[GitHub/mt8127/android_kernel_alcatel_ttab.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 <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 = 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;
	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->channel_type == NL80211_CHAN_NO_HT)
			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->channel_type == NL80211_CHAN_HT40MINUS) ||
		    (txrc->bss_conf->channel_type == NL80211_CHAN_HT40PLUS))
			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);
}
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>
3a9a231d	14	#include <linux/module.h>
2c8dccc7	15	#include "rate.h"
f0706e82	16	#include "ieee80211_i.h"
4b7679a5	17	#include "debugfs.h"
f0706e82 JB	18
	19	struct rate_control_alg {
	20	struct list_head list;
	21	struct rate_control_ops *ops;
	22	};
	23
	24	static LIST_HEAD(rate_ctrl_algs);
	25	static DEFINE_MUTEX(rate_ctrl_mutex);
	26
c21b39ac SB	27	static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
	28	module_param(ieee80211_default_rc_algo, charp, 0644);
	29	MODULE_PARM_DESC(ieee80211_default_rc_algo,
	30	"Default rate control algorithm for mac80211 to use");
	31
f0706e82 JB	32	int ieee80211_rate_control_register(struct rate_control_ops *ops)
	33	{
	34	struct rate_control_alg *alg;
	35
ac71c691 JB	36	if (!ops->name)
	37	return -EINVAL;
	38
999acd9c JB	39	mutex_lock(&rate_ctrl_mutex);
	40	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	41	if (!strcmp(alg->ops->name, ops->name)) {
	42	/* don't register an algorithm twice */
	43	WARN_ON(1);
b808ab16	44	mutex_unlock(&rate_ctrl_mutex);
999acd9c JB	45	return -EALREADY;
	46	}
	47	}
	48
dd00cc48	49	alg = kzalloc(sizeof(*alg), GFP_KERNEL);
f0706e82	50	if (alg == NULL) {
999acd9c	51	mutex_unlock(&rate_ctrl_mutex);
f0706e82 JB	52	return -ENOMEM;
f0706e82 JB	53	}
f0706e82 JB	54	alg->ops = ops;
f0706e82 JB	55
f0706e82 JB	56	list_add_tail(&alg->list, &rate_ctrl_algs);
	57	mutex_unlock(&rate_ctrl_mutex);
	58
	59	return 0;
	60	}
	61	EXPORT_SYMBOL(ieee80211_rate_control_register);
	62
	63	void ieee80211_rate_control_unregister(struct rate_control_ops *ops)
	64	{
	65	struct rate_control_alg *alg;
	66
	67	mutex_lock(&rate_ctrl_mutex);
	68	list_for_each_entry(alg, &rate_ctrl_algs, list) {
	69	if (alg->ops == ops) {
	70	list_del(&alg->list);
20880e89	71	kfree(alg);
f0706e82 JB	72	break;
	73	}
	74	}
	75	mutex_unlock(&rate_ctrl_mutex);
f0706e82 JB	76	}
	77	EXPORT_SYMBOL(ieee80211_rate_control_unregister);
	78
	79	static struct rate_control_ops *
	80	ieee80211_try_rate_control_ops_get(const char *name)
	81	{
	82	struct rate_control_alg *alg;
	83	struct rate_control_ops *ops = NULL;
	84
ac71c691 JB	85	if (!name)
	86	return NULL;
	87
f0706e82 JB	88	mutex_lock(&rate_ctrl_mutex);
f0706e82 JB	89	list_for_each_entry(alg, &rate_ctrl_algs, list) {
ac71c691	90	if (!strcmp(alg->ops->name, name))
f0706e82 JB	91	if (try_module_get(alg->ops->module)) {
	92	ops = alg->ops;
	93	break;
	94	}
	95	}
	96	mutex_unlock(&rate_ctrl_mutex);
	97	return ops;
	98	}
	99
c21b39ac	100	/* Get the rate control algorithm. */
f0706e82 JB	101	static struct rate_control_ops *
	102	ieee80211_rate_control_ops_get(const char *name)
	103	{
	104	struct rate_control_ops *ops;
c21b39ac	105	const char *alg_name;
f0706e82	106
d6d1b650	107	kparam_block_sysfs_write(ieee80211_default_rc_algo);
ac71c691	108	if (!name)
c21b39ac SB	109	alg_name = ieee80211_default_rc_algo;
	110	else
	111	alg_name = name;
ac71c691	112
c21b39ac	113	ops = ieee80211_try_rate_control_ops_get(alg_name);
f0706e82	114	if (!ops) {
c21b39ac SB	115	request_module("rc80211_%s", alg_name);
c21b39ac SB	116	ops = ieee80211_try_rate_control_ops_get(alg_name);
f0706e82	117	}
c21b39ac SB	118	if (!ops && name)
	119	/* try default if specific alg requested but not found */
	120	ops = ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo);
	121
4b475898 JB	122	/* try built-in one if specific alg requested but not found */
	123	if (!ops && strlen(CONFIG_MAC80211_RC_DEFAULT))
	124	ops = ieee80211_try_rate_control_ops_get(CONFIG_MAC80211_RC_DEFAULT);
d6d1b650	125	kparam_unblock_sysfs_write(ieee80211_default_rc_algo);
4b475898	126
f0706e82 JB	127	return ops;
	128	}
	129
	130	static void ieee80211_rate_control_ops_put(struct rate_control_ops *ops)
	131	{
	132	module_put(ops->module);
	133	}
	134
4b7679a5 JB	135	#ifdef CONFIG_MAC80211_DEBUGFS
	136	static ssize_t rcname_read(struct file file, char __user userbuf,
	137	size_t count, loff_t *ppos)
	138	{
	139	struct rate_control_ref *ref = file->private_data;
	140	int len = strlen(ref->ops->name);
	141
	142	return simple_read_from_buffer(userbuf, count, ppos,
	143	ref->ops->name, len);
	144	}
	145
	146	static const struct file_operations rcname_ops = {
	147	.read = rcname_read,
	148	.open = mac80211_open_file_generic,
6038f373	149	.llseek = default_llseek,
4b7679a5 JB	150	};
	151	#endif
	152
209c671d	153	static struct rate_control_ref rate_control_alloc(const char name,
f0706e82 JB	154	struct ieee80211_local *local)
f0706e82 JB	155	{
4b7679a5	156	struct dentry *debugfsdir = NULL;
f0706e82 JB	157	struct rate_control_ref *ref;
	158
	159	ref = kmalloc(sizeof(struct rate_control_ref), GFP_KERNEL);
	160	if (!ref)
	161	goto fail_ref;
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
889cbb91	186	static void rate_control_free(struct rate_control_ref *ctrl_ref)
f0706e82	187	{
f0706e82	188	ctrl_ref->ops->free(ctrl_ref->priv);
4b7679a5 JB	189
4b7679a5 JB	190	#ifdef CONFIG_MAC80211_DEBUGFS
7bcfaf2f	191	debugfs_remove_recursive(ctrl_ref->local->debugfs.rcdir);
4b7679a5 JB	192	ctrl_ref->local->debugfs.rcdir = NULL;
	193	#endif
	194
f0706e82 JB	195	ieee80211_rate_control_ops_put(ctrl_ref->ops);
	196	kfree(ctrl_ref);
	197	}
	198
b6f35301	199	static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control *txrc)
4c6d4f5c LR	200	{
	201	struct sk_buff *skb = txrc->skb;
	202	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	203	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
	204	__le16 fc;
	205
	206	fc = hdr->frame_control;
	207
b6f35301 RM	208	return (info->flags & (IEEE80211_TX_CTL_NO_ACK \|
	209	IEEE80211_TX_CTL_USE_MINRATE)) \|\|
	210	!ieee80211_is_data(fc);
4c6d4f5c LR	211	}
4c6d4f5c LR	212
dd5b4cc7	213	static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
8f0729b1	214	struct ieee80211_supported_band *sband)
e00cfce0 JM	215	{
	216	u8 i;
	217
	218	if (basic_rates == 0)
	219	return; /* assume basic rates unknown and accept rate */
	220	if (*idx < 0)
	221	return;
	222	if (basic_rates & (1 << *idx))
	223	return; /* selected rate is a basic rate */
	224
8f0729b1	225	for (i = *idx + 1; i <= sband->n_bitrates; i++) {
e00cfce0 JM	226	if (basic_rates & (1 << i)) {
	227	*idx = i;
	228	return;
	229	}
	230	}
	231
	232	/* could not find a basic rate; use original selection */
	233	}
	234
aad14ceb RM	235	static inline s8
	236	rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
	237	struct ieee80211_sta *sta)
	238	{
	239	int i;
	240
	241	for (i = 0; i < sband->n_bitrates; i++) {
	242	struct ieee80211_rate *srate = &sband->bitrates[i];
	243	if ((srate->bitrate == 10) \|\| (srate->bitrate == 20) \|\|
	244	(srate->bitrate == 55) \|\| (srate->bitrate == 110))
	245	continue;
	246
	247	if (rate_supported(sta, sband->band, i))
	248	return i;
	249	}
	250
	251	/* No matching rate found */
	252	return 0;
	253	}
	254
	255
4c6d4f5c LR	256	bool rate_control_send_low(struct ieee80211_sta *sta,
	257	void *priv_sta,
	258	struct ieee80211_tx_rate_control *txrc)
	259	{
	260	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
dd5b4cc7 FF	261	struct ieee80211_supported_band *sband = txrc->sband;
dd5b4cc7 FF	262	int mcast_rate;
4c6d4f5c	263
b6f35301	264	if (!sta \|\| !priv_sta \|\| rc_no_data_or_no_ack_use_min(txrc)) {
aad14ceb RM	265	if ((sband->band != IEEE80211_BAND_2GHZ) \|\|
	266	!(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
	267	info->control.rates[0].idx =
	268	rate_lowest_index(txrc->sband, sta);
	269	else
	270	info->control.rates[0].idx =
	271	rate_lowest_non_cck_index(txrc->sband, sta);
4c6d4f5c LR	272	info->control.rates[0].count =
	273	(info->flags & IEEE80211_TX_CTL_NO_ACK) ?
	274	1 : txrc->hw->max_rate_tries;
dd5b4cc7 FF	275	if (!sta && txrc->bss) {
	276	mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
	277	if (mcast_rate > 0) {
	278	info->control.rates[0].idx = mcast_rate - 1;
	279	return true;
	280	}
	281
e00cfce0 JM	282	rc_send_low_broadcast(&info->control.rates[0].idx,
e00cfce0 JM	283	txrc->bss_conf->basic_rates,
dd5b4cc7 FF	284	sband);
dd5b4cc7 FF	285	}
4c6d4f5c LR	286	return true;
	287	}
	288	return false;
	289	}
	290	EXPORT_SYMBOL(rate_control_send_low);
	291
19468413 SW	292	static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate *rate,
19468413 SW	293	int n_bitrates, u32 mask)
37eb0b16 JM	294	{
	295	int j;
	296
	297	/* See whether the selected rate or anything below it is allowed. */
	298	for (j = rate->idx; j >= 0; j--) {
	299	if (mask & (1 << j)) {
	300	/* Okay, found a suitable rate. Use it. */
	301	rate->idx = j;
19468413	302	return true;
37eb0b16 JM	303	}
	304	}
	305
	306	/* Try to find a higher rate that would be allowed */
	307	for (j = rate->idx + 1; j < n_bitrates; j++) {
	308	if (mask & (1 << j)) {
	309	/* Okay, found a suitable rate. Use it. */
	310	rate->idx = j;
19468413 SW	311	return true;
	312	}
	313	}
	314	return false;
	315	}
	316
	317	static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate *rate,
	318	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
	319	{
	320	int i, j;
	321	int ridx, rbit;
	322
	323	ridx = rate->idx / 8;
	324	rbit = rate->idx % 8;
	325
	326	/* sanity check */
910570b5	327	if (ridx < 0 \|\| ridx >= IEEE80211_HT_MCS_MASK_LEN)
19468413 SW	328	return false;
	329
	330	/* See whether the selected rate or anything below it is allowed. */
	331	for (i = ridx; i >= 0; i--) {
	332	for (j = rbit; j >= 0; j--)
	333	if (mcs_mask[i] & BIT(j)) {
	334	rate->idx = i * 8 + j;
	335	return true;
	336	}
	337	rbit = 7;
	338	}
	339
	340	/* Try to find a higher rate that would be allowed */
	341	ridx = (rate->idx + 1) / 8;
	342	rbit = (rate->idx + 1) % 8;
	343
	344	for (i = ridx; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
	345	for (j = rbit; j < 8; j++)
	346	if (mcs_mask[i] & BIT(j)) {
	347	rate->idx = i * 8 + j;
	348	return true;
	349	}
	350	rbit = 0;
	351	}
	352	return false;
	353	}
	354
	355
	356
	357	static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
	358	struct ieee80211_tx_rate_control *txrc,
	359	u32 mask,
	360	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN])
	361	{
	362	struct ieee80211_tx_rate alt_rate;
	363
	364	/* handle HT rates */
	365	if (rate->flags & IEEE80211_TX_RC_MCS) {
	366	if (rate_idx_match_mcs_mask(rate, mcs_mask))
	367	return;
	368
	369	/* also try the legacy rates. */
	370	alt_rate.idx = 0;
	371	/* keep protection flags */
	372	alt_rate.flags = rate->flags &
	373	(IEEE80211_TX_RC_USE_RTS_CTS \|
	374	IEEE80211_TX_RC_USE_CTS_PROTECT \|
	375	IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
	376	alt_rate.count = rate->count;
	377	if (rate_idx_match_legacy_mask(&alt_rate,
	378	txrc->sband->n_bitrates,
	379	mask)) {
	380	*rate = alt_rate;
	381	return;
	382	}
	383	} else {
	384	struct sk_buff *skb = txrc->skb;
	385	struct ieee80211_hdr hdr = (struct ieee80211_hdr ) skb->data;
	386	__le16 fc;
	387
	388	/* handle legacy rates */
	389	if (rate_idx_match_legacy_mask(rate, txrc->sband->n_bitrates,
	390	mask))
	391	return;
392
393	/* if HT BSS, and we handle a data frame, also try HT rates */
394	if (txrc->bss_conf->channel_type == NL80211_CHAN_NO_HT)
395	return;
396
397	fc = hdr->frame_control;
398	if (!ieee80211_is_data(fc))
399	return;
400
401	alt_rate.idx = 0;
402	/* keep protection flags */
403	alt_rate.flags = rate->flags &
404	(IEEE80211_TX_RC_USE_RTS_CTS \|
405	IEEE80211_TX_RC_USE_CTS_PROTECT \|
406	IEEE80211_TX_RC_USE_SHORT_PREAMBLE);
407	alt_rate.count = rate->count;
408
409	alt_rate.flags \|= IEEE80211_TX_RC_MCS;
410
411	if ((txrc->bss_conf->channel_type == NL80211_CHAN_HT40MINUS) \|\|
412	(txrc->bss_conf->channel_type == NL80211_CHAN_HT40PLUS))
413	alt_rate.flags \|= IEEE80211_TX_RC_40_MHZ_WIDTH;
414
415	if (rate_idx_match_mcs_mask(&alt_rate, mcs_mask)) {
416	*rate = alt_rate;
37eb0b16 JM	417	return;
	418	}
	419	}
	420
	421	/*
	422	* Uh.. No suitable rate exists. This should not really happen with
	423	* sane TX rate mask configurations. However, should someone manage to
	424	* configure supported rates and TX rate mask in incompatible way,
	425	* allow the frame to be transmitted with whatever the rate control
	426	* selected.
	427	*/
	428	}
	429
4b7679a5	430	void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
e6a9854b JB	431	struct sta_info *sta,
e6a9854b JB	432	struct ieee80211_tx_rate_control *txrc)
1abbe498	433	{
4b7679a5 JB	434	struct rate_control_ref *ref = sdata->local->rate_ctrl;
	435	void *priv_sta = NULL;
	436	struct ieee80211_sta *ista = NULL;
e6a9854b	437	struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1abbe498	438	int i;
37eb0b16	439	u32 mask;
19468413	440	u8 mcs_mask[IEEE80211_HT_MCS_MASK_LEN];
1abbe498	441
e1936e94	442	if (sta && test_sta_flag(sta, WLAN_STA_RATE_CONTROL)) {
4b7679a5 JB	443	ista = &sta->sta;
	444	priv_sta = sta->rate_ctrl_priv;
	445	}
	446
e6a9854b JB	447	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
	448	info->control.rates[i].idx = -1;
	449	info->control.rates[i].flags = 0;
8617b093	450	info->control.rates[i].count = 0;
e6a9854b JB	451	}
e6a9854b JB	452
5affcd6b JO	453	if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
	454	return;
	455
37eb0b16	456	ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
e6a9854b JB	457
e6a9854b JB	458	/*
37eb0b16 JM	459	* Try to enforce the rateidx mask the user wanted. skip this if the
	460	* default mask (allow all rates) is used to save some processing for
	461	* the common case.
e6a9854b	462	*/
37eb0b16	463	mask = sdata->rc_rateidx_mask[info->band];
19468413 SW	464	memcpy(mcs_mask, sdata->rc_rateidx_mcs_mask[info->band],
19468413 SW	465	sizeof(mcs_mask));
37eb0b16 JM	466	if (mask != (1 << txrc->sband->n_bitrates) - 1) {
	467	if (sta) {
	468	/* Filter out rates that the STA does not support */
	469	mask &= sta->sta.supp_rates[info->band];
19468413 SW	470	for (i = 0; i < sizeof(mcs_mask); i++)
19468413 SW	471	mcs_mask[i] &= sta->sta.ht_cap.mcs.rx_mask[i];
37eb0b16 JM	472	}
	473	/*
	474	* Make sure the rate index selected for each TX rate is
	475	* included in the configured mask and change the rate indexes
	476	* if needed.
	477	*/
e6a9854b	478	for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
5f4e6b2d CL	479	/* Skip invalid rates */
	480	if (info->control.rates[i].idx < 0)
	481	break;
19468413 SW	482	rate_idx_match_mask(&info->control.rates[i], txrc,
19468413 SW	483	mask, mcs_mask);
37eb0b16	484	}
1abbe498	485	}
e6a9854b JB	486
e6a9854b JB	487	BUG_ON(info->control.rates[0].idx < 0);
1abbe498 MN	488	}
1abbe498 MN	489
ff688089 JB	490	int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
	491	const char *name)
	492	{
889cbb91	493	struct rate_control_ref *ref;
ff688089 JB	494
ff688089 JB	495	ASSERT_RTNL();
af65cd96	496
3b8d81e0	497	if (local->open_count)
ff688089 JB	498	return -EBUSY;
ff688089 JB	499
af65cd96 JB	500	if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
	501	if (WARN_ON(!local->ops->set_rts_threshold))
	502	return -EINVAL;
	503	return 0;
	504	}
	505
ff688089 JB	506	ref = rate_control_alloc(name, local);
ff688089 JB	507	if (!ref) {
0fb9a9ec JP	508	wiphy_warn(local->hw.wiphy,
0fb9a9ec JP	509	"Failed to select rate control algorithm\n");
ff688089 JB	510	return -ENOENT;
	511	}
	512
889cbb91	513	WARN_ON(local->rate_ctrl);
ff688089	514	local->rate_ctrl = ref;
ff688089	515
0fb9a9ec JP	516	wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
0fb9a9ec JP	517	ref->ops->name);
ff688089	518
ff688089 JB	519	return 0;
	520	}
	521
	522	void rate_control_deinitialize(struct ieee80211_local *local)
	523	{
	524	struct rate_control_ref *ref;
	525
	526	ref = local->rate_ctrl;
af65cd96 JB	527
	528	if (!ref)
	529	return;
	530
ff688089	531	local->rate_ctrl = NULL;
889cbb91	532	rate_control_free(ref);
ff688089	533	}
c21b39ac	534