From 1219b0c667cd0ca6c9385f6fe33bf65aa25d74e4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Thu, 14 Sep 2023 20:44:25 +0206 Subject: [PATCH 094/204] serial: sunsu: 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/20230914183831.587273-69-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/sunsu.c | 46 ++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) Index: linux-6.6.58-rt45/drivers/tty/serial/sunsu.c =================================================================== @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:215 @ static void enable_rsa(struct uart_sunsu { if (up->port.type == PORT_RSA) { if (up->port.uartclk != SERIAL_RSA_BAUD_BASE * 16) { - spin_lock_irq(&up->port.lock); + uart_port_lock_irq(&up->port); __enable_rsa(up); - spin_unlock_irq(&up->port.lock); + uart_port_unlock_irq(&up->port); } if (up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) serial_outp(up, UART_RSA_FRR, 0); @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:237 @ static void disable_rsa(struct uart_suns if (up->port.type == PORT_RSA && up->port.uartclk == SERIAL_RSA_BAUD_BASE * 16) { - spin_lock_irq(&up->port.lock); + uart_port_lock_irq(&up->port); mode = serial_inp(up, UART_RSA_MSR); result = !(mode & UART_RSA_MSR_FIFO); @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:250 @ static void disable_rsa(struct uart_suns if (result) up->port.uartclk = SERIAL_RSA_BAUD_BASE_LO * 16; - spin_unlock_irq(&up->port.lock); + uart_port_unlock_irq(&up->port); } } #endif /* CONFIG_SERIAL_8250_RSA */ @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:314 @ static void sunsu_enable_ms(struct uart_ container_of(port, struct uart_sunsu_port, port); unsigned long flags; - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); up->ier |= UART_IER_MSI; serial_out(up, UART_IER, up->ier); - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); } static void @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:459 @ static irqreturn_t sunsu_serial_interrup unsigned long flags; unsigned char status; - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); do { status = serial_inp(up, UART_LSR); @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:473 @ static irqreturn_t sunsu_serial_interrup } while (!(serial_in(up, UART_IIR) & UART_IIR_NO_INT)); - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); return IRQ_HANDLED; } @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:548 @ static unsigned int sunsu_tx_empty(struc unsigned long flags; unsigned int ret; - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); ret = serial_in(up, UART_LSR) & UART_LSR_TEMT ? TIOCSER_TEMT : 0; - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); return ret; } @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:602 @ static void sunsu_break_ctl(struct uart_ container_of(port, struct uart_sunsu_port, port); unsigned long flags; - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); if (break_state == -1) up->lcr |= UART_LCR_SBC; else up->lcr &= ~UART_LCR_SBC; serial_out(up, UART_LCR, up->lcr); - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); } static int sunsu_startup(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:686 @ static int sunsu_startup(struct uart_por */ serial_outp(up, UART_LCR, UART_LCR_WLEN8); - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); up->port.mctrl |= TIOCM_OUT2; sunsu_set_mctrl(&up->port, up->port.mctrl); - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); /* * Finally, enable interrupts. Note: Modem status interrupts @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:734 @ static void sunsu_shutdown(struct uart_p up->ier = 0; serial_outp(up, UART_IER, 0); - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); if (up->port.flags & UPF_FOURPORT) { /* reset interrupts on the AST Fourport board */ inb((up->port.iobase & 0xfe0) | 0x1f); @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:743 @ static void sunsu_shutdown(struct uart_p up->port.mctrl &= ~TIOCM_OUT2; sunsu_set_mctrl(&up->port, up->port.mctrl); - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); /* * Disable break condition and FIFOs @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:829 @ sunsu_change_speed(struct uart_port *por * Ok, we're now changing the port state. Do it with * interrupts disabled. */ - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); /* * Update the per-port timeout. @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:894 @ sunsu_change_speed(struct uart_port *por up->cflag = cflag; - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); } static void @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:1041 @ static void sunsu_autoconfig(struct uart up->type_probed = PORT_UNKNOWN; up->port.iotype = UPIO_MEM; - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); if (!(up->port.flags & UPF_BUGGY_UART)) { /* @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:1176 @ static void sunsu_autoconfig(struct uart serial_outp(up, UART_IER, 0); out: - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); } static struct uart_driver sunsu_reg = { @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:1301 @ static void sunsu_console_write(struct c int locked = 1; if (up->port.sysrq || oops_in_progress) - locked = spin_trylock_irqsave(&up->port.lock, flags); + locked = uart_port_trylock_irqsave(&up->port, &flags); else - spin_lock_irqsave(&up->port.lock, flags); + uart_port_lock_irqsave(&up->port, &flags); /* * First save the UER then disable the interrupts @ linux-6.6.58-rt45/drivers/tty/serial/sunsu.c:1321 @ static void sunsu_console_write(struct c serial_out(up, UART_IER, ier); if (locked) - spin_unlock_irqrestore(&up->port.lock, flags); + uart_port_unlock_irqrestore(&up->port, flags); } /*