Add interrupt support for emulator

This provides us a way to inject interrupts during a test. If a test has
interrupt_generator() defined, it will run in a separate thread. The
generator can then trigger interrupts when it decides to. The current
running task is suspended while emulator is executing ISR.

Also fixes a bug that tasks run without scheduler notifying them during
emulator start-up.

BUG=chrome-os-partner:19235
TEST=Repeatedly run all tests.
BRANCH=None

Change-Id: I0f921c47c0f848a9626da6272d9040e2b7c5ac86
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/55671

1 files changed, 82 insertions, 0 deletions

diff --git a/test/interrupt.c b/test/interrupt.c
new file mode 100644
index 0000000000..b7a42d1588
--- /dev/null
+++ b/test/interrupt.c
@@ -0,0 +1,82 @@
+/* Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Test interrupt support of EC emulator.
+ */
+#include <stdio.h>
+
+#include "common.h"
+#include "console.h"
+#include "test_util.h"
+#include "task.h"
+#include "timer.h"
+#include "util.h"
+
+static int main_count;
+static int has_error;
+static int interrupt_count;
+
+/* period between 50us and 3.2ms */
+#define PERIOD_US(num) (((num % 64) + 1) * 50)
+
+void my_isr(void)
+{
+	int i = main_count;
+	udelay(3 * PERIOD_US(prng_no_seed()));
+	if (i != main_count || !in_interrupt_context())
+		has_error = 1;
+	interrupt_count++;
+}
+
+void interrupt_generator(void)
+{
+	while (1) {
+		udelay(3 * PERIOD_US(prng_no_seed()));
+		task_trigger_test_interrupt(my_isr);
+	}
+}
+
+static int interrupt_test(void)
+{
+	timestamp_t deadline = get_time();
+	deadline.val += SECOND / 2;
+	while (!timestamp_expired(deadline, NULL))
+		++main_count;
+
+	ccprintf("Interrupt count: %d\n", interrupt_count);
+	ccprintf("Main thread tick: %d\n", main_count);
+
+	TEST_ASSERT(!has_error);
+	TEST_ASSERT(!in_interrupt_context());
+
+	return EC_SUCCESS;
+}
+
+static int interrupt_disable_test(void)
+{
+	timestamp_t deadline = get_time();
+	int start_int_cnt, end_int_cnt;
+	deadline.val += SECOND / 2;
+
+	interrupt_disable();
+	start_int_cnt = interrupt_count;
+	while (!timestamp_expired(deadline, NULL))
+		;
+	end_int_cnt = interrupt_count;
+	interrupt_enable();
+
+	TEST_ASSERT(start_int_cnt == end_int_cnt);
+
+	return EC_SUCCESS;
+}
+
+void run_test(void)
+{
+	test_reset();
+
+	RUN_TEST(interrupt_test);
+	RUN_TEST(interrupt_disable_test);
+
+	test_print_result();
+}