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 #include <linux/dma-mapping.h> 14 15 #include <kunit/test.h> 16 #include <kunit/device.h> 17 #include <kunit/resource.h> 18 19 #include "device-impl.h" 20 21 /* Wrappers for use with kunit_add_action() */ 22 KUNIT_DEFINE_ACTION_WRAPPER(device_unregister_wrapper, device_unregister, struct device *); 23 KUNIT_DEFINE_ACTION_WRAPPER(driver_unregister_wrapper, driver_unregister, struct device_driver *); 24 25 /* The root device for the KUnit bus, parent of all kunit_devices. */ 26 static struct device *kunit_bus_device; 27 28 /* A device owned by a KUnit test. */ 29 struct kunit_device { 30 struct device dev; 31 /* The KUnit test which owns this device. */ 32 struct kunit *owner; 33 /* If the driver is managed by KUnit and unique to this device. */ 34 const struct device_driver *driver; 35 }; 36 37 #define to_kunit_device(d) container_of_const(d, struct kunit_device, dev) 38 39 static const struct bus_type kunit_bus_type = { 40 .name = "kunit", 41 }; 42 43 /* Register the 'kunit_bus' used for fake devices. */ 44 int kunit_bus_init(void) 45 { 46 int error; 47 48 kunit_bus_device = root_device_register("kunit"); 49 if (IS_ERR(kunit_bus_device)) 50 return PTR_ERR(kunit_bus_device); 51 52 error = bus_register(&kunit_bus_type); 53 if (error) 54 root_device_unregister(kunit_bus_device); 55 return error; 56 } 57 58 /* Unregister the 'kunit_bus' in case the KUnit module is unloaded. */ 59 void kunit_bus_shutdown(void) 60 { 61 /* Make sure the bus exists before we unregister it. */ 62 if (IS_ERR_OR_NULL(kunit_bus_device)) 63 return; 64 65 bus_unregister(&kunit_bus_type); 66 67 root_device_unregister(kunit_bus_device); 68 69 kunit_bus_device = NULL; 70 } 71 72 /* Release a 'fake' KUnit device. */ 73 static void kunit_device_release(struct device *d) 74 { 75 kfree(to_kunit_device(d)); 76 } 77 78 /* 79 * Create and register a KUnit-managed struct device_driver on the kunit_bus. 80 * Returns an error pointer on failure. 81 */ 82 struct device_driver *kunit_driver_create(struct kunit *test, const char *name) 83 { 84 struct device_driver *driver; 85 int err = -ENOMEM; 86 87 driver = kunit_kzalloc(test, sizeof(*driver), GFP_KERNEL); 88 89 if (!driver) 90 return ERR_PTR(err); 91 92 driver->name = name; 93 driver->bus = &kunit_bus_type; 94 driver->owner = THIS_MODULE; 95 96 err = driver_register(driver); 97 if (err) { 98 kunit_kfree(test, driver); 99 return ERR_PTR(err); 100 } 101 102 kunit_add_action(test, driver_unregister_wrapper, driver); 103 return driver; 104 } 105 EXPORT_SYMBOL_GPL(kunit_driver_create); 106 107 /* Helper which creates a kunit_device, attaches it to the kunit_bus*/ 108 static struct kunit_device *kunit_device_register_internal(struct kunit *test, 109 const char *name, 110 const struct device_driver *drv) 111 { 112 struct kunit_device *kunit_dev; 113 int err = -ENOMEM; 114 115 kunit_dev = kzalloc(sizeof(*kunit_dev), GFP_KERNEL); 116 if (!kunit_dev) 117 return ERR_PTR(err); 118 119 kunit_dev->owner = test; 120 121 err = dev_set_name(&kunit_dev->dev, "%s.%s", test->name, name); 122 if (err) { 123 kfree(kunit_dev); 124 return ERR_PTR(err); 125 } 126 127 kunit_dev->dev.release = kunit_device_release; 128 kunit_dev->dev.bus = &kunit_bus_type; 129 kunit_dev->dev.parent = kunit_bus_device; 130 131 err = device_register(&kunit_dev->dev); 132 if (err) { 133 put_device(&kunit_dev->dev); 134 return ERR_PTR(err); 135 } 136 137 kunit_dev->dev.dma_mask = &kunit_dev->dev.coherent_dma_mask; 138 kunit_dev->dev.coherent_dma_mask = DMA_BIT_MASK(32); 139 140 kunit_add_action(test, device_unregister_wrapper, &kunit_dev->dev); 141 142 return kunit_dev; 143 } 144 145 /* 146 * Create and register a new KUnit-managed device, using the user-supplied device_driver. 147 * On failure, returns an error pointer. 148 */ 149 struct device *kunit_device_register_with_driver(struct kunit *test, 150 const char *name, 151 const struct device_driver *drv) 152 { 153 struct kunit_device *kunit_dev = kunit_device_register_internal(test, name, drv); 154 155 if (IS_ERR_OR_NULL(kunit_dev)) 156 return ERR_CAST(kunit_dev); 157 158 return &kunit_dev->dev; 159 } 160 EXPORT_SYMBOL_GPL(kunit_device_register_with_driver); 161 162 /* 163 * Create and register a new KUnit-managed device, including a matching device_driver. 164 * On failure, returns an error pointer. 165 */ 166 struct device *kunit_device_register(struct kunit *test, const char *name) 167 { 168 struct device_driver *drv; 169 struct kunit_device *dev; 170 171 drv = kunit_driver_create(test, name); 172 if (IS_ERR(drv)) 173 return ERR_CAST(drv); 174 175 dev = kunit_device_register_internal(test, name, drv); 176 if (IS_ERR(dev)) { 177 kunit_release_action(test, driver_unregister_wrapper, (void *)drv); 178 return ERR_CAST(dev); 179 } 180 181 /* Request the driver be freed. */ 182 dev->driver = drv; 183 184 185 return &dev->dev; 186 } 187 EXPORT_SYMBOL_GPL(kunit_device_register); 188 189 /* Unregisters a KUnit-managed device early (including the driver, if automatically created). */ 190 void kunit_device_unregister(struct kunit *test, struct device *dev) 191 { 192 const struct device_driver *driver = to_kunit_device(dev)->driver; 193 194 kunit_release_action(test, device_unregister_wrapper, dev); 195 if (driver) 196 kunit_release_action(test, driver_unregister_wrapper, (void *)driver); 197 } 198 EXPORT_SYMBOL_GPL(kunit_device_unregister); 199 200