From: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Date: Thu, 14 Aug 2025 07:24:44 +0000 (+0200)
Subject: serial: 8250: introduce RPM guard()s
X-Git-Tag: v6.18-rc1~77^2~32
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=9f8da7b2f90cb5fb4c585d5e8aa89dfd724bd377;p=thirdparty%2Fkernel%2Flinux.git

serial: 8250: introduce RPM guard()s

Having this, guards like these work:
  guard(serial8250_rpm)(up);
or
  scoped_guard(serial8250_rpm, up) {
    ...
  }

See e.g. "serial: 8250: use guard()s" later in this series.

And make them available to anyone (EXPORT + put in 8250.h) as drivers
open code this anyway.

The _tx ones are not defined as they would have no user.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250814072456.182853-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index cfe6ba286b45..58e64c4e1e3a 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -186,6 +186,11 @@ static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
 
 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
 
+void serial8250_rpm_get(struct uart_8250_port *p);
+void serial8250_rpm_put(struct uart_8250_port *p);
+DEFINE_GUARD(serial8250_rpm, struct uart_8250_port *,
+	     serial8250_rpm_get(_T), serial8250_rpm_put(_T));
+
 static inline u32 serial_dl_read(struct uart_8250_port *up)
 {
 	return up->dl_read(up);
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 2da9db960d09..5afae4025696 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -508,20 +508,22 @@ void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p)
 }
 EXPORT_SYMBOL_GPL(serial8250_clear_and_reinit_fifos);
 
-static void serial8250_rpm_get(struct uart_8250_port *p)
+void serial8250_rpm_get(struct uart_8250_port *p)
 {
 	if (!(p->capabilities & UART_CAP_RPM))
 		return;
 	pm_runtime_get_sync(p->port.dev);
 }
+EXPORT_SYMBOL_GPL(serial8250_rpm_get);
 
-static void serial8250_rpm_put(struct uart_8250_port *p)
+void serial8250_rpm_put(struct uart_8250_port *p)
 {
 	if (!(p->capabilities & UART_CAP_RPM))
 		return;
 	pm_runtime_mark_last_busy(p->port.dev);
 	pm_runtime_put_autosuspend(p->port.dev);
 }
+EXPORT_SYMBOL_GPL(serial8250_rpm_put);
 
 /**
  *	serial8250_em485_init() - put uart_8250_port into rs485 emulating