xen/pvcalls: use WARN_ON(1) instead of __WARN()

__WARN() is an internal helper that is only available on
some architectures, but causes a build error e.g. on ARM64
in some configurations:

drivers/xen/pvcalls-back.c: In function 'set_backend_state':
drivers/xen/pvcalls-back.c:1097:5: error: implicit declaration of function '__WARN' [-Werror=implicit-function-declaration]

Unfortunately, there is no equivalent of BUG() that takes no
arguments, but WARN_ON(1) is commonly used in other drivers
and works on all configurations.

Fixes: 7160378206b2 ("xen/pvcalls: xenbus state handling")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c
index 3201a0c5dbcf70b65dafdc3d1bcf6f935c07fea0..b209cd44bb8dce76fe44e10e0349af51fee7880c 100644 (file)
--- a/drivers/xen/pvcalls-back.c
+++ b/drivers/xen/pvcalls-back.c
@@ -1098,7 +1098,7 @@ static void set_backend_state(struct xenbus_device *dev,
                                xenbus_switch_state(dev, XenbusStateClosing);
                                break;
                        default:
-                               __WARN();
+                               WARN_ON(1);
                        }
                        break;
                case XenbusStateInitWait:
@@ -1113,7 +1113,7 @@ static void set_backend_state(struct xenbus_device *dev,
                                xenbus_switch_state(dev, XenbusStateClosing);
                                break;
                        default:
-                               __WARN();
+                               WARN_ON(1);
                        }
                        break;
                case XenbusStateConnected:
@@ -1127,7 +1127,7 @@ static void set_backend_state(struct xenbus_device *dev,
                                xenbus_switch_state(dev, XenbusStateClosing);
                                break;
                        default:
-                               __WARN();
+                               WARN_ON(1);
                        }
                        break;
                case XenbusStateClosing:
@@ -1138,11 +1138,11 @@ static void set_backend_state(struct xenbus_device *dev,
                                xenbus_switch_state(dev, XenbusStateClosed);
                                break;
                        default:
-                               __WARN();
+                               WARN_ON(1);
                        }
                        break;
                default:
-                       __WARN();
+                       WARN_ON(1);
                }
        }
 }