139 lines
4.7 KiB
Diff
139 lines
4.7 KiB
Diff
From 174bb9e1e1fa3d4ef2c46054621435dbf7a7dc66 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 20:43:31 +0206
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Subject: [PATCH 041/195] serial: altera_jtaguart: 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/20230914183831.587273-15-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/altera_jtaguart.c | 28 ++++++++++++++--------------
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1 file changed, 14 insertions(+), 14 deletions(-)
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diff --git a/drivers/tty/serial/altera_jtaguart.c b/drivers/tty/serial/altera_jtaguart.c
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index 5fab4c978891..7090b251dd4d 100644
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--- a/drivers/tty/serial/altera_jtaguart.c
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+++ b/drivers/tty/serial/altera_jtaguart.c
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@@ -147,14 +147,14 @@ static irqreturn_t altera_jtaguart_interrupt(int irq, void *data)
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isr = (readl(port->membase + ALTERA_JTAGUART_CONTROL_REG) >>
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ALTERA_JTAGUART_CONTROL_RI_OFF) & port->read_status_mask;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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if (isr & ALTERA_JTAGUART_CONTROL_RE_MSK)
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altera_jtaguart_rx_chars(port);
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if (isr & ALTERA_JTAGUART_CONTROL_WE_MSK)
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altera_jtaguart_tx_chars(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return IRQ_RETVAL(isr);
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}
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@@ -180,14 +180,14 @@ static int altera_jtaguart_startup(struct uart_port *port)
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return ret;
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}
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* Enable RX interrupts now */
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port->read_status_mask = ALTERA_JTAGUART_CONTROL_RE_MSK;
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writel(port->read_status_mask,
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port->membase + ALTERA_JTAGUART_CONTROL_REG);
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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 0;
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}
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@@ -196,14 +196,14 @@ static void altera_jtaguart_shutdown(struct uart_port *port)
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{
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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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/* Disable all interrupts now */
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port->read_status_mask = 0;
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writel(port->read_status_mask,
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port->membase + ALTERA_JTAGUART_CONTROL_REG);
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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free_irq(port->irq, port);
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}
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@@ -264,33 +264,33 @@ static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c
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unsigned long flags;
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u32 status;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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while (!altera_jtaguart_tx_space(port, &status)) {
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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if ((status & ALTERA_JTAGUART_CONTROL_AC_MSK) == 0) {
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return; /* no connection activity */
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}
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cpu_relax();
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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}
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writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
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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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#else
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static void altera_jtaguart_console_putc(struct uart_port *port, unsigned char c)
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{
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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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while (!altera_jtaguart_tx_space(port, NULL)) {
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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cpu_relax();
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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}
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writel(c, port->membase + ALTERA_JTAGUART_DATA_REG);
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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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#endif
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--
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2.43.0
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