[PATCH v3 32/34] iommu: Remove add_device()/remove_device() code-paths

Joerg Roedel
2020-04-29T13:38:34Z

All drivers are converted to use the probe/release_device()
call-backs, so the add_device/remove_device() pointers are unused and
the code using them can be removed.

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 | 158 ++++++++++--------------------------------
include/linux/iommu.h | 4 --
2 files changed, 38 insertions(+), 124 deletions(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 397fd4fd0c32..7f99e5ae432c 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -220,12 +220,20 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
return ret;
}

-static int __iommu_probe_device_helper(struct device *dev)
+int iommu_probe_device(struct device *dev)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
struct iommu_group *group;
int ret;

+ if (!dev_iommu_get(dev))
+ return -ENOMEM;
+
+ if (!try_module_get(ops->owner)) {
+ ret = -EINVAL;
+ goto err_out;
+ }
+
ret = __iommu_probe_device(dev, NULL);
if (ret)
goto err_out;
@@ -259,75 +267,23 @@ static int __iommu_probe_device_helper(struct device *dev)

err_release:
iommu_release_device(dev);
+
err_out:
return ret;

}

-int iommu_probe_device(struct device *dev)
+void iommu_release_device(struct device *dev)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
- struct iommu_group *group;
- int ret;
-
- WARN_ON(dev->iommu_group);
-
- if (!ops)
- return -EINVAL;
-
- if (!dev_iommu_get(dev))
- return -ENOMEM;
-
- if (!try_module_get(ops->owner)) {
- ret = -EINVAL;
- goto err_free_dev_param;
- }
-
- if (ops->probe_device)
- return __iommu_probe_device_helper(dev);
-
- ret = ops->add_device(dev);
- if (ret)
- goto err_module_put;

- group = iommu_group_get(dev);
- iommu_create_device_direct_mappings(group, dev);
- iommu_group_put(group);
-
- if (ops->probe_finalize)
- ops->probe_finalize(dev);
-
- return 0;
-
-err_module_put:
- module_put(ops->owner);
-err_free_dev_param:
- dev_iommu_free(dev);
- return ret;
-}
-
-static void __iommu_release_device(struct device *dev)
-{
- const struct iommu_ops *ops = dev->bus->iommu_ops;
+ if (!dev->iommu)
+ return;

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

module_put(ops->owner);
dev_iommu_free(dev);
@@ -1560,23 +1516,6 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
if (ret)
goto out_put_group;

- /*
- * Try to allocate a default domain - needs support from the
- * IOMMU driver. There are still some drivers which don't support
- * default domains, so the return value is not yet checked. Only
- * allocate the domain here when the driver still has the
- * add_device/remove_device call-backs implemented.
- */
- if (!ops->probe_device) {
- iommu_alloc_default_domain(dev);
-
- if (group->default_domain)
- ret = __iommu_attach_device(group->default_domain, dev);
-
- if (ret)
- goto out_put_group;
- }
-
return group;

out_put_group:
@@ -1591,21 +1530,6 @@ struct iommu_domain *iommu_group_default_domain(struct iommu_group *group)
return group->default_domain;
}

-static int add_iommu_group(struct device *dev, void *data)
-{
- int ret = iommu_probe_device(dev);
-
- /*
- * We ignore -ENODEV errors for now, as they just mean that the
- * device is not translated by an IOMMU. We still care about
- * other errors and fail to initialize when they happen.
- */
- if (ret == -ENODEV)
- ret = 0;
-
- return ret;
-}
-
static int probe_iommu_group(struct device *dev, void *data)
{
const struct iommu_ops *ops = dev->bus->iommu_ops;
@@ -1793,47 +1717,41 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group)

int bus_iommu_probe(struct bus_type *bus)
{
- const struct iommu_ops *ops = bus->iommu_ops;
+ struct iommu_group *group, *next;
+ LIST_HEAD(group_list);
int ret;

- if (ops->probe_device) {
- struct iommu_group *group, *next;
- LIST_HEAD(group_list);
-
- /*
- * This code-path does not allocate the default domain when
- * creating the iommu group, so do it after the groups are
- * created.
- */
- ret = bus_for_each_dev(bus, NULL, &group_list, probe_iommu_group);
- if (ret)
- return ret;
+ /*
+ * This code-path does not allocate the default domain when
+ * creating the iommu group, so do it after the groups are
+ * created.
+ */
+ ret = bus_for_each_dev(bus, NULL, &group_list, probe_iommu_group);
+ if (ret)
+ return ret;

- list_for_each_entry_safe(group, next, &group_list, entry) {
- /* Remove item from the list */
- list_del_init(&group->entry);
+ list_for_each_entry_safe(group, next, &group_list, entry) {
+ /* Remove item from the list */
+ list_del_init(&group->entry);

- mutex_lock(&group->mutex);
+ mutex_lock(&group->mutex);

- /* Try to allocate default domain */
- probe_alloc_default_domain(bus, group);
+ /* Try to allocate default domain */
+ probe_alloc_default_domain(bus, group);

- if (!group->default_domain) {
- mutex_unlock(&group->mutex);
- continue;
- }
+ if (!group->default_domain) {
+ mutex_unlock(&group->mutex);
+ continue;
+ }

- iommu_group_create_direct_mappings(group);
+ iommu_group_create_direct_mappings(group);

- ret = __iommu_group_dma_attach(group);
+ ret = __iommu_group_dma_attach(group);

- mutex_unlock(&group->mutex);
+ mutex_unlock(&group->mutex);

- if (ret)
- break;
- }
- } else {
- ret = bus_for_each_dev(bus, NULL, NULL, add_iommu_group);
+ if (ret)
+ break;
}

return ret;
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index fea1622408ad..dd076366383f 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -223,8 +223,6 @@ struct iommu_iotlb_gather {
* @iotlb_sync: Flush all queued ranges from the hardware TLBs and empty flush
* queue
* @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
@@ -277,8 +275,6 @@ struct iommu_ops {
void (*iotlb_sync)(struct iommu_domain *domain,
struct iommu_iotlb_gather *iotlb_gather);
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);