Commit 886f8e26 authored by Vladimir Oltean's avatar Vladimir Oltean Committed by Jakub Kicinski
Browse files

net: dsa: document the existing switch tree notifiers and add a new one 

The existence of dsa_broadcast has generated some confusion in the past:
https://www.mail-archive.com/netdev@vger.kernel.org/msg365042.html



So let's document the existing dsa_port_notify and dsa_broadcast
functions and explain when each of them should be used.

Also, in fact, the in-between function has always been there but was
lacking a name, and is the main reason for this patch: dsa_tree_notify.
Refactor dsa_broadcast to use it.

This patch also moves dsa_broadcast (a top-level function) to dsa2.c,
where it really belonged in the first place, but had no companion so it
stood with dsa_port_notify.

Signed-off-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent cacea62f

net/dsa/dsa2.c

+43 −0
Original line number Diff line number Diff line
@@ -21,6 +21,49 @@ 
static DEFINE_MUTEX(dsa2_mutex);

LIST_HEAD(dsa_tree_list);



/**

 * dsa_tree_notify - Execute code for all switches in a DSA switch tree.

 * @dst: collection of struct dsa_switch devices to notify.

 * @e: event, must be of type DSA_NOTIFIER_*

 * @v: event-specific value.

 *

 * Given a struct dsa_switch_tree, this can be used to run a function once for

 * each member DSA switch. The other alternative of traversing the tree is only

 * through its ports list, which does not uniquely list the switches.

 */

int dsa_tree_notify(struct dsa_switch_tree *dst, unsigned long e, void *v)

{

	struct raw_notifier_head *nh = &dst->nh;

	int err;



	err = raw_notifier_call_chain(nh, e, v);



	return notifier_to_errno(err);

}



/**

 * dsa_broadcast - Notify all DSA trees in the system.

 * @e: event, must be of type DSA_NOTIFIER_*

 * @v: event-specific value.

 *

 * Can be used to notify the switching fabric of events such as cross-chip

 * bridging between disjoint trees (such as islands of tagger-compatible

 * switches bridged by an incompatible middle switch).

 */

int dsa_broadcast(unsigned long e, void *v)

{

	struct dsa_switch_tree *dst;

	int err = 0;



	list_for_each_entry(dst, &dsa_tree_list, list) {

		err = dsa_tree_notify(dst, e, v);

		if (err)

			break;

	}



	return err;

}



/**

 * dsa_lag_map() - Map LAG netdev to a linear LAG ID

 * @dst: Tree in which to record the mapping.

net/dsa/dsa_priv.h

+2 −0
Original line number Diff line number Diff line
@@ -283,6 +283,8 @@ void dsa_switch_unregister_notifier(struct dsa_switch *ds); 
/* dsa2.c */

void dsa_lag_map(struct dsa_switch_tree *dst, struct net_device *lag);

void dsa_lag_unmap(struct dsa_switch_tree *dst, struct net_device *lag);

int dsa_tree_notify(struct dsa_switch_tree *dst, unsigned long e, void *v);

int dsa_broadcast(unsigned long e, void *v);



extern struct list_head dsa_tree_list;

net/dsa/port.c

+13 −23
Original line number Diff line number Diff line
@@ -13,31 +13,21 @@ 


#include "dsa_priv.h"



static int dsa_broadcast(unsigned long e, void *v)

{

	struct dsa_switch_tree *dst;

	int err = 0;



	list_for_each_entry(dst, &dsa_tree_list, list) {

		struct raw_notifier_head *nh = &dst->nh;



		err = raw_notifier_call_chain(nh, e, v);

		err = notifier_to_errno(err);

		if (err)

			break;

	}



	return err;

}



/**

 * dsa_port_notify - Notify the switching fabric of changes to a port

 * @dp: port on which change occurred

 * @e: event, must be of type DSA_NOTIFIER_*

 * @v: event-specific value.

 *

 * Notify all switches in the DSA tree that this port's switch belongs to,

 * including this switch itself, of an event. Allows the other switches to

 * reconfigure themselves for cross-chip operations. Can also be used to

 * reconfigure ports without net_devices (CPU ports, DSA links) whenever

 * a user port's state changes.

 */

static int dsa_port_notify(const struct dsa_port *dp, unsigned long e, void *v)

{

	struct raw_notifier_head *nh = &dp->ds->dst->nh;

	int err;



	err = raw_notifier_call_chain(nh, e, v);



	return notifier_to_errno(err);

	return dsa_tree_notify(dp->ds->dst, e, v);

}



int dsa_port_set_state(struct dsa_port *dp, u8 state)