[PATCH v3 21/24] iommu/mediatek: Add support for multi domain

Yong Wu
2020-09-30T07:15:50Z

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 allocate a special iova_range for
each a special requirement and create each a iommu domain for each
a iova_range.

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.wu@mediatek.com>
---
drivers/iommu/mtk_iommu.c | 47 +++++++++++++++++++++++++++++++--------
drivers/iommu/mtk_iommu.h | 3 ++-
2 files changed, 40 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 16760e318648..1d5d3e76d2d1 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -350,6 +350,14 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom)
{
struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();

+ /* Use the exist domain as there is only one m4u 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;
+ return 0;
+ }
+
dom->cfg = (struct io_pgtable_cfg) {
.quirks = IO_PGTABLE_QUIRK_ARM_NS |
IO_PGTABLE_QUIRK_NO_PERMS |
@@ -375,6 +383,8 @@ static int mtk_iommu_domain_finalise(struct mtk_iommu_domain *dom)

static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
{
+ struct mtk_iommu_data *data = mtk_iommu_get_m4u_data();
+ const struct mtk_iommu_iova_region *region;
struct mtk_iommu_domain *dom;

if (type != IOMMU_DOMAIN_DMA)
@@ -390,8 +400,9 @@ static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
if (mtk_iommu_domain_finalise(dom))
goto put_dma_cookie;

- dom->domain.geometry.aperture_start = 0;
- dom->domain.geometry.aperture_end = DMA_BIT_MASK(32);
+ region = data->plat_data->iova_region + data->cur_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 &dom->domain;
@@ -535,19 +546,31 @@ 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_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+ struct iommu_group *group;
+ int domid;

if (!data)
return ERR_PTR(-ENODEV);

- /* 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))
+ domid = MTK_M4U_TO_DOM(fwspec->ids[0]);
+ if (domid >= data->plat_data->iova_region_nr) {
+ dev_err(dev, "iommu domain id(%d/%d) is error.\n", domid,
+ data->plat_data->iova_region_nr);
+ return ERR_PTR(-EINVAL);
+ }
+
+ group = data->m4u_group[domid];
+ if (!group) {
+ group = iommu_group_alloc();
+ if (IS_ERR(group))
dev_err(dev, "Failed to allocate M4U IOMMU group\n");
+ data->m4u_group[domid] = group;
} else {
- iommu_group_ref_get(data->m4u_group);
+ iommu_group_ref_get(group);
}
- return data->m4u_group;
+ data->cur_domid = domid;
+ return group;
}

static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
@@ -576,14 +599,20 @@ 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;
+ const struct mtk_iommu_iova_region *resv, *curdom;
struct iommu_resv_region *region;
int prot = IOMMU_WRITE | IOMMU_READ;
unsigned int i;

+ curdom = data->plat_data->iova_region + data->cur_domid;
for (i = 0; i < data->plat_data->iova_region_nr; i++) {
resv = data->plat_data->iova_region + i;

+ /* Only reserve when the region is in the current domain */
+ if (resv->iova_base <= curdom->iova_base ||
+ resv->iova_base + resv->size >= curdom->iova_base + curdom->size)
+ continue;
+
region = iommu_alloc_resv_region(resv->iova_base, resv->size,
prot, IOMMU_RESV_RESERVED);
if (!region)
diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index d45c13c9d324..5e346464cdf8 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -66,7 +66,7 @@ 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_M4U_DOM_NR_MAX];
bool enable_4GB;
spinlock_t tlb_lock; /* lock for tlb range flush */

@@ -76,6 +76,7 @@ struct mtk_iommu_data {

struct dma_iommu_mapping *mapping; /* For mtk_iommu_v1.c */

+ unsigned int cur_domid;
struct list_head list;
struct mtk_smi_larb_iommu larb_imu[MTK_LARB_NR_MAX];
};
--
2.18.0