cxl/core: Generalize dport enumeration in the core

The core houses infrastructure for decoder resources. A CXL port's
dports are more closely related to decoder infrastructure than topology
enumeration. Implement generic PCI based dport enumeration in the core,
i.e. arrange for existing root port enumeration from cxl_acpi to share
code with switch port enumeration which just amounts to a small
difference in a pci_walk_bus() invocation once the appropriate 'struct
pci_bus' has been retrieved.

Set the convention that decoder objects are registered after all dports
are enumerated. This enables userspace to know when the CXL core is
finished establishing 'dportX' links underneath the 'portX' object.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/164368114191.354031.5270501846455462665.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

5 files changed, 71 insertions, 128 deletions

diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index ddaee8a2c418..61123544aa49 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -3,8 +3,8 @@ ldflags-y += --wrap=acpi_table_parse_cedt
 ldflags-y += --wrap=is_acpi_device_node
 ldflags-y += --wrap=acpi_evaluate_integer
 ldflags-y += --wrap=acpi_pci_find_root
-ldflags-y += --wrap=pci_walk_bus
 ldflags-y += --wrap=nvdimm_bus_register
+ldflags-y += --wrap=devm_cxl_port_enumerate_dports
 
 DRIVERS := ../../../drivers
 CXL_SRC := $(DRIVERS)/cxl
@@ -30,6 +30,7 @@ cxl_core-y += $(CXL_CORE_SRC)/pmem.o
 cxl_core-y += $(CXL_CORE_SRC)/regs.o
 cxl_core-y += $(CXL_CORE_SRC)/memdev.o
 cxl_core-y += $(CXL_CORE_SRC)/mbox.o
+cxl_core-y += $(CXL_CORE_SRC)/pci.o
 cxl_core-y += config_check.o
 
 obj-m += test/
diff --git a/tools/testing/cxl/mock_acpi.c b/tools/testing/cxl/mock_acpi.c
index c953e3ab6494..55813de26d46 100644
--- a/tools/testing/cxl/mock_acpi.c
+++ b/tools/testing/cxl/mock_acpi.c
@@ -4,7 +4,6 @@
 #include <linux/platform_device.h>
 #include <linux/device.h>
 #include <linux/acpi.h>
-#include <linux/pci.h>
 #include <cxl.h>
 #include "test/mock.h"
 
@@ -34,80 +33,3 @@ out:
 	put_cxl_mock_ops(index);
 	return found;
 }
-
-static int match_add_root_port(struct pci_dev *pdev, void *data)
-{
-	struct cxl_walk_context *ctx = data;
-	struct pci_bus *root_bus = ctx->root;
-	struct cxl_port *port = ctx->port;
-	int type = pci_pcie_type(pdev);
-	struct device *dev = ctx->dev;
-	u32 lnkcap, port_num;
-	int rc;
-
-	if (pdev->bus != root_bus)
-		return 0;
-	if (!pci_is_pcie(pdev))
-		return 0;
-	if (type != PCI_EXP_TYPE_ROOT_PORT)
-		return 0;
-	if (pci_read_config_dword(pdev, pci_pcie_cap(pdev) + PCI_EXP_LNKCAP,
-				  &lnkcap) != PCIBIOS_SUCCESSFUL)
-		return 0;
-
-	/* TODO walk DVSEC to find component register base */
-	port_num = FIELD_GET(PCI_EXP_LNKCAP_PN, lnkcap);
-	cxl_device_lock(&port->dev);
-	rc = cxl_add_dport(port, &pdev->dev, port_num, CXL_RESOURCE_NONE);
-	cxl_device_unlock(&port->dev);
-	if (rc) {
-		dev_err(dev, "failed to add dport: %s (%d)\n",
-			dev_name(&pdev->dev), rc);
-		ctx->error = rc;
-		return rc;
-	}
-	ctx->count++;
-
-	dev_dbg(dev, "add dport%d: %s\n", port_num, dev_name(&pdev->dev));
-
-	return 0;
-}
-
-static int mock_add_root_port(struct platform_device *pdev, void *data)
-{
-	struct cxl_walk_context *ctx = data;
-	struct cxl_port *port = ctx->port;
-	struct device *dev = ctx->dev;
-	int rc;
-
-	cxl_device_lock(&port->dev);
-	rc = cxl_add_dport(port, &pdev->dev, pdev->id, CXL_RESOURCE_NONE);
-	cxl_device_unlock(&port->dev);
-	if (rc) {
-		dev_err(dev, "failed to add dport: %s (%d)\n",
-			dev_name(&pdev->dev), rc);
-		ctx->error = rc;
-		return rc;
-	}
-	ctx->count++;
-
-	dev_dbg(dev, "add dport%d: %s\n", pdev->id, dev_name(&pdev->dev));
-
-	return 0;
-}
-
-int match_add_root_ports(struct pci_dev *dev, void *data)
-{
-	int index, rc;
-	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
-	struct platform_device *pdev = (struct platform_device *) dev;
-
-	if (ops && ops->is_mock_port(pdev))
-		rc = mock_add_root_port(pdev, data);
-	else
-		rc = match_add_root_port(dev, data);
-
-	put_cxl_mock_ops(index);
-
-	return rc;
-}
diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 736d99006fb7..ef002e909d38 100644
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -317,6 +317,19 @@ static bool is_mock_bridge(struct device *dev)
 	for (i = 0; i < ARRAY_SIZE(cxl_host_bridge); i++)
 		if (dev == &cxl_host_bridge[i]->dev)
 			return true;
+	return false;
+}
+
+static bool is_mock_port(struct device *dev)
+{
+	int i;
+
+	if (is_mock_bridge(dev))
+		return true;
+
+	for (i = 0; i < ARRAY_SIZE(cxl_root_port); i++)
+		if (dev == &cxl_root_port[i]->dev)
+			return true;
 
 	return false;
 }
@@ -366,26 +379,6 @@ static struct acpi_pci_root mock_pci_root[NR_CXL_HOST_BRIDGES] = {
 	},
 };
 
-static struct platform_device *mock_cxl_root_port(struct pci_bus *bus, int index)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(mock_pci_bus); i++)
-		if (bus == &mock_pci_bus[i])
-			return cxl_root_port[index + i * NR_CXL_ROOT_PORTS];
-	return NULL;
-}
-
-static bool is_mock_port(struct platform_device *pdev)
-{
-	int i;
-
-	for (i = 0; i < ARRAY_SIZE(cxl_root_port); i++)
-		if (pdev == cxl_root_port[i])
-			return true;
-	return false;
-}
-
 static bool is_mock_bus(struct pci_bus *bus)
 {
 	int i;
@@ -405,16 +398,47 @@ static struct acpi_pci_root *mock_acpi_pci_find_root(acpi_handle handle)
 	return &mock_pci_root[host_bridge_index(adev)];
 }
 
+static int mock_cxl_port_enumerate_dports(struct device *host,
+					  struct cxl_port *port)
+{
+	struct device *dev = &port->dev;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(cxl_root_port); i++) {
+		struct platform_device *pdev = cxl_root_port[i];
+		struct cxl_dport *dport;
+
+		if (pdev->dev.parent != port->uport)
+			continue;
+
+		cxl_device_lock(&port->dev);
+		dport = devm_cxl_add_dport(host, port, &pdev->dev, pdev->id,
+					   CXL_RESOURCE_NONE);
+		cxl_device_unlock(&port->dev);
+
+		if (IS_ERR(dport)) {
+			dev_err(dev, "failed to add dport: %s (%ld)\n",
+				dev_name(&pdev->dev), PTR_ERR(dport));
+			return PTR_ERR(dport);
+		}
+
+		dev_dbg(dev, "add dport%d: %s\n", pdev->id,
+			dev_name(&pdev->dev));
+	}
+
+	return 0;
+}
+
 static struct cxl_mock_ops cxl_mock_ops = {
 	.is_mock_adev = is_mock_adev,
 	.is_mock_bridge = is_mock_bridge,
 	.is_mock_bus = is_mock_bus,
 	.is_mock_port = is_mock_port,
 	.is_mock_dev = is_mock_dev,
-	.mock_port = mock_cxl_root_port,
 	.acpi_table_parse_cedt = mock_acpi_table_parse_cedt,
 	.acpi_evaluate_integer = mock_acpi_evaluate_integer,
 	.acpi_pci_find_root = mock_acpi_pci_find_root,
+	.devm_cxl_port_enumerate_dports = mock_cxl_port_enumerate_dports,
 	.list = LIST_HEAD_INIT(cxl_mock_ops.list),
 };
 
@@ -598,3 +622,4 @@ module_init(cxl_test_init);
 module_exit(cxl_test_exit);
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(ACPI);
+MODULE_IMPORT_NS(CXL);
diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index 17408f892df4..56b4b7d734bc 100644
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -7,6 +7,8 @@
 #include <linux/export.h>
 #include <linux/acpi.h>
 #include <linux/pci.h>
+#include <cxlmem.h>
+#include <cxlpci.h>
 #include "mock.h"
 
 static LIST_HEAD(mock);
@@ -114,32 +116,6 @@ struct acpi_pci_root *__wrap_acpi_pci_find_root(acpi_handle handle)
 }
 EXPORT_SYMBOL_GPL(__wrap_acpi_pci_find_root);
 
-void __wrap_pci_walk_bus(struct pci_bus *bus,
-			 int (*cb)(struct pci_dev *, void *), void *userdata)
-{
-	int index;
-	struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
-
-	if (ops && ops->is_mock_bus(bus)) {
-		int rc, i;
-
-		/*
-		 * Simulate 2 root ports per host-bridge and no
-		 * depth recursion.
-		 */
-		for (i = 0; i < 2; i++) {
-			rc = cb((struct pci_dev *) ops->mock_port(bus, i),
-				userdata);
-			if (rc)
-				break;
-		}
-	} else
-		pci_walk_bus(bus, cb, userdata);
-
-	put_cxl_mock_ops(index);
-}
-EXPORT_SYMBOL_GPL(__wrap_pci_walk_bus);
-
 struct nvdimm_bus *
 __wrap_nvdimm_bus_register(struct device *dev,
 			   struct nvdimm_bus_descriptor *nd_desc)
@@ -155,5 +131,22 @@ __wrap_nvdimm_bus_register(struct device *dev,
 }
 EXPORT_SYMBOL_GPL(__wrap_nvdimm_bus_register);
 
+int __wrap_devm_cxl_port_enumerate_dports(struct device *host,
+					  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))
+		rc = ops->devm_cxl_port_enumerate_dports(host, port);
+	else
+		rc = devm_cxl_port_enumerate_dports(host, port);
+	put_cxl_mock_ops(index);
+
+	return rc;
+}
+EXPORT_SYMBOL_NS_GPL(__wrap_devm_cxl_port_enumerate_dports, CXL);
+
 MODULE_LICENSE("GPL v2");
 MODULE_IMPORT_NS(ACPI);
+MODULE_IMPORT_NS(CXL);
diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
index 15ed0fd877e4..99e7ff38090d 100644
--- a/tools/testing/cxl/test/mock.h
+++ b/tools/testing/cxl/test/mock.h
@@ -2,6 +2,7 @@
 
 #include <linux/list.h>
 #include <linux/acpi.h>
+#include <cxl.h>
 
 struct cxl_mock_ops {
 	struct list_head list;
@@ -15,10 +16,11 @@ struct cxl_mock_ops {
 					     struct acpi_object_list *arguments,
 					     unsigned long long *data);
 	struct acpi_pci_root *(*acpi_pci_find_root)(acpi_handle handle);
-	struct platform_device *(*mock_port)(struct pci_bus *bus, int index);
 	bool (*is_mock_bus)(struct pci_bus *bus);
-	bool (*is_mock_port)(struct platform_device *pdev);
+	bool (*is_mock_port)(struct device *dev);
 	bool (*is_mock_dev)(struct device *dev);
+	int (*devm_cxl_port_enumerate_dports)(struct device *host,
+					      struct cxl_port *port);
 };
 
 void register_cxl_mock_ops(struct cxl_mock_ops *ops);