134 lines
4.6 KiB
Diff
134 lines
4.6 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:44:16 +0206
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Subject: [PATCH 059/134] serial: txx9: Use port lock wrappers
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz
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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/20230914183831.587273-60-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/serial_txx9.c | 26 +++++++++++++-------------
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1 file changed, 13 insertions(+), 13 deletions(-)
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--- a/drivers/tty/serial/serial_txx9.c
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+++ b/drivers/tty/serial/serial_txx9.c
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@@ -335,13 +335,13 @@ static irqreturn_t serial_txx9_interrupt
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unsigned int status;
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while (1) {
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- spin_lock(&up->lock);
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+ uart_port_lock(up);
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status = sio_in(up, TXX9_SIDISR);
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if (!(sio_in(up, TXX9_SIDICR) & TXX9_SIDICR_TIE))
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status &= ~TXX9_SIDISR_TDIS;
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if (!(status & (TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS |
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TXX9_SIDISR_TOUT))) {
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- spin_unlock(&up->lock);
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+ uart_port_unlock(up);
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break;
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}
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@@ -353,7 +353,7 @@ static irqreturn_t serial_txx9_interrupt
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sio_mask(up, TXX9_SIDISR,
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TXX9_SIDISR_TDIS | TXX9_SIDISR_RDIS |
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TXX9_SIDISR_TOUT);
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- spin_unlock(&up->lock);
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+ uart_port_unlock(up);
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if (pass_counter++ > PASS_LIMIT)
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break;
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@@ -367,9 +367,9 @@ static unsigned int serial_txx9_tx_empty
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unsigned long flags;
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unsigned int ret;
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- spin_lock_irqsave(&up->lock, flags);
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+ uart_port_lock_irqsave(up, &flags);
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ret = (sio_in(up, TXX9_SICISR) & TXX9_SICISR_TXALS) ? TIOCSER_TEMT : 0;
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- spin_unlock_irqrestore(&up->lock, flags);
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+ uart_port_unlock_irqrestore(up, flags);
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return ret;
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}
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@@ -399,12 +399,12 @@ static void serial_txx9_break_ctl(struct
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{
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unsigned long flags;
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- spin_lock_irqsave(&up->lock, flags);
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+ uart_port_lock_irqsave(up, &flags);
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if (break_state == -1)
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sio_set(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
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else
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sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_TBRK);
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- spin_unlock_irqrestore(&up->lock, flags);
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+ uart_port_unlock_irqrestore(up, flags);
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}
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#if defined(CONFIG_SERIAL_TXX9_CONSOLE) || defined(CONFIG_CONSOLE_POLL)
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@@ -517,9 +517,9 @@ static int serial_txx9_startup(struct ua
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/*
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* Now, initialize the UART
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*/
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- spin_lock_irqsave(&up->lock, flags);
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+ uart_port_lock_irqsave(up, &flags);
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serial_txx9_set_mctrl(up, up->mctrl);
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- spin_unlock_irqrestore(&up->lock, flags);
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+ uart_port_unlock_irqrestore(up, flags);
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/* Enable RX/TX */
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sio_mask(up, TXX9_SIFLCR, TXX9_SIFLCR_RSDE | TXX9_SIFLCR_TSDE);
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@@ -541,9 +541,9 @@ static void serial_txx9_shutdown(struct
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*/
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sio_out(up, TXX9_SIDICR, 0); /* disable all intrs */
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- spin_lock_irqsave(&up->lock, flags);
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+ uart_port_lock_irqsave(up, &flags);
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serial_txx9_set_mctrl(up, up->mctrl);
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- spin_unlock_irqrestore(&up->lock, flags);
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+ uart_port_unlock_irqrestore(up, flags);
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/*
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* Disable break condition
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@@ -625,7 +625,7 @@ serial_txx9_set_termios(struct uart_port
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* Ok, we're now changing the port state. Do it with
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* interrupts disabled.
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*/
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- spin_lock_irqsave(&up->lock, flags);
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+ uart_port_lock_irqsave(up, &flags);
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/*
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* Update the per-port timeout.
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@@ -676,7 +676,7 @@ serial_txx9_set_termios(struct uart_port
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sio_out(up, TXX9_SIFCR, fcr);
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serial_txx9_set_mctrl(up, up->mctrl);
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- spin_unlock_irqrestore(&up->lock, flags);
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+ uart_port_unlock_irqrestore(up, flags);
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}
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static void
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