[PATCH v3 17/18] iommu: Remove iommu group changes notifier

Lu Baolu
2021-12-06T02:01:38Z

The iommu group changes notifer is not referenced in the tree. Remove it
to avoid dead code.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
include/linux/iommu.h | 23 -------------
drivers/iommu/iommu.c | 75 -------------------------------------------
2 files changed, 98 deletions(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 8c81ba11ae8c..e7eeac801bcd 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -419,13 +419,6 @@ static inline void iommu_iotlb_gather_init(struct iommu_iotlb_gather *gather)
};
}

-#define IOMMU_GROUP_NOTIFY_ADD_DEVICE 1 /* Device added */
-#define IOMMU_GROUP_NOTIFY_DEL_DEVICE 2 /* Pre Device removed */
-#define IOMMU_GROUP_NOTIFY_BIND_DRIVER 3 /* Pre Driver bind */
-#define IOMMU_GROUP_NOTIFY_BOUND_DRIVER 4 /* Post Driver bind */
-#define IOMMU_GROUP_NOTIFY_UNBIND_DRIVER 5 /* Pre Driver unbind */
-#define IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER 6 /* Post Driver unbind */
-
extern int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops);
extern int bus_iommu_probe(struct bus_type *bus);
extern bool iommu_present(struct bus_type *bus);
@@ -498,10 +491,6 @@ extern int iommu_group_for_each_dev(struct iommu_group *group, void *data,
extern struct iommu_group *iommu_group_get(struct device *dev);
extern struct iommu_group *iommu_group_ref_get(struct iommu_group *group);
extern void iommu_group_put(struct iommu_group *group);
-extern int iommu_group_register_notifier(struct iommu_group *group,
- struct notifier_block *nb);
-extern int iommu_group_unregister_notifier(struct iommu_group *group,
- struct notifier_block *nb);
extern int iommu_register_device_fault_handler(struct device *dev,
iommu_dev_fault_handler_t handler,
void *data);
@@ -915,18 +904,6 @@ static inline void iommu_group_put(struct iommu_group *group)
{
}

-static inline int iommu_group_register_notifier(struct iommu_group *group,
- struct notifier_block *nb)
-{
- return -ENODEV;
-}
-
-static inline int iommu_group_unregister_notifier(struct iommu_group *group,
- struct notifier_block *nb)
-{
- return 0;
-}
-
static inline
int iommu_register_device_fault_handler(struct device *dev,
iommu_dev_fault_handler_t handler,
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 6dc6e6ad6069..6f122e656ccb 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -18,7 +18,6 @@
#include <linux/errno.h>
#include <linux/iommu.h>
#include <linux/idr.h>
-#include <linux/notifier.h>
#include <linux/err.h>
#include <linux/pci.h>
#include <linux/bitops.h>
@@ -40,7 +39,6 @@ struct iommu_group {
struct kobject *devices_kobj;
struct list_head devices;
struct mutex mutex;
- struct blocking_notifier_head notifier;
void *iommu_data;
void (*iommu_data_release)(void *iommu_data);
char *name;
@@ -629,7 +627,6 @@ struct iommu_group *iommu_group_alloc(void)
mutex_init(&group->mutex);
INIT_LIST_HEAD(&group->devices);
INIT_LIST_HEAD(&group->entry);
- BLOCKING_INIT_NOTIFIER_HEAD(&group->notifier);
group->dma_owner = DMA_OWNER_NONE;

ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL);
@@ -905,10 +902,6 @@ int iommu_group_add_device(struct iommu_group *group, struct device *dev)
if (ret)
goto err_put_group;

- /* Notify any listeners about change to group. */
- blocking_notifier_call_chain(&group->notifier,
- IOMMU_GROUP_NOTIFY_ADD_DEVICE, dev);
-
trace_add_device_to_group(group->id, dev);

dev_info(dev, "Adding to iommu group %d\n", group->id);
@@ -950,10 +943,6 @@ void iommu_group_remove_device(struct device *dev)

dev_info(dev, "Removing from iommu group %d\n", group->id);

- /* Pre-notify listeners that a device is being removed. */
- blocking_notifier_call_chain(&group->notifier,
- IOMMU_GROUP_NOTIFY_DEL_DEVICE, dev);
-
mutex_lock(&group->mutex);
list_for_each_entry(tmp_device, &group->devices, list) {
if (tmp_device->dev == dev) {
@@ -1076,36 +1065,6 @@ void iommu_group_put(struct iommu_group *group)
}
EXPORT_SYMBOL_GPL(iommu_group_put);

-/**
- * iommu_group_register_notifier - Register a notifier for group changes
- * @group: the group to watch
- * @nb: notifier block to signal
- *
- * This function allows iommu group users to track changes in a group.
- * See include/linux/iommu.h for actions sent via this notifier. Caller
- * should hold a reference to the group throughout notifier registration.
- */
-int iommu_group_register_notifier(struct iommu_group *group,
- struct notifier_block *nb)
-{
- return blocking_notifier_chain_register(&group->notifier, nb);
-}
-EXPORT_SYMBOL_GPL(iommu_group_register_notifier);
-
-/**
- * iommu_group_unregister_notifier - Unregister a notifier
- * @group: the group to watch
- * @nb: notifier block to signal
- *
- * Unregister a previously registered group notifier block.
- */
-int iommu_group_unregister_notifier(struct iommu_group *group,
- struct notifier_block *nb)
-{
- return blocking_notifier_chain_unregister(&group->notifier, nb);
-}
-EXPORT_SYMBOL_GPL(iommu_group_unregister_notifier);
-
/**
* iommu_register_device_fault_handler() - Register a device fault handler
* @dev: the device
@@ -1654,14 +1613,8 @@ static int remove_iommu_group(struct device *dev, void *data)
static int iommu_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data)
{
- unsigned long group_action = 0;
struct device *dev = data;
- struct iommu_group *group;

- /*
- * ADD/DEL call into iommu driver ops if provided, which may
- * result in ADD/DEL notifiers to group->notifier
- */
if (action == BUS_NOTIFY_ADD_DEVICE) {
int ret;

@@ -1672,34 +1625,6 @@ static int iommu_bus_notifier(struct notifier_block *nb,
return NOTIFY_OK;
}

- /*
- * Remaining BUS_NOTIFYs get filtered and republished to the
- * group, if anyone is listening
- */
- group = iommu_group_get(dev);
- if (!group)
- return 0;
-
- switch (action) {
- case BUS_NOTIFY_BIND_DRIVER:
- group_action = IOMMU_GROUP_NOTIFY_BIND_DRIVER;
- break;
- case BUS_NOTIFY_BOUND_DRIVER:
- group_action = IOMMU_GROUP_NOTIFY_BOUND_DRIVER;
- break;
- case BUS_NOTIFY_UNBIND_DRIVER:
- group_action = IOMMU_GROUP_NOTIFY_UNBIND_DRIVER;
- break;
- case BUS_NOTIFY_UNBOUND_DRIVER:
- group_action = IOMMU_GROUP_NOTIFY_UNBOUND_DRIVER;
- break;
- }
-
- if (group_action)
- blocking_notifier_call_chain(&group->notifier,
- group_action, dev);
-
- iommu_group_put(group);
return 0;
}

--
2.25.1