[v5,1/5] cxl: Introduce put_cxl_root() helper

Commit Message

Dave Jiang Jan. 5, 2024, 6:03 p.m. UTC

Add a helper function put_cxl_root() to maintain symmetry for
find_cxl_root() function instead of relying on open coding of the
put_device() in order to dereference the 'struct device' that happens via
get_device() in find_cxl_root().

Suggested-by: Robert Richter <[e-mail]>
Signed-off-by: Dave Jiang <[e-mail]>
---
v5:
- Move out usages for follow on cleanup. (Dan)
v4:
- Adjust ordering of this patch to front. (Dan)
v3:
- Adjust for cxl_root as parameter for find_cxl_root()
- Add NULL ptr check fore __free(). (Dan)
- Fix DEFINE_FREE() macro to name it put_cxl_root (Dan)
- Cleanup all functions calling put_cxl_root() and related calls. (Dan)
v2:
- Make put_cxl_root() an exported function to be symmetric to
  find_cxl_root(). (Robert)
---
 drivers/cxl/core/port.c |    9 +++++++++
 drivers/cxl/cxl.h       |    1 +
 2 files changed, 10 insertions(+)

Patch

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 8c00fd6be730..64f30d5fe1f6 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -986,6 +986,15 @@  struct cxl_port *find_cxl_root(struct cxl_port *port)
 }
 EXPORT_SYMBOL_NS_GPL(find_cxl_root, CXL);
 
+void put_cxl_root(struct cxl_root *cxl_root)
+{
+	if (!cxl_root)
+		return;
+
+	put_device(&cxl_root->port.dev);
+}
+EXPORT_SYMBOL_NS_GPL(put_cxl_root, CXL);
+
 static struct cxl_dport *find_dport(struct cxl_port *port, int id)
 {
 	struct cxl_dport *dport;
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 492dbf63935f..ffa56af7b0d4 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -735,6 +735,7 @@  struct cxl_port *devm_cxl_add_port(struct device *host,
 struct cxl_root *devm_cxl_add_root(struct device *host,
 				   const struct cxl_root_ops *ops);
 struct cxl_port *find_cxl_root(struct cxl_port *port);
+void put_cxl_root(struct cxl_root *cxl_root);
 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
 void cxl_bus_rescan(void);
 void cxl_bus_drain(void);