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authorPetr Machata <petrm@mellanox.com>2018-07-27 15:26:56 +0300
committerDavid S. Miller <davem@davemloft.net>2018-07-27 13:17:50 -0700
commitb67c540b8a987e365dc548e5b2ddf023946e3d63 (patch)
tree98470408a7e0a379e016af2bc52ae1e540dd8d8e /net/dcb
parent08193d1a893c802c4b807e4d522865061f4e9f4f (diff)
downloadlinux-b67c540b8a987e365dc548e5b2ddf023946e3d63.tar.bz2
net: dcb: Add priority-to-DSCP map getters
On ingress, a network device such as a switch assigns to packets priority based on various criteria. Common options include interpreting PCP and DSCP fields according to user configuration. When a packet egresses the switch, a reverse process may rewrite PCP and/or DSCP values according to packet priority. The following three functions support a) obtaining a DSCP-to-priority map or vice versa, and b) finding default-priority entries in APP database. The DCB subsystem supports for APP entries a very generous M:N mapping between priorities and protocol identifiers. Understandably, several (say) DSCP values can map to the same priority. But this asymmetry holds the other way around as well--one priority can map to several DSCP values. For this reason, the following functions operate in terms of bitmaps, with ones in positions that match some APP entry. - dcb_ieee_getapp_dscp_prio_mask_map() to compute for a given netdevice a map of DSCP-to-priority-mask, which gives for each DSCP value a bitmap of priorities related to that DSCP value by APP, along the lines of dcb_ieee_getapp_mask(). - dcb_ieee_getapp_prio_dscp_mask_map() similarly to compute for a given netdevice a map from priorities to a bitmap of DSCPs. - dcb_ieee_getapp_default_prio_mask() which finds all default-priority rules for a given port in APP database, and returns a mask of priorities allowed by these default-priority rules. Signed-off-by: Petr Machata <petrm@mellanox.com> Signed-off-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dcb')
-rw-r--r--net/dcb/dcbnl.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 013fdb6fa07a..a556cd708885 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c
@@ -1958,6 +1958,92 @@ int dcb_ieee_delapp(struct net_device *dev, struct dcb_app *del)
}
EXPORT_SYMBOL(dcb_ieee_delapp);
+/**
+ * dcb_ieee_getapp_prio_dscp_mask_map - For a given device, find mapping from
+ * priorities to the DSCP values assigned to that priority. Initialize p_map
+ * such that each map element holds a bit mask of DSCP values configured for
+ * that priority by APP entries.
+ */
+void dcb_ieee_getapp_prio_dscp_mask_map(const struct net_device *dev,
+ struct dcb_ieee_app_prio_map *p_map)
+{
+ int ifindex = dev->ifindex;
+ struct dcb_app_type *itr;
+ u8 prio;
+
+ memset(p_map->map, 0, sizeof(p_map->map));
+
+ spin_lock_bh(&dcb_lock);
+ list_for_each_entry(itr, &dcb_app_list, list) {
+ if (itr->ifindex == ifindex &&
+ itr->app.selector == IEEE_8021QAZ_APP_SEL_DSCP &&
+ itr->app.protocol < 64 &&
+ itr->app.priority < IEEE_8021QAZ_MAX_TCS) {
+ prio = itr->app.priority;
+ p_map->map[prio] |= 1ULL << itr->app.protocol;
+ }
+ }
+ spin_unlock_bh(&dcb_lock);
+}
+EXPORT_SYMBOL(dcb_ieee_getapp_prio_dscp_mask_map);
+
+/**
+ * dcb_ieee_getapp_dscp_prio_mask_map - For a given device, find mapping from
+ * DSCP values to the priorities assigned to that DSCP value. Initialize p_map
+ * such that each map element holds a bit mask of priorities configured for a
+ * given DSCP value by APP entries.
+ */
+void
+dcb_ieee_getapp_dscp_prio_mask_map(const struct net_device *dev,
+ struct dcb_ieee_app_dscp_map *p_map)
+{
+ int ifindex = dev->ifindex;
+ struct dcb_app_type *itr;
+
+ memset(p_map->map, 0, sizeof(p_map->map));
+
+ spin_lock_bh(&dcb_lock);
+ list_for_each_entry(itr, &dcb_app_list, list) {
+ if (itr->ifindex == ifindex &&
+ itr->app.selector == IEEE_8021QAZ_APP_SEL_DSCP &&
+ itr->app.protocol < 64 &&
+ itr->app.priority < IEEE_8021QAZ_MAX_TCS)
+ p_map->map[itr->app.protocol] |= 1 << itr->app.priority;
+ }
+ spin_unlock_bh(&dcb_lock);
+}
+EXPORT_SYMBOL(dcb_ieee_getapp_dscp_prio_mask_map);
+
+/**
+ * Per 802.1Q-2014, the selector value of 1 is used for matching on Ethernet
+ * type, with valid PID values >= 1536. A special meaning is then assigned to
+ * protocol value of 0: "default priority. For use when priority is not
+ * otherwise specified".
+ *
+ * dcb_ieee_getapp_default_prio_mask - For a given device, find all APP entries
+ * of the form {$PRIO, ETHERTYPE, 0} and construct a bit mask of all default
+ * priorities set by these entries.
+ */
+u8 dcb_ieee_getapp_default_prio_mask(const struct net_device *dev)
+{
+ int ifindex = dev->ifindex;
+ struct dcb_app_type *itr;
+ u8 mask = 0;
+
+ spin_lock_bh(&dcb_lock);
+ list_for_each_entry(itr, &dcb_app_list, list) {
+ if (itr->ifindex == ifindex &&
+ itr->app.selector == IEEE_8021QAZ_APP_SEL_ETHERTYPE &&
+ itr->app.protocol == 0 &&
+ itr->app.priority < IEEE_8021QAZ_MAX_TCS)
+ mask |= 1 << itr->app.priority;
+ }
+ spin_unlock_bh(&dcb_lock);
+
+ return mask;
+}
+EXPORT_SYMBOL(dcb_ieee_getapp_default_prio_mask);
+
static int __init dcbnl_init(void)
{
INIT_LIST_HEAD(&dcb_app_list);