Re: [PATCH v5 11/20] iommu/mediatek: Move vld_pa_rng into plat_data

From: Yong Wu
Date: Wed Jan 30 2019 - 22:20:58 EST


On Wed, 2019-01-30 at 10:30 -0800, Evan Green wrote:
> On Mon, Dec 31, 2018 at 7:58 PM Yong Wu <yong.wu@xxxxxxxxxxxx> wrote:
> >
> > Both mt8173 and mt8183 don't have this vld_pa_rng(valid physical address
> > range) register while mt2712 have. Move it into the plat_data.
> >
> > Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
> > ---
> > drivers/iommu/mtk_iommu.c | 3 ++-
> > drivers/iommu/mtk_iommu.h | 1 +
> > 2 files changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> > index 8d8ab21..2913ddb 100644
> > --- a/drivers/iommu/mtk_iommu.c
> > +++ b/drivers/iommu/mtk_iommu.c
> > @@ -548,7 +548,7 @@ static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
> > upper_32_bits(data->protect_base);
> > writel_relaxed(regval, data->base + REG_MMU_IVRP_PADDR);
> >
> > - if (data->enable_4GB && data->plat_data->m4u_plat != M4U_MT8173) {
> > + if (data->enable_4GB && data->plat_data->vld_pa_rng) {
> > /*
> > * If 4GB mode is enabled, the validate PA range is from
> > * 0x1_0000_0000 to 0x1_ffff_ffff. here record bit[32:30].
> > @@ -741,6 +741,7 @@ static int __maybe_unused mtk_iommu_resume(struct device *dev)
> > .m4u_plat = M4U_MT2712,
> > .has_4gb_mode = true,
> > .has_bclk = true,
> > + .vld_pa_rng = true,
> > .larbid_remap = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9},
> > };
> >
> > diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
> > index b46aeaa..a8c5d1e 100644
> > --- a/drivers/iommu/mtk_iommu.h
> > +++ b/drivers/iommu/mtk_iommu.h
> > @@ -48,6 +48,7 @@ struct mtk_iommu_plat_data {
> > /* HW will use the EMI clock if there isn't the "bclk". */
> > bool has_bclk;
> > bool reset_axi;
> > + bool vld_pa_rng;
>
> I agree with Nicolas that valid_pa_range would be much clearer...
> although, even now that I know what it's supposed to mean, I don't get
> what it represents. What is this saying?

This register in the coda is called "vld_pa_rng".

How about I change it to "has_vld_pa_rng"?. In the comment above, I have
explained the meaning(valid physical address range).

>
> -Evan