From: Yong Wu <yong.wu@mediatek.com>
To: Robin Murphy <robin.murphy@arm.com>
Cc: youlin.pei@mediatek.com, anan.sun@mediatek.com,
Nicolas Boichat <drinkcat@chromium.org>,
cui.zhang@mediatek.com, srv_heupstream@mediatek.com,
edison.hsieh@mediatek.com, Joerg Roedel <joro@8bytes.org>,
Will Deacon <will.deacon@arm.com>,
linux-kernel@vger.kernel.org, Evan Green <evgreen@chromium.org>,
chao.hao@mediatek.com, Tomasz Figa <tfiga@google.com>,
iommu@lists.linux-foundation.org,
linux-mediatek@lists.infradead.org,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH v3 6/7] iommu/mediatek: Use writel for TLB range invalidation
Date: Tue, 15 Oct 2019 13:25:41 +0800 [thread overview]
Message-ID: <1571117141.19130.82.camel@mhfsdcap03> (raw)
In-Reply-To: <c87e2a9c-5ed3-e44c-3b17-067db173eae9@arm.com>
On Mon, 2019-10-14 at 15:04 +0100, Robin Murphy wrote:
> On 14/10/2019 07:38, Yong Wu wrote:
> > Use writel for the register F_MMU_INV_RANGE which is for triggering the
> > HW work. We expect all the setting(iova_start/iova_end...) have already
> > been finished before F_MMU_INV_RANGE.
>
> For Arm CPUs, these registers should be mapped as Device memory,
> therefore the same-peripheral rule should implicitly enforce that the
> accesses are made in program order, hence you're unlikely to have seen a
> problem in reality. However, the logical reasoning for the change seems
> valid in general, so I'd argue that it's still worth making if only for
> the sake of good practice:
>
> Acked-by: Robin Murphy <robin.murphy@arm.com>
Thanks very much for the view. If this patch is not so necessary, I will
remove it this time.
>
> > Signed-off-by: Anan.Sun <anan.sun@mediatek.com>
> > Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> > ---
> > drivers/iommu/mtk_iommu.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index dbbacc3..d285457 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -187,8 +187,7 @@ static void mtk_iommu_tlb_flush_range_sync(unsigned long iova, size_t size,
> > writel_relaxed(iova, data->base + REG_MMU_INVLD_START_A);
> > writel_relaxed(iova + size - 1,
> > data->base + REG_MMU_INVLD_END_A);
> > - writel_relaxed(F_MMU_INV_RANGE,
> > - data->base + REG_MMU_INVALIDATE);
> > + writel(F_MMU_INV_RANGE, data->base + REG_MMU_INVALIDATE);
> >
> > /* tlb sync */
> > ret = readl_poll_timeout_atomic(data->base + REG_MMU_CPE_DONE,
> >
>
> _______________________________________________
> Linux-mediatek mailing list
> Linux-mediatek@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-mediatek
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next prev parent reply other threads:[~2019-10-15 5:35 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-14 6:38 [PATCH v3 0/7] Improve tlb range flush Yong Wu
2019-10-14 6:38 ` [PATCH v3 1/7] iommu/mediatek: Correct the flush_iotlb_all callback Yong Wu
2019-10-14 14:06 ` Robin Murphy
2019-10-14 6:38 ` [PATCH v3 2/7] iommu/mediatek: Add pgtlock in the iotlb_sync Yong Wu
2019-10-14 6:38 ` [PATCH v3 3/7] iommu/mediatek: Use gather to achieve the tlb range flush Yong Wu
2019-10-14 14:21 ` Robin Murphy
2019-10-15 5:26 ` Yong Wu
2019-10-15 11:38 ` Robin Murphy
2019-10-14 6:38 ` [PATCH v3 4/7] iommu/mediatek: Delete the leaf in the tlb flush Yong Wu
2019-10-14 14:22 ` Robin Murphy
2019-10-15 5:25 ` Yong Wu
2019-10-15 11:24 ` Robin Murphy
2019-10-14 6:38 ` [PATCH v3 5/7] iommu/mediatek: Move the tlb_sync into tlb_flush Yong Wu
2019-10-14 6:38 ` [PATCH v3 6/7] iommu/mediatek: Use writel for TLB range invalidation Yong Wu
2019-10-14 14:04 ` Robin Murphy
2019-10-15 5:25 ` Yong Wu [this message]
2019-10-14 6:38 ` [PATCH v3 7/7] iommu/mediatek: Reduce the tlb flush timeout value Yong Wu
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