From 83f8182725ea2cc467daf42dd5394bed7229e548 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Thu, 14 Sep 2023 20:44:10 +0206 Subject: [PATCH 079/204] serial: samsung_tty: 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/20230914183831.587273-54-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/samsung_tty.c | 50 +++++++++++++++++++-------------------- 1 file changed, 25 insertions(+), 25 deletions(-) Index: linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c =================================================================== @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:251 @ static void s3c24xx_serial_rx_enable(str unsigned int ucon, ufcon; int count = 10000; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); while (--count && !s3c24xx_serial_txempty_nofifo(port)) udelay(100); @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:265 @ static void s3c24xx_serial_rx_enable(str wr_regl(port, S3C2410_UCON, ucon); ourport->rx_enabled = 1; - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void s3c24xx_serial_rx_disable(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:274 @ static void s3c24xx_serial_rx_disable(st unsigned long flags; unsigned int ucon; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ucon = rd_regl(port, S3C2410_UCON); ucon &= ~S3C2410_UCON_RXIRQMODE; wr_regl(port, S3C2410_UCON, ucon); ourport->rx_enabled = 0; - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void s3c24xx_serial_stop_tx(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:347 @ static void s3c24xx_serial_tx_dma_comple dma->tx_transfer_addr, dma->tx_size, DMA_TO_DEVICE); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); uart_xmit_advance(port, count); ourport->tx_in_progress = 0; @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:356 @ static void s3c24xx_serial_tx_dma_comple uart_write_wakeup(port); s3c24xx_serial_start_next_tx(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void enable_tx_dma(struct s3c24xx_uart_port *ourport) @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:622 @ static void s3c24xx_serial_rx_dma_comple received = dma->rx_bytes_requested - state.residue; async_tx_ack(dma->rx_desc); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); if (received) s3c24xx_uart_copy_rx_to_tty(ourport, t, received); @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:634 @ static void s3c24xx_serial_rx_dma_comple s3c64xx_start_rx_dma(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void s3c64xx_start_rx_dma(struct s3c24xx_uart_port *ourport) @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:725 @ static irqreturn_t s3c24xx_serial_rx_cha utrstat = rd_regl(port, S3C2410_UTRSTAT); rd_regl(port, S3C2410_UFSTAT); - spin_lock(&port->lock); + uart_port_lock(port); if (!(utrstat & S3C2410_UTRSTAT_TIMEOUT)) { s3c64xx_start_rx_dma(ourport); @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:754 @ static irqreturn_t s3c24xx_serial_rx_cha wr_regl(port, S3C2410_UTRSTAT, S3C2410_UTRSTAT_TIMEOUT); finish: - spin_unlock(&port->lock); + uart_port_unlock(port); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:852 @ static irqreturn_t s3c24xx_serial_rx_cha struct s3c24xx_uart_port *ourport = dev_id; struct uart_port *port = &ourport->port; - spin_lock(&port->lock); + uart_port_lock(port); s3c24xx_serial_rx_drain_fifo(ourport); - spin_unlock(&port->lock); + uart_port_unlock(port); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:935 @ static irqreturn_t s3c24xx_serial_tx_irq struct s3c24xx_uart_port *ourport = id; struct uart_port *port = &ourport->port; - spin_lock(&port->lock); + uart_port_lock(port); s3c24xx_serial_tx_chars(ourport); - spin_unlock(&port->lock); + uart_port_unlock(port); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1035 @ static void s3c24xx_serial_break_ctl(str unsigned long flags; unsigned int ucon; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ucon = rd_regl(port, S3C2410_UCON); @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1046 @ static void s3c24xx_serial_break_ctl(str wr_regl(port, S3C2410_UCON, ucon); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1305 @ static int s3c64xx_serial_startup(struct ourport->rx_enabled = 1; ourport->tx_enabled = 0; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ufcon = rd_regl(port, S3C2410_UFCON); ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8; @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1315 @ static int s3c64xx_serial_startup(struct enable_rx_pio(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); /* Enable Rx Interrupt */ s3c24xx_clear_bit(port, S3C64XX_UINTM_RXD, S3C64XX_UINTM); @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1343 @ static int apple_s5l_serial_startup(stru ourport->rx_enabled = 1; ourport->tx_enabled = 0; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); ufcon = rd_regl(port, S3C2410_UFCON); ufcon |= S3C2410_UFCON_RESETRX | S5PV210_UFCON_RXTRIG8; @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1353 @ static int apple_s5l_serial_startup(stru enable_rx_pio(ourport); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); /* Enable Rx Interrupt */ s3c24xx_set_bit(port, APPLE_S5L_UCON_RXTHRESH_ENA, S3C2410_UCON); @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1628 @ static void s3c24xx_serial_set_termios(s ulcon |= S3C2410_LCON_PNONE; } - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); dev_dbg(port->dev, "setting ulcon to %08x, brddiv to %d, udivslot %08x\n", @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:1686 @ static void s3c24xx_serial_set_termios(s if ((termios->c_cflag & CREAD) == 0) port->ignore_status_mask |= RXSTAT_DUMMY_READ; - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static const char *s3c24xx_serial_type(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/samsung_tty.c:2378 @ s3c24xx_serial_console_write(struct cons if (cons_uart->sysrq) locked = false; else if (oops_in_progress) - locked = spin_trylock_irqsave(&cons_uart->lock, flags); + locked = uart_port_trylock_irqsave(cons_uart, &flags); else - spin_lock_irqsave(&cons_uart->lock, flags); + uart_port_lock_irqsave(cons_uart, &flags); uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar); if (locked) - spin_unlock_irqrestore(&cons_uart->lock, flags); + uart_port_unlock_irqrestore(cons_uart, flags); } /* Shouldn't be __init, as it can be instantiated from other module */