From 6db3240aa133b6ad9287c13c85e67b591422b9c7 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Thu, 14 Sep 2023 20:44:17 +0206 Subject: [PATCH 086/204] serial: sh-sci: Use port lock wrappers 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/20230914183831.587273-61-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/sh-sci.c | 68 ++++++++++++++++++++++---------------------- 1 file changed, 34 insertions(+), 34 deletions(-) Index: linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c =================================================================== @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1208 @ static void sci_dma_tx_complete(void *ar dev_dbg(port->dev, "%s(%d)\n", __func__, port->line); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); uart_xmit_advance(port, s->tx_dma_len); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1232 @ static void sci_dma_tx_complete(void *ar } } - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } /* Locking: called with port lock held */ @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1328 @ static void sci_dma_rx_complete(void *ar dev_dbg(port->dev, "%s(%d) active cookie %d\n", __func__, port->line, s->active_rx); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); active = sci_dma_rx_find_active(s); if (active >= 0) @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1355 @ static void sci_dma_rx_complete(void *ar dma_async_issue_pending(chan); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); dev_dbg(port->dev, "%s: cookie %d #%d, new active cookie %d\n", __func__, s->cookie_rx[active], active, s->active_rx); return; fail: - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n"); /* Switch to PIO */ - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); dmaengine_terminate_async(chan); sci_dma_rx_chan_invalidate(s); sci_dma_rx_reenable_irq(s); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void sci_dma_tx_release(struct sci_port *s) @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1417 @ static int sci_dma_rx_submit(struct sci_ fail: /* Switch to PIO */ if (!port_lock_held) - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); if (i) dmaengine_terminate_async(chan); sci_dma_rx_chan_invalidate(s); sci_start_rx(port); if (!port_lock_held) - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return -EAGAIN; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1445 @ static void sci_dma_tx_work_fn(struct wo * transmit till the end, and then the rest. Take the port lock to get a * consistent xmit buffer state. */ - spin_lock_irq(&port->lock); + uart_port_lock_irq(port); head = xmit->head; tail = xmit->tail; buf = s->tx_dma_addr + tail; s->tx_dma_len = CIRC_CNT_TO_END(head, tail, UART_XMIT_SIZE); if (!s->tx_dma_len) { /* Transmit buffer has been flushed */ - spin_unlock_irq(&port->lock); + uart_port_unlock_irq(port); return; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1460 @ static void sci_dma_tx_work_fn(struct wo DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT | DMA_CTRL_ACK); if (!desc) { - spin_unlock_irq(&port->lock); + uart_port_unlock_irq(port); dev_warn(port->dev, "Failed preparing Tx DMA descriptor\n"); goto switch_to_pio; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1472 @ static void sci_dma_tx_work_fn(struct wo desc->callback_param = s; s->cookie_tx = dmaengine_submit(desc); if (dma_submit_error(s->cookie_tx)) { - spin_unlock_irq(&port->lock); + uart_port_unlock_irq(port); dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n"); goto switch_to_pio; } - spin_unlock_irq(&port->lock); + uart_port_unlock_irq(port); dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__, xmit->buf, tail, head, s->cookie_tx); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1485 @ static void sci_dma_tx_work_fn(struct wo return; switch_to_pio: - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); s->chan_tx = NULL; sci_start_tx(port); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1505 @ static enum hrtimer_restart sci_dma_rx_t dev_dbg(port->dev, "DMA Rx timed out\n"); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); active = sci_dma_rx_find_active(s); if (active < 0) { - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return HRTIMER_NORESTART; } status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state); if (status == DMA_COMPLETE) { - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); dev_dbg(port->dev, "Cookie %d #%d has already completed\n", s->active_rx, active); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1533 @ static enum hrtimer_restart sci_dma_rx_t */ status = dmaengine_tx_status(s->chan_rx, s->active_rx, &state); if (status == DMA_COMPLETE) { - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); dev_dbg(port->dev, "Transaction complete after DMA engine was stopped"); return HRTIMER_NORESTART; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1554 @ static enum hrtimer_restart sci_dma_rx_t sci_dma_rx_reenable_irq(s); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return HRTIMER_NORESTART; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1778 @ static irqreturn_t sci_tx_interrupt(int struct uart_port *port = ptr; unsigned long flags; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); sci_transmit_chars(port); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:1794 @ static irqreturn_t sci_tx_end_interrupt( if (port->type != PORT_SCI) return sci_tx_interrupt(irq, ptr); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ctrl = serial_port_in(port, SCSCR); ctrl &= ~(SCSCR_TE | SCSCR_TEIE); serial_port_out(port, SCSCR, ctrl); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:2195 @ static void sci_break_ctl(struct uart_po return; } - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); scsptr = serial_port_in(port, SCSPTR); scscr = serial_port_in(port, SCSCR); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:2209 @ static void sci_break_ctl(struct uart_po serial_port_out(port, SCSPTR, scsptr); serial_port_out(port, SCSCR, scscr); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static int sci_startup(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:2241 @ static void sci_shutdown(struct uart_por s->autorts = false; mctrl_gpio_disable_ms(to_sci_port(port)->gpios); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); sci_stop_rx(port); sci_stop_tx(port); /* @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:2251 @ static void sci_shutdown(struct uart_por scr = serial_port_in(port, SCSCR); serial_port_out(port, SCSCR, scr & (SCSCR_CKE1 | SCSCR_CKE0 | s->hscif_tot)); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); #ifdef CONFIG_SERIAL_SH_SCI_DMA if (s->chan_rx_saved) { @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:2553 @ done: serial_port_out(port, SCCKS, sccks); } - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); sci_reset(port); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:2675 @ done: if ((termios->c_cflag & CREAD) != 0) sci_start_rx(port); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); sci_port_disable(s); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:3060 @ static void serial_console_write(struct if (port->sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock_irqsave(&port->lock, flags); + locked = uart_port_trylock_irqsave(port, &flags); else - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); /* first save SCSCR then disable interrupts, keep clock source */ ctrl = serial_port_in(port, SCSCR); @ linux-6.6.58-rt45/drivers/tty/serial/sh-sci.c:3082 @ static void serial_console_write(struct serial_port_out(port, SCSCR, ctrl); if (locked) - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static int serial_console_setup(struct console *co, char *options)