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Diffstat (limited to 'include/kunit/resource.h')
-rw-r--r-- | include/kunit/resource.h | 390 |
1 files changed, 390 insertions, 0 deletions
diff --git a/include/kunit/resource.h b/include/kunit/resource.h new file mode 100644 index 000000000..cf6fb8f2a --- /dev/null +++ b/include/kunit/resource.h @@ -0,0 +1,390 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * KUnit resource API for test managed resources (allocations, etc.). + * + * Copyright (C) 2022, Google LLC. + * Author: Daniel Latypov <dlatypov@google.com> + */ + +#ifndef _KUNIT_RESOURCE_H +#define _KUNIT_RESOURCE_H + +#include <kunit/test.h> + +#include <linux/kref.h> +#include <linux/list.h> +#include <linux/slab.h> +#include <linux/spinlock.h> + +struct kunit_resource; + +typedef int (*kunit_resource_init_t)(struct kunit_resource *, void *); +typedef void (*kunit_resource_free_t)(struct kunit_resource *); + +/** + * struct kunit_resource - represents a *test managed resource* + * @data: for the user to store arbitrary data. + * @name: optional name + * @free: a user supplied function to free the resource. + * + * Represents a *test managed resource*, a resource which will automatically be + * cleaned up at the end of a test case. This cleanup is performed by the 'free' + * function. The struct kunit_resource itself is freed automatically with + * kfree() if it was allocated by KUnit (e.g., by kunit_alloc_resource()), but + * must be freed by the user otherwise. + * + * Resources are reference counted so if a resource is retrieved via + * kunit_alloc_and_get_resource() or kunit_find_resource(), we need + * to call kunit_put_resource() to reduce the resource reference count + * when finished with it. Note that kunit_alloc_resource() does not require a + * kunit_resource_put() because it does not retrieve the resource itself. + * + * Example: + * + * .. code-block:: c + * + * struct kunit_kmalloc_params { + * size_t size; + * gfp_t gfp; + * }; + * + * static int kunit_kmalloc_init(struct kunit_resource *res, void *context) + * { + * struct kunit_kmalloc_params *params = context; + * res->data = kmalloc(params->size, params->gfp); + * + * if (!res->data) + * return -ENOMEM; + * + * return 0; + * } + * + * static void kunit_kmalloc_free(struct kunit_resource *res) + * { + * kfree(res->data); + * } + * + * void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp) + * { + * struct kunit_kmalloc_params params; + * + * params.size = size; + * params.gfp = gfp; + * + * return kunit_alloc_resource(test, kunit_kmalloc_init, + * kunit_kmalloc_free, ¶ms); + * } + * + * Resources can also be named, with lookup/removal done on a name + * basis also. kunit_add_named_resource(), kunit_find_named_resource() + * and kunit_destroy_named_resource(). Resource names must be + * unique within the test instance. + */ +struct kunit_resource { + void *data; + const char *name; + kunit_resource_free_t free; + + /* private: internal use only. */ + struct kref refcount; + struct list_head node; + bool should_kfree; +}; + +/** + * kunit_get_resource() - Hold resource for use. Should not need to be used + * by most users as we automatically get resources + * retrieved by kunit_find_resource*(). + * @res: resource + */ +static inline void kunit_get_resource(struct kunit_resource *res) +{ + kref_get(&res->refcount); +} + +/* + * Called when refcount reaches zero via kunit_put_resource(); + * should not be called directly. + */ +static inline void kunit_release_resource(struct kref *kref) +{ + struct kunit_resource *res = container_of(kref, struct kunit_resource, + refcount); + + if (res->free) + res->free(res); + + /* 'res' is valid here, as if should_kfree is set, res->free may not free + * 'res' itself, just res->data + */ + if (res->should_kfree) + kfree(res); +} + +/** + * kunit_put_resource() - When caller is done with retrieved resource, + * kunit_put_resource() should be called to drop + * reference count. The resource list maintains + * a reference count on resources, so if no users + * are utilizing a resource and it is removed from + * the resource list, it will be freed via the + * associated free function (if any). Only + * needs to be used if we alloc_and_get() or + * find() resource. + * @res: resource + */ +static inline void kunit_put_resource(struct kunit_resource *res) +{ + kref_put(&res->refcount, kunit_release_resource); +} + +/** + * __kunit_add_resource() - Internal helper to add a resource. + * + * res->should_kfree is not initialised. + * @test: The test context object. + * @init: a user-supplied function to initialize the result (if needed). If + * none is supplied, the resource data value is simply set to @data. + * If an init function is supplied, @data is passed to it instead. + * @free: a user-supplied function to free the resource (if needed). + * @res: The resource. + * @data: value to pass to init function or set in resource data field. + */ +int __kunit_add_resource(struct kunit *test, + kunit_resource_init_t init, + kunit_resource_free_t free, + struct kunit_resource *res, + void *data); + +/** + * kunit_add_resource() - Add a *test managed resource*. + * @test: The test context object. + * @init: a user-supplied function to initialize the result (if needed). If + * none is supplied, the resource data value is simply set to @data. + * If an init function is supplied, @data is passed to it instead. + * @free: a user-supplied function to free the resource (if needed). + * @res: The resource. + * @data: value to pass to init function or set in resource data field. + */ +static inline int kunit_add_resource(struct kunit *test, + kunit_resource_init_t init, + kunit_resource_free_t free, + struct kunit_resource *res, + void *data) +{ + res->should_kfree = false; + return __kunit_add_resource(test, init, free, res, data); +} + +static inline struct kunit_resource * +kunit_find_named_resource(struct kunit *test, const char *name); + +/** + * kunit_add_named_resource() - Add a named *test managed resource*. + * @test: The test context object. + * @init: a user-supplied function to initialize the resource data, if needed. + * @free: a user-supplied function to free the resource data, if needed. + * @res: The resource. + * @name: name to be set for resource. + * @data: value to pass to init function or set in resource data field. + */ +static inline int kunit_add_named_resource(struct kunit *test, + kunit_resource_init_t init, + kunit_resource_free_t free, + struct kunit_resource *res, + const char *name, + void *data) +{ + struct kunit_resource *existing; + + if (!name) + return -EINVAL; + + existing = kunit_find_named_resource(test, name); + if (existing) { + kunit_put_resource(existing); + return -EEXIST; + } + + res->name = name; + res->should_kfree = false; + + return __kunit_add_resource(test, init, free, res, data); +} + +/** + * kunit_alloc_and_get_resource() - Allocates and returns a *test managed resource*. + * @test: The test context object. + * @init: a user supplied function to initialize the resource. + * @free: a user supplied function to free the resource (if needed). + * @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL + * @context: for the user to pass in arbitrary data to the init function. + * + * Allocates a *test managed resource*, a resource which will automatically be + * cleaned up at the end of a test case. See &struct kunit_resource for an + * example. + * + * This is effectively identical to kunit_alloc_resource, but returns the + * struct kunit_resource pointer, not just the 'data' pointer. It therefore + * also increments the resource's refcount, so kunit_put_resource() should be + * called when you've finished with it. + * + * Note: KUnit needs to allocate memory for a kunit_resource object. You must + * specify an @internal_gfp that is compatible with the use context of your + * resource. + */ +static inline struct kunit_resource * +kunit_alloc_and_get_resource(struct kunit *test, + kunit_resource_init_t init, + kunit_resource_free_t free, + gfp_t internal_gfp, + void *context) +{ + struct kunit_resource *res; + int ret; + + res = kzalloc(sizeof(*res), internal_gfp); + if (!res) + return NULL; + + res->should_kfree = true; + + ret = __kunit_add_resource(test, init, free, res, context); + if (!ret) { + /* + * bump refcount for get; kunit_resource_put() should be called + * when done. + */ + kunit_get_resource(res); + return res; + } + return NULL; +} + +/** + * kunit_alloc_resource() - Allocates a *test managed resource*. + * @test: The test context object. + * @init: a user supplied function to initialize the resource. + * @free: a user supplied function to free the resource (if needed). + * @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL + * @context: for the user to pass in arbitrary data to the init function. + * + * Allocates a *test managed resource*, a resource which will automatically be + * cleaned up at the end of a test case. See &struct kunit_resource for an + * example. + * + * Note: KUnit needs to allocate memory for a kunit_resource object. You must + * specify an @internal_gfp that is compatible with the use context of your + * resource. + */ +static inline void *kunit_alloc_resource(struct kunit *test, + kunit_resource_init_t init, + kunit_resource_free_t free, + gfp_t internal_gfp, + void *context) +{ + struct kunit_resource *res; + + res = kzalloc(sizeof(*res), internal_gfp); + if (!res) + return NULL; + + res->should_kfree = true; + if (!__kunit_add_resource(test, init, free, res, context)) + return res->data; + + return NULL; +} + +typedef bool (*kunit_resource_match_t)(struct kunit *test, + struct kunit_resource *res, + void *match_data); + +/** + * kunit_resource_name_match() - Match a resource with the same name. + * @test: Test case to which the resource belongs. + * @res: The resource. + * @match_name: The name to match against. + */ +static inline bool kunit_resource_name_match(struct kunit *test, + struct kunit_resource *res, + void *match_name) +{ + return res->name && strcmp(res->name, match_name) == 0; +} + +/** + * kunit_find_resource() - Find a resource using match function/data. + * @test: Test case to which the resource belongs. + * @match: match function to be applied to resources/match data. + * @match_data: data to be used in matching. + */ +static inline struct kunit_resource * +kunit_find_resource(struct kunit *test, + kunit_resource_match_t match, + void *match_data) +{ + struct kunit_resource *res, *found = NULL; + unsigned long flags; + + spin_lock_irqsave(&test->lock, flags); + + list_for_each_entry_reverse(res, &test->resources, node) { + if (match(test, res, (void *)match_data)) { + found = res; + kunit_get_resource(found); + break; + } + } + + spin_unlock_irqrestore(&test->lock, flags); + + return found; +} + +/** + * kunit_find_named_resource() - Find a resource using match name. + * @test: Test case to which the resource belongs. + * @name: match name. + */ +static inline struct kunit_resource * +kunit_find_named_resource(struct kunit *test, + const char *name) +{ + return kunit_find_resource(test, kunit_resource_name_match, + (void *)name); +} + +/** + * kunit_destroy_resource() - Find a kunit_resource and destroy it. + * @test: Test case to which the resource belongs. + * @match: Match function. Returns whether a given resource matches @match_data. + * @match_data: Data passed into @match. + * + * RETURNS: + * 0 if kunit_resource is found and freed, -ENOENT if not found. + */ +int kunit_destroy_resource(struct kunit *test, + kunit_resource_match_t match, + void *match_data); + +static inline int kunit_destroy_named_resource(struct kunit *test, + const char *name) +{ + return kunit_destroy_resource(test, kunit_resource_name_match, + (void *)name); +} + +/** + * kunit_remove_resource() - remove resource from resource list associated with + * test. + * @test: The test context object. + * @res: The resource to be removed. + * + * Note that the resource will not be immediately freed since it is likely + * the caller has a reference to it via alloc_and_get() or find(); + * in this case a final call to kunit_put_resource() is required. + */ +void kunit_remove_resource(struct kunit *test, struct kunit_resource *res); + +#endif /* _KUNIT_RESOURCE_H */ |