From 750bc1d0a093645df37e9e53c963309fa06b5d55 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Thu, 14 Sep 2023 20:43:46 +0206 Subject: [PATCH 055/204] serial: imx: 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/20230914183831.587273-30-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/imx.c | 84 +++++++++++++++++++++++------------------------ 1 file changed, 42 insertions(+), 42 deletions(-) Index: linux-6.6.58-rt45/drivers/tty/serial/imx.c =================================================================== @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:589 @ static void imx_uart_dma_tx_callback(voi unsigned long flags; u32 ucr1; - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE); @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:614 @ static void imx_uart_dma_tx_callback(voi imx_uart_writel(sport, ucr4, UCR4); } - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); } /* called with port.lock taken and irqs off */ @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:800 @ static irqreturn_t imx_uart_rtsint(int i struct imx_port *sport = dev_id; irqreturn_t ret; - spin_lock(&sport->port.lock); + uart_port_lock(&sport->port); ret = __imx_uart_rtsint(irq, dev_id); - spin_unlock(&sport->port.lock); + uart_port_unlock(&sport->port); return ret; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:813 @ static irqreturn_t imx_uart_txint(int ir { struct imx_port *sport = dev_id; - spin_lock(&sport->port.lock); + uart_port_lock(&sport->port); imx_uart_transmit_buffer(sport); - spin_unlock(&sport->port.lock); + uart_port_unlock(&sport->port); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:929 @ static irqreturn_t imx_uart_rxint(int ir struct imx_port *sport = dev_id; irqreturn_t ret; - spin_lock(&sport->port.lock); + uart_port_lock(&sport->port); ret = __imx_uart_rxint(irq, dev_id); - spin_unlock(&sport->port.lock); + uart_port_unlock(&sport->port); return ret; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:996 @ static irqreturn_t imx_uart_int(int irq, unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4; irqreturn_t ret = IRQ_NONE; - spin_lock(&sport->port.lock); + uart_port_lock(&sport->port); usr1 = imx_uart_readl(sport, USR1); usr2 = imx_uart_readl(sport, USR2); @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1066 @ static irqreturn_t imx_uart_int(int irq, ret = IRQ_HANDLED; } - spin_unlock(&sport->port.lock); + uart_port_unlock(&sport->port); return ret; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1149 @ static void imx_uart_break_ctl(struct ua unsigned long flags; u32 ucr1; - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK; @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1158 @ static void imx_uart_break_ctl(struct ua imx_uart_writel(sport, ucr1, UCR1); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); } /* @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1171 @ static void imx_uart_timeout(struct time unsigned long flags; if (sport->port.state) { - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); imx_uart_mctrl_check(sport); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT); } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1203 @ static void imx_uart_dma_rx_callback(voi status = dmaengine_tx_status(chan, sport->rx_cookie, &state); if (status == DMA_ERROR) { - spin_lock(&sport->port.lock); + uart_port_lock(&sport->port); imx_uart_clear_rx_errors(sport); - spin_unlock(&sport->port.lock); + uart_port_unlock(&sport->port); return; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1234 @ static void imx_uart_dma_rx_callback(voi r_bytes = rx_ring->head - rx_ring->tail; /* If we received something, check for 0xff flood */ - spin_lock(&sport->port.lock); + uart_port_lock(&sport->port); imx_uart_check_flood(sport, imx_uart_readl(sport, USR2)); - spin_unlock(&sport->port.lock); + uart_port_unlock(&sport->port); if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) { @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1494 @ static int imx_uart_startup(struct uart_ if (!uart_console(port) && imx_uart_dma_init(sport) == 0) dma_is_inited = 1; - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); /* Reset fifo's and state machines */ imx_uart_soft_reset(sport); @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1567 @ static int imx_uart_startup(struct uart_ imx_uart_disable_loopback_rs485(sport); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); return 0; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1592 @ static void imx_uart_shutdown(struct uar sport->dma_is_rxing = 0; } - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); imx_uart_stop_tx(port); imx_uart_stop_rx(port); imx_uart_disable_dma(sport); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); imx_uart_dma_exit(sport); } mctrl_gpio_disable_ms(sport->gpios); - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); ucr2 = imx_uart_readl(sport, UCR2); ucr2 &= ~(UCR2_TXEN | UCR2_ATEN); imx_uart_writel(sport, ucr2, UCR2); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); /* * Stop our timer. @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1617 @ static void imx_uart_shutdown(struct uar * Disable all interrupts, port and break condition. */ - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); ucr1 = imx_uart_readl(sport, UCR1); ucr1 &= ~(UCR1_TRDYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_RXDMAEN | @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1639 @ static void imx_uart_shutdown(struct uar ucr4 &= ~UCR4_TCEN; imx_uart_writel(sport, ucr4, UCR4); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); clk_disable_unprepare(sport->clk_per); clk_disable_unprepare(sport->clk_ipg); @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1702 @ imx_uart_set_termios(struct uart_port *p baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16); quot = uart_get_divisor(port, baud); - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); /* * Read current UCR2 and save it for future use, then clear all the bits @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1830 @ imx_uart_set_termios(struct uart_port *p if (UART_ENABLE_MS(&sport->port, termios->c_cflag)) imx_uart_enable_ms(&sport->port); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); } static const char *imx_uart_type(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1892 @ static int imx_uart_poll_init(struct uar imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT); - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); /* * Be careful about the order of enabling bits here. First enable the @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:1920 @ static int imx_uart_poll_init(struct uar imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1); imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); return 0; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2040 @ imx_uart_console_write(struct console *c if (sport->port.sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock_irqsave(&sport->port.lock, flags); + locked = uart_port_trylock_irqsave(&sport->port, &flags); else - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); /* * First, save UCR1/2/3 and then disable interrupts @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2070 @ imx_uart_console_write(struct console *c imx_uart_ucrs_restore(sport, &old_ucr); if (locked) - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); } /* @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2228 @ static enum hrtimer_restart imx_trigger_ struct imx_port *sport = container_of(t, struct imx_port, trigger_start_tx); unsigned long flags; - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); if (sport->tx_state == WAIT_AFTER_RTS) imx_uart_start_tx(&sport->port); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); return HRTIMER_NORESTART; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2241 @ static enum hrtimer_restart imx_trigger_ struct imx_port *sport = container_of(t, struct imx_port, trigger_stop_tx); unsigned long flags; - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); if (sport->tx_state == WAIT_AFTER_SEND) imx_uart_stop_tx(&sport->port); - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); return HRTIMER_NORESTART; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2511 @ static void imx_uart_restore_context(str { unsigned long flags; - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); if (!sport->context_saved) { - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); return; } @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2528 @ static void imx_uart_restore_context(str imx_uart_writel(sport, sport->saved_reg[2], UCR3); imx_uart_writel(sport, sport->saved_reg[3], UCR4); sport->context_saved = false; - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); } static void imx_uart_save_context(struct imx_port *sport) @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2536 @ static void imx_uart_save_context(struct unsigned long flags; /* Save necessary regs */ - spin_lock_irqsave(&sport->port.lock, flags); + uart_port_lock_irqsave(&sport->port, &flags); sport->saved_reg[0] = imx_uart_readl(sport, UCR1); sport->saved_reg[1] = imx_uart_readl(sport, UCR2); sport->saved_reg[2] = imx_uart_readl(sport, UCR3); @ linux-6.6.58-rt45/drivers/tty/serial/imx.c:2548 @ static void imx_uart_save_context(struct sport->saved_reg[8] = imx_uart_readl(sport, UBMR); sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS); sport->context_saved = true; - spin_unlock_irqrestore(&sport->port.lock, flags); + uart_port_unlock_irqrestore(&sport->port, flags); } static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)