xref: /linux/net/ethtool/rss.c (revision dbcedec3a31119d7594baacc743300d127c99c56)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include "netlink.h"
4 #include "common.h"
5 
6 struct rss_req_info {
7 	struct ethnl_req_info		base;
8 	u32				rss_context;
9 };
10 
11 struct rss_reply_data {
12 	struct ethnl_reply_data		base;
13 	u32				indir_size;
14 	u32				hkey_size;
15 	u32				hfunc;
16 	u32				input_xfrm;
17 	u32				*indir_table;
18 	u8				*hkey;
19 };
20 
21 #define RSS_REQINFO(__req_base) \
22 	container_of(__req_base, struct rss_req_info, base)
23 
24 #define RSS_REPDATA(__reply_base) \
25 	container_of(__reply_base, struct rss_reply_data, base)
26 
27 const struct nla_policy ethnl_rss_get_policy[] = {
28 	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
29 	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32 },
30 };
31 
32 static int
33 rss_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
34 		  struct netlink_ext_ack *extack)
35 {
36 	struct rss_req_info *request = RSS_REQINFO(req_info);
37 
38 	if (tb[ETHTOOL_A_RSS_CONTEXT])
39 		request->rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
40 
41 	return 0;
42 }
43 
44 static int
45 rss_prepare_data(const struct ethnl_req_info *req_base,
46 		 struct ethnl_reply_data *reply_base,
47 		 const struct genl_info *info)
48 {
49 	struct rss_reply_data *data = RSS_REPDATA(reply_base);
50 	struct rss_req_info *request = RSS_REQINFO(req_base);
51 	struct net_device *dev = reply_base->dev;
52 	struct ethtool_rxfh_param rxfh = {};
53 	const struct ethtool_ops *ops;
54 	u32 total_size, indir_bytes;
55 	u8 *rss_config;
56 	int ret;
57 
58 	ops = dev->ethtool_ops;
59 	if (!ops->get_rxfh)
60 		return -EOPNOTSUPP;
61 
62 	/* Some drivers don't handle rss_context */
63 	if (request->rss_context && !ops->cap_rss_ctx_supported)
64 		return -EOPNOTSUPP;
65 
66 	ret = ethnl_ops_begin(dev);
67 	if (ret < 0)
68 		return ret;
69 
70 	data->indir_size = 0;
71 	data->hkey_size = 0;
72 	if (ops->get_rxfh_indir_size)
73 		data->indir_size = ops->get_rxfh_indir_size(dev);
74 	if (ops->get_rxfh_key_size)
75 		data->hkey_size = ops->get_rxfh_key_size(dev);
76 
77 	indir_bytes = data->indir_size * sizeof(u32);
78 	total_size = indir_bytes + data->hkey_size;
79 	rss_config = kzalloc(total_size, GFP_KERNEL);
80 	if (!rss_config) {
81 		ret = -ENOMEM;
82 		goto out_ops;
83 	}
84 
85 	if (data->indir_size)
86 		data->indir_table = (u32 *)rss_config;
87 	if (data->hkey_size)
88 		data->hkey = rss_config + indir_bytes;
89 
90 	rxfh.indir_size = data->indir_size;
91 	rxfh.indir = data->indir_table;
92 	rxfh.key_size = data->hkey_size;
93 	rxfh.key = data->hkey;
94 	rxfh.rss_context = request->rss_context;
95 
96 	ret = ops->get_rxfh(dev, &rxfh);
97 	if (ret)
98 		goto out_ops;
99 
100 	data->hfunc = rxfh.hfunc;
101 	data->input_xfrm = rxfh.input_xfrm;
102 out_ops:
103 	ethnl_ops_complete(dev);
104 	return ret;
105 }
106 
107 static int
108 rss_reply_size(const struct ethnl_req_info *req_base,
109 	       const struct ethnl_reply_data *reply_base)
110 {
111 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
112 	int len;
113 
114 	len = nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
115 	      nla_total_size(sizeof(u32)) +	/* _RSS_INPUT_XFRM */
116 	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
117 	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
118 
119 	return len;
120 }
121 
122 static int
123 rss_fill_reply(struct sk_buff *skb, const struct ethnl_req_info *req_base,
124 	       const struct ethnl_reply_data *reply_base)
125 {
126 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
127 
128 	if ((data->hfunc &&
129 	     nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc)) ||
130 	    (data->input_xfrm &&
131 	     nla_put_u32(skb, ETHTOOL_A_RSS_INPUT_XFRM, data->input_xfrm)) ||
132 	    (data->indir_size &&
133 	     nla_put(skb, ETHTOOL_A_RSS_INDIR,
134 		     sizeof(u32) * data->indir_size, data->indir_table)) ||
135 	    (data->hkey_size &&
136 	     nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey)))
137 		return -EMSGSIZE;
138 
139 	return 0;
140 }
141 
142 static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
143 {
144 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
145 
146 	kfree(data->indir_table);
147 }
148 
149 const struct ethnl_request_ops ethnl_rss_request_ops = {
150 	.request_cmd		= ETHTOOL_MSG_RSS_GET,
151 	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
152 	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
153 	.req_info_size		= sizeof(struct rss_req_info),
154 	.reply_data_size	= sizeof(struct rss_reply_data),
155 
156 	.parse_request		= rss_parse_request,
157 	.prepare_data		= rss_prepare_data,
158 	.reply_size		= rss_reply_size,
159 	.fill_reply		= rss_fill_reply,
160 	.cleanup_data		= rss_cleanup_data,
161 };
162