[PATCH 5/9] drm: kselftest for drm_mm and alignment

[Chris Wilson]

Check that we can request alignment to any power-of-two or prime using a
plain drm_mm_node_insert().

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/drm_mm_selftests.h |   3 +
 drivers/gpu/drm/test-drm_mm.c      | 113 +++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)

diff --git a/drivers/gpu/drm/drm_mm_selftests.h b/drivers/gpu/drm/drm_mm_selftests.h
index 4070123daffc..591d34aa233a 100644
--- a/drivers/gpu/drm/drm_mm_selftests.h
+++ b/drivers/gpu/drm/drm_mm_selftests.h
@@ -5,6 +5,9 @@
  *
  * Tests are executed in reverse order by igt/drm_mm
  */
+selftest(align64, igt_align64)
+selftest(align32, igt_align32)
+selftest(align, igt_align)
 selftest(insert_range, igt_insert_range)
 selftest(insert, igt_insert)
 selftest(reserve, igt_reserve)
diff --git a/drivers/gpu/drm/test-drm_mm.c b/drivers/gpu/drm/test-drm_mm.c
index 494a470e08f3..8cdcde580da3 100644
--- a/drivers/gpu/drm/test-drm_mm.c
+++ b/drivers/gpu/drm/test-drm_mm.c
@@ -662,6 +662,119 @@ static int igt_insert_range(void *ignored)
 	return 0;
 }
 
+static int igt_align(void *ignored)
+{
+	struct drm_mm mm;
+	struct drm_mm_node *node, *next;
+	int ret = -EINVAL;
+	int n;
+
+	drm_mm_init(&mm, 1, -2);
+	if (!drm_mm_clean(&mm)) {
+		pr_err("mm not empty on creation\n");
+		goto out;
+	}
+
+	for_each_prime(n, 8192) {
+		int err;
+
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		err = drm_mm_insert_node_generic(&mm, node,
+						 next_prime_number(n),/* size */
+						 n, /* alignment */
+						 0,
+						 DRM_MM_SEARCH_DEFAULT,
+						 DRM_MM_CREATE_DEFAULT);
+		if (err) {
+			pr_err("insert failed with alignment=%d", n);
+			ret = err;
+			goto out;
+		}
+
+		if (node->start % n) {
+			pr_err("node inserted into wrong location %llx, expected alignment to %d\n",
+			       node->start, n);
+			goto out;
+		}
+	}
+
+	ret = 0;
+out:
+	list_for_each_entry_safe(node, next,
+				 &mm.head_node.node_list, node_list) {
+		drm_mm_remove_node(node);
+		kfree(node);
+	}
+	drm_mm_takedown(&mm);
+	return ret;
+}
+
+static int igt_align_pot(int max)
+{
+	struct drm_mm mm;
+	struct drm_mm_node *node, *next;
+	int bit;
+	int ret = -EINVAL;
+
+	drm_mm_init(&mm, 1, -2);
+	if (!drm_mm_clean(&mm)) {
+		pr_err("mm not empty on creation\n");
+		goto out;
+	}
+
+	for (bit = max - 1; bit; bit--) {
+		int err;
+
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		err = drm_mm_insert_node_generic(&mm, node, 1,
+						 BIT_ULL(bit), bit,
+						 DRM_MM_SEARCH_DEFAULT,
+						 DRM_MM_CREATE_DEFAULT);
+		if (err) {
+			pr_err("insert failed with alignment=%llx [%d]",
+			       BIT_ULL(bit), bit);
+			ret = err;
+			goto out;
+		}
+
+		if (node->start & (BIT_ULL(bit) - 1)) {
+			pr_err("node inserted into wrong location %llx, expected alignment to %llx [%d]\n",
+			       node->start, BIT_ULL(bit), bit);
+			goto out;
+		}
+	}
+
+	ret = 0;
+out:
+	list_for_each_entry_safe(node, next,
+				 &mm.head_node.node_list, node_list) {
+		drm_mm_remove_node(node);
+		kfree(node);
+	}
+	drm_mm_takedown(&mm);
+	return ret;
+}
+
+static int igt_align32(void *ignored)
+{
+	return igt_align_pot(32);
+}
+
+static int igt_align64(void *ignored)
+{
+	return igt_align_pot(64);
+}
+
 #include "drm_selftest.c"
 
 static int __init test_drm_mm_init(void)
-- 
2.11.0