/*
* Fill in the rate array information based on the current
* node configuration and the choices made by the rate
* selection code and ath_buf setup code.
*
* Later on, this may end up also being made by the
* rate control code, but for now it can live here.
*
* This needs to be called just before the packet is
* queued to the software queue or hardware queue,
* so all of the needed fields in bf_state are setup.
*/
void
ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
{
struct ieee80211_node *ni = bf->bf_node;
struct ieee80211com *ic = ni->ni_ic;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct ath_rc_series *rc = bf->bf_state.bfs_rc;
uint8_t rate;
int i;
for (i = 0; i < ATH_RC_NUM; i++) {
rc[i].flags = 0;
if (rc[i].tries == 0)
continue;
rate = rt->info[rc[i].rix].rateCode;
/*
* XXX only do this for legacy rates?
*/
if (bf->bf_state.bfs_shpream)
rate |= rt->info[rc[i].rix].shortPreamble;
/*
* Save this, used by the TX and completion code
*/
rc[i].ratecode = rate;
if (bf->bf_state.bfs_txflags &
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
rc[i].flags |= ATH_RC_RTSCTS_FLAG;
/* Only enable shortgi, 2040, dual-stream if HT is set */
if (IS_HT_RATE(rate)) {
rc[i].flags |= ATH_RC_HT_FLAG;
if (ni->ni_chw == 40)
rc[i].flags |= ATH_RC_CW40_FLAG;
if (ni->ni_chw == 40 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40)
rc[i].flags |= ATH_RC_SGI_FLAG;
if (ni->ni_chw == 20 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20)
rc[i].flags |= ATH_RC_SGI_FLAG;
/* XXX dual stream? and 3-stream? */
}
/*
* Calculate the maximum 4ms frame length based
* on the MCS rate, SGI and channel width flags.
*/
if ((rc[i].flags & ATH_RC_HT_FLAG) &&
(HT_RC_2_MCS(rate) < 32)) {
int j;
if (rc[i].flags & ATH_RC_CW40_FLAG) {
if (rc[i].flags & ATH_RC_SGI_FLAG)
j = MCS_HT40_SGI;
else
j = MCS_HT40;
} else {
if (rc[i].flags & ATH_RC_SGI_FLAG)
j = MCS_HT20_SGI;
else
j = MCS_HT20;
}
rc[i].max4msframelen =
ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
} else
rc[i].max4msframelen = 0;
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
__func__, i, rate, rc[i].flags, rc[i].max4msframelen);
}
}
/*
* Return the number of delimiters to be added to
* meet the minimum required mpdudensity.
*
* Caller should make sure that the rate is HT.
*
* TODO: is this delimiter calculation supposed to be the
* total frame length, the hdr length, the data length (including
* delimiters, padding, CRC, etc) or ?
*
* TODO: this should ensure that the rate control information
* HAS been setup for the first rate.
*
* TODO: ensure this is only called for MCS rates.
*
* TODO: enforce MCS < 31
*/
static int
ath_compute_num_delims(struct ath_softc *sc, struct ath_buf *first_bf,
uint16_t pktlen)
{
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct ieee80211_node *ni = first_bf->bf_node;
struct ieee80211vap *vap = ni->ni_vap;
int ndelim, mindelim = 0;
int mpdudensity; /* in 1/100'th of a microsecond */
uint8_t rc, rix, flags;
int width, half_gi;
uint32_t nsymbits, nsymbols;
uint16_t minlen;
/*
* vap->iv_ampdu_density is a value, rather than the actual
* density.
*/
if (vap->iv_ampdu_density > IEEE80211_HTCAP_MPDUDENSITY_16)
mpdudensity = 1600; /* maximum density */
else
mpdudensity = ieee80211_mpdudensity_map[vap->iv_ampdu_density];
/* Select standard number of delimiters based on frame length */
ndelim = ATH_AGGR_GET_NDELIM(pktlen);
/*
* If encryption is enabled, add extra delimiters to let the
* crypto hardware catch up. This could be tuned per-MAC and
* per-rate, but for now we'll simply assume encryption is
* always enabled.
*/
ndelim += ATH_AGGR_ENCRYPTDELIM;
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: pktlen=%d, ndelim=%d, mpdudensity=%d\n",
__func__, pktlen, ndelim, mpdudensity);
/*
* If the MPDU density is 0, we can return here.
* Otherwise, we need to convert the desired mpdudensity
* into a byte length, based on the rate in the subframe.
*/
if (mpdudensity == 0)
return ndelim;
/*
* Convert desired mpdu density from microeconds to bytes based
* on highest rate in rate series (i.e. first rate) to determine
* required minimum length for subframe. Take into account
* whether high rate is 20 or 40Mhz and half or full GI.
*/
rix = first_bf->bf_state.bfs_rc[0].rix;
rc = rt->info[rix].rateCode;
flags = first_bf->bf_state.bfs_rc[0].flags;
width = !! (flags & ATH_RC_CW40_FLAG);
half_gi = !! (flags & ATH_RC_SGI_FLAG);
/*
* mpdudensity is in 1/100th of a usec, so divide by 100
*/
if (half_gi)
nsymbols = NUM_SYMBOLS_PER_USEC_HALFGI(mpdudensity);
else
nsymbols = NUM_SYMBOLS_PER_USEC(mpdudensity);
nsymbols /= 100;
if (nsymbols == 0)
nsymbols = 1;
nsymbits = bits_per_symbol[HT_RC_2_MCS(rc)][width];
minlen = (nsymbols * nsymbits) / BITS_PER_BYTE;
/*
* Min length is the minimum frame length for the
* required MPDU density.
*/
if (pktlen < minlen) {
mindelim = (minlen - pktlen) / ATH_AGGR_DELIM_SZ;
ndelim = MAX(mindelim, ndelim);
}
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: pktlen=%d, minlen=%d, rix=%x, rc=%x, width=%d, hgi=%d, ndelim=%d\n",
__func__, pktlen, minlen, rix, rc, width, half_gi, ndelim);
return ndelim;
}
/*
* Fill in the rate array information based on the current
* node configuration and the choices made by the rate
* selection code and ath_buf setup code.
*
* Later on, this may end up also being made by the
* rate control code, but for now it can live here.
*
* This needs to be called just before the packet is
* queued to the software queue or hardware queue,
* so all of the needed fields in bf_state are setup.
*/
void
ath_tx_rate_fill_rcflags(struct ath_softc *sc, struct ath_buf *bf)
{
struct ieee80211_node *ni = bf->bf_node;
struct ieee80211vap *vap = ni->ni_vap;
struct ieee80211com *ic = ni->ni_ic;
const HAL_RATE_TABLE *rt = sc->sc_currates;
struct ath_rc_series *rc = bf->bf_state.bfs_rc;
uint8_t rate;
int i;
int do_ldpc;
int do_stbc;
/*
* We only do LDPC if the rate is 11n, both we and the
* receiver support LDPC and it's enabled.
*
* It's a global flag, not a per-try flag, so we clear
* it if any of the rate entries aren't 11n.
*/
do_ldpc = 0;
if ((ni->ni_vap->iv_htcaps & IEEE80211_HTCAP_LDPC) &&
(ni->ni_htcap & IEEE80211_HTCAP_LDPC))
do_ldpc = 1;
do_stbc = 0;
for (i = 0; i < ATH_RC_NUM; i++) {
rc[i].flags = 0;
if (rc[i].tries == 0)
continue;
rate = rt->info[rc[i].rix].rateCode;
/*
* Only enable short preamble for legacy rates
*/
if ((! IS_HT_RATE(rate)) && bf->bf_state.bfs_shpream)
rate |= rt->info[rc[i].rix].shortPreamble;
/*
* Save this, used by the TX and completion code
*/
rc[i].ratecode = rate;
if (bf->bf_state.bfs_txflags &
(HAL_TXDESC_RTSENA | HAL_TXDESC_CTSENA))
rc[i].flags |= ATH_RC_RTSCTS_FLAG;
/*
* If we can't do LDPC, don't.
*/
if (! IS_HT_RATE(rate))
do_ldpc = 0;
/* Only enable shortgi, 2040, dual-stream if HT is set */
if (IS_HT_RATE(rate)) {
rc[i].flags |= ATH_RC_HT_FLAG;
if (ni->ni_chw == 40)
rc[i].flags |= ATH_RC_CW40_FLAG;
if (ni->ni_chw == 40 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI40 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI40 &&
vap->iv_flags_ht & IEEE80211_FHT_SHORTGI40)
rc[i].flags |= ATH_RC_SGI_FLAG;
if (ni->ni_chw == 20 &&
ic->ic_htcaps & IEEE80211_HTCAP_SHORTGI20 &&
ni->ni_htcap & IEEE80211_HTCAP_SHORTGI20 &&
vap->iv_flags_ht & IEEE80211_FHT_SHORTGI20)
rc[i].flags |= ATH_RC_SGI_FLAG;
/*
* If we have STBC TX enabled and the receiver
* can receive (at least) 1 stream STBC, AND it's
* MCS 0-7, AND we have at least two chains enabled,
* enable STBC.
*
* XXX TODO: .. and the rate is an 11n rate?
*/
if (ic->ic_htcaps & IEEE80211_HTCAP_TXSTBC &&
ni->ni_vap->iv_flags_ht & IEEE80211_FHT_STBC_TX &&
ni->ni_htcap & IEEE80211_HTCAP_RXSTBC_1STREAM &&
(sc->sc_cur_txchainmask > 1) &&
HT_RC_2_STREAMS(rate) == 1) {
rc[i].flags |= ATH_RC_STBC_FLAG;
do_stbc = 1;
}
/*
* Dual / Triple stream rate?
*/
if (HT_RC_2_STREAMS(rate) == 2)
rc[i].flags |= ATH_RC_DS_FLAG;
else if (HT_RC_2_STREAMS(rate) == 3)
rc[i].flags |= ATH_RC_TS_FLAG;
}
/*
* Calculate the maximum TX power cap for the current
* node.
*/
rc[i].tx_power_cap = ieee80211_get_node_txpower(ni);
/*
* Calculate the maximum 4ms frame length based
* on the MCS rate, SGI and channel width flags.
*/
if ((rc[i].flags & ATH_RC_HT_FLAG) &&
(HT_RC_2_MCS(rate) < 32)) {
int j;
if (rc[i].flags & ATH_RC_CW40_FLAG) {
if (rc[i].flags & ATH_RC_SGI_FLAG)
j = MCS_HT40_SGI;
else
j = MCS_HT40;
} else {
if (rc[i].flags & ATH_RC_SGI_FLAG)
j = MCS_HT20_SGI;
else
j = MCS_HT20;
}
rc[i].max4msframelen =
ath_max_4ms_framelen[j][HT_RC_2_MCS(rate)];
} else
rc[i].max4msframelen = 0;
DPRINTF(sc, ATH_DEBUG_SW_TX_AGGR,
"%s: i=%d, rate=0x%x, flags=0x%x, max4ms=%d\n",
__func__, i, rate, rc[i].flags, rc[i].max4msframelen);
}
/*
* LDPC is a global flag, so ...
*/
if (do_ldpc) {
bf->bf_state.bfs_txflags |= HAL_TXDESC_LDPC;
sc->sc_stats.ast_tx_ldpc++;
}
if (do_stbc) {
sc->sc_stats.ast_tx_stbc++;
}
}
