drm/i915: Track pinned vma in intel_plane_state

With atomic plane states we are able to track an allocation right from
preparation, during use and through to the final free after being
swapped out for a new plane. We can couple the VMA we pin for the
framebuffer (and its rotation) to this lifetime and avoid all the clumsy
lookups in between.

v2: Remove residual vma on plane cleanup (Chris)
v3: Add a description for the vma destruction in
    intel_plane_destroy_state (Maarten)

References: https://bugs.freedesktop.org/show_bug.cgi?id=98829
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170116152131.18089-1-chris@chris-wilson.co.uk
Acked-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
index 4612ffd555a7..41fd94e62d3c 100644
--- a/drivers/gpu/drm/i915/intel_atomic_plane.c
+++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
@@ -85,6 +85,8 @@ intel_plane_duplicate_state(struct drm_plane *plane)
 
 	__drm_atomic_helper_plane_duplicate_state(plane, state);
 
+	intel_state->vma = NULL;
+
 	return state;
 }
 
@@ -100,6 +102,24 @@ void
 intel_plane_destroy_state(struct drm_plane *plane,
 			  struct drm_plane_state *state)
 {
+	struct i915_vma *vma;
+
+	vma = fetch_and_zero(&to_intel_plane_state(state)->vma);
+
+	/*
+	 * FIXME: Normally intel_cleanup_plane_fb handles destruction of vma.
+	 * We currently don't clear all planes during driver unload, so we have
+	 * to be able to unpin vma here for now.
+	 *
+	 * Normally this can only happen during unload when kmscon is disabled
+	 * and userspace doesn't attempt to set a framebuffer at all.
+	 */
+	if (vma) {
+		mutex_lock(&plane->dev->struct_mutex);
+		intel_unpin_fb_vma(vma);
+		mutex_unlock(&plane->dev->struct_mutex);
+	}
+
 	drm_atomic_helper_plane_destroy_state(plane, state);
 }