tty: We want the port object to be persistent
Move the tty_port and uart_info bits around a little. By embedding the uart_info
into the uart_port we get rid of lots of corner case testing and also get the
ability to go port<->state<->info which is a bit more elegant than the current
data structures.
Downsides - we allocate a tiny bit more memory for unused ports, upside we've
removed as much code as it saved for most users..
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index feb3b93..2395969 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -316,35 +316,13 @@
};
/*
- * This is the state information which is persistent across opens.
- * The low level driver must not to touch any elements contained
- * within.
- */
-struct uart_state {
- unsigned int close_delay; /* msec */
- unsigned int closing_wait; /* msec */
-
-#define USF_CLOSING_WAIT_INF (0)
-#define USF_CLOSING_WAIT_NONE (~0U)
-
- int count;
- int pm_state;
- struct uart_info *info;
- struct uart_port *port;
-
- struct mutex mutex;
-};
-
-#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
+ * is open; it may be cleared the core driver once the device has
* been closed. Either the low level driver or the core can modify
* stuff here.
*/
+typedef unsigned int __bitwise__ uif_t;
+
struct uart_info {
struct tty_port port;
struct circ_buf xmit;
@@ -366,6 +344,29 @@
wait_queue_head_t delta_msr_wait;
};
+/*
+ * This is the state information which is persistent across opens.
+ * The low level driver must not to touch any elements contained
+ * within.
+ */
+struct uart_state {
+ unsigned int close_delay; /* msec */
+ unsigned int closing_wait; /* msec */
+
+#define USF_CLOSING_WAIT_INF (0)
+#define USF_CLOSING_WAIT_NONE (~0U)
+
+ int count;
+ int pm_state;
+ struct uart_info info;
+ struct uart_port *port;
+
+ struct mutex mutex;
+};
+
+#define UART_XMIT_SIZE PAGE_SIZE
+
+
/* number of characters left in xmit buffer before we ask for more */
#define WAKEUP_CHARS 256
@@ -439,8 +440,13 @@
#define uart_circ_chars_free(circ) \
(CIRC_SPACE((circ)->head, (circ)->tail, UART_XMIT_SIZE))
-#define uart_tx_stopped(portp) \
- ((portp)->info->port.tty->stopped || (portp)->info->port.tty->hw_stopped)
+static inline int uart_tx_stopped(struct uart_port *port)
+{
+ struct tty_struct *tty = port->info->port.tty;
+ if(tty->stopped || tty->hw_stopped)
+ return 1;
+ return 0;
+}
/*
* The following are helper functions for the low level drivers.
@@ -451,7 +457,7 @@
#ifdef SUPPORT_SYSRQ
if (port->sysrq) {
if (ch && time_before(jiffies, port->sysrq)) {
- handle_sysrq(ch, port->info ? port->info->port.tty : NULL);
+ handle_sysrq(ch, port->info->port.tty);
port->sysrq = 0;
return 1;
}