xref: /openbmc/linux/net/core/timestamping.c (revision 7051924f771722c6dd235e693742cda6488ac700)
1 /*
2  * PTP 1588 clock support - support for timestamping in PHY devices
3  *
4  * Copyright (C) 2010 OMICRON electronics GmbH
5  *
6  *  This program is free software; you can redistribute it and/or modify
7  *  it under the terms of the GNU General Public License as published by
8  *  the Free Software Foundation; either version 2 of the License, or
9  *  (at your option) any later version.
10  *
11  *  This program is distributed in the hope that it will be useful,
12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  *  GNU General Public License for more details.
15  *
16  *  You should have received a copy of the GNU General Public License
17  *  along with this program; if not, write to the Free Software
18  *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19  */
20 #include <linux/errqueue.h>
21 #include <linux/phy.h>
22 #include <linux/ptp_classify.h>
23 #include <linux/skbuff.h>
24 #include <linux/export.h>
25 
26 static unsigned int classify(const struct sk_buff *skb)
27 {
28 	if (likely(skb->dev && skb->dev->phydev &&
29 		   skb->dev->phydev->drv))
30 		return ptp_classify_raw(skb);
31 	else
32 		return PTP_CLASS_NONE;
33 }
34 
35 void skb_clone_tx_timestamp(struct sk_buff *skb)
36 {
37 	struct phy_device *phydev;
38 	struct sk_buff *clone;
39 	struct sock *sk = skb->sk;
40 	unsigned int type;
41 
42 	if (!sk)
43 		return;
44 
45 	type = classify(skb);
46 	if (type == PTP_CLASS_NONE)
47 		return;
48 
49 	phydev = skb->dev->phydev;
50 	if (likely(phydev->drv->txtstamp)) {
51 		if (!atomic_inc_not_zero(&sk->sk_refcnt))
52 			return;
53 
54 		clone = skb_clone(skb, GFP_ATOMIC);
55 		if (!clone) {
56 			sock_put(sk);
57 			return;
58 		}
59 
60 		clone->sk = sk;
61 		phydev->drv->txtstamp(phydev, clone, type);
62 	}
63 }
64 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
65 
66 void skb_complete_tx_timestamp(struct sk_buff *skb,
67 			       struct skb_shared_hwtstamps *hwtstamps)
68 {
69 	struct sock *sk = skb->sk;
70 	struct sock_exterr_skb *serr;
71 	int err;
72 
73 	if (!hwtstamps) {
74 		sock_put(sk);
75 		kfree_skb(skb);
76 		return;
77 	}
78 
79 	*skb_hwtstamps(skb) = *hwtstamps;
80 
81 	serr = SKB_EXT_ERR(skb);
82 	memset(serr, 0, sizeof(*serr));
83 	serr->ee.ee_errno = ENOMSG;
84 	serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
85 	skb->sk = NULL;
86 
87 	err = sock_queue_err_skb(sk, skb);
88 
89 	sock_put(sk);
90 	if (err)
91 		kfree_skb(skb);
92 }
93 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
94 
95 bool skb_defer_rx_timestamp(struct sk_buff *skb)
96 {
97 	struct phy_device *phydev;
98 	unsigned int type;
99 
100 	if (skb_headroom(skb) < ETH_HLEN)
101 		return false;
102 	__skb_push(skb, ETH_HLEN);
103 
104 	type = classify(skb);
105 
106 	__skb_pull(skb, ETH_HLEN);
107 
108 	if (type == PTP_CLASS_NONE)
109 		return false;
110 
111 	phydev = skb->dev->phydev;
112 	if (likely(phydev->drv->rxtstamp))
113 		return phydev->drv->rxtstamp(phydev, skb, type);
114 
115 	return false;
116 }
117 EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);
118