obj-$(CONFIG_MAC80211) += mac80211.o
mac80211-objs-$(CONFIG_MAC80211_LEDS) += ieee80211_led.o
-mac80211-objs-$(CONFIG_MAC80211_DEBUGFS) += debugfs.o debugfs_sta.o debugfs_netdev.o debugfs_key.o
mac80211-objs-$(CONFIG_NET_SCHED) += wme.o
mac80211-objs-$(CONFIG_MAC80211_RC_SIMPLE) += rc80211_simple.o
-mac80211-objs-$(CONFIG_MAC80211_RC_PID) += rc80211_pid.o
+mac80211-objs-$(CONFIG_MAC80211_RC_PID) += rc80211_pid_algo.o
+
+mac80211-debugfs-objs-$(CONFIG_MAC80211_RC_PID) += rc80211_pid_debugfs.o
+mac80211-objs-$(CONFIG_MAC80211_DEBUGFS) += \
+ debugfs.o \
+ debugfs_sta.o \
+ debugfs_netdev.o \
+ debugfs_key.o \
+ $(mac80211-debugfs-objs-y)
mac80211-objs := \
ieee80211.o \
+++ /dev/null
-/*
- * Copyright 2002-2005, Instant802 Networks, Inc.
- * Copyright 2005, Devicescape Software, Inc.
- * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
- * Copyright 2007, Stefano Brivio <stefano.brivio@polimi.it>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
-
-#include <linux/netdevice.h>
-#include <linux/types.h>
-#include <linux/skbuff.h>
-
-#include <net/mac80211.h>
-#include "ieee80211_rate.h"
-
-
-/* This is an implementation of a TX rate control algorithm that uses a PID
- * controller. Given a target failed frames rate, the controller decides about
- * TX rate changes to meet the target failed frames rate.
- *
- * The controller basically computes the following:
- *
- * adj = CP * err + CI * err_avg + CD * (err - last_err) * (1 + sharpening)
- *
- * where
- * adj adjustment value that is used to switch TX rate (see below)
- * err current error: target vs. current failed frames percentage
- * last_err last error
- * err_avg average (i.e. poor man's integral) of recent errors
- * sharpening non-zero when fast response is needed (i.e. right after
- * association or no frames sent for a long time), heading
- * to zero over time
- * CP Proportional coefficient
- * CI Integral coefficient
- * CD Derivative coefficient
- *
- * CP, CI, CD are subject to careful tuning.
- *
- * The integral component uses a exponential moving average approach instead of
- * an actual sliding window. The advantage is that we don't need to keep an
- * array of the last N error values and computation is easier.
- *
- * Once we have the adj value, we map it to a rate by means of a learning
- * algorithm. This algorithm keeps the state of the percentual failed frames
- * difference between rates. The behaviour of the lowest available rate is kept
- * as a reference value, and every time we switch between two rates, we compute
- * the difference between the failed frames each rate exhibited. By doing so,
- * we compare behaviours which different rates exhibited in adjacent timeslices,
- * thus the comparison is minimally affected by external conditions. This
- * difference gets propagated to the whole set of measurements, so that the
- * reference is always the same. Periodically, we normalize this set so that
- * recent events weigh the most. By comparing the adj value with this set, we
- * avoid pejorative switches to lower rates and allow for switches to higher
- * rates if they behaved well.
- *
- * Note that for the computations we use a fixed-point representation to avoid
- * floating point arithmetic. Hence, all values are shifted left by
- * RC_PID_ARITH_SHIFT.
- */
-
-/* Sampling period for measuring percentage of failed frames. */
-#define RC_PID_INTERVAL (HZ / 8)
-
-/* Exponential averaging smoothness (used for I part of PID controller) */
-#define RC_PID_SMOOTHING_SHIFT 3
-#define RC_PID_SMOOTHING (1 << RC_PID_SMOOTHING_SHIFT)
-
-/* Sharpening factor (used for D part of PID controller) */
-#define RC_PID_SHARPENING_FACTOR 0
-#define RC_PID_SHARPENING_DURATION 0
-
-/* Fixed point arithmetic shifting amount. */
-#define RC_PID_ARITH_SHIFT 8
-
-/* Fixed point arithmetic factor. */
-#define RC_PID_ARITH_FACTOR (1 << RC_PID_ARITH_SHIFT)
-
-/* Proportional PID component coefficient. */
-#define RC_PID_COEFF_P 15
-/* Integral PID component coefficient. */
-#define RC_PID_COEFF_I 9
-/* Derivative PID component coefficient. */
-#define RC_PID_COEFF_D 15
-
-/* Target failed frames rate for the PID controller. NB: This effectively gives
- * maximum failed frames percentage we're willing to accept. If the wireless
- * link quality is good, the controller will fail to adjust failed frames
- * percentage to the target. This is intentional.
- */
-#define RC_PID_TARGET_PF (11 << RC_PID_ARITH_SHIFT)
-
-/* Rate behaviour normalization quantity over time. */
-#define RC_PID_NORM_OFFSET 3
-
-/* Push high rates right after loading. */
-#define RC_PID_FAST_START 0
-
-/* Arithmetic right shift for positive and negative values for ISO C. */
-#define RC_PID_DO_ARITH_RIGHT_SHIFT(x, y) \
- (x) < 0 ? -((-(x)) >> (y)) : (x) >> (y)
-
-struct rc_pid_sta_info {
- unsigned long last_change;
- unsigned long last_sample;
-
- u32 tx_num_failed;
- u32 tx_num_xmit;
-
- /* Average failed frames percentage error (i.e. actual vs. target
- * percentage), scaled by RC_PID_SMOOTHING. This value is computed
- * using using an exponential weighted average technique:
- *
- * (RC_PID_SMOOTHING - 1) * err_avg_old + err
- * err_avg = ------------------------------------------
- * RC_PID_SMOOTHING
- *
- * where err_avg is the new approximation, err_avg_old the previous one
- * and err is the error w.r.t. to the current failed frames percentage
- * sample. Note that the bigger RC_PID_SMOOTHING the more weight is
- * given to the previous estimate, resulting in smoother behavior (i.e.
- * corresponding to a longer integration window).
- *
- * For computation, we actually don't use the above formula, but this
- * one:
- *
- * err_avg_scaled = err_avg_old_scaled - err_avg_old + err
- *
- * where:
- * err_avg_scaled = err * RC_PID_SMOOTHING
- * err_avg_old_scaled = err_avg_old * RC_PID_SMOOTHING
- *
- * This avoids floating point numbers and the per_failed_old value can
- * easily be obtained by shifting per_failed_old_scaled right by
- * RC_PID_SMOOTHING_SHIFT.
- */
- s32 err_avg_sc;
-
- /* Last framed failes percentage sample. */
- u32 last_pf;
-
- /* Sharpening needed. */
- u8 sharp_cnt;
-};
-
-/* Algorithm parameters. We keep them on a per-algorithm approach, so they can
- * be tuned individually for each interface.
- */
-struct rc_pid_rateinfo {
-
- /* Map sorted rates to rates in ieee80211_hw_mode. */
- int index;
-
- /* Map rates in ieee80211_hw_mode to sorted rates. */
- int rev_index;
-
- /* Comparison with the lowest rate. */
- int diff;
-};
-
-struct rc_pid_info {
-
- /* The failed frames percentage target. */
- u32 target;
-
- /* P, I and D coefficients. */
- s32 coeff_p;
- s32 coeff_i;
- s32 coeff_d;
-
- /* Rates information. */
- struct rc_pid_rateinfo *rinfo;
-
- /* Index of the last used rate. */
- int oldrate;
-};
-
-/* Shift the adjustment so that we won't switch to a lower rate if it exhibited
- * a worse failed frames behaviour and we'll choose the highest rate whose
- * failed frames behaviour is not worse than the one of the original rate
- * target. While at it, check that the adjustment is within the ranges. Then,
- * provide the new rate index. */
-static int rate_control_pid_shift_adjust(struct rc_pid_rateinfo *r,
- int adj, int cur, int l)
-{
- int i, j, k, tmp;
-
- if (cur + adj < 0)
- return 0;
- if (cur + adj >= l)
- return l - 1;
-
- i = r[cur + adj].rev_index;
-
- j = r[cur].rev_index;
-
- if (adj < 0) {
- tmp = i;
- for (k = j; k >= i; k--)
- if (r[k].diff <= r[j].diff)
- tmp = k;
- return r[tmp].index;
- } else if (adj > 0) {
- tmp = i;
- for (k = i + 1; k + i < l; k++)
- if (r[k].diff <= r[i].diff)
- tmp = k;
- return r[tmp].index;
- }
- return cur + adj;
-}
-
-static void rate_control_pid_adjust_rate(struct ieee80211_local *local,
- struct sta_info *sta, int adj,
- struct rc_pid_rateinfo *rinfo)
-{
- struct ieee80211_sub_if_data *sdata;
- struct ieee80211_hw_mode *mode;
- int newidx;
- int maxrate;
- int back = (adj > 0) ? 1 : -1;
-
- sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
- if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
- /* forced unicast rate - do not change STA rate */
- return;
- }
-
- mode = local->oper_hw_mode;
- maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
-
- newidx = rate_control_pid_shift_adjust(rinfo, adj, sta->txrate,
- mode->num_rates);
-
- while (newidx != sta->txrate) {
- if (rate_supported(sta, mode, newidx) &&
- (maxrate < 0 || newidx <= maxrate)) {
- sta->txrate = newidx;
- break;
- }
-
- newidx += back;
- }
-}
-
-/* Normalize the failed frames per-rate differences. */
-static void rate_control_pid_normalize(struct rc_pid_rateinfo *r, int l)
-{
- int i;
-
- if (r[0].diff > RC_PID_NORM_OFFSET)
- r[0].diff -= RC_PID_NORM_OFFSET;
- else if (r[0].diff < -RC_PID_NORM_OFFSET)
- r[0].diff += RC_PID_NORM_OFFSET;
- for (i = 0; i < l - 1; i++)
- if (r[i + 1].diff > r[i].diff + RC_PID_NORM_OFFSET)
- r[i + 1].diff -= RC_PID_NORM_OFFSET;
- else if (r[i + 1].diff <= r[i].diff)
- r[i + 1].diff += RC_PID_NORM_OFFSET;
-}
-
-static void rate_control_pid_sample(struct rc_pid_info *pinfo,
- struct ieee80211_local *local,
- struct sta_info *sta)
-{
- struct rc_pid_sta_info *spinfo = sta->rate_ctrl_priv;
- struct rc_pid_rateinfo *rinfo = pinfo->rinfo;
- struct ieee80211_hw_mode *mode;
- u32 pf;
- s32 err_avg;
- s32 err_prop;
- s32 err_int;
- s32 err_der;
- int adj, i, j, tmp;
-
- mode = local->oper_hw_mode;
- spinfo = sta->rate_ctrl_priv;
-
- /* In case nothing happened during the previous control interval, turn
- * the sharpening factor on. */
- if (jiffies - spinfo->last_sample > 2 * RC_PID_INTERVAL)
- spinfo->sharp_cnt = RC_PID_SHARPENING_DURATION;
-
- spinfo->last_sample = jiffies;
-
- /* This should never happen, but in case, we assume the old sample is
- * still a good measurement and copy it. */
- if (unlikely(spinfo->tx_num_xmit == 0))
- pf = spinfo->last_pf;
- else {
- pf = spinfo->tx_num_failed * 100 / spinfo->tx_num_xmit;
- pf <<= RC_PID_ARITH_SHIFT;
- }
-
- spinfo->tx_num_xmit = 0;
- spinfo->tx_num_failed = 0;
-
- /* If we just switched rate, update the rate behaviour info. */
- if (pinfo->oldrate != sta->txrate) {
-
- i = rinfo[pinfo->oldrate].rev_index;
- j = rinfo[sta->txrate].rev_index;
-
- tmp = (pf - spinfo->last_pf);
- tmp = RC_PID_DO_ARITH_RIGHT_SHIFT(tmp, RC_PID_ARITH_SHIFT);
-
- rinfo[j].diff = rinfo[i].diff + tmp;
- pinfo->oldrate = sta->txrate;
- }
- rate_control_pid_normalize(rinfo, mode->num_rates);
-
- /* Compute the proportional, integral and derivative errors. */
- err_prop = RC_PID_TARGET_PF - pf;
-
- err_avg = spinfo->err_avg_sc >> RC_PID_SMOOTHING_SHIFT;
- spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop;
- err_int = spinfo->err_avg_sc >> RC_PID_SMOOTHING_SHIFT;
-
- err_der = pf - spinfo->last_pf
- * (1 + RC_PID_SHARPENING_FACTOR * spinfo->sharp_cnt);
- spinfo->last_pf = pf;
- if (spinfo->sharp_cnt)
- spinfo->sharp_cnt--;
-
- /* Compute the controller output. */
- adj = (err_prop * pinfo->coeff_p + err_int * pinfo->coeff_i
- + err_der * pinfo->coeff_d);
- adj = RC_PID_DO_ARITH_RIGHT_SHIFT(adj, 2 * RC_PID_ARITH_SHIFT);
-
- /* Change rate. */
- if (adj)
- rate_control_pid_adjust_rate(local, sta, adj, rinfo);
-}
-
-static void rate_control_pid_tx_status(void *priv, struct net_device *dev,
- struct sk_buff *skb,
- struct ieee80211_tx_status *status)
-{
- struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
- struct rc_pid_info *pinfo = priv;
- struct sta_info *sta;
- struct rc_pid_sta_info *spinfo;
-
- sta = sta_info_get(local, hdr->addr1);
-
- if (!sta)
- return;
-
- /* Ignore all frames that were sent with a different rate than the rate
- * we currently advise mac80211 to use. */
- if (status->control.rate != &local->oper_hw_mode->rates[sta->txrate])
- return;
-
- spinfo = sta->rate_ctrl_priv;
- spinfo->tx_num_xmit++;
-
- /* We count frames that totally failed to be transmitted as two bad
- * frames, those that made it out but had some retries as one good and
- * one bad frame. */
- if (status->excessive_retries) {
- spinfo->tx_num_failed += 2;
- spinfo->tx_num_xmit++;
- } else if (status->retry_count) {
- spinfo->tx_num_failed++;
- spinfo->tx_num_xmit++;
- }
-
- if (status->excessive_retries) {
- sta->tx_retry_failed++;
- sta->tx_num_consecutive_failures++;
- sta->tx_num_mpdu_fail++;
- } else {
- sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
- sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
- sta->last_ack_rssi[2] = status->ack_signal;
- sta->tx_num_consecutive_failures = 0;
- sta->tx_num_mpdu_ok++;
- }
- sta->tx_retry_count += status->retry_count;
- sta->tx_num_mpdu_fail += status->retry_count;
-
- /* Update PID controller state. */
- if (time_after(jiffies, spinfo->last_sample + RC_PID_INTERVAL))
- rate_control_pid_sample(pinfo, local, sta);
-
- sta_info_put(sta);
-}
-
-static void rate_control_pid_get_rate(void *priv, struct net_device *dev,
- struct ieee80211_hw_mode *mode,
- struct sk_buff *skb,
- struct rate_selection *sel)
-{
- struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
- struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
- struct sta_info *sta;
- int rateidx;
-
- sta = sta_info_get(local, hdr->addr1);
-
- if (!sta) {
- sel->rate = rate_lowest(local, mode, NULL);
- sta_info_put(sta);
- return;
- }
-
- rateidx = sta->txrate;
-
- if (rateidx >= mode->num_rates)
- rateidx = mode->num_rates - 1;
-
- sta_info_put(sta);
-
- sel->rate = &mode->rates[rateidx];
-}
-
-static void rate_control_pid_rate_init(void *priv, void *priv_sta,
- struct ieee80211_local *local,
- struct sta_info *sta)
-{
- /* TODO: This routine should consider using RSSI from previous packets
- * as we need to have IEEE 802.1X auth succeed immediately after assoc..
- * Until that method is implemented, we will use the lowest supported
- * rate as a workaround. */
- sta->txrate = rate_lowest_index(local, local->oper_hw_mode, sta);
-}
-
-static void *rate_control_pid_alloc(struct ieee80211_local *local)
-{
- struct rc_pid_info *pinfo;
- struct rc_pid_rateinfo *rinfo;
- struct ieee80211_hw_mode *mode;
- int i, j, tmp;
- bool s;
-
- pinfo = kmalloc(sizeof(*pinfo), GFP_ATOMIC);
- if (!pinfo)
- return NULL;
-
- /* We can safely assume that oper_hw_mode won't change unless we get
- * reinitialized. */
- mode = local->oper_hw_mode;
- rinfo = kmalloc(sizeof(*rinfo) * mode->num_rates, GFP_ATOMIC);
- if (!rinfo) {
- kfree(pinfo);
- return NULL;
- }
-
- /* Sort the rates. This is optimized for the most common case (i.e.
- * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed
- * mapping too. */
- for (i = 0; i < mode->num_rates; i++) {
- rinfo[i].index = i;
- rinfo[i].rev_index = i;
- if (RC_PID_FAST_START)
- rinfo[i].diff = 0;
- else
- rinfo[i].diff = i * RC_PID_NORM_OFFSET;
- }
- for (i = 1; i < mode->num_rates; i++) {
- s = 0;
- for (j = 0; j < mode->num_rates - i; j++)
- if (unlikely(mode->rates[rinfo[j].index].rate >
- mode->rates[rinfo[j + 1].index].rate)) {
- tmp = rinfo[j].index;
- rinfo[j].index = rinfo[j + 1].index;
- rinfo[j + 1].index = tmp;
- rinfo[rinfo[j].index].rev_index = j;
- rinfo[rinfo[j + 1].index].rev_index = j + 1;
- s = 1;
- }
- if (!s)
- break;
- }
-
- pinfo->target = RC_PID_TARGET_PF;
- pinfo->coeff_p = RC_PID_COEFF_P;
- pinfo->coeff_i = RC_PID_COEFF_I;
- pinfo->coeff_d = RC_PID_COEFF_D;
- pinfo->rinfo = rinfo;
- pinfo->oldrate = 0;
-
- return pinfo;
-}
-
-static void rate_control_pid_free(void *priv)
-{
- struct rc_pid_info *pinfo = priv;
- kfree(pinfo->rinfo);
- kfree(pinfo);
-}
-
-static void rate_control_pid_clear(void *priv)
-{
-}
-
-static void *rate_control_pid_alloc_sta(void *priv, gfp_t gfp)
-{
- struct rc_pid_sta_info *spinfo;
-
- spinfo = kzalloc(sizeof(*spinfo), gfp);
-
- return spinfo;
-}
-
-static void rate_control_pid_free_sta(void *priv, void *priv_sta)
-{
- struct rc_pid_sta_info *spinfo = priv_sta;
- kfree(spinfo);
-}
-
-struct rate_control_ops mac80211_rcpid = {
- .name = "pid",
- .tx_status = rate_control_pid_tx_status,
- .get_rate = rate_control_pid_get_rate,
- .rate_init = rate_control_pid_rate_init,
- .clear = rate_control_pid_clear,
- .alloc = rate_control_pid_alloc,
- .free = rate_control_pid_free,
- .alloc_sta = rate_control_pid_alloc_sta,
- .free_sta = rate_control_pid_free_sta,
-};
--- /dev/null
+/*
+ * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#ifndef RC80211_PID_H
+#define RC80211_PID_H
+
+/* Sampling period for measuring percentage of failed frames. */
+#define RC_PID_INTERVAL (HZ / 8)
+
+/* Exponential averaging smoothness (used for I part of PID controller) */
+#define RC_PID_SMOOTHING_SHIFT 3
+#define RC_PID_SMOOTHING (1 << RC_PID_SMOOTHING_SHIFT)
+
+/* Sharpening factor (used for D part of PID controller) */
+#define RC_PID_SHARPENING_FACTOR 0
+#define RC_PID_SHARPENING_DURATION 0
+
+/* Fixed point arithmetic shifting amount. */
+#define RC_PID_ARITH_SHIFT 8
+
+/* Fixed point arithmetic factor. */
+#define RC_PID_ARITH_FACTOR (1 << RC_PID_ARITH_SHIFT)
+
+/* Proportional PID component coefficient. */
+#define RC_PID_COEFF_P 15
+/* Integral PID component coefficient. */
+#define RC_PID_COEFF_I 9
+/* Derivative PID component coefficient. */
+#define RC_PID_COEFF_D 15
+
+/* Target failed frames rate for the PID controller. NB: This effectively gives
+ * maximum failed frames percentage we're willing to accept. If the wireless
+ * link quality is good, the controller will fail to adjust failed frames
+ * percentage to the target. This is intentional.
+ */
+#define RC_PID_TARGET_PF (11 << RC_PID_ARITH_SHIFT)
+
+/* Rate behaviour normalization quantity over time. */
+#define RC_PID_NORM_OFFSET 3
+
+/* Push high rates right after loading. */
+#define RC_PID_FAST_START 0
+
+/* Arithmetic right shift for positive and negative values for ISO C. */
+#define RC_PID_DO_ARITH_RIGHT_SHIFT(x, y) \
+ (x) < 0 ? -((-(x)) >> (y)) : (x) >> (y)
+
+enum rc_pid_event_type {
+ RC_PID_EVENT_TYPE_TX_STATUS,
+ RC_PID_EVENT_TYPE_RATE_CHANGE,
+ RC_PID_EVENT_TYPE_TX_RATE,
+ RC_PID_EVENT_TYPE_PF_SAMPLE,
+};
+
+union rc_pid_event_data {
+ /* RC_PID_EVENT_TX_STATUS */
+ struct {
+ struct ieee80211_tx_status tx_status;
+ };
+ /* RC_PID_EVENT_TYPE_RATE_CHANGE */
+ /* RC_PID_EVENT_TYPE_TX_RATE */
+ struct {
+ int index;
+ int rate;
+ };
+ /* RC_PID_EVENT_TYPE_PF_SAMPLE */
+ struct {
+ s32 pf_sample;
+ s32 prop_err;
+ s32 int_err;
+ s32 der_err;
+ };
+};
+
+struct rc_pid_event {
+ /* The time when the event occured */
+ unsigned long timestamp;
+
+ /* Event ID number */
+ unsigned int id;
+
+ /* Type of event */
+ enum rc_pid_event_type type;
+
+ /* type specific data */
+ union rc_pid_event_data data;
+};
+
+/* Size of the event ring buffer. */
+#define RC_PID_EVENT_RING_SIZE 32
+
+struct rc_pid_event_buffer {
+ /* Counter that generates event IDs */
+ unsigned int ev_count;
+
+ /* Ring buffer of events */
+ struct rc_pid_event ring[RC_PID_EVENT_RING_SIZE];
+
+ /* Index to the entry in events_buf to be reused */
+ unsigned int next_entry;
+
+ /* Lock that guards against concurrent access to this buffer struct */
+ spinlock_t lock;
+
+ /* Wait queue for poll/select and blocking I/O */
+ wait_queue_head_t waitqueue;
+};
+
+struct rc_pid_events_file_info {
+ /* The event buffer we read */
+ struct rc_pid_event_buffer *events;
+
+ /* The entry we have should read next */
+ unsigned int next_entry;
+};
+
+void rate_control_pid_event_tx_status(struct rc_pid_event_buffer *buf,
+ struct ieee80211_tx_status *stat);
+
+void rate_control_pid_event_rate_change(struct rc_pid_event_buffer *buf,
+ int index, int rate);
+
+void rate_control_pid_event_tx_rate(struct rc_pid_event_buffer *buf,
+ int index, int rate);
+
+void rate_control_pid_event_pf_sample(struct rc_pid_event_buffer *buf,
+ s32 pf_sample, s32 prop_err,
+ s32 int_err, s32 der_err);
+
+void rate_control_pid_add_sta_debugfs(void *priv, void *priv_sta,
+ struct dentry *dir);
+
+void rate_control_pid_remove_sta_debugfs(void *priv, void *priv_sta);
+
+struct rc_pid_sta_info {
+ unsigned long last_change;
+ unsigned long last_sample;
+
+ u32 tx_num_failed;
+ u32 tx_num_xmit;
+
+ /* Average failed frames percentage error (i.e. actual vs. target
+ * percentage), scaled by RC_PID_SMOOTHING. This value is computed
+ * using using an exponential weighted average technique:
+ *
+ * (RC_PID_SMOOTHING - 1) * err_avg_old + err
+ * err_avg = ------------------------------------------
+ * RC_PID_SMOOTHING
+ *
+ * where err_avg is the new approximation, err_avg_old the previous one
+ * and err is the error w.r.t. to the current failed frames percentage
+ * sample. Note that the bigger RC_PID_SMOOTHING the more weight is
+ * given to the previous estimate, resulting in smoother behavior (i.e.
+ * corresponding to a longer integration window).
+ *
+ * For computation, we actually don't use the above formula, but this
+ * one:
+ *
+ * err_avg_scaled = err_avg_old_scaled - err_avg_old + err
+ *
+ * where:
+ * err_avg_scaled = err * RC_PID_SMOOTHING
+ * err_avg_old_scaled = err_avg_old * RC_PID_SMOOTHING
+ *
+ * This avoids floating point numbers and the per_failed_old value can
+ * easily be obtained by shifting per_failed_old_scaled right by
+ * RC_PID_SMOOTHING_SHIFT.
+ */
+ s32 err_avg_sc;
+
+ /* Last framed failes percentage sample. */
+ u32 last_pf;
+
+ /* Sharpening needed. */
+ u8 sharp_cnt;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+ /* Event buffer */
+ struct rc_pid_event_buffer events;
+
+ /* Events debugfs file entry */
+ struct dentry *events_entry;
+#endif
+};
+
+/* Algorithm parameters. We keep them on a per-algorithm approach, so they can
+ * be tuned individually for each interface.
+ */
+struct rc_pid_rateinfo {
+
+ /* Map sorted rates to rates in ieee80211_hw_mode. */
+ int index;
+
+ /* Map rates in ieee80211_hw_mode to sorted rates. */
+ int rev_index;
+
+ /* Did we do any measurement on this rate? */
+ bool valid;
+
+ /* Comparison with the lowest rate. */
+ int diff;
+};
+
+struct rc_pid_info {
+
+ /* The failed frames percentage target. */
+ unsigned int target;
+
+ /* Rate at which failed frames percentage is sampled in 0.001s. */
+ unsigned int sampling_period;
+
+ /* P, I and D coefficients. */
+ int coeff_p;
+ int coeff_i;
+ int coeff_d;
+
+ /* Exponential averaging shift. */
+ unsigned int smoothing_shift;
+
+ /* Sharpening shift and duration. */
+ unsigned int sharpen_shift;
+ unsigned int sharpen_duration;
+
+ /* Normalization offset. */
+ unsigned int norm_offset;
+
+ /* Fast starst parameter. */
+ unsigned int fast_start;
+
+ /* Rates information. */
+ struct rc_pid_rateinfo *rinfo;
+
+ /* Index of the last used rate. */
+ int oldrate;
+};
+
+#endif /* RC80211_PID_H */
--- /dev/null
+/*
+ * Copyright 2002-2005, Instant802 Networks, Inc.
+ * Copyright 2005, Devicescape Software, Inc.
+ * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
+ * Copyright 2007, Stefano Brivio <stefano.brivio@polimi.it>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/netdevice.h>
+#include <linux/types.h>
+#include <linux/skbuff.h>
+
+#include <net/mac80211.h>
+#include "ieee80211_rate.h"
+
+#include "rc80211_pid.h"
+
+
+/* This is an implementation of a TX rate control algorithm that uses a PID
+ * controller. Given a target failed frames rate, the controller decides about
+ * TX rate changes to meet the target failed frames rate.
+ *
+ * The controller basically computes the following:
+ *
+ * adj = CP * err + CI * err_avg + CD * (err - last_err) * (1 + sharpening)
+ *
+ * where
+ * adj adjustment value that is used to switch TX rate (see below)
+ * err current error: target vs. current failed frames percentage
+ * last_err last error
+ * err_avg average (i.e. poor man's integral) of recent errors
+ * sharpening non-zero when fast response is needed (i.e. right after
+ * association or no frames sent for a long time), heading
+ * to zero over time
+ * CP Proportional coefficient
+ * CI Integral coefficient
+ * CD Derivative coefficient
+ *
+ * CP, CI, CD are subject to careful tuning.
+ *
+ * The integral component uses a exponential moving average approach instead of
+ * an actual sliding window. The advantage is that we don't need to keep an
+ * array of the last N error values and computation is easier.
+ *
+ * Once we have the adj value, we map it to a rate by means of a learning
+ * algorithm. This algorithm keeps the state of the percentual failed frames
+ * difference between rates. The behaviour of the lowest available rate is kept
+ * as a reference value, and every time we switch between two rates, we compute
+ * the difference between the failed frames each rate exhibited. By doing so,
+ * we compare behaviours which different rates exhibited in adjacent timeslices,
+ * thus the comparison is minimally affected by external conditions. This
+ * difference gets propagated to the whole set of measurements, so that the
+ * reference is always the same. Periodically, we normalize this set so that
+ * recent events weigh the most. By comparing the adj value with this set, we
+ * avoid pejorative switches to lower rates and allow for switches to higher
+ * rates if they behaved well.
+ *
+ * Note that for the computations we use a fixed-point representation to avoid
+ * floating point arithmetic. Hence, all values are shifted left by
+ * RC_PID_ARITH_SHIFT.
+ */
+
+
+/* Shift the adjustment so that we won't switch to a lower rate if it exhibited
+ * a worse failed frames behaviour and we'll choose the highest rate whose
+ * failed frames behaviour is not worse than the one of the original rate
+ * target. While at it, check that the adjustment is within the ranges. Then,
+ * provide the new rate index. */
+static int rate_control_pid_shift_adjust(struct rc_pid_rateinfo *r,
+ int adj, int cur, int l)
+{
+ int i, j, k, tmp;
+
+ if (cur + adj < 0)
+ return 0;
+ if (cur + adj >= l)
+ return l - 1;
+
+ i = r[cur + adj].rev_index;
+
+ j = r[cur].rev_index;
+
+ if (adj < 0) {
+ tmp = i;
+ for (k = j; k >= i; k--)
+ if (r[k].diff <= r[j].diff)
+ tmp = k;
+ return r[tmp].index;
+ } else if (adj > 0) {
+ tmp = i;
+ for (k = i + 1; k + i < l; k++)
+ if (r[k].diff <= r[i].diff)
+ tmp = k;
+ return r[tmp].index;
+ }
+ return cur + adj;
+}
+
+static void rate_control_pid_adjust_rate(struct ieee80211_local *local,
+ struct sta_info *sta, int adj,
+ struct rc_pid_rateinfo *rinfo)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_hw_mode *mode;
+ int newidx;
+ int maxrate;
+ int back = (adj > 0) ? 1 : -1;
+
+ sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev);
+ if (sdata->bss && sdata->bss->force_unicast_rateidx > -1) {
+ /* forced unicast rate - do not change STA rate */
+ return;
+ }
+
+ mode = local->oper_hw_mode;
+ maxrate = sdata->bss ? sdata->bss->max_ratectrl_rateidx : -1;
+
+ newidx = rate_control_pid_shift_adjust(rinfo, adj, sta->txrate,
+ mode->num_rates);
+
+ while (newidx != sta->txrate) {
+ if (rate_supported(sta, mode, newidx) &&
+ (maxrate < 0 || newidx <= maxrate)) {
+ sta->txrate = newidx;
+ break;
+ }
+
+ newidx += back;
+ }
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+ rate_control_pid_event_rate_change(
+ &((struct rc_pid_sta_info *)sta->rate_ctrl_priv)->events,
+ newidx, mode->rates[newidx].rate);
+#endif
+}
+
+/* Normalize the failed frames per-rate differences. */
+static void rate_control_pid_normalize(struct rc_pid_rateinfo *r, int l)
+{
+ int i;
+
+ if (r[0].diff > RC_PID_NORM_OFFSET)
+ r[0].diff -= RC_PID_NORM_OFFSET;
+ else if (r[0].diff < -RC_PID_NORM_OFFSET)
+ r[0].diff += RC_PID_NORM_OFFSET;
+ for (i = 0; i < l - 1; i++)
+ if (r[i + 1].diff > r[i].diff + RC_PID_NORM_OFFSET)
+ r[i + 1].diff -= RC_PID_NORM_OFFSET;
+ else if (r[i + 1].diff <= r[i].diff)
+ r[i + 1].diff += RC_PID_NORM_OFFSET;
+}
+
+static void rate_control_pid_sample(struct rc_pid_info *pinfo,
+ struct ieee80211_local *local,
+ struct sta_info *sta)
+{
+ struct rc_pid_sta_info *spinfo = sta->rate_ctrl_priv;
+ struct rc_pid_rateinfo *rinfo = pinfo->rinfo;
+ struct ieee80211_hw_mode *mode;
+ u32 pf;
+ s32 err_avg;
+ s32 err_prop;
+ s32 err_int;
+ s32 err_der;
+ int adj, i, j, tmp;
+
+ mode = local->oper_hw_mode;
+ spinfo = sta->rate_ctrl_priv;
+
+ /* In case nothing happened during the previous control interval, turn
+ * the sharpening factor on. */
+ if (jiffies - spinfo->last_sample > 2 * RC_PID_INTERVAL)
+ spinfo->sharp_cnt = RC_PID_SHARPENING_DURATION;
+
+ spinfo->last_sample = jiffies;
+
+ /* This should never happen, but in case, we assume the old sample is
+ * still a good measurement and copy it. */
+ if (unlikely(spinfo->tx_num_xmit == 0))
+ pf = spinfo->last_pf;
+ else {
+ pf = spinfo->tx_num_failed * 100 / spinfo->tx_num_xmit;
+ pf <<= RC_PID_ARITH_SHIFT;
+ }
+
+ spinfo->tx_num_xmit = 0;
+ spinfo->tx_num_failed = 0;
+
+ /* If we just switched rate, update the rate behaviour info. */
+ if (pinfo->oldrate != sta->txrate) {
+
+ i = rinfo[pinfo->oldrate].rev_index;
+ j = rinfo[sta->txrate].rev_index;
+
+ tmp = (pf - spinfo->last_pf);
+ tmp = RC_PID_DO_ARITH_RIGHT_SHIFT(tmp, RC_PID_ARITH_SHIFT);
+
+ rinfo[j].diff = rinfo[i].diff + tmp;
+ pinfo->oldrate = sta->txrate;
+ }
+ rate_control_pid_normalize(rinfo, mode->num_rates);
+
+ /* Compute the proportional, integral and derivative errors. */
+ err_prop = RC_PID_TARGET_PF - pf;
+
+ err_avg = spinfo->err_avg_sc >> RC_PID_SMOOTHING_SHIFT;
+ spinfo->err_avg_sc = spinfo->err_avg_sc - err_avg + err_prop;
+ err_int = spinfo->err_avg_sc >> RC_PID_SMOOTHING_SHIFT;
+
+ err_der = pf - spinfo->last_pf
+ * (1 + RC_PID_SHARPENING_FACTOR * spinfo->sharp_cnt);
+ spinfo->last_pf = pf;
+ if (spinfo->sharp_cnt)
+ spinfo->sharp_cnt--;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+ rate_control_pid_event_pf_sample(&spinfo->events, pf, err_prop, err_int,
+ err_der);
+#endif
+
+ /* Compute the controller output. */
+ adj = (err_prop * pinfo->coeff_p + err_int * pinfo->coeff_i
+ + err_der * pinfo->coeff_d);
+ adj = RC_PID_DO_ARITH_RIGHT_SHIFT(adj, 2 * RC_PID_ARITH_SHIFT);
+
+ /* Change rate. */
+ if (adj)
+ rate_control_pid_adjust_rate(local, sta, adj, rinfo);
+}
+
+static void rate_control_pid_tx_status(void *priv, struct net_device *dev,
+ struct sk_buff *skb,
+ struct ieee80211_tx_status *status)
+{
+ struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct rc_pid_info *pinfo = priv;
+ struct sta_info *sta;
+ struct rc_pid_sta_info *spinfo;
+
+ sta = sta_info_get(local, hdr->addr1);
+
+ if (!sta)
+ return;
+
+ /* Ignore all frames that were sent with a different rate than the rate
+ * we currently advise mac80211 to use. */
+ if (status->control.rate != &local->oper_hw_mode->rates[sta->txrate])
+ return;
+
+ spinfo = sta->rate_ctrl_priv;
+ spinfo->tx_num_xmit++;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+ rate_control_pid_event_tx_status(&spinfo->events, status);
+#endif
+
+ /* We count frames that totally failed to be transmitted as two bad
+ * frames, those that made it out but had some retries as one good and
+ * one bad frame. */
+ if (status->excessive_retries) {
+ spinfo->tx_num_failed += 2;
+ spinfo->tx_num_xmit++;
+ } else if (status->retry_count) {
+ spinfo->tx_num_failed++;
+ spinfo->tx_num_xmit++;
+ }
+
+ if (status->excessive_retries) {
+ sta->tx_retry_failed++;
+ sta->tx_num_consecutive_failures++;
+ sta->tx_num_mpdu_fail++;
+ } else {
+ sta->last_ack_rssi[0] = sta->last_ack_rssi[1];
+ sta->last_ack_rssi[1] = sta->last_ack_rssi[2];
+ sta->last_ack_rssi[2] = status->ack_signal;
+ sta->tx_num_consecutive_failures = 0;
+ sta->tx_num_mpdu_ok++;
+ }
+ sta->tx_retry_count += status->retry_count;
+ sta->tx_num_mpdu_fail += status->retry_count;
+
+ /* Update PID controller state. */
+ if (time_after(jiffies, spinfo->last_sample + RC_PID_INTERVAL))
+ rate_control_pid_sample(pinfo, local, sta);
+
+ sta_info_put(sta);
+}
+
+static void rate_control_pid_get_rate(void *priv, struct net_device *dev,
+ struct ieee80211_hw_mode *mode,
+ struct sk_buff *skb,
+ struct rate_selection *sel)
+{
+ struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
+ struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ struct sta_info *sta;
+ int rateidx;
+
+ sta = sta_info_get(local, hdr->addr1);
+
+ if (!sta) {
+ sel->rate = rate_lowest(local, mode, NULL);
+ sta_info_put(sta);
+ return;
+ }
+
+ rateidx = sta->txrate;
+
+ if (rateidx >= mode->num_rates)
+ rateidx = mode->num_rates - 1;
+
+ sta_info_put(sta);
+
+ sel->rate = &mode->rates[rateidx];
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+ rate_control_pid_event_tx_rate(
+ &((struct rc_pid_sta_info *) sta->rate_ctrl_priv)->events,
+ rateidx, mode->rates[rateidx].rate);
+#endif
+}
+
+static void rate_control_pid_rate_init(void *priv, void *priv_sta,
+ struct ieee80211_local *local,
+ struct sta_info *sta)
+{
+ /* TODO: This routine should consider using RSSI from previous packets
+ * as we need to have IEEE 802.1X auth succeed immediately after assoc..
+ * Until that method is implemented, we will use the lowest supported
+ * rate as a workaround. */
+ sta->txrate = rate_lowest_index(local, local->oper_hw_mode, sta);
+}
+
+static void *rate_control_pid_alloc(struct ieee80211_local *local)
+{
+ struct rc_pid_info *pinfo;
+ struct rc_pid_rateinfo *rinfo;
+ struct ieee80211_hw_mode *mode;
+ int i, j, tmp;
+ bool s;
+
+ pinfo = kmalloc(sizeof(*pinfo), GFP_ATOMIC);
+ if (!pinfo)
+ return NULL;
+
+ /* We can safely assume that oper_hw_mode won't change unless we get
+ * reinitialized. */
+ mode = local->oper_hw_mode;
+ rinfo = kmalloc(sizeof(*rinfo) * mode->num_rates, GFP_ATOMIC);
+ if (!rinfo) {
+ kfree(pinfo);
+ return NULL;
+ }
+
+ /* Sort the rates. This is optimized for the most common case (i.e.
+ * almost-sorted CCK+OFDM rates). Kind of bubble-sort with reversed
+ * mapping too. */
+ for (i = 0; i < mode->num_rates; i++) {
+ rinfo[i].index = i;
+ rinfo[i].rev_index = i;
+ if (RC_PID_FAST_START)
+ rinfo[i].diff = 0;
+ else
+ rinfo[i].diff = i * RC_PID_NORM_OFFSET;
+ }
+ for (i = 1; i < mode->num_rates; i++) {
+ s = 0;
+ for (j = 0; j < mode->num_rates - i; j++)
+ if (unlikely(mode->rates[rinfo[j].index].rate >
+ mode->rates[rinfo[j + 1].index].rate)) {
+ tmp = rinfo[j].index;
+ rinfo[j].index = rinfo[j + 1].index;
+ rinfo[j + 1].index = tmp;
+ rinfo[rinfo[j].index].rev_index = j;
+ rinfo[rinfo[j + 1].index].rev_index = j + 1;
+ s = 1;
+ }
+ if (!s)
+ break;
+ }
+
+ pinfo->target = RC_PID_TARGET_PF;
+ pinfo->coeff_p = RC_PID_COEFF_P;
+ pinfo->coeff_i = RC_PID_COEFF_I;
+ pinfo->coeff_d = RC_PID_COEFF_D;
+ pinfo->rinfo = rinfo;
+ pinfo->oldrate = 0;
+
+ return pinfo;
+}
+
+static void rate_control_pid_free(void *priv)
+{
+ struct rc_pid_info *pinfo = priv;
+ kfree(pinfo->rinfo);
+ kfree(pinfo);
+}
+
+static void rate_control_pid_clear(void *priv)
+{
+}
+
+static void *rate_control_pid_alloc_sta(void *priv, gfp_t gfp)
+{
+ struct rc_pid_sta_info *spinfo;
+
+ spinfo = kzalloc(sizeof(*spinfo), gfp);
+ if (spinfo == NULL)
+ return NULL;
+
+#ifdef CONFIG_MAC80211_DEBUGFS
+ spin_lock_init(&spinfo->events.lock);
+ init_waitqueue_head(&spinfo->events.waitqueue);
+#endif
+
+ return spinfo;
+}
+
+static void rate_control_pid_free_sta(void *priv, void *priv_sta)
+{
+ struct rc_pid_sta_info *spinfo = priv_sta;
+ kfree(spinfo);
+}
+
+struct rate_control_ops mac80211_rcpid = {
+ .name = "pid",
+ .tx_status = rate_control_pid_tx_status,
+ .get_rate = rate_control_pid_get_rate,
+ .rate_init = rate_control_pid_rate_init,
+ .clear = rate_control_pid_clear,
+ .alloc = rate_control_pid_alloc,
+ .free = rate_control_pid_free,
+ .alloc_sta = rate_control_pid_alloc_sta,
+ .free_sta = rate_control_pid_free_sta,
+#ifdef CONFIG_MAC80211_DEBUGFS
+ .add_sta_debugfs = rate_control_pid_add_sta_debugfs,
+ .remove_sta_debugfs = rate_control_pid_remove_sta_debugfs,
+#endif
+};
--- /dev/null
+/*
+ * Copyright 2007, Mattias Nissler <mattias.nissler@gmx.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/poll.h>
+#include <linux/netdevice.h>
+#include <linux/types.h>
+#include <linux/skbuff.h>
+
+#include <net/mac80211.h>
+#include "ieee80211_rate.h"
+
+#include "rc80211_pid.h"
+
+static void rate_control_pid_event(struct rc_pid_event_buffer *buf,
+ enum rc_pid_event_type type,
+ union rc_pid_event_data *data)
+{
+ struct rc_pid_event *ev;
+ unsigned long status;
+
+ spin_lock_irqsave(&buf->lock, status);
+ ev = &(buf->ring[buf->next_entry]);
+ buf->next_entry = (buf->next_entry + 1) % RC_PID_EVENT_RING_SIZE;
+
+ ev->timestamp = jiffies;
+ ev->id = buf->ev_count++;
+ ev->type = type;
+ ev->data = *data;
+
+ spin_unlock_irqrestore(&buf->lock, status);
+
+ wake_up_all(&buf->waitqueue);
+}
+
+void rate_control_pid_event_tx_status(struct rc_pid_event_buffer *buf,
+ struct ieee80211_tx_status *stat)
+{
+ union rc_pid_event_data evd;
+
+ memcpy(&evd.tx_status, stat, sizeof(struct ieee80211_tx_status));
+ rate_control_pid_event(buf, RC_PID_EVENT_TYPE_TX_STATUS, &evd);
+}
+
+void rate_control_pid_event_rate_change(struct rc_pid_event_buffer *buf,
+ int index, int rate)
+{
+ union rc_pid_event_data evd;
+
+ evd.index = index;
+ evd.rate = rate;
+ rate_control_pid_event(buf, RC_PID_EVENT_TYPE_RATE_CHANGE, &evd);
+}
+
+void rate_control_pid_event_tx_rate(struct rc_pid_event_buffer *buf,
+ int index, int rate)
+{
+ union rc_pid_event_data evd;
+
+ evd.index = index;
+ evd.rate = rate;
+ rate_control_pid_event(buf, RC_PID_EVENT_TYPE_TX_RATE, &evd);
+}
+
+void rate_control_pid_event_pf_sample(struct rc_pid_event_buffer *buf,
+ s32 pf_sample, s32 prop_err,
+ s32 int_err, s32 der_err)
+{
+ union rc_pid_event_data evd;
+
+ evd.pf_sample = pf_sample;
+ evd.prop_err = prop_err;
+ evd.int_err = int_err;
+ evd.der_err = der_err;
+ rate_control_pid_event(buf, RC_PID_EVENT_TYPE_PF_SAMPLE, &evd);
+}
+
+static int rate_control_pid_events_open(struct inode *inode, struct file *file)
+{
+ struct rc_pid_sta_info *sinfo = inode->i_private;
+ struct rc_pid_event_buffer *events = &sinfo->events;
+ struct rc_pid_events_file_info *file_info;
+ unsigned int status;
+
+ /* Allocate a state struct */
+ file_info = kmalloc(sizeof(*file_info), GFP_KERNEL);
+ if (file_info == NULL)
+ return -ENOMEM;
+
+ spin_lock_irqsave(&events->lock, status);
+
+ file_info->next_entry = events->next_entry;
+ file_info->events = events;
+
+ spin_unlock_irqrestore(&events->lock, status);
+
+ file->private_data = file_info;
+
+ return 0;
+}
+
+static int rate_control_pid_events_release(struct inode *inode,
+ struct file *file)
+{
+ struct rc_pid_events_file_info *file_info = file->private_data;
+
+ kfree(file_info);
+
+ return 0;
+}
+
+static unsigned int rate_control_pid_events_poll(struct file *file,
+ poll_table *wait)
+{
+ struct rc_pid_events_file_info *file_info = file->private_data;
+
+ poll_wait(file, &file_info->events->waitqueue, wait);
+
+ return POLLIN | POLLRDNORM;
+}
+
+#define RC_PID_PRINT_BUF_SIZE 64
+
+static ssize_t rate_control_pid_events_read(struct file *file, char __user *buf,
+ size_t length, loff_t *offset)
+{
+ struct rc_pid_events_file_info *file_info = file->private_data;
+ struct rc_pid_event_buffer *events = file_info->events;
+ struct rc_pid_event *ev;
+ char pb[RC_PID_PRINT_BUF_SIZE];
+ int ret;
+ int p;
+ unsigned int status;
+
+ /* Check if there is something to read. */
+ if (events->next_entry == file_info->next_entry) {
+ if (file->f_flags & O_NONBLOCK)
+ return -EAGAIN;
+
+ /* Wait */
+ ret = wait_event_interruptible(events->waitqueue,
+ events->next_entry != file_info->next_entry);
+
+ if (ret)
+ return ret;
+ }
+
+ /* Write out one event per call. I don't care whether it's a little
+ * inefficient, this is debugging code anyway. */
+ spin_lock_irqsave(&events->lock, status);
+
+ /* Get an event */
+ ev = &(events->ring[file_info->next_entry]);
+ file_info->next_entry = (file_info->next_entry + 1) %
+ RC_PID_EVENT_RING_SIZE;
+
+ /* Print information about the event. Note that userpace needs to
+ * provide large enough buffers. */
+ length = length < RC_PID_PRINT_BUF_SIZE ?
+ length : RC_PID_PRINT_BUF_SIZE;
+ p = snprintf(pb, length, "%u %lu ", ev->id, ev->timestamp);
+ switch (ev->type) {
+ case RC_PID_EVENT_TYPE_TX_STATUS:
+ p += snprintf(pb + p, length - p, "tx_status %u %u",
+ ev->data.tx_status.excessive_retries,
+ ev->data.tx_status.retry_count);
+ break;
+ case RC_PID_EVENT_TYPE_RATE_CHANGE:
+ p += snprintf(pb + p, length - p, "rate_change %d %d",
+ ev->data.index, ev->data.rate);
+ break;
+ case RC_PID_EVENT_TYPE_TX_RATE:
+ p += snprintf(pb + p, length - p, "tx_rate %d %d",
+ ev->data.index, ev->data.rate);
+ break;
+ case RC_PID_EVENT_TYPE_PF_SAMPLE:
+ p += snprintf(pb + p, length - p,
+ "pf_sample %d %d %d %d",
+ ev->data.pf_sample, ev->data.prop_err,
+ ev->data.int_err, ev->data.der_err);
+ break;
+ }
+ p += snprintf(pb + p, length - p, "\n");
+
+ spin_unlock_irqrestore(&events->lock, status);
+
+ if (copy_to_user(buf, pb, p))
+ return -EFAULT;
+
+ return p;
+}
+
+#undef RC_PID_PRINT_BUF_SIZE
+
+struct file_operations rc_pid_fop_events = {
+ .owner = THIS_MODULE,
+ .read = rate_control_pid_events_read,
+ .poll = rate_control_pid_events_poll,
+ .open = rate_control_pid_events_open,
+ .release = rate_control_pid_events_release,
+};
+
+void rate_control_pid_add_sta_debugfs(void *priv, void *priv_sta,
+ struct dentry *dir)
+{
+ struct rc_pid_sta_info *spinfo = priv_sta;
+
+ spinfo->events_entry = debugfs_create_file("rc_pid_events", S_IRUGO,
+ dir, spinfo,
+ &rc_pid_fop_events);
+}
+
+void rate_control_pid_remove_sta_debugfs(void *priv, void *priv_sta)
+{
+ struct rc_pid_sta_info *spinfo = priv_sta;
+
+ debugfs_remove(spinfo->events_entry);
+}
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff