From: Toke Høiland-Jørgensen <[email protected]>
Felix recently added code to calculate airtime of packets to the mt76
driver. Import this into mac80211 so we can use it for airtime queue limit
calculations.
The airtime.c file is copied verbatim from the mt76 driver, and adjusted to
be usable in mac80211. This involves:
- Switching to mac80211 data structures.
- Adding support for 160 MHz channels and HE mode.
- Moving the symbol and duration calculations around a bit to avoid
rounding with the higher rates and longer symbol times used for HE rates.
The per-rate TX rate calculation is also split out to its own function so
it can be used directly for the AQL calculations later.
Signed-off-by: Toke Høiland-Jørgensen <[email protected]>
---
include/net/mac80211.h | 29 ++
net/mac80211/Makefile | 3 +-
net/mac80211/airtime.c | 597 +++++++++++++++++++++++++++++++++++++
net/mac80211/ieee80211_i.h | 4 +
4 files changed, 632 insertions(+), 1 deletion(-)
create mode 100644 net/mac80211/airtime.c
diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index c643a19dce96..6fc26a051ba0 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -6424,4 +6424,33 @@ void ieee80211_nan_func_match(struct ieee80211_vif *vif,
struct cfg80211_nan_match_params *match,
gfp_t gfp);
+/**
+ * ieee80211_calc_rx_airtime - calculate estimated transmission airtime for RX.
+ *
+ * This function calculates the estimated airtime usage of a frame based on the
+ * rate information in the RX status struct and the frame length.
+ *
+ * @hw: pointer as obtained from ieee80211_alloc_hw()
+ * @status: &struct ieee80211_rx_status containing the transmission rate
+ * information.
+ * @len: frame length in bytes
+ */
+u32 ieee80211_calc_rx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_rx_status *status,
+ int len);
+
+/**
+ * ieee80211_calc_tx_airtime - calculate estimated transmission airtime for TX.
+ *
+ * This function calculates the estimated airtime usage of a frame based on the
+ * rate information in the TX info struct and the frame length.
+ *
+ * @hw: pointer as obtained from ieee80211_alloc_hw()
+ * @info: &struct ieee80211_tx_info of the frame.
+ * @len: frame length in bytes
+ */
+u32 ieee80211_calc_tx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_tx_info *info,
+ int len);
+
#endif /* MAC80211_H */
diff --git a/net/mac80211/Makefile b/net/mac80211/Makefile
index 4f03ebe732fa..6cbb1286d6c0 100644
--- a/net/mac80211/Makefile
+++ b/net/mac80211/Makefile
@@ -32,7 +32,8 @@ mac80211-y := \
chan.o \
trace.o mlme.o \
tdls.o \
- ocb.o
+ ocb.o \
+ airtime.o
mac80211-$(CONFIG_MAC80211_LEDS) += led.o
mac80211-$(CONFIG_MAC80211_DEBUGFS) += \
diff --git a/net/mac80211/airtime.c b/net/mac80211/airtime.c
new file mode 100644
index 000000000000..0c2a0bb94727
--- /dev/null
+++ b/net/mac80211/airtime.c
@@ -0,0 +1,597 @@
+// SPDX-License-Identifier: ISC
+/*
+ * Copyright (C) 2019 Felix Fietkau <[email protected]>
+ */
+
+#include <net/mac80211.h>
+#include "ieee80211_i.h"
+#include "sta_info.h"
+
+#define AVG_PKT_SIZE 1024
+
+/* Number of bits for an average sized packet */
+#define MCS_NBITS (AVG_PKT_SIZE << 3)
+
+/* Number of kilo-symbols (symbols * 1024) for a packet with (bps) bits per
+ * symbol. We use k-symbols to avoid rounding in the _TIME macros below.
+ */
+#define MCS_N_KSYMS(bps) DIV_ROUND_UP(MCS_NBITS << 10, (bps))
+
+/* Transmission time (in 1024 * usec) for a packet containing (ksyms) * 1024
+ * symbols.
+ */
+#define MCS_SYMBOL_TIME(sgi, ksyms) \
+ (sgi ? \
+ ((ksyms) * 4 * 18) / 20 : /* 3.6 us per sym */ \
+ ((ksyms) * 4) /* 4.0 us per sym */ \
+ )
+
+/* Transmit duration for the raw data part of an average sized packet */
+#define MCS_DURATION(streams, sgi, bps) \
+ ((u32)MCS_SYMBOL_TIME(sgi, MCS_N_KSYMS((streams) * (bps))))
+
+#define MCS_DURATION_S(shift, streams, sgi, bps) \
+ ((u16)((MCS_DURATION(streams, sgi, bps) >> shift)))
+
+/* These should match the values in enum nl80211_he_gi */
+#define HE_GI_08 0
+#define HE_GI_16 1
+#define HE_GI_32 2
+
+/* Transmission time (1024 usec) for a packet containing (ksyms) * k-symbols */
+#define HE_SYMBOL_TIME(gi, ksyms) \
+ (gi == HE_GI_08 ? \
+ ((ksyms) * 16 * 17) / 20 : /* 13.6 us per sym */ \
+ (gi == HE_GI_16 ? \
+ ((ksyms) * 16 * 18) / 20 : /* 14.4 us per sym */ \
+ ((ksyms) * 16) /* 16.0 us per sym */ \
+ ))
+
+/* Transmit duration for the raw data part of an average sized packet */
+#define HE_DURATION(streams, gi, bps) \
+ ((u32)HE_SYMBOL_TIME(gi, MCS_N_KSYMS((streams) * (bps))))
+
+#define HE_DURATION_S(shift, streams, gi, bps) \
+ (HE_DURATION(streams, gi, bps) >> shift)
+
+#define BW_20 0
+#define BW_40 1
+#define BW_80 2
+#define BW_160 3
+
+/*
+ * Define group sort order: HT40 -> SGI -> #streams
+ */
+#define IEEE80211_MAX_STREAMS 4
+#define IEEE80211_HT_STREAM_GROUPS 4 /* BW(=2) * SGI(=2) */
+#define IEEE80211_VHT_STREAM_GROUPS 8 /* BW(=4) * SGI(=2) */
+
+#define IEEE80211_HE_MAX_STREAMS 8
+#define IEEE80211_HE_STREAM_GROUPS 12 /* BW(=4) * GI(=3) */
+
+#define IEEE80211_HT_GROUPS_NB (IEEE80211_MAX_STREAMS * \
+ IEEE80211_HT_STREAM_GROUPS)
+#define IEEE80211_VHT_GROUPS_NB (IEEE80211_MAX_STREAMS * \
+ IEEE80211_VHT_STREAM_GROUPS)
+#define IEEE80211_HE_GROUPS_NB (IEEE80211_HE_MAX_STREAMS * \
+ IEEE80211_HE_STREAM_GROUPS)
+#define IEEE80211_GROUPS_NB (IEEE80211_HT_GROUPS_NB + \
+ IEEE80211_VHT_GROUPS_NB + \
+ IEEE80211_HE_GROUPS_NB)
+
+#define IEEE80211_HT_GROUP_0 0
+#define IEEE80211_VHT_GROUP_0 (IEEE80211_HT_GROUP_0 + IEEE80211_HT_GROUPS_NB)
+#define IEEE80211_HE_GROUP_0 (IEEE80211_VHT_GROUP_0 + IEEE80211_VHT_GROUPS_NB)
+
+#define MCS_GROUP_RATES 12
+
+#define HT_GROUP_IDX(_streams, _sgi, _ht40) \
+ IEEE80211_HT_GROUP_0 + \
+ IEEE80211_MAX_STREAMS * 2 * _ht40 + \
+ IEEE80211_MAX_STREAMS * _sgi + \
+ _streams - 1
+
+#define _MAX(a, b) (((a)>(b))?(a):(b))
+
+#define GROUP_SHIFT(duration) \
+ _MAX(0, 16 - __builtin_clz(duration))
+
+/* MCS rate information for an MCS group */
+#define __MCS_GROUP(_streams, _sgi, _ht40, _s) \
+ [HT_GROUP_IDX(_streams, _sgi, _ht40)] = { \
+ .shift = _s, \
+ .duration = { \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 54 : 26), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 108 : 52), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 162 : 78), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 216 : 104), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 324 : 156), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 432 : 208), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 486 : 234), \
+ MCS_DURATION_S(_s, _streams, _sgi, _ht40 ? 540 : 260) \
+ } \
+}
+
+#define MCS_GROUP_SHIFT(_streams, _sgi, _ht40) \
+ GROUP_SHIFT(MCS_DURATION(_streams, _sgi, _ht40 ? 54 : 26))
+
+#define MCS_GROUP(_streams, _sgi, _ht40) \
+ __MCS_GROUP(_streams, _sgi, _ht40, \
+ MCS_GROUP_SHIFT(_streams, _sgi, _ht40))
+
+#define VHT_GROUP_IDX(_streams, _sgi, _bw) \
+ (IEEE80211_VHT_GROUP_0 + \
+ IEEE80211_MAX_STREAMS * 2 * (_bw) + \
+ IEEE80211_MAX_STREAMS * (_sgi) + \
+ (_streams) - 1)
+
+#define BW2VBPS(_bw, r4, r3, r2, r1) \
+ (_bw == BW_160 ? r4 : _bw == BW_80 ? r3 : _bw == BW_40 ? r2 : r1)
+
+#define __VHT_GROUP(_streams, _sgi, _bw, _s) \
+ [VHT_GROUP_IDX(_streams, _sgi, _bw)] = { \
+ .shift = _s, \
+ .duration = { \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 234, 117, 54, 26)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 468, 234, 108, 52)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 702, 351, 162, 78)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 936, 468, 216, 104)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 1404, 702, 324, 156)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 1872, 936, 432, 208)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 2106, 1053, 486, 234)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 2340, 1170, 540, 260)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 2808, 1404, 648, 312)), \
+ MCS_DURATION_S(_s, _streams, _sgi, \
+ BW2VBPS(_bw, 3120, 1560, 720, 346)) \
+ } \
+}
+
+#define VHT_GROUP_SHIFT(_streams, _sgi, _bw) \
+ GROUP_SHIFT(MCS_DURATION(_streams, _sgi, \
+ BW2VBPS(_bw, 243, 117, 54, 26)))
+
+#define VHT_GROUP(_streams, _sgi, _bw) \
+ __VHT_GROUP(_streams, _sgi, _bw, \
+ VHT_GROUP_SHIFT(_streams, _sgi, _bw))
+
+
+#define HE_GROUP_IDX(_streams, _gi, _bw) \
+ (IEEE80211_HE_GROUP_0 + \
+ IEEE80211_HE_MAX_STREAMS * 2 * (_bw) + \
+ IEEE80211_HE_MAX_STREAMS * (_gi) + \
+ (_streams) - 1)
+
+#define __HE_GROUP(_streams, _gi, _bw, _s) \
+ [HE_GROUP_IDX(_streams, _gi, _bw)] = { \
+ .shift = _s, \
+ .duration = { \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 979, 489, 230, 115)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 1958, 979, 475, 230)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 2937, 1468, 705, 345)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 3916, 1958, 936, 475)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 5875, 2937, 1411, 705)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 7833, 3916, 1872, 936)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 8827, 4406, 2102, 1051)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 9806, 4896, 2347, 1166)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 11764, 5875, 2808, 1411)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 13060, 6523, 3124, 1555)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 14702, 7344, 3513, 1756)), \
+ HE_DURATION_S(_s, _streams, _gi, \
+ BW2VBPS(_bw, 16329, 8164, 3902, 1944)) \
+ } \
+}
+
+#define HE_GROUP_SHIFT(_streams, _gi, _bw) \
+ GROUP_SHIFT(HE_DURATION(_streams, _gi, \
+ BW2VBPS(_bw, 979, 489, 230, 115)))
+
+#define HE_GROUP(_streams, _gi, _bw) \
+ __HE_GROUP(_streams, _gi, _bw, \
+ HE_GROUP_SHIFT(_streams, _gi, _bw))
+struct mcs_group {
+ u8 shift;
+ u16 duration[MCS_GROUP_RATES];
+};
+
+static const struct mcs_group airtime_mcs_groups[] = {
+ MCS_GROUP(1, 0, BW_20),
+ MCS_GROUP(2, 0, BW_20),
+ MCS_GROUP(3, 0, BW_20),
+ MCS_GROUP(4, 0, BW_20),
+
+ MCS_GROUP(1, 1, BW_20),
+ MCS_GROUP(2, 1, BW_20),
+ MCS_GROUP(3, 1, BW_20),
+ MCS_GROUP(4, 1, BW_20),
+
+ MCS_GROUP(1, 0, BW_40),
+ MCS_GROUP(2, 0, BW_40),
+ MCS_GROUP(3, 0, BW_40),
+ MCS_GROUP(4, 0, BW_40),
+
+ MCS_GROUP(1, 1, BW_40),
+ MCS_GROUP(2, 1, BW_40),
+ MCS_GROUP(3, 1, BW_40),
+ MCS_GROUP(4, 1, BW_40),
+
+ VHT_GROUP(1, 0, BW_20),
+ VHT_GROUP(2, 0, BW_20),
+ VHT_GROUP(3, 0, BW_20),
+ VHT_GROUP(4, 0, BW_20),
+
+ VHT_GROUP(1, 1, BW_20),
+ VHT_GROUP(2, 1, BW_20),
+ VHT_GROUP(3, 1, BW_20),
+ VHT_GROUP(4, 1, BW_20),
+
+ VHT_GROUP(1, 0, BW_40),
+ VHT_GROUP(2, 0, BW_40),
+ VHT_GROUP(3, 0, BW_40),
+ VHT_GROUP(4, 0, BW_40),
+
+ VHT_GROUP(1, 1, BW_40),
+ VHT_GROUP(2, 1, BW_40),
+ VHT_GROUP(3, 1, BW_40),
+ VHT_GROUP(4, 1, BW_40),
+
+ VHT_GROUP(1, 0, BW_80),
+ VHT_GROUP(2, 0, BW_80),
+ VHT_GROUP(3, 0, BW_80),
+ VHT_GROUP(4, 0, BW_80),
+
+ VHT_GROUP(1, 1, BW_80),
+ VHT_GROUP(2, 1, BW_80),
+ VHT_GROUP(3, 1, BW_80),
+ VHT_GROUP(4, 1, BW_80),
+
+ VHT_GROUP(1, 0, BW_160),
+ VHT_GROUP(2, 0, BW_160),
+ VHT_GROUP(3, 0, BW_160),
+ VHT_GROUP(4, 0, BW_160),
+
+ VHT_GROUP(1, 1, BW_160),
+ VHT_GROUP(2, 1, BW_160),
+ VHT_GROUP(3, 1, BW_160),
+ VHT_GROUP(4, 1, BW_160),
+
+ HE_GROUP(1, HE_GI_08, BW_20),
+ HE_GROUP(2, HE_GI_08, BW_20),
+ HE_GROUP(3, HE_GI_08, BW_20),
+ HE_GROUP(4, HE_GI_08, BW_20),
+ HE_GROUP(5, HE_GI_08, BW_20),
+ HE_GROUP(6, HE_GI_08, BW_20),
+ HE_GROUP(7, HE_GI_08, BW_20),
+ HE_GROUP(8, HE_GI_08, BW_20),
+
+ HE_GROUP(1, HE_GI_16, BW_20),
+ HE_GROUP(2, HE_GI_16, BW_20),
+ HE_GROUP(3, HE_GI_16, BW_20),
+ HE_GROUP(4, HE_GI_16, BW_20),
+ HE_GROUP(5, HE_GI_16, BW_20),
+ HE_GROUP(6, HE_GI_16, BW_20),
+ HE_GROUP(7, HE_GI_16, BW_20),
+ HE_GROUP(8, HE_GI_16, BW_20),
+
+ HE_GROUP(1, HE_GI_32, BW_20),
+ HE_GROUP(2, HE_GI_32, BW_20),
+ HE_GROUP(3, HE_GI_32, BW_20),
+ HE_GROUP(4, HE_GI_32, BW_20),
+ HE_GROUP(5, HE_GI_32, BW_20),
+ HE_GROUP(6, HE_GI_32, BW_20),
+ HE_GROUP(7, HE_GI_32, BW_20),
+ HE_GROUP(8, HE_GI_32, BW_20),
+
+ HE_GROUP(1, HE_GI_08, BW_40),
+ HE_GROUP(2, HE_GI_08, BW_40),
+ HE_GROUP(3, HE_GI_08, BW_40),
+ HE_GROUP(4, HE_GI_08, BW_40),
+ HE_GROUP(5, HE_GI_08, BW_40),
+ HE_GROUP(6, HE_GI_08, BW_40),
+ HE_GROUP(7, HE_GI_08, BW_40),
+ HE_GROUP(8, HE_GI_08, BW_40),
+
+ HE_GROUP(1, HE_GI_16, BW_40),
+ HE_GROUP(2, HE_GI_16, BW_40),
+ HE_GROUP(3, HE_GI_16, BW_40),
+ HE_GROUP(4, HE_GI_16, BW_40),
+ HE_GROUP(5, HE_GI_16, BW_40),
+ HE_GROUP(6, HE_GI_16, BW_40),
+ HE_GROUP(7, HE_GI_16, BW_40),
+ HE_GROUP(8, HE_GI_16, BW_40),
+
+ HE_GROUP(1, HE_GI_32, BW_40),
+ HE_GROUP(2, HE_GI_32, BW_40),
+ HE_GROUP(3, HE_GI_32, BW_40),
+ HE_GROUP(4, HE_GI_32, BW_40),
+ HE_GROUP(5, HE_GI_32, BW_40),
+ HE_GROUP(6, HE_GI_32, BW_40),
+ HE_GROUP(7, HE_GI_32, BW_40),
+ HE_GROUP(8, HE_GI_32, BW_40),
+
+ HE_GROUP(1, HE_GI_08, BW_80),
+ HE_GROUP(2, HE_GI_08, BW_80),
+ HE_GROUP(3, HE_GI_08, BW_80),
+ HE_GROUP(4, HE_GI_08, BW_80),
+ HE_GROUP(5, HE_GI_08, BW_80),
+ HE_GROUP(6, HE_GI_08, BW_80),
+ HE_GROUP(7, HE_GI_08, BW_80),
+ HE_GROUP(8, HE_GI_08, BW_80),
+
+ HE_GROUP(1, HE_GI_16, BW_80),
+ HE_GROUP(2, HE_GI_16, BW_80),
+ HE_GROUP(3, HE_GI_16, BW_80),
+ HE_GROUP(4, HE_GI_16, BW_80),
+ HE_GROUP(5, HE_GI_16, BW_80),
+ HE_GROUP(6, HE_GI_16, BW_80),
+ HE_GROUP(7, HE_GI_16, BW_80),
+ HE_GROUP(8, HE_GI_16, BW_80),
+
+ HE_GROUP(1, HE_GI_32, BW_80),
+ HE_GROUP(2, HE_GI_32, BW_80),
+ HE_GROUP(3, HE_GI_32, BW_80),
+ HE_GROUP(4, HE_GI_32, BW_80),
+ HE_GROUP(5, HE_GI_32, BW_80),
+ HE_GROUP(6, HE_GI_32, BW_80),
+ HE_GROUP(7, HE_GI_32, BW_80),
+ HE_GROUP(8, HE_GI_32, BW_80),
+
+ HE_GROUP(1, HE_GI_08, BW_160),
+ HE_GROUP(2, HE_GI_08, BW_160),
+ HE_GROUP(3, HE_GI_08, BW_160),
+ HE_GROUP(4, HE_GI_08, BW_160),
+ HE_GROUP(5, HE_GI_08, BW_160),
+ HE_GROUP(6, HE_GI_08, BW_160),
+ HE_GROUP(7, HE_GI_08, BW_160),
+ HE_GROUP(8, HE_GI_08, BW_160),
+
+ HE_GROUP(1, HE_GI_16, BW_160),
+ HE_GROUP(2, HE_GI_16, BW_160),
+ HE_GROUP(3, HE_GI_16, BW_160),
+ HE_GROUP(4, HE_GI_16, BW_160),
+ HE_GROUP(5, HE_GI_16, BW_160),
+ HE_GROUP(6, HE_GI_16, BW_160),
+ HE_GROUP(7, HE_GI_16, BW_160),
+ HE_GROUP(8, HE_GI_16, BW_160),
+
+ HE_GROUP(1, HE_GI_32, BW_160),
+ HE_GROUP(2, HE_GI_32, BW_160),
+ HE_GROUP(3, HE_GI_32, BW_160),
+ HE_GROUP(4, HE_GI_32, BW_160),
+ HE_GROUP(5, HE_GI_32, BW_160),
+ HE_GROUP(6, HE_GI_32, BW_160),
+ HE_GROUP(7, HE_GI_32, BW_160),
+ HE_GROUP(8, HE_GI_32, BW_160),
+};
+
+static u32
+ieee80211_calc_legacy_rate_duration(u16 bitrate, bool short_pre,
+ bool cck, int len)
+{
+ u32 duration;
+
+ if (cck) {
+ duration = 144 + 48; /* preamble + PLCP */
+ if (short_pre)
+ duration >>= 1;
+
+ duration += 10; /* SIFS */
+ } else {
+ duration = 20 + 16; /* premable + SIFS */
+ }
+
+ len <<= 3;
+ duration += (len * 10) / bitrate;
+
+ return duration;
+}
+
+u32 ieee80211_calc_rx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_rx_status *status,
+ int len)
+{
+ struct ieee80211_supported_band *sband;
+ const struct ieee80211_rate *rate;
+ bool sgi = status->enc_flags & RX_ENC_FLAG_SHORT_GI;
+ bool sp = status->enc_flags & RX_ENC_FLAG_SHORTPRE;
+ int bw, streams;
+ int group, idx;
+ u32 duration;
+ bool cck;
+
+ switch (status->bw) {
+ case RATE_INFO_BW_20:
+ bw = BW_20;
+ break;
+ case RATE_INFO_BW_40:
+ bw = BW_40;
+ break;
+ case RATE_INFO_BW_80:
+ bw = BW_80;
+ break;
+ case RATE_INFO_BW_160:
+ bw = BW_160;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ switch (status->encoding) {
+ case RX_ENC_LEGACY:
+ if (WARN_ON_ONCE(status->band > NL80211_BAND_5GHZ))
+ return 0;
+
+ sband = hw->wiphy->bands[status->band];
+ if (!sband || status->rate_idx > sband->n_bitrates)
+ return 0;
+
+ rate = &sband->bitrates[status->rate_idx];
+ cck = rate->flags & IEEE80211_RATE_MANDATORY_B;
+
+ return ieee80211_calc_legacy_rate_duration(rate->bitrate, sp,
+ cck, len);
+
+ case RX_ENC_VHT:
+ streams = status->nss;
+ idx = status->rate_idx;
+ group = VHT_GROUP_IDX(streams, sgi, bw);
+ break;
+ case RX_ENC_HT:
+ streams = ((status->rate_idx >> 3) & 3) + 1;
+ idx = status->rate_idx & 7;
+ group = HT_GROUP_IDX(streams, sgi, bw);
+ break;
+ case RX_ENC_HE:
+ streams = status->nss;
+ idx = status->rate_idx;
+ group = HE_GROUP_IDX(streams, status->he_gi, bw);
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return 0;
+ }
+
+ if (WARN_ON_ONCE((status->encoding != RX_ENC_HE && streams > 4) ||
+ (status->encoding == RX_ENC_HE && streams > 8)))
+ return 0;
+
+ duration = airtime_mcs_groups[group].duration[idx];
+ duration <<= airtime_mcs_groups[group].shift;
+ duration *= len;
+ duration /= AVG_PKT_SIZE;
+ duration /= 1024;
+
+ duration += 36 + (streams << 2);
+
+ return duration;
+}
+EXPORT_SYMBOL_GPL(ieee80211_calc_rx_airtime);
+
+static u32 ieee80211_calc_tx_airtime_rate(struct ieee80211_hw *hw,
+ struct ieee80211_tx_rate *rate,
+ u8 band, int len)
+{
+ struct ieee80211_rx_status stat = {
+ .band = band,
+ };
+
+ if (rate->idx < 0 || !rate->count)
+ return 0;
+
+ if (rate->flags & IEEE80211_TX_RC_80_MHZ_WIDTH)
+ stat.bw = RATE_INFO_BW_80;
+ else if (rate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
+ stat.bw = RATE_INFO_BW_40;
+ else
+ stat.bw = RATE_INFO_BW_20;
+
+ stat.enc_flags = 0;
+ if (rate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
+ stat.enc_flags |= RX_ENC_FLAG_SHORTPRE;
+ if (rate->flags & IEEE80211_TX_RC_SHORT_GI)
+ stat.enc_flags |= RX_ENC_FLAG_SHORT_GI;
+
+ stat.rate_idx = rate->idx;
+ if (rate->flags & IEEE80211_TX_RC_VHT_MCS) {
+ stat.encoding = RX_ENC_VHT;
+ stat.rate_idx = ieee80211_rate_get_vht_mcs(rate);
+ stat.nss = ieee80211_rate_get_vht_nss(rate);
+ } else if (rate->flags & IEEE80211_TX_RC_MCS) {
+ stat.encoding = RX_ENC_HT;
+ } else {
+ stat.encoding = RX_ENC_LEGACY;
+ }
+
+ return ieee80211_calc_rx_airtime(hw, &stat, len);
+}
+
+u32 ieee80211_calc_tx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_tx_info *info,
+ int len)
+{
+ u32 duration = 0;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(info->status.rates); i++) {
+ struct ieee80211_tx_rate *rate = &info->status.rates[i];
+ u32 cur_duration;
+
+ cur_duration = ieee80211_calc_tx_airtime_rate(hw, rate,
+ info->band, len);
+ if (!cur_duration)
+ break;
+
+ duration += cur_duration * rate->count;
+ }
+
+ return duration;
+}
+EXPORT_SYMBOL_GPL(ieee80211_calc_tx_airtime);
+
+u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_sta *pubsta,
+ int len)
+{
+ struct ieee80211_supported_band *sband;
+ struct ieee80211_chanctx_conf *conf;
+ int rateidx, shift = 0;
+ bool cck, short_pream;
+ u32 basic_rates;
+ u8 band = 0;
+ u16 rate;
+
+ len += 38; /* Ethernet header length */
+
+ conf = rcu_dereference(vif->chanctx_conf);
+ if (conf) {
+ band = conf->def.chan->band;
+ shift = ieee80211_chandef_get_shift(&conf->def);
+ }
+
+ if (pubsta) {
+ struct sta_info *sta = container_of(pubsta, struct sta_info,
+ sta);
+
+ return ieee80211_calc_tx_airtime_rate(hw,
+ &sta->tx_stats.last_rate,
+ band, len);
+ }
+
+ if (!conf)
+ return 0;
+
+ /* No station to get latest rate from, so calculate the worst-case
+ * duration using the lowest configured basic rate.
+ */
+ sband = hw->wiphy->bands[band];
+
+ basic_rates = vif->bss_conf.basic_rates;
+ short_pream = vif->bss_conf.use_short_preamble;
+
+ rateidx = basic_rates ? ffs(basic_rates) - 1 : 0;
+ rate = sband->bitrates[rateidx].bitrate << shift;
+ cck = sband->bitrates[rateidx].flags & IEEE80211_RATE_MANDATORY_B;
+
+ return ieee80211_calc_legacy_rate_duration(rate, short_pream, cck, len);
+}
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 05406e9c05b3..225ea4e3cd76 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -2249,6 +2249,10 @@ const char *ieee80211_get_reason_code_string(u16 reason_code);
extern const struct ethtool_ops ieee80211_ethtool_ops;
+u32 ieee80211_calc_expected_tx_airtime(struct ieee80211_hw *hw,
+ struct ieee80211_vif *vif,
+ struct ieee80211_sta *pubsta,
+ int len);
#ifdef CONFIG_MAC80211_NOINLINE
#define debug_noinline noinline
#else
--
2.24.0.432.g9d3f5f5b63-goog
On Mon, 2019-11-18 at 22:06 -0800, Kan Yan wrote:
> From: Toke Høiland-Jørgensen <[email protected]>
>
> Felix recently added code to calculate airtime of packets to the mt76
> driver. Import this into mac80211 so we can use it for airtime queue limit
> calculations.
>
> The airtime.c file is copied verbatim from the mt76 driver, and adjusted to
> be usable in mac80211. This involves:
>
> - Switching to mac80211 data structures.
> - Adding support for 160 MHz channels and HE mode.
> - Moving the symbol and duration calculations around a bit to avoid
> rounding with the higher rates and longer symbol times used for HE rates.
:)
I'll apply this, I guess, but I do wonder to what extent it overlaps
with cfg80211_calculate_bitrate()?
johannes
On Mon, 2019-11-18 at 22:06 -0800, Kan Yan wrote:
>
> +#define HE_GROUP_IDX(_streams, _gi, _bw) \
> + (IEEE80211_HE_GROUP_0 + \
> + IEEE80211_HE_MAX_STREAMS * 2 * (_bw) + \
> + IEEE80211_HE_MAX_STREAMS * (_gi) + \
> + (_streams) - 1)
I'll also fix that to be " * 3" instead of 2, since there are 3 possible
_gi values.
johannes
Johannes Berg <[email protected]> writes:
> On Mon, 2019-11-18 at 22:06 -0800, Kan Yan wrote:
>> From: Toke Høiland-Jørgensen <[email protected]>
>>
>> Felix recently added code to calculate airtime of packets to the mt76
>> driver. Import this into mac80211 so we can use it for airtime queue limit
>> calculations.
>>
>> The airtime.c file is copied verbatim from the mt76 driver, and adjusted to
>> be usable in mac80211. This involves:
>>
>> - Switching to mac80211 data structures.
>> - Adding support for 160 MHz channels and HE mode.
>> - Moving the symbol and duration calculations around a bit to avoid
>> rounding with the higher rates and longer symbol times used for HE rates.
>
> :)
>
> I'll apply this, I guess,
Great!
> but I do wonder to what extent it overlaps with
> cfg80211_calculate_bitrate()?
Well, one calculates bitrates while the other calculates airtime? ;)
But yeah, I get what you mean. I think Felix went through quite some
pains to structure this code to avoid divisions in the fast path. I
guess that is the main blocker for cfg80211_calculate_bitrate() to be
used instead (assuming we do want to consolidate them eventually). Not
sure if that can be fixed easily though?
-Toke
Johannes Berg <[email protected]> writes:
> On Mon, 2019-11-18 at 22:06 -0800, Kan Yan wrote:
>>
>> +#define HE_GROUP_IDX(_streams, _gi, _bw) \
>> + (IEEE80211_HE_GROUP_0 + \
>> + IEEE80211_HE_MAX_STREAMS * 2 * (_bw) + \
>> + IEEE80211_HE_MAX_STREAMS * (_gi) + \
>> + (_streams) - 1)
>
> I'll also fix that to be " * 3" instead of 2, since there are 3 possible
> _gi values.
Ah yes, good catch, thanks!
-Toke
> Well, one calculates bitrates while the other calculates airtime? ;)
:)
> But yeah, I get what you mean. I think Felix went through quite some
> pains to structure this code to avoid divisions in the fast path. I
> guess that is the main blocker for cfg80211_calculate_bitrate() to be
> used instead (assuming we do want to consolidate them eventually). Not
> sure if that can be fixed easily though?
We could also do it the other way around?
Or maybe we should keep both and use them as a sanity check for each
other :P
johannes
Johannes Berg <[email protected]> writes:
>> Well, one calculates bitrates while the other calculates airtime? ;)
>
> :)
>
>> But yeah, I get what you mean. I think Felix went through quite some
>> pains to structure this code to avoid divisions in the fast path. I
>> guess that is the main blocker for cfg80211_calculate_bitrate() to be
>> used instead (assuming we do want to consolidate them eventually). Not
>> sure if that can be fixed easily though?
>
> We could also do it the other way around?
as in bitrate = 1/airtime? Dunno, maybe? How important is precision to
the bitrate calculations?
> Or maybe we should keep both and use them as a sanity check for each
> other :P
Hmm, yeah, it should be possible to write a selftest to iterate through
all rates and compare the output of each calculation, shouldn't it?
Where would be a good place to put that?
-Toke
On Fri, 2019-11-22 at 14:11 +0100, Toke Høiland-Jørgensen wrote:
>
> as in bitrate = 1/airtime? Dunno, maybe? How important is precision to
> the bitrate calculations?
Not *that* important, it's just sort of advisory for userspace.
Though I think there's at least one place in mac80211 related to
radiotap that actually does use it for airtime calculation, which should
probably be changed to the new code now ...
> > Or maybe we should keep both and use them as a sanity check for each
> > other :P
>
> Hmm, yeah, it should be possible to write a selftest to iterate through
> all rates and compare the output of each calculation, shouldn't it?
> Where would be a good place to put that?
No idea ... make a new kselftest thing for wireless?
johannes
Johannes Berg <[email protected]> writes:
> On Fri, 2019-11-22 at 14:11 +0100, Toke Høiland-Jørgensen wrote:
>>
>> as in bitrate = 1/airtime? Dunno, maybe? How important is precision to
>> the bitrate calculations?
>
> Not *that* important, it's just sort of advisory for userspace.
>
> Though I think there's at least one place in mac80211 related to
> radiotap that actually does use it for airtime calculation, which should
> probably be changed to the new code now ...
Yeah, I guess so. The ath9k driver is also doing software calculations
for RX, so that could also be converted; and mt76 should be, of course...
>> > Or maybe we should keep both and use them as a sanity check for each
>> > other :P
>>
>> Hmm, yeah, it should be possible to write a selftest to iterate through
>> all rates and compare the output of each calculation, shouldn't it?
>> Where would be a good place to put that?
>
> No idea ... make a new kselftest thing for wireless?
Right; was just wondering if there was something like that already which
I didn't know about :)
-Toke