[PATCH v3 07/34] iommu: Add probe_device() and release_device() call-backs

Joerg Roedel
2020-04-29T13:40:26Z

Add call-backs to 'struct iommu_ops' as an alternative to the
add_device() and remove_device() call-backs, which will be removed when
all drivers are converted.

The new call-backs will not setup IOMMU groups and domains anymore,
so also add a probe_finalize() call-back where the IOMMU driver can do
per-device setup work which require the device to be set up with a
group and a domain.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/iommu.c | 63 ++++++++++++++++++++++++++++++++++++++-----
include/linux/iommu.h | 9 +++++++
2 files changed, 66 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5877abd9b693..6cfe7799dc8c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -174,6 +174,36 @@ static void dev_iommu_free(struct device *dev)
dev->iommu = NULL;
}

+static int __iommu_probe_device(struct device *dev)
+{
+ const struct iommu_ops *ops = dev->bus->iommu_ops;
+ struct iommu_device *iommu_dev;
+ struct iommu_group *group;
+ int ret;
+
+ iommu_dev = ops->probe_device(dev);
+ if (IS_ERR(iommu_dev))
+ return PTR_ERR(iommu_dev);
+
+ dev->iommu->iommu_dev = iommu_dev;
+
+ group = iommu_group_get_for_dev(dev);
+ if (!IS_ERR(group)) {
+ ret = PTR_ERR(group);
+ goto out_release;
+ }
+ iommu_group_put(group);
+
+ iommu_device_link(iommu_dev, dev);
+
+ return 0;
+
+out_release:
+ ops->release_device(dev);
+
+ return ret;
+}
+
int iommu_probe_device(struct device *dev)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
@@ -191,10 +221,17 @@ int iommu_probe_device(struct device *dev)
goto err_free_dev_param;
}

- ret = ops->add_device(dev);
+ if (ops->probe_device)
+ ret = __iommu_probe_device(dev);
+ else
+ ret = ops->add_device(dev);
+
if (ret)
goto err_module_put;

+ if (ops->probe_finalize)
+ ops->probe_finalize(dev);
+
return 0;

err_module_put:
@@ -204,17 +241,31 @@ int iommu_probe_device(struct device *dev)
return ret;
}

+static void __iommu_release_device(struct device *dev)
+{
+ const struct iommu_ops *ops = dev->bus->iommu_ops;
+
+ iommu_device_unlink(dev->iommu->iommu_dev, dev);
+
+ iommu_group_remove_device(dev);
+
+ ops->release_device(dev);
+}
+
void iommu_release_device(struct device *dev)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;

- if (dev->iommu_group)
+ if (!dev->iommu)
+ return;
+
+ if (ops->release_device)
+ __iommu_release_device(dev);
+ else if (dev->iommu_group)
ops->remove_device(dev);

- if (dev->iommu) {
- module_put(ops->owner);
- dev_iommu_free(dev);
- }
+ module_put(ops->owner);
+ dev_iommu_free(dev);
}

static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 1f027b07e499..30170d191e5e 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -225,6 +225,10 @@ struct iommu_iotlb_gather {
* @iova_to_phys: translate iova to physical address
* @add_device: add device to iommu grouping
* @remove_device: remove device from iommu grouping
+ * @probe_device: Add device to iommu driver handling
+ * @release_device: Remove device from iommu driver handling
+ * @probe_finalize: Do final setup work after the device is added to an IOMMU
+ * group and attached to the groups domain
* @device_group: find iommu group for a particular device
* @domain_get_attr: Query domain attributes
* @domain_set_attr: Change domain attributes
@@ -275,6 +279,9 @@ struct iommu_ops {
phys_addr_t (*iova_to_phys)(struct iommu_domain *domain, dma_addr_t iova);
int (*add_device)(struct device *dev);
void (*remove_device)(struct device *dev);
+ struct iommu_device *(*probe_device)(struct device *dev);
+ void (*release_device)(struct device *dev);
+ void (*probe_finalize)(struct device *dev);
struct iommu_group *(*device_group)(struct device *dev);
int (*domain_get_attr)(struct iommu_domain *domain,
enum iommu_attr attr, void *data);
@@ -375,6 +382,7 @@ struct iommu_fault_param {
*
* @fault_param: IOMMU detected device fault reporting data
* @fwspec: IOMMU fwspec data
+ * @iommu_dev: IOMMU device this device is linked to
* @priv: IOMMU Driver private data
*
* TODO: migrate other per device data pointers under iommu_dev_data, e.g.
@@ -384,6 +392,7 @@ struct dev_iommu {
struct mutex lock;
struct iommu_fault_param *fault_param;
struct iommu_fwspec *fwspec;
+ struct iommu_device *iommu_dev;
void *priv;
};

--
2.17.1