114 lines
4.2 KiB
Diff
114 lines
4.2 KiB
Diff
From 2afc44181b5734d06a4719ac7d4b12264dce9deb 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 20:43:59 +0206
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Subject: [PATCH 068/198] serial: mvebu-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/20230914183831.587273-43-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/mvebu-uart.c | 18 +++++++++---------
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1 file changed, 9 insertions(+), 9 deletions(-)
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diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
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index ea924e9b913b..0255646bc175 100644
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--- a/drivers/tty/serial/mvebu-uart.c
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+++ b/drivers/tty/serial/mvebu-uart.c
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@@ -187,9 +187,9 @@ static unsigned int mvebu_uart_tx_empty(struct uart_port *port)
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unsigned long flags;
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unsigned int st;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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st = readl(port->membase + UART_STAT);
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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 (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
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}
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@@ -249,14 +249,14 @@ static void mvebu_uart_break_ctl(struct uart_port *port, int brk)
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unsigned int ctl;
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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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ctl = readl(port->membase + UART_CTRL(port));
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if (brk == -1)
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ctl |= CTRL_SND_BRK_SEQ;
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else
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ctl &= ~CTRL_SND_BRK_SEQ;
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writel(ctl, port->membase + UART_CTRL(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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static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
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@@ -540,7 +540,7 @@ static void mvebu_uart_set_termios(struct uart_port *port,
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unsigned long flags;
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unsigned int baud, min_baud, max_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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port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
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STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
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@@ -589,7 +589,7 @@ static void mvebu_uart_set_termios(struct uart_port *port,
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uart_update_timeout(port, termios->c_cflag, baud);
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}
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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 *mvebu_uart_type(struct uart_port *port)
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@@ -735,9 +735,9 @@ static void mvebu_uart_console_write(struct console *co, const char *s,
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int locked = 1;
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if (oops_in_progress)
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- locked = spin_trylock_irqsave(&port->lock, flags);
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+ locked = uart_port_trylock_irqsave(port, &flags);
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else
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
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intr = readl(port->membase + UART_INTR(port)) &
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@@ -758,7 +758,7 @@ static void mvebu_uart_console_write(struct console *co, const char *s,
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}
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if (locked)
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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 mvebu_uart_console_setup(struct console *co, char *options)
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--
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2.44.0
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