[PATCH 2/3] lib: tests: Add test for atomic_t

[Ivan Orlov <ivan.orlov0322@gmail.com>]

Implement the test which covers some of the functions from the
`riscv_atomic.h` header file. The test contains 9 test cases:

1) atomic read/write test
2) add/return test
3) sub/return test
4) cmpxchg test
5) atomic_xchg test
6) atomic_raw_set_bit test
7) atomic_raw_clear_bit test
8) atomic_set_bit test
9) atomic_clear_bit test

Some of the test cases operate on the `test_atomic` variable. It gets
initialized in the suite init function.

Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
---
 lib/sbi/tests/objects.mk          |   3 +
 lib/sbi/tests/riscv_atomic_test.c | 143 ++++++++++++++++++++++++++++++
 2 files changed, 146 insertions(+)
 create mode 100644 lib/sbi/tests/riscv_atomic_test.c

diff --git a/lib/sbi/tests/objects.mk b/lib/sbi/tests/objects.mk
index 5ce188a..ba588dc 100644
--- a/lib/sbi/tests/objects.mk
+++ b/lib/sbi/tests/objects.mk
@@ -6,3 +6,6 @@ libsbi-objs-$(CONFIG_SBIUNIT) += tests/sbi_bitmap_test.o
 
 carray-sbi_unit_tests-$(CONFIG_SBIUNIT) += console_test_suite
 libsbi-objs-$(CONFIG_SBIUNIT) += tests/sbi_console_test.o
+
+carray-sbi_unit_tests-$(CONFIG_SBIUNIT) += atomic_test_suite
+libsbi-objs-$(CONFIG_SBIUNIT) += tests/riscv_atomic_test.o
diff --git a/lib/sbi/tests/riscv_atomic_test.c b/lib/sbi/tests/riscv_atomic_test.c
new file mode 100644
index 0000000..8a17a5f
--- /dev/null
+++ b/lib/sbi/tests/riscv_atomic_test.c
@@ -0,0 +1,143 @@
+#include <sbi/sbi_unit_test.h>
+#include <sbi/riscv_atomic.h>
+#include <sbi/sbi_bitops.h>
+
+#define ATOMIC_TEST_VAL1 239l
+#define ATOMIC_TEST_VAL2 30l
+#define ATOMIC_TEST_VAL3 2024l
+
+#define ATOMIC_TEST_BIT_NUM 3
+
+#define ATOMIC_TEST_RAW_BIT_CELL 1
+#define ATOMIC_TEST_RAW_BIT_NUM 15
+
+static atomic_t test_atomic;
+
+static void atomic_test_suite_init(void)
+{
+	ATOMIC_INIT(&test_atomic, 0);
+}
+
+static void atomic_rw_test(struct sbiunit_test_case *test)
+{
+	/* We should read the same value as we've written */
+	atomic_write(&test_atomic, ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), ATOMIC_TEST_VAL1);
+	/* Negative value should also work */
+	atomic_write(&test_atomic, -ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), -ATOMIC_TEST_VAL1);
+}
+
+static void add_return_test(struct sbiunit_test_case *test)
+{
+	atomic_write(&test_atomic, ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_add_return(&test_atomic, ATOMIC_TEST_VAL2),
+			  ATOMIC_TEST_VAL1 + ATOMIC_TEST_VAL2);
+	/* The atomic value should be updated as well */
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), ATOMIC_TEST_VAL1 + ATOMIC_TEST_VAL2);
+}
+
+static void sub_return_test(struct sbiunit_test_case *test)
+{
+	atomic_write(&test_atomic, ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_sub_return(&test_atomic, ATOMIC_TEST_VAL2),
+			  ATOMIC_TEST_VAL1 - ATOMIC_TEST_VAL2);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), ATOMIC_TEST_VAL1 - ATOMIC_TEST_VAL2);
+}
+
+static void cmpxchg_test(struct sbiunit_test_case *test)
+{
+	atomic_write(&test_atomic, ATOMIC_TEST_VAL1);
+	/* if current value != expected, it stays the same */
+	SBIUNIT_EXPECT_EQ(test, atomic_cmpxchg(&test_atomic, ATOMIC_TEST_VAL2, ATOMIC_TEST_VAL3),
+			  ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), ATOMIC_TEST_VAL1);
+	/* if current value == expected, it gets updated */
+	SBIUNIT_EXPECT_EQ(test, atomic_cmpxchg(&test_atomic, ATOMIC_TEST_VAL1, ATOMIC_TEST_VAL2),
+			  ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), ATOMIC_TEST_VAL2);
+}
+
+static void atomic_xchg_test(struct sbiunit_test_case *test)
+{
+	atomic_write(&test_atomic, ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_xchg(&test_atomic, ATOMIC_TEST_VAL2), ATOMIC_TEST_VAL1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), ATOMIC_TEST_VAL2);
+}
+
+static void atomic_raw_set_bit_test(struct sbiunit_test_case *test)
+{
+	unsigned long data[] = {0, 0, 0};
+	/* the bitpos points to the bit of one of the elements of the `data` array */
+	size_t bitpos = ATOMIC_TEST_RAW_BIT_CELL * BITS_PER_LONG + ATOMIC_TEST_RAW_BIT_NUM;
+
+	/* check if the bit we set actually gets set */
+	SBIUNIT_EXPECT_EQ(test, atomic_raw_set_bit(bitpos, data), 0);
+	SBIUNIT_EXPECT_EQ(test, data[ATOMIC_TEST_RAW_BIT_CELL], 1 << ATOMIC_TEST_RAW_BIT_NUM);
+
+	/* Other elements of the `data` array should stay untouched */
+	SBIUNIT_EXPECT_EQ(test, data[0], 0);
+	SBIUNIT_EXPECT_EQ(test, data[2], 0);
+
+	/* check that if we set the bit twice it stays set */
+	SBIUNIT_EXPECT_EQ(test, atomic_raw_set_bit(bitpos, data), 1);
+	SBIUNIT_EXPECT_EQ(test, data[ATOMIC_TEST_RAW_BIT_CELL], 1 << ATOMIC_TEST_RAW_BIT_NUM);
+}
+
+static void atomic_raw_clear_bit_test(struct sbiunit_test_case *test)
+{
+	unsigned long data[] = {~1UL, 1 << ATOMIC_TEST_RAW_BIT_NUM, ~1UL};
+	/* the bitpos points to the bit of one of the elements of the `data` array */
+	size_t bitpos = ATOMIC_TEST_RAW_BIT_CELL * BITS_PER_LONG + ATOMIC_TEST_RAW_BIT_NUM;
+
+	/* check if the bit we clear actually gets cleared */
+	SBIUNIT_EXPECT_EQ(test, atomic_raw_clear_bit(bitpos, data), 1);
+	SBIUNIT_EXPECT_EQ(test, data[ATOMIC_TEST_RAW_BIT_CELL], 0);
+
+	/* Other elements of the `data` array should stay untouched */
+	SBIUNIT_EXPECT_EQ(test, data[0], ~1UL);
+	SBIUNIT_EXPECT_EQ(test, data[2], ~1UL);
+
+	/* check that if we clear the bit twice it stays cleared */
+	SBIUNIT_EXPECT_EQ(test, atomic_raw_clear_bit(bitpos, data), 0);
+	SBIUNIT_EXPECT_EQ(test, data[ATOMIC_TEST_RAW_BIT_CELL], 0);
+}
+
+static void atomic_set_bit_test(struct sbiunit_test_case *test)
+{
+	atomic_write(&test_atomic, 0);
+	SBIUNIT_EXPECT_EQ(test, atomic_set_bit(ATOMIC_TEST_BIT_NUM, &test_atomic), 0);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), 1 << ATOMIC_TEST_BIT_NUM);
+	/* If we set the bit twice, it stays 1 */
+	SBIUNIT_EXPECT_EQ(test, atomic_set_bit(ATOMIC_TEST_BIT_NUM, &test_atomic), 1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), 1 << ATOMIC_TEST_BIT_NUM);
+}
+
+static void atomic_clear_bit_test(struct sbiunit_test_case *test)
+{
+	atomic_write(&test_atomic, 1 << ATOMIC_TEST_BIT_NUM);
+	SBIUNIT_EXPECT_EQ(test, atomic_clear_bit(ATOMIC_TEST_BIT_NUM, &test_atomic), 1);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), 0);
+	/* if we clear the bit twice, it stays 0 */
+	SBIUNIT_EXPECT_EQ(test, atomic_clear_bit(ATOMIC_TEST_BIT_NUM, &test_atomic), 0);
+	SBIUNIT_EXPECT_EQ(test, atomic_read(&test_atomic), 0);
+}
+
+static struct sbiunit_test_case atomic_test_cases[] = {
+	SBIUNIT_TEST_CASE(atomic_rw_test),
+	SBIUNIT_TEST_CASE(add_return_test),
+	SBIUNIT_TEST_CASE(sub_return_test),
+	SBIUNIT_TEST_CASE(cmpxchg_test),
+	SBIUNIT_TEST_CASE(atomic_xchg_test),
+	SBIUNIT_TEST_CASE(atomic_raw_set_bit_test),
+	SBIUNIT_TEST_CASE(atomic_raw_clear_bit_test),
+	SBIUNIT_TEST_CASE(atomic_set_bit_test),
+	SBIUNIT_TEST_CASE(atomic_clear_bit_test),
+	SBIUNIT_END_CASE,
+};
+
+const struct sbiunit_test_suite atomic_test_suite = {
+	.name = "atomic_test_suite",
+	.cases = atomic_test_cases,
+	.init = atomic_test_suite_init
+};
-- 
2.34.1