83 lines
3.2 KiB
Diff
83 lines
3.2 KiB
Diff
From ad44b165b3fe2140abff5cab7910d10866706978 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 20:43:28 +0206
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Subject: [PATCH 037/196] serial: 8250_mtk: 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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Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Link: https://lore.kernel.org/r/20230914183831.587273-12-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/8250/8250_mtk.c | 8 ++++----
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1 file changed, 4 insertions(+), 4 deletions(-)
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diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c
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index 74da5676ce67..23457daae8a1 100644
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--- a/drivers/tty/serial/8250/8250_mtk.c
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+++ b/drivers/tty/serial/8250/8250_mtk.c
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@@ -102,7 +102,7 @@ static void mtk8250_dma_rx_complete(void *param)
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if (data->rx_status == DMA_RX_SHUTDOWN)
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return;
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- spin_lock_irqsave(&up->port.lock, flags);
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+ uart_port_lock_irqsave(&up->port, &flags);
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dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state);
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total = dma->rx_size - state.residue;
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@@ -128,7 +128,7 @@ static void mtk8250_dma_rx_complete(void *param)
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mtk8250_rx_dma(up);
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- spin_unlock_irqrestore(&up->port.lock, flags);
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+ uart_port_unlock_irqrestore(&up->port, flags);
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}
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static void mtk8250_rx_dma(struct uart_8250_port *up)
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@@ -368,7 +368,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
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* Ok, we're now changing the port state. Do it with
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* interrupts disabled.
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*/
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/*
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* Update the per-port timeout.
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@@ -416,7 +416,7 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
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if (uart_console(port))
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up->port.cons->cflag = termios->c_cflag;
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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/* Don't rewrite B0 */
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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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2.43.2
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