[PATCH 11/13] iommu/mediatek: Add iova reserved function

[Chao Hao]

For multiple iommu_domains, we need to reserve some iova
regions, so we will add mtk_iommu_resv_iova_region structure.
It includes the start address and size of iova and iommu_resv_type.
Based on the function, we will realize multiple mtk_iommu_domains

Signed-off-by: Anan Sun <anan.sun@xxxxxxxxxxxx>
Signed-off-by: Chao Hao <chao.hao@xxxxxxxxxxxx>
---
 drivers/iommu/mtk_iommu.c | 47 +++++++++++++++++++++++++++++++++++++++
 drivers/iommu/mtk_iommu.h | 12 ++++++++++
 2 files changed, 59 insertions(+)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 8c06d2a793a7..c0cd7da71c2c 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -697,6 +697,51 @@ static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
 	return iommu_fwspec_add_ids(dev, args->args, 1);
 }
 
+/* reserve/dir-map iova region */
+static void mtk_iommu_get_resv_regions(struct device *dev,
+				       struct list_head *head)
+{
+	struct mtk_iommu_data *data = dev_iommu_fwspec_get(dev)->iommu_priv;
+	unsigned int i, total_cnt = data->plat_data->resv_cnt;
+	const struct mtk_iommu_resv_iova_region *resv_data;
+	struct iommu_resv_region *region;
+	unsigned long base = 0;
+	size_t size = 0;
+	int prot = IOMMU_WRITE | IOMMU_READ;
+
+	resv_data = data->plat_data->resv_region;
+
+	for (i = 0; i < total_cnt; i++) {
+		size = 0;
+		if (resv_data[i].iova_size) {
+			base = (unsigned long)resv_data[i].iova_base;
+			size = resv_data[i].iova_size;
+		}
+		if (!size)
+			continue;
+
+		region = iommu_alloc_resv_region(base, size, prot,
+						 resv_data[i].type);
+		if (!region)
+			return;
+
+		list_add_tail(&region->list, head);
+
+		dev_dbg(data->dev, "%s iova 0x%x ~ 0x%x\n",
+			(resv_data[i].type == IOMMU_RESV_DIRECT) ? "dm" : "rsv",
+			(unsigned int)base, (unsigned int)(base + size - 1));
+	}
+}
+
+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);
+}
+
 static const struct iommu_ops mtk_iommu_ops = {
 	.domain_alloc	= mtk_iommu_domain_alloc,
 	.domain_free	= mtk_iommu_domain_free,
@@ -711,6 +756,8 @@ static const struct iommu_ops mtk_iommu_ops = {
 	.remove_device	= mtk_iommu_remove_device,
 	.device_group	= mtk_iommu_device_group,
 	.of_xlate	= mtk_iommu_of_xlate,
+	.get_resv_regions = mtk_iommu_get_resv_regions,
+	.put_resv_regions = mtk_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 d8aef0d57b1a..10476b23adee 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -36,6 +36,12 @@ enum mtk_iommu_plat {
 	M4U_MT8183,
 };
 
+struct mtk_iommu_resv_iova_region {
+	dma_addr_t		iova_base;
+	size_t			iova_size;
+	enum iommu_resv_type	type;
+};
+
 /*
  * reserved IOVA Domain for IOMMU users of HW limitation.
  */
@@ -68,6 +74,12 @@ struct mtk_iommu_plat_data {
 	u32		    dom_cnt;
 	unsigned char       larbid_remap[2][MTK_LARB_NR_MAX];
 	const struct mtk_domain_data	*dom_data;
+	/*
+	 * reserve/dir-mapping iova region data
+	 * todo: for different reserve needs on multiple iommu domains
+	 */
+	const unsigned int  resv_cnt;
+	const struct mtk_iommu_resv_iova_region *resv_region;
 };
 
 struct mtk_iommu_domain;
-- 
2.18.0