Introduce grab and ungrab upcalls. When the kernel desires to grab the

console, it calls the grab functions. These functions should turn off
the RX interrupts, and any others that interfere. This makes mountroot
prompt work again. If there's more generalized need other than
prompting, many of these routines should be expanded to do those new
things.

Should have been part of r260889, but waasn't due to command line typo.

Reviewed by:	bde (with reservations)

1 files changed, 27 insertions, 0 deletions

diff --git a/sys/dev/uart/uart_core.c b/sys/dev/uart/uart_core.c
index 17dabd7..08ac576 100644
--- a/sys/dev/uart/uart_core.c
+++ b/sys/dev/uart/uart_core.c
@@ -412,6 +412,13 @@ uart_bus_attach(device_t dev)
 		sc = sc0;
 
 	/*
+	 * Now that we know the softc for this device, connect the back
+	 * pointer from the sysdev for this device, if any
+	 */
+	if (sc->sc_sysdev != NULL)
+		sc->sc_sysdev->sc = sc;
+
+	/*
 	 * Protect ourselves against interrupts while we're not completely
 	 * finished attaching and initializing. We don't expect interrupts
 	 * until after UART_ATTACH() though.
@@ -617,3 +624,23 @@ uart_bus_resume(device_t dev)
 	sc = device_get_softc(dev);
 	return (UART_ATTACH(sc));
 }
+
+void
+uart_grab(struct uart_devinfo *di)
+{
+
+	uart_lock(di->hwmtx);
+	if (di->sc)
+		UART_GRAB(di->sc);
+	uart_unlock(di->hwmtx);
+}
+
+void
+uart_ungrab(struct uart_devinfo *di)
+{
+
+	uart_lock(di->hwmtx);
+	if (di->sc)
+		UART_UNGRAB(di->sc);
+	uart_unlock(di->hwmtx);
+}