119 lines
4.3 KiB
Diff
119 lines
4.3 KiB
Diff
From ab7a1a85b420f839afe9b6ac94e420c0016f47a7 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 20:43:41 +0206
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Subject: [PATCH 051/195] serial: digicolor: 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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Acked-by: Baruch Siach <baruch@tkos.co.il>
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Signed-off-by: John Ogness <john.ogness@linutronix.de>
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Link: https://lore.kernel.org/r/20230914183831.587273-25-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/digicolor-usart.c | 18 +++++++++---------
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1 file changed, 9 insertions(+), 9 deletions(-)
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diff --git a/drivers/tty/serial/digicolor-usart.c b/drivers/tty/serial/digicolor-usart.c
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index 128b5479e813..5004125f3045 100644
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--- a/drivers/tty/serial/digicolor-usart.c
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+++ b/drivers/tty/serial/digicolor-usart.c
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@@ -133,7 +133,7 @@ static void digicolor_uart_rx(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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while (1) {
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u8 status, ch, ch_flag;
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@@ -172,7 +172,7 @@ static void digicolor_uart_rx(struct uart_port *port)
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ch_flag);
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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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tty_flip_buffer_push(&port->state->port);
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}
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@@ -185,7 +185,7 @@ static void digicolor_uart_tx(struct uart_port *port)
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if (digicolor_uart_tx_full(port))
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return;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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if (port->x_char) {
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writeb_relaxed(port->x_char, port->membase + UA_EMI_REC);
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@@ -211,7 +211,7 @@ static void digicolor_uart_tx(struct uart_port *port)
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uart_write_wakeup(port);
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out:
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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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static irqreturn_t digicolor_uart_int(int irq, void *dev_id)
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@@ -333,7 +333,7 @@ static void digicolor_uart_set_termios(struct uart_port *port,
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port->ignore_status_mask |= UA_STATUS_OVERRUN_ERR
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| UA_STATUS_PARITY_ERR | UA_STATUS_FRAME_ERR;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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uart_update_timeout(port, termios->c_cflag, baud);
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@@ -341,7 +341,7 @@ static void digicolor_uart_set_termios(struct uart_port *port,
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writeb_relaxed(divisor & 0xff, port->membase + UA_HBAUD_LO);
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writeb_relaxed(divisor >> 8, port->membase + UA_HBAUD_HI);
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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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static const char *digicolor_uart_type(struct uart_port *port)
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@@ -398,14 +398,14 @@ static void digicolor_uart_console_write(struct console *co, const char *c,
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int locked = 1;
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if (oops_in_progress)
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- locked = spin_trylock_irqsave(&port->lock, flags);
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+ locked = uart_port_trylock_irqsave(port, &flags);
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else
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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uart_console_write(port, c, n, digicolor_uart_console_putchar);
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if (locked)
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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/* Wait for transmitter to become empty */
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do {
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--
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2.43.0
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