xref: /linux/net/ethtool/rss.c (revision 0ce92d548b44649a8de706f9bb9e74a4ed2f18a7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 #include <net/netdev_lock.h>
4 
5 #include "netlink.h"
6 #include "common.h"
7 
8 struct rss_req_info {
9 	struct ethnl_req_info		base;
10 	u32				rss_context;
11 };
12 
13 struct rss_reply_data {
14 	struct ethnl_reply_data		base;
15 	bool				no_key_fields;
16 	u32				indir_size;
17 	u32				hkey_size;
18 	u32				hfunc;
19 	u32				input_xfrm;
20 	u32				*indir_table;
21 	u8				*hkey;
22 };
23 
24 #define RSS_REQINFO(__req_base) \
25 	container_of(__req_base, struct rss_req_info, base)
26 
27 #define RSS_REPDATA(__reply_base) \
28 	container_of(__reply_base, struct rss_reply_data, base)
29 
30 const struct nla_policy ethnl_rss_get_policy[] = {
31 	[ETHTOOL_A_RSS_HEADER] = NLA_POLICY_NESTED(ethnl_header_policy),
32 	[ETHTOOL_A_RSS_CONTEXT] = { .type = NLA_U32 },
33 	[ETHTOOL_A_RSS_START_CONTEXT] = { .type = NLA_U32 },
34 };
35 
36 static int
37 rss_parse_request(struct ethnl_req_info *req_info, struct nlattr **tb,
38 		  struct netlink_ext_ack *extack)
39 {
40 	struct rss_req_info *request = RSS_REQINFO(req_info);
41 
42 	if (tb[ETHTOOL_A_RSS_CONTEXT])
43 		request->rss_context = nla_get_u32(tb[ETHTOOL_A_RSS_CONTEXT]);
44 	if (tb[ETHTOOL_A_RSS_START_CONTEXT]) {
45 		NL_SET_BAD_ATTR(extack, tb[ETHTOOL_A_RSS_START_CONTEXT]);
46 		return -EINVAL;
47 	}
48 
49 	return 0;
50 }
51 
52 static int
53 rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
54 		struct rss_reply_data *data, const struct genl_info *info)
55 {
56 	struct ethtool_rxfh_param rxfh = {};
57 	const struct ethtool_ops *ops;
58 	u32 total_size, indir_bytes;
59 	u8 *rss_config;
60 	int ret;
61 
62 	ops = dev->ethtool_ops;
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 	if (data->hkey_size)
86 		data->hkey = rss_config + indir_bytes;
87 
88 	rxfh.indir_size = data->indir_size;
89 	rxfh.indir = data->indir_table;
90 	rxfh.key_size = data->hkey_size;
91 	rxfh.key = data->hkey;
92 
93 	ret = ops->get_rxfh(dev, &rxfh);
94 	if (ret)
95 		goto out_ops;
96 
97 	data->hfunc = rxfh.hfunc;
98 	data->input_xfrm = rxfh.input_xfrm;
99 out_ops:
100 	ethnl_ops_complete(dev);
101 	return ret;
102 }
103 
104 static int
105 rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
106 		struct rss_reply_data *data, const struct genl_info *info)
107 {
108 	struct ethtool_rxfh_context *ctx;
109 	u32 total_size, indir_bytes;
110 	u8 *rss_config;
111 
112 	data->no_key_fields = !dev->ethtool_ops->rxfh_per_ctx_key;
113 
114 	ctx = xa_load(&dev->ethtool->rss_ctx, request->rss_context);
115 	if (!ctx)
116 		return -ENOENT;
117 
118 	data->indir_size = ctx->indir_size;
119 	data->hkey_size = ctx->key_size;
120 	data->hfunc = ctx->hfunc;
121 	data->input_xfrm = ctx->input_xfrm;
122 
123 	indir_bytes = data->indir_size * sizeof(u32);
124 	total_size = indir_bytes + data->hkey_size;
125 	rss_config = kzalloc(total_size, GFP_KERNEL);
126 	if (!rss_config)
127 		return -ENOMEM;
128 
129 	data->indir_table = (u32 *)rss_config;
130 	memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx), indir_bytes);
131 
132 	if (data->hkey_size) {
133 		data->hkey = rss_config + indir_bytes;
134 		memcpy(data->hkey, ethtool_rxfh_context_key(ctx),
135 		       data->hkey_size);
136 	}
137 
138 	return 0;
139 }
140 
141 static int
142 rss_prepare(const struct rss_req_info *request, struct net_device *dev,
143 	    struct rss_reply_data *data, const struct genl_info *info)
144 {
145 	if (request->rss_context)
146 		return rss_prepare_ctx(request, dev, data, info);
147 	return rss_prepare_get(request, dev, data, info);
148 }
149 
150 static int
151 rss_prepare_data(const struct ethnl_req_info *req_base,
152 		 struct ethnl_reply_data *reply_base,
153 		 const struct genl_info *info)
154 {
155 	struct rss_reply_data *data = RSS_REPDATA(reply_base);
156 	struct rss_req_info *request = RSS_REQINFO(req_base);
157 	struct net_device *dev = reply_base->dev;
158 	const struct ethtool_ops *ops;
159 	int ret;
160 
161 	ops = dev->ethtool_ops;
162 	if (!ops->get_rxfh)
163 		return -EOPNOTSUPP;
164 
165 	/* Some drivers don't handle rss_context */
166 	if (request->rss_context &&
167 	    !ops->cap_rss_ctx_supported && !ops->create_rxfh_context)
168 		return -EOPNOTSUPP;
169 
170 	mutex_lock(&dev->ethtool->rss_lock);
171 	ret = rss_prepare(request, dev, data, info);
172 	mutex_unlock(&dev->ethtool->rss_lock);
173 
174 	return ret;
175 }
176 
177 static int
178 rss_reply_size(const struct ethnl_req_info *req_base,
179 	       const struct ethnl_reply_data *reply_base)
180 {
181 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
182 	int len;
183 
184 	len = nla_total_size(sizeof(u32)) +	/* _RSS_CONTEXT */
185 	      nla_total_size(sizeof(u32)) +	/* _RSS_HFUNC */
186 	      nla_total_size(sizeof(u32)) +	/* _RSS_INPUT_XFRM */
187 	      nla_total_size(sizeof(u32) * data->indir_size) + /* _RSS_INDIR */
188 	      nla_total_size(data->hkey_size);	/* _RSS_HKEY */
189 
190 	return len;
191 }
192 
193 static int
194 rss_fill_reply(struct sk_buff *skb, const struct ethnl_req_info *req_base,
195 	       const struct ethnl_reply_data *reply_base)
196 {
197 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
198 	struct rss_req_info *request = RSS_REQINFO(req_base);
199 
200 	if (request->rss_context &&
201 	    nla_put_u32(skb, ETHTOOL_A_RSS_CONTEXT, request->rss_context))
202 		return -EMSGSIZE;
203 
204 	if ((data->indir_size &&
205 	     nla_put(skb, ETHTOOL_A_RSS_INDIR,
206 		     sizeof(u32) * data->indir_size, data->indir_table)))
207 		return -EMSGSIZE;
208 
209 	if (data->no_key_fields)
210 		return 0;
211 
212 	if ((data->hfunc &&
213 	     nla_put_u32(skb, ETHTOOL_A_RSS_HFUNC, data->hfunc)) ||
214 	    (data->input_xfrm &&
215 	     nla_put_u32(skb, ETHTOOL_A_RSS_INPUT_XFRM, data->input_xfrm)) ||
216 	    (data->hkey_size &&
217 	     nla_put(skb, ETHTOOL_A_RSS_HKEY, data->hkey_size, data->hkey)))
218 		return -EMSGSIZE;
219 
220 	return 0;
221 }
222 
223 static void rss_cleanup_data(struct ethnl_reply_data *reply_base)
224 {
225 	const struct rss_reply_data *data = RSS_REPDATA(reply_base);
226 
227 	kfree(data->indir_table);
228 }
229 
230 struct rss_nl_dump_ctx {
231 	unsigned long		ifindex;
232 	unsigned long		ctx_idx;
233 
234 	/* User wants to only dump contexts from given ifindex */
235 	unsigned int		match_ifindex;
236 	unsigned int		start_ctx;
237 };
238 
239 static struct rss_nl_dump_ctx *rss_dump_ctx(struct netlink_callback *cb)
240 {
241 	NL_ASSERT_CTX_FITS(struct rss_nl_dump_ctx);
242 
243 	return (struct rss_nl_dump_ctx *)cb->ctx;
244 }
245 
246 int ethnl_rss_dump_start(struct netlink_callback *cb)
247 {
248 	const struct genl_info *info = genl_info_dump(cb);
249 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
250 	struct ethnl_req_info req_info = {};
251 	struct nlattr **tb = info->attrs;
252 	int ret;
253 
254 	/* Filtering by context not supported */
255 	if (tb[ETHTOOL_A_RSS_CONTEXT]) {
256 		NL_SET_BAD_ATTR(info->extack, tb[ETHTOOL_A_RSS_CONTEXT]);
257 		return -EINVAL;
258 	}
259 	if (tb[ETHTOOL_A_RSS_START_CONTEXT]) {
260 		ctx->start_ctx = nla_get_u32(tb[ETHTOOL_A_RSS_START_CONTEXT]);
261 		ctx->ctx_idx = ctx->start_ctx;
262 	}
263 
264 	ret = ethnl_parse_header_dev_get(&req_info,
265 					 tb[ETHTOOL_A_RSS_HEADER],
266 					 sock_net(cb->skb->sk), cb->extack,
267 					 false);
268 	if (req_info.dev) {
269 		ctx->match_ifindex = req_info.dev->ifindex;
270 		ctx->ifindex = ctx->match_ifindex;
271 		ethnl_parse_header_dev_put(&req_info);
272 		req_info.dev = NULL;
273 	}
274 
275 	return ret;
276 }
277 
278 static int
279 rss_dump_one_ctx(struct sk_buff *skb, struct netlink_callback *cb,
280 		 struct net_device *dev, u32 rss_context)
281 {
282 	const struct genl_info *info = genl_info_dump(cb);
283 	struct rss_reply_data data = {};
284 	struct rss_req_info req = {};
285 	void *ehdr;
286 	int ret;
287 
288 	req.rss_context = rss_context;
289 
290 	ehdr = ethnl_dump_put(skb, cb, ETHTOOL_MSG_RSS_GET_REPLY);
291 	if (!ehdr)
292 		return -EMSGSIZE;
293 
294 	ret = ethnl_fill_reply_header(skb, dev, ETHTOOL_A_RSS_HEADER);
295 	if (ret < 0)
296 		goto err_cancel;
297 
298 	/* Context 0 is not currently storred or cached in the XArray */
299 	if (!rss_context)
300 		ret = rss_prepare_get(&req, dev, &data, info);
301 	else
302 		ret = rss_prepare_ctx(&req, dev, &data, info);
303 	if (ret)
304 		goto err_cancel;
305 
306 	ret = rss_fill_reply(skb, &req.base, &data.base);
307 	if (ret)
308 		goto err_cleanup;
309 	genlmsg_end(skb, ehdr);
310 
311 	rss_cleanup_data(&data.base);
312 	return 0;
313 
314 err_cleanup:
315 	rss_cleanup_data(&data.base);
316 err_cancel:
317 	genlmsg_cancel(skb, ehdr);
318 	return ret;
319 }
320 
321 static int
322 rss_dump_one_dev(struct sk_buff *skb, struct netlink_callback *cb,
323 		 struct net_device *dev)
324 {
325 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
326 	int ret;
327 
328 	if (!dev->ethtool_ops->get_rxfh)
329 		return 0;
330 
331 	if (!ctx->ctx_idx) {
332 		ret = rss_dump_one_ctx(skb, cb, dev, 0);
333 		if (ret)
334 			return ret;
335 		ctx->ctx_idx++;
336 	}
337 
338 	for (; xa_find(&dev->ethtool->rss_ctx, &ctx->ctx_idx,
339 		       ULONG_MAX, XA_PRESENT); ctx->ctx_idx++) {
340 		ret = rss_dump_one_ctx(skb, cb, dev, ctx->ctx_idx);
341 		if (ret)
342 			return ret;
343 	}
344 	ctx->ctx_idx = ctx->start_ctx;
345 
346 	return 0;
347 }
348 
349 int ethnl_rss_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
350 {
351 	struct rss_nl_dump_ctx *ctx = rss_dump_ctx(cb);
352 	struct net *net = sock_net(skb->sk);
353 	struct net_device *dev;
354 	int ret = 0;
355 
356 	rtnl_lock();
357 	for_each_netdev_dump(net, dev, ctx->ifindex) {
358 		if (ctx->match_ifindex && ctx->match_ifindex != ctx->ifindex)
359 			break;
360 
361 		netdev_lock_ops(dev);
362 		ret = rss_dump_one_dev(skb, cb, dev);
363 		netdev_unlock_ops(dev);
364 		if (ret)
365 			break;
366 	}
367 	rtnl_unlock();
368 
369 	return ret;
370 }
371 
372 /* RSS_NTF */
373 
374 void ethtool_rss_notify(struct net_device *dev, u32 rss_context)
375 {
376 	struct rss_req_info req_info = {
377 		.rss_context = rss_context,
378 	};
379 
380 	ethnl_notify(dev, ETHTOOL_MSG_RSS_NTF, &req_info.base);
381 }
382 
383 const struct ethnl_request_ops ethnl_rss_request_ops = {
384 	.request_cmd		= ETHTOOL_MSG_RSS_GET,
385 	.reply_cmd		= ETHTOOL_MSG_RSS_GET_REPLY,
386 	.hdr_attr		= ETHTOOL_A_RSS_HEADER,
387 	.req_info_size		= sizeof(struct rss_req_info),
388 	.reply_data_size	= sizeof(struct rss_reply_data),
389 
390 	.parse_request		= rss_parse_request,
391 	.prepare_data		= rss_prepare_data,
392 	.reply_size		= rss_reply_size,
393 	.fill_reply		= rss_fill_reply,
394 	.cleanup_data		= rss_cleanup_data,
395 };
396