In preparation for switch port enumeration while also preserving the
potential for multi-domain / multi-root CXL topologies. Introduce a
'struct device' generic mechanism for retrieving a root CXL port, if one
is registered. Note that the only know multi-domain CXL configurations
are running the cxl_test unit test on a system that also publishes an
ACPI0017 device.
With this in hand the nvdimm-bridge lookup can be with
device_find_child() instead of bus_find_device() + custom mocked lookup
infrastructure in cxl_test.
The mechanism looks for a 2nd level port since the root level topology
is platform-firmware specific and the 2nd level down follows standard
PCIe topology expectations. The cxl_acpi 2nd level is associated with a
PCIe Root Port.
Reported-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
Changes since v4
- Fix root lookup in the presence of ACPI Host Bridge topology. Previous
version was only tested with cxl_test. (Ben)
drivers/cxl/core/pmem.c | 14 +++++++++---
drivers/cxl/core/port.c | 48 +++++++++++++++++++++++++++++++++++++++++
drivers/cxl/cxl.h | 1 +
tools/testing/cxl/Kbuild | 2 --
tools/testing/cxl/mock_pmem.c | 24 ---------------------
5 files changed, 59 insertions(+), 30 deletions(-)
delete mode 100644 tools/testing/cxl/mock_pmem.c
diff --git a/drivers/cxl/core/pmem.c b/drivers/cxl/core/pmem.c
index 40b3f5030496..8de240c4d96b 100644
--- a/drivers/cxl/core/pmem.c
+++ b/drivers/cxl/core/pmem.c
@@ -57,24 +57,30 @@ bool is_cxl_nvdimm_bridge(struct device *dev)
}
EXPORT_SYMBOL_NS_GPL(is_cxl_nvdimm_bridge, CXL);
-__mock int match_nvdimm_bridge(struct device *dev, const void *data)
+static int match_nvdimm_bridge(struct device *dev, void *data)
{
return is_cxl_nvdimm_bridge(dev);
}
struct cxl_nvdimm_bridge *cxl_find_nvdimm_bridge(struct cxl_nvdimm *cxl_nvd)
{
+ struct cxl_port *port = find_cxl_root(&cxl_nvd->dev);
struct device *dev;
- dev = bus_find_device(&cxl_bus_type, NULL, cxl_nvd, match_nvdimm_bridge);
+ if (!port)
+ return NULL;
+
+ dev = device_find_child(&port->dev, NULL, match_nvdimm_bridge);
+ put_device(&port->dev);
+
if (!dev)
return NULL;
+
return to_cxl_nvdimm_bridge(dev);
}
EXPORT_SYMBOL_NS_GPL(cxl_find_nvdimm_bridge, CXL);
-static struct cxl_nvdimm_bridge *
-cxl_nvdimm_bridge_alloc(struct cxl_port *port)
+static struct cxl_nvdimm_bridge *cxl_nvdimm_bridge_alloc(struct cxl_port *port)
{
struct cxl_nvdimm_bridge *cxl_nvb;
struct device *dev;
diff --git a/drivers/cxl/core/port.c b/drivers/cxl/core/port.c
index 4c921c49f967..89f445b04b7b 100644
--- a/drivers/cxl/core/port.c
+++ b/drivers/cxl/core/port.c
@@ -457,6 +457,54 @@ int devm_cxl_register_pci_bus(struct device *host, struct device *uport,
}
EXPORT_SYMBOL_NS_GPL(devm_cxl_register_pci_bus, CXL);
+/* Find a 2nd level CXL port that has a dport that is an ancestor of @match */
+static int match_cxl_root_child(struct device *dev, const void *match)
+{
+ const struct device *iter = match;
+ struct cxl_port *port, *parent;
+ struct cxl_dport *dport;
+
+ if (!is_cxl_port(dev))
+ return 0;
+
+ port = to_cxl_port(dev);
+ if (is_cxl_root(port))
+ return 0;
+
+ parent = to_cxl_port(port->dev.parent);
+ if (!is_cxl_root(parent))
+ return 0;
+
+ cxl_device_lock(&port->dev);
+ list_for_each_entry(dport, &port->dports, list)
+ while (iter) {
+ if (iter == dport->dport)
+ goto out;
+ iter = iter->parent;
+ }
+out:
+ cxl_device_unlock(&port->dev);
+
+ return !!iter;
+}
+
+struct cxl_port *find_cxl_root(struct device *dev)
+{
+ struct device *port_dev;
+ struct cxl_port *root;
+
+ port_dev =
+ bus_find_device(&cxl_bus_type, NULL, dev, match_cxl_root_child);
+ if (!port_dev)
+ return NULL;
+
+ root = to_cxl_port(port_dev->parent);
+ get_device(&root->dev);
+ put_device(port_dev);
+ return root;
+}
+EXPORT_SYMBOL_NS_GPL(find_cxl_root, 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 4e8d504546c5..7523e4d60953 100644
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -298,6 +298,7 @@ struct cxl_port *devm_cxl_add_port(struct device *host, struct device *uport,
int cxl_add_dport(struct cxl_port *port, struct device *dport, int port_id,
resource_size_t component_reg_phys);
+struct cxl_port *find_cxl_root(struct device *dev);
struct cxl_decoder *to_cxl_decoder(struct device *dev);
bool is_root_decoder(struct device *dev);
diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index 3299fb0977b2..ddaee8a2c418 100644
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -32,6 +32,4 @@ cxl_core-y += $(CXL_CORE_SRC)/memdev.o
cxl_core-y += $(CXL_CORE_SRC)/mbox.o
cxl_core-y += config_check.o
-cxl_core-y += mock_pmem.o
-
obj-m += test/
diff --git a/tools/testing/cxl/mock_pmem.c b/tools/testing/cxl/mock_pmem.c
deleted file mode 100644
index f7315e6f52c0..000000000000
--- a/tools/testing/cxl/mock_pmem.c
+++ /dev/null
@@ -1,24 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-/* Copyright(c) 2021 Intel Corporation. All rights reserved. */
-#include <cxl.h>
-#include "test/mock.h"
-#include <core/core.h>
-
-int match_nvdimm_bridge(struct device *dev, const void *data)
-{
- int index, rc = 0;
- struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
- const struct cxl_nvdimm *cxl_nvd = data;
-
- if (ops) {
- if (dev->type == &cxl_nvdimm_bridge_type &&
- (ops->is_mock_dev(dev->parent->parent) ==
- ops->is_mock_dev(cxl_nvd->dev.parent->parent)))
- rc = 1;
- } else
- rc = dev->type == &cxl_nvdimm_bridge_type;
-
- put_cxl_mock_ops(index);
-
- return rc;
-}
