[PATCH 3/5] cxl/memdev: Pin parents for entire memdev lifetime

[Dan Williams <djbw@kernel.org>]

In order to be able to manage the driver that uses a memdev attach
mechanism the parent needs to stick around for the
device_release_driver(cxlmd->dev.parent) event.

Fixes: 29317f8dc6ed ("cxl/mem: Introduce cxl_memdev_attach for CXL-dependent operation")
Signed-off-by: Dan Williams <djbw@kernel.org>
---
 drivers/cxl/core/memdev.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/cxl/core/memdev.c b/drivers/cxl/core/memdev.c
index 80e65690eb77..91c99eeea92c 100644
--- a/drivers/cxl/core/memdev.c
+++ b/drivers/cxl/core/memdev.c
@@ -25,9 +25,11 @@ static DEFINE_IDA(cxl_memdev_ida);
 static void cxl_memdev_release(struct device *dev)
 {
 	struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
+	struct device *parent = dev->parent;
 
 	ida_free(&cxl_memdev_ida, cxlmd->id);
 	kfree(cxlmd);
+	put_device(parent);
 }
 
 static char *cxl_memdev_devnode(const struct device *dev, umode_t *mode, kuid_t *uid,
@@ -707,7 +709,7 @@ static struct cxl_memdev *cxl_memdev_alloc(struct cxl_dev_state *cxlds,
 	dev = &cxlmd->dev;
 	device_initialize(dev);
 	lockdep_set_class(&dev->mutex, &cxl_memdev_key);
-	dev->parent = cxlds->dev;
+	dev->parent = get_device(cxlds->dev);
 	dev->bus = &cxl_bus_type;
 	dev->devt = MKDEV(cxl_mem_major, cxlmd->id);
 	dev->type = &cxl_memdev_type;
-- 
2.53.0