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) 2017-2019, Silicon Laboratories, Inc.
   6  * Copyright (c) 2010, ST-Ericsson
   7  */
   8 #include <linux/sched.h>
   9 #include <net/mac80211.h>
  10
  11 #include "queue.h"
  12 #include "wfx.h"
  13 #include "sta.h"
  14 #include "data_tx.h"
  15
  16 void wfx_tx_lock(struct wfx_dev *wdev)
  17 {
  18         atomic_inc(&wdev->tx_lock);
  19 }
  20
  21 void wfx_tx_unlock(struct wfx_dev *wdev)
  22 {
  23         int tx_lock = atomic_dec_return(&wdev->tx_lock);
  24
  25         WARN(tx_lock < 0, "inconsistent tx_lock value");
  26         if (!tx_lock)
  27                 wfx_bh_request_tx(wdev);
  28 }
  29
  30 void wfx_tx_flush(struct wfx_dev *wdev)
  31 {
  32         int ret;
  33
  34         // Do not wait for any reply if chip is frozen
  35         if (wdev->chip_frozen)
  36                 return;
  37
  38         wfx_tx_lock(wdev);
  39         mutex_lock(&wdev->hif_cmd.lock);
  40         ret = wait_event_timeout(wdev->hif.tx_buffers_empty,
  41                                  !wdev->hif.tx_buffers_used,
  42                                  msecs_to_jiffies(3000));
  43         if (!ret) {
  44                 dev_warn(wdev->dev, "cannot flush tx buffers (%d still busy)\n",
  45                          wdev->hif.tx_buffers_used);
  46                 wfx_pending_dump_old_frames(wdev, 3000);
  47                 // FIXME: drop pending frames here
  48                 wdev->chip_frozen = true;
  49         }
  50         mutex_unlock(&wdev->hif_cmd.lock);
  51         wfx_tx_unlock(wdev);
  52 }
  53
  54 void wfx_tx_lock_flush(struct wfx_dev *wdev)
  55 {
  56         wfx_tx_lock(wdev);
  57         wfx_tx_flush(wdev);
  58 }
  59
  60 void wfx_tx_queues_init(struct wfx_dev *wdev)
  61 {
  62         int i;
  63
  64         skb_queue_head_init(&wdev->tx_pending);
  65         init_waitqueue_head(&wdev->tx_dequeue);
  66         for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
  67                 skb_queue_head_init(&wdev->tx_queue[i].normal);
  68                 skb_queue_head_init(&wdev->tx_queue[i].cab);
  69         }
  70 }
  71
  72 void wfx_tx_queues_check_empty(struct wfx_dev *wdev)
  73 {
  74         int i;
  75
  76         WARN_ON(!skb_queue_empty_lockless(&wdev->tx_pending));
  77         for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
  78                 WARN_ON(atomic_read(&wdev->tx_queue[i].pending_frames));
  79                 WARN_ON(!skb_queue_empty_lockless(&wdev->tx_queue[i].normal));
  80                 WARN_ON(!skb_queue_empty_lockless(&wdev->tx_queue[i].cab));
  81         }
  82 }
  83
  84 static bool __wfx_tx_queue_empty(struct wfx_dev *wdev,
  85                                  struct sk_buff_head *skb_queue, int vif_id)
  86 {
  87         struct hif_msg *hif_msg;
  88         struct sk_buff *skb;
  89
  90         spin_lock_bh(&skb_queue->lock);
  91         skb_queue_walk(skb_queue, skb) {
  92                 hif_msg = (struct hif_msg *)skb->data;
  93                 if (vif_id < 0 || hif_msg->interface == vif_id) {
  94                         spin_unlock_bh(&skb_queue->lock);
  95                         return false;
  96                 }
  97         }
  98         spin_unlock_bh(&skb_queue->lock);
  99         return true;
 100 }
 101
 102 bool wfx_tx_queue_empty(struct wfx_dev *wdev,
 103                         struct wfx_queue *queue, int vif_id)
 104 {
 105         return __wfx_tx_queue_empty(wdev, &queue->normal, vif_id) &&
 106                __wfx_tx_queue_empty(wdev, &queue->cab, vif_id);
 107 }
 108
 109 static void __wfx_tx_queue_drop(struct wfx_dev *wdev,
 110                                 struct sk_buff_head *skb_queue, int vif_id,
 111                                 struct sk_buff_head *dropped)
 112 {
 113         struct sk_buff *skb, *tmp;
 114         struct hif_msg *hif_msg;
 115
 116         spin_lock_bh(&skb_queue->lock);
 117         skb_queue_walk_safe(skb_queue, skb, tmp) {
 118                 hif_msg = (struct hif_msg *)skb->data;
 119                 if (vif_id < 0 || hif_msg->interface == vif_id) {
 120                         __skb_unlink(skb, skb_queue);
 121                         skb_queue_head(dropped, skb);
 122                 }
 123         }
 124         spin_unlock_bh(&skb_queue->lock);
 125 }
 126
 127 void wfx_tx_queue_drop(struct wfx_dev *wdev, struct wfx_queue *queue,
 128                        int vif_id, struct sk_buff_head *dropped)
 129 {
 130         __wfx_tx_queue_drop(wdev, &queue->cab, vif_id, dropped);
 131         __wfx_tx_queue_drop(wdev, &queue->normal, vif_id, dropped);
 132         wake_up(&wdev->tx_dequeue);
 133 }
 134
 135 void wfx_tx_queues_put(struct wfx_dev *wdev, struct sk_buff *skb)
 136 {
 137         struct wfx_queue *queue = &wdev->tx_queue[skb_get_queue_mapping(skb)];
 138         struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
 139
 140         if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM)
 141                 skb_queue_tail(&queue->cab, skb);
 142         else
 143                 skb_queue_tail(&queue->normal, skb);
 144 }
 145
 146 void wfx_pending_drop(struct wfx_dev *wdev, struct sk_buff_head *dropped)
 147 {
 148         struct wfx_queue *queue;
 149         struct sk_buff *skb;
 150
 151         WARN(!wdev->chip_frozen, "%s should only be used to recover a frozen device",
 152              __func__);
 153         while ((skb = skb_dequeue(&wdev->tx_pending)) != NULL) {
 154                 queue = &wdev->tx_queue[skb_get_queue_mapping(skb)];
 155                 WARN_ON(skb_get_queue_mapping(skb) > 3);
 156                 WARN_ON(!atomic_read(&queue->pending_frames));
 157                 atomic_dec(&queue->pending_frames);
 158                 skb_queue_head(dropped, skb);
 159         }
 160 }
 161
 162 struct sk_buff *wfx_pending_get(struct wfx_dev *wdev, u32 packet_id)
 163 {
 164         struct wfx_queue *queue;
 165         struct hif_req_tx *req;
 166         struct sk_buff *skb;
 167
 168         spin_lock_bh(&wdev->tx_pending.lock);
 169         skb_queue_walk(&wdev->tx_pending, skb) {
 170                 req = wfx_skb_txreq(skb);
 171                 if (req->packet_id == packet_id) {
 172                         spin_unlock_bh(&wdev->tx_pending.lock);
 173                         queue = &wdev->tx_queue[skb_get_queue_mapping(skb)];
 174                         WARN_ON(skb_get_queue_mapping(skb) > 3);
 175                         WARN_ON(!atomic_read(&queue->pending_frames));
 176                         atomic_dec(&queue->pending_frames);
 177                         skb_unlink(skb, &wdev->tx_pending);
 178                         return skb;
 179                 }
 180         }
 181         spin_unlock_bh(&wdev->tx_pending.lock);
 182         WARN(1, "cannot find packet in pending queue");
 183         return NULL;
 184 }
 185
 186 void wfx_pending_dump_old_frames(struct wfx_dev *wdev, unsigned int limit_ms)
 187 {
 188         ktime_t now = ktime_get();
 189         struct wfx_tx_priv *tx_priv;
 190         struct hif_req_tx *req;
 191         struct sk_buff *skb;
 192         bool first = true;
 193
 194         spin_lock_bh(&wdev->tx_pending.lock);
 195         skb_queue_walk(&wdev->tx_pending, skb) {
 196                 tx_priv = wfx_skb_tx_priv(skb);
 197                 req = wfx_skb_txreq(skb);
 198                 if (ktime_after(now, ktime_add_ms(tx_priv->xmit_timestamp,
 199                                                   limit_ms))) {
 200                         if (first) {
 201                                 dev_info(wdev->dev, "frames stuck in firmware since %dms or more:\n",
 202                                          limit_ms);
 203                                 first = false;
 204                         }
 205                         dev_info(wdev->dev, "   id %08x sent %lldms ago\n",
 206                                  req->packet_id,
 207                                  ktime_ms_delta(now, tx_priv->xmit_timestamp));
 208                 }
 209         }
 210         spin_unlock_bh(&wdev->tx_pending.lock);
 211 }
 212
 213 unsigned int wfx_pending_get_pkt_us_delay(struct wfx_dev *wdev,
 214                                           struct sk_buff *skb)
 215 {
 216         ktime_t now = ktime_get();
 217         struct wfx_tx_priv *tx_priv = wfx_skb_tx_priv(skb);
 218
 219         return ktime_us_delta(now, tx_priv->xmit_timestamp);
 220 }
 221
 222 bool wfx_tx_queues_has_cab(struct wfx_vif *wvif)
 223 {
 224         struct wfx_dev *wdev = wvif->wdev;
 225         int i;
 226
 227         if (wvif->vif->type != NL80211_IFTYPE_AP)
 228                 return false;
 229         for (i = 0; i < IEEE80211_NUM_ACS; ++i)
 230                 // Note: since only AP can have mcast frames in queue and only
 231                 // one vif can be AP, all queued frames has same interface id
 232                 if (!skb_queue_empty_lockless(&wdev->tx_queue[i].cab))
 233                         return true;
 234         return false;
 235 }
 236
 237 static struct sk_buff *wfx_tx_queues_get_skb(struct wfx_dev *wdev)
 238 {
 239         struct wfx_queue *sorted_queues[IEEE80211_NUM_ACS];
 240         struct wfx_vif *wvif;
 241         struct hif_msg *hif;
 242         struct sk_buff *skb;
 243         int i, j;
 244
 245         // bubble sort
 246         for (i = 0; i < IEEE80211_NUM_ACS; i++) {
 247                 sorted_queues[i] = &wdev->tx_queue[i];
 248                 for (j = i; j > 0; j--)
 249                         if (atomic_read(&sorted_queues[j]->pending_frames) >
 250                             atomic_read(&sorted_queues[j - 1]->pending_frames))
 251                                 swap(sorted_queues[j - 1], sorted_queues[j]);
 252         }
 253         wvif = NULL;
 254         while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
 255                 if (!wvif->after_dtim_tx_allowed)
 256                         continue;
 257                 for (i = 0; i < IEEE80211_NUM_ACS; i++) {
 258                         skb = skb_dequeue(&sorted_queues[i]->cab);
 259                         if (!skb)
 260                                 continue;
 261                         // Note: since only AP can have mcast frames in queue
 262                         // and only one vif can be AP, all queued frames has
 263                         // same interface id
 264                         hif = (struct hif_msg *)skb->data;
 265                         WARN_ON(hif->interface != wvif->id);
 266                         WARN_ON(sorted_queues[i] !=
 267                                 &wdev->tx_queue[skb_get_queue_mapping(skb)]);
 268                         atomic_inc(&sorted_queues[i]->pending_frames);
 269                         return skb;
 270                 }
 271                 // No more multicast to sent
 272                 wvif->after_dtim_tx_allowed = false;
 273                 schedule_work(&wvif->update_tim_work);
 274         }
 275         for (i = 0; i < IEEE80211_NUM_ACS; i++) {
 276                 skb = skb_dequeue(&sorted_queues[i]->normal);
 277                 if (skb) {
 278                         WARN_ON(sorted_queues[i] !=
 279                                 &wdev->tx_queue[skb_get_queue_mapping(skb)]);
 280                         atomic_inc(&sorted_queues[i]->pending_frames);
 281                         return skb;
 282                 }
 283         }
 284         return NULL;
 285 }
 286
 287 struct hif_msg *wfx_tx_queues_get(struct wfx_dev *wdev)
 288 {
 289         struct wfx_tx_priv *tx_priv;
 290         struct sk_buff *skb;
 291
 292         if (atomic_read(&wdev->tx_lock))
 293                 return NULL;
 294
 295         for (;;) {
 296                 skb = wfx_tx_queues_get_skb(wdev);
 297                 if (!skb)
 298                         return NULL;
 299                 skb_queue_tail(&wdev->tx_pending, skb);
 300                 wake_up(&wdev->tx_dequeue);
 301                 tx_priv = wfx_skb_tx_priv(skb);
 302                 tx_priv->xmit_timestamp = ktime_get();
 303                 return (struct hif_msg *)skb->data;
 304         }
 305 }