[PATCH v4 16/24] iommu/mediatek: Add iova reserved function

[Yong Wu]

For multiple iommu_domains, we need to reserve some iova regions. Take a
example, If the default iova region is 0 ~ 4G, but the 0x4000_0000 ~
0x43ff_ffff is only for the special CCU0 domain. Thus we should exclude
this region for the default iova region.

This patch adds iova reserved flow. It's a preparing patch for supporting
multi-domain.

Signed-off-by: Anan sun <anan.sun at mediatek.com>
Signed-off-by: Chao Hao <chao.hao at mediatek.com>
Signed-off-by: Yong Wu <yong.wu at mediatek.com>
---
 drivers/iommu/mtk_iommu.c | 28 ++++++++++++++++++++++++++++
 drivers/iommu/mtk_iommu.h |  5 +++++
 2 files changed, 33 insertions(+)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 90aae34f4da0..bf3f4e0f4748 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -156,6 +156,11 @@ static LIST_HEAD(m4ulist);	/* List all the M4U HWs */
 
 #define for_each_m4u(data)	list_for_each_entry(data, &m4ulist, list)
 
+struct mtk_iommu_iova_region {
+	dma_addr_t		iova_base;
+	unsigned long long	size;
+};
+
 /*
  * There may be 1 or 2 M4U HWs, But we always expect they are in the same domain
  * for the performance.
@@ -544,6 +549,27 @@ static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
 	return iommu_fwspec_add_ids(dev, args->args, 1);
 }
 
+static void mtk_iommu_get_resv_regions(struct device *dev,
+				       struct list_head *head)
+{
+	struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
+	const struct mtk_iommu_iova_region *resv;
+	struct iommu_resv_region *region;
+	int prot = IOMMU_WRITE | IOMMU_READ;
+	unsigned int i;
+
+	for (i = 0; i < data->plat_data->iova_region_nr; i++) {
+		resv = data->plat_data->iova_region + i;
+
+		region = iommu_alloc_resv_region(resv->iova_base, resv->size,
+						 prot, IOMMU_RESV_RESERVED);
+		if (!region)
+			return;
+
+		list_add_tail(&region->list, head);
+	}
+}
+
 static const struct iommu_ops mtk_iommu_ops = {
 	.domain_alloc	= mtk_iommu_domain_alloc,
 	.domain_free	= mtk_iommu_domain_free,
@@ -558,6 +584,8 @@ static const struct iommu_ops mtk_iommu_ops = {
 	.release_device	= mtk_iommu_release_device,
 	.device_group	= mtk_iommu_device_group,
 	.of_xlate	= mtk_iommu_of_xlate,
+	.get_resv_regions = mtk_iommu_get_resv_regions,
+	.put_resv_regions = generic_iommu_put_resv_regions,
 	.pgsize_bitmap	= SZ_4K | SZ_64K | SZ_1M | SZ_16M,
 };
 
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index 5e03a029c4dc..e867cd3aeeac 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -45,10 +45,15 @@ enum mtk_iommu_plat {
 	M4U_MT8183,
 };
 
+struct mtk_iommu_iova_region;
+
 struct mtk_iommu_plat_data {
 	enum mtk_iommu_plat m4u_plat;
 	u32                 flags;
 	u32                 inv_sel_reg;
+
+	unsigned int        iova_region_nr;
+	const struct mtk_iommu_iova_region   *iova_region;
 	unsigned char       larbid_remap[MTK_LARB_COM_MAX][MTK_LARB_SUBCOM_MAX];
 };
 
-- 
2.18.0