[igt-dev] [PATCH] selftests/i915_gem_gtt: Create igt_ggtt_scratch subtest

[Ewelina Musial]

Test have similar functionality that gem_cs_prefetch IGT test
but gem_cs_prefetch is not up to date and there was an idea
to move this test to kselftests so this is respond for this
request.

There is another patch on igt_dev which is removing gem_cs_prefetch
test from IGT.
---
 drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 134 ++++++++++++++++++++++++++
 1 file changed, 134 insertions(+)

diff --git a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
index 89b6ca9b14a7..42403da610c6 100644
--- a/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/selftests/i915_gem_gtt.c
@@ -1625,6 +1625,139 @@ static int igt_gtt_insert(void *arg)
 	return err;
 }
 
+#define COUNT 10
+static int igt_ggtt_scratch(void *arg)
+{
+	static struct insert_mode {
+		const char *name;
+		enum drm_mm_insert_mode mode;
+	}  modes[] = {
+		{ "bottom-up", DRM_MM_INSERT_LOW },
+		{ "top-down", DRM_MM_INSERT_HIGH },
+		{}
+	};
+
+	I915_RND_STATE(prng);
+
+	struct insert_mode *mode;
+	struct drm_i915_private *i915 = arg;
+	struct i915_ggtt *ggtt = &i915->ggtt;
+	struct drm_i915_gem_object *obj;
+	struct drm_mm_node *node;
+	struct drm_mm_node tmp[COUNT];
+	unsigned int *order;
+	int err = 0;
+	int n, m;
+	u64 hole_start, hole_end = 0;
+	u64 offset;
+	u32 __iomem *vaddr;
+	u32 val;
+
+  	mutex_lock(&i915->drm.struct_mutex);
+
+	for (mode = modes; mode->name; mode++) {
+		order = i915_random_order(COUNT, &prng);
+		if (!order) {
+			err = -ENOMEM;
+		}
+
+		obj = i915_gem_object_create_internal(i915, PAGE_SIZE);
+		if (IS_ERR(obj)) {
+			err = PTR_ERR(obj);
+			goto out_unlock;
+		}
+
+		drm_mm_for_each_hole(node, &ggtt->base.mm, hole_start, hole_end) {
+
+			err = i915_gem_object_pin_pages(obj);
+			if (err)
+				goto out_free;
+
+			intel_runtime_pm_get(i915);
+			for (m = 0; m < COUNT; m++) {
+				memset(&tmp[order[m]], 0, sizeof(tmp[order[m]]));
+
+				err = drm_mm_insert_node_in_range(&ggtt->base.mm, &tmp[order[m]],
+								  3 * PAGE_SIZE, 0,
+								  I915_COLOR_UNEVICTABLE,
+								  0, ggtt->mappable_end,
+								  mode->mode);
+				if (err)
+					goto out_unpin;
+
+				offset = tmp[order[m]].start;
+				ggtt->base.insert_page(&ggtt->base,
+						       i915_gem_object_get_dma_address(obj, 0),
+						       offset + PAGE_SIZE, I915_CACHE_NONE, 0);
+			}
+
+			i915_random_reorder(order, COUNT, &prng);
+
+			for (m = 0; m < COUNT; m++) {
+				for ( n = 0; n <= 2; n++)
+				{
+					offset = tmp[order[m]].start + n * PAGE_SIZE;
+					vaddr = io_mapping_map_atomic_wc(&ggtt->iomap, offset);
+					iowrite32(n, vaddr);
+					io_mapping_unmap_atomic(vaddr);
+				}
+
+				i915_gem_flush_ggtt_writes(i915);
+
+				for ( n = 0; n <= 2; n++)
+				{
+					offset = tmp[order[m]].start + n * PAGE_SIZE;
+					vaddr = io_mapping_map_atomic_wc(&ggtt->iomap, offset);
+					val = ioread32(vaddr);
+					io_mapping_unmap_atomic(vaddr);
+
+					if ((n != 1) && (val != 2)) {
+						pr_err("insert page failed: found %d, expected %d\n",
+						       val, 2);
+						err = -EINVAL;
+						break;
+					} else if ((n == 1) && (val != n)) {
+						pr_err("insert page failed: found %d, expected %d\n",
+						       val, n);
+						err = -EINVAL;
+						break;
+					}
+				}
+
+				ggtt->base.clear_range(&ggtt->base, tmp[order[m]].start, tmp[order[m]].size);
+				ggtt->invalidate(i915);
+
+				for ( n = 0; n <= 2; n++)
+				{
+					offset = tmp[order[m]].start + n * PAGE_SIZE;
+					vaddr = io_mapping_map_atomic_wc(&ggtt->iomap, offset);
+					val = ioread32(vaddr);
+					io_mapping_unmap_atomic(vaddr);
+
+					if (val != 2) {
+						pr_err("insert page failed: found %d, expected %d\n",
+						       val, 2);
+						err = -EINVAL;
+						break;
+					}
+				}
+			}
+			for (m = 0; m < COUNT; m++) {
+				drm_mm_remove_node(&tmp[m]);
+			}
+out_unpin:
+			intel_runtime_pm_put(i915);
+			i915_gem_object_unpin_pages(obj);
+		}
+out_free:
+		i915_gem_object_put(obj);
+		kfree(order);
+	}
+out_unlock:
+	   mutex_unlock(&i915->drm.struct_mutex);
+	   return err;
+}
+
 int i915_gem_gtt_mock_selftests(void)
 {
 	static const struct i915_subtest tests[] = {
@@ -1667,6 +1800,7 @@ int i915_gem_gtt_live_selftests(struct drm_i915_private *i915)
 		SUBTEST(igt_ggtt_pot),
 		SUBTEST(igt_ggtt_fill),
 		SUBTEST(igt_ggtt_page),
+		SUBTEST(igt_ggtt_scratch),
 	};
 
 	GEM_BUG_ON(offset_in_page(i915->ggtt.base.total));
-- 
2.14.3