xref: /openbmc/linux/net/core/timestamping.c (revision 6c870213d6f3a25981c10728f46294a3bed1703f)
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 
47 	switch (type) {
48 	case PTP_CLASS_V1_IPV4:
49 	case PTP_CLASS_V1_IPV6:
50 	case PTP_CLASS_V2_IPV4:
51 	case PTP_CLASS_V2_IPV6:
52 	case PTP_CLASS_V2_L2:
53 	case PTP_CLASS_V2_VLAN:
54 		phydev = skb->dev->phydev;
55 		if (likely(phydev->drv->txtstamp)) {
56 			if (!atomic_inc_not_zero(&sk->sk_refcnt))
57 				return;
58 
59 			clone = skb_clone(skb, GFP_ATOMIC);
60 			if (!clone) {
61 				sock_put(sk);
62 				return;
63 			}
64 
65 			clone->sk = sk;
66 			phydev->drv->txtstamp(phydev, clone, type);
67 		}
68 		break;
69 	default:
70 		break;
71 	}
72 }
73 EXPORT_SYMBOL_GPL(skb_clone_tx_timestamp);
74 
75 void skb_complete_tx_timestamp(struct sk_buff *skb,
76 			       struct skb_shared_hwtstamps *hwtstamps)
77 {
78 	struct sock *sk = skb->sk;
79 	struct sock_exterr_skb *serr;
80 	int err;
81 
82 	if (!hwtstamps) {
83 		sock_put(sk);
84 		kfree_skb(skb);
85 		return;
86 	}
87 
88 	*skb_hwtstamps(skb) = *hwtstamps;
89 
90 	serr = SKB_EXT_ERR(skb);
91 	memset(serr, 0, sizeof(*serr));
92 	serr->ee.ee_errno = ENOMSG;
93 	serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING;
94 	skb->sk = NULL;
95 
96 	err = sock_queue_err_skb(sk, skb);
97 
98 	sock_put(sk);
99 	if (err)
100 		kfree_skb(skb);
101 }
102 EXPORT_SYMBOL_GPL(skb_complete_tx_timestamp);
103 
104 bool skb_defer_rx_timestamp(struct sk_buff *skb)
105 {
106 	struct phy_device *phydev;
107 	unsigned int type;
108 
109 	if (skb_headroom(skb) < ETH_HLEN)
110 		return false;
111 	__skb_push(skb, ETH_HLEN);
112 
113 	type = classify(skb);
114 
115 	__skb_pull(skb, ETH_HLEN);
116 
117 	switch (type) {
118 	case PTP_CLASS_V1_IPV4:
119 	case PTP_CLASS_V1_IPV6:
120 	case PTP_CLASS_V2_IPV4:
121 	case PTP_CLASS_V2_IPV6:
122 	case PTP_CLASS_V2_L2:
123 	case PTP_CLASS_V2_VLAN:
124 		phydev = skb->dev->phydev;
125 		if (likely(phydev->drv->rxtstamp))
126 			return phydev->drv->rxtstamp(phydev, skb, type);
127 		break;
128 	default:
129 		break;
130 	}
131 
132 	return false;
133 }
134 EXPORT_SYMBOL_GPL(skb_defer_rx_timestamp);
135