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 
> Cc: Yong Wu 
> Signed-off-by: Chao Hao 

Reviewed-by: Matthias Brugger 

> ---
>  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 |
> 

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

[Chao Hao]

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 
Cc: Yong Wu 
Signed-off-by: Chao Hao 
---
 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 |
-- 
2.18.0