[mirror_ubuntu-artful-kernel.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,
	.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;
	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, u32 mcast_rate,
				  struct ieee80211_supported_band *sband)
{
	u8 i;

	if (mcast_rate) {
		for (i = 0; i < sband->n_bitrates; i++) {
			if (sband->bitrates[i].bitrate == mcast_rate) {
				*idx = i;
				return;
			}
		}
	}

	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 */
}

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->bss)
			rc_send_low_broadcast(&info->control.rates[0].idx,
					      txrc->bss_conf->basic_rates,
					      txrc->bss_conf->mcast_rate,
					      txrc->sband);
		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++) {
			/* Skip invalid rates */
			if (info->control.rates[i].idx < 0)
				break;
			/* 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) {
		wiphy_warn(local->hw.wiphy,
			   "Failed to select rate control algorithm\n");
		return -ENOENT;
	}

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

	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_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,
6038f373	148	.llseek = default_llseek,
4b7679a5 JB	149	};
	150	#endif
	151
209c671d	152	static struct rate_control_ref rate_control_alloc(const char name,
f0706e82 JB	153	struct ieee80211_local *local)
f0706e82 JB	154	{
4b7679a5	155	struct dentry *debugfsdir = NULL;
f0706e82 JB	156	struct rate_control_ref *ref;
	157
	158	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
	159	if (!ref)
	160	goto fail_ref;
	161	kref_init(&ref->kref);
4b7679a5	162	ref->local = local;
f0706e82 JB	163	ref->ops = ieee80211_rate_control_ops_get(name);
	164	if (!ref->ops)
	165	goto fail_ops;
4b7679a5 JB	166
	167	#ifdef CONFIG_MAC80211_DEBUGFS
	168	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
	169	local->debugfs.rcdir = debugfsdir;
7bcfaf2f	170	debugfs_create_file("name", 0400, debugfsdir, ref, &rcname_ops);
4b7679a5 JB	171	#endif
	172
	173	ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
f0706e82 JB	174	if (!ref->priv)
	175	goto fail_priv;
	176	return ref;
	177
	178	fail_priv:
	179	ieee80211_rate_control_ops_put(ref->ops);
	180	fail_ops:
	181	kfree(ref);
	182	fail_ref:
	183	return NULL;
	184	}
	185
	186	static void rate_control_release(struct kref *kref)
	187	{
	188	struct rate_control_ref *ctrl_ref;
	189
	190	ctrl_ref = container_of(kref, struct rate_control_ref, kref);
	191	ctrl_ref->ops->free(ctrl_ref->priv);
4b7679a5 JB	192
4b7679a5 JB	193	#ifdef CONFIG_MAC80211_DEBUGFS
7bcfaf2f	194	debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
4b7679a5 JB	195	ctrl_ref->local->debugfs.rcdir = NULL;
	196	#endif
	197
f0706e82 JB	198	ieee80211_rate_control_ops_put(ctrl_ref->ops);
	199	kfree(ctrl_ref);
	200	}
	201
4c6d4f5c LR	202	static bool rc_no_data_or_no_ack(struct ieee80211_tx_rate_control *txrc)
	203	{
	204	struct sk_buff *skb = txrc->skb;
	205	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	206	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	207	__le16 fc;
	208
	209	fc = hdr->frame_control;
	210
a02cec21	211	return (info->flags & IEEE80211_TX_CTL_NO_ACK) \|\| !ieee80211_is_data(fc);
4c6d4f5c LR	212	}
4c6d4f5c LR	213
8f0729b1 FF	214	static void rc_send_low_broadcast(s8 *idx, u32 basic_rates, u32 mcast_rate,
8f0729b1 FF	215	struct ieee80211_supported_band *sband)
e00cfce0 JM	216	{
	217	u8 i;
	218
8f0729b1 FF	219	if (mcast_rate) {
	220	for (i = 0; i < sband->n_bitrates; i++) {
	221	if (sband->bitrates[i].bitrate == mcast_rate) {
	222	*idx = i;
	223	return;
	224	}
	225	}
	226	}
	227
e00cfce0 JM	228	if (basic_rates == 0)
	229	return; /* assume basic rates unknown and accept rate */
	230	if (*idx < 0)
	231	return;
	232	if (basic_rates & (1 << *idx))
	233	return; /* selected rate is a basic rate */
	234
8f0729b1	235	for (i = *idx + 1; i <= sband->n_bitrates; i++) {
e00cfce0 JM	236	if (basic_rates & (1 << i)) {
	237	*idx = i;
	238	return;
	239	}
	240	}
	241
	242	/* could not find a basic rate; use original selection */
	243	}
	244
4c6d4f5c LR	245	bool rate_control_send_low(struct ieee80211_sta *sta,
	246	void *priv_sta,
	247	struct ieee80211_tx_rate_control *txrc)
	248	{
	249	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
	250
	251	if (!sta \|\| !priv_sta \|\| rc_no_data_or_no_ack(txrc)) {
	252	info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
	253	info->control.rates[0].count =
	254	(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
	255	1 : txrc->hw->max_rate_tries;
8f0729b1	256	if (!sta && txrc->bss)
e00cfce0 JM	257	rc_send_low_broadcast(&info->control.rates[0].idx,
e00cfce0 JM	258	txrc->bss_conf->basic_rates,
8f0729b1 FF	259	txrc->bss_conf->mcast_rate,
8f0729b1 FF	260	txrc->sband);
4c6d4f5c LR	261	return true;
	262	}
	263	return false;
	264	}
	265	EXPORT_SYMBOL(rate_control_send_low);
	266
37eb0b16 JM	267	static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
	268	int n_bitrates, u32 mask)
	269	{
	270	int j;
	271
	272	/* See whether the selected rate or anything below it is allowed. */
	273	for (j = rate->idx; j >= 0; j--) {
	274	if (mask & (1 << j)) {
	275	/* Okay, found a suitable rate. Use it. */
	276	rate->idx = j;
	277	return;
	278	}
	279	}
	280
	281	/* Try to find a higher rate that would be allowed */
	282	for (j = rate->idx + 1; j < n_bitrates; j++) {
	283	if (mask & (1 << j)) {
	284	/* Okay, found a suitable rate. Use it. */
	285	rate->idx = j;
	286	return;
	287	}
	288	}
	289
	290	/*
	291	* Uh.. No suitable rate exists. This should not really happen with
	292	* sane TX rate mask configurations. However, should someone manage to
	293	* configure supported rates and TX rate mask in incompatible way,
	294	* allow the frame to be transmitted with whatever the rate control
	295	* selected.
	296	*/
	297	}
	298
4b7679a5	299	void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
e6a9854b JB	300	struct sta_info *sta,
e6a9854b JB	301	struct ieee80211_tx_rate_control *txrc)
1abbe498	302	{
4b7679a5 JB	303	struct rate_control_ref *ref = sdata->local->rate_ctrl;
	304	void *priv_sta = NULL;
	305	struct ieee80211_sta *ista = NULL;
e6a9854b	306	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1abbe498	307	int i;
37eb0b16	308	u32 mask;
1abbe498	309
4b7679a5 JB	310	if (sta) {
	311	ista = &sta->sta;
	312	priv_sta = sta->rate_ctrl_priv;
	313	}
	314
e6a9854b JB	315	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	316	info->control.rates[i].idx = -1;
	317	info->control.rates[i].flags = 0;
	318	info->control.rates[i].count = 1;
	319	}
	320
5affcd6b JO	321	if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
	322	return;
	323
37eb0b16	324	ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
e6a9854b JB	325
e6a9854b JB	326	/*
37eb0b16 JM	327	* Try to enforce the rateidx mask the user wanted. skip this if the
	328	* default mask (allow all rates) is used to save some processing for
	329	* the common case.
e6a9854b	330	*/
37eb0b16 JM	331	mask = sdata->rc_rateidx_mask[info->band];
	332	if (mask != (1 << txrc->sband->n_bitrates) - 1) {
	333	if (sta) {
	334	/* Filter out rates that the STA does not support */
	335	mask &= sta->sta.supp_rates[info->band];
	336	}
	337	/*
	338	* Make sure the rate index selected for each TX rate is
	339	* included in the configured mask and change the rate indexes
	340	* if needed.
	341	*/
e6a9854b	342	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
5f4e6b2d CL	343	/* Skip invalid rates */
	344	if (info->control.rates[i].idx < 0)
	345	break;
37eb0b16	346	/* Rate masking supports only legacy rates for now */
e6a9854b JB	347	if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
e6a9854b JB	348	continue;
37eb0b16 JM	349	rate_idx_match_mask(&info->control.rates[i],
	350	txrc->sband->n_bitrates, mask);
	351	}
1abbe498	352	}
e6a9854b JB	353
e6a9854b JB	354	BUG_ON(info->control.rates[0].idx < 0);
1abbe498 MN	355	}
1abbe498 MN	356
f0706e82 JB	357	struct rate_control_ref rate_control_get(struct rate_control_ref ref)
	358	{
	359	kref_get(&ref->kref);
	360	return ref;
	361	}
	362
	363	void rate_control_put(struct rate_control_ref *ref)
	364	{
	365	kref_put(&ref->kref, rate_control_release);
	366	}
ff688089 JB	367
	368	int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
	369	const char *name)
	370	{
	371	struct rate_control_ref ref, old;
	372
	373	ASSERT_RTNL();
af65cd96	374
3b8d81e0	375	if (local->open_count)
ff688089 JB	376	return -EBUSY;
ff688089 JB	377
af65cd96 JB	378	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
	379	if (WARN_ON(!local->ops->set_rts_threshold))
	380	return -EINVAL;
	381	return 0;
	382	}
	383
ff688089 JB	384	ref = rate_control_alloc(name, local);
ff688089 JB	385	if (!ref) {
0fb9a9ec JP	386	wiphy_warn(local->hw.wiphy,
0fb9a9ec JP	387	"Failed to select rate control algorithm\n");
ff688089 JB	388	return -ENOENT;
	389	}
	390
	391	old = local->rate_ctrl;
	392	local->rate_ctrl = ref;
	393	if (old) {
	394	rate_control_put(old);
	395	sta_info_flush(local, NULL);
	396	}
	397
0fb9a9ec JP	398	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
0fb9a9ec JP	399	ref->ops->name);
ff688089	400
ff688089 JB	401	return 0;
	402	}
	403
	404	void rate_control_deinitialize(struct ieee80211_local *local)
	405	{
	406	struct rate_control_ref *ref;
	407
	408	ref = local->rate_ctrl;
af65cd96 JB	409
	410	if (!ref)
	411	return;
	412
ff688089 JB	413	local->rate_ctrl = NULL;
	414	rate_control_put(ref);
	415	}
c21b39ac	416