[net-next-2.6.git] / net / mac80211 / rate.c

/*
 * 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 "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 = mac80211_open_file_generic,
};
#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;
	kref_init(&ref->kref);
	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_release(struct kref *kref)
{
	struct rate_control_ref *ctrl_ref;

	ctrl_ref = container_of(kref, struct rate_control_ref, kref);
	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(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_is_data(fc));
}

static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx)
{
	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 <= max_rate_idx; i++) {
		if (basic_rates & (1 << i)) {
			*idx = i;
			return;
		}
	}

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

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);

	if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) {
		info->control.rates[0].idx = rate_lowest_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->ap)
			rc_send_low_broadcast(&info->control.rates[0].idx,
					      txrc->bss_conf->basic_rates,
					      txrc->sband->n_bitrates);
		return true;
	}
	return false;
}
EXPORT_SYMBOL(rate_control_send_low);

static void rate_idx_match_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;
		}
	}

	/* 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;
		}
	}

	/*
	 * 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;

	if (sta) {
		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 = 1;
	}

	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];
	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];
		}
		/*
		 * 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++) {
			/* Rate masking supports only legacy rates for now */
			if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
				continue;
			rate_idx_match_mask(&info->control.rates[i],
					    txrc->sband->n_bitrates, mask);
		}
	}

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

struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
{
	kref_get(&ref->kref);
	return ref;
}

void rate_control_put(struct rate_control_ref *ref)
{
	kref_put(&ref->kref, rate_control_release);
}

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

	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) {
		printk(KERN_WARNING "%s: Failed to select rate control "
		       "algorithm\n", wiphy_name(local->hw.wiphy));
		return -ENOENT;
	}

	old = local->rate_ctrl;
	local->rate_ctrl = ref;
	if (old) {
		rate_control_put(old);
		sta_info_flush(local, NULL);
	}

	printk(KERN_DEBUG "%s: Selected rate control "
	       "algorithm '%s'\n", wiphy_name(local->hw.wiphy),
	       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_put(ref);
}
Commit	Line	Data
f0706e82 JB	1	/*
	2	* Copyright 2002-2005, Instant802 Networks, Inc.
	3	* Copyright 2005-2006, Devicescape Software, Inc.
	4	* Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10
	11	#include <linux/kernel.h>
ff688089	12	#include <linux/rtnetlink.h>
5a0e3ad6	13	#include <linux/slab.h>
2c8dccc7	14	#include "rate.h"
f0706e82	15	#include "ieee80211_i.h"
4b7679a5	16	#include "debugfs.h"
f0706e82 JB	17
	18	struct rate_control_alg {
	19	struct list_head list;
	20	struct rate_control_ops *ops;
	21	};
	22
	23	static LIST_HEAD(rate_ctrl_algs);
	24	static DEFINE_MUTEX(rate_ctrl_mutex);
	25
c21b39ac SB	26	static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
	27	module_param(ieee80211_default_rc_algo, charp, 0644);
	28	MODULE_PARM_DESC(ieee80211_default_rc_algo,
	29	"Default rate control algorithm for mac80211 to use");
	30
f0706e82 JB	31	int ieee80211_rate_control_register(struct rate_control_ops *ops)
	32	{
	33	struct rate_control_alg *alg;
	34
ac71c691 JB	35	if (!ops->name)
	36	return -EINVAL;
	37
999acd9c JB	38	mutex_lock(&rate_ctrl_mutex);
	39	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	40	if (!strcmp(alg->ops->name, ops->name)) {
	41	/* don't register an algorithm twice */
	42	WARN_ON(1);
b808ab16	43	mutex_unlock(&rate_ctrl_mutex);
999acd9c JB	44	return -EALREADY;
	45	}
	46	}
	47
dd00cc48	48	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
f0706e82	49	if (alg == NULL) {
999acd9c	50	mutex_unlock(&rate_ctrl_mutex);
f0706e82 JB	51	return -ENOMEM;
f0706e82 JB	52	}
f0706e82 JB	53	alg->ops = ops;
f0706e82 JB	54
f0706e82 JB	55	list_add_tail(&alg->list, &rate_ctrl_algs);
	56	mutex_unlock(&rate_ctrl_mutex);
	57
	58	return 0;
	59	}
	60	EXPORT_SYMBOL(ieee80211_rate_control_register);
	61
	62	void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
	63	{
	64	struct rate_control_alg *alg;
	65
	66	mutex_lock(&rate_ctrl_mutex);
	67	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	68	if (alg->ops == ops) {
	69	list_del(&alg->list);
20880e89	70	kfree(alg);
f0706e82 JB	71	break;
	72	}
	73	}
	74	mutex_unlock(&rate_ctrl_mutex);
f0706e82 JB	75	}
	76	EXPORT_SYMBOL(ieee80211_rate_control_unregister);
	77
	78	static struct rate_control_ops *
	79	ieee80211_try_rate_control_ops_get(const char *name)
	80	{
	81	struct rate_control_alg *alg;
	82	struct rate_control_ops *ops = NULL;
	83
ac71c691 JB	84	if (!name)
	85	return NULL;
	86
f0706e82 JB	87	mutex_lock(&rate_ctrl_mutex);
f0706e82 JB	88	list_for_each_entry(alg, &rate_ctrl_algs, list) {
ac71c691	89	if (!strcmp(alg->ops->name, name))
f0706e82 JB	90	if (try_module_get(alg->ops->module)) {
	91	ops = alg->ops;
	92	break;
	93	}
	94	}
	95	mutex_unlock(&rate_ctrl_mutex);
	96	return ops;
	97	}
	98
c21b39ac	99	/* Get the rate control algorithm. */
f0706e82 JB	100	static struct rate_control_ops *
	101	ieee80211_rate_control_ops_get(const char *name)
	102	{
	103	struct rate_control_ops *ops;
c21b39ac	104	const char *alg_name;
f0706e82	105
d6d1b650	106	kparam_block_sysfs_write(ieee80211_default_rc_algo);
ac71c691	107	if (!name)
c21b39ac SB	108	alg_name = ieee80211_default_rc_algo;
	109	else
	110	alg_name = name;
ac71c691	111
c21b39ac	112	ops = ieee80211_try_rate_control_ops_get(alg_name);
f0706e82	113	if (!ops) {
c21b39ac SB	114	request_module("rc80211_%s", alg_name);
c21b39ac SB	115	ops = ieee80211_try_rate_control_ops_get(alg_name);
f0706e82	116	}
c21b39ac SB	117	if (!ops && name)
	118	/* try default if specific alg requested but not found */
	119	ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
	120
4b475898 JB	121	/* try built-in one if specific alg requested but not found */
	122	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
	123	ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
d6d1b650	124	kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
4b475898	125
f0706e82 JB	126	return ops;
	127	}
	128
	129	static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
	130	{
	131	module_put(ops->module);
	132	}
	133
4b7679a5 JB	134	#ifdef CONFIG_MAC80211_DEBUGFS
	135	static ssize_t rcname_read(struct file file, char __user userbuf,
	136	size_t count, loff_t *ppos)
	137	{
	138	struct rate_control_ref *ref = file->private_data;
	139	int len = strlen(ref->ops->name);
	140
	141	return simple_read_from_buffer(userbuf, count, ppos,
	142	ref->ops->name, len);
	143	}
	144
	145	static const struct file_operations rcname_ops = {
	146	.read = rcname_read,
	147	.open = mac80211_open_file_generic,
	148	};
	149	#endif
	150
209c671d	151	static struct rate_control_ref rate_control_alloc(const char name,
f0706e82 JB	152	struct ieee80211_local *local)
f0706e82 JB	153	{
4b7679a5	154	struct dentry *debugfsdir = NULL;
f0706e82 JB	155	struct rate_control_ref *ref;
	156
	157	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
	158	if (!ref)
	159	goto fail_ref;
	160	kref_init(&ref->kref);
4b7679a5	161	ref->local = local;
f0706e82 JB	162	ref->ops = ieee80211_rate_control_ops_get(name);
	163	if (!ref->ops)
	164	goto fail_ops;
4b7679a5 JB	165
	166	#ifdef CONFIG_MAC80211_DEBUGFS
	167	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
	168	local->debugfs.rcdir = debugfsdir;
7bcfaf2f	169	debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
4b7679a5 JB	170	#endif
	171
	172	ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
f0706e82 JB	173	if (!ref->priv)
	174	goto fail_priv;
	175	return ref;
	176
	177	fail_priv:
	178	ieee80211_rate_control_ops_put(ref->ops);
	179	fail_ops:
	180	kfree(ref);
	181	fail_ref:
	182	return NULL;
	183	}
	184
	185	static void rate_control_release(struct kref *kref)
	186	{
	187	struct rate_control_ref *ctrl_ref;
	188
	189	ctrl_ref = container_of(kref, struct rate_control_ref, kref);
	190	ctrl_ref->ops->free(ctrl_ref->priv);
4b7679a5 JB	191
4b7679a5 JB	192	#ifdef CONFIG_MAC80211_DEBUGFS
7bcfaf2f	193	debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
4b7679a5 JB	194	ctrl_ref->local->debugfs.rcdir = NULL;
	195	#endif
	196
f0706e82 JB	197	ieee80211_rate_control_ops_put(ctrl_ref->ops);
	198	kfree(ctrl_ref);
	199	}
	200
4c6d4f5c LR	201	static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc)
	202	{
	203	struct sk_buff *skb = txrc->skb;
	204	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	205	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	206	__le16 fc;
	207
	208	fc = hdr->frame_control;
	209
	210	return ((info->flags & IEEE80211_TX_CTL_NO_ACK) \|\| !ieee80211_is_data(fc));
	211	}
	212
e00cfce0 JM	213	static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u8 max_rate_idx)
	214	{
	215	u8 i;
	216
	217	if (basic_rates == 0)
	218	return; /* assume basic rates unknown and accept rate */
	219	if (*idx < 0)
	220	return;
	221	if (basic_rates & (1 << *idx))
	222	return; /* selected rate is a basic rate */
	223
	224	for (i = *idx + 1; i <= max_rate_idx; i++) {
	225	if (basic_rates & (1 << i)) {
	226	*idx = i;
	227	return;
	228	}
	229	}
	230
	231	/* could not find a basic rate; use original selection */
	232	}
	233
4c6d4f5c LR	234	bool rate_control_send_low(struct ieee80211_sta *sta,
	235	void *priv_sta,
	236	struct ieee80211_tx_rate_control *txrc)
	237	{
	238	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
	239
	240	if (!sta \|\| !priv_sta \|\| rc_no_data_or_no_ack(txrc)) {
	241	info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
	242	info->control.rates[0].count =
	243	(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
	244	1 : txrc->hw->max_rate_tries;
e00cfce0 JM	245	if (!sta && txrc->ap)
	246	rc_send_low_broadcast(&info->control.rates[0].idx,
	247	txrc->bss_conf->basic_rates,
	248	txrc->sband->n_bitrates);
4c6d4f5c LR	249	return true;
	250	}
	251	return false;
	252	}
	253	EXPORT_SYMBOL(rate_control_send_low);
	254
37eb0b16 JM	255	static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
	256	int n_bitrates, u32 mask)
	257	{
	258	int j;
	259
	260	/* See whether the selected rate or anything below it is allowed. */
	261	for (j = rate->idx; j >= 0; j--) {
	262	if (mask & (1 << j)) {
	263	/* Okay, found a suitable rate. Use it. */
	264	rate->idx = j;
	265	return;
	266	}
	267	}
	268
	269	/* Try to find a higher rate that would be allowed */
	270	for (j = rate->idx + 1; j < n_bitrates; j++) {
	271	if (mask & (1 << j)) {
	272	/* Okay, found a suitable rate. Use it. */
	273	rate->idx = j;
	274	return;
	275	}
	276	}
	277
	278	/*
	279	* Uh.. No suitable rate exists. This should not really happen with
	280	* sane TX rate mask configurations. However, should someone manage to
	281	* configure supported rates and TX rate mask in incompatible way,
	282	* allow the frame to be transmitted with whatever the rate control
	283	* selected.
	284	*/
	285	}
	286
4b7679a5	287	void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
e6a9854b JB	288	struct sta_info *sta,
e6a9854b JB	289	struct ieee80211_tx_rate_control *txrc)
1abbe498	290	{
4b7679a5 JB	291	struct rate_control_ref *ref = sdata->local->rate_ctrl;
	292	void *priv_sta = NULL;
	293	struct ieee80211_sta *ista = NULL;
e6a9854b	294	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1abbe498	295	int i;
37eb0b16	296	u32 mask;
1abbe498	297
4b7679a5 JB	298	if (sta) {
	299	ista = &sta->sta;
	300	priv_sta = sta->rate_ctrl_priv;
	301	}
	302
e6a9854b JB	303	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	304	info->control.rates[i].idx = -1;
	305	info->control.rates[i].flags = 0;
	306	info->control.rates[i].count = 1;
	307	}
	308
5affcd6b JO	309	if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
	310	return;
	311
37eb0b16	312	ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
e6a9854b JB	313
e6a9854b JB	314	/*
37eb0b16 JM	315	* Try to enforce the rateidx mask the user wanted. skip this if the
	316	* default mask (allow all rates) is used to save some processing for
	317	* the common case.
e6a9854b	318	*/
37eb0b16 JM	319	mask = sdata->rc_rateidx_mask[info->band];
	320	if (mask != (1 << txrc->sband->n_bitrates) - 1) {
	321	if (sta) {
	322	/* Filter out rates that the STA does not support */
	323	mask &= sta->sta.supp_rates[info->band];
	324	}
	325	/*
	326	* Make sure the rate index selected for each TX rate is
	327	* included in the configured mask and change the rate indexes
	328	* if needed.
	329	*/
e6a9854b	330	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
37eb0b16	331	/* Rate masking supports only legacy rates for now */
e6a9854b JB	332	if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
e6a9854b JB	333	continue;
37eb0b16 JM	334	rate_idx_match_mask(&info->control.rates[i],
	335	txrc->sband->n_bitrates, mask);
	336	}
1abbe498	337	}
e6a9854b JB	338
e6a9854b JB	339	BUG_ON(info->control.rates[0].idx < 0);
1abbe498 MN	340	}
1abbe498 MN	341
f0706e82 JB	342	struct rate_control_ref rate_control_get(struct rate_control_ref ref)
	343	{
	344	kref_get(&ref->kref);
	345	return ref;
	346	}
	347
	348	void rate_control_put(struct rate_control_ref *ref)
	349	{
	350	kref_put(&ref->kref, rate_control_release);
	351	}
ff688089 JB	352
	353	int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
	354	const char *name)
	355	{
	356	struct rate_control_ref ref, old;
	357
	358	ASSERT_RTNL();
af65cd96	359
3b8d81e0	360	if (local->open_count)
ff688089 JB	361	return -EBUSY;
ff688089 JB	362
af65cd96 JB	363	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
	364	if (WARN_ON(!local->ops->set_rts_threshold))
	365	return -EINVAL;
	366	return 0;
	367	}
	368
ff688089 JB	369	ref = rate_control_alloc(name, local);
	370	if (!ref) {
	371	printk(KERN_WARNING "%s: Failed to select rate control "
dd1cd4c6	372	"algorithm\n", wiphy_name(local->hw.wiphy));
ff688089 JB	373	return -ENOENT;
	374	}
	375
	376	old = local->rate_ctrl;
	377	local->rate_ctrl = ref;
	378	if (old) {
	379	rate_control_put(old);
	380	sta_info_flush(local, NULL);
	381	}
	382
	383	printk(KERN_DEBUG "%s: Selected rate control "
dd1cd4c6	384	"algorithm '%s'\n", wiphy_name(local->hw.wiphy),
ff688089 JB	385	ref->ops->name);
ff688089 JB	386
ff688089 JB	387	return 0;
	388	}
	389
	390	void rate_control_deinitialize(struct ieee80211_local *local)
	391	{
	392	struct rate_control_ref *ref;
	393
	394	ref = local->rate_ctrl;
af65cd96 JB	395
	396	if (!ref)
	397	return;
	398
ff688089 JB	399	local->rate_ctrl = NULL;
	400	rate_control_put(ref);
	401	}
c21b39ac	402