149 lines
4.9 KiB
Diff
149 lines
4.9 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:44:22 +0206
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Subject: [PATCH 065/134] serial: sunhv: 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/20230914183831.587273-66-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/sunhv.c | 28 ++++++++++++++--------------
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1 file changed, 14 insertions(+), 14 deletions(-)
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--- a/drivers/tty/serial/sunhv.c
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+++ b/drivers/tty/serial/sunhv.c
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@@ -217,10 +217,10 @@ static irqreturn_t sunhv_interrupt(int i
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struct tty_port *tport;
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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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tport = receive_chars(port);
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transmit_chars(port);
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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 (tport)
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tty_flip_buffer_push(tport);
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@@ -271,7 +271,7 @@ static void sunhv_send_xchar(struct uart
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if (ch == __DISABLED_CHAR)
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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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while (limit-- > 0) {
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long status = sun4v_con_putchar(ch);
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@@ -280,7 +280,7 @@ static void sunhv_send_xchar(struct uart
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udelay(1);
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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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/* port->lock held by caller. */
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@@ -295,7 +295,7 @@ static void sunhv_break_ctl(struct uart_
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unsigned long flags;
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int limit = 10000;
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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 (limit-- > 0) {
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long status = sun4v_con_putchar(CON_BREAK);
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@@ -304,7 +304,7 @@ static void sunhv_break_ctl(struct uart_
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udelay(1);
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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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}
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@@ -328,7 +328,7 @@ static void sunhv_set_termios(struct uar
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unsigned int iflag, cflag;
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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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iflag = termios->c_iflag;
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cflag = termios->c_cflag;
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@@ -343,7 +343,7 @@ static void sunhv_set_termios(struct uar
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uart_update_timeout(port, cflag,
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(port->uartclk / (16 * quot)));
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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 *sunhv_type(struct uart_port *port)
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@@ -437,9 +437,9 @@ static void sunhv_console_write_paged(st
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int locked = 1;
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if (port->sysrq || 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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while (n > 0) {
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unsigned long ra = __pa(con_write_page);
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@@ -470,7 +470,7 @@ static void sunhv_console_write_paged(st
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}
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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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}
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static inline void sunhv_console_putchar(struct uart_port *port, char c)
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@@ -492,9 +492,9 @@ static void sunhv_console_write_bychar(s
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int i, locked = 1;
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if (port->sysrq || 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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for (i = 0; i < n; i++) {
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if (*s == '\n')
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@@ -503,7 +503,7 @@ static void sunhv_console_write_bychar(s
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}
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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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}
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static struct console sunhv_console = {
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