[PATCH v3 16/24] iommu/mediatek: Add iova reserved function

Yong Wu
2020-09-30T07:22:39Z

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@mediatek.com>
Signed-off-by: Chao Hao <chao.hao@mediatek.com>
Signed-off-by: Yong Wu <yong.wu@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 1e6e6d3fa7f1..8e2a8e29d13c 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -153,6 +153,11 @@ 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.
@@ -539,6 +544,27 @@ 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,
@@ -553,6 +579,8 @@ 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 ae7909815cdb..d45c13c9d324 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -44,10 +44,15 @@ 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