xref: /linux/net/core/page_pool_user.c (revision 55f1b540d893da740a81200450014c45a8103f54)
1 // SPDX-License-Identifier: GPL-2.0
2 
3 #include <linux/mutex.h>
4 #include <linux/netdevice.h>
5 #include <linux/xarray.h>
6 #include <net/net_debug.h>
7 #include <net/netdev_rx_queue.h>
8 #include <net/page_pool/helpers.h>
9 #include <net/page_pool/types.h>
10 #include <net/sock.h>
11 
12 #include "devmem.h"
13 #include "page_pool_priv.h"
14 #include "netdev-genl-gen.h"
15 
16 static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
17 /* Protects: page_pools, netdevice->page_pools, pool->slow.netdev, pool->user.
18  * Ordering: inside rtnl_lock
19  */
20 static DEFINE_MUTEX(page_pools_lock);
21 
22 /* Page pools are only reachable from user space (via netlink) if they are
23  * linked to a netdev at creation time. Following page pool "visibility"
24  * states are possible:
25  *  - normal
26  *    - user.list: linked to real netdev, netdev: real netdev
27  *  - orphaned - real netdev has disappeared
28  *    - user.list: linked to lo, netdev: lo
29  *  - invisible - either (a) created without netdev linking, (b) unlisted due
30  *      to error, or (c) the entire namespace which owned this pool disappeared
31  *    - user.list: unhashed, netdev: unknown
32  */
33 
34 typedef int (*pp_nl_fill_cb)(struct sk_buff *rsp, const struct page_pool *pool,
35 			     const struct genl_info *info);
36 
37 static int
38 netdev_nl_page_pool_get_do(struct genl_info *info, u32 id, pp_nl_fill_cb fill)
39 {
40 	struct page_pool *pool;
41 	struct sk_buff *rsp;
42 	int err;
43 
44 	mutex_lock(&page_pools_lock);
45 	pool = xa_load(&page_pools, id);
46 	if (!pool || hlist_unhashed(&pool->user.list) ||
47 	    !net_eq(dev_net(pool->slow.netdev), genl_info_net(info))) {
48 		err = -ENOENT;
49 		goto err_unlock;
50 	}
51 
52 	rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
53 	if (!rsp) {
54 		err = -ENOMEM;
55 		goto err_unlock;
56 	}
57 
58 	err = fill(rsp, pool, info);
59 	if (err)
60 		goto err_free_msg;
61 
62 	mutex_unlock(&page_pools_lock);
63 
64 	return genlmsg_reply(rsp, info);
65 
66 err_free_msg:
67 	nlmsg_free(rsp);
68 err_unlock:
69 	mutex_unlock(&page_pools_lock);
70 	return err;
71 }
72 
73 struct page_pool_dump_cb {
74 	unsigned long ifindex;
75 	u32 pp_id;
76 };
77 
78 static int
79 netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
80 			     pp_nl_fill_cb fill)
81 {
82 	struct page_pool_dump_cb *state = (void *)cb->ctx;
83 	const struct genl_info *info = genl_info_dump(cb);
84 	struct net *net = sock_net(skb->sk);
85 	struct net_device *netdev;
86 	struct page_pool *pool;
87 	int err = 0;
88 
89 	rtnl_lock();
90 	mutex_lock(&page_pools_lock);
91 	for_each_netdev_dump(net, netdev, state->ifindex) {
92 		hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
93 			if (state->pp_id && state->pp_id < pool->user.id)
94 				continue;
95 
96 			state->pp_id = pool->user.id;
97 			err = fill(skb, pool, info);
98 			if (err)
99 				goto out;
100 		}
101 
102 		state->pp_id = 0;
103 	}
104 out:
105 	mutex_unlock(&page_pools_lock);
106 	rtnl_unlock();
107 
108 	return err;
109 }
110 
111 static int
112 page_pool_nl_stats_fill(struct sk_buff *rsp, const struct page_pool *pool,
113 			const struct genl_info *info)
114 {
115 #ifdef CONFIG_PAGE_POOL_STATS
116 	struct page_pool_stats stats = {};
117 	struct nlattr *nest;
118 	void *hdr;
119 
120 	if (!page_pool_get_stats(pool, &stats))
121 		return 0;
122 
123 	hdr = genlmsg_iput(rsp, info);
124 	if (!hdr)
125 		return -EMSGSIZE;
126 
127 	nest = nla_nest_start(rsp, NETDEV_A_PAGE_POOL_STATS_INFO);
128 
129 	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id) ||
130 	    (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
131 	     nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
132 			 pool->slow.netdev->ifindex)))
133 		goto err_cancel_nest;
134 
135 	nla_nest_end(rsp, nest);
136 
137 	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST,
138 			 stats.alloc_stats.fast) ||
139 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW,
140 			 stats.alloc_stats.slow) ||
141 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER,
142 			 stats.alloc_stats.slow_high_order) ||
143 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY,
144 			 stats.alloc_stats.empty) ||
145 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL,
146 			 stats.alloc_stats.refill) ||
147 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE,
148 			 stats.alloc_stats.waive) ||
149 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED,
150 			 stats.recycle_stats.cached) ||
151 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL,
152 			 stats.recycle_stats.cache_full) ||
153 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING,
154 			 stats.recycle_stats.ring) ||
155 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL,
156 			 stats.recycle_stats.ring_full) ||
157 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT,
158 			 stats.recycle_stats.released_refcnt))
159 		goto err_cancel_msg;
160 
161 	genlmsg_end(rsp, hdr);
162 
163 	return 0;
164 err_cancel_nest:
165 	nla_nest_cancel(rsp, nest);
166 err_cancel_msg:
167 	genlmsg_cancel(rsp, hdr);
168 	return -EMSGSIZE;
169 #else
170 	GENL_SET_ERR_MSG(info, "kernel built without CONFIG_PAGE_POOL_STATS");
171 	return -EOPNOTSUPP;
172 #endif
173 }
174 
175 int netdev_nl_page_pool_stats_get_doit(struct sk_buff *skb,
176 				       struct genl_info *info)
177 {
178 	struct nlattr *tb[ARRAY_SIZE(netdev_page_pool_info_nl_policy)];
179 	struct nlattr *nest;
180 	int err;
181 	u32 id;
182 
183 	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_STATS_INFO))
184 		return -EINVAL;
185 
186 	nest = info->attrs[NETDEV_A_PAGE_POOL_STATS_INFO];
187 	err = nla_parse_nested(tb, ARRAY_SIZE(tb) - 1, nest,
188 			       netdev_page_pool_info_nl_policy,
189 			       info->extack);
190 	if (err)
191 		return err;
192 
193 	if (NL_REQ_ATTR_CHECK(info->extack, nest, tb, NETDEV_A_PAGE_POOL_ID))
194 		return -EINVAL;
195 	if (tb[NETDEV_A_PAGE_POOL_IFINDEX]) {
196 		NL_SET_ERR_MSG_ATTR(info->extack,
197 				    tb[NETDEV_A_PAGE_POOL_IFINDEX],
198 				    "selecting by ifindex not supported");
199 		return -EINVAL;
200 	}
201 
202 	id = nla_get_uint(tb[NETDEV_A_PAGE_POOL_ID]);
203 
204 	return netdev_nl_page_pool_get_do(info, id, page_pool_nl_stats_fill);
205 }
206 
207 int netdev_nl_page_pool_stats_get_dumpit(struct sk_buff *skb,
208 					 struct netlink_callback *cb)
209 {
210 	return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_stats_fill);
211 }
212 
213 static int
214 page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
215 		  const struct genl_info *info)
216 {
217 	struct net_devmem_dmabuf_binding *binding = pool->mp_priv;
218 	size_t inflight, refsz;
219 	void *hdr;
220 
221 	hdr = genlmsg_iput(rsp, info);
222 	if (!hdr)
223 		return -EMSGSIZE;
224 
225 	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id))
226 		goto err_cancel;
227 
228 	if (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
229 	    nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
230 			pool->slow.netdev->ifindex))
231 		goto err_cancel;
232 	if (pool->user.napi_id &&
233 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_NAPI_ID, pool->user.napi_id))
234 		goto err_cancel;
235 
236 	inflight = page_pool_inflight(pool, false);
237 	refsz =	PAGE_SIZE << pool->p.order;
238 	if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT, inflight) ||
239 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
240 			 inflight * refsz))
241 		goto err_cancel;
242 	if (pool->user.detach_time &&
243 	    nla_put_uint(rsp, NETDEV_A_PAGE_POOL_DETACH_TIME,
244 			 pool->user.detach_time))
245 		goto err_cancel;
246 
247 	if (binding && nla_put_u32(rsp, NETDEV_A_PAGE_POOL_DMABUF, binding->id))
248 		goto err_cancel;
249 
250 	genlmsg_end(rsp, hdr);
251 
252 	return 0;
253 err_cancel:
254 	genlmsg_cancel(rsp, hdr);
255 	return -EMSGSIZE;
256 }
257 
258 static void netdev_nl_page_pool_event(const struct page_pool *pool, u32 cmd)
259 {
260 	struct genl_info info;
261 	struct sk_buff *ntf;
262 	struct net *net;
263 
264 	lockdep_assert_held(&page_pools_lock);
265 
266 	/* 'invisible' page pools don't matter */
267 	if (hlist_unhashed(&pool->user.list))
268 		return;
269 	net = dev_net(pool->slow.netdev);
270 
271 	if (!genl_has_listeners(&netdev_nl_family, net, NETDEV_NLGRP_PAGE_POOL))
272 		return;
273 
274 	genl_info_init_ntf(&info, &netdev_nl_family, cmd);
275 
276 	ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
277 	if (!ntf)
278 		return;
279 
280 	if (page_pool_nl_fill(ntf, pool, &info)) {
281 		nlmsg_free(ntf);
282 		return;
283 	}
284 
285 	genlmsg_multicast_netns(&netdev_nl_family, net, ntf,
286 				0, NETDEV_NLGRP_PAGE_POOL, GFP_KERNEL);
287 }
288 
289 int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info)
290 {
291 	u32 id;
292 
293 	if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_ID))
294 		return -EINVAL;
295 
296 	id = nla_get_uint(info->attrs[NETDEV_A_PAGE_POOL_ID]);
297 
298 	return netdev_nl_page_pool_get_do(info, id, page_pool_nl_fill);
299 }
300 
301 int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
302 				   struct netlink_callback *cb)
303 {
304 	return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_fill);
305 }
306 
307 int page_pool_list(struct page_pool *pool)
308 {
309 	static u32 id_alloc_next;
310 	int err;
311 
312 	mutex_lock(&page_pools_lock);
313 	err = xa_alloc_cyclic(&page_pools, &pool->user.id, pool, xa_limit_32b,
314 			      &id_alloc_next, GFP_KERNEL);
315 	if (err < 0)
316 		goto err_unlock;
317 
318 	INIT_HLIST_NODE(&pool->user.list);
319 	if (pool->slow.netdev) {
320 		hlist_add_head(&pool->user.list,
321 			       &pool->slow.netdev->page_pools);
322 		pool->user.napi_id = pool->p.napi ? pool->p.napi->napi_id : 0;
323 
324 		netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_ADD_NTF);
325 	}
326 
327 	mutex_unlock(&page_pools_lock);
328 	return 0;
329 
330 err_unlock:
331 	mutex_unlock(&page_pools_lock);
332 	return err;
333 }
334 
335 void page_pool_detached(struct page_pool *pool)
336 {
337 	mutex_lock(&page_pools_lock);
338 	pool->user.detach_time = ktime_get_boottime_seconds();
339 	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
340 	mutex_unlock(&page_pools_lock);
341 }
342 
343 void page_pool_unlist(struct page_pool *pool)
344 {
345 	mutex_lock(&page_pools_lock);
346 	netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_DEL_NTF);
347 	xa_erase(&page_pools, pool->user.id);
348 	if (!hlist_unhashed(&pool->user.list))
349 		hlist_del(&pool->user.list);
350 	mutex_unlock(&page_pools_lock);
351 }
352 
353 int page_pool_check_memory_provider(struct net_device *dev,
354 				    struct netdev_rx_queue *rxq)
355 {
356 	struct net_devmem_dmabuf_binding *binding = rxq->mp_params.mp_priv;
357 	struct page_pool *pool;
358 	struct hlist_node *n;
359 
360 	if (!binding)
361 		return 0;
362 
363 	mutex_lock(&page_pools_lock);
364 	hlist_for_each_entry_safe(pool, n, &dev->page_pools, user.list) {
365 		if (pool->mp_priv != binding)
366 			continue;
367 
368 		if (pool->slow.queue_idx == get_netdev_rx_queue_index(rxq)) {
369 			mutex_unlock(&page_pools_lock);
370 			return 0;
371 		}
372 	}
373 	mutex_unlock(&page_pools_lock);
374 	return -ENODATA;
375 }
376 
377 static void page_pool_unreg_netdev_wipe(struct net_device *netdev)
378 {
379 	struct page_pool *pool;
380 	struct hlist_node *n;
381 
382 	mutex_lock(&page_pools_lock);
383 	hlist_for_each_entry_safe(pool, n, &netdev->page_pools, user.list) {
384 		hlist_del_init(&pool->user.list);
385 		pool->slow.netdev = NET_PTR_POISON;
386 	}
387 	mutex_unlock(&page_pools_lock);
388 }
389 
390 static void page_pool_unreg_netdev(struct net_device *netdev)
391 {
392 	struct page_pool *pool, *last;
393 	struct net_device *lo;
394 
395 	lo = dev_net(netdev)->loopback_dev;
396 
397 	mutex_lock(&page_pools_lock);
398 	last = NULL;
399 	hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
400 		pool->slow.netdev = lo;
401 		netdev_nl_page_pool_event(pool,
402 					  NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
403 		last = pool;
404 	}
405 	if (last)
406 		hlist_splice_init(&netdev->page_pools, &last->user.list,
407 				  &lo->page_pools);
408 	mutex_unlock(&page_pools_lock);
409 }
410 
411 static int
412 page_pool_netdevice_event(struct notifier_block *nb,
413 			  unsigned long event, void *ptr)
414 {
415 	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
416 
417 	if (event != NETDEV_UNREGISTER)
418 		return NOTIFY_DONE;
419 
420 	if (hlist_empty(&netdev->page_pools))
421 		return NOTIFY_OK;
422 
423 	if (netdev->ifindex != LOOPBACK_IFINDEX)
424 		page_pool_unreg_netdev(netdev);
425 	else
426 		page_pool_unreg_netdev_wipe(netdev);
427 	return NOTIFY_OK;
428 }
429 
430 static struct notifier_block page_pool_netdevice_nb = {
431 	.notifier_call = page_pool_netdevice_event,
432 };
433 
434 static int __init page_pool_user_init(void)
435 {
436 	return register_netdevice_notifier(&page_pool_netdevice_nb);
437 }
438 
439 subsys_initcall(page_pool_user_init);
440