test: shim system.c system_reset()

Add test that verifies the system_reset() function saves system encoded
reset flags, calls chip-specific cros system soc reset routine, and
makes 1000 calls to watchdog_reload() if the SYSTEM_RESET_WAIT_EXT reset
flag is set.

BRANCH=none
BUG=b:236074898
TEST=twister --clobber -i -s zephyr/test/system_shim/system_shim.default

Signed-off-by: Aaron Massey <aaronmassey@google.com>
Change-Id: I2cdbb99028dc5b48a1b244380e76472624bad5e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3935639
Reviewed-by: Sam Hurst <shurst@google.com>
Code-Coverage: Zoss <zoss-cl-coverage@prod.google.com>

3 files changed, 52 insertions, 1 deletions

diff --git a/include/watchdog.h b/include/watchdog.h
index 9bfed9c192..d6768425ce 100644
--- a/include/watchdog.h
+++ b/include/watchdog.h
@@ -49,7 +49,7 @@ void watchdog_stop_and_unlock(void);
 #ifdef CONFIG_WATCHDOG
 void watchdog_reload(void);
 #else
-static inline void watchdog_reload(void)
+test_mockable_static_inline void watchdog_reload(void)
 {
 }
 #endif
diff --git a/zephyr/shim/src/system.c b/zephyr/shim/src/system.c
index b3dd2c121b..53e651ec03 100644
--- a/zephyr/shim/src/system.c
+++ b/zephyr/shim/src/system.c
@@ -244,9 +244,15 @@ test_mockable void system_reset(int flags)
 	if (err < 0)
 		LOG_ERR("soc reset failed");
 
+	/*
+	 * Ignore infinite loop for coverage as the test would fail via timeout
+	 * and not report regardless of executing code.
+	 */
+	/* LCOV_EXCL_START */
 	/* should never return */
 	while (1)
 		continue;
+	/* LCOV_EXCL_STOP */
 }
 
 static int check_reset_cause(void)
diff --git a/zephyr/test/system_shim/test_system.c b/zephyr/test/system_shim/test_system.c
index de54fda1fb..3bf43d6669 100644
--- a/zephyr/test/system_shim/test_system.c
+++ b/zephyr/test/system_shim/test_system.c
@@ -34,6 +34,8 @@ FAKE_VALUE_FUNC(const char *, cros_system_native_posix_get_chip_name,
 		const struct device *);
 FAKE_VALUE_FUNC(const char *, cros_system_native_posix_get_chip_revision,
 		const struct device *);
+FAKE_VALUE_FUNC(int, cros_system_native_posix_soc_reset, const struct device *);
+FAKE_VOID_FUNC(watchdog_reload);
 
 static void system_before_after(void *test_data)
 {
@@ -187,6 +189,49 @@ ZTEST(system, test_system_get_chip_values)
 		      sys_dev);
 }
 
+static int _test_cros_system_native_posix_soc_reset(const struct device *dev)
+{
+	printf("called from soc reset");
+	longjmp(jmp_hibernate, 1);
+
+	return 0;
+}
+
+ZTEST(system, test_system_reset)
+{
+	/*
+	 * Despite using setjmp this test consistently covers the code under
+	 * test. Context: https://github.com/llvm/llvm-project/issues/50119
+	 */
+	const struct device *sys_dev = device_get_binding("CROS_SYSTEM");
+	int ret = setjmp(jmp_hibernate);
+	uint32_t arbitrary_flags_w_reset_wait_ext = 0x1234 |
+						    SYSTEM_RESET_WAIT_EXT;
+	uint32_t encoded_arbitrary_flags_w_reset_wait_ext;
+
+	system_encode_save_flags(arbitrary_flags_w_reset_wait_ext,
+				 &encoded_arbitrary_flags_w_reset_wait_ext);
+
+	zassert_not_null(sys_dev);
+
+	cros_system_native_posix_soc_reset_fake.custom_fake =
+		_test_cros_system_native_posix_soc_reset;
+
+	if (ret == 0) {
+		system_reset(arbitrary_flags_w_reset_wait_ext);
+	}
+
+	zassert_not_null(sys_dev);
+
+	zassert_equal(chip_read_reset_flags(),
+		      encoded_arbitrary_flags_w_reset_wait_ext);
+
+	zassert_equal(watchdog_reload_fake.call_count, 1000);
+	zassert_equal(cros_system_native_posix_soc_reset_fake.call_count, 1);
+	zassert_equal(cros_system_native_posix_soc_reset_fake.arg0_val,
+		      sys_dev);
+}
+
 ZTEST_USER(system, test_system_console_cmd__idlestats)
 {
 	const struct device *sys_dev = device_get_binding("CROS_SYSTEM");