Re: [PATCH v6 09/10] iommu/mediatek: Modify MMU_CTRL register setting

[Matthias Brugger]

On 03/07/2020 06:41, Chao Hao wrote:
> The MMU_CTRL register of MT8173 is different from other SoCs.
> The in_order_wr_en is bit[9] which is zero by default.
> Other SoCs have the vitcim_tlb_en feature mapped to bit[12].
> This bit is set to one by default. We need to preserve the bit
> when setting F_MMU_TF_PROT_TO_PROGRAM_ADDR as otherwise the
> bit will be cleared and IOMMU performance will drop.
> 
> Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
> Cc: Yong Wu <yong.wu@xxxxxxxxxxxx>
> Signed-off-by: Chao Hao <chao.hao@xxxxxxxxxxxx>

Reviewed-by: Matthias Brugger <matthias.bgg@xxxxxxxxx>

> ---
>  drivers/iommu/mtk_iommu.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
> index e71003037ffa..a816030d00f1 100644
> --- a/drivers/iommu/mtk_iommu.c
> +++ b/drivers/iommu/mtk_iommu.c
> @@ -555,11 +555,13 @@ static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
>  		return ret;
>  	}
>  
> -	if (data->plat_data->m4u_plat == M4U_MT8173)
> +	if (data->plat_data->m4u_plat == M4U_MT8173) {
>  		regval = F_MMU_PREFETCH_RT_REPLACE_MOD |
>  			 F_MMU_TF_PROT_TO_PROGRAM_ADDR_MT8173;
> -	else
> -		regval = F_MMU_TF_PROT_TO_PROGRAM_ADDR;
> +	} else {
> +		regval = readl_relaxed(data->base + REG_MMU_CTRL_REG);
> +		regval |= F_MMU_TF_PROT_TO_PROGRAM_ADDR;
> +	}
>  	writel_relaxed(regval, data->base + REG_MMU_CTRL_REG);
>  
>  	regval = F_L2_MULIT_HIT_EN |
>