exynos allocates a per-device struct in the of_xlate() that can point to
multiple instances of the iommu. It looks like each iommu instance can
point to only one device however.
Move the allocation of the per-device struct to the top of probe and use
iommu_of_xlate() to fill in the linked list. Rely on the core code to
locate the iommu.
Solve a few issues:
- A bus probe was failing by accident because the of_xlate not being
called left a NULL owner in the priv, and other code tended to free the
dev->iommu. iommu_of_xlate() will fail bus probe directly
- Missing validation that the node in the iommus instance is actually
pointing at this driver
- Don't leak the owner. It is allocated during probe, freed on probe
failure, and freed in release_device() on probe success. Previously it
would allocate it in of_xlate and leak it in some possible error flows.
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 79 +++++++++++++++++-------------------
1 file changed, 38 insertions(+), 41 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index 2c6e9094f1e979..c301aa87fe0ff0 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -13,6 +13,7 @@
#include <linux/err.h>
#include <linux/io.h>
#include <linux/iommu.h>
+#include <linux/iommu-driver.h>
#include <linux/interrupt.h>
#include <linux/kmemleak.h>
#include <linux/list.h>
@@ -26,6 +27,9 @@ typedef u32 sysmmu_iova_t;
typedef u32 sysmmu_pte_t;
static struct iommu_domain exynos_identity_domain;
+static int exynos_iommu_of_xlate(struct iommu_device *iommu,
+ struct of_phandle_args *args, void *priv);
+
/* We do not consider super section mapping (16MB) */
#define SECT_ORDER 20
#define LPAGE_ORDER 16
@@ -168,8 +172,6 @@ static u32 lv2ent_offset(sysmmu_iova_t iova)
#define REG_V7_CAPA1 0x874
#define REG_V7_CTRL_VM 0x8000
-#define has_sysmmu(dev) (dev_iommu_priv_get(dev) != NULL)
-
static struct device *dma_dev;
static struct kmem_cache *lv2table_kmem_cache;
static sysmmu_pte_t *zero_lv2_table;
@@ -779,8 +781,6 @@ static int exynos_sysmmu_probe(struct platform_device *pdev)
if (ret)
return ret;
- platform_set_drvdata(pdev, data);
-
if (PG_ENT_SHIFT < 0) {
if (MMU_MAJ_VER(data->version) < 5) {
PG_ENT_SHIFT = SYSMMU_PG_ENT_SHIFT;
@@ -1393,15 +1393,29 @@ static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *iommu_domain,
return phys;
}
-static struct iommu_device *exynos_iommu_probe_device(struct device *dev)
+static struct iommu_device *
+exynos_iommu_probe_device(struct iommu_probe_info *pinf)
{
- struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
+ struct exynos_iommu_owner *owner;
+ struct device *dev = pinf->dev;
struct sysmmu_drvdata *data;
+ int ret;
- if (!has_sysmmu(dev))
- return ERR_PTR(-ENODEV);
+ owner = kzalloc(sizeof(*owner), GFP_KERNEL);
+ if (!owner)
+ return ERR_PTR(-ENOMEM);
+
+ INIT_LIST_HEAD(&owner->controllers);
+ mutex_init(&owner->rpm_lock);
+ owner->domain = &exynos_identity_domain;
+
+ ret = iommu_of_xlate(pinf, &exynos_iommu_ops, -1,
+ &exynos_iommu_of_xlate, owner);
+ if (ret)
+ goto err_free;
list_for_each_entry(data, &owner->controllers, owner_node) {
+ data->master = dev;
/*
* SYSMMU will be runtime activated via device link
* (dependency) to its master device, so there are no
@@ -1412,11 +1426,17 @@ static struct iommu_device *exynos_iommu_probe_device(struct device *dev)
DL_FLAG_PM_RUNTIME);
}
- /* There is always at least one entry, see exynos_iommu_of_xlate() */
+ /* iommu_of_xlate() fails if there are no entries */
data = list_first_entry(&owner->controllers,
struct sysmmu_drvdata, owner_node);
+ dev_iommu_priv_set(dev, owner);
+
return &data->iommu;
+
+err_free:
+ kfree(owner);
+ return ERR_PTR(ret);
}
static void exynos_iommu_release_device(struct device *dev)
@@ -1430,42 +1450,19 @@ static void exynos_iommu_release_device(struct device *dev)
device_link_del(data->link);
}
-static int exynos_iommu_of_xlate(struct device *dev,
- struct of_phandle_args *spec)
+static int exynos_iommu_of_xlate(struct iommu_device *iommu,
+ struct of_phandle_args *args, void *priv)
{
- struct platform_device *sysmmu = of_find_device_by_node(spec->np);
- struct exynos_iommu_owner *owner = dev_iommu_priv_get(dev);
- struct sysmmu_drvdata *data, *entry;
-
- if (!sysmmu)
- return -ENODEV;
-
- data = platform_get_drvdata(sysmmu);
- if (!data) {
- put_device(&sysmmu->dev);
- return -ENODEV;
- }
-
- if (!owner) {
- owner = kzalloc(sizeof(*owner), GFP_KERNEL);
- if (!owner) {
- put_device(&sysmmu->dev);
- return -ENOMEM;
- }
-
- INIT_LIST_HEAD(&owner->controllers);
- mutex_init(&owner->rpm_lock);
- owner->domain = &exynos_identity_domain;
- dev_iommu_priv_set(dev, owner);
- }
+ struct sysmmu_drvdata *data =
+ container_of(iommu, struct sysmmu_drvdata, iommu);
+ struct exynos_iommu_owner *owner = priv;
+ struct sysmmu_drvdata *entry;
+ /* FIXME this relies on iommu_probe_device_lock */
list_for_each_entry(entry, &owner->controllers, owner_node)
if (entry == data)
return 0;
-
list_add_tail(&data->owner_node, &owner->controllers);
- data->master = dev;
-
return 0;
}
@@ -1473,10 +1470,10 @@ static const struct iommu_ops exynos_iommu_ops = {
.identity_domain = &exynos_identity_domain,
.domain_alloc_paging = exynos_iommu_domain_alloc_paging,
.device_group = generic_device_group,
- .probe_device = exynos_iommu_probe_device,
+ .probe_device_pinf = exynos_iommu_probe_device,
.release_device = exynos_iommu_release_device,
.pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
- .of_xlate = exynos_iommu_of_xlate,
+ .of_xlate = iommu_dummy_of_xlate,
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = exynos_iommu_attach_device,
.map_pages = exynos_iommu_map,
--
2.42.0
