109 lines
3.7 KiB
Diff
109 lines
3.7 KiB
Diff
From f3a08238f90b3ada6988a984fa2fade2bf26f007 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 20:43:57 +0206
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Subject: [PATCH 066/198] serial: mps2-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/20230914183831.587273-41-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/mps2-uart.c | 16 ++++++++--------
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1 file changed, 8 insertions(+), 8 deletions(-)
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diff --git a/drivers/tty/serial/mps2-uart.c b/drivers/tty/serial/mps2-uart.c
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index ea5a7911cb15..2a4c09f3a834 100644
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--- a/drivers/tty/serial/mps2-uart.c
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+++ b/drivers/tty/serial/mps2-uart.c
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@@ -188,12 +188,12 @@ static irqreturn_t mps2_uart_rxirq(int irq, void *data)
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if (unlikely(!(irqflag & UARTn_INT_RX)))
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return IRQ_NONE;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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mps2_uart_write8(port, UARTn_INT_RX, UARTn_INT);
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mps2_uart_rx_chars(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return IRQ_HANDLED;
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}
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@@ -206,12 +206,12 @@ static irqreturn_t mps2_uart_txirq(int irq, void *data)
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if (unlikely(!(irqflag & UARTn_INT_TX)))
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return IRQ_NONE;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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mps2_uart_write8(port, UARTn_INT_TX, UARTn_INT);
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mps2_uart_tx_chars(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return IRQ_HANDLED;
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}
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@@ -222,7 +222,7 @@ static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
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struct uart_port *port = data;
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u8 irqflag = mps2_uart_read8(port, UARTn_INT);
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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if (irqflag & UARTn_INT_RX_OVERRUN) {
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struct tty_port *tport = &port->state->port;
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@@ -244,7 +244,7 @@ static irqreturn_t mps2_uart_oerrirq(int irq, void *data)
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handled = IRQ_HANDLED;
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}
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return handled;
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}
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@@ -356,12 +356,12 @@ mps2_uart_set_termios(struct uart_port *port, struct ktermios *termios,
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bauddiv = DIV_ROUND_CLOSEST(port->uartclk, 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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uart_update_timeout(port, termios->c_cflag, baud);
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mps2_uart_write32(port, bauddiv, UARTn_BAUDDIV);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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if (tty_termios_baud_rate(termios))
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tty_termios_encode_baud_rate(termios, baud, baud);
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--
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2.44.0
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