[PATCH 9/9] drm: kselftest for drm_mm and color adjustment

[Chris Wilson]

Check that after applying the driver's color adjustment, fitting of the
node and its alignment are still correct.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/drm_mm_selftests.h |   1 +
 drivers/gpu/drm/test-drm_mm.c      | 178 +++++++++++++++++++++++++++++++++++++
 2 files changed, 179 insertions(+)

diff --git a/drivers/gpu/drm/drm_mm_selftests.h b/drivers/gpu/drm/drm_mm_selftests.h
index 6bbdbb929714..30b4f2134248 100644
--- a/drivers/gpu/drm/drm_mm_selftests.h
+++ b/drivers/gpu/drm/drm_mm_selftests.h
@@ -5,6 +5,7 @@
  *
  * Tests are executed in reverse order by igt/drm_mm
  */
+selftest(color, igt_color)
 selftest(topdown_align, igt_topdown_align)
 selftest(topdown, igt_topdown)
 selftest(evict, igt_evict)
diff --git a/drivers/gpu/drm/test-drm_mm.c b/drivers/gpu/drm/test-drm_mm.c
index 7699e7e2c698..f320ded75cab 100644
--- a/drivers/gpu/drm/test-drm_mm.c
+++ b/drivers/gpu/drm/test-drm_mm.c
@@ -1130,6 +1130,184 @@ static int igt_topdown_align(void *ignored)
 	return ret;
 }
 
+static void no_color_touching(struct drm_mm_node *node,
+			      unsigned long color,
+			      u64 *start,
+			      u64 *end)
+{
+	if (node->allocated && node->color != color)
+		++*start;
+
+	node = list_next_entry(node, node_list);
+	if (node->allocated && node->color != color)
+		--*end;
+}
+
+static int igt_color(void *ignored)
+{
+	const int count = 4096;
+	struct drm_mm mm;
+	struct drm_mm_node *node, *nn;
+	const struct modes {
+		const char *name;
+		unsigned int search;
+		unsigned int create;
+	} modes[] = {
+		{ "default", DRM_MM_SEARCH_DEFAULT, DRM_MM_CREATE_DEFAULT },
+		{ "best", DRM_MM_SEARCH_BEST, DRM_MM_CREATE_DEFAULT },
+		{ "top-down", DRM_MM_SEARCH_BELOW, DRM_MM_CREATE_TOP },
+	};
+	int ret = -EINVAL;
+	int n, m;
+
+	drm_mm_init(&mm, 0, ~0ull);
+
+	for (n = 1; n <= count; n++) {
+		int err;
+
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		err = drm_mm_insert_node_generic(&mm, node, n, 0, n,
+						 DRM_MM_SEARCH_DEFAULT,
+						 DRM_MM_CREATE_DEFAULT);
+		if (err) {
+			pr_err("insert failed, step %d\n", n);
+			kfree(node);
+			ret = err;
+			goto out;
+		}
+	}
+
+	list_for_each_entry_safe(node, nn, &mm.head_node.node_list, node_list) {
+		if (node->color != node->size) {
+			pr_err("invalid color stored: expected %lld, found %ld\n",
+			       node->size, node->color);
+
+			goto out;
+		}
+
+		drm_mm_remove_node(node);
+		kfree(node);
+	}
+
+	/* Now, let's start experimenting with applying a color callback */
+	mm.color_adjust = no_color_touching;
+	for (m = 0; m < ARRAY_SIZE(modes); m++) {
+		u64 last;
+		int err;
+
+		node = kzalloc(sizeof(*node), GFP_KERNEL);
+		if (!node) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		node->size = 1 + 2*count;
+		node->color = node->size;
+
+		err = drm_mm_reserve_node(&mm, node);
+		if (err) {
+			pr_err("intial reserve failed!\n");
+			goto out;
+		}
+
+		last = node->start + node->size;
+
+		for (n = 1; n <= count; n++) {
+			int rem;
+
+			node = kzalloc(sizeof(*node), GFP_KERNEL);
+			if (!node) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			node->start = last;
+			node->size = n + count;
+			node->color = node->size;
+
+			err = drm_mm_reserve_node(&mm, node);
+			if (err != -ENOSPC) {
+				pr_err("reserve %d did not report color overlap! err=%d\n",
+				       n, err);
+				goto out;
+			}
+
+			node->start += n + 1;
+			rem = node->start;
+			rem %= n + count;
+			node->start += n + count - rem;
+
+			err = drm_mm_reserve_node(&mm, node);
+			if (err) {
+				pr_err("reserve %d failed, err=%d\n", n, err);
+				goto out;
+			}
+
+			last = node->start + node->size;
+		}
+
+		for (n = 1; n <= count; n++) {
+			node = kzalloc(sizeof(*node), GFP_KERNEL);
+			if (!node) {
+				ret = -ENOMEM;
+				goto out;
+			}
+
+			err = drm_mm_insert_node_generic(&mm, node, n, n, n,
+							 modes[m].search,
+							 modes[m].create);
+			if (err) {
+				pr_err("%s insert failed, step %d, err=%d\n",
+				       modes[m].name, n, err);
+				kfree(node);
+				ret = err;
+				goto out;
+			}
+		}
+
+		list_for_each_entry_safe(node, nn,
+					 &mm.head_node.node_list, node_list) {
+			u64 rem;
+
+			if (node->color != node->size) {
+				pr_err("%s invalid color stored: expected %lld, found %ld\n",
+				       modes[m].name, node->size, node->color);
+
+				goto out;
+			}
+
+			if (!node->hole_follows) {
+				pr_err("%s colors abutt!\n", modes[m].name);
+				goto out;
+			}
+
+			div64_u64_rem(node->start, node->size, &rem);
+			if (rem) {
+				pr_err("%s colored node misaligned, start=%llx expected alignment=%lld [rem=%lld]\n",
+				       modes[m].name, node->start, node->size, rem);
+				goto out;
+			}
+
+			drm_mm_remove_node(node);
+			kfree(node);
+		}
+	}
+
+	ret = 0;
+out:
+	list_for_each_entry_safe(node, nn, &mm.head_node.node_list, node_list) {
+		drm_mm_remove_node(node);
+		kfree(node);
+	}
+	drm_mm_takedown(&mm);
+	return ret;
+}
+
 #include "drm_selftest.c"
 
 static int __init test_drm_mm_init(void)
-- 
2.11.0