103 lines
3.6 KiB
Diff
103 lines
3.6 KiB
Diff
From 0898d04709fe45ddfbc0268f1bc4e1d6e7ef2c13 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 20:43:37 +0206
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Subject: [PATCH 047/195] serial: arc_uart: 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/20230914183831.587273-21-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/arc_uart.c | 16 ++++++++--------
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1 file changed, 8 insertions(+), 8 deletions(-)
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diff --git a/drivers/tty/serial/arc_uart.c b/drivers/tty/serial/arc_uart.c
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index ad4ae19b6ce3..1aa5b2b49c26 100644
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--- a/drivers/tty/serial/arc_uart.c
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+++ b/drivers/tty/serial/arc_uart.c
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@@ -279,9 +279,9 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id)
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if (status & RXIENB) {
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/* already in ISR, no need of xx_irqsave */
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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arc_serial_rx_chars(port, status);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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}
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if ((status & TXIENB) && (status & TXEMPTY)) {
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@@ -291,12 +291,12 @@ static irqreturn_t arc_serial_isr(int irq, void *dev_id)
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*/
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UART_TX_IRQ_DISABLE(port);
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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if (!uart_tx_stopped(port))
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arc_serial_tx_chars(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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}
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return IRQ_HANDLED;
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@@ -366,7 +366,7 @@ arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
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uartl = hw_val & 0xFF;
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uarth = (hw_val >> 8) & 0xFF;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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UART_ALL_IRQ_DISABLE(port);
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@@ -391,7 +391,7 @@ arc_serial_set_termios(struct uart_port *port, struct ktermios *new,
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uart_update_timeout(port, new->c_cflag, 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 *arc_serial_type(struct uart_port *port)
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@@ -521,9 +521,9 @@ static void arc_serial_console_write(struct console *co, const char *s,
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struct uart_port *port = &arc_uart_ports[co->index].port;
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unsigned long flags;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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uart_console_write(port, s, count, arc_serial_console_putchar);
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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 struct console arc_console = {
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--
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2.43.0
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