From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi1-f197.google.com (mail-oi1-f197.google.com [209.85.167.197]) by kanga.kvack.org (Postfix) with ESMTP id 97C286B2672 for ; Wed, 21 Nov 2018 11:46:25 -0500 (EST) Received: by mail-oi1-f197.google.com with SMTP id p128so2436054oib.2 for ; Wed, 21 Nov 2018 08:46:25 -0800 (PST) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id k3si6581330otn.156.2018.11.21.08.46.23 for ; Wed, 21 Nov 2018 08:46:23 -0800 (PST) Date: Wed, 21 Nov 2018 16:46:38 +0000 From: Will Deacon Subject: Re: [PATCH v2 3/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging Message-ID: <20181121164638.GD24883@arm.com> References: <20181111090341.120786-1-drinkcat@chromium.org> <20181111090341.120786-4-drinkcat@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181111090341.120786-4-drinkcat@chromium.org> Sender: owner-linux-mm@kvack.org List-ID: To: Nicolas Boichat Cc: Robin Murphy , Joerg Roedel , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Michal Hocko , Mel Gorman , Levin Alexander , Huaisheng Ye , Mike Rapoport , linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Yong Wu , Matthias Brugger , Tomasz Figa , yingjoe.chen@mediatek.com On Sun, Nov 11, 2018 at 05:03:41PM +0800, Nicolas Boichat wrote: > For level 1/2 pages, ensure GFP_DMA32 is used if CONFIG_ZONE_DMA32 > is defined (e.g. on arm64 platforms). > > For level 2 pages, allocate a slab cache in SLAB_CACHE_DMA32. > > Also, print an error when the physical address does not fit in > 32-bit, to make debugging easier in the future. > > Fixes: ad67f5a6545f ("arm64: replace ZONE_DMA with ZONE_DMA32") > Signed-off-by: Nicolas Boichat > --- > > Changes since v1: > - Changed approach to use SLAB_CACHE_DMA32 added by the previous > commit. > - Use DMA or DMA32 depending on the architecture (DMA for arm, > DMA32 for arm64). > > drivers/iommu/io-pgtable-arm-v7s.c | 20 ++++++++++++++++---- > 1 file changed, 16 insertions(+), 4 deletions(-) > > diff --git a/drivers/iommu/io-pgtable-arm-v7s.c b/drivers/iommu/io-pgtable-arm-v7s.c > index 445c3bde04800c..996f7b6d00b44a 100644 > --- a/drivers/iommu/io-pgtable-arm-v7s.c > +++ b/drivers/iommu/io-pgtable-arm-v7s.c > @@ -161,6 +161,14 @@ > > #define ARM_V7S_TCR_PD1 BIT(5) > > +#ifdef CONFIG_ZONE_DMA32 > +#define ARM_V7S_TABLE_GFP_DMA GFP_DMA32 > +#define ARM_V7S_TABLE_SLAB_CACHE SLAB_CACHE_DMA32 > +#else > +#define ARM_V7S_TABLE_GFP_DMA GFP_DMA > +#define ARM_V7S_TABLE_SLAB_CACHE SLAB_CACHE_DMA > +#endif It's a bit grotty that GFP_DMA32 doesn't just map to GFP_DMA on 32-bit architectures, since then we wouldn't need this #ifdeffery afaict. Will