From: Yong Wu <yong.wu@xxxxxxxxxxxx> [ Upstream commit 76ce65464fcd2c21db84391572b7938b716aceb0 ] In M4U 4GB mode, the physical address is remapped as below: CPU Physical address: ==================== 0 1G 2G 3G 4G 5G |---A---|---B---|---C---|---D---|---E---| +--I/O--+------------Memory-------------+ IOMMU output physical address: ============================= 4G 5G 6G 7G 8G |---E---|---B---|---C---|---D---| +------------Memory-------------+ The Region 'A'(I/O) can not be mapped by M4U; For Region 'B'/'C'/'D', the bit32 of the CPU physical address always is needed to set, and for Region 'E', the CPU physical address keep as is. something looks like this: CPU PA -> M4U OUTPUT PA 0x4000_0000 0x1_4000_0000 (Add bit32) 0x8000_0000 0x1_8000_0000 ... 0xc000_0000 0x1_c000_0000 ... 0x1_0000_0000 0x1_0000_0000 (No change) Additionally, the iommu consumers always use the CPU phyiscal address. The PA in the iova_to_phys that is got from v7s always is u32, But from the CPU point of view, PA only need add BIT(32) when PA < 0x4000_0000. Fixes: 30e2fccf9512 ("iommu/mediatek: Enlarge the validate PA range for 4GB mode") Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/iommu/mtk_iommu.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index 154cf44439cb6..8e75f34ac8868 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -115,6 +115,30 @@ struct mtk_iommu_domain { static struct iommu_ops mtk_iommu_ops; +/* + * In M4U 4GB mode, the physical address is remapped as below: + * + * CPU Physical address: + * ==================== + * + * 0 1G 2G 3G 4G 5G + * |---A---|---B---|---C---|---D---|---E---| + * +--I/O--+------------Memory-------------+ + * + * IOMMU output physical address: + * ============================= + * + * 4G 5G 6G 7G 8G + * |---E---|---B---|---C---|---D---| + * +------------Memory-------------+ + * + * The Region 'A'(I/O) can NOT be mapped by M4U; For Region 'B'/'C'/'D', the + * bit32 of the CPU physical address always is needed to set, and for Region + * 'E', the CPU physical address keep as is. + * Additionally, The iommu consumers always use the CPU phyiscal address. + */ +#define MTK_IOMMU_4GB_MODE_REMAP_BASE 0x40000000 + static LIST_HEAD(m4ulist); /* List all the M4U HWs */ #define for_each_m4u(data) list_for_each_entry(data, &m4ulist, list) @@ -409,7 +433,7 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain, pa = dom->iop->iova_to_phys(dom->iop, iova); spin_unlock_irqrestore(&dom->pgtlock, flags); - if (data->enable_4GB) + if (data->enable_4GB && pa < MTK_IOMMU_4GB_MODE_REMAP_BASE) pa |= BIT_ULL(32); return pa; -- 2.20.1