[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 "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;

	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);

	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

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;
	local->debugfs.rcname = 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(ctrl_ref->local->debugfs.rcname);
	ctrl_ref->local->debugfs.rcname = NULL;
	debugfs_remove(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));
}

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;
		return true;
	}
	return false;
}
EXPORT_SYMBOL(rate_control_send_low);

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;

	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 (sta && sdata->force_unicast_rateidx > -1) {
		info->control.rates[0].idx = sdata->force_unicast_rateidx;
	} else {
		ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
		info->flags |= IEEE80211_TX_INTFL_RCALGO;
	}

	/*
	 * try to enforce the maximum rate the user wanted
	 */
	if (sdata->max_ratectrl_rateidx > -1)
		for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
			if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
				continue;
			info->control.rates[i].idx =
				min_t(s8, info->control.rates[i].idx,
				      sdata->max_ratectrl_rateidx);
	}

	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;

	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;
	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>
2c8dccc7	13	#include "rate.h"
f0706e82	14	#include "ieee80211_i.h"
4b7679a5	15	#include "debugfs.h"
f0706e82 JB	16
	17	struct rate_control_alg {
	18	struct list_head list;
	19	struct rate_control_ops *ops;
	20	};
	21
	22	static LIST_HEAD(rate_ctrl_algs);
	23	static DEFINE_MUTEX(rate_ctrl_mutex);
	24
c21b39ac SB	25	static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
	26	module_param(ieee80211_default_rc_algo, charp, 0644);
	27	MODULE_PARM_DESC(ieee80211_default_rc_algo,
	28	"Default rate control algorithm for mac80211 to use");
	29
f0706e82 JB	30	int ieee80211_rate_control_register(struct rate_control_ops *ops)
	31	{
	32	struct rate_control_alg *alg;
	33
ac71c691 JB	34	if (!ops->name)
	35	return -EINVAL;
	36
999acd9c JB	37	mutex_lock(&rate_ctrl_mutex);
	38	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	39	if (!strcmp(alg->ops->name, ops->name)) {
	40	/* don't register an algorithm twice */
	41	WARN_ON(1);
b808ab16	42	mutex_unlock(&rate_ctrl_mutex);
999acd9c JB	43	return -EALREADY;
	44	}
	45	}
	46
dd00cc48	47	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
f0706e82	48	if (alg == NULL) {
999acd9c	49	mutex_unlock(&rate_ctrl_mutex);
f0706e82 JB	50	return -ENOMEM;
f0706e82 JB	51	}
f0706e82 JB	52	alg->ops = ops;
f0706e82 JB	53
f0706e82 JB	54	list_add_tail(&alg->list, &rate_ctrl_algs);
	55	mutex_unlock(&rate_ctrl_mutex);
	56
	57	return 0;
	58	}
	59	EXPORT_SYMBOL(ieee80211_rate_control_register);
	60
	61	void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
	62	{
	63	struct rate_control_alg *alg;
	64
	65	mutex_lock(&rate_ctrl_mutex);
	66	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	67	if (alg->ops == ops) {
	68	list_del(&alg->list);
20880e89	69	kfree(alg);
f0706e82 JB	70	break;
	71	}
	72	}
	73	mutex_unlock(&rate_ctrl_mutex);
f0706e82 JB	74	}
	75	EXPORT_SYMBOL(ieee80211_rate_control_unregister);
	76
	77	static struct rate_control_ops *
	78	ieee80211_try_rate_control_ops_get(const char *name)
	79	{
	80	struct rate_control_alg *alg;
	81	struct rate_control_ops *ops = NULL;
	82
ac71c691 JB	83	if (!name)
	84	return NULL;
	85
f0706e82 JB	86	mutex_lock(&rate_ctrl_mutex);
f0706e82 JB	87	list_for_each_entry(alg, &rate_ctrl_algs, list) {
ac71c691	88	if (!strcmp(alg->ops->name, name))
f0706e82 JB	89	if (try_module_get(alg->ops->module)) {
	90	ops = alg->ops;
	91	break;
	92	}
	93	}
	94	mutex_unlock(&rate_ctrl_mutex);
	95	return ops;
	96	}
	97
c21b39ac	98	/* Get the rate control algorithm. */
f0706e82 JB	99	static struct rate_control_ops *
	100	ieee80211_rate_control_ops_get(const char *name)
	101	{
	102	struct rate_control_ops *ops;
c21b39ac	103	const char *alg_name;
f0706e82	104
ac71c691	105	if (!name)
c21b39ac SB	106	alg_name = ieee80211_default_rc_algo;
	107	else
	108	alg_name = name;
ac71c691	109
c21b39ac	110	ops = ieee80211_try_rate_control_ops_get(alg_name);
f0706e82	111	if (!ops) {
c21b39ac SB	112	request_module("rc80211_%s", alg_name);
c21b39ac SB	113	ops = ieee80211_try_rate_control_ops_get(alg_name);
f0706e82	114	}
c21b39ac SB	115	if (!ops && name)
	116	/* try default if specific alg requested but not found */
	117	ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
	118
4b475898 JB	119	/* try built-in one if specific alg requested but not found */
	120	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
	121	ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
	122
f0706e82 JB	123	return ops;
	124	}
	125
	126	static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
	127	{
	128	module_put(ops->module);
	129	}
	130
4b7679a5 JB	131	#ifdef CONFIG_MAC80211_DEBUGFS
	132	static ssize_t rcname_read(struct file file, char __user userbuf,
	133	size_t count, loff_t *ppos)
	134	{
	135	struct rate_control_ref *ref = file->private_data;
	136	int len = strlen(ref->ops->name);
	137
	138	return simple_read_from_buffer(userbuf, count, ppos,
	139	ref->ops->name, len);
	140	}
	141
	142	static const struct file_operations rcname_ops = {
	143	.read = rcname_read,
	144	.open = mac80211_open_file_generic,
	145	};
	146	#endif
	147
f0706e82 JB	148	struct rate_control_ref rate_control_alloc(const char name,
	149	struct ieee80211_local *local)
	150	{
4b7679a5	151	struct dentry *debugfsdir = NULL;
f0706e82 JB	152	struct rate_control_ref *ref;
	153
	154	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
	155	if (!ref)
	156	goto fail_ref;
	157	kref_init(&ref->kref);
4b7679a5	158	ref->local = local;
f0706e82 JB	159	ref->ops = ieee80211_rate_control_ops_get(name);
	160	if (!ref->ops)
	161	goto fail_ops;
4b7679a5 JB	162
	163	#ifdef CONFIG_MAC80211_DEBUGFS
	164	debugfsdir = debugfs_create_dir("rc", local->hw.wiphy->debugfsdir);
	165	local->debugfs.rcdir = debugfsdir;
	166	local->debugfs.rcname = debugfs_create_file("name", 0400, debugfsdir,
	167	ref, &rcname_ops);
	168	#endif
	169
	170	ref->priv = ref->ops->alloc(&local->hw, debugfsdir);
f0706e82 JB	171	if (!ref->priv)
	172	goto fail_priv;
	173	return ref;
	174
	175	fail_priv:
	176	ieee80211_rate_control_ops_put(ref->ops);
	177	fail_ops:
	178	kfree(ref);
	179	fail_ref:
	180	return NULL;
	181	}
	182
	183	static void rate_control_release(struct kref *kref)
	184	{
	185	struct rate_control_ref *ctrl_ref;
	186
	187	ctrl_ref = container_of(kref, struct rate_control_ref, kref);
	188	ctrl_ref->ops->free(ctrl_ref->priv);
4b7679a5 JB	189
	190	#ifdef CONFIG_MAC80211_DEBUGFS
	191	debugfs_remove(ctrl_ref->local->debugfs.rcname);
	192	ctrl_ref->local->debugfs.rcname = NULL;
	193	debugfs_remove(ctrl_ref->local->debugfs.rcdir);
	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
	213	bool rate_control_send_low(struct ieee80211_sta *sta,
	214	void *priv_sta,
	215	struct ieee80211_tx_rate_control *txrc)
	216	{
	217	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
	218
	219	if (!sta \|\| !priv_sta \|\| rc_no_data_or_no_ack(txrc)) {
	220	info->control.rates[0].idx = rate_lowest_index(txrc->sband, sta);
	221	info->control.rates[0].count =
	222	(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
	223	1 : txrc->hw->max_rate_tries;
	224	return true;
	225	}
	226	return false;
	227	}
	228	EXPORT_SYMBOL(rate_control_send_low);
	229
4b7679a5	230	void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
e6a9854b JB	231	struct sta_info *sta,
e6a9854b JB	232	struct ieee80211_tx_rate_control *txrc)
1abbe498	233	{
4b7679a5 JB	234	struct rate_control_ref *ref = sdata->local->rate_ctrl;
	235	void *priv_sta = NULL;
	236	struct ieee80211_sta *ista = NULL;
e6a9854b	237	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1abbe498	238	int i;
1abbe498	239
4b7679a5 JB	240	if (sta) {
	241	ista = &sta->sta;
	242	priv_sta = sta->rate_ctrl_priv;
	243	}
	244
e6a9854b JB	245	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	246	info->control.rates[i].idx = -1;
	247	info->control.rates[i].flags = 0;
	248	info->control.rates[i].count = 1;
	249	}
	250
2b874e83	251	if (sta && sdata->force_unicast_rateidx > -1) {
e6a9854b	252	info->control.rates[0].idx = sdata->force_unicast_rateidx;
2b874e83	253	} else {
e6a9854b	254	ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
2b874e83 JB	255	info->flags \|= IEEE80211_TX_INTFL_RCALGO;
2b874e83 JB	256	}
e6a9854b JB	257
	258	/*
	259	* try to enforce the maximum rate the user wanted
	260	*/
	261	if (sdata->max_ratectrl_rateidx > -1)
	262	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	263	if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
	264	continue;
	265	info->control.rates[i].idx =
	266	min_t(s8, info->control.rates[i].idx,
	267	sdata->max_ratectrl_rateidx);
1abbe498	268	}
e6a9854b JB	269
e6a9854b JB	270	BUG_ON(info->control.rates[0].idx < 0);
1abbe498 MN	271	}
1abbe498 MN	272
f0706e82 JB	273	struct rate_control_ref rate_control_get(struct rate_control_ref ref)
	274	{
	275	kref_get(&ref->kref);
	276	return ref;
	277	}
	278
	279	void rate_control_put(struct rate_control_ref *ref)
	280	{
	281	kref_put(&ref->kref, rate_control_release);
	282	}
ff688089 JB	283
	284	int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
	285	const char *name)
	286	{
	287	struct rate_control_ref ref, old;
	288
	289	ASSERT_RTNL();
3b8d81e0	290	if (local->open_count)
ff688089 JB	291	return -EBUSY;
	292
	293	ref = rate_control_alloc(name, local);
	294	if (!ref) {
	295	printk(KERN_WARNING "%s: Failed to select rate control "
dd1cd4c6	296	"algorithm\n", wiphy_name(local->hw.wiphy));
ff688089 JB	297	return -ENOENT;
	298	}
	299
	300	old = local->rate_ctrl;
	301	local->rate_ctrl = ref;
	302	if (old) {
	303	rate_control_put(old);
	304	sta_info_flush(local, NULL);
	305	}
	306
	307	printk(KERN_DEBUG "%s: Selected rate control "
dd1cd4c6	308	"algorithm '%s'\n", wiphy_name(local->hw.wiphy),
ff688089 JB	309	ref->ops->name);
	310
	311
	312	return 0;
	313	}
	314
	315	void rate_control_deinitialize(struct ieee80211_local *local)
	316	{
	317	struct rate_control_ref *ref;
	318
	319	ref = local->rate_ctrl;
	320	local->rate_ctrl = NULL;
	321	rate_control_put(ref);
	322	}
c21b39ac	323