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 <[e-mail]>
Signed-off-by: John Ogness <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/tty/serial/sh-sci.c

···
 
 	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);
 
···
 		}
 	}
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 }
 
 /* Locking: called with port lock held */
···
 	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)
···
 
 	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)
···
 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;
 }
 
···
 	 * 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;
 	}
 
···
 					   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;
 	}
···
 	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);
 
···
 	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;
 }
 
···
 
 	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);
 
···
 	 */
 	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;
 	}
···
 
 	sci_dma_rx_reenable_irq(s);
 
-	spin_unlock_irqrestore(&port->lock, flags);
+	uart_port_unlock_irqrestore(port, flags);
 
 	return HRTIMER_NORESTART;
 }
···
 	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;
 }
···
 	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;
 }
···
 		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);
 
···
 
 	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)
···
 	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);
 	/*
···
 	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) {
···
 		serial_port_out(port, SCCKS, sccks);
 	}
 
-	spin_lock_irqsave(&port->lock, flags);
+	uart_port_lock_irqsave(port, &flags);
 
 	sci_reset(port);
 
···
 	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);
 
···
 	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);
···
 	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)