146 lines
5.1 KiB
Diff
146 lines
5.1 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:44:23 +0206
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Subject: [PATCH 066/134] serial: sunplus-uart: Use port lock wrappers
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz
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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/20230914183831.587273-67-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/sunplus-uart.c | 26 +++++++++++++-------------
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1 file changed, 13 insertions(+), 13 deletions(-)
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--- a/drivers/tty/serial/sunplus-uart.c
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+++ b/drivers/tty/serial/sunplus-uart.c
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@@ -184,7 +184,7 @@ static void sunplus_break_ctl(struct uar
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unsigned long flags;
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unsigned int lcr;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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lcr = readl(port->membase + SUP_UART_LCR);
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@@ -195,7 +195,7 @@ static void sunplus_break_ctl(struct uar
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writel(lcr, port->membase + SUP_UART_LCR);
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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 void transmit_chars(struct uart_port *port)
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@@ -277,7 +277,7 @@ static irqreturn_t sunplus_uart_irq(int
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struct uart_port *port = args;
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unsigned int isc;
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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isc = readl(port->membase + SUP_UART_ISC);
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@@ -287,7 +287,7 @@ static irqreturn_t sunplus_uart_irq(int
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if (isc & SUP_UART_ISC_TX)
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transmit_chars(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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return IRQ_HANDLED;
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}
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@@ -302,14 +302,14 @@ static int sunplus_startup(struct uart_p
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if (ret)
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return ret;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* isc define Bit[7:4] int setting, Bit[3:0] int status
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* isc register will clean Bit[3:0] int status after read
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* only do a write to Bit[7:4] int setting
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*/
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isc |= SUP_UART_ISC_RXM;
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writel(isc, port->membase + SUP_UART_ISC);
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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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@@ -318,13 +318,13 @@ static void sunplus_shutdown(struct uart
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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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/* isc define Bit[7:4] int setting, Bit[3:0] int status
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* isc register will clean Bit[3:0] int status after read
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* only do a write to Bit[7:4] int setting
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*/
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writel(0, port->membase + SUP_UART_ISC); /* disable all interrupt */
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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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@@ -372,7 +372,7 @@ static void sunplus_set_termios(struct u
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lcr |= UART_LCR_EPAR;
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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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uart_update_timeout(port, termios->c_cflag, baud);
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@@ -407,7 +407,7 @@ static void sunplus_set_termios(struct u
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writel(div_l, port->membase + SUP_UART_DIV_L);
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writel(lcr, port->membase + SUP_UART_LCR);
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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 void sunplus_set_ldisc(struct uart_port *port, struct ktermios *termios)
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@@ -517,15 +517,15 @@ static void sunplus_console_write(struct
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if (sunplus_console_ports[co->index]->port.sysrq)
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locked = 0;
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else if (oops_in_progress)
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- locked = spin_trylock(&sunplus_console_ports[co->index]->port.lock);
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+ locked = uart_port_trylock(&sunplus_console_ports[co->index]->port);
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else
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- spin_lock(&sunplus_console_ports[co->index]->port.lock);
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+ uart_port_lock(&sunplus_console_ports[co->index]->port);
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uart_console_write(&sunplus_console_ports[co->index]->port, s, count,
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sunplus_uart_console_putchar);
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if (locked)
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- spin_unlock(&sunplus_console_ports[co->index]->port.lock);
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+ uart_port_unlock(&sunplus_console_ports[co->index]->port);
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local_irq_restore(flags);
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}
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