69 lines
2.7 KiB
Diff
69 lines
2.7 KiB
Diff
From b7a99e7acecb90b637d07620ed35754c7152004e 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 20:43:27 +0206
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Subject: [PATCH 037/195] serial: 8250_fsl: 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/20230914183831.587273-11-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_fsl.c | 6 +++---
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1 file changed, 3 insertions(+), 3 deletions(-)
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diff --git a/drivers/tty/serial/8250/8250_fsl.c b/drivers/tty/serial/8250/8250_fsl.c
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index 6af4e1c1210a..f522eb5026c9 100644
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--- a/drivers/tty/serial/8250/8250_fsl.c
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+++ b/drivers/tty/serial/8250/8250_fsl.c
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@@ -30,11 +30,11 @@ int fsl8250_handle_irq(struct uart_port *port)
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unsigned int iir;
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struct uart_8250_port *up = up_to_u8250p(port);
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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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iir = port->serial_in(port, UART_IIR);
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if (iir & UART_IIR_NO_INT) {
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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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return 0;
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}
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@@ -54,7 +54,7 @@ int fsl8250_handle_irq(struct uart_port *port)
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if (unlikely(up->lsr_saved_flags & UART_LSR_BI)) {
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up->lsr_saved_flags &= ~UART_LSR_BI;
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port->serial_in(port, UART_RX);
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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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return 1;
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}
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--
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2.43.0
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