[PATCH 04/14] drm: add helper to implement legacy dirtyfb

[Deepak Rawat]

From: Rob Clark <robdclark at gmail.com>

Add an atomic helper to implement dirtyfb support.  This is needed to
support DSI command-mode panels with x11 userspace (ie. when we can't
rely on pageflips to trigger a flush to the panel).

v2: Modified the helper to use plane fb_damage_clips property and
removed plane_state::dirty flag.

Signed-off-by: Rob Clark <robdclark at gmail.com>
Signed-off-by: Deepak Rawat <drawat at vmware.com>
---
 drivers/gpu/drm/drm_damage_helper.c | 116 ++++++++++++++++++++++++++++
 include/drm/drm_damage_helper.h     |   4 +
 2 files changed, 120 insertions(+)

diff --git a/drivers/gpu/drm/drm_damage_helper.c b/drivers/gpu/drm/drm_damage_helper.c
index 7d70f6001889..b016ec375295 100644
--- a/drivers/gpu/drm/drm_damage_helper.c
+++ b/drivers/gpu/drm/drm_damage_helper.c
@@ -26,6 +26,7 @@
  *
  * Authors:
  * Deepak Rawat <drawat at vmware.com>
+ * Rob Clark <robdclark at gmail.com>
  *
  **************************************************************************/
 
@@ -81,6 +82,21 @@ static int convert_fixed_to_32(int fixed)
 	return ((fixed >> 15) & 1) + (fixed >> 16);
 }
 
+static void convert_clip_rect_to_rect(const struct drm_clip_rect *src,
+				      struct drm_rect *dest,
+				      uint32_t num_clips)
+{
+	while (num_clips > 0) {
+		dest->x1 = src->x1;
+		dest->y1 = src->y1;
+		dest->x2 = src->x2;
+		dest->y2 = src->y2;
+		src++;
+		dest++;
+		num_clips--;
+	}
+}
+
 /**
  * drm_plane_enable_fb_damage_clips - enables plane fb damage clips property
  * @plane: plane on which to enable damage clips property
@@ -183,3 +199,103 @@ drm_atomic_helper_damage_iter_next(struct drm_atomic_helper_damage_iter *iter,
 	return ret;
 }
 EXPORT_SYMBOL(drm_atomic_helper_damage_iter_next);
+
+/**
+ * drm_atomic_helper_dirtyfb - helper for dirtyfb
+ * @fb: DRM framebuffer
+ * @file_priv: drm file for the ioctl call
+ * @flags: dirty fb annotate flags
+ * @color: color for annotate fill
+ * @clips: dirty region
+ * @num_clips: count of clip in clips
+ *
+ * A helper to implement drm_framebuffer_funcs::dirty. This helper will do a
+ * full update in case of annotate flags.
+ *
+ * Returns: Zero on success, negative errno on failure.
+ */
+int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
+			      struct drm_file *file_priv, unsigned flags,
+			      unsigned color, struct drm_clip_rect *clips,
+			      unsigned num_clips)
+{
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_property_blob *damage = NULL;
+	struct drm_atomic_state *state;
+	struct drm_plane *plane;
+	struct drm_rect *rects = NULL;
+	int ret = 0;
+
+	/*
+	 * When called from ioctl, we are interruptable, but not when called
+	 * internally (ie. defio worker)
+	 */
+	drm_modeset_acquire_init(&ctx,
+		file_priv ? DRM_MODESET_ACQUIRE_INTERRUPTIBLE : 0);
+
+	state = drm_atomic_state_alloc(fb->dev);
+	if (!state) {
+		ret = -ENOMEM;
+		goto out;
+	}
+	state->acquire_ctx = &ctx;
+
+	WARN_ONCE(flags & DRM_MODE_FB_DIRTY_FLAGS,
+		  "Full update for dirtyfb with DRM_MODE_FB_DIRTY_FLAGS\n");
+
+	if (!(flags & DRM_MODE_FB_DIRTY_FLAGS)) {
+		rects = kcalloc(num_clips, sizeof(*rects), GFP_KERNEL);
+		if (!rects) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		convert_clip_rect_to_rect(clips, rects, num_clips);
+		damage = drm_property_create_blob(fb->dev,
+						  num_clips * sizeof(*rects),
+						  rects);
+		if (IS_ERR(damage)) {
+			ret = PTR_ERR(damage);
+			damage = NULL;
+			goto out;
+		}
+	}
+
+retry:
+	drm_for_each_plane(plane, fb->dev) {
+		struct drm_plane_state *plane_state;
+
+		if (plane->state->fb != fb)
+			continue;
+
+		plane_state = drm_atomic_get_plane_state(state, plane);
+		if (IS_ERR(plane_state)) {
+			ret = PTR_ERR(plane_state);
+			goto out;
+		}
+
+		drm_property_replace_blob(&plane_state->fb_damage_clips,
+					  damage);
+	}
+
+	ret = drm_atomic_commit(state);
+
+out:
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		ret = drm_modeset_backoff(&ctx);
+		if (!ret)
+			goto retry;
+	}
+
+	drm_property_blob_put(damage);
+	kfree(rects);
+	drm_atomic_state_put(state);
+
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+
+	return ret;
+
+}
+EXPORT_SYMBOL(drm_atomic_helper_dirtyfb);
diff --git a/include/drm/drm_damage_helper.h b/include/drm/drm_damage_helper.h
index 1f988f7fdd72..9d5c9444761b 100644
--- a/include/drm/drm_damage_helper.h
+++ b/include/drm/drm_damage_helper.h
@@ -89,5 +89,9 @@ drm_atomic_helper_damage_iter_init(struct drm_atomic_helper_damage_iter *iter,
 bool
 drm_atomic_helper_damage_iter_next(struct drm_atomic_helper_damage_iter *iter,
 				   struct drm_rect *rect);
+int drm_atomic_helper_dirtyfb(struct drm_framebuffer *fb,
+			      struct drm_file *file_priv, unsigned flags,
+			      unsigned color, struct drm_clip_rect *clips,
+			      unsigned num_clips);
 
 #endif
-- 
2.17.1