wifi: mac80211: reduce iflist_mtx

We now hold the wiphy mutex everywhere that we use or
needed the iflist_mtx, so we don't need this mutex any
more in mac80211. However, drivers may also iterate,
and in some cases (e.g. mt76) do so from high-priority
contexts. Thus, keep the mutex around but remove its
usage in mac80211 apart from those driver-visible parts
that are still needed.

Most of this change was done automatically with spatch,
with the parts that are still needed as described above
reverted manually.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index dada3ca0b9e072c4b662fed493ba23508c8f6baf..0201a33201363242215c9da3a405edac0d7be716 100644 (file)
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -2980,6 +2980,8 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
        bool update_txp_type = false;
        bool has_monitor = false;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        if (wdev) {
                sdata = IEEE80211_WDEV_TO_SUB_IF(wdev);
 
@@ -3027,7 +3029,6 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
                break;
        }
 
-       mutex_lock(&local->iflist_mtx);
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (sdata->vif.type == NL80211_IFTYPE_MONITOR) {
                        has_monitor = true;
@@ -3043,7 +3044,6 @@ static int ieee80211_set_tx_power(struct wiphy *wiphy,
                        continue;
                ieee80211_recalc_txpower(sdata, update_txp_type);
        }
-       mutex_unlock(&local->iflist_mtx);
 
        if (has_monitor) {
                sdata = wiphy_dereference(local->hw.wiphy,
@@ -4636,6 +4636,8 @@ static void
 ieee80211_color_change_bss_config_notify(struct ieee80211_sub_if_data *sdata,
                                         u8 color, int enable, u64 changed)
 {
+       lockdep_assert_wiphy(sdata->local->hw.wiphy);
+
        sdata->vif.bss_conf.he_bss_color.color = color;
        sdata->vif.bss_conf.he_bss_color.enabled = enable;
        changed |= BSS_CHANGED_HE_BSS_COLOR;
@@ -4645,7 +4647,6 @@ ieee80211_color_change_bss_config_notify(struct ieee80211_sub_if_data *sdata,
        if (!sdata->vif.bss_conf.nontransmitted && sdata->vif.mbssid_tx_vif) {
                struct ieee80211_sub_if_data *child;
 
-               mutex_lock(&sdata->local->iflist_mtx);
                list_for_each_entry(child, &sdata->local->interfaces, list) {
                        if (child != sdata && child->vif.mbssid_tx_vif == &sdata->vif) {
                                child->vif.bss_conf.he_bss_color.color = color;
@@ -4655,7 +4656,6 @@ ieee80211_color_change_bss_config_notify(struct ieee80211_sub_if_data *sdata,
                                                                  BSS_CHANGED_HE_BSS_COLOR);
                        }
                }
-               mutex_unlock(&sdata->local->iflist_mtx);
        }
 }
 

diff --git a/net/mac80211/ibss.c b/net/mac80211/ibss.c
index 3c63703772340a61123602e241f41ec5aaddc357..b95098c1315307e2ff78cbd6ecee997aed589b06 100644 (file)
--- a/net/mac80211/ibss.c
+++ b/net/mac80211/ibss.c
@@ -1738,7 +1738,8 @@ void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
 {
        struct ieee80211_sub_if_data *sdata;
 
-       mutex_lock(&local->iflist_mtx);
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (!ieee80211_sdata_running(sdata))
                        continue;
@@ -1746,7 +1747,6 @@ void ieee80211_ibss_notify_scan_completed(struct ieee80211_local *local)
                        continue;
                sdata->u.ibss.last_scan_completed = jiffies;
        }
-       mutex_unlock(&local->iflist_mtx);
 }
 
 int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata,

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 9724a3d4545be073fecb6ff25cfb96170505e36a..f7f58c3e8349472e058d25c399355b3e661cc95c 100644 (file)
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -33,14 +33,13 @@
  * The interface list in each struct ieee80211_local is protected
  * three-fold:
  *
- * (1) modifications may only be done under the RTNL
- * (2) modifications and readers are protected against each other by
- *     the iflist_mtx.
- * (3) modifications are done in an RCU manner so atomic readers
+ * (1) modifications may only be done under the RTNL *and* wiphy mutex
+ *     *and* iflist_mtx
+ * (2) modifications are done in an RCU manner so atomic readers
  *     can traverse the list in RCU-safe blocks.
  *
  * As a consequence, reads (traversals) of the list can be protected
- * by either the RTNL, the iflist_mtx or RCU.
+ * by either the RTNL, the wiphy mutex, the iflist_mtx or RCU.
  */
 
 static void ieee80211_iface_work(struct wiphy *wiphy, struct wiphy_work *work);
@@ -160,6 +159,8 @@ static int ieee80211_verify_mac(struct ieee80211_sub_if_data *sdata, u8 *addr,
        u8 *m;
        int ret = 0;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        if (is_zero_ether_addr(local->hw.wiphy->addr_mask))
                return 0;
 
@@ -176,7 +177,6 @@ static int ieee80211_verify_mac(struct ieee80211_sub_if_data *sdata, u8 *addr,
        if (!check_dup)
                return ret;
 
-       mutex_lock(&local->iflist_mtx);
        list_for_each_entry(iter, &local->interfaces, list) {
                if (iter == sdata)
                        continue;
@@ -195,7 +195,6 @@ static int ieee80211_verify_mac(struct ieee80211_sub_if_data *sdata, u8 *addr,
                        break;
                }
        }
-       mutex_unlock(&local->iflist_mtx);
 
        return ret;
 }
@@ -1049,7 +1048,7 @@ void ieee80211_recalc_offload(struct ieee80211_local *local)
        if (!ieee80211_hw_check(&local->hw, SUPPORTS_TX_ENCAP_OFFLOAD))
                return;
 
-       mutex_lock(&local->iflist_mtx);
+       lockdep_assert_wiphy(local->hw.wiphy);
 
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (!ieee80211_sdata_running(sdata))
@@ -1057,8 +1056,6 @@ void ieee80211_recalc_offload(struct ieee80211_local *local)
 
                ieee80211_recalc_sdata_offload(sdata);
        }
-
-       mutex_unlock(&local->iflist_mtx);
 }
 
 void ieee80211_adjust_monitor_flags(struct ieee80211_sub_if_data *sdata,
@@ -1917,6 +1914,8 @@ static void ieee80211_assign_perm_addr(struct ieee80211_local *local,
        u8 tmp_addr[ETH_ALEN];
        int i;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        /* default ... something at least */
        memcpy(perm_addr, local->hw.wiphy->perm_addr, ETH_ALEN);
 
@@ -1924,8 +1923,6 @@ static void ieee80211_assign_perm_addr(struct ieee80211_local *local,
            local->hw.wiphy->n_addresses <= 1)
                return;
 
-       mutex_lock(&local->iflist_mtx);
-
        switch (type) {
        case NL80211_IFTYPE_MONITOR:
                /* doesn't matter */
@@ -1949,7 +1946,7 @@ static void ieee80211_assign_perm_addr(struct ieee80211_local *local,
                                if (!ieee80211_sdata_running(sdata))
                                        continue;
                                memcpy(perm_addr, sdata->vif.addr, ETH_ALEN);
-                               goto out_unlock;
+                               return;
                        }
                }
                fallthrough;
@@ -2035,9 +2032,6 @@ static void ieee80211_assign_perm_addr(struct ieee80211_local *local,
 
                break;
        }
-
- out_unlock:
-       mutex_unlock(&local->iflist_mtx);
 }
 
 int ieee80211_if_add(struct ieee80211_local *local, const char *name,
@@ -2051,6 +2045,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
        int ret, i;
 
        ASSERT_RTNL();
+       lockdep_assert_wiphy(local->hw.wiphy);
 
        if (type == NL80211_IFTYPE_P2P_DEVICE || type == NL80211_IFTYPE_NAN) {
                struct wireless_dev *wdev;
@@ -2217,6 +2212,7 @@ int ieee80211_if_add(struct ieee80211_local *local, const char *name,
 void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 {
        ASSERT_RTNL();
+       lockdep_assert_wiphy(sdata->local->hw.wiphy);
 
        mutex_lock(&sdata->local->iflist_mtx);
        list_del_rcu(&sdata->list);

diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 43bf2f4090004938e483da36731637637d52f737..195e7202d51d6a13e276d9470e1b07ccbd728906 100644 (file)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -2799,6 +2799,8 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
        u64 vif_changed = BSS_CHANGED_ASSOC;
        unsigned int link_id;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        sdata->u.mgd.associated = true;
 
        for (link_id = 0; link_id < IEEE80211_MLD_MAX_NUM_LINKS; link_id++) {
@@ -2860,9 +2862,7 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata,
                                                 vif_changed | changed[0]);
        }
 
-       mutex_lock(&local->iflist_mtx);
        ieee80211_recalc_ps(local);
-       mutex_unlock(&local->iflist_mtx);
 
        /* leave this here to not change ordering in non-MLO cases */
        if (!ieee80211_vif_is_mld(&sdata->vif))
@@ -3069,9 +3069,7 @@ static void ieee80211_reset_ap_probe(struct ieee80211_sub_if_data *sdata)
 
        __ieee80211_stop_poll(sdata);
 
-       mutex_lock(&local->iflist_mtx);
        ieee80211_recalc_ps(local);
-       mutex_unlock(&local->iflist_mtx);
 
        if (ieee80211_hw_check(&sdata->local->hw, CONNECTION_MONITOR))
                return;
@@ -3267,9 +3265,7 @@ static void ieee80211_mgd_probe_ap(struct ieee80211_sub_if_data *sdata,
        if (already)
                goto out;
 
-       mutex_lock(&sdata->local->iflist_mtx);
        ieee80211_recalc_ps(sdata->local);
-       mutex_unlock(&sdata->local->iflist_mtx);
 
        ifmgd->probe_send_count = 0;
        ieee80211_mgd_probe_ap_send(sdata);
@@ -6094,9 +6090,7 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_link_data *link,
                changed |= BSS_CHANGED_BEACON_INFO;
                link->u.mgd.have_beacon = true;
 
-               mutex_lock(&local->iflist_mtx);
                ieee80211_recalc_ps(local);
-               mutex_unlock(&local->iflist_mtx);
 
                ieee80211_recalc_ps_vif(sdata);
        }

diff --git a/net/mac80211/offchannel.c b/net/mac80211/offchannel.c
index 0e7e7561d0eb5cc1d9c6a116408bd0e3b14edc6a..8325fbb1645ea8c60b661d91fc052664e13a7ceb 100644 (file)
--- a/net/mac80211/offchannel.c
+++ b/net/mac80211/offchannel.c
@@ -84,6 +84,8 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
 {
        struct ieee80211_sub_if_data *sdata;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        if (WARN_ON(local->use_chanctx))
                return;
 
@@ -101,7 +103,6 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
                                        false);
        ieee80211_flush_queues(local, NULL, false);
 
-       mutex_lock(&local->iflist_mtx);
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (!ieee80211_sdata_running(sdata))
                        continue;
@@ -127,17 +128,17 @@ void ieee80211_offchannel_stop_vifs(struct ieee80211_local *local)
                    sdata->u.mgd.associated)
                        ieee80211_offchannel_ps_enable(sdata);
        }
-       mutex_unlock(&local->iflist_mtx);
 }
 
 void ieee80211_offchannel_return(struct ieee80211_local *local)
 {
        struct ieee80211_sub_if_data *sdata;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        if (WARN_ON(local->use_chanctx))
                return;
 
-       mutex_lock(&local->iflist_mtx);
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (sdata->vif.type == NL80211_IFTYPE_P2P_DEVICE)
                        continue;
@@ -161,7 +162,6 @@ void ieee80211_offchannel_return(struct ieee80211_local *local)
                                BSS_CHANGED_BEACON_ENABLED);
                }
        }
-       mutex_unlock(&local->iflist_mtx);
 
        ieee80211_wake_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP,
                                        IEEE80211_QUEUE_STOP_REASON_OFFCHANNEL,

diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c
index 0ea86a418edaf3d6c9bfcd0bf40edbf6dac15013..58d525e41f6b5caff35227098bd335f54e9a5571 100644 (file)
--- a/net/mac80211/scan.c
+++ b/net/mac80211/scan.c
@@ -555,20 +555,18 @@ static bool __ieee80211_can_leave_ch(struct ieee80211_sub_if_data *sdata)
        struct ieee80211_local *local = sdata->local;
        struct ieee80211_sub_if_data *sdata_iter;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        if (!ieee80211_is_radar_required(local))
                return true;
 
        if (!regulatory_pre_cac_allowed(local->hw.wiphy))
                return false;
 
-       mutex_lock(&local->iflist_mtx);
        list_for_each_entry(sdata_iter, &local->interfaces, list) {
-               if (sdata_iter->wdev.cac_started) {
-                       mutex_unlock(&local->iflist_mtx);
+               if (sdata_iter->wdev.cac_started)
                        return false;
-               }
        }
-       mutex_unlock(&local->iflist_mtx);
 
        return true;
 }
@@ -860,12 +858,13 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
        enum mac80211_scan_state next_scan_state;
        struct cfg80211_scan_request *scan_req;
 
+       lockdep_assert_wiphy(local->hw.wiphy);
+
        /*
         * check if at least one STA interface is associated,
         * check if at least one STA interface has pending tx frames
         * and grab the lowest used beacon interval
         */
-       mutex_lock(&local->iflist_mtx);
        list_for_each_entry(sdata, &local->interfaces, list) {
                if (!ieee80211_sdata_running(sdata))
                        continue;
@@ -881,7 +880,6 @@ static void ieee80211_scan_state_decision(struct ieee80211_local *local,
                        }
                }
        }
-       mutex_unlock(&local->iflist_mtx);
 
        scan_req = rcu_dereference_protected(local->scan_req,
                                             lockdep_is_held(&local->hw.wiphy->mtx));

diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index 0873c7d60a4d5fb8560bf6966b48110ecc05e96c..7833043b0a4e06a696c9820096647c2788d5a257 100644 (file)
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -4322,7 +4322,6 @@ void ieee80211_dfs_cac_cancel(struct ieee80211_local *local)
        struct ieee80211_sub_if_data *sdata;
        struct cfg80211_chan_def chandef;
 
-       /* for interface list, to avoid linking iflist_mtx and chanctx_mtx */
        lockdep_assert_wiphy(local->hw.wiphy);
 
        list_for_each_entry(sdata, &local->interfaces, list) {