From 6bb0e3a59a089e23eecc0af3b6f6012b2a9affba Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Wed, 16 Jul 2008 21:52:36 +0100 Subject: Subject: [PATCH 1/2] serial: Add flush_buffer() operation to uart_ops Serial drivers using DMA (like the atmel_serial driver) tend to get very confused when the xmit buffer is flushed and nobody told them. They also tend to spew a lot of garbage since the DMA engine keeps running after the buffer is flushed and possibly refilled with unrelated data. This patch adds a new flush_buffer operation to the uart_ops struct, along with a call to it from uart_flush_buffer() right after the xmit buffer has been cleared. The driver can implement this in order to syncronize its internal DMA state with the xmit buffer when the buffer is flushed. Signed-off-by: Haavard Skinnemoen Acked-by: Alan Cox Signed-off-by: Linus Torvalds --- include/linux/serial_core.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/serial_core.h') diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index d8f31de632c5..1d2faa6592ae 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -190,6 +190,7 @@ struct uart_ops { void (*break_ctl)(struct uart_port *, int ctl); int (*startup)(struct uart_port *); void (*shutdown)(struct uart_port *); + void (*flush_buffer)(struct uart_port *); void (*set_termios)(struct uart_port *, struct ktermios *new, struct ktermios *old); void (*set_ldisc)(struct uart_port *); -- cgit v1.2.3 From df4f4dd429870f435f8d5d9d561db029a29f063b Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 16 Jul 2008 21:53:50 +0100 Subject: serial: use tty_port Switch the serial_core based drivers to use the new tty_port structure. We can't quite use all of it yet because of the dynamically allocated extras in the serial_core layer. Signed-off-by: Alan Cox Signed-off-by: Linus Torvalds --- drivers/serial/8250.c | 2 +- drivers/serial/jsm/jsm_neo.c | 2 +- drivers/serial/jsm/jsm_tty.c | 8 ++--- drivers/serial/serial_core.c | 80 +++++++++++++++++++++++--------------------- include/linux/serial_core.h | 26 +++++++------- 5 files changed, 60 insertions(+), 58 deletions(-) (limited to 'include/linux/serial_core.h') diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c index ac4f20cbfe41..ce948b66bbd4 100644 --- a/drivers/serial/8250.c +++ b/drivers/serial/8250.c @@ -1287,7 +1287,7 @@ static void serial8250_enable_ms(struct uart_port *port) static void receive_chars(struct uart_8250_port *up, unsigned int *status) { - struct tty_struct *tty = up->port.info->tty; + struct tty_struct *tty = up->port.info->port.tty; unsigned char ch, lsr = *status; int max_count = 256; char flag; diff --git a/drivers/serial/jsm/jsm_neo.c b/drivers/serial/jsm/jsm_neo.c index b2d6f5b1a7c2..b7584ca55ade 100644 --- a/drivers/serial/jsm/jsm_neo.c +++ b/drivers/serial/jsm/jsm_neo.c @@ -998,7 +998,7 @@ static void neo_param(struct jsm_channel *ch) { 50, B50 }, }; - cflag = C_BAUD(ch->uart_port.info->tty); + cflag = C_BAUD(ch->uart_port.info->port.tty); baud = 9600; for (i = 0; i < ARRAY_SIZE(baud_rates); i++) { if (baud_rates[i].cflag == cflag) { diff --git a/drivers/serial/jsm/jsm_tty.c b/drivers/serial/jsm/jsm_tty.c index 94ec66372508..a697914ae3d0 100644 --- a/drivers/serial/jsm/jsm_tty.c +++ b/drivers/serial/jsm/jsm_tty.c @@ -145,7 +145,7 @@ static void jsm_tty_send_xchar(struct uart_port *port, char ch) struct ktermios *termios; spin_lock_irqsave(&port->lock, lock_flags); - termios = port->info->tty->termios; + termios = port->info->port.tty->termios; if (ch == termios->c_cc[VSTART]) channel->ch_bd->bd_ops->send_start_character(channel); @@ -239,7 +239,7 @@ static int jsm_tty_open(struct uart_port *port) channel->ch_cached_lsr = 0; channel->ch_stops_sent = 0; - termios = port->info->tty->termios; + termios = port->info->port.tty->termios; channel->ch_c_cflag = termios->c_cflag; channel->ch_c_iflag = termios->c_iflag; channel->ch_c_oflag = termios->c_oflag; @@ -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->tty->termios; + ts = channel->uart_port.info->port.tty->termios; channel->ch_flags &= ~(CH_STOPI); @@ -515,7 +515,7 @@ void jsm_input(struct jsm_channel *ch) if (!ch) return; - tp = ch->uart_port.info->tty; + tp = ch->uart_port.info->port.tty; bd = ch->ch_bd; if(!bd) diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index 9884bc9eecb1..0bce1fe2c62a 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -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->blocked_open : 0)) +#define uart_users(state) ((state)->count + ((state)->info ? (state)->info->port.blocked_open : 0)) #ifdef CONFIG_SERIAL_CORE_CONSOLE #define uart_console(port) ((port)->cons && (port)->cons->index == (port)->line) @@ -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->tty); + tty_wakeup(state->info->port.tty); } static inline void @@ -135,7 +135,7 @@ uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) /* * Startup the port. This will be called once per open. All calls - * will be serialised by the per-port semaphore. + * will be serialised by the per-port mutex. */ static int uart_startup(struct uart_state *state, int init_hw) { @@ -152,7 +152,7 @@ static int uart_startup(struct uart_state *state, int init_hw) * once we have successfully opened the port. Also set * up the tty->alt_speed kludge */ - set_bit(TTY_IO_ERROR, &info->tty->flags); + set_bit(TTY_IO_ERROR, &info->port.tty->flags); if (port->type == PORT_UNKNOWN) return 0; @@ -162,6 +162,7 @@ static int uart_startup(struct uart_state *state, int init_hw) * buffer. */ if (!info->xmit.buf) { + /* This is protected by the per port mutex */ page = get_zeroed_page(GFP_KERNEL); if (!page) return -ENOMEM; @@ -182,20 +183,20 @@ static int uart_startup(struct uart_state *state, int init_hw) * Setup the RTS and DTR signals once the * port is open and ready to respond. */ - if (info->tty->termios->c_cflag & CBAUD) + if (info->port.tty->termios->c_cflag & CBAUD) uart_set_mctrl(port, TIOCM_RTS | TIOCM_DTR); } if (info->flags & UIF_CTS_FLOW) { spin_lock_irq(&port->lock); if (!(port->ops->get_mctrl(port) & TIOCM_CTS)) - info->tty->hw_stopped = 1; + info->port.tty->hw_stopped = 1; spin_unlock_irq(&port->lock); } info->flags |= UIF_INITIALIZED; - clear_bit(TTY_IO_ERROR, &info->tty->flags); + clear_bit(TTY_IO_ERROR, &info->port.tty->flags); } if (retval && capable(CAP_SYS_ADMIN)) @@ -217,8 +218,8 @@ static void uart_shutdown(struct uart_state *state) /* * Set the TTY IO error marker */ - if (info->tty) - set_bit(TTY_IO_ERROR, &info->tty->flags); + if (info->port.tty) + set_bit(TTY_IO_ERROR, &info->port.tty->flags); if (info->flags & UIF_INITIALIZED) { info->flags &= ~UIF_INITIALIZED; @@ -226,7 +227,7 @@ static void uart_shutdown(struct uart_state *state) /* * Turn off DTR and RTS early. */ - if (!info->tty || (info->tty->termios->c_cflag & HUPCL)) + if (!info->port.tty || (info->port.tty->termios->c_cflag & HUPCL)) uart_clear_mctrl(port, TIOCM_DTR | TIOCM_RTS); /* @@ -426,7 +427,7 @@ EXPORT_SYMBOL(uart_get_divisor); static void uart_change_speed(struct uart_state *state, struct ktermios *old_termios) { - struct tty_struct *tty = state->info->tty; + struct tty_struct *tty = state->info->port.tty; struct uart_port *port = state->port; struct ktermios *termios; @@ -836,8 +837,8 @@ 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->tty) - state->info->tty->low_latency = + if (state->info->port.tty) + state->info->port.tty->low_latency = (port->flags & UPF_LOW_LATENCY) ? 1 : 0; check_and_exit: @@ -857,7 +858,7 @@ 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->tty, buf)); + tty_name(state->info->port.tty, buf)); } uart_change_speed(state, NULL); } @@ -889,7 +890,7 @@ static int uart_get_lsr_info(struct uart_state *state, */ if (port->x_char || ((uart_circ_chars_pending(&state->info->xmit) > 0) && - !state->info->tty->stopped && !state->info->tty->hw_stopped)) + !state->info->port.tty->stopped && !state->info->port.tty->hw_stopped)) result &= ~TIOCSER_TEMT; return put_user(result, value); @@ -1239,7 +1240,7 @@ 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->open_wait); + wake_up_interruptible(&state->info->port.open_wait); #endif } @@ -1320,9 +1321,9 @@ static void uart_close(struct tty_struct *tty, struct file *filp) tty_ldisc_flush(tty); tty->closing = 0; - state->info->tty = NULL; + state->info->port.tty = NULL; - if (state->info->blocked_open) { + if (state->info->port.blocked_open) { if (state->close_delay) msleep_interruptible(state->close_delay); } else if (!uart_console(port)) { @@ -1333,7 +1334,7 @@ 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->open_wait); + wake_up_interruptible(&state->info->port.open_wait); done: mutex_unlock(&state->mutex); @@ -1417,8 +1418,8 @@ static void uart_hangup(struct tty_struct *tty) uart_shutdown(state); state->count = 0; state->info->flags &= ~UIF_NORMAL_ACTIVE; - state->info->tty = NULL; - wake_up_interruptible(&state->info->open_wait); + state->info->port.tty = NULL; + wake_up_interruptible(&state->info->port.open_wait); wake_up_interruptible(&state->info->delta_msr_wait); } mutex_unlock(&state->mutex); @@ -1432,7 +1433,7 @@ static void uart_hangup(struct tty_struct *tty) */ static void uart_update_termios(struct uart_state *state) { - struct tty_struct *tty = state->info->tty; + struct tty_struct *tty = state->info->port.tty; struct uart_port *port = state->port; if (uart_console(port) && port->cons->cflag) { @@ -1471,17 +1472,17 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) struct uart_port *port = state->port; unsigned int mctrl; - info->blocked_open++; + info->port.blocked_open++; state->count--; - add_wait_queue(&info->open_wait, &wait); + add_wait_queue(&info->port.open_wait, &wait); while (1) { set_current_state(TASK_INTERRUPTIBLE); /* * If we have been hung up, tell userspace/restart open. */ - if (tty_hung_up_p(filp) || info->tty == NULL) + if (tty_hung_up_p(filp) || info->port.tty == NULL) break; /* @@ -1500,8 +1501,8 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) * have set TTY_IO_ERROR for a non-existant port. */ if ((filp->f_flags & O_NONBLOCK) || - (info->tty->termios->c_cflag & CLOCAL) || - (info->tty->flags & (1 << TTY_IO_ERROR))) + (info->port.tty->termios->c_cflag & CLOCAL) || + (info->port.tty->flags & (1 << TTY_IO_ERROR))) break; /* @@ -1509,7 +1510,7 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) * not set RTS here - we want to make sure we catch * the data from the modem. */ - if (info->tty->termios->c_cflag & CBAUD) + if (info->port.tty->termios->c_cflag & CBAUD) uart_set_mctrl(port, TIOCM_DTR); /* @@ -1531,15 +1532,15 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) break; } set_current_state(TASK_RUNNING); - remove_wait_queue(&info->open_wait, &wait); + remove_wait_queue(&info->port.open_wait, &wait); state->count++; - info->blocked_open--; + info->port.blocked_open--; if (signal_pending(current)) return -ERESTARTSYS; - if (!info->tty || tty_hung_up_p(filp)) + if (!info->port.tty || tty_hung_up_p(filp)) return -EAGAIN; return 0; @@ -1562,10 +1563,13 @@ static struct uart_state *uart_get(struct uart_driver *drv, int line) 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->open_wait); + init_waitqueue_head(&state->info->port.open_wait); init_waitqueue_head(&state->info->delta_msr_wait); /* @@ -1622,7 +1626,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp) * be re-entered while allocating the info structure, or while we * request any IRQs that the driver may need. This also has the nice * side-effect that it delays the action of uart_hangup, so we can - * guarantee that info->tty will always contain something reasonable. + * guarantee that info->port.tty will always contain something reasonable. */ state = uart_get(drv, line); if (IS_ERR(state)) { @@ -1638,7 +1642,7 @@ static int uart_open(struct tty_struct *tty, struct file *filp) tty->driver_data = state; tty->low_latency = (state->port->flags & UPF_LOW_LATENCY) ? 1 : 0; tty->alt_speed = 0; - state->info->tty = tty; + state->info->port.tty = tty; /* * If the port is in the middle of closing, bail out now. @@ -2101,8 +2105,8 @@ 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->tty && termios.c_cflag == 0) - termios = *state->info->tty->termios; + if (state->info && 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); @@ -2521,8 +2525,8 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port) tty_unregister_device(drv->tty_driver, port->line); info = state->info; - if (info && info->tty) - tty_vhangup(info->tty); + if (info && info->port.tty) + tty_vhangup(info->port.tty); /* * All users of this port should now be disconnected from diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 1d2faa6592ae..f3a1c0e45021 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -344,13 +344,15 @@ typedef unsigned int __bitwise__ uif_t; * stuff here. */ struct uart_info { - struct tty_struct *tty; + struct tty_port port; struct circ_buf xmit; uif_t flags; /* * Definitions for info->flags. These are _private_ to serial_core, and * are specific to this structure. They may be queried by low level drivers. + * + * FIXME: use the ASY_ definitions */ #define UIF_CHECK_CD ((__force uif_t) (1 << 25)) #define UIF_CTS_FLOW ((__force uif_t) (1 << 26)) @@ -358,11 +360,7 @@ struct uart_info { #define UIF_INITIALIZED ((__force uif_t) (1 << 31)) #define UIF_SUSPENDED ((__force uif_t) (1 << 30)) - int blocked_open; - struct tasklet_struct tlet; - - wait_queue_head_t open_wait; wait_queue_head_t delta_msr_wait; }; @@ -439,8 +437,8 @@ 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(port) \ - ((port)->info->tty->stopped || (port)->info->tty->hw_stopped) +#define uart_tx_stopped(portp) \ + ((portp)->info->port.tty->stopped || (portp)->info->port.tty->hw_stopped) /* * The following are helper functions for the low level drivers. @@ -451,7 +449,7 @@ 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->tty : NULL); + handle_sysrq(ch, port->info ? port->info->port.tty : NULL); port->sysrq = 0; return 1; } @@ -480,7 +478,7 @@ static inline int uart_handle_break(struct uart_port *port) } #endif if (port->flags & UPF_SAK) - do_SAK(info->tty); + do_SAK(info->port.tty); return 0; } @@ -503,9 +501,9 @@ uart_handle_dcd_change(struct uart_port *port, unsigned int status) if (info->flags & UIF_CHECK_CD) { if (status) - wake_up_interruptible(&info->open_wait); - else if (info->tty) - tty_hangup(info->tty); + wake_up_interruptible(&info->port.open_wait); + else if (info->port.tty) + tty_hangup(info->port.tty); } } @@ -518,7 +516,7 @@ static inline void uart_handle_cts_change(struct uart_port *port, unsigned int status) { struct uart_info *info = port->info; - struct tty_struct *tty = info->tty; + struct tty_struct *tty = info->port.tty; port->icount.cts++; @@ -544,7 +542,7 @@ static inline void uart_insert_char(struct uart_port *port, unsigned int status, unsigned int overrun, unsigned int ch, unsigned int flag) { - struct tty_struct *tty = port->info->tty; + struct tty_struct *tty = port->info->port.tty; if ((status & port->ignore_status_mask & ~overrun) == 0) tty_insert_flip_char(tty, ch, flag); -- cgit v1.2.3