116 lines
4.3 KiB
Diff
116 lines
4.3 KiB
Diff
From e52ba1ff3e44ce867023e6c23c97edfd8dbc3388 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 20:44:20 +0206
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Subject: [PATCH 089/198] serial: st-asc: 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/20230914183831.587273-64-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/st-asc.c | 18 +++++++++---------
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1 file changed, 9 insertions(+), 9 deletions(-)
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diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
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index 92b9f6894006..a821f5d76a26 100644
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--- a/drivers/tty/serial/st-asc.c
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+++ b/drivers/tty/serial/st-asc.c
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@@ -319,7 +319,7 @@ static irqreturn_t asc_interrupt(int irq, void *ptr)
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struct uart_port *port = ptr;
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u32 status;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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status = asc_in(port, ASC_STA);
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@@ -334,7 +334,7 @@ static irqreturn_t asc_interrupt(int irq, void *ptr)
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asc_transmit_chars(port);
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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 IRQ_HANDLED;
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}
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@@ -452,10 +452,10 @@ static void asc_pm(struct uart_port *port, unsigned int state,
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* we can come to turning it off. Note this is not called with
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* the port spinlock held.
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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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ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
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asc_out(port, ASC_CTL, ctl);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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clk_disable_unprepare(ascport->clk);
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break;
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}
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@@ -480,7 +480,7 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
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baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
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cflag = termios->c_cflag;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* read control register */
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ctrl_val = asc_in(port, ASC_CTL);
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@@ -594,7 +594,7 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
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/* write final value and enable port */
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asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
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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 *asc_type(struct uart_port *port)
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@@ -849,9 +849,9 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
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if (port->sysrq)
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locked = 0; /* asc_interrupt has already claimed the lock */
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else if (oops_in_progress)
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- locked = spin_trylock_irqsave(&port->lock, flags);
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+ locked = uart_port_trylock_irqsave(port, &flags);
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else
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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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* Disable interrupts so we don't get the IRQ line bouncing
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@@ -869,7 +869,7 @@ static void asc_console_write(struct console *co, const char *s, unsigned count)
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asc_out(port, ASC_INTEN, intenable);
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if (locked)
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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 asc_console_setup(struct console *co, char *options)
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--
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2.44.0
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