From 48280c59c752339f0b444ff3acce8fc9af7c700c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner <tglx@linutronix.de> Date: Thu, 14 Sep 2023 20:43:34 +0206 Subject: [PATCH 043/204] serial: amba-pl011: 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/20230914183831.587273-18-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/amba-pl011.c | 72 ++++++++++++++++++++-------------------- 1 file changed, 36 insertions(+), 36 deletions(-) Index: linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c =================================================================== @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:350 @ static int pl011_fifo_to_tty(struct uart flag = TTY_FRAME; } - spin_unlock(&uap->port.lock); + uart_port_unlock(&uap->port); sysrq = uart_handle_sysrq_char(&uap->port, ch & 255); - spin_lock(&uap->port.lock); + uart_port_lock(&uap->port); if (!sysrq) uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag); @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:547 @ static void pl011_dma_tx_callback(void * unsigned long flags; u16 dmacr; - spin_lock_irqsave(&uap->port.lock, flags); + uart_port_lock_irqsave(&uap->port, &flags); if (uap->dmatx.queued) dma_unmap_single(dmatx->chan->device->dev, dmatx->dma, dmatx->len, DMA_TO_DEVICE); @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:568 @ static void pl011_dma_tx_callback(void * if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) || uart_circ_empty(&uap->port.state->xmit)) { uap->dmatx.queued = false; - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); return; } @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:579 @ static void pl011_dma_tx_callback(void * */ pl011_start_tx_pio(uap); - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); } /* @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1007 @ static void pl011_dma_rx_callback(void * * routine to flush out the secondary DMA buffer while * we immediately trigger the next DMA job. */ - spin_lock_irq(&uap->port.lock); + uart_port_lock_irq(&uap->port); /* * Rx data can be taken by the UART interrupts during * the DMA irq handler. So we check the residue here. @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1023 @ static void pl011_dma_rx_callback(void * ret = pl011_dma_rx_trigger_dma(uap); pl011_dma_rx_chars(uap, pending, lastbuf, false); - spin_unlock_irq(&uap->port.lock); + uart_port_unlock_irq(&uap->port); /* * Do this check after we picked the DMA chars so we don't * get some IRQ immediately from RX. @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1089 @ static void pl011_dma_rx_poll(struct tim if (jiffies_to_msecs(jiffies - dmarx->last_jiffies) > uap->dmarx.poll_timeout) { - spin_lock_irqsave(&uap->port.lock, flags); + uart_port_lock_irqsave(&uap->port, &flags); pl011_dma_rx_stop(uap); uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); uap->dmarx.running = false; dmaengine_terminate_all(rxchan); @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1189 @ static void pl011_dma_shutdown(struct ua while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy) cpu_relax(); - spin_lock_irq(&uap->port.lock); + uart_port_lock_irq(&uap->port); uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE); pl011_write(uap->dmacr, uap, REG_DMACR); - spin_unlock_irq(&uap->port.lock); + uart_port_unlock_irq(&uap->port); if (uap->using_tx_dma) { /* In theory, this should already be done by pl011_dma_flush_buffer */ @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1403 @ static void pl011_throttle_rx(struct uar { unsigned long flags; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); pl011_stop_rx(port); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void pl011_enable_ms(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1423 @ __acquires(&uap->port.lock) { pl011_fifo_to_tty(uap); - spin_unlock(&uap->port.lock); + uart_port_unlock(&uap->port); tty_flip_buffer_push(&uap->port.state->port); /* * If we were temporarily out of DMA mode for a while, @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1448 @ __acquires(&uap->port.lock) #endif } } - spin_lock(&uap->port.lock); + uart_port_lock(&uap->port); } static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c, @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1554 @ static irqreturn_t pl011_int(int irq, vo unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT; int handled = 0; - spin_lock_irqsave(&uap->port.lock, flags); + uart_port_lock_irqsave(&uap->port, &flags); status = pl011_read(uap, REG_RIS) & uap->im; if (status) { do { @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1584 @ static irqreturn_t pl011_int(int irq, vo handled = 1; } - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); return IRQ_RETVAL(handled); } @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1656 @ static void pl011_break_ctl(struct uart_ unsigned long flags; unsigned int lcr_h; - spin_lock_irqsave(&uap->port.lock, flags); + uart_port_lock_irqsave(&uap->port, &flags); lcr_h = pl011_read(uap, REG_LCRH_TX); if (break_state == -1) lcr_h |= UART01x_LCRH_BRK; else lcr_h &= ~UART01x_LCRH_BRK; pl011_write(lcr_h, uap, REG_LCRH_TX); - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); } #ifdef CONFIG_CONSOLE_POLL @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1802 @ static void pl011_enable_interrupts(stru unsigned long flags; unsigned int i; - spin_lock_irqsave(&uap->port.lock, flags); + uart_port_lock_irqsave(&uap->port, &flags); /* Clear out any spuriously appearing RX interrupts */ pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR); @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1824 @ static void pl011_enable_interrupts(stru if (!pl011_dma_rx_running(uap)) uap->im |= UART011_RXIM; pl011_write(uap->im, uap, REG_IMSC); - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); } static void pl011_unthrottle_rx(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1832 @ static void pl011_unthrottle_rx(struct u struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port); unsigned long flags; - spin_lock_irqsave(&uap->port.lock, flags); + uart_port_lock_irqsave(&uap->port, &flags); uap->im = UART011_RTIM; if (!pl011_dma_rx_running(uap)) @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1840 @ static void pl011_unthrottle_rx(struct u pl011_write(uap->im, uap, REG_IMSC); - spin_unlock_irqrestore(&uap->port.lock, flags); + uart_port_unlock_irqrestore(&uap->port, flags); } static int pl011_startup(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1860 @ static int pl011_startup(struct uart_por pl011_write(uap->vendor->ifls, uap, REG_IFLS); - spin_lock_irq(&uap->port.lock); + uart_port_lock_irq(&uap->port); cr = pl011_read(uap, REG_CR); cr &= UART011_CR_RTS | UART011_CR_DTR; @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1871 @ static int pl011_startup(struct uart_por pl011_write(cr, uap, REG_CR); - spin_unlock_irq(&uap->port.lock); + uart_port_unlock_irq(&uap->port); /* * initialise the old status of the modem signals @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1932 @ static void pl011_disable_uart(struct ua unsigned int cr; uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS); - spin_lock_irq(&uap->port.lock); + uart_port_lock_irq(&uap->port); cr = pl011_read(uap, REG_CR); cr &= UART011_CR_RTS | UART011_CR_DTR; cr |= UART01x_CR_UARTEN | UART011_CR_TXE; pl011_write(cr, uap, REG_CR); - spin_unlock_irq(&uap->port.lock); + uart_port_unlock_irq(&uap->port); /* * disable break condition and fifos @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:1949 @ static void pl011_disable_uart(struct ua static void pl011_disable_interrupts(struct uart_amba_port *uap) { - spin_lock_irq(&uap->port.lock); + uart_port_lock_irq(&uap->port); /* mask all interrupts and clear all pending ones */ uap->im = 0; pl011_write(uap->im, uap, REG_IMSC); pl011_write(0xffff, uap, REG_ICR); - spin_unlock_irq(&uap->port.lock); + uart_port_unlock_irq(&uap->port); } static void pl011_shutdown(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:2101 @ pl011_set_termios(struct uart_port *port bits = tty_get_frame_size(termios->c_cflag); - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); /* * Update the per-port timeout. @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:2175 @ pl011_set_termios(struct uart_port *port old_cr |= UART011_CR_RXE; pl011_write(old_cr, uap, REG_CR); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static void @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:2193 @ sbsa_uart_set_termios(struct uart_port * termios->c_cflag &= ~(CMSPAR | CRTSCTS); termios->c_cflag |= CS8 | CLOCAL; - spin_lock_irqsave(&port->lock, flags); + uart_port_lock_irqsave(port, &flags); uart_update_timeout(port, CS8, uap->fixed_baud); pl011_setup_status_masks(port, termios); - spin_unlock_irqrestore(&port->lock, flags); + uart_port_unlock_irqrestore(port, flags); } static const char *pl011_type(struct uart_port *port) @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:2335 @ pl011_console_write(struct console *co, if (uap->port.sysrq) locked = 0; else if (oops_in_progress) - locked = spin_trylock(&uap->port.lock); + locked = uart_port_trylock(&uap->port); else - spin_lock(&uap->port.lock); + uart_port_lock(&uap->port); /* * First save the CR then disable the interrupts @ linux-6.6.58-rt45/drivers/tty/serial/amba-pl011.c:2363 @ pl011_console_write(struct console *co, pl011_write(old_cr, uap, REG_CR); if (locked) - spin_unlock(&uap->port.lock); + uart_port_unlock(&uap->port); local_irq_restore(flags); clk_disable(uap->clk);