111 lines
4.2 KiB
Diff
111 lines
4.2 KiB
Diff
From ef2a7b964c311147671f8da0f1a029600f8feb11 Mon Sep 17 00:00:00 2001
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From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:44:28 +0206
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Subject: [PATCH 097/196] serial: uartlite: Use port lock wrappers
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When a serial port is used for kernel console output, then all
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modifications to the UART registers which are done from other contexts,
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e.g. getty, termios, are interference points for the kernel console.
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So far this has been ignored and the printk output is based on the
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principle of hope. The rework of the console infrastructure which aims to
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support threaded and atomic consoles, requires to mark sections which
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modify the UART registers as unsafe. This allows the atomic write function
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to make informed decisions and eventually to restore operational state. It
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also allows to prevent the regular UART code from modifying UART registers
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while printk output is in progress.
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All modifications of UART registers are guarded by the UART port lock,
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which provides an obvious synchronization point with the console
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infrastructure.
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To avoid adding this functionality to all UART drivers, wrap the
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spin_[un]lock*() invocations for uart_port::lock into helper functions
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which just contain the spin_[un]lock*() invocations for now. In a
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subsequent step these helpers will gain the console synchronization
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mechanisms.
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Converted with coccinelle. No functional change.
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Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Link: https://lore.kernel.org/r/20230914183831.587273-72-john.ogness@linutronix.de
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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drivers/tty/serial/uartlite.c | 18 +++++++++---------
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1 file changed, 9 insertions(+), 9 deletions(-)
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diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
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index b225a78f6175..404c14acafa5 100644
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--- a/drivers/tty/serial/uartlite.c
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+++ b/drivers/tty/serial/uartlite.c
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@@ -216,11 +216,11 @@ static irqreturn_t ulite_isr(int irq, void *dev_id)
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unsigned long flags;
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do {
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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stat = uart_in32(ULITE_STATUS, port);
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busy = ulite_receive(port, stat);
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busy |= ulite_transmit(port, stat);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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n++;
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} while (busy);
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@@ -238,9 +238,9 @@ static unsigned int ulite_tx_empty(struct uart_port *port)
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unsigned long flags;
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unsigned int ret;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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ret = uart_in32(ULITE_STATUS, port);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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return ret & ULITE_STATUS_TXEMPTY ? TIOCSER_TEMT : 0;
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}
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@@ -323,7 +323,7 @@ static void ulite_set_termios(struct uart_port *port,
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termios->c_cflag |= pdata->cflags & (PARENB | PARODD | CSIZE);
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tty_termios_encode_baud_rate(termios, pdata->baud, pdata->baud);
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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port->read_status_mask = ULITE_STATUS_RXVALID | ULITE_STATUS_OVERRUN
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| ULITE_STATUS_TXFULL;
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@@ -346,7 +346,7 @@ static void ulite_set_termios(struct uart_port *port,
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/* update timeout */
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uart_update_timeout(port, termios->c_cflag, pdata->baud);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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}
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static const char *ulite_type(struct uart_port *port)
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@@ -495,9 +495,9 @@ static void ulite_console_write(struct console *co, const char *s,
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int locked = 1;
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if (oops_in_progress) {
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- locked = spin_trylock_irqsave(&port->lock, flags);
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+ locked = uart_port_trylock_irqsave(port, &flags);
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} else
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* save and disable interrupt */
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ier = uart_in32(ULITE_STATUS, port) & ULITE_STATUS_IE;
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@@ -512,7 +512,7 @@ static void ulite_console_write(struct console *co, const char *s,
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uart_out32(ULITE_CONTROL_IE, ULITE_CONTROL, port);
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if (locked)
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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}
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static int ulite_console_setup(struct console *co, char *options)
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--
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2.43.2
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