diff options
Diffstat (limited to '')
-rw-r--r-- | debian/patches-rt/0057-serial-core-Use-port-lock-wrappers.patch | 365 |
1 files changed, 365 insertions, 0 deletions
diff --git a/debian/patches-rt/0057-serial-core-Use-port-lock-wrappers.patch b/debian/patches-rt/0057-serial-core-Use-port-lock-wrappers.patch new file mode 100644 index 0000000000..33c2703827 --- /dev/null +++ b/debian/patches-rt/0057-serial-core-Use-port-lock-wrappers.patch @@ -0,0 +1,365 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:14 +0206 +Subject: [PATCH 057/134] serial: core: 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/20230914183831.587273-58-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/serial_core.c | 92 +++++++++++++++++++-------------------- + drivers/tty/serial/serial_port.c | 4 - + 2 files changed, 48 insertions(+), 48 deletions(-) + +--- a/drivers/tty/serial/serial_core.c ++++ b/drivers/tty/serial/serial_core.c +@@ -79,7 +79,7 @@ + ({ \ + struct uart_port *__uport = uart_port_ref(state); \ + if (__uport) \ +- spin_lock_irqsave(&__uport->lock, flags); \ ++ uart_port_lock_irqsave(__uport, &flags); \ + __uport; \ + }) + +@@ -87,7 +87,7 @@ + ({ \ + struct uart_port *__uport = uport; \ + if (__uport) { \ +- spin_unlock_irqrestore(&__uport->lock, flags); \ ++ uart_port_unlock_irqrestore(__uport, flags); \ + uart_port_deref(__uport); \ + } \ + }) +@@ -179,12 +179,12 @@ + unsigned long flags; + unsigned int old; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + old = port->mctrl; + port->mctrl = (old & ~clear) | set; + if (old != port->mctrl && !(port->rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + + #define uart_set_mctrl(port, set) uart_update_mctrl(port, set, 0) +@@ -219,7 +219,7 @@ + /* + * Set modem status enables based on termios cflag + */ +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + if (termios->c_cflag & CRTSCTS) + uport->status |= UPSTAT_CTS_ENABLE; + else +@@ -240,7 +240,7 @@ + else + __uart_start(state); + } +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + } + + /* +@@ -702,11 +702,11 @@ + if (port->ops->send_xchar) + port->ops->send_xchar(port, ch); + else { +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + port->x_char = ch; + if (ch) + port->ops->start_tx(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + } + uart_port_deref(port); + } +@@ -1085,9 +1085,9 @@ + + if (!tty_io_error(tty)) { + result = uport->mctrl; +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + result |= uport->ops->get_mctrl(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + } + out: + mutex_unlock(&port->mutex); +@@ -1223,16 +1223,16 @@ + uport = uart_port_ref(state); + if (!uport) + return -EIO; +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + memcpy(&cprev, &uport->icount, sizeof(struct uart_icount)); + uart_enable_ms(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + + add_wait_queue(&port->delta_msr_wait, &wait); + for (;;) { +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + + set_current_state(TASK_INTERRUPTIBLE); + +@@ -1277,9 +1277,9 @@ + uport = uart_port_ref(state); + if (!uport) + return -EIO; +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + memcpy(&cnow, &uport->icount, sizeof(struct uart_icount)); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + uart_port_deref(uport); + + icount->cts = cnow.cts; +@@ -1432,9 +1432,9 @@ + uart_set_rs485_termination(port, rs485); + uart_set_rs485_rx_during_tx(port, rs485); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + ret = port->rs485_config(port, NULL, rs485); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + if (ret) { + memset(rs485, 0, sizeof(*rs485)); + /* unset GPIOs */ +@@ -1451,9 +1451,9 @@ + unsigned long flags; + struct serial_rs485 aux; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + aux = port->rs485; +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + if (copy_to_user(rs485, &aux, sizeof(aux))) + return -EFAULT; +@@ -1481,7 +1481,7 @@ + uart_set_rs485_termination(port, &rs485); + uart_set_rs485_rx_during_tx(port, &rs485); + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + ret = port->rs485_config(port, &tty->termios, &rs485); + if (!ret) { + port->rs485 = rs485; +@@ -1490,7 +1490,7 @@ + if (!(rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); + } +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + if (ret) { + /* restore old GPIO settings */ + gpiod_set_value_cansleep(port->rs485_term_gpio, +@@ -1515,9 +1515,9 @@ + if (!port->iso7816_config) + return -ENOTTY; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + aux = port->iso7816; +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + if (copy_to_user(iso7816, &aux, sizeof(aux))) + return -EFAULT; +@@ -1546,9 +1546,9 @@ + if (iso7816.reserved[i]) + return -EINVAL; + +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + ret = port->iso7816_config(port, &iso7816); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + if (ret) + return ret; + +@@ -1765,9 +1765,9 @@ + if (WARN(!uport, "detached port still initialized!\n")) + return; + +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + uport->ops->stop_rx(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + + uart_port_shutdown(port); + +@@ -1781,10 +1781,10 @@ + /* + * Free the transmit buffer. + */ +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + buf = state->xmit.buf; + state->xmit.buf = NULL; +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + + free_page((unsigned long)buf); + +@@ -1927,10 +1927,10 @@ + */ + if (WARN_ON(!uport)) + return true; +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + uart_enable_ms(uport); + mctrl = uport->ops->get_mctrl(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + uart_port_deref(uport); + + return mctrl & TIOCM_CAR; +@@ -2047,9 +2047,9 @@ + pm_state = state->pm_state; + if (pm_state != UART_PM_STATE_ON) + uart_change_pm(state, UART_PM_STATE_ON); +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + status = uport->ops->get_mctrl(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + if (pm_state != UART_PM_STATE_ON) + uart_change_pm(state, pm_state); + +@@ -2388,9 +2388,9 @@ + */ + if (!console_suspend_enabled && uart_console(uport)) { + if (uport->ops->start_rx) { +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + uport->ops->stop_rx(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + } + goto unlock; + } +@@ -2405,7 +2405,7 @@ + tty_port_set_suspended(port, true); + tty_port_set_initialized(port, false); + +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + ops->stop_tx(uport); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, 0); +@@ -2413,7 +2413,7 @@ + mctrl = uport->mctrl; + uport->mctrl = 0; + ops->stop_rx(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + + /* + * Wait for the transmitter to empty. +@@ -2485,9 +2485,9 @@ + uart_change_pm(state, UART_PM_STATE_ON); + uport->ops->set_termios(uport, &termios, NULL); + if (!console_suspend_enabled && uport->ops->start_rx) { +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + uport->ops->start_rx(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + } + if (console_suspend_enabled) + console_start(uport->cons); +@@ -2498,10 +2498,10 @@ + int ret; + + uart_change_pm(state, UART_PM_STATE_ON); +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, 0); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + if (console_suspend_enabled || !uart_console(uport)) { + /* Protected by port mutex for now */ + struct tty_struct *tty = port->tty; +@@ -2511,11 +2511,11 @@ + if (tty) + uart_change_line_settings(tty, state, NULL); + uart_rs485_config(uport); +- spin_lock_irq(&uport->lock); ++ uart_port_lock_irq(uport); + if (!(uport->rs485.flags & SER_RS485_ENABLED)) + ops->set_mctrl(uport, uport->mctrl); + ops->start_tx(uport); +- spin_unlock_irq(&uport->lock); ++ uart_port_unlock_irq(uport); + tty_port_set_initialized(port, true); + } else { + /* +@@ -2618,11 +2618,11 @@ + * keep the DTR setting that is set in uart_set_options() + * We probably don't need a spinlock around this, but + */ +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + port->mctrl &= TIOCM_DTR; + if (!(port->rs485.flags & SER_RS485_ENABLED)) + port->ops->set_mctrl(port, port->mctrl); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + uart_rs485_config(port); + +--- a/drivers/tty/serial/serial_port.c ++++ b/drivers/tty/serial/serial_port.c +@@ -35,10 +35,10 @@ + goto out; + + /* Flush any pending TX for the port */ +- spin_lock_irqsave(&port->lock, flags); ++ uart_port_lock_irqsave(port, &flags); + if (__serial_port_busy(port)) + port->ops->start_tx(port); +- spin_unlock_irqrestore(&port->lock, flags); ++ uart_port_unlock_irqrestore(port, flags); + + out: + pm_runtime_mark_last_busy(dev); |