[PATCH] Serial: Add uart_insert_char()

Add uart_insert_char(), which handles inserting characters into the
flip buffer.  This helper function handles the correct semantics
for handling overrun in addition to inserting normal characters.
Signed-off-by: Russell King <rmk@arm.linux.org.uk>

drivers/serial/21285.c

@@ -126,18 +126,8 @@ static irqreturn_t serial21285_rx_chars(int irq, void *dev_id, struct pt_regs *r
 				flag = TTY_FRAME;
 		}
 
-		if ((rxs & port->ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-		if ((rxs & RXSTAT_OVERRUN) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character.
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+		uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag);
+
 		status = *CSR_UARTFLG;
 	}
 	tty_flip_buffer_push(tty);

drivers/serial/8250.c

@@ -1122,18 +1122,9 @@ receive_chars(struct uart_8250_port *up, int *status, struct pt_regs *regs)
 		}
 		if (uart_handle_sysrq_char(&up->port, ch, regs))
 			goto ignore_char;
-		if ((lsr & up->port.ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-		if ((lsr & UART_LSR_OE) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character.
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+
+		uart_insert_char(&up->port, lsr, UART_LSR_OE, ch, flag);
+
 	ignore_char:
 		lsr = serial_inp(up, UART_LSR);
 	} while ((lsr & UART_LSR_DR) && (max_count-- > 0));

drivers/serial/amba-pl010.c

@@ -198,18 +198,8 @@ pl010_rx_chars(struct uart_port *port)
 		if (uart_handle_sysrq_char(port, ch, regs))
 			goto ignore_char;
 
-		if ((rsr & port->ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-		if ((rsr & UART01x_RSR_OE) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+		uart_insert_char(port, rsr, UART01x_RSR_OE, ch, flag);
+
 	ignore_char:
 		status = UART_GET_FR(port);
 	}

drivers/serial/amba-pl011.c

@@ -163,18 +163,8 @@ pl011_rx_chars(struct uart_amba_port *uap)
 		if (uart_handle_sysrq_char(&uap->port, ch, regs))
 			goto ignore_char;
 
-		if ((rsr & uap->port.ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-		if ((rsr & UART01x_RSR_OE) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+		uart_insert_char(&uap->port, rsr, UART01x_RSR_OE, ch, flag);
+
 	ignore_char:
 		status = readw(uap->port.membase + UART01x_FR);
 	}

drivers/serial/clps711x.c

@@ -143,10 +143,7 @@ static irqreturn_t clps711xuart_int_rx(int irq, void *dev_id, struct pt_regs *re
 		 * CHECK: does overrun affect the current character?
 		 * ASSUMPTION: it does not.
 		 */
-		if ((ch & port->ignore_status_mask & ~RXSTAT_OVERRUN) == 0)
-			tty_insert_flip_char(tty, ch, flg);
-		if ((ch & ~port->ignore_status_mask & RXSTAT_OVERRUN) == 0)
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		uart_insert_char(port, ch, UARTDR_OVERR, ch, flg);
 
 	ignore_char:
 		status = clps_readl(SYSFLG(port));

drivers/serial/pxa.c

@@ -161,20 +161,12 @@ receive_chars(struct uart_pxa_port *up, int *status, struct pt_regs *regs)
 			else if (*status & UART_LSR_FE)
 				flag = TTY_FRAME;
 		}
+
 		if (uart_handle_sysrq_char(&up->port, ch, regs))
 			goto ignore_char;
-		if ((*status & up->port.ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-		if ((*status & UART_LSR_OE) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character.
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+
+		uart_insert_char(&up->port, *status, UART_LSR_OE, ch, flag);
+
 	ignore_char:
 		*status = serial_in(up, UART_LSR);
 	} while ((*status & UART_LSR_DR) && (max_count-- > 0));

drivers/serial/s3c2410.c

@@ -394,20 +394,7 @@ s3c24xx_serial_rx_chars(int irq, void *dev_id, struct pt_regs *regs)
 		if (uart_handle_sysrq_char(port, ch, regs))
 			goto ignore_char;
 
-		if ((uerstat & port->ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-
-		if ((uerstat & S3C2410_UERSTAT_OVERRUN) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character.
-			 */
-
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+		uart_insert_char(port, uerstat, S3C2410_UERSTAT_OVERRUN, ch, flag);
 
 	ignore_char:
 		continue;

drivers/serial/sa1100.c

@@ -237,10 +237,7 @@ sa1100_rx_chars(struct sa1100_port *sport, struct pt_regs *regs)
 		if (uart_handle_sysrq_char(&sport->port, ch, regs))
 			goto ignore_char;
 
-		if ((status & port->ignore_status_mask & ~UTSR1_TO_SM(UTSR1_ROR)) == 0)
-			tty_insert_flip_char(tty, ch, flg);
-		if (status & ~port->ignore_status_mask & UTSR1_TO_SM(UTSR1_ROR))
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+		uart_insert_char(&sport->port, status, UTSR1_TO_SM(UTSR1_ROR), ch, flg);
 
 	ignore_char:
 		status = UTSR1_TO_SM(UART_GET_UTSR1(sport)) |

drivers/serial/serial_lh7a40x.c

@@ -190,18 +190,7 @@ lh7a40xuart_rx_chars (struct uart_port* port)
 		if (uart_handle_sysrq_char (port, (unsigned char) data, regs))
 			continue;
 
-		if ((data & port->ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, data, flag);
-		}
-		if ((data & RxOverrunError)
-		    && tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+		uart_insert_char(port, data, RxOverrunError, data, flag);
 	}
 	tty_flip_buffer_push (tty);
 	return;

drivers/serial/serial_txx9.c

@@ -350,18 +350,9 @@ receive_chars(struct uart_txx9_port *up, unsigned int *status, struct pt_regs *r
 		}
 		if (uart_handle_sysrq_char(&up->port, ch, regs))
 			goto ignore_char;
-		if ((disr & up->port.ignore_status_mask) == 0) {
-			tty_insert_flip_char(tty, ch, flag);
-		}
-		if ((disr & TXX9_SIDISR_UOER) &&
-		    tty->flip.count < TTY_FLIPBUF_SIZE) {
-			/*
-			 * Overrun is special, since it's reported
-			 * immediately, and doesn't affect the current
-			 * character.
-			 */
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
-		}
+
+		uart_insert_char(&up->port, disr, TXX9_SIDISR_UOER, ch, flag);
+
 	ignore_char:
 		disr = sio_in(up, TXX9_SIDISR);
 	} while (!(disr & TXX9_SIDISR_UVALID) && (max_count-- > 0));

drivers/serial/vr41xx_siu.c

@@ -412,10 +412,8 @@ static inline void receive_chars(struct uart_port *port, uint8_t *status,
 
 		if (uart_handle_sysrq_char(port, ch, regs))
 			goto ignore_char;
-		if ((lsr & port->ignore_status_mask) == 0)
-			tty_insert_flip_char(tty, ch, flag);
-		if ((lsr & UART_LSR_OE) && (tty->flip.count < TTY_FLIPBUF_SIZE))
-			tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+
+		uart_insert_char(port, lsr, UART_LSR_OE, ch, flag);
 
 	ignore_char:
 		lsr = siu_read(port, UART_LSR);

include/linux/serial_core.h

@@ -479,6 +479,25 @@ uart_handle_cts_change(struct uart_port *port, unsigned int status)
 	}
 }
 
+#include <linux/tty_flip.h>
+
+static inline void
+uart_insert_char(struct uart_port *port, unsigned int status,
+		 unsigned int overrun, unsigned int ch, unsigned int flag)
+{
+	struct tty_struct *tty = port->info->tty;
+
+	if ((status & port->ignore_status_mask & ~overrun) == 0)
+		tty_insert_flip_char(tty, ch, flag);
+
+	/*
+	 * Overrun is special.  Since it's reported immediately,
+	 * it doesn't affect the current character.
+	 */
+	if (status & ~port->ignore_status_mask & overrun)
+		tty_insert_flip_char(tty, 0, TTY_OVERRUN);
+}
+
 /*
  *	UART_ENABLE_MS - determine if port should enable modem status irqs
  */