[PATCH 37/37] drm: kselftest for drm_mm and bottom-up allocation

[Chris Wilson]

Check that if we request bottom-up allocation from drm_mm_insert_node()
we receive the next available hole from the bottom.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
---
 drivers/gpu/drm/selftests/drm_mm_selftests.h |  1 +
 drivers/gpu/drm/selftests/test-drm_mm.c      | 87 ++++++++++++++++++++++++++++
 2 files changed, 88 insertions(+)

diff --git a/drivers/gpu/drm/selftests/drm_mm_selftests.h b/drivers/gpu/drm/selftests/drm_mm_selftests.h
index 6a4575fdc1c0..37bbdac52896 100644
--- a/drivers/gpu/drm/selftests/drm_mm_selftests.h
+++ b/drivers/gpu/drm/selftests/drm_mm_selftests.h
@@ -17,6 +17,7 @@ selftest(align32, igt_align32)
 selftest(align64, igt_align64)
 selftest(evict, igt_evict)
 selftest(evict_range, igt_evict_range)
+selftest(bottomup, igt_bottomup)
 selftest(topdown, igt_topdown)
 selftest(color, igt_color)
 selftest(color_evict, igt_color_evict)
diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c b/drivers/gpu/drm/selftests/test-drm_mm.c
index bd23fe5baf55..d9ecfe3af68d 100644
--- a/drivers/gpu/drm/selftests/test-drm_mm.c
+++ b/drivers/gpu/drm/selftests/test-drm_mm.c
@@ -1551,6 +1551,93 @@ static int igt_topdown(void *ignored)
 	return ret;
 }
 
+static int igt_bottomup(void *ignored)
+{
+	RND_STATE(prng, random_seed);
+	const unsigned int size = min(8192u, max_iterations);
+	unsigned long *bitmap;
+	struct drm_mm mm;
+	struct drm_mm_node *nodes, *node, *next;
+	unsigned int *order, n, m, o = 0;
+	int ret, err;
+
+	ret = -ENOMEM;
+	nodes = vzalloc(size * sizeof(*nodes));
+	if (!nodes)
+		goto err;
+
+	bitmap = kzalloc(size / BITS_PER_LONG * sizeof(unsigned long),
+			 GFP_TEMPORARY);
+	if (!bitmap)
+		goto err_nodes;
+
+	order = drm_random_order(size, &prng);
+	if (!order)
+		goto err_bitmap;
+
+	ret = -EINVAL;
+	drm_mm_init(&mm, 0, size);
+	for (n = 0; n < size; n++) {
+		err = drm_mm_insert_node_generic(&mm, &nodes[n], 1, 0, 0,
+						 DRM_MM_INSERT_LOW);
+		if (err) {
+			pr_err("bottomup insert failed, step %d\n", n);
+			ret = err;
+			goto out;
+		}
+
+		if (assert_singular_hole(&mm, n + 1, size))
+			goto out;
+	}
+
+	if (!assert_continuous(&mm, 1))
+		goto out;
+
+	drm_for_each_prime(n, min(size, max_prime)) {
+		for (m = 0; m < n; m++) {
+			node = &nodes[order[(o + m) % size]];
+			drm_mm_remove_node(node);
+			__set_bit(node->start, bitmap);
+		}
+
+		for (m = 0; m < n; m++) {
+			unsigned int first;
+
+			node = &nodes[order[(o + m) % size]];
+			err = drm_mm_insert_node_generic(&mm, node, 1, 0, 0,
+							 DRM_MM_INSERT_LOW);
+			if (err) {
+				pr_err("insert failed, step %d/%d\n", m, n);
+				ret = err;
+				goto out;
+			}
+
+			first = find_first_bit(bitmap, size);
+			if (node->start != first) {
+				pr_err("node %d/%d not inserted into bottom hole, expected %d, found %lld\n",
+				       m, n, first, node->start);
+				goto out;
+			}
+			__clear_bit(first, bitmap);
+		}
+
+		o += n;
+	}
+
+	ret = 0;
+out:
+	drm_mm_for_each_node_safe(node, next, &mm)
+		drm_mm_remove_node(node);
+	drm_mm_takedown(&mm);
+	kfree(order);
+err_bitmap:
+	kfree(bitmap);
+err_nodes:
+	vfree(nodes);
+err:
+	return ret;
+}
+
 static void no_color_touching(const struct drm_mm_node *node,
 			      unsigned long color,
 			      u64 *start,
-- 
2.11.0