mac80211: add helper functions for tracking P2P NoA state
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 531785f..f838af8 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -4652,4 +4652,51 @@
struct ieee80211_vif *vif, struct sk_buff *skb,
int band, struct ieee80211_sta **sta);
+/**
+ * struct ieee80211_noa_data - holds temporary data for tracking P2P NoA state
+ *
+ * @next_tsf: TSF timestamp of the next absent state change
+ * @has_next_tsf: next absent state change event pending
+ *
+ * @absent: descriptor bitmask, set if GO is currently absent
+ *
+ * private:
+ *
+ * @count: count fields from the NoA descriptors
+ * @desc: adjusted data from the NoA
+ */
+struct ieee80211_noa_data {
+ u32 next_tsf;
+ bool has_next_tsf;
+
+ u8 absent;
+
+ u8 count[IEEE80211_P2P_NOA_DESC_MAX];
+ struct {
+ u32 start;
+ u32 duration;
+ u32 interval;
+ } desc[IEEE80211_P2P_NOA_DESC_MAX];
+};
+
+/**
+ * ieee80211_parse_p2p_noa - initialize NoA tracking data from P2P IE
+ *
+ * @attr: P2P NoA IE
+ * @data: NoA tracking data
+ * @tsf: current TSF timestamp
+ *
+ * Return: number of successfully parsed descriptors
+ */
+int ieee80211_parse_p2p_noa(const struct ieee80211_p2p_noa_attr *attr,
+ struct ieee80211_noa_data *data, u32 tsf);
+
+/**
+ * ieee80211_update_p2p_noa - get next pending P2P GO absent state change
+ *
+ * @data: NoA tracking data
+ * @tsf: current TSF timestamp
+ */
+void ieee80211_update_p2p_noa(struct ieee80211_noa_data *data, u32 tsf);
+
#endif /* MAC80211_H */
diff --git a/net/mac80211/util.c b/net/mac80211/util.c
index ed93504..df00f19 100644
--- a/net/mac80211/util.c
+++ b/net/mac80211/util.c
@@ -2594,3 +2594,143 @@
return headroom;
}
+
+static bool
+ieee80211_extend_noa_desc(struct ieee80211_noa_data *data, u32 tsf, int i)
+{
+ s32 end = data->desc[i].start + data->desc[i].duration - (tsf + 1);
+ int skip;
+
+ if (end > 0)
+ return false;
+
+ /* End time is in the past, check for repetitions */
+ skip = DIV_ROUND_UP(-end, data->desc[i].interval);
+ if (data->count[i] < 255) {
+ if (data->count[i] <= skip) {
+ data->count[i] = 0;
+ return false;
+ }
+
+ data->count[i] -= skip;
+ }
+
+ data->desc[i].start += skip * data->desc[i].interval;
+
+ return true;
+}
+
+static bool
+ieee80211_extend_absent_time(struct ieee80211_noa_data *data, u32 tsf,
+ s32 *offset)
+{
+ bool ret = false;
+ int i;
+
+ for (i = 0; i < IEEE80211_P2P_NOA_DESC_MAX; i++) {
+ s32 cur;
+
+ if (!data->count[i])
+ continue;
+
+ if (ieee80211_extend_noa_desc(data, tsf + *offset, i))
+ ret = true;
+
+ cur = data->desc[i].start - tsf;
+ if (cur > *offset)
+ continue;
+
+ cur = data->desc[i].start + data->desc[i].duration - tsf;
+ if (cur > *offset)
+ *offset = cur;
+ }
+
+ return ret;
+}
+
+static u32
+ieee80211_get_noa_absent_time(struct ieee80211_noa_data *data, u32 tsf)
+{
+ s32 offset = 0;
+ int tries = 0;
+ /*
+ * arbitrary limit, used to avoid infinite loops when combined NoA
+ * descriptors cover the full time period.
+ */
+ int max_tries = 5;
+
+ ieee80211_extend_absent_time(data, tsf, &offset);
+ do {
+ if (!ieee80211_extend_absent_time(data, tsf, &offset))
+ break;
+
+ tries++;
+ } while (tries < max_tries);
+
+ return offset;
+}
+
+void ieee80211_update_p2p_noa(struct ieee80211_noa_data *data, u32 tsf)
+{
+ u32 next_offset = BIT(31) - 1;
+ int i;
+
+ data->absent = 0;
+ data->has_next_tsf = false;
+ for (i = 0; i < IEEE80211_P2P_NOA_DESC_MAX; i++) {
+ s32 start;
+
+ if (!data->count[i])
+ continue;
+
+ ieee80211_extend_noa_desc(data, tsf, i);
+ start = data->desc[i].start - tsf;
+ if (start <= 0)
+ data->absent |= BIT(i);
+
+ if (next_offset > start)
+ next_offset = start;
+
+ data->has_next_tsf = true;
+ }
+
+ if (data->absent)
+ next_offset = ieee80211_get_noa_absent_time(data, tsf);
+
+ data->next_tsf = tsf + next_offset;
+}
+EXPORT_SYMBOL(ieee80211_update_p2p_noa);
+
+int ieee80211_parse_p2p_noa(const struct ieee80211_p2p_noa_attr *attr,
+ struct ieee80211_noa_data *data, u32 tsf)
+{
+ int ret = 0;
+ int i;
+
+ memset(data, 0, sizeof(*data));
+
+ for (i = 0; i < IEEE80211_P2P_NOA_DESC_MAX; i++) {
+ const struct ieee80211_p2p_noa_desc *desc = &attr->desc[i];
+
+ if (!desc->count || !desc->duration)
+ continue;
+
+ data->count[i] = desc->count;
+ data->desc[i].start = le32_to_cpu(desc->start_time);
+ data->desc[i].duration = le32_to_cpu(desc->duration);
+ data->desc[i].interval = le32_to_cpu(desc->interval);
+
+ if (data->count[i] > 1 &&
+ data->desc[i].interval < data->desc[i].duration)
+ continue;
+
+ ieee80211_extend_noa_desc(data, tsf, i);
+ ret++;
+ }
+
+ if (ret)
+ ieee80211_update_p2p_noa(data, tsf);
+
+ return ret;
+}
+EXPORT_SYMBOL(ieee80211_parse_p2p_noa);