99 lines
3.3 KiB
Diff
99 lines
3.3 KiB
Diff
From e20fab51907c073d83831b2810d06305e037bdc1 Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Thu, 14 Sep 2023 20:43:19 +0206
|
|
Subject: [PATCH 028/196] serial: core: Use lock wrappers
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
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>
|
|
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
|
|
Signed-off-by: John Ogness <john.ogness@linutronix.de>
|
|
Link: https://lore.kernel.org/r/20230914183831.587273-3-john.ogness@linutronix.de
|
|
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
include/linux/serial_core.h | 12 ++++++------
|
|
1 file changed, 6 insertions(+), 6 deletions(-)
|
|
|
|
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
|
|
index 27a26092493a..f43aca7f3b01 100644
|
|
--- a/include/linux/serial_core.h
|
|
+++ b/include/linux/serial_core.h
|
|
@@ -1057,14 +1057,14 @@ static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
|
|
u8 sysrq_ch;
|
|
|
|
if (!port->has_sysrq) {
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
return;
|
|
}
|
|
|
|
sysrq_ch = port->sysrq_ch;
|
|
port->sysrq_ch = 0;
|
|
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
|
|
if (sysrq_ch)
|
|
handle_sysrq(sysrq_ch);
|
|
@@ -1076,14 +1076,14 @@ static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port
|
|
u8 sysrq_ch;
|
|
|
|
if (!port->has_sysrq) {
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
return;
|
|
}
|
|
|
|
sysrq_ch = port->sysrq_ch;
|
|
port->sysrq_ch = 0;
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
|
|
if (sysrq_ch)
|
|
handle_sysrq(sysrq_ch);
|
|
@@ -1099,12 +1099,12 @@ static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
|
|
}
|
|
static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
|
|
{
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
}
|
|
static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
|
|
unsigned long flags)
|
|
{
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
#endif /* CONFIG_MAGIC_SYSRQ_SERIAL */
|
|
|
|
--
|
|
2.43.2
|
|
|