mac80211: introduce channel context skeleton code

Channel context are the foundation for multi-channel operation. They are are immutable and are re-created (or re-used if other interfaces are bound to a certain channel and a compatible channel type) on channel switching. This is an initial implementation and more features will come in separate patches. Signed-off-by: Michal Kazior <michal.kazior@tieto.com> [some changes including RCU protection] Signed-off-by: Johannes Berg <johannes.berg@intel.com>
author: Michal Kazior <michal.kazior@tieto.com> 2012-06-26 08:37:16 -0400
committer: Johannes Berg <johannes.berg@intel.com> 2012-10-16 14:22:41 -0400
commit: d01a1e658606a0a69100f49c2ef09aacaf74d3e7 (patch)
tree: 30de068699ed95997ad44f4d0f703a6deb0ad95b /net/mac80211/chan.c
parent: ddffeb8c4d0331609ef2581d84de4d763607bd37 (diff)
1 files changed, 147 insertions, 0 deletions
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c
index 0bfc914ddd15..4ae94860a161 100644
--- a/net/mac80211/chan.c
+++ b/net/mac80211/chan.c
@@ -168,3 +168,150 @@ bool ieee80211_set_channel_type(struct ieee80211_local *local,
        return true;
 }
+static struct ieee80211_chanctx *
+ieee80211_find_chanctx(struct ieee80211_local *local,
+                       struct ieee80211_channel *channel,
+                       enum nl80211_channel_type channel_type,
+                       enum ieee80211_chanctx_mode mode)
+{
+        struct ieee80211_chanctx *ctx;
+        lockdep_assert_held(&local->chanctx_mtx);
+        if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
+                return NULL;
+        if (WARN_ON(!channel))
+                return NULL;
+        list_for_each_entry(ctx, &local->chanctx_list, list) {
+                if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
+                        continue;
+                if (ctx->conf.channel != channel)
+                        continue;
+                if (ctx->conf.channel_type != channel_type)
+                        continue;
+                return ctx;
+        }
+        return NULL;
+}
+static struct ieee80211_chanctx *
+ieee80211_new_chanctx(struct ieee80211_local *local,
+                      struct ieee80211_channel *channel,
+                      enum nl80211_channel_type channel_type,
+                      enum ieee80211_chanctx_mode mode)
+{
+        struct ieee80211_chanctx *ctx;
+        lockdep_assert_held(&local->chanctx_mtx);
+        ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
+        if (!ctx)
+                return ERR_PTR(-ENOMEM);
+        ctx->conf.channel = channel;
+        ctx->conf.channel_type = channel_type;
+        ctx->mode = mode;
+        list_add(&ctx->list, &local->chanctx_list);
+        return ctx;
+}
+static void ieee80211_free_chanctx(struct ieee80211_local *local,
+                                   struct ieee80211_chanctx *ctx)
+{
+        lockdep_assert_held(&local->chanctx_mtx);
+        WARN_ON_ONCE(ctx->refcount != 0);
+        list_del(&ctx->list);
+        kfree_rcu(ctx, rcu_head);
+}
+static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
+                                        struct ieee80211_chanctx *ctx)
+{
+        struct ieee80211_local *local __maybe_unused = sdata->local;
+        lockdep_assert_held(&local->chanctx_mtx);
+        rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
+        ctx->refcount++;
+        return 0;
+}
+static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
+                                           struct ieee80211_chanctx *ctx)
+{
+        struct ieee80211_local *local __maybe_unused = sdata->local;
+        lockdep_assert_held(&local->chanctx_mtx);
+        ctx->refcount--;
+        rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
+}
+static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
+{
+        struct ieee80211_local *local = sdata->local;
+        struct ieee80211_chanctx_conf *conf;
+        struct ieee80211_chanctx *ctx;
+        lockdep_assert_held(&local->chanctx_mtx);
+        conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
+                                         lockdep_is_held(&local->chanctx_mtx));
+        if (!conf)
+                return;
+        ctx = container_of(conf, struct ieee80211_chanctx, conf);
+        ieee80211_unassign_vif_chanctx(sdata, ctx);
+        if (ctx->refcount == 0)
+                ieee80211_free_chanctx(local, ctx);
+}
+int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
+                              struct ieee80211_channel *channel,
+                              enum nl80211_channel_type channel_type,
+                              enum ieee80211_chanctx_mode mode)
+{
+        struct ieee80211_local *local = sdata->local;
+        struct ieee80211_chanctx *ctx;
+        int ret;
+        mutex_lock(&local->chanctx_mtx);
+        __ieee80211_vif_release_channel(sdata);
+        ctx = ieee80211_find_chanctx(local, channel, channel_type, mode);
+        if (!ctx)
+                ctx = ieee80211_new_chanctx(local, channel, channel_type, mode);
+        if (IS_ERR(ctx)) {
+                ret = PTR_ERR(ctx);
+                goto out;
+        }
+        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;
+        }
+ out:
+        mutex_unlock(&local->chanctx_mtx);
+        return ret;
+}
+void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
+{
+        mutex_lock(&sdata->local->chanctx_mtx);
+        __ieee80211_vif_release_channel(sdata);
+        mutex_unlock(&sdata->local->chanctx_mtx);
+}
author	Michal Kazior <michal.kazior@tieto.com>	2012-06-26 08:37:16 -0400
committer	Johannes Berg <johannes.berg@intel.com>	2012-10-16 14:22:41 -0400
commit	d01a1e658606a0a69100f49c2ef09aacaf74d3e7 (patch)
tree	30de068699ed95997ad44f4d0f703a6deb0ad95b /net/mac80211/chan.c
parent	ddffeb8c4d0331609ef2581d84de4d763607bd37 (diff)

diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 0bfc914ddd15..4ae94860a161 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c
@@ -168,3 +168,150 @@ bool ieee80211_set_channel_type(struct ieee80211_local *local,
168	return true;	168	return true;
169		169
170	}	170	}
		171
		172	static struct ieee80211_chanctx *
		173	ieee80211_find_chanctx(struct ieee80211_local *local,
		174	struct ieee80211_channel *channel,
		175	enum nl80211_channel_type channel_type,
		176	enum ieee80211_chanctx_mode mode)
		177	{
		178	struct ieee80211_chanctx *ctx;
		179
		180	lockdep_assert_held(&local->chanctx_mtx);
		181
		182	if (mode == IEEE80211_CHANCTX_EXCLUSIVE)
		183	return NULL;
		184	if (WARN_ON(!channel))
		185	return NULL;
		186
		187	list_for_each_entry(ctx, &local->chanctx_list, list) {
		188	if (ctx->mode == IEEE80211_CHANCTX_EXCLUSIVE)
		189	continue;
		190	if (ctx->conf.channel != channel)
		191	continue;
		192	if (ctx->conf.channel_type != channel_type)
		193	continue;
		194
		195	return ctx;
		196	}
		197
		198	return NULL;
		199	}
		200
		201	static struct ieee80211_chanctx *
		202	ieee80211_new_chanctx(struct ieee80211_local *local,
		203	struct ieee80211_channel *channel,
		204	enum nl80211_channel_type channel_type,
		205	enum ieee80211_chanctx_mode mode)
		206	{
		207	struct ieee80211_chanctx *ctx;
		208
		209	lockdep_assert_held(&local->chanctx_mtx);
		210
		211	ctx = kzalloc(sizeof(*ctx) + local->hw.chanctx_data_size, GFP_KERNEL);
		212	if (!ctx)
		213	return ERR_PTR(-ENOMEM);
		214
		215	ctx->conf.channel = channel;
		216	ctx->conf.channel_type = channel_type;
		217	ctx->mode = mode;
		218
		219	list_add(&ctx->list, &local->chanctx_list);
		220
		221	return ctx;
		222	}
		223
		224	static void ieee80211_free_chanctx(struct ieee80211_local *local,
		225	struct ieee80211_chanctx *ctx)
		226	{
		227	lockdep_assert_held(&local->chanctx_mtx);
		228
		229	WARN_ON_ONCE(ctx->refcount != 0);
		230
		231	list_del(&ctx->list);
		232	kfree_rcu(ctx, rcu_head);
		233	}
		234
		235	static int ieee80211_assign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
		236	struct ieee80211_chanctx *ctx)
		237	{
		238	struct ieee80211_local *local __maybe_unused = sdata->local;
		239
		240	lockdep_assert_held(&local->chanctx_mtx);
		241
		242	rcu_assign_pointer(sdata->vif.chanctx_conf, &ctx->conf);
		243	ctx->refcount++;
		244
		245	return 0;
		246	}
		247
		248	static void ieee80211_unassign_vif_chanctx(struct ieee80211_sub_if_data *sdata,
		249	struct ieee80211_chanctx *ctx)
		250	{
		251	struct ieee80211_local *local __maybe_unused = sdata->local;
		252
		253	lockdep_assert_held(&local->chanctx_mtx);
		254
		255	ctx->refcount--;
		256	rcu_assign_pointer(sdata->vif.chanctx_conf, NULL);
		257	}
		258
		259	static void __ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
		260	{
		261	struct ieee80211_local *local = sdata->local;
		262	struct ieee80211_chanctx_conf *conf;
		263	struct ieee80211_chanctx *ctx;
		264
		265	lockdep_assert_held(&local->chanctx_mtx);
		266
		267	conf = rcu_dereference_protected(sdata->vif.chanctx_conf,
		268	lockdep_is_held(&local->chanctx_mtx));
		269	if (!conf)
		270	return;
		271
		272	ctx = container_of(conf, struct ieee80211_chanctx, conf);
		273
		274	ieee80211_unassign_vif_chanctx(sdata, ctx);
		275	if (ctx->refcount == 0)
		276	ieee80211_free_chanctx(local, ctx);
		277	}
		278
		279	int ieee80211_vif_use_channel(struct ieee80211_sub_if_data *sdata,
		280	struct ieee80211_channel *channel,
		281	enum nl80211_channel_type channel_type,
		282	enum ieee80211_chanctx_mode mode)
		283	{
		284	struct ieee80211_local *local = sdata->local;
		285	struct ieee80211_chanctx *ctx;
		286	int ret;
		287
		288	mutex_lock(&local->chanctx_mtx);
		289	__ieee80211_vif_release_channel(sdata);
		290
		291	ctx = ieee80211_find_chanctx(local, channel, channel_type, mode);
		292	if (!ctx)
		293	ctx = ieee80211_new_chanctx(local, channel, channel_type, mode);
		294	if (IS_ERR(ctx)) {
		295	ret = PTR_ERR(ctx);
		296	goto out;
		297	}
		298
		299	ret = ieee80211_assign_vif_chanctx(sdata, ctx);
		300	if (ret) {
		301	/* if assign fails refcount stays the same */
		302	if (ctx->refcount == 0)
		303	ieee80211_free_chanctx(local, ctx);
		304	goto out;
		305	}
		306
		307	out:
		308	mutex_unlock(&local->chanctx_mtx);
		309	return ret;
		310	}
		311
		312	void ieee80211_vif_release_channel(struct ieee80211_sub_if_data *sdata)
		313	{
		314	mutex_lock(&sdata->local->chanctx_mtx);
		315	__ieee80211_vif_release_channel(sdata);
		316	mutex_unlock(&sdata->local->chanctx_mtx);
		317	}