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