For multiple iommu_domains, we need to reserve some iova regions, so we
will add mtk_iommu_iova_region structure. It includes the base address
and size of the range.
This is a preparing patch for supporting multi-domain.

Signed-off-by: Anan sun<redacted>
Signed-off-by: Hao Chao<redacted>
Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 37 +++++++++++++++++++++++++++++++++++++
 drivers/iommu/mtk_iommu.h |  5 +++++
 2 files changed, 42 insertions(+)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 03a6d66f4bef..fdfdb75706e0 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c

@@ -151,6 +151,11 @@ static LIST_HEAD(m4ulist); /* List all the M4U HWs */

...
+
+static void mtk_iommu_put_resv_regions(struct device *dev,
+                                      struct list_head *head)
+{
+       struct iommu_resv_region *entry, *next;
+
+       list_for_each_entry_safe(entry, next, head, list)
+               kfree(entry);
+}
+