media: v4l2: Add mem2mem helpers for REMOVE_BUFS ioctl

Create v4l2-mem2mem helpers for VIDIOC_REMOVE_BUFS ioctl and
make test drivers use it.

Signed-off-by: Benjamin Gaignard <[e-mail]>
Reviewed-by: Mauro Carvalho Chehab <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/test-drivers/vicodec/vicodec-core.c

···
 	.vidioc_prepare_buf	= v4l2_m2m_ioctl_prepare_buf,
 	.vidioc_create_bufs	= v4l2_m2m_ioctl_create_bufs,
 	.vidioc_expbuf		= v4l2_m2m_ioctl_expbuf,
+	.vidioc_remove_bufs	= v4l2_m2m_ioctl_remove_bufs,
 
 	.vidioc_streamon	= v4l2_m2m_ioctl_streamon,
 	.vidioc_streamoff	= v4l2_m2m_ioctl_streamoff,

drivers/media/test-drivers/vimc/vimc-capture.c

···
 	.vidioc_expbuf = vb2_ioctl_expbuf,
 	.vidioc_streamon = vb2_ioctl_streamon,
 	.vidioc_streamoff = vb2_ioctl_streamoff,
+	.vidioc_remove_bufs = vb2_ioctl_remove_bufs,
 };
 
 static void vimc_capture_return_all_buffers(struct vimc_capture_device *vcapture,

drivers/media/test-drivers/visl/visl-video.c

···
 	.vidioc_prepare_buf		= v4l2_m2m_ioctl_prepare_buf,
 	.vidioc_create_bufs		= v4l2_m2m_ioctl_create_bufs,
 	.vidioc_expbuf			= v4l2_m2m_ioctl_expbuf,
+	.vidioc_remove_bufs		= v4l2_m2m_ioctl_remove_bufs,
 
 	.vidioc_streamon		= v4l2_m2m_ioctl_streamon,
 	.vidioc_streamoff		= v4l2_m2m_ioctl_streamoff,

drivers/media/test-drivers/vivid/vivid-core.c

···
 	.vidioc_expbuf			= vb2_ioctl_expbuf,
 	.vidioc_streamon		= vb2_ioctl_streamon,
 	.vidioc_streamoff		= vb2_ioctl_streamoff,
+	.vidioc_remove_bufs		= vb2_ioctl_remove_bufs,
 
 	.vidioc_enum_input		= vivid_enum_input,
 	.vidioc_g_input			= vivid_g_input,

drivers/media/v4l2-core/v4l2-mem2mem.c

···
 }
 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_create_bufs);
 
+int v4l2_m2m_ioctl_remove_bufs(struct file *file, void *priv,
+			       struct v4l2_remove_buffers *remove)
+{
+	struct v4l2_fh *fh = file->private_data;
+	struct vb2_queue *q = v4l2_m2m_get_vq(fh->m2m_ctx, remove->type);
+
+	if (!q)
+		return -EINVAL;
+	if (q->type != remove->type)
+		return -EINVAL;
+
+	return vb2_core_remove_bufs(q, remove->index, remove->count);
+}
+EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_remove_bufs);
+
 int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv,
 				struct v4l2_buffer *buf)
 {

include/media/v4l2-mem2mem.h

···
 				struct v4l2_requestbuffers *rb);
 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *fh,
 				struct v4l2_create_buffers *create);
+int v4l2_m2m_ioctl_remove_bufs(struct file *file, void *priv,
+			       struct v4l2_remove_buffers *d);
 int v4l2_m2m_ioctl_querybuf(struct file *file, void *fh,
 				struct v4l2_buffer *buf);
 int v4l2_m2m_ioctl_expbuf(struct file *file, void *fh,