From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757920AbdKOOl1 (ORCPT ); Wed, 15 Nov 2017 09:41:27 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:40530 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756639AbdKOOlT (ORCPT ); Wed, 15 Nov 2017 09:41:19 -0500 Date: Wed, 15 Nov 2017 14:41:17 +0000 From: Liviu Dudau To: Noralf =?utf-8?Q?Tr=C3=B8nnes?= Cc: Laurent Pinchart , David Airlie , intel-gfx@lists.freedesktop.org, LKML , DRI-devel , Mali DP Maintainers , Daniel Vetter Subject: Re: [PATCH v2] drm: gem_cma_helper.c: Allow importing of contiguous scatterlists with nents > 1 Message-ID: <20171115144117.GC31361@e110455-lin.cambridge.arm.com> References: <2213365.Z1vsgl9bDt@avalon> <20171110133310.1225-1-Liviu.Dudau@arm.com> <26071297.cMn4QuKrlS@avalon> <20171115130450.GA31361@e110455-lin.cambridge.arm.com> <14804f07-697f-cfc9-d325-6eb3888b04e3@tronnes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <14804f07-697f-cfc9-d325-6eb3888b04e3@tronnes.org> User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 15, 2017 at 03:24:41PM +0100, Noralf Trønnes wrote: > > Den 15.11.2017 14.04, skrev Liviu Dudau: > > Hi, > > > > On Sat, Nov 11, 2017 at 02:47:35PM +0200, Laurent Pinchart wrote: > > > Hi Liviu, > > > > > > Thank you for the patch. > > > > > > On Friday, 10 November 2017 15:33:10 EET Liviu Dudau wrote: > > > > drm_gem_cma_prime_import_sg_table() will fail if the number of entries > > > > in the sg_table > 1. However, you can have a device that uses an IOMMU > > > > engine and can map a discontiguous buffer with multiple entries that > > > > have consecutive sg_dma_addresses, effectively making it contiguous. > > > > Allow for that scenario by testing the entries in the sg_table for > > > > contiguous coverage. > > > > > > > > Reviewed-by: Laurent Pinchart > > > > Signed-off-by: Liviu Dudau > > > > --- > > > > > > > > Laurent, > > > > > > > > Thanks for the review! I would like to ask for one more favour: if you > > > > are OK with this version, can you pull this patch through the drm-misc tree? > > > I could, but I'd first need to set dim up, and I'm currently abroad with a bad > > > internet connection and a big deadline for the middle of next week (I know, > > > lots of excuses), so it's not very convenient for me at this time. > > Any other drm-misc maintainers feeling helpful and willing to take this > > patch in? > > Sure, I can do it this evening. Cheers, much appreciated! Best regards, Liviu > > Noralf. > > > Otherwise I can send it through the mali-dp tree if no one > > objects. > > > > Best regards, > > Liviu > > > > > > drivers/gpu/drm/drm_gem_cma_helper.c | 22 ++++++++++++++++++++-- > > > > include/drm/drm_gem_cma_helper.h | 4 +++- > > > > 2 files changed, 23 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c > > > > b/drivers/gpu/drm/drm_gem_cma_helper.c index 020e7668dfaba..43b179212052d > > > > 100644 > > > > --- a/drivers/gpu/drm/drm_gem_cma_helper.c > > > > +++ b/drivers/gpu/drm/drm_gem_cma_helper.c > > > > @@ -482,8 +482,26 @@ drm_gem_cma_prime_import_sg_table(struct drm_device > > > > *dev, { > > > > struct drm_gem_cma_object *cma_obj; > > > > > > > > - if (sgt->nents != 1) > > > > - return ERR_PTR(-EINVAL); > > > > + if (sgt->nents != 1) { > > > > + /* check if the entries in the sg_table are contiguous */ > > > > + dma_addr_t next_addr = sg_dma_address(sgt->sgl); > > > > + struct scatterlist *s; > > > > + unsigned int i; > > > > + > > > > + for_each_sg(sgt->sgl, s, sgt->nents, i) { > > > > + /* > > > > + * sg_dma_address(s) is only valid for entries > > > > + * that have sg_dma_len(s) != 0 > > > > + */ > > > > + if (!sg_dma_len(s)) > > > > + continue; > > > > + > > > > + if (sg_dma_address(s) != next_addr) > > > > + return ERR_PTR(-EINVAL); > > > > + > > > > + next_addr = sg_dma_address(s) + sg_dma_len(s); > > > > + } > > > > + } > > > > > > > > /* Create a CMA GEM buffer. */ > > > > cma_obj = __drm_gem_cma_create(dev, attach->dmabuf->size); > > > > diff --git a/include/drm/drm_gem_cma_helper.h > > > > b/include/drm/drm_gem_cma_helper.h index 58a739bf15f1f..214aa85adc8d5 > > > > 100644 > > > > --- a/include/drm/drm_gem_cma_helper.h > > > > +++ b/include/drm/drm_gem_cma_helper.h > > > > @@ -8,7 +8,9 @@ > > > > * struct drm_gem_cma_object - GEM object backed by CMA memory allocations > > > > * @base: base GEM object > > > > * @paddr: physical address of the backing memory > > > > - * @sgt: scatter/gather table for imported PRIME buffers > > > > + * @sgt: scatter/gather table for imported PRIME buffers. The table can > > > > have + * more than one entry but they are guaranteed to have > > > > contiguous + * DMA addresses. > > > > * @vaddr: kernel virtual address of the backing memory > > > > */ > > > > struct drm_gem_cma_object { > > > -- > > > Regards, > > > > > > Laurent Pinchart > > > > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯