95 lines
3.3 KiB
Diff
95 lines
3.3 KiB
Diff
From 20988af9eed091714c307e7a6d080cf51ef874b1 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 20:43:56 +0206
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Subject: [PATCH 065/198] serial: mpc52xx: 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/20230914183831.587273-40-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/mpc52xx_uart.c | 12 ++++++------
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1 file changed, 6 insertions(+), 6 deletions(-)
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diff --git a/drivers/tty/serial/mpc52xx_uart.c b/drivers/tty/serial/mpc52xx_uart.c
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index 916507b8f31d..a252465e745f 100644
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--- a/drivers/tty/serial/mpc52xx_uart.c
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+++ b/drivers/tty/serial/mpc52xx_uart.c
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@@ -1096,14 +1096,14 @@ static void
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mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
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{
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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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if (ctl == -1)
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psc_ops->command(port, MPC52xx_PSC_START_BRK);
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else
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psc_ops->command(port, MPC52xx_PSC_STOP_BRK);
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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 int
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@@ -1214,7 +1214,7 @@ mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
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}
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/* Get the lock */
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* Do our best to flush TX & RX, so we don't lose anything */
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/* But we don't wait indefinitely ! */
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@@ -1250,7 +1250,7 @@ mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
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psc_ops->command(port, MPC52xx_PSC_RX_ENABLE);
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/* We're all set, release the lock */
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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 *
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@@ -1477,11 +1477,11 @@ mpc52xx_uart_int(int irq, void *dev_id)
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struct uart_port *port = dev_id;
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irqreturn_t ret;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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ret = psc_ops->handle_irq(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return ret;
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}
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--
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2.44.0
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