queue.c

  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
 27static 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
 37static 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
 48static 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
 58static 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
 67static 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
 79static 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
 89static 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
132static void cw1200_queue_gc(struct timer_list *t)
133{
134	LIST_HEAD(list);
135	struct cw1200_queue *queue =
136		timer_container_of(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
144int 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
164int 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
202int 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
238void cw1200_queue_stats_deinit(struct cw1200_queue_stats *stats)
239{
240	kfree(stats->link_map_cache);
241	stats->link_map_cache = NULL;
242}
243
244void cw1200_queue_deinit(struct cw1200_queue *queue)
245{
246	cw1200_queue_clear(queue);
247	timer_delete_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
256size_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
280int 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
331int 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
372int 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
414int cw1200_queue_remove(struct cw1200_queue *queue, u32 packet_id)
415{
416	int ret = 0;
417	u8 queue_generation, queue_id, item_generation, item_id;
418	struct cw1200_queue_item *item;
419	struct cw1200_queue_stats *stats = queue->stats;
420	struct sk_buff *gc_skb = NULL;
421	struct cw1200_txpriv gc_txpriv;
422
423	cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
424			      &item_generation, &item_id);
425
426	item = &queue->pool[item_id];
427
428	spin_lock_bh(&queue->lock);
429	BUG_ON(queue_id != queue->queue_id);
430	if (queue_generation != queue->generation) {
431		ret = -ENOENT;
432	} else if (item_id >= (unsigned) queue->capacity) {
433		WARN_ON(1);
434		ret = -EINVAL;
435	} else if (item->generation != item_generation) {
436		WARN_ON(1);
437		ret = -ENOENT;
438	} else {
439		gc_txpriv = item->txpriv;
440		gc_skb = item->skb;
441		item->skb = NULL;
442		--queue->num_pending;
443		--queue->num_queued;
444		++queue->num_sent;
445		++item->generation;
446		/* Do not use list_move_tail here, but list_move:
447		 * try to utilize cache row.
448		 */
449		list_move(&item->head, &queue->free_pool);
450
451		if (queue->overfull &&
452		    (queue->num_queued <= (queue->capacity >> 1))) {
453			queue->overfull = false;
454			__cw1200_queue_unlock(queue);
455		}
456	}
457	spin_unlock_bh(&queue->lock);
458
459	if (gc_skb)
460		stats->skb_dtor(stats->priv, gc_skb, &gc_txpriv);
461
462	return ret;
463}
464
465int cw1200_queue_get_skb(struct cw1200_queue *queue, u32 packet_id,
466			 struct sk_buff **skb,
467			 const struct cw1200_txpriv **txpriv)
468{
469	int ret = 0;
470	u8 queue_generation, queue_id, item_generation, item_id;
471	struct cw1200_queue_item *item;
472	cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
473			      &item_generation, &item_id);
474
475	item = &queue->pool[item_id];
476
477	spin_lock_bh(&queue->lock);
478	BUG_ON(queue_id != queue->queue_id);
479	if (queue_generation != queue->generation) {
480		ret = -ENOENT;
481	} else if (item_id >= (unsigned) queue->capacity) {
482		WARN_ON(1);
483		ret = -EINVAL;
484	} else if (item->generation != item_generation) {
485		WARN_ON(1);
486		ret = -ENOENT;
487	} else {
488		*skb = item->skb;
489		*txpriv = &item->txpriv;
490	}
491	spin_unlock_bh(&queue->lock);
492	return ret;
493}
494
495void cw1200_queue_lock(struct cw1200_queue *queue)
496{
497	spin_lock_bh(&queue->lock);
498	__cw1200_queue_lock(queue);
499	spin_unlock_bh(&queue->lock);
500}
501
502void cw1200_queue_unlock(struct cw1200_queue *queue)
503{
504	spin_lock_bh(&queue->lock);
505	__cw1200_queue_unlock(queue);
506	spin_unlock_bh(&queue->lock);
507}
508
509bool cw1200_queue_get_xmit_timestamp(struct cw1200_queue *queue,
510				     unsigned long *timestamp,
511				     u32 pending_frame_id)
512{
513	struct cw1200_queue_item *item;
514	bool ret;
515
516	spin_lock_bh(&queue->lock);
517	ret = !list_empty(&queue->pending);
518	if (ret) {
519		list_for_each_entry(item, &queue->pending, head) {
520			if (item->packet_id != pending_frame_id)
521				if (time_before(item->xmit_timestamp,
522						*timestamp))
523					*timestamp = item->xmit_timestamp;
524		}
525	}
526	spin_unlock_bh(&queue->lock);
527	return ret;
528}
529
530bool cw1200_queue_stats_is_empty(struct cw1200_queue_stats *stats,
531				 u32 link_id_map)
532{
533	bool empty = true;
534
535	spin_lock_bh(&stats->lock);
536	if (link_id_map == (u32)-1) {
537		empty = stats->num_queued == 0;
538	} else {
539		int i;
540		for (i = 0; i < stats->map_capacity; ++i) {
541			if (link_id_map & BIT(i)) {
542				if (stats->link_map_cache[i]) {
543					empty = false;
544					break;
545				}
546			}
547		}
548	}
549	spin_unlock_bh(&stats->lock);
550
551	return empty;
552}