134 lines
4.5 KiB
Diff
134 lines
4.5 KiB
Diff
From bc56987ad8ef8a8948ba64ffa8302ea324913079 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 20:43:39 +0206
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Subject: [PATCH 048/196] serial: bcm63xx-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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Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Link: https://lore.kernel.org/r/20230914183831.587273-23-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/bcm63xx_uart.c | 22 +++++++++++-----------
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1 file changed, 11 insertions(+), 11 deletions(-)
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diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
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index 0dd8cceb837c..4a08fd5ee61b 100644
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--- a/drivers/tty/serial/bcm63xx_uart.c
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+++ b/drivers/tty/serial/bcm63xx_uart.c
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@@ -201,7 +201,7 @@ static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
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unsigned long flags;
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unsigned int val;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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val = bcm_uart_readl(port, UART_CTL_REG);
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if (ctl)
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@@ -210,7 +210,7 @@ static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
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val &= ~UART_CTL_XMITBRK_MASK;
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bcm_uart_writel(port, val, UART_CTL_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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/*
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@@ -332,7 +332,7 @@ static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
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unsigned int irqstat;
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port = dev_id;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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irqstat = bcm_uart_readl(port, UART_IR_REG);
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if (irqstat & UART_RX_INT_STAT)
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@@ -353,7 +353,7 @@ static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
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estat & UART_EXTINP_DCD_MASK);
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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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@@ -451,9 +451,9 @@ static void bcm_uart_shutdown(struct uart_port *port)
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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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bcm_uart_writel(port, 0, UART_IR_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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bcm_uart_disable(port);
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bcm_uart_flush(port);
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@@ -470,7 +470,7 @@ static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
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unsigned long flags;
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int tries;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* Drain the hot tub fully before we power it off for the winter. */
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for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
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@@ -546,7 +546,7 @@ static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
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uart_update_timeout(port, new->c_cflag, baud);
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bcm_uart_enable(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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}
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/*
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@@ -712,9 +712,9 @@ static void bcm_console_write(struct console *co, const char *s,
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/* bcm_uart_interrupt() already took the lock */
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locked = 0;
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} else if (oops_in_progress) {
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- locked = spin_trylock(&port->lock);
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+ locked = uart_port_trylock(port);
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} else {
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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locked = 1;
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}
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@@ -725,7 +725,7 @@ static void bcm_console_write(struct console *co, const char *s,
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wait_for_xmitr(port);
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if (locked)
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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local_irq_restore(flags);
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}
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--
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2.43.2
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