156 lines
5.5 KiB
Diff
156 lines
5.5 KiB
Diff
From 562160975c4f9073ed4f010cc11718b5134a42fd 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 20:44:05 +0206
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Subject: [PATCH 074/198] serial: pxa: 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/20230914183831.587273-49-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/pxa.c | 30 +++++++++++++++---------------
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1 file changed, 15 insertions(+), 15 deletions(-)
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diff --git a/drivers/tty/serial/pxa.c b/drivers/tty/serial/pxa.c
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index 73c60f5ea027..46e70e155aab 100644
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--- a/drivers/tty/serial/pxa.c
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+++ b/drivers/tty/serial/pxa.c
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@@ -225,14 +225,14 @@ static inline irqreturn_t serial_pxa_irq(int irq, void *dev_id)
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iir = serial_in(up, UART_IIR);
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if (iir & UART_IIR_NO_INT)
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return IRQ_NONE;
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- spin_lock(&up->port.lock);
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+ uart_port_lock(&up->port);
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lsr = serial_in(up, UART_LSR);
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if (lsr & UART_LSR_DR)
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receive_chars(up, &lsr);
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check_modem_status(up);
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if (lsr & UART_LSR_THRE)
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transmit_chars(up);
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- spin_unlock(&up->port.lock);
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+ uart_port_unlock(&up->port);
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return IRQ_HANDLED;
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}
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@@ -242,9 +242,9 @@ static unsigned int serial_pxa_tx_empty(struct uart_port *port)
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unsigned long flags;
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unsigned int ret;
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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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ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0;
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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 ret;
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}
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@@ -295,13 +295,13 @@ static void serial_pxa_break_ctl(struct uart_port *port, int break_state)
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struct uart_pxa_port *up = (struct uart_pxa_port *)port;
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unsigned long flags;
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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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if (break_state == -1)
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up->lcr |= UART_LCR_SBC;
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else
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up->lcr &= ~UART_LCR_SBC;
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serial_out(up, UART_LCR, up->lcr);
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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 int serial_pxa_startup(struct uart_port *port)
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@@ -346,10 +346,10 @@ static int serial_pxa_startup(struct uart_port *port)
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*/
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serial_out(up, UART_LCR, UART_LCR_WLEN8);
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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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up->port.mctrl |= TIOCM_OUT2;
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serial_pxa_set_mctrl(&up->port, up->port.mctrl);
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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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* Finally, enable interrupts. Note: Modem status interrupts
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@@ -383,10 +383,10 @@ static void serial_pxa_shutdown(struct uart_port *port)
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up->ier = 0;
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serial_out(up, UART_IER, 0);
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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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up->port.mctrl &= ~TIOCM_OUT2;
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serial_pxa_set_mctrl(&up->port, up->port.mctrl);
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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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* Disable break condition and FIFOs
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@@ -434,7 +434,7 @@ serial_pxa_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(&up->port.lock, flags);
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+ uart_port_lock_irqsave(&up->port, &flags);
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/*
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* Ensure the port will be enabled.
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@@ -504,7 +504,7 @@ serial_pxa_set_termios(struct uart_port *port, struct ktermios *termios,
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up->lcr = cval; /* Save LCR */
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serial_pxa_set_mctrl(&up->port, up->port.mctrl);
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serial_out(up, UART_FCR, fcr);
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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
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@@ -608,9 +608,9 @@ serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
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if (up->port.sysrq)
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locked = 0;
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else if (oops_in_progress)
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- locked = spin_trylock(&up->port.lock);
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+ locked = uart_port_trylock(&up->port);
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else
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- spin_lock(&up->port.lock);
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+ uart_port_lock(&up->port);
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/*
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* First save the IER then disable the interrupts
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@@ -628,7 +628,7 @@ serial_pxa_console_write(struct console *co, const char *s, unsigned int count)
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serial_out(up, UART_IER, ier);
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if (locked)
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- spin_unlock(&up->port.lock);
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+ uart_port_unlock(&up->port);
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local_irq_restore(flags);
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clk_disable(up->clk);
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--
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2.44.0
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