99 lines
3.3 KiB
Diff
99 lines
3.3 KiB
Diff
From e642eaa68ae3692f66e9f8b987f23aebc709e326 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 20:43:19 +0206
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Subject: [PATCH 029/195] serial: core: Use lock wrappers
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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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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Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Link: https://lore.kernel.org/r/20230914183831.587273-3-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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include/linux/serial_core.h | 12 ++++++------
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1 file changed, 6 insertions(+), 6 deletions(-)
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diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
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index f1d5c0d1568c..3091c62ec37b 100644
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--- a/include/linux/serial_core.h
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+++ b/include/linux/serial_core.h
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@@ -1035,14 +1035,14 @@ static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
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u8 sysrq_ch;
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if (!port->has_sysrq) {
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return;
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}
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sysrq_ch = port->sysrq_ch;
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port->sysrq_ch = 0;
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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if (sysrq_ch)
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handle_sysrq(sysrq_ch);
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@@ -1054,14 +1054,14 @@ static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port
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u8 sysrq_ch;
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if (!port->has_sysrq) {
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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;
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}
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sysrq_ch = port->sysrq_ch;
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port->sysrq_ch = 0;
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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 (sysrq_ch)
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handle_sysrq(sysrq_ch);
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@@ -1077,12 +1077,12 @@ static inline int uart_prepare_sysrq_char(struct uart_port *port, u8 ch)
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}
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static inline void uart_unlock_and_check_sysrq(struct uart_port *port)
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{
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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}
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static inline void uart_unlock_and_check_sysrq_irqrestore(struct uart_port *port,
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unsigned long flags)
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{
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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 /* CONFIG_MAGIC_SYSRQ_SERIAL */
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--
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2.43.0
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