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 cfe6ba286b45fc9ced2b39bf9bb82f3631922e02..58e64c4e1e3a876a5124f03818a76d5116bdc839 100644 (file)
--- 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 2da9db960d09f13d31cd195c3505115910119171..5afae40256964b783ad294208b97b75dd7706f02 100644 (file)
--- 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