[SERIAL] Make uart_port flags a bitwise type

Same reasoning as commit 747c8a55946ed037bf7d62454c3c599c02af2262
but this time we're making uart_port flags a bitwise type - not
all of these flags correspond with the old ASYNC_ flags, so there
is the possibility for bugs if the wrong ASYNC_* constants are
used.  Always use UPF_* constants for uart_port->flags.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/serial/serial_core.c

@@ -332,7 +332,7 @@ uart_get_baud_rate(struct uart_port *port, struct termios *termios,
 		   struct termios *old, unsigned int min, unsigned int max)
 {
 	unsigned int try, baud, altbaud = 38400;
-	unsigned int flags = port->flags & UPF_SPD_MASK;
+	upf_t flags = port->flags & UPF_SPD_MASK;
 
 	if (flags == UPF_SPD_HI)
 		altbaud = 57600;
@@ -615,8 +615,9 @@ static int uart_set_info(struct uart_state *state,
 	struct serial_struct new_serial;
 	struct uart_port *port = state->port;
 	unsigned long new_port;
-	unsigned int change_irq, change_port, old_flags, closing_wait;
+	unsigned int change_irq, change_port, closing_wait;
 	unsigned int old_custom_divisor, close_delay;
+	upf_t old_flags, new_flags;
 	int retval = 0;
 
 	if (copy_from_user(&new_serial, newinfo, sizeof(new_serial)))
@@ -655,6 +656,7 @@ static int uart_set_info(struct uart_state *state,
 		      new_serial.type != port->type;
 
 	old_flags = port->flags;
+	new_flags = new_serial.flags;
 	old_custom_divisor = port->custom_divisor;
 
 	if (!capable(CAP_SYS_ADMIN)) {
@@ -664,10 +666,10 @@ static int uart_set_info(struct uart_state *state,
 		    (close_delay != state->close_delay) ||
 		    (closing_wait != state->closing_wait) ||
 		    (new_serial.xmit_fifo_size != port->fifosize) ||
-		    (((new_serial.flags ^ old_flags) & ~UPF_USR_MASK) != 0))
+		    (((new_flags ^ old_flags) & ~UPF_USR_MASK) != 0))
 			goto exit;
 		port->flags = ((port->flags & ~UPF_USR_MASK) |
-			       (new_serial.flags & UPF_USR_MASK));
+			       (new_flags & UPF_USR_MASK));
 		port->custom_divisor = new_serial.custom_divisor;
 		goto check_and_exit;
 	}
@@ -764,7 +766,7 @@ static int uart_set_info(struct uart_state *state,
 	port->irq              = new_serial.irq;
 	port->uartclk          = new_serial.baud_base * 16;
 	port->flags            = (port->flags & ~UPF_CHANGE_MASK) |
-				 (new_serial.flags & UPF_CHANGE_MASK);
+				 (new_flags & UPF_CHANGE_MASK);
 	port->custom_divisor   = new_serial.custom_divisor;
 	state->close_delay     = close_delay;
 	state->closing_wait    = closing_wait;

include/linux/serial_8250.h

@@ -26,7 +26,7 @@ struct plat_serial8250_port {
 	unsigned char	regshift;	/* register shift */
 	unsigned char	iotype;		/* UPIO_* */
 	unsigned char	hub6;
-	unsigned int	flags;		/* UPF_* flags */
+	upf_t		flags;		/* UPF_* flags */
 };
 
 /*

include/linux/serial_core.h

@@ -203,6 +203,8 @@ struct uart_icount {
 	__u32	buf_overrun;
 };
 
+typedef unsigned int __bitwise__ upf_t;
+
 struct uart_port {
 	spinlock_t		lock;			/* port lock */
 	unsigned int		iobase;			/* in/out[bwl] */
@@ -230,29 +232,29 @@ struct uart_port {
 	unsigned long		sysrq;			/* sysrq timeout */
 #endif
 
-	unsigned int		flags;
-
-#define UPF_FOURPORT		(1 << 1)
-#define UPF_SAK			(1 << 2)
-#define UPF_SPD_MASK		(0x1030)
-#define UPF_SPD_HI		(0x0010)
-#define UPF_SPD_VHI		(0x0020)
-#define UPF_SPD_CUST		(0x0030)
-#define UPF_SPD_SHI		(0x1000)
-#define UPF_SPD_WARP		(0x1010)
-#define UPF_SKIP_TEST		(1 << 6)
-#define UPF_AUTO_IRQ		(1 << 7)
-#define UPF_HARDPPS_CD		(1 << 11)
-#define UPF_LOW_LATENCY		(1 << 13)
-#define UPF_BUGGY_UART		(1 << 14)
-#define UPF_MAGIC_MULTIPLIER	(1 << 16)
-#define UPF_CONS_FLOW		(1 << 23)
-#define UPF_SHARE_IRQ		(1 << 24)
-#define UPF_BOOT_AUTOCONF	(1 << 28)
-#define UPF_IOREMAP		(1 << 31)
-
-#define UPF_CHANGE_MASK		(0x17fff)
-#define UPF_USR_MASK		(UPF_SPD_MASK|UPF_LOW_LATENCY)
+	upf_t			flags;
+
+#define UPF_FOURPORT		((__force upf_t) (1 << 1))
+#define UPF_SAK			((__force upf_t) (1 << 2))
+#define UPF_SPD_MASK		((__force upf_t) (0x1030))
+#define UPF_SPD_HI		((__force upf_t) (0x0010))
+#define UPF_SPD_VHI		((__force upf_t) (0x0020))
+#define UPF_SPD_CUST		((__force upf_t) (0x0030))
+#define UPF_SPD_SHI		((__force upf_t) (0x1000))
+#define UPF_SPD_WARP		((__force upf_t) (0x1010))
+#define UPF_SKIP_TEST		((__force upf_t) (1 << 6))
+#define UPF_AUTO_IRQ		((__force upf_t) (1 << 7))
+#define UPF_HARDPPS_CD		((__force upf_t) (1 << 11))
+#define UPF_LOW_LATENCY		((__force upf_t) (1 << 13))
+#define UPF_BUGGY_UART		((__force upf_t) (1 << 14))
+#define UPF_MAGIC_MULTIPLIER	((__force upf_t) (1 << 16))
+#define UPF_CONS_FLOW		((__force upf_t) (1 << 23))
+#define UPF_SHARE_IRQ		((__force upf_t) (1 << 24))
+#define UPF_BOOT_AUTOCONF	((__force upf_t) (1 << 28))
+#define UPF_IOREMAP		((__force upf_t) (1 << 31))
+
+#define UPF_CHANGE_MASK		((__force upf_t) (0x17fff))
+#define UPF_USR_MASK		((__force upf_t) (UPF_SPD_MASK|UPF_LOW_LATENCY))
 
 	unsigned int		mctrl;			/* current modem ctrl settings */
 	unsigned int		timeout;		/* character-based timeout */