// SPDX-License-Identifier: GPL-2.0/* * KUnit test for the generic kernel FIFO implementation. * * Copyright (C) 2024 Diego Vieira <diego.daniel.professional@gmail.com> */#include <kunit/test.h> #include <linux/kfifo.h> #define KFIFO_SIZE 32#define N_ELEMENTS 5 static void kfifo_test_reset_should_clear_the_fifo(struct kunit *test){	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	kfifo_put(&my_fifo, 1);	kfifo_put(&my_fifo, 2);	kfifo_put(&my_fifo, 3);	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 3); 	kfifo_reset(&my_fifo); 	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 0);	KUNIT_EXPECT_TRUE(test, kfifo_is_empty(&my_fifo));} static void kfifo_test_define_should_define_an_empty_fifo(struct kunit *test){	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	KUNIT_EXPECT_TRUE(test, kfifo_initialized(&my_fifo));	KUNIT_EXPECT_TRUE(test, kfifo_is_empty(&my_fifo));	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 0);} static void kfifo_test_len_should_ret_n_of_stored_elements(struct kunit *test){	u8 buffer1[N_ELEMENTS]; 	for (int i = 0; i < N_ELEMENTS; i++)		buffer1[i] = i + 1; 	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 0); 	kfifo_in(&my_fifo, buffer1, N_ELEMENTS);	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), N_ELEMENTS); 	kfifo_in(&my_fifo, buffer1, N_ELEMENTS);	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), N_ELEMENTS * 2); 	kfifo_reset(&my_fifo);	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 0);} static void kfifo_test_put_should_insert_and_get_should_pop(struct kunit *test){	u8 out_data = 0;	int processed_elements;	u8 elements[] = { 3, 5, 11 }; 	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	// If the fifo is empty, get returns 0	processed_elements = kfifo_get(&my_fifo, &out_data);	KUNIT_EXPECT_EQ(test, processed_elements, 0);	KUNIT_EXPECT_EQ(test, out_data, 0); 	for (int i = 0; i < 3; i++)		kfifo_put(&my_fifo, elements[i]); 	for (int i = 0; i < 3; i++) {		processed_elements = kfifo_get(&my_fifo, &out_data);		KUNIT_EXPECT_EQ(test, processed_elements, 1);		KUNIT_EXPECT_EQ(test, out_data, elements[i]);	}} static void kfifo_test_in_should_insert_multiple_elements(struct kunit *test){	u8 in_buffer[] = { 11, 25, 65 };	u8 out_data;	int processed_elements; 	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	kfifo_in(&my_fifo, in_buffer, 3); 	for (int i = 0; i < 3; i++) {		processed_elements = kfifo_get(&my_fifo, &out_data);		KUNIT_EXPECT_EQ(test, processed_elements, 1);		KUNIT_EXPECT_EQ(test, out_data, in_buffer[i]);	}} static void kfifo_test_out_should_pop_multiple_elements(struct kunit *test){	u8 in_buffer[] = { 11, 25, 65 };	u8 out_buffer[3];	int copied_elements; 	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	for (int i = 0; i < 3; i++)		kfifo_put(&my_fifo, in_buffer[i]); 	copied_elements = kfifo_out(&my_fifo, out_buffer, 3);	KUNIT_EXPECT_EQ(test, copied_elements, 3); 	for (int i = 0; i < 3; i++)		KUNIT_EXPECT_EQ(test, out_buffer[i], in_buffer[i]);	KUNIT_EXPECT_TRUE(test, kfifo_is_empty(&my_fifo));} static void kfifo_test_dec_init_should_define_an_empty_fifo(struct kunit *test){	DECLARE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	INIT_KFIFO(my_fifo); 	// my_fifo is a struct with an inplace buffer	KUNIT_EXPECT_FALSE(test, __is_kfifo_ptr(&my_fifo)); 	KUNIT_EXPECT_TRUE(test, kfifo_initialized(&my_fifo));} static void kfifo_test_define_should_equal_declare_init(struct kunit *test){	// declare a variable my_fifo of type struct kfifo of u8	DECLARE_KFIFO(my_fifo1, u8, KFIFO_SIZE);	// initialize the my_fifo variable	INIT_KFIFO(my_fifo1); 	// DEFINE_KFIFO declares the variable with the initial value	// essentially the same as calling DECLARE_KFIFO and INIT_KFIFO	DEFINE_KFIFO(my_fifo2, u8, KFIFO_SIZE); 	// my_fifo1 and my_fifo2 have the same size	KUNIT_EXPECT_EQ(test, sizeof(my_fifo1), sizeof(my_fifo2));	KUNIT_EXPECT_EQ(test, kfifo_initialized(&my_fifo1),			kfifo_initialized(&my_fifo2));	KUNIT_EXPECT_EQ(test, kfifo_is_empty(&my_fifo1),			kfifo_is_empty(&my_fifo2));} static void kfifo_test_alloc_should_initiliaze_a_ptr_fifo(struct kunit *test){	int ret;	DECLARE_KFIFO_PTR(my_fifo, u8); 	INIT_KFIFO(my_fifo); 	// kfifo_initialized returns false signaling the buffer pointer is NULL	KUNIT_EXPECT_FALSE(test, kfifo_initialized(&my_fifo)); 	// kfifo_alloc allocates the buffer	ret = kfifo_alloc(&my_fifo, KFIFO_SIZE, GFP_KERNEL);	KUNIT_EXPECT_EQ_MSG(test, ret, 0, "Memory allocation should succeed");	KUNIT_EXPECT_TRUE(test, kfifo_initialized(&my_fifo)); 	// kfifo_free frees the buffer	kfifo_free(&my_fifo);} static void kfifo_test_peek_should_not_remove_elements(struct kunit *test){	u8 out_data;	int processed_elements; 	DEFINE_KFIFO(my_fifo, u8, KFIFO_SIZE); 	// If the fifo is empty, peek returns 0	processed_elements = kfifo_peek(&my_fifo, &out_data);	KUNIT_EXPECT_EQ(test, processed_elements, 0); 	kfifo_put(&my_fifo, 3);	kfifo_put(&my_fifo, 5);	kfifo_put(&my_fifo, 11); 	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 3); 	processed_elements = kfifo_peek(&my_fifo, &out_data);	KUNIT_EXPECT_EQ(test, processed_elements, 1);	KUNIT_EXPECT_EQ(test, out_data, 3); 	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 3); 	// Using peek doesn't remove the element	// so the read element and the fifo length	// remains the same	processed_elements = kfifo_peek(&my_fifo, &out_data);	KUNIT_EXPECT_EQ(test, processed_elements, 1);	KUNIT_EXPECT_EQ(test, out_data, 3); 	KUNIT_EXPECT_EQ(test, kfifo_len(&my_fifo), 3);} static struct kunit_case kfifo_test_cases[] = {	KUNIT_CASE(kfifo_test_reset_should_clear_the_fifo),	KUNIT_CASE(kfifo_test_define_should_define_an_empty_fifo),	KUNIT_CASE(kfifo_test_len_should_ret_n_of_stored_elements),	KUNIT_CASE(kfifo_test_put_should_insert_and_get_should_pop),	KUNIT_CASE(kfifo_test_in_should_insert_multiple_elements),	KUNIT_CASE(kfifo_test_out_should_pop_multiple_elements),	KUNIT_CASE(kfifo_test_dec_init_should_define_an_empty_fifo),	KUNIT_CASE(kfifo_test_define_should_equal_declare_init),	KUNIT_CASE(kfifo_test_alloc_should_initiliaze_a_ptr_fifo),	KUNIT_CASE(kfifo_test_peek_should_not_remove_elements),	{},}; static struct kunit_suite kfifo_test_module = {	.name = "kfifo",	.test_cases = kfifo_test_cases,}; kunit_test_suites(&kfifo_test_module); MODULE_LICENSE("GPL");MODULE_AUTHOR("Diego Vieira <diego.daniel.professional@gmail.com>");MODULE_DESCRIPTION("KUnit test for the kernel FIFO");