serial: 8250: Split base port operations from universal driver

Refactor base port operations into new file; 8250_port.c.

Legacy irq handling, RSA port support, port storage for universal
driver, driver definition, module parameters and linkage remain in
8250_core.c

The source file split and resulting modules is diagrammed below:

  8250_core.c ====>   8250_core.c __
              \                     \
               \                     +-- 8250.ko (alias 8250_core)
                \     8250_pnp.c  __/     (universal driver)
                 \
                  =>  8250_port.c __
                                    \
                                     +-- 8250_base.ko
                      8250_dma.c  __/     (port operations)
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/8250/8250.h

@@ -211,3 +211,14 @@ static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
 	}
 	return 1;
 }
+
+static inline int serial_index(struct uart_port *port)
+{
+	return port->minor - 64;
+}
+
+#if 0
+#define DEBUG_INTR(fmt...)	printk(fmt)
+#else
+#define DEBUG_INTR(fmt...)	do { } while (0)
+#endif

drivers/tty/serial/8250/Makefile

@@ -2,10 +2,11 @@
 # Makefile for the 8250 serial device drivers.
 #
 
-obj-$(CONFIG_SERIAL_8250)		+= 8250.o
+obj-$(CONFIG_SERIAL_8250)		+= 8250.o 8250_base.o
 8250-y					:= 8250_core.o
 8250-$(CONFIG_SERIAL_8250_PNP)		+= 8250_pnp.o
-8250-$(CONFIG_SERIAL_8250_DMA)		+= 8250_dma.o
+8250_base-y				:= 8250_port.o
+8250_base-$(CONFIG_SERIAL_8250_DMA)	+= 8250_dma.o
 obj-$(CONFIG_SERIAL_8250_GSC)		+= 8250_gsc.o
 obj-$(CONFIG_SERIAL_8250_PCI)		+= 8250_pci.o
 obj-$(CONFIG_SERIAL_8250_HP300)		+= 8250_hp300.o

include/linux/serial_8250.h

@@ -152,6 +152,11 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir);
 unsigned char serial8250_rx_chars(struct uart_8250_port *up, unsigned char lsr);
 void serial8250_tx_chars(struct uart_8250_port *up);
 unsigned int serial8250_modem_status(struct uart_8250_port *up);
+void serial8250_init_port(struct uart_8250_port *up);
+void serial8250_set_defaults(struct uart_8250_port *up);
+void serial8250_console_write(struct uart_8250_port *up, const char *s,
+			      unsigned int count);
+int serial8250_console_setup(struct uart_port *port, char *options, bool probe);
 
 extern void serial8250_set_isa_configurator(void (*v)
 					(int port, struct uart_port *up,