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https://github.com/OpenVoiceOS/OpenVoiceOS
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86 lines
3.2 KiB
Diff
86 lines
3.2 KiB
Diff
From e6d006d61488b46458c637b77c156484ee68cc6a 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 20:44:02 +0206
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Subject: [PATCH 072/195] serial: pch: 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/20230914183831.587273-46-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/pch_uart.c | 10 +++++-----
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1 file changed, 5 insertions(+), 5 deletions(-)
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diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
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index cc83b772b7ca..436cc6d52a11 100644
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--- a/drivers/tty/serial/pch_uart.c
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+++ b/drivers/tty/serial/pch_uart.c
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@@ -1347,7 +1347,7 @@ static void pch_uart_set_termios(struct uart_port *port,
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baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
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spin_lock_irqsave(&priv->lock, flags);
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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uart_update_timeout(port, termios->c_cflag, baud);
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rtn = pch_uart_hal_set_line(priv, baud, parity, bits, stb);
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@@ -1360,7 +1360,7 @@ static void pch_uart_set_termios(struct uart_port *port,
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tty_termios_encode_baud_rate(termios, baud, baud);
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out:
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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spin_unlock_irqrestore(&priv->lock, flags);
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}
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@@ -1581,10 +1581,10 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
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port_locked = 0;
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} else if (oops_in_progress) {
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priv_locked = spin_trylock(&priv->lock);
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- port_locked = spin_trylock(&priv->port.lock);
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+ port_locked = uart_port_trylock(&priv->port);
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} else {
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spin_lock(&priv->lock);
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- spin_lock(&priv->port.lock);
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+ uart_port_lock(&priv->port);
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}
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/*
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@@ -1604,7 +1604,7 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
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iowrite8(ier, priv->membase + UART_IER);
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if (port_locked)
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- spin_unlock(&priv->port.lock);
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+ uart_port_unlock(&priv->port);
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if (priv_locked)
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spin_unlock(&priv->lock);
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local_irq_restore(flags);
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--
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2.43.0
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