184 lines
6.9 KiB
Diff
184 lines
6.9 KiB
Diff
From: Thomas Gleixner <tglx@linutronix.de>
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Date: Thu, 14 Sep 2023 20:44:21 +0206
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Subject: [PATCH 064/134] serial: stm32: 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/20230914183831.587273-65-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/stm32-usart.c | 38 +++++++++++++++++++-------------------
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1 file changed, 19 insertions(+), 19 deletions(-)
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--- a/drivers/tty/serial/stm32-usart.c
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+++ b/drivers/tty/serial/stm32-usart.c
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@@ -537,7 +537,7 @@ static void stm32_usart_rx_dma_complete(
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unsigned int size;
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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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size = stm32_usart_receive_chars(port, false);
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uart_unlock_and_check_sysrq_irqrestore(port, flags);
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if (size)
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@@ -643,9 +643,9 @@ static void stm32_usart_tx_dma_complete(
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stm32_usart_tx_dma_terminate(stm32port);
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/* Let's see if we have pending data to send */
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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stm32_usart_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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}
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static void stm32_usart_tx_interrupt_enable(struct uart_port *port)
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@@ -889,7 +889,7 @@ static irqreturn_t stm32_usart_interrupt
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if (!stm32_port->throttled) {
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if (((sr & USART_SR_RXNE) && !stm32_usart_rx_dma_started(stm32_port)) ||
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((sr & USART_SR_ERR_MASK) && stm32_usart_rx_dma_started(stm32_port))) {
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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size = stm32_usart_receive_chars(port, false);
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uart_unlock_and_check_sysrq(port);
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if (size)
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@@ -898,14 +898,14 @@ static irqreturn_t stm32_usart_interrupt
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}
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if ((sr & USART_SR_TXE) && !(stm32_port->tx_ch)) {
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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stm32_usart_transmit_chars(port);
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- spin_unlock(&port->lock);
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+ uart_port_unlock(port);
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}
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/* Receiver timeout irq for DMA RX */
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if (stm32_usart_rx_dma_started(stm32_port) && !stm32_port->throttled) {
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- spin_lock(&port->lock);
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+ uart_port_lock(port);
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size = stm32_usart_receive_chars(port, false);
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uart_unlock_and_check_sysrq(port);
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if (size)
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@@ -993,7 +993,7 @@ static void stm32_usart_throttle(struct
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const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
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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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/*
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* Pause DMA transfer, so the RX data gets queued into the FIFO.
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@@ -1006,7 +1006,7 @@ static void stm32_usart_throttle(struct
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stm32_usart_clr_bits(port, ofs->cr3, stm32_port->cr3_irq);
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stm32_port->throttled = true;
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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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/* Unthrottle the remote, the input buffer can now accept data. */
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@@ -1016,7 +1016,7 @@ static void stm32_usart_unthrottle(struc
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const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
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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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stm32_usart_set_bits(port, ofs->cr1, stm32_port->cr1_irq);
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if (stm32_port->cr3_irq)
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stm32_usart_set_bits(port, ofs->cr3, stm32_port->cr3_irq);
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@@ -1030,7 +1030,7 @@ static void stm32_usart_unthrottle(struc
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if (stm32_port->rx_ch)
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stm32_usart_rx_dma_start_or_resume(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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}
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/* Receive stop */
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@@ -1158,7 +1158,7 @@ static void stm32_usart_set_termios(stru
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baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 8);
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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ret = readl_relaxed_poll_timeout_atomic(port->membase + ofs->isr,
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isr,
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@@ -1349,7 +1349,7 @@ static void stm32_usart_set_termios(stru
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writel_relaxed(cr1, port->membase + ofs->cr1);
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stm32_usart_set_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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/* Handle modem control interrupts */
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if (UART_ENABLE_MS(port, termios->c_cflag))
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@@ -1399,9 +1399,9 @@ static void stm32_usart_pm(struct uart_p
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pm_runtime_get_sync(port->dev);
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break;
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case UART_PM_STATE_OFF:
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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stm32_usart_clr_bits(port, ofs->cr1, BIT(cfg->uart_enable_bit));
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- spin_unlock_irqrestore(&port->lock, flags);
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+ uart_port_unlock_irqrestore(port, flags);
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pm_runtime_put_sync(port->dev);
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break;
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}
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@@ -1884,9 +1884,9 @@ static void stm32_usart_console_write(st
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int locked = 1;
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if (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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/* Save and disable interrupts, enable the transmitter */
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old_cr1 = readl_relaxed(port->membase + ofs->cr1);
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@@ -1900,7 +1900,7 @@ static void stm32_usart_console_write(st
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writel_relaxed(old_cr1, port->membase + ofs->cr1);
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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 int stm32_usart_console_setup(struct console *co, char *options)
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@@ -2035,7 +2035,7 @@ static int __maybe_unused stm32_usart_se
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* low-power mode.
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*/
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if (stm32_port->rx_ch) {
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- spin_lock_irqsave(&port->lock, flags);
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+ uart_port_lock_irqsave(port, &flags);
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/* Poll data from DMA RX buffer if any */
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if (!stm32_usart_rx_dma_pause(stm32_port))
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size += stm32_usart_receive_chars(port, true);
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