Now that the driver core can properly handle constant struct bus_type,
move the cxl_bus_type variable to be a constant structure as well,
placing it into read-only memory which can not be modified at runtime.

Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Jonathan Cameron <jonathan.cameron@huawei.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linux-cxl@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/cxl/core/port.c | 2 +-
 drivers/cxl/cxl.h       | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index eb46c6764d20..0696f7fcef56 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -2293,7 +2293,7 @@ static const struct attribute_group *cxl_bus_attribute_groups[] = {
 	NULL,
 };
 
-struct bus_type cxl_bus_type = {
+const struct bus_type cxl_bus_type = {
 	.name = "cxl",
 	.uevent = cxl_bus_uevent,
 	.match = cxl_bus_match,
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 3f1695c96abc..e7b66ca1d423 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -815,7 +815,7 @@ int cxl_dvsec_rr_decode(struct cxl_dev_state *cxlds,
 
 bool is_cxl_region(struct device *dev);
 
-extern struct bus_type cxl_bus_type;
+extern const struct bus_type cxl_bus_type;
 
 struct cxl_driver {
 	const char *name;
-- 
2.50.0

On Tue, Jul 01, 2025 at 01:53:13PM +0200, Greg Kroah-Hartman wrote:
> Now that the driver core can properly handle constant struct bus_type,
> move the cxl_bus_type variable to be a constant structure as well,
> placing it into read-only memory which can not be modified at runtime.

Ugh, got the subject wrong, let me go fix up...