drm/vkms: Compute CRC with Cursor Plane

This patch compute CRC for output frame with cursor and primary plane.
Blend cursor with primary plane and compute CRC on the resulted frame.

This currently passes cursor-size-change, and cursor-64x64-[onscreen,
offscreen, sliding, random, dpms, rapid-movement] from igt
kms_cursor_crc tests.
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/b1749f5c90da5721a481f12740e2e370edb4a752.1536210181.git.hamohammed.sa@gmail.com

drivers/gpu/drm/vkms/vkms_crc.c

 // SPDX-License-Identifier: GPL-2.0
 #include "vkms_drv.h"
 #include <linux/crc32.h>
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 
-static uint32_t _vkms_get_crc(struct vkms_crc_data *crc_data)
+/**
+ * compute_crc - Compute CRC value on output frame
+ *
+ * @vaddr_out: address to final framebuffer
+ * @crc_out: framebuffer's metadata
+ *
+ * returns CRC value computed using crc32 on the visible portion of
+ * the final framebuffer at vaddr_out
+ */
+static uint32_t compute_crc(void *vaddr_out, struct vkms_crc_data *crc_out)
+{
+	int i, j, src_offset;
+	int x_src = crc_out->src.x1 >> 16;
+	int y_src = crc_out->src.y1 >> 16;
+	int h_src = drm_rect_height(&crc_out->src) >> 16;
+	int w_src = drm_rect_width(&crc_out->src) >> 16;
+	u32 crc = 0;
+
+	for (i = y_src; i < y_src + h_src; ++i) {
+		for (j = x_src; j < x_src + w_src; ++j) {
+			src_offset = crc_out->offset
+				     + (i * crc_out->pitch)
+				     + (j * crc_out->cpp);
+			/* XRGB format ignores Alpha channel */
+			memset(vaddr_out + src_offset + 24, 0,  8);
+			crc = crc32_le(crc, vaddr_out + src_offset,
+				       sizeof(u32));
+		}
+	}
+
+	return crc;
+}
+
+/**
+ * blend - belnd value at vaddr_src with value at vaddr_dst
+ * @vaddr_dst: destination address
+ * @vaddr_src: source address
+ * @crc_dst: destination framebuffer's metadata
+ * @crc_src: source framebuffer's metadata
+ *
+ * Blend value at vaddr_src with value at vaddr_dst.
+ * Currently, this function write value at vaddr_src on value
+ * at vaddr_dst using buffer's metadata to locate the new values
+ * from vaddr_src and their distenation at vaddr_dst.
+ *
+ * Todo: Use the alpha value to blend vaddr_src with vaddr_dst
+ *	 instead of overwriting it.
+ */
+static void blend(void *vaddr_dst, void *vaddr_src,
+		  struct vkms_crc_data *crc_dst,
+		  struct vkms_crc_data *crc_src)
 {
-	struct drm_framebuffer *fb = &crc_data->fb;
+	int i, j, j_dst, i_dst;
+	int offset_src, offset_dst;
+
+	int x_src = crc_src->src.x1 >> 16;
+	int y_src = crc_src->src.y1 >> 16;
+
+	int x_dst = crc_src->dst.x1;
+	int y_dst = crc_src->dst.y1;
+	int h_dst = drm_rect_height(&crc_src->dst);
+	int w_dst = drm_rect_width(&crc_src->dst);
+
+	int y_limit = y_src + h_dst;
+	int x_limit = x_src + w_dst;
+
+	for (i = y_src, i_dst = y_dst; i < y_limit; ++i) {
+		for (j = x_src, j_dst = x_dst; j < x_limit; ++j) {
+			offset_dst = crc_dst->offset
+				     + (i_dst * crc_dst->pitch)
+				     + (j_dst++ * crc_dst->cpp);
+			offset_src = crc_src->offset
+				     + (i * crc_src->pitch)
+				     + (j * crc_src->cpp);
+
+			memcpy(vaddr_dst + offset_dst,
+			       vaddr_src + offset_src, sizeof(u32));
+		}
+		i_dst++;
+	}
+}
+
+static void compose_cursor(struct vkms_crc_data *cursor_crc,
+			   struct vkms_crc_data *primary_crc, void *vaddr_out)
+{
+	struct drm_gem_object *cursor_obj;
+	struct vkms_gem_object *cursor_vkms_obj;
+
+	cursor_obj = drm_gem_fb_get_obj(&cursor_crc->fb, 0);
+	cursor_vkms_obj = drm_gem_to_vkms_gem(cursor_obj);
+
+	mutex_lock(&cursor_vkms_obj->pages_lock);
+	if (!cursor_vkms_obj->vaddr) {
+		DRM_WARN("cursor plane vaddr is NULL");
+		goto out;
+	}
+
+	blend(vaddr_out, cursor_vkms_obj->vaddr, primary_crc, cursor_crc);
+
+out:
+	mutex_unlock(&cursor_vkms_obj->pages_lock);
+}
+
+static uint32_t _vkms_get_crc(struct vkms_crc_data *primary_crc,
+			      struct vkms_crc_data *cursor_crc)
+{
+	struct drm_framebuffer *fb = &primary_crc->fb;
 	struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0);
 	struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(gem_obj);
+	void *vaddr_out = kzalloc(vkms_obj->gem.size, GFP_KERNEL);
 	u32 crc = 0;
-	int i = 0;
-	unsigned int x = crc_data->src.x1 >> 16;
-	unsigned int y = crc_data->src.y1 >> 16;
-	unsigned int height = drm_rect_height(&crc_data->src) >> 16;
-	unsigned int width = drm_rect_width(&crc_data->src) >> 16;
-	unsigned int cpp = fb->format->cpp[0];
-	unsigned int src_offset;
-	unsigned int size_byte = width * cpp;
-	void *vaddr;
 
-	mutex_lock(&vkms_obj->pages_lock);
-	vaddr = vkms_obj->vaddr;
-	if (WARN_ON(!vaddr))
-		goto out;
+	if (!vaddr_out) {
+		DRM_ERROR("Failed to allocate memory for output frame.");
+		return 0;
+	}
 
-	for (i = y; i < y + height; i++) {
-		src_offset = fb->offsets[0] + (i * fb->pitches[0]) + (x * cpp);
-		crc = crc32_le(crc, vaddr + src_offset, size_byte);
+	mutex_lock(&vkms_obj->pages_lock);
+	if (WARN_ON(!vkms_obj->vaddr)) {
+		mutex_unlock(&vkms_obj->pages_lock);
+		return crc;
 	}
 
-out:
+	memcpy(vaddr_out, vkms_obj->vaddr, vkms_obj->gem.size);
 	mutex_unlock(&vkms_obj->pages_lock);
+
+	if (cursor_crc)
+		compose_cursor(cursor_crc, primary_crc, vaddr_out);
+
+	crc = compute_crc(vaddr_out, primary_crc);
+
+	kfree(vaddr_out);
+
 	return crc;
 }
 
@@ -53,6 +160,7 @@ void vkms_crc_work_handle(struct work_struct *work)
 	struct vkms_device *vdev = container_of(out, struct vkms_device,
 						output);
 	struct vkms_crc_data *primary_crc = NULL;
+	struct vkms_crc_data *cursor_crc = NULL;
 	struct drm_plane *plane;
 	u32 crc32 = 0;
 	u64 frame_start, frame_end;
@@ -77,14 +185,14 @@ void vkms_crc_work_handle(struct work_struct *work)
 		if (drm_framebuffer_read_refcount(&crc_data->fb) == 0)
 			continue;
 
-		if (plane->type == DRM_PLANE_TYPE_PRIMARY) {
+		if (plane->type == DRM_PLANE_TYPE_PRIMARY)
 			primary_crc = crc_data;
-			break;
-		}
+		else
+			cursor_crc = crc_data;
 	}
 
 	if (primary_crc)
-		crc32 = _vkms_get_crc(primary_crc);
+		crc32 = _vkms_get_crc(primary_crc, cursor_crc);
 
 	frame_end = drm_crtc_accurate_vblank_count(crtc);
 

drivers/gpu/drm/vkms/vkms_drv.h

@@ -25,8 +25,11 @@ static const u32 vkms_cursor_formats[] = {
 };
 
 struct vkms_crc_data {
-	struct drm_rect src;
 	struct drm_framebuffer fb;
+	struct drm_rect src, dst;
+	unsigned int offset;
+	unsigned int pitch;
+	unsigned int cpp;
 };
 
 /**

drivers/gpu/drm/vkms/vkms_plane.c

@@ -85,16 +85,22 @@ static void vkms_plane_atomic_update(struct drm_plane *plane,
 				     struct drm_plane_state *old_state)
 {
 	struct vkms_plane_state *vkms_plane_state;
+	struct drm_framebuffer *fb = plane->state->fb;
 	struct vkms_crc_data *crc_data;
 
-	if (!plane->state->crtc || !plane->state->fb)
+	if (!plane->state->crtc || !fb)
 		return;
 
 	vkms_plane_state = to_vkms_plane_state(plane->state);
+
 	crc_data = vkms_plane_state->crc_data;
 	memcpy(&crc_data->src, &plane->state->src, sizeof(struct drm_rect));
-	memcpy(&crc_data->fb, plane->state->fb, sizeof(struct drm_framebuffer));
+	memcpy(&crc_data->dst, &plane->state->dst, sizeof(struct drm_rect));
+	memcpy(&crc_data->fb, fb, sizeof(struct drm_framebuffer));
 	drm_framebuffer_get(&crc_data->fb);
+	crc_data->offset = fb->offsets[0];
+	crc_data->pitch = fb->pitches[0];
+	crc_data->cpp = fb->format->cpp[0];
 }
 
 static int vkms_plane_atomic_check(struct drm_plane *plane,