2 * Copyright 2002-2005, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 * Copyright (c) 2006 Jiri Benc <jbenc@suse.cz>
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.
11 #include <linux/kernel.h>
12 #include <linux/rtnetlink.h>
13 #include <linux/slab.h>
14 #include <linux/module.h>
16 #include "ieee80211_i.h"
19 struct rate_control_alg
{
20 struct list_head list
;
21 struct rate_control_ops
*ops
;
24 static LIST_HEAD(rate_ctrl_algs
);
25 static DEFINE_MUTEX(rate_ctrl_mutex
);
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");
32 int ieee80211_rate_control_register(struct rate_control_ops
*ops
)
34 struct rate_control_alg
*alg
;
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 */
44 mutex_unlock(&rate_ctrl_mutex
);
49 alg
= kzalloc(sizeof(*alg
), GFP_KERNEL
);
51 mutex_unlock(&rate_ctrl_mutex
);
56 list_add_tail(&alg
->list
, &rate_ctrl_algs
);
57 mutex_unlock(&rate_ctrl_mutex
);
61 EXPORT_SYMBOL(ieee80211_rate_control_register
);
63 void ieee80211_rate_control_unregister(struct rate_control_ops
*ops
)
65 struct rate_control_alg
*alg
;
67 mutex_lock(&rate_ctrl_mutex
);
68 list_for_each_entry(alg
, &rate_ctrl_algs
, list
) {
69 if (alg
->ops
== ops
) {
75 mutex_unlock(&rate_ctrl_mutex
);
77 EXPORT_SYMBOL(ieee80211_rate_control_unregister
);
79 static struct rate_control_ops
*
80 ieee80211_try_rate_control_ops_get(const char *name
)
82 struct rate_control_alg
*alg
;
83 struct rate_control_ops
*ops
= NULL
;
88 mutex_lock(&rate_ctrl_mutex
);
89 list_for_each_entry(alg
, &rate_ctrl_algs
, list
) {
90 if (!strcmp(alg
->ops
->name
, name
))
91 if (try_module_get(alg
->ops
->module
)) {
96 mutex_unlock(&rate_ctrl_mutex
);
100 /* Get the rate control algorithm. */
101 static struct rate_control_ops
*
102 ieee80211_rate_control_ops_get(const char *name
)
104 struct rate_control_ops
*ops
;
105 const char *alg_name
;
107 kparam_block_sysfs_write(ieee80211_default_rc_algo
);
109 alg_name
= ieee80211_default_rc_algo
;
113 ops
= ieee80211_try_rate_control_ops_get(alg_name
);
115 request_module("rc80211_%s", alg_name
);
116 ops
= ieee80211_try_rate_control_ops_get(alg_name
);
119 /* try default if specific alg requested but not found */
120 ops
= ieee80211_try_rate_control_ops_get(ieee80211_default_rc_algo
);
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
);
125 kparam_unblock_sysfs_write(ieee80211_default_rc_algo
);
130 static void ieee80211_rate_control_ops_put(struct rate_control_ops
*ops
)
132 module_put(ops
->module
);
135 #ifdef CONFIG_MAC80211_DEBUGFS
136 static ssize_t
rcname_read(struct file
*file
, char __user
*userbuf
,
137 size_t count
, loff_t
*ppos
)
139 struct rate_control_ref
*ref
= file
->private_data
;
140 int len
= strlen(ref
->ops
->name
);
142 return simple_read_from_buffer(userbuf
, count
, ppos
,
143 ref
->ops
->name
, len
);
146 static const struct file_operations rcname_ops
= {
149 .llseek
= default_llseek
,
153 static struct rate_control_ref
*rate_control_alloc(const char *name
,
154 struct ieee80211_local
*local
)
156 struct dentry
*debugfsdir
= NULL
;
157 struct rate_control_ref
*ref
;
159 ref
= kmalloc(sizeof(struct rate_control_ref
), GFP_KERNEL
);
163 ref
->ops
= ieee80211_rate_control_ops_get(name
);
167 #ifdef CONFIG_MAC80211_DEBUGFS
168 debugfsdir
= debugfs_create_dir("rc", local
->hw
.wiphy
->debugfsdir
);
169 local
->debugfs
.rcdir
= debugfsdir
;
170 debugfs_create_file("name", 0400, debugfsdir
, ref
, &rcname_ops
);
173 ref
->priv
= ref
->ops
->alloc(&local
->hw
, debugfsdir
);
179 ieee80211_rate_control_ops_put(ref
->ops
);
186 static void rate_control_free(struct rate_control_ref
*ctrl_ref
)
188 ctrl_ref
->ops
->free(ctrl_ref
->priv
);
190 #ifdef CONFIG_MAC80211_DEBUGFS
191 debugfs_remove_recursive(ctrl_ref
->local
->debugfs
.rcdir
);
192 ctrl_ref
->local
->debugfs
.rcdir
= NULL
;
195 ieee80211_rate_control_ops_put(ctrl_ref
->ops
);
199 static bool rc_no_data_or_no_ack_use_min(struct ieee80211_tx_rate_control
*txrc
)
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
);
206 fc
= hdr
->frame_control
;
208 return (info
->flags
& (IEEE80211_TX_CTL_NO_ACK
|
209 IEEE80211_TX_CTL_USE_MINRATE
)) ||
210 !ieee80211_is_data(fc
);
213 static void rc_send_low_basicrate(s8
*idx
, u32 basic_rates
,
214 struct ieee80211_supported_band
*sband
)
218 if (basic_rates
== 0)
219 return; /* assume basic rates unknown and accept rate */
222 if (basic_rates
& (1 << *idx
))
223 return; /* selected rate is a basic rate */
225 for (i
= *idx
+ 1; i
<= sband
->n_bitrates
; i
++) {
226 if (basic_rates
& (1 << i
)) {
232 /* could not find a basic rate; use original selection */
235 static void __rate_control_send_low(struct ieee80211_hw
*hw
,
236 struct ieee80211_supported_band
*sband
,
237 struct ieee80211_sta
*sta
,
238 struct ieee80211_tx_info
*info
)
242 ieee80211_chandef_rate_flags(&hw
->conf
.chandef
);
244 if ((sband
->band
== IEEE80211_BAND_2GHZ
) &&
245 (info
->flags
& IEEE80211_TX_CTL_NO_CCK_RATE
))
246 rate_flags
|= IEEE80211_RATE_ERP_G
;
248 info
->control
.rates
[0].idx
= 0;
249 for (i
= 0; i
< sband
->n_bitrates
; i
++) {
250 if (!rate_supported(sta
, sband
->band
, i
))
253 info
->control
.rates
[0].idx
= i
;
256 WARN_ON_ONCE(i
== sband
->n_bitrates
);
258 info
->control
.rates
[0].count
=
259 (info
->flags
& IEEE80211_TX_CTL_NO_ACK
) ?
260 1 : hw
->max_rate_tries
;
262 info
->control
.skip_table
= 1;
266 bool rate_control_send_low(struct ieee80211_sta
*pubsta
,
268 struct ieee80211_tx_rate_control
*txrc
)
270 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(txrc
->skb
);
271 struct ieee80211_supported_band
*sband
= txrc
->sband
;
272 struct sta_info
*sta
;
274 bool use_basicrate
= false;
276 if (!pubsta
|| !priv_sta
|| rc_no_data_or_no_ack_use_min(txrc
)) {
277 __rate_control_send_low(txrc
->hw
, sband
, pubsta
, info
);
279 if (!pubsta
&& txrc
->bss
) {
280 mcast_rate
= txrc
->bss_conf
->mcast_rate
[sband
->band
];
281 if (mcast_rate
> 0) {
282 info
->control
.rates
[0].idx
= mcast_rate
- 1;
285 use_basicrate
= true;
287 sta
= container_of(pubsta
, struct sta_info
, sta
);
288 if (ieee80211_vif_is_mesh(&sta
->sdata
->vif
))
289 use_basicrate
= true;
293 rc_send_low_basicrate(&info
->control
.rates
[0].idx
,
294 txrc
->bss_conf
->basic_rates
,
301 EXPORT_SYMBOL(rate_control_send_low
);
303 static bool rate_idx_match_legacy_mask(struct ieee80211_tx_rate
*rate
,
304 int n_bitrates
, u32 mask
)
308 /* See whether the selected rate or anything below it is allowed. */
309 for (j
= rate
->idx
; j
>= 0; j
--) {
310 if (mask
& (1 << j
)) {
311 /* Okay, found a suitable rate. Use it. */
317 /* Try to find a higher rate that would be allowed */
318 for (j
= rate
->idx
+ 1; j
< n_bitrates
; j
++) {
319 if (mask
& (1 << j
)) {
320 /* Okay, found a suitable rate. Use it. */
328 static bool rate_idx_match_mcs_mask(struct ieee80211_tx_rate
*rate
,
329 u8 mcs_mask
[IEEE80211_HT_MCS_MASK_LEN
])
334 ridx
= rate
->idx
/ 8;
335 rbit
= rate
->idx
% 8;
338 if (ridx
< 0 || ridx
>= IEEE80211_HT_MCS_MASK_LEN
)
341 /* See whether the selected rate or anything below it is allowed. */
342 for (i
= ridx
; i
>= 0; i
--) {
343 for (j
= rbit
; j
>= 0; j
--)
344 if (mcs_mask
[i
] & BIT(j
)) {
345 rate
->idx
= i
* 8 + j
;
351 /* Try to find a higher rate that would be allowed */
352 ridx
= (rate
->idx
+ 1) / 8;
353 rbit
= (rate
->idx
+ 1) % 8;
355 for (i
= ridx
; i
< IEEE80211_HT_MCS_MASK_LEN
; i
++) {
356 for (j
= rbit
; j
< 8; j
++)
357 if (mcs_mask
[i
] & BIT(j
)) {
358 rate
->idx
= i
* 8 + j
;
368 static void rate_idx_match_mask(struct ieee80211_tx_rate
*rate
,
369 struct ieee80211_supported_band
*sband
,
370 enum nl80211_chan_width chan_width
,
372 u8 mcs_mask
[IEEE80211_HT_MCS_MASK_LEN
])
374 struct ieee80211_tx_rate alt_rate
;
376 /* handle HT rates */
377 if (rate
->flags
& IEEE80211_TX_RC_MCS
) {
378 if (rate_idx_match_mcs_mask(rate
, mcs_mask
))
381 /* also try the legacy rates. */
383 /* keep protection flags */
384 alt_rate
.flags
= rate
->flags
&
385 (IEEE80211_TX_RC_USE_RTS_CTS
|
386 IEEE80211_TX_RC_USE_CTS_PROTECT
|
387 IEEE80211_TX_RC_USE_SHORT_PREAMBLE
);
388 alt_rate
.count
= rate
->count
;
389 if (rate_idx_match_legacy_mask(&alt_rate
,
390 sband
->n_bitrates
, mask
)) {
395 /* handle legacy rates */
396 if (rate_idx_match_legacy_mask(rate
, sband
->n_bitrates
, mask
))
399 /* if HT BSS, and we handle a data frame, also try HT rates */
400 switch (chan_width
) {
401 case NL80211_CHAN_WIDTH_20_NOHT
:
402 case NL80211_CHAN_WIDTH_5
:
403 case NL80211_CHAN_WIDTH_10
:
410 /* keep protection flags */
411 alt_rate
.flags
= rate
->flags
&
412 (IEEE80211_TX_RC_USE_RTS_CTS
|
413 IEEE80211_TX_RC_USE_CTS_PROTECT
|
414 IEEE80211_TX_RC_USE_SHORT_PREAMBLE
);
415 alt_rate
.count
= rate
->count
;
417 alt_rate
.flags
|= IEEE80211_TX_RC_MCS
;
419 if (chan_width
== NL80211_CHAN_WIDTH_40
)
420 alt_rate
.flags
|= IEEE80211_TX_RC_40_MHZ_WIDTH
;
422 if (rate_idx_match_mcs_mask(&alt_rate
, mcs_mask
)) {
429 * Uh.. No suitable rate exists. This should not really happen with
430 * sane TX rate mask configurations. However, should someone manage to
431 * configure supported rates and TX rate mask in incompatible way,
432 * allow the frame to be transmitted with whatever the rate control
437 static void rate_fixup_ratelist(struct ieee80211_vif
*vif
,
438 struct ieee80211_supported_band
*sband
,
439 struct ieee80211_tx_info
*info
,
440 struct ieee80211_tx_rate
*rates
,
443 struct ieee80211_rate
*rate
;
448 * Set up the RTS/CTS rate as the fastest basic rate
449 * that is not faster than the data rate unless there
450 * is no basic rate slower than the data rate, in which
451 * case we pick the slowest basic rate
453 * XXX: Should this check all retry rates?
455 if (!(rates
[0].flags
& IEEE80211_TX_RC_MCS
)) {
456 u32 basic_rates
= vif
->bss_conf
.basic_rates
;
457 s8 baserate
= basic_rates
? ffs(basic_rates
- 1) : 0;
459 rate
= &sband
->bitrates
[rates
[0].idx
];
461 for (i
= 0; i
< sband
->n_bitrates
; i
++) {
462 /* must be a basic rate */
463 if (!(basic_rates
& BIT(i
)))
465 /* must not be faster than the data rate */
466 if (sband
->bitrates
[i
].bitrate
> rate
->bitrate
)
469 if (sband
->bitrates
[baserate
].bitrate
<
470 sband
->bitrates
[i
].bitrate
)
474 info
->control
.rts_cts_rate_idx
= baserate
;
477 for (i
= 0; i
< max_rates
; i
++) {
479 * make sure there's no valid rate following
480 * an invalid one, just in case drivers don't
481 * take the API seriously to stop at -1.
487 if (rates
[i
].idx
< 0) {
493 * For now assume MCS is already set up correctly, this
496 if (rates
[i
].flags
& IEEE80211_TX_RC_MCS
) {
497 WARN_ON(rates
[i
].idx
> 76);
499 if (!(rates
[i
].flags
& IEEE80211_TX_RC_USE_RTS_CTS
) &&
500 info
->control
.use_cts_prot
)
502 IEEE80211_TX_RC_USE_CTS_PROTECT
;
506 if (rates
[i
].flags
& IEEE80211_TX_RC_VHT_MCS
) {
507 WARN_ON(ieee80211_rate_get_vht_mcs(&rates
[i
]) > 9);
511 /* set up RTS protection if desired */
512 if (info
->control
.use_rts
) {
513 rates
[i
].flags
|= IEEE80211_TX_RC_USE_RTS_CTS
;
514 info
->control
.use_cts_prot
= false;
518 if (WARN_ON_ONCE(rates
[i
].idx
>= sband
->n_bitrates
)) {
523 rate
= &sband
->bitrates
[rates
[i
].idx
];
525 /* set up short preamble */
526 if (info
->control
.short_preamble
&&
527 rate
->flags
& IEEE80211_RATE_SHORT_PREAMBLE
)
528 rates
[i
].flags
|= IEEE80211_TX_RC_USE_SHORT_PREAMBLE
;
530 /* set up G protection */
531 if (!(rates
[i
].flags
& IEEE80211_TX_RC_USE_RTS_CTS
) &&
532 info
->control
.use_cts_prot
&&
533 rate
->flags
& IEEE80211_RATE_ERP_G
)
534 rates
[i
].flags
|= IEEE80211_TX_RC_USE_CTS_PROTECT
;
539 static void rate_control_fill_sta_table(struct ieee80211_sta
*sta
,
540 struct ieee80211_tx_info
*info
,
541 struct ieee80211_tx_rate
*rates
,
544 struct ieee80211_sta_rates
*ratetbl
= NULL
;
547 if (sta
&& !info
->control
.skip_table
)
548 ratetbl
= rcu_dereference(sta
->rates
);
550 /* Fill remaining rate slots with data from the sta rate table. */
551 max_rates
= min_t(int, max_rates
, IEEE80211_TX_RATE_TABLE_SIZE
);
552 for (i
= 0; i
< max_rates
; i
++) {
553 if (i
< ARRAY_SIZE(info
->control
.rates
) &&
554 info
->control
.rates
[i
].idx
>= 0 &&
555 info
->control
.rates
[i
].count
) {
556 if (rates
!= info
->control
.rates
)
557 rates
[i
] = info
->control
.rates
[i
];
558 } else if (ratetbl
) {
559 rates
[i
].idx
= ratetbl
->rate
[i
].idx
;
560 rates
[i
].flags
= ratetbl
->rate
[i
].flags
;
561 if (info
->control
.use_rts
)
562 rates
[i
].count
= ratetbl
->rate
[i
].count_rts
;
563 else if (info
->control
.use_cts_prot
)
564 rates
[i
].count
= ratetbl
->rate
[i
].count_cts
;
566 rates
[i
].count
= ratetbl
->rate
[i
].count
;
572 if (rates
[i
].idx
< 0 || !rates
[i
].count
)
577 static void rate_control_apply_mask(struct ieee80211_sub_if_data
*sdata
,
578 struct ieee80211_sta
*sta
,
579 struct ieee80211_supported_band
*sband
,
580 struct ieee80211_tx_info
*info
,
581 struct ieee80211_tx_rate
*rates
,
584 enum nl80211_chan_width chan_width
;
585 u8 mcs_mask
[IEEE80211_HT_MCS_MASK_LEN
];
592 * Try to enforce the rateidx mask the user wanted. skip this if the
593 * default mask (allow all rates) is used to save some processing for
596 mask
= sdata
->rc_rateidx_mask
[info
->band
];
597 has_mcs_mask
= sdata
->rc_has_mcs_mask
[info
->band
];
599 ieee80211_chandef_rate_flags(&sdata
->vif
.bss_conf
.chandef
);
600 for (i
= 0; i
< sband
->n_bitrates
; i
++)
601 if ((rate_flags
& sband
->bitrates
[i
].flags
) != rate_flags
)
604 if (mask
== (1 << sband
->n_bitrates
) - 1 && !has_mcs_mask
)
608 memcpy(mcs_mask
, sdata
->rc_rateidx_mcs_mask
[info
->band
],
611 memset(mcs_mask
, 0xff, sizeof(mcs_mask
));
614 /* Filter out rates that the STA does not support */
615 mask
&= sta
->supp_rates
[info
->band
];
616 for (i
= 0; i
< sizeof(mcs_mask
); i
++)
617 mcs_mask
[i
] &= sta
->ht_cap
.mcs
.rx_mask
[i
];
621 * Make sure the rate index selected for each TX rate is
622 * included in the configured mask and change the rate indexes
625 chan_width
= sdata
->vif
.bss_conf
.chandef
.width
;
626 for (i
= 0; i
< max_rates
; i
++) {
627 /* Skip invalid rates */
628 if (rates
[i
].idx
< 0)
631 rate_idx_match_mask(&rates
[i
], sband
, chan_width
, mask
,
636 void ieee80211_get_tx_rates(struct ieee80211_vif
*vif
,
637 struct ieee80211_sta
*sta
,
639 struct ieee80211_tx_rate
*dest
,
642 struct ieee80211_sub_if_data
*sdata
;
643 struct ieee80211_hdr
*hdr
= (struct ieee80211_hdr
*) skb
->data
;
644 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(skb
);
645 struct ieee80211_supported_band
*sband
;
647 rate_control_fill_sta_table(sta
, info
, dest
, max_rates
);
652 sdata
= vif_to_sdata(vif
);
653 sband
= sdata
->local
->hw
.wiphy
->bands
[info
->band
];
655 if (ieee80211_is_data(hdr
->frame_control
))
656 rate_control_apply_mask(sdata
, sta
, sband
, info
, dest
, max_rates
);
659 __rate_control_send_low(&sdata
->local
->hw
, sband
, sta
, info
);
662 rate_fixup_ratelist(vif
, sband
, info
, dest
, max_rates
);
664 EXPORT_SYMBOL(ieee80211_get_tx_rates
);
666 void rate_control_get_rate(struct ieee80211_sub_if_data
*sdata
,
667 struct sta_info
*sta
,
668 struct ieee80211_tx_rate_control
*txrc
)
670 struct rate_control_ref
*ref
= sdata
->local
->rate_ctrl
;
671 void *priv_sta
= NULL
;
672 struct ieee80211_sta
*ista
= NULL
;
673 struct ieee80211_tx_info
*info
= IEEE80211_SKB_CB(txrc
->skb
);
676 if (sta
&& test_sta_flag(sta
, WLAN_STA_RATE_CONTROL
)) {
678 priv_sta
= sta
->rate_ctrl_priv
;
681 for (i
= 0; i
< IEEE80211_TX_MAX_RATES
; i
++) {
682 info
->control
.rates
[i
].idx
= -1;
683 info
->control
.rates
[i
].flags
= 0;
684 info
->control
.rates
[i
].count
= 0;
687 if (sdata
->local
->hw
.flags
& IEEE80211_HW_HAS_RATE_CONTROL
)
690 ref
->ops
->get_rate(ref
->priv
, ista
, priv_sta
, txrc
);
692 if (sdata
->local
->hw
.flags
& IEEE80211_HW_SUPPORTS_RC_TABLE
)
695 ieee80211_get_tx_rates(&sdata
->vif
, ista
, txrc
->skb
,
697 ARRAY_SIZE(info
->control
.rates
));
700 int rate_control_set_rates(struct ieee80211_hw
*hw
,
701 struct ieee80211_sta
*pubsta
,
702 struct ieee80211_sta_rates
*rates
)
704 struct ieee80211_sta_rates
*old
;
707 * mac80211 guarantees that this function will not be called
708 * concurrently, so the following RCU access is safe, even without
709 * extra locking. This can not be checked easily, so we just set
710 * the condition to true.
712 old
= rcu_dereference_protected(pubsta
->rates
, true);
713 rcu_assign_pointer(pubsta
->rates
, rates
);
715 kfree_rcu(old
, rcu_head
);
719 EXPORT_SYMBOL(rate_control_set_rates
);
721 int ieee80211_init_rate_ctrl_alg(struct ieee80211_local
*local
,
724 struct rate_control_ref
*ref
;
728 if (local
->open_count
)
731 if (local
->hw
.flags
& IEEE80211_HW_HAS_RATE_CONTROL
) {
732 if (WARN_ON(!local
->ops
->set_rts_threshold
))
737 ref
= rate_control_alloc(name
, local
);
739 wiphy_warn(local
->hw
.wiphy
,
740 "Failed to select rate control algorithm\n");
744 WARN_ON(local
->rate_ctrl
);
745 local
->rate_ctrl
= ref
;
747 wiphy_debug(local
->hw
.wiphy
, "Selected rate control algorithm '%s'\n",
753 void rate_control_deinitialize(struct ieee80211_local
*local
)
755 struct rate_control_ref
*ref
;
757 ref
= local
->rate_ctrl
;
762 local
->rate_ctrl
= NULL
;
763 rate_control_free(ref
);