118 lines
4.0 KiB
Diff
118 lines
4.0 KiB
Diff
From c3a76ebbc1bc4735df825ef0639312c01bb0e07c 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 20:43:33 +0206
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Subject: [PATCH 043/195] serial: amba-pl010: 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/20230914183831.587273-17-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/amba-pl010.c | 20 ++++++++++----------
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1 file changed, 10 insertions(+), 10 deletions(-)
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diff --git a/drivers/tty/serial/amba-pl010.c b/drivers/tty/serial/amba-pl010.c
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index b5a7404cbacb..eabbf8afc9b5 100644
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--- a/drivers/tty/serial/amba-pl010.c
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+++ b/drivers/tty/serial/amba-pl010.c
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@@ -207,7 +207,7 @@ static irqreturn_t pl010_int(int irq, void *dev_id)
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unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
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int handled = 0;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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status = readb(port->membase + UART010_IIR);
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if (status) {
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@@ -228,7 +228,7 @@ static irqreturn_t pl010_int(int irq, void *dev_id)
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handled = 1;
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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_RETVAL(handled);
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}
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@@ -270,14 +270,14 @@ static void pl010_break_ctl(struct uart_port *port, int break_state)
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unsigned long flags;
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unsigned int lcr_h;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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lcr_h = readb(port->membase + UART010_LCRH);
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if (break_state == -1)
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lcr_h |= UART01x_LCRH_BRK;
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else
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lcr_h &= ~UART01x_LCRH_BRK;
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writel(lcr_h, port->membase + UART010_LCRH);
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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 pl010_startup(struct uart_port *port)
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@@ -385,7 +385,7 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
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if (port->fifosize > 1)
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lcr_h |= UART01x_LCRH_FEN;
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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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* Update the per-port timeout.
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@@ -438,22 +438,22 @@ pl010_set_termios(struct uart_port *port, struct ktermios *termios,
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writel(lcr_h, port->membase + UART010_LCRH);
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writel(old_cr, port->membase + UART010_CR);
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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 pl010_set_ldisc(struct uart_port *port, struct ktermios *termios)
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{
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if (termios->c_line == N_PPS) {
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port->flags |= UPF_HARDPPS_CD;
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- spin_lock_irq(&port->lock);
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+ uart_port_lock_irq(port);
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pl010_enable_ms(port);
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- spin_unlock_irq(&port->lock);
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+ uart_port_unlock_irq(port);
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} else {
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port->flags &= ~UPF_HARDPPS_CD;
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if (!UART_ENABLE_MS(port, termios->c_cflag)) {
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- spin_lock_irq(&port->lock);
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+ uart_port_lock_irq(port);
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pl010_disable_ms(port);
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- spin_unlock_irq(&port->lock);
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+ uart_port_unlock_irq(port);
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}
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}
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}
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--
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2.43.0
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