xref: /openbmc/linux/net/dsa/master.c (revision 82e6fdd6)
1 /*
2  * Handling of a master device, switching frames via its switch fabric CPU port
3  *
4  * Copyright (c) 2017 Savoir-faire Linux Inc.
5  *	Vivien Didelot <vivien.didelot@savoirfairelinux.com>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  */
12 
13 #include "dsa_priv.h"
14 
15 static void dsa_master_get_ethtool_stats(struct net_device *dev,
16 					 struct ethtool_stats *stats,
17 					 uint64_t *data)
18 {
19 	struct dsa_port *cpu_dp = dev->dsa_ptr;
20 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
21 	struct dsa_switch *ds = cpu_dp->ds;
22 	int port = cpu_dp->index;
23 	int count = 0;
24 
25 	if (ops && ops->get_sset_count && ops->get_ethtool_stats) {
26 		count = ops->get_sset_count(dev, ETH_SS_STATS);
27 		ops->get_ethtool_stats(dev, stats, data);
28 	}
29 
30 	if (ds->ops->get_ethtool_stats)
31 		ds->ops->get_ethtool_stats(ds, port, data + count);
32 }
33 
34 static int dsa_master_get_sset_count(struct net_device *dev, int sset)
35 {
36 	struct dsa_port *cpu_dp = dev->dsa_ptr;
37 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
38 	struct dsa_switch *ds = cpu_dp->ds;
39 	int count = 0;
40 
41 	if (ops && ops->get_sset_count)
42 		count += ops->get_sset_count(dev, sset);
43 
44 	if (sset == ETH_SS_STATS && ds->ops->get_sset_count)
45 		count += ds->ops->get_sset_count(ds);
46 
47 	return count;
48 }
49 
50 static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
51 				   uint8_t *data)
52 {
53 	struct dsa_port *cpu_dp = dev->dsa_ptr;
54 	const struct ethtool_ops *ops = cpu_dp->orig_ethtool_ops;
55 	struct dsa_switch *ds = cpu_dp->ds;
56 	int port = cpu_dp->index;
57 	int len = ETH_GSTRING_LEN;
58 	int mcount = 0, count;
59 	unsigned int i;
60 	uint8_t pfx[4];
61 	uint8_t *ndata;
62 
63 	snprintf(pfx, sizeof(pfx), "p%.2d", port);
64 	/* We do not want to be NULL-terminated, since this is a prefix */
65 	pfx[sizeof(pfx) - 1] = '_';
66 
67 	if (ops && ops->get_sset_count && ops->get_strings) {
68 		mcount = ops->get_sset_count(dev, ETH_SS_STATS);
69 		ops->get_strings(dev, stringset, data);
70 	}
71 
72 	if (stringset == ETH_SS_STATS && ds->ops->get_strings) {
73 		ndata = data + mcount * len;
74 		/* This function copies ETH_GSTRINGS_LEN bytes, we will mangle
75 		 * the output after to prepend our CPU port prefix we
76 		 * constructed earlier
77 		 */
78 		ds->ops->get_strings(ds, port, ndata);
79 		count = ds->ops->get_sset_count(ds);
80 		for (i = 0; i < count; i++) {
81 			memmove(ndata + (i * len + sizeof(pfx)),
82 				ndata + i * len, len - sizeof(pfx));
83 			memcpy(ndata + i * len, pfx, sizeof(pfx));
84 		}
85 	}
86 }
87 
88 static int dsa_master_ethtool_setup(struct net_device *dev)
89 {
90 	struct dsa_port *cpu_dp = dev->dsa_ptr;
91 	struct dsa_switch *ds = cpu_dp->ds;
92 	struct ethtool_ops *ops;
93 
94 	ops = devm_kzalloc(ds->dev, sizeof(*ops), GFP_KERNEL);
95 	if (!ops)
96 		return -ENOMEM;
97 
98 	cpu_dp->orig_ethtool_ops = dev->ethtool_ops;
99 	if (cpu_dp->orig_ethtool_ops)
100 		memcpy(ops, cpu_dp->orig_ethtool_ops, sizeof(*ops));
101 
102 	ops->get_sset_count = dsa_master_get_sset_count;
103 	ops->get_ethtool_stats = dsa_master_get_ethtool_stats;
104 	ops->get_strings = dsa_master_get_strings;
105 
106 	dev->ethtool_ops = ops;
107 
108 	return 0;
109 }
110 
111 static void dsa_master_ethtool_teardown(struct net_device *dev)
112 {
113 	struct dsa_port *cpu_dp = dev->dsa_ptr;
114 
115 	dev->ethtool_ops = cpu_dp->orig_ethtool_ops;
116 	cpu_dp->orig_ethtool_ops = NULL;
117 }
118 
119 int dsa_master_setup(struct net_device *dev, struct dsa_port *cpu_dp)
120 {
121 	/* If we use a tagging format that doesn't have an ethertype
122 	 * field, make sure that all packets from this point on get
123 	 * sent to the tag format's receive function.
124 	 */
125 	wmb();
126 
127 	dev->dsa_ptr = cpu_dp;
128 
129 	return dsa_master_ethtool_setup(dev);
130 }
131 
132 void dsa_master_teardown(struct net_device *dev)
133 {
134 	dsa_master_ethtool_teardown(dev);
135 
136 	dev->dsa_ptr = NULL;
137 
138 	/* If we used a tagging format that doesn't have an ethertype
139 	 * field, make sure that all packets from this point get sent
140 	 * without the tag and go through the regular receive path.
141 	 */
142 	wmb();
143 }
144