[PATCH 09/18] iommu/mediatek-v1: Add IOMMU_DOMAIN_DMA support

Robin Murphy
2020-08-20T15:12:16Z

Now that arch/arm is wired up for default domains and iommu-dma,
implement the corresponding driver-side support for groups and DMA
domains to replace the shared mapping workaround.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
drivers/iommu/mtk_iommu.h | 2 -
drivers/iommu/mtk_iommu_v1.c | 153 +++++++++++------------------------
2 files changed, 48 insertions(+), 107 deletions(-)

diff --git a/drivers/iommu/mtk_iommu.h b/drivers/iommu/mtk_iommu.h
index 122925dbe547..6253e98d810c 100644
--- a/drivers/iommu/mtk_iommu.h
+++ b/drivers/iommu/mtk_iommu.h
@@ -67,8 +67,6 @@ struct mtk_iommu_data {
struct iommu_device iommu;
const struct mtk_iommu_plat_data *plat_data;

- struct dma_iommu_mapping *mapping; /* For mtk_iommu_v1.c */
-
struct list_head list;
struct mtk_smi_larb_iommu larb_imu[MTK_LARB_NR_MAX];
};
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 82ddfe9170d4..40c89b8d3ac4 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -28,7 +28,6 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <asm/barrier.h>
-#include <asm/dma-iommu.h>
#include <linux/init.h>
#include <dt-bindings/memory/mt2701-larb-port.h>
#include <soc/mediatek/smi.h>
@@ -240,13 +239,18 @@ static struct iommu_domain *mtk_iommu_domain_alloc(unsigned type)
{
struct mtk_iommu_domain *dom;

- if (type != IOMMU_DOMAIN_UNMANAGED)
+ if (type != IOMMU_DOMAIN_UNMANAGED && type != IOMMU_DOMAIN_DMA)
return NULL;

dom = kzalloc(sizeof(*dom), GFP_KERNEL);
if (!dom)
return NULL;

+ if (type == IOMMU_DOMAIN_DMA && iommu_get_dma_cookie(&dom->domain)) {
+ kfree(dom);
+ return NULL;
+ }
+
return &dom->domain;
}

@@ -257,6 +261,7 @@ static void mtk_iommu_domain_free(struct iommu_domain *domain)

dma_free_coherent(data->dev, M2701_IOMMU_PGT_SIZE,
dom->pgt_va, dom->pgt_pa);
+ iommu_put_dma_cookie(domain);
kfree(to_mtk_domain(domain));
}

@@ -265,14 +270,8 @@ static int mtk_iommu_attach_device(struct iommu_domain *domain,
{
struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
struct mtk_iommu_domain *dom = to_mtk_domain(domain);
- struct dma_iommu_mapping *mtk_mapping;
int ret;

- /* Only allow the domain created internally. */
- mtk_mapping = data->mapping;
- if (mtk_mapping->domain != domain)
- return 0;
-
if (!data->m4u_dom) {
data->m4u_dom = dom;
ret = mtk_iommu_domain_finalise(data);
@@ -358,18 +357,39 @@ static phys_addr_t mtk_iommu_iova_to_phys(struct iommu_domain *domain,

static const struct iommu_ops mtk_iommu_ops;

-/*
- * MTK generation one iommu HW only support one iommu domain, and all the client
- * sharing the same iova address space.
- */
-static int mtk_iommu_create_mapping(struct device *dev,
- struct of_phandle_args *args)
+static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
{
struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
struct mtk_iommu_data *data;
+
+ if (!fwspec || fwspec->ops != &mtk_iommu_ops)
+ return ERR_PTR(-ENODEV); /* Not a iommu client device */
+
+ data = dev_iommu_priv_get(dev);
+
+ return &data->iommu;
+}
+
+static void mtk_iommu_release_device(struct device *dev)
+{
+ struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+ if (!fwspec || fwspec->ops != &mtk_iommu_ops)
+ return;
+
+ iommu_fwspec_free(dev);
+}
+
+static struct iommu_group *mtk_iommu_device_group(struct device *dev)
+{
+ struct mtk_iommu_data *data = dev_iommu_priv_get(dev);
+
+ return iommu_group_ref_get(data->m4u_group);
+}
+
+static int mtk_iommu_of_xlate(struct device *dev, struct of_phandle_args *args)
+{
struct platform_device *m4updev;
- struct dma_iommu_mapping *mtk_mapping;
- int ret;

if (args->args_count != 1) {
dev_err(dev, "invalid #iommu-cells(%d) property for IOMMU\n",
@@ -377,15 +397,6 @@ static int mtk_iommu_create_mapping(struct device *dev,
return -EINVAL;
}

- if (!fwspec) {
- ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_ops);
- if (ret)
- return ret;
- fwspec = dev_iommu_fwspec_get(dev);
- } else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_ops) {
- return -EINVAL;
- }
-
if (!dev_iommu_priv_get(dev)) {
/* Get the m4u device */
m4updev = of_find_device_by_node(args->np);
@@ -395,83 +406,7 @@ static int mtk_iommu_create_mapping(struct device *dev,
dev_iommu_priv_set(dev, platform_get_drvdata(m4updev));
}

- ret = iommu_fwspec_add_ids(dev, args->args, 1);
- if (ret)
- return ret;
-
- data = dev_iommu_priv_get(dev);
- mtk_mapping = data->mapping;
- if (!mtk_mapping) {
- /* MTK iommu support 4GB iova address space. */
- mtk_mapping = arm_iommu_create_mapping(&platform_bus_type,
- 0, 1ULL << 32);
- if (IS_ERR(mtk_mapping))
- return PTR_ERR(mtk_mapping);
-
- data->mapping = mtk_mapping;
- }
-
- return 0;
-}
-
-static int mtk_iommu_def_domain_type(struct device *dev)
-{
- return IOMMU_DOMAIN_UNMANAGED;
-}
-
-static struct iommu_device *mtk_iommu_probe_device(struct device *dev)
-{
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
- struct of_phandle_args iommu_spec;
- struct of_phandle_iterator it;
- struct mtk_iommu_data *data;
- int err;
-
- of_for_each_phandle(&it, err, dev->of_node, "iommus",
- "#iommu-cells", -1) {
- int count = of_phandle_iterator_args(&it, iommu_spec.args,
- MAX_PHANDLE_ARGS);
- iommu_spec.np = of_node_get(it.node);
- iommu_spec.args_count = count;
-
- mtk_iommu_create_mapping(dev, &iommu_spec);
-
- /* dev->iommu_fwspec might have changed */
- fwspec = dev_iommu_fwspec_get(dev);
-
- of_node_put(iommu_spec.np);
- }
-
- if (!fwspec || fwspec->ops != &mtk_iommu_ops)
- return ERR_PTR(-ENODEV); /* Not a iommu client device */
-
- data = dev_iommu_priv_get(dev);
-
- return &data->iommu;
-}
-
-static void mtk_iommu_probe_finalize(struct device *dev)
-{
- struct dma_iommu_mapping *mtk_mapping;
- struct mtk_iommu_data *data;
- int err;
-
- data = dev_iommu_priv_get(dev);
- mtk_mapping = data->mapping;
-
- err = arm_iommu_attach_device(dev, mtk_mapping);
- if (err)
- dev_err(dev, "Can't create IOMMU mapping - DMA-OPS will not work\n");
-}
-
-static void mtk_iommu_release_device(struct device *dev)
-{
- struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-
- if (!fwspec || fwspec->ops != &mtk_iommu_ops)
- return;
-
- iommu_fwspec_free(dev);
+ return iommu_fwspec_add_ids(dev, args->args, 1);
}

static int mtk_iommu_hw_init(const struct mtk_iommu_data *data)
@@ -524,10 +459,9 @@ static const struct iommu_ops mtk_iommu_ops = {
.unmap = mtk_iommu_unmap,
.iova_to_phys = mtk_iommu_iova_to_phys,
.probe_device = mtk_iommu_probe_device,
- .probe_finalize = mtk_iommu_probe_finalize,
.release_device = mtk_iommu_release_device,
- .def_domain_type = mtk_iommu_def_domain_type,
- .device_group = generic_device_group,
+ .device_group = mtk_iommu_device_group,
+ .of_xlate = mtk_iommu_of_xlate,
.pgsize_bitmap = ~0UL << MT2701_IOMMU_PAGE_SHIFT,
};

@@ -626,6 +560,14 @@ static int mtk_iommu_probe(struct platform_device *pdev)
if (ret)
return ret;

+ /*
+ * MTK generation one iommu HW only support one iommu domain,
+ * and all the client sharing the same iova address space.
+ */
+ data->m4u_group = iommu_group_alloc();
+ if (IS_ERR(data->m4u_group))
+ return PTR_ERR(data->m4u_group);
+
if (!iommu_present(&platform_bus_type))
bus_set_iommu(&platform_bus_type, &mtk_iommu_ops);

@@ -636,6 +578,7 @@ static int mtk_iommu_remove(struct platform_device *pdev)
{
struct mtk_iommu_data *data = platform_get_drvdata(pdev);

+ iommu_group_put(data->m4u_group);
iommu_device_sysfs_remove(&data->iommu);
iommu_device_unregister(&data->iommu);

--
2.28.0.dirty