xref: /openbmc/linux/net/ethtool/rss.c (revision e8254a8e)
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				*indir_table;
17 	u8				*hkey;
18 };
19 
20 #define RSS_REQINFO(__req_base) \
21 	container_of(__req_base, struct rss_req_info, base)
22 
23 #define RSS_REPDATA(__reply_base) \
24 	container_of(__reply_base, struct rss_reply_data, base)
25 
26 const struct nla_policy ethnl_rss_get_policy[] = {
27 	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
28 	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32 },
29 };
30 
31 static int
32 rss_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
33 		  struct netlink_ext_ack *extack)
34 {
35 	struct rss_req_info *request = RSS_REQINFO(req_info);
36 
37 	if (tb[ETHTOOL_A_RSS_CONTEXT])
38 		request->rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
39 
40 	return 0;
41 }
42 
43 static int
44 rss_prepare_data(const struct ethnl_req_info *req_base,
45 		 struct ethnl_reply_data *reply_base, struct genl_info *info)
46 {
47 	struct rss_reply_data *data = RSS_REPDATA(reply_base);
48 	struct rss_req_info *request = RSS_REQINFO(req_base);
49 	struct net_device *dev = reply_base->dev;
50 	const struct ethtool_ops *ops;
51 	u32 total_size, indir_bytes;
52 	u8 dev_hfunc = 0;
53 	u8 *rss_config;
54 	int ret;
55 
56 	ops = dev->ethtool_ops;
57 	if (!ops->get_rxfh)
58 		return -EOPNOTSUPP;
59 
60 	/* Some drivers don't handle rss_context */
61 	if (request->rss_context && !ops->get_rxfh_context)
62 		return -EOPNOTSUPP;
63 
64 	ret = ethnl_ops_begin(dev);
65 	if (ret < 0)
66 		return ret;
67 
68 	data->indir_size = 0;
69 	data->hkey_size = 0;
70 	if (ops->get_rxfh_indir_size)
71 		data->indir_size = ops->get_rxfh_indir_size(dev);
72 	if (ops->get_rxfh_key_size)
73 		data->hkey_size = ops->get_rxfh_key_size(dev);
74 
75 	indir_bytes = data->indir_size * sizeof(u32);
76 	total_size = indir_bytes + data->hkey_size;
77 	rss_config = kzalloc(total_size, GFP_KERNEL);
78 	if (!rss_config) {
79 		ret = -ENOMEM;
80 		goto out_ops;
81 	}
82 
83 	if (data->indir_size)
84 		data->indir_table = (u32 *)rss_config;
85 
86 	if (data->hkey_size)
87 		data->hkey = rss_config + indir_bytes;
88 
89 	if (request->rss_context)
90 		ret = ops->get_rxfh_context(dev, data->indir_table, data->hkey,
91 					    &dev_hfunc, request->rss_context);
92 	else
93 		ret = ops->get_rxfh(dev, data->indir_table, data->hkey,
94 				    &dev_hfunc);
95 
96 	if (ret)
97 		goto out_ops;
98 
99 	data->hfunc = dev_hfunc;
100 out_ops:
101 	ethnl_ops_complete(dev);
102 	return ret;
103 }
104 
105 static int
106 rss_reply_size(const struct ethnl_req_info *req_base,
107 	       const struct ethnl_reply_data *reply_base)
108 {
109 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
110 	int len;
111 
112 	len = nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
113 	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
114 	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
115 
116 	return len;
117 }
118 
119 static int
120 rss_fill_reply(struct sk_buff *skb, const struct ethnl_req_info *req_base,
121 	       const struct ethnl_reply_data *reply_base)
122 {
123 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
124 
125 	if (nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc) ||
126 	    nla_put(skb, ETHTOOL_A_RSS_INDIR,
127 		    sizeof(u32) * data->indir_size, data->indir_table) ||
128 	    nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey))
129 		return -EMSGSIZE;
130 
131 	return 0;
132 }
133 
134 static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
135 {
136 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
137 
138 	kfree(data->indir_table);
139 }
140 
141 const struct ethnl_request_ops ethnl_rss_request_ops = {
142 	.request_cmd		= ETHTOOL_MSG_RSS_GET,
143 	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
144 	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
145 	.req_info_size		= sizeof(struct rss_req_info),
146 	.reply_data_size	= sizeof(struct rss_reply_data),
147 
148 	.parse_request		= rss_parse_request,
149 	.prepare_data		= rss_prepare_data,
150 	.reply_size		= rss_reply_size,
151 	.fill_reply		= rss_fill_reply,
152 	.cleanup_data		= rss_cleanup_data,
153 };
154