serial: introduce uart_port_lock() guard()s

Having this, guards like these work:
  guard(uart_port_lock_irq)(&up->port);
or
  scoped_guard(uart_port_lock_irqsave, port) {
    ...
  }

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

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250814072456.182853-4-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index 84b4648ead7e041af0460cc1ac35258c5db1d6cb..666430b4789977ae19641442b369eb1c773233f4 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -788,6 +788,19 @@ static inline void uart_port_unlock_irqrestore(struct uart_port *up, unsigned lo
        spin_unlock_irqrestore(&up->lock, flags);
 }
 
+DEFINE_GUARD(uart_port_lock, struct uart_port *, uart_port_lock(_T), uart_port_unlock(_T));
+DEFINE_GUARD_COND(uart_port_lock, _try, uart_port_trylock(_T));
+
+DEFINE_GUARD(uart_port_lock_irq, struct uart_port *, uart_port_lock_irq(_T),
+            uart_port_unlock_irq(_T));
+
+DEFINE_LOCK_GUARD_1(uart_port_lock_irqsave, struct uart_port,
+                    uart_port_lock_irqsave(_T->lock, &_T->flags),
+                    uart_port_unlock_irqrestore(_T->lock, _T->flags),
+                    unsigned long flags);
+DEFINE_LOCK_GUARD_1_COND(uart_port_lock_irqsave, _try,
+                        uart_port_trylock_irqsave(_T->lock, &_T->flags));
+
 static inline int serial_port_in(struct uart_port *up, int offset)
 {
        return up->serial_in(up, offset);