149 lines
4.9 KiB
Diff
149 lines
4.9 KiB
Diff
From 9ab5733ab07134629faf9863da976517fefa5d2a 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 20:43:43 +0206
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Subject: [PATCH 052/196] serial: linflexuart: 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/20230914183831.587273-27-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/fsl_linflexuart.c | 26 +++++++++++++-------------
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1 file changed, 13 insertions(+), 13 deletions(-)
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diff --git a/drivers/tty/serial/fsl_linflexuart.c b/drivers/tty/serial/fsl_linflexuart.c
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index 249cb380c3c6..7fa809a405e8 100644
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--- a/drivers/tty/serial/fsl_linflexuart.c
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+++ b/drivers/tty/serial/fsl_linflexuart.c
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@@ -203,7 +203,7 @@ static irqreturn_t linflex_txint(int irq, void *dev_id)
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struct circ_buf *xmit = &sport->state->xmit;
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unsigned long flags;
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- spin_lock_irqsave(&sport->lock, flags);
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+ uart_port_lock_irqsave(sport, &flags);
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if (sport->x_char) {
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linflex_put_char(sport, sport->x_char);
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@@ -217,7 +217,7 @@ static irqreturn_t linflex_txint(int irq, void *dev_id)
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linflex_transmit_buffer(sport);
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out:
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- spin_unlock_irqrestore(&sport->lock, flags);
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+ uart_port_unlock_irqrestore(sport, flags);
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return IRQ_HANDLED;
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}
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@@ -230,7 +230,7 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
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unsigned char rx;
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bool brk;
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- spin_lock_irqsave(&sport->lock, flags);
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+ uart_port_lock_irqsave(sport, &flags);
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status = readl(sport->membase + UARTSR);
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while (status & LINFLEXD_UARTSR_RMB) {
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@@ -266,7 +266,7 @@ static irqreturn_t linflex_rxint(int irq, void *dev_id)
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}
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}
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- spin_unlock_irqrestore(&sport->lock, flags);
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+ uart_port_unlock_irqrestore(sport, flags);
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tty_flip_buffer_push(port);
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@@ -369,11 +369,11 @@ static int linflex_startup(struct uart_port *port)
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int ret = 0;
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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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linflex_setup_watermark(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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ret = devm_request_irq(port->dev, port->irq, linflex_int, 0,
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DRIVER_NAME, port);
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@@ -386,14 +386,14 @@ static void linflex_shutdown(struct uart_port *port)
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unsigned long ier;
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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 interrupts */
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ier = readl(port->membase + LINIER);
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ier &= ~(LINFLEXD_LINIER_DRIE | LINFLEXD_LINIER_DTIE);
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writel(ier, port->membase + LINIER);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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devm_free_irq(port->dev, port->irq, port);
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}
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@@ -474,7 +474,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
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cr &= ~LINFLEXD_UARTCR_PCE;
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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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port->read_status_mask = 0;
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@@ -507,7 +507,7 @@ linflex_set_termios(struct uart_port *port, struct ktermios *termios,
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writel(cr1, port->membase + LINCR1);
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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 *linflex_type(struct uart_port *port)
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@@ -646,14 +646,14 @@ linflex_console_write(struct console *co, const char *s, unsigned int count)
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if (sport->sysrq)
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locked = 0;
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else if (oops_in_progress)
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- locked = spin_trylock_irqsave(&sport->lock, flags);
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+ locked = uart_port_trylock_irqsave(sport, &flags);
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else
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- spin_lock_irqsave(&sport->lock, flags);
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+ uart_port_lock_irqsave(sport, &flags);
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linflex_string_write(sport, s, count);
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if (locked)
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- spin_unlock_irqrestore(&sport->lock, flags);
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+ uart_port_unlock_irqrestore(sport, flags);
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}
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/*
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--
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2.43.2
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