On Tue, 2015-07-21 at 15:59 +0100, Will Deacon wrote:
> Hi Yong Wu,
>
> On Thu, Jul 16, 2015 at 10:04:34AM +0100, Yong Wu wrote:
> > This patch adds support for mediatek m4u (MultiMedia Memory Management
> > Unit).
>
> [...]
>
> > +static void mtk_iommu_tlb_flush_all(void *cookie)
> > +{
> > + struct mtk_iommu_domain *domain = cookie;
> > + void __iomem *base;
> > +
> > + base = domain->data->base;
> > + writel(F_INVLD_EN1 | F_INVLD_EN0, base + REG_MMU_INV_SEL);
> > + writel(F_ALL_INVLD, base + REG_MMU_INVALIDATE);
>
> This needs to be synchronous, so you probably want to call
> mtk_iommu_tlb_sync at the end.
>From our spec, we have to wait until HW done after tlb flush range.
But it don't need wait after tlb flush all.
so It isn't necessary to add mtk_iommu_tlb_sync in tlb_flush_all here.
>
> > +}
> > +
> > +static void mtk_iommu_tlb_add_flush(unsigned long iova, size_t size,
> > + bool leaf, void *cookie)
> > +{
> > + struct mtk_iommu_domain *domain = cookie;
> > + void __iomem *base = domain->data->base;
> > + unsigned int iova_start = iova, iova_end = iova + size - 1;
> > +
> > + writel(F_INVLD_EN1 | F_INVLD_EN0, base + REG_MMU_INV_SEL);
> > +
> > + writel(iova_start, base + REG_MMU_INVLD_START_A);
> > + writel(iova_end, base + REG_MMU_INVLD_END_A);
> > + writel(F_MMU_INV_RANGE, base + REG_MMU_INVALIDATE);
>
> Why are you using writel instead of writel_relaxed? I asked this before
> but I don't think you replied.
Sorry, I didn't notice _relax last time. I will improve in next version.
Thanks very much.
>
> Will
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