drm/i915/selftests: Add mock selftest for remapped vmas

Extend the rotated vma mock selftest to cover remapped vmas as
well.

TODO: reindent the loops I guess? Left like this for now to
ease review

v2: Include the vma type in the error message (Chris)
v3: Deal with trimmed sg
v4: Drop leftover debugs

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190509122159.24376-3-ville.syrjala@linux.intel.com
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>

drivers/gpu/drm/i915/selftests/i915_vma.c

@@ -59,7 +59,7 @@ static bool assert_vma(struct i915_vma *vma,
 static struct i915_vma *
 checked_vma_instance(struct drm_i915_gem_object *obj,
 		     struct i915_address_space *vm,
-		     struct i915_ggtt_view *view)
+		     const struct i915_ggtt_view *view)
 {
 	struct i915_vma *vma;
 	bool ok = true;
@@ -397,13 +397,74 @@ assert_rotated(struct drm_i915_gem_object *obj,
 	return sg;
 }
 
+static unsigned long remapped_index(const struct intel_remapped_info *r,
+				    unsigned int n,
+				    unsigned int x,
+				    unsigned int y)
+{
+	return (r->plane[n].stride * y +
+		r->plane[n].offset + x);
+}
+
+static struct scatterlist *
+assert_remapped(struct drm_i915_gem_object *obj,
+		const struct intel_remapped_info *r, unsigned int n,
+		struct scatterlist *sg)
+{
+	unsigned int x, y;
+	unsigned int left = 0;
+	unsigned int offset;
+
+	for (y = 0; y < r->plane[n].height; y++) {
+		for (x = 0; x < r->plane[n].width; x++) {
+			unsigned long src_idx;
+			dma_addr_t src;
+
+			if (!sg) {
+				pr_err("Invalid sg table: too short at plane %d, (%d, %d)!\n",
+				       n, x, y);
+				return ERR_PTR(-EINVAL);
+			}
+			if (!left) {
+				offset = 0;
+				left = sg_dma_len(sg);
+			}
+
+			src_idx = remapped_index(r, n, x, y);
+			src = i915_gem_object_get_dma_address(obj, src_idx);
+
+			if (left < PAGE_SIZE || left & (PAGE_SIZE-1)) {
+				pr_err("Invalid sg.length, found %d, expected %lu for remapped page (%d, %d) [src index %lu]\n",
+				       sg_dma_len(sg), PAGE_SIZE,
+				       x, y, src_idx);
+				return ERR_PTR(-EINVAL);
+			}
+
+			if (sg_dma_address(sg) + offset != src) {
+				pr_err("Invalid address for remapped page (%d, %d) [src index %lu]\n",
+				       x, y, src_idx);
+				return ERR_PTR(-EINVAL);
+			}
+
+			left -= PAGE_SIZE;
+			offset += PAGE_SIZE;
+
+
+			if (!left)
+				sg = sg_next(sg);
+		}
+	}
+
+	return sg;
+}
+
 static unsigned int rotated_size(const struct intel_remapped_plane_info *a,
 				 const struct intel_remapped_plane_info *b)
 {
 	return a->width * a->height + b->width * b->height;
 }
 
-static int igt_vma_rotate(void *arg)
+static int igt_vma_rotate_remap(void *arg)
 {
 	struct i915_ggtt *ggtt = arg;
 	struct i915_address_space *vm = &ggtt->vm;
@@ -426,6 +487,11 @@ static int igt_vma_rotate(void *arg)
 		{ .width = 6, .height = 4, .stride = 6 },
 		{ }
 	}, *a, *b;
+	enum i915_ggtt_view_type types[] = {
+		I915_GGTT_VIEW_ROTATED,
+		I915_GGTT_VIEW_REMAPPED,
+		0,
+	}, *t;
 	const unsigned int max_pages = 64;
 	int err = -ENOMEM;
 
@@ -437,6 +503,7 @@ static int igt_vma_rotate(void *arg)
 	if (IS_ERR(obj))
 		goto out;
 
+	for (t = types; *t; t++) {
 	for (a = planes; a->width; a++) {
 		for (b = planes + ARRAY_SIZE(planes); b-- != planes; ) {
 			struct i915_ggtt_view view;
@@ -447,7 +514,7 @@ static int igt_vma_rotate(void *arg)
 			GEM_BUG_ON(max_offset > max_pages);
 			max_offset = max_pages - max_offset;
 
-			view.type = I915_GGTT_VIEW_ROTATED;
+			view.type = *t;
 			view.rotated.plane[0] = *a;
 			view.rotated.plane[1] = *b;
 
@@ -468,14 +535,23 @@ static int igt_vma_rotate(void *arg)
 						goto out_object;
 					}
 
-					if (vma->size != rotated_size(a, b) * PAGE_SIZE) {
+					if (view.type == I915_GGTT_VIEW_ROTATED &&
+					    vma->size != rotated_size(a, b) * PAGE_SIZE) {
 						pr_err("VMA is wrong size, expected %lu, found %llu\n",
 						       PAGE_SIZE * rotated_size(a, b), vma->size);
 						err = -EINVAL;
 						goto out_object;
 					}
 
-					if (vma->pages->nents != rotated_size(a, b)) {
+					if (view.type == I915_GGTT_VIEW_REMAPPED &&
+					    vma->size > rotated_size(a, b) * PAGE_SIZE) {
+						pr_err("VMA is wrong size, expected %lu, found %llu\n",
+						       PAGE_SIZE * rotated_size(a, b), vma->size);
+						err = -EINVAL;
+						goto out_object;
+					}
+
+					if (vma->pages->nents > rotated_size(a, b)) {
 						pr_err("sg table is wrong sizeo, expected %u, found %u nents\n",
 						       rotated_size(a, b), vma->pages->nents);
 						err = -EINVAL;
@@ -497,9 +573,14 @@ static int igt_vma_rotate(void *arg)
 
 					sg = vma->pages->sgl;
 					for (n = 0; n < ARRAY_SIZE(view.rotated.plane); n++) {
-						sg = assert_rotated(obj, &view.rotated, n, sg);
+						if (view.type == I915_GGTT_VIEW_ROTATED)
+							sg = assert_rotated(obj, &view.rotated, n, sg);
+						else
+							sg = assert_remapped(obj, &view.remapped, n, sg);
 						if (IS_ERR(sg)) {
-							pr_err("Inconsistent VMA pages for plane %d: [(%d, %d, %d, %d), (%d, %d, %d, %d)]\n", n,
+							pr_err("Inconsistent %s VMA pages for plane %d: [(%d, %d, %d, %d), (%d, %d, %d, %d)]\n",
+							       view.type == I915_GGTT_VIEW_ROTATED ?
+							       "rotated" : "remapped", n,
 							       view.rotated.plane[0].width,
 							       view.rotated.plane[0].height,
 							       view.rotated.plane[0].stride,
@@ -518,6 +599,7 @@ static int igt_vma_rotate(void *arg)
 			}
 		}
 	}
+	}
 
 out_object:
 	i915_gem_object_put(obj);
@@ -721,7 +803,7 @@ int i915_vma_mock_selftests(void)
 	static const struct i915_subtest tests[] = {
 		SUBTEST(igt_vma_create),
 		SUBTEST(igt_vma_pin1),
-		SUBTEST(igt_vma_rotate),
+		SUBTEST(igt_vma_rotate_remap),
 		SUBTEST(igt_vma_partial),
 	};
 	struct drm_i915_private *i915;