cxl: Fix devm host device for CXL fwctl initialization

Testing revealed the following error message for a CXL memdev that has
Feature support:
[   56.690430] cxl mem0: Resources present before probing

Attach the allocation of cxl_fwctl to the parent device of cxl_memdev.
devm_add_* calls for cxl_memdev should not happen before the memdev
probe function or outside the scope of the memdev driver.

cxl_test missed this bug because cxl_test always arranges for the
cxl_mem driver to be loaded before cxl_mock_mem runs. So the driver core
always finds the devres list idle in that case.

[DJ: Updated subject title and added commit log suggestion from djbw]

Fixes: 858ce2f ("cxl: Add FWCTL support to CXL")
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Link: https://lore.kernel.org/linux-cxl/6801aea053466_71fe2944c@dwillia2-xfh.jf.intel.com.notmuch/
Link: https://patch.msgid.link/20250418002933.406439-1-dave.jiang@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: davejiang

drivers/cxl/core/features.c

@@ -677,7 +677,7 @@ static void free_memdev_fwctl(void *_fwctl_dev)
 	fwctl_put(fwctl_dev);
 }
 
-int devm_cxl_setup_fwctl(struct cxl_memdev *cxlmd)
+int devm_cxl_setup_fwctl(struct device *host, struct cxl_memdev *cxlmd)
 {
 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
 	struct cxl_features_state *cxlfs;
@@ -700,7 +700,7 @@ int devm_cxl_setup_fwctl(struct cxl_memdev *cxlmd)
 	if (rc)
 		return rc;
 
-	return devm_add_action_or_reset(&cxlmd->dev, free_memdev_fwctl,
+	return devm_add_action_or_reset(host, free_memdev_fwctl,
 					no_free_ptr(fwctl_dev));
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_fwctl, "CXL");

drivers/cxl/pci.c

@@ -1018,7 +1018,7 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	if (rc)
 		return rc;
 
-	rc = devm_cxl_setup_fwctl(cxlmd);
+	rc = devm_cxl_setup_fwctl(&pdev->dev, cxlmd);
 	if (rc)
 		dev_dbg(&pdev->dev, "No CXL FWCTL setup\n");
 

include/cxl/features.h

@@ -66,7 +66,7 @@ struct cxl_memdev;
 #ifdef CONFIG_CXL_FEATURES
 inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds);
 int devm_cxl_setup_features(struct cxl_dev_state *cxlds);
-int devm_cxl_setup_fwctl(struct cxl_memdev *cxlmd);
+int devm_cxl_setup_fwctl(struct device *host, struct cxl_memdev *cxlmd);
 #else
 static inline struct cxl_features_state *to_cxlfs(struct cxl_dev_state *cxlds)
 {
@@ -78,7 +78,8 @@ static inline int devm_cxl_setup_features(struct cxl_dev_state *cxlds)
 	return -EOPNOTSUPP;
 }
 
-static inline int devm_cxl_setup_fwctl(struct cxl_memdev *cxlmd)
+static inline int devm_cxl_setup_fwctl(struct device *host,
+				       struct cxl_memdev *cxlmd)
 {
 	return -EOPNOTSUPP;
 }

tools/testing/cxl/test/mem.c

@@ -1780,7 +1780,7 @@ static int cxl_mock_mem_probe(struct platform_device *pdev)
 	if (rc)
 		return rc;
 
-	rc = devm_cxl_setup_fwctl(cxlmd);
+	rc = devm_cxl_setup_fwctl(&pdev->dev, cxlmd);
 	if (rc)
 		dev_dbg(dev, "No CXL FWCTL setup\n");