xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mac80211: introduce channel context skeleton code

Browse Source 
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>
This commit is contained in:
Michal Kazior
2012-06-26 14:37:16 +02:00
committed by Johannes Berg
parent ddffeb8c4d
commit d01a1e6586
4 changed files with 221 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

147
net/mac80211/chan.c
View File

@@ -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);
}