From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751537AbeE3Ka5 (ORCPT ); Wed, 30 May 2018 06:30:57 -0400 Received: from mail-wm0-f68.google.com ([74.125.82.68]:51039 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388AbeE3Kaz (ORCPT ); Wed, 30 May 2018 06:30:55 -0400 X-Google-Smtp-Source: ADUXVKKn8UqvQ16fD+Jzekm4dHiGccaVnmGc4PGvwkfogPXlchunv2GNNbQrTuI/M1oI6WPUEVU3GQ== Date: Wed, 30 May 2018 12:30:51 +0200 From: Daniel Vetter To: Gerd Hoffmann Cc: dri-devel@lists.freedesktop.org, Daniel Vetter , Sumit Semwal , "open list:DMA BUFFER SHARING FRAMEWORK" , "moderated list:DMA BUFFER SHARING FRAMEWORK" , open list Subject: Re: [PATCH] dma-buf: make map_atomic and map function pointers optional Message-ID: <20180530103051.GK3438@phenom.ffwll.local> Mail-Followup-To: Gerd Hoffmann , dri-devel@lists.freedesktop.org, Sumit Semwal , "open list:DMA BUFFER SHARING FRAMEWORK" , "moderated list:DMA BUFFER SHARING FRAMEWORK" , open list References: <20180529135918.19729-1-kraxel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180529135918.19729-1-kraxel@redhat.com> X-Operating-System: Linux phenom 4.15.0-3-amd64 User-Agent: Mutt/1.9.5 (2018-04-13) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 29, 2018 at 03:59:18PM +0200, Gerd Hoffmann wrote: > So drivers don't need dummy functions just returning NULL. > > Cc: Daniel Vetter > Signed-off-by: Gerd Hoffmann Reviewed-by: Daniel Vetter Please push to drm-misc-next (maybe after a few more days of waiting for feedback). -Daniel > --- > include/linux/dma-buf.h | 4 ++-- > drivers/dma-buf/dma-buf.c | 4 ++++ > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/include/linux/dma-buf.h b/include/linux/dma-buf.h > index 085db2fee2..88917fa796 100644 > --- a/include/linux/dma-buf.h > +++ b/include/linux/dma-buf.h > @@ -39,12 +39,12 @@ struct dma_buf_attachment; > > /** > * struct dma_buf_ops - operations possible on struct dma_buf > - * @map_atomic: maps a page from the buffer into kernel address > + * @map_atomic: [optional] maps a page from the buffer into kernel address > * space, users may not block until the subsequent unmap call. > * This callback must not sleep. > * @unmap_atomic: [optional] unmaps a atomically mapped page from the buffer. > * This Callback must not sleep. > - * @map: maps a page from the buffer into kernel address space. > + * @map: [optional] maps a page from the buffer into kernel address space. > * @unmap: [optional] unmaps a page from the buffer. > * @vmap: [optional] creates a virtual mapping for the buffer into kernel > * address space. Same restrictions as for vmap and friends apply. > diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c > index d78d5fc173..4c45e31258 100644 > --- a/drivers/dma-buf/dma-buf.c > +++ b/drivers/dma-buf/dma-buf.c > @@ -872,6 +872,8 @@ void *dma_buf_kmap_atomic(struct dma_buf *dmabuf, unsigned long page_num) > { > WARN_ON(!dmabuf); > > + if (!dmabuf->ops->map_atomic) > + return NULL; > return dmabuf->ops->map_atomic(dmabuf, page_num); > } > EXPORT_SYMBOL_GPL(dma_buf_kmap_atomic); > @@ -907,6 +909,8 @@ void *dma_buf_kmap(struct dma_buf *dmabuf, unsigned long page_num) > { > WARN_ON(!dmabuf); > > + if (!dmabuf->ops->map) > + return NULL; > return dmabuf->ops->map(dmabuf, page_num); > } > EXPORT_SYMBOL_GPL(dma_buf_kmap); > -- > 2.9.3 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch