diff options
Diffstat (limited to 'debian/patches-rt/0030-serial-ip22zilog-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0030-serial-ip22zilog-Use-port-lock-wrappers.patch | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/debian/patches-rt/0030-serial-ip22zilog-Use-port-lock-wrappers.patch b/debian/patches-rt/0030-serial-ip22zilog-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..c1307a246b --- /dev/null +++ b/debian/patches-rt/0030-serial-ip22zilog-Use-port-lock-wrappers.patch @@ -0,0 +1,185 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:47 +0206 +Subject: [PATCH 030/134] serial: ip22zilog: Use port lock wrappers +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +When a serial port is used for kernel console output, then all +modifications to the UART registers which are done from other contexts, +e.g. getty, termios, are interference points for the kernel console. + +So far this has been ignored and the printk output is based on the +principle of hope. The rework of the console infrastructure which aims to +support threaded and atomic consoles, requires to mark sections which +modify the UART registers as unsafe. This allows the atomic write function +to make informed decisions and eventually to restore operational state. It +also allows to prevent the regular UART code from modifying UART registers +while printk output is in progress. + +All modifications of UART registers are guarded by the UART port lock, +which provides an obvious synchronization point with the console +infrastructure. + +To avoid adding this functionality to all UART drivers, wrap the +spin_[un]lock*() invocations for uart_port::lock into helper functions +which just contain the spin_[un]lock*() invocations for now. In a +subsequent step these helpers will gain the console synchronization +mechanisms. + +Converted with coccinelle. No functional change. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-31-john.ogness@linutronix.de +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/ip22zilog.c | 36 ++++++++++++++++++------------------ + 1 file changed, 18 insertions(+), 18 deletions(-) + +--- a/drivers/tty/serial/ip22zilog.c ++++ b/drivers/tty/serial/ip22zilog.c +@@ -432,7 +432,7 @@ static irqreturn_t ip22zilog_interrupt(i + unsigned char r3; + bool push = false; + +- spin_lock(&up->port.lock); ++ uart_port_lock(&up->port); + r3 = read_zsreg(channel, R3); + + /* Channel A */ +@@ -448,7 +448,7 @@ static irqreturn_t ip22zilog_interrupt(i + if (r3 & CHATxIP) + ip22zilog_transmit_chars(up, channel); + } +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + + if (push) + tty_flip_buffer_push(&up->port.state->port); +@@ -458,7 +458,7 @@ static irqreturn_t ip22zilog_interrupt(i + channel = ZILOG_CHANNEL_FROM_PORT(&up->port); + push = false; + +- spin_lock(&up->port.lock); ++ uart_port_lock(&up->port); + if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) { + writeb(RES_H_IUS, &channel->control); + ZSDELAY(); +@@ -471,7 +471,7 @@ static irqreturn_t ip22zilog_interrupt(i + if (r3 & CHBTxIP) + ip22zilog_transmit_chars(up, channel); + } +- spin_unlock(&up->port.lock); ++ uart_port_unlock(&up->port); + + if (push) + tty_flip_buffer_push(&up->port.state->port); +@@ -504,11 +504,11 @@ static unsigned int ip22zilog_tx_empty(s + unsigned char status; + unsigned int ret; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + status = ip22zilog_read_channel_status(port); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + if (status & Tx_BUF_EMP) + ret = TIOCSER_TEMT; +@@ -664,7 +664,7 @@ static void ip22zilog_break_ctl(struct u + else + clear_bits |= SND_BRK; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + new_reg = (up->curregs[R5] | set_bits) & ~clear_bits; + if (new_reg != up->curregs[R5]) { +@@ -674,7 +674,7 @@ static void ip22zilog_break_ctl(struct u + write_zsreg(channel, R5, up->curregs[R5]); + } + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + static void __ip22zilog_reset(struct uart_ip22zilog_port *up) +@@ -735,9 +735,9 @@ static int ip22zilog_startup(struct uart + if (ZS_IS_CONS(up)) + return 0; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + __ip22zilog_startup(up); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + return 0; + } + +@@ -775,7 +775,7 @@ static void ip22zilog_shutdown(struct ua + if (ZS_IS_CONS(up)) + return; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + + channel = ZILOG_CHANNEL_FROM_PORT(port); + +@@ -788,7 +788,7 @@ static void ip22zilog_shutdown(struct ua + up->curregs[R5] &= ~SND_BRK; + ip22zilog_maybe_update_regs(up, channel); + +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + /* Shared by TTY driver and serial console setup. The port lock is held +@@ -880,7 +880,7 @@ ip22zilog_set_termios(struct uart_port * + + baud = uart_get_baud_rate(port, termios, old, 1200, 76800); + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + brg = BPS_TO_BRG(baud, ZS_CLOCK / ZS_CLOCK_DIVISOR); + +@@ -894,7 +894,7 @@ ip22zilog_set_termios(struct uart_port * + ip22zilog_maybe_update_regs(up, ZILOG_CHANNEL_FROM_PORT(port)); + uart_update_timeout(port, termios->c_cflag, baud); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static const char *ip22zilog_type(struct uart_port *port) +@@ -1016,10 +1016,10 @@ ip22zilog_console_write(struct console * + struct uart_ip22zilog_port *up = &ip22zilog_port_table[con->index]; + unsigned long flags; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + uart_console_write(&up->port, s, count, ip22zilog_put_char); + udelay(2); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static int __init ip22zilog_console_setup(struct console *con, char *options) +@@ -1034,13 +1034,13 @@ static int __init ip22zilog_console_setu + + printk(KERN_INFO "Console: ttyS%d (IP22-Zilog)\n", con->index); + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + up->curregs[R15] |= BRKIE; + + __ip22zilog_startup(up); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); |