108 lines
4 KiB
Diff
108 lines
4 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Thu, 14 Sep 2023 20:43:59 +0206
|
|
Subject: [PATCH 042/134] serial: mvebu-uart: Use port lock wrappers
|
|
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz
|
|
|
|
When a serial port is used for kernel console output, then all
|
|
modifications to the UART registers which are done from other contexts,
|
|
e.g. getty, termios, are interference points for the kernel console.
|
|
|
|
So far this has been ignored and the printk output is based on the
|
|
principle of hope. The rework of the console infrastructure which aims to
|
|
support threaded and atomic consoles, requires to mark sections which
|
|
modify the UART registers as unsafe. This allows the atomic write function
|
|
to make informed decisions and eventually to restore operational state. It
|
|
also allows to prevent the regular UART code from modifying UART registers
|
|
while printk output is in progress.
|
|
|
|
All modifications of UART registers are guarded by the UART port lock,
|
|
which provides an obvious synchronization point with the console
|
|
infrastructure.
|
|
|
|
To avoid adding this functionality to all UART drivers, wrap the
|
|
spin_[un]lock*() invocations for uart_port::lock into helper functions
|
|
which just contain the spin_[un]lock*() invocations for now. In a
|
|
subsequent step these helpers will gain the console synchronization
|
|
mechanisms.
|
|
|
|
Converted with coccinelle. No functional change.
|
|
|
|
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Signed-off-by: John Ogness <john.ogness@linutronix.de>
|
|
Link: https://lore.kernel.org/r/20230914183831.587273-43-john.ogness@linutronix.de
|
|
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
drivers/tty/serial/mvebu-uart.c | 18 +++++++++---------
|
|
1 file changed, 9 insertions(+), 9 deletions(-)
|
|
|
|
--- a/drivers/tty/serial/mvebu-uart.c
|
|
+++ b/drivers/tty/serial/mvebu-uart.c
|
|
@@ -187,9 +187,9 @@ static unsigned int mvebu_uart_tx_empty(
|
|
unsigned long flags;
|
|
unsigned int st;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
st = readl(port->membase + UART_STAT);
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
|
|
return (st & STAT_TX_EMP) ? TIOCSER_TEMT : 0;
|
|
}
|
|
@@ -249,14 +249,14 @@ static void mvebu_uart_break_ctl(struct
|
|
unsigned int ctl;
|
|
unsigned long flags;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
ctl = readl(port->membase + UART_CTRL(port));
|
|
if (brk == -1)
|
|
ctl |= CTRL_SND_BRK_SEQ;
|
|
else
|
|
ctl &= ~CTRL_SND_BRK_SEQ;
|
|
writel(ctl, port->membase + UART_CTRL(port));
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static void mvebu_uart_rx_chars(struct uart_port *port, unsigned int status)
|
|
@@ -540,7 +540,7 @@ static void mvebu_uart_set_termios(struc
|
|
unsigned long flags;
|
|
unsigned int baud, min_baud, max_baud;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
port->read_status_mask = STAT_RX_RDY(port) | STAT_OVR_ERR |
|
|
STAT_TX_RDY(port) | STAT_TX_FIFO_FUL;
|
|
@@ -589,7 +589,7 @@ static void mvebu_uart_set_termios(struc
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
}
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static const char *mvebu_uart_type(struct uart_port *port)
|
|
@@ -735,9 +735,9 @@ static void mvebu_uart_console_write(str
|
|
int locked = 1;
|
|
|
|
if (oops_in_progress)
|
|
- locked = spin_trylock_irqsave(&port->lock, flags);
|
|
+ locked = uart_port_trylock_irqsave(port, &flags);
|
|
else
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
ier = readl(port->membase + UART_CTRL(port)) & CTRL_BRK_INT;
|
|
intr = readl(port->membase + UART_INTR(port)) &
|
|
@@ -758,7 +758,7 @@ static void mvebu_uart_console_write(str
|
|
}
|
|
|
|
if (locked)
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static int mvebu_uart_console_setup(struct console *co, char *options)
|