From 3448c0058327356049f140116fc6632bbfd0c122 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 11 Sep 2012 17:57:42 +0200 Subject: [PATCH] mac80211: add channel context iterator Drivers may need to iterate the active channel contexts, export an iterator function to allow that. To make it possible, use RCU-safe list functions. Signed-off-by: Johannes Berg --- include/net/mac80211.h | 21 +++++++++++++++++++++ net/mac80211/chan.c | 22 ++++++++++++++++++++-- 2 files changed, 41 insertions(+), 2 deletions(-) diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 3560881d17ee..f12df5bb529f 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -3596,6 +3596,27 @@ void ieee80211_iter_keys(struct ieee80211_hw *hw, void *data), void *iter_data); +/** + * ieee80211_iter_chan_contexts_atomic - iterate channel contexts + * @hw: pointre obtained from ieee80211_alloc_hw(). + * @iter: iterator function + * @iter_data: data passed to iterator function + * + * Iterate all active channel contexts. This function is atomic and + * doesn't acquire any locks internally that might be held in other + * places while calling into the driver. + * + * The iterator will not find a context that's being added (during + * the driver callback to add it) but will find it while it's being + * removed. + */ +void ieee80211_iter_chan_contexts_atomic( + struct ieee80211_hw *hw, + void (*iter)(struct ieee80211_hw *hw, + struct ieee80211_chanctx_conf *chanctx_conf, + void *data), + void *iter_data); + /** * ieee80211_ap_probereq_get - retrieve a Probe Request template * @hw: pointer obtained from ieee80211_alloc_hw(). diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index bfaa486d928c..f84b86028a9c 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -3,6 +3,7 @@ */ #include +#include #include #include "ieee80211_i.h" #include "driver-ops.h" @@ -134,7 +135,7 @@ ieee80211_new_chanctx(struct ieee80211_local *local, } } - list_add(&ctx->list, &local->chanctx_list); + list_add_rcu(&ctx->list, &local->chanctx_list); return ctx; } @@ -153,7 +154,7 @@ static void ieee80211_free_chanctx(struct ieee80211_local *local, drv_remove_chanctx(local, ctx); } - list_del(&ctx->list); + list_del_rcu(&ctx->list); kfree_rcu(ctx, rcu_head); } @@ -379,3 +380,20 @@ void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata) __ieee80211_vif_release_channel(sdata); mutex_unlock(&sdata->local->chanctx_mtx); } + +void ieee80211_iter_chan_contexts_atomic( + struct ieee80211_hw *hw, + void (*iter)(struct ieee80211_hw *hw, + struct ieee80211_chanctx_conf *chanctx_conf, + void *data), + void *iter_data) +{ + struct ieee80211_local *local = hw_to_local(hw); + struct ieee80211_chanctx *ctx; + + rcu_read_lock(); + list_for_each_entry_rcu(ctx, &local->chanctx_list, list) + iter(hw, &ctx->conf, iter_data); + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(ieee80211_iter_chan_contexts_atomic); -- 2.30.2