[SERIAL] Make uart_info flags a bitwise type

The potential for confusing the flags is fairly high.  Make
uart_info's flags a bitwise type so sparse can check that the
right flag definitions are used with the right structure.

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

1 files changed, 10 insertions, 8 deletions

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index b74ff34469b..90f681789a6 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -287,6 +287,9 @@ struct uart_state {
 };
 
 #define UART_XMIT_SIZE  PAGE_SIZE
+
+typedef unsigned int __bitwise__ uif_t;
+
 /*
  * This is the state information which is only valid when the port
  * is open; it may be freed by the core driver once the device has
@@ -296,17 +299,16 @@ struct uart_state {
 struct uart_info {
         struct tty_struct       *tty;
         struct circ_buf         xmit;
-        unsigned int            flags;
+        uif_t                   flags;
 
 /*
- * These are the flags that specific to info->flags, and reflect our
- * internal state.  They can not be accessed via port->flags.  Low
- * level drivers must not change these, but may query them instead.
+ * Definitions for info->flags.  These are _private_ to serial_core, and
+ * are specific to this structure.  They may be queried by low level drivers.
  */
-#define UIF_CHECK_CD            (1 << 25)
-#define UIF_CTS_FLOW            (1 << 26)
-#define UIF_NORMAL_ACTIVE       (1 << 29)
-#define UIF_INITIALIZED         (1 << 31)
+#define UIF_CHECK_CD            ((__force uif_t) (1 << 25))
+#define UIF_CTS_FLOW            ((__force uif_t) (1 << 26))
+#define UIF_NORMAL_ACTIVE       ((__force uif_t) (1 << 29))
+#define UIF_INITIALIZED         ((__force uif_t) (1 << 31))
 
         int                     blocked_open;