net/mac80211/rate.c - kernel/msm-4.9 - Gitiles

 /*
  * Copyright 2002-2005, Instant802 Networks, Inc.
  * Copyright 2005-2006, Devicescape Software, Inc.
  * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
  *
  * 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/kernel.h>
 #include <linux/rtnetlink.h>
 #include <linux/slab.h>
 #include <linux/module.h>
 #include "rate.h"
 #include "ieee80211_i.h"
 #include "debugfs.h"

 struct rate_control_alg {
 	struct list_head list;
 	struct rate_control_ops *ops;
 };

 static LIST_HEAD(rate_ctrl_algs);
 static DEFINE_MUTEX(rate_ctrl_mutex);

 static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
 module_param(ieee80211_default_rc_algo, charp, 0644);
 MODULE_PARM_DESC(ieee80211_default_rc_algo,
 		 "Default rate control algorithm for mac80211 to use");

 int ieee80211_rate_control_register(struct rate_control_ops *ops)
 {
 	struct rate_control_alg *alg;

 	if (!ops->name)
 		return -EINVAL;

 	mutex_lock(&rate_ctrl_mutex);
 	list_for_each_entry(alg, &rate_ctrl_algs, list) {
 		if (!strcmp(alg->ops->name, ops->name)) {
 			/* don't register an algorithm twice */
 			WARN_ON(1);
 			mutex_unlock(&rate_ctrl_mutex);
 			return -EALREADY;
 		}
 	}

 	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
 	if (alg == NULL) {
 		mutex_unlock(&rate_ctrl_mutex);
 		return -ENOMEM;
 	}
 	alg->ops = ops;

 	list_add_tail(&alg->list, &rate_ctrl_algs);
 	mutex_unlock(&rate_ctrl_mutex);

 	return 0;
 }
 EXPORT_SYMBOL(ieee80211_rate_control_register);

 void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
 {
 	struct rate_control_alg *alg;

 	mutex_lock(&rate_ctrl_mutex);
 	list_for_each_entry(alg, &rate_ctrl_algs, list) {
 		if (alg->ops == ops) {
 			list_del(&alg->list);
 			kfree(alg);
 			break;
 		}
 	}
 	mutex_unlock(&rate_ctrl_mutex);
 }
 EXPORT_SYMBOL(ieee80211_rate_control_unregister);

 static struct rate_control_ops *
 ieee80211_try_rate_control_ops_get(const char *name)
 {
 	struct rate_control_alg *alg;
 	struct rate_control_ops *ops = NULL;

 	if (!name)
 		return NULL;

 	mutex_lock(&rate_ctrl_mutex);
 	list_for_each_entry(alg, &rate_ctrl_algs, list) {
 		if (!strcmp(alg->ops->name, name))
 			if (try_module_get(alg->ops->module)) {
 				ops = alg->ops;
 				break;
 			}
 	}
 	mutex_unlock(&rate_ctrl_mutex);
 	return ops;
 }

 /* Get the rate control algorithm. */
 static struct rate_control_ops *
 ieee80211_rate_control_ops_get(const char *name)
 {
 	struct rate_control_ops *ops;
 	const char *alg_name;

 	kparam_block_sysfs_write(ieee80211_default_rc_algo);
 	if (!name)
 		alg_name = ieee80211_default_rc_algo;
 	else
 		alg_name = name;

 	ops = ieee80211_try_rate_control_ops_get(alg_name);
 	if (!ops) {
 		request_module("rc80211_%s", alg_name);
 		ops = ieee80211_try_rate_control_ops_get(alg_name);
 	}
 	if (!ops && name)
 		/* try default if specific alg requested but not found */
 		ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);

 	/* try built-in one if specific alg requested but not found */
 	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
 		ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
 	kparam_unblock_sysfs_write(ieee80211_default_rc_algo);

 	return ops;
 }

 static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
 {
 	module_put(ops->module);
 }

 #ifdef CONFIG_MAC80211_DEBUGFS
 static ssize_t rcname_read(struct file *file, char __user *userbuf,
 			   size_t count, loff_t *ppos)
 {
 	struct rate_control_ref *ref = file->private_data;
 	int len = strlen(ref->ops->name);

 	return simple_read_from_buffer(userbuf, count, ppos,
 				       ref->ops->name, len);
 }

 static const struct file_operations rcname_ops = {
 	.read = rcname_read,
 	.open = simple_open,
 	.llseek = default_llseek,
 };
 #endif

 static struct rate_control_ref *rate_control_alloc(const char *name,
 					    struct ieee80211_local *local)
 {
 	struct dentry *debugfsdir = NULL;
 	struct rate_control_ref *ref;

 	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
 	if (!ref)
 		goto fail_ref;
 	ref->local = local;
 	ref->ops = ieee80211_rate_control_ops_get(name);
 	if (!ref->ops)
 		goto fail_ops;

 #ifdef CONFIG_MAC80211_DEBUGFS
 	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
 	local->debugfs.rcdir = debugfsdir;
 	debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
 #endif

 	ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
 	if (!ref->priv)
 		goto fail_priv;
 	return ref;

 fail_priv:
 	ieee80211_rate_control_ops_put(ref->ops);
 fail_ops:
 	kfree(ref);
 fail_ref:
 	return NULL;
 }

 static void rate_control_free(struct rate_control_ref *ctrl_ref)
 {
 	ctrl_ref->ops->free(ctrl_ref->priv);

 #ifdef CONFIG_MAC80211_DEBUGFS
 	debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
 	ctrl_ref->local->debugfs.rcdir = NULL;
 #endif

 	ieee80211_rate_control_ops_put(ctrl_ref->ops);
 	kfree(ctrl_ref);
 }

 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
 {
 	struct sk_buff *skb = txrc->skb;
 	struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
 	__le16 fc;

 	fc = hdr->frame_control;

 	return (info->flags & (IEEE80211_TX_CTL_NO_ACK |
 			       IEEE80211_TX_CTL_USE_MINRATE)) ||
 		!ieee80211_is_data(fc);
 }

 static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
 				  struct ieee80211_supported_band *sband)
 {
 	u8 i;

 	if (basic_rates == 0)
 		return; /* assume basic rates unknown and accept rate */
 	if (*idx < 0)
 		return;
 	if (basic_rates & (1 << *idx))
 		return; /* selected rate is a basic rate */

 	for (i = *idx + 1; i <= sband->n_bitrates; i++) {
 		if (basic_rates & (1 << i)) {
 			*idx = i;
 			return;
 		}
 	}

 	/* could not find a basic rate; use original selection */
 }

 static inline s8
 rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
 			  struct ieee80211_sta *sta)
 {
 	int i;

 	for (i = 0; i < sband->n_bitrates; i++) {
 		struct ieee80211_rate *srate = &sband->bitrates[i];
 		if ((srate->bitrate == 10) || (srate->bitrate == 20) ||
 		    (srate->bitrate == 55) || (srate->bitrate == 110))
 			continue;

 		if (rate_supported(sta, sband->band, i))
 			return i;
 	}

 	/* No matching rate found */
 	return 0;
 }


 bool rate_control_send_low(struct ieee80211_sta *sta,
 			   void *priv_sta,
 			   struct ieee80211_tx_rate_control *txrc)
 {
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 	struct ieee80211_supported_band *sband = txrc->sband;
 	int mcast_rate;

 	if (!sta || !priv_sta || rc_no_data_or_no_ack_use_min(txrc)) {
 		if ((sband->band != IEEE80211_BAND_2GHZ) ||
 		    !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
 			info->control.rates[0].idx =
 				rate_lowest_index(txrc->sband, sta);
 		else
 			info->control.rates[0].idx =
 				rate_lowest_non_cck_index(txrc->sband, sta);
 		info->control.rates[0].count =
 			(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
 			1 : txrc->hw->max_rate_tries;
 		if (!sta && txrc->bss) {
 			mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
 			if (mcast_rate > 0) {
 				info->control.rates[0].idx = mcast_rate - 1;
 				return true;
 			}

 			rc_send_low_broadcast(&info->control.rates[0].idx,
 					      txrc->bss_conf->basic_rates,
 					      sband);
 		}
 		return true;
 	}
 	return false;
 }
 EXPORT_SYMBOL(rate_control_send_low);

 static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
 				       int n_bitrates, u32 mask)
 {
 	int j;

 	/* See whether the selected rate or anything below it is allowed. */
 	for (j = rate->idx; j >= 0; j--) {
 		if (mask & (1 << j)) {
 			/* Okay, found a suitable rate. Use it. */
 			rate->idx = j;
 			return true;
 		}
 	}

 	/* Try to find a higher rate that would be allowed */
 	for (j = rate->idx + 1; j < n_bitrates; j++) {
 		if (mask & (1 << j)) {
 			/* Okay, found a suitable rate. Use it. */
 			rate->idx = j;
 			return true;
 		}
 	}
 	return false;
 }

 static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
 				    u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
 {
 	int i, j;
 	int ridx, rbit;

 	ridx = rate->idx / 8;
 	rbit = rate->idx % 8;

 	/* sanity check */
 	if (ridx < 0 || ridx >= IEEE80211_HT_MCS_MASK_LEN)
 		return false;

 	/* See whether the selected rate or anything below it is allowed. */
 	for (i = ridx; i >= 0; i--) {
 		for (j = rbit; j >= 0; j--)
 			if (mcs_mask[i] & BIT(j)) {
 				rate->idx = i * 8 + j;
 				return true;
 			}
 		rbit = 7;
 	}

 	/* Try to find a higher rate that would be allowed */
 	ridx = (rate->idx + 1) / 8;
 	rbit = (rate->idx + 1) % 8;

 	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
 		for (j = rbit; j < 8; j++)
 			if (mcs_mask[i] & BIT(j)) {
 				rate->idx = i * 8 + j;
 				return true;
 			}
 		rbit = 0;
 	}
 	return false;
 }


 static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
 				struct ieee80211_tx_rate_control *txrc,
 				u32 mask,
 				u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
 {
 	struct ieee80211_tx_rate alt_rate;

 	/* handle HT rates */
 	if (rate->flags & IEEE80211_TX_RC_MCS) {
 		if (rate_idx_match_mcs_mask(rate, mcs_mask))
 			return;

 		/* also try the legacy rates. */
 		alt_rate.idx = 0;
 		/* keep protection flags */
 		alt_rate.flags = rate->flags &
 				 (IEEE80211_TX_RC_USE_RTS_CTS |
 				  IEEE80211_TX_RC_USE_CTS_PROTECT |
 				  IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 		alt_rate.count = rate->count;
 		if (rate_idx_match_legacy_mask(&alt_rate,
 					       txrc->sband->n_bitrates,
 					       mask)) {
 			*rate = alt_rate;
 			return;
 		}
 	} else {
 		struct sk_buff *skb = txrc->skb;
 		struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
 		__le16 fc;

 		/* handle legacy rates */
 		if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
 					       mask))
 			return;

 		/* if HT BSS, and we handle a data frame, also try HT rates */
 		if (txrc->bss_conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT)
 			return;

 		fc = hdr->frame_control;
 		if (!ieee80211_is_data(fc))
 			return;

 		alt_rate.idx = 0;
 		/* keep protection flags */
 		alt_rate.flags = rate->flags &
 				 (IEEE80211_TX_RC_USE_RTS_CTS |
 				  IEEE80211_TX_RC_USE_CTS_PROTECT |
 				  IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
 		alt_rate.count = rate->count;

 		alt_rate.flags |= IEEE80211_TX_RC_MCS;

 		if (txrc->bss_conf->chandef.width == NL80211_CHAN_WIDTH_40)
 			alt_rate.flags |= IEEE80211_TX_RC_40_MHZ_WIDTH;

 		if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
 			*rate = alt_rate;
 			return;
 		}
 	}

 	/*
 	 * Uh.. No suitable rate exists. This should not really happen with
 	 * sane TX rate mask configurations. However, should someone manage to
 	 * configure supported rates and TX rate mask in incompatible way,
 	 * allow the frame to be transmitted with whatever the rate control
 	 * selected.
 	 */
 }

 void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
 			   struct sta_info *sta,
 			   struct ieee80211_tx_rate_control *txrc)
 {
 	struct rate_control_ref *ref = sdata->local->rate_ctrl;
 	void *priv_sta = NULL;
 	struct ieee80211_sta *ista = NULL;
 	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
 	int i;
 	u32 mask;
 	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];

 	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
 		ista = &sta->sta;
 		priv_sta = sta->rate_ctrl_priv;
 	}

 	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 		info->control.rates[i].idx = -1;
 		info->control.rates[i].flags = 0;
 		info->control.rates[i].count = 0;
 	}

 	if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
 		return;

 	ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);

 	/*
 	 * Try to enforce the rateidx mask the user wanted. skip this if the
 	 * default mask (allow all rates) is used to save some processing for
 	 * the common case.
 	 */
 	mask = sdata->rc_rateidx_mask[info->band];
 	memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
 	       sizeof(mcs_mask));
 	if (mask != (1 << txrc->sband->n_bitrates) - 1) {
 		if (sta) {
 			/* Filter out rates that the STA does not support */
 			mask &= sta->sta.supp_rates[info->band];
 			for (i = 0; i < sizeof(mcs_mask); i++)
 				mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
 		}
 		/*
 		 * Make sure the rate index selected for each TX rate is
 		 * included in the configured mask and change the rate indexes
 		 * if needed.
 		 */
 		for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
 			/* Skip invalid rates */
 			if (info->control.rates[i].idx < 0)
 				break;
 			rate_idx_match_mask(&info->control.rates[i], txrc,
 					    mask, mcs_mask);
 		}
 	}

 	BUG_ON(info->control.rates[0].idx < 0);
 }

 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
 				 const char *name)
 {
 	struct rate_control_ref *ref;

 	ASSERT_RTNL();

 	if (local->open_count)
 		return -EBUSY;

 	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
 		if (WARN_ON(!local->ops->set_rts_threshold))
 			return -EINVAL;
 		return 0;
 	}

 	ref = rate_control_alloc(name, local);
 	if (!ref) {
 		wiphy_warn(local->hw.wiphy,
 			   "Failed to select rate control algorithm\n");
 		return -ENOENT;
 	}

 	WARN_ON(local->rate_ctrl);
 	local->rate_ctrl = ref;

 	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
 		    ref->ops->name);

 	return 0;
 }

 void rate_control_deinitialize(struct ieee80211_local *local)
 {
 	struct rate_control_ref *ref;

 	ref = local->rate_ctrl;

 	if (!ref)
 		return;

 	local->rate_ctrl = NULL;
 	rate_control_free(ref);
 }
	/*
	* Copyright 2002-2005, Instant802 Networks, Inc.
	* Copyright 2005-2006, Devicescape Software, Inc.
	* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
	*
	* 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/kernel.h>
	#include <linux/rtnetlink.h>
	#include <linux/slab.h>
	#include <linux/module.h>
	#include "rate.h"
	#include "ieee80211_i.h"
	#include "debugfs.h"

	struct rate_control_alg {
	struct list_head list;
	struct rate_control_ops *ops;
	};

	static LIST_HEAD(rate_ctrl_algs);
	static DEFINE_MUTEX(rate_ctrl_mutex);

	static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
	module_param(ieee80211_default_rc_algo, charp, 0644);
	MODULE_PARM_DESC(ieee80211_default_rc_algo,
	"Default rate control algorithm for mac80211 to use");

	int ieee80211_rate_control_register(struct rate_control_ops *ops)
	{
	struct rate_control_alg *alg;

	if (!ops->name)
	return -EINVAL;

	mutex_lock(&rate_ctrl_mutex);
	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	if (!strcmp(alg->ops->name, ops->name)) {
	/* don't register an algorithm twice */
	WARN_ON(1);
	mutex_unlock(&rate_ctrl_mutex);
	return -EALREADY;
	}
	}

	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
	if (alg == NULL) {
	mutex_unlock(&rate_ctrl_mutex);
	return -ENOMEM;
	}
	alg->ops = ops;

	list_add_tail(&alg->list, &rate_ctrl_algs);
	mutex_unlock(&rate_ctrl_mutex);

	return 0;
	}
	EXPORT_SYMBOL(ieee80211_rate_control_register);

	void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
	{
	struct rate_control_alg *alg;

	mutex_lock(&rate_ctrl_mutex);
	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	if (alg->ops == ops) {
	list_del(&alg->list);
	kfree(alg);
	break;
	}
	}
	mutex_unlock(&rate_ctrl_mutex);
	}
	EXPORT_SYMBOL(ieee80211_rate_control_unregister);

	static struct rate_control_ops *
	ieee80211_try_rate_control_ops_get(const char *name)
	{
	struct rate_control_alg *alg;
	struct rate_control_ops *ops = NULL;

	if (!name)
	return NULL;

	mutex_lock(&rate_ctrl_mutex);
	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	if (!strcmp(alg->ops->name, name))
	if (try_module_get(alg->ops->module)) {
	ops = alg->ops;
	break;
	}
	}
	mutex_unlock(&rate_ctrl_mutex);
	return ops;
	}

	/* Get the rate control algorithm. */
	static struct rate_control_ops *
	ieee80211_rate_control_ops_get(const char *name)
	{
	struct rate_control_ops *ops;
	const char *alg_name;

	kparam_block_sysfs_write(ieee80211_default_rc_algo);
	if (!name)
	alg_name = ieee80211_default_rc_algo;
	else
	alg_name = name;

	ops = ieee80211_try_rate_control_ops_get(alg_name);
	if (!ops) {
	request_module("rc80211_%s", alg_name);
	ops = ieee80211_try_rate_control_ops_get(alg_name);
	}
	if (!ops && name)
	/* try default if specific alg requested but not found */
	ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);

	/* try built-in one if specific alg requested but not found */
	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
	ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
	kparam_unblock_sysfs_write(ieee80211_default_rc_algo);

	return ops;
	}

	static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
	{
	module_put(ops->module);
	}

	#ifdef CONFIG_MAC80211_DEBUGFS
	static ssize_t rcname_read(struct file file, char __user userbuf,
	size_t count, loff_t *ppos)
	{
	struct rate_control_ref *ref = file->private_data;
	int len = strlen(ref->ops->name);

	return simple_read_from_buffer(userbuf, count, ppos,
	ref->ops->name, len);
	}

	static const struct file_operations rcname_ops = {
	.read = rcname_read,
	.open = simple_open,
	.llseek = default_llseek,
	};
	#endif

	static struct rate_control_ref rate_control_alloc(const char name,
	struct ieee80211_local *local)
	{
	struct dentry *debugfsdir = NULL;
	struct rate_control_ref *ref;

	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
	if (!ref)
	goto fail_ref;
	ref->local = local;
	ref->ops = ieee80211_rate_control_ops_get(name);
	if (!ref->ops)
	goto fail_ops;

	#ifdef CONFIG_MAC80211_DEBUGFS
	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
	local->debugfs.rcdir = debugfsdir;
	debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
	#endif

	ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
	if (!ref->priv)
	goto fail_priv;
	return ref;

	fail_priv:
	ieee80211_rate_control_ops_put(ref->ops);
	fail_ops:
	kfree(ref);
	fail_ref:
	return NULL;
	}

	static void rate_control_free(struct rate_control_ref *ctrl_ref)
	{
	ctrl_ref->ops->free(ctrl_ref->priv);

	#ifdef CONFIG_MAC80211_DEBUGFS
	debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
	ctrl_ref->local->debugfs.rcdir = NULL;
	#endif

	ieee80211_rate_control_ops_put(ctrl_ref->ops);
	kfree(ctrl_ref);
	}

	static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
	{
	struct sk_buff *skb = txrc->skb;
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	__le16 fc;

	fc = hdr->frame_control;

	return (info->flags & (IEEE80211_TX_CTL_NO_ACK \|
	IEEE80211_TX_CTL_USE_MINRATE)) \|\|
	!ieee80211_is_data(fc);
	}

	static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
	struct ieee80211_supported_band *sband)
	{
	u8 i;

	if (basic_rates == 0)
	return; /* assume basic rates unknown and accept rate */
	if (*idx < 0)
	return;
	if (basic_rates & (1 << *idx))
	return; /* selected rate is a basic rate */

	for (i = *idx + 1; i <= sband->n_bitrates; i++) {
	if (basic_rates & (1 << i)) {
	*idx = i;
	return;
	}
	}

	/* could not find a basic rate; use original selection */
	}

	static inline s8
	rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
	struct ieee80211_sta *sta)
	{
	int i;

	for (i = 0; i < sband->n_bitrates; i++) {
	struct ieee80211_rate *srate = &sband->bitrates[i];
	if ((srate->bitrate == 10) \|\| (srate->bitrate == 20) \|\|
	(srate->bitrate == 55) \|\| (srate->bitrate == 110))
	continue;

	if (rate_supported(sta, sband->band, i))
	return i;
	}

	/* No matching rate found */
	return 0;
	}


	bool rate_control_send_low(struct ieee80211_sta *sta,
	void *priv_sta,
	struct ieee80211_tx_rate_control *txrc)
	{
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
	struct ieee80211_supported_band *sband = txrc->sband;
	int mcast_rate;

	if (!sta \|\| !priv_sta \|\| rc_no_data_or_no_ack_use_min(txrc)) {
	if ((sband->band != IEEE80211_BAND_2GHZ) \|\|
	!(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
	info->control.rates[0].idx =
	rate_lowest_index(txrc->sband, sta);
	else
	info->control.rates[0].idx =
	rate_lowest_non_cck_index(txrc->sband, sta);
	info->control.rates[0].count =
	(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
	1 : txrc->hw->max_rate_tries;
	if (!sta && txrc->bss) {
	mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
	if (mcast_rate > 0) {
	info->control.rates[0].idx = mcast_rate - 1;
	return true;
	}

	rc_send_low_broadcast(&info->control.rates[0].idx,
	txrc->bss_conf->basic_rates,
	sband);
	}
	return true;
	}
	return false;
	}
	EXPORT_SYMBOL(rate_control_send_low);

	static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
	int n_bitrates, u32 mask)
	{
	int j;

	/* See whether the selected rate or anything below it is allowed. */
	for (j = rate->idx; j >= 0; j--) {
	if (mask & (1 << j)) {
	/* Okay, found a suitable rate. Use it. */
	rate->idx = j;
	return true;
	}
	}

	/* Try to find a higher rate that would be allowed */
	for (j = rate->idx + 1; j < n_bitrates; j++) {
	if (mask & (1 << j)) {
	/* Okay, found a suitable rate. Use it. */
	rate->idx = j;
	return true;
	}
	}
	return false;
	}

	static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
	{
	int i, j;
	int ridx, rbit;

	ridx = rate->idx / 8;
	rbit = rate->idx % 8;

	/* sanity check */
	if (ridx < 0 \|\| ridx >= IEEE80211_HT_MCS_MASK_LEN)
	return false;

	/* See whether the selected rate or anything below it is allowed. */
	for (i = ridx; i >= 0; i--) {
	for (j = rbit; j >= 0; j--)
	if (mcs_mask[i] & BIT(j)) {
	rate->idx = i * 8 + j;
	return true;
	}
	rbit = 7;
	}

	/* Try to find a higher rate that would be allowed */
	ridx = (rate->idx + 1) / 8;
	rbit = (rate->idx + 1) % 8;

	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
	for (j = rbit; j < 8; j++)
	if (mcs_mask[i] & BIT(j)) {
	rate->idx = i * 8 + j;
	return true;
	}
	rbit = 0;
	}
	return false;
	}



	static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
	struct ieee80211_tx_rate_control *txrc,
	u32 mask,
	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
	{
	struct ieee80211_tx_rate alt_rate;

	/* handle HT rates */
	if (rate->flags & IEEE80211_TX_RC_MCS) {
	if (rate_idx_match_mcs_mask(rate, mcs_mask))
	return;

	/* also try the legacy rates. */
	alt_rate.idx = 0;
	/* keep protection flags */
	alt_rate.flags = rate->flags &
	(IEEE80211_TX_RC_USE_RTS_CTS \|
	IEEE80211_TX_RC_USE_CTS_PROTECT \|
	IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
	alt_rate.count = rate->count;
	if (rate_idx_match_legacy_mask(&alt_rate,
	txrc->sband->n_bitrates,
	mask)) {
	*rate = alt_rate;
	return;
	}
	} else {
	struct sk_buff *skb = txrc->skb;
	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	__le16 fc;

	/* handle legacy rates */
	if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
	mask))
	return;

	/* if HT BSS, and we handle a data frame, also try HT rates */
	if (txrc->bss_conf->chandef.width == NL80211_CHAN_WIDTH_20_NOHT)
	return;

	fc = hdr->frame_control;
	if (!ieee80211_is_data(fc))
	return;

	alt_rate.idx = 0;
	/* keep protection flags */
	alt_rate.flags = rate->flags &
	(IEEE80211_TX_RC_USE_RTS_CTS \|
	IEEE80211_TX_RC_USE_CTS_PROTECT \|
	IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
	alt_rate.count = rate->count;

	alt_rate.flags \|= IEEE80211_TX_RC_MCS;

	if (txrc->bss_conf->chandef.width == NL80211_CHAN_WIDTH_40)
	alt_rate.flags \|= IEEE80211_TX_RC_40_MHZ_WIDTH;

	if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
	*rate = alt_rate;
	return;
	}
	}

	/*
	* Uh.. No suitable rate exists. This should not really happen with
	* sane TX rate mask configurations. However, should someone manage to
	* configure supported rates and TX rate mask in incompatible way,
	* allow the frame to be transmitted with whatever the rate control
	* selected.
	*/
	}

	void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
	struct sta_info *sta,
	struct ieee80211_tx_rate_control *txrc)
	{
	struct rate_control_ref *ref = sdata->local->rate_ctrl;
	void *priv_sta = NULL;
	struct ieee80211_sta *ista = NULL;
	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
	int i;
	u32 mask;
	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];

	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
	ista = &sta->sta;
	priv_sta = sta->rate_ctrl_priv;
	}

	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	info->control.rates[i].idx = -1;
	info->control.rates[i].flags = 0;
	info->control.rates[i].count = 0;
	}

	if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
	return;

	ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);

	/*
	* Try to enforce the rateidx mask the user wanted. skip this if the
	* default mask (allow all rates) is used to save some processing for
	* the common case.
	*/
	mask = sdata->rc_rateidx_mask[info->band];
	memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
	sizeof(mcs_mask));
	if (mask != (1 << txrc->sband->n_bitrates) - 1) {
	if (sta) {
	/* Filter out rates that the STA does not support */
	mask &= sta->sta.supp_rates[info->band];
	for (i = 0; i < sizeof(mcs_mask); i++)
	mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
	}
	/*
	* Make sure the rate index selected for each TX rate is
	* included in the configured mask and change the rate indexes
	* if needed.
	*/
	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	/* Skip invalid rates */
	if (info->control.rates[i].idx < 0)
	break;
	rate_idx_match_mask(&info->control.rates[i], txrc,
	mask, mcs_mask);
	}
	}

	BUG_ON(info->control.rates[0].idx < 0);
	}

	int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
	const char *name)
	{
	struct rate_control_ref *ref;

	ASSERT_RTNL();

	if (local->open_count)
	return -EBUSY;

	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
	if (WARN_ON(!local->ops->set_rts_threshold))
	return -EINVAL;
	return 0;
	}

	ref = rate_control_alloc(name, local);
	if (!ref) {
	wiphy_warn(local->hw.wiphy,
	"Failed to select rate control algorithm\n");
	return -ENOENT;
	}

	WARN_ON(local->rate_ctrl);
	local->rate_ctrl = ref;

	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
	ref->ops->name);

	return 0;
	}

	void rate_control_deinitialize(struct ieee80211_local *local)
	{
	struct rate_control_ref *ref;

	ref = local->rate_ctrl;

	if (!ref)
	return;

	local->rate_ctrl = NULL;
	rate_control_free(ref);
	}