Bootlin logo

Elixir Cross Referencer

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
/*
 * Copyright (C) 2017-2018 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/bpf.h>
#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/jiffies.h>
#include <linux/skbuff.h>
#include <linux/wait.h>

#include "../nfp_app.h"
#include "../nfp_net.h"
#include "fw.h"
#include "main.h"

#define NFP_BPF_TAG_ALLOC_SPAN	(U16_MAX / 4)

static bool nfp_bpf_all_tags_busy(struct nfp_app_bpf *bpf)
{
	u16 used_tags;

	used_tags = bpf->tag_alloc_next - bpf->tag_alloc_last;

	return used_tags > NFP_BPF_TAG_ALLOC_SPAN;
}

static int nfp_bpf_alloc_tag(struct nfp_app_bpf *bpf)
{
	/* All FW communication for BPF is request-reply.  To make sure we
	 * don't reuse the message ID too early after timeout - limit the
	 * number of requests in flight.
	 */
	if (nfp_bpf_all_tags_busy(bpf)) {
		cmsg_warn(bpf, "all FW request contexts busy!\n");
		return -EAGAIN;
	}

	WARN_ON(__test_and_set_bit(bpf->tag_alloc_next, bpf->tag_allocator));
	return bpf->tag_alloc_next++;
}

static void nfp_bpf_free_tag(struct nfp_app_bpf *bpf, u16 tag)
{
	WARN_ON(!__test_and_clear_bit(tag, bpf->tag_allocator));

	while (!test_bit(bpf->tag_alloc_last, bpf->tag_allocator) &&
	       bpf->tag_alloc_last != bpf->tag_alloc_next)
		bpf->tag_alloc_last++;
}

static struct sk_buff *
nfp_bpf_cmsg_alloc(struct nfp_app_bpf *bpf, unsigned int size)
{
	struct sk_buff *skb;

	skb = nfp_app_ctrl_msg_alloc(bpf->app, size, GFP_KERNEL);
	skb_put(skb, size);

	return skb;
}

static struct sk_buff *
nfp_bpf_cmsg_map_req_alloc(struct nfp_app_bpf *bpf, unsigned int n)
{
	unsigned int size;

	size = sizeof(struct cmsg_req_map_op);
	size += sizeof(struct cmsg_key_value_pair) * n;

	return nfp_bpf_cmsg_alloc(bpf, size);
}

static u8 nfp_bpf_cmsg_get_type(struct sk_buff *skb)
{
	struct cmsg_hdr *hdr;

	hdr = (struct cmsg_hdr *)skb->data;

	return hdr->type;
}

static unsigned int nfp_bpf_cmsg_get_tag(struct sk_buff *skb)
{
	struct cmsg_hdr *hdr;

	hdr = (struct cmsg_hdr *)skb->data;

	return be16_to_cpu(hdr->tag);
}

static struct sk_buff *__nfp_bpf_reply(struct nfp_app_bpf *bpf, u16 tag)
{
	unsigned int msg_tag;
	struct sk_buff *skb;

	skb_queue_walk(&bpf->cmsg_replies, skb) {
		msg_tag = nfp_bpf_cmsg_get_tag(skb);
		if (msg_tag == tag) {
			nfp_bpf_free_tag(bpf, tag);
			__skb_unlink(skb, &bpf->cmsg_replies);
			return skb;
		}
	}

	return NULL;
}

static struct sk_buff *nfp_bpf_reply(struct nfp_app_bpf *bpf, u16 tag)
{
	struct sk_buff *skb;

	nfp_ctrl_lock(bpf->app->ctrl);
	skb = __nfp_bpf_reply(bpf, tag);
	nfp_ctrl_unlock(bpf->app->ctrl);

	return skb;
}

static struct sk_buff *nfp_bpf_reply_drop_tag(struct nfp_app_bpf *bpf, u16 tag)
{
	struct sk_buff *skb;

	nfp_ctrl_lock(bpf->app->ctrl);
	skb = __nfp_bpf_reply(bpf, tag);
	if (!skb)
		nfp_bpf_free_tag(bpf, tag);
	nfp_ctrl_unlock(bpf->app->ctrl);

	return skb;
}

static struct sk_buff *
nfp_bpf_cmsg_wait_reply(struct nfp_app_bpf *bpf, enum nfp_bpf_cmsg_type type,
			int tag)
{
	struct sk_buff *skb;
	int i, err;

	for (i = 0; i < 50; i++) {
		udelay(4);
		skb = nfp_bpf_reply(bpf, tag);
		if (skb)
			return skb;
	}

	err = wait_event_interruptible_timeout(bpf->cmsg_wq,
					       skb = nfp_bpf_reply(bpf, tag),
					       msecs_to_jiffies(5000));
	/* We didn't get a response - try last time and atomically drop
	 * the tag even if no response is matched.
	 */
	if (!skb)
		skb = nfp_bpf_reply_drop_tag(bpf, tag);
	if (err < 0) {
		cmsg_warn(bpf, "%s waiting for response to 0x%02x: %d\n",
			  err == ERESTARTSYS ? "interrupted" : "error",
			  type, err);
		return ERR_PTR(err);
	}
	if (!skb) {
		cmsg_warn(bpf, "timeout waiting for response to 0x%02x\n",
			  type);
		return ERR_PTR(-ETIMEDOUT);
	}

	return skb;
}

static struct sk_buff *
nfp_bpf_cmsg_communicate(struct nfp_app_bpf *bpf, struct sk_buff *skb,
			 enum nfp_bpf_cmsg_type type, unsigned int reply_size)
{
	struct cmsg_hdr *hdr;
	int tag;

	nfp_ctrl_lock(bpf->app->ctrl);
	tag = nfp_bpf_alloc_tag(bpf);
	if (tag < 0) {
		nfp_ctrl_unlock(bpf->app->ctrl);
		dev_kfree_skb_any(skb);
		return ERR_PTR(tag);
	}

	hdr = (void *)skb->data;
	hdr->ver = CMSG_MAP_ABI_VERSION;
	hdr->type = type;
	hdr->tag = cpu_to_be16(tag);

	__nfp_app_ctrl_tx(bpf->app, skb);

	nfp_ctrl_unlock(bpf->app->ctrl);

	skb = nfp_bpf_cmsg_wait_reply(bpf, type, tag);
	if (IS_ERR(skb))
		return skb;

	hdr = (struct cmsg_hdr *)skb->data;
	if (hdr->type != __CMSG_REPLY(type)) {
		cmsg_warn(bpf, "cmsg drop - wrong type 0x%02x != 0x%02lx!\n",
			  hdr->type, __CMSG_REPLY(type));
		goto err_free;
	}
	/* 0 reply_size means caller will do the validation */
	if (reply_size && skb->len != reply_size) {
		cmsg_warn(bpf, "cmsg drop - type 0x%02x wrong size %d != %d!\n",
			  type, skb->len, reply_size);
		goto err_free;
	}

	return skb;
err_free:
	dev_kfree_skb_any(skb);
	return ERR_PTR(-EIO);
}

static int
nfp_bpf_ctrl_rc_to_errno(struct nfp_app_bpf *bpf,
			 struct cmsg_reply_map_simple *reply)
{
	static const int res_table[] = {
		[CMSG_RC_SUCCESS]	= 0,
		[CMSG_RC_ERR_MAP_FD]	= -EBADFD,
		[CMSG_RC_ERR_MAP_NOENT]	= -ENOENT,
		[CMSG_RC_ERR_MAP_ERR]	= -EINVAL,
		[CMSG_RC_ERR_MAP_PARSE]	= -EIO,
		[CMSG_RC_ERR_MAP_EXIST]	= -EEXIST,
		[CMSG_RC_ERR_MAP_NOMEM]	= -ENOMEM,
		[CMSG_RC_ERR_MAP_E2BIG]	= -E2BIG,
	};
	u32 rc;

	rc = be32_to_cpu(reply->rc);
	if (rc >= ARRAY_SIZE(res_table)) {
		cmsg_warn(bpf, "FW responded with invalid status: %u\n", rc);
		return -EIO;
	}

	return res_table[rc];
}

long long int
nfp_bpf_ctrl_alloc_map(struct nfp_app_bpf *bpf, struct bpf_map *map)
{
	struct cmsg_reply_map_alloc_tbl *reply;
	struct cmsg_req_map_alloc_tbl *req;
	struct sk_buff *skb;
	u32 tid;
	int err;

	skb = nfp_bpf_cmsg_alloc(bpf, sizeof(*req));
	if (!skb)
		return -ENOMEM;

	req = (void *)skb->data;
	req->key_size = cpu_to_be32(map->key_size);
	req->value_size = cpu_to_be32(map->value_size);
	req->max_entries = cpu_to_be32(map->max_entries);
	req->map_type = cpu_to_be32(map->map_type);
	req->map_flags = 0;

	skb = nfp_bpf_cmsg_communicate(bpf, skb, CMSG_TYPE_MAP_ALLOC,
				       sizeof(*reply));
	if (IS_ERR(skb))
		return PTR_ERR(skb);

	reply = (void *)skb->data;
	err = nfp_bpf_ctrl_rc_to_errno(bpf, &reply->reply_hdr);
	if (err)
		goto err_free;

	tid = be32_to_cpu(reply->tid);
	dev_consume_skb_any(skb);

	return tid;
err_free:
	dev_kfree_skb_any(skb);
	return err;
}

void nfp_bpf_ctrl_free_map(struct nfp_app_bpf *bpf, struct nfp_bpf_map *nfp_map)
{
	struct cmsg_reply_map_free_tbl *reply;
	struct cmsg_req_map_free_tbl *req;
	struct sk_buff *skb;
	int err;

	skb = nfp_bpf_cmsg_alloc(bpf, sizeof(*req));
	if (!skb) {
		cmsg_warn(bpf, "leaking map - failed to allocate msg\n");
		return;
	}

	req = (void *)skb->data;
	req->tid = cpu_to_be32(nfp_map->tid);

	skb = nfp_bpf_cmsg_communicate(bpf, skb, CMSG_TYPE_MAP_FREE,
				       sizeof(*reply));
	if (IS_ERR(skb)) {
		cmsg_warn(bpf, "leaking map - I/O error\n");
		return;
	}

	reply = (void *)skb->data;
	err = nfp_bpf_ctrl_rc_to_errno(bpf, &reply->reply_hdr);
	if (err)
		cmsg_warn(bpf, "leaking map - FW responded with: %d\n", err);

	dev_consume_skb_any(skb);
}

static int
nfp_bpf_ctrl_entry_op(struct bpf_offloaded_map *offmap,
		      enum nfp_bpf_cmsg_type op,
		      u8 *key, u8 *value, u64 flags, u8 *out_key, u8 *out_value)
{
	struct nfp_bpf_map *nfp_map = offmap->dev_priv;
	struct nfp_app_bpf *bpf = nfp_map->bpf;
	struct bpf_map *map = &offmap->map;
	struct cmsg_reply_map_op *reply;
	struct cmsg_req_map_op *req;
	struct sk_buff *skb;
	int err;

	/* FW messages have no space for more than 32 bits of flags */
	if (flags >> 32)
		return -EOPNOTSUPP;

	skb = nfp_bpf_cmsg_map_req_alloc(bpf, 1);
	if (!skb)
		return -ENOMEM;

	req = (void *)skb->data;
	req->tid = cpu_to_be32(nfp_map->tid);
	req->count = cpu_to_be32(1);
	req->flags = cpu_to_be32(flags);

	/* Copy inputs */
	if (key)
		memcpy(&req->elem[0].key, key, map->key_size);
	if (value)
		memcpy(&req->elem[0].value, value, map->value_size);

	skb = nfp_bpf_cmsg_communicate(bpf, skb, op,
				       sizeof(*reply) + sizeof(*reply->elem));
	if (IS_ERR(skb))
		return PTR_ERR(skb);

	reply = (void *)skb->data;
	err = nfp_bpf_ctrl_rc_to_errno(bpf, &reply->reply_hdr);
	if (err)
		goto err_free;

	/* Copy outputs */
	if (out_key)
		memcpy(out_key, &reply->elem[0].key, map->key_size);
	if (out_value)
		memcpy(out_value, &reply->elem[0].value, map->value_size);

	dev_consume_skb_any(skb);

	return 0;
err_free:
	dev_kfree_skb_any(skb);
	return err;
}

int nfp_bpf_ctrl_update_entry(struct bpf_offloaded_map *offmap,
			      void *key, void *value, u64 flags)
{
	return nfp_bpf_ctrl_entry_op(offmap, CMSG_TYPE_MAP_UPDATE,
				     key, value, flags, NULL, NULL);
}

int nfp_bpf_ctrl_del_entry(struct bpf_offloaded_map *offmap, void *key)
{
	return nfp_bpf_ctrl_entry_op(offmap, CMSG_TYPE_MAP_DELETE,
				     key, NULL, 0, NULL, NULL);
}

int nfp_bpf_ctrl_lookup_entry(struct bpf_offloaded_map *offmap,
			      void *key, void *value)
{
	return nfp_bpf_ctrl_entry_op(offmap, CMSG_TYPE_MAP_LOOKUP,
				     key, NULL, 0, NULL, value);
}

int nfp_bpf_ctrl_getfirst_entry(struct bpf_offloaded_map *offmap,
				void *next_key)
{
	return nfp_bpf_ctrl_entry_op(offmap, CMSG_TYPE_MAP_GETFIRST,
				     NULL, NULL, 0, next_key, NULL);
}

int nfp_bpf_ctrl_getnext_entry(struct bpf_offloaded_map *offmap,
			       void *key, void *next_key)
{
	return nfp_bpf_ctrl_entry_op(offmap, CMSG_TYPE_MAP_GETNEXT,
				     key, NULL, 0, next_key, NULL);
}

void nfp_bpf_ctrl_msg_rx(struct nfp_app *app, struct sk_buff *skb)
{
	struct nfp_app_bpf *bpf = app->priv;
	unsigned int tag;

	if (unlikely(skb->len < sizeof(struct cmsg_reply_map_simple))) {
		cmsg_warn(bpf, "cmsg drop - too short %d!\n", skb->len);
		goto err_free;
	}

	if (nfp_bpf_cmsg_get_type(skb) == CMSG_TYPE_BPF_EVENT) {
		if (!nfp_bpf_event_output(bpf, skb->data, skb->len))
			dev_consume_skb_any(skb);
		else
			dev_kfree_skb_any(skb);
		return;
	}

	nfp_ctrl_lock(bpf->app->ctrl);

	tag = nfp_bpf_cmsg_get_tag(skb);
	if (unlikely(!test_bit(tag, bpf->tag_allocator))) {
		cmsg_warn(bpf, "cmsg drop - no one is waiting for tag %u!\n",
			  tag);
		goto err_unlock;
	}

	__skb_queue_tail(&bpf->cmsg_replies, skb);
	wake_up_interruptible_all(&bpf->cmsg_wq);

	nfp_ctrl_unlock(bpf->app->ctrl);

	return;
err_unlock:
	nfp_ctrl_unlock(bpf->app->ctrl);
err_free:
	dev_kfree_skb_any(skb);
}

void
nfp_bpf_ctrl_msg_rx_raw(struct nfp_app *app, const void *data, unsigned int len)
{
	struct nfp_app_bpf *bpf = app->priv;
	const struct cmsg_hdr *hdr = data;

	if (unlikely(len < sizeof(struct cmsg_reply_map_simple))) {
		cmsg_warn(bpf, "cmsg drop - too short %d!\n", len);
		return;
	}

	if (hdr->type == CMSG_TYPE_BPF_EVENT)
		nfp_bpf_event_output(bpf, data, len);
	else
		cmsg_warn(bpf, "cmsg drop - msg type %d with raw buffer!\n",
			  hdr->type);
}