[PATCH v2] mac80211: mesh: Add support for HW RC implementation

From: Maxim Altshul
Date: Thu Jun 23 2016 - 09:51:41 EST


Mesh HWMP module will be able to rely on the HW
RC algorithm if it exists, for path metric calculations.

This allows the metric calculation mechanism to calculate
a correct metric, based on PER and last TX rate both via
HW RC algorithm if it exists or via parameters collected
by the SW.

Signed-off-by: Maxim Altshul <maxim.altshul@xxxxxx>
---
Changed previous implementation according to Johannes's
comment. Combined the RC test and throughput assignment
to a sta_get_expected_throughput function.
Using the function both from airtime_link_metric and
from sta_set_sinfo.

net/mac80211/mesh_hwmp.c | 22 ++++++++++++++--------
net/mac80211/sta_info.c | 22 +++++++++++++++++-----
net/mac80211/sta_info.h | 2 ++
3 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c
index c6be0b4..39f9541 100644
--- a/net/mac80211/mesh_hwmp.c
+++ b/net/mac80211/mesh_hwmp.c
@@ -322,19 +322,25 @@ static u32 airtime_link_metric_get(struct ieee80211_local *local,
int device_constant = 1 << ARITH_SHIFT;
int test_frame_len = TEST_FRAME_LEN << ARITH_SHIFT;
int s_unit = 1 << ARITH_SHIFT;
- int rate, err;
+ int rate = 0, err = 0;
u32 tx_time, estimated_retx;
u64 result;

- if (sta->mesh->fail_avg >= 100)
- return MAX_METRIC;
+ /* try to get rate based on HW/SW RC algorithm */
+ sta_get_expected_throughput(sta, &rate);

- sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
- rate = cfg80211_calculate_bitrate(&rinfo);
- if (WARN_ON(!rate))
- return MAX_METRIC;
+ /* if we did not get a rate */
+ if (!rate) {
+ if (sta->mesh->fail_avg >= 100)
+ return MAX_METRIC;

- err = (sta->mesh->fail_avg << ARITH_SHIFT) / 100;
+ sta_set_rate_info_tx(sta, &sta->tx_stats.last_rate, &rinfo);
+ rate = cfg80211_calculate_bitrate(&rinfo);
+ if (WARN_ON(!rate))
+ return MAX_METRIC;
+
+ err = (sta->mesh->fail_avg << ARITH_SHIFT) / 100;
+ }

/* bitrate is in units of 100 Kbps, while we need rate in units of
* 1Mbps. This will be corrected on tx_time computation.
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c
index 63ea6cb..9580946 100644
--- a/net/mac80211/sta_info.c
+++ b/net/mac80211/sta_info.c
@@ -2069,14 +2069,26 @@ void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo)
if (test_sta_flag(sta, WLAN_STA_TDLS_PEER))
sinfo->sta_flags.set |= BIT(NL80211_STA_FLAG_TDLS_PEER);

- /* check if the driver has a SW RC implementation */
- if (ref && ref->ops->get_expected_throughput)
- thr = ref->ops->get_expected_throughput(sta->rate_ctrl_priv);
- else
- thr = drv_get_expected_throughput(local, &sta->sta);
+ sta_get_expected_throughput(sta, &thr);

if (thr != 0) {
sinfo->filled |= BIT(NL80211_STA_INFO_EXPECTED_THROUGHPUT);
sinfo->expected_throughput = thr;
}
}
+
+void sta_get_expected_throughput(struct sta_info *sta, u32 *thr)
+{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+ struct ieee80211_local *local = sdata->local;
+ struct rate_control_ref *ref = NULL;
+
+ if (test_sta_flag(sta, WLAN_STA_RATE_CONTROL))
+ ref = local->rate_ctrl;
+
+ /* check if the driver has a SW RC implementation */
+ if (ref && ref->ops->get_expected_throughput)
+ *thr = ref->ops->get_expected_throughput(sta->rate_ctrl_priv);
+ else
+ *thr = drv_get_expected_throughput(local, &sta->sta);
+}
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 2cafb21..8535443 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -661,6 +661,8 @@ void sta_set_rate_info_tx(struct sta_info *sta,
struct rate_info *rinfo);
void sta_set_sinfo(struct sta_info *sta, struct station_info *sinfo);

+void sta_get_expected_throughput(struct sta_info *sta, u32 *thr);
+
void ieee80211_sta_expire(struct ieee80211_sub_if_data *sdata,
unsigned long exp_time);
u8 sta_info_tx_streams(struct sta_info *sta);
--
2.9.0