[v6,3/3] mac80211: allow reservation of a running chanctx

Message ID	1394376039-9644-4-git-send-email-luciano.coelho@intel.com (mailing list archive)
State	Not Applicable, archived
Headers	show Return-Path: <linux-wireless-owner@kernel.org> From: Luciano Coelho <luciano.coelho@intel.com> To: linux-wireless@vger.kernel.org Cc: johannes@sipsolutions.net, michal.kazior@tieto.com, sw@simonwunderlich.de, andrei.otcheretianski@intel.com Subject: [PATCH v6 3/3] mac80211: allow reservation of a running chanctx Date: Sun, 9 Mar 2014 16:40:39 +0200 Message-Id: <1394376039-9644-4-git-send-email-luciano.coelho@intel.com> In-Reply-To: <1394376039-9644-1-git-send-email-luciano.coelho@intel.com> References: <1394376039-9644-1-git-send-email-luciano.coelho@intel.com> Sender: linux-wireless-owner@vger.kernel.org Precedence: bulk

diff --git a/include/net/mac80211.h b/include/net/mac80211.h index 86faa41..b35c608 100644 --- a/include/net/mac80211.h +++ b/include/net/mac80211.h @@ -1553,6 +1553,12 @@ struct ieee80211_tx_control { * for a single active channel while using channel contexts. When support * is not enabled the default action is to disconnect when getting the * CSA frame. + * + * @IEEE80211_HW_CHANGE_RUNNING_CHANCTX: The hardware can change a + * channel context on-the-fly. This is needed for channel switch + * on single-channel hardware. It can also be used as an + * optimization in certain channel switch cases with + * multi-channel. */ enum ieee80211_hw_flags { IEEE80211_HW_HAS_RATE_CONTROL = 1<<0, @@ -1584,6 +1590,7 @@ enum ieee80211_hw_flags { IEEE80211_HW_TIMING_BEACON_ONLY = 1<<26, IEEE80211_HW_SUPPORTS_HT_CCK_RATES = 1<<27, IEEE80211_HW_CHANCTX_STA_CSA = 1<<28, + IEEE80211_HW_CHANGE_RUNNING_CHANCTX = 1<<29, }; /** diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 2acf973..a6fdc14 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -162,6 +162,27 @@ static void ieee80211_change_chanctx(struct ieee80211_local *local, } } +static bool ieee80211_chanctx_is_reserved(struct ieee80211_local *local, + struct ieee80211_chanctx *ctx) +{ + struct ieee80211_sub_if_data *sdata; + bool ret = false; + + lockdep_assert_held(&local->chanctx_mtx); + rcu_read_lock(); + list_for_each_entry_rcu(sdata, &local->interfaces, list) { + if (!ieee80211_sdata_running(sdata)) + continue; + if (sdata->reserved_chanctx == ctx) { + ret = true; + break; + } + } + + rcu_read_unlock(); + return ret; +} + static struct ieee80211_chanctx * ieee80211_find_chanctx(struct ieee80211_local *local, const struct cfg80211_chan_def *chandef, @@ -177,7 +198,12 @@ ieee80211_find_chanctx(struct ieee80211_local *local, list_for_each_entry(ctx, &local->chanctx_list, list) { const struct cfg80211_chan_def *compat; - if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) + /* We don't support chanctx reservation for multiple + * vifs yet, so don't allow reserved chanctxs to be + * reused. + */ + if ((ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE) || + ieee80211_chanctx_is_reserved(local, ctx)) continue; compat = cfg80211_chandef_compatible(&ctx->conf.def, chandef); @@ -652,11 +678,20 @@ int ieee80211_vif_reserve_chanctx(struct ieee80211_sub_if_data *sdata, /* try to find another context with the chandef we want */ new_ctx = ieee80211_find_chanctx(local, chandef, mode); if (!new_ctx) { - /* create a new context */ - new_ctx = ieee80211_new_chanctx(local, chandef, mode); - if (IS_ERR(new_ctx)) { - ret = PTR_ERR(new_ctx); - goto out; + if (curr_ctx->refcount == 1 && + (local->hw.flags & IEEE80211_HW_CHANGE_RUNNING_CHANCTX)) { + /* if we're the only users of the chanctx and + * the driver supports changing a running + * context, reserve our current context + */ + new_ctx = curr_ctx; + } else { + /* create a new context and reserve it */ + new_ctx = ieee80211_new_chanctx(local, chandef, mode); + if (IS_ERR(new_ctx)) { + ret = PTR_ERR(new_ctx); + goto out; + } } } @@ -701,37 +736,45 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata, ieee80211_stop_queues_by_reason(&local->hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_CHANCTX); + /* unref our reservation */ + ctx->refcount--; + sdata->reserved_chanctx = NULL; - ieee80211_unassign_vif_chanctx(sdata, old_ctx); - if (old_ctx->refcount == 0) - ieee80211_free_chanctx(local, old_ctx); + if (old_ctx == ctx) { + /* This is our own context, just change it */ + ret = __ieee80211_vif_change_channel(sdata, old_ctx, + &local_changed); + if (ret) + goto out; + } else { + ieee80211_unassign_vif_chanctx(sdata, old_ctx); + if (old_ctx->refcount == 0) + ieee80211_free_chanctx(local, old_ctx); - if (sdata->vif.bss_conf.chandef.width != sdata->reserved_chandef.width) - local_changed |= BSS_CHANGED_BANDWIDTH; + if (sdata->vif.bss_conf.chandef.width != + sdata->reserved_chandef.width) + local_changed |= BSS_CHANGED_BANDWIDTH; - sdata->vif.bss_conf.chandef = sdata->reserved_chandef; + sdata->vif.bss_conf.chandef = sdata->reserved_chandef; - /* unref our reservation before assigning */ - ctx->refcount--; - sdata->reserved_chanctx = NULL; - ret = ieee80211_assign_vif_chanctx(sdata, ctx); - if (ret) { - /* if assign fails refcount stays the same */ - if (ctx->refcount == 0) - ieee80211_free_chanctx(local, ctx); - goto out_wake; + ret = ieee80211_assign_vif_chanctx(sdata, ctx); + if (ret) { + /* if assign fails refcount stays the same */ + if (ctx->refcount == 0) + ieee80211_free_chanctx(local, ctx); + goto out; + } + + ieee80211_recalc_chanctx_chantype(local, ctx); + ieee80211_recalc_smps_chanctx(local, ctx); + ieee80211_recalc_radar_chanctx(local, ctx); } *changed = local_changed; - - ieee80211_recalc_chanctx_chantype(local, ctx); - ieee80211_recalc_smps_chanctx(local, ctx); - ieee80211_recalc_radar_chanctx(local, ctx); -out_wake: +out: ieee80211_wake_queues_by_reason(&sdata->local->hw, IEEE80211_MAX_QUEUE_MAP, IEEE80211_QUEUE_STOP_REASON_CHANCTX); -out: mutex_unlock(&local->chanctx_mtx); return ret; }

[v6,3/3] mac80211: allow reservation of a running chanctx

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