[RFC PATCH 13/20] cxl/mem: Refactor cxl pmem region auto-assembling

[Neeraj Kumar <s.neeraj@samsung.com>]

In 84ec985944ef3, For cxl pmem region auto-assembly after endpoint port
probing, cxl_nvd presence was required. And for cxl region persistency,
region creation happens during nvdimm_probe which need the completion
of endpoint probe.

It is therefore refactored cxl pmem region auto-assembly after endpoint
probing to cxl mem probing

Signed-off-by: Neeraj Kumar <s.neeraj@samsung.com>
---
 drivers/cxl/core/port.c | 38 ++++++++++++++++++++++++++++++++++++++
 drivers/cxl/cxl.h       |  1 +
 drivers/cxl/mem.c       | 27 ++++++++++++++++++---------
 drivers/cxl/port.c      | 38 --------------------------------------
 4 files changed, 57 insertions(+), 47 deletions(-)

diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 78a5c2c25982..bca668193c49 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -1038,6 +1038,44 @@ void put_cxl_root(struct cxl_root *cxl_root)
 }
 EXPORT_SYMBOL_NS_GPL(put_cxl_root, "CXL");
 
+static int discover_region(struct device *dev, void *root)
+{
+	struct cxl_endpoint_decoder *cxled;
+	int rc;
+
+	if (!is_endpoint_decoder(dev))
+		return 0;
+
+	cxled = to_cxl_endpoint_decoder(dev);
+	if ((cxled->cxld.flags & CXL_DECODER_F_ENABLE) == 0)
+		return 0;
+
+	if (cxled->state != CXL_DECODER_STATE_AUTO)
+		return 0;
+
+	/*
+	 * Region enumeration is opportunistic, if this add-event fails,
+	 * continue to the next endpoint decoder.
+	 */
+	rc = cxl_add_to_region(root, cxled);
+	if (rc)
+		dev_dbg(dev, "failed to add to region: %#llx-%#llx\n",
+			cxled->cxld.hpa_range.start, cxled->cxld.hpa_range.end);
+
+	return 0;
+}
+
+void cxl_region_discovery(struct cxl_port *port)
+{
+	struct cxl_port *root;
+	struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
+
+	root = &cxl_root->port;
+
+	device_for_each_child(&port->dev, root, discover_region);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_region_discovery, "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 dcf2a127efc7..9423ea3509ad 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -869,6 +869,7 @@ bool is_cxl_nvdimm(struct device *dev);
 bool is_cxl_nvdimm_bridge(struct device *dev);
 int devm_cxl_add_nvdimm(struct cxl_port *parent_port, struct cxl_memdev *cxlmd);
 struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_port *port);
+void cxl_region_discovery(struct cxl_port *port);
 
 #ifdef CONFIG_CXL_REGION
 bool is_cxl_pmem_region(struct device *dev);
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 2f03a4d5606e..aaea4eb178ef 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -152,15 +152,6 @@ static int cxl_mem_probe(struct device *dev)
 		return -ENXIO;
 	}
 
-	if (resource_size(&cxlds->pmem_res) && IS_ENABLED(CONFIG_CXL_PMEM)) {
-		rc = devm_cxl_add_nvdimm(parent_port, cxlmd);
-		if (rc) {
-			if (rc == -ENODEV)
-				dev_info(dev, "PMEM disabled by platform\n");
-			return rc;
-		}
-	}
-
 	if (dport->rch)
 		endpoint_parent = parent_port->uport_dev;
 	else
@@ -180,6 +171,24 @@ static int cxl_mem_probe(struct device *dev)
 			return rc;
 	}
 
+	if (resource_size(&cxlds->pmem_res) && IS_ENABLED(CONFIG_CXL_PMEM)) {
+		rc = devm_cxl_add_nvdimm(parent_port, cxlmd);
+		if (rc) {
+			if (rc == -ENODEV)
+				dev_info(dev, "PMEM disabled by platform\n");
+			return rc;
+		}
+	}
+
+	/*
+	 * Now that all endpoint decoders are successfully enumerated, try to
+	 * assemble region autodiscovery from committed decoders.
+	 * Earlier it was part of cxl_endpoint_port_probe, So moved it here
+	 * as cxl_nvd of the memdev needs to be available during the pmem
+	 * region auto-assembling
+	 */
+	cxl_region_discovery(cxlmd->endpoint);
+
 	/*
 	 * The kernel may be operating out of CXL memory on this device,
 	 * there is no spec defined way to determine whether this device
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index d2bfd1ff5492..361544760a4c 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -30,33 +30,6 @@ static void schedule_detach(void *cxlmd)
 	schedule_cxl_memdev_detach(cxlmd);
 }
 
-static int discover_region(struct device *dev, void *root)
-{
-	struct cxl_endpoint_decoder *cxled;
-	int rc;
-
-	if (!is_endpoint_decoder(dev))
-		return 0;
-
-	cxled = to_cxl_endpoint_decoder(dev);
-	if ((cxled->cxld.flags & CXL_DECODER_F_ENABLE) == 0)
-		return 0;
-
-	if (cxled->state != CXL_DECODER_STATE_AUTO)
-		return 0;
-
-	/*
-	 * Region enumeration is opportunistic, if this add-event fails,
-	 * continue to the next endpoint decoder.
-	 */
-	rc = cxl_add_to_region(root, cxled);
-	if (rc)
-		dev_dbg(dev, "failed to add to region: %#llx-%#llx\n",
-			cxled->cxld.hpa_range.start, cxled->cxld.hpa_range.end);
-
-	return 0;
-}
-
 static int cxl_switch_port_probe(struct cxl_port *port)
 {
 	struct cxl_hdm *cxlhdm;
@@ -95,7 +68,6 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
 	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
 	struct cxl_hdm *cxlhdm;
-	struct cxl_port *root;
 	int rc;
 
 	rc = cxl_dvsec_rr_decode(cxlds, &info);
@@ -125,20 +97,10 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
 	rc = devm_cxl_enumerate_decoders(cxlhdm, &info);
 	if (rc)
 		return rc;
-
 	/*
 	 * This can't fail in practice as CXL root exit unregisters all
 	 * descendant ports and that in turn synchronizes with cxl_port_probe()
 	 */
-	struct cxl_root *cxl_root __free(put_cxl_root) = find_cxl_root(port);
-
-	root = &cxl_root->port;
-
-	/*
-	 * Now that all endpoint decoders are successfully enumerated, try to
-	 * assemble regions from committed decoders
-	 */
-	device_for_each_child(&port->dev, root, discover_region);
 
 	return 0;
 }
-- 
2.34.1