[PATCH 12/40] drm: kselftest for drm_mm_insert_node()

[Chris Wilson]

Exercise drm_mm_insert_node(), check that we can't overfill a range and
that the lists are correct after reserving/removing.

v2: Extract helpers for the repeated tests
v3: Iterate over all allocation flags

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/selftests/drm_mm_selftests.h |   1 +
 drivers/gpu/drm/selftests/test-drm_mm.c      | 188 +++++++++++++++++++++++++++
 2 files changed, 189 insertions(+)

diff --git a/drivers/gpu/drm/selftests/drm_mm_selftests.h b/drivers/gpu/drm/selftests/drm_mm_selftests.h
index 693d85677e7f..727c6d7255e0 100644
--- a/drivers/gpu/drm/selftests/drm_mm_selftests.h
+++ b/drivers/gpu/drm/selftests/drm_mm_selftests.h
@@ -9,3 +9,4 @@ selftest(sanitycheck, igt_sanitycheck) /* keep first (selfcheck for igt) */
 selftest(init, igt_init)
 selftest(debug, igt_debug)
 selftest(reserve, igt_reserve)
+selftest(insert, igt_insert)
diff --git a/drivers/gpu/drm/selftests/test-drm_mm.c b/drivers/gpu/drm/selftests/test-drm_mm.c
index b5c768248ff0..285579dbc532 100644
--- a/drivers/gpu/drm/selftests/test-drm_mm.c
+++ b/drivers/gpu/drm/selftests/test-drm_mm.c
@@ -440,6 +440,194 @@ static int igt_reserve(void *ignored)
 	return 0;
 }
 
+static bool expect_insert_fail(struct drm_mm *mm, u64 size)
+{
+	struct drm_mm_node tmp = {};
+	int err;
+
+	err = drm_mm_insert_node(mm, &tmp, size, 0, DRM_MM_SEARCH_DEFAULT);
+	if (err != -ENOSPC)  {
+		if (!err) {
+			pr_err("impossible insert succeeded, node %llu + %llu\n",
+			       tmp.start, tmp.size);
+			drm_mm_remove_node(&tmp);
+		} else {
+			pr_err("impossible insert failed with wrong error %d [expected %d], size %llu\n",
+			       err, -ENOSPC, size);
+		}
+		return false;
+	}
+
+	return true;
+}
+
+static const struct insert_mode {
+	const char *name;
+	unsigned int search_flags;
+	unsigned int create_flags;
+} insert_modes[] = {
+	{ "default", DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT },
+	{ "top-down", DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP },
+	{ "best", DRM_MM_SEARCH_BEST, DRM_MM_CREATE_DEFAULT },
+	{}
+};
+
+static int __igt_insert(unsigned int count, u64 size)
+{
+	RND_STATE(prng, random_seed);
+	const struct insert_mode *mode;
+	struct drm_mm mm;
+	struct drm_mm_node *nodes, *node, *next;
+	unsigned int *order, n, m, o = 0;
+	int ret, err;
+
+	/* Fill a range with lots of nodes, check it doesn't fail too early */
+
+	ret = -ENOMEM;
+	nodes = vzalloc(count * sizeof(*nodes));
+	if (!nodes)
+		goto err;
+
+	order = drm_random_order(count, &prng);
+	if (!order)
+		goto err_nodes;
+
+	ret = -EINVAL;
+	drm_mm_init(&mm, 0, count * size);
+
+	for (mode = insert_modes; mode->name; mode++) {
+		for (n = 0; n < count; n++) {
+			node = &nodes[n];
+			err = drm_mm_insert_node_generic(&mm, node, size, 0, n,
+							 mode->search_flags,
+							 mode->create_flags);
+			if (err) {
+				pr_err("%s insert failed, step %d, start %llu\n",
+				       mode->name, n, nodes[n].start);
+				ret = err;
+				goto out;
+			}
+
+			if (!drm_mm_node_allocated(node)) {
+				pr_err("inserted node not allocated! step %d, start %llu\n",
+				       n, node->start);
+				goto out;
+			}
+
+			if (node->mm != &mm ||
+			    node->size != size ||
+			    node->color != n) {
+				pr_err("inserted node did not inherit user parameters expected (mm=%p, size=%llx, colour=%u), found (mm=%p, size=%llx, colour=%lu)\n",
+				       &mm, size, n, node->mm, node->size, node->color);
+				goto out;
+			}
+		}
+
+		/* After random insertion the nodes should be in order */
+		if (!assert_continuous(&mm, size))
+			goto out;
+
+		/* Repeated use should then fail */
+		if (!expect_insert_fail(&mm, size))
+			goto out;
+
+		/* Remove one and reinsert, as the only hole it should refill itself */
+		for (n = 0; n < count; n++) {
+			u64 addr = nodes[n].start;
+
+			drm_mm_remove_node(&nodes[n]);
+			err = drm_mm_insert_node_generic(&mm,
+							 &nodes[n], size, 0, n,
+							 mode->search_flags,
+							 mode->create_flags);
+			if (err) {
+				pr_err("%s reinsert failed, step %d\n",
+				       mode->name, n);
+				ret = err;
+				goto out;
+			}
+
+			if (nodes[n].start != addr) {
+				pr_err("%s reinsert node moved, step %d, expected %llx, found %llx\n",
+				       mode->name, n, addr, nodes[n].start);
+				goto out;
+			}
+
+			if (!assert_continuous(&mm, size))
+				goto out;
+		}
+
+		/* Remove several, reinsert, check full */
+		drm_for_each_prime(n, min(max_prime, count)) {
+			for (m = 0; m < n; m++) {
+				node = &nodes[order[(o + m) % count]];
+				drm_mm_remove_node(node);
+			}
+
+			for (m = 0; m < n; m++) {
+				node = &nodes[order[(o + m) % count]];
+				err = drm_mm_insert_node_generic(&mm,
+								 node, size, 0, n,
+								 mode->search_flags,
+								 mode->create_flags);
+				if (err) {
+					pr_err("insert failed, step %d, start %llu\n",
+					       n, node->start);
+					ret = err;
+					goto out;
+				}
+			}
+
+			o += n;
+
+			if (!assert_continuous(&mm, size))
+				goto out;
+
+			if (!expect_insert_fail(&mm, size))
+				goto out;
+		}
+
+		drm_mm_for_each_node_safe(node, next, &mm)
+			drm_mm_remove_node(node);
+	}
+
+	ret = 0;
+out:
+	drm_mm_for_each_node_safe(node, next, &mm)
+		drm_mm_remove_node(node);
+	drm_mm_takedown(&mm);
+	kfree(order);
+err_nodes:
+	vfree(nodes);
+err:
+	return ret;
+}
+
+static int igt_insert(void *ignored)
+{
+	const unsigned int count = min_t(unsigned int, BIT(10), max_iterations);
+	unsigned int n;
+	int ret;
+
+	drm_for_each_prime(n, 54) {
+		u64 size = BIT_ULL(n);
+
+		ret = __igt_insert(count, size - 1);
+		if (ret)
+			return ret;
+
+		ret = __igt_insert(count, size);
+		if (ret)
+			return ret;
+
+		ret = __igt_insert(count, size + 1);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
 #include "drm_selftest.c"
 
 static int __init test_drm_mm_init(void)
-- 
2.11.0