294 lines
6.9 KiB
C
294 lines
6.9 KiB
C
/*
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* mac80211 - channel management
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*/
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#include <linux/nl80211.h>
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#include <net/cfg80211.h>
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#include "ieee80211_i.h"
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#include "driver-ops.h"
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static bool
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ieee80211_channel_types_are_compatible(enum nl80211_channel_type chantype1,
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enum nl80211_channel_type chantype2,
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enum nl80211_channel_type *compat)
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{
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/*
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* start out with chantype1 being the result,
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* overwriting later if needed
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*/
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if (compat)
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*compat = chantype1;
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switch (chantype1) {
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case NL80211_CHAN_NO_HT:
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if (compat)
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*compat = chantype2;
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break;
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case NL80211_CHAN_HT20:
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/*
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* allow any change that doesn't go to no-HT
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* (if it already is no-HT no change is needed)
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*/
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if (chantype2 == NL80211_CHAN_NO_HT)
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break;
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if (compat)
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*compat = chantype2;
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break;
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case NL80211_CHAN_HT40PLUS:
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case NL80211_CHAN_HT40MINUS:
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/* allow smaller bandwidth and same */
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if (chantype2 == NL80211_CHAN_NO_HT)
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break;
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if (chantype2 == NL80211_CHAN_HT20)
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break;
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if (chantype2 == chantype1)
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break;
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return false;
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}
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return true;
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}
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static void ieee80211_change_chantype(struct ieee80211_local *local,
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struct ieee80211_chanctx *ctx,
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enum nl80211_channel_type chantype)
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{
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if (chantype == ctx->conf.channel_type)
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return;
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ctx->conf.channel_type = chantype;
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drv_change_chanctx(local, ctx, IEEE80211_CHANCTX_CHANGE_CHANNEL_TYPE);
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if (!local->use_chanctx) {
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local->_oper_channel_type = chantype;
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ieee80211_hw_config(local, 0);
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}
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}
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static struct ieee80211_chanctx *
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ieee80211_find_chanctx(struct ieee80211_local *local,
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struct ieee80211_channel *channel,
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enum nl80211_channel_type channel_type,
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enum ieee80211_chanctx_mode mode)
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{
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struct ieee80211_chanctx *ctx;
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enum nl80211_channel_type compat_type;
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lockdep_assert_held(&local->chanctx_mtx);
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if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
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return NULL;
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if (WARN_ON(!channel))
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return NULL;
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list_for_each_entry(ctx, &local->chanctx_list, list) {
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compat_type = ctx->conf.channel_type;
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if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
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continue;
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if (ctx->conf.channel != channel)
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continue;
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if (!ieee80211_channel_types_are_compatible(ctx->conf.channel_type,
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channel_type,
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&compat_type))
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continue;
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ieee80211_change_chantype(local, ctx, compat_type);
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return ctx;
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}
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return NULL;
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}
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static struct ieee80211_chanctx *
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ieee80211_new_chanctx(struct ieee80211_local *local,
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struct ieee80211_channel *channel,
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enum nl80211_channel_type channel_type,
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enum ieee80211_chanctx_mode mode)
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{
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struct ieee80211_chanctx *ctx;
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int err;
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lockdep_assert_held(&local->chanctx_mtx);
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ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
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if (!ctx)
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return ERR_PTR(-ENOMEM);
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ctx->conf.channel = channel;
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ctx->conf.channel_type = channel_type;
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ctx->mode = mode;
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if (!local->use_chanctx) {
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local->_oper_channel_type = channel_type;
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local->_oper_channel = channel;
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ieee80211_hw_config(local, 0);
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} else {
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err = drv_add_chanctx(local, ctx);
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if (err) {
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kfree(ctx);
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return ERR_PTR(err);
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}
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}
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list_add(&ctx->list, &local->chanctx_list);
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return ctx;
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}
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static void ieee80211_free_chanctx(struct ieee80211_local *local,
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struct ieee80211_chanctx *ctx)
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{
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lockdep_assert_held(&local->chanctx_mtx);
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WARN_ON_ONCE(ctx->refcount != 0);
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if (!local->use_chanctx) {
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local->_oper_channel_type = NL80211_CHAN_NO_HT;
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ieee80211_hw_config(local, 0);
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} else {
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drv_remove_chanctx(local, ctx);
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}
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list_del(&ctx->list);
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kfree_rcu(ctx, rcu_head);
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}
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static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
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struct ieee80211_chanctx *ctx)
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{
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struct ieee80211_local *local = sdata->local;
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int ret;
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lockdep_assert_held(&local->chanctx_mtx);
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ret = drv_assign_vif_chanctx(local, sdata, ctx);
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if (ret)
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return ret;
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rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
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ctx->refcount++;
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return 0;
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}
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static enum nl80211_channel_type
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ieee80211_calc_chantype(struct ieee80211_local *local,
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struct ieee80211_chanctx *ctx)
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{
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struct ieee80211_chanctx_conf *conf = &ctx->conf;
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struct ieee80211_sub_if_data *sdata;
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enum nl80211_channel_type result = NL80211_CHAN_NO_HT;
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lockdep_assert_held(&local->chanctx_mtx);
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rcu_read_lock();
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list_for_each_entry_rcu(sdata, &local->interfaces, list) {
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if (!ieee80211_sdata_running(sdata))
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continue;
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if (rcu_access_pointer(sdata->vif.chanctx_conf) != conf)
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continue;
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WARN_ON_ONCE(!ieee80211_channel_types_are_compatible(
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sdata->vif.bss_conf.channel_type,
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result, &result));
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}
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rcu_read_unlock();
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return result;
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}
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static void ieee80211_recalc_chanctx_chantype(struct ieee80211_local *local,
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struct ieee80211_chanctx *ctx)
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{
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enum nl80211_channel_type chantype;
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lockdep_assert_held(&local->chanctx_mtx);
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chantype = ieee80211_calc_chantype(local, ctx);
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ieee80211_change_chantype(local, ctx, chantype);
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}
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static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
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struct ieee80211_chanctx *ctx)
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{
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struct ieee80211_local *local = sdata->local;
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lockdep_assert_held(&local->chanctx_mtx);
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ctx->refcount--;
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rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
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drv_unassign_vif_chanctx(local, sdata, ctx);
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if (ctx->refcount > 0)
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ieee80211_recalc_chanctx_chantype(sdata->local, ctx);
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}
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static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_chanctx_conf *conf;
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struct ieee80211_chanctx *ctx;
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lockdep_assert_held(&local->chanctx_mtx);
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conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
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lockdep_is_held(&local->chanctx_mtx));
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if (!conf)
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return;
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ctx = container_of(conf, struct ieee80211_chanctx, conf);
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ieee80211_unassign_vif_chanctx(sdata, ctx);
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if (ctx->refcount == 0)
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ieee80211_free_chanctx(local, ctx);
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}
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int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
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struct ieee80211_channel *channel,
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enum nl80211_channel_type channel_type,
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enum ieee80211_chanctx_mode mode)
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{
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struct ieee80211_local *local = sdata->local;
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struct ieee80211_chanctx *ctx;
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int ret;
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WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
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mutex_lock(&local->chanctx_mtx);
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__ieee80211_vif_release_channel(sdata);
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ctx = ieee80211_find_chanctx(local, channel, channel_type, mode);
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if (!ctx)
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ctx = ieee80211_new_chanctx(local, channel, channel_type, mode);
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if (IS_ERR(ctx)) {
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ret = PTR_ERR(ctx);
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goto out;
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}
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sdata->vif.bss_conf.channel_type = channel_type;
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ret = ieee80211_assign_vif_chanctx(sdata, ctx);
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if (ret) {
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/* if assign fails refcount stays the same */
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if (ctx->refcount == 0)
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ieee80211_free_chanctx(local, ctx);
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goto out;
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}
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out:
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mutex_unlock(&local->chanctx_mtx);
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return ret;
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}
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void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
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{
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WARN_ON(sdata->dev && netif_carrier_ok(sdata->dev));
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mutex_lock(&sdata->local->chanctx_mtx);
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__ieee80211_vif_release_channel(sdata);
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mutex_unlock(&sdata->local->chanctx_mtx);
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}
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