From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) by kanga.kvack.org (Postfix) with ESMTP id 5C2CF6B26EA for ; Wed, 21 Nov 2018 13:02:24 -0500 (EST) Received: by mail-ed1-f72.google.com with SMTP id c3so3426874eda.3 for ; Wed, 21 Nov 2018 10:02:24 -0800 (PST) Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id j1-v6si15632658ejc.323.2018.11.21.10.02.23 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 21 Nov 2018 10:02:23 -0800 (PST) Date: Wed, 21 Nov 2018 19:02:20 +0100 From: Michal Hocko Subject: Re: [PATCH v2 3/3] iommu/io-pgtable-arm-v7s: Request DMA32 memory, and improve debugging Message-ID: <20181121180000.GU12932@dhcp22.suse.cz> References: <20181111090341.120786-1-drinkcat@chromium.org> <20181111090341.120786-4-drinkcat@chromium.org> <20181121164638.GD24883@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181121164638.GD24883@arm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Will Deacon Cc: Nicolas Boichat , Robin Murphy , Joerg Roedel , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , 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 Wed 21-11-18 16:46:38, Will Deacon wrote: > 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. But GFP_DMA32 should map to GFP_KERNEL on 32b, no? Or what exactly is going on in here? -- Michal Hocko SUSE Labs