Some HW IP(ex: CCU) require the special iova range. That means the iova
got from dma_alloc_attrs for that devices must locate in his special range.
In this patch, we prepare a iommu group(domain) for each a iova range
requirement.

Meanwhile we still use one pagetable which support 16GB iova.

After this patch, If the iova range of a master is over 4G, the master
should:
a) Declare its special dma-ranges in its dtsi node. For example, If we
   preassign the iova 4G-8G for vcodec, then the vcodec dtsi node should
   add this:
   /*
    * iova start at 0x1_0000_0000, pa still start at 0x4000_0000
    * size is 0x1_0000_0000.
    */
   dma-ranges = <0x1 0x0 0x0 0x40000000 0x1 0x0>;  /* 4G ~ 8G */
 Note: we don't have a actual bus concept here. the master doesn't have its
 special parent node, thus this dma-ranges can only be put in the master's
 node.

b) Update the dma_mask:
  dma_set_mask_and_coherent(dev, DMA_BIT_MASK(33));

Signed-off-by: Yong Wu <yong...@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 37 ++++++++++++++++++++++++++-----------
 drivers/iommu/mtk_iommu.h |  4 +++-
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 8fc17158bc28..b42fd2535b77 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -369,8 +369,19 @@ static void mtk_iommu_config(struct mtk_iommu_data *data,
 }
 
 static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom,
-                                    struct mtk_iommu_data *data)
+                                    struct mtk_iommu_data *data,
+                                    unsigned int domid)
 {
+       const struct mtk_iommu_iova_region *region;
+
+       /* Use the exist domain as there is only one pgtable here. */
+       if (data->m4u_dom) {
+               dom->iop = data->m4u_dom->iop;
+               dom->cfg = data->m4u_dom->cfg;
+               dom->domain.pgsize_bitmap = data->m4u_dom->cfg.pgsize_bitmap;
+               goto update_iova_region;
+       }
+
        dom->cfg = (struct io_pgtable_cfg) {
                .quirks = IO_PGTABLE_QUIRK_ARM_NS |
                        IO_PGTABLE_QUIRK_NO_PERMS |
@@ -394,8 +405,11 @@ static int mtk_iommu_domain_finalise(struct 
mtk_iommu_domain *dom,
        /* Update our support page sizes bitmap */
        dom->domain.pgsize_bitmap = dom->cfg.pgsize_bitmap;
 
-       dom->domain.geometry.aperture_start = 0;
-       dom->domain.geometry.aperture_end = DMA_BIT_MASK(32);
+update_iova_region:
+       /* Update the iova region for this domain */
+       region = data->plat_data->iova_region + domid;
+       dom->domain.geometry.aperture_start = region->iova_base;
+       dom->domain.geometry.aperture_end = region->iova_base + region->size - 
1;
        dom->domain.geometry.force_aperture = true;
        return 0;
 }
@@ -441,7 +455,7 @@ static int mtk_iommu_attach_device(struct iommu_domain 
*domain,
                return domid;
 
        if (!dom->data) {
-               if (mtk_iommu_domain_finalise(dom, data))
+               if (mtk_iommu_domain_finalise(dom, data, domid))
                        return -ENODEV;
                dom->data = data;
        }
@@ -569,6 +583,7 @@ static void mtk_iommu_release_device(struct device *dev)
 static struct iommu_group *mtk_iommu_device_group(struct device *dev)
 {
        struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
+       struct iommu_group *group;
        int domid;
 
        if (!data)
@@ -578,15 +593,15 @@ static struct iommu_group *mtk_iommu_device_group(struct 
device *dev)
        if (domid < 0)
                return ERR_PTR(domid);
 
-       /* All the client devices are in the same m4u iommu-group */
-       if (!data->m4u_group) {
-               data->m4u_group = iommu_group_alloc();
-               if (IS_ERR(data->m4u_group))
-                       dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+       group = data->m4u_group[domid];
+       if (!group) {
+               group = iommu_group_alloc();
+               if (!IS_ERR(group))
+                       data->m4u_group[domid] = group;
        } else {
-               iommu_group_ref_get(data->m4u_group);
+               iommu_group_ref_get(group);
        }
-       return data->m4u_group;
+       return group;
 }
 
 static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index 118170af1974..6f2168e3222d 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -22,6 +22,8 @@
 #define MTK_LARB_COM_MAX       8
 #define MTK_LARB_SUBCOM_MAX    4
 
+#define MTK_IOMMU_GROUP_MAX    8
+
 struct mtk_iommu_suspend_reg {
        union {
                u32                     standard_axi_mode;/* v1 */
@@ -67,7 +69,7 @@ struct mtk_iommu_data {
        phys_addr_t                     protect_base; /* protect memory base */
        struct mtk_iommu_suspend_reg    reg;
        struct mtk_iommu_domain         *m4u_dom;
-       struct iommu_group              *m4u_group;
+       struct iommu_group              *m4u_group[MTK_IOMMU_GROUP_MAX];
        bool                            enable_4GB;
        spinlock_t                      tlb_lock; /* lock for tlb range flush */
 
-- 
2.18.0

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