167 lines
5.6 KiB
Diff
167 lines
5.6 KiB
Diff
From 279159191fb892ad19a47abfe969e4cdc19d8ff0 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 20:43:42 +0206
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Subject: [PATCH 051/196] serial: dz: 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/20230914183831.587273-26-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/dz.c | 32 ++++++++++++++++----------------
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1 file changed, 16 insertions(+), 16 deletions(-)
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diff --git a/drivers/tty/serial/dz.c b/drivers/tty/serial/dz.c
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index 667f52e83277..6df7af9edc1c 100644
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--- a/drivers/tty/serial/dz.c
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+++ b/drivers/tty/serial/dz.c
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@@ -268,9 +268,9 @@ static inline void dz_transmit_chars(struct dz_mux *mux)
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}
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/* If nothing to do or stopped or hardware stopped. */
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if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) {
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- spin_lock(&dport->port.lock);
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+ uart_port_lock(&dport->port);
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dz_stop_tx(&dport->port);
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- spin_unlock(&dport->port.lock);
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+ uart_port_unlock(&dport->port);
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return;
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}
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@@ -287,9 +287,9 @@ static inline void dz_transmit_chars(struct dz_mux *mux)
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/* Are we are done. */
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if (uart_circ_empty(xmit)) {
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- spin_lock(&dport->port.lock);
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+ uart_port_lock(&dport->port);
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dz_stop_tx(&dport->port);
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- spin_unlock(&dport->port.lock);
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+ uart_port_unlock(&dport->port);
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}
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}
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@@ -415,14 +415,14 @@ static int dz_startup(struct uart_port *uport)
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return ret;
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}
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- spin_lock_irqsave(&dport->port.lock, flags);
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+ uart_port_lock_irqsave(&dport->port, &flags);
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/* Enable interrupts. */
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tmp = dz_in(dport, DZ_CSR);
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tmp |= DZ_RIE | DZ_TIE;
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dz_out(dport, DZ_CSR, tmp);
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- spin_unlock_irqrestore(&dport->port.lock, flags);
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+ uart_port_unlock_irqrestore(&dport->port, flags);
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return 0;
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}
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@@ -443,9 +443,9 @@ static void dz_shutdown(struct uart_port *uport)
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int irq_guard;
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u16 tmp;
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- spin_lock_irqsave(&dport->port.lock, flags);
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+ uart_port_lock_irqsave(&dport->port, &flags);
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dz_stop_tx(&dport->port);
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- spin_unlock_irqrestore(&dport->port.lock, flags);
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+ uart_port_unlock_irqrestore(&dport->port, flags);
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irq_guard = atomic_add_return(-1, &mux->irq_guard);
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if (!irq_guard) {
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@@ -491,14 +491,14 @@ static void dz_break_ctl(struct uart_port *uport, int break_state)
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unsigned long flags;
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unsigned short tmp, mask = 1 << dport->port.line;
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- spin_lock_irqsave(&uport->lock, flags);
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+ uart_port_lock_irqsave(uport, &flags);
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tmp = dz_in(dport, DZ_TCR);
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if (break_state)
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tmp |= mask;
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else
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tmp &= ~mask;
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dz_out(dport, DZ_TCR, tmp);
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- spin_unlock_irqrestore(&uport->lock, flags);
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+ uart_port_unlock_irqrestore(uport, flags);
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}
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static int dz_encode_baud_rate(unsigned int baud)
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@@ -608,7 +608,7 @@ static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
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if (termios->c_cflag & CREAD)
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cflag |= DZ_RXENAB;
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- spin_lock_irqsave(&dport->port.lock, flags);
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+ uart_port_lock_irqsave(&dport->port, &flags);
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uart_update_timeout(uport, termios->c_cflag, baud);
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@@ -631,7 +631,7 @@ static void dz_set_termios(struct uart_port *uport, struct ktermios *termios,
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if (termios->c_iflag & IGNBRK)
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dport->port.ignore_status_mask |= DZ_BREAK;
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- spin_unlock_irqrestore(&dport->port.lock, flags);
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+ uart_port_unlock_irqrestore(&dport->port, flags);
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}
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/*
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@@ -645,12 +645,12 @@ static void dz_pm(struct uart_port *uport, unsigned int state,
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struct dz_port *dport = to_dport(uport);
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unsigned long flags;
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- spin_lock_irqsave(&dport->port.lock, flags);
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+ uart_port_lock_irqsave(&dport->port, &flags);
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if (state < 3)
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dz_start_tx(&dport->port);
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else
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dz_stop_tx(&dport->port);
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- spin_unlock_irqrestore(&dport->port.lock, flags);
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+ uart_port_unlock_irqrestore(&dport->port, flags);
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}
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@@ -811,7 +811,7 @@ static void dz_console_putchar(struct uart_port *uport, unsigned char ch)
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unsigned short csr, tcr, trdy, mask;
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int loops = 10000;
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- spin_lock_irqsave(&dport->port.lock, flags);
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+ uart_port_lock_irqsave(&dport->port, &flags);
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csr = dz_in(dport, DZ_CSR);
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dz_out(dport, DZ_CSR, csr & ~DZ_TIE);
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tcr = dz_in(dport, DZ_TCR);
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@@ -819,7 +819,7 @@ static void dz_console_putchar(struct uart_port *uport, unsigned char ch)
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mask = tcr;
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dz_out(dport, DZ_TCR, mask);
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iob();
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- spin_unlock_irqrestore(&dport->port.lock, flags);
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+ uart_port_unlock_irqrestore(&dport->port, flags);
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do {
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trdy = dz_in(dport, DZ_CSR);
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--
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2.43.2
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