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> --- 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