| 1 |
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| 2 | |
| 3 | * KUnit resource API for test managed resources (allocations, etc.).
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| 4 | *
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| 5 | * Copyright (C) 2022, Google LLC.
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| 6 | * Author: Daniel Latypov <[email protected]>
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| 7 |
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| 8 |
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| 9 | #ifndef _KUNIT_RESOURCE_H
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| 10 | #define _KUNIT_RESOURCE_H
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| 11 |
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| 12 | #include <kunit/test.h>
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| 13 |
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| 14 | #include <linux/kref.h>
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| 15 | #include <linux/list.h>
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| 16 | #include <linux/slab.h>
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| 17 | #include <linux/spinlock.h>
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| 18 |
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| 19 | struct kunit_resource;
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| 20 |
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| 21 | typedef int (*kunit_resource_init_t)(struct kunit_resource *, void *);
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| 22 | typedef void (*kunit_resource_free_t)(struct kunit_resource *);
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| 23 |
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| 24 | |
| 25 | * struct kunit_resource - represents a *test managed resource*
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| 26 | * @data: for the user to store arbitrary data.
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| 27 | * @name: optional name
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| 28 | * @free: a user supplied function to free the resource.
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| 29 | *
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| 30 | * Represents a *test managed resource*, a resource which will automatically be
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| 31 | * cleaned up at the end of a test case. This cleanup is performed by the 'free'
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| 32 | * function. The struct kunit_resource itself is freed automatically with
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| 33 | * kfree() if it was allocated by KUnit (e.g., by kunit_alloc_resource()), but
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| 34 | * must be freed by the user otherwise.
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| 35 | *
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| 36 | * Resources are reference counted so if a resource is retrieved via
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| 37 | * kunit_alloc_and_get_resource() or kunit_find_resource(), we need
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| 38 | * to call kunit_put_resource() to reduce the resource reference count
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| 39 | * when finished with it. Note that kunit_alloc_resource() does not require a
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| 40 | * kunit_resource_put() because it does not retrieve the resource itself.
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| 41 | *
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| 42 | * Example:
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| 43 | *
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| 44 | * .. code-block:: c
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| 45 | *
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| 46 | * struct kunit_kmalloc_params {
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| 47 | * size_t size;
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| 48 | * gfp_t gfp;
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| 49 | * };
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| 50 | *
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| 51 | * static int kunit_kmalloc_init(struct kunit_resource *res, void *context)
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| 52 | * {
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| 53 | * struct kunit_kmalloc_params *params = context;
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| 54 | * res->data = kmalloc(params->size, params->gfp);
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| 55 | *
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| 56 | * if (!res->data)
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| 57 | * return -ENOMEM;
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| 58 | *
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| 59 | * return 0;
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| 60 | * }
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| 61 | *
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| 62 | * static void kunit_kmalloc_free(struct kunit_resource *res)
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| 63 | * {
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| 64 | * kfree(res->data);
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| 65 | * }
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| 66 | *
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| 67 | * void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp)
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| 68 | * {
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| 69 | * struct kunit_kmalloc_params params;
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| 70 | *
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| 71 | * params.size = size;
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| 72 | * params.gfp = gfp;
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| 73 | *
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| 74 | * return kunit_alloc_resource(test, kunit_kmalloc_init,
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| 75 | * kunit_kmalloc_free, gfp, ¶ms);
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| 76 | * }
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| 77 | *
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| 78 | * Resources can also be named, with lookup/removal done on a name
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| 79 | * basis also. kunit_add_named_resource(), kunit_find_named_resource()
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| 80 | * and kunit_destroy_named_resource(). Resource names must be
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| 81 | * unique within the test instance.
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| 82 |
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| 83 | struct kunit_resource {
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| 84 | void *data;
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| 85 | const char *name;
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| 86 | kunit_resource_free_t free;
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| 87 |
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| 88 |
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| 89 | struct kref refcount;
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| 90 | struct list_head node;
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| 91 | bool should_kfree;
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| 92 | };
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| 93 |
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| 94 | |
| 95 | * kunit_get_resource() - Hold resource for use. Should not need to be used
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| 96 | * by most users as we automatically get resources
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| 97 | * retrieved by kunit_find_resource*().
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| 98 | * @res: resource
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| 99 |
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| 100 | static inline void kunit_get_resource(struct kunit_resource *res)
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| 101 | {
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| 102 | kref_get(&res->refcount);
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| 103 | }
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| 104 |
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| 105 | |
| 106 | * Called when refcount reaches zero via kunit_put_resource();
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| 107 | * should not be called directly.
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| 108 |
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| 109 | static inline void kunit_release_resource(struct kref *kref)
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| 110 | {
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| 111 | struct kunit_resource *res = container_of(kref, struct kunit_resource,
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| 112 | refcount);
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| 113 |
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| 114 | if (res->free)
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| 115 | res->free(res);
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| 116 |
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| 117 | |
| 118 | * 'res' itself, just res->data
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| 119 |
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| 120 | if (res->should_kfree)
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| 121 | kfree(res);
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| 122 | }
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| 123 |
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| 124 | |
| 125 | * kunit_put_resource() - When caller is done with retrieved resource,
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| 126 | * kunit_put_resource() should be called to drop
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| 127 | * reference count. The resource list maintains
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| 128 | * a reference count on resources, so if no users
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| 129 | * are utilizing a resource and it is removed from
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| 130 | * the resource list, it will be freed via the
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| 131 | * associated free function (if any). Only
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| 132 | * needs to be used if we alloc_and_get() or
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| 133 | * find() resource.
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| 134 | * @res: resource
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| 135 |
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| 136 | static inline void kunit_put_resource(struct kunit_resource *res)
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| 137 | {
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| 138 | kref_put(&res->refcount, kunit_release_resource);
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| 139 | }
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| 140 |
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| 141 | |
| 142 | * __kunit_add_resource() - Internal helper to add a resource.
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| 143 | *
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| 144 | * res->should_kfree is not initialised.
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| 145 | * @test: The test context object.
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| 146 | * @init: a user-supplied function to initialize the result (if needed). If
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| 147 | * none is supplied, the resource data value is simply set to @data.
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| 148 | * If an init function is supplied, @data is passed to it instead.
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| 149 | * @free: a user-supplied function to free the resource (if needed).
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| 150 | * @res: The resource.
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| 151 | * @data: value to pass to init function or set in resource data field.
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| 152 |
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| 153 | int __kunit_add_resource(struct kunit *test,
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| 154 | kunit_resource_init_t init,
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| 155 | kunit_resource_free_t free,
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| 156 | struct kunit_resource *res,
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| 157 | void *data);
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| 158 |
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| 159 | |
| 160 | * kunit_add_resource() - Add a *test managed resource*.
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| 161 | * @test: The test context object.
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| 162 | * @init: a user-supplied function to initialize the result (if needed). If
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| 163 | * none is supplied, the resource data value is simply set to @data.
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| 164 | * If an init function is supplied, @data is passed to it instead.
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| 165 | * @free: a user-supplied function to free the resource (if needed).
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| 166 | * @res: The resource.
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| 167 | * @data: value to pass to init function or set in resource data field.
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| 168 |
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| 169 | static inline int kunit_add_resource(struct kunit *test,
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| 170 | kunit_resource_init_t init,
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| 171 | kunit_resource_free_t free,
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| 172 | struct kunit_resource *res,
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| 173 | void *data)
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| 174 | {
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| 175 | res->should_kfree = false;
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| 176 | return __kunit_add_resource(test, init, free, res, data);
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| 177 | }
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| 178 |
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| 179 | static inline struct kunit_resource *
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| 180 | kunit_find_named_resource(struct kunit *test, const char *name);
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| 181 |
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| 182 | |
| 183 | * kunit_add_named_resource() - Add a named *test managed resource*.
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| 184 | * @test: The test context object.
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| 185 | * @init: a user-supplied function to initialize the resource data, if needed.
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| 186 | * @free: a user-supplied function to free the resource data, if needed.
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| 187 | * @res: The resource.
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| 188 | * @name: name to be set for resource.
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| 189 | * @data: value to pass to init function or set in resource data field.
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| 190 |
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| 191 | static inline int kunit_add_named_resource(struct kunit *test,
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| 192 | kunit_resource_init_t init,
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| 193 | kunit_resource_free_t free,
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| 194 | struct kunit_resource *res,
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| 195 | const char *name,
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| 196 | void *data)
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| 197 | {
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| 198 | struct kunit_resource *existing;
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| 199 |
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| 200 | if (!name)
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| 201 | return -EINVAL;
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| 202 |
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| 203 | existing = kunit_find_named_resource(test, name);
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| 204 | if (existing) {
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| 205 | kunit_put_resource(existing);
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| 206 | return -EEXIST;
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| 207 | }
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| 208 |
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| 209 | res->name = name;
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| 210 | res->should_kfree = false;
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| 211 |
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| 212 | return __kunit_add_resource(test, init, free, res, data);
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| 213 | }
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| 214 |
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| 215 | |
| 216 | * kunit_alloc_and_get_resource() - Allocates and returns a *test managed resource*.
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| 217 | * @test: The test context object.
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| 218 | * @init: a user supplied function to initialize the resource.
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| 219 | * @free: a user supplied function to free the resource (if needed).
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| 220 | * @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL
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| 221 | * @context: for the user to pass in arbitrary data to the init function.
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| 222 | *
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| 223 | * Allocates a *test managed resource*, a resource which will automatically be
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| 224 | * cleaned up at the end of a test case. See &struct kunit_resource for an
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| 225 | * example.
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| 226 | *
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| 227 | * This is effectively identical to kunit_alloc_resource, but returns the
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| 228 | * struct kunit_resource pointer, not just the 'data' pointer. It therefore
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| 229 | * also increments the resource's refcount, so kunit_put_resource() should be
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| 230 | * called when you've finished with it.
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| 231 | *
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| 232 | * Note: KUnit needs to allocate memory for a kunit_resource object. You must
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| 233 | * specify an @internal_gfp that is compatible with the use context of your
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| 234 | * resource.
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| 235 |
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| 236 | static inline struct kunit_resource *
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| 237 | kunit_alloc_and_get_resource(struct kunit *test,
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| 238 | kunit_resource_init_t init,
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| 239 | kunit_resource_free_t free,
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| 240 | gfp_t internal_gfp,
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| 241 | void *context)
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| 242 | {
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| 243 | struct kunit_resource *res;
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| 244 | int ret;
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| 245 |
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| 246 | res = kzalloc_obj(*res, internal_gfp);
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| 247 | if (!res)
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| 248 | return NULL;
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| 249 |
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| 250 | res->should_kfree = true;
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| 251 |
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| 252 | ret = __kunit_add_resource(test, init, free, res, context);
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| 253 | if (!ret) {
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| 254 | |
| 255 | * bump refcount for get; kunit_resource_put() should be called
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| 256 | * when done.
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| 257 |
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| 258 | kunit_get_resource(res);
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| 259 | return res;
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| 260 | }
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| 261 | return NULL;
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| 262 | }
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| 263 |
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| 264 | |
| 265 | * kunit_alloc_resource() - Allocates a *test managed resource*.
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| 266 | * @test: The test context object.
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| 267 | * @init: a user supplied function to initialize the resource.
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| 268 | * @free: a user supplied function to free the resource (if needed).
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| 269 | * @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL
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| 270 | * @context: for the user to pass in arbitrary data to the init function.
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| 271 | *
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| 272 | * Allocates a *test managed resource*, a resource which will automatically be
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| 273 | * cleaned up at the end of a test case. See &struct kunit_resource for an
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| 274 | * example.
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| 275 | *
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| 276 | * Note: KUnit needs to allocate memory for a kunit_resource object. You must
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| 277 | * specify an @internal_gfp that is compatible with the use context of your
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| 278 | * resource.
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| 279 |
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| 280 | static inline void *kunit_alloc_resource(struct kunit *test,
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| 281 | kunit_resource_init_t init,
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| 282 | kunit_resource_free_t free,
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| 283 | gfp_t internal_gfp,
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| 284 | void *context)
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| 285 | {
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| 286 | struct kunit_resource *res;
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| 287 |
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| 288 | res = kzalloc_obj(*res, internal_gfp);
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| 289 | if (!res)
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| 290 | return NULL;
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| 291 |
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| 292 | res->should_kfree = true;
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| 293 | if (!__kunit_add_resource(test, init, free, res, context))
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| 294 | return res->data;
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| 295 |
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| 296 | return NULL;
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| 297 | }
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| 298 |
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| 299 | typedef bool (*kunit_resource_match_t)(struct kunit *test,
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| 300 | struct kunit_resource *res,
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| 301 | void *match_data);
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| 302 |
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| 303 | |
| 304 | * kunit_resource_name_match() - Match a resource with the same name.
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| 305 | * @test: Test case to which the resource belongs.
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| 306 | * @res: The resource.
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| 307 | * @match_name: The name to match against.
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| 308 |
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| 309 | static inline bool kunit_resource_name_match(struct kunit *test,
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| 310 | struct kunit_resource *res,
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| 311 | void *match_name)
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| 312 | {
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| 313 | return res->name && strcmp(res->name, match_name) == 0;
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| 314 | }
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| 315 |
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| 316 | |
| 317 | * kunit_find_resource() - Find a resource using match function/data.
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| 318 | * @test: Test case to which the resource belongs.
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| 319 | * @match: match function to be applied to resources/match data.
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| 320 | * @match_data: data to be used in matching.
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| 321 |
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| 322 | static inline struct kunit_resource *
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| 323 | kunit_find_resource(struct kunit *test,
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| 324 | kunit_resource_match_t match,
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| 325 | void *match_data)
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| 326 | {
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| 327 | struct kunit_resource *res, *found = NULL;
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| 328 | unsigned long flags;
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| 329 |
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| 330 | spin_lock_irqsave(&test->lock, flags);
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| 331 |
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| 332 | list_for_each_entry_reverse(res, &test->resources, node) {
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| 333 | if (match(test, res, (void *)match_data)) {
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| 334 | found = res;
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| 335 | kunit_get_resource(found);
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| 336 | break;
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| 337 | }
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| 338 | }
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| 339 |
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| 340 | spin_unlock_irqrestore(&test->lock, flags);
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| 341 |
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| 342 | return found;
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| 343 | }
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| 344 |
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| 345 | |
| 346 | * kunit_find_named_resource() - Find a resource using match name.
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| 347 | * @test: Test case to which the resource belongs.
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| 348 | * @name: match name.
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| 349 |
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| 350 | static inline struct kunit_resource *
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| 351 | kunit_find_named_resource(struct kunit *test,
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| 352 | const char *name)
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| 353 | {
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| 354 | return kunit_find_resource(test, kunit_resource_name_match,
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| 355 | (void *)name);
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| 356 | }
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| 357 |
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| 358 | |
| 359 | * kunit_destroy_resource() - Find a kunit_resource and destroy it.
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| 360 | * @test: Test case to which the resource belongs.
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| 361 | * @match: Match function. Returns whether a given resource matches @match_data.
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| 362 | * @match_data: Data passed into @match.
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| 363 | *
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| 364 | * RETURNS:
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| 365 | * 0 if kunit_resource is found and freed, -ENOENT if not found.
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| 366 |
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| 367 | int kunit_destroy_resource(struct kunit *test,
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| 368 | kunit_resource_match_t match,
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| 369 | void *match_data);
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| 370 |
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| 371 | static inline int kunit_destroy_named_resource(struct kunit *test,
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| 372 | const char *name)
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| 373 | {
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| 374 | return kunit_destroy_resource(test, kunit_resource_name_match,
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| 375 | (void *)name);
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| 376 | }
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| 377 |
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| 378 | |
| 379 | * kunit_remove_resource() - remove resource from resource list associated with
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| 380 | * test.
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| 381 | * @test: The test context object.
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| 382 | * @res: The resource to be removed.
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| 383 | *
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| 384 | * Note that the resource will not be immediately freed since it is likely
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| 385 | * the caller has a reference to it via alloc_and_get() or find();
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| 386 | * in this case a final call to kunit_put_resource() is required.
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| 387 |
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| 388 | void kunit_remove_resource(struct kunit *test, struct kunit_resource *res);
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| 389 |
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| 390 |
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| 391 | typedef void (kunit_action_t)(void *);
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| 392 |
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| 393 | |
| 394 | * KUNIT_DEFINE_ACTION_WRAPPER() - Wrap a function for use as a deferred action.
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| 395 | *
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| 396 | * @wrapper: The name of the new wrapper function define.
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| 397 | * @orig: The original function to wrap.
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| 398 | * @arg_type: The type of the argument accepted by @orig.
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| 399 | *
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| 400 | * Defines a wrapper for a function which accepts a single, pointer-sized
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| 401 | * argument. This wrapper can then be passed to kunit_add_action() and
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| 402 | * similar. This should be used in preference to casting a function
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| 403 | * directly to kunit_action_t, as casting function pointers will break
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| 404 | * control flow integrity (CFI), leading to crashes.
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| 405 |
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| 406 | #define KUNIT_DEFINE_ACTION_WRAPPER(wrapper, orig, arg_type) \
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| 407 | static void wrapper(void *in) \
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| 408 | { \
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| 409 | arg_type arg = (arg_type)in; \
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| 410 | orig(arg); \
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| 411 | }
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| 412 |
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| 413 |
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| 414 | |
| 415 | * kunit_add_action() - Call a function when the test ends.
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| 416 | * @test: Test case to associate the action with.
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| 417 | * @action: The function to run on test exit
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| 418 | * @ctx: Data passed into @func
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| 419 | *
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| 420 | * Defer the execution of a function until the test exits, either normally or
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| 421 | * due to a failure. @ctx is passed as additional context. All functions
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| 422 | * registered with kunit_add_action() will execute in the opposite order to that
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| 423 | * they were registered in.
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| 424 | *
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| 425 | * This is useful for cleaning up allocated memory and resources, as these
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| 426 | * functions are called even if the test aborts early due to, e.g., a failed
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| 427 | * assertion.
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| 428 | *
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| 429 | * See also: devm_add_action() for the devres equivalent.
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| 430 | *
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| 431 | * Returns:
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| 432 | * 0 on success, an error if the action could not be deferred.
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| 433 |
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| 434 | int kunit_add_action(struct kunit *test, kunit_action_t *action, void *ctx);
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| 435 |
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| 436 | |
| 437 | * kunit_add_action_or_reset() - Call a function when the test ends.
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| 438 | * @test: Test case to associate the action with.
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| 439 | * @action: The function to run on test exit
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| 440 | * @ctx: Data passed into @func
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| 441 | *
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| 442 | * Defer the execution of a function until the test exits, either normally or
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| 443 | * due to a failure. @ctx is passed as additional context. All functions
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| 444 | * registered with kunit_add_action() will execute in the opposite order to that
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| 445 | * they were registered in.
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| 446 | *
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| 447 | * This is useful for cleaning up allocated memory and resources, as these
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| 448 | * functions are called even if the test aborts early due to, e.g., a failed
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| 449 | * assertion.
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| 450 | *
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| 451 | * If the action cannot be created (e.g., due to the system being out of memory),
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| 452 | * then action(ctx) will be called immediately, and an error will be returned.
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| 453 | *
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| 454 | * See also: devm_add_action_or_reset() for the devres equivalent.
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| 455 | *
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| 456 | * Returns:
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| 457 | * 0 on success, an error if the action could not be deferred.
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| 458 |
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| 459 | int kunit_add_action_or_reset(struct kunit *test, kunit_action_t *action,
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| 460 | void *ctx);
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| 461 |
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| 462 | |
| 463 | * kunit_remove_action() - Cancel a matching deferred action.
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| 464 | * @test: Test case the action is associated with.
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| 465 | * @action: The deferred function to cancel.
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| 466 | * @ctx: The context passed to the deferred function to trigger.
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| 467 | *
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| 468 | * Prevent an action deferred via kunit_add_action() from executing when the
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| 469 | * test terminates.
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| 470 | *
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| 471 | * If the function/context pair was deferred multiple times, only the most
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| 472 | * recent one will be cancelled.
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| 473 | *
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| 474 | * See also: devm_remove_action() for the devres equivalent.
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| 475 |
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| 476 | void kunit_remove_action(struct kunit *test,
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| 477 | kunit_action_t *action,
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| 478 | void *ctx);
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| 479 |
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| 480 | |
| 481 | * kunit_release_action() - Run a matching action call immediately.
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| 482 | * @test: Test case the action is associated with.
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| 483 | * @action: The deferred function to trigger.
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| 484 | * @ctx: The context passed to the deferred function to trigger.
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| 485 | *
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| 486 | * Execute a function deferred via kunit_add_action()) immediately, rather than
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| 487 | * when the test ends.
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| 488 | *
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| 489 | * If the function/context pair was deferred multiple times, it will only be
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| 490 | * executed once here. The most recent deferral will no longer execute when
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| 491 | * the test ends.
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| 492 | *
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| 493 | * kunit_release_action(test, func, ctx);
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| 494 | * is equivalent to
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| 495 | * func(ctx);
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| 496 | * kunit_remove_action(test, func, ctx);
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| 497 | *
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| 498 | * See also: devm_release_action() for the devres equivalent.
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| 499 |
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| 500 | void kunit_release_action(struct kunit *test,
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| 501 | kunit_action_t *action,
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| 502 | void *ctx);
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| 503 | #endif
|