Il 17/03/23 09:55, Yong Wu ha scritto:
From: "Chengci.Xu" <chengci.xu@xxxxxxxxxxxx> Prepare for mt8188 to fix a two IOMMU HWs share pagetable issue. We have two MM IOMMU HWs in mt8188, one is VPP-IOMMU, another is VDO-IOMMU. The 2 MM IOMMU HWs share pagetable don't work in this case: a) VPP-IOMMU probe firstly. b) VDO-IOMMU probe. c) The master for VDO-IOMMU probe (means frstdata is vpp-iommu). d) The master in another domain probe. No matter it is vdo or vpp. Then it still create a new pagetable in step d). The problem is "frstdata->bank[0]->m4u_dom" was not initialized. Then when d) enter, it still create a new one. In this patch, we create a new variable "share_dom" for this share pgtable case, it should be helpful for readable. and put all the share pgtable logic in the mtk_iommu_domain_finalise. In mt8195, the master of VPP-IOMMU probes before than VDO-IOMMU from its dtsi node sequence, we don't see this issue in it. Prepare for mt8188. Signed-off-by: Chengci.Xu <chengci.xu@xxxxxxxxxxxx> Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
I'm not sure whether this is *not* a fix... if a specific platform wasn't affected, this may still be a logic mistake... to be cautious, I would still add a Fixes tag to this one. Otherwise, I would reword the commit title and remove the "Fix" word, so that it would look something like... iommu/mediatek: Prepare for pagetables domain sharing I'm sorry for noticing that only at v9, but the previous versions had a bit more stuff to address and couldn't really focus on analyzing this one. If there's anything I've misunderstood about this patch, please feel free to explain. Regards, Angelo
