Merge branch 'for-6.5/cxl-rch-eh' into for-6.5/cxl

Pick up the first half of the RCH error handling series. The back half
needs some fixups for test regressions. Small conflicts with the PMU
work around register enumeration and setup helpers.

16 files changed, 488 insertions, 326 deletions

diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index 603e5df8aec0..658e6b84a769 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -327,66 +327,21 @@ __mock struct acpi_device *to_cxl_host_bridge(struct device *host,
 	return NULL;
 }
 
-/*
- * A host bridge is a dport to a CFMWS decode and it is a uport to the
- * dport (PCIe Root Ports) in the host bridge.
- */
-static int add_host_bridge_uport(struct device *match, void *arg)
-{
-	struct cxl_port *root_port = arg;
-	struct device *host = root_port->dev.parent;
-	struct acpi_device *hb = to_cxl_host_bridge(host, match);
-	struct acpi_pci_root *pci_root;
-	struct cxl_dport *dport;
-	struct cxl_port *port;
-	struct device *bridge;
-	int rc;
-
-	if (!hb)
-		return 0;
-
-	pci_root = acpi_pci_find_root(hb->handle);
-	bridge = pci_root->bus->bridge;
-	dport = cxl_find_dport_by_dev(root_port, bridge);
-	if (!dport) {
-		dev_dbg(host, "host bridge expected and not found\n");
-		return 0;
-	}
-
-	if (dport->rch) {
-		dev_info(bridge, "host supports CXL (restricted)\n");
-		return 0;
-	}
-
-	rc = devm_cxl_register_pci_bus(host, bridge, pci_root->bus);
-	if (rc)
-		return rc;
-
-	port = devm_cxl_add_port(host, bridge, dport->component_reg_phys,
-				 dport);
-	if (IS_ERR(port))
-		return PTR_ERR(port);
-
-	dev_info(bridge, "host supports CXL\n");
-
-	return 0;
-}
-
+/* Note, @dev is used by mock_acpi_table_parse_cedt() */
 struct cxl_chbs_context {
 	struct device *dev;
 	unsigned long long uid;
-	resource_size_t rcrb;
-	resource_size_t chbcr;
+	resource_size_t base;
 	u32 cxl_version;
 };
 
-static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
-			 const unsigned long end)
+static int cxl_get_chbs_iter(union acpi_subtable_headers *header, void *arg,
+			     const unsigned long end)
 {
 	struct cxl_chbs_context *ctx = arg;
 	struct acpi_cedt_chbs *chbs;
 
-	if (ctx->chbcr)
+	if (ctx->base != CXL_RESOURCE_NONE)
 		return 0;
 
 	chbs = (struct acpi_cedt_chbs *) header;
@@ -395,23 +350,39 @@ static int cxl_get_chbcr(union acpi_subtable_headers *header, void *arg,
 		return 0;
 
 	ctx->cxl_version = chbs->cxl_version;
-	ctx->rcrb = CXL_RESOURCE_NONE;
-	ctx->chbcr = CXL_RESOURCE_NONE;
-
 	if (!chbs->base)
 		return 0;
 
-	if (chbs->cxl_version != ACPI_CEDT_CHBS_VERSION_CXL11) {
-		ctx->chbcr = chbs->base;
+	if (chbs->cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11 &&
+	    chbs->length != CXL_RCRB_SIZE)
 		return 0;
+
+	ctx->base = chbs->base;
+
+	return 0;
+}
+
+static int cxl_get_chbs(struct device *dev, struct acpi_device *hb,
+			struct cxl_chbs_context *ctx)
+{
+	unsigned long long uid;
+	int rc;
+
+	rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid);
+	if (rc != AE_OK) {
+		dev_err(dev, "unable to retrieve _UID\n");
+		return -ENOENT;
 	}
 
-	if (chbs->length != CXL_RCRB_SIZE)
-		return 0;
+	dev_dbg(dev, "UID found: %lld\n", uid);
+	*ctx = (struct cxl_chbs_context) {
+		.dev = dev,
+		.uid = uid,
+		.base = CXL_RESOURCE_NONE,
+		.cxl_version = UINT_MAX,
+	};
 
-	ctx->rcrb = chbs->base;
-	ctx->chbcr = cxl_rcrb_to_component(ctx->dev, chbs->base,
-					   CXL_RCRB_DOWNSTREAM);
+	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbs_iter, ctx);
 
 	return 0;
 }
@@ -420,7 +391,6 @@ static int add_host_bridge_dport(struct device *match, void *arg)
 {
 	acpi_status rc;
 	struct device *bridge;
-	unsigned long long uid;
 	struct cxl_dport *dport;
 	struct cxl_chbs_context ctx;
 	struct acpi_pci_root *pci_root;
@@ -431,51 +401,107 @@ static int add_host_bridge_dport(struct device *match, void *arg)
 	if (!hb)
 		return 0;
 
-	rc = acpi_evaluate_integer(hb->handle, METHOD_NAME__UID, NULL, &uid);
-	if (rc != AE_OK) {
-		dev_err(match, "unable to retrieve _UID\n");
-		return -ENODEV;
-	}
-
-	dev_dbg(match, "UID found: %lld\n", uid);
-
-	ctx = (struct cxl_chbs_context) {
-		.dev = match,
-		.uid = uid,
-	};
-	acpi_table_parse_cedt(ACPI_CEDT_TYPE_CHBS, cxl_get_chbcr, &ctx);
+	rc = cxl_get_chbs(match, hb, &ctx);
+	if (rc)
+		return rc;
 
-	if (!ctx.chbcr) {
+	if (ctx.cxl_version == UINT_MAX) {
 		dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n",
-			 uid);
+			 ctx.uid);
 		return 0;
 	}
 
-	if (ctx.rcrb != CXL_RESOURCE_NONE)
-		dev_dbg(match, "RCRB found for UID %lld: %pa\n", uid, &ctx.rcrb);
-
-	if (ctx.chbcr == CXL_RESOURCE_NONE) {
-		dev_warn(match, "CHBCR invalid for Host Bridge (UID %lld)\n",
-			 uid);
+	if (ctx.base == CXL_RESOURCE_NONE) {
+		dev_warn(match, "CHBS invalid for Host Bridge (UID %lld)\n",
+			 ctx.uid);
 		return 0;
 	}
 
-	dev_dbg(match, "CHBCR found: %pa\n", &ctx.chbcr);
-
 	pci_root = acpi_pci_find_root(hb->handle);
 	bridge = pci_root->bus->bridge;
-	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11)
-		dport = devm_cxl_add_rch_dport(root_port, bridge, uid,
-					       ctx.chbcr, ctx.rcrb);
-	else
-		dport = devm_cxl_add_dport(root_port, bridge, uid,
-					   ctx.chbcr);
+
+	/*
+	 * In RCH mode, bind the component regs base to the dport. In
+	 * VH mode it will be bound to the CXL host bridge's port
+	 * object later in add_host_bridge_uport().
+	 */
+	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) {
+		dev_dbg(match, "RCRB found for UID %lld: %pa\n", ctx.uid,
+			&ctx.base);
+		dport = devm_cxl_add_rch_dport(root_port, bridge, ctx.uid,
+					       ctx.base);
+	} else {
+		dport = devm_cxl_add_dport(root_port, bridge, ctx.uid,
+					   CXL_RESOURCE_NONE);
+	}
+
 	if (IS_ERR(dport))
 		return PTR_ERR(dport);
 
 	return 0;
 }
 
+/*
+ * A host bridge is a dport to a CFMWS decode and it is a uport to the
+ * dport (PCIe Root Ports) in the host bridge.
+ */
+static int add_host_bridge_uport(struct device *match, void *arg)
+{
+	struct cxl_port *root_port = arg;
+	struct device *host = root_port->dev.parent;
+	struct acpi_device *hb = to_cxl_host_bridge(host, match);
+	struct acpi_pci_root *pci_root;
+	struct cxl_dport *dport;
+	struct cxl_port *port;
+	struct device *bridge;
+	struct cxl_chbs_context ctx;
+	resource_size_t component_reg_phys;
+	int rc;
+
+	if (!hb)
+		return 0;
+
+	pci_root = acpi_pci_find_root(hb->handle);
+	bridge = pci_root->bus->bridge;
+	dport = cxl_find_dport_by_dev(root_port, bridge);
+	if (!dport) {
+		dev_dbg(host, "host bridge expected and not found\n");
+		return 0;
+	}
+
+	if (dport->rch) {
+		dev_info(bridge, "host supports CXL (restricted)\n");
+		return 0;
+	}
+
+	rc = cxl_get_chbs(match, hb, &ctx);
+	if (rc)
+		return rc;
+
+	if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) {
+		dev_warn(bridge,
+			 "CXL CHBS version mismatch, skip port registration\n");
+		return 0;
+	}
+
+	component_reg_phys = ctx.base;
+	if (component_reg_phys != CXL_RESOURCE_NONE)
+		dev_dbg(match, "CHBCR found for UID %lld: %pa\n",
+			ctx.uid, &component_reg_phys);
+
+	rc = devm_cxl_register_pci_bus(host, bridge, pci_root->bus);
+	if (rc)
+		return rc;
+
+	port = devm_cxl_add_port(host, bridge, component_reg_phys, dport);
+	if (IS_ERR(port))
+		return PTR_ERR(port);
+
+	dev_info(bridge, "host supports CXL\n");
+
+	return 0;
+}
+
 static int add_root_nvdimm_bridge(struct device *match, void *data)
 {
 	struct cxl_decoder *cxld;
diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index 99d4a967eca6..45e7e044cf4a 100644
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -64,6 +64,16 @@ int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size);
 int cxl_dpa_free(struct cxl_endpoint_decoder *cxled);
 resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled);
 resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled);
+
+enum cxl_rcrb {
+	CXL_RCRB_DOWNSTREAM,
+	CXL_RCRB_UPSTREAM,
+};
+struct cxl_rcrb_info;
+resource_size_t __rcrb_to_component(struct device *dev,
+				    struct cxl_rcrb_info *ri,
+				    enum cxl_rcrb which);
+
 extern struct rw_semaphore cxl_dpa_rwsem;
 
 int cxl_memdev_init(void);
diff --git a/drivers/cxl/core/hdm.c b/drivers/cxl/core/hdm.c
index 715c1f103739..4449b34a80cc 100644
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -85,6 +85,7 @@ static int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb,
 				struct cxl_component_regs *regs)
 {
 	struct cxl_register_map map = {
+		.dev = &port->dev,
 		.resource = port->component_reg_phys,
 		.base = crb,
 		.max_size = CXL_COMPONENT_REG_BLOCK_SIZE,
@@ -97,8 +98,7 @@ static int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb,
 		return -ENODEV;
 	}
 
-	return cxl_map_component_regs(&port->dev, regs, &map,
-				      BIT(CXL_CM_CAP_CAP_ID_HDM));
+	return cxl_map_component_regs(&map, regs, BIT(CXL_CM_CAP_CAP_ID_HDM));
 }
 
 static bool should_emulate_decoders(struct cxl_endpoint_dvsec_info *info)
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 74962b18e3b2..c7a7887ebdcf 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -67,7 +67,7 @@ static int match_add_dports(struct pci_dev *pdev, void *data)
 
 /**
  * devm_cxl_port_enumerate_dports - enumerate downstream ports of the upstream port
- * @port: cxl_port whose ->uport is the upstream of dports to be enumerated
+ * @port: cxl_port whose ->uport_dev is the upstream of dports to be enumerated
  *
  * Returns a positive number of dports enumerated or a negative error
  * code.
@@ -603,7 +603,7 @@ static int cxl_cdat_read_table(struct device *dev,
  */
 void read_cdat_data(struct cxl_port *port)
 {
-	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport);
+	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport_dev);
 	struct device *host = cxlmd->dev.parent;
 	struct device *dev = &port->dev;
 	struct pci_doe_mb *cdat_doe;
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 835064a189a1..724be8448eb4 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -563,9 +563,9 @@ static void unregister_port(void *_port)
 	 * unregistered while holding their parent port lock.
 	 */
 	if (!parent)
-		lock_dev = port->uport;
+		lock_dev = port->uport_dev;
 	else if (is_cxl_root(parent))
-		lock_dev = parent->uport;
+		lock_dev = parent->uport_dev;
 	else
 		lock_dev = &parent->dev;
 
@@ -585,7 +585,8 @@ static int devm_cxl_link_uport(struct device *host, struct cxl_port *port)
 {
 	int rc;
 
-	rc = sysfs_create_link(&port->dev.kobj, &port->uport->kobj, "uport");
+	rc = sysfs_create_link(&port->dev.kobj, &port->uport_dev->kobj,
+			       "uport");
 	if (rc)
 		return rc;
 	return devm_add_action_or_reset(host, cxl_unlink_uport, port);
@@ -607,7 +608,7 @@ static int devm_cxl_link_parent_dport(struct device *host,
 	if (!parent_dport)
 		return 0;
 
-	rc = sysfs_create_link(&port->dev.kobj, &parent_dport->dport->kobj,
+	rc = sysfs_create_link(&port->dev.kobj, &parent_dport->dport_dev->kobj,
 			       "parent_dport");
 	if (rc)
 		return rc;
@@ -616,7 +617,7 @@ static int devm_cxl_link_parent_dport(struct device *host,
 
 static struct lock_class_key cxl_port_key;
 
-static struct cxl_port *cxl_port_alloc(struct device *uport,
+static struct cxl_port *cxl_port_alloc(struct device *uport_dev,
 				       resource_size_t component_reg_phys,
 				       struct cxl_dport *parent_dport)
 {
@@ -632,7 +633,7 @@ static struct cxl_port *cxl_port_alloc(struct device *uport,
 	if (rc < 0)
 		goto err;
 	port->id = rc;
-	port->uport = uport;
+	port->uport_dev = uport_dev;
 
 	/*
 	 * The top-level cxl_port "cxl_root" does not have a cxl_port as
@@ -660,12 +661,13 @@ static struct cxl_port *cxl_port_alloc(struct device *uport,
 		if (iter->host_bridge)
 			port->host_bridge = iter->host_bridge;
 		else if (parent_dport->rch)
-			port->host_bridge = parent_dport->dport;
+			port->host_bridge = parent_dport->dport_dev;
 		else
-			port->host_bridge = iter->uport;
-		dev_dbg(uport, "host-bridge: %s\n", dev_name(port->host_bridge));
+			port->host_bridge = iter->uport_dev;
+		dev_dbg(uport_dev, "host-bridge: %s\n",
+			dev_name(port->host_bridge));
 	} else
-		dev->parent = uport;
+		dev->parent = uport_dev;
 
 	port->component_reg_phys = component_reg_phys;
 	ida_init(&port->decoder_ida);
@@ -688,8 +690,38 @@ err:
 	return ERR_PTR(rc);
 }
 
+static int cxl_setup_comp_regs(struct device *dev, struct cxl_register_map *map,
+			       resource_size_t component_reg_phys)
+{
+	if (component_reg_phys == CXL_RESOURCE_NONE)
+		return 0;
+
+	*map = (struct cxl_register_map) {
+		.dev = dev,
+		.reg_type = CXL_REGLOC_RBI_COMPONENT,
+		.resource = component_reg_phys,
+		.max_size = CXL_COMPONENT_REG_BLOCK_SIZE,
+	};
+
+	return cxl_setup_regs(map);
+}
+
+static inline int cxl_port_setup_regs(struct cxl_port *port,
+				      resource_size_t component_reg_phys)
+{
+	return cxl_setup_comp_regs(&port->dev, &port->comp_map,
+				   component_reg_phys);
+}
+
+static inline int cxl_dport_setup_regs(struct cxl_dport *dport,
+				       resource_size_t component_reg_phys)
+{
+	return cxl_setup_comp_regs(dport->dport_dev, &dport->comp_map,
+				   component_reg_phys);
+}
+
 static struct cxl_port *__devm_cxl_add_port(struct device *host,
-					    struct device *uport,
+					    struct device *uport_dev,
 					    resource_size_t component_reg_phys,
 					    struct cxl_dport *parent_dport)
 {
@@ -697,12 +729,12 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
 	struct device *dev;
 	int rc;
 
-	port = cxl_port_alloc(uport, component_reg_phys, parent_dport);
+	port = cxl_port_alloc(uport_dev, component_reg_phys, parent_dport);
 	if (IS_ERR(port))
 		return port;
 
 	dev = &port->dev;
-	if (is_cxl_memdev(uport))
+	if (is_cxl_memdev(uport_dev))
 		rc = dev_set_name(dev, "endpoint%d", port->id);
 	else if (parent_dport)
 		rc = dev_set_name(dev, "port%d", port->id);
@@ -711,6 +743,10 @@ static struct cxl_port *__devm_cxl_add_port(struct device *host,
 	if (rc)
 		goto err;
 
+	rc = cxl_port_setup_regs(port, component_reg_phys);
+	if (rc)
+		goto err;
+
 	rc = device_add(dev);
 	if (rc)
 		goto err;
@@ -737,28 +773,29 @@ err:
 /**
  * devm_cxl_add_port - register a cxl_port in CXL memory decode hierarchy
  * @host: host device for devm operations
- * @uport: "physical" device implementing this upstream port
+ * @uport_dev: "physical" device implementing this upstream port
  * @component_reg_phys: (optional) for configurable cxl_port instances
  * @parent_dport: next hop up in the CXL memory decode hierarchy
  */
-struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
+struct cxl_port *devm_cxl_add_port(struct device *host,
+				   struct device *uport_dev,
 				   resource_size_t component_reg_phys,
 				   struct cxl_dport *parent_dport)
 {
 	struct cxl_port *port, *parent_port;
 
-	port = __devm_cxl_add_port(host, uport, component_reg_phys,
+	port = __devm_cxl_add_port(host, uport_dev, component_reg_phys,
 				   parent_dport);
 
 	parent_port = parent_dport ? parent_dport->port : NULL;
 	if (IS_ERR(port)) {
-		dev_dbg(uport, "Failed to add%s%s%s: %ld\n",
+		dev_dbg(uport_dev, "Failed to add%s%s%s: %ld\n",
 			parent_port ? " port to " : "",
 			parent_port ? dev_name(&parent_port->dev) : "",
 			parent_port ? "" : " root port",
 			PTR_ERR(port));
 	} else {
-		dev_dbg(uport, "%s added%s%s%s\n",
+		dev_dbg(uport_dev, "%s added%s%s%s\n",
 			dev_name(&port->dev),
 			parent_port ? " to " : "",
 			parent_port ? dev_name(&parent_port->dev) : "",
@@ -775,33 +812,34 @@ struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port)
 	if (is_cxl_root(port))
 		return NULL;
 
-	if (dev_is_pci(port->uport)) {
-		struct pci_dev *pdev = to_pci_dev(port->uport);
+	if (dev_is_pci(port->uport_dev)) {
+		struct pci_dev *pdev = to_pci_dev(port->uport_dev);
 
 		return pdev->subordinate;
 	}
 
-	return xa_load(&cxl_root_buses, (unsigned long)port->uport);
+	return xa_load(&cxl_root_buses, (unsigned long)port->uport_dev);
 }
 EXPORT_SYMBOL_NS_GPL(cxl_port_to_pci_bus, CXL);
 
-static void unregister_pci_bus(void *uport)
+static void unregister_pci_bus(void *uport_dev)
 {
-	xa_erase(&cxl_root_buses, (unsigned long)uport);
+	xa_erase(&cxl_root_buses, (unsigned long)uport_dev);
 }
 
-int devm_cxl_register_pci_bus(struct device *host, struct device *uport,
+int devm_cxl_register_pci_bus(struct device *host, struct device *uport_dev,
 			      struct pci_bus *bus)
 {
 	int rc;
 
-	if (dev_is_pci(uport))
+	if (dev_is_pci(uport_dev))
 		return -EINVAL;
 
-	rc = xa_insert(&cxl_root_buses, (unsigned long)uport, bus, GFP_KERNEL);
+	rc = xa_insert(&cxl_root_buses, (unsigned long)uport_dev, bus,
+		       GFP_KERNEL);
 	if (rc)
 		return rc;
-	return devm_add_action_or_reset(host, unregister_pci_bus, uport);
+	return devm_add_action_or_reset(host, unregister_pci_bus, uport_dev);
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_register_pci_bus, CXL);
 
@@ -849,22 +887,22 @@ static struct cxl_dport *find_dport(struct cxl_port *port, int id)
 	return NULL;
 }
 
-static int add_dport(struct cxl_port *port, struct cxl_dport *new)
+static int add_dport(struct cxl_port *port, struct cxl_dport *dport)
 {
 	struct cxl_dport *dup;
 	int rc;
 
 	device_lock_assert(&port->dev);
-	dup = find_dport(port, new->port_id);
+	dup = find_dport(port, dport->port_id);
 	if (dup) {
 		dev_err(&port->dev,
 			"unable to add dport%d-%s non-unique port id (%s)\n",
-			new->port_id, dev_name(new->dport),
-			dev_name(dup->dport));
+			dport->port_id, dev_name(dport->dport_dev),
+			dev_name(dup->dport_dev));
 		return -EBUSY;
 	}
 
-	rc = xa_insert(&port->dports, (unsigned long)new->dport, new,
+	rc = xa_insert(&port->dports, (unsigned long)dport->dport_dev, dport,
 		       GFP_KERNEL);
 	if (rc)
 		return rc;
@@ -897,8 +935,8 @@ static void cxl_dport_remove(void *data)
 	struct cxl_dport *dport = data;
 	struct cxl_port *port = dport->port;
 
-	xa_erase(&port->dports, (unsigned long) dport->dport);
-	put_device(dport->dport);
+	xa_erase(&port->dports, (unsigned long) dport->dport_dev);
+	put_device(dport->dport_dev);
 }
 
 static void cxl_dport_unlink(void *data)
@@ -922,7 +960,7 @@ __devm_cxl_add_dport(struct cxl_port *port, struct device *dport_dev,
 	int rc;
 
 	if (is_cxl_root(port))
-		host = port->uport;
+		host = port->uport_dev;
 	else
 		host = &port->dev;
 
@@ -940,13 +978,29 @@ __devm_cxl_add_dport(struct cxl_port *port, struct device *dport_dev,
 	if (!dport)
 		return ERR_PTR(-ENOMEM);
 
-	dport->dport = dport_dev;
+	if (rcrb != CXL_RESOURCE_NONE) {
+		dport->rcrb.base = rcrb;
+		component_reg_phys = __rcrb_to_component(dport_dev, &dport->rcrb,
+							 CXL_RCRB_DOWNSTREAM);
+		if (component_reg_phys == CXL_RESOURCE_NONE) {
+			dev_warn(dport_dev, "Invalid Component Registers in RCRB");
+			return ERR_PTR(-ENXIO);
+		}
+
+		dport->rch = true;
+	}
+
+	if (component_reg_phys != CXL_RESOURCE_NONE)
+		dev_dbg(dport_dev, "Component Registers found for dport: %pa\n",
+			&component_reg_phys);
+
+	dport->dport_dev = dport_dev;
 	dport->port_id = port_id;
-	dport->component_reg_phys = component_reg_phys;
 	dport->port = port;
-	if (rcrb != CXL_RESOURCE_NONE)
-		dport->rch = true;
-	dport->rcrb = rcrb;
+
+	rc = cxl_dport_setup_regs(dport, component_reg_phys);
+	if (rc)
+		return ERR_PTR(rc);
 
 	cond_cxl_root_lock(port);
 	rc = add_dport(port, dport);
@@ -1006,14 +1060,12 @@ EXPORT_SYMBOL_NS_GPL(devm_cxl_add_dport, CXL);
  * @port: the cxl_port that references this dport
  * @dport_dev: firmware or PCI device representing the dport
  * @port_id: identifier for this dport in a decoder's target list
- * @component_reg_phys: optional location of CXL component registers
  * @rcrb: mandatory location of a Root Complex Register Block
  *
  * See CXL 3.0 9.11.8 CXL Devices Attached to an RCH
  */
 struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
 					 struct device *dport_dev, int port_id,
-					 resource_size_t component_reg_phys,
 					 resource_size_t rcrb)
 {
 	struct cxl_dport *dport;
@@ -1024,7 +1076,7 @@ struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
 	}
 
 	dport = __devm_cxl_add_dport(port, dport_dev, port_id,
-				     component_reg_phys, rcrb);
+				     CXL_RESOURCE_NONE, rcrb);
 	if (IS_ERR(dport)) {
 		dev_dbg(dport_dev, "failed to add RCH dport to %s: %ld\n",
 			dev_name(&port->dev), PTR_ERR(dport));
@@ -1366,7 +1418,7 @@ out:
 		rc = PTR_ERR(port);
 	else {
 		dev_dbg(&cxlmd->dev, "add to new port %s:%s\n",
-			dev_name(&port->dev), dev_name(port->uport));
+			dev_name(&port->dev), dev_name(port->uport_dev));
 		rc = cxl_add_ep(dport, &cxlmd->dev);
 		if (rc == -EBUSY) {
 			/*
@@ -1428,7 +1480,8 @@ retry:
 		if (port) {
 			dev_dbg(&cxlmd->dev,
 				"found already registered port %s:%s\n",
-				dev_name(&port->dev), dev_name(port->uport));
+				dev_name(&port->dev),
+				dev_name(port->uport_dev));
 			rc = cxl_add_ep(dport, &cxlmd->dev);
 
 			/*
@@ -1468,6 +1521,13 @@ retry:
 }
 EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_ports, CXL);
 
+struct cxl_port *cxl_pci_find_port(struct pci_dev *pdev,
+				   struct cxl_dport **dport)
+{
+	return find_cxl_port(pdev->dev.parent, dport);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_pci_find_port, CXL);
+
 struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd,
 				   struct cxl_dport **dport)
 {
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
index 38db377e13f1..e115ba382e04 100644
--- a/drivers/cxl/core/region.c
+++ b/drivers/cxl/core/region.c
@@ -962,10 +962,10 @@ static int cxl_port_attach_region(struct cxl_port *port,
 
 	dev_dbg(&cxlr->dev,
 		"%s:%s %s add: %s:%s @ %d next: %s nr_eps: %d nr_targets: %d\n",
-		dev_name(port->uport), dev_name(&port->dev),
+		dev_name(port->uport_dev), dev_name(&port->dev),
 		dev_name(&cxld->dev), dev_name(&cxlmd->dev),
 		dev_name(&cxled->cxld.dev), pos,
-		ep ? ep->next ? dev_name(ep->next->uport) :
+		ep ? ep->next ? dev_name(ep->next->uport_dev) :
 				      dev_name(&cxlmd->dev) :
 			   "none",
 		cxl_rr->nr_eps, cxl_rr->nr_targets);
@@ -1040,7 +1040,7 @@ static int check_last_peer(struct cxl_endpoint_decoder *cxled,
 	 */
 	if (pos < distance) {
 		dev_dbg(&cxlr->dev, "%s:%s: cannot host %s:%s at %d\n",
-			dev_name(port->uport), dev_name(&port->dev),
+			dev_name(port->uport_dev), dev_name(&port->dev),
 			dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos);
 		return -ENXIO;
 	}
@@ -1050,7 +1050,7 @@ static int check_last_peer(struct cxl_endpoint_decoder *cxled,
 	if (ep->dport != ep_peer->dport) {
 		dev_dbg(&cxlr->dev,
 			"%s:%s: %s:%s pos %d mismatched peer %s:%s\n",
-			dev_name(port->uport), dev_name(&port->dev),
+			dev_name(port->uport_dev), dev_name(&port->dev),
 			dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos,
 			dev_name(&cxlmd_peer->dev),
 			dev_name(&cxled_peer->cxld.dev));
@@ -1082,7 +1082,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 	 */
 	if (!is_power_of_2(cxl_rr->nr_targets)) {
 		dev_dbg(&cxlr->dev, "%s:%s: invalid target count %d\n",
-			dev_name(port->uport), dev_name(&port->dev),
+			dev_name(port->uport_dev), dev_name(&port->dev),
 			cxl_rr->nr_targets);
 		return -EINVAL;
 	}
@@ -1132,7 +1132,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 	rc = granularity_to_eig(parent_ig, &peig);
 	if (rc) {
 		dev_dbg(&cxlr->dev, "%s:%s: invalid parent granularity: %d\n",
-			dev_name(parent_port->uport),
+			dev_name(parent_port->uport_dev),
 			dev_name(&parent_port->dev), parent_ig);
 		return rc;
 	}
@@ -1140,7 +1140,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 	rc = ways_to_eiw(parent_iw, &peiw);
 	if (rc) {
 		dev_dbg(&cxlr->dev, "%s:%s: invalid parent interleave: %d\n",
-			dev_name(parent_port->uport),
+			dev_name(parent_port->uport_dev),
 			dev_name(&parent_port->dev), parent_iw);
 		return rc;
 	}
@@ -1149,7 +1149,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 	rc = ways_to_eiw(iw, &eiw);
 	if (rc) {
 		dev_dbg(&cxlr->dev, "%s:%s: invalid port interleave: %d\n",
-			dev_name(port->uport), dev_name(&port->dev), iw);
+			dev_name(port->uport_dev), dev_name(&port->dev), iw);
 		return rc;
 	}
 
@@ -1169,7 +1169,7 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 	rc = eig_to_granularity(eig, &ig);
 	if (rc) {
 		dev_dbg(&cxlr->dev, "%s:%s: invalid interleave: %d\n",
-			dev_name(port->uport), dev_name(&port->dev),
+			dev_name(port->uport_dev), dev_name(&port->dev),
 			256 << eig);
 		return rc;
 	}
@@ -1182,11 +1182,11 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 		    ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)) {
 			dev_err(&cxlr->dev,
 				"%s:%s %s expected iw: %d ig: %d %pr\n",
-				dev_name(port->uport), dev_name(&port->dev),
+				dev_name(port->uport_dev), dev_name(&port->dev),
 				__func__, iw, ig, p->res);
 			dev_err(&cxlr->dev,
 				"%s:%s %s got iw: %d ig: %d state: %s %#llx:%#llx\n",
-				dev_name(port->uport), dev_name(&port->dev),
+				dev_name(port->uport_dev), dev_name(&port->dev),
 				__func__, cxld->interleave_ways,
 				cxld->interleave_granularity,
 				(cxld->flags & CXL_DECODER_F_ENABLE) ?
@@ -1203,22 +1203,22 @@ static int cxl_port_setup_targets(struct cxl_port *port,
 			.end = p->res->end,
 		};
 	}
-	dev_dbg(&cxlr->dev, "%s:%s iw: %d ig: %d\n", dev_name(port->uport),
+	dev_dbg(&cxlr->dev, "%s:%s iw: %d ig: %d\n", dev_name(port->uport_dev),
 		dev_name(&port->dev), iw, ig);
 add_target:
 	if (cxl_rr->nr_targets_set == cxl_rr->nr_targets) {
 		dev_dbg(&cxlr->dev,
 			"%s:%s: targets full trying to add %s:%s at %d\n",
-			dev_name(port->uport), dev_name(&port->dev),
+			dev_name(port->uport_dev), dev_name(&port->dev),
 			dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos);
 		return -ENXIO;
 	}
 	if (test_bit(CXL_REGION_F_AUTO, &cxlr->flags)) {
 		if (cxlsd->target[cxl_rr->nr_targets_set] != ep->dport) {
 			dev_dbg(&cxlr->dev, "%s:%s: %s expected %s at %d\n",
-				dev_name(port->uport), dev_name(&port->dev),
+				dev_name(port->uport_dev), dev_name(&port->dev),
 				dev_name(&cxlsd->cxld.dev),
-				dev_name(ep->dport->dport),
+				dev_name(ep->dport->dport_dev),
 				cxl_rr->nr_targets_set);
 			return -ENXIO;
 		}
@@ -1228,8 +1228,8 @@ add_target:
 out_target_set:
 	cxl_rr->nr_targets_set += inc;
 	dev_dbg(&cxlr->dev, "%s:%s target[%d] = %s for %s:%s @ %d\n",
-		dev_name(port->uport), dev_name(&port->dev),
-		cxl_rr->nr_targets_set - 1, dev_name(ep->dport->dport),
+		dev_name(port->uport_dev), dev_name(&port->dev),
+		cxl_rr->nr_targets_set - 1, dev_name(ep->dport->dport_dev),
 		dev_name(&cxlmd->dev), dev_name(&cxled->cxld.dev), pos);
 
 	return 0;
@@ -1548,7 +1548,7 @@ static int cmp_decode_pos(const void *a, const void *b)
 	if (!dev) {
 		struct range *range = &cxled_a->cxld.hpa_range;
 
-		dev_err(port->uport,
+		dev_err(port->uport_dev,
 			"failed to find decoder that maps %#llx-%#llx\n",
 			range->start, range->end);
 		goto err;
@@ -1563,14 +1563,15 @@ static int cmp_decode_pos(const void *a, const void *b)
 	put_device(dev);
 
 	if (a_pos < 0 || b_pos < 0) {
-		dev_err(port->uport,
+		dev_err(port->uport_dev,
 			"failed to find shared decoder for %s and %s\n",
 			dev_name(cxlmd_a->dev.parent),
 			dev_name(cxlmd_b->dev.parent));
 		goto err;
 	}
 
-	dev_dbg(port->uport, "%s comes %s %s\n", dev_name(cxlmd_a->dev.parent),
+	dev_dbg(port->uport_dev, "%s comes %s %s\n",
+		dev_name(cxlmd_a->dev.parent),
 		a_pos - b_pos < 0 ? "before" : "after",
 		dev_name(cxlmd_b->dev.parent));
 
@@ -2114,11 +2115,11 @@ static struct cxl_region *devm_cxl_add_region(struct cxl_root_decoder *cxlrd,
 	if (rc)
 		goto err;
 
-	rc = devm_add_action_or_reset(port->uport, unregister_region, cxlr);
+	rc = devm_add_action_or_reset(port->uport_dev, unregister_region, cxlr);
 	if (rc)
 		return ERR_PTR(rc);
 
-	dev_dbg(port->uport, "%s: created %s\n",
+	dev_dbg(port->uport_dev, "%s: created %s\n",
 		dev_name(&cxlrd->cxlsd.cxld.dev), dev_name(dev));
 	return cxlr;
 
@@ -2246,7 +2247,7 @@ static ssize_t delete_region_store(struct device *dev,
 	if (IS_ERR(cxlr))
 		return PTR_ERR(cxlr);
 
-	devm_release_action(port->uport, unregister_region, cxlr);
+	devm_release_action(port->uport_dev, unregister_region, cxlr);
 	put_device(&cxlr->dev);
 
 	return len;
@@ -2411,7 +2412,8 @@ int cxl_get_poison_by_endpoint(struct cxl_port *port)
 
 	rc = device_for_each_child(&port->dev, &ctx, poison_by_decoder);
 	if (rc == 1)
-		rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport), &ctx);
+		rc = cxl_get_poison_unmapped(to_cxl_memdev(port->uport_dev),
+					     &ctx);
 
 	up_read(&cxl_region_rwsem);
 	return rc;
@@ -2787,7 +2789,7 @@ static struct cxl_region *construct_region(struct cxl_root_decoder *cxlrd,
 
 err:
 	up_write(&cxl_region_rwsem);
-	devm_release_action(port->uport, unregister_region, cxlr);
+	devm_release_action(port->uport_dev, unregister_region, cxlr);
 	return ERR_PTR(rc);
 }
 
diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
index b7d8db922fd9..6281127b3e9d 100644
--- a/drivers/cxl/core/regs.c
+++ b/drivers/cxl/core/regs.c
@@ -200,9 +200,11 @@ void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
 	return ret_val;
 }
 
-int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
-			   const struct cxl_register_map *map, unsigned long map_mask)
+int cxl_map_component_regs(const struct cxl_register_map *map,
+			   struct cxl_component_regs *regs,
+			   unsigned long map_mask)
 {
+	struct device *dev = map->dev;
 	struct mapinfo {
 		const struct cxl_reg_map *rmap;
 		void __iomem **addr;
@@ -232,10 +234,10 @@ int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
 }
 EXPORT_SYMBOL_NS_GPL(cxl_map_component_regs, CXL);
 
-int cxl_map_device_regs(struct device *dev,
-			struct cxl_device_regs *regs,
-			const struct cxl_register_map *map)
+int cxl_map_device_regs(const struct cxl_register_map *map,
+			struct cxl_device_regs *regs)
 {
+	struct device *dev = map->dev;
 	resource_size_t phys_addr = map->resource;
 	struct mapinfo {
 		const struct cxl_reg_map *rmap;
@@ -306,7 +308,11 @@ int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type,
 	int instance = 0;
 	int regloc, i;
 
-	map->resource = CXL_RESOURCE_NONE;
+	*map = (struct cxl_register_map) {
+		.dev = &pdev->dev,
+		.resource = CXL_RESOURCE_NONE,
+	};
+
 	regloc = pci_find_dvsec_capability(pdev, PCI_DVSEC_VENDOR_ID_CXL,
 					   CXL_DVSEC_REG_LOCATOR);
 	if (!regloc)
@@ -395,11 +401,80 @@ int cxl_map_pmu_regs(struct pci_dev *pdev, struct cxl_pmu_regs *regs,
 }
 EXPORT_SYMBOL_NS_GPL(cxl_map_pmu_regs, CXL);
 
-resource_size_t cxl_rcrb_to_component(struct device *dev,
-				      resource_size_t rcrb,
-				      enum cxl_rcrb which)
+static int cxl_map_regblock(struct cxl_register_map *map)
+{
+	struct device *dev = map->dev;
+
+	map->base = ioremap(map->resource, map->max_size);
+	if (!map->base) {
+		dev_err(dev, "failed to map registers\n");
+		return -ENOMEM;
+	}
+
+	dev_dbg(dev, "Mapped CXL Memory Device resource %pa\n", &map->resource);
+	return 0;
+}
+
+static void cxl_unmap_regblock(struct cxl_register_map *map)
+{
+	iounmap(map->base);
+	map->base = NULL;
+}
+
+static int cxl_probe_regs(struct cxl_register_map *map)
+{
+	struct cxl_component_reg_map *comp_map;
+	struct cxl_device_reg_map *dev_map;
+	struct device *dev = map->dev;
+	void __iomem *base = map->base;
+
+	switch (map->reg_type) {
+	case CXL_REGLOC_RBI_COMPONENT:
+		comp_map = &map->component_map;
+		cxl_probe_component_regs(dev, base, comp_map);
+		dev_dbg(dev, "Set up component registers\n");
+		break;
+	case CXL_REGLOC_RBI_MEMDEV:
+		dev_map = &map->device_map;
+		cxl_probe_device_regs(dev, base, dev_map);
+		if (!dev_map->status.valid || !dev_map->mbox.valid ||
+		    !dev_map->memdev.valid) {
+			dev_err(dev, "registers not found: %s%s%s\n",
+				!dev_map->status.valid ? "status " : "",
+				!dev_map->mbox.valid ? "mbox " : "",
+				!dev_map->memdev.valid ? "memdev " : "");
+			return -ENXIO;
+		}
+
+		dev_dbg(dev, "Probing device registers...\n");
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+int cxl_setup_regs(struct cxl_register_map *map)
+{
+	int rc;
+
+	rc = cxl_map_regblock(map);
+	if (rc)
+		return rc;
+
+	rc = cxl_probe_regs(map);
+	cxl_unmap_regblock(map);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(cxl_setup_regs, CXL);
+
+resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri,
+				    enum cxl_rcrb which)
 {
 	resource_size_t component_reg_phys;
+	resource_size_t rcrb = ri->base;
 	void __iomem *addr;
 	u32 bar0, bar1;
 	u16 cmd;
@@ -458,4 +533,12 @@ resource_size_t cxl_rcrb_to_component(struct device *dev,
 
 	return component_reg_phys;
 }
-EXPORT_SYMBOL_NS_GPL(cxl_rcrb_to_component, CXL);
+
+resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
+					   struct cxl_dport *dport)
+{
+	if (!dport->rch)
+		return CXL_RESOURCE_NONE;
+	return __rcrb_to_component(dev, &dport->rcrb, CXL_RCRB_UPSTREAM);
+}
+EXPORT_SYMBOL_NS_GPL(cxl_rcd_component_reg_phys, CXL);
diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index bc917a75333f..76d92561af29 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -247,6 +247,7 @@ struct cxl_pmu_reg_map {
 
 /**
  * struct cxl_register_map - DVSEC harvested register block mapping parameters
+ * @dev: device for devm operations and logging
  * @base: virtual base of the register-block-BAR + @block_offset
  * @resource: physical resource base of the register block
  * @max_size: maximum mapping size to perform register search
@@ -256,6 +257,7 @@ struct cxl_pmu_reg_map {
  * @pmu_map: cxl_reg_maps for CXL Performance Monitoring Units
  */
 struct cxl_register_map {
+	struct device *dev;
 	void __iomem *base;
 	resource_size_t resource;
 	resource_size_t max_size;
@@ -271,11 +273,11 @@ void cxl_probe_component_regs(struct device *dev, void __iomem *base,
 			      struct cxl_component_reg_map *map);
 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
 			   struct cxl_device_reg_map *map);
-int cxl_map_component_regs(struct device *dev, struct cxl_component_regs *regs,
-			   const struct cxl_register_map *map,
+int cxl_map_component_regs(const struct cxl_register_map *map,
+			   struct cxl_component_regs *regs,
 			   unsigned long map_mask);
-int cxl_map_device_regs(struct device *dev, struct cxl_device_regs *regs,
-			const struct cxl_register_map *map);
+int cxl_map_device_regs(const struct cxl_register_map *map,
+			struct cxl_device_regs *regs);
 int cxl_map_pmu_regs(struct pci_dev *pdev, struct cxl_pmu_regs *regs,
 		     struct cxl_register_map *map);
 
@@ -285,14 +287,10 @@ int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type,
 			       struct cxl_register_map *map, int index);
 int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
 		      struct cxl_register_map *map);
-
-enum cxl_rcrb {
-	CXL_RCRB_DOWNSTREAM,
-	CXL_RCRB_UPSTREAM,
-};
-resource_size_t cxl_rcrb_to_component(struct device *dev,
-				      resource_size_t rcrb,
-				      enum cxl_rcrb which);
+int cxl_setup_regs(struct cxl_register_map *map);
+struct cxl_dport;
+resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
+					   struct cxl_dport *dport);
 
 #define CXL_RESOURCE_NONE ((resource_size_t) -1)
 #define CXL_TARGET_STRLEN 20
@@ -566,7 +564,7 @@ struct cxl_dax_region {
  *		     downstream port devices to construct a CXL memory
  *		     decode hierarchy.
  * @dev: this port's device
- * @uport: PCI or platform device implementing the upstream port capability
+ * @uport_dev: PCI or platform device implementing the upstream port capability
  * @host_bridge: Shortcut to the platform attach point for this port
  * @id: id for port device-name
  * @dports: cxl_dport instances referenced by decoders
@@ -574,6 +572,7 @@ struct cxl_dax_region {
  * @regions: cxl_region_ref instances, regions mapped by this port
  * @parent_dport: dport that points to this port in the parent
  * @decoder_ida: allocator for decoder ids
+ * @comp_map: component register capability mappings
  * @nr_dports: number of entries in @dports
  * @hdm_end: track last allocated HDM decoder instance for allocation ordering
  * @commit_end: cursor to track highest committed decoder for commit ordering
@@ -585,7 +584,7 @@ struct cxl_dax_region {
  */
 struct cxl_port {
 	struct device dev;
-	struct device *uport;
+	struct device *uport_dev;
 	struct device *host_bridge;
 	int id;
 	struct xarray dports;
@@ -593,6 +592,7 @@ struct cxl_port {
 	struct xarray regions;
 	struct cxl_dport *parent_dport;
 	struct ida decoder_ida;
+	struct cxl_register_map comp_map;
 	int nr_dports;
 	int hdm_end;
 	int commit_end;
@@ -612,20 +612,25 @@ cxl_find_dport_by_dev(struct cxl_port *port, const struct device *dport_dev)
 	return xa_load(&port->dports, (unsigned long)dport_dev);
 }
 
+struct cxl_rcrb_info {
+	resource_size_t base;
+	u16 aer_cap;
+};
+
 /**
  * struct cxl_dport - CXL downstream port
- * @dport: PCI bridge or firmware device representing the downstream link
+ * @dport_dev: PCI bridge or firmware device representing the downstream link
+ * @comp_map: component register capability mappings
  * @port_id: unique hardware identifier for dport in decoder target list
- * @component_reg_phys: downstream port component registers
- * @rcrb: base address for the Root Complex Register Block
+ * @rcrb: Data about the Root Complex Register Block layout
  * @rch: Indicate whether this dport was enumerated in RCH or VH mode
  * @port: reference to cxl_port that contains this downstream port
  */
 struct cxl_dport {
-	struct device *dport;
+	struct device *dport_dev;
+	struct cxl_register_map comp_map;
 	int port_id;
-	resource_size_t component_reg_phys;
-	resource_size_t rcrb;
+	struct cxl_rcrb_info rcrb;
 	bool rch;
 	struct cxl_port *port;
 };
@@ -666,27 +671,30 @@ struct cxl_region_ref {
 /*
  * The platform firmware device hosting the root is also the top of the
  * CXL port topology. All other CXL ports have another CXL port as their
- * parent and their ->uport / host device is out-of-line of the port
+ * parent and their ->uport_dev / host device is out-of-line of the port
  * ancestry.
  */
 static inline bool is_cxl_root(struct cxl_port *port)
 {
-	return port->uport == port->dev.parent;
+	return port->uport_dev == port->dev.parent;
 }
 
 bool is_cxl_port(const struct device *dev);
 struct cxl_port *to_cxl_port(const struct device *dev);
 struct pci_bus;
-int devm_cxl_register_pci_bus(struct device *host, struct device *uport,
+int devm_cxl_register_pci_bus(struct device *host, struct device *uport_dev,
 			      struct pci_bus *bus);
 struct pci_bus *cxl_port_to_pci_bus(struct cxl_port *port);
-struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
+struct cxl_port *devm_cxl_add_port(struct device *host,
+				   struct device *uport_dev,
 				   resource_size_t component_reg_phys,
 				   struct cxl_dport *parent_dport);
 struct cxl_port *find_cxl_root(struct cxl_port *port);
 int devm_cxl_enumerate_ports(struct cxl_memdev *cxlmd);
 void cxl_bus_rescan(void);
 void cxl_bus_drain(void);
+struct cxl_port *cxl_pci_find_port(struct pci_dev *pdev,
+				   struct cxl_dport **dport);
 struct cxl_port *cxl_mem_find_port(struct cxl_memdev *cxlmd,
 				   struct cxl_dport **dport);
 bool schedule_cxl_memdev_detach(struct cxl_memdev *cxlmd);
@@ -696,7 +704,6 @@ struct cxl_dport *devm_cxl_add_dport(struct cxl_port *port,
 				     resource_size_t component_reg_phys);
 struct cxl_dport *devm_cxl_add_rch_dport(struct cxl_port *port,
 					 struct device *dport_dev, int port_id,
-					 resource_size_t component_reg_phys,
 					 resource_size_t rcrb);
 
 struct cxl_decoder *to_cxl_decoder(struct device *dev);
diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 25234a491371..79e99c873ca2 100644
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -75,13 +75,13 @@ cxled_to_memdev(struct cxl_endpoint_decoder *cxled)
 {
 	struct cxl_port *port = to_cxl_port(cxled->cxld.dev.parent);
 
-	return to_cxl_memdev(port->uport);
+	return to_cxl_memdev(port->uport_dev);
 }
 
 bool is_cxl_memdev(const struct device *dev);
 static inline bool is_cxl_endpoint(struct cxl_port *port)
 {
-	return is_cxl_memdev(port->uport);
+	return is_cxl_memdev(port->uport_dev);
 }
 
 struct cxl_memdev *devm_cxl_add_memdev(struct cxl_dev_state *cxlds);
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 584f9eec57e4..317c7548e4e9 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -51,7 +51,6 @@ static int devm_cxl_add_endpoint(struct device *host, struct cxl_memdev *cxlmd,
 	struct cxl_port *parent_port = parent_dport->port;
 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
 	struct cxl_port *endpoint, *iter, *down;
-	resource_size_t component_reg_phys;
 	int rc;
 
 	/*
@@ -66,17 +65,8 @@ static int devm_cxl_add_endpoint(struct device *host, struct cxl_memdev *cxlmd,
 		ep->next = down;
 	}
 
-	/*
-	 * The component registers for an RCD might come from the
-	 * host-bridge RCRB if they are not already mapped via the
-	 * typical register locator mechanism.
-	 */
-	if (parent_dport->rch && cxlds->component_reg_phys == CXL_RESOURCE_NONE)
-		component_reg_phys = cxl_rcrb_to_component(
-			&cxlmd->dev, parent_dport->rcrb, CXL_RCRB_UPSTREAM);
-	else
-		component_reg_phys = cxlds->component_reg_phys;
-	endpoint = devm_cxl_add_port(host, &cxlmd->dev, component_reg_phys,
+	endpoint = devm_cxl_add_port(host, &cxlmd->dev,
+				     cxlds->component_reg_phys,
 				     parent_dport);
 	if (IS_ERR(endpoint))
 		return PTR_ERR(endpoint);
@@ -164,7 +154,7 @@ static int cxl_mem_probe(struct device *dev)
 	}
 
 	if (dport->rch)
-		endpoint_parent = parent_port->uport;
+		endpoint_parent = parent_port->uport_dev;
 	else
 		endpoint_parent = &parent_port->dev;
 
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 270d63d11e17..48f88d96029d 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -467,95 +467,64 @@ mbox_poll:
 	return 0;
 }
 
-static int cxl_map_regblock(struct pci_dev *pdev, struct cxl_register_map *map)
+/*
+ * Assume that any RCIEP that emits the CXL memory expander class code
+ * is an RCD
+ */
+static bool is_cxl_restricted(struct pci_dev *pdev)
 {
-	struct device *dev = &pdev->dev;
-
-	map->base = ioremap(map->resource, map->max_size);
-	if (!map->base) {
-		dev_err(dev, "failed to map registers\n");
-		return -ENOMEM;
-	}
-
-	dev_dbg(dev, "Mapped CXL Memory Device resource %pa\n", &map->resource);
-	return 0;
+	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
 }
 
-static void cxl_unmap_regblock(struct pci_dev *pdev,
-			       struct cxl_register_map *map)
+static int cxl_rcrb_get_comp_regs(struct pci_dev *pdev,
+				  struct cxl_register_map *map)
 {
-	iounmap(map->base);
-	map->base = NULL;
-}
+	struct cxl_port *port;
+	struct cxl_dport *dport;
+	resource_size_t component_reg_phys;
 
-static int cxl_probe_regs(struct pci_dev *pdev, struct cxl_register_map *map)
-{
-	struct cxl_component_reg_map *comp_map;
-	struct cxl_device_reg_map *dev_map;
-	struct device *dev = &pdev->dev;
-	void __iomem *base = map->base;
-
-	switch (map->reg_type) {
-	case CXL_REGLOC_RBI_COMPONENT:
-		comp_map = &map->component_map;
-		cxl_probe_component_regs(dev, base, comp_map);
-		if (!comp_map->hdm_decoder.valid) {
-			dev_err(dev, "HDM decoder registers not found\n");
-			return -ENXIO;
-		}
+	*map = (struct cxl_register_map) {
+		.dev = &pdev->dev,
+		.resource = CXL_RESOURCE_NONE,
+	};
 
-		if (!comp_map->ras.valid)
-			dev_dbg(dev, "RAS registers not found\n");
-
-		dev_dbg(dev, "Set up component registers\n");
-		break;
-	case CXL_REGLOC_RBI_MEMDEV:
-		dev_map = &map->device_map;
-		cxl_probe_device_regs(dev, base, dev_map);
-		if (!dev_map->status.valid || !dev_map->mbox.valid ||
-		    !dev_map->memdev.valid) {
-			dev_err(dev, "registers not found: %s%s%s\n",
-				!dev_map->status.valid ? "status " : "",
-				!dev_map->mbox.valid ? "mbox " : "",
-				!dev_map->memdev.valid ? "memdev " : "");
-			return -ENXIO;
-		}
+	port = cxl_pci_find_port(pdev, &dport);
+	if (!port)
+		return -EPROBE_DEFER;
 
-		dev_dbg(dev, "Probing device registers...\n");
-		break;
-	default:
-		break;
-	}
+	component_reg_phys = cxl_rcd_component_reg_phys(&pdev->dev, dport);
+
+	put_device(&port->dev);
+
+	if (component_reg_phys == CXL_RESOURCE_NONE)
+		return -ENXIO;
+
+	map->resource = component_reg_phys;
+	map->reg_type = CXL_REGLOC_RBI_COMPONENT;
+	map->max_size = CXL_COMPONENT_REG_BLOCK_SIZE;
 
 	return 0;
 }
 
-static int cxl_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
-			  struct cxl_register_map *map)
+static int cxl_pci_setup_regs(struct pci_dev *pdev, enum cxl_regloc_type type,
+			      struct cxl_register_map *map)
 {
 	int rc;
 
 	rc = cxl_find_regblock(pdev, type, map);
-	if (rc)
-		return rc;
 
-	rc = cxl_map_regblock(pdev, map);
+	/*
+	 * If the Register Locator DVSEC does not exist, check if it
+	 * is an RCH and try to extract the Component Registers from
+	 * an RCRB.
+	 */
+	if (rc && type == CXL_REGLOC_RBI_COMPONENT && is_cxl_restricted(pdev))
+		rc = cxl_rcrb_get_comp_regs(pdev, map);
+
 	if (rc)
 		return rc;
 
-	rc = cxl_probe_regs(pdev, map);
-	cxl_unmap_regblock(pdev, map);
-
-	return rc;
-}
-
-/*
- * Assume that any RCIEP that emits the CXL memory expander class code
- * is an RCD
- */
-static bool is_cxl_restricted(struct pci_dev *pdev)
-{
-	return pci_pcie_type(pdev) == PCI_EXP_TYPE_RC_END;
+	return cxl_setup_regs(map);
 }
 
 static int cxl_pci_ras_unmask(struct pci_dev *pdev)
@@ -854,11 +823,11 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 		dev_warn(&pdev->dev,
 			 "Device DVSEC not present, skip CXL.mem init\n");
 
-	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
+	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_MEMDEV, &map);
 	if (rc)
 		return rc;
 
-	rc = cxl_map_device_regs(&pdev->dev, &cxlds->regs.device_regs, &map);
+	rc = cxl_map_device_regs(&map, &cxlds->regs.device_regs);
 	if (rc)
 		return rc;
 
@@ -867,14 +836,16 @@ static int cxl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	 * still be useful for management functions so don't return an error.
 	 */
 	cxlds->component_reg_phys = CXL_RESOURCE_NONE;
-	rc = cxl_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
+	rc = cxl_pci_setup_regs(pdev, CXL_REGLOC_RBI_COMPONENT, &map);
 	if (rc)
 		dev_warn(&pdev->dev, "No component registers (%d)\n", rc);
+	else if (!map.component_map.ras.valid)
+		dev_dbg(&pdev->dev, "RAS registers not found\n");
 
 	cxlds->component_reg_phys = map.resource;
 
-	rc = cxl_map_component_regs(&pdev->dev, &cxlds->regs.component,
-				    &map, BIT(CXL_CM_CAP_CAP_ID_RAS));
+	rc = cxl_map_component_regs(&map, &cxlds->regs.component,
+				    BIT(CXL_CM_CAP_CAP_ID_RAS));
 	if (rc)
 		dev_dbg(&pdev->dev, "Failed to map RAS capability.\n");
 
diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c
index 07c5ac598da1..6240e05b9542 100644
--- a/drivers/cxl/port.c
+++ b/drivers/cxl/port.c
@@ -87,7 +87,7 @@ static int cxl_switch_port_probe(struct cxl_port *port)
 static int cxl_endpoint_port_probe(struct cxl_port *port)
 {
 	struct cxl_endpoint_dvsec_info info = { .port = port };
-	struct cxl_memdev *cxlmd = to_cxl_memdev(port->uport);
+	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;
@@ -98,8 +98,11 @@ static int cxl_endpoint_port_probe(struct cxl_port *port)
 		return rc;
 
 	cxlhdm = devm_cxl_setup_hdm(port, &info);
-	if (IS_ERR(cxlhdm))
+	if (IS_ERR(cxlhdm)) {
+		if (PTR_ERR(cxlhdm) == -ENODEV)
+			dev_err(&port->dev, "HDM decoder registers not found\n");
 		return PTR_ERR(cxlhdm);
+	}
 
 	/* Cache the data early to ensure is_visible() works */
 	read_cdat_data(port);
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index 93cc6825d982..90f3c9802ffb 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -11,7 +11,8 @@ ldflags-y += --wrap=devm_cxl_enumerate_decoders
 ldflags-y += --wrap=cxl_await_media_ready
 ldflags-y += --wrap=cxl_hdm_decode_init
 ldflags-y += --wrap=cxl_dvsec_rr_decode
-ldflags-y += --wrap=cxl_rcrb_to_component
+ldflags-y += --wrap=devm_cxl_add_rch_dport
+ldflags-y += --wrap=cxl_rcd_component_reg_phys
 
 DRIVERS := ../../../drivers
 CXL_SRC := $(DRIVERS)/cxl
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 5565164d6658..0e78d8e19895 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -754,7 +754,7 @@ static void mock_init_hdm_decoder(struct cxl_decoder *cxld)
 		/* check is endpoint is attach to host-bridge0 */
 		port = cxled_to_port(cxled);
 		do {
-			if (port->uport == &cxl_host_bridge[0]->dev) {
+			if (port->uport_dev == &cxl_host_bridge[0]->dev) {
 				hb0 = true;
 				break;
 			}
@@ -889,7 +889,7 @@ static int mock_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
 		mock_init_hdm_decoder(cxld);
 
 		if (target_count) {
-			rc = device_for_each_child(port->uport, &ctx,
+			rc = device_for_each_child(port->uport_dev, &ctx,
 						   map_targets);
 			if (rc) {
 				put_device(&cxld->dev);
@@ -919,29 +919,29 @@ static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
 	int i, array_size;
 
 	if (port->depth == 1) {
-		if (is_multi_bridge(port->uport)) {
+		if (is_multi_bridge(port->uport_dev)) {
 			array_size = ARRAY_SIZE(cxl_root_port);
 			array = cxl_root_port;
-		} else if (is_single_bridge(port->uport)) {
+		} else if (is_single_bridge(port->uport_dev)) {
 			array_size = ARRAY_SIZE(cxl_root_single);
 			array = cxl_root_single;
 		} else {
 			dev_dbg(&port->dev, "%s: unknown bridge type\n",
-				dev_name(port->uport));
+				dev_name(port->uport_dev));
 			return -ENXIO;
 		}
 	} else if (port->depth == 2) {
 		struct cxl_port *parent = to_cxl_port(port->dev.parent);
 
-		if (is_multi_bridge(parent->uport)) {
+		if (is_multi_bridge(parent->uport_dev)) {
 			array_size = ARRAY_SIZE(cxl_switch_dport);
 			array = cxl_switch_dport;
-		} else if (is_single_bridge(parent->uport)) {
+		} else if (is_single_bridge(parent->uport_dev)) {
 			array_size = ARRAY_SIZE(cxl_swd_single);
 			array = cxl_swd_single;
 		} else {
 			dev_dbg(&port->dev, "%s: unknown bridge type\n",
-				dev_name(port->uport));
+				dev_name(port->uport_dev));
 			return -ENXIO;
 		}
 	} else {
@@ -954,9 +954,9 @@ static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
 		struct platform_device *pdev = array[i];
 		struct cxl_dport *dport;
 
-		if (pdev->dev.parent != port->uport) {
+		if (pdev->dev.parent != port->uport_dev) {
 			dev_dbg(&port->dev, "%s: mismatch parent %s\n",
-				dev_name(port->uport),
+				dev_name(port->uport_dev),
 				dev_name(pdev->dev.parent));
 			continue;
 		}
@@ -971,15 +971,6 @@ static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
 	return 0;
 }
 
-resource_size_t mock_cxl_rcrb_to_component(struct device *dev,
-					   resource_size_t rcrb,
-					   enum cxl_rcrb which)
-{
-	dev_dbg(dev, "rcrb: %pa which: %d\n", &rcrb, which);
-
-	return (resource_size_t) which + 1;
-}
-
 static struct cxl_mock_ops cxl_mock_ops = {
 	.is_mock_adev = is_mock_adev,
 	.is_mock_bridge = is_mock_bridge,
@@ -988,7 +979,6 @@ static struct cxl_mock_ops cxl_mock_ops = {
 	.is_mock_dev = is_mock_dev,
 	.acpi_table_parse_cedt = mock_acpi_table_parse_cedt,
 	.acpi_evaluate_integer = mock_acpi_evaluate_integer,
-	.cxl_rcrb_to_component = mock_cxl_rcrb_to_component,
 	.acpi_pci_find_root = mock_acpi_pci_find_root,
 	.devm_cxl_port_enumerate_dports = mock_cxl_port_enumerate_dports,
 	.devm_cxl_setup_hdm = mock_cxl_setup_hdm,
diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index de3933a776fd..1a61e68e3095 100644
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -139,7 +139,7 @@ struct cxl_hdm *__wrap_devm_cxl_setup_hdm(struct cxl_port *port,
 	struct cxl_hdm *cxlhdm;
 	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
 
-	if (ops && ops->is_mock_port(port->uport))
+	if (ops && ops->is_mock_port(port->uport_dev))
 		cxlhdm = ops->devm_cxl_setup_hdm(port, info);
 	else
 		cxlhdm = devm_cxl_setup_hdm(port, info);
@@ -154,7 +154,7 @@ int __wrap_devm_cxl_add_passthrough_decoder(struct cxl_port *port)
 	int rc, index;
 	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
 
-	if (ops && ops->is_mock_port(port->uport))
+	if (ops && ops->is_mock_port(port->uport_dev))
 		rc = ops->devm_cxl_add_passthrough_decoder(port);
 	else
 		rc = devm_cxl_add_passthrough_decoder(port);
@@ -171,7 +171,7 @@ int __wrap_devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
 	struct cxl_port *port = cxlhdm->port;
 	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
 
-	if (ops && ops->is_mock_port(port->uport))
+	if (ops && ops->is_mock_port(port->uport_dev))
 		rc = ops->devm_cxl_enumerate_decoders(cxlhdm, info);
 	else
 		rc = devm_cxl_enumerate_decoders(cxlhdm, info);
@@ -186,7 +186,7 @@ int __wrap_devm_cxl_port_enumerate_dports(struct cxl_port *port)
 	int rc, index;
 	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
 
-	if (ops && ops->is_mock_port(port->uport))
+	if (ops && ops->is_mock_port(port->uport_dev))
 		rc = ops->devm_cxl_port_enumerate_dports(port);
 	else
 		rc = devm_cxl_port_enumerate_dports(port);
@@ -244,24 +244,46 @@ int __wrap_cxl_dvsec_rr_decode(struct device *dev, int dvsec,
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_cxl_dvsec_rr_decode, CXL);
 
-resource_size_t __wrap_cxl_rcrb_to_component(struct device *dev,
-					     resource_size_t rcrb,
-					     enum cxl_rcrb which)
+struct cxl_dport *__wrap_devm_cxl_add_rch_dport(struct cxl_port *port,
+						struct device *dport_dev,
+						int port_id,
+						resource_size_t rcrb)
+{
+	int index;
+	struct cxl_dport *dport;
+	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
+
+	if (ops && ops->is_mock_port(dport_dev)) {
+		dport = devm_cxl_add_dport(port, dport_dev, port_id,
+					   CXL_RESOURCE_NONE);
+		if (!IS_ERR(dport)) {
+			dport->rcrb.base = rcrb;
+			dport->rch = true;
+		}
+	} else
+		dport = devm_cxl_add_rch_dport(port, dport_dev, port_id, rcrb);
+	put_cxl_mock_ops(index);
+
+	return dport;
+}
+EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_add_rch_dport, CXL);
+
+resource_size_t __wrap_cxl_rcd_component_reg_phys(struct device *dev,
+						  struct cxl_dport *dport)
 {
 	int index;
 	resource_size_t component_reg_phys;
 	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
 
 	if (ops && ops->is_mock_port(dev))
-		component_reg_phys =
-			ops->cxl_rcrb_to_component(dev, rcrb, which);
+		component_reg_phys = CXL_RESOURCE_NONE;
 	else
-		component_reg_phys = cxl_rcrb_to_component(dev, rcrb, which);
+		component_reg_phys = cxl_rcd_component_reg_phys(dev, dport);
 	put_cxl_mock_ops(index);
 
 	return component_reg_phys;
 }
-EXPORT_SYMBOL_NS_GPL(__wrap_cxl_rcrb_to_component, CXL);
+EXPORT_SYMBOL_NS_GPL(__wrap_cxl_rcd_component_reg_phys, CXL);
 
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(ACPI);
diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
index bef8817b01f2..a94223750346 100644
--- a/tools/testing/cxl/test/mock.h
+++ b/tools/testing/cxl/test/mock.h
@@ -15,9 +15,6 @@ struct cxl_mock_ops {
 					     acpi_string pathname,
 					     struct acpi_object_list *arguments,
 					     unsigned long long *data);
-	resource_size_t (*cxl_rcrb_to_component)(struct device *dev,
-						 resource_size_t rcrb,
-						 enum cxl_rcrb which);
 	struct acpi_pci_root *(*acpi_pci_find_root)(acpi_handle handle);
 	bool (*is_mock_bus)(struct pci_bus *bus);
 	bool (*is_mock_port)(struct device *dev);