From: Johannes Berg <johannes.berg@xxxxxxxxx>
In the channel context code we have quite a few instances
of nested loops iterating the interfaces and then links.
Add a new for_each_sdata_link() macro and use it. Also,
since it's easier, convert all the loops and a few other
places away from RCU as we now hold the wiphy mutex
everywhere anyway.
This does cause a little bit more work (such as checking
interface types for each link of an interface rather than
not iterating links in some cases), but that's not a huge
issue and seems like an acceptable trade-off, readability
is important too.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
net/mac80211/chan.c | 246 ++++++++++++-------------------------
net/mac80211/ieee80211_i.h | 13 ++
2 files changed, 89 insertions(+), 170 deletions(-)
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 2d1e8d2f5382..4838fd055694 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -211,7 +211,7 @@ static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta,
enum ieee80211_sta_rx_bandwidth width;
struct link_sta_info *link_sta;
- link_sta = rcu_dereference(sta->link[link_id]);
+ link_sta = wiphy_dereference(sta->local->hw.wiphy, sta->link[link_id]);
/* no effect if this STA has no presence on this link */
if (!link_sta)
@@ -249,9 +249,10 @@ static enum nl80211_chan_width ieee80211_get_sta_bw(struct sta_info *sta,
}
static enum nl80211_chan_width
-ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata,
- unsigned int link_id)
+ieee80211_get_max_required_bw(struct ieee80211_link_data *link)
{
+ struct ieee80211_sub_if_data *sdata = link->sdata;
+ unsigned int link_id = link->link_id;
enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
struct sta_info *sta;
@@ -267,31 +268,25 @@ ieee80211_get_max_required_bw(struct ieee80211_sub_if_data *sdata,
}
static enum nl80211_chan_width
-ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata,
- struct ieee80211_chanctx *ctx,
- struct ieee80211_link_data *rsvd_for)
+ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
+ struct ieee80211_chanctx *ctx,
+ struct ieee80211_link_data *rsvd_for)
{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_link_data *link;
enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
- struct ieee80211_vif *vif = &sdata->vif;
- int link_id;
- rcu_read_lock();
- for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
+ for_each_sdata_link(local, link) {
enum nl80211_chan_width width = NL80211_CHAN_WIDTH_20_NOHT;
- struct ieee80211_link_data *link =
- rcu_dereference(sdata->link[link_id]);
-
- if (!link)
- continue;
if (link != rsvd_for &&
rcu_access_pointer(link->conf->chanctx_conf) != &ctx->conf)
continue;
- switch (vif->type) {
+ switch (link->sdata->vif.type) {
case NL80211_IFTYPE_AP:
case NL80211_IFTYPE_AP_VLAN:
- width = ieee80211_get_max_required_bw(sdata, link_id);
+ width = ieee80211_get_max_required_bw(link);
break;
case NL80211_IFTYPE_STATION:
/*
@@ -300,7 +295,7 @@ ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata,
* account also for TDLS peers
*/
width = max(link->conf->chanreq.oper.width,
- ieee80211_get_max_required_bw(sdata, link_id));
+ ieee80211_get_max_required_bw(link));
break;
case NL80211_IFTYPE_P2P_DEVICE:
case NL80211_IFTYPE_NAN:
@@ -321,40 +316,13 @@ ieee80211_get_chanctx_vif_max_required_bw(struct ieee80211_sub_if_data *sdata,
max_bw = max(max_bw, width);
}
- rcu_read_unlock();
-
- return max_bw;
-}
-
-static enum nl80211_chan_width
-ieee80211_get_chanctx_max_required_bw(struct ieee80211_local *local,
- struct ieee80211_chanctx *ctx,
- struct ieee80211_link_data *rsvd_for)
-{
- struct ieee80211_sub_if_data *sdata;
- enum nl80211_chan_width max_bw = NL80211_CHAN_WIDTH_20_NOHT;
-
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- enum nl80211_chan_width width;
-
- if (!ieee80211_sdata_running(sdata))
- continue;
-
- width = ieee80211_get_chanctx_vif_max_required_bw(sdata, ctx,
- rsvd_for);
-
- max_bw = max(max_bw, width);
- }
/* use the configured bandwidth in case of monitor interface */
- sdata = rcu_dereference(local->monitor_sdata);
+ sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
if (sdata &&
rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &ctx->conf)
max_bw = max(max_bw, ctx->conf.def.width);
- rcu_read_unlock();
-
return max_bw;
}
@@ -575,26 +543,14 @@ ieee80211_find_chanctx(struct ieee80211_local *local,
bool ieee80211_is_radar_required(struct ieee80211_local *local)
{
- struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_link_data *link;
lockdep_assert_wiphy(local->hw.wiphy);
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- unsigned int link_id;
-
- for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
- struct ieee80211_link_data *link;
-
- link = rcu_dereference(sdata->link[link_id]);
-
- if (link && link->radar_required) {
- rcu_read_unlock();
- return true;
- }
- }
+ for_each_sdata_link(local, link) {
+ if (link->radar_required)
+ return true;
}
- rcu_read_unlock();
return false;
}
@@ -604,38 +560,19 @@ ieee80211_chanctx_radar_required(struct ieee80211_local *local,
struct ieee80211_chanctx *ctx)
{
struct ieee80211_chanctx_conf *conf = &ctx->conf;
- struct ieee80211_sub_if_data *sdata;
- bool required = false;
+ struct ieee80211_link_data *link;
lockdep_assert_wiphy(local->hw.wiphy);
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- unsigned int link_id;
-
- if (!ieee80211_sdata_running(sdata))
+ for_each_sdata_link(local, link) {
+ if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
continue;
- for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
- struct ieee80211_link_data *link;
-
- link = rcu_dereference(sdata->link[link_id]);
- if (!link)
- continue;
-
- if (rcu_access_pointer(link->conf->chanctx_conf) != conf)
- continue;
- if (!link->radar_required)
- continue;
- required = true;
- break;
- }
-
- if (required)
- break;
+ if (!link->radar_required)
+ continue;
+ return true;
}
- rcu_read_unlock();
- return required;
+ return false;
}
static struct ieee80211_chanctx *
@@ -735,50 +672,38 @@ void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
struct ieee80211_chanctx *ctx)
{
struct ieee80211_chanctx_conf *conf = &ctx->conf;
- struct ieee80211_sub_if_data *sdata;
const struct cfg80211_chan_def *compat = NULL;
+ struct ieee80211_link_data *link;
struct ieee80211_chan_req chanreq = {};
struct sta_info *sta;
lockdep_assert_wiphy(local->hw.wiphy);
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
- int link_id;
+ for_each_sdata_link(local, link) {
+ struct ieee80211_bss_conf *link_conf;
- if (!ieee80211_sdata_running(sdata))
+ if (link->sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
continue;
- if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
- continue;
-
- for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
- struct ieee80211_bss_conf *link_conf =
- rcu_dereference(sdata->vif.link_conf[link_id]);
+ link_conf = link->conf;
- if (!link_conf)
- continue;
-
- if (rcu_access_pointer(link_conf->chanctx_conf) != conf)
- continue;
+ if (rcu_access_pointer(link_conf->chanctx_conf) != conf)
+ continue;
- if (!compat)
- compat = &link_conf->chanreq.oper;
+ if (!compat)
+ compat = &link_conf->chanreq.oper;
- compat = cfg80211_chandef_compatible(&link_conf->chanreq.oper,
- compat);
- if (WARN_ON_ONCE(!compat))
- break;
- }
+ compat = cfg80211_chandef_compatible(&link_conf->chanreq.oper,
+ compat);
+ if (WARN_ON_ONCE(!compat))
+ return;
}
- if (WARN_ON_ONCE(!compat)) {
- rcu_read_unlock();
+ if (WARN_ON_ONCE(!compat))
return;
- }
/* TDLS peers can sometimes affect the chandef width */
- list_for_each_entry_rcu(sta, &local->sta_list, list) {
+ list_for_each_entry(sta, &local->sta_list, list) {
if (!sta->uploaded ||
!test_sta_flag(sta, WLAN_STA_TDLS_WIDER_BW) ||
!test_sta_flag(sta, WLAN_STA_AUTHORIZED) ||
@@ -788,9 +713,8 @@ void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
compat = cfg80211_chandef_compatible(&sta->tdls_chandef,
compat);
if (WARN_ON_ONCE(!compat))
- break;
+ return;
}
- rcu_read_unlock();
if (!compat)
return;
@@ -884,23 +808,19 @@ void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
{
struct ieee80211_sub_if_data *sdata;
u8 rx_chains_static, rx_chains_dynamic;
+ struct ieee80211_link_data *link;
lockdep_assert_wiphy(local->hw.wiphy);
rx_chains_static = 1;
rx_chains_dynamic = 1;
- rcu_read_lock();
- list_for_each_entry_rcu(sdata, &local->interfaces, list) {
+ for_each_sdata_link(local, link) {
u8 needed_static, needed_dynamic;
- unsigned int link_id;
- if (!ieee80211_sdata_running(sdata))
- continue;
-
- switch (sdata->vif.type) {
+ switch (link->sdata->vif.type) {
case NL80211_IFTYPE_STATION:
- if (!sdata->u.mgd.associated)
+ if (!link->sdata->u.mgd.associated)
continue;
break;
case NL80211_IFTYPE_AP:
@@ -912,49 +832,38 @@ void ieee80211_recalc_smps_chanctx(struct ieee80211_local *local,
continue;
}
- for (link_id = 0; link_id < ARRAY_SIZE(sdata->link); link_id++) {
- struct ieee80211_link_data *link;
+ if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
+ continue;
- link = rcu_dereference(sdata->link[link_id]);
-
- if (!link)
- continue;
-
- if (rcu_access_pointer(link->conf->chanctx_conf) != &chanctx->conf)
- continue;
-
- switch (link->smps_mode) {
- default:
- WARN_ONCE(1, "Invalid SMPS mode %d\n",
- link->smps_mode);
- fallthrough;
- case IEEE80211_SMPS_OFF:
- needed_static = link->needed_rx_chains;
- needed_dynamic = link->needed_rx_chains;
- break;
- case IEEE80211_SMPS_DYNAMIC:
- needed_static = 1;
- needed_dynamic = link->needed_rx_chains;
- break;
- case IEEE80211_SMPS_STATIC:
- needed_static = 1;
- needed_dynamic = 1;
- break;
- }
-
- rx_chains_static = max(rx_chains_static, needed_static);
- rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
+ switch (link->smps_mode) {
+ default:
+ WARN_ONCE(1, "Invalid SMPS mode %d\n",
+ link->smps_mode);
+ fallthrough;
+ case IEEE80211_SMPS_OFF:
+ needed_static = link->needed_rx_chains;
+ needed_dynamic = link->needed_rx_chains;
+ break;
+ case IEEE80211_SMPS_DYNAMIC:
+ needed_static = 1;
+ needed_dynamic = link->needed_rx_chains;
+ break;
+ case IEEE80211_SMPS_STATIC:
+ needed_static = 1;
+ needed_dynamic = 1;
+ break;
}
+
+ rx_chains_static = max(rx_chains_static, needed_static);
+ rx_chains_dynamic = max(rx_chains_dynamic, needed_dynamic);
}
/* Disable SMPS for the monitor interface */
- sdata = rcu_dereference(local->monitor_sdata);
+ sdata = wiphy_dereference(local->hw.wiphy, local->monitor_sdata);
if (sdata &&
rcu_access_pointer(sdata->vif.bss_conf.chanctx_conf) == &chanctx->conf)
rx_chains_dynamic = rx_chains_static = local->rx_chains;
- rcu_read_unlock();
-
if (rx_chains_static == chanctx->conf.rx_chains_static &&
rx_chains_dynamic == chanctx->conf.rx_chains_dynamic)
return;
@@ -993,17 +902,16 @@ __ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
if (clear)
conf = NULL;
- rcu_read_lock();
list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
struct ieee80211_bss_conf *vlan_conf;
- vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
+ vlan_conf = wiphy_dereference(local->hw.wiphy,
+ vlan->vif.link_conf[link_id]);
if (WARN_ON(!vlan_conf))
continue;
rcu_assign_pointer(vlan_conf->chanctx_conf, conf);
}
- rcu_read_unlock();
}
void ieee80211_link_copy_chanctx_to_vlans(struct ieee80211_link_data *link,
@@ -1193,17 +1101,16 @@ ieee80211_link_update_chanreq(struct ieee80211_link_data *link,
if (sdata->vif.type != NL80211_IFTYPE_AP)
return;
- rcu_read_lock();
list_for_each_entry(vlan, &sdata->u.ap.vlans, u.vlan.list) {
struct ieee80211_bss_conf *vlan_conf;
- vlan_conf = rcu_dereference(vlan->vif.link_conf[link_id]);
+ vlan_conf = wiphy_dereference(sdata->local->hw.wiphy,
+ vlan->vif.link_conf[link_id]);
if (WARN_ON(!vlan_conf))
continue;
vlan_conf->chanreq = *chanreq;
}
- rcu_read_unlock();
}
static int
@@ -1944,12 +1851,11 @@ void ieee80211_link_vlan_copy_chanctx(struct ieee80211_link_data *link)
ap = container_of(sdata->bss, struct ieee80211_sub_if_data, u.ap);
- rcu_read_lock();
- ap_conf = rcu_dereference(ap->vif.link_conf[link_id]);
- conf = rcu_dereference_protected(ap_conf->chanctx_conf,
- lockdep_is_held(&local->hw.wiphy->mtx));
+ ap_conf = wiphy_dereference(local->hw.wiphy,
+ ap->vif.link_conf[link_id]);
+ conf = wiphy_dereference(local->hw.wiphy,
+ ap_conf->chanctx_conf);
rcu_assign_pointer(link_conf->chanctx_conf, conf);
- rcu_read_unlock();
}
void ieee80211_iter_chan_contexts_atomic(
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 2a72495615a9..9632c4398860 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1172,6 +1172,19 @@ struct ieee80211_sub_if_data *vif_to_sdata(struct ieee80211_vif *p)
#define sdata_dereference(p, sdata) \
wiphy_dereference(sdata->local->hw.wiphy, p)
+#define for_each_sdata_link(_local, _link) \
+ /* outer loop just to define the variables ... */ \
+ for (struct ieee80211_sub_if_data *___sdata = NULL; \
+ !___sdata; \
+ ___sdata = (void *)~0 /* always stop */) \
+ list_for_each_entry(___sdata, &(_local)->interfaces, list) \
+ if (ieee80211_sdata_running(___sdata)) \
+ for (int ___link_id = 0; \
+ ___link_id < ARRAY_SIZE(___sdata->link); \
+ ___link_id++) \
+ if ((_link = wiphy_dereference((local)->hw.wiphy, \
+ ___sdata->link[___link_id])))
+
static inline int
ieee80211_get_mbssid_beacon_len(struct cfg80211_mbssid_elems *elems,
struct cfg80211_rnr_elems *rnr_elems,
--
2.42.0
