[PATCH v2 03/10] scsi: libsas: Add dev_parent_is_expander() helper

[Niklas Cassel <cassel@kernel.org>]

Many libsas drivers check if the parent of the device is an expander.
Create a helper that the libsas drivers will use in follow up commits.

Suggested-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Niklas Cassel <cassel@kernel.org>
---
 drivers/scsi/libsas/sas_expander.c | 5 +----
 include/scsi/libsas.h              | 8 ++++++++
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/scsi/libsas/sas_expander.c b/drivers/scsi/libsas/sas_expander.c
index 869b5d4db44c..d953225f6cc2 100644
--- a/drivers/scsi/libsas/sas_expander.c
+++ b/drivers/scsi/libsas/sas_expander.c
@@ -1313,10 +1313,7 @@ static int sas_check_parent_topology(struct domain_device *child)
 	int i;
 	int res = 0;
 
-	if (!child->parent)
-		return 0;
-
-	if (!dev_is_expander(child->parent->dev_type))
+	if (!dev_parent_is_expander(child))
 		return 0;
 
 	parent_ex = &child->parent->ex_dev;
diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index ba460b6c0374..8d38565e99fa 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -203,6 +203,14 @@ static inline bool dev_is_expander(enum sas_device_type type)
 	       type == SAS_FANOUT_EXPANDER_DEVICE;
 }
 
+static inline bool dev_parent_is_expander(struct domain_device *dev)
+{
+	if (!dev->parent)
+		return false;
+
+	return dev_is_expander(dev->parent->dev_type);
+}
+
 static inline void INIT_SAS_WORK(struct sas_work *sw, void (*fn)(struct work_struct *))
 {
 	INIT_WORK(&sw->work, fn);
-- 
2.50.1