net:rfkill: add a gpio setup function into GPIO rfkill
[deliverable/linux.git] / net / mac80211 / rate.c
CommitLineData
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
18struct rate_control_alg {
19 struct list_head list;
20 struct rate_control_ops *ops;
21};
22
23static LIST_HEAD(rate_ctrl_algs);
24static DEFINE_MUTEX(rate_ctrl_mutex);
25
c21b39ac
SB
26static char *ieee80211_default_rc_algo = CONFIG_MAC80211_RC_DEFAULT;
27module_param(ieee80211_default_rc_algo, charp, 0644);
28MODULE_PARM_DESC(ieee80211_default_rc_algo,
29 "Default rate control algorithm for mac80211 to use");
30
f0706e82
JB
31int 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;
52 }
f0706e82
JB
53 alg->ops = ops;
54
f0706e82
JB
55 list_add_tail(&alg->list, &rate_ctrl_algs);
56 mutex_unlock(&rate_ctrl_mutex);
57
58 return 0;
59}
60EXPORT_SYMBOL(ieee80211_rate_control_register);
61
62void 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}
76EXPORT_SYMBOL(ieee80211_rate_control_unregister);
77
78static struct rate_control_ops *
79ieee80211_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);
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
100static struct rate_control_ops *
101ieee80211_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);
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
129static 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
135static 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
145static 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 152static struct rate_control_ref *rate_control_alloc(const char *name,
f0706e82
JB
153 struct ieee80211_local *local)
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
178fail_priv:
179 ieee80211_rate_control_ops_put(ref->ops);
180fail_ops:
181 kfree(ref);
182fail_ref:
183 return NULL;
184}
185
186static 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
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
202static 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}
213
dd5b4cc7 214static void rc_send_low_broadcast(s8 *idx, u32 basic_rates,
8f0729b1 215 struct ieee80211_supported_band *sband)
e00cfce0
JM
216{
217 u8 i;
218
219 if (basic_rates == 0)
220 return; /* assume basic rates unknown and accept rate */
221 if (*idx < 0)
222 return;
223 if (basic_rates & (1 << *idx))
224 return; /* selected rate is a basic rate */
225
8f0729b1 226 for (i = *idx + 1; i <= sband->n_bitrates; i++) {
e00cfce0
JM
227 if (basic_rates & (1 << i)) {
228 *idx = i;
229 return;
230 }
231 }
232
233 /* could not find a basic rate; use original selection */
234}
235
aad14ceb
RM
236static inline s8
237rate_lowest_non_cck_index(struct ieee80211_supported_band *sband,
238 struct ieee80211_sta *sta)
239{
240 int i;
241
242 for (i = 0; i < sband->n_bitrates; i++) {
243 struct ieee80211_rate *srate = &sband->bitrates[i];
244 if ((srate->bitrate == 10) || (srate->bitrate == 20) ||
245 (srate->bitrate == 55) || (srate->bitrate == 110))
246 continue;
247
248 if (rate_supported(sta, sband->band, i))
249 return i;
250 }
251
252 /* No matching rate found */
253 return 0;
254}
255
256
4c6d4f5c
LR
257bool rate_control_send_low(struct ieee80211_sta *sta,
258 void *priv_sta,
259 struct ieee80211_tx_rate_control *txrc)
260{
261 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
dd5b4cc7
FF
262 struct ieee80211_supported_band *sband = txrc->sband;
263 int mcast_rate;
4c6d4f5c
LR
264
265 if (!sta || !priv_sta || rc_no_data_or_no_ack(txrc)) {
aad14ceb
RM
266 if ((sband->band != IEEE80211_BAND_2GHZ) ||
267 !(info->flags & IEEE80211_TX_CTL_NO_CCK_RATE))
268 info->control.rates[0].idx =
269 rate_lowest_index(txrc->sband, sta);
270 else
271 info->control.rates[0].idx =
272 rate_lowest_non_cck_index(txrc->sband, sta);
4c6d4f5c
LR
273 info->control.rates[0].count =
274 (info->flags & IEEE80211_TX_CTL_NO_ACK) ?
275 1 : txrc->hw->max_rate_tries;
dd5b4cc7
FF
276 if (!sta && txrc->bss) {
277 mcast_rate = txrc->bss_conf->mcast_rate[sband->band];
278 if (mcast_rate > 0) {
279 info->control.rates[0].idx = mcast_rate - 1;
280 return true;
281 }
282
e00cfce0
JM
283 rc_send_low_broadcast(&info->control.rates[0].idx,
284 txrc->bss_conf->basic_rates,
dd5b4cc7
FF
285 sband);
286 }
4c6d4f5c
LR
287 return true;
288 }
289 return false;
290}
291EXPORT_SYMBOL(rate_control_send_low);
292
37eb0b16
JM
293static void rate_idx_match_mask(struct ieee80211_tx_rate *rate,
294 int n_bitrates, u32 mask)
295{
296 int j;
297
298 /* See whether the selected rate or anything below it is allowed. */
299 for (j = rate->idx; j >= 0; j--) {
300 if (mask & (1 << j)) {
301 /* Okay, found a suitable rate. Use it. */
302 rate->idx = j;
303 return;
304 }
305 }
306
307 /* Try to find a higher rate that would be allowed */
308 for (j = rate->idx + 1; j < n_bitrates; j++) {
309 if (mask & (1 << j)) {
310 /* Okay, found a suitable rate. Use it. */
311 rate->idx = j;
312 return;
313 }
314 }
315
316 /*
317 * Uh.. No suitable rate exists. This should not really happen with
318 * sane TX rate mask configurations. However, should someone manage to
319 * configure supported rates and TX rate mask in incompatible way,
320 * allow the frame to be transmitted with whatever the rate control
321 * selected.
322 */
323}
324
4b7679a5 325void rate_control_get_rate(struct ieee80211_sub_if_data *sdata,
e6a9854b
JB
326 struct sta_info *sta,
327 struct ieee80211_tx_rate_control *txrc)
1abbe498 328{
4b7679a5
JB
329 struct rate_control_ref *ref = sdata->local->rate_ctrl;
330 void *priv_sta = NULL;
331 struct ieee80211_sta *ista = NULL;
e6a9854b 332 struct ieee80211_tx_info *info = IEEE80211_SKB_CB(txrc->skb);
1abbe498 333 int i;
37eb0b16 334 u32 mask;
1abbe498 335
4b7679a5
JB
336 if (sta) {
337 ista = &sta->sta;
338 priv_sta = sta->rate_ctrl_priv;
339 }
340
e6a9854b
JB
341 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
342 info->control.rates[i].idx = -1;
343 info->control.rates[i].flags = 0;
344 info->control.rates[i].count = 1;
345 }
346
5affcd6b
JO
347 if (sdata->local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
348 return;
349
37eb0b16 350 ref->ops->get_rate(ref->priv, ista, priv_sta, txrc);
e6a9854b
JB
351
352 /*
37eb0b16
JM
353 * Try to enforce the rateidx mask the user wanted. skip this if the
354 * default mask (allow all rates) is used to save some processing for
355 * the common case.
e6a9854b 356 */
37eb0b16
JM
357 mask = sdata->rc_rateidx_mask[info->band];
358 if (mask != (1 << txrc->sband->n_bitrates) - 1) {
359 if (sta) {
360 /* Filter out rates that the STA does not support */
361 mask &= sta->sta.supp_rates[info->band];
362 }
363 /*
364 * Make sure the rate index selected for each TX rate is
365 * included in the configured mask and change the rate indexes
366 * if needed.
367 */
e6a9854b 368 for (i = 0; i < IEEE80211_TX_MAX_RATES; i++) {
5f4e6b2d
CL
369 /* Skip invalid rates */
370 if (info->control.rates[i].idx < 0)
371 break;
37eb0b16 372 /* Rate masking supports only legacy rates for now */
e6a9854b
JB
373 if (info->control.rates[i].flags & IEEE80211_TX_RC_MCS)
374 continue;
37eb0b16
JM
375 rate_idx_match_mask(&info->control.rates[i],
376 txrc->sband->n_bitrates, mask);
377 }
1abbe498 378 }
e6a9854b
JB
379
380 BUG_ON(info->control.rates[0].idx < 0);
1abbe498
MN
381}
382
f0706e82
JB
383struct rate_control_ref *rate_control_get(struct rate_control_ref *ref)
384{
385 kref_get(&ref->kref);
386 return ref;
387}
388
389void rate_control_put(struct rate_control_ref *ref)
390{
391 kref_put(&ref->kref, rate_control_release);
392}
ff688089
JB
393
394int ieee80211_init_rate_ctrl_alg(struct ieee80211_local *local,
395 const char *name)
396{
397 struct rate_control_ref *ref, *old;
398
399 ASSERT_RTNL();
af65cd96 400
3b8d81e0 401 if (local->open_count)
ff688089
JB
402 return -EBUSY;
403
af65cd96
JB
404 if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL) {
405 if (WARN_ON(!local->ops->set_rts_threshold))
406 return -EINVAL;
407 return 0;
408 }
409
ff688089
JB
410 ref = rate_control_alloc(name, local);
411 if (!ref) {
0fb9a9ec
JP
412 wiphy_warn(local->hw.wiphy,
413 "Failed to select rate control algorithm\n");
ff688089
JB
414 return -ENOENT;
415 }
416
417 old = local->rate_ctrl;
418 local->rate_ctrl = ref;
419 if (old) {
420 rate_control_put(old);
421 sta_info_flush(local, NULL);
422 }
423
0fb9a9ec
JP
424 wiphy_debug(local->hw.wiphy, "Selected rate control algorithm '%s'\n",
425 ref->ops->name);
ff688089 426
ff688089
JB
427 return 0;
428}
429
430void rate_control_deinitialize(struct ieee80211_local *local)
431{
432 struct rate_control_ref *ref;
433
434 ref = local->rate_ctrl;
af65cd96
JB
435
436 if (!ref)
437 return;
438
ff688089
JB
439 local->rate_ctrl = NULL;
440 rate_control_put(ref);
441}
c21b39ac 442
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