xref: /linux/net/ethtool/channels.c (revision c79c3c34f75d72a066e292b10aa50fc758c97c89)
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 const struct nla_policy ethnl_channels_get_policy[] = {
21 	[ETHTOOL_A_CHANNELS_HEADER]		=
22 		NLA_POLICY_NESTED(ethnl_header_policy),
23 };
24 
25 static int channels_prepare_data(const struct ethnl_req_info *req_base,
26 				 struct ethnl_reply_data *reply_base,
27 				 struct genl_info *info)
28 {
29 	struct channels_reply_data *data = CHANNELS_REPDATA(reply_base);
30 	struct net_device *dev = reply_base->dev;
31 	int ret;
32 
33 	if (!dev->ethtool_ops->get_channels)
34 		return -EOPNOTSUPP;
35 	ret = ethnl_ops_begin(dev);
36 	if (ret < 0)
37 		return ret;
38 	dev->ethtool_ops->get_channels(dev, &data->channels);
39 	ethnl_ops_complete(dev);
40 
41 	return 0;
42 }
43 
44 static int channels_reply_size(const struct ethnl_req_info *req_base,
45 			       const struct ethnl_reply_data *reply_base)
46 {
47 	return nla_total_size(sizeof(u32)) +	/* _CHANNELS_RX_MAX */
48 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_TX_MAX */
49 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_OTHER_MAX */
50 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_COMBINED_MAX */
51 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_RX_COUNT */
52 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_TX_COUNT */
53 	       nla_total_size(sizeof(u32)) +	/* _CHANNELS_OTHER_COUNT */
54 	       nla_total_size(sizeof(u32));	/* _CHANNELS_COMBINED_COUNT */
55 }
56 
57 static int channels_fill_reply(struct sk_buff *skb,
58 			       const struct ethnl_req_info *req_base,
59 			       const struct ethnl_reply_data *reply_base)
60 {
61 	const struct channels_reply_data *data = CHANNELS_REPDATA(reply_base);
62 	const struct ethtool_channels *channels = &data->channels;
63 
64 	if ((channels->max_rx &&
65 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_RX_MAX,
66 			  channels->max_rx) ||
67 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_RX_COUNT,
68 			  channels->rx_count))) ||
69 	    (channels->max_tx &&
70 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_TX_MAX,
71 			  channels->max_tx) ||
72 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_TX_COUNT,
73 			  channels->tx_count))) ||
74 	    (channels->max_other &&
75 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_OTHER_MAX,
76 			  channels->max_other) ||
77 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_OTHER_COUNT,
78 			  channels->other_count))) ||
79 	    (channels->max_combined &&
80 	     (nla_put_u32(skb, ETHTOOL_A_CHANNELS_COMBINED_MAX,
81 			  channels->max_combined) ||
82 	      nla_put_u32(skb, ETHTOOL_A_CHANNELS_COMBINED_COUNT,
83 			  channels->combined_count))))
84 		return -EMSGSIZE;
85 
86 	return 0;
87 }
88 
89 const struct ethnl_request_ops ethnl_channels_request_ops = {
90 	.request_cmd		= ETHTOOL_MSG_CHANNELS_GET,
91 	.reply_cmd		= ETHTOOL_MSG_CHANNELS_GET_REPLY,
92 	.hdr_attr		= ETHTOOL_A_CHANNELS_HEADER,
93 	.req_info_size		= sizeof(struct channels_req_info),
94 	.reply_data_size	= sizeof(struct channels_reply_data),
95 
96 	.prepare_data		= channels_prepare_data,
97 	.reply_size		= channels_reply_size,
98 	.fill_reply		= channels_fill_reply,
99 };
100 
101 /* CHANNELS_SET */
102 
103 const struct nla_policy ethnl_channels_set_policy[] = {
104 	[ETHTOOL_A_CHANNELS_HEADER]		=
105 		NLA_POLICY_NESTED(ethnl_header_policy),
106 	[ETHTOOL_A_CHANNELS_RX_COUNT]		= { .type = NLA_U32 },
107 	[ETHTOOL_A_CHANNELS_TX_COUNT]		= { .type = NLA_U32 },
108 	[ETHTOOL_A_CHANNELS_OTHER_COUNT]	= { .type = NLA_U32 },
109 	[ETHTOOL_A_CHANNELS_COMBINED_COUNT]	= { .type = NLA_U32 },
110 };
111 
112 int ethnl_set_channels(struct sk_buff *skb, struct genl_info *info)
113 {
114 	unsigned int from_channel, old_total, i;
115 	bool mod = false, mod_combined = false;
116 	struct ethtool_channels channels = {};
117 	struct ethnl_req_info req_info = {};
118 	struct nlattr **tb = info->attrs;
119 	const struct nlattr *err_attr;
120 	const struct ethtool_ops *ops;
121 	struct net_device *dev;
122 	u32 max_rx_in_use = 0;
123 	int ret;
124 
125 	ret = ethnl_parse_header_dev_get(&req_info,
126 					 tb[ETHTOOL_A_CHANNELS_HEADER],
127 					 genl_info_net(info), info->extack,
128 					 true);
129 	if (ret < 0)
130 		return ret;
131 	dev = req_info.dev;
132 	ops = dev->ethtool_ops;
133 	ret = -EOPNOTSUPP;
134 	if (!ops->get_channels || !ops->set_channels)
135 		goto out_dev;
136 
137 	rtnl_lock();
138 	ret = ethnl_ops_begin(dev);
139 	if (ret < 0)
140 		goto out_rtnl;
141 	ops->get_channels(dev, &channels);
142 	old_total = channels.combined_count +
143 		    max(channels.rx_count, channels.tx_count);
144 
145 	ethnl_update_u32(&channels.rx_count, tb[ETHTOOL_A_CHANNELS_RX_COUNT],
146 			 &mod);
147 	ethnl_update_u32(&channels.tx_count, tb[ETHTOOL_A_CHANNELS_TX_COUNT],
148 			 &mod);
149 	ethnl_update_u32(&channels.other_count,
150 			 tb[ETHTOOL_A_CHANNELS_OTHER_COUNT], &mod);
151 	ethnl_update_u32(&channels.combined_count,
152 			 tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT], &mod_combined);
153 	mod |= mod_combined;
154 	ret = 0;
155 	if (!mod)
156 		goto out_ops;
157 
158 	/* ensure new channel counts are within limits */
159 	if (channels.rx_count > channels.max_rx)
160 		err_attr = tb[ETHTOOL_A_CHANNELS_RX_COUNT];
161 	else if (channels.tx_count > channels.max_tx)
162 		err_attr = tb[ETHTOOL_A_CHANNELS_TX_COUNT];
163 	else if (channels.other_count > channels.max_other)
164 		err_attr = tb[ETHTOOL_A_CHANNELS_OTHER_COUNT];
165 	else if (channels.combined_count > channels.max_combined)
166 		err_attr = tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT];
167 	else
168 		err_attr = NULL;
169 	if (err_attr) {
170 		ret = -EINVAL;
171 		NL_SET_ERR_MSG_ATTR(info->extack, err_attr,
172 				    "requested channel count exceeds maximum");
173 		goto out_ops;
174 	}
175 
176 	/* ensure there is at least one RX and one TX channel */
177 	if (!channels.combined_count && !channels.rx_count)
178 		err_attr = tb[ETHTOOL_A_CHANNELS_RX_COUNT];
179 	else if (!channels.combined_count && !channels.tx_count)
180 		err_attr = tb[ETHTOOL_A_CHANNELS_TX_COUNT];
181 	else
182 		err_attr = NULL;
183 	if (err_attr) {
184 		if (mod_combined)
185 			err_attr = tb[ETHTOOL_A_CHANNELS_COMBINED_COUNT];
186 		ret = -EINVAL;
187 		NL_SET_ERR_MSG_ATTR(info->extack, err_attr, "requested channel counts would result in no RX or TX channel being configured");
188 		goto out_ops;
189 	}
190 
191 	/* ensure the new Rx count fits within the configured Rx flow
192 	 * indirection table settings
193 	 */
194 	if (netif_is_rxfh_configured(dev) &&
195 	    !ethtool_get_max_rxfh_channel(dev, &max_rx_in_use) &&
196 	    (channels.combined_count + channels.rx_count) <= max_rx_in_use) {
197 		ret = -EINVAL;
198 		GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing indirection table settings");
199 		goto out_ops;
200 	}
201 
202 	/* Disabling channels, query zero-copy AF_XDP sockets */
203 	from_channel = channels.combined_count +
204 		       min(channels.rx_count, channels.tx_count);
205 	for (i = from_channel; i < old_total; i++)
206 		if (xsk_get_pool_from_qid(dev, i)) {
207 			ret = -EINVAL;
208 			GENL_SET_ERR_MSG(info, "requested channel counts are too low for existing zerocopy AF_XDP sockets");
209 			goto out_ops;
210 		}
211 
212 	ret = dev->ethtool_ops->set_channels(dev, &channels);
213 	if (ret < 0)
214 		goto out_ops;
215 	ethtool_notify(dev, ETHTOOL_MSG_CHANNELS_NTF, NULL);
216 
217 out_ops:
218 	ethnl_ops_complete(dev);
219 out_rtnl:
220 	rtnl_unlock();
221 out_dev:
222 	dev_put(dev);
223 	return ret;
224 }
225