kunit: Add APIs for managing devices Tests for drivers often require a struct device to pass to other functions. While it's possible to create these with root_device_register(), or to use something like a platform device, this is both a misuse of those APIs, and can be difficult to clean up after, for example, a failed assertion. Add some KUnit-specific functions for registering and unregistering a struct device: - kunit_device_register() - kunit_device_register_with_driver() - kunit_device_unregister() These helpers allocate a on a 'kunit' bus which will either probe the driver passed in (kunit_device_register_with_driver), or will create a stub driver (kunit_device_register) which is cleaned up on test shutdown. Devices are automatically unregistered on test shutdown, but can be manually unregistered earlier with kunit_device_unregister() in order to, for example, test device release code. Signed-off-by: David Gow <davidgow@google.com>
diff --git a/include/kunit/device.h b/include/kunit/device.h new file mode 100644 index 0000000..141461e --- /dev/null +++ b/include/kunit/device.h
@@ -0,0 +1,28 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * KUnit basic device implementation + * + * Implementation of struct kunit_device helpers. + * + * Copyright (C) 2023, Google LLC. + * Author: David Gow <davidgow@google.com> + */ + +#ifndef _KUNIT_DEVICE_H +#define _KUNIT_DEVICE_H + +#if IS_ENABLED(CONFIG_KUNIT) + +#include <kunit/test.h> + +struct kunit_device; +struct device; +struct device_driver; + +struct device *kunit_device_register(struct kunit *test, const char *name); +struct device *kunit_device_register_with_driver(struct kunit *test, const char *name, struct device_driver *drv); +void kunit_device_unregister(struct kunit *test, struct device *dev); + +#endif + +#endif
diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index cb417f5..b9bd059 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile
@@ -6,6 +6,7 @@ string-stream.o \ assert.o \ try-catch.o \ + device.o \ executor.o ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
diff --git a/lib/kunit/device.c b/lib/kunit/device.c new file mode 100644 index 0000000..ec49951 --- /dev/null +++ b/lib/kunit/device.c
@@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KUnit basic device implementation + * + * Implementation of struct kunit_device helpers. + * + * Copyright (C) 2023, Google LLC. + * Author: David Gow <davidgow@google.com> + */ + +#include <linux/device.h> + +#include <kunit/test.h> +#include <kunit/resource.h> + +static struct device kunit_bus = { + .init_name = "kunit" +}; + +/* A device owned by a KUnit test. */ +struct kunit_device { + struct device dev; + struct kunit *owner; + /* Force binding to a specific driver. */ + struct device_driver *driver; +}; + +static inline struct kunit_device *to_kunit_device(struct device *d) +{ + return container_of(d, struct kunit_device, dev); +} + +static int kunit_bus_match(struct device *dev, struct device_driver *driver) +{ + struct kunit_device *kunit_dev = to_kunit_device(dev); + + if (kunit_dev->driver == driver) + return 1; + + return 0; +} + +static struct bus_type kunit_bus_type = { + .name = "kunit", + .match = kunit_bus_match +}; + +int kunit_bus_init(void) +{ + int error; + + error = bus_register(&kunit_bus_type); + if (!error) { + error = device_register(&kunit_bus); + if (error) + bus_unregister(&kunit_bus_type); + } + return error; +} +late_initcall(kunit_bus_init); + +static void kunit_device_release(struct device *d) +{ + kfree(to_kunit_device(d)); +} + +struct device_driver *kunit_driver_create(struct kunit *test, const char *name) +{ + struct device_driver *driver; + int err = -ENOMEM; + + driver = kunit_kzalloc(test, sizeof(*driver), GFP_KERNEL); + + if (!driver) + return ERR_PTR(err); + + driver->name = name; + driver->bus = &kunit_bus_type; + /* TODO: Make this point to the individual test module, not KUnit itself. */ + driver->owner = THIS_MODULE; + /* TODO: mod_name */ + + err = driver_register(driver); + if (err) { + kunit_kfree(test, driver); + return ERR_PTR(err); + } + + kunit_defer(test, (kunit_defer_function_t)driver_unregister, driver, GFP_KERNEL); + return driver; +} + +struct device *kunit_device_register_with_driver(struct kunit *test, const char *name, struct device_driver *drv) +{ + struct kunit_device *kunit_dev; + int err = -ENOMEM; + + kunit_dev = kzalloc(sizeof(struct kunit_device), GFP_KERNEL); + if (!kunit_dev) + return ERR_PTR(err); + + kunit_dev->owner = test; + + err = dev_set_name(&kunit_dev->dev, "%s.%s", test->name, name); + if (err) { + kfree(kunit_dev); + return ERR_PTR(err); + } + + /* Set the expected driver pointer, so we match. */ + kunit_dev->driver = drv; + + kunit_dev->dev.release = kunit_device_release; + kunit_dev->dev.bus = &kunit_bus_type; + kunit_dev->dev.parent = &kunit_bus; + + err = device_register(&kunit_dev->dev); + if (err) { + put_device(&kunit_dev->dev); + return ERR_PTR(err); + } + + kunit_defer(test, (kunit_defer_function_t)device_unregister, &kunit_dev->dev, GFP_KERNEL); + + return &kunit_dev->dev; +} +EXPORT_SYMBOL_GPL(kunit_device_register_with_driver); + +struct device *kunit_device_register(struct kunit *test, const char *name) +{ + struct device_driver *drv = kunit_driver_create(test, name); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, drv); + return kunit_device_register_with_driver(test, name, drv); +} +EXPORT_SYMBOL_GPL(kunit_device_register); + +void kunit_device_unregister(struct kunit *test, struct device *dev) +{ + kunit_defer_trigger(test, (kunit_defer_function_t)device_unregister, dev); +} +EXPORT_SYMBOL_GPL(kunit_device_unregister); +
diff --git a/lib/kunit/test.c b/lib/kunit/test.c index e2910b2..d1700d9 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c
@@ -802,12 +802,16 @@ void kunit_cleanup(struct kunit *test) } EXPORT_SYMBOL_GPL(kunit_cleanup); +int kunit_bus_init(void); + static int __init kunit_init(void) { /* Install the KUnit hook functions. */ kunit_install_hooks(); kunit_debugfs_init(); + + kunit_bus_init(); #ifdef CONFIG_MODULES return register_module_notifier(&kunit_mod_nb); #else