xref: /linux/net/mac802154/util.c (revision 54618888d1ea7a26f8bccfb89e3c2420350c8047)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  * Authors:
5  * Alexander Aring <aar@pengutronix.de>
6  *
7  * Based on: net/mac80211/util.c
8  */
9 
10 #include "ieee802154_i.h"
11 #include "driver-ops.h"
12 
13 /* privid for wpan_phys to determine whether they belong to us or not */
14 const void *const mac802154_wpan_phy_privid = &mac802154_wpan_phy_privid;
15 
16 /**
17  * ieee802154_wake_queue - wake ieee802154 queue
18  * @hw: main hardware object
19  *
20  * Tranceivers usually have either one transmit framebuffer or one framebuffer
21  * for both transmitting and receiving. Hence, the core currently only handles
22  * one frame at a time for each phy, which means we had to stop the queue to
23  * avoid new skb to come during the transmission. The queue then needs to be
24  * woken up after the operation.
25  */
26 static void ieee802154_wake_queue(struct ieee802154_hw *hw)
27 {
28 	struct ieee802154_local *local = hw_to_local(hw);
29 	struct ieee802154_sub_if_data *sdata;
30 
31 	rcu_read_lock();
32 	clear_bit(WPAN_PHY_FLAG_STATE_QUEUE_STOPPED, &local->phy->flags);
33 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
34 		if (!sdata->dev)
35 			continue;
36 
37 		netif_wake_queue(sdata->dev);
38 	}
39 	rcu_read_unlock();
40 }
41 
42 /**
43  * ieee802154_stop_queue - stop ieee802154 queue
44  * @hw: main hardware object
45  *
46  * Tranceivers usually have either one transmit framebuffer or one framebuffer
47  * for both transmitting and receiving. Hence, the core currently only handles
48  * one frame at a time for each phy, which means we need to tell upper layers to
49  * stop giving us new skbs while we are busy with the transmitted one. The queue
50  * must then be stopped before transmitting.
51  */
52 static void ieee802154_stop_queue(struct ieee802154_hw *hw)
53 {
54 	struct ieee802154_local *local = hw_to_local(hw);
55 	struct ieee802154_sub_if_data *sdata;
56 
57 	rcu_read_lock();
58 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
59 		if (!sdata->dev)
60 			continue;
61 
62 		netif_stop_queue(sdata->dev);
63 	}
64 	rcu_read_unlock();
65 }
66 
67 void ieee802154_hold_queue(struct ieee802154_local *local)
68 {
69 	unsigned long flags;
70 
71 	spin_lock_irqsave(&local->phy->queue_lock, flags);
72 	if (!atomic_fetch_inc(&local->phy->hold_txs))
73 		ieee802154_stop_queue(&local->hw);
74 	spin_unlock_irqrestore(&local->phy->queue_lock, flags);
75 }
76 
77 void ieee802154_release_queue(struct ieee802154_local *local)
78 {
79 	unsigned long flags;
80 
81 	spin_lock_irqsave(&local->phy->queue_lock, flags);
82 	if (atomic_dec_and_test(&local->phy->hold_txs))
83 		ieee802154_wake_queue(&local->hw);
84 	spin_unlock_irqrestore(&local->phy->queue_lock, flags);
85 }
86 
87 void ieee802154_disable_queue(struct ieee802154_local *local)
88 {
89 	struct ieee802154_sub_if_data *sdata;
90 
91 	rcu_read_lock();
92 	list_for_each_entry_rcu(sdata, &local->interfaces, list) {
93 		if (!sdata->dev)
94 			continue;
95 
96 		netif_tx_disable(sdata->dev);
97 	}
98 	rcu_read_unlock();
99 }
100 
101 enum hrtimer_restart ieee802154_xmit_ifs_timer(struct hrtimer *timer)
102 {
103 	struct ieee802154_local *local =
104 		container_of(timer, struct ieee802154_local, ifs_timer);
105 
106 	ieee802154_release_queue(local);
107 
108 	return HRTIMER_NORESTART;
109 }
110 
111 void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb,
112 			      bool ifs_handling)
113 {
114 	struct ieee802154_local *local = hw_to_local(hw);
115 
116 	local->tx_result = IEEE802154_SUCCESS;
117 
118 	if (ifs_handling) {
119 		u8 max_sifs_size;
120 
121 		/* If transceiver sets CRC on his own we need to use lifs
122 		 * threshold len above 16 otherwise 18, because it's not
123 		 * part of skb->len.
124 		 */
125 		if (hw->flags & IEEE802154_HW_TX_OMIT_CKSUM)
126 			max_sifs_size = IEEE802154_MAX_SIFS_FRAME_SIZE -
127 					IEEE802154_FCS_LEN;
128 		else
129 			max_sifs_size = IEEE802154_MAX_SIFS_FRAME_SIZE;
130 
131 		if (skb->len > max_sifs_size)
132 			hrtimer_start(&local->ifs_timer,
133 				      hw->phy->lifs_period * NSEC_PER_USEC,
134 				      HRTIMER_MODE_REL);
135 		else
136 			hrtimer_start(&local->ifs_timer,
137 				      hw->phy->sifs_period * NSEC_PER_USEC,
138 				      HRTIMER_MODE_REL);
139 	} else {
140 		ieee802154_release_queue(local);
141 	}
142 
143 	dev_consume_skb_any(skb);
144 	if (atomic_dec_and_test(&hw->phy->ongoing_txs))
145 		wake_up(&hw->phy->sync_txq);
146 }
147 EXPORT_SYMBOL(ieee802154_xmit_complete);
148 
149 void ieee802154_xmit_error(struct ieee802154_hw *hw, struct sk_buff *skb,
150 			   int reason)
151 {
152 	struct ieee802154_local *local = hw_to_local(hw);
153 
154 	local->tx_result = reason;
155 	ieee802154_release_queue(local);
156 	dev_kfree_skb_any(skb);
157 	if (atomic_dec_and_test(&hw->phy->ongoing_txs))
158 		wake_up(&hw->phy->sync_txq);
159 }
160 EXPORT_SYMBOL(ieee802154_xmit_error);
161 
162 void ieee802154_xmit_hw_error(struct ieee802154_hw *hw, struct sk_buff *skb)
163 {
164 	ieee802154_xmit_error(hw, skb, IEEE802154_SYSTEM_ERROR);
165 }
166 EXPORT_SYMBOL(ieee802154_xmit_hw_error);
167 
168 void ieee802154_stop_device(struct ieee802154_local *local)
169 {
170 	flush_workqueue(local->workqueue);
171 	hrtimer_cancel(&local->ifs_timer);
172 	drv_stop(local);
173 }
174