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Message-Id: <20210121023616.1696021-7-olteanv@gmail.com>
Date: Thu, 21 Jan 2021 04:36:12 +0200
From: Vladimir Oltean <olteanv@...il.com>
To: "David S . Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>, netdev@...r.kernel.org
Cc: Andrew Lunn <andrew@...n.ch>,
Florian Fainelli <f.fainelli@...il.com>,
Vivien Didelot <vivien.didelot@...il.com>,
Richard Cochran <richardcochran@...il.com>,
Claudiu Manoil <claudiu.manoil@....com>,
Alexandru Marginean <alexandru.marginean@....com>,
Alexandre Belloni <alexandre.belloni@...tlin.com>,
Xiaoliang Yang <xiaoliang.yang_1@....com>,
Hongbo Wang <hongbo.wang@....com>,
Vladimir Oltean <vladimir.oltean@....com>,
Po Liu <po.liu@....com>, Yangbo Lu <yangbo.lu@....com>,
Maxim Kochetkov <fido_max@...ox.ru>,
Eldar Gasanov <eldargasanov2@...il.com>,
Andrey L <al@...omtech.com>,
Tobias Waldekranz <tobias@...dekranz.com>,
UNGLinuxDriver@...rochip.com
Subject: [PATCH v5 net-next 06/10] net: dsa: document the existing switch tree notifiers and add a new one
From: Vladimir Oltean <vladimir.oltean@....com>
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: Vladimir Oltean <vladimir.oltean@....com>
---
Changes in v5:
Patch is new.
net/dsa/dsa2.c | 43 +++++++++++++++++++++++++++++++++++++++++++
net/dsa/dsa_priv.h | 2 ++
net/dsa/port.c | 36 +++++++++++++-----------------------
3 files changed, 58 insertions(+), 23 deletions(-)
diff --git a/net/dsa/dsa2.c b/net/dsa/dsa2.c
index cc13549120e5..2953d0c1c7bc 100644
--- a/net/dsa/dsa2.c
+++ b/net/dsa/dsa2.c
@@ -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.
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 2ce46bb87703..3cc1e6d76e3a 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -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;
diff --git a/net/dsa/port.c b/net/dsa/port.c
index f5b0f72ee7cd..a8886cf40160 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -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)
--
2.25.1
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