On 2/11/26 22:10, Cheatham, Benjamin wrote:

On 2/1/2026 9:54 AM, alejandro.lucero-palau@amd.com wrote:

quoted

From: Alejandro Lucero <redacted>

By definition a type2 cxl device will use the host managed memory for
specific functionality, therefore it should not be available to other
uses.

Signed-off-by: Alejandro Lucero <redacted>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Davidlohr Bueso <redacted>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ben Cheatham <redacted>
---
  drivers/cxl/core/region.c | 7 +++++++
  1 file changed, 7 insertions(+)

diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 293e63dfef22..12df717cc881 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c

@@ -4441,6 +4441,13 @@ static int cxl_region_probe(struct device *dev)
  	if (rc)
  		return rc;
  
+	/*
+	 * HDM-D[B] (device-memory) regions have accelerator specific usage.
+	 * Skip device-dax registration.
+	 */
+	if (cxlr->type == CXL_DECODER_DEVMEM)
+		return 0;

Minor nit: Should probably move this to be the first thing in the function. It would save
having to acquire a lock in cxl_region_can_probe() above. Keep my reviewed-by either way,
it's really just a minor optimization.

It makes sense. I'll do it.

Thanks

quoted

+
  	/*
  	 * From this point on any path that changes the region's state away from
  	 * CXL_CONFIG_COMMIT is also responsible for releasing the driver.