drm/virtio: batch display update commands.

When the driver submits multiple commands in a row it makes sense to
notify the host only after submitting the last one, so the host can
process them all at once, with a single vmexit.

Add functions to enable/disable notifications to allow that.  Use the
new functions for primary plane updates.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20191212125346.8334-3-kraxel@redhat.com

diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
index eedae2a7b532da7296690a2b08d92c6c9d66927e..29cf005ed6b93411f83ef45560c21bdb86741e9a 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_drv.h
+++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
@@ -183,6 +183,9 @@ struct virtio_gpu_device {
        struct kmem_cache *vbufs;
        bool vqs_ready;
 
+       bool disable_notify;
+       bool pending_notify;
+
        struct ida      resource_ida;
 
        wait_queue_head_t resp_wq;
@@ -335,6 +338,9 @@ void virtio_gpu_dequeue_ctrl_func(struct work_struct *work);
 void virtio_gpu_dequeue_cursor_func(struct work_struct *work);
 void virtio_gpu_dequeue_fence_func(struct work_struct *work);
 
+void virtio_gpu_disable_notify(struct virtio_gpu_device *vgdev);
+void virtio_gpu_enable_notify(struct virtio_gpu_device *vgdev);
+
 /* virtio_gpu_display.c */
 int virtio_gpu_framebuffer_init(struct drm_device *dev,
                                struct virtio_gpu_framebuffer *vgfb,

diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
index 32de6bd9893a546699cefc562c3aedaa04378d4b..93086090653601d013717e880f59537bfd44531b 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_plane.c
+++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
@@ -146,6 +146,8 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
                return;
        }
 
+       virtio_gpu_disable_notify(vgdev);
+
        vgfb = to_virtio_gpu_framebuffer(plane->state->fb);
        bo = gem_to_virtio_gpu_obj(vgfb->base.obj[0]);
        if (bo->dumb)
@@ -177,6 +179,8 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
                                      plane->state->src_y >> 16,
                                      plane->state->src_w >> 16,
                                      plane->state->src_h >> 16);
+
+       virtio_gpu_enable_notify(vgdev);
 }
 
 static int virtio_gpu_cursor_prepare_fb(struct drm_plane *plane,

diff --git a/drivers/gpu/drm/virtio/virtgpu_vq.c b/drivers/gpu/drm/virtio/virtgpu_vq.c
index 9274c4063c701565734b914470da2f68c04738a1..5914e79d3429fab541008f518000cc2df15e396e 100644 (file)
--- a/drivers/gpu/drm/virtio/virtgpu_vq.c
+++ b/drivers/gpu/drm/virtio/virtgpu_vq.c
@@ -404,8 +404,12 @@ again:
        }
        notify = virtio_gpu_queue_ctrl_buffer_locked(vgdev, vbuf, vout);
        spin_unlock(&vgdev->ctrlq.qlock);
-       if (notify)
-               virtqueue_notify(vgdev->ctrlq.vq);
+       if (notify) {
+               if (vgdev->disable_notify)
+                       vgdev->pending_notify = true;
+               else
+                       virtqueue_notify(vgdev->ctrlq.vq);
+       }
 
        if (sgt) {
                sg_free_table(sgt);
@@ -413,6 +417,21 @@ again:
        }
 }
 
+void virtio_gpu_disable_notify(struct virtio_gpu_device *vgdev)
+{
+       vgdev->disable_notify = true;
+}
+
+void virtio_gpu_enable_notify(struct virtio_gpu_device *vgdev)
+{
+       vgdev->disable_notify = false;
+
+       if (!vgdev->pending_notify)
+               return;
+       vgdev->pending_notify = false;
+       virtqueue_notify(vgdev->ctrlq.vq);
+}
+
 static void virtio_gpu_queue_ctrl_buffer(struct virtio_gpu_device *vgdev,
                                         struct virtio_gpu_vbuffer *vbuf)
 {