serial: avoid fully initializing unused consoles

Defer calling the drivers' post-IRQ initialization functions (generally
doing allocation of transmit buffers) until it is known that the
respective console is actually going to be used.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/xen/include/xen/serial.h b/xen/include/xen/serial.h
index fdcc614e2a..0434956c1d 100644
--- a/xen/include/xen/serial.h
+++ b/xen/include/xen/serial.h
@@ -25,10 +25,17 @@ extern unsigned int serial_txbufsz;
 
 struct uart_driver;
 
+enum serial_port_state {
+    serial_unused,
+    serial_parsed,
+    serial_initialized
+};
+
 struct serial_port {
     /* Uart-driver parameters. */
     struct uart_driver *driver;
     void               *uart;
+    enum serial_port_state state;
     /* Number of characters the port can hold for transmit. */
     int                 tx_fifo_size;
     /* Transmit data buffer (interrupt-driven uart). */