drivers/staging/wfx/queue.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * O(1) TX queue with built-in allocator.
   4  *
   5  * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
   6  * Copyright (c) 2010, ST-Ericsson
   7  */
   8 #include <net/mac80211.h>
   9
  10 #include "wfx.h"
  11 #include "traces.h"
  12
  13 void wfx_tx_lock(struct wfx_dev *wdev)
  14 {
  15         atomic_inc(&wdev->tx_lock);
  16 }
  17
  18 void wfx_tx_unlock(struct wfx_dev *wdev)
  19 {
  20         int tx_lock = atomic_dec_return(&wdev->tx_lock);
  21
  22         WARN(tx_lock < 0, "inconsistent tx_lock value");
  23         if (!tx_lock)
  24                 wfx_bh_request_tx(wdev);
  25 }
  26
  27 void wfx_tx_flush(struct wfx_dev *wdev)
  28 {
  29         int ret;
  30
  31         // Do not wait for any reply if chip is frozen
  32         if (wdev->chip_frozen)
  33                 return;
  34
  35         wfx_tx_lock(wdev);
  36         mutex_lock(&wdev->hif_cmd.lock);
  37         ret = wait_event_timeout(wdev->hif.tx_buffers_empty,
  38                                  !wdev->hif.tx_buffers_used,
  39                                  msecs_to_jiffies(3000));
  40         if (!ret) {
  41                 dev_warn(wdev->dev, "cannot flush tx buffers (%d still busy)\n",
  42                          wdev->hif.tx_buffers_used);
  43                 wfx_pending_dump_old_frames(wdev, 3000);
  44                 // FIXME: drop pending frames here
  45                 wdev->chip_frozen = true;
  46         }
  47         mutex_unlock(&wdev->hif_cmd.lock);
  48         wfx_tx_unlock(wdev);
  49 }
  50
  51 void wfx_tx_lock_flush(struct wfx_dev *wdev)
  52 {
  53         wfx_tx_lock(wdev);
  54         wfx_tx_flush(wdev);
  55 }
  56
  57 void wfx_tx_queues_init(struct wfx_vif *wvif)
  58 {
  59         // The device is in charge to respect the details of the QoS parameters.
  60         // The driver just ensure that it roughtly respect the priorities to
  61         // avoid any shortage.
  62         const int priorities[IEEE80211_NUM_ACS] = { 1, 2, 64, 128 };
  63         int i;
  64
  65         for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
  66                 skb_queue_head_init(&wvif->tx_queue[i].normal);
  67                 skb_queue_head_init(&wvif->tx_queue[i].cab);
  68                 wvif->tx_queue[i].priority = priorities[i];
  69         }
  70 }
  71
  72 void wfx_tx_queues_check_empty(struct wfx_vif *wvif)
  73 {
  74         int i;
  75
  76         for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
  77                 WARN_ON(atomic_read(&wvif->tx_queue[i].pending_frames));
  78                 WARN_ON(!skb_queue_empty_lockless(&wvif->tx_queue[i].normal));
  79                 WARN_ON(!skb_queue_empty_lockless(&wvif->tx_queue[i].cab));
  80         }
  81 }
  82
  83 bool wfx_tx_queue_empty(struct wfx_vif *wvif, struct wfx_queue *queue)
  84 {
  85         return skb_queue_empty(&queue->normal) && skb_queue_empty(&queue->cab);
  86 }
  87
  88 static void __wfx_tx_queue_drop(struct wfx_vif *wvif,
  89                                 struct sk_buff_head *skb_queue,
  90                                 struct sk_buff_head *dropped)
  91 {
  92         struct sk_buff *skb, *tmp;
  93
  94         spin_lock_bh(&skb_queue->lock);
  95         skb_queue_walk_safe(skb_queue, skb, tmp) {
  96                 __skb_unlink(skb, skb_queue);
  97                 skb_queue_head(dropped, skb);
  98         }
  99         spin_unlock_bh(&skb_queue->lock);
 100 }
 101
 102 void wfx_tx_queue_drop(struct wfx_vif *wvif, struct wfx_queue *queue,
 103                        struct sk_buff_head *dropped)
 104 {
 105         __wfx_tx_queue_drop(wvif, &queue->cab, dropped);
 106         __wfx_tx_queue_drop(wvif, &queue->normal, dropped);
 107         wake_up(&wvif->wdev->tx_dequeue);
 108 }
 109
 110 void wfx_tx_queues_put(struct wfx_vif *wvif, struct sk_buff *skb)
 111 {
 112         struct wfx_queue *queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
 113         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
 114
 115         if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM)
 116                 skb_queue_tail(&queue->cab, skb);
 117         else
 118                 skb_queue_tail(&queue->normal, skb);
 119 }
 120
 121 void wfx_pending_drop(struct wfx_dev *wdev, struct sk_buff_head *dropped)
 122 {
 123         struct wfx_queue *queue;
 124         struct wfx_vif *wvif;
 125         struct hif_msg *hif;
 126         struct sk_buff *skb;
 127
 128         WARN(!wdev->chip_frozen, "%s should only be used to recover a frozen device",
 129              __func__);
 130         while ((skb = skb_dequeue(&wdev->tx_pending)) != NULL) {
 131                 hif = (struct hif_msg *)skb->data;
 132                 wvif = wdev_to_wvif(wdev, hif->interface);
 133                 if (wvif) {
 134                         queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
 135                         WARN_ON(skb_get_queue_mapping(skb) > 3);
 136                         WARN_ON(!atomic_read(&queue->pending_frames));
 137                         atomic_dec(&queue->pending_frames);
 138                 }
 139                 skb_queue_head(dropped, skb);
 140         }
 141 }
 142
 143 struct sk_buff *wfx_pending_get(struct wfx_dev *wdev, u32 packet_id)
 144 {
 145         struct wfx_queue *queue;
 146         struct hif_req_tx *req;
 147         struct wfx_vif *wvif;
 148         struct hif_msg *hif;
 149         struct sk_buff *skb;
 150
 151         spin_lock_bh(&wdev->tx_pending.lock);
 152         skb_queue_walk(&wdev->tx_pending, skb) {
 153                 hif = (struct hif_msg *)skb->data;
 154                 req = (struct hif_req_tx *)hif->body;
 155                 if (req->packet_id != packet_id)
 156                         continue;
 157                 spin_unlock_bh(&wdev->tx_pending.lock);
 158                 wvif = wdev_to_wvif(wdev, hif->interface);
 159                 if (wvif) {
 160                         queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
 161                         WARN_ON(skb_get_queue_mapping(skb) > 3);
 162                         WARN_ON(!atomic_read(&queue->pending_frames));
 163                         atomic_dec(&queue->pending_frames);
 164                 }
 165                 skb_unlink(skb, &wdev->tx_pending);
 166                 return skb;
 167         }
 168         spin_unlock_bh(&wdev->tx_pending.lock);
 169         WARN(1, "cannot find packet in pending queue");
 170         return NULL;
 171 }
 172
 173 void wfx_pending_dump_old_frames(struct wfx_dev *wdev, unsigned int limit_ms)
 174 {
 175         ktime_t now = ktime_get();
 176         struct wfx_tx_priv *tx_priv;
 177         struct hif_req_tx *req;
 178         struct sk_buff *skb;
 179         bool first = true;
 180
 181         spin_lock_bh(&wdev->tx_pending.lock);
 182         skb_queue_walk(&wdev->tx_pending, skb) {
 183                 tx_priv = wfx_skb_tx_priv(skb);
 184                 req = wfx_skb_txreq(skb);
 185                 if (ktime_after(now, ktime_add_ms(tx_priv->xmit_timestamp,
 186                                                   limit_ms))) {
 187                         if (first) {
 188                                 dev_info(wdev->dev, "frames stuck in firmware since %dms or more:\n",
 189                                          limit_ms);
 190                                 first = false;
 191                         }
 192                         dev_info(wdev->dev, "   id %08x sent %lldms ago\n",
 193                                  req->packet_id,
 194                                  ktime_ms_delta(now, tx_priv->xmit_timestamp));
 195                 }
 196         }
 197         spin_unlock_bh(&wdev->tx_pending.lock);
 198 }
 199
 200 unsigned int wfx_pending_get_pkt_us_delay(struct wfx_dev *wdev,
 201                                           struct sk_buff *skb)
 202 {
 203         ktime_t now = ktime_get();
 204         struct wfx_tx_priv *tx_priv = wfx_skb_tx_priv(skb);
 205
 206         return ktime_us_delta(now, tx_priv->xmit_timestamp);
 207 }
 208
 209 bool wfx_tx_queues_has_cab(struct wfx_vif *wvif)
 210 {
 211         int i;
 212
 213         if (wvif->vif->type != NL80211_IFTYPE_AP)
 214                 return false;
 215         for (i = 0; i < IEEE80211_NUM_ACS; ++i)
 216                 // Note: since only AP can have mcast frames in queue and only
 217                 // one vif can be AP, all queued frames has same interface id
 218                 if (!skb_queue_empty_lockless(&wvif->tx_queue[i].cab))
 219                         return true;
 220         return false;
 221 }
 222
 223 static int wfx_tx_queue_get_weight(struct wfx_queue *queue)
 224 {
 225         return atomic_read(&queue->pending_frames) * queue->priority;
 226 }
 227
 228 static struct sk_buff *wfx_tx_queues_get_skb(struct wfx_dev *wdev)
 229 {
 230         struct wfx_queue *queues[IEEE80211_NUM_ACS * ARRAY_SIZE(wdev->vif)];
 231         int i, j, num_queues = 0;
 232         struct wfx_vif *wvif;
 233         struct hif_msg *hif;
 234         struct sk_buff *skb;
 235
 236         // sort the queues
 237         wvif = NULL;
 238         while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
 239                 for (i = 0; i < IEEE80211_NUM_ACS; i++) {
 240                         WARN_ON(num_queues >= ARRAY_SIZE(queues));
 241                         queues[num_queues] = &wvif->tx_queue[i];
 242                         for (j = num_queues; j > 0; j--)
 243                                 if (wfx_tx_queue_get_weight(queues[j]) <
 244                                     wfx_tx_queue_get_weight(queues[j - 1]))
 245                                         swap(queues[j - 1], queues[j]);
 246                         num_queues++;
 247                 }
 248         }
 249
 250         wvif = NULL;
 251         while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
 252                 if (!wvif->after_dtim_tx_allowed)
 253                         continue;
 254                 for (i = 0; i < num_queues; i++) {
 255                         skb = skb_dequeue(&queues[i]->cab);
 256                         if (!skb)
 257                                 continue;
 258                         // Note: since only AP can have mcast frames in queue
 259                         // and only one vif can be AP, all queued frames has
 260                         // same interface id
 261                         hif = (struct hif_msg *)skb->data;
 262                         WARN_ON(hif->interface != wvif->id);
 263                         WARN_ON(queues[i] !=
 264                                 &wvif->tx_queue[skb_get_queue_mapping(skb)]);
 265                         atomic_inc(&queues[i]->pending_frames);
 266                         trace_queues_stats(wdev, queues[i]);
 267                         return skb;
 268                 }
 269                 // No more multicast to sent
 270                 wvif->after_dtim_tx_allowed = false;
 271                 schedule_work(&wvif->update_tim_work);
 272         }
 273
 274         for (i = 0; i < num_queues; i++) {
 275                 skb = skb_dequeue(&queues[i]->normal);
 276                 if (skb) {
 277                         atomic_inc(&queues[i]->pending_frames);
 278                         trace_queues_stats(wdev, queues[i]);
 279                         return skb;
 280                 }
 281         }
 282         return NULL;
 283 }
 284
 285 struct hif_msg *wfx_tx_queues_get(struct wfx_dev *wdev)
 286 {
 287         struct wfx_tx_priv *tx_priv;
 288         struct sk_buff *skb;
 289
 290         if (atomic_read(&wdev->tx_lock))
 291                 return NULL;
 292         skb = wfx_tx_queues_get_skb(wdev);
 293         if (!skb)
 294                 return NULL;
 295         skb_queue_tail(&wdev->tx_pending, skb);
 296         wake_up(&wdev->tx_dequeue);
 297         tx_priv = wfx_skb_tx_priv(skb);
 298         tx_priv->xmit_timestamp = ktime_get();
 299         return (struct hif_msg *)skb->data;
 300 }