From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4CFFC433DF for ; Tue, 28 Jul 2020 09:30:41 +0000 (UTC) Received: from fraxinus.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6D51520714 for ; Tue, 28 Jul 2020 09:30:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6D51520714 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from localhost (localhost [127.0.0.1]) by fraxinus.osuosl.org (Postfix) with ESMTP id 2C49C84F2A; Tue, 28 Jul 2020 09:30:41 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from fraxinus.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id djF8Rr4lS5Mq; Tue, 28 Jul 2020 09:30:40 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by fraxinus.osuosl.org (Postfix) with ESMTP id 4EA01844BD; Tue, 28 Jul 2020 09:30:40 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 265AAC004F; Tue, 28 Jul 2020 09:30:40 +0000 (UTC) Received: from hemlock.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by lists.linuxfoundation.org (Postfix) with ESMTP id 2BECAC004D for ; Tue, 28 Jul 2020 09:30:38 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by hemlock.osuosl.org (Postfix) with ESMTP id 1316F8839E for ; Tue, 28 Jul 2020 09:30:38 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from hemlock.osuosl.org ([127.0.0.1]) by localhost (.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id eQN429HcPLBh for ; Tue, 28 Jul 2020 09:30:36 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by hemlock.osuosl.org (Postfix) with ESMTPS id AA4EE88396 for ; Tue, 28 Jul 2020 09:30:35 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 83AADB692; Tue, 28 Jul 2020 09:30:44 +0000 (UTC) Message-ID: Subject: Re: [PATCH] dma-pool: Do not allocate pool memory from CMA From: Nicolas Saenz Julienne To: Christoph Hellwig Date: Tue, 28 Jul 2020 11:30:32 +0200 In-Reply-To: <20200728091335.GA23744@lst.de> References: <011994f8a717a00dcd9ed7682a1ddeb421c2c43f.camel@suse.de> <01831596e4a2a6c9c066138b23bd30435f8e5569.camel@suse.de> <6db722947546221ed99d3f473f78e1a6de65d7d6.camel@suse.de> <0dc1e922bf87fa73790e7471b3974528dd261486.camel@suse.de> <20200724134114.GA3152@lst.de> <20200728091335.GA23744@lst.de> User-Agent: Evolution 3.36.4 MIME-Version: 1.0 Cc: Amit Pundir , lkml , jeremy.linton@arm.com, iommu@lists.linux-foundation.org, John Stultz , linux-rpi-kernel@lists.infradead.org, David Rientjes , Robin Murphy , Sumit Semwal X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============8888429204203383071==" Errors-To: iommu-bounces@lists.linux-foundation.org Sender: "iommu" --===============8888429204203383071== Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-wHIEAVE4ttgv4yIfz1Kv" --=-wHIEAVE4ttgv4yIfz1Kv Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2020-07-28 at 11:13 +0200, Christoph Hellwig wrote: > On Mon, Jul 27, 2020 at 07:56:56PM +0200, Nicolas Saenz Julienne wrote: > > Hi Christoph, > > thanks for having a look at this! > >=20 > > On Fri, 2020-07-24 at 15:41 +0200, Christoph Hellwig wrote: > > > Yes, the iommu is an interesting case, and the current code is > > > wrong for that. > >=20 > > Care to expand on this? I do get that checking dma_coherent_ok() on mem= ory > > that'll later on be mapped into an iommu is kind of silly, although I t= hink > > harmless in Amir's specific case, since devices have wide enough dma- ranges.=20 > > Is > > there more to it? >=20 > I think the problem is that it can lead to not finding suitable memory. >=20 > > > Can you try the patch below? It contains a modified version of Nicol= as' > > > patch to try CMA again for the expansion and a new (for now hackish) = way > > > to > > > not apply the addressability check for dma-iommu allocations. > > >=20 > > > diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c > > > index 6bc74a2d51273e..ec5e525d2b9309 100644 > > > --- a/kernel/dma/pool.c > > > +++ b/kernel/dma/pool.c > > > @@ -3,7 +3,9 @@ > > > * Copyright (C) 2012 ARM Ltd. > > > * Copyright (C) 2020 Google LLC > > > */ > > > +#include > > > #include > > > +#include > > > #include > > > #include > > > #include > > > @@ -55,6 +57,31 @@ static void dma_atomic_pool_size_add(gfp_t gfp, si= ze_t > > > size) > > > pool_size_kernel +=3D size; > > > } > > > =20 > > > +static bool cma_in_zone(gfp_t gfp) > > > +{ > > > + phys_addr_t end; > > > + unsigned long size; > > > + struct cma *cma; > > > + > > > + cma =3D dev_get_cma_area(NULL); > > > + if (!cma) > > > + return false; > > > + > > > + size =3D cma_get_size(cma); > > > + if (!size) > > > + return false; > > > + end =3D cma_get_base(cma) - memblock_start_of_DRAM() + size - 1; > > > + > > > + /* CMA can't cross zone boundaries, see cma_activate_area() */ > > > + if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA) && > > > + end <=3D DMA_BIT_MASK(zone_dma_bits)) > > > + return true; > > > + if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32) && > > > + end <=3D DMA_BIT_MASK(32)) > > > + return true; > > > + return true; > >=20 > > IIUC this will always return true given a CMA is present. Which reverts= to > > the > > previous behaviour (previous as in breaking some rpi4 setups), isn't it= ? >=20 > Was that really what broke the PI? I'll try to get the split out series > today, which might have a few more tweaks, and then we'll need to test it > both on these rpi4 setups and Amits phone. There was two issues with RPi: - Not validating that pool allocated memory was OK for the device - Locating all atomic pools in CMA, which doesn't work for all RPi4 device= s*, and IMO misses the point of having multiple pools. * With ACPI RPi4 we have CMA located in ZONE_DMA32, yet have an atomic pool consumer, PCIe, that only wants memory in the [0 3GB] area, effectively nee= ding ZONE_DMA memory. --=-wHIEAVE4ttgv4yIfz1Kv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iQEzBAABCAAdFiEErOkkGDHCg2EbPcGjlfZmHno8x/4FAl8f8DgACgkQlfZmHno8 x/5mTQf/cqxoM8tP7mr8vpxiY6n4EllJJCx63LubstRNKPv8WRjVJDxreEglcwUj FtoXednsUjhTSLvr7yJeRMbQoWUV0FiEYmOOgQnJ/r+R+M+3bLufnDoOnhqBi/u7 a38DxawJc6hUZAIKfni6q/zrWOnsySMAbaPPCOoGtHZBRHs66rfvJblDbe0mkdx7 lVLRDBzygsn6uyx4T9zam8r9RUFXnfJaLIe/Ews2Lo7u29tMSFDa/OreqJnqmox1 /JsE7V1KVd5yLpbWu07S8OCPGf5MIJwNKq5DmPP7KtMyrbD9bjmktuyRig4Y4MmJ yPAkxK6puUm+s9fTdQJJtzv94QTiVA== =lyxT -----END PGP SIGNATURE----- --=-wHIEAVE4ttgv4yIfz1Kv-- --===============8888429204203383071== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu --===============8888429204203383071==--