efi_selftest: test task priority levels

Run a 10 ms periodic timer and check that it is called 10 times
while waiting for 100 ms single shot timer.

Raise the TPL level to the level of the 10 ms timer and observe
that the notification function is not called again.

Lower the TPL level and check that the queued notification
function is called.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_selftest/Makefile

@@ -13,8 +13,11 @@ CFLAGS_efi_selftest_console.o := $(CFLAGS_EFI)
 CFLAGS_REMOVE_efi_selftest_console.o := $(CFLAGS_NON_EFI)
 CFLAGS_efi_selftest_events.o := $(CFLAGS_EFI)
 CFLAGS_REMOVE_efi_selftest_events.o := $(CFLAGS_NON_EFI)
+CFLAGS_efi_selftest_tpl.o := $(CFLAGS_EFI)
+CFLAGS_REMOVE_efi_selftest_tpl.o := $(CFLAGS_NON_EFI)
 
 obj-$(CONFIG_CMD_BOOTEFI_SELFTEST) += \
 efi_selftest.o \
 efi_selftest_console.o \
-efi_selftest_events.o
+efi_selftest_events.o \
+efi_selftest_tpl.o

lib/efi_selftest/efi_selftest_tpl.c

@@ -0,0 +1,214 @@
+/*
+ * efi_selftest_events
+ *
+ * Copyright (c) 2017 Heinrich Schuchardt <xypron.glpk@gmx.de>
+ *
+ * SPDX-License-Identifier:     GPL-2.0+
+ *
+ * This unit test uses timer events to check the handling of
+ * task priority levels.
+ */
+
+#include <efi_selftest.h>
+
+static struct efi_event *event_notify;
+static struct efi_event *event_wait;
+static unsigned int counter;
+static struct efi_boot_services *boottime;
+
+/*
+ * Notification function, increments a counter.
+ *
+ * @event	notified event
+ * @context	pointer to the counter
+ */
+static void EFIAPI notify(struct efi_event *event, void *context)
+{
+	if (!context)
+		return;
+	++*(unsigned int *)context;
+}
+
+/*
+ * Setup unit test.
+ *
+ * Create two timer events.
+ * One with EVT_NOTIFY_SIGNAL, the other with EVT_NOTIFY_WAIT.
+ *
+ * @handle:	handle of the loaded image
+ * @systable:	system table
+ */
+static int setup(const efi_handle_t handle,
+		 const struct efi_system_table *systable)
+{
+	efi_status_t ret;
+
+	boottime = systable->boottime;
+
+	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_SIGNAL,
+				     TPL_CALLBACK, notify, (void *)&counter,
+				     &event_notify);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("could not create event\n");
+		return 1;
+	}
+	ret = boottime->create_event(EVT_TIMER | EVT_NOTIFY_WAIT,
+				     TPL_HIGH_LEVEL, notify, NULL, &event_wait);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("could not create event\n");
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * Tear down unit test.
+ *
+ * Close the events created in setup.
+ */
+static int teardown(void)
+{
+	efi_status_t ret;
+
+	if (event_notify) {
+		ret = boottime->close_event(event_notify);
+		event_notify = NULL;
+		if (ret != EFI_SUCCESS) {
+			efi_st_error("could not close event\n");
+			return 1;
+		}
+	}
+	if (event_wait) {
+		ret = boottime->close_event(event_wait);
+		event_wait = NULL;
+		if (ret != EFI_SUCCESS) {
+			efi_st_error("could not close event\n");
+			return 1;
+		}
+	}
+	boottime->restore_tpl(TPL_APPLICATION);
+	return 0;
+}
+
+/*
+ * Execute unit test.
+ *
+ * Run a 10 ms periodic timer and check that it is called 10 times
+ * while waiting for 100 ms single shot timer.
+ *
+ * Raise the TPL level to the level of the 10 ms timer and observe
+ * that the notification function is not called again.
+ *
+ * Lower the TPL level and check that the queued notification
+ * function is called.
+ */
+static int execute(void)
+{
+	unsigned long index;
+	efi_status_t ret;
+	UINTN old_tpl;
+
+	/* Set 10 ms timer */
+	counter = 0;
+	ret = boottime->set_timer(event_notify, EFI_TIMER_PERIODIC, 100000);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not set timer\n");
+		return 1;
+	}
+	/* Set 100 ms timer */
+	ret = boottime->set_timer(event_wait, EFI_TIMER_RELATIVE, 1000000);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not set timer\n");
+		return 1;
+	}
+	index = 5;
+	ret = boottime->wait_for_event(1, &event_wait, &index);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not wait for event\n");
+		return 1;
+	}
+	ret = boottime->check_event(event_wait);
+	if (ret != EFI_NOT_READY) {
+		efi_st_error("Signaled state was not cleared.\n");
+		efi_st_printf("ret = %u\n", (unsigned int)ret);
+		return 1;
+	}
+	if (index != 0) {
+		efi_st_error("WaitForEvent returned wrong index\n");
+		return 1;
+	}
+	efi_st_printf("Counter with TPL level TPL_APPLICATION: %u\n", counter);
+	if (counter < 8 || counter > 12) {
+		efi_st_error("Incorrect timing of events\n");
+		return 1;
+	}
+	ret = boottime->set_timer(event_notify, EFI_TIMER_STOP, 0);
+	if (index != 0) {
+		efi_st_error("Could not cancel timer\n");
+		return 1;
+	}
+	/* Raise TPL level */
+	old_tpl = boottime->raise_tpl(TPL_CALLBACK);
+	if (old_tpl != TPL_APPLICATION) {
+		efi_st_error("Initial TPL level was not TPL_APPLICATION");
+		return 1;
+	}
+	/* Set 10 ms timer */
+	counter = 0;
+	ret = boottime->set_timer(event_notify, EFI_TIMER_PERIODIC, 100000);
+	if (index != 0) {
+		efi_st_error("Could not set timer\n");
+		return 1;
+	}
+	/* Set 100 ms timer */
+	ret = boottime->set_timer(event_wait, EFI_TIMER_RELATIVE, 1000000);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not set timer\n");
+		return 1;
+	}
+	do {
+		ret = boottime->check_event(event_wait);
+	} while (ret == EFI_NOT_READY);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not check event\n");
+		return 1;
+	}
+	efi_st_printf("Counter with TPL level TPL_CALLBACK: %u\n", counter);
+	if (counter != 0) {
+		efi_st_error("Suppressed timer fired\n");
+		return 1;
+	}
+	/* Set 1 ms timer */
+	ret = boottime->set_timer(event_wait, EFI_TIMER_RELATIVE, 1000);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not set timer\n");
+		return 1;
+	}
+	/* Restore the old TPL level */
+	boottime->restore_tpl(TPL_APPLICATION);
+	ret = boottime->wait_for_event(1, &event_wait, &index);
+	if (ret != EFI_SUCCESS) {
+		efi_st_error("Could not wait for event\n");
+		return 1;
+	}
+	efi_st_printf("Counter with TPL level TPL_APPLICATION: %u\n", counter);
+	if (counter < 1) {
+		efi_st_error("Queued timer event did not fire\n");
+		return 1;
+	}
+	ret = boottime->set_timer(event_wait, EFI_TIMER_STOP, 0);
+	if (index != 0) {
+		efi_st_error("Could not cancel timer\n");
+		return 1;
+	}
+
+	return 0;
+}
+
+EFI_UNIT_TEST(tpl) = {
+	.name = "task priority levels",
+	.phase = EFI_EXECUTE_BEFORE_BOOTTIME_EXIT,
+	.setup = setup,
+	.execute = execute,
+	.teardown = teardown,
+};