cxl/test: Add mock version of devm_cxl_add_dport_by_dev()

devm_cxl_add_dport_by_dev() outside of cxl_test is done through PCI
hierarchy. However with cxl_test, it needs to be done through the
platform device hierarchy. Add the mock function for
devm_cxl_add_dport_by_dev().

When cxl_core calls a cxl_core exported function and that function is
mocked by cxl_test, the call chain causes a circular dependency issue. Dan
provided a workaround to avoid this issue. Apply the method to changes from
the late dport allocation changes in order to enable cxl-test.

In cxl_core they are defined with "__" added in front of the function. A
macro is used to define the original function names for when non-test
version of the kernel is built. A bit of macros and typedefs are used to
allow mocking of those functions in cxl_test.

Co-developed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Reviewed-by: Li Ming <ming.li@zohomail.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Tested-by: Robert Richter <rrichter@amd.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
index e18425f119bd01207b8c16780c6640225005f592..b07490aa93c7c063d7baab3307b634125a3639f7 100644 (file)
--- a/drivers/cxl/core/core.h
+++ b/drivers/cxl/core/core.h
@@ -146,8 +146,6 @@ int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
 int cxl_ras_init(void);
 void cxl_ras_exit(void);
 int cxl_gpf_port_setup(struct cxl_dport *dport);
-struct cxl_dport *devm_cxl_add_dport_by_dev(struct cxl_port *port,
-                                           struct device *dport_dev);
 
 struct cxl_hdm;
 int cxl_hdm_decode_init(struct cxl_dev_state *cxlds, struct cxl_hdm *cxlhdm,

diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index 9ec288ed39aea17c681a96925fd1c0ac259e2de4..18825e1505d6ad732e59aa1682689eca5b9971a7 100644 (file)
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -41,14 +41,14 @@ static int pci_get_port_num(struct pci_dev *pdev)
 }
 
 /**
- * devm_cxl_add_dport_by_dev - allocate a dport by the dport device
+ * __devm_cxl_add_dport_by_dev - allocate a dport by dport device
  * @port: cxl_port that hosts the dport
  * @dport_dev: 'struct device' of the dport
  *
  * Returns the allocated dport on success or ERR_PTR() of -errno on error
  */
-struct cxl_dport *devm_cxl_add_dport_by_dev(struct cxl_port *port,
-                                           struct device *dport_dev)
+struct cxl_dport *__devm_cxl_add_dport_by_dev(struct cxl_port *port,
+                                             struct device *dport_dev)
 {
        struct cxl_register_map map;
        struct pci_dev *pdev;
@@ -69,6 +69,7 @@ struct cxl_dport *devm_cxl_add_dport_by_dev(struct cxl_port *port,
        device_lock_assert(&port->dev);
        return devm_cxl_add_dport(port, dport_dev, port_num, map.resource);
 }
+EXPORT_SYMBOL_NS_GPL(__devm_cxl_add_dport_by_dev, "CXL");
 
 struct cxl_walk_context {
        struct pci_bus *bus;

diff --git a/drivers/cxl/cxl.h b/drivers/cxl/cxl.h
index 672f43b7a87fc75bf39abf9be6e8559ed6744fde..99d358455032c7a1c559aec450d987e6e1cb1db7 100644 (file)
--- a/drivers/cxl/cxl.h
+++ b/drivers/cxl/cxl.h
@@ -906,6 +906,10 @@ void cxl_coordinates_combine(struct access_coordinate *out,
                             struct access_coordinate *c2);
 
 bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
+struct cxl_dport *devm_cxl_add_dport_by_dev(struct cxl_port *port,
+                                           struct device *dport_dev);
+struct cxl_dport *__devm_cxl_add_dport_by_dev(struct cxl_port *port,
+                                             struct device *dport_dev);
 
 /*
  * Unit test builds overrides this to __weak, find the 'strong' version
@@ -916,4 +920,20 @@ bool cxl_endpoint_decoder_reset_detected(struct cxl_port *port);
 #endif
 
 u16 cxl_gpf_get_dvsec(struct device *dev);
+
+/*
+ * Declaration for functions that are mocked by cxl_test that are called by
+ * cxl_core. The respective functions are defined as __foo() and called by
+ * cxl_core as foo(). The macros below ensures that those functions would
+ * exist as foo(). See tools/testing/cxl/cxl_core_exports.c and
+ * tools/testing/cxl/exports.h for setting up the mock functions. The dance
+ * is done to avoid a circular dependency where cxl_core calls a function that
+ * ends up being a mock function and goes to * cxl_test where it calls a
+ * cxl_core function.
+ */
+#ifndef CXL_TEST_ENABLE
+#define DECLARE_TESTABLE(x) __##x
+#define devm_cxl_add_dport_by_dev DECLARE_TESTABLE(devm_cxl_add_dport_by_dev)
+#endif
+
 #endif /* __CXL_H__ */

diff --git a/tools/testing/cxl/Kbuild b/tools/testing/cxl/Kbuild
index 51b8ab289eae95369cbf0df3df18b97c9d9ea582..81e3795673c5a5feed97d6f80aef561c381a4a7e 100644 (file)
--- a/tools/testing/cxl/Kbuild
+++ b/tools/testing/cxl/Kbuild
@@ -18,6 +18,7 @@ CXL_SRC := $(DRIVERS)/cxl
 CXL_CORE_SRC := $(DRIVERS)/cxl/core
 ccflags-y := -I$(srctree)/drivers/cxl/
 ccflags-y += -D__mock=__weak
+ccflags-y += -DCXL_TEST_ENABLE=1
 ccflags-y += -DTRACE_INCLUDE_PATH=$(CXL_CORE_SRC) -I$(srctree)/drivers/cxl/core/
 
 obj-m += cxl_acpi.o

diff --git a/tools/testing/cxl/cxl_core_exports.c b/tools/testing/cxl/cxl_core_exports.c
index f088792a8925f0c59ea3985a73b17c75301576ae..0d18abc1f5a31a82261a1ee928d55db446878955 100644 (file)
--- a/tools/testing/cxl/cxl_core_exports.c
+++ b/tools/testing/cxl/cxl_core_exports.c
@@ -2,6 +2,18 @@
 /* Copyright(c) 2022 Intel Corporation. All rights reserved. */
 
 #include "cxl.h"
+#include "exports.h"
 
 /* Exporting of cxl_core symbols that are only used by cxl_test */
 EXPORT_SYMBOL_NS_GPL(cxl_num_decoders_committed, "CXL");
+
+cxl_add_dport_by_dev_fn _devm_cxl_add_dport_by_dev =
+       __devm_cxl_add_dport_by_dev;
+EXPORT_SYMBOL_NS_GPL(_devm_cxl_add_dport_by_dev, "CXL");
+
+struct cxl_dport *devm_cxl_add_dport_by_dev(struct cxl_port *port,
+                                           struct device *dport_dev)
+{
+       return _devm_cxl_add_dport_by_dev(port, dport_dev);
+}
+EXPORT_SYMBOL_NS_GPL(devm_cxl_add_dport_by_dev, "CXL");

diff --git a/tools/testing/cxl/exports.h b/tools/testing/cxl/exports.h
new file mode 100644 (file)
index 0000000..9261ce6
--- /dev/null
+++ b/tools/testing/cxl/exports.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright(c) 2025 Intel Corporation */
+#ifndef __MOCK_CXL_EXPORTS_H_
+#define __MOCK_CXL_EXPORTS_H_
+
+typedef struct cxl_dport *(*cxl_add_dport_by_dev_fn)(struct cxl_port *port,
+                                                         struct device *dport_dev);
+extern cxl_add_dport_by_dev_fn _devm_cxl_add_dport_by_dev;
+
+#endif

diff --git a/tools/testing/cxl/test/cxl.c b/tools/testing/cxl/test/cxl.c
index 8b5c559a4a8c9c77f98736c302375e25ec647979..e3b4dc265a3be048f0d61423f86bbd8b65745be5 100644 (file)
--- a/tools/testing/cxl/test/cxl.c
+++ b/tools/testing/cxl/test/cxl.c
@@ -944,10 +944,12 @@ static int mock_cxl_endpoint_decoders_setup(struct cxl_port *port)
        return __mock_cxl_decoders_setup(port);
 }
 
-static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
+static int get_port_array(struct cxl_port *port,
+                         struct platform_device ***port_array,
+                         int *port_array_size)
 {
        struct platform_device **array;
-       int i, array_size;
+       int array_size;
 
        if (port->depth == 1) {
                if (is_multi_bridge(port->uport_dev)) {
@@ -981,6 +983,22 @@ static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
                return -ENXIO;
        }
 
+       *port_array = array;
+       *port_array_size = array_size;
+
+       return 0;
+}
+
+static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
+{
+       struct platform_device **array;
+       int i, array_size;
+       int rc;
+
+       rc = get_port_array(port, &array, &array_size);
+       if (rc)
+               return rc;
+
        for (i = 0; i < array_size; i++) {
                struct platform_device *pdev = array[i];
                struct cxl_dport *dport;
@@ -1002,6 +1020,36 @@ static int mock_cxl_port_enumerate_dports(struct cxl_port *port)
        return 0;
 }
 
+static struct cxl_dport *mock_cxl_add_dport_by_dev(struct cxl_port *port,
+                                                  struct device *dport_dev)
+{
+       struct platform_device **array;
+       int rc, i, array_size;
+
+       rc = get_port_array(port, &array, &array_size);
+       if (rc)
+               return ERR_PTR(rc);
+
+       for (i = 0; i < array_size; i++) {
+               struct platform_device *pdev = array[i];
+
+               if (pdev->dev.parent != port->uport_dev) {
+                       dev_dbg(&port->dev, "%s: mismatch parent %s\n",
+                               dev_name(port->uport_dev),
+                               dev_name(pdev->dev.parent));
+                       continue;
+               }
+
+               if (&pdev->dev != dport_dev)
+                       continue;
+
+               return devm_cxl_add_dport(port, &pdev->dev, pdev->id,
+                                         CXL_RESOURCE_NONE);
+       }
+
+       return ERR_PTR(-ENODEV);
+}
+
 /*
  * Faking the cxl_dpa_perf for the memdev when appropriate.
  */
@@ -1062,6 +1110,7 @@ static struct cxl_mock_ops cxl_mock_ops = {
        .devm_cxl_endpoint_decoders_setup = mock_cxl_endpoint_decoders_setup,
        .devm_cxl_port_enumerate_dports = mock_cxl_port_enumerate_dports,
        .cxl_endpoint_parse_cdat = mock_cxl_endpoint_parse_cdat,
+       .devm_cxl_add_dport_by_dev = mock_cxl_add_dport_by_dev,
        .list = LIST_HEAD_INIT(cxl_mock_ops.list),
 };
 

diff --git a/tools/testing/cxl/test/mock.c b/tools/testing/cxl/test/mock.c
index f335889b7756ae4dfadc945848a466bd15e62fa1..e98101f083cd3bafe01e86ad2b5d96be00b76c1a 100644 (file)
--- a/tools/testing/cxl/test/mock.c
+++ b/tools/testing/cxl/test/mock.c
@@ -10,12 +10,18 @@
 #include <cxlmem.h>
 #include <cxlpci.h>
 #include "mock.h"
+#include "../exports.h"
 
 static LIST_HEAD(mock);
 
+static struct cxl_dport *
+redirect_devm_cxl_add_dport_by_dev(struct cxl_port *port,
+                                  struct device *dport_dev);
+
 void register_cxl_mock_ops(struct cxl_mock_ops *ops)
 {
        list_add_rcu(&ops->list, &mock);
+       _devm_cxl_add_dport_by_dev = redirect_devm_cxl_add_dport_by_dev;
 }
 EXPORT_SYMBOL_GPL(register_cxl_mock_ops);
 
@@ -23,6 +29,7 @@ DEFINE_STATIC_SRCU(cxl_mock_srcu);
 
 void unregister_cxl_mock_ops(struct cxl_mock_ops *ops)
 {
+       _devm_cxl_add_dport_by_dev = __devm_cxl_add_dport_by_dev;
        list_del_rcu(&ops->list);
        synchronize_srcu(&cxl_mock_srcu);
 }
@@ -258,6 +265,22 @@ void __wrap_cxl_dport_init_ras_reporting(struct cxl_dport *dport, struct device
 }
 EXPORT_SYMBOL_NS_GPL(__wrap_cxl_dport_init_ras_reporting, "CXL");
 
+struct cxl_dport *redirect_devm_cxl_add_dport_by_dev(struct cxl_port *port,
+                                                    struct device *dport_dev)
+{
+       int index;
+       struct cxl_mock_ops *ops = get_cxl_mock_ops(&index);
+       struct cxl_dport *dport;
+
+       if (ops && ops->is_mock_port(port->uport_dev))
+               dport = ops->devm_cxl_add_dport_by_dev(port, dport_dev);
+       else
+               dport = __devm_cxl_add_dport_by_dev(port, dport_dev);
+       put_cxl_mock_ops(index);
+
+       return dport;
+}
+
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("cxl_test: emulation module");
 MODULE_IMPORT_NS("ACPI");

diff --git a/tools/testing/cxl/test/mock.h b/tools/testing/cxl/test/mock.h
index 9d5ad3fd55ecc696d8fca3a03c7fdec7908e9218..4ed932e76aae89fd75aa39ffe97244ab2e7f1001 100644 (file)
--- a/tools/testing/cxl/test/mock.h
+++ b/tools/testing/cxl/test/mock.h
@@ -23,6 +23,8 @@ struct cxl_mock_ops {
        int (*devm_cxl_switch_port_decoders_setup)(struct cxl_port *port);
        int (*devm_cxl_endpoint_decoders_setup)(struct cxl_port *port);
        void (*cxl_endpoint_parse_cdat)(struct cxl_port *port);
+       struct cxl_dport *(*devm_cxl_add_dport_by_dev)(struct cxl_port *port,
+                                                      struct device *dport_dev);
 };
 
 void register_cxl_mock_ops(struct cxl_mock_ops *ops);