From mboxrd@z Thu Jan 1 00:00:00 1970 From: Robin Murphy Subject: Re: [PATCH v10 09/23] iommu/io-pgtable-arm-v7s: Extend to support PA[33:32] for MediaTek Date: Wed, 21 Aug 2019 16:34:27 +0100 Message-ID: <22a79977-5074-7af1-97b8-8a3e549b23c1@arm.com> References: <1566395606-7975-1-git-send-email-yong.wu@mediatek.com> <1566395606-7975-10-git-send-email-yong.wu@mediatek.com> <20190821152448.qmoqjh5zznfpdi6n@willie-the-truck> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190821152448.qmoqjh5zznfpdi6n@willie-the-truck> Content-Language: en-GB Sender: linux-kernel-owner@vger.kernel.org To: Will Deacon , Yong Wu Cc: Joerg Roedel , Matthias Brugger , Rob Herring , Evan Green , Tomasz Figa , linux-mediatek@lists.infradead.org, srv_heupstream@mediatek.com, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, iommu@lists.linux-foundation.org, youlin.pei@mediatek.com, Nicolas Boichat , anan.sun@mediatek.com, Matthias Kaehlcke , cui.zhang@mediatek.com, chao.hao@mediatek.com, ming-fan.chen@mediatek.com List-Id: devicetree@vger.kernel.org On 21/08/2019 16:24, Will Deacon wrote: > On Wed, Aug 21, 2019 at 09:53:12PM +0800, Yong Wu wrote: >> MediaTek extend the arm v7s descriptor to support up to 34 bits PA where >> the bit32 and bit33 are encoded in the bit9 and bit4 of the PTE >> respectively. Meanwhile the iova still is 32bits. >> >> Regarding whether the pagetable address could be over 4GB, the mt8183 >> support it while the previous mt8173 don't, thus keep it as is. >> >> Signed-off-by: Yong Wu >> --- >> drivers/iommu/io-pgtable-arm-v7s.c | 32 +++++++++++++++++++++++++------- >> include/linux/io-pgtable.h | 7 +++---- >> 2 files changed, 28 insertions(+), 11 deletions(-) > > [...] > >> @@ -731,7 +747,9 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct io_pgtable_cfg *cfg, >> { >> struct arm_v7s_io_pgtable *data; >> >> - if (cfg->ias > ARM_V7S_ADDR_BITS || cfg->oas > ARM_V7S_ADDR_BITS) >> + if (cfg->ias > ARM_V7S_ADDR_BITS || >> + (cfg->oas > ARM_V7S_ADDR_BITS && >> + !(cfg->quirks & IO_PGTABLE_QUIRK_ARM_MTK_EXT))) > > Please can you instead change arm_v7s_alloc_pgtable() so that it allows an > ias of up to 34 when the IO_PGTABLE_QUIRK_ARM_MTK_EXT is set? You mean oas, right? I believe the hardware *does* actually support a 32-bit ias as well, but we shouldn't pretend to support that while __arm_v7s_alloc_table() still only knows how to allocate normal-sized tables. Robin. > > With that change: > > Acked-by: Will Deacon > > Will >