xref: /openbmc/linux/net/ethtool/channels.c (revision 3a83e4e6)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <net/xdp_sock_drv.h>
4 
5 #include "netlink.h"
6 #include "common.h"
7 
8 struct channels_req_info {
9 	struct ethnl_req_info		base;
10 };
11 
12 struct channels_reply_data {
13 	struct ethnl_reply_data		base;
14 	struct ethtool_channels		channels;
15 };
16 
17 #define CHANNELS_REPDATA(__reply_base) \
18 	container_of(__reply_base, struct channels_reply_data, base)
19 
20 static const struct nla_policy
21 channels_get_policy[ETHTOOL_A_CHANNELS_MAX + 1] = {
22 	[ETHTOOL_A_CHANNELS_UNSPEC]		= { .type = NLA_REJECT },
23 	[ETHTOOL_A_CHANNELS_HEADER]		= { .type = NLA_NESTED },
24 	[ETHTOOL_A_CHANNELS_RX_MAX]		= { .type = NLA_REJECT },
25 	[ETHTOOL_A_CHANNELS_TX_MAX]		= { .type = NLA_REJECT },
26 	[ETHTOOL_A_CHANNELS_OTHER_MAX]		= { .type = NLA_REJECT },
27 	[ETHTOOL_A_CHANNELS_COMBINED_MAX]	= { .type = NLA_REJECT },
28 	[ETHTOOL_A_CHANNELS_RX_COUNT]		= { .type = NLA_REJECT },
29 	[ETHTOOL_A_CHANNELS_TX_COUNT]		= { .type = NLA_REJECT },
30 	[ETHTOOL_A_CHANNELS_OTHER_COUNT]	= { .type = NLA_REJECT },
31 	[ETHTOOL_A_CHANNELS_COMBINED_COUNT]	= { .type = NLA_REJECT },
32 };
33 
34 static int channels_prepare_data(const struct ethnl_req_info *req_base,
35 				 struct ethnl_reply_data *reply_base,
36 				 struct genl_info *info)
37 {
38 	struct channels_reply_data *data = CHANNELS_REPDATA(reply_base);
39 	struct net_device *dev = reply_base->dev;
40 	int ret;
41 
42 	if (!dev->ethtool_ops->get_channels)
43 		return -EOPNOTSUPP;
44 	ret = ethnl_ops_begin(dev);
45 	if (ret < 0)
46 		return ret;
47 	dev->ethtool_ops->get_channels(dev, &data->channels);
48 	ethnl_ops_complete(dev);
49 
50 	return 0;
51 }
52 
53 static int channels_reply_size(const struct ethnl_req_info *req_base,
54 			       const struct ethnl_reply_data *reply_base)
55 {
56 	return nla_total_size(sizeof(u32)) +	/* _CHANNELS_RX_MAX */
57 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_TX_MAX */
58 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_OTHER_MAX */
59 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_COMBINED_MAX */
60 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_RX_COUNT */
61 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_TX_COUNT */
62 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_OTHER_COUNT */
63 	       nla_total_size(sizeof(u32));	/* _CHANNELS_COMBINED_COUNT */
64 }
65 
66 static int channels_fill_reply(struct sk_buff *skb,
67 			       const struct ethnl_req_info *req_base,
68 			       const struct ethnl_reply_data *reply_base)
69 {
70 	const struct channels_reply_data *data = CHANNELS_REPDATA(reply_base);
71 	const struct ethtool_channels *channels = &data->channels;
72 
73 	if ((channels->max_rx &&
74 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_RX_MAX,
75 			  channels->max_rx) ||
76 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_RX_COUNT,
77 			  channels->rx_count))) ||
78 	    (channels->max_tx &&
79 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_TX_MAX,
80 			  channels->max_tx) ||
81 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_TX_COUNT,
82 			  channels->tx_count))) ||
83 	    (channels->max_other &&
84 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_OTHER_MAX,
85 			  channels->max_other) ||
86 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_OTHER_COUNT,
87 			  channels->other_count))) ||
88 	    (channels->max_combined &&
89 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_COMBINED_MAX,
90 			  channels->max_combined) ||
91 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_COMBINED_COUNT,
92 			  channels->combined_count))))
93 		return -EMSGSIZE;
94 
95 	return 0;
96 }
97 
98 const struct ethnl_request_ops ethnl_channels_request_ops = {
99 	.request_cmd		= ETHTOOL_MSG_CHANNELS_GET,
100 	.reply_cmd		= ETHTOOL_MSG_CHANNELS_GET_REPLY,
101 	.hdr_attr		= ETHTOOL_A_CHANNELS_HEADER,
102 	.max_attr		= ETHTOOL_A_CHANNELS_MAX,
103 	.req_info_size		= sizeof(struct channels_req_info),
104 	.reply_data_size	= sizeof(struct channels_reply_data),
105 	.request_policy		= channels_get_policy,
106 
107 	.prepare_data		= channels_prepare_data,
108 	.reply_size		= channels_reply_size,
109 	.fill_reply		= channels_fill_reply,
110 };
111 
112 /* CHANNELS_SET */
113 
114 static const struct nla_policy
115 channels_set_policy[ETHTOOL_A_CHANNELS_MAX + 1] = {
116 	[ETHTOOL_A_CHANNELS_UNSPEC]		= { .type = NLA_REJECT },
117 	[ETHTOOL_A_CHANNELS_HEADER]		= { .type = NLA_NESTED },
118 	[ETHTOOL_A_CHANNELS_RX_MAX]		= { .type = NLA_REJECT },
119 	[ETHTOOL_A_CHANNELS_TX_MAX]		= { .type = NLA_REJECT },
120 	[ETHTOOL_A_CHANNELS_OTHER_MAX]		= { .type = NLA_REJECT },
121 	[ETHTOOL_A_CHANNELS_COMBINED_MAX]	= { .type = NLA_REJECT },
122 	[ETHTOOL_A_CHANNELS_RX_COUNT]		= { .type = NLA_U32 },
123 	[ETHTOOL_A_CHANNELS_TX_COUNT]		= { .type = NLA_U32 },
124 	[ETHTOOL_A_CHANNELS_OTHER_COUNT]	= { .type = NLA_U32 },
125 	[ETHTOOL_A_CHANNELS_COMBINED_COUNT]	= { .type = NLA_U32 },
126 };
127 
128 int ethnl_set_channels(struct sk_buff *skb, struct genl_info *info)
129 {
130 	struct nlattr *tb[ETHTOOL_A_CHANNELS_MAX + 1];
131 	unsigned int from_channel, old_total, i;
132 	bool mod = false, mod_combined = false;
133 	struct ethtool_channels channels = {};
134 	struct ethnl_req_info req_info = {};
135 	const struct nlattr *err_attr;
136 	const struct ethtool_ops *ops;
137 	struct net_device *dev;
138 	u32 max_rx_in_use = 0;
139 	int ret;
140 
141 	ret = nlmsg_parse(info->nlhdr, GENL_HDRLEN, tb,
142 			  ETHTOOL_A_CHANNELS_MAX, channels_set_policy,
143 			  info->extack);
144 	if (ret < 0)
145 		return ret;
146 	ret = ethnl_parse_header_dev_get(&req_info,
147 					 tb[ETHTOOL_A_CHANNELS_HEADER],
148 					 genl_info_net(info), info->extack,
149 					 true);
150 	if (ret < 0)
151 		return ret;
152 	dev = req_info.dev;
153 	ops = dev->ethtool_ops;
154 	ret = -EOPNOTSUPP;
155 	if (!ops->get_channels || !ops->set_channels)
156 		goto out_dev;
157 
158 	rtnl_lock();
159 	ret = ethnl_ops_begin(dev);
160 	if (ret < 0)
161 		goto out_rtnl;
162 	ops->get_channels(dev, &channels);
163 	old_total = channels.combined_count +
164 		    max(channels.rx_count, channels.tx_count);
165 
166 	ethnl_update_u32(&channels.rx_count, tb[ETHTOOL_A_CHANNELS_RX_COUNT],
167 			 &mod);
168 	ethnl_update_u32(&channels.tx_count, tb[ETHTOOL_A_CHANNELS_TX_COUNT],
169 			 &mod);
170 	ethnl_update_u32(&channels.other_count,
171 			 tb[ETHTOOL_A_CHANNELS_OTHER_COUNT], &mod);
172 	ethnl_update_u32(&channels.combined_count,
173 			 tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT], &mod_combined);
174 	mod |= mod_combined;
175 	ret = 0;
176 	if (!mod)
177 		goto out_ops;
178 
179 	/* ensure new channel counts are within limits */
180 	if (channels.rx_count > channels.max_rx)
181 		err_attr = tb[ETHTOOL_A_CHANNELS_RX_COUNT];
182 	else if (channels.tx_count > channels.max_tx)
183 		err_attr = tb[ETHTOOL_A_CHANNELS_TX_COUNT];
184 	else if (channels.other_count > channels.max_other)
185 		err_attr = tb[ETHTOOL_A_CHANNELS_OTHER_COUNT];
186 	else if (channels.combined_count > channels.max_combined)
187 		err_attr = tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT];
188 	else
189 		err_attr = NULL;
190 	if (err_attr) {
191 		ret = -EINVAL;
192 		NL_SET_ERR_MSG_ATTR(info->extack, err_attr,
193 				    "requested channel count exceeds maximum");
194 		goto out_ops;
195 	}
196 
197 	/* ensure there is at least one RX and one TX channel */
198 	if (!channels.combined_count && !channels.rx_count)
199 		err_attr = tb[ETHTOOL_A_CHANNELS_RX_COUNT];
200 	else if (!channels.combined_count && !channels.tx_count)
201 		err_attr = tb[ETHTOOL_A_CHANNELS_TX_COUNT];
202 	else
203 		err_attr = NULL;
204 	if (err_attr) {
205 		if (mod_combined)
206 			err_attr = tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT];
207 		ret = -EINVAL;
208 		NL_SET_ERR_MSG_ATTR(info->extack, err_attr, "requested channel counts would result in no RX or TX channel being configured");
209 		goto out_ops;
210 	}
211 
212 	/* ensure the new Rx count fits within the configured Rx flow
213 	 * indirection table settings
214 	 */
215 	if (netif_is_rxfh_configured(dev) &&
216 	    !ethtool_get_max_rxfh_channel(dev, &max_rx_in_use) &&
217 	    (channels.combined_count + channels.rx_count) <= max_rx_in_use) {
218 		GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing indirection table settings");
219 		return -EINVAL;
220 	}
221 
222 	/* Disabling channels, query zero-copy AF_XDP sockets */
223 	from_channel = channels.combined_count +
224 		       min(channels.rx_count, channels.tx_count);
225 	for (i = from_channel; i < old_total; i++)
226 		if (xdp_get_umem_from_qid(dev, i)) {
227 			GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing zerocopy AF_XDP sockets");
228 			return -EINVAL;
229 		}
230 
231 	ret = dev->ethtool_ops->set_channels(dev, &channels);
232 	if (ret < 0)
233 		goto out_ops;
234 	ethtool_notify(dev, ETHTOOL_MSG_CHANNELS_NTF, NULL);
235 
236 out_ops:
237 	ethnl_ops_complete(dev);
238 out_rtnl:
239 	rtnl_unlock();
240 out_dev:
241 	dev_put(dev);
242 	return ret;
243 }
244