cw1200: add driver for the ST-E CW1100 & CW1200 WLAN chipsets

Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/cw1200/queue.c

@@ -0,0 +1,583 @@
+/*
+ * 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>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#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 = kmalloc(sizeof(struct cw1200_queue_item),
+			GFP_ATOMIC);
+	BUG_ON(!gc_item);
+	memcpy(gc_item, item, sizeof(struct cw1200_queue_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(unsigned long arg)
+{
+	LIST_HEAD(list);
+	struct cw1200_queue *queue =
+		(struct cw1200_queue *)arg;
+
+	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 = kzalloc(sizeof(int) * map_capacity,
+					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);
+	init_timer(&queue->gc);
+	queue->gc.data = (unsigned long)queue;
+	queue->gc.function = cw1200_queue_gc;
+
+	queue->pool = kzalloc(sizeof(struct cw1200_queue_item) * capacity,
+			GFP_KERNEL);
+	if (!queue->pool)
+		return -ENOMEM;
+
+	queue->link_map_cache = kzalloc(sizeof(int) * stats->map_capacity,
+			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;
+	LIST_HEAD(gc_list);
+	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 = __cpu_to_le32(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;
+}