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// SPDX-License-Identifier: GPL-2.0-only
/*
* O(1) TX queue with built-in allocator for ST-Ericsson CW1200 drivers
*
* Copyright (c) 2010, ST-Ericsson
* Author: Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
*/
#include <net/mac80211.h>
#include <linux/sched.h>
#include "queue.h"
#include "cw1200.h"
#include "debug.h"
/* private */ struct cw1200_queue_item
{
struct list_head head;
struct sk_buff *skb;
u32 packet_id;
unsigned long queue_timestamp;
unsigned long xmit_timestamp;
struct cw1200_txpriv txpriv;
u8 generation;
};
static inline void __cw1200_queue_lock(struct cw1200_queue *queue)
{
struct cw1200_queue_stats *stats = queue->stats;
if (queue->tx_locked_cnt++ == 0) {
pr_debug("[TX] Queue %d is locked.\n",
queue->queue_id);
ieee80211_stop_queue(stats->priv->hw, queue->queue_id);
}
}
static inline void __cw1200_queue_unlock(struct cw1200_queue *queue)
{
struct cw1200_queue_stats *stats = queue->stats;
BUG_ON(!queue->tx_locked_cnt);
if (--queue->tx_locked_cnt == 0) {
pr_debug("[TX] Queue %d is unlocked.\n",
queue->queue_id);
ieee80211_wake_queue(stats->priv->hw, queue->queue_id);
}
}
static inline void cw1200_queue_parse_id(u32 packet_id, u8 *queue_generation,
u8 *queue_id, u8 *item_generation,
u8 *item_id)
{
*item_id = (packet_id >> 0) & 0xFF;
*item_generation = (packet_id >> 8) & 0xFF;
*queue_id = (packet_id >> 16) & 0xFF;
*queue_generation = (packet_id >> 24) & 0xFF;
}
static inline u32 cw1200_queue_mk_packet_id(u8 queue_generation, u8 queue_id,
u8 item_generation, u8 item_id)
{
return ((u32)item_id << 0) |
((u32)item_generation << 8) |
((u32)queue_id << 16) |
((u32)queue_generation << 24);
}
static void cw1200_queue_post_gc(struct cw1200_queue_stats *stats,
struct list_head *gc_list)
{
struct cw1200_queue_item *item, *tmp;
list_for_each_entry_safe(item, tmp, gc_list, head) {
list_del(&item->head);
stats->skb_dtor(stats->priv, item->skb, &item->txpriv);
kfree(item);
}
}
static void cw1200_queue_register_post_gc(struct list_head *gc_list,
struct cw1200_queue_item *item)
{
struct cw1200_queue_item *gc_item;
gc_item = kmemdup(item, sizeof(struct cw1200_queue_item),
GFP_ATOMIC);
BUG_ON(!gc_item);
list_add_tail(&gc_item->head, gc_list);
}
static void __cw1200_queue_gc(struct cw1200_queue *queue,
struct list_head *head,
bool unlock)
{
struct cw1200_queue_stats *stats = queue->stats;
struct cw1200_queue_item *item = NULL, *tmp;
bool wakeup_stats = false;
list_for_each_entry_safe(item, tmp, &queue->queue, head) {
if (jiffies - item->queue_timestamp < queue->ttl)
break;
--queue->num_queued;
--queue->link_map_cache[item->txpriv.link_id];
spin_lock_bh(&stats->lock);
--stats->num_queued;
if (!--stats->link_map_cache[item->txpriv.link_id])
wakeup_stats = true;
spin_unlock_bh(&stats->lock);
cw1200_debug_tx_ttl(stats->priv);
cw1200_queue_register_post_gc(head, item);
item->skb = NULL;
list_move_tail(&item->head, &queue->free_pool);
}
if (wakeup_stats)
wake_up(&stats->wait_link_id_empty);
if (queue->overfull) {
if (queue->num_queued <= (queue->capacity >> 1)) {
queue->overfull = false;
if (unlock)
__cw1200_queue_unlock(queue);
} else if (item) {
unsigned long tmo = item->queue_timestamp + queue->ttl;
mod_timer(&queue->gc, tmo);
cw1200_pm_stay_awake(&stats->priv->pm_state,
tmo - jiffies);
}
}
}
static void cw1200_queue_gc(struct timer_list *t)
{
LIST_HEAD(list);
struct cw1200_queue *queue =
from_timer(queue, t, gc);
spin_lock_bh(&queue->lock);
__cw1200_queue_gc(queue, &list, true);
spin_unlock_bh(&queue->lock);
cw1200_queue_post_gc(queue->stats, &list);
}
int cw1200_queue_stats_init(struct cw1200_queue_stats *stats,
size_t map_capacity,
cw1200_queue_skb_dtor_t skb_dtor,
struct cw1200_common *priv)
{
memset(stats, 0, sizeof(*stats));
stats->map_capacity = map_capacity;
stats->skb_dtor = skb_dtor;
stats->priv = priv;
spin_lock_init(&stats->lock);
init_waitqueue_head(&stats->wait_link_id_empty);
stats->link_map_cache = kcalloc(map_capacity, sizeof(int),
GFP_KERNEL);
if (!stats->link_map_cache)
return -ENOMEM;
return 0;
}
int cw1200_queue_init(struct cw1200_queue *queue,
struct cw1200_queue_stats *stats,
u8 queue_id,
size_t capacity,
unsigned long ttl)
{
size_t i;
memset(queue, 0, sizeof(*queue));
queue->stats = stats;
queue->capacity = capacity;
queue->queue_id = queue_id;
queue->ttl = ttl;
INIT_LIST_HEAD(&queue->queue);
INIT_LIST_HEAD(&queue->pending);
INIT_LIST_HEAD(&queue->free_pool);
spin_lock_init(&queue->lock);
timer_setup(&queue->gc, cw1200_queue_gc, 0);
queue->pool = kcalloc(capacity, sizeof(struct cw1200_queue_item),
GFP_KERNEL);
if (!queue->pool)
return -ENOMEM;
queue->link_map_cache = kcalloc(stats->map_capacity, sizeof(int),
GFP_KERNEL);
if (!queue->link_map_cache) {
kfree(queue->pool);
queue->pool = NULL;
return -ENOMEM;
}
for (i = 0; i < capacity; ++i)
list_add_tail(&queue->pool[i].head, &queue->free_pool);
return 0;
}
int cw1200_queue_clear(struct cw1200_queue *queue)
{
int i;
LIST_HEAD(gc_list);
struct cw1200_queue_stats *stats = queue->stats;
struct cw1200_queue_item *item, *tmp;
spin_lock_bh(&queue->lock);
queue->generation++;
list_splice_tail_init(&queue->queue, &queue->pending);
list_for_each_entry_safe(item, tmp, &queue->pending, head) {
WARN_ON(!item->skb);
cw1200_queue_register_post_gc(&gc_list, item);
item->skb = NULL;
list_move_tail(&item->head, &queue->free_pool);
}
queue->num_queued = 0;
queue->num_pending = 0;
spin_lock_bh(&stats->lock);
for (i = 0; i < stats->map_capacity; ++i) {
stats->num_queued -= queue->link_map_cache[i];
stats->link_map_cache[i] -= queue->link_map_cache[i];
queue->link_map_cache[i] = 0;
}
spin_unlock_bh(&stats->lock);
if (queue->overfull) {
queue->overfull = false;
__cw1200_queue_unlock(queue);
}
spin_unlock_bh(&queue->lock);
wake_up(&stats->wait_link_id_empty);
cw1200_queue_post_gc(stats, &gc_list);
return 0;
}
void cw1200_queue_stats_deinit(struct cw1200_queue_stats *stats)
{
kfree(stats->link_map_cache);
stats->link_map_cache = NULL;
}
void cw1200_queue_deinit(struct cw1200_queue *queue)
{
cw1200_queue_clear(queue);
del_timer_sync(&queue->gc);
INIT_LIST_HEAD(&queue->free_pool);
kfree(queue->pool);
kfree(queue->link_map_cache);
queue->pool = NULL;
queue->link_map_cache = NULL;
queue->capacity = 0;
}
size_t cw1200_queue_get_num_queued(struct cw1200_queue *queue,
u32 link_id_map)
{
size_t ret;
int i, bit;
size_t map_capacity = queue->stats->map_capacity;
if (!link_id_map)
return 0;
spin_lock_bh(&queue->lock);
if (link_id_map == (u32)-1) {
ret = queue->num_queued - queue->num_pending;
} else {
ret = 0;
for (i = 0, bit = 1; i < map_capacity; ++i, bit <<= 1) {
if (link_id_map & bit)
ret += queue->link_map_cache[i];
}
}
spin_unlock_bh(&queue->lock);
return ret;
}
int cw1200_queue_put(struct cw1200_queue *queue,
struct sk_buff *skb,
struct cw1200_txpriv *txpriv)
{
int ret = 0;
struct cw1200_queue_stats *stats = queue->stats;
if (txpriv->link_id >= queue->stats->map_capacity)
return -EINVAL;
spin_lock_bh(&queue->lock);
if (!WARN_ON(list_empty(&queue->free_pool))) {
struct cw1200_queue_item *item = list_first_entry(
&queue->free_pool, struct cw1200_queue_item, head);
BUG_ON(item->skb);
list_move_tail(&item->head, &queue->queue);
item->skb = skb;
item->txpriv = *txpriv;
item->generation = 0;
item->packet_id = cw1200_queue_mk_packet_id(queue->generation,
queue->queue_id,
item->generation,
item - queue->pool);
item->queue_timestamp = jiffies;
++queue->num_queued;
++queue->link_map_cache[txpriv->link_id];
spin_lock_bh(&stats->lock);
++stats->num_queued;
++stats->link_map_cache[txpriv->link_id];
spin_unlock_bh(&stats->lock);
/* TX may happen in parallel sometimes.
* Leave extra queue slots so we don't overflow.
*/
if (queue->overfull == false &&
queue->num_queued >=
(queue->capacity - (num_present_cpus() - 1))) {
queue->overfull = true;
__cw1200_queue_lock(queue);
mod_timer(&queue->gc, jiffies);
}
} else {
ret = -ENOENT;
}
spin_unlock_bh(&queue->lock);
return ret;
}
int 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)
{
int ret = -ENOENT;
struct cw1200_queue_item *item;
struct cw1200_queue_stats *stats = queue->stats;
bool wakeup_stats = false;
spin_lock_bh(&queue->lock);
list_for_each_entry(item, &queue->queue, head) {
if (link_id_map & BIT(item->txpriv.link_id)) {
ret = 0;
break;
}
}
if (!WARN_ON(ret)) {
*tx = (struct wsm_tx *)item->skb->data;
*tx_info = IEEE80211_SKB_CB(item->skb);
*txpriv = &item->txpriv;
(*tx)->packet_id = item->packet_id;
list_move_tail(&item->head, &queue->pending);
++queue->num_pending;
--queue->link_map_cache[item->txpriv.link_id];
item->xmit_timestamp = jiffies;
spin_lock_bh(&stats->lock);
--stats->num_queued;
if (!--stats->link_map_cache[item->txpriv.link_id])
wakeup_stats = true;
spin_unlock_bh(&stats->lock);
}
spin_unlock_bh(&queue->lock);
if (wakeup_stats)
wake_up(&stats->wait_link_id_empty);
return ret;
}
int cw1200_queue_requeue(struct cw1200_queue *queue, u32 packet_id)
{
int ret = 0;
u8 queue_generation, queue_id, item_generation, item_id;
struct cw1200_queue_item *item;
struct cw1200_queue_stats *stats = queue->stats;
cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
&item_generation, &item_id);
item = &queue->pool[item_id];
spin_lock_bh(&queue->lock);
BUG_ON(queue_id != queue->queue_id);
if (queue_generation != queue->generation) {
ret = -ENOENT;
} else if (item_id >= (unsigned) queue->capacity) {
WARN_ON(1);
ret = -EINVAL;
} else if (item->generation != item_generation) {
WARN_ON(1);
ret = -ENOENT;
} else {
--queue->num_pending;
++queue->link_map_cache[item->txpriv.link_id];
spin_lock_bh(&stats->lock);
++stats->num_queued;
++stats->link_map_cache[item->txpriv.link_id];
spin_unlock_bh(&stats->lock);
item->generation = ++item_generation;
item->packet_id = cw1200_queue_mk_packet_id(queue_generation,
queue_id,
item_generation,
item_id);
list_move(&item->head, &queue->queue);
}
spin_unlock_bh(&queue->lock);
return ret;
}
int cw1200_queue_requeue_all(struct cw1200_queue *queue)
{
struct cw1200_queue_item *item, *tmp;
struct cw1200_queue_stats *stats = queue->stats;
spin_lock_bh(&queue->lock);
list_for_each_entry_safe_reverse(item, tmp, &queue->pending, head) {
--queue->num_pending;
++queue->link_map_cache[item->txpriv.link_id];
spin_lock_bh(&stats->lock);
++stats->num_queued;
++stats->link_map_cache[item->txpriv.link_id];
spin_unlock_bh(&stats->lock);
++item->generation;
item->packet_id = cw1200_queue_mk_packet_id(queue->generation,
queue->queue_id,
item->generation,
item - queue->pool);
list_move(&item->head, &queue->queue);
}
spin_unlock_bh(&queue->lock);
return 0;
}
int cw1200_queue_remove(struct cw1200_queue *queue, u32 packet_id)
{
int ret = 0;
u8 queue_generation, queue_id, item_generation, item_id;
struct cw1200_queue_item *item;
struct cw1200_queue_stats *stats = queue->stats;
struct sk_buff *gc_skb = NULL;
struct cw1200_txpriv gc_txpriv;
cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
&item_generation, &item_id);
item = &queue->pool[item_id];
spin_lock_bh(&queue->lock);
BUG_ON(queue_id != queue->queue_id);
if (queue_generation != queue->generation) {
ret = -ENOENT;
} else if (item_id >= (unsigned) queue->capacity) {
WARN_ON(1);
ret = -EINVAL;
} else if (item->generation != item_generation) {
WARN_ON(1);
ret = -ENOENT;
} else {
gc_txpriv = item->txpriv;
gc_skb = item->skb;
item->skb = NULL;
--queue->num_pending;
--queue->num_queued;
++queue->num_sent;
++item->generation;
/* Do not use list_move_tail here, but list_move:
* try to utilize cache row.
*/
list_move(&item->head, &queue->free_pool);
if (queue->overfull &&
(queue->num_queued <= (queue->capacity >> 1))) {
queue->overfull = false;
__cw1200_queue_unlock(queue);
}
}
spin_unlock_bh(&queue->lock);
if (gc_skb)
stats->skb_dtor(stats->priv, gc_skb, &gc_txpriv);
return ret;
}
int cw1200_queue_get_skb(struct cw1200_queue *queue, u32 packet_id,
struct sk_buff **skb,
const struct cw1200_txpriv **txpriv)
{
int ret = 0;
u8 queue_generation, queue_id, item_generation, item_id;
struct cw1200_queue_item *item;
cw1200_queue_parse_id(packet_id, &queue_generation, &queue_id,
&item_generation, &item_id);
item = &queue->pool[item_id];
spin_lock_bh(&queue->lock);
BUG_ON(queue_id != queue->queue_id);
if (queue_generation != queue->generation) {
ret = -ENOENT;
} else if (item_id >= (unsigned) queue->capacity) {
WARN_ON(1);
ret = -EINVAL;
} else if (item->generation != item_generation) {
WARN_ON(1);
ret = -ENOENT;
} else {
*skb = item->skb;
*txpriv = &item->txpriv;
}
spin_unlock_bh(&queue->lock);
return ret;
}
void cw1200_queue_lock(struct cw1200_queue *queue)
{
spin_lock_bh(&queue->lock);
__cw1200_queue_lock(queue);
spin_unlock_bh(&queue->lock);
}
void cw1200_queue_unlock(struct cw1200_queue *queue)
{
spin_lock_bh(&queue->lock);
__cw1200_queue_unlock(queue);
spin_unlock_bh(&queue->lock);
}
bool cw1200_queue_get_xmit_timestamp(struct cw1200_queue *queue,
unsigned long *timestamp,
u32 pending_frame_id)
{
struct cw1200_queue_item *item;
bool ret;
spin_lock_bh(&queue->lock);
ret = !list_empty(&queue->pending);
if (ret) {
list_for_each_entry(item, &queue->pending, head) {
if (item->packet_id != pending_frame_id)
if (time_before(item->xmit_timestamp,
*timestamp))
*timestamp = item->xmit_timestamp;
}
}
spin_unlock_bh(&queue->lock);
return ret;
}
bool cw1200_queue_stats_is_empty(struct cw1200_queue_stats *stats,
u32 link_id_map)
{
bool empty = true;
spin_lock_bh(&stats->lock);
if (link_id_map == (u32)-1) {
empty = stats->num_queued == 0;
} else {
int i;
for (i = 0; i < stats->map_capacity; ++i) {
if (link_id_map & BIT(i)) {
if (stats->link_map_cache[i]) {
empty = false;
break;
}
}
}
}
spin_unlock_bh(&stats->lock);
return empty;
}