tests/drv_missed_irq.c

/*
 * Copyright © 2016 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 */

#include <sched.h>

#include "igt.h"
#include "igt_debugfs.h"
#include "igt_dummyload.h"
#include "igt_sysfs.h"

IGT_TEST_DESCRIPTION("Inject missed interrupts and make sure they are caught");

static void trigger_missed_interrupt(int fd, unsigned ring)
{
	igt_spin_t *spin = __igt_spin_batch_new(fd, 0, ring, 0);

	igt_fork(child, 1) {
		/* We are now a low priority child on the *same* CPU as the
		 * parent. We will have to wait for our parent to sleep
		 * (gem_sync -> i915_wait_request) before we run.
		 */
		igt_assert(gem_bo_busy(fd, spin->handle));
		igt_spin_batch_end(spin);
	}

	gem_sync(fd, spin->handle);
	igt_waitchildren();

	igt_spin_batch_free(fd, spin);
}

static void bind_to_cpu(int cpu)
{
	const int ncpus = sysconf(_SC_NPROCESSORS_ONLN);
	struct sched_param rt = {.sched_priority = 99 };
	cpu_set_t allowed;

	igt_assert(sched_setscheduler(getpid(), SCHED_RR | SCHED_RESET_ON_FORK, &rt) == 0);

	CPU_ZERO(&allowed);
	CPU_SET(cpu % ncpus, &allowed);
	igt_assert(sched_setaffinity(getpid(), sizeof(cpu_set_t), &allowed) == 0);
}

static void enable_missed_irq(int dir)
{
	igt_sysfs_printf(dir, "i915_ring_test_irq", "0x%x", -1);
}

static uint32_t disable_missed_irq(int dir)
{
	uint32_t mask = 0;

	igt_sysfs_scanf(dir, "i915_ring_test_irq", "%x", &mask);
	igt_sysfs_set(dir, "i915_ring_test_irq", "0");

	return mask;
}

static uint32_t engine_mask(int dir)
{
	enable_missed_irq(dir);
	return disable_missed_irq(dir);
}

igt_simple_main
{
	const struct intel_execution_engine *e;
	unsigned expect_rings;
	unsigned missed_rings;
	unsigned check_rings;
	int debugfs, device;

	igt_skip_on_simulation();
	bind_to_cpu(0);

	device = drm_open_driver(DRIVER_INTEL);
	igt_require_gem(device);
	igt_skip_on(gem_has_guc_submission(device)); /* irq forced for guc */
	gem_require_mmap_wc(device);
	igt_fork_hang_detector(device);

	debugfs = igt_debugfs_dir(device);

	expect_rings = engine_mask(debugfs);

	igt_debug("Clearing rings %x\n", expect_rings);
	intel_detect_and_clear_missed_interrupts(device);
	for (e = intel_execution_engines; e->name; e++) {
		if (expect_rings == -1 && e->exec_id)
			continue;

		if (expect_rings != -1 && e->exec_id == 0)
			continue;

		if (!gem_has_ring(device, e->exec_id | e->flags))
			continue;

		igt_debug("Clearing ring %s [%x]\n",
			  e->name, e->exec_id | e->flags);
		trigger_missed_interrupt(device, e->exec_id | e->flags);
	}
	igt_assert_eq(intel_detect_and_clear_missed_interrupts(device), 0);

	igt_debug("Testing rings %x\n", expect_rings);
	enable_missed_irq(debugfs);
	for (e = intel_execution_engines; e->name; e++) {
		if (expect_rings == -1 && e->exec_id)
			continue;

		if (expect_rings != -1 && e->exec_id == 0)
			continue;

		if (!gem_has_ring(device, e->exec_id | e->flags))
			continue;

		igt_debug("Executing on ring %s [%x]\n",
			  e->name, e->exec_id | e->flags);
		trigger_missed_interrupt(device, e->exec_id | e->flags);
	}
	missed_rings = intel_detect_and_clear_missed_interrupts(device);

	check_rings = disable_missed_irq(debugfs);
	igt_assert_eq_u32(check_rings, expect_rings);

	if (expect_rings == -1)
		igt_assert_eq_u32(missed_rings, 1);
	else
		igt_assert_eq_u32(missed_rings, expect_rings);

	close(debugfs);
	igt_stop_hang_detector();
	close(device);
}