Message-Id: <20201012104648.985256-17-Jerome.Pouiller@silabs.com>
Date:   Mon, 12 Oct 2020 12:46:41 +0200
From:   Jerome Pouiller <Jerome.Pouiller@...abs.com>
To:     linux-wireless@...r.kernel.org, netdev@...r.kernel.org
Cc:     devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Kalle Valo <kvalo@...eaurora.org>,
        "David S . Miller" <davem@...emloft.net>,
        devicetree@...r.kernel.org, Rob Herring <robh+dt@...nel.org>,
        Jérôme Pouiller 
        <jerome.pouiller@...abs.com>
Subject: [PATCH 16/23] wfx: add queue.c/queue.h

From: Jérôme Pouiller <jerome.pouiller@...abs.com>

Signed-off-by: Jérôme Pouiller <jerome.pouiller@...abs.com>
---
 drivers/net/wireless/silabs/wfx/queue.c | 304 ++++++++++++++++++++++++
 drivers/net/wireless/silabs/wfx/queue.h |  45 ++++
 2 files changed, 349 insertions(+)
 create mode 100644 drivers/net/wireless/silabs/wfx/queue.c
 create mode 100644 drivers/net/wireless/silabs/wfx/queue.h

diff --git a/drivers/net/wireless/silabs/wfx/queue.c b/drivers/net/wireless/silabs/wfx/queue.c
new file mode 100644
index 000000000000..31c37f69c295
--- /dev/null
+++ b/drivers/net/wireless/silabs/wfx/queue.c
@@ -0,0 +1,304 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * O(1) TX queue with built-in allocator.
+ *
+ * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
+ * Copyright (c) 2010, ST-Ericsson
+ */
+#include <linux/sched.h>
+#include <net/mac80211.h>
+
+#include "queue.h"
+#include "wfx.h"
+#include "sta.h"
+#include "data_tx.h"
+#include "traces.h"
+
+void wfx_tx_lock(struct wfx_dev *wdev)
+{
+	atomic_inc(&wdev->tx_lock);
+}
+
+void wfx_tx_unlock(struct wfx_dev *wdev)
+{
+	int tx_lock = atomic_dec_return(&wdev->tx_lock);
+
+	WARN(tx_lock < 0, "inconsistent tx_lock value");
+	if (!tx_lock)
+		wfx_bh_request_tx(wdev);
+}
+
+void wfx_tx_flush(struct wfx_dev *wdev)
+{
+	int ret;
+
+	// Do not wait for any reply if chip is frozen
+	if (wdev->chip_frozen)
+		return;
+
+	wfx_tx_lock(wdev);
+	mutex_lock(&wdev->hif_cmd.lock);
+	ret = wait_event_timeout(wdev->hif.tx_buffers_empty,
+				 !wdev->hif.tx_buffers_used,
+				 msecs_to_jiffies(3000));
+	if (!ret) {
+		dev_warn(wdev->dev, "cannot flush tx buffers (%d still busy)\n",
+			 wdev->hif.tx_buffers_used);
+		wfx_pending_dump_old_frames(wdev, 3000);
+		// FIXME: drop pending frames here
+		wdev->chip_frozen = true;
+	}
+	mutex_unlock(&wdev->hif_cmd.lock);
+	wfx_tx_unlock(wdev);
+}
+
+void wfx_tx_lock_flush(struct wfx_dev *wdev)
+{
+	wfx_tx_lock(wdev);
+	wfx_tx_flush(wdev);
+}
+
+void wfx_tx_queues_init(struct wfx_vif *wvif)
+{
+	// The device is in charge to respect the details of the QoS parameters.
+	// The driver just ensure that it roughtly respect the priorities to
+	// avoid any shortage.
+	const int priorities[IEEE80211_NUM_ACS] = { 1, 2, 64, 128 };
+	int i;
+
+	for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
+		skb_queue_head_init(&wvif->tx_queue[i].normal);
+		skb_queue_head_init(&wvif->tx_queue[i].cab);
+		wvif->tx_queue[i].priority = priorities[i];
+	}
+}
+
+void wfx_tx_queues_check_empty(struct wfx_vif *wvif)
+{
+	int i;
+
+	for (i = 0; i < IEEE80211_NUM_ACS; ++i) {
+		WARN_ON(atomic_read(&wvif->tx_queue[i].pending_frames));
+		WARN_ON(!skb_queue_empty_lockless(&wvif->tx_queue[i].normal));
+		WARN_ON(!skb_queue_empty_lockless(&wvif->tx_queue[i].cab));
+	}
+}
+
+bool wfx_tx_queue_empty(struct wfx_vif *wvif, struct wfx_queue *queue)
+{
+	return skb_queue_empty(&queue->normal) && skb_queue_empty(&queue->cab);
+}
+
+static void __wfx_tx_queue_drop(struct wfx_vif *wvif,
+				struct sk_buff_head *skb_queue,
+				struct sk_buff_head *dropped)
+{
+	struct sk_buff *skb, *tmp;
+
+	spin_lock_bh(&skb_queue->lock);
+	skb_queue_walk_safe(skb_queue, skb, tmp) {
+		__skb_unlink(skb, skb_queue);
+		skb_queue_head(dropped, skb);
+	}
+	spin_unlock_bh(&skb_queue->lock);
+}
+
+void wfx_tx_queue_drop(struct wfx_vif *wvif, struct wfx_queue *queue,
+		       struct sk_buff_head *dropped)
+{
+	__wfx_tx_queue_drop(wvif, &queue->cab, dropped);
+	__wfx_tx_queue_drop(wvif, &queue->normal, dropped);
+	wake_up(&wvif->wdev->tx_dequeue);
+}
+
+void wfx_tx_queues_put(struct wfx_vif *wvif, struct sk_buff *skb)
+{
+	struct wfx_queue *queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
+	struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb);
+
+	if (tx_info->flags & IEEE80211_TX_CTL_SEND_AFTER_DTIM)
+		skb_queue_tail(&queue->cab, skb);
+	else
+		skb_queue_tail(&queue->normal, skb);
+}
+
+void wfx_pending_drop(struct wfx_dev *wdev, struct sk_buff_head *dropped)
+{
+	struct wfx_queue *queue;
+	struct wfx_vif *wvif;
+	struct hif_msg *hif;
+	struct sk_buff *skb;
+
+	WARN(!wdev->chip_frozen, "%s should only be used to recover a frozen device",
+	     __func__);
+	while ((skb = skb_dequeue(&wdev->tx_pending)) != NULL) {
+		hif = (struct hif_msg *)skb->data;
+		wvif = wdev_to_wvif(wdev, hif->interface);
+		if (wvif) {
+			queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
+			WARN_ON(skb_get_queue_mapping(skb) > 3);
+			WARN_ON(!atomic_read(&queue->pending_frames));
+			atomic_dec(&queue->pending_frames);
+		}
+		skb_queue_head(dropped, skb);
+	}
+}
+
+struct sk_buff *wfx_pending_get(struct wfx_dev *wdev, u32 packet_id)
+{
+	struct wfx_queue *queue;
+	struct hif_req_tx *req;
+	struct wfx_vif *wvif;
+	struct hif_msg *hif;
+	struct sk_buff *skb;
+
+	spin_lock_bh(&wdev->tx_pending.lock);
+	skb_queue_walk(&wdev->tx_pending, skb) {
+		hif = (struct hif_msg *)skb->data;
+		req = (struct hif_req_tx *)hif->body;
+		if (req->packet_id != packet_id)
+			continue;
+		spin_unlock_bh(&wdev->tx_pending.lock);
+		wvif = wdev_to_wvif(wdev, hif->interface);
+		if (wvif) {
+			queue = &wvif->tx_queue[skb_get_queue_mapping(skb)];
+			WARN_ON(skb_get_queue_mapping(skb) > 3);
+			WARN_ON(!atomic_read(&queue->pending_frames));
+			atomic_dec(&queue->pending_frames);
+		}
+		skb_unlink(skb, &wdev->tx_pending);
+		return skb;
+	}
+	spin_unlock_bh(&wdev->tx_pending.lock);
+	WARN(1, "cannot find packet in pending queue");
+	return NULL;
+}
+
+void wfx_pending_dump_old_frames(struct wfx_dev *wdev, unsigned int limit_ms)
+{
+	ktime_t now = ktime_get();
+	struct wfx_tx_priv *tx_priv;
+	struct hif_req_tx *req;
+	struct sk_buff *skb;
+	bool first = true;
+
+	spin_lock_bh(&wdev->tx_pending.lock);
+	skb_queue_walk(&wdev->tx_pending, skb) {
+		tx_priv = wfx_skb_tx_priv(skb);
+		req = wfx_skb_txreq(skb);
+		if (ktime_after(now, ktime_add_ms(tx_priv->xmit_timestamp,
+						  limit_ms))) {
+			if (first) {
+				dev_info(wdev->dev, "frames stuck in firmware since %dms or more:\n",
+					 limit_ms);
+				first = false;
+			}
+			dev_info(wdev->dev, "   id %08x sent %lldms ago\n",
+				 req->packet_id,
+				 ktime_ms_delta(now, tx_priv->xmit_timestamp));
+		}
+	}
+	spin_unlock_bh(&wdev->tx_pending.lock);
+}
+
+unsigned int wfx_pending_get_pkt_us_delay(struct wfx_dev *wdev,
+					  struct sk_buff *skb)
+{
+	ktime_t now = ktime_get();
+	struct wfx_tx_priv *tx_priv = wfx_skb_tx_priv(skb);
+
+	return ktime_us_delta(now, tx_priv->xmit_timestamp);
+}
+
+bool wfx_tx_queues_has_cab(struct wfx_vif *wvif)
+{
+	int i;
+
+	if (wvif->vif->type != NL80211_IFTYPE_AP)
+		return false;
+	for (i = 0; i < IEEE80211_NUM_ACS; ++i)
+		// Note: since only AP can have mcast frames in queue and only
+		// one vif can be AP, all queued frames has same interface id
+		if (!skb_queue_empty_lockless(&wvif->tx_queue[i].cab))
+			return true;
+	return false;
+}
+
+static int wfx_tx_queue_get_weight(struct wfx_queue *queue)
+{
+	return atomic_read(&queue->pending_frames) * queue->priority;
+}
+
+static struct sk_buff *wfx_tx_queues_get_skb(struct wfx_dev *wdev)
+{
+	struct wfx_queue *queues[IEEE80211_NUM_ACS * ARRAY_SIZE(wdev->vif)];
+	int i, j, num_queues = 0;
+	struct wfx_vif *wvif;
+	struct hif_msg *hif;
+	struct sk_buff *skb;
+
+	// sort the queues
+	wvif = NULL;
+	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
+		for (i = 0; i < IEEE80211_NUM_ACS; i++) {
+			WARN_ON(num_queues >= ARRAY_SIZE(queues));
+			queues[num_queues] = &wvif->tx_queue[i];
+			for (j = num_queues; j > 0; j--)
+				if (wfx_tx_queue_get_weight(queues[j]) <
+				    wfx_tx_queue_get_weight(queues[j - 1]))
+					swap(queues[j - 1], queues[j]);
+			num_queues++;
+		}
+	}
+
+	wvif = NULL;
+	while ((wvif = wvif_iterate(wdev, wvif)) != NULL) {
+		if (!wvif->after_dtim_tx_allowed)
+			continue;
+		for (i = 0; i < num_queues; i++) {
+			skb = skb_dequeue(&queues[i]->cab);
+			if (!skb)
+				continue;
+			// Note: since only AP can have mcast frames in queue
+			// and only one vif can be AP, all queued frames has
+			// same interface id
+			hif = (struct hif_msg *)skb->data;
+			WARN_ON(hif->interface != wvif->id);
+			WARN_ON(queues[i] !=
+				&wvif->tx_queue[skb_get_queue_mapping(skb)]);
+			atomic_inc(&queues[i]->pending_frames);
+			trace_queues_stats(wdev, queues[i]);
+			return skb;
+		}
+		// No more multicast to sent
+		wvif->after_dtim_tx_allowed = false;
+		schedule_work(&wvif->update_tim_work);
+	}
+
+	for (i = 0; i < num_queues; i++) {
+		skb = skb_dequeue(&queues[i]->normal);
+		if (skb) {
+			atomic_inc(&queues[i]->pending_frames);
+			trace_queues_stats(wdev, queues[i]);
+			return skb;
+		}
+	}
+	return NULL;
+}
+
+struct hif_msg *wfx_tx_queues_get(struct wfx_dev *wdev)
+{
+	struct wfx_tx_priv *tx_priv;
+	struct sk_buff *skb;
+
+	if (atomic_read(&wdev->tx_lock))
+		return NULL;
+	skb = wfx_tx_queues_get_skb(wdev);
+	if (!skb)
+		return NULL;
+	skb_queue_tail(&wdev->tx_pending, skb);
+	wake_up(&wdev->tx_dequeue);
+	tx_priv = wfx_skb_tx_priv(skb);
+	tx_priv->xmit_timestamp = ktime_get();
+	return (struct hif_msg *)skb->data;
+}
diff --git a/drivers/net/wireless/silabs/wfx/queue.h b/drivers/net/wireless/silabs/wfx/queue.h
new file mode 100644
index 000000000000..80ba19455ef3
--- /dev/null
+++ b/drivers/net/wireless/silabs/wfx/queue.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * O(1) TX queue with built-in allocator.
+ *
+ * Copyright (c) 2017-2020, Silicon Laboratories, Inc.
+ * Copyright (c) 2010, ST-Ericsson
+ */
+#ifndef WFX_QUEUE_H
+#define WFX_QUEUE_H
+
+#include <linux/skbuff.h>
+#include <linux/atomic.h>
+
+struct wfx_dev;
+struct wfx_vif;
+
+struct wfx_queue {
+	struct sk_buff_head	normal;
+	struct sk_buff_head	cab; // Content After (DTIM) Beacon
+	atomic_t		pending_frames;
+	int			priority;
+};
+
+void wfx_tx_lock(struct wfx_dev *wdev);
+void wfx_tx_unlock(struct wfx_dev *wdev);
+void wfx_tx_flush(struct wfx_dev *wdev);
+void wfx_tx_lock_flush(struct wfx_dev *wdev);
+
+void wfx_tx_queues_init(struct wfx_vif *wvif);
+void wfx_tx_queues_check_empty(struct wfx_vif *wvif);
+bool wfx_tx_queues_has_cab(struct wfx_vif *wvif);
+void wfx_tx_queues_put(struct wfx_vif *wvif, struct sk_buff *skb);
+struct hif_msg *wfx_tx_queues_get(struct wfx_dev *wdev);
+
+bool wfx_tx_queue_empty(struct wfx_vif *wvif, struct wfx_queue *queue);
+void wfx_tx_queue_drop(struct wfx_vif *wvif, struct wfx_queue *queue,
+		       struct sk_buff_head *dropped);
+
+struct sk_buff *wfx_pending_get(struct wfx_dev *wdev, u32 packet_id);
+void wfx_pending_drop(struct wfx_dev *wdev, struct sk_buff_head *dropped);
+unsigned int wfx_pending_get_pkt_us_delay(struct wfx_dev *wdev,
+					  struct sk_buff *skb);
+void wfx_pending_dump_old_frames(struct wfx_dev *wdev, unsigned int limit_ms);
+
+#endif /* WFX_QUEUE_H */
-- 
2.28.0

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