1 files changed, 214 insertions, 666 deletions

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 914e0e6251bf..0e81f78c6063 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -6,15 +6,14 @@
  *
  *  Copyright (C) 2001 Russell King.
  *
- *  Supports: ISA-compatible 8250/16550 ports
- *	      PNP 8250/16550 ports
+ *  Supports:
  *	      early_serial_setup() ports
  *	      userspace-configurable "phantom" ports
- *	      "serial8250" platform devices
  *	      serial8250_register_8250_port() ports
  */
 
 #include <linux/acpi.h>
+#include <linux/hashtable.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/ioport.h>
@@ -35,52 +34,13 @@
 #include <linux/string_helpers.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
-#ifdef CONFIG_SPARC
-#include <linux/sunserialcore.h>
-#endif
 
 #include <asm/irq.h>
 
 #include "8250.h"
 
-/*
- * Configuration:
- *   share_irqs - whether we pass IRQF_SHARED to request_irq().  This option
- *                is unsafe when used on edge-triggered interrupts.
- */
-static unsigned int share_irqs = SERIAL8250_SHARE_IRQS;
-
-static unsigned int nr_uarts = CONFIG_SERIAL_8250_RUNTIME_UARTS;
-
-static struct uart_driver serial8250_reg;
-
-static unsigned int skip_txen_test; /* force skip of txen test at init time */
-
 #define PASS_LIMIT	512
 
-#include <asm/serial.h>
-/*
- * SERIAL_PORT_DFNS tells us about built-in ports that have no
- * standard enumeration mechanism.   Platforms that can find all
- * serial ports via mechanisms like ACPI or PCI need not supply it.
- */
-#ifndef SERIAL_PORT_DFNS
-#define SERIAL_PORT_DFNS
-#endif
-
-static const struct old_serial_port old_serial_port[] = {
-	SERIAL_PORT_DFNS /* defined in asm/serial.h */
-};
-
-#define UART_NR	CONFIG_SERIAL_8250_NR_UARTS
-
-#ifdef CONFIG_SERIAL_8250_RSA
-
-#define PORT_RSA_MAX 4
-static unsigned long probe_rsa[PORT_RSA_MAX];
-static unsigned int probe_rsa_count;
-#endif /* CONFIG_SERIAL_8250_RSA  */
-
 struct irq_info {
 	struct			hlist_node node;
 	int			irq;
@@ -88,10 +48,14 @@ struct irq_info {
 	struct list_head	*head;
 };
 
-#define NR_IRQ_HASH		32	/* Can be adjusted later */
-static struct hlist_head irq_lists[NR_IRQ_HASH];
+#define IRQ_HASH_BITS		5	/* Can be adjusted later */
+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.
  *
@@ -112,17 +76,12 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
 	struct list_head *l, *end = NULL;
 	int pass_counter = 0, handled = 0;
 
-	pr_debug("%s(%d): start\n", __func__, irq);
-
-	spin_lock(&i->lock);
+	guard(spinlock)(&i->lock);
 
 	l = i->head;
 	do {
-		struct uart_8250_port *up;
-		struct uart_port *port;
-
-		up = list_entry(l, struct uart_8250_port, list);
-		port = &up->port;
+		struct uart_8250_port *up = list_entry(l, struct uart_8250_port, list);
+		struct uart_port *port = &up->port;
 
 		if (port->handle_irq(port)) {
 			handled = 1;
@@ -136,10 +95,6 @@ static irqreturn_t serial8250_interrupt(int irq, void *dev_id)
 			break;
 	} while (l != end);
 
-	spin_unlock(&i->lock);
-
-	pr_debug("%s(%d): end\n", __func__, irq);
-
 	return IRQ_RETVAL(handled);
 }
 
@@ -170,73 +125,79 @@ static void serial_do_unlink(struct irq_info *i, struct uart_8250_port *up)
 	}
 }
 
-static int serial_link_irq_chain(struct uart_8250_port *up)
+/*
+ * Either:
+ * - find the corresponding info in the hashtable and return it, or
+ * - allocate a new one, add it to the hashtable and return it.
+ */
+static struct irq_info *serial_get_or_create_irq_info(const struct uart_8250_port *up)
 {
-	struct hlist_head *h;
 	struct irq_info *i;
-	int ret;
-
-	mutex_lock(&hash_mutex);
 
-	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+	guard(mutex)(&hash_mutex);
 
-	hlist_for_each_entry(i, h, node)
+	hash_for_each_possible(irq_lists, i, node, up->port.irq)
 		if (i->irq == up->port.irq)
-			break;
+			return i;
 
-	if (i == NULL) {
-		i = kzalloc(sizeof(struct irq_info), GFP_KERNEL);
-		if (i == NULL) {
-			mutex_unlock(&hash_mutex);
-			return -ENOMEM;
-		}
-		spin_lock_init(&i->lock);
-		i->irq = up->port.irq;
-		hlist_add_head(&i->node, h);
-	}
-	mutex_unlock(&hash_mutex);
+	i = kzalloc(sizeof(*i), GFP_KERNEL);
+	if (i == NULL)
+		return ERR_PTR(-ENOMEM);
 
-	spin_lock_irq(&i->lock);
+	spin_lock_init(&i->lock);
+	i->irq = up->port.irq;
+	hash_add(irq_lists, &i->node, i->irq);
 
-	if (i->head) {
-		list_add(&up->list, i->head);
-		spin_unlock_irq(&i->lock);
+	return i;
+}
+
+static int serial_link_irq_chain(struct uart_8250_port *up)
+{
+	struct irq_info *i;
+	int ret;
+
+	i = serial_get_or_create_irq_info(up);
+	if (IS_ERR(i))
+		return PTR_ERR(i);
+
+	scoped_guard(spinlock_irq, &i->lock) {
+		if (i->head) {
+			list_add(&up->list, i->head);
+
+			return 0;
+		}
 
-		ret = 0;
-	} else {
 		INIT_LIST_HEAD(&up->list);
 		i->head = &up->list;
-		spin_unlock_irq(&i->lock);
-		ret = request_irq(up->port.irq, serial8250_interrupt,
-				  up->port.irqflags, up->port.name, i);
-		if (ret < 0)
-			serial_do_unlink(i, up);
 	}
 
+	ret = request_irq(up->port.irq, serial8250_interrupt, up->port.irqflags, up->port.name, i);
+	if (ret < 0)
+		serial_do_unlink(i, up);
+
 	return ret;
 }
 
 static void serial_unlink_irq_chain(struct uart_8250_port *up)
 {
 	struct irq_info *i;
-	struct hlist_head *h;
 
-	mutex_lock(&hash_mutex);
+	guard(mutex)(&hash_mutex);
 
-	h = &irq_lists[up->port.irq % NR_IRQ_HASH];
+	hash_for_each_possible(irq_lists, i, node, up->port.irq)
+		if (i->irq == up->port.irq) {
+			if (WARN_ON(i->head == NULL))
+				return;
 
-	hlist_for_each_entry(i, h, node)
-		if (i->irq == up->port.irq)
-			break;
+			if (list_empty(i->head))
+				free_irq(up->port.irq, i);
 
-	BUG_ON(i == NULL);
-	BUG_ON(i->head == NULL);
+			serial_do_unlink(i, up);
 
-	if (list_empty(i->head))
-		free_irq(up->port.irq, i);
+			return;
+		}
 
-	serial_do_unlink(i, up);
-	mutex_unlock(&hash_mutex);
+	WARN_ON(1);
 }
 
 /*
@@ -247,7 +208,7 @@ static void serial_unlink_irq_chain(struct uart_8250_port *up)
  */
 static void serial8250_timeout(struct timer_list *t)
 {
-	struct uart_8250_port *up = from_timer(up, t, timer);
+	struct uart_8250_port *up = timer_container_of(up, t, timer);
 
 	up->port.handle_irq(&up->port);
 	mod_timer(&up->timer, jiffies + uart_poll_timeout(&up->port));
@@ -255,11 +216,11 @@ static void serial8250_timeout(struct timer_list *t)
 
 static void serial8250_backup_timeout(struct timer_list *t)
 {
-	struct uart_8250_port *up = from_timer(up, t, timer);
+	struct uart_8250_port *up = timer_container_of(up, t, timer);
 	unsigned int iir, ier = 0, lsr;
 	unsigned long flags;
 
-	spin_lock_irqsave(&up->port.lock, flags);
+	uart_port_lock_irqsave(&up->port, &flags);
 
 	/*
 	 * Must disable interrupts or else we risk racing with the interrupt
@@ -280,7 +241,8 @@ static void serial8250_backup_timeout(struct timer_list *t)
 	 */
 	lsr = serial_lsr_in(up);
 	if ((iir & UART_IIR_NO_INT) && (up->ier & UART_IER_THRI) &&
-	    (!uart_circ_empty(&up->port.state->xmit) || up->port.x_char) &&
+	    (!kfifo_is_empty(&up->port.state->port.xmit_fifo) ||
+	     up->port.x_char) &&
 	    (lsr & UART_LSR_THRE)) {
 		iir &= ~(UART_IIR_ID | UART_IIR_NO_INT);
 		iir |= UART_IIR_THRI;
@@ -292,7 +254,7 @@ static void serial8250_backup_timeout(struct timer_list *t)
 	if (up->port.irq)
 		serial_out(up, UART_IER, ier);
 
-	spin_unlock_irqrestore(&up->port.lock, flags);
+	uart_port_unlock_irqrestore(&up->port, flags);
 
 	/* Standard timer interval plus 0.2s to keep the port running */
 	mod_timer(&up->timer,
@@ -338,51 +300,14 @@ static void univ8250_release_irq(struct uart_8250_port *up)
 {
 	struct uart_port *port = &up->port;
 
-	del_timer_sync(&up->timer);
+	timer_delete_sync(&up->timer);
 	up->timer.function = serial8250_timeout;
 	if (port->irq)
 		serial_unlink_irq_chain(up);
 }
 
-#ifdef CONFIG_SERIAL_8250_RSA
-static int serial8250_request_rsa_resource(struct uart_8250_port *up)
-{
-	unsigned long start = UART_RSA_BASE << up->port.regshift;
-	unsigned int size = 8 << up->port.regshift;
-	struct uart_port *port = &up->port;
-	int ret = -EINVAL;
-
-	switch (port->iotype) {
-	case UPIO_HUB6:
-	case UPIO_PORT:
-		start += port->iobase;
-		if (request_region(start, size, "serial-rsa"))
-			ret = 0;
-		else
-			ret = -EBUSY;
-		break;
-	}
-
-	return ret;
-}
-
-static void serial8250_release_rsa_resource(struct uart_8250_port *up)
-{
-	unsigned long offset = UART_RSA_BASE << up->port.regshift;
-	unsigned int size = 8 << up->port.regshift;
-	struct uart_port *port = &up->port;
-
-	switch (port->iotype) {
-	case UPIO_HUB6:
-	case UPIO_PORT:
-		release_region(port->iobase + offset, size);
-		break;
-	}
-}
-#endif
-
-static const struct uart_ops *base_ops;
-static struct uart_ops univ8250_port_ops;
+const struct uart_ops *univ8250_port_base_ops;
+struct uart_ops univ8250_port_ops;
 
 static const struct uart_8250_ops univ8250_driver_ops = {
 	.setup_irq	= univ8250_setup_irq,
@@ -410,85 +335,12 @@ struct uart_8250_port *serial8250_get_port(int line)
 }
 EXPORT_SYMBOL_GPL(serial8250_get_port);
 
-static void (*serial8250_isa_config)(int port, struct uart_port *up,
-	u32 *capabilities);
-
-void serial8250_set_isa_configurator(
-	void (*v)(int port, struct uart_port *up, u32 *capabilities))
-{
-	serial8250_isa_config = v;
-}
-EXPORT_SYMBOL(serial8250_set_isa_configurator);
-
-#ifdef CONFIG_SERIAL_8250_RSA
-
-static void univ8250_config_port(struct uart_port *port, int flags)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	up->probe &= ~UART_PROBE_RSA;
-	if (port->type == PORT_RSA) {
-		if (serial8250_request_rsa_resource(up) == 0)
-			up->probe |= UART_PROBE_RSA;
-	} else if (flags & UART_CONFIG_TYPE) {
-		int i;
-
-		for (i = 0; i < probe_rsa_count; i++) {
-			if (probe_rsa[i] == up->port.iobase) {
-				if (serial8250_request_rsa_resource(up) == 0)
-					up->probe |= UART_PROBE_RSA;
-				break;
-			}
-		}
-	}
-
-	base_ops->config_port(port, flags);
-
-	if (port->type != PORT_RSA && up->probe & UART_PROBE_RSA)
-		serial8250_release_rsa_resource(up);
-}
-
-static int univ8250_request_port(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-	int ret;
-
-	ret = base_ops->request_port(port);
-	if (ret == 0 && port->type == PORT_RSA) {
-		ret = serial8250_request_rsa_resource(up);
-		if (ret < 0)
-			base_ops->release_port(port);
-	}
-
-	return ret;
-}
-
-static void univ8250_release_port(struct uart_port *port)
-{
-	struct uart_8250_port *up = up_to_u8250p(port);
-
-	if (port->type == PORT_RSA)
-		serial8250_release_rsa_resource(up);
-	base_ops->release_port(port);
-}
-
-static void univ8250_rsa_support(struct uart_ops *ops)
-{
-	ops->config_port  = univ8250_config_port;
-	ops->request_port = univ8250_request_port;
-	ops->release_port = univ8250_release_port;
-}
-
-#else
-#define univ8250_rsa_support(x)		do { } while (0)
-#endif /* CONFIG_SERIAL_8250_RSA */
-
 static inline void serial8250_apply_quirks(struct uart_8250_port *up)
 {
 	up->port.quirks |= skip_txen_test ? UPQ_NO_TXEN_TEST : 0;
 }
 
-static struct uart_8250_port *serial8250_setup_port(int index)
+struct uart_8250_port *serial8250_setup_port(int index)
 {
 	struct uart_8250_port *up;
 
@@ -497,76 +349,23 @@ static struct uart_8250_port *serial8250_setup_port(int index)
 
 	up = &serial8250_ports[index];
 	up->port.line = index;
+	up->port.port_id = index;
 
 	serial8250_init_port(up);
-	if (!base_ops)
-		base_ops = up->port.ops;
+	if (!univ8250_port_base_ops)
+		univ8250_port_base_ops = up->port.ops;
 	up->port.ops = &univ8250_port_ops;
 
 	timer_setup(&up->timer, serial8250_timeout, 0);
 
 	up->ops = &univ8250_driver_ops;
 
-	if (IS_ENABLED(CONFIG_ALPHA_JENSEN) ||
-	    (IS_ENABLED(CONFIG_ALPHA_GENERIC) && alpha_jensen()))
-		up->port.set_mctrl = alpha_jensen_set_mctrl;
-
 	serial8250_set_defaults(up);
 
 	return up;
 }
 
-static void __init serial8250_isa_init_ports(void)
-{
-	struct uart_8250_port *up;
-	static int first = 1;
-	int i, irqflag = 0;
-
-	if (!first)
-		return;
-	first = 0;
-
-	if (nr_uarts > UART_NR)
-		nr_uarts = UART_NR;
-
-	/*
-	 * Set up initial isa ports based on nr_uart module param, or else
-	 * default to CONFIG_SERIAL_8250_RUNTIME_UARTS. Note that we do not
-	 * need to increase nr_uarts when setting up the initial isa ports.
-	 */
-	for (i = 0; i < nr_uarts; i++)
-		serial8250_setup_port(i);
-
-	/* chain base port ops to support Remote Supervisor Adapter */
-	univ8250_port_ops = *base_ops;
-	univ8250_rsa_support(&univ8250_port_ops);
-
-	if (share_irqs)
-		irqflag = IRQF_SHARED;
-
-	for (i = 0, up = serial8250_ports;
-	     i < ARRAY_SIZE(old_serial_port) && i < nr_uarts;
-	     i++, up++) {
-		struct uart_port *port = &up->port;
-
-		port->iobase   = old_serial_port[i].port;
-		port->irq      = irq_canonicalize(old_serial_port[i].irq);
-		port->irqflags = 0;
-		port->uartclk  = old_serial_port[i].baud_base * 16;
-		port->flags    = old_serial_port[i].flags;
-		port->hub6     = 0;
-		port->membase  = old_serial_port[i].iomem_base;
-		port->iotype   = old_serial_port[i].io_type;
-		port->regshift = old_serial_port[i].iomem_reg_shift;
-
-		port->irqflags |= irqflag;
-		if (serial8250_isa_config != NULL)
-			serial8250_isa_config(i, &up->port, &up->capabilities);
-	}
-}
-
-static void __init
-serial8250_register_ports(struct uart_driver *drv, struct device *dev)
+void __init serial8250_register_ports(struct uart_driver *drv, struct device *dev)
 {
 	int i;
 
@@ -610,7 +409,7 @@ static int univ8250_console_setup(struct console *co, char *options)
 	 * if so, search for the first available port that does have
 	 * console support.
 	 */
-	if (co->index >= UART_NR)
+	if (co->index < 0 || co->index >= UART_NR)
 		co->index = 0;
 
 	/*
@@ -626,11 +425,11 @@ static int univ8250_console_setup(struct console *co, char *options)
 
 	port = &serial8250_ports[co->index].port;
 	/* link port to console */
-	port->cons = co;
+	uart_port_set_cons(port, co);
 
 	retval = serial8250_console_setup(port, options, false);
 	if (retval != 0)
-		port->cons = NULL;
+		uart_port_set_cons(port, NULL);
 	return retval;
 }
 
@@ -664,7 +463,7 @@ static int univ8250_console_match(struct console *co, char *name, int idx,
 				  char *options)
 {
 	char match[] = "uart";	/* 8250-specific earlycon name */
-	unsigned char iotype;
+	enum uart_iotype iotype;
 	resource_size_t addr;
 	int i;
 
@@ -688,7 +487,7 @@ static int univ8250_console_match(struct console *co, char *name, int idx,
 			continue;
 
 		co->index = i;
-		port->cons = co;
+		uart_port_set_cons(port, co);
 		return serial8250_console_setup(port, options, true);
 	}
 
@@ -723,7 +522,7 @@ console_initcall(univ8250_console_init);
 #define SERIAL8250_CONSOLE	NULL
 #endif
 
-static struct uart_driver serial8250_reg = {
+struct uart_driver serial8250_reg = {
 	.owner			= THIS_MODULE,
 	.driver_name		= "serial",
 	.dev_name		= "ttyS",
@@ -825,121 +624,6 @@ void serial8250_resume_port(int line)
 EXPORT_SYMBOL(serial8250_resume_port);
 
 /*
- * Register a set of serial devices attached to a platform device.  The
- * list is terminated with a zero flags entry, which means we expect
- * all entries to have at least UPF_BOOT_AUTOCONF set.
- */
-static int serial8250_probe(struct platform_device *dev)
-{
-	struct plat_serial8250_port *p = dev_get_platdata(&dev->dev);
-	struct uart_8250_port uart;
-	int ret, i, irqflag = 0;
-
-	memset(&uart, 0, sizeof(uart));
-
-	if (share_irqs)
-		irqflag = IRQF_SHARED;
-
-	for (i = 0; p && p->flags != 0; p++, i++) {
-		uart.port.iobase	= p->iobase;
-		uart.port.membase	= p->membase;
-		uart.port.irq		= p->irq;
-		uart.port.irqflags	= p->irqflags;
-		uart.port.uartclk	= p->uartclk;
-		uart.port.regshift	= p->regshift;
-		uart.port.iotype	= p->iotype;
-		uart.port.flags		= p->flags;
-		uart.port.mapbase	= p->mapbase;
-		uart.port.mapsize	= p->mapsize;
-		uart.port.hub6		= p->hub6;
-		uart.port.has_sysrq	= p->has_sysrq;
-		uart.port.private_data	= p->private_data;
-		uart.port.type		= p->type;
-		uart.bugs		= p->bugs;
-		uart.port.serial_in	= p->serial_in;
-		uart.port.serial_out	= p->serial_out;
-		uart.dl_read		= p->dl_read;
-		uart.dl_write		= p->dl_write;
-		uart.port.handle_irq	= p->handle_irq;
-		uart.port.handle_break	= p->handle_break;
-		uart.port.set_termios	= p->set_termios;
-		uart.port.set_ldisc	= p->set_ldisc;
-		uart.port.get_mctrl	= p->get_mctrl;
-		uart.port.pm		= p->pm;
-		uart.port.dev		= &dev->dev;
-		uart.port.irqflags	|= irqflag;
-		ret = serial8250_register_8250_port(&uart);
-		if (ret < 0) {
-			dev_err(&dev->dev, "unable to register port at index %d "
-				"(IO%lx MEM%llx IRQ%d): %d\n", i,
-				p->iobase, (unsigned long long)p->mapbase,
-				p->irq, ret);
-		}
-	}
-	return 0;
-}
-
-/*
- * Remove serial ports registered against a platform device.
- */
-static int serial8250_remove(struct platform_device *dev)
-{
-	int i;
-
-	for (i = 0; i < nr_uarts; i++) {
-		struct uart_8250_port *up = &serial8250_ports[i];
-
-		if (up->port.dev == &dev->dev)
-			serial8250_unregister_port(i);
-	}
-	return 0;
-}
-
-static int serial8250_suspend(struct platform_device *dev, pm_message_t state)
-{
-	int i;
-
-	for (i = 0; i < UART_NR; i++) {
-		struct uart_8250_port *up = &serial8250_ports[i];
-
-		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
-			uart_suspend_port(&serial8250_reg, &up->port);
-	}
-
-	return 0;
-}
-
-static int serial8250_resume(struct platform_device *dev)
-{
-	int i;
-
-	for (i = 0; i < UART_NR; i++) {
-		struct uart_8250_port *up = &serial8250_ports[i];
-
-		if (up->port.type != PORT_UNKNOWN && up->port.dev == &dev->dev)
-			serial8250_resume_port(i);
-	}
-
-	return 0;
-}
-
-static struct platform_driver serial8250_isa_driver = {
-	.probe		= serial8250_probe,
-	.remove		= serial8250_remove,
-	.suspend	= serial8250_suspend,
-	.resume		= serial8250_resume,
-	.driver		= {
-		.name	= "serial8250",
-	},
-};
-
-/*
- * This "device" covers _all_ ISA 8250-compatible serial devices listed
- * in the table in include/asm/serial.h
- */
-static struct platform_device *serial8250_isa_devs;
-
-/*
  * serial8250_register_8250_port and serial8250_unregister_port allows for
  * 16x50 serial ports to be configured at run-time, to support PCMCIA
  * modems and PCI multiport cards.
@@ -985,17 +669,12 @@ static struct uart_8250_port *serial8250_find_match_or_unused(const struct uart_
 
 static void serial_8250_overrun_backoff_work(struct work_struct *work)
 {
-	struct uart_8250_port *up =
-	    container_of(to_delayed_work(work), struct uart_8250_port,
-			 overrun_backoff);
-	struct uart_port *port = &up->port;
-	unsigned long flags;
+	struct uart_8250_port *up = container_of(to_delayed_work(work), struct uart_8250_port,
+						 overrun_backoff);
 
-	spin_lock_irqsave(&port->lock, flags);
+	guard(uart_port_lock_irqsave)(&up->port);
 	up->ier |= UART_IER_RLSI | UART_IER_RDI;
-	up->port.read_status_mask |= UART_LSR_DR;
 	serial_out(up, UART_IER, up->ier);
-	spin_unlock_irqrestore(&port->lock, flags);
 }
 
 /**
@@ -1014,12 +693,12 @@ static void serial_8250_overrun_backoff_work(struct work_struct *work)
 int serial8250_register_8250_port(const struct uart_8250_port *up)
 {
 	struct uart_8250_port *uart;
-	int ret = -ENOSPC;
+	int ret;
 
 	if (up->port.uartclk == 0)
 		return -EINVAL;
 
-	mutex_lock(&serial_mutex);
+	guard(mutex)(&serial_mutex);
 
 	uart = serial8250_find_match_or_unused(&up->port);
 	if (!uart) {
@@ -1029,149 +708,150 @@ int serial8250_register_8250_port(const struct uart_8250_port *up)
 		 */
 		uart = serial8250_setup_port(nr_uarts);
 		if (!uart)
-			goto unlock;
+			return -ENOSPC;
 		nr_uarts++;
 	}
 
-	if (uart->port.type != PORT_8250_CIR) {
-		struct mctrl_gpios *gpios;
-
-		if (uart->port.dev)
-			uart_remove_one_port(&serial8250_reg, &uart->port);
-
-		uart->port.ctrl_id	= up->port.ctrl_id;
-		uart->port.iobase       = up->port.iobase;
-		uart->port.membase      = up->port.membase;
-		uart->port.irq          = up->port.irq;
-		uart->port.irqflags     = up->port.irqflags;
-		uart->port.uartclk      = up->port.uartclk;
-		uart->port.fifosize     = up->port.fifosize;
-		uart->port.regshift     = up->port.regshift;
-		uart->port.iotype       = up->port.iotype;
-		uart->port.flags        = up->port.flags | UPF_BOOT_AUTOCONF;
-		uart->bugs		= up->bugs;
-		uart->port.mapbase      = up->port.mapbase;
-		uart->port.mapsize      = up->port.mapsize;
-		uart->port.private_data = up->port.private_data;
-		uart->tx_loadsz		= up->tx_loadsz;
-		uart->capabilities	= up->capabilities;
-		uart->port.throttle	= up->port.throttle;
-		uart->port.unthrottle	= up->port.unthrottle;
-		uart->port.rs485_config	= up->port.rs485_config;
-		uart->port.rs485_supported = up->port.rs485_supported;
-		uart->port.rs485	= up->port.rs485;
-		uart->rs485_start_tx	= up->rs485_start_tx;
-		uart->rs485_stop_tx	= up->rs485_stop_tx;
-		uart->lsr_save_mask	= up->lsr_save_mask;
-		uart->dma		= up->dma;
-
-		/* Take tx_loadsz from fifosize if it wasn't set separately */
-		if (uart->port.fifosize && !uart->tx_loadsz)
-			uart->tx_loadsz = uart->port.fifosize;
-
-		if (up->port.dev) {
-			uart->port.dev = up->port.dev;
-			ret = uart_get_rs485_mode(&uart->port);
-			if (ret)
-				goto err;
-		}
+	/* Check if it is CIR already. We check this below again, see there why. */
+	if (uart->port.type == PORT_8250_CIR)
+		return -ENODEV;
 
-		if (up->port.flags & UPF_FIXED_TYPE)
-			uart->port.type = up->port.type;
+	if (uart->port.dev)
+		uart_remove_one_port(&serial8250_reg, &uart->port);
+
+	uart->port.ctrl_id	= up->port.ctrl_id;
+	uart->port.port_id	= up->port.port_id;
+	uart->port.iobase       = up->port.iobase;
+	uart->port.membase      = up->port.membase;
+	uart->port.irq          = up->port.irq;
+	uart->port.irqflags     = up->port.irqflags;
+	uart->port.uartclk      = up->port.uartclk;
+	uart->port.fifosize     = up->port.fifosize;
+	uart->port.regshift     = up->port.regshift;
+	uart->port.iotype       = up->port.iotype;
+	uart->port.flags        = up->port.flags | UPF_BOOT_AUTOCONF;
+	uart->bugs		= up->bugs;
+	uart->port.mapbase      = up->port.mapbase;
+	uart->port.mapsize      = up->port.mapsize;
+	uart->port.private_data = up->port.private_data;
+	uart->tx_loadsz		= up->tx_loadsz;
+	uart->capabilities	= up->capabilities;
+	uart->port.throttle	= up->port.throttle;
+	uart->port.unthrottle	= up->port.unthrottle;
+	uart->port.rs485_config	= up->port.rs485_config;
+	uart->port.rs485_supported = up->port.rs485_supported;
+	uart->port.rs485	= up->port.rs485;
+	uart->rs485_start_tx	= up->rs485_start_tx;
+	uart->rs485_stop_tx	= up->rs485_stop_tx;
+	uart->lsr_save_mask	= up->lsr_save_mask;
+	uart->dma		= up->dma;
+
+	/* Take tx_loadsz from fifosize if it wasn't set separately */
+	if (uart->port.fifosize && !uart->tx_loadsz)
+		uart->tx_loadsz = uart->port.fifosize;
+
+	if (up->port.dev) {
+		uart->port.dev = up->port.dev;
+		ret = uart_get_rs485_mode(&uart->port);
+		if (ret)
+			goto err;
+	}
 
-		/*
-		 * Only call mctrl_gpio_init(), if the device has no ACPI
-		 * companion device
-		 */
-		if (!has_acpi_companion(uart->port.dev)) {
-			gpios = mctrl_gpio_init(&uart->port, 0);
-			if (IS_ERR(gpios)) {
-				ret = PTR_ERR(gpios);
-				goto err;
-			} else {
-				uart->gpios = gpios;
-			}
-		}
+	if (up->port.flags & UPF_FIXED_TYPE)
+		uart->port.type = up->port.type;
 
-		serial8250_set_defaults(uart);
-
-		/* Possibly override default I/O functions.  */
-		if (up->port.serial_in)
-			uart->port.serial_in = up->port.serial_in;
-		if (up->port.serial_out)
-			uart->port.serial_out = up->port.serial_out;
-		if (up->port.handle_irq)
-			uart->port.handle_irq = up->port.handle_irq;
-		/*  Possibly override set_termios call */
-		if (up->port.set_termios)
-			uart->port.set_termios = up->port.set_termios;
-		if (up->port.set_ldisc)
-			uart->port.set_ldisc = up->port.set_ldisc;
-		if (up->port.get_mctrl)
-			uart->port.get_mctrl = up->port.get_mctrl;
-		if (up->port.set_mctrl)
-			uart->port.set_mctrl = up->port.set_mctrl;
-		if (up->port.get_divisor)
-			uart->port.get_divisor = up->port.get_divisor;
-		if (up->port.set_divisor)
-			uart->port.set_divisor = up->port.set_divisor;
-		if (up->port.startup)
-			uart->port.startup = up->port.startup;
-		if (up->port.shutdown)
-			uart->port.shutdown = up->port.shutdown;
-		if (up->port.pm)
-			uart->port.pm = up->port.pm;
-		if (up->port.handle_break)
-			uart->port.handle_break = up->port.handle_break;
-		if (up->dl_read)
-			uart->dl_read = up->dl_read;
-		if (up->dl_write)
-			uart->dl_write = up->dl_write;
-
-		if (uart->port.type != PORT_8250_CIR) {
-			if (serial8250_isa_config != NULL)
-				serial8250_isa_config(0, &uart->port,
-						&uart->capabilities);
-
-			serial8250_apply_quirks(uart);
-			ret = uart_add_one_port(&serial8250_reg,
-						&uart->port);
-			if (ret)
-				goto err;
-
-			ret = uart->port.line;
+	/*
+	 * Only call mctrl_gpio_init(), if the device has no ACPI
+	 * companion device
+	 */
+	if (!has_acpi_companion(uart->port.dev)) {
+		struct mctrl_gpios *gpios = mctrl_gpio_init(&uart->port, 0);
+		if (IS_ERR(gpios)) {
+			ret = PTR_ERR(gpios);
+			goto err;
 		} else {
-			dev_info(uart->port.dev,
-				"skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
-				uart->port.iobase,
-				(unsigned long long)uart->port.mapbase,
-				uart->port.irq);
-
-			ret = 0;
+			uart->gpios = gpios;
 		}
+	}
 
-		if (!uart->lsr_save_mask)
-			uart->lsr_save_mask = LSR_SAVE_FLAGS;	/* Use default LSR mask */
+	serial8250_set_defaults(uart);
+
+	/* Possibly override default I/O functions.  */
+	if (up->port.serial_in)
+		uart->port.serial_in = up->port.serial_in;
+	if (up->port.serial_out)
+		uart->port.serial_out = up->port.serial_out;
+	if (up->port.handle_irq)
+		uart->port.handle_irq = up->port.handle_irq;
+	/*  Possibly override set_termios call */
+	if (up->port.set_termios)
+		uart->port.set_termios = up->port.set_termios;
+	if (up->port.set_ldisc)
+		uart->port.set_ldisc = up->port.set_ldisc;
+	if (up->port.get_mctrl)
+		uart->port.get_mctrl = up->port.get_mctrl;
+	if (up->port.set_mctrl)
+		uart->port.set_mctrl = up->port.set_mctrl;
+	if (up->port.get_divisor)
+		uart->port.get_divisor = up->port.get_divisor;
+	if (up->port.set_divisor)
+		uart->port.set_divisor = up->port.set_divisor;
+	if (up->port.startup)
+		uart->port.startup = up->port.startup;
+	if (up->port.shutdown)
+		uart->port.shutdown = up->port.shutdown;
+	if (up->port.pm)
+		uart->port.pm = up->port.pm;
+	if (up->port.handle_break)
+		uart->port.handle_break = up->port.handle_break;
+	if (up->dl_read)
+		uart->dl_read = up->dl_read;
+	if (up->dl_write)
+		uart->dl_write = up->dl_write;
+
+	/* Check the type (again)! It might have changed by the port.type assignment above. */
+	if (uart->port.type != PORT_8250_CIR) {
+		if (uart_console_registered(&uart->port))
+			pm_runtime_get_sync(uart->port.dev);
 
-		/* Initialise interrupt backoff work if required */
-		if (up->overrun_backoff_time_ms > 0) {
-			uart->overrun_backoff_time_ms =
-				up->overrun_backoff_time_ms;
-			INIT_DELAYED_WORK(&uart->overrun_backoff,
-					serial_8250_overrun_backoff_work);
-		} else {
-			uart->overrun_backoff_time_ms = 0;
-		}
+		if (serial8250_isa_config != NULL)
+			serial8250_isa_config(0, &uart->port,
+					&uart->capabilities);
+
+		serial8250_apply_quirks(uart);
+		ret = uart_add_one_port(&serial8250_reg,
+					&uart->port);
+		if (ret)
+			goto err;
+
+		ret = uart->port.line;
+	} else {
+		dev_info(uart->port.dev,
+			"skipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
+			uart->port.iobase,
+			(unsigned long long)uart->port.mapbase,
+			uart->port.irq);
+
+		ret = 0;
 	}
 
-unlock:
-	mutex_unlock(&serial_mutex);
+	if (!uart->lsr_save_mask)
+		uart->lsr_save_mask = LSR_SAVE_FLAGS;	/* Use default LSR mask */
+
+	/* Initialise interrupt backoff work if required */
+	if (up->overrun_backoff_time_ms > 0) {
+		uart->overrun_backoff_time_ms =
+			up->overrun_backoff_time_ms;
+		INIT_DELAYED_WORK(&uart->overrun_backoff,
+				serial_8250_overrun_backoff_work);
+	} else {
+		uart->overrun_backoff_time_ms = 0;
+	}
 
 	return ret;
 
 err:
 	uart->port.dev = NULL;
-	mutex_unlock(&serial_mutex);
 	return ret;
 }
 EXPORT_SYMBOL(serial8250_register_8250_port);
@@ -1187,14 +867,11 @@ void serial8250_unregister_port(int line)
 {
 	struct uart_8250_port *uart = &serial8250_ports[line];
 
-	mutex_lock(&serial_mutex);
+	guard(mutex)(&serial_mutex);
 
 	if (uart->em485) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&uart->port.lock, flags);
+		guard(uart_port_lock_irqsave)(&uart->port);
 		serial8250_em485_destroy(uart);
-		spin_unlock_irqrestore(&uart->port.lock, flags);
 	}
 
 	uart_remove_one_port(&serial8250_reg, &uart->port);
@@ -1202,6 +879,7 @@ void serial8250_unregister_port(int line)
 		uart->port.flags &= ~UPF_BOOT_AUTOCONF;
 		uart->port.type = PORT_UNKNOWN;
 		uart->port.dev = &serial8250_isa_devs->dev;
+		uart->port.port_id = line;
 		uart->capabilities = 0;
 		serial8250_init_port(uart);
 		serial8250_apply_quirks(uart);
@@ -1209,138 +887,8 @@ void serial8250_unregister_port(int line)
 	} else {
 		uart->port.dev = NULL;
 	}
-	mutex_unlock(&serial_mutex);
 }
 EXPORT_SYMBOL(serial8250_unregister_port);
 
-static int __init serial8250_init(void)
-{
-	int ret;
-
-	if (nr_uarts == 0)
-		return -ENODEV;
-
-	serial8250_isa_init_ports();
-
-	pr_info("Serial: 8250/16550 driver, %d ports, IRQ sharing %s\n",
-		nr_uarts, str_enabled_disabled(share_irqs));
-
-#ifdef CONFIG_SPARC
-	ret = sunserial_register_minors(&serial8250_reg, UART_NR);
-#else
-	serial8250_reg.nr = UART_NR;
-	ret = uart_register_driver(&serial8250_reg);
-#endif
-	if (ret)
-		goto out;
-
-	ret = serial8250_pnp_init();
-	if (ret)
-		goto unreg_uart_drv;
-
-	serial8250_isa_devs = platform_device_alloc("serial8250",
-						    PLAT8250_DEV_LEGACY);
-	if (!serial8250_isa_devs) {
-		ret = -ENOMEM;
-		goto unreg_pnp;
-	}
-
-	ret = platform_device_add(serial8250_isa_devs);
-	if (ret)
-		goto put_dev;
-
-	serial8250_register_ports(&serial8250_reg, &serial8250_isa_devs->dev);
-
-	ret = platform_driver_register(&serial8250_isa_driver);
-	if (ret == 0)
-		goto out;
-
-	platform_device_del(serial8250_isa_devs);
-put_dev:
-	platform_device_put(serial8250_isa_devs);
-unreg_pnp:
-	serial8250_pnp_exit();
-unreg_uart_drv:
-#ifdef CONFIG_SPARC
-	sunserial_unregister_minors(&serial8250_reg, UART_NR);
-#else
-	uart_unregister_driver(&serial8250_reg);
-#endif
-out:
-	return ret;
-}
-
-static void __exit serial8250_exit(void)
-{
-	struct platform_device *isa_dev = serial8250_isa_devs;
-
-	/*
-	 * This tells serial8250_unregister_port() not to re-register
-	 * the ports (thereby making serial8250_isa_driver permanently
-	 * in use.)
-	 */
-	serial8250_isa_devs = NULL;
-
-	platform_driver_unregister(&serial8250_isa_driver);
-	platform_device_unregister(isa_dev);
-
-	serial8250_pnp_exit();
-
-#ifdef CONFIG_SPARC
-	sunserial_unregister_minors(&serial8250_reg, UART_NR);
-#else
-	uart_unregister_driver(&serial8250_reg);
-#endif
-}
-
-module_init(serial8250_init);
-module_exit(serial8250_exit);
-
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Generic 8250/16x50 serial driver");
-
-module_param_hw(share_irqs, uint, other, 0644);
-MODULE_PARM_DESC(share_irqs, "Share IRQs with other non-8250/16x50 devices (unsafe)");
-
-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");
-
-#ifdef CONFIG_SERIAL_8250_RSA
-module_param_hw_array(probe_rsa, ulong, ioport, &probe_rsa_count, 0444);
-MODULE_PARM_DESC(probe_rsa, "Probe I/O ports for RSA");
-#endif
-MODULE_ALIAS_CHARDEV_MAJOR(TTY_MAJOR);
-
-#ifdef CONFIG_SERIAL_8250_DEPRECATED_OPTIONS
-#ifndef MODULE
-/* This module was renamed to 8250_core in 3.7.  Keep the old "8250" name
- * working as well for the module options so we don't break people.  We
- * need to keep the names identical and the convenient macros will happily
- * refuse to let us do that by failing the build with redefinition errors
- * of global variables.  So we stick them inside a dummy function to avoid
- * those conflicts.  The options still get parsed, and the redefined
- * MODULE_PARAM_PREFIX lets us keep the "8250." syntax alive.
- *
- * This is hacky.  I'm sorry.
- */
-static void __used s8250_options(void)
-{
-#undef MODULE_PARAM_PREFIX
-#define MODULE_PARAM_PREFIX "8250_core."
-
-	module_param_cb(share_irqs, &param_ops_uint, &share_irqs, 0644);
-	module_param_cb(nr_uarts, &param_ops_uint, &nr_uarts, 0644);
-	module_param_cb(skip_txen_test, &param_ops_uint, &skip_txen_test, 0644);
-#ifdef CONFIG_SERIAL_8250_RSA
-	__module_param_call(MODULE_PARAM_PREFIX, probe_rsa,
-		&param_array_ops, .arr = &__param_arr_probe_rsa,
-		0444, -1, 0);
-#endif
-}
-#else
-MODULE_ALIAS("8250_core");
-#endif
-#endif