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switchdev: Remove unused transaction item queue

Browse source 
There are no more in tree users of the
switchdev_trans_item_{dequeue,enqueue} or switchdev_trans_item structure
in the kernel since commit 00fc0c51e3 ("rocker: Change world_ops API
and implementation to be switchdev independant").

Remove this unused code and update the documentation accordingly since.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Florian Fainelli 2019-02-27 16:29:16 -08:00 committed by David S. Miller
parent 9bfc445e0e
commit 91cf8eceff
3 changed files with 2 additions and 129 deletions
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19
Documentation/networking/switchdev.txt
View file

@ -371,22 +371,3 @@ The driver can monitor for updates to arp_tbl using the netevent notifier
NETEVENT_NEIGH_UPDATE. The device can be programmed with resolved nexthops
for the routes as arp_tbl updates. The driver implements ndo_neigh_destroy
to know when arp_tbl neighbor entries are purged from the port.
Transaction item queue
^^^^^^^^^^^^^^^^^^^^^^
For switchdev ops attr_set and obj_add, there is a 2 phase transaction model
used. First phase is to "prepare" anything needed, including various checks,
memory allocation, etc. The goal is to handle the stuff that is not unlikely
to fail here. The second phase is to "commit" the actual changes.
Switchdev provides an infrastructure for sharing items (for example memory
allocations) between the two phases.
The object created by a driver in "prepare" phase and it is queued up by:
switchdev_trans_item_enqueue()
During the "commit" phase, the driver gets the object by:
switchdev_trans_item_dequeue()
If a transaction is aborted during "prepare" phase, switchdev code will handle
cleanup of the queued-up objects.

12
include/net/switchdev.h
View file

@ -20,14 +20,7 @@
#define SWITCHDEV_F_SKIP_EOPNOTSUPP BIT(1)
#define SWITCHDEV_F_DEFER BIT(2)
struct switchdev_trans_item {
struct list_head list;
void *data;
void (*destructor)(const void *data);
};
struct switchdev_trans {
struct list_head item_list;
bool ph_prepare;
};
@ -105,11 +98,6 @@ struct switchdev_obj_port_mdb {
#define SWITCHDEV_OBJ_PORT_MDB(OBJ) \
container_of((OBJ), struct switchdev_obj_port_mdb, obj)
void switchdev_trans_item_enqueue(struct switchdev_trans *trans,
void *data, void (*destructor)(void const *),
struct switchdev_trans_item *tritem);
void *switchdev_trans_item_dequeue(struct switchdev_trans *trans);
typedef int switchdev_obj_dump_cb_t(struct switchdev_obj *obj);
enum switchdev_notifier_type {

100
net/switchdev/switchdev.c
View file

@ -23,78 +23,6 @@
#include <linux/rtnetlink.h>
#include <net/switchdev.h>
/**
* switchdev_trans_item_enqueue - Enqueue data item to transaction queue
*
* @trans: transaction
* @data: pointer to data being queued
* @destructor: data destructor
* @tritem: transaction item being queued
*
* Enqeueue data item to transaction queue. tritem is typically placed in
* cointainter pointed at by data pointer. Destructor is called on
* transaction abort and after successful commit phase in case
* the caller did not dequeue the item before.
*/
void switchdev_trans_item_enqueue(struct switchdev_trans *trans,
void *data, void (*destructor)(void const *),
struct switchdev_trans_item *tritem)
{
tritem->data = data;
tritem->destructor = destructor;
list_add_tail(&tritem->list, &trans->item_list);
}
EXPORT_SYMBOL_GPL(switchdev_trans_item_enqueue);
static struct switchdev_trans_item *
__switchdev_trans_item_dequeue(struct switchdev_trans *trans)
{
struct switchdev_trans_item *tritem;
if (list_empty(&trans->item_list))
return NULL;
tritem = list_first_entry(&trans->item_list,
struct switchdev_trans_item, list);
list_del(&tritem->list);
return tritem;
}
/**
* switchdev_trans_item_dequeue - Dequeue data item from transaction queue
*
* @trans: transaction
*/
void *switchdev_trans_item_dequeue(struct switchdev_trans *trans)
{
struct switchdev_trans_item *tritem;
tritem = __switchdev_trans_item_dequeue(trans);
BUG_ON(!tritem);
return tritem->data;
}
EXPORT_SYMBOL_GPL(switchdev_trans_item_dequeue);
static void switchdev_trans_init(struct switchdev_trans *trans)
{
INIT_LIST_HEAD(&trans->item_list);
}
static void switchdev_trans_items_destroy(struct switchdev_trans *trans)
{
struct switchdev_trans_item *tritem;
while ((tritem = __switchdev_trans_item_dequeue(trans)))
tritem->destructor(tritem->data);
}
static void switchdev_trans_items_warn_destroy(struct net_device *dev,
struct switchdev_trans *trans)
{
WARN(!list_empty(&trans->item_list), "%s: transaction item queue is not empty.\n",
dev->name);
switchdev_trans_items_destroy(trans);
}
static LIST_HEAD(deferred);
static DEFINE_SPINLOCK(deferred_lock);
@ -208,8 +136,6 @@ static int switchdev_port_attr_set_now(struct net_device *dev,
struct switchdev_trans trans;
int err;
switchdev_trans_init(&trans);
/* Phase I: prepare for attr set. Driver/device should fail
* here if there are going to be issues in the commit phase,
* such as lack of resources or support. The driver/device
@ -220,17 +146,8 @@ static int switchdev_port_attr_set_now(struct net_device *dev,
trans.ph_prepare = true;
err = switchdev_port_attr_notify(SWITCHDEV_PORT_ATTR_SET, dev, attr,
&trans);
if (err) {
/* Prepare phase failed: abort the transaction. Any
* resources reserved in the prepare phase are
* released.
*/
if (err != -EOPNOTSUPP)
switchdev_trans_items_destroy(&trans);
if (err)
return err;
}
/* Phase II: commit attr set. This cannot fail as a fault
* of driver/device. If it does, it's a bug in the driver/device
@ -242,7 +159,6 @@ static int switchdev_port_attr_set_now(struct net_device *dev,
&trans);
WARN(err, "%s: Commit of attribute (id=%d) failed.\n",
dev->name, attr->id);
switchdev_trans_items_warn_destroy(dev, &trans);
return err;
}
@ -341,8 +257,6 @@ static int switchdev_port_obj_add_now(struct net_device *dev,
ASSERT_RTNL();
switchdev_trans_init(&trans);
/* Phase I: prepare for obj add. Driver/device should fail
* here if there are going to be issues in the commit phase,
* such as lack of resources or support. The driver/device
@ -353,17 +267,8 @@ static int switchdev_port_obj_add_now(struct net_device *dev,
trans.ph_prepare = true;
err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
dev, obj, &trans, extack);
if (err) {
/* Prepare phase failed: abort the transaction. Any
* resources reserved in the prepare phase are
* released.
*/
if (err != -EOPNOTSUPP)
switchdev_trans_items_destroy(&trans);
if (err)
return err;
}
/* Phase II: commit obj add. This cannot fail as a fault
* of driver/device. If it does, it's a bug in the driver/device
@ -374,7 +279,6 @@ static int switchdev_port_obj_add_now(struct net_device *dev,
err = switchdev_port_obj_notify(SWITCHDEV_PORT_OBJ_ADD,
dev, obj, &trans, extack);
WARN(err, "%s: Commit of object (id=%d) failed.\n", dev->name, obj->id);
switchdev_trans_items_warn_destroy(dev, &trans);
return err;
}