR, &tty->flags);

		if (info->flags & UIF_INITIALIZED) {
		info->flags &= ~UIF_INITIALIZED;
		@@ -227,7 +228,7 @@ static void uart_shutdown(struct uart_state *state)
		/*
		* Turn off DTR and RTS early.
		*/
		if (!info->port.tty \|\| (info->port.tty->termios->c_cflag & HUPCL))
		if (!tty \|\| (tty->termios->c_cflag & HUPCL))
		uart_clear_mctrl(port, TIOCM_DTR \| TIOCM_RTS);

		/*
		@@ -427,7 +428,7 @@ EXPORT_SYMBOL(uart_get_divisor);
		static void
		uart_change_speed(struct uart_state state, struct ktermios old_termios)
		{
		struct tty_struct *tty = state->info->port.tty;
		struct tty_struct *tty = state->info.port.tty;
		struct uart_port *port = state->port;
		struct ktermios *termios;

		@@ -444,14 +445,14 @@ uart_change_speed(struct uart_state state, struct ktermios old_termios)
		* Set flags based on termios cflag
		*/
		if (termios->c_cflag & CRTSCTS)
		state->info->flags \|= UIF_CTS_FLOW;
		state->info.flags \|= UIF_CTS_FLOW;
		else
		state->info->flags &= ~UIF_CTS_FLOW;
		state->info.flags &= ~UIF_CTS_FLOW;

		if (termios->c_cflag & CLOCAL)
		state->info->flags &= ~UIF_CHECK_CD;
		state->info.flags &= ~UIF_CHECK_CD;
		else
		state->info->flags \|= UIF_CHECK_CD;
		state->info.flags \|= UIF_CHECK_CD;

		port->ops->set_termios(port, termios, old_termios);
		}
		@@ -479,7 +480,7 @@ static int uart_put_char(struct tty_struct *tty, unsigned char ch)
		{
		struct uart_state *state = tty->driver_data;

		return __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)
		@@ -500,13 +501,13 @@ uart_write(struct tty_struct tty, const unsigned char buf, int count)
		* This means you called this function _after_ the port was
		* closed. No cookie for you.
		*/
		if (!state \|\| !state->info) {
		if (!state) {
		WARN_ON(1);
		return -EL3HLT;
		}

		port = state->port;
		circ = &state->info->xmit;
		circ = &state->info.xmit;

		if (!circ->buf)
		return 0;
		@@ -537,7 +538,7 @@ static int uart_write_room(struct tty_struct *tty)
		int ret;

		spin_lock_irqsave(&state->port->lock, flags);
		ret = uart_circ_chars_free(&state->info->xmit);
		ret = uart_circ_chars_free(&state->info.xmit);
		spin_unlock_irqrestore(&state->port->lock, flags);
		return ret;
		}
		@@ -549,7 +550,7 @@ static int uart_chars_in_buffer(struct tty_struct *tty)
		int ret;

		spin_lock_irqsave(&state->port->lock, flags);
		ret = uart_circ_chars_pending(&state->info->xmit);
		ret = uart_circ_chars_pending(&state->info.xmit);
		spin_unlock_irqrestore(&state->port->lock, flags);
		return ret;
		}
		@@ -564,7 +565,7 @@ static void uart_flush_buffer(struct tty_struct *tty)
		* This means you called this function _after_ the port was
		* closed. No cookie for you.
		*/
		if (!state \|\| !state->info) {
		if (!state) {
		WARN_ON(1);
		return;
		}
		@@ -573,7 +574,7 @@ static void uart_flush_buffer(struct tty_struct *tty)
		pr_debug("uart_flush_buffer(%d) called\n", tty->index);

		spin_lock_irqsave(&port->lock, flags);
		uart_circ_clear(&state->info->xmit);
		uart_circ_clear(&state->info.xmit);
		if (port->ops->flush_buffer)
		port->ops->flush_buffer(port);
		spin_unlock_irqrestore(&port->lock, flags);
		@@ -837,15 +838,15 @@ static int uart_set_info(struct uart_state *state,
		state->closing_wait = closing_wait;
		if (new_serial.xmit_fifo_size)
		port->fifosize = new_serial.xmit_fifo_size;
		if (state->info->port.tty)
		state->info->port.tty->low_latency =
		if (state->info.port.tty)
		state->info.port.tty->low_latency =
		(port->flags & UPF_LOW_LATENCY) ? 1 : 0;

		check_and_exit:
		retval = 0;
		if (port->type == PORT_UNKNOWN)
		goto exit;
		if (state->info->flags & UIF_INITIALIZED) {
		if (state->info.flags & UIF_INITIALIZED) {
		if (((old_flags ^ port->flags) & UPF_SPD_MASK) \|\|
		old_custom_divisor != port->custom_divisor) {
		/*
		@@ -858,7 +859,7 @@ static int uart_set_info(struct uart_state *state,
		printk(KERN_NOTICE
		"%s sets custom speed on %s. This "
		"is deprecated.\n", current->comm,
		tty_name(state->info->port.tty, buf));
		tty_name(state->info.port.tty, buf));
		}
		uart_change_speed(state, NULL);
		}
		@@ -889,8 +890,8 @@ static int uart_get_lsr_info(struct uart_state *state,
		* interrupt happens).
		*/
		if (port->x_char \|\|
		((uart_circ_chars_pending(&state->info->xmit) > 0) &&
		!state->info->port.tty->stopped && !state->info->port.tty->hw_stopped))
		((uart_circ_chars_pending(&state->info.xmit) > 0) &&
		!state->info.port.tty->stopped && !state->info.port.tty->hw_stopped))
		result &= ~TIOCSER_TEMT;

		return put_user(result, value);
		@@ -1017,7 +1018,7 @@ uart_wait_modem_status(struct uart_state *state, unsigned long arg)
		port->ops->enable_ms(port);
		spin_unlock_irq(&port->lock);

		add_wait_queue(&state->info->delta_msr_wait, &wait);
		add_wait_queue(&state->info.delta_msr_wait, &wait);
		for (;;) {
		spin_lock_irq(&port->lock);
		memcpy(&cnow, &port->icount, sizeof(struct uart_icount));
		@@ -1045,7 +1046,7 @@ uart_wait_modem_status(struct uart_state *state, unsigned long arg)
		}

		current->state = TASK_RUNNING;
		remove_wait_queue(&state->info->delta_msr_wait, &wait);
		remove_wait_queue(&state->info.delta_msr_wait, &wait);

		return ret;
		}
		@@ -1241,7 +1242,7 @@ static void uart_set_termios(struct tty_struct *tty,
		*/
		if (!(old_termios->c_cflag & CLOCAL) &&
		(tty->termios->c_cflag & CLOCAL))
		wake_up_interruptible(&state->info->port.open_wait);
		wake_up_interruptible(&info->port.open_wait);
		#endif
		}

		@@ -1303,7 +1304,7 @@ static void uart_close(struct tty_struct tty, struct file filp)
		* At this point, we stop accepting input. To do this, we
		* disable the receive line status interrupts.
		*/
		if (state->info->flags & UIF_INITIALIZED) {
		if (state->info.flags & UIF_INITIALIZED) {
		unsigned long flags;
		spin_lock_irqsave(&port->lock, flags);
		port->ops->stop_rx(port);
		@@ -1322,9 +1323,9 @@ static void uart_close(struct tty_struct tty, struct file filp)
		tty_ldisc_flush(tty);

		tty->closing = 0;
		state->info->port.tty = NULL;
		state->info.port.tty = NULL;

		if (state->info->port.blocked_open) {
		if (state->info.port.blocked_open) {
		if (state->close_delay)
		msleep_interruptible(state->close_delay);
		} else if (!uart_console(port)) {
		@@ -1334,8 +1335,8 @@ static void uart_close(struct tty_struct tty, struct file filp)
		/*
		* Wake up anyone trying to open this port.
		*/
		state->info->flags &= ~UIF_NORMAL_ACTIVE;
		wake_up_interruptible(&state->info->port.open_wait);
		state->info.flags &= ~UIF_NORMAL_ACTIVE;
		wake_up_interruptible(&state->info.port.open_wait);

		done:
		mutex_unlock(&state->mutex);
		@@ -1409,19 +1410,20 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
		static void uart_hangup(struct tty_struct *tty)
		{
		struct uart_state *state = tty->driver_data;
		struct uart_info *info = &state->info;

		BUG_ON(!kernel_locked());
		pr_debug("uart_hangup(%d)\n", state->port->line);

		mutex_lock(&state->mutex);
		if (state->info && state->info->flags & UIF_NORMAL_ACTIVE) {
		if (info->flags & UIF_NORMAL_ACTIVE) {
		uart_flush_buffer(tty);
		uart_shutdown(state);
		state->count = 0;
		state->info->flags &= ~UIF_NORMAL_ACTIVE;
		state->info->port.tty = NULL;
		wake_up_interruptible(&state->info->port.open_wait);
		wake_up_interruptible(&state->info->delta_msr_wait);
		info->flags &= ~UIF_NORMAL_ACTIVE;
		info->port.tty = NULL;
		wake_up_interruptible(&info->port.open_wait);
		wake_up_interruptible(&info->delta_msr_wait);
		}
		mutex_unlock(&state->mutex);
		}
		@@ -1434,7 +1436,7 @@ static void uart_hangup(struct tty_struct *tty)
		*/
		static void uart_update_termios(struct uart_state *state)
		{
		struct tty_struct *tty = state->info->port.tty;
		struct tty_struct *tty = state->info.port.tty;
		struct uart_port *port = state->port;

		if (uart_console(port) && port->cons->cflag) {
		@@ -1469,7 +1471,7 @@ static int
		uart_block_til_ready(struct file filp, struct uart_state state)
		{
		DECLARE_WAITQUEUE(wait, current);
		struct uart_info *info = state->info;
		struct uart_info *info = &state->info;
		struct uart_port *port = state->port;
		unsigned int mctrl;

		@@ -1563,28 +1565,6 @@ static struct uart_state uart_get(struct uart_driver drv, int line)
		ret = -ENXIO;
		goto err_unlock;
		}

		/* BKL: RACE HERE - LEAK */
		/* We should move this into the uart_state structure and kill off
		this whole complexity */
		if (!state->info) {
		state->info = kzalloc(sizeof(struct uart_info), GFP_KERNEL);
		if (state->info) {
		init_waitqueue_head(&state->info->port.open_wait);
		init_waitqueue_head(&state->info->delta_msr_wait);

		/*
		* Link the info into the other structures.
		*/
		state->port->info = state->info;

		tasklet_init(&state->info->tlet, uart_tasklet_action,
		(unsigned long)state);
		} else {
		ret = -ENOMEM;
		goto err_unlock;
		}
		}
		return state;

		err_unlock:
		@@ -1641,9 +1621,10 @@ static int uart_open(struct tty_struct tty, struct file filp)
		* Any failures from here onwards should not touch the count.
		*/
		tty->driver_data = state;
		state->port->info = &state->info;
		tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0;
		tty->alt_speed = 0;
		state->info->port.tty = tty;
		state->info.port.tty = tty;

		/*
		* If the port is in the middle of closing, bail out now.
		@@ -1676,8 +1657,8 @@ static int uart_open(struct tty_struct tty, struct file filp)
		/*
		* If this is the first open to succeed, adjust things to suit.
		*/
		if (retval == 0 && !(state->info->flags & UIF_NORMAL_ACTIVE)) {
		state->info->flags \|= UIF_NORMAL_ACTIVE;
		if (retval == 0 && !(state->info.flags & UIF_NORMAL_ACTIVE)) {
		state->info.flags \|= UIF_NORMAL_ACTIVE;

		uart_update_termios(state);
		}
		@@ -2028,11 +2009,11 @@ int uart_suspend_port(struct uart_driver drv, struct uart_port port)
		}
		port->suspended = 1;

		if (state->info && state->info->flags & UIF_INITIALIZED) {
		if (state->info.flags & UIF_INITIALIZED) {
		const struct uart_ops *ops = port->ops;
		int tries;

		state->info->flags = (state->info->flags & ~UIF_INITIALIZED)
		state->info.flags = (state->info.flags & ~UIF_INITIALIZED)
		\| UIF_SUSPENDED;

		spin_lock_irq(&port->lock);
		@@ -2107,15 +2088,15 @@ int uart_resume_port(struct uart_driver drv, struct uart_port port)
		/*
		* If that's unset, use the tty termios setting.
		*/
		if (state->info && state->info->port.tty && termios.c_cflag == 0)
		termios = *state->info->port.tty->termios;
		if (state->info.port.tty && termios.c_cflag == 0)
		termios = *state->info.port.tty->termios;

		uart_change_pm(state, 0);
		port->ops->set_termios(port, &termios, NULL);
		console_start(port->cons);
		}

		if (state->info && state->info->flags & UIF_SUSPENDED) {
		if (state->info.flags & UIF_SUSPENDED) {
		const struct uart_ops *ops = port->ops;
		int ret;

		@@ -2130,7 +2111,7 @@ int uart_resume_port(struct uart_driver drv, struct uart_port port)
		ops->set_mctrl(port, port->mctrl);
		ops->start_tx(port);
		spin_unlock_irq(&port->lock);
		state->info->flags \|= UIF_INITIALIZED;
		state->info.flags \|= UIF_INITIALIZED;
		} else {
		/*
		* Failed to resume - maybe hardware went away?
		@@ -2140,7 +2121,7 @@ int uart_resume_port(struct uart_driver drv, struct uart_port port)
		uart_shutdown(state);
		}

		state->info->flags &= ~UIF_SUSPENDED;
		state->info.flags &= ~UIF_SUSPENDED;
		}

		mutex_unlock(&state->mutex);
		@@ -2383,8 +2364,12 @@ int uart_register_driver(struct uart_driver *drv)

		state->close_delay = 500; /* .5 seconds */
		state->closing_wait = 30000; /* 30 seconds */

		mutex_init(&state->mutex);

		tty_port_init(&state->info.port);
		init_waitqueue_head(&state->info.delta_msr_wait);
		tasklet_init(&state->info.tlet, uart_tasklet_action,
		(unsigned long)state);
		}

		retval = tty_register_driver(normal);
		@@ -2455,7 +2440,7 @@ int uart_add_one_port(struct uart_driver drv, struct uart_port port)
		state->pm_state = -1;

		port->cons = drv->cons;
		port->info = state->info;
		port->info = &state->info;

		/*
		* If this port is a console, then the spinlock is already
		@@ -2527,17 +2512,10 @@ int uart_remove_one_port(struct uart_driver drv, struct uart_port port)
		*/
		tty_unregister_device(drv->tty_driver, port->line);

		info = state->info;
		info = &state->info;
		if (info && info->port.tty)
		tty_vhangup(info->port.tty);

		/*
		* All users of this port should now be disconnected from
		* this driver, and the port shut down. We should be the
		* only thread fiddling with this port from now on.
		*/
		state->info = NULL;

		/*
		* Free the port IO and memory resources, if any.
		*/

include/linux/serial_core.h

+34 −28

Original line number	Diff line number	Diff line
		@@ -315,36 +315,14 @@ struct uart_port {
		void private_data; / generic platform data pointer */
		};

		/*
		* This is the state information which is persistent across opens.
		* The low level driver must not to touch any elements contained
		* within.
		*/
		struct uart_state {
		unsigned int close_delay; /* msec */
		unsigned int closing_wait; /* msec */

		#define USF_CLOSING_WAIT_INF (0)
		#define USF_CLOSING_WAIT_NONE (~0U)

		int count;
		int pm_state;
		struct uart_info *info;
		struct uart_port *port;

		struct mutex mutex;
		};

		#define UART_XMIT_SIZE PAGE_SIZE

		typedef unsigned int __bitwise__ uif_t;

		/*
		* This is the state information which is only valid when the port
		* is open; it may be freed by the core driver once the device has
		* is open; it may be cleared the core driver once the device has
		* been closed. Either the low level driver or the core can modify
		* stuff here.
		*/
		typedef unsigned int __bitwise__ uif_t;

		struct uart_info {
		struct tty_port port;
		struct circ_buf xmit;
		@@ -366,6 +344,29 @@ struct uart_info {
		wait_queue_head_t delta_msr_wait;
		};

		/*
		* This is the state information which is persistent across opens.
		* The low level driver must not to touch any elements contained
		* within.
		*/
		struct uart_state {
		unsigned int close_delay; /* msec */
		unsigned int closing_wait; /* msec */

		#define USF_CLOSING_WAIT_INF (0)
		#define USF_CLOSING_WAIT_NONE (~0U)

		int count;
		int pm_state;
		struct uart_info info;
		struct uart_port *port;

		struct mutex mutex;
		};

		#define UART_XMIT_SIZE PAGE_SIZE


		/* number of characters left in xmit buffer before we ask for more */
		#define WAKEUP_CHARS 256

		@@ -439,8 +440,13 @@ int uart_resume_port(struct uart_driver reg, struct uart_port port);
		#define uart_circ_chars_free(circ) \
		(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))

		#define uart_tx_stopped(portp) \
		((portp)->info->port.tty->stopped \|\| (portp)->info->port.tty->hw_stopped)
		static inline int uart_tx_stopped(struct uart_port *port)
		{
		struct tty_struct *tty = port->info->port.tty;
		if(tty->stopped \|\| tty->hw_stopped)
		return 1;
		return 0;
		}

		/*
		* The following are helper functions for the low level drivers.
		@@ -451,7 +457,7 @@ uart_handle_sysrq_char(struct uart_port *port, unsigned int ch)
		#ifdef SUPPORT_SYSRQ
		if (port->sysrq) {
		if (ch && time_before(jiffies, port->sysrq)) {
		handle_sysrq(ch, port->info ? port->info->port.tty : NULL);
		handle_sysrq(ch, port->info->port.tty);
		port->sysrq = 0;
		return 1;
		}

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