serial: 8250: move skip_txen_test to core

8250_core is the only place where skip_txen_test is used. And platform
and core end up in 8250.ko, so there is no change in module name (param
prefix). Therefore, move skip_txen_test there and make it local.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://patch.msgid.link/20251119092457.826789-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Jiri Slaby (SUSE)

drivers/tty/serial/8250/8250.h

@@ -105,7 +105,6 @@ extern unsigned int nr_uarts;
 #endif
 
 extern unsigned int share_irqs;
-extern unsigned int skip_txen_test;
 
 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags)		\
 	{							\

drivers/tty/serial/8250/8250_core.c

@@ -52,6 +52,10 @@ struct irq_info {
 static DEFINE_HASHTABLE(irq_lists, IRQ_HASH_BITS);
 static DEFINE_MUTEX(hash_mutex);	/* Used to walk the hash */
 
+static bool skip_txen_test;
+module_param(skip_txen_test, bool, 0644);
+MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
+
 /*
  * This is the serial driver's interrupt routine.
  *

drivers/tty/serial/8250/8250_platform.c

@@ -29,10 +29,8 @@
  * Configuration:
  * share_irqs:     Whether we pass IRQF_SHARED to request_irq().
  *                 This option is unsafe when used on edge-triggered interrupts.
- * skip_txen_test: Force skip of txen test at init time.
  */
 unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
-unsigned int skip_txen_test;
 
 unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
 
@@ -386,7 +384,4 @@ MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsa
 module_param(nr_uarts, uint, 0644);
 MODULE_PARM_DESC(nr_uarts, "Maximum number of UARTs supported. (1-" __MODULE_STRING(CONFIG_SERIAL_8250_NR_UARTS) ")");
 
-module_param(skip_txen_test, uint, 0644);
-MODULE_PARM_DESC(skip_txen_test, "Skip checking for the TXEN bug at init time");
-
 MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);