/**
* il3945_rate_scale_flush_wins - flush out the rate scale wins
*
* Returns the number of wins that have gathered data but were
* not flushed. If there were any that were not flushed, then
* reschedule the rate flushing routine.
*/
static int
il3945_rate_scale_flush_wins(struct il3945_rs_sta *rs_sta)
{
int unflushed = 0;
int i;
unsigned long flags;
struct il_priv *il __maybe_unused = rs_sta->il;
/*
* For each rate, if we have collected data on that rate
* and it has been more than RATE_WIN_FLUSH
* since we flushed, clear out the gathered stats
*/
for (i = 0; i < RATE_COUNT_3945; i++) {
if (!rs_sta->win[i].counter)
continue;
spin_lock_irqsave(&rs_sta->lock, flags);
if (time_after(jiffies, rs_sta->win[i].stamp + RATE_WIN_FLUSH)) {
D_RATE("flushing %d samples of rate " "idx %d\n",
rs_sta->win[i].counter, i);
il3945_clear_win(&rs_sta->win[i]);
} else
unflushed++;
spin_unlock_irqrestore(&rs_sta->lock, flags);
}
return unflushed;
}
static void *
il3945_rs_alloc_sta(void *il_priv, struct ieee80211_sta *sta, gfp_t gfp)
{
struct il3945_rs_sta *rs_sta;
struct il3945_sta_priv *psta = (void *)sta->drv_priv;
struct il_priv *il __maybe_unused = il_priv;
D_RATE("enter\n");
rs_sta = &psta->rs_sta;
spin_lock_init(&rs_sta->lock);
init_timer(&rs_sta->rate_scale_flush);
D_RATE("leave\n");
return rs_sta;
}
/**
* il3945_hw_build_tx_cmd_rate - Add rate portion to TX_CMD:
*
*/
void
il3945_hw_build_tx_cmd_rate(struct il_priv *il, struct il_device_cmd *cmd,
struct ieee80211_tx_info *info,
struct ieee80211_hdr *hdr, int sta_id)
{
u16 hw_value = ieee80211_get_tx_rate(il->hw, info)->hw_value;
u16 rate_idx = min(hw_value & 0xffff, RATE_COUNT_3945 - 1);
u16 rate_mask;
int rate;
const u8 rts_retry_limit = 7;
u8 data_retry_limit;
__le32 tx_flags;
__le16 fc = hdr->frame_control;
struct il3945_tx_cmd *tx_cmd = (struct il3945_tx_cmd *)cmd->cmd.payload;
rate = il3945_rates[rate_idx].plcp;
tx_flags = tx_cmd->tx_flags;
/* We need to figure out how to get the sta->supp_rates while
* in this running context */
rate_mask = RATES_MASK_3945;
/* Set retry limit on DATA packets and Probe Responses */
if (ieee80211_is_probe_resp(fc))
data_retry_limit = 3;
else
data_retry_limit = IL_DEFAULT_TX_RETRY;
tx_cmd->data_retry_limit = data_retry_limit;
/* Set retry limit on RTS packets */
tx_cmd->rts_retry_limit = min(data_retry_limit, rts_retry_limit);
tx_cmd->rate = rate;
tx_cmd->tx_flags = tx_flags;
/* OFDM */
tx_cmd->supp_rates[0] =
((rate_mask & IL_OFDM_RATES_MASK) >> IL_FIRST_OFDM_RATE) & 0xFF;
/* CCK */
tx_cmd->supp_rates[1] = (rate_mask & 0xF);
D_RATE("Tx sta id: %d, rate: %d (plcp), flags: 0x%4X "
"cck/ofdm mask: 0x%x/0x%x\n", sta_id, tx_cmd->rate,
le32_to_cpu(tx_cmd->tx_flags), tx_cmd->supp_rates[1],
tx_cmd->supp_rates[0]);
}
static u8
il3945_sync_sta(struct il_priv *il, int sta_id, u16 tx_rate)
{
unsigned long flags_spin;
struct il_station_entry *station;
if (sta_id == IL_INVALID_STATION)
return IL_INVALID_STATION;
spin_lock_irqsave(&il->sta_lock, flags_spin);
station = &il->stations[sta_id];
station->sta.sta.modify_mask = STA_MODIFY_TX_RATE_MSK;
station->sta.rate_n_flags = cpu_to_le16(tx_rate);
station->sta.mode = STA_CONTROL_MODIFY_MSK;
il_send_add_sta(il, &station->sta, CMD_ASYNC);
spin_unlock_irqrestore(&il->sta_lock, flags_spin);
D_RATE("SCALE sync station %d to rate %d\n", sta_id, tx_rate);
return sta_id;
}
/**
* il3945_rs_tx_status - Update rate control values based on Tx results
*
* NOTE: Uses il_priv->retry_rate for the # of retries attempted by
* the hardware for each rate.
*/
static void
il3945_rs_tx_status(void *il_rate, struct ieee80211_supported_band *sband,
struct ieee80211_sta *sta, void *il_sta,
struct sk_buff *skb)
{
s8 retries = 0, current_count;
int scale_rate_idx, first_idx, last_idx;
unsigned long flags;
struct il_priv *il = (struct il_priv *)il_rate;
struct il3945_rs_sta *rs_sta = il_sta;
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
D_RATE("enter\n");
retries = info->status.rates[0].count;
/* Sanity Check for retries */
if (retries > RATE_RETRY_TH)
retries = RATE_RETRY_TH;
first_idx = sband->bitrates[info->status.rates[0].idx].hw_value;
if (first_idx < 0 || first_idx >= RATE_COUNT_3945) {
D_RATE("leave: Rate out of bounds: %d\n", first_idx);
return;
}
if (!il_sta) {
D_RATE("leave: No STA il data to update!\n");
return;
}
/* Treat uninitialized rate scaling data same as non-existing. */
if (!rs_sta->il) {
D_RATE("leave: STA il data uninitialized!\n");
return;
}
rs_sta->tx_packets++;
scale_rate_idx = first_idx;
last_idx = first_idx;
/*
* Update the win for each rate. We determine which rates
* were Tx'd based on the total number of retries vs. the number
* of retries configured for each rate -- currently set to the
* il value 'retry_rate' vs. rate specific
*
* On exit from this while loop last_idx indicates the rate
* at which the frame was finally transmitted (or failed if no
* ACK)
*/
while (retries > 1) {
if ((retries - 1) < il->retry_rate) {
current_count = (retries - 1);
last_idx = scale_rate_idx;
} else {
current_count = il->retry_rate;
last_idx = il3945_rs_next_rate(il, scale_rate_idx);
}
/* Update this rate accounting for as many retries
* as was used for it (per current_count) */
il3945_collect_tx_data(rs_sta, &rs_sta->win[scale_rate_idx], 0,
current_count, scale_rate_idx);
D_RATE("Update rate %d for %d retries.\n", scale_rate_idx,
current_count);
retries -= current_count;
scale_rate_idx = last_idx;
}
/* Update the last idx win with success/failure based on ACK */
D_RATE("Update rate %d with %s.\n", last_idx,
(info->flags & IEEE80211_TX_STAT_ACK) ? "success" : "failure");
il3945_collect_tx_data(rs_sta, &rs_sta->win[last_idx],
info->flags & IEEE80211_TX_STAT_ACK, 1,
last_idx);
/* We updated the rate scale win -- if its been more than
* flush_time since the last run, schedule the flush
* again */
spin_lock_irqsave(&rs_sta->lock, flags);
if (!rs_sta->flush_pending &&
time_after(jiffies, rs_sta->last_flush + rs_sta->flush_time)) {
rs_sta->last_partial_flush = jiffies;
rs_sta->flush_pending = 1;
mod_timer(&rs_sta->rate_scale_flush,
jiffies + rs_sta->flush_time);
}
spin_unlock_irqrestore(&rs_sta->lock, flags);
D_RATE("leave\n");
}
/**
* il3945_collect_tx_data - Update the success/failure sliding win
*
* We keep a sliding win of the last 64 packets transmitted
* at this rate. win->data contains the bitmask of successful
* packets.
*/
static void
il3945_collect_tx_data(struct il3945_rs_sta *rs_sta,
struct il3945_rate_scale_data *win, int success,
int retries, int idx)
{
unsigned long flags;
s32 fail_count;
struct il_priv *il __maybe_unused = rs_sta->il;
if (!retries) {
D_RATE("leave: retries == 0 -- should be at least 1\n");
return;
}
spin_lock_irqsave(&rs_sta->lock, flags);
/*
* Keep track of only the latest 62 tx frame attempts in this rate's
* history win; anything older isn't really relevant any more.
* If we have filled up the sliding win, drop the oldest attempt;
* if the oldest attempt (highest bit in bitmap) shows "success",
* subtract "1" from the success counter (this is the main reason
* we keep these bitmaps!).
* */
while (retries > 0) {
if (win->counter >= RATE_MAX_WINDOW) {
/* remove earliest */
win->counter = RATE_MAX_WINDOW - 1;
if (win->data & (1ULL << (RATE_MAX_WINDOW - 1))) {
win->data &= ~(1ULL << (RATE_MAX_WINDOW - 1));
win->success_counter--;
}
}
/* Increment frames-attempted counter */
win->counter++;
/* Shift bitmap by one frame (throw away oldest history),
* OR in "1", and increment "success" if this
* frame was successful. */
win->data <<= 1;
if (success > 0) {
win->success_counter++;
win->data |= 0x1;
success--;
}
retries--;
}
/* Calculate current success ratio, avoid divide-by-0! */
if (win->counter > 0)
win->success_ratio =
128 * (100 * win->success_counter) / win->counter;
else
win->success_ratio = IL_INVALID_VALUE;
fail_count = win->counter - win->success_counter;
/* Calculate average throughput, if we have enough history. */
if (fail_count >= RATE_MIN_FAILURE_TH ||
win->success_counter >= RATE_MIN_SUCCESS_TH)
win->average_tpt =
((win->success_ratio * rs_sta->expected_tpt[idx] +
64) / 128);
else
win->average_tpt = IL_INVALID_VALUE;
/* Tag this win as having been updated */
win->stamp = jiffies;
spin_unlock_irqrestore(&rs_sta->lock, flags);
}
static void
il3945_bg_rate_scale_flush(unsigned long data)
{
struct il3945_rs_sta *rs_sta = (void *)data;
struct il_priv *il __maybe_unused = rs_sta->il;
int unflushed = 0;
unsigned long flags;
u32 packet_count, duration, pps;
D_RATE("enter\n");
unflushed = il3945_rate_scale_flush_wins(rs_sta);
spin_lock_irqsave(&rs_sta->lock, flags);
/* Number of packets Rx'd since last time this timer ran */
packet_count = (rs_sta->tx_packets - rs_sta->last_tx_packets) + 1;
rs_sta->last_tx_packets = rs_sta->tx_packets + 1;
if (unflushed) {
duration =
jiffies_to_msecs(jiffies - rs_sta->last_partial_flush);
D_RATE("Tx'd %d packets in %dms\n", packet_count, duration);
/* Determine packets per second */
if (duration)
pps = (packet_count * 1000) / duration;
else
pps = 0;
if (pps) {
duration = (IL_AVERAGE_PACKETS * 1000) / pps;
if (duration < RATE_FLUSH_MIN)
duration = RATE_FLUSH_MIN;
else if (duration > RATE_FLUSH_MAX)
duration = RATE_FLUSH_MAX;
} else
duration = RATE_FLUSH_MAX;
rs_sta->flush_time = msecs_to_jiffies(duration);
D_RATE("new flush period: %d msec ave %d\n", duration,
packet_count);
mod_timer(&rs_sta->rate_scale_flush,
jiffies + rs_sta->flush_time);
rs_sta->last_partial_flush = jiffies;
} else {
rs_sta->flush_time = RATE_FLUSH;
rs_sta->flush_pending = 0;
}
/* If there weren't any unflushed entries, we don't schedule the timer
* to run again */
rs_sta->last_flush = jiffies;
spin_unlock_irqrestore(&rs_sta->lock, flags);
D_RATE("leave\n");
}
