1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * KUnit test for the FPGA Bridge
4  *
5  * Copyright (C) 2023 Red Hat, Inc.
6  *
7  * Author: Marco Pagani <marpagan@redhat.com>
8  */
9 
10 #include <kunit/device.h>
11 #include <kunit/test.h>
12 #include <linux/fpga/fpga-bridge.h>
13 #include <linux/module.h>
14 #include <linux/types.h>
15 
16 struct bridge_stats {
17 	bool enable;
18 };
19 
20 struct bridge_ctx {
21 	struct fpga_bridge *bridge;
22 	struct device *dev;
23 	struct bridge_stats stats;
24 };
25 
26 /*
27  * Wrapper to avoid a cast warning when passing the action function directly
28  * to kunit_add_action().
29  */
30 KUNIT_DEFINE_ACTION_WRAPPER(fpga_bridge_unregister_wrapper, fpga_bridge_unregister,
31 			    struct fpga_bridge *);
32 
op_enable_set(struct fpga_bridge * bridge,bool enable)33 static int op_enable_set(struct fpga_bridge *bridge, bool enable)
34 {
35 	struct bridge_stats *stats = bridge->priv;
36 
37 	stats->enable = enable;
38 
39 	return 0;
40 }
41 
42 /*
43  * Fake FPGA bridge that implements only the enable_set op to track
44  * the state.
45  */
46 static const struct fpga_bridge_ops fake_bridge_ops = {
47 	.enable_set = op_enable_set,
48 };
49 
50 /**
51  * register_test_bridge() - Register a fake FPGA bridge for testing.
52  * @test: KUnit test context object.
53  * @dev_name: name of the kunit device to be registered
54  *
55  * Return: Context of the newly registered FPGA bridge.
56  */
register_test_bridge(struct kunit * test,const char * dev_name)57 static struct bridge_ctx *register_test_bridge(struct kunit *test, const char *dev_name)
58 {
59 	struct bridge_ctx *ctx;
60 	int ret;
61 
62 	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
63 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
64 
65 	ctx->dev = kunit_device_register(test, dev_name);
66 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->dev);
67 
68 	ctx->bridge = fpga_bridge_register(ctx->dev, "Fake FPGA bridge", &fake_bridge_ops,
69 					   &ctx->stats);
70 	KUNIT_ASSERT_FALSE(test, IS_ERR_OR_NULL(ctx->bridge));
71 
72 	ret = kunit_add_action_or_reset(test, fpga_bridge_unregister_wrapper, ctx->bridge);
73 	KUNIT_ASSERT_EQ(test, ret, 0);
74 
75 	return ctx;
76 }
77 
fpga_bridge_test_get(struct kunit * test)78 static void fpga_bridge_test_get(struct kunit *test)
79 {
80 	struct bridge_ctx *ctx = test->priv;
81 	struct fpga_bridge *bridge;
82 
83 	bridge = fpga_bridge_get(ctx->dev, NULL);
84 	KUNIT_EXPECT_PTR_EQ(test, bridge, ctx->bridge);
85 
86 	bridge = fpga_bridge_get(ctx->dev, NULL);
87 	KUNIT_EXPECT_EQ(test, PTR_ERR(bridge), -EBUSY);
88 
89 	fpga_bridge_put(ctx->bridge);
90 }
91 
fpga_bridge_test_toggle(struct kunit * test)92 static void fpga_bridge_test_toggle(struct kunit *test)
93 {
94 	struct bridge_ctx *ctx = test->priv;
95 	int ret;
96 
97 	ret = fpga_bridge_disable(ctx->bridge);
98 	KUNIT_EXPECT_EQ(test, ret, 0);
99 	KUNIT_EXPECT_FALSE(test, ctx->stats.enable);
100 
101 	ret = fpga_bridge_enable(ctx->bridge);
102 	KUNIT_EXPECT_EQ(test, ret, 0);
103 	KUNIT_EXPECT_TRUE(test, ctx->stats.enable);
104 }
105 
106 /* Test the functions for getting and controlling a list of bridges */
fpga_bridge_test_get_put_list(struct kunit * test)107 static void fpga_bridge_test_get_put_list(struct kunit *test)
108 {
109 	struct list_head bridge_list;
110 	struct bridge_ctx *ctx_0, *ctx_1;
111 	int ret;
112 
113 	ctx_0 = test->priv;
114 	ctx_1 = register_test_bridge(test, "fpga-bridge-test-dev-1");
115 
116 	INIT_LIST_HEAD(&bridge_list);
117 
118 	/* Get bridge 0 and add it to the list */
119 	ret = fpga_bridge_get_to_list(ctx_0->dev, NULL, &bridge_list);
120 	KUNIT_EXPECT_EQ(test, ret, 0);
121 
122 	KUNIT_EXPECT_PTR_EQ(test, ctx_0->bridge,
123 			    list_first_entry_or_null(&bridge_list, struct fpga_bridge, node));
124 
125 	/* Get bridge 1 and add it to the list */
126 	ret = fpga_bridge_get_to_list(ctx_1->dev, NULL, &bridge_list);
127 	KUNIT_EXPECT_EQ(test, ret, 0);
128 
129 	KUNIT_EXPECT_PTR_EQ(test, ctx_1->bridge,
130 			    list_first_entry_or_null(&bridge_list, struct fpga_bridge, node));
131 
132 	/* Disable an then enable both bridges from the list */
133 	ret = fpga_bridges_disable(&bridge_list);
134 	KUNIT_EXPECT_EQ(test, ret, 0);
135 
136 	KUNIT_EXPECT_FALSE(test, ctx_0->stats.enable);
137 	KUNIT_EXPECT_FALSE(test, ctx_1->stats.enable);
138 
139 	ret = fpga_bridges_enable(&bridge_list);
140 	KUNIT_EXPECT_EQ(test, ret, 0);
141 
142 	KUNIT_EXPECT_TRUE(test, ctx_0->stats.enable);
143 	KUNIT_EXPECT_TRUE(test, ctx_1->stats.enable);
144 
145 	/* Put and remove both bridges from the list */
146 	fpga_bridges_put(&bridge_list);
147 
148 	KUNIT_EXPECT_TRUE(test, list_empty(&bridge_list));
149 }
150 
fpga_bridge_test_init(struct kunit * test)151 static int fpga_bridge_test_init(struct kunit *test)
152 {
153 	test->priv = register_test_bridge(test, "fpga-bridge-test-dev-0");
154 
155 	return 0;
156 }
157 
158 static struct kunit_case fpga_bridge_test_cases[] = {
159 	KUNIT_CASE(fpga_bridge_test_get),
160 	KUNIT_CASE(fpga_bridge_test_toggle),
161 	KUNIT_CASE(fpga_bridge_test_get_put_list),
162 	{}
163 };
164 
165 static struct kunit_suite fpga_bridge_suite = {
166 	.name = "fpga_bridge",
167 	.init = fpga_bridge_test_init,
168 	.test_cases = fpga_bridge_test_cases,
169 };
170 
171 kunit_test_suite(fpga_bridge_suite);
172 
173 MODULE_LICENSE("GPL");
174