@@ -107,6 +107,30 @@ struct mtk_iommu_domain {
static const 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)
@@ -401,7 +425,7 @@ 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;
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@mediatek.com> --- drivers/iommu/mtk_iommu.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)