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/busy_poll.h>
7 #include <net/net_debug.h>
8 #include <net/netdev_rx_queue.h>
9 #include <net/page_pool/helpers.h>
10 #include <net/page_pool/types.h>
11 #include <net/sock.h>
12
13 #include "devmem.h"
14 #include "page_pool_priv.h"
15 #include "netdev-genl-gen.h"
16
17 static DEFINE_XARRAY_FLAGS(page_pools, XA_FLAGS_ALLOC1);
18 /* Protects: page_pools, netdevice->page_pools, pool->p.napi, pool->slow.netdev,
19 * pool->user.
20 * Ordering: inside rtnl_lock
21 */
22 DEFINE_MUTEX(page_pools_lock);
23
24 /* Page pools are only reachable from user space (via netlink) if they are
25 * linked to a netdev at creation time. Following page pool "visibility"
26 * states are possible:
27 * - normal
28 * - user.list: linked to real netdev, netdev: real netdev
29 * - orphaned - real netdev has disappeared
30 * - user.list: linked to lo, netdev: lo
31 * - invisible - either (a) created without netdev linking, (b) unlisted due
32 * to error, or (c) the entire namespace which owned this pool disappeared
33 * - user.list: unhashed, netdev: unknown
34 */
35
36 typedef int (*pp_nl_fill_cb)(struct sk_buff *rsp, const struct page_pool *pool,
37 const struct genl_info *info);
38
39 static int
netdev_nl_page_pool_get_do(struct genl_info * info,u32 id,pp_nl_fill_cb fill)40 netdev_nl_page_pool_get_do(struct genl_info *info, u32 id, pp_nl_fill_cb fill)
41 {
42 struct page_pool *pool;
43 struct sk_buff *rsp;
44 int err;
45
46 mutex_lock(&page_pools_lock);
47 pool = xa_load(&page_pools, id);
48 if (!pool || hlist_unhashed(&pool->user.list) ||
49 !net_eq(dev_net(pool->slow.netdev), genl_info_net(info))) {
50 err = -ENOENT;
51 goto err_unlock;
52 }
53
54 rsp = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
55 if (!rsp) {
56 err = -ENOMEM;
57 goto err_unlock;
58 }
59
60 err = fill(rsp, pool, info);
61 if (err)
62 goto err_free_msg;
63
64 mutex_unlock(&page_pools_lock);
65
66 return genlmsg_reply(rsp, info);
67
68 err_free_msg:
69 nlmsg_free(rsp);
70 err_unlock:
71 mutex_unlock(&page_pools_lock);
72 return err;
73 }
74
75 struct page_pool_dump_cb {
76 unsigned long ifindex;
77 u32 pp_id;
78 };
79
80 static int
netdev_nl_page_pool_get_dump(struct sk_buff * skb,struct netlink_callback * cb,pp_nl_fill_cb fill)81 netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
82 pp_nl_fill_cb fill)
83 {
84 struct page_pool_dump_cb *state = (void *)cb->ctx;
85 const struct genl_info *info = genl_info_dump(cb);
86 struct net *net = sock_net(skb->sk);
87 struct net_device *netdev;
88 struct page_pool *pool;
89 int err = 0;
90
91 rtnl_lock();
92 mutex_lock(&page_pools_lock);
93 for_each_netdev_dump(net, netdev, state->ifindex) {
94 hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
95 if (state->pp_id && state->pp_id < pool->user.id)
96 continue;
97
98 state->pp_id = pool->user.id;
99 err = fill(skb, pool, info);
100 if (err)
101 goto out;
102 }
103
104 state->pp_id = 0;
105 }
106 out:
107 mutex_unlock(&page_pools_lock);
108 rtnl_unlock();
109
110 return err;
111 }
112
113 static int
page_pool_nl_stats_fill(struct sk_buff * rsp,const struct page_pool * pool,const struct genl_info * info)114 page_pool_nl_stats_fill(struct sk_buff *rsp, const struct page_pool *pool,
115 const struct genl_info *info)
116 {
117 #ifdef CONFIG_PAGE_POOL_STATS
118 struct page_pool_stats stats = {};
119 struct nlattr *nest;
120 void *hdr;
121
122 if (!page_pool_get_stats(pool, &stats))
123 return 0;
124
125 hdr = genlmsg_iput(rsp, info);
126 if (!hdr)
127 return -EMSGSIZE;
128
129 nest = nla_nest_start(rsp, NETDEV_A_PAGE_POOL_STATS_INFO);
130
131 if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id) ||
132 (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
133 nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
134 pool->slow.netdev->ifindex)))
135 goto err_cancel_nest;
136
137 nla_nest_end(rsp, nest);
138
139 if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_FAST,
140 stats.alloc_stats.fast) ||
141 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW,
142 stats.alloc_stats.slow) ||
143 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_SLOW_HIGH_ORDER,
144 stats.alloc_stats.slow_high_order) ||
145 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_EMPTY,
146 stats.alloc_stats.empty) ||
147 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_REFILL,
148 stats.alloc_stats.refill) ||
149 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_ALLOC_WAIVE,
150 stats.alloc_stats.waive) ||
151 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHED,
152 stats.recycle_stats.cached) ||
153 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_CACHE_FULL,
154 stats.recycle_stats.cache_full) ||
155 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING,
156 stats.recycle_stats.ring) ||
157 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RING_FULL,
158 stats.recycle_stats.ring_full) ||
159 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_STATS_RECYCLE_RELEASED_REFCNT,
160 stats.recycle_stats.released_refcnt))
161 goto err_cancel_msg;
162
163 genlmsg_end(rsp, hdr);
164
165 return 0;
166 err_cancel_nest:
167 nla_nest_cancel(rsp, nest);
168 err_cancel_msg:
169 genlmsg_cancel(rsp, hdr);
170 return -EMSGSIZE;
171 #else
172 GENL_SET_ERR_MSG(info, "kernel built without CONFIG_PAGE_POOL_STATS");
173 return -EOPNOTSUPP;
174 #endif
175 }
176
netdev_nl_page_pool_stats_get_doit(struct sk_buff * skb,struct genl_info * info)177 int netdev_nl_page_pool_stats_get_doit(struct sk_buff *skb,
178 struct genl_info *info)
179 {
180 struct nlattr *tb[ARRAY_SIZE(netdev_page_pool_info_nl_policy)];
181 struct nlattr *nest;
182 int err;
183 u32 id;
184
185 if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_STATS_INFO))
186 return -EINVAL;
187
188 nest = info->attrs[NETDEV_A_PAGE_POOL_STATS_INFO];
189 err = nla_parse_nested(tb, ARRAY_SIZE(tb) - 1, nest,
190 netdev_page_pool_info_nl_policy,
191 info->extack);
192 if (err)
193 return err;
194
195 if (NL_REQ_ATTR_CHECK(info->extack, nest, tb, NETDEV_A_PAGE_POOL_ID))
196 return -EINVAL;
197 if (tb[NETDEV_A_PAGE_POOL_IFINDEX]) {
198 NL_SET_ERR_MSG_ATTR(info->extack,
199 tb[NETDEV_A_PAGE_POOL_IFINDEX],
200 "selecting by ifindex not supported");
201 return -EINVAL;
202 }
203
204 id = nla_get_uint(tb[NETDEV_A_PAGE_POOL_ID]);
205
206 return netdev_nl_page_pool_get_do(info, id, page_pool_nl_stats_fill);
207 }
208
netdev_nl_page_pool_stats_get_dumpit(struct sk_buff * skb,struct netlink_callback * cb)209 int netdev_nl_page_pool_stats_get_dumpit(struct sk_buff *skb,
210 struct netlink_callback *cb)
211 {
212 return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_stats_fill);
213 }
214
215 static int
page_pool_nl_fill(struct sk_buff * rsp,const struct page_pool * pool,const struct genl_info * info)216 page_pool_nl_fill(struct sk_buff *rsp, const struct page_pool *pool,
217 const struct genl_info *info)
218 {
219 struct net_devmem_dmabuf_binding *binding = pool->mp_priv;
220 size_t inflight, refsz;
221 unsigned int napi_id;
222 void *hdr;
223
224 hdr = genlmsg_iput(rsp, info);
225 if (!hdr)
226 return -EMSGSIZE;
227
228 if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_ID, pool->user.id))
229 goto err_cancel;
230
231 if (pool->slow.netdev->ifindex != LOOPBACK_IFINDEX &&
232 nla_put_u32(rsp, NETDEV_A_PAGE_POOL_IFINDEX,
233 pool->slow.netdev->ifindex))
234 goto err_cancel;
235
236 napi_id = pool->p.napi ? READ_ONCE(pool->p.napi->napi_id) : 0;
237 if (napi_id >= MIN_NAPI_ID &&
238 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_NAPI_ID, napi_id))
239 goto err_cancel;
240
241 inflight = page_pool_inflight(pool, false);
242 refsz = PAGE_SIZE << pool->p.order;
243 if (nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT, inflight) ||
244 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_INFLIGHT_MEM,
245 inflight * refsz))
246 goto err_cancel;
247 if (pool->user.detach_time &&
248 nla_put_uint(rsp, NETDEV_A_PAGE_POOL_DETACH_TIME,
249 pool->user.detach_time))
250 goto err_cancel;
251
252 if (binding && nla_put_u32(rsp, NETDEV_A_PAGE_POOL_DMABUF, binding->id))
253 goto err_cancel;
254
255 genlmsg_end(rsp, hdr);
256
257 return 0;
258 err_cancel:
259 genlmsg_cancel(rsp, hdr);
260 return -EMSGSIZE;
261 }
262
netdev_nl_page_pool_event(const struct page_pool * pool,u32 cmd)263 static void netdev_nl_page_pool_event(const struct page_pool *pool, u32 cmd)
264 {
265 struct genl_info info;
266 struct sk_buff *ntf;
267 struct net *net;
268
269 lockdep_assert_held(&page_pools_lock);
270
271 /* 'invisible' page pools don't matter */
272 if (hlist_unhashed(&pool->user.list))
273 return;
274 net = dev_net(pool->slow.netdev);
275
276 if (!genl_has_listeners(&netdev_nl_family, net, NETDEV_NLGRP_PAGE_POOL))
277 return;
278
279 genl_info_init_ntf(&info, &netdev_nl_family, cmd);
280
281 ntf = genlmsg_new(GENLMSG_DEFAULT_SIZE, GFP_KERNEL);
282 if (!ntf)
283 return;
284
285 if (page_pool_nl_fill(ntf, pool, &info)) {
286 nlmsg_free(ntf);
287 return;
288 }
289
290 genlmsg_multicast_netns(&netdev_nl_family, net, ntf,
291 0, NETDEV_NLGRP_PAGE_POOL, GFP_KERNEL);
292 }
293
netdev_nl_page_pool_get_doit(struct sk_buff * skb,struct genl_info * info)294 int netdev_nl_page_pool_get_doit(struct sk_buff *skb, struct genl_info *info)
295 {
296 u32 id;
297
298 if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_PAGE_POOL_ID))
299 return -EINVAL;
300
301 id = nla_get_uint(info->attrs[NETDEV_A_PAGE_POOL_ID]);
302
303 return netdev_nl_page_pool_get_do(info, id, page_pool_nl_fill);
304 }
305
netdev_nl_page_pool_get_dumpit(struct sk_buff * skb,struct netlink_callback * cb)306 int netdev_nl_page_pool_get_dumpit(struct sk_buff *skb,
307 struct netlink_callback *cb)
308 {
309 return netdev_nl_page_pool_get_dump(skb, cb, page_pool_nl_fill);
310 }
311
page_pool_list(struct page_pool * pool)312 int page_pool_list(struct page_pool *pool)
313 {
314 static u32 id_alloc_next;
315 int err;
316
317 mutex_lock(&page_pools_lock);
318 err = xa_alloc_cyclic(&page_pools, &pool->user.id, pool, xa_limit_32b,
319 &id_alloc_next, GFP_KERNEL);
320 if (err < 0)
321 goto err_unlock;
322
323 INIT_HLIST_NODE(&pool->user.list);
324 if (pool->slow.netdev) {
325 hlist_add_head(&pool->user.list,
326 &pool->slow.netdev->page_pools);
327 netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_ADD_NTF);
328 }
329
330 mutex_unlock(&page_pools_lock);
331 return 0;
332
333 err_unlock:
334 mutex_unlock(&page_pools_lock);
335 return err;
336 }
337
page_pool_detached(struct page_pool * pool)338 void page_pool_detached(struct page_pool *pool)
339 {
340 mutex_lock(&page_pools_lock);
341 pool->user.detach_time = ktime_get_boottime_seconds();
342 netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
343 mutex_unlock(&page_pools_lock);
344 }
345
page_pool_unlist(struct page_pool * pool)346 void page_pool_unlist(struct page_pool *pool)
347 {
348 mutex_lock(&page_pools_lock);
349 netdev_nl_page_pool_event(pool, NETDEV_CMD_PAGE_POOL_DEL_NTF);
350 xa_erase(&page_pools, pool->user.id);
351 if (!hlist_unhashed(&pool->user.list))
352 hlist_del(&pool->user.list);
353 mutex_unlock(&page_pools_lock);
354 }
355
page_pool_check_memory_provider(struct net_device * dev,struct netdev_rx_queue * rxq)356 int page_pool_check_memory_provider(struct net_device *dev,
357 struct netdev_rx_queue *rxq)
358 {
359 struct net_devmem_dmabuf_binding *binding = rxq->mp_params.mp_priv;
360 struct page_pool *pool;
361 struct hlist_node *n;
362
363 if (!binding)
364 return 0;
365
366 mutex_lock(&page_pools_lock);
367 hlist_for_each_entry_safe(pool, n, &dev->page_pools, user.list) {
368 if (pool->mp_priv != binding)
369 continue;
370
371 if (pool->slow.queue_idx == get_netdev_rx_queue_index(rxq)) {
372 mutex_unlock(&page_pools_lock);
373 return 0;
374 }
375 }
376 mutex_unlock(&page_pools_lock);
377 return -ENODATA;
378 }
379
page_pool_unreg_netdev_wipe(struct net_device * netdev)380 static void page_pool_unreg_netdev_wipe(struct net_device *netdev)
381 {
382 struct page_pool *pool;
383 struct hlist_node *n;
384
385 mutex_lock(&page_pools_lock);
386 hlist_for_each_entry_safe(pool, n, &netdev->page_pools, user.list) {
387 hlist_del_init(&pool->user.list);
388 pool->slow.netdev = NET_PTR_POISON;
389 }
390 mutex_unlock(&page_pools_lock);
391 }
392
page_pool_unreg_netdev(struct net_device * netdev)393 static void page_pool_unreg_netdev(struct net_device *netdev)
394 {
395 struct page_pool *pool, *last;
396 struct net_device *lo;
397
398 lo = dev_net(netdev)->loopback_dev;
399
400 mutex_lock(&page_pools_lock);
401 last = NULL;
402 hlist_for_each_entry(pool, &netdev->page_pools, user.list) {
403 pool->slow.netdev = lo;
404 netdev_nl_page_pool_event(pool,
405 NETDEV_CMD_PAGE_POOL_CHANGE_NTF);
406 last = pool;
407 }
408 if (last)
409 hlist_splice_init(&netdev->page_pools, &last->user.list,
410 &lo->page_pools);
411 mutex_unlock(&page_pools_lock);
412 }
413
414 static int
page_pool_netdevice_event(struct notifier_block * nb,unsigned long event,void * ptr)415 page_pool_netdevice_event(struct notifier_block *nb,
416 unsigned long event, void *ptr)
417 {
418 struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
419
420 if (event != NETDEV_UNREGISTER)
421 return NOTIFY_DONE;
422
423 if (hlist_empty(&netdev->page_pools))
424 return NOTIFY_OK;
425
426 if (netdev->ifindex != LOOPBACK_IFINDEX)
427 page_pool_unreg_netdev(netdev);
428 else
429 page_pool_unreg_netdev_wipe(netdev);
430 return NOTIFY_OK;
431 }
432
433 static struct notifier_block page_pool_netdevice_nb = {
434 .notifier_call = page_pool_netdevice_event,
435 };
436
page_pool_user_init(void)437 static int __init page_pool_user_init(void)
438 {
439 return register_netdevice_notifier(&page_pool_netdevice_nb);
440 }
441
442 subsys_initcall(page_pool_user_init);
443