174 lines
5.8 KiB
Diff
174 lines
5.8 KiB
Diff
From 348c0f05fb287f150e7eaa783c40cb73910f589d Mon Sep 17 00:00:00 2001
|
|
From: Thomas Gleixner <tglx@linutronix.de>
|
|
Date: Thu, 14 Sep 2023 20:43:54 +0206
|
|
Subject: [PATCH 064/195] serial: meson: Use port lock wrappers
|
|
|
|
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>
|
|
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
|
|
Signed-off-by: John Ogness <john.ogness@linutronix.de>
|
|
Link: https://lore.kernel.org/r/20230914183831.587273-38-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/meson_uart.c | 30 +++++++++++++++---------------
|
|
1 file changed, 15 insertions(+), 15 deletions(-)
|
|
|
|
diff --git a/drivers/tty/serial/meson_uart.c b/drivers/tty/serial/meson_uart.c
|
|
index 9388b9ddea3b..4c1d2089a0bb 100644
|
|
--- a/drivers/tty/serial/meson_uart.c
|
|
+++ b/drivers/tty/serial/meson_uart.c
|
|
@@ -129,14 +129,14 @@ static void meson_uart_shutdown(struct uart_port *port)
|
|
|
|
free_irq(port->irq, port);
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
val = readl(port->membase + AML_UART_CONTROL);
|
|
val &= ~AML_UART_RX_EN;
|
|
val &= ~(AML_UART_RX_INT_EN | AML_UART_TX_INT_EN);
|
|
writel(val, port->membase + AML_UART_CONTROL);
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static void meson_uart_start_tx(struct uart_port *port)
|
|
@@ -238,7 +238,7 @@ static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
|
|
{
|
|
struct uart_port *port = (struct uart_port *)dev_id;
|
|
|
|
- spin_lock(&port->lock);
|
|
+ uart_port_lock(port);
|
|
|
|
if (!(readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY))
|
|
meson_receive_chars(port);
|
|
@@ -248,7 +248,7 @@ static irqreturn_t meson_uart_interrupt(int irq, void *dev_id)
|
|
meson_uart_start_tx(port);
|
|
}
|
|
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
@@ -284,7 +284,7 @@ static int meson_uart_startup(struct uart_port *port)
|
|
u32 val;
|
|
int ret = 0;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
val = readl(port->membase + AML_UART_CONTROL);
|
|
val |= AML_UART_CLEAR_ERR;
|
|
@@ -301,7 +301,7 @@ static int meson_uart_startup(struct uart_port *port)
|
|
val = (AML_UART_RECV_IRQ(1) | AML_UART_XMIT_IRQ(port->fifosize / 2));
|
|
writel(val, port->membase + AML_UART_MISC);
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
|
|
ret = request_irq(port->irq, meson_uart_interrupt, 0,
|
|
port->name, port);
|
|
@@ -341,7 +341,7 @@ static void meson_uart_set_termios(struct uart_port *port,
|
|
unsigned long flags;
|
|
u32 val;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
cflags = termios->c_cflag;
|
|
iflags = termios->c_iflag;
|
|
@@ -405,7 +405,7 @@ static void meson_uart_set_termios(struct uart_port *port,
|
|
AML_UART_FRAME_ERR;
|
|
|
|
uart_update_timeout(port, termios->c_cflag, baud);
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
static int meson_uart_verify_port(struct uart_port *port,
|
|
@@ -464,14 +464,14 @@ static int meson_uart_poll_get_char(struct uart_port *port)
|
|
u32 c;
|
|
unsigned long flags;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
if (readl(port->membase + AML_UART_STATUS) & AML_UART_RX_EMPTY)
|
|
c = NO_POLL_CHAR;
|
|
else
|
|
c = readl(port->membase + AML_UART_RFIFO);
|
|
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
|
|
return c;
|
|
}
|
|
@@ -482,7 +482,7 @@ static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
|
|
u32 reg;
|
|
int ret;
|
|
|
|
- spin_lock_irqsave(&port->lock, flags);
|
|
+ uart_port_lock_irqsave(port, &flags);
|
|
|
|
/* Wait until FIFO is empty or timeout */
|
|
ret = readl_poll_timeout_atomic(port->membase + AML_UART_STATUS, reg,
|
|
@@ -506,7 +506,7 @@ static void meson_uart_poll_put_char(struct uart_port *port, unsigned char c)
|
|
dev_err(port->dev, "Timeout waiting for UART TX EMPTY\n");
|
|
|
|
out:
|
|
- spin_unlock_irqrestore(&port->lock, flags);
|
|
+ uart_port_unlock_irqrestore(port, flags);
|
|
}
|
|
|
|
#endif /* CONFIG_CONSOLE_POLL */
|
|
@@ -563,9 +563,9 @@ static void meson_serial_port_write(struct uart_port *port, const char *s,
|
|
if (port->sysrq) {
|
|
locked = 0;
|
|
} else if (oops_in_progress) {
|
|
- locked = spin_trylock(&port->lock);
|
|
+ locked = uart_port_trylock(port);
|
|
} else {
|
|
- spin_lock(&port->lock);
|
|
+ uart_port_lock(port);
|
|
locked = 1;
|
|
}
|
|
|
|
@@ -577,7 +577,7 @@ static void meson_serial_port_write(struct uart_port *port, const char *s,
|
|
writel(val, port->membase + AML_UART_CONTROL);
|
|
|
|
if (locked)
|
|
- spin_unlock(&port->lock);
|
|
+ uart_port_unlock(port);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
--
|
|
2.43.0
|
|
|