1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * O(1) TX queue with built-in allocator for ST-Ericsson CW1200 drivers
4 *
5 * Copyright (c) 2010, ST-Ericsson
6 * Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
7 */
8
9 #include <net/mac80211.h>
10 #include <linux/sched.h>
11 #include <linux/jiffies.h>
12 #include "queue.h"
13 #include "cw1200.h"
14 #include "debug.h"
15
16 /* private */ struct cw1200_queue_item
17 {
18 struct list_head head;
19 struct sk_buff *skb;
20 u32 packet_id;
21 unsigned long queue_timestamp;
22 unsigned long xmit_timestamp;
23 struct cw1200_txpriv txpriv;
24 u8 generation;
25 };
26
__cw1200_queue_lock(struct cw1200_queue * queue)27 static inline void __cw1200_queue_lock(struct cw1200_queue *queue)
28 {
29 struct cw1200_queue_stats *stats = queue->stats;
30 if (queue->tx_locked_cnt++ == 0) {
31 pr_debug("[TX] Queue %d is locked.\n",
32 queue->queue_id);
33 ieee80211_stop_queue(stats->priv->hw, queue->queue_id);
34 }
35 }
36
__cw1200_queue_unlock(struct cw1200_queue * queue)37 static inline void __cw1200_queue_unlock(struct cw1200_queue *queue)
38 {
39 struct cw1200_queue_stats *stats = queue->stats;
40 BUG_ON(!queue->tx_locked_cnt);
41 if (--queue->tx_locked_cnt == 0) {
42 pr_debug("[TX] Queue %d is unlocked.\n",
43 queue->queue_id);
44 ieee80211_wake_queue(stats->priv->hw, queue->queue_id);
45 }
46 }
47
cw1200_queue_parse_id(u32 packet_id,u8 * queue_generation,u8 * queue_id,u8 * item_generation,u8 * item_id)48 static inline void cw1200_queue_parse_id(u32 packet_id, u8 *queue_generation,
49 u8 *queue_id, u8 *item_generation,
50 u8 *item_id)
51 {
52 *item_id = (packet_id >> 0) & 0xFF;
53 *item_generation = (packet_id >> 8) & 0xFF;
54 *queue_id = (packet_id >> 16) & 0xFF;
55 *queue_generation = (packet_id >> 24) & 0xFF;
56 }
57
cw1200_queue_mk_packet_id(u8 queue_generation,u8 queue_id,u8 item_generation,u8 item_id)58 static inline u32 cw1200_queue_mk_packet_id(u8 queue_generation, u8 queue_id,
59 u8 item_generation, u8 item_id)
60 {
61 return ((u32)item_id << 0) |
62 ((u32)item_generation << 8) |
63 ((u32)queue_id << 16) |
64 ((u32)queue_generation << 24);
65 }
66
cw1200_queue_post_gc(struct cw1200_queue_stats * stats,struct list_head * gc_list)67 static void cw1200_queue_post_gc(struct cw1200_queue_stats *stats,
68 struct list_head *gc_list)
69 {
70 struct cw1200_queue_item *item, *tmp;
71
72 list_for_each_entry_safe(item, tmp, gc_list, head) {
73 list_del(&item->head);
74 stats->skb_dtor(stats->priv, item->skb, &item->txpriv);
75 kfree(item);
76 }
77 }
78
cw1200_queue_register_post_gc(struct list_head * gc_list,struct cw1200_queue_item * item)79 static void cw1200_queue_register_post_gc(struct list_head *gc_list,
80 struct cw1200_queue_item *item)
81 {
82 struct cw1200_queue_item *gc_item;
83 gc_item = kmemdup(item, sizeof(struct cw1200_queue_item),
84 GFP_ATOMIC);
85 BUG_ON(!gc_item);
86 list_add_tail(&gc_item->head, gc_list);
87 }
88
__cw1200_queue_gc(struct cw1200_queue * queue,struct list_head * head,bool unlock)89 static void __cw1200_queue_gc(struct cw1200_queue *queue,
90 struct list_head *head,
91 bool unlock)
92 {
93 struct cw1200_queue_stats *stats = queue->stats;
94 struct cw1200_queue_item *item = NULL, *iter, *tmp;
95 bool wakeup_stats = false;
96
97 list_for_each_entry_safe(iter, tmp, &queue->queue, head) {
98 if (time_is_after_jiffies(iter->queue_timestamp + queue->ttl)) {
99 item = iter;
100 break;
101 }
102 --queue->num_queued;
103 --queue->link_map_cache[iter->txpriv.link_id];
104 spin_lock_bh(&stats->lock);
105 --stats->num_queued;
106 if (!--stats->link_map_cache[iter->txpriv.link_id])
107 wakeup_stats = true;
108 spin_unlock_bh(&stats->lock);
109 cw1200_debug_tx_ttl(stats->priv);
110 cw1200_queue_register_post_gc(head, iter);
111 iter->skb = NULL;
112 list_move_tail(&iter->head, &queue->free_pool);
113 }
114
115 if (wakeup_stats)
116 wake_up(&stats->wait_link_id_empty);
117
118 if (queue->overfull) {
119 if (queue->num_queued <= (queue->capacity >> 1)) {
120 queue->overfull = false;
121 if (unlock)
122 __cw1200_queue_unlock(queue);
123 } else if (item) {
124 unsigned long tmo = item->queue_timestamp + queue->ttl;
125 mod_timer(&queue->gc, tmo);
126 cw1200_pm_stay_awake(&stats->priv->pm_state,
127 tmo - jiffies);
128 }
129 }
130 }
131
cw1200_queue_gc(struct timer_list * t)132 static void cw1200_queue_gc(struct timer_list *t)
133 {
134 LIST_HEAD(list);
135 struct cw1200_queue *queue =
136 from_timer(queue, t, gc);
137
138 spin_lock_bh(&queue->lock);
139 __cw1200_queue_gc(queue, &list, true);
140 spin_unlock_bh(&queue->lock);
141 cw1200_queue_post_gc(queue->stats, &list);
142 }
143
cw1200_queue_stats_init(struct cw1200_queue_stats * stats,size_t map_capacity,cw1200_queue_skb_dtor_t skb_dtor,struct cw1200_common * priv)144 int cw1200_queue_stats_init(struct cw1200_queue_stats *stats,
145 size_t map_capacity,
146 cw1200_queue_skb_dtor_t skb_dtor,
147 struct cw1200_common *priv)
148 {
149 memset(stats, 0, sizeof(*stats));
150 stats->map_capacity = map_capacity;
151 stats->skb_dtor = skb_dtor;
152 stats->priv = priv;
153 spin_lock_init(&stats->lock);
154 init_waitqueue_head(&stats->wait_link_id_empty);
155
156 stats->link_map_cache = kcalloc(map_capacity, sizeof(int),
157 GFP_KERNEL);
158 if (!stats->link_map_cache)
159 return -ENOMEM;
160
161 return 0;
162 }
163
cw1200_queue_init(struct cw1200_queue * queue,struct cw1200_queue_stats * stats,u8 queue_id,size_t capacity,unsigned long ttl)164 int cw1200_queue_init(struct cw1200_queue *queue,
165 struct cw1200_queue_stats *stats,
166 u8 queue_id,
167 size_t capacity,
168 unsigned long ttl)
169 {
170 size_t i;
171
172 memset(queue, 0, sizeof(*queue));
173 queue->stats = stats;
174 queue->capacity = capacity;
175 queue->queue_id = queue_id;
176 queue->ttl = ttl;
177 INIT_LIST_HEAD(&queue->queue);
178 INIT_LIST_HEAD(&queue->pending);
179 INIT_LIST_HEAD(&queue->free_pool);
180 spin_lock_init(&queue->lock);
181 timer_setup(&queue->gc, cw1200_queue_gc, 0);
182
183 queue->pool = kcalloc(capacity, sizeof(struct cw1200_queue_item),
184 GFP_KERNEL);
185 if (!queue->pool)
186 return -ENOMEM;
187
188 queue->link_map_cache = kcalloc(stats->map_capacity, sizeof(int),
189 GFP_KERNEL);
190 if (!queue->link_map_cache) {
191 kfree(queue->pool);
192 queue->pool = NULL;
193 return -ENOMEM;
194 }
195
196 for (i = 0; i < capacity; ++i)
197 list_add_tail(&queue->pool[i].head, &queue->free_pool);
198
199 return 0;
200 }
201
cw1200_queue_clear(struct cw1200_queue * queue)202 int cw1200_queue_clear(struct cw1200_queue *queue)
203 {
204 int i;
205 LIST_HEAD(gc_list);
206 struct cw1200_queue_stats *stats = queue->stats;
207 struct cw1200_queue_item *item, *tmp;
208
209 spin_lock_bh(&queue->lock);
210 queue->generation++;
211 list_splice_tail_init(&queue->queue, &queue->pending);
212 list_for_each_entry_safe(item, tmp, &queue->pending, head) {
213 WARN_ON(!item->skb);
214 cw1200_queue_register_post_gc(&gc_list, item);
215 item->skb = NULL;
216 list_move_tail(&item->head, &queue->free_pool);
217 }
218 queue->num_queued = 0;
219 queue->num_pending = 0;
220
221 spin_lock_bh(&stats->lock);
222 for (i = 0; i < stats->map_capacity; ++i) {
223 stats->num_queued -= queue->link_map_cache[i];
224 stats->link_map_cache[i] -= queue->link_map_cache[i];
225 queue->link_map_cache[i] = 0;
226 }
227 spin_unlock_bh(&stats->lock);
228 if (queue->overfull) {
229 queue->overfull = false;
230 __cw1200_queue_unlock(queue);
231 }
232 spin_unlock_bh(&queue->lock);
233 wake_up(&stats->wait_link_id_empty);
234 cw1200_queue_post_gc(stats, &gc_list);
235 return 0;
236 }
237
cw1200_queue_stats_deinit(struct cw1200_queue_stats * stats)238 void cw1200_queue_stats_deinit(struct cw1200_queue_stats *stats)
239 {
240 kfree(stats->link_map_cache);
241 stats->link_map_cache = NULL;
242 }
243
cw1200_queue_deinit(struct cw1200_queue * queue)244 void cw1200_queue_deinit(struct cw1200_queue *queue)
245 {
246 cw1200_queue_clear(queue);
247 del_timer_sync(&queue->gc);
248 INIT_LIST_HEAD(&queue->free_pool);
249 kfree(queue->pool);
250 kfree(queue->link_map_cache);
251 queue->pool = NULL;
252 queue->link_map_cache = NULL;
253 queue->capacity = 0;
254 }
255
cw1200_queue_get_num_queued(struct cw1200_queue * queue,u32 link_id_map)256 size_t cw1200_queue_get_num_queued(struct cw1200_queue *queue,
257 u32 link_id_map)
258 {
259 size_t ret;
260 int i, bit;
261 size_t map_capacity = queue->stats->map_capacity;
262
263 if (!link_id_map)
264 return 0;
265
266 spin_lock_bh(&queue->lock);
267 if (link_id_map == (u32)-1) {
268 ret = queue->num_queued - queue->num_pending;
269 } else {
270 ret = 0;
271 for (i = 0, bit = 1; i < map_capacity; ++i, bit <<= 1) {
272 if (link_id_map & bit)
273 ret += queue->link_map_cache[i];
274 }
275 }
276 spin_unlock_bh(&queue->lock);
277 return ret;
278 }
279
cw1200_queue_put(struct cw1200_queue * queue,struct sk_buff * skb,struct cw1200_txpriv * txpriv)280 int cw1200_queue_put(struct cw1200_queue *queue,
281 struct sk_buff *skb,
282 struct cw1200_txpriv *txpriv)
283 {
284 int ret = 0;
285 struct cw1200_queue_stats *stats = queue->stats;
286
287 if (txpriv->link_id >= queue->stats->map_capacity)
288 return -EINVAL;
289
290 spin_lock_bh(&queue->lock);
291 if (!WARN_ON(list_empty(&queue->free_pool))) {
292 struct cw1200_queue_item *item = list_first_entry(
293 &queue->free_pool, struct cw1200_queue_item, head);
294 BUG_ON(item->skb);
295
296 list_move_tail(&item->head, &queue->queue);
297 item->skb = skb;
298 item->txpriv = *txpriv;
299 item->generation = 0;
300 item->packet_id = cw1200_queue_mk_packet_id(queue->generation,
301 queue->queue_id,
302 item->generation,
303 item - queue->pool);
304 item->queue_timestamp = jiffies;
305
306 ++queue->num_queued;
307 ++queue->link_map_cache[txpriv->link_id];
308
309 spin_lock_bh(&stats->lock);
310 ++stats->num_queued;
311 ++stats->link_map_cache[txpriv->link_id];
312 spin_unlock_bh(&stats->lock);
313
314 /* TX may happen in parallel sometimes.
315 * Leave extra queue slots so we don't overflow.
316 */
317 if (queue->overfull == false &&
318 queue->num_queued >=
319 (queue->capacity - (num_present_cpus() - 1))) {
320 queue->overfull = true;
321 __cw1200_queue_lock(queue);
322 mod_timer(&queue->gc, jiffies);
323 }
324 } else {
325 ret = -ENOENT;
326 }
327 spin_unlock_bh(&queue->lock);
328 return ret;
329 }
330
cw1200_queue_get(struct cw1200_queue * queue,u32 link_id_map,struct wsm_tx ** tx,struct ieee80211_tx_info ** tx_info,const struct cw1200_txpriv ** txpriv)331 int cw1200_queue_get(struct cw1200_queue *queue,
332 u32 link_id_map,
333 struct wsm_tx **tx,
334 struct ieee80211_tx_info **tx_info,
335 const struct cw1200_txpriv **txpriv)
336 {
337 int ret = -ENOENT;
338 struct cw1200_queue_item *item;
339 struct cw1200_queue_stats *stats = queue->stats;
340 bool wakeup_stats = false;
341
342 spin_lock_bh(&queue->lock);
343 list_for_each_entry(item, &queue->queue, head) {
344 if (link_id_map & BIT(item->txpriv.link_id)) {
345 ret = 0;
346 break;
347 }
348 }
349
350 if (!WARN_ON(ret)) {
351 *tx = (struct wsm_tx *)item->skb->data;
352 *tx_info = IEEE80211_SKB_CB(item->skb);
353 *txpriv = &item->txpriv;
354 (*tx)->packet_id = item->packet_id;
355 list_move_tail(&item->head, &queue->pending);
356 ++queue->num_pending;
357 --queue->link_map_cache[item->txpriv.link_id];
358 item->xmit_timestamp = jiffies;
359
360 spin_lock_bh(&stats->lock);
361 --stats->num_queued;
362 if (!--stats->link_map_cache[item->txpriv.link_id])
363 wakeup_stats = true;
364 spin_unlock_bh(&stats->lock);
365 }
366 spin_unlock_bh(&queue->lock);
367 if (wakeup_stats)
368 wake_up(&stats->wait_link_id_empty);
369 return ret;
370 }
371
cw1200_queue_requeue(struct cw1200_queue * queue,u32 packet_id)372 int cw1200_queue_requeue(struct cw1200_queue *queue, u32 packet_id)
373 {
374 int ret = 0;
375 u8 queue_generation, queue_id, item_generation, item_id;
376 struct cw1200_queue_item *item;
377 struct cw1200_queue_stats *stats = queue->stats;
378
379 cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
380 &item_generation, &item_id);
381
382 item = &queue->pool[item_id];
383
384 spin_lock_bh(&queue->lock);
385 BUG_ON(queue_id != queue->queue_id);
386 if (queue_generation != queue->generation) {
387 ret = -ENOENT;
388 } else if (item_id >= (unsigned) queue->capacity) {
389 WARN_ON(1);
390 ret = -EINVAL;
391 } else if (item->generation != item_generation) {
392 WARN_ON(1);
393 ret = -ENOENT;
394 } else {
395 --queue->num_pending;
396 ++queue->link_map_cache[item->txpriv.link_id];
397
398 spin_lock_bh(&stats->lock);
399 ++stats->num_queued;
400 ++stats->link_map_cache[item->txpriv.link_id];
401 spin_unlock_bh(&stats->lock);
402
403 item->generation = ++item_generation;
404 item->packet_id = cw1200_queue_mk_packet_id(queue_generation,
405 queue_id,
406 item_generation,
407 item_id);
408 list_move(&item->head, &queue->queue);
409 }
410 spin_unlock_bh(&queue->lock);
411 return ret;
412 }
413
cw1200_queue_requeue_all(struct cw1200_queue * queue)414 int cw1200_queue_requeue_all(struct cw1200_queue *queue)
415 {
416 struct cw1200_queue_item *item, *tmp;
417 struct cw1200_queue_stats *stats = queue->stats;
418 spin_lock_bh(&queue->lock);
419
420 list_for_each_entry_safe_reverse(item, tmp, &queue->pending, head) {
421 --queue->num_pending;
422 ++queue->link_map_cache[item->txpriv.link_id];
423
424 spin_lock_bh(&stats->lock);
425 ++stats->num_queued;
426 ++stats->link_map_cache[item->txpriv.link_id];
427 spin_unlock_bh(&stats->lock);
428
429 ++item->generation;
430 item->packet_id = cw1200_queue_mk_packet_id(queue->generation,
431 queue->queue_id,
432 item->generation,
433 item - queue->pool);
434 list_move(&item->head, &queue->queue);
435 }
436 spin_unlock_bh(&queue->lock);
437
438 return 0;
439 }
440
cw1200_queue_remove(struct cw1200_queue * queue,u32 packet_id)441 int cw1200_queue_remove(struct cw1200_queue *queue, u32 packet_id)
442 {
443 int ret = 0;
444 u8 queue_generation, queue_id, item_generation, item_id;
445 struct cw1200_queue_item *item;
446 struct cw1200_queue_stats *stats = queue->stats;
447 struct sk_buff *gc_skb = NULL;
448 struct cw1200_txpriv gc_txpriv;
449
450 cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
451 &item_generation, &item_id);
452
453 item = &queue->pool[item_id];
454
455 spin_lock_bh(&queue->lock);
456 BUG_ON(queue_id != queue->queue_id);
457 if (queue_generation != queue->generation) {
458 ret = -ENOENT;
459 } else if (item_id >= (unsigned) queue->capacity) {
460 WARN_ON(1);
461 ret = -EINVAL;
462 } else if (item->generation != item_generation) {
463 WARN_ON(1);
464 ret = -ENOENT;
465 } else {
466 gc_txpriv = item->txpriv;
467 gc_skb = item->skb;
468 item->skb = NULL;
469 --queue->num_pending;
470 --queue->num_queued;
471 ++queue->num_sent;
472 ++item->generation;
473 /* Do not use list_move_tail here, but list_move:
474 * try to utilize cache row.
475 */
476 list_move(&item->head, &queue->free_pool);
477
478 if (queue->overfull &&
479 (queue->num_queued <= (queue->capacity >> 1))) {
480 queue->overfull = false;
481 __cw1200_queue_unlock(queue);
482 }
483 }
484 spin_unlock_bh(&queue->lock);
485
486 if (gc_skb)
487 stats->skb_dtor(stats->priv, gc_skb, &gc_txpriv);
488
489 return ret;
490 }
491
cw1200_queue_get_skb(struct cw1200_queue * queue,u32 packet_id,struct sk_buff ** skb,const struct cw1200_txpriv ** txpriv)492 int cw1200_queue_get_skb(struct cw1200_queue *queue, u32 packet_id,
493 struct sk_buff **skb,
494 const struct cw1200_txpriv **txpriv)
495 {
496 int ret = 0;
497 u8 queue_generation, queue_id, item_generation, item_id;
498 struct cw1200_queue_item *item;
499 cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
500 &item_generation, &item_id);
501
502 item = &queue->pool[item_id];
503
504 spin_lock_bh(&queue->lock);
505 BUG_ON(queue_id != queue->queue_id);
506 if (queue_generation != queue->generation) {
507 ret = -ENOENT;
508 } else if (item_id >= (unsigned) queue->capacity) {
509 WARN_ON(1);
510 ret = -EINVAL;
511 } else if (item->generation != item_generation) {
512 WARN_ON(1);
513 ret = -ENOENT;
514 } else {
515 *skb = item->skb;
516 *txpriv = &item->txpriv;
517 }
518 spin_unlock_bh(&queue->lock);
519 return ret;
520 }
521
cw1200_queue_lock(struct cw1200_queue * queue)522 void cw1200_queue_lock(struct cw1200_queue *queue)
523 {
524 spin_lock_bh(&queue->lock);
525 __cw1200_queue_lock(queue);
526 spin_unlock_bh(&queue->lock);
527 }
528
cw1200_queue_unlock(struct cw1200_queue * queue)529 void cw1200_queue_unlock(struct cw1200_queue *queue)
530 {
531 spin_lock_bh(&queue->lock);
532 __cw1200_queue_unlock(queue);
533 spin_unlock_bh(&queue->lock);
534 }
535
cw1200_queue_get_xmit_timestamp(struct cw1200_queue * queue,unsigned long * timestamp,u32 pending_frame_id)536 bool cw1200_queue_get_xmit_timestamp(struct cw1200_queue *queue,
537 unsigned long *timestamp,
538 u32 pending_frame_id)
539 {
540 struct cw1200_queue_item *item;
541 bool ret;
542
543 spin_lock_bh(&queue->lock);
544 ret = !list_empty(&queue->pending);
545 if (ret) {
546 list_for_each_entry(item, &queue->pending, head) {
547 if (item->packet_id != pending_frame_id)
548 if (time_before(item->xmit_timestamp,
549 *timestamp))
550 *timestamp = item->xmit_timestamp;
551 }
552 }
553 spin_unlock_bh(&queue->lock);
554 return ret;
555 }
556
cw1200_queue_stats_is_empty(struct cw1200_queue_stats * stats,u32 link_id_map)557 bool cw1200_queue_stats_is_empty(struct cw1200_queue_stats *stats,
558 u32 link_id_map)
559 {
560 bool empty = true;
561
562 spin_lock_bh(&stats->lock);
563 if (link_id_map == (u32)-1) {
564 empty = stats->num_queued == 0;
565 } else {
566 int i;
567 for (i = 0; i < stats->map_capacity; ++i) {
568 if (link_id_map & BIT(i)) {
569 if (stats->link_map_cache[i]) {
570 empty = false;
571 break;
572 }
573 }
574 }
575 }
576 spin_unlock_bh(&stats->lock);
577
578 return empty;
579 }
580