diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/mtk_iommu.c | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c index c6e6dc343771..9ba270620767 100644 --- a/drivers/iommu/mtk_iommu.c +++ b/drivers/iommu/mtk_iommu.c @@ -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; |