108 lines
3.8 KiB
Diff
108 lines
3.8 KiB
Diff
From 964adde6bb8848877f53d30a33ad1cabba18ee8f 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 20:44:18 +0206
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Subject: [PATCH 087/198] serial: sifive: 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/20230914183831.587273-62-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/sifive.c | 16 ++++++++--------
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1 file changed, 8 insertions(+), 8 deletions(-)
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diff --git a/drivers/tty/serial/sifive.c b/drivers/tty/serial/sifive.c
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index d195c5de52e7..b296e57a9dee 100644
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--- a/drivers/tty/serial/sifive.c
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+++ b/drivers/tty/serial/sifive.c
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@@ -521,11 +521,11 @@ static irqreturn_t sifive_serial_irq(int irq, void *dev_id)
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struct sifive_serial_port *ssp = dev_id;
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u32 ip;
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- spin_lock(&ssp->port.lock);
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+ uart_port_lock(&ssp->port);
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ip = __ssp_readl(ssp, SIFIVE_SERIAL_IP_OFFS);
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if (!ip) {
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- spin_unlock(&ssp->port.lock);
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+ uart_port_unlock(&ssp->port);
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return IRQ_NONE;
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}
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@@ -534,7 +534,7 @@ static irqreturn_t sifive_serial_irq(int irq, void *dev_id)
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if (ip & SIFIVE_SERIAL_IP_TXWM_MASK)
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__ssp_transmit_chars(ssp);
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- spin_unlock(&ssp->port.lock);
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+ uart_port_unlock(&ssp->port);
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return IRQ_HANDLED;
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}
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@@ -653,7 +653,7 @@ static void sifive_serial_set_termios(struct uart_port *port,
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ssp->port.uartclk / 16);
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__ssp_update_baud_rate(ssp, rate);
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- spin_lock_irqsave(&ssp->port.lock, flags);
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+ uart_port_lock_irqsave(&ssp->port, &flags);
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/* Update the per-port timeout */
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uart_update_timeout(port, termios->c_cflag, rate);
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@@ -670,7 +670,7 @@ static void sifive_serial_set_termios(struct uart_port *port,
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if (v != old_v)
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__ssp_writel(v, SIFIVE_SERIAL_RXCTRL_OFFS, ssp);
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- spin_unlock_irqrestore(&ssp->port.lock, flags);
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+ uart_port_unlock_irqrestore(&ssp->port, flags);
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}
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static void sifive_serial_release_port(struct uart_port *port)
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@@ -795,9 +795,9 @@ static void sifive_serial_console_write(struct console *co, const char *s,
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if (ssp->port.sysrq)
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locked = 0;
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else if (oops_in_progress)
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- locked = spin_trylock(&ssp->port.lock);
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+ locked = uart_port_trylock(&ssp->port);
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else
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- spin_lock(&ssp->port.lock);
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+ uart_port_lock(&ssp->port);
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ier = __ssp_readl(ssp, SIFIVE_SERIAL_IE_OFFS);
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__ssp_writel(0, SIFIVE_SERIAL_IE_OFFS, ssp);
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@@ -807,7 +807,7 @@ static void sifive_serial_console_write(struct console *co, const char *s,
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__ssp_writel(ier, SIFIVE_SERIAL_IE_OFFS, ssp);
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if (locked)
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- spin_unlock(&ssp->port.lock);
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+ uart_port_unlock(&ssp->port);
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local_irq_restore(flags);
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}
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--
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2.44.0
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