diff options
| -rw-r--r-- | net/mac80211/chan.c | 141 |
1 files changed, 72 insertions, 69 deletions
diff --git a/net/mac80211/chan.c b/net/mac80211/chan.c index 12bad02da561..9aa3b9e25228 100644 --- a/net/mac80211/chan.c +++ b/net/mac80211/chan.c @@ -1089,6 +1089,71 @@ int ieee80211_link_unreserve_chanctx(struct ieee80211_link_data *link) return 0; } +static struct ieee80211_chanctx * +ieee80211_replace_chanctx(struct ieee80211_local *local, + const struct ieee80211_chan_req *chanreq, + enum ieee80211_chanctx_mode mode, + struct ieee80211_chanctx *curr_ctx) +{ + struct ieee80211_chanctx *new_ctx, *ctx; + + if (!curr_ctx || (curr_ctx->replace_state == + IEEE80211_CHANCTX_WILL_BE_REPLACED) || + !list_empty(&curr_ctx->reserved_links)) { + /* + * Another link already requested this context for a + * reservation. Find another one hoping all links assigned + * to it will also switch soon enough. + * + * TODO: This needs a little more work as some cases + * (more than 2 chanctx capable devices) may fail which could + * otherwise succeed provided some channel context juggling was + * performed. + * + * Consider ctx1..3, link1..6, each ctx has 2 links. link1 and + * link2 from ctx1 request new different chandefs starting 2 + * in-place reserations with ctx4 and ctx5 replacing ctx1 and + * ctx2 respectively. Next link5 and link6 from ctx3 reserve + * ctx4. If link3 and link4 remain on ctx2 as they are then this + * fails unless `replace_ctx` from ctx5 is replaced with ctx3. + */ + list_for_each_entry(ctx, &local->chanctx_list, list) { + if (ctx->replace_state != + IEEE80211_CHANCTX_REPLACE_NONE) + continue; + + if (!list_empty(&ctx->reserved_links)) + continue; + + curr_ctx = ctx; + break; + } + } + + /* + * If that's true then all available contexts already have reservations + * and cannot be used. + */ + if (!curr_ctx || (curr_ctx->replace_state == + IEEE80211_CHANCTX_WILL_BE_REPLACED) || + !list_empty(&curr_ctx->reserved_links)) + return ERR_PTR(-EBUSY); + + new_ctx = ieee80211_alloc_chanctx(local, chanreq, mode, -1); + if (!new_ctx) + return ERR_PTR(-ENOMEM); + + new_ctx->replace_ctx = curr_ctx; + new_ctx->replace_state = IEEE80211_CHANCTX_REPLACES_OTHER; + + curr_ctx->replace_ctx = new_ctx; + curr_ctx->replace_state = IEEE80211_CHANCTX_WILL_BE_REPLACED; + + list_add_rcu(&new_ctx->list, &local->chanctx_list); + + return new_ctx; +} + int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link, const struct ieee80211_chan_req *chanreq, enum ieee80211_chanctx_mode mode, @@ -1096,7 +1161,7 @@ int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link, { struct ieee80211_sub_if_data *sdata = link->sdata; struct ieee80211_local *local = sdata->local; - struct ieee80211_chanctx *new_ctx, *curr_ctx, *ctx; + struct ieee80211_chanctx *new_ctx, *curr_ctx; lockdep_assert_wiphy(local->hw.wiphy); @@ -1106,76 +1171,14 @@ int ieee80211_link_reserve_chanctx(struct ieee80211_link_data *link, new_ctx = ieee80211_find_reservation_chanctx(local, chanreq, mode); if (!new_ctx) { - if (ieee80211_can_create_new_chanctx(local, -1)) { + if (ieee80211_can_create_new_chanctx(local, -1)) new_ctx = ieee80211_new_chanctx(local, chanreq, mode, false); - if (IS_ERR(new_ctx)) - return PTR_ERR(new_ctx); - } else { - if (!curr_ctx || - (curr_ctx->replace_state == - IEEE80211_CHANCTX_WILL_BE_REPLACED) || - !list_empty(&curr_ctx->reserved_links)) { - /* - * Another link already requested this context - * for a reservation. Find another one hoping - * all links assigned to it will also switch - * soon enough. - * - * TODO: This needs a little more work as some - * cases (more than 2 chanctx capable devices) - * may fail which could otherwise succeed - * provided some channel context juggling was - * performed. - * - * Consider ctx1..3, link1..6, each ctx has 2 - * links. link1 and link2 from ctx1 request new - * different chandefs starting 2 in-place - * reserations with ctx4 and ctx5 replacing - * ctx1 and ctx2 respectively. Next link5 and - * link6 from ctx3 reserve ctx4. If link3 and - * link4 remain on ctx2 as they are then this - * fails unless `replace_ctx` from ctx5 is - * replaced with ctx3. - */ - list_for_each_entry(ctx, &local->chanctx_list, - list) { - if (ctx->replace_state != - IEEE80211_CHANCTX_REPLACE_NONE) - continue; - - if (!list_empty(&ctx->reserved_links)) - continue; - - curr_ctx = ctx; - break; - } - } - - /* - * If that's true then all available contexts already - * have reservations and cannot be used. - */ - if (!curr_ctx || - (curr_ctx->replace_state == - IEEE80211_CHANCTX_WILL_BE_REPLACED) || - !list_empty(&curr_ctx->reserved_links)) - return -EBUSY; - - new_ctx = ieee80211_alloc_chanctx(local, chanreq, mode, -1); - if (!new_ctx) - return -ENOMEM; - - new_ctx->replace_ctx = curr_ctx; - new_ctx->replace_state = - IEEE80211_CHANCTX_REPLACES_OTHER; - - curr_ctx->replace_ctx = new_ctx; - curr_ctx->replace_state = - IEEE80211_CHANCTX_WILL_BE_REPLACED; - - list_add_rcu(&new_ctx->list, &local->chanctx_list); - } + else + new_ctx = ieee80211_replace_chanctx(local, chanreq, + mode, curr_ctx); + if (IS_ERR(new_ctx)) + return PTR_ERR(new_ctx); } list_add(&link->reserved_chanctx_list, &new_ctx->reserved_links); |