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6#include <linux/init.h>
7#include <linux/sched/mm.h>
8#include <linux/sched/signal.h>
9#include <linux/sched/task.h>
10#include <linux/uaccess.h>
11#include <linux/slab.h>
12#include <linux/bpf.h>
13#include <linux/mm.h>
14#include <linux/netdevice.h>
15#include <linux/rtnetlink.h>
16#include <linux/idr.h>
17#include <linux/vmalloc.h>
18
19#include "xdp_umem.h"
20#include "xsk_queue.h"
21
22#define XDP_UMEM_MIN_CHUNK_SIZE 2048
23
24static DEFINE_IDA(umem_ida);
25
26void xdp_add_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
27{
28 unsigned long flags;
29
30 if (!xs->tx)
31 return;
32
33 spin_lock_irqsave(&umem->xsk_tx_list_lock, flags);
34 list_add_rcu(&xs->list, &umem->xsk_tx_list);
35 spin_unlock_irqrestore(&umem->xsk_tx_list_lock, flags);
36}
37
38void xdp_del_sk_umem(struct xdp_umem *umem, struct xdp_sock *xs)
39{
40 unsigned long flags;
41
42 if (!xs->tx)
43 return;
44
45 spin_lock_irqsave(&umem->xsk_tx_list_lock, flags);
46 list_del_rcu(&xs->list);
47 spin_unlock_irqrestore(&umem->xsk_tx_list_lock, flags);
48}
49
50
51
52
53
54static int xdp_reg_umem_at_qid(struct net_device *dev, struct xdp_umem *umem,
55 u16 queue_id)
56{
57 if (queue_id >= max_t(unsigned int,
58 dev->real_num_rx_queues,
59 dev->real_num_tx_queues))
60 return -EINVAL;
61
62 if (queue_id < dev->real_num_rx_queues)
63 dev->_rx[queue_id].umem = umem;
64 if (queue_id < dev->real_num_tx_queues)
65 dev->_tx[queue_id].umem = umem;
66
67 return 0;
68}
69
70struct xdp_umem *xdp_get_umem_from_qid(struct net_device *dev,
71 u16 queue_id)
72{
73 if (queue_id < dev->real_num_rx_queues)
74 return dev->_rx[queue_id].umem;
75 if (queue_id < dev->real_num_tx_queues)
76 return dev->_tx[queue_id].umem;
77
78 return NULL;
79}
80EXPORT_SYMBOL(xdp_get_umem_from_qid);
81
82static void xdp_clear_umem_at_qid(struct net_device *dev, u16 queue_id)
83{
84 if (queue_id < dev->real_num_rx_queues)
85 dev->_rx[queue_id].umem = NULL;
86 if (queue_id < dev->real_num_tx_queues)
87 dev->_tx[queue_id].umem = NULL;
88}
89
90int xdp_umem_assign_dev(struct xdp_umem *umem, struct net_device *dev,
91 u16 queue_id, u16 flags)
92{
93 bool force_zc, force_copy;
94 struct netdev_bpf bpf;
95 int err = 0;
96
97 ASSERT_RTNL();
98
99 force_zc = flags & XDP_ZEROCOPY;
100 force_copy = flags & XDP_COPY;
101
102 if (force_zc && force_copy)
103 return -EINVAL;
104
105 if (xdp_get_umem_from_qid(dev, queue_id))
106 return -EBUSY;
107
108 err = xdp_reg_umem_at_qid(dev, umem, queue_id);
109 if (err)
110 return err;
111
112 umem->dev = dev;
113 umem->queue_id = queue_id;
114
115 if (flags & XDP_USE_NEED_WAKEUP) {
116 umem->flags |= XDP_UMEM_USES_NEED_WAKEUP;
117
118
119
120
121 xsk_set_tx_need_wakeup(umem);
122 }
123
124 dev_hold(dev);
125
126 if (force_copy)
127
128 return 0;
129
130 if (!dev->netdev_ops->ndo_bpf || !dev->netdev_ops->ndo_xsk_wakeup) {
131 err = -EOPNOTSUPP;
132 goto err_unreg_umem;
133 }
134
135 bpf.command = XDP_SETUP_XSK_UMEM;
136 bpf.xsk.umem = umem;
137 bpf.xsk.queue_id = queue_id;
138
139 err = dev->netdev_ops->ndo_bpf(dev, &bpf);
140 if (err)
141 goto err_unreg_umem;
142
143 umem->zc = true;
144 return 0;
145
146err_unreg_umem:
147 if (!force_zc)
148 err = 0;
149 if (err)
150 xdp_clear_umem_at_qid(dev, queue_id);
151 return err;
152}
153
154void xdp_umem_clear_dev(struct xdp_umem *umem)
155{
156 struct netdev_bpf bpf;
157 int err;
158
159 ASSERT_RTNL();
160
161 if (!umem->dev)
162 return;
163
164 if (umem->zc) {
165 bpf.command = XDP_SETUP_XSK_UMEM;
166 bpf.xsk.umem = NULL;
167 bpf.xsk.queue_id = umem->queue_id;
168
169 err = umem->dev->netdev_ops->ndo_bpf(umem->dev, &bpf);
170
171 if (err)
172 WARN(1, "failed to disable umem!\n");
173 }
174
175 xdp_clear_umem_at_qid(umem->dev, umem->queue_id);
176
177 dev_put(umem->dev);
178 umem->dev = NULL;
179 umem->zc = false;
180}
181
182static void xdp_umem_unpin_pages(struct xdp_umem *umem)
183{
184 unpin_user_pages_dirty_lock(umem->pgs, umem->npgs, true);
185
186 kfree(umem->pgs);
187 umem->pgs = NULL;
188}
189
190static void xdp_umem_unaccount_pages(struct xdp_umem *umem)
191{
192 if (umem->user) {
193 atomic_long_sub(umem->npgs, &umem->user->locked_vm);
194 free_uid(umem->user);
195 }
196}
197
198static void xdp_umem_release(struct xdp_umem *umem)
199{
200 rtnl_lock();
201 xdp_umem_clear_dev(umem);
202 rtnl_unlock();
203
204 ida_simple_remove(&umem_ida, umem->id);
205
206 if (umem->fq) {
207 xskq_destroy(umem->fq);
208 umem->fq = NULL;
209 }
210
211 if (umem->cq) {
212 xskq_destroy(umem->cq);
213 umem->cq = NULL;
214 }
215
216 xp_destroy(umem->pool);
217 xdp_umem_unpin_pages(umem);
218
219 xdp_umem_unaccount_pages(umem);
220 kfree(umem);
221}
222
223static void xdp_umem_release_deferred(struct work_struct *work)
224{
225 struct xdp_umem *umem = container_of(work, struct xdp_umem, work);
226
227 xdp_umem_release(umem);
228}
229
230void xdp_get_umem(struct xdp_umem *umem)
231{
232 refcount_inc(&umem->users);
233}
234
235void xdp_put_umem(struct xdp_umem *umem)
236{
237 if (!umem)
238 return;
239
240 if (refcount_dec_and_test(&umem->users)) {
241 INIT_WORK(&umem->work, xdp_umem_release_deferred);
242 schedule_work(&umem->work);
243 }
244}
245
246static int xdp_umem_pin_pages(struct xdp_umem *umem, unsigned long address)
247{
248 unsigned int gup_flags = FOLL_WRITE;
249 long npgs;
250 int err;
251
252 umem->pgs = kcalloc(umem->npgs, sizeof(*umem->pgs),
253 GFP_KERNEL | __GFP_NOWARN);
254 if (!umem->pgs)
255 return -ENOMEM;
256
257 mmap_read_lock(current->mm);
258 npgs = pin_user_pages(address, umem->npgs,
259 gup_flags | FOLL_LONGTERM, &umem->pgs[0], NULL);
260 mmap_read_unlock(current->mm);
261
262 if (npgs != umem->npgs) {
263 if (npgs >= 0) {
264 umem->npgs = npgs;
265 err = -ENOMEM;
266 goto out_pin;
267 }
268 err = npgs;
269 goto out_pgs;
270 }
271 return 0;
272
273out_pin:
274 xdp_umem_unpin_pages(umem);
275out_pgs:
276 kfree(umem->pgs);
277 umem->pgs = NULL;
278 return err;
279}
280
281static int xdp_umem_account_pages(struct xdp_umem *umem)
282{
283 unsigned long lock_limit, new_npgs, old_npgs;
284
285 if (capable(CAP_IPC_LOCK))
286 return 0;
287
288 lock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
289 umem->user = get_uid(current_user());
290
291 do {
292 old_npgs = atomic_long_read(&umem->user->locked_vm);
293 new_npgs = old_npgs + umem->npgs;
294 if (new_npgs > lock_limit) {
295 free_uid(umem->user);
296 umem->user = NULL;
297 return -ENOBUFS;
298 }
299 } while (atomic_long_cmpxchg(&umem->user->locked_vm, old_npgs,
300 new_npgs) != old_npgs);
301 return 0;
302}
303
304static int xdp_umem_reg(struct xdp_umem *umem, struct xdp_umem_reg *mr)
305{
306 u32 npgs_rem, chunk_size = mr->chunk_size, headroom = mr->headroom;
307 bool unaligned_chunks = mr->flags & XDP_UMEM_UNALIGNED_CHUNK_FLAG;
308 u64 npgs, addr = mr->addr, size = mr->len;
309 unsigned int chunks, chunks_rem;
310 int err;
311
312 if (chunk_size < XDP_UMEM_MIN_CHUNK_SIZE || chunk_size > PAGE_SIZE) {
313
314
315
316
317
318
319 return -EINVAL;
320 }
321
322 if (mr->flags & ~(XDP_UMEM_UNALIGNED_CHUNK_FLAG |
323 XDP_UMEM_USES_NEED_WAKEUP))
324 return -EINVAL;
325
326 if (!unaligned_chunks && !is_power_of_2(chunk_size))
327 return -EINVAL;
328
329 if (!PAGE_ALIGNED(addr)) {
330
331
332
333 return -EINVAL;
334 }
335
336 if ((addr + size) < addr)
337 return -EINVAL;
338
339 npgs = div_u64_rem(size, PAGE_SIZE, &npgs_rem);
340 if (npgs_rem)
341 npgs++;
342 if (npgs > U32_MAX)
343 return -EINVAL;
344
345 chunks = (unsigned int)div_u64_rem(size, chunk_size, &chunks_rem);
346 if (chunks == 0)
347 return -EINVAL;
348
349 if (!unaligned_chunks && chunks_rem)
350 return -EINVAL;
351
352 if (headroom >= chunk_size - XDP_PACKET_HEADROOM)
353 return -EINVAL;
354
355 umem->size = size;
356 umem->headroom = headroom;
357 umem->chunk_size = chunk_size;
358 umem->npgs = (u32)npgs;
359 umem->pgs = NULL;
360 umem->user = NULL;
361 umem->flags = mr->flags;
362 INIT_LIST_HEAD(&umem->xsk_tx_list);
363 spin_lock_init(&umem->xsk_tx_list_lock);
364
365 refcount_set(&umem->users, 1);
366
367 err = xdp_umem_account_pages(umem);
368 if (err)
369 return err;
370
371 err = xdp_umem_pin_pages(umem, (unsigned long)addr);
372 if (err)
373 goto out_account;
374
375 umem->pool = xp_create(umem->pgs, umem->npgs, chunks, chunk_size,
376 headroom, size, unaligned_chunks);
377 if (!umem->pool) {
378 err = -ENOMEM;
379 goto out_pin;
380 }
381 return 0;
382
383out_pin:
384 xdp_umem_unpin_pages(umem);
385out_account:
386 xdp_umem_unaccount_pages(umem);
387 return err;
388}
389
390struct xdp_umem *xdp_umem_create(struct xdp_umem_reg *mr)
391{
392 struct xdp_umem *umem;
393 int err;
394
395 umem = kzalloc(sizeof(*umem), GFP_KERNEL);
396 if (!umem)
397 return ERR_PTR(-ENOMEM);
398
399 err = ida_simple_get(&umem_ida, 0, 0, GFP_KERNEL);
400 if (err < 0) {
401 kfree(umem);
402 return ERR_PTR(err);
403 }
404 umem->id = err;
405
406 err = xdp_umem_reg(umem, mr);
407 if (err) {
408 ida_simple_remove(&umem_ida, umem->id);
409 kfree(umem);
410 return ERR_PTR(err);
411 }
412
413 return umem;
414}
415
416bool xdp_umem_validate_queues(struct xdp_umem *umem)
417{
418 return umem->fq && umem->cq;
419}
420
