185 lines
6.2 KiB
Diff
185 lines
6.2 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:43:47 +0206
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Subject: [PATCH 030/134] serial: ip22zilog: 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/20230914183831.587273-31-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/ip22zilog.c | 36 ++++++++++++++++++------------------
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1 file changed, 18 insertions(+), 18 deletions(-)
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--- a/drivers/tty/serial/ip22zilog.c
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+++ b/drivers/tty/serial/ip22zilog.c
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@@ -432,7 +432,7 @@ static irqreturn_t ip22zilog_interrupt(i
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unsigned char r3;
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bool push = false;
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- spin_lock(&up->port.lock);
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+ uart_port_lock(&up->port);
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r3 = read_zsreg(channel, R3);
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/* Channel A */
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@@ -448,7 +448,7 @@ static irqreturn_t ip22zilog_interrupt(i
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if (r3 & CHATxIP)
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ip22zilog_transmit_chars(up, channel);
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}
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- spin_unlock(&up->port.lock);
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+ uart_port_unlock(&up->port);
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if (push)
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tty_flip_buffer_push(&up->port.state->port);
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@@ -458,7 +458,7 @@ static irqreturn_t ip22zilog_interrupt(i
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channel = ZILOG_CHANNEL_FROM_PORT(&up->port);
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push = false;
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- spin_lock(&up->port.lock);
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+ uart_port_lock(&up->port);
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if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) {
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writeb(RES_H_IUS, &channel->control);
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ZSDELAY();
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@@ -471,7 +471,7 @@ static irqreturn_t ip22zilog_interrupt(i
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if (r3 & CHBTxIP)
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ip22zilog_transmit_chars(up, channel);
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}
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- spin_unlock(&up->port.lock);
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+ uart_port_unlock(&up->port);
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if (push)
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tty_flip_buffer_push(&up->port.state->port);
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@@ -504,11 +504,11 @@ static unsigned int ip22zilog_tx_empty(s
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unsigned char status;
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unsigned int 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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status = ip22zilog_read_channel_status(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 (status & Tx_BUF_EMP)
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ret = TIOCSER_TEMT;
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@@ -664,7 +664,7 @@ static void ip22zilog_break_ctl(struct u
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else
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clear_bits |= SND_BRK;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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new_reg = (up->curregs[R5] | set_bits) & ~clear_bits;
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if (new_reg != up->curregs[R5]) {
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@@ -674,7 +674,7 @@ static void ip22zilog_break_ctl(struct u
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write_zsreg(channel, R5, up->curregs[R5]);
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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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static void __ip22zilog_reset(struct uart_ip22zilog_port *up)
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@@ -735,9 +735,9 @@ static int ip22zilog_startup(struct uart
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if (ZS_IS_CONS(up))
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return 0;
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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__ip22zilog_startup(up);
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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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@@ -775,7 +775,7 @@ static void ip22zilog_shutdown(struct ua
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if (ZS_IS_CONS(up))
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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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channel = ZILOG_CHANNEL_FROM_PORT(port);
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@@ -788,7 +788,7 @@ static void ip22zilog_shutdown(struct ua
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up->curregs[R5] &= ~SND_BRK;
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ip22zilog_maybe_update_regs(up, channel);
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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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/* Shared by TTY driver and serial console setup. The port lock is held
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@@ -880,7 +880,7 @@ ip22zilog_set_termios(struct uart_port *
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baud = uart_get_baud_rate(port, termios, old, 1200, 76800);
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- spin_lock_irqsave(&up->port.lock, flags);
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+ uart_port_lock_irqsave(&up->port, &flags);
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brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR);
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@@ -894,7 +894,7 @@ ip22zilog_set_termios(struct uart_port *
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ip22zilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port));
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uart_update_timeout(port, termios->c_cflag, baud);
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- spin_unlock_irqrestore(&up->port.lock, flags);
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+ uart_port_unlock_irqrestore(&up->port, flags);
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}
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static const char *ip22zilog_type(struct uart_port *port)
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@@ -1016,10 +1016,10 @@ ip22zilog_console_write(struct console *
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struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index];
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unsigned long flags;
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- spin_lock_irqsave(&up->port.lock, flags);
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+ uart_port_lock_irqsave(&up->port, &flags);
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uart_console_write(&up->port, s, count, ip22zilog_put_char);
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udelay(2);
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- spin_unlock_irqrestore(&up->port.lock, flags);
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+ uart_port_unlock_irqrestore(&up->port, flags);
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}
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static int __init ip22zilog_console_setup(struct console *con, char *options)
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@@ -1034,13 +1034,13 @@ static int __init ip22zilog_console_setu
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printk(KERN_INFO "Console: ttyS%d (IP22-Zilog)\n", con->index);
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- spin_lock_irqsave(&up->port.lock, flags);
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+ uart_port_lock_irqsave(&up->port, &flags);
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up->curregs[R15] |= BRKIE;
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__ip22zilog_startup(up);
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- spin_unlock_irqrestore(&up->port.lock, flags);
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+ uart_port_unlock_irqrestore(&up->port, flags);
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if (options)
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uart_parse_options(options, &baud, &parity, &bits, &flow);
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