Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * KUnit-managed device implementation
4 *
5 * Implementation of struct kunit_device helpers for fake devices whose
6 * lifecycle is managed by KUnit.
7 *
8 * Copyright (C) 2023, Google LLC.
9 * Author: David Gow <davidgow@google.com>
10 */
11
12#include <linux/device.h>
13
14#include <kunit/test.h>
15#include <kunit/device.h>
16#include <kunit/resource.h>
17
18#include "device-impl.h"
19
20/* Wrappers for use with kunit_add_action() */
21KUNIT_DEFINE_ACTION_WRAPPER(device_unregister_wrapper, device_unregister, struct device *);
22KUNIT_DEFINE_ACTION_WRAPPER(driver_unregister_wrapper, driver_unregister, struct device_driver *);
23
24/* The root device for the KUnit bus, parent of all kunit_devices. */
25static struct device *kunit_bus_device;
26
27/* A device owned by a KUnit test. */
28struct kunit_device {
29 struct device dev;
30 /* The KUnit test which owns this device. */
31 struct kunit *owner;
32 /* If the driver is managed by KUnit and unique to this device. */
33 const struct device_driver *driver;
34};
35
36#define to_kunit_device(d) container_of_const(d, struct kunit_device, dev)
37
38static struct bus_type kunit_bus_type = {
39 .name = "kunit",
40};
41
42/* Register the 'kunit_bus' used for fake devices. */
43int kunit_bus_init(void)
44{
45 int error;
46
47 kunit_bus_device = root_device_register("kunit");
48 if (IS_ERR(kunit_bus_device))
49 return PTR_ERR(kunit_bus_device);
50
51 error = bus_register(&kunit_bus_type);
52 if (error)
53 bus_unregister(&kunit_bus_type);
54 return error;
55}
56
57/* Release a 'fake' KUnit device. */
58static void kunit_device_release(struct device *d)
59{
60 kfree(to_kunit_device(d));
61}
62
63/*
64 * Create and register a KUnit-managed struct device_driver on the kunit_bus.
65 * Returns an error pointer on failure.
66 */
67struct device_driver *kunit_driver_create(struct kunit *test, const char *name)
68{
69 struct device_driver *driver;
70 int err = -ENOMEM;
71
72 driver = kunit_kzalloc(test, sizeof(*driver), GFP_KERNEL);
73
74 if (!driver)
75 return ERR_PTR(err);
76
77 driver->name = name;
78 driver->bus = &kunit_bus_type;
79 driver->owner = THIS_MODULE;
80
81 err = driver_register(driver);
82 if (err) {
83 kunit_kfree(test, driver);
84 return ERR_PTR(err);
85 }
86
87 kunit_add_action(test, driver_unregister_wrapper, driver);
88 return driver;
89}
90EXPORT_SYMBOL_GPL(kunit_driver_create);
91
92/* Helper which creates a kunit_device, attaches it to the kunit_bus*/
93static struct kunit_device *kunit_device_register_internal(struct kunit *test,
94 const char *name,
95 const struct device_driver *drv)
96{
97 struct kunit_device *kunit_dev;
98 int err = -ENOMEM;
99
100 kunit_dev = kzalloc(sizeof(*kunit_dev), GFP_KERNEL);
101 if (!kunit_dev)
102 return ERR_PTR(err);
103
104 kunit_dev->owner = test;
105
106 err = dev_set_name(&kunit_dev->dev, "%s.%s", test->name, name);
107 if (err) {
108 kfree(kunit_dev);
109 return ERR_PTR(err);
110 }
111
112 kunit_dev->dev.release = kunit_device_release;
113 kunit_dev->dev.bus = &kunit_bus_type;
114 kunit_dev->dev.parent = kunit_bus_device;
115
116 err = device_register(&kunit_dev->dev);
117 if (err) {
118 put_device(&kunit_dev->dev);
119 return ERR_PTR(err);
120 }
121
122 kunit_add_action(test, device_unregister_wrapper, &kunit_dev->dev);
123
124 return kunit_dev;
125}
126
127/*
128 * Create and register a new KUnit-managed device, using the user-supplied device_driver.
129 * On failure, returns an error pointer.
130 */
131struct device *kunit_device_register_with_driver(struct kunit *test,
132 const char *name,
133 const struct device_driver *drv)
134{
135 struct kunit_device *kunit_dev = kunit_device_register_internal(test, name, drv);
136
137 if (IS_ERR_OR_NULL(kunit_dev))
138 return ERR_CAST(kunit_dev);
139
140 return &kunit_dev->dev;
141}
142EXPORT_SYMBOL_GPL(kunit_device_register_with_driver);
143
144/*
145 * Create and register a new KUnit-managed device, including a matching device_driver.
146 * On failure, returns an error pointer.
147 */
148struct device *kunit_device_register(struct kunit *test, const char *name)
149{
150 struct device_driver *drv;
151 struct kunit_device *dev;
152
153 drv = kunit_driver_create(test, name);
154 if (IS_ERR(drv))
155 return ERR_CAST(drv);
156
157 dev = kunit_device_register_internal(test, name, drv);
158 if (IS_ERR(dev)) {
159 kunit_release_action(test, driver_unregister_wrapper, (void *)drv);
160 return ERR_CAST(dev);
161 }
162
163 /* Request the driver be freed. */
164 dev->driver = drv;
165
166
167 return &dev->dev;
168}
169EXPORT_SYMBOL_GPL(kunit_device_register);
170
171/* Unregisters a KUnit-managed device early (including the driver, if automatically created). */
172void kunit_device_unregister(struct kunit *test, struct device *dev)
173{
174 const struct device_driver *driver = to_kunit_device(dev)->driver;
175
176 kunit_release_action(test, device_unregister_wrapper, dev);
177 if (driver)
178 kunit_release_action(test, driver_unregister_wrapper, (void *)driver);
179}
180EXPORT_SYMBOL_GPL(kunit_device_unregister);
181