diff options
Diffstat (limited to 'drivers/tty/serial/serial_core.c')
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 3033 |
1 files changed, 1899 insertions, 1134 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 28cdd2829139..9930023e924c 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0+ /* * Driver core for serial ports * @@ -5,37 +6,33 @@ * * Copyright 1999 ARM Limited * Copyright (C) 2000-2001 Deep Blue Solutions Ltd. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/module.h> #include <linux/tty.h> #include <linux/tty_flip.h> #include <linux/slab.h> +#include <linux/sched/signal.h> #include <linux/init.h> #include <linux/console.h> +#include <linux/gpio/consumer.h> +#include <linux/kernel.h> +#include <linux/of.h> +#include <linux/pm_runtime.h> #include <linux/proc_fs.h> #include <linux/seq_file.h> #include <linux/device.h> #include <linux/serial.h> /* for serial_state and serial_icounter_struct */ #include <linux/serial_core.h> +#include <linux/sysrq.h> #include <linux/delay.h> #include <linux/mutex.h> +#include <linux/math64.h> +#include <linux/security.h> + +#include <linux/irq.h> +#include <linux/uaccess.h> -#include <asm/irq.h> -#include <asm/uaccess.h> +#include "serial_base.h" /* * This is used to lock changes in serial line configuration. @@ -50,17 +47,68 @@ static struct lock_class_key port_lock_key; #define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8) -static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, - struct ktermios *old_termios); -static void uart_wait_until_sent(struct tty_struct *tty, int timeout); +/* + * Max time with active RTS before/after data is sent. + */ +#define RS485_MAX_RTS_DELAY 100 /* msecs */ + static void uart_change_pm(struct uart_state *state, enum uart_pm_state pm_state); static void uart_port_shutdown(struct tty_port *port); -/* - * This routine is used by the interrupt handler to schedule processing in - * the software interrupt portion of the driver. +static int uart_dcd_enabled(struct uart_port *uport) +{ + return !!(uport->status & UPSTAT_DCD_ENABLE); +} + +static inline struct uart_port *uart_port_ref(struct uart_state *state) +{ + if (atomic_add_unless(&state->refcount, 1, 0)) + return state->uart_port; + return NULL; +} + +static inline void uart_port_deref(struct uart_port *uport) +{ + if (atomic_dec_and_test(&uport->state->refcount)) + wake_up(&uport->state->remove_wait); +} + +static inline struct uart_port *uart_port_ref_lock(struct uart_state *state, unsigned long *flags) +{ + struct uart_port *uport = uart_port_ref(state); + + if (uport) + uart_port_lock_irqsave(uport, flags); + + return uport; +} + +static inline void uart_port_unlock_deref(struct uart_port *uport, unsigned long flags) +{ + if (uport) { + uart_port_unlock_irqrestore(uport, flags); + uart_port_deref(uport); + } +} + +static inline struct uart_port *uart_port_check(struct uart_state *state) +{ + lockdep_assert_held(&state->port.mutex); + return state->uart_port; +} + +/** + * uart_write_wakeup - schedule write processing + * @port: port to be processed + * + * This routine is used by the interrupt handler to schedule processing in the + * software interrupt portion of the driver. A driver is expected to call this + * function when the number of characters in the transmit buffer have dropped + * below a threshold. + * + * Locking: @port->lock should be held */ void uart_write_wakeup(struct uart_port *port) { @@ -70,113 +118,227 @@ void uart_write_wakeup(struct uart_port *port) * closed. No cookie for you. */ BUG_ON(!state); - tty_wakeup(state->port.tty); + tty_port_tty_wakeup(&state->port); } +EXPORT_SYMBOL(uart_write_wakeup); static void uart_stop(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; - struct uart_port *port = state->uart_port; + struct uart_port *port; unsigned long flags; - spin_lock_irqsave(&port->lock, flags); - port->ops->stop_tx(port); - spin_unlock_irqrestore(&port->lock, flags); + port = uart_port_ref_lock(state, &flags); + if (port) + port->ops->stop_tx(port); + uart_port_unlock_deref(port, flags); } -static void __uart_start(struct tty_struct *tty) +static void __uart_start(struct uart_state *state) { - struct uart_state *state = tty->driver_data; struct uart_port *port = state->uart_port; + struct serial_port_device *port_dev; + int err; - if (!uart_circ_empty(&state->xmit) && state->xmit.buf && - !tty->stopped && !tty->hw_stopped) + if (!port || port->flags & UPF_DEAD || uart_tx_stopped(port)) + return; + + port_dev = port->port_dev; + + /* Increment the runtime PM usage count for the active check below */ + err = pm_runtime_get(&port_dev->dev); + if (err < 0 && err != -EINPROGRESS) { + pm_runtime_put_noidle(&port_dev->dev); + return; + } + + /* + * Start TX if enabled, and kick runtime PM. If the device is not + * enabled, serial_port_runtime_resume() calls start_tx() again + * after enabling the device. + */ + if (!pm_runtime_enabled(port->dev) || pm_runtime_active(&port_dev->dev)) port->ops->start_tx(port); + pm_runtime_mark_last_busy(&port_dev->dev); + pm_runtime_put_autosuspend(&port_dev->dev); } static void uart_start(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; - struct uart_port *port = state->uart_port; + struct uart_port *port; unsigned long flags; - spin_lock_irqsave(&port->lock, flags); - __uart_start(tty); - spin_unlock_irqrestore(&port->lock, flags); + port = uart_port_ref_lock(state, &flags); + __uart_start(state); + uart_port_unlock_deref(port, flags); } -static inline void +static void uart_update_mctrl(struct uart_port *port, unsigned int set, unsigned int clear) { - unsigned long flags; unsigned int old; - spin_lock_irqsave(&port->lock, flags); + guard(uart_port_lock_irqsave)(port); old = port->mctrl; port->mctrl = (old & ~clear) | set; - if (old != port->mctrl) + if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED)) port->ops->set_mctrl(port, port->mctrl); - spin_unlock_irqrestore(&port->lock, flags); } #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) #define uart_clear_mctrl(port, clear) uart_update_mctrl(port, 0, clear) +static void uart_port_dtr_rts(struct uart_port *uport, bool active) +{ + if (active) + uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); + else + uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); +} + +/* Caller holds port mutex */ +static void uart_change_line_settings(struct tty_struct *tty, struct uart_state *state, + const struct ktermios *old_termios) +{ + struct uart_port *uport = uart_port_check(state); + struct ktermios *termios; + bool old_hw_stopped; + + /* + * If we have no tty, termios, or the port does not exist, + * then we can't set the parameters for this port. + */ + if (!tty || uport->type == PORT_UNKNOWN) + return; + + termios = &tty->termios; + uport->ops->set_termios(uport, termios, old_termios); + + /* + * Set modem status enables based on termios cflag + */ + guard(uart_port_lock_irq)(uport); + if (termios->c_cflag & CRTSCTS) + uport->status |= UPSTAT_CTS_ENABLE; + else + uport->status &= ~UPSTAT_CTS_ENABLE; + + if (termios->c_cflag & CLOCAL) + uport->status &= ~UPSTAT_DCD_ENABLE; + else + uport->status |= UPSTAT_DCD_ENABLE; + + /* reset sw-assisted CTS flow control based on (possibly) new mode */ + old_hw_stopped = uport->hw_stopped; + uport->hw_stopped = uart_softcts_mode(uport) && + !(uport->ops->get_mctrl(uport) & TIOCM_CTS); + if (uport->hw_stopped != old_hw_stopped) { + if (!old_hw_stopped) + uport->ops->stop_tx(uport); + else + __uart_start(state); + } +} + +static int uart_alloc_xmit_buf(struct tty_port *port) +{ + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + unsigned long flags; + unsigned long page; + + /* + * Initialise and allocate the transmit and temporary + * buffer. + */ + page = get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + + uport = uart_port_ref_lock(state, &flags); + if (!state->port.xmit_buf) { + state->port.xmit_buf = (unsigned char *)page; + kfifo_init(&state->port.xmit_fifo, state->port.xmit_buf, + PAGE_SIZE); + uart_port_unlock_deref(uport, flags); + } else { + uart_port_unlock_deref(uport, flags); + /* + * Do not free() the page under the port lock, see + * uart_free_xmit_buf(). + */ + free_page(page); + } + + return 0; +} + +static void uart_free_xmit_buf(struct tty_port *port) +{ + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + unsigned long flags; + char *xmit_buf; + + /* + * Do not free() the transmit buffer page under the port lock since + * this can create various circular locking scenarios. For instance, + * console driver may need to allocate/free a debug object, which + * can end up in printk() recursion. + */ + uport = uart_port_ref_lock(state, &flags); + xmit_buf = port->xmit_buf; + port->xmit_buf = NULL; + INIT_KFIFO(port->xmit_fifo); + uart_port_unlock_deref(uport, flags); + + free_page((unsigned long)xmit_buf); +} + /* * Startup the port. This will be called once per open. All calls * will be serialised by the per-port mutex. */ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, - int init_hw) + bool init_hw) { - struct uart_port *uport = state->uart_port; - struct tty_port *port = &state->port; - unsigned long page; - int retval = 0; + struct uart_port *uport = uart_port_check(state); + int retval; if (uport->type == PORT_UNKNOWN) return 1; /* - * Initialise and allocate the transmit and temporary - * buffer. + * Make sure the device is in D0 state. */ - if (!state->xmit.buf) { - /* This is protected by the per port mutex */ - page = get_zeroed_page(GFP_KERNEL); - if (!page) - return -ENOMEM; + uart_change_pm(state, UART_PM_STATE_ON); - state->xmit.buf = (unsigned char *) page; - uart_circ_clear(&state->xmit); - } + retval = uart_alloc_xmit_buf(&state->port); + if (retval) + return retval; retval = uport->ops->startup(uport); if (retval == 0) { if (uart_console(uport) && uport->cons->cflag) { tty->termios.c_cflag = uport->cons->cflag; + tty->termios.c_ispeed = uport->cons->ispeed; + tty->termios.c_ospeed = uport->cons->ospeed; uport->cons->cflag = 0; + uport->cons->ispeed = 0; + uport->cons->ospeed = 0; } /* * Initialise the hardware port settings. */ - uart_change_speed(tty, state, NULL); - - if (init_hw) { - /* - * Setup the RTS and DTR signals once the - * port is open and ready to respond. - */ - if (tty->termios.c_cflag & CBAUD) - uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR); - } + uart_change_line_settings(tty, state, NULL); - if (tty_port_cts_enabled(port)) { - spin_lock_irq(&uport->lock); - if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) - tty->hw_stopped = 1; - spin_unlock_irq(&uport->lock); - } + /* + * Setup the RTS and DTR signals once the + * port is open and ready to respond. + */ + if (init_hw && C_BAUD(tty)) + uart_port_dtr_rts(uport, true); } /* @@ -191,38 +353,41 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state, } static int uart_startup(struct tty_struct *tty, struct uart_state *state, - int init_hw) + bool init_hw) { struct tty_port *port = &state->port; + struct uart_port *uport; int retval; - if (port->flags & ASYNC_INITIALIZED) - return 0; - - /* - * Set the TTY IO error marker - we will only clear this - * once we have successfully opened the port. - */ - set_bit(TTY_IO_ERROR, &tty->flags); + if (tty_port_initialized(port)) + goto out_base_port_startup; retval = uart_port_startup(tty, state, init_hw); - if (!retval) { - set_bit(ASYNCB_INITIALIZED, &port->flags); - clear_bit(TTY_IO_ERROR, &tty->flags); - } else if (retval > 0) - retval = 0; + if (retval) { + set_bit(TTY_IO_ERROR, &tty->flags); + return retval; + } - return retval; +out_base_port_startup: + uport = uart_port_check(state); + if (!uport) + return -EIO; + + serial_base_port_startup(uport); + + return 0; } /* * This routine will shutdown a serial port; interrupts are disabled, and * DTR is dropped if the hangup on close termio flag is on. Calls to * uart_shutdown are serialised by the per-port semaphore. + * + * uport == NULL if uart_port has already been removed */ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) { - struct uart_port *uport = state->uart_port; + struct uart_port *uport = uart_port_check(state); struct tty_port *port = &state->port; /* @@ -231,12 +396,25 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) if (tty) set_bit(TTY_IO_ERROR, &tty->flags); - if (test_and_clear_bit(ASYNCB_INITIALIZED, &port->flags)) { + if (uport) + serial_base_port_shutdown(uport); + + if (tty_port_initialized(port)) { + tty_port_set_initialized(port, false); + /* * Turn off DTR and RTS early. */ - if (!tty || (tty->termios.c_cflag & HUPCL)) - uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); + if (uport) { + if (uart_console(uport) && tty) { + uport->cons->cflag = tty->termios.c_cflag; + uport->cons->ispeed = tty->termios.c_ispeed; + uport->cons->ospeed = tty->termios.c_ospeed; + } + + if (!tty || C_HUPCL(tty)) + uart_port_dtr_rts(uport, false); + } uart_port_shutdown(port); } @@ -246,102 +424,82 @@ static void uart_shutdown(struct tty_struct *tty, struct uart_state *state) * a DCD drop (hangup) at just the right time. Clear suspended bit so * we don't try to resume a port that has been shutdown. */ - clear_bit(ASYNCB_SUSPENDED, &port->flags); + tty_port_set_suspended(port, false); - /* - * Free the transmit buffer page. - */ - if (state->xmit.buf) { - free_page((unsigned long)state->xmit.buf); - state->xmit.buf = NULL; - } + uart_free_xmit_buf(port); } /** - * uart_update_timeout - update per-port FIFO timeout. - * @port: uart_port structure describing the port - * @cflag: termios cflag value - * @baud: speed of the port + * uart_update_timeout - update per-port frame timing information + * @port: uart_port structure describing the port + * @cflag: termios cflag value + * @baud: speed of the port * - * Set the port FIFO timeout value. The @cflag value should - * reflect the actual hardware settings. + * Set the @port frame timing information from which the FIFO timeout value is + * derived. The @cflag value should reflect the actual hardware settings as + * number of bits, parity, stop bits and baud rate is taken into account here. + * + * Locking: caller is expected to take @port->lock */ void uart_update_timeout(struct uart_port *port, unsigned int cflag, unsigned int baud) { - unsigned int bits; + u64 temp = tty_get_frame_size(cflag); - /* byte size and parity */ - switch (cflag & CSIZE) { - case CS5: - bits = 7; - break; - case CS6: - bits = 8; - break; - case CS7: - bits = 9; - break; - default: - bits = 10; - break; /* CS8 */ - } - - if (cflag & CSTOPB) - bits++; - if (cflag & PARENB) - bits++; - - /* - * The total number of bits to be transmitted in the fifo. - */ - bits = bits * port->fifosize; - - /* - * Figure the timeout to send the above number of bits. - * Add .02 seconds of slop - */ - port->timeout = (HZ * bits) / baud + HZ/50; + temp *= NSEC_PER_SEC; + port->frame_time = (unsigned int)DIV64_U64_ROUND_UP(temp, baud); } - EXPORT_SYMBOL(uart_update_timeout); /** - * uart_get_baud_rate - return baud rate for a particular port - * @port: uart_port structure describing the port in question. - * @termios: desired termios settings. - * @old: old termios (or NULL) - * @min: minimum acceptable baud rate - * @max: maximum acceptable baud rate + * uart_get_baud_rate - return baud rate for a particular port + * @port: uart_port structure describing the port in question. + * @termios: desired termios settings + * @old: old termios (or %NULL) + * @min: minimum acceptable baud rate + * @max: maximum acceptable baud rate + * + * Decode the termios structure into a numeric baud rate, taking account of the + * magic 38400 baud rate (with spd_* flags), and mapping the %B0 rate to 9600 + * baud. * - * Decode the termios structure into a numeric baud rate, - * taking account of the magic 38400 baud rate (with spd_* - * flags), and mapping the %B0 rate to 9600 baud. + * If the new baud rate is invalid, try the @old termios setting. If it's still + * invalid, we try 9600 baud. If that is also invalid 0 is returned. * - * If the new baud rate is invalid, try the old termios setting. - * If it's still invalid, we try 9600 baud. + * The @termios structure is updated to reflect the baud rate we're actually + * going to be using. Don't do this for the case where B0 is requested ("hang + * up"). * - * Update the @termios structure to reflect the baud rate - * we're actually going to be using. Don't do this for the case - * where B0 is requested ("hang up"). + * Locking: caller dependent */ unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, - struct ktermios *old, unsigned int min, unsigned int max) + const struct ktermios *old, unsigned int min, unsigned int max) { - unsigned int try, baud, altbaud = 38400; + unsigned int try; + unsigned int baud; + unsigned int altbaud; int hung_up = 0; upf_t flags = port->flags & UPF_SPD_MASK; - if (flags == UPF_SPD_HI) + switch (flags) { + case UPF_SPD_HI: altbaud = 57600; - else if (flags == UPF_SPD_VHI) + break; + case UPF_SPD_VHI: altbaud = 115200; - else if (flags == UPF_SPD_SHI) + break; + case UPF_SPD_SHI: altbaud = 230400; - else if (flags == UPF_SPD_WARP) + break; + case UPF_SPD_WARP: altbaud = 460800; + break; + default: + altbaud = 38400; + break; + } for (try = 0; try < 2; try++) { baud = tty_termios_baud_rate(termios); @@ -350,7 +508,7 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, * The spd_hi, spd_vhi, spd_shi, spd_warp kludge... * Die! Die! Die! */ - if (baud == 38400) + if (try == 0 && baud == 38400) baud = altbaud; /* @@ -391,19 +549,22 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, max - 1, max - 1); } } - /* Should never happen */ - WARN_ON(1); return 0; } - EXPORT_SYMBOL(uart_get_baud_rate); /** - * uart_get_divisor - return uart clock divisor - * @port: uart_port structure describing the port. - * @baud: desired baud rate + * uart_get_divisor - return uart clock divisor + * @port: uart_port structure describing the port + * @baud: desired baud rate + * + * Calculate the divisor (baud_base / baud) for the specified @baud, + * appropriately rounded. * - * Calculate the uart clock divisor for the port. + * If 38400 baud and custom divisor is selected, return the custom divisor + * instead. + * + * Locking: caller dependent */ unsigned int uart_get_divisor(struct uart_port *port, unsigned int baud) @@ -420,66 +581,25 @@ uart_get_divisor(struct uart_port *port, unsigned int baud) return quot; } - EXPORT_SYMBOL(uart_get_divisor); -/* FIXME: Consistent locking policy */ -static void uart_change_speed(struct tty_struct *tty, struct uart_state *state, - struct ktermios *old_termios) -{ - struct tty_port *port = &state->port; - struct uart_port *uport = state->uart_port; - struct ktermios *termios; - - /* - * If we have no tty, termios, or the port does not exist, - * then we can't set the parameters for this port. - */ - if (!tty || uport->type == PORT_UNKNOWN) - return; - - termios = &tty->termios; - - /* - * Set flags based on termios cflag - */ - if (termios->c_cflag & CRTSCTS) - set_bit(ASYNCB_CTS_FLOW, &port->flags); - else - clear_bit(ASYNCB_CTS_FLOW, &port->flags); - - if (termios->c_cflag & CLOCAL) - clear_bit(ASYNCB_CHECK_CD, &port->flags); - else - set_bit(ASYNCB_CHECK_CD, &port->flags); - - uport->ops->set_termios(uport, termios, old_termios); -} - -static inline int __uart_put_char(struct uart_port *port, - struct circ_buf *circ, unsigned char c) +static int uart_put_char(struct tty_struct *tty, u8 c) { + struct uart_state *state = tty->driver_data; + struct uart_port *port; unsigned long flags; int ret = 0; - if (!circ->buf) + port = uart_port_ref_lock(state, &flags); + if (!state->port.xmit_buf) { + uart_port_unlock_deref(port, flags); 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 int uart_put_char(struct tty_struct *tty, unsigned char ch) -{ - struct uart_state *state = tty->driver_data; - return __uart_put_char(state->uart_port, &state->xmit, ch); + if (port) + ret = kfifo_put(&state->port.xmit_fifo, c); + uart_port_unlock_deref(port, flags); + return ret; } static void uart_flush_chars(struct tty_struct *tty) @@ -487,70 +607,57 @@ static void uart_flush_chars(struct tty_struct *tty) uart_start(tty); } -static int uart_write(struct tty_struct *tty, - const unsigned char *buf, int count) +static ssize_t uart_write(struct tty_struct *tty, const u8 *buf, size_t count) { struct uart_state *state = tty->driver_data; struct uart_port *port; - struct circ_buf *circ; unsigned long flags; - int c, ret = 0; + int ret = 0; /* * This means you called this function _after_ the port was * closed. No cookie for you. */ - if (!state) { - WARN_ON(1); + if (WARN_ON(!state)) return -EL3HLT; - } - port = state->uart_port; - circ = &state->xmit; - - if (!circ->buf) + port = uart_port_ref_lock(state, &flags); + if (!state->port.xmit_buf) { + uart_port_unlock_deref(port, flags); return 0; - - spin_lock_irqsave(&port->lock, flags); - while (1) { - c = CIRC_SPACE_TO_END(circ->head, circ->tail, UART_XMIT_SIZE); - if (count < c) - c = count; - if (c <= 0) - break; - memcpy(circ->buf + circ->head, buf, c); - circ->head = (circ->head + c) & (UART_XMIT_SIZE - 1); - buf += c; - count -= c; - ret += c; } - spin_unlock_irqrestore(&port->lock, flags); - uart_start(tty); + if (port) + ret = kfifo_in(&state->port.xmit_fifo, buf, count); + + __uart_start(state); + uart_port_unlock_deref(port, flags); return ret; } -static int uart_write_room(struct tty_struct *tty) +static unsigned int uart_write_room(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; + struct uart_port *port; unsigned long flags; - int ret; + unsigned int ret; - spin_lock_irqsave(&state->uart_port->lock, flags); - ret = uart_circ_chars_free(&state->xmit); - spin_unlock_irqrestore(&state->uart_port->lock, flags); + port = uart_port_ref_lock(state, &flags); + ret = kfifo_avail(&state->port.xmit_fifo); + uart_port_unlock_deref(port, flags); return ret; } -static int uart_chars_in_buffer(struct tty_struct *tty) +static unsigned int uart_chars_in_buffer(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; + struct uart_port *port; unsigned long flags; - int ret; + unsigned int ret; - spin_lock_irqsave(&state->uart_port->lock, flags); - ret = uart_circ_chars_pending(&state->xmit); - spin_unlock_irqrestore(&state->uart_port->lock, flags); + port = uart_port_ref_lock(state, &flags); + ret = kfifo_len(&state->port.xmit_fifo); + uart_port_unlock_deref(port, flags); return ret; } @@ -564,101 +671,133 @@ 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) { - WARN_ON(1); + if (WARN_ON(!state)) return; - } - port = state->uart_port; pr_debug("uart_flush_buffer(%d) called\n", tty->index); - spin_lock_irqsave(&port->lock, flags); - uart_circ_clear(&state->xmit); + port = uart_port_ref_lock(state, &flags); + if (!port) + return; + kfifo_reset(&state->port.xmit_fifo); if (port->ops->flush_buffer) port->ops->flush_buffer(port); - spin_unlock_irqrestore(&port->lock, flags); - tty_wakeup(tty); + uart_port_unlock_deref(port, flags); + tty_port_tty_wakeup(&state->port); +} + +/* + * This function performs low-level write of high-priority XON/XOFF + * character and accounting for it. + * + * Requires uart_port to implement .serial_out(). + */ +void uart_xchar_out(struct uart_port *uport, int offset) +{ + serial_port_out(uport, offset, uport->x_char); + uport->icount.tx++; + uport->x_char = 0; } +EXPORT_SYMBOL_GPL(uart_xchar_out); /* * This function is used to send a high-priority XON/XOFF character to * the device */ -static void uart_send_xchar(struct tty_struct *tty, char ch) +static void uart_send_xchar(struct tty_struct *tty, u8 ch) { struct uart_state *state = tty->driver_data; - struct uart_port *port = state->uart_port; - unsigned long flags; + struct uart_port *port; + + port = uart_port_ref(state); + if (!port) + return; if (port->ops->send_xchar) port->ops->send_xchar(port, ch); else { + guard(uart_port_lock_irqsave)(port); port->x_char = ch; - if (ch) { - spin_lock_irqsave(&port->lock, flags); + if (ch) port->ops->start_tx(port); - spin_unlock_irqrestore(&port->lock, flags); - } } + uart_port_deref(port); } static void uart_throttle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; - struct uart_port *port = state->uart_port; - uint32_t mask = 0; + upstat_t mask = UPSTAT_SYNC_FIFO; + struct uart_port *port; + + port = uart_port_ref(state); + if (!port) + return; if (I_IXOFF(tty)) - mask |= UPF_SOFT_FLOW; - if (tty->termios.c_cflag & CRTSCTS) - mask |= UPF_HARD_FLOW; + mask |= UPSTAT_AUTOXOFF; + if (C_CRTSCTS(tty)) + mask |= UPSTAT_AUTORTS; - if (port->flags & mask) { + if (port->status & mask) { port->ops->throttle(port); - mask &= ~port->flags; + mask &= ~port->status; } - if (mask & UPF_SOFT_FLOW) + if (mask & UPSTAT_AUTORTS) + uart_clear_mctrl(port, TIOCM_RTS); + + if (mask & UPSTAT_AUTOXOFF) uart_send_xchar(tty, STOP_CHAR(tty)); - if (mask & UPF_HARD_FLOW) - uart_clear_mctrl(port, TIOCM_RTS); + uart_port_deref(port); } static void uart_unthrottle(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; - struct uart_port *port = state->uart_port; - uint32_t mask = 0; + upstat_t mask = UPSTAT_SYNC_FIFO; + struct uart_port *port; + + port = uart_port_ref(state); + if (!port) + return; if (I_IXOFF(tty)) - mask |= UPF_SOFT_FLOW; - if (tty->termios.c_cflag & CRTSCTS) - mask |= UPF_HARD_FLOW; + mask |= UPSTAT_AUTOXOFF; + if (C_CRTSCTS(tty)) + mask |= UPSTAT_AUTORTS; - if (port->flags & mask) { + if (port->status & mask) { port->ops->unthrottle(port); - mask &= ~port->flags; - } - - if (mask & UPF_SOFT_FLOW) { - if (port->x_char) - port->x_char = 0; - else - uart_send_xchar(tty, START_CHAR(tty)); + mask &= ~port->status; } - if (mask & UPF_HARD_FLOW) + if (mask & UPSTAT_AUTORTS) uart_set_mctrl(port, TIOCM_RTS); + + if (mask & UPSTAT_AUTOXOFF) + uart_send_xchar(tty, START_CHAR(tty)); + + uart_port_deref(port); } -static void do_uart_get_info(struct tty_port *port, - struct serial_struct *retinfo) +static int uart_get_info(struct tty_port *port, struct serial_struct *retinfo) { struct uart_state *state = container_of(port, struct uart_state, port); - struct uart_port *uport = state->uart_port; + struct uart_port *uport; + + /* Initialize structure in case we error out later to prevent any stack info leakage. */ + *retinfo = (struct serial_struct){}; - memset(retinfo, 0, sizeof(*retinfo)); + /* + * Ensure the state we copy is consistent and no hardware changes + * occur as we go + */ + guard(mutex)(&port->mutex); + uport = uart_port_check(state); + if (!uport) + return -ENODEV; retinfo->type = uport->type; retinfo->line = uport->line; @@ -666,7 +805,7 @@ static void do_uart_get_info(struct tty_port *port, if (HIGH_BITS_OFFSET) retinfo->port_high = (long) uport->iobase >> HIGH_BITS_OFFSET; retinfo->irq = uport->irq; - retinfo->flags = uport->flags; + retinfo->flags = (__force int)uport->flags; retinfo->xmit_fifo_size = uport->fifosize; retinfo->baud_base = uport->uartclk / 16; retinfo->close_delay = jiffies_to_msecs(port->close_delay) / 10; @@ -678,39 +817,87 @@ static void do_uart_get_info(struct tty_port *port, retinfo->io_type = uport->iotype; retinfo->iomem_reg_shift = uport->regshift; retinfo->iomem_base = (void *)(unsigned long)uport->mapbase; + + return 0; } -static void uart_get_info(struct tty_port *port, - struct serial_struct *retinfo) +static int uart_get_info_user(struct tty_struct *tty, + struct serial_struct *ss) { - /* Ensure the state we copy is consistent and no hardware changes - occur as we go */ - mutex_lock(&port->mutex); - do_uart_get_info(port, retinfo); - mutex_unlock(&port->mutex); + struct uart_state *state = tty->driver_data; + struct tty_port *port = &state->port; + + return uart_get_info(port, ss) < 0 ? -EIO : 0; } -static int uart_get_info_user(struct tty_port *port, - struct serial_struct __user *retinfo) +static int uart_change_port(struct uart_port *uport, + const struct serial_struct *new_info, + unsigned long new_port) { - struct serial_struct tmp; - uart_get_info(port, &tmp); + unsigned long old_iobase, old_mapbase; + unsigned int old_type, old_iotype, old_hub6, old_shift; + int retval; - if (copy_to_user(retinfo, &tmp, sizeof(*retinfo))) - return -EFAULT; - return 0; + old_iobase = uport->iobase; + old_mapbase = uport->mapbase; + old_type = uport->type; + old_hub6 = uport->hub6; + old_iotype = uport->iotype; + old_shift = uport->regshift; + + if (old_type != PORT_UNKNOWN && uport->ops->release_port) + uport->ops->release_port(uport); + + uport->iobase = new_port; + uport->type = new_info->type; + uport->hub6 = new_info->hub6; + uport->iotype = new_info->io_type; + uport->regshift = new_info->iomem_reg_shift; + uport->mapbase = (unsigned long)new_info->iomem_base; + + if (uport->type == PORT_UNKNOWN || !uport->ops->request_port) + return 0; + + retval = uport->ops->request_port(uport); + if (retval == 0) + return 0; /* succeeded => done */ + + /* + * If we fail to request resources for the new port, try to restore the + * old settings. + */ + uport->iobase = old_iobase; + uport->type = old_type; + uport->hub6 = old_hub6; + uport->iotype = old_iotype; + uport->regshift = old_shift; + uport->mapbase = old_mapbase; + + if (old_type == PORT_UNKNOWN) + return retval; + + retval = uport->ops->request_port(uport); + /* If we failed to restore the old settings, we fail like this. */ + if (retval) + uport->type = PORT_UNKNOWN; + + /* We failed anyway. */ + return -EBUSY; } static int uart_set_info(struct tty_struct *tty, struct tty_port *port, struct uart_state *state, struct serial_struct *new_info) { - struct uart_port *uport = state->uart_port; + struct uart_port *uport = uart_port_check(state); unsigned long new_port; - unsigned int change_irq, change_port, closing_wait; - unsigned int old_custom_divisor, close_delay; + unsigned int old_custom_divisor, close_delay, closing_wait; + bool change_irq, change_port; upf_t old_flags, new_flags; - int retval = 0; + int retval; + + if (!uport) + return -EIO; new_port = new_info->port; if (HIGH_BITS_OFFSET) @@ -740,11 +927,16 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, new_info->type != uport->type); old_flags = uport->flags; - new_flags = new_info->flags; + new_flags = (__force upf_t)new_info->flags; old_custom_divisor = uport->custom_divisor; + if (!(uport->flags & UPF_FIXED_PORT)) { + unsigned int uartclk = new_info->baud_base * 16; + /* check needs to be done here before other settings made */ + if (uartclk == 0) + return -EINVAL; + } if (!capable(CAP_SYS_ADMIN)) { - retval = -EPERM; if (change_irq || change_port || (new_info->baud_base != uport->uartclk / 16) || (close_delay != port->close_delay) || @@ -752,34 +944,34 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, (new_info->xmit_fifo_size && new_info->xmit_fifo_size != uport->fifosize) || (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0)) - goto exit; + return -EPERM; uport->flags = ((uport->flags & ~UPF_USR_MASK) | (new_flags & UPF_USR_MASK)); uport->custom_divisor = new_info->custom_divisor; goto check_and_exit; } - /* - * Ask the low level driver to verify the settings. - */ - if (uport->ops->verify_port) + if (change_irq || change_port) { + retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); + if (retval) + return retval; + } + + /* Ask the low level driver to verify the settings. */ + if (uport->ops->verify_port) { retval = uport->ops->verify_port(uport, new_info); + if (retval) + return retval; + } - if ((new_info->irq >= nr_irqs) || (new_info->irq < 0) || + if ((new_info->irq >= irq_get_nr_irqs()) || (new_info->irq < 0) || (new_info->baud_base < 9600)) - retval = -EINVAL; - - if (retval) - goto exit; + return -EINVAL; if (change_port || change_irq) { - retval = -EBUSY; - - /* - * Make sure that we are the sole user of this port. - */ + /* Make sure that we are the sole user of this port. */ if (tty_port_users(port) > 1) - goto exit; + return -EBUSY; /* * We need to shutdown the serial port at the old @@ -789,65 +981,9 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, } if (change_port) { - unsigned long old_iobase, old_mapbase; - unsigned int old_type, old_iotype, old_hub6, old_shift; - - old_iobase = uport->iobase; - old_mapbase = uport->mapbase; - old_type = uport->type; - old_hub6 = uport->hub6; - old_iotype = uport->iotype; - old_shift = uport->regshift; - - /* - * Free and release old regions - */ - if (old_type != PORT_UNKNOWN) - uport->ops->release_port(uport); - - uport->iobase = new_port; - uport->type = new_info->type; - uport->hub6 = new_info->hub6; - uport->iotype = new_info->io_type; - uport->regshift = new_info->iomem_reg_shift; - uport->mapbase = (unsigned long)new_info->iomem_base; - - /* - * Claim and map the new regions - */ - if (uport->type != PORT_UNKNOWN) { - retval = uport->ops->request_port(uport); - } else { - /* Always success - Jean II */ - retval = 0; - } - - /* - * If we fail to request resources for the - * new port, try to restore the old settings. - */ - if (retval && old_type != PORT_UNKNOWN) { - uport->iobase = old_iobase; - uport->type = old_type; - uport->hub6 = old_hub6; - uport->iotype = old_iotype; - uport->regshift = old_shift; - uport->mapbase = old_mapbase; - retval = uport->ops->request_port(uport); - /* - * If we failed to restore the old settings, - * we fail like this. - */ - if (retval) - uport->type = PORT_UNKNOWN; - - /* - * We failed anyway. - */ - retval = -EBUSY; - /* Added to return the correct error -Ram Gupta */ - goto exit; - } + retval = uart_change_port(uport, new_info, new_port); + if (retval) + return retval; } if (change_irq) @@ -861,45 +997,45 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, port->closing_wait = closing_wait; if (new_info->xmit_fifo_size) uport->fifosize = new_info->xmit_fifo_size; - port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0; check_and_exit: - retval = 0; if (uport->type == PORT_UNKNOWN) - goto exit; - if (port->flags & ASYNC_INITIALIZED) { + return 0; + + if (tty_port_initialized(port)) { if (((old_flags ^ uport->flags) & UPF_SPD_MASK) || old_custom_divisor != uport->custom_divisor) { /* * If they're setting up a custom divisor or speed, - * instead of clearing it, then bitch about it. No - * need to rate-limit; it's CAP_SYS_ADMIN only. + * instead of clearing it, then bitch about it. */ if (uport->flags & UPF_SPD_MASK) { - char buf[64]; - printk(KERN_NOTICE - "%s sets custom speed on %s. This " - "is deprecated.\n", current->comm, - tty_name(port->tty, buf)); + dev_notice_ratelimited(uport->dev, + "%s sets custom speed on %s. This is deprecated.\n", + current->comm, + tty_name(port->tty)); } - uart_change_speed(tty, state, NULL); + uart_change_line_settings(tty, state, NULL); } - } else - retval = uart_startup(tty, state, 1); - exit: - return retval; + + return 0; + } + + retval = uart_startup(tty, state, true); + if (retval < 0) + return retval; + if (retval == 0) + tty_port_set_initialized(port, true); + + return 0; } -static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state, - struct serial_struct __user *newinfo) +static int uart_set_info_user(struct tty_struct *tty, struct serial_struct *ss) { - struct serial_struct new_serial; + struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; - int retval; - - if (copy_from_user(&new_serial, newinfo, sizeof(new_serial))) - return -EFAULT; + guard(rwsem_write)(&tty->termios_rwsem); /* * This semaphore protects port->count. It is also * very useful to prevent opens. Also, take the @@ -907,24 +1043,20 @@ static int uart_set_info_user(struct tty_struct *tty, struct uart_state *state, * module insertion/removal doesn't change anything * under us. */ - mutex_lock(&port->mutex); - retval = uart_set_info(tty, port, state, &new_serial); - mutex_unlock(&port->mutex); - return retval; + guard(mutex)(&port->mutex); + return uart_set_info(tty, port, state, ss); } /** - * uart_get_lsr_info - get line status register info - * @tty: tty associated with the UART - * @state: UART being queried - * @value: returned modem value - * - * Note: uart_ioctl protects us against hangups. + * uart_get_lsr_info - get line status register info + * @tty: tty associated with the UART + * @state: UART being queried + * @value: returned modem value */ static int uart_get_lsr_info(struct tty_struct *tty, struct uart_state *state, unsigned int __user *value) { - struct uart_port *uport = state->uart_port; + struct uart_port *uport = uart_port_check(state); unsigned int result; result = uport->ops->tx_empty(uport); @@ -936,8 +1068,8 @@ static int uart_get_lsr_info(struct tty_struct *tty, * interrupt happens). */ if (uport->x_char || - ((uart_circ_chars_pending(&state->xmit) > 0) && - !tty->stopped && !tty->hw_stopped)) + (!kfifo_is_empty(&state->port.xmit_fifo) && + !uart_tx_stopped(uport))) result &= ~TIOCSER_TEMT; return put_user(result, value); @@ -947,57 +1079,59 @@ static int uart_tiocmget(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; - struct uart_port *uport = state->uart_port; - int result = -EIO; + struct uart_port *uport; - mutex_lock(&port->mutex); - if (!(tty->flags & (1 << TTY_IO_ERROR))) { - result = uport->mctrl; - spin_lock_irq(&uport->lock); - result |= uport->ops->get_mctrl(uport); - spin_unlock_irq(&uport->lock); - } - mutex_unlock(&port->mutex); + guard(mutex)(&port->mutex); + + uport = uart_port_check(state); + if (!uport || tty_io_error(tty)) + return -EIO; + + guard(uart_port_lock_irq)(uport); - return result; + return uport->mctrl | uport->ops->get_mctrl(uport); } static int uart_tiocmset(struct tty_struct *tty, unsigned int set, unsigned int clear) { struct uart_state *state = tty->driver_data; - struct uart_port *uport = state->uart_port; struct tty_port *port = &state->port; - int ret = -EIO; + struct uart_port *uport; - mutex_lock(&port->mutex); - if (!(tty->flags & (1 << TTY_IO_ERROR))) { - uart_update_mctrl(uport, set, clear); - ret = 0; - } - mutex_unlock(&port->mutex); - return ret; + guard(mutex)(&port->mutex); + + uport = uart_port_check(state); + if (!uport || tty_io_error(tty)) + return -EIO; + + uart_update_mctrl(uport, set, clear); + + return 0; } static int uart_break_ctl(struct tty_struct *tty, int break_state) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; - struct uart_port *uport = state->uart_port; + struct uart_port *uport; + + guard(mutex)(&port->mutex); - mutex_lock(&port->mutex); + uport = uart_port_check(state); + if (!uport) + return -EIO; - if (uport->type != PORT_UNKNOWN) + if (uport->type != PORT_UNKNOWN && uport->ops->break_ctl) uport->ops->break_ctl(uport, break_state); - mutex_unlock(&port->mutex); return 0; } -static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) +static int uart_do_autoconfig(struct tty_struct *tty, struct uart_state *state) { - struct uart_port *uport = state->uart_port; struct tty_port *port = &state->port; + struct uart_port *uport; int flags, ret; if (!capable(CAP_SYS_ADMIN)) @@ -1008,18 +1142,21 @@ static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) * changing, and hence any extra opens of the port while * we're auto-configuring. */ - if (mutex_lock_interruptible(&port->mutex)) - return -ERESTARTSYS; + scoped_cond_guard(mutex_intr, return -ERESTARTSYS, &port->mutex) { + uport = uart_port_check(state); + if (!uport) + return -EIO; + + if (tty_port_users(port) != 1) + return -EBUSY; - ret = -EBUSY; - if (tty_port_users(port) == 1) { uart_shutdown(tty, state); /* * If we already have a port type configured, * we must release its resources. */ - if (uport->type != PORT_UNKNOWN) + if (uport->type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); flags = UART_CONFIG_TYPE; @@ -1032,10 +1169,25 @@ static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) */ uport->ops->config_port(uport, flags); - ret = uart_startup(tty, state, 1); + ret = uart_startup(tty, state, true); + if (ret < 0) + return ret; + if (ret > 0) + return 0; + + tty_port_set_initialized(port, true); } - mutex_unlock(&port->mutex); - return ret; + + return 0; +} + +static void uart_enable_ms(struct uart_port *uport) +{ + /* + * Force modem status interrupts on + */ + if (uport->ops->enable_ms) + uport->ops->enable_ms(uport); } /* @@ -1047,10 +1199,9 @@ static int uart_do_autoconfig(struct tty_struct *tty,struct uart_state *state) * FIXME: This wants extracting into a common all driver implementation * of TIOCMWAIT using tty_port. */ -static int -uart_wait_modem_status(struct uart_state *state, unsigned long arg) +static int uart_wait_modem_status(struct uart_state *state, unsigned long arg) { - struct uart_port *uport = state->uart_port; + struct uart_port *uport; struct tty_port *port = &state->port; DECLARE_WAITQUEUE(wait, current); struct uart_icount cprev, cnow; @@ -1059,20 +1210,18 @@ uart_wait_modem_status(struct uart_state *state, unsigned long arg) /* * note the counters on entry */ - spin_lock_irq(&uport->lock); - memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); - - /* - * Force modem status interrupts on - */ - uport->ops->enable_ms(uport); - spin_unlock_irq(&uport->lock); + uport = uart_port_ref(state); + if (!uport) + return -EIO; + scoped_guard(uart_port_lock_irq, uport) { + memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); + uart_enable_ms(uport); + } add_wait_queue(&port->delta_msr_wait, &wait); for (;;) { - spin_lock_irq(&uport->lock); - memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); - spin_unlock_irq(&uport->lock); + scoped_guard(uart_port_lock_irq, uport) + memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); set_current_state(TASK_INTERRUPTIBLE); @@ -1094,9 +1243,9 @@ uart_wait_modem_status(struct uart_state *state, unsigned long arg) cprev = cnow; } - - current->state = TASK_RUNNING; + __set_current_state(TASK_RUNNING); remove_wait_queue(&port->delta_msr_wait, &wait); + uart_port_deref(uport); return ret; } @@ -1112,11 +1261,14 @@ static int uart_get_icount(struct tty_struct *tty, { struct uart_state *state = tty->driver_data; struct uart_icount cnow; - struct uart_port *uport = state->uart_port; + struct uart_port *uport; + unsigned long flags; - spin_lock_irq(&uport->lock); + uport = uart_port_ref_lock(state, &flags); + if (!uport) + return -EIO; memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); - spin_unlock_irq(&uport->lock); + uart_port_unlock_deref(uport, flags); icount->cts = cnow.cts; icount->dsr = cnow.dsr; @@ -1133,109 +1285,370 @@ static int uart_get_icount(struct tty_struct *tty, return 0; } -/* - * Called via sys_ioctl. We can use spin_lock_irq() here. - */ -static int -uart_ioctl(struct tty_struct *tty, unsigned int cmd, - unsigned long arg) +#define SER_RS485_LEGACY_FLAGS (SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | \ + SER_RS485_RTS_AFTER_SEND | SER_RS485_RX_DURING_TX | \ + SER_RS485_TERMINATE_BUS) + +static int uart_check_rs485_flags(struct uart_port *port, struct serial_rs485 *rs485) { - struct uart_state *state = tty->driver_data; - struct tty_port *port = &state->port; - void __user *uarg = (void __user *)arg; - int ret = -ENOIOCTLCMD; + u32 flags = rs485->flags; + /* Don't return -EINVAL for unsupported legacy flags */ + flags &= ~SER_RS485_LEGACY_FLAGS; /* - * These ioctls don't rely on the hardware to be present. + * For any bit outside of the legacy ones that is not supported by + * the driver, return -EINVAL. */ - switch (cmd) { - case TIOCGSERIAL: - ret = uart_get_info_user(port, uarg); - break; + if (flags & ~port->rs485_supported.flags) + return -EINVAL; - case TIOCSSERIAL: - ret = uart_set_info_user(tty, state, uarg); - break; + /* Asking for address w/o addressing mode? */ + if (!(rs485->flags & SER_RS485_ADDRB) && + (rs485->flags & (SER_RS485_ADDR_RECV|SER_RS485_ADDR_DEST))) + return -EINVAL; - case TIOCSERCONFIG: - ret = uart_do_autoconfig(tty, state); - break; + /* Address given but not enabled? */ + if (!(rs485->flags & SER_RS485_ADDR_RECV) && rs485->addr_recv) + return -EINVAL; + if (!(rs485->flags & SER_RS485_ADDR_DEST) && rs485->addr_dest) + return -EINVAL; - case TIOCSERGWILD: /* obsolete */ - case TIOCSERSWILD: /* obsolete */ - ret = 0; - break; + return 0; +} + +static void uart_sanitize_serial_rs485_delays(struct uart_port *port, + struct serial_rs485 *rs485) +{ + if (!port->rs485_supported.delay_rts_before_send) { + if (rs485->delay_rts_before_send) { + dev_warn_ratelimited(port->dev, + "%s (%u): RTS delay before sending not supported\n", + port->name, port->line); + } + rs485->delay_rts_before_send = 0; + } else if (rs485->delay_rts_before_send > RS485_MAX_RTS_DELAY) { + rs485->delay_rts_before_send = RS485_MAX_RTS_DELAY; + dev_warn_ratelimited(port->dev, + "%s (%u): RTS delay before sending clamped to %u ms\n", + port->name, port->line, rs485->delay_rts_before_send); } - if (ret != -ENOIOCTLCMD) - goto out; + if (!port->rs485_supported.delay_rts_after_send) { + if (rs485->delay_rts_after_send) { + dev_warn_ratelimited(port->dev, + "%s (%u): RTS delay after sending not supported\n", + port->name, port->line); + } + rs485->delay_rts_after_send = 0; + } else if (rs485->delay_rts_after_send > RS485_MAX_RTS_DELAY) { + rs485->delay_rts_after_send = RS485_MAX_RTS_DELAY; + dev_warn_ratelimited(port->dev, + "%s (%u): RTS delay after sending clamped to %u ms\n", + port->name, port->line, rs485->delay_rts_after_send); + } +} - if (tty->flags & (1 << TTY_IO_ERROR)) { - ret = -EIO; - goto out; +static void uart_sanitize_serial_rs485(struct uart_port *port, struct serial_rs485 *rs485) +{ + u32 supported_flags = port->rs485_supported.flags; + + if (!(rs485->flags & SER_RS485_ENABLED)) { + memset(rs485, 0, sizeof(*rs485)); + return; } - /* - * The following should only be used when hardware is present. - */ - switch (cmd) { - case TIOCMIWAIT: - ret = uart_wait_modem_status(state, arg); - break; + /* Clear other RS485 flags but SER_RS485_TERMINATE_BUS and return if enabling RS422 */ + if (rs485->flags & SER_RS485_MODE_RS422) { + rs485->flags &= (SER_RS485_ENABLED | SER_RS485_MODE_RS422 | SER_RS485_TERMINATE_BUS); + return; } - if (ret != -ENOIOCTLCMD) - goto out; + rs485->flags &= supported_flags; + + /* Pick sane settings if the user hasn't */ + if (!(rs485->flags & SER_RS485_RTS_ON_SEND) == + !(rs485->flags & SER_RS485_RTS_AFTER_SEND)) { + if (supported_flags & SER_RS485_RTS_ON_SEND) { + rs485->flags |= SER_RS485_RTS_ON_SEND; + rs485->flags &= ~SER_RS485_RTS_AFTER_SEND; - mutex_lock(&port->mutex); + dev_warn_ratelimited(port->dev, + "%s (%u): invalid RTS setting, using RTS_ON_SEND instead\n", + port->name, port->line); + } else { + rs485->flags |= SER_RS485_RTS_AFTER_SEND; + rs485->flags &= ~SER_RS485_RTS_ON_SEND; - if (tty->flags & (1 << TTY_IO_ERROR)) { - ret = -EIO; - goto out_up; + dev_warn_ratelimited(port->dev, + "%s (%u): invalid RTS setting, using RTS_AFTER_SEND instead\n", + port->name, port->line); + } } + uart_sanitize_serial_rs485_delays(port, rs485); + + /* Return clean padding area to userspace */ + memset(rs485->padding0, 0, sizeof(rs485->padding0)); + memset(rs485->padding1, 0, sizeof(rs485->padding1)); +} + +static void uart_set_rs485_termination(struct uart_port *port, + const struct serial_rs485 *rs485) +{ + if (!(rs485->flags & SER_RS485_ENABLED)) + return; + + gpiod_set_value_cansleep(port->rs485_term_gpio, + !!(rs485->flags & SER_RS485_TERMINATE_BUS)); +} + +static void uart_set_rs485_rx_during_tx(struct uart_port *port, + const struct serial_rs485 *rs485) +{ + if (!(rs485->flags & SER_RS485_ENABLED)) + return; + + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, + !!(rs485->flags & SER_RS485_RX_DURING_TX)); +} + +static int uart_rs485_config(struct uart_port *port) +{ + struct serial_rs485 *rs485 = &port->rs485; + int ret; + + if (!(rs485->flags & SER_RS485_ENABLED)) + return 0; + + uart_sanitize_serial_rs485(port, rs485); + uart_set_rs485_termination(port, rs485); + uart_set_rs485_rx_during_tx(port, rs485); + + scoped_guard(uart_port_lock_irqsave, port) + ret = port->rs485_config(port, NULL, rs485); + if (ret) { + memset(rs485, 0, sizeof(*rs485)); + /* unset GPIOs */ + gpiod_set_value_cansleep(port->rs485_term_gpio, 0); + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, 0); + } + + return ret; +} + +static int uart_get_rs485_config(struct uart_port *port, + struct serial_rs485 __user *rs485) +{ + struct serial_rs485 aux; + + scoped_guard(uart_port_lock_irqsave, port) + aux = port->rs485; + + if (copy_to_user(rs485, &aux, sizeof(aux))) + return -EFAULT; + + return 0; +} + +static int uart_set_rs485_config(struct tty_struct *tty, struct uart_port *port, + struct serial_rs485 __user *rs485_user) +{ + struct serial_rs485 rs485; + int ret; + + if (!(port->rs485_supported.flags & SER_RS485_ENABLED)) + return -ENOTTY; + + if (copy_from_user(&rs485, rs485_user, sizeof(*rs485_user))) + return -EFAULT; + + ret = uart_check_rs485_flags(port, &rs485); + if (ret) + return ret; + uart_sanitize_serial_rs485(port, &rs485); + uart_set_rs485_termination(port, &rs485); + uart_set_rs485_rx_during_tx(port, &rs485); + + scoped_guard(uart_port_lock_irqsave, port) { + ret = port->rs485_config(port, &tty->termios, &rs485); + if (!ret) { + port->rs485 = rs485; + + /* Reset RTS and other mctrl lines when disabling RS485 */ + if (!(rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); + } + } + if (ret) { + /* restore old GPIO settings */ + gpiod_set_value_cansleep(port->rs485_term_gpio, + !!(port->rs485.flags & SER_RS485_TERMINATE_BUS)); + gpiod_set_value_cansleep(port->rs485_rx_during_tx_gpio, + !!(port->rs485.flags & SER_RS485_RX_DURING_TX)); + return ret; + } + + if (copy_to_user(rs485_user, &port->rs485, sizeof(port->rs485))) + return -EFAULT; + + return 0; +} + +static int uart_get_iso7816_config(struct uart_port *port, + struct serial_iso7816 __user *iso7816) +{ + struct serial_iso7816 aux; + + if (!port->iso7816_config) + return -ENOTTY; + + scoped_guard(uart_port_lock_irqsave, port) + aux = port->iso7816; + + if (copy_to_user(iso7816, &aux, sizeof(aux))) + return -EFAULT; + + return 0; +} + +static int uart_set_iso7816_config(struct uart_port *port, + struct serial_iso7816 __user *iso7816_user) +{ + struct serial_iso7816 iso7816; + int i; + + if (!port->iso7816_config) + return -ENOTTY; + + if (copy_from_user(&iso7816, iso7816_user, sizeof(*iso7816_user))) + return -EFAULT; + /* - * All these rely on hardware being present and need to be - * protected against the tty being hung up. + * There are 5 words reserved for future use. Check that userspace + * doesn't put stuff in there to prevent breakages in the future. */ - switch (cmd) { - case TIOCSERGETLSR: /* Get line status register */ - ret = uart_get_lsr_info(tty, state, uarg); - break; + for (i = 0; i < ARRAY_SIZE(iso7816.reserved); i++) + if (iso7816.reserved[i]) + return -EINVAL; - default: { - struct uart_port *uport = state->uart_port; - if (uport->ops->ioctl) - ret = uport->ops->ioctl(uport, cmd, arg); - break; + scoped_guard(uart_port_lock_irqsave, port) { + int ret = port->iso7816_config(port, &iso7816); + if (ret) + return ret; } + + if (copy_to_user(iso7816_user, &port->iso7816, sizeof(port->iso7816))) + return -EFAULT; + + return 0; +} + +/* + * Called via sys_ioctl. We can use spin_lock_irq() here. + */ +static int +uart_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg) +{ + struct uart_state *state = tty->driver_data; + struct tty_port *port = &state->port; + struct uart_port *uport; + void __user *uarg = (void __user *)arg; + int ret = -ENOIOCTLCMD; + + /* This ioctl doesn't rely on the hardware to be present. */ + if (cmd == TIOCSERCONFIG) { + guard(rwsem_write)(&tty->termios_rwsem); + return uart_do_autoconfig(tty, state); } -out_up: - mutex_unlock(&port->mutex); -out: + + if (tty_io_error(tty)) + return -EIO; + + /* This should only be used when the hardware is present. */ + if (cmd == TIOCMIWAIT) + return uart_wait_modem_status(state, arg); + + /* rs485_config requires more locking than others */ + if (cmd == TIOCSRS485) + down_write(&tty->termios_rwsem); + + scoped_guard(mutex, &port->mutex) { + uport = uart_port_check(state); + + if (!uport || tty_io_error(tty)) { + ret = -EIO; + break; + } + + /* + * All these rely on hardware being present and need to be + * protected against the tty being hung up. + */ + + switch (cmd) { + case TIOCSERGETLSR: /* Get line status register */ + ret = uart_get_lsr_info(tty, state, uarg); + break; + + case TIOCGRS485: + ret = uart_get_rs485_config(uport, uarg); + break; + + case TIOCSRS485: + ret = uart_set_rs485_config(tty, uport, uarg); + break; + + case TIOCSISO7816: + ret = uart_set_iso7816_config(state->uart_port, uarg); + break; + + case TIOCGISO7816: + ret = uart_get_iso7816_config(state->uart_port, uarg); + break; + default: + if (uport->ops->ioctl) + ret = uport->ops->ioctl(uport, cmd, arg); + break; + } + } + + if (cmd == TIOCSRS485) + up_write(&tty->termios_rwsem); + return ret; } static void uart_set_ldisc(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; - struct uart_port *uport = state->uart_port; + struct uart_port *uport; + struct tty_port *port = &state->port; - if (uport->ops->set_ldisc) - uport->ops->set_ldisc(uport, tty->termios.c_line); + if (!tty_port_initialized(port)) + return; + + guard(mutex)(&state->port.mutex); + uport = uart_port_check(state); + if (uport && uport->ops->set_ldisc) + uport->ops->set_ldisc(uport, &tty->termios); } static void uart_set_termios(struct tty_struct *tty, - struct ktermios *old_termios) + const struct ktermios *old_termios) { struct uart_state *state = tty->driver_data; - struct uart_port *uport = state->uart_port; - unsigned long flags; + struct uart_port *uport; unsigned int cflag = tty->termios.c_cflag; unsigned int iflag_mask = IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK; bool sw_changed = false; + guard(mutex)(&state->port.mutex); + + uport = uart_port_check(state); + if (!uport) + return; + /* * Drivers doing software flow control also need to know * about changes to these input settings. @@ -1257,133 +1670,96 @@ static void uart_set_termios(struct tty_struct *tty, tty->termios.c_ospeed == old_termios->c_ospeed && tty->termios.c_ispeed == old_termios->c_ispeed && ((tty->termios.c_iflag ^ old_termios->c_iflag) & iflag_mask) == 0 && - !sw_changed) { + !sw_changed) return; - } - uart_change_speed(tty, state, old_termios); + uart_change_line_settings(tty, state, old_termios); + /* reload cflag from termios; port driver may have overridden flags */ + cflag = tty->termios.c_cflag; /* Handle transition to B0 status */ - if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD)) + if (((old_termios->c_cflag & CBAUD) != B0) && ((cflag & CBAUD) == B0)) uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR); /* Handle transition away from B0 status */ - else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) { + else if (((old_termios->c_cflag & CBAUD) == B0) && ((cflag & CBAUD) != B0)) { unsigned int mask = TIOCM_DTR; - if (!(cflag & CRTSCTS) || - !test_bit(TTY_THROTTLED, &tty->flags)) + + if (!(cflag & CRTSCTS) || !tty_throttled(tty)) mask |= TIOCM_RTS; uart_set_mctrl(uport, mask); } - - /* - * If the port is doing h/w assisted flow control, do nothing. - * We assume that tty->hw_stopped has never been set. - */ - if (uport->flags & UPF_HARD_FLOW) - return; - - /* Handle turning off CRTSCTS */ - if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { - spin_lock_irqsave(&uport->lock, flags); - tty->hw_stopped = 0; - __uart_start(tty); - spin_unlock_irqrestore(&uport->lock, flags); - } - /* Handle turning on CRTSCTS */ - else if (!(old_termios->c_cflag & CRTSCTS) && (cflag & CRTSCTS)) { - spin_lock_irqsave(&uport->lock, flags); - if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS)) { - tty->hw_stopped = 1; - uport->ops->stop_tx(uport); - } - spin_unlock_irqrestore(&uport->lock, flags); - } } /* * Calls to uart_close() are serialised via the tty_lock in * drivers/tty/tty_io.c:tty_release() * drivers/tty/tty_io.c:do_tty_hangup() - * This runs from a workqueue and can sleep for a _short_ time only. */ static void uart_close(struct tty_struct *tty, struct file *filp) { struct uart_state *state = tty->driver_data; - struct tty_port *port; - struct uart_port *uport; - unsigned long flags; - if (!state) + if (!state) { + struct uart_driver *drv = tty->driver->driver_state; + struct tty_port *port; + + state = drv->state + tty->index; + port = &state->port; + guard(spinlock_irq)(&port->lock); + --port->count; return; + } - uport = state->uart_port; - port = &state->port; + pr_debug("uart_close(%d) called\n", tty->index); - pr_debug("uart_close(%d) called\n", uport->line); + tty_port_close(tty->port, tty, filp); +} - if (tty_port_close_start(port, tty, filp) == 0) - return; +static void uart_tty_port_shutdown(struct tty_port *port) +{ + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport = uart_port_check(state); /* * At this point, we stop accepting input. To do this, we * disable the receive line status interrupts. */ - if (port->flags & ASYNC_INITIALIZED) { - unsigned long flags; - spin_lock_irqsave(&uport->lock, flags); - uport->ops->stop_rx(uport); - spin_unlock_irqrestore(&uport->lock, flags); - /* - * Before we drop DTR, make sure the UART transmitter - * has completely drained; this is especially - * important if there is a transmit FIFO! - */ - uart_wait_until_sent(tty, uport->timeout); - } - - mutex_lock(&port->mutex); - uart_shutdown(tty, state); - uart_flush_buffer(tty); - - tty_ldisc_flush(tty); + if (WARN(!uport, "detached port still initialized!\n")) + return; - tty_port_tty_set(port, NULL); - spin_lock_irqsave(&port->lock, flags); - tty->closing = 0; + scoped_guard(uart_port_lock_irq, uport) + uport->ops->stop_rx(uport); - if (port->blocked_open) { - spin_unlock_irqrestore(&port->lock, flags); - if (port->close_delay) - msleep_interruptible( - jiffies_to_msecs(port->close_delay)); - spin_lock_irqsave(&port->lock, flags); - } else if (!uart_console(uport)) { - spin_unlock_irqrestore(&port->lock, flags); - uart_change_pm(state, UART_PM_STATE_OFF); - spin_lock_irqsave(&port->lock, flags); - } + serial_base_port_shutdown(uport); + uart_port_shutdown(port); /* - * Wake up anyone trying to open this port. + * It's possible for shutdown to be called after suspend if we get + * a DCD drop (hangup) at just the right time. Clear suspended bit so + * we don't try to resume a port that has been shutdown. */ - clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); - clear_bit(ASYNCB_CLOSING, &port->flags); - spin_unlock_irqrestore(&port->lock, flags); - wake_up_interruptible(&port->open_wait); - wake_up_interruptible(&port->close_wait); + tty_port_set_suspended(port, false); + + uart_free_xmit_buf(port); - mutex_unlock(&port->mutex); + uart_change_pm(state, UART_PM_STATE_OFF); } static void uart_wait_until_sent(struct tty_struct *tty, int timeout) { struct uart_state *state = tty->driver_data; - struct uart_port *port = state->uart_port; - unsigned long char_time, expire; + struct uart_port *port; + unsigned long char_time, expire, fifo_timeout; - if (port->type == PORT_UNKNOWN || port->fifosize == 0) + port = uart_port_ref(state); + if (!port) return; + if (port->type == PORT_UNKNOWN || port->fifosize == 0) { + uart_port_deref(port); + return; + } + /* * 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 @@ -1392,28 +1768,29 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout) * Note: we have to use pretty tight timings here to satisfy * the NIST-PCTS. */ - char_time = (port->timeout - HZ/50) / port->fifosize; - char_time = char_time / 5; - if (char_time == 0) - char_time = 1; + char_time = max(nsecs_to_jiffies(port->frame_time / 5), 1UL); + if (timeout && timeout < char_time) char_time = timeout; - /* - * If the transmitter hasn't cleared in twice the approximate - * amount of time to send the entire FIFO, it probably won't - * ever clear. This assumes the UART isn't doing flow - * control, which is currently the case. Hence, if it ever - * takes longer than port->timeout, this is probably due to a - * UART bug of some kind. So, we clamp the timeout parameter at - * 2*port->timeout. - */ - if (timeout == 0 || timeout > 2 * port->timeout) - timeout = 2 * port->timeout; + if (!uart_cts_enabled(port)) { + /* + * If the transmitter hasn't cleared in twice the approximate + * amount of time to send the entire FIFO, it probably won't + * ever clear. This assumes the UART isn't doing flow + * control, which is currently the case. Hence, if it ever + * takes longer than FIFO timeout, this is probably due to a + * UART bug of some kind. So, we clamp the timeout parameter at + * 2 * FIFO timeout. + */ + fifo_timeout = uart_fifo_timeout(port); + if (timeout == 0 || timeout > 2 * fifo_timeout) + timeout = 2 * fifo_timeout; + } expire = jiffies + timeout; - pr_debug("uart_wait_until_sent(%d), jiffies=%lu, expire=%lu...\n", + pr_debug("uart_wait_until_sent(%u), jiffies=%lu, expire=%lu...\n", port->line, jiffies, expire); /* @@ -1425,9 +1802,10 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout) msleep_interruptible(jiffies_to_msecs(char_time)); if (signal_pending(current)) break; - if (time_after(jiffies, expire)) + if (timeout && time_after(jiffies, expire)) break; } + uart_port_deref(port); } /* @@ -1439,34 +1817,33 @@ static void uart_hangup(struct tty_struct *tty) { struct uart_state *state = tty->driver_data; struct tty_port *port = &state->port; - unsigned long flags; + struct uart_port *uport; + + pr_debug("uart_hangup(%d)\n", tty->index); - pr_debug("uart_hangup(%d)\n", state->uart_port->line); + guard(mutex)(&port->mutex); + uport = uart_port_check(state); + WARN(!uport, "hangup of detached port!\n"); - mutex_lock(&port->mutex); - if (port->flags & ASYNC_NORMAL_ACTIVE) { + if (tty_port_active(port)) { uart_flush_buffer(tty); uart_shutdown(tty, state); - spin_lock_irqsave(&port->lock, flags); - port->count = 0; - clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags); - spin_unlock_irqrestore(&port->lock, flags); + scoped_guard(spinlock_irqsave, &port->lock) + port->count = 0; + tty_port_set_active(port, false); tty_port_tty_set(port, NULL); + if (uport && !uart_console(uport)) + uart_change_pm(state, UART_PM_STATE_OFF); wake_up_interruptible(&port->open_wait); wake_up_interruptible(&port->delta_msr_wait); } - mutex_unlock(&port->mutex); -} - -static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) -{ - return 0; } +/* uport == NULL if uart_port has already been removed */ static void uart_port_shutdown(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); - struct uart_port *uport = state->uart_port; + struct uart_port *uport = uart_port_check(state); /* * clear delta_msr_wait queue to avoid mem leaks: we may free @@ -1477,40 +1854,58 @@ static void uart_port_shutdown(struct tty_port *port) */ wake_up_interruptible(&port->delta_msr_wait); - /* - * Free the IRQ and disable the port. - */ - uport->ops->shutdown(uport); + if (uport) { + /* Free the IRQ and disable the port. */ + uport->ops->shutdown(uport); - /* - * Ensure that the IRQ handler isn't running on another CPU. - */ - synchronize_irq(uport->irq); + /* Ensure that the IRQ handler isn't running on another CPU. */ + synchronize_irq(uport->irq); + } } -static int uart_carrier_raised(struct tty_port *port) +static bool uart_carrier_raised(struct tty_port *port) { struct uart_state *state = container_of(port, struct uart_state, port); - struct uart_port *uport = state->uart_port; + struct uart_port *uport; + unsigned long flags; int mctrl; - spin_lock_irq(&uport->lock); - uport->ops->enable_ms(uport); + + uport = uart_port_ref_lock(state, &flags); + /* + * Should never observe uport == NULL since checks for hangup should + * abort the tty_port_block_til_ready() loop before checking for carrier + * raised -- but report carrier raised if it does anyway so open will + * continue and not sleep + */ + if (WARN_ON(!uport)) + return true; + uart_enable_ms(uport); mctrl = uport->ops->get_mctrl(uport); - spin_unlock_irq(&uport->lock); - if (mctrl & TIOCM_CAR) - return 1; - return 0; + uart_port_unlock_deref(uport, flags); + + return mctrl & TIOCM_CAR; } -static void uart_dtr_rts(struct tty_port *port, int onoff) +static void uart_dtr_rts(struct tty_port *port, bool active) { struct uart_state *state = container_of(port, struct uart_state, port); - struct uart_port *uport = state->uart_port; + struct uart_port *uport; - if (onoff) - uart_set_mctrl(uport, TIOCM_DTR | TIOCM_RTS); - else - uart_clear_mctrl(uport, TIOCM_DTR | TIOCM_RTS); + uport = uart_port_ref(state); + if (!uport) + return; + uart_port_dtr_rts(uport, active); + uart_port_deref(uport); +} + +static int uart_install(struct tty_driver *driver, struct tty_struct *tty) +{ + struct uart_driver *drv = driver->driver_state; + struct uart_state *state = drv->state + tty->index; + + tty->driver_data = state; + + return tty_standard_install(driver, tty); } /* @@ -1525,74 +1920,34 @@ static void uart_dtr_rts(struct tty_port *port, int onoff) */ static int uart_open(struct tty_struct *tty, struct file *filp) { - struct uart_driver *drv = (struct uart_driver *)tty->driver->driver_state; - int retval, line = tty->index; - struct uart_state *state = drv->state + line; - struct tty_port *port = &state->port; - - pr_debug("uart_open(%d) called\n", line); - - /* - * We take the semaphore here to guarantee that we won't be re-entered - * while allocating the state 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 - * state->port.tty will always contain something reasonable. - */ - if (mutex_lock_interruptible(&port->mutex)) { - retval = -ERESTARTSYS; - goto end; - } + struct uart_state *state = tty->driver_data; + int retval; - port->count++; - if (!state->uart_port || state->uart_port->flags & UPF_DEAD) { - retval = -ENXIO; - goto err_dec_count; - } + retval = tty_port_open(&state->port, tty, filp); + if (retval > 0) + retval = 0; - /* - * Once we set tty->driver_data here, we are guaranteed that - * uart_close() will decrement the driver module use count. - * Any failures from here onwards should not touch the count. - */ - tty->driver_data = state; - state->uart_port->state = state; - state->port.low_latency = - (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0; - tty_port_tty_set(port, tty); + return retval; +} - /* - * If the port is in the middle of closing, bail out now. - */ - if (tty_hung_up_p(filp)) { - retval = -EAGAIN; - goto err_dec_count; - } +static int uart_port_activate(struct tty_port *port, struct tty_struct *tty) +{ + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + int ret; - /* - * Make sure the device is in D0 state. - */ - if (port->count == 1) - uart_change_pm(state, UART_PM_STATE_ON); + uport = uart_port_check(state); + if (!uport || uport->flags & UPF_DEAD) + return -ENXIO; /* * Start up the serial port. */ - retval = uart_startup(tty, state, 0); - - /* - * If we succeeded, wait until the port is ready. - */ - mutex_unlock(&port->mutex); - if (retval == 0) - retval = tty_port_block_til_ready(port, tty, filp); + ret = uart_startup(tty, state, false); + if (ret > 0) + tty_port_set_active(port, true); -end: - return retval; -err_dec_count: - port->count--; - mutex_unlock(&port->mutex); - goto end; + return ret; } static const char *uart_type(struct uart_port *port) @@ -1610,21 +1965,23 @@ static const char *uart_type(struct uart_port *port) #ifdef CONFIG_PROC_FS -static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) +static void uart_line_info(struct seq_file *m, struct uart_state *state) { - struct uart_state *state = drv->state + i; struct tty_port *port = &state->port; enum uart_pm_state pm_state; - struct uart_port *uport = state->uart_port; + struct uart_port *uport; char stat_buf[32]; unsigned int status; int mmio; + guard(mutex)(&port->mutex); + + uport = uart_port_check(state); if (!uport) return; mmio = uport->iotype >= UPIO_MEM; - seq_printf(m, "%d: uart:%s %s%08llX irq:%d", + seq_printf(m, "%u: uart:%s %s%08llX irq:%u", uport->line, uart_type(uport), mmio ? "mmio:0x" : "port:", mmio ? (unsigned long long)uport->mapbase @@ -1637,31 +1994,26 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i) } if (capable(CAP_SYS_ADMIN)) { - mutex_lock(&port->mutex); pm_state = state->pm_state; if (pm_state != UART_PM_STATE_ON) uart_change_pm(state, UART_PM_STATE_ON); - spin_lock_irq(&uport->lock); - status = uport->ops->get_mctrl(uport); - spin_unlock_irq(&uport->lock); + scoped_guard(uart_port_lock_irq, uport) + status = uport->ops->get_mctrl(uport); if (pm_state != UART_PM_STATE_ON) uart_change_pm(state, pm_state); - mutex_unlock(&port->mutex); - seq_printf(m, " tx:%d rx:%d", + seq_printf(m, " tx:%u rx:%u", uport->icount.tx, uport->icount.rx); if (uport->icount.frame) - seq_printf(m, " fe:%d", - uport->icount.frame); + seq_printf(m, " fe:%u", uport->icount.frame); if (uport->icount.parity) - seq_printf(m, " pe:%d", - uport->icount.parity); + seq_printf(m, " pe:%u", uport->icount.parity); if (uport->icount.brk) - seq_printf(m, " brk:%d", - uport->icount.brk); + seq_printf(m, " brk:%u", uport->icount.brk); if (uport->icount.overrun) - seq_printf(m, " oe:%d", - uport->icount.overrun); + seq_printf(m, " oe:%u", uport->icount.overrun); + if (uport->icount.buf_overrun) + seq_printf(m, " bo:%u", uport->icount.buf_overrun); #define INFOBIT(bit, str) \ if (uport->mctrl & (bit)) \ @@ -1696,38 +2048,30 @@ static int uart_proc_show(struct seq_file *m, void *v) struct uart_driver *drv = ttydrv->driver_state; int i; - seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", - "", "", ""); + seq_printf(m, "serinfo:1.0 driver%s%s revision:%s\n", "", "", ""); for (i = 0; i < drv->nr; i++) - uart_line_info(m, drv, i); + uart_line_info(m, drv->state + i); return 0; } +#endif -static int uart_proc_open(struct inode *inode, struct file *file) +static void uart_port_spin_lock_init(struct uart_port *port) { - return single_open(file, uart_proc_show, PDE_DATA(inode)); + spin_lock_init(&port->lock); + lockdep_set_class(&port->lock, &port_lock_key); } -static const struct file_operations uart_proc_fops = { - .owner = THIS_MODULE, - .open = uart_proc_open, - .read = seq_read, - .llseek = seq_lseek, - .release = single_release, -}; -#endif - #if defined(CONFIG_SERIAL_CORE_CONSOLE) || defined(CONFIG_CONSOLE_POLL) -/* - * uart_console_write - write a console message to a serial port - * @port: the port to write the message - * @s: array of characters - * @count: number of characters in string to write - * @write: function to write character to port +/** + * uart_console_write - write a console message to a serial port + * @port: the port to write the message + * @s: array of characters + * @count: number of characters in string to write + * @putchar: function to write character to port */ void uart_console_write(struct uart_port *port, const char *s, unsigned int count, - void (*putchar)(struct uart_port *, int)) + void (*putchar)(struct uart_port *, unsigned char)) { unsigned int i; @@ -1739,44 +2083,84 @@ void uart_console_write(struct uart_port *port, const char *s, } EXPORT_SYMBOL_GPL(uart_console_write); -/* - * Check whether an invalid uart number has been specified, and - * if so, search for the first available port that does have - * console support. +/** + * uart_parse_earlycon - Parse earlycon options + * @p: ptr to 2nd field (ie., just beyond '<name>,') + * @iotype: ptr for decoded iotype (out) + * @addr: ptr for decoded mapbase/iobase (out) + * @options: ptr for <options> field; %NULL if not present (out) + * + * Decodes earlycon kernel command line parameters of the form: + * * earlycon=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> + * * console=<name>,io|mmio|mmio16|mmio32|mmio32be|mmio32native,<addr>,<options> + * + * The optional form: + * * earlycon=<name>,0x<addr>,<options> + * * console=<name>,0x<addr>,<options> + * + * is also accepted; the returned @iotype will be %UPIO_MEM. + * + * Returns: 0 on success or -%EINVAL on failure */ -struct uart_port * __init -uart_get_console(struct uart_port *ports, int nr, struct console *co) -{ - int idx = co->index; - - if (idx < 0 || idx >= nr || (ports[idx].iobase == 0 && - ports[idx].membase == NULL)) - for (idx = 0; idx < nr; idx++) - if (ports[idx].iobase != 0 || - ports[idx].membase != NULL) - break; +int uart_parse_earlycon(char *p, enum uart_iotype *iotype, + resource_size_t *addr, char **options) +{ + if (strncmp(p, "mmio,", 5) == 0) { + *iotype = UPIO_MEM; + p += 5; + } else if (strncmp(p, "mmio16,", 7) == 0) { + *iotype = UPIO_MEM16; + p += 7; + } else if (strncmp(p, "mmio32,", 7) == 0) { + *iotype = UPIO_MEM32; + p += 7; + } else if (strncmp(p, "mmio32be,", 9) == 0) { + *iotype = UPIO_MEM32BE; + p += 9; + } else if (strncmp(p, "mmio32native,", 13) == 0) { + *iotype = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) ? + UPIO_MEM32BE : UPIO_MEM32; + p += 13; + } else if (strncmp(p, "io,", 3) == 0) { + *iotype = UPIO_PORT; + p += 3; + } else if (strncmp(p, "0x", 2) == 0) { + *iotype = UPIO_MEM; + } else { + return -EINVAL; + } - co->index = idx; + /* + * Before you replace it with kstrtoull(), think about options separator + * (',') it will not tolerate + */ + *addr = simple_strtoull(p, NULL, 0); + p = strchr(p, ','); + if (p) + p++; - return ports + idx; + *options = p; + return 0; } +EXPORT_SYMBOL_GPL(uart_parse_earlycon); /** - * uart_parse_options - Parse serial port baud/parity/bits/flow contro. - * @options: pointer to option string - * @baud: pointer to an 'int' variable for the baud rate. - * @parity: pointer to an 'int' variable for the parity. - * @bits: pointer to an 'int' variable for the number of data bits. - * @flow: pointer to an 'int' variable for the flow control character. + * uart_parse_options - Parse serial port baud/parity/bits/flow control. + * @options: pointer to option string + * @baud: pointer to an 'int' variable for the baud rate. + * @parity: pointer to an 'int' variable for the parity. + * @bits: pointer to an 'int' variable for the number of data bits. + * @flow: pointer to an 'int' variable for the flow control character. * - * uart_parse_options decodes a string containing the serial console - * options. The format of the string is <baud><parity><bits><flow>, - * eg: 115200n8r + * uart_parse_options() decodes a string containing the serial console + * options. The format of the string is <baud><parity><bits><flow>, + * eg: 115200n8r */ void -uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) +uart_parse_options(const char *options, int *baud, int *parity, + int *bits, int *flow) { - char *s = options; + const char *s = options; *baud = simple_strtoul(s, NULL, 10); while (*s >= '0' && *s <= '9') @@ -1790,34 +2174,17 @@ uart_parse_options(char *options, int *baud, int *parity, int *bits, int *flow) } EXPORT_SYMBOL_GPL(uart_parse_options); -struct baud_rates { - unsigned int rate; - unsigned int cflag; -}; - -static const struct baud_rates baud_rates[] = { - { 921600, B921600 }, - { 460800, B460800 }, - { 230400, B230400 }, - { 115200, B115200 }, - { 57600, B57600 }, - { 38400, B38400 }, - { 19200, B19200 }, - { 9600, B9600 }, - { 4800, B4800 }, - { 2400, B2400 }, - { 1200, B1200 }, - { 0, B38400 } -}; - /** - * uart_set_options - setup the serial console parameters - * @port: pointer to the serial ports uart_port structure - * @co: console pointer - * @baud: baud rate - * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) - * @bits: number of data bits - * @flow: flow control character - 'r' (rts) + * uart_set_options - setup the serial console parameters + * @port: pointer to the serial ports uart_port structure + * @co: console pointer + * @baud: baud rate + * @parity: parity character - 'n' (none), 'o' (odd), 'e' (even) + * @bits: number of data bits + * @flow: flow control character - 'r' (rts) + * + * Locking: Caller must hold console_list_lock in order to serialize + * early initialization of the serial-console lock. */ int uart_set_options(struct uart_port *port, struct console *co, @@ -1825,27 +2192,21 @@ uart_set_options(struct uart_port *port, struct console *co, { struct ktermios termios; static struct ktermios dummy; - int i; /* - * Ensure that the serial console lock is initialised - * early. + * Ensure that the serial-console lock is initialised early. + * + * Note that the console-registered check is needed because + * kgdboc can call uart_set_options() for an already registered + * console via tty_find_polling_driver() and uart_poll_init(). */ - spin_lock_init(&port->lock); - lockdep_set_class(&port->lock, &port_lock_key); + if (!uart_console_registered_locked(port) && !port->console_reinit) + uart_port_spin_lock_init(port); memset(&termios, 0, sizeof(struct ktermios)); - termios.c_cflag = CREAD | HUPCL | CLOCAL; - - /* - * Construct a cflag setting. - */ - for (i = 0; baud_rates[i].rate; i++) - if (baud_rates[i].rate <= baud) - break; - - termios.c_cflag |= baud_rates[i].cflag; + termios.c_cflag |= CREAD | HUPCL | CLOCAL; + tty_termios_encode_baud_rate(&termios, baud, baud); if (bits == 7) termios.c_cflag |= CS7; @@ -1855,7 +2216,7 @@ uart_set_options(struct uart_port *port, struct console *co, switch (parity) { case 'o': case 'O': termios.c_cflag |= PARODD; - /*fall through*/ + fallthrough; case 'e': case 'E': termios.c_cflag |= PARENB; break; @@ -1875,8 +2236,11 @@ uart_set_options(struct uart_port *port, struct console *co, * Allow the setting of the UART parameters with a NULL console * too: */ - if (co) + if (co) { co->cflag = termios.c_cflag; + co->ispeed = termios.c_ispeed; + co->ospeed = termios.c_ospeed; + } return 0; } @@ -1894,10 +2258,10 @@ EXPORT_SYMBOL_GPL(uart_set_options); static void uart_change_pm(struct uart_state *state, enum uart_pm_state pm_state) { - struct uart_port *port = state->uart_port; + struct uart_port *port = uart_port_check(state); if (state->pm_state != pm_state) { - if (port->ops->pm) + if (port && port->ops->pm) port->ops->pm(port, pm_state, state->pm_state); state->pm_state = pm_state; } @@ -1908,9 +2272,9 @@ struct uart_match { struct uart_driver *driver; }; -static int serial_match_port(struct device *dev, void *data) +static int serial_match_port(struct device *dev, const void *data) { - struct uart_match *match = data; + const struct uart_match *match = data; struct tty_driver *tty_drv = match->driver->tty_driver; dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) + match->port->line; @@ -1925,34 +2289,49 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) struct device *tty_dev; struct uart_match match = {uport, drv}; - mutex_lock(&port->mutex); + guard(mutex)(&port->mutex); - tty_dev = device_find_child(uport->dev, &match, serial_match_port); - if (device_may_wakeup(tty_dev)) { - if (!enable_irq_wake(uport->irq)) - uport->irq_wake = 1; + tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port); + if (tty_dev && device_may_wakeup(tty_dev)) { + enable_irq_wake(uport->irq); put_device(tty_dev); - mutex_unlock(&port->mutex); return 0; } put_device(tty_dev); - if (console_suspend_enabled || !uart_console(uport)) - uport->suspended = 1; + /* + * Nothing to do if the console is not suspending + * except stop_rx to prevent any asynchronous data + * over RX line. However ensure that we will be + * able to Re-start_rx later. + */ + if (!console_suspend_enabled && uart_console(uport)) { + if (uport->ops->start_rx) { + guard(uart_port_lock_irq)(uport); + uport->ops->stop_rx(uport); + } + device_set_awake_path(uport->dev); + return 0; + } - if (port->flags & ASYNC_INITIALIZED) { + uport->suspended = 1; + + if (tty_port_initialized(port)) { const struct uart_ops *ops = uport->ops; int tries; + unsigned int mctrl; - if (console_suspend_enabled || !uart_console(uport)) { - set_bit(ASYNCB_SUSPENDED, &port->flags); - clear_bit(ASYNCB_INITIALIZED, &port->flags); + tty_port_set_suspended(port, true); + tty_port_set_initialized(port, false); - spin_lock_irq(&uport->lock); + scoped_guard(uart_port_lock_irq, uport) { ops->stop_tx(uport); - ops->set_mctrl(uport, 0); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, 0); + /* save mctrl so it can be restored on resume */ + mctrl = uport->mctrl; + uport->mctrl = 0; ops->stop_rx(uport); - spin_unlock_irq(&uport->lock); } /* @@ -1961,30 +2340,24 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport) for (tries = 3; !ops->tx_empty(uport) && tries; tries--) msleep(10); if (!tries) - printk(KERN_ERR "%s%s%s%d: Unable to drain " - "transmitter\n", - uport->dev ? dev_name(uport->dev) : "", - uport->dev ? ": " : "", - drv->dev_name, - drv->tty_driver->name_base + uport->line); + dev_err(uport->dev, "%s: Unable to drain transmitter\n", + uport->name); - if (console_suspend_enabled || !uart_console(uport)) - ops->shutdown(uport); + ops->shutdown(uport); + uport->mctrl = mctrl; } /* - * Disable the console device before suspending. + * Suspend the console device before suspending the port. */ - if (console_suspend_enabled && uart_console(uport)) - console_stop(uport->cons); - - if (console_suspend_enabled || !uart_console(uport)) - uart_change_pm(state, UART_PM_STATE_OFF); + if (uart_console(uport)) + console_suspend(uport->cons); - mutex_unlock(&port->mutex); + uart_change_pm(state, UART_PM_STATE_OFF); return 0; } +EXPORT_SYMBOL(uart_suspend_port); int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) { @@ -1994,16 +2367,13 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) struct uart_match match = {uport, drv}; struct ktermios termios; - mutex_lock(&port->mutex); + guard(mutex)(&port->mutex); - tty_dev = device_find_child(uport->dev, &match, serial_match_port); + tty_dev = device_find_child(&uport->port_dev->dev, &match, serial_match_port); if (!uport->suspended && device_may_wakeup(tty_dev)) { - if (uport->irq_wake) { + if (irqd_is_wakeup_set(irq_get_irq_data((uport->irq)))) disable_irq_wake(uport->irq); - uport->irq_wake = 0; - } put_device(tty_dev); - mutex_unlock(&port->mutex); return 0; } put_device(tty_dev); @@ -2018,6 +2388,8 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) */ memset(&termios, 0, sizeof(struct ktermios)); termios.c_cflag = uport->cons->cflag; + termios.c_ispeed = uport->cons->ispeed; + termios.c_ospeed = uport->cons->ospeed; /* * If that's unset, use the tty termios setting. @@ -2028,30 +2400,37 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) if (console_suspend_enabled) uart_change_pm(state, UART_PM_STATE_ON); uport->ops->set_termios(uport, &termios, NULL); + if (!console_suspend_enabled && uport->ops->start_rx) { + guard(uart_port_lock_irq)(uport); + uport->ops->start_rx(uport); + } if (console_suspend_enabled) - console_start(uport->cons); + console_resume(uport->cons); } - if (port->flags & ASYNC_SUSPENDED) { + if (tty_port_suspended(port)) { const struct uart_ops *ops = uport->ops; int ret; uart_change_pm(state, UART_PM_STATE_ON); - spin_lock_irq(&uport->lock); - ops->set_mctrl(uport, 0); - spin_unlock_irq(&uport->lock); + scoped_guard(uart_port_lock_irq, uport) + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, 0); if (console_suspend_enabled || !uart_console(uport)) { /* Protected by port mutex for now */ struct tty_struct *tty = port->tty; + ret = ops->startup(uport); if (ret == 0) { if (tty) - uart_change_speed(tty, state, NULL); - spin_lock_irq(&uport->lock); - ops->set_mctrl(uport, uport->mctrl); - ops->start_tx(uport); - spin_unlock_irq(&uport->lock); - set_bit(ASYNCB_INITIALIZED, &port->flags); + uart_change_line_settings(tty, state, NULL); + uart_rs485_config(uport); + scoped_guard(uart_port_lock_irq, uport) { + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, uport->mctrl); + ops->start_tx(uport); + } + tty_port_set_initialized(port, true); } else { /* * Failed to resume - maybe hardware went away? @@ -2062,13 +2441,12 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport) } } - clear_bit(ASYNCB_SUSPENDED, &port->flags); + tty_port_set_suspended(port, false); } - mutex_unlock(&port->mutex); - return 0; } +EXPORT_SYMBOL(uart_resume_port); static inline void uart_report_port(struct uart_driver *drv, struct uart_port *port) @@ -2084,23 +2462,32 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port) "I/O 0x%lx offset 0x%x", port->iobase, port->hub6); break; case UPIO_MEM: + case UPIO_MEM16: case UPIO_MEM32: + case UPIO_MEM32BE: case UPIO_AU: case UPIO_TSI: snprintf(address, sizeof(address), "MMIO 0x%llx", (unsigned long long)port->mapbase); break; default: - strlcpy(address, "*unknown*", sizeof(address)); + strscpy(address, "*unknown*", sizeof(address)); break; } - printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n", + pr_info("%s%s%s at %s (irq = %u, base_baud = %u) is a %s\n", port->dev ? dev_name(port->dev) : "", port->dev ? ": " : "", - drv->dev_name, - drv->tty_driver->name_base + port->line, - address, port->irq, uart_type(port)); + port->name, + address, port->irq, port->uartclk / 16, uart_type(port)); + + /* The magic multiplier feature is a bit obscure, so report it too. */ + if (port->flags & UPF_MAGIC_MULTIPLIER) + pr_info("%s%s%s extra baud rates supported: %u, %u", + port->dev ? dev_name(port->dev) : "", + port->dev ? ": " : "", + port->name, + port->uartclk / 8, port->uartclk / 4); } static void @@ -2127,14 +2514,21 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, port->type = PORT_UNKNOWN; flags |= UART_CONFIG_TYPE; } + /* Synchronize with possible boot console. */ + if (uart_console(port)) + console_lock(); port->ops->config_port(port, flags); + if (uart_console(port)) + console_unlock(); } if (port->type != PORT_UNKNOWN) { - unsigned long flags; - uart_report_port(drv, port); + /* Synchronize with possible boot console. */ + if (uart_console(port)) + console_lock(); + /* Power up port for set_mctrl() */ uart_change_pm(state, UART_PM_STATE_ON); @@ -2143,16 +2537,23 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state, * keep the DTR setting that is set in uart_set_options() * We probably don't need a spinlock around this, but */ - spin_lock_irqsave(&port->lock, flags); - port->ops->set_mctrl(port, port->mctrl & TIOCM_DTR); - spin_unlock_irqrestore(&port->lock, flags); + scoped_guard(uart_port_lock_irqsave, port) { + port->mctrl &= TIOCM_DTR; + if (!(port->rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); + } + + uart_rs485_config(port); + + if (uart_console(port)) + console_unlock(); /* * If this driver supports console, and it hasn't been * successfully registered yet, try to re-register it. * It may be that the port was not available. */ - if (port->cons && !(port->cons->flags & CON_ENABLED)) + if (port->cons && !console_is_registered(port->cons)) register_console(port->cons); /* @@ -2170,42 +2571,47 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; + enum uart_pm_state pm_state; + struct tty_port *tport; struct uart_port *port; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; - int ret; + int ret = 0; - if (!state || !state->uart_port) - return -1; + tport = &state->port; + + guard(mutex)(&tport->mutex); - port = state->uart_port; - if (!(port->ops->poll_get_char && port->ops->poll_put_char)) + port = uart_port_check(state); + if (!port || port->type == PORT_UNKNOWN || + !(port->ops->poll_get_char && port->ops->poll_put_char)) return -1; - if (port->ops->poll_init) { - struct tty_port *tport = &state->port; + pm_state = state->pm_state; + uart_change_pm(state, UART_PM_STATE_ON); - ret = 0; - mutex_lock(&tport->mutex); + if (port->ops->poll_init) { /* - * We don't set ASYNCB_INITIALIZED as we only initialized the - * hw, e.g. state->xmit is still uninitialized. + * We don't set initialized as we only initialized the hw, + * e.g. state->xmit is still uninitialized. */ - if (!test_bit(ASYNCB_INITIALIZED, &tport->flags)) + if (!tty_port_initialized(tport)) ret = port->ops->poll_init(port); - mutex_unlock(&tport->mutex); - if (ret) - return ret; } - if (options) { + if (!ret && options) { uart_parse_options(options, &baud, &parity, &bits, &flow); - return uart_set_options(port, NULL, baud, parity, bits, flow); + console_list_lock(); + ret = uart_set_options(port, NULL, baud, parity, bits, flow); + console_list_unlock(); } - return 0; + if (ret) + uart_change_pm(state, pm_state); + + return ret; } static int uart_poll_get_char(struct tty_driver *driver, int line) @@ -2213,12 +2619,15 @@ static int uart_poll_get_char(struct tty_driver *driver, int line) struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; struct uart_port *port; + int ret = -1; - if (!state || !state->uart_port) - return -1; + port = uart_port_ref(state); + if (port) { + ret = port->ops->poll_get_char(port); + uart_port_deref(port); + } - port = state->uart_port; - return port->ops->poll_get_char(port); + return ret; } static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) @@ -2227,15 +2636,19 @@ static void uart_poll_put_char(struct tty_driver *driver, int line, char ch) struct uart_state *state = drv->state + line; struct uart_port *port; - if (!state || !state->uart_port) + port = uart_port_ref(state); + if (!port) return; - port = state->uart_port; + if (ch == '\n') + port->ops->poll_put_char(port, '\r'); port->ops->poll_put_char(port, ch); + uart_port_deref(port); } #endif static const struct tty_operations uart_ops = { + .install = uart_install, .open = uart_open, .close = uart_close, .write = uart_write, @@ -2256,10 +2669,12 @@ static const struct tty_operations uart_ops = { .break_ctl = uart_break_ctl, .wait_until_sent= uart_wait_until_sent, #ifdef CONFIG_PROC_FS - .proc_fops = &uart_proc_fops, + .proc_show = uart_proc_show, #endif .tiocmget = uart_tiocmget, .tiocmset = uart_tiocmset, + .set_serial = uart_set_info_user, + .get_serial = uart_get_info_user, .get_icount = uart_get_icount, #ifdef CONFIG_CONSOLE_POLL .poll_init = uart_poll_init, @@ -2269,29 +2684,31 @@ static const struct tty_operations uart_ops = { }; static const struct tty_port_operations uart_port_ops = { - .activate = uart_port_activate, - .shutdown = uart_port_shutdown, .carrier_raised = uart_carrier_raised, .dtr_rts = uart_dtr_rts, + .activate = uart_port_activate, + .shutdown = uart_tty_port_shutdown, }; /** - * uart_register_driver - register a driver with the uart core layer - * @drv: low level driver structure + * uart_register_driver - register a driver with the uart core layer + * @drv: low level driver structure * - * Register a uart driver with the core driver. We in turn register - * with the tty layer, and initialise the core driver per-port state. + * Register a uart driver with the core driver. We in turn register with the + * tty layer, and initialise the core driver per-port state. * - * We have a proc file in /proc/tty/driver which is named after the - * normal driver. + * We have a proc file in /proc/tty/driver which is named after the normal + * driver. * - * drv->port should be NULL, and the per-port structures should be - * registered using uart_add_one_port after this call has succeeded. + * @drv->port should be %NULL, and the per-port structures should be registered + * using uart_add_one_port() after this call has succeeded. + * + * Locking: none, Interrupts: enabled */ int uart_register_driver(struct uart_driver *drv) { struct tty_driver *normal; - int i, retval; + int i, retval = -ENOMEM; BUG_ON(drv->state); @@ -2299,13 +2716,16 @@ int uart_register_driver(struct uart_driver *drv) * Maybe we should be using a slab cache for this, especially if * we have a large number of ports to handle. */ - drv->state = kzalloc(sizeof(struct uart_state) * drv->nr, GFP_KERNEL); + drv->state = kcalloc(drv->nr, sizeof(struct uart_state), GFP_KERNEL); if (!drv->state) goto out; - normal = alloc_tty_driver(drv->nr); - if (!normal) + normal = tty_alloc_driver(drv->nr, TTY_DRIVER_REAL_RAW | + TTY_DRIVER_DYNAMIC_DEV); + if (IS_ERR(normal)) { + retval = PTR_ERR(normal); goto out_kfree; + } drv->tty_driver = normal; @@ -2318,7 +2738,6 @@ int uart_register_driver(struct uart_driver *drv) normal->init_termios = tty_std_termios; normal->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL; normal->init_termios.c_ispeed = normal->init_termios.c_ospeed = 9600; - normal->flags = TTY_DRIVER_REAL_RAW | TTY_DRIVER_DYNAMIC_DEV; normal->driver_state = drv; tty_set_operations(normal, &uart_ops); @@ -2331,8 +2750,6 @@ int uart_register_driver(struct uart_driver *drv) tty_port_init(port); port->ops = &uart_port_ops; - port->close_delay = HZ / 2; /* .5 seconds */ - port->closing_wait = 30 * HZ;/* 30 seconds */ } retval = tty_register_driver(normal); @@ -2341,21 +2758,23 @@ int uart_register_driver(struct uart_driver *drv) for (i = 0; i < drv->nr; i++) tty_port_destroy(&drv->state[i].port); - put_tty_driver(normal); + tty_driver_kref_put(normal); out_kfree: kfree(drv->state); out: - return -ENOMEM; + return retval; } +EXPORT_SYMBOL(uart_register_driver); /** - * uart_unregister_driver - remove a driver from the uart core layer - * @drv: low level driver structure + * uart_unregister_driver - remove a driver from the uart core layer + * @drv: low level driver structure * - * Remove all references to a driver from the core driver. The low - * level driver must have removed all its ports via the - * uart_remove_one_port() if it registered them with uart_add_one_port(). - * (ie, drv->port == NULL) + * Remove all references to a driver from the core driver. The low level + * driver must have removed all its ports via the uart_remove_one_port() if it + * registered them with uart_add_one_port(). (I.e. @drv->port is %NULL.) + * + * Locking: none, Interrupts: enabled */ void uart_unregister_driver(struct uart_driver *drv) { @@ -2363,13 +2782,14 @@ void uart_unregister_driver(struct uart_driver *drv) unsigned int i; tty_unregister_driver(p); - put_tty_driver(p); + tty_driver_kref_put(p); for (i = 0; i < drv->nr; i++) tty_port_destroy(&drv->state[i].port); kfree(drv->state); drv->state = NULL; drv->tty_driver = NULL; } +EXPORT_SYMBOL(uart_unregister_driver); struct tty_driver *uart_console_device(struct console *co, int *index) { @@ -2377,37 +2797,39 @@ struct tty_driver *uart_console_device(struct console *co, int *index) *index = co->index; return p->tty_driver; } +EXPORT_SYMBOL_GPL(uart_console_device); -static ssize_t uart_get_attr_uartclk(struct device *dev, +static ssize_t uartclk_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.baud_base * 16); + return sprintf(buf, "%d\n", tmp.baud_base * 16); } -static ssize_t uart_get_attr_type(struct device *dev, +static ssize_t type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.type); + return sprintf(buf, "%d\n", tmp.type); } -static ssize_t uart_get_attr_line(struct device *dev, + +static ssize_t line_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.line); + return sprintf(buf, "%d\n", tmp.line); } -static ssize_t uart_get_attr_port(struct device *dev, +static ssize_t port_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; @@ -2418,160 +2840,205 @@ static ssize_t uart_get_attr_port(struct device *dev, ioaddr = tmp.port; if (HIGH_BITS_OFFSET) ioaddr |= (unsigned long)tmp.port_high << HIGH_BITS_OFFSET; - return snprintf(buf, PAGE_SIZE, "0x%lX\n", ioaddr); + return sprintf(buf, "0x%lX\n", ioaddr); } -static ssize_t uart_get_attr_irq(struct device *dev, +static ssize_t irq_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.irq); + return sprintf(buf, "%d\n", tmp.irq); } -static ssize_t uart_get_attr_flags(struct device *dev, +static ssize_t flags_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "0x%X\n", tmp.flags); + return sprintf(buf, "0x%X\n", tmp.flags); } -static ssize_t uart_get_attr_xmit_fifo_size(struct device *dev, +static ssize_t xmit_fifo_size_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.xmit_fifo_size); + return sprintf(buf, "%d\n", tmp.xmit_fifo_size); } - -static ssize_t uart_get_attr_close_delay(struct device *dev, +static ssize_t close_delay_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.close_delay); + return sprintf(buf, "%u\n", tmp.close_delay); } - -static ssize_t uart_get_attr_closing_wait(struct device *dev, +static ssize_t closing_wait_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.closing_wait); + return sprintf(buf, "%u\n", tmp.closing_wait); } -static ssize_t uart_get_attr_custom_divisor(struct device *dev, +static ssize_t custom_divisor_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.custom_divisor); + return sprintf(buf, "%d\n", tmp.custom_divisor); } -static ssize_t uart_get_attr_io_type(struct device *dev, +static ssize_t io_type_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.io_type); + return sprintf(buf, "%u\n", tmp.io_type); } -static ssize_t uart_get_attr_iomem_base(struct device *dev, +static ssize_t iomem_base_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "0x%lX\n", (unsigned long)tmp.iomem_base); + return sprintf(buf, "0x%lX\n", (unsigned long)tmp.iomem_base); } -static ssize_t uart_get_attr_iomem_reg_shift(struct device *dev, +static ssize_t iomem_reg_shift_show(struct device *dev, struct device_attribute *attr, char *buf) { struct serial_struct tmp; struct tty_port *port = dev_get_drvdata(dev); uart_get_info(port, &tmp); - return snprintf(buf, PAGE_SIZE, "%d\n", tmp.iomem_reg_shift); -} - -static DEVICE_ATTR(type, S_IRUSR | S_IRGRP, uart_get_attr_type, NULL); -static DEVICE_ATTR(line, S_IRUSR | S_IRGRP, uart_get_attr_line, NULL); -static DEVICE_ATTR(port, S_IRUSR | S_IRGRP, uart_get_attr_port, NULL); -static DEVICE_ATTR(irq, S_IRUSR | S_IRGRP, uart_get_attr_irq, NULL); -static DEVICE_ATTR(flags, S_IRUSR | S_IRGRP, uart_get_attr_flags, NULL); -static DEVICE_ATTR(xmit_fifo_size, S_IRUSR | S_IRGRP, uart_get_attr_xmit_fifo_size, NULL); -static DEVICE_ATTR(uartclk, S_IRUSR | S_IRGRP, uart_get_attr_uartclk, NULL); -static DEVICE_ATTR(close_delay, S_IRUSR | S_IRGRP, uart_get_attr_close_delay, NULL); -static DEVICE_ATTR(closing_wait, S_IRUSR | S_IRGRP, uart_get_attr_closing_wait, NULL); -static DEVICE_ATTR(custom_divisor, S_IRUSR | S_IRGRP, uart_get_attr_custom_divisor, NULL); -static DEVICE_ATTR(io_type, S_IRUSR | S_IRGRP, uart_get_attr_io_type, NULL); -static DEVICE_ATTR(iomem_base, S_IRUSR | S_IRGRP, uart_get_attr_iomem_base, NULL); -static DEVICE_ATTR(iomem_reg_shift, S_IRUSR | S_IRGRP, uart_get_attr_iomem_reg_shift, NULL); + return sprintf(buf, "%u\n", tmp.iomem_reg_shift); +} + +static ssize_t console_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct tty_port *port = dev_get_drvdata(dev); + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + bool console = false; + + scoped_guard(mutex, &port->mutex) { + uport = uart_port_check(state); + if (uport) + console = uart_console_registered(uport); + } + + return sprintf(buf, "%c\n", console ? 'Y' : 'N'); +} + +static ssize_t console_store(struct device *dev, + struct device_attribute *attr, const char *buf, size_t count) +{ + struct tty_port *port = dev_get_drvdata(dev); + struct uart_state *state = container_of(port, struct uart_state, port); + struct uart_port *uport; + bool oldconsole, newconsole; + int ret; + + ret = kstrtobool(buf, &newconsole); + if (ret) + return ret; + + guard(mutex)(&port->mutex); + uport = uart_port_check(state); + if (!uport) + return -ENXIO; + + oldconsole = uart_console_registered(uport); + if (oldconsole && !newconsole) { + ret = unregister_console(uport->cons); + if (ret < 0) + return ret; + } else if (!oldconsole && newconsole) { + if (!uart_console(uport)) + return -ENOENT; + + uport->console_reinit = 1; + register_console(uport->cons); + } + + return count; +} + +static DEVICE_ATTR_RO(uartclk); +static DEVICE_ATTR_RO(type); +static DEVICE_ATTR_RO(line); +static DEVICE_ATTR_RO(port); +static DEVICE_ATTR_RO(irq); +static DEVICE_ATTR_RO(flags); +static DEVICE_ATTR_RO(xmit_fifo_size); +static DEVICE_ATTR_RO(close_delay); +static DEVICE_ATTR_RO(closing_wait); +static DEVICE_ATTR_RO(custom_divisor); +static DEVICE_ATTR_RO(io_type); +static DEVICE_ATTR_RO(iomem_base); +static DEVICE_ATTR_RO(iomem_reg_shift); +static DEVICE_ATTR_RW(console); static struct attribute *tty_dev_attrs[] = { + &dev_attr_uartclk.attr, &dev_attr_type.attr, &dev_attr_line.attr, &dev_attr_port.attr, &dev_attr_irq.attr, &dev_attr_flags.attr, &dev_attr_xmit_fifo_size.attr, - &dev_attr_uartclk.attr, &dev_attr_close_delay.attr, &dev_attr_closing_wait.attr, &dev_attr_custom_divisor.attr, &dev_attr_io_type.attr, &dev_attr_iomem_base.attr, &dev_attr_iomem_reg_shift.attr, - NULL, - }; + &dev_attr_console.attr, + NULL +}; static const struct attribute_group tty_dev_attr_group = { .attrs = tty_dev_attrs, - }; - -static const struct attribute_group *tty_dev_attr_groups[] = { - &tty_dev_attr_group, - NULL - }; - +}; /** - * uart_add_one_port - attach a driver-defined port structure - * @drv: pointer to the uart low level driver structure for this port - * @uport: uart port structure to use for this port. + * serial_core_add_one_port - attach a driver-defined port structure + * @drv: pointer to the uart low level driver structure for this port + * @uport: uart port structure to use for this port. * - * This allows the driver to register its own uart_port structure - * with the core driver. The main purpose is to allow the low - * level uart drivers to expand uart_port, rather than having yet - * more levels of structures. + * Context: task context, might sleep + * + * This allows the driver @drv to register its own uart_port structure with the + * core driver. The main purpose is to allow the low level uart drivers to + * expand uart_port, rather than having yet more levels of structures. + * Caller must hold port_mutex. */ -int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) +static int serial_core_add_one_port(struct uart_driver *drv, struct uart_port *uport) { struct uart_state *state; struct tty_port *port; - int ret = 0; struct device *tty_dev; - - BUG_ON(in_interrupt()); + int num_groups; if (uport->line >= drv->nr) return -EINVAL; @@ -2579,162 +3046,324 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) state = drv->state + uport->line; port = &state->port; - mutex_lock(&port_mutex); - mutex_lock(&port->mutex); - if (state->uart_port) { - ret = -EINVAL; - goto out; - } + guard(mutex)(&port->mutex); + if (state->uart_port) + return -EINVAL; + /* Link the port to the driver state table and vice versa */ + atomic_set(&state->refcount, 1); + init_waitqueue_head(&state->remove_wait); state->uart_port = uport; - state->pm_state = UART_PM_STATE_UNDEFINED; - - uport->cons = drv->cons; uport->state = state; /* - * If this port is a console, then the spinlock is already + * If this port is in use as a console then the spinlock is already * initialised. */ - if (!(uart_console(uport) && (uport->cons->flags & CON_ENABLED))) { - spin_lock_init(&uport->lock); - lockdep_set_class(&uport->lock, &port_lock_key); - } + if (!uart_console_registered(uport)) + uart_port_spin_lock_init(uport); + + state->pm_state = UART_PM_STATE_UNDEFINED; + uart_port_set_cons(uport, drv->cons); + uport->minor = drv->tty_driver->minor_start + uport->line; + uport->name = kasprintf(GFP_KERNEL, "%s%u", drv->dev_name, + drv->tty_driver->name_base + uport->line); + if (!uport->name) + return -ENOMEM; + + if (uport->cons && uport->dev) + of_console_check(uport->dev->of_node, uport->cons->name, uport->line); uart_configure_port(drv, state, uport); + port->console = uart_console(uport); + + num_groups = 2; + if (uport->attr_group) + num_groups++; + + uport->tty_groups = kcalloc(num_groups, sizeof(*uport->tty_groups), + GFP_KERNEL); + if (!uport->tty_groups) + return -ENOMEM; + + uport->tty_groups[0] = &tty_dev_attr_group; + if (uport->attr_group) + uport->tty_groups[1] = uport->attr_group; + + /* Ensure serdev drivers can call serdev_device_open() right away */ + uport->flags &= ~UPF_DEAD; + /* * Register the port whether it's detected or not. This allows - * setserial to be used to alter this ports parameters. + * setserial to be used to alter this port's parameters. */ - tty_dev = tty_port_register_device_attr(port, drv->tty_driver, - uport->line, uport->dev, port, tty_dev_attr_groups); - if (likely(!IS_ERR(tty_dev))) { + tty_dev = tty_port_register_device_attr_serdev(port, drv->tty_driver, + uport->line, uport->dev, &uport->port_dev->dev, port, + uport->tty_groups); + if (!IS_ERR(tty_dev)) { device_set_wakeup_capable(tty_dev, 1); } else { - printk(KERN_ERR "Cannot register tty device on line %d\n", + uport->flags |= UPF_DEAD; + dev_err(uport->dev, "Cannot register tty device on line %u\n", uport->line); } - /* - * Ensure UPF_DEAD is not set. - */ - uport->flags &= ~UPF_DEAD; - - out: - mutex_unlock(&port->mutex); - mutex_unlock(&port_mutex); - - return ret; + return 0; } /** - * uart_remove_one_port - detach a driver defined port structure - * @drv: pointer to the uart low level driver structure for this port - * @uport: uart port structure for this port + * serial_core_remove_one_port - detach a driver defined port structure + * @drv: pointer to the uart low level driver structure for this port + * @uport: uart port structure for this port * - * This unhooks (and hangs up) the specified port structure from the - * core driver. No further calls will be made to the low-level code - * for this port. + * Context: task context, might sleep + * + * This unhooks (and hangs up) the specified port structure from the core + * driver. No further calls will be made to the low-level code for this port. + * Caller must hold port_mutex. */ -int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport) +static void serial_core_remove_one_port(struct uart_driver *drv, + struct uart_port *uport) { struct uart_state *state = drv->state + uport->line; struct tty_port *port = &state->port; - int ret = 0; - - BUG_ON(in_interrupt()); - - if (state->uart_port != uport) - printk(KERN_ALERT "Removing wrong port: %p != %p\n", - state->uart_port, uport); + struct uart_port *uart_port; - mutex_lock(&port_mutex); + scoped_guard(mutex, &port->mutex) { + uart_port = uart_port_check(state); + if (uart_port != uport) + dev_alert(uport->dev, "Removing wrong port: %p != %p\n", uart_port, uport); - /* - * Mark the port "dead" - this prevents any opens from - * succeeding while we shut down the port. - */ - mutex_lock(&port->mutex); - if (!state->uart_port) { - mutex_unlock(&port->mutex); - ret = -EINVAL; - goto out; + if (!uart_port) + return; } - uport->flags |= UPF_DEAD; - mutex_unlock(&port->mutex); /* * Remove the devices from the tty layer */ - tty_unregister_device(drv->tty_driver, uport->line); + tty_port_unregister_device(port, drv->tty_driver, uport->line); - if (port->tty) - tty_vhangup(port->tty); + tty_port_tty_vhangup(port); + + /* + * If the port is used as a console, unregister it + */ + if (uart_console(uport)) + unregister_console(uport->cons); /* * Free the port IO and memory resources, if any. */ - if (uport->type != PORT_UNKNOWN) + if (uport->type != PORT_UNKNOWN && uport->ops->release_port) uport->ops->release_port(uport); + kfree(uport->tty_groups); + kfree(uport->name); /* * Indicate that there isn't a port here anymore. */ uport->type = PORT_UNKNOWN; + uport->port_dev = NULL; + guard(mutex)(&port->mutex); + WARN_ON(atomic_dec_return(&state->refcount) < 0); + wait_event(state->remove_wait, !atomic_read(&state->refcount)); state->uart_port = NULL; -out: - mutex_unlock(&port_mutex); - - return ret; } -/* - * Are the two ports equivalent? +/** + * uart_match_port - are the two ports equivalent? + * @port1: first port + * @port2: second port + * + * This utility function can be used to determine whether two uart_port + * structures describe the same port. */ -int uart_match_port(struct uart_port *port1, struct uart_port *port2) +bool uart_match_port(const struct uart_port *port1, + const struct uart_port *port2) { if (port1->iotype != port2->iotype) - return 0; + return false; switch (port1->iotype) { case UPIO_PORT: - return (port1->iobase == port2->iobase); + return port1->iobase == port2->iobase; case UPIO_HUB6: - return (port1->iobase == port2->iobase) && - (port1->hub6 == port2->hub6); + return port1->iobase == port2->iobase && + port1->hub6 == port2->hub6; case UPIO_MEM: + case UPIO_MEM16: case UPIO_MEM32: + case UPIO_MEM32BE: case UPIO_AU: case UPIO_TSI: - return (port1->mapbase == port2->mapbase); + return port1->mapbase == port2->mapbase; + default: + return false; } - return 0; } EXPORT_SYMBOL(uart_match_port); +static struct serial_ctrl_device * +serial_core_get_ctrl_dev(struct serial_port_device *port_dev) +{ + struct device *dev = &port_dev->dev; + + return to_serial_base_ctrl_device(dev->parent); +} + +/* + * Find a registered serial core controller device if one exists. Returns + * the first device matching the ctrl_id. Caller must hold port_mutex. + */ +static struct serial_ctrl_device *serial_core_ctrl_find(struct uart_driver *drv, + struct device *phys_dev, + int ctrl_id) +{ + struct uart_state *state; + int i; + + lockdep_assert_held(&port_mutex); + + for (i = 0; i < drv->nr; i++) { + state = drv->state + i; + if (!state->uart_port || !state->uart_port->port_dev) + continue; + + if (state->uart_port->dev == phys_dev && + state->uart_port->ctrl_id == ctrl_id) + return serial_core_get_ctrl_dev(state->uart_port->port_dev); + } + + return NULL; +} + +static struct serial_ctrl_device *serial_core_ctrl_device_add(struct uart_port *port) +{ + return serial_base_ctrl_add(port, port->dev); +} + +static int serial_core_port_device_add(struct serial_ctrl_device *ctrl_dev, + struct uart_port *port) +{ + struct serial_port_device *port_dev; + + port_dev = serial_base_port_add(port, ctrl_dev); + if (IS_ERR(port_dev)) + return PTR_ERR(port_dev); + + port->port_dev = port_dev; + + return 0; +} + +/* + * Initialize a serial core port device, and a controller device if needed. + */ +int serial_core_register_port(struct uart_driver *drv, struct uart_port *port) +{ + struct serial_ctrl_device *ctrl_dev, *new_ctrl_dev = NULL; + int ret; + + guard(mutex)(&port_mutex); + + /* + * Prevent serial_port_runtime_resume() from trying to use the port + * until serial_core_add_one_port() has completed + */ + port->flags |= UPF_DEAD; + + /* Inititalize a serial core controller device if needed */ + ctrl_dev = serial_core_ctrl_find(drv, port->dev, port->ctrl_id); + if (!ctrl_dev) { + new_ctrl_dev = serial_core_ctrl_device_add(port); + if (IS_ERR(new_ctrl_dev)) + return PTR_ERR(new_ctrl_dev); + ctrl_dev = new_ctrl_dev; + } + + /* + * Initialize a serial core port device. Tag the port dead to prevent + * serial_port_runtime_resume() trying to do anything until port has + * been registered. It gets cleared by serial_core_add_one_port(). + */ + ret = serial_core_port_device_add(ctrl_dev, port); + if (ret) + goto err_unregister_ctrl_dev; + + ret = serial_base_match_and_update_preferred_console(drv, port); + if (ret) + goto err_unregister_port_dev; + + ret = serial_core_add_one_port(drv, port); + if (ret) + goto err_unregister_port_dev; + + return 0; + +err_unregister_port_dev: + serial_base_port_device_remove(port->port_dev); + +err_unregister_ctrl_dev: + serial_base_ctrl_device_remove(new_ctrl_dev); + + return ret; +} + +/* + * Removes a serial core port device, and the related serial core controller + * device if the last instance. + */ +void serial_core_unregister_port(struct uart_driver *drv, struct uart_port *port) +{ + struct device *phys_dev = port->dev; + struct serial_port_device *port_dev = port->port_dev; + struct serial_ctrl_device *ctrl_dev = serial_core_get_ctrl_dev(port_dev); + int ctrl_id = port->ctrl_id; + + guard(mutex)(&port_mutex); + + port->flags |= UPF_DEAD; + + serial_core_remove_one_port(drv, port); + + /* Note that struct uart_port *port is no longer valid at this point */ + serial_base_port_device_remove(port_dev); + + /* Drop the serial core controller device if no ports are using it */ + if (!serial_core_ctrl_find(drv, phys_dev, ctrl_id)) + serial_base_ctrl_device_remove(ctrl_dev); +} + /** - * uart_handle_dcd_change - handle a change of carrier detect state - * @uport: uart_port structure for the open port - * @status: new carrier detect status, nonzero if active + * uart_handle_dcd_change - handle a change of carrier detect state + * @uport: uart_port structure for the open port + * @active: new carrier detect status + * + * Caller must hold uport->lock. */ -void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) +void uart_handle_dcd_change(struct uart_port *uport, bool active) { struct tty_port *port = &uport->state->port; struct tty_struct *tty = port->tty; - struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL; + struct tty_ldisc *ld; - if (ld) { - if (ld->ops->dcd_change) - ld->ops->dcd_change(tty, status); - tty_ldisc_deref(ld); + lockdep_assert_held_once(&uport->lock); + + if (tty) { + ld = tty_ldisc_ref(tty); + if (ld) { + if (ld->ops->dcd_change) + ld->ops->dcd_change(tty, active); + tty_ldisc_deref(ld); + } } uport->icount.dcd++; - if (port->flags & ASYNC_CHECK_CD) { - if (status) + if (uart_dcd_enabled(uport)) { + if (active) wake_up_interruptible(&port->open_wait); else if (tty) tty_hangup(tty); @@ -2743,30 +3372,32 @@ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status) EXPORT_SYMBOL_GPL(uart_handle_dcd_change); /** - * uart_handle_cts_change - handle a change of clear-to-send state - * @uport: uart_port structure for the open port - * @status: new clear to send status, nonzero if active + * uart_handle_cts_change - handle a change of clear-to-send state + * @uport: uart_port structure for the open port + * @active: new clear-to-send status + * + * Caller must hold uport->lock. */ -void uart_handle_cts_change(struct uart_port *uport, unsigned int status) +void uart_handle_cts_change(struct uart_port *uport, bool active) { - struct tty_port *port = &uport->state->port; - struct tty_struct *tty = port->tty; + lockdep_assert_held_once(&uport->lock); uport->icount.cts++; - if (tty_port_cts_enabled(port)) { - if (tty->hw_stopped) { - if (status) { - tty->hw_stopped = 0; + if (uart_softcts_mode(uport)) { + if (uport->hw_stopped) { + if (active) { + uport->hw_stopped = false; uport->ops->start_tx(uport); uart_write_wakeup(uport); } } else { - if (!status) { - tty->hw_stopped = 1; + if (!active) { + uport->hw_stopped = true; uport->ops->stop_tx(uport); } } + } } EXPORT_SYMBOL_GPL(uart_handle_cts_change); @@ -2784,7 +3415,7 @@ EXPORT_SYMBOL_GPL(uart_handle_cts_change); * @flag: flag for the character (see TTY_NORMAL and friends) */ void uart_insert_char(struct uart_port *port, unsigned int status, - unsigned int overrun, unsigned int ch, unsigned int flag) + unsigned int overrun, u8 ch, u8 flag) { struct tty_port *tport = &port->state->port; @@ -2802,13 +3433,147 @@ void uart_insert_char(struct uart_port *port, unsigned int status, } EXPORT_SYMBOL_GPL(uart_insert_char); -EXPORT_SYMBOL(uart_write_wakeup); -EXPORT_SYMBOL(uart_register_driver); -EXPORT_SYMBOL(uart_unregister_driver); -EXPORT_SYMBOL(uart_suspend_port); -EXPORT_SYMBOL(uart_resume_port); -EXPORT_SYMBOL(uart_add_one_port); -EXPORT_SYMBOL(uart_remove_one_port); +#ifdef CONFIG_MAGIC_SYSRQ_SERIAL +static const u8 sysrq_toggle_seq[] = CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE; + +static void uart_sysrq_on(struct work_struct *w) +{ + int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); + + sysrq_toggle_support(1); + pr_info("SysRq is enabled by magic sequence '%*pE' on serial\n", + sysrq_toggle_seq_len, sysrq_toggle_seq); +} +static DECLARE_WORK(sysrq_enable_work, uart_sysrq_on); + +/** + * uart_try_toggle_sysrq - Enables SysRq from serial line + * @port: uart_port structure where char(s) after BREAK met + * @ch: new character in the sequence after received BREAK + * + * Enables magic SysRq when the required sequence is met on port + * (see CONFIG_MAGIC_SYSRQ_SERIAL_SEQUENCE). + * + * Returns: %false if @ch is out of enabling sequence and should be + * handled some other way, %true if @ch was consumed. + */ +bool uart_try_toggle_sysrq(struct uart_port *port, u8 ch) +{ + int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); + + if (!sysrq_toggle_seq_len) + return false; + + BUILD_BUG_ON(ARRAY_SIZE(sysrq_toggle_seq) >= U8_MAX); + if (sysrq_toggle_seq[port->sysrq_seq] != ch) { + port->sysrq_seq = 0; + return false; + } + + if (++port->sysrq_seq < sysrq_toggle_seq_len) { + port->sysrq = jiffies + SYSRQ_TIMEOUT; + return true; + } + + schedule_work(&sysrq_enable_work); + + port->sysrq = 0; + return true; +} +EXPORT_SYMBOL_GPL(uart_try_toggle_sysrq); +#endif + +/** + * uart_get_rs485_mode() - retrieve rs485 properties for given uart + * @port: uart device's target port + * + * This function implements the device tree binding described in + * Documentation/devicetree/bindings/serial/rs485.txt. + */ +int uart_get_rs485_mode(struct uart_port *port) +{ + struct serial_rs485 *rs485conf = &port->rs485; + struct device *dev = port->dev; + enum gpiod_flags dflags; + struct gpio_desc *desc; + u32 rs485_delay[2]; + int ret; + + if (!(port->rs485_supported.flags & SER_RS485_ENABLED)) + return 0; + + /* + * Retrieve properties only if a firmware node exists. If no firmware + * node exists, then don't touch rs485 config and keep initial rs485 + * properties set by driver. + */ + if (!dev_fwnode(dev)) + return 0; + + ret = device_property_read_u32_array(dev, "rs485-rts-delay", + rs485_delay, 2); + if (!ret) { + rs485conf->delay_rts_before_send = rs485_delay[0]; + rs485conf->delay_rts_after_send = rs485_delay[1]; + } else { + rs485conf->delay_rts_before_send = 0; + rs485conf->delay_rts_after_send = 0; + } + + uart_sanitize_serial_rs485_delays(port, rs485conf); + + /* + * Clear full-duplex and enabled flags, set RTS polarity to active high + * to get to a defined state with the following properties: + */ + rs485conf->flags &= ~(SER_RS485_RX_DURING_TX | SER_RS485_ENABLED | + SER_RS485_TERMINATE_BUS | + SER_RS485_RTS_AFTER_SEND); + rs485conf->flags |= SER_RS485_RTS_ON_SEND; + + if (device_property_read_bool(dev, "rs485-rx-during-tx")) + rs485conf->flags |= SER_RS485_RX_DURING_TX; + + if (device_property_read_bool(dev, "linux,rs485-enabled-at-boot-time")) + rs485conf->flags |= SER_RS485_ENABLED; + + if (device_property_read_bool(dev, "rs485-rts-active-low")) { + rs485conf->flags &= ~SER_RS485_RTS_ON_SEND; + rs485conf->flags |= SER_RS485_RTS_AFTER_SEND; + } + + /* + * Disabling termination by default is the safe choice: Else if many + * bus participants enable it, no communication is possible at all. + * Works fine for short cables and users may enable for longer cables. + */ + desc = devm_gpiod_get_optional(dev, "rs485-term", GPIOD_OUT_LOW); + if (IS_ERR(desc)) + return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-term-gpios\n"); + port->rs485_term_gpio = desc; + if (port->rs485_term_gpio) + port->rs485_supported.flags |= SER_RS485_TERMINATE_BUS; + + dflags = (rs485conf->flags & SER_RS485_RX_DURING_TX) ? + GPIOD_OUT_HIGH : GPIOD_OUT_LOW; + desc = devm_gpiod_get_optional(dev, "rs485-rx-during-tx", dflags); + if (IS_ERR(desc)) + return dev_err_probe(dev, PTR_ERR(desc), "Cannot get rs485-rx-during-tx-gpios\n"); + port->rs485_rx_during_tx_gpio = desc; + if (port->rs485_rx_during_tx_gpio) + port->rs485_supported.flags |= SER_RS485_RX_DURING_TX; + + return 0; +} +EXPORT_SYMBOL_GPL(uart_get_rs485_mode); + +/* Compile-time assertions for serial_rs485 layout */ +static_assert(offsetof(struct serial_rs485, padding) == + (offsetof(struct serial_rs485, delay_rts_after_send) + sizeof(__u32))); +static_assert(offsetof(struct serial_rs485, padding1) == + offsetof(struct serial_rs485, padding[1])); +static_assert((offsetof(struct serial_rs485, padding[4]) + sizeof(__u32)) == + sizeof(struct serial_rs485)); MODULE_DESCRIPTION("Serial driver core"); MODULE_LICENSE("GPL"); |