122 lines
4.4 KiB
Diff
122 lines
4.4 KiB
Diff
From 9f6bc0c5b8dabce9436c34fea6a89469b652c41a 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 20:43:32 +0206
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Subject: [PATCH 042/195] serial: altera_uart: 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/20230914183831.587273-16-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/altera_uart.c | 20 ++++++++++----------
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1 file changed, 10 insertions(+), 10 deletions(-)
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diff --git a/drivers/tty/serial/altera_uart.c b/drivers/tty/serial/altera_uart.c
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index a9c41942190c..77835ac68df2 100644
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--- a/drivers/tty/serial/altera_uart.c
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+++ b/drivers/tty/serial/altera_uart.c
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@@ -164,13 +164,13 @@ static void altera_uart_break_ctl(struct uart_port *port, int break_state)
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struct altera_uart *pp = container_of(port, struct altera_uart, port);
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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 (break_state == -1)
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pp->imr |= ALTERA_UART_CONTROL_TRBK_MSK;
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else
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pp->imr &= ~ALTERA_UART_CONTROL_TRBK_MSK;
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altera_uart_update_ctrl_reg(pp);
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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 void altera_uart_set_termios(struct uart_port *port,
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@@ -187,10 +187,10 @@ static void altera_uart_set_termios(struct uart_port *port,
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tty_termios_copy_hw(termios, old);
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tty_termios_encode_baud_rate(termios, baud, baud);
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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uart_update_timeout(port, termios->c_cflag, baud);
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altera_uart_writel(port, baudclk, ALTERA_UART_DIVISOR_REG);
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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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* FIXME: port->read_status_mask and port->ignore_status_mask
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@@ -264,12 +264,12 @@ static irqreturn_t altera_uart_interrupt(int irq, void *data)
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isr = altera_uart_readl(port, ALTERA_UART_STATUS_REG) & pp->imr;
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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 (isr & ALTERA_UART_STATUS_RRDY_MSK)
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altera_uart_rx_chars(port);
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if (isr & ALTERA_UART_STATUS_TRDY_MSK)
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altera_uart_tx_chars(port);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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return IRQ_RETVAL(isr);
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}
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@@ -313,13 +313,13 @@ static int altera_uart_startup(struct uart_port *port)
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}
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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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/* Enable RX interrupts now */
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pp->imr = ALTERA_UART_CONTROL_RRDY_MSK;
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altera_uart_update_ctrl_reg(pp);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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return 0;
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}
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@@ -329,13 +329,13 @@ static void altera_uart_shutdown(struct uart_port *port)
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struct altera_uart *pp = container_of(port, struct altera_uart, port);
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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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/* Disable all interrupts now */
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pp->imr = 0;
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altera_uart_update_ctrl_reg(pp);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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if (port->irq)
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free_irq(port->irq, port);
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--
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2.43.0
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