2 files changed, 212 insertions, 0 deletions

diff --git a/include/net/switchdev.h b/include/net/switchdev.h
index 97b556daeef7..282043844bcf 100644
--- a/include/net/switchdev.h
+++ b/include/net/switchdev.h
@@ -14,6 +14,25 @@
 #include <linux/netdevice.h>
 #include <linux/notifier.h>
 
+#define SWITCHDEV_F_NO_RECURSE          BIT(0)
+
+enum switchdev_trans {
+        SWITCHDEV_TRANS_NONE,
+        SWITCHDEV_TRANS_PREPARE,
+        SWITCHDEV_TRANS_ABORT,
+        SWITCHDEV_TRANS_COMMIT,
+};
+
+enum switchdev_attr_id {
+        SWITCHDEV_ATTR_UNDEFINED,
+};
+
+struct switchdev_attr {
+        enum switchdev_attr_id id;
+        enum switchdev_trans trans;
+        u32 flags;
+};
+
 struct fib_info;
 
 /**
@@ -23,6 +42,10 @@ struct fib_info;
  *   is part of.  If driver implements this, it indicates that it
  *   represents a port of a switch chip.
  *
+ * @switchdev_port_attr_get: Get a port attribute (see switchdev_attr).
+ *
+ * @switchdev_port_attr_set: Set a port attribute (see switchdev_attr).
+ *
  * @switchdev_port_stp_update: Called to notify switch device port of bridge
  *   port STP state change.
  *
@@ -33,6 +56,10 @@ struct fib_info;
 struct switchdev_ops {
         int     (*switchdev_parent_id_get)(struct net_device *dev,
                                            struct netdev_phys_item_id *psid);
+        int     (*switchdev_port_attr_get)(struct net_device *dev,
+                                           struct switchdev_attr *attr);
+        int     (*switchdev_port_attr_set)(struct net_device *dev,
+                                           struct switchdev_attr *attr);
         int     (*switchdev_port_stp_update)(struct net_device *dev, u8 state);
         int     (*switchdev_fib_ipv4_add)(struct net_device *dev, __be32 dst,
                                           int dst_len, struct fib_info *fi,
@@ -68,6 +95,10 @@ switchdev_notifier_info_to_dev(const struct switchdev_notifier_info *info)
 
 int switchdev_parent_id_get(struct net_device *dev,
                             struct netdev_phys_item_id *psid);
+int switchdev_port_attr_get(struct net_device *dev,
+                            struct switchdev_attr *attr);
+int switchdev_port_attr_set(struct net_device *dev,
+                            struct switchdev_attr *attr);
 int switchdev_port_stp_update(struct net_device *dev, u8 state);
 int register_switchdev_notifier(struct notifier_block *nb);
 int unregister_switchdev_notifier(struct notifier_block *nb);
@@ -95,6 +126,18 @@ static inline int switchdev_parent_id_get(struct net_device *dev,
         return -EOPNOTSUPP;
 }
 
+static inline int switchdev_port_attr_get(struct net_device *dev,
+                                          struct switchdev_attr *attr)
+{
+        return -EOPNOTSUPP;
+}
+
+static inline int switchdev_port_attr_set(struct net_device *dev,
+                                          struct switchdev_attr *attr)
+{
+        return -EOPNOTSUPP;
+}
+
 static inline int switchdev_port_stp_update(struct net_device *dev,
                                             u8 state)
 {
diff --git a/net/switchdev/switchdev.c b/net/switchdev/switchdev.c
index b7f44a23def5..8f47187dc185 100644
--- a/net/switchdev/switchdev.c
+++ b/net/switchdev/switchdev.c
@@ -37,6 +37,175 @@ int switchdev_parent_id_get(struct net_device *dev,
 EXPORT_SYMBOL_GPL(switchdev_parent_id_get);
 
 /**
+ *      switchdev_port_attr_get - Get port attribute
+ *
+ *      @dev: port device
+ *      @attr: attribute to get
+ */
+int switchdev_port_attr_get(struct net_device *dev, struct switchdev_attr *attr)
+{
+        const struct switchdev_ops *ops = dev->switchdev_ops;
+        struct net_device *lower_dev;
+        struct list_head *iter;
+        struct switchdev_attr first = {
+                .id = SWITCHDEV_ATTR_UNDEFINED
+        };
+        int err = -EOPNOTSUPP;
+
+        if (ops && ops->switchdev_port_attr_get)
+                return ops->switchdev_port_attr_get(dev, attr);
+
+        if (attr->flags & SWITCHDEV_F_NO_RECURSE)
+                return err;
+
+        /* Switch device port(s) may be stacked under
+         * bond/team/vlan dev, so recurse down to get attr on
+         * each port.  Return -ENODATA if attr values don't
+         * compare across ports.
+         */
+
+        netdev_for_each_lower_dev(dev, lower_dev, iter) {
+                err = switchdev_port_attr_get(lower_dev, attr);
+                if (err)
+                        break;
+                if (first.id == SWITCHDEV_ATTR_UNDEFINED)
+                        first = *attr;
+                else if (memcmp(&first, attr, sizeof(*attr)))
+                        return -ENODATA;
+        }
+
+        return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_port_attr_get);
+
+static int __switchdev_port_attr_set(struct net_device *dev,
+                                     struct switchdev_attr *attr)
+{
+        const struct switchdev_ops *ops = dev->switchdev_ops;
+        struct net_device *lower_dev;
+        struct list_head *iter;
+        int err = -EOPNOTSUPP;
+
+        if (ops && ops->switchdev_port_attr_set)
+                return ops->switchdev_port_attr_set(dev, attr);
+
+        if (attr->flags & SWITCHDEV_F_NO_RECURSE)
+                return err;
+
+        /* Switch device port(s) may be stacked under
+         * bond/team/vlan dev, so recurse down to set attr on
+         * each port.
+         */
+
+        netdev_for_each_lower_dev(dev, lower_dev, iter) {
+                err = __switchdev_port_attr_set(lower_dev, attr);
+                if (err)
+                        break;
+        }
+
+        return err;
+}
+
+struct switchdev_attr_set_work {
+        struct work_struct work;
+        struct net_device *dev;
+        struct switchdev_attr attr;
+};
+
+static void switchdev_port_attr_set_work(struct work_struct *work)
+{
+        struct switchdev_attr_set_work *asw =
+                container_of(work, struct switchdev_attr_set_work, work);
+        int err;
+
+        rtnl_lock();
+        err = switchdev_port_attr_set(asw->dev, &asw->attr);
+        BUG_ON(err);
+        rtnl_unlock();
+
+        dev_put(asw->dev);
+        kfree(work);
+}
+
+static int switchdev_port_attr_set_defer(struct net_device *dev,
+                                         struct switchdev_attr *attr)
+{
+        struct switchdev_attr_set_work *asw;
+
+        asw = kmalloc(sizeof(*asw), GFP_ATOMIC);
+        if (!asw)
+                return -ENOMEM;
+
+        INIT_WORK(&asw->work, switchdev_port_attr_set_work);
+
+        dev_hold(dev);
+        asw->dev = dev;
+        memcpy(&asw->attr, attr, sizeof(asw->attr));
+
+        schedule_work(&asw->work);
+
+        return 0;
+}
+
+/**
+ *      switchdev_port_attr_set - Set port attribute
+ *
+ *      @dev: port device
+ *      @attr: attribute to set
+ *
+ *      Use a 2-phase prepare-commit transaction model to ensure
+ *      system is not left in a partially updated state due to
+ *      failure from driver/device.
+ */
+int switchdev_port_attr_set(struct net_device *dev, struct switchdev_attr *attr)
+{
+        int err;
+
+        if (!rtnl_is_locked()) {
+                /* Running prepare-commit transaction across stacked
+                 * devices requires nothing moves, so if rtnl_lock is
+                 * not held, schedule a worker thread to hold rtnl_lock
+                 * while setting attr.
+                 */
+
+                return switchdev_port_attr_set_defer(dev, attr);
+        }
+
+        /* 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
+         * should reserve resources needed for the commit phase here,
+         * but should not commit the attr.
+         */
+
+        attr->trans = SWITCHDEV_TRANS_PREPARE;
+        err = __switchdev_port_attr_set(dev, attr);
+        if (err) {
+                /* Prepare phase failed: abort the transaction.  Any
+                 * resources reserved in the prepare phase are
+                 * released.
+                 */
+
+                attr->trans = SWITCHDEV_TRANS_ABORT;
+                __switchdev_port_attr_set(dev, attr);
+
+                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
+         * because the driver said everythings was OK in phase I.
+         */
+
+        attr->trans = SWITCHDEV_TRANS_COMMIT;
+        err = __switchdev_port_attr_set(dev, attr);
+        BUG_ON(err);
+
+        return err;
+}
+EXPORT_SYMBOL_GPL(switchdev_port_attr_set);
+
+/**
  *      switchdev_port_stp_update - Notify switch device port of STP
  *                                      state change
  *      @dev: port device