drivers/gpu/drm/selftests/test-drm_mm.c

/*
 * Test cases for the drm_mm range manager
 */

#define pr_fmt(fmt) "drm_mm: " fmt

#include <linux/module.h>
#include <linux/prime_numbers.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/vmalloc.h>

#include <drm/drm_mm.h>

#include "../lib/drm_random.h"

#define TESTS "drm_mm_selftests.h"
#include "drm_selftest.h"

static unsigned int random_seed;
static unsigned int max_iterations = 8192;
static unsigned int max_prime = 128;

static int igt_sanitycheck(void *ignored)
{
	pr_info("%s - ok!\n", __func__);
	return 0;
}

static bool assert_no_holes(const struct drm_mm *mm)
{
	struct drm_mm_node *hole;
	u64 hole_start, hole_end;
	unsigned long count;

	count = 0;
	drm_mm_for_each_hole(hole, mm, hole_start, hole_end)
		count++;
	if (count) {
		pr_err("Expected to find no holes (after reserve), found %lu instead\n", count);
		return false;
	}

	drm_mm_for_each_node(hole, mm) {
		if (hole->hole_follows) {
			pr_err("Hole follows node, expected none!\n");
			return false;
		}
	}

	return true;
}

static bool assert_one_hole(const struct drm_mm *mm, u64 start, u64 end)
{
	struct drm_mm_node *hole;
	u64 hole_start, hole_end;
	unsigned long count;
	bool ok = true;

	if (end <= start)
		return true;

	count = 0;
	drm_mm_for_each_hole(hole, mm, hole_start, hole_end) {
		if (start != hole_start || end != hole_end) {
			if (ok)
				pr_err("empty mm has incorrect hole, found (%llx, %llx), expect (%llx, %llx)\n",
				       hole_start, hole_end,
				       start, end);
			ok = false;
		}
		count++;
	}
	if (count != 1) {
		pr_err("Expected to find one hole, found %lu instead\n", count);
		ok = false;
	}

	return ok;
}

static int igt_init(void *ignored)
{
	const unsigned int size = 4096;
	struct drm_mm mm;
	struct drm_mm_node tmp;
	int ret = -EINVAL;

	/* Start with some simple checks on initialising the struct drm_mm */
	memset(&mm, 0, sizeof(mm));
	if (drm_mm_initialized(&mm)) {
		pr_err("zeroed mm claims to be initialized\n");
		return ret;
	}

	memset(&mm, 0xff, sizeof(mm));
	drm_mm_init(&mm, 0, size);
	if (!drm_mm_initialized(&mm)) {
		pr_err("mm claims not to be initialized\n");
		goto out;
	}

	if (!drm_mm_clean(&mm)) {
		pr_err("mm not empty on creation\n");
		goto out;
	}

	/* After creation, it should all be one massive hole */
	if (!assert_one_hole(&mm, 0, size)) {
		ret = -EINVAL;
		goto out;
	}

	memset(&tmp, 0, sizeof(tmp));
	tmp.start = 0;
	tmp.size = size;
	ret = drm_mm_reserve_node(&mm, &tmp);
	if (ret) {
		pr_err("failed to reserve whole drm_mm\n");
		goto out;
	}

	/* After filling the range entirely, there should be no holes */
	if (!assert_no_holes(&mm)) {
		ret = -EINVAL;
		goto out;
	}

	/* And then after emptying it again, the massive hole should be back */
	drm_mm_remove_node(&tmp);
	if (!assert_one_hole(&mm, 0, size)) {
		ret = -EINVAL;
		goto out;
	}

out:
	if (ret)
		drm_mm_debug_table(&mm, __func__);
	drm_mm_takedown(&mm);
	return ret;
}

#include "drm_selftest.c"

static int __init test_drm_mm_init(void)
{
	int err;

	while (!random_seed)
		random_seed = get_random_int();

	pr_info("Testing DRM range manger (struct drm_mm), with random_seed=0x%x max_iterations=%u max_prime=%u\n",
		random_seed, max_iterations, max_prime);
	err = run_selftests(selftests, ARRAY_SIZE(selftests), NULL);

	return err > 0 ? 0 : err;
}

static void __exit test_drm_mm_exit(void)
{
}

module_init(test_drm_mm_init);
module_exit(test_drm_mm_exit);

module_param(random_seed, uint, 0400);
module_param(max_iterations, uint, 0400);
module_param(max_prime, uint, 0400);

MODULE_AUTHOR("Intel Corporation");
MODULE_LICENSE("GPL");