summaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/netronome/nfp/bpf/offload.c
blob: 06927ba5a3ae03611bc8effafea03b9601654a75 (plain)
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
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2016-2018 Netronome Systems, Inc. */

/*
 * nfp_net_offload.c
 * Netronome network device driver: TC offload functions for PF and VF
 */

#define pr_fmt(fmt)	"NFP net bpf: " fmt

#include <linux/bpf.h>
#include <linux/kernel.h>
#include <linux/netdevice.h>
#include <linux/pci.h>
#include <linux/jiffies.h>
#include <linux/timer.h>
#include <linux/list.h>
#include <linux/mm.h>

#include <net/pkt_cls.h>
#include <net/tc_act/tc_gact.h>
#include <net/tc_act/tc_mirred.h>

#include "main.h"
#include "../ccm.h"
#include "../nfp_app.h"
#include "../nfp_net_ctrl.h"
#include "../nfp_net.h"

static int
nfp_map_ptr_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog,
		   struct bpf_map *map)
{
	struct nfp_bpf_neutral_map *record;
	int err;

	/* Reuse path - other offloaded program is already tracking this map. */
	record = rhashtable_lookup_fast(&bpf->maps_neutral, &map->id,
					nfp_bpf_maps_neutral_params);
	if (record) {
		nfp_prog->map_records[nfp_prog->map_records_cnt++] = record;
		record->count++;
		return 0;
	}

	/* Grab a single ref to the map for our record.  The prog destroy ndo
	 * happens after free_used_maps().
	 */
	bpf_map_inc(map);

	record = kmalloc(sizeof(*record), GFP_KERNEL);
	if (!record) {
		err = -ENOMEM;
		goto err_map_put;
	}

	record->ptr = map;
	record->map_id = map->id;
	record->count = 1;

	err = rhashtable_insert_fast(&bpf->maps_neutral, &record->l,
				     nfp_bpf_maps_neutral_params);
	if (err)
		goto err_free_rec;

	nfp_prog->map_records[nfp_prog->map_records_cnt++] = record;

	return 0;

err_free_rec:
	kfree(record);
err_map_put:
	bpf_map_put(map);
	return err;
}

static void
nfp_map_ptrs_forget(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog)
{
	bool freed = false;
	int i;

	for (i = 0; i < nfp_prog->map_records_cnt; i++) {
		if (--nfp_prog->map_records[i]->count) {
			nfp_prog->map_records[i] = NULL;
			continue;
		}

		WARN_ON(rhashtable_remove_fast(&bpf->maps_neutral,
					       &nfp_prog->map_records[i]->l,
					       nfp_bpf_maps_neutral_params));
		freed = true;
	}

	if (freed) {
		synchronize_rcu();

		for (i = 0; i < nfp_prog->map_records_cnt; i++)
			if (nfp_prog->map_records[i]) {
				bpf_map_put(nfp_prog->map_records[i]->ptr);
				kfree(nfp_prog->map_records[i]);
			}
	}

	kfree(nfp_prog->map_records);
	nfp_prog->map_records = NULL;
	nfp_prog->map_records_cnt = 0;
}

static int
nfp_map_ptrs_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog,
		    struct bpf_prog *prog)
{
	int i, cnt, err;

	/* Quickly count the maps we will have to remember */
	cnt = 0;
	for (i = 0; i < prog->aux->used_map_cnt; i++)
		if (bpf_map_offload_neutral(prog->aux->used_maps[i]))
			cnt++;
	if (!cnt)
		return 0;

	nfp_prog->map_records = kmalloc_array(cnt,
					      sizeof(nfp_prog->map_records[0]),
					      GFP_KERNEL);
	if (!nfp_prog->map_records)
		return -ENOMEM;

	for (i = 0; i < prog->aux->used_map_cnt; i++)
		if (bpf_map_offload_neutral(prog->aux->used_maps[i])) {
			err = nfp_map_ptr_record(bpf, nfp_prog,
						 prog->aux->used_maps[i]);
			if (err) {
				nfp_map_ptrs_forget(bpf, nfp_prog);
				return err;
			}
		}
	WARN_ON(cnt != nfp_prog->map_records_cnt);

	return 0;
}

static int
nfp_prog_prepare(struct nfp_prog *nfp_prog, const struct bpf_insn *prog,
		 unsigned int cnt)
{
	struct nfp_insn_meta *meta;
	unsigned int i;

	for (i = 0; i < cnt; i++) {
		meta = kzalloc(sizeof(*meta), GFP_KERNEL);
		if (!meta)
			return -ENOMEM;

		meta->insn = prog[i];
		meta->n = i;
		if (is_mbpf_alu(meta)) {
			meta->umin_src = U64_MAX;
			meta->umin_dst = U64_MAX;
		}

		list_add_tail(&meta->l, &nfp_prog->insns);
	}
	nfp_prog->n_insns = cnt;

	nfp_bpf_jit_prepare(nfp_prog);

	return 0;
}

static void nfp_prog_free(struct nfp_prog *nfp_prog)
{
	struct nfp_insn_meta *meta, *tmp;

	kfree(nfp_prog->subprog);

	list_for_each_entry_safe(meta, tmp, &nfp_prog->insns, l) {
		list_del(&meta->l);
		kfree(meta);
	}
	kfree(nfp_prog);
}

static int nfp_bpf_verifier_prep(struct bpf_prog *prog)
{
	struct nfp_prog *nfp_prog;
	int ret;

	nfp_prog = kzalloc(sizeof(*nfp_prog), GFP_KERNEL);
	if (!nfp_prog)
		return -ENOMEM;
	prog->aux->offload->dev_priv = nfp_prog;

	INIT_LIST_HEAD(&nfp_prog->insns);
	nfp_prog->type = prog->type;
	nfp_prog->bpf = bpf_offload_dev_priv(prog->aux->offload->offdev);

	ret = nfp_prog_prepare(nfp_prog, prog->insnsi, prog->len);
	if (ret)
		goto err_free;

	nfp_prog->verifier_meta = nfp_prog_first_meta(nfp_prog);

	return 0;

err_free:
	nfp_prog_free(nfp_prog);

	return ret;
}

static int nfp_bpf_translate(struct bpf_prog *prog)
{
	struct nfp_net *nn = netdev_priv(prog->aux->offload->netdev);
	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
	unsigned int max_instr;
	int err;

	/* We depend on dead code elimination succeeding */
	if (prog->aux->offload->opt_failed)
		return -EINVAL;

	max_instr = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
	nfp_prog->__prog_alloc_len = max_instr * sizeof(u64);

	nfp_prog->prog = kvmalloc(nfp_prog->__prog_alloc_len, GFP_KERNEL);
	if (!nfp_prog->prog)
		return -ENOMEM;

	err = nfp_bpf_jit(nfp_prog);
	if (err)
		return err;

	prog->aux->offload->jited_len = nfp_prog->prog_len * sizeof(u64);
	prog->aux->offload->jited_image = nfp_prog->prog;

	return nfp_map_ptrs_record(nfp_prog->bpf, nfp_prog, prog);
}

static void nfp_bpf_destroy(struct bpf_prog *prog)
{
	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;

	kvfree(nfp_prog->prog);
	nfp_map_ptrs_forget(nfp_prog->bpf, nfp_prog);
	nfp_prog_free(nfp_prog);
}

/* Atomic engine requires values to be in big endian, we need to byte swap
 * the value words used with xadd.
 */
static void nfp_map_bpf_byte_swap(struct nfp_bpf_map *nfp_map, void *value)
{
	u32 *word = value;
	unsigned int i;

	for (i = 0; i < DIV_ROUND_UP(nfp_map->offmap->map.value_size, 4); i++)
		if (nfp_map->use_map[i].type == NFP_MAP_USE_ATOMIC_CNT)
			word[i] = (__force u32)cpu_to_be32(word[i]);
}

/* Mark value as unsafely initialized in case it becomes atomic later
 * and we didn't byte swap something non-byte swap neutral.
 */
static void
nfp_map_bpf_byte_swap_record(struct nfp_bpf_map *nfp_map, void *value)
{
	u32 *word = value;
	unsigned int i;

	for (i = 0; i < DIV_ROUND_UP(nfp_map->offmap->map.value_size, 4); i++)
		if (nfp_map->use_map[i].type == NFP_MAP_UNUSED &&
		    word[i] != (__force u32)cpu_to_be32(word[i]))
			nfp_map->use_map[i].non_zero_update = 1;
}

static int
nfp_bpf_map_lookup_entry(struct bpf_offloaded_map *offmap,
			 void *key, void *value)
{
	int err;

	err = nfp_bpf_ctrl_lookup_entry(offmap, key, value);
	if (err)
		return err;

	nfp_map_bpf_byte_swap(offmap->dev_priv, value);
	return 0;
}

static int
nfp_bpf_map_update_entry(struct bpf_offloaded_map *offmap,
			 void *key, void *value, u64 flags)
{
	nfp_map_bpf_byte_swap(offmap->dev_priv, value);
	nfp_map_bpf_byte_swap_record(offmap->dev_priv, value);
	return nfp_bpf_ctrl_update_entry(offmap, key, value, flags);
}

static int
nfp_bpf_map_get_next_key(struct bpf_offloaded_map *offmap,
			 void *key, void *next_key)
{
	if (!key)
		return nfp_bpf_ctrl_getfirst_entry(offmap, next_key);
	return nfp_bpf_ctrl_getnext_entry(offmap, key, next_key);
}

static int
nfp_bpf_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
{
	if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
		return -EINVAL;
	return nfp_bpf_ctrl_del_entry(offmap, key);
}

static const struct bpf_map_dev_ops nfp_bpf_map_ops = {
	.map_get_next_key	= nfp_bpf_map_get_next_key,
	.map_lookup_elem	= nfp_bpf_map_lookup_entry,
	.map_update_elem	= nfp_bpf_map_update_entry,
	.map_delete_elem	= nfp_bpf_map_delete_elem,
};

static int
nfp_bpf_map_alloc(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
{
	struct nfp_bpf_map *nfp_map;
	unsigned int use_map_size;
	long long int res;

	if (!bpf->maps.types)
		return -EOPNOTSUPP;

	if (offmap->map.map_flags ||
	    offmap->map.numa_node != NUMA_NO_NODE) {
		pr_info("map flags are not supported\n");
		return -EINVAL;
	}

	if (!(bpf->maps.types & 1 << offmap->map.map_type)) {
		pr_info("map type not supported\n");
		return -EOPNOTSUPP;
	}
	if (bpf->maps.max_maps == bpf->maps_in_use) {
		pr_info("too many maps for a device\n");
		return -ENOMEM;
	}
	if (bpf->maps.max_elems - bpf->map_elems_in_use <
	    offmap->map.max_entries) {
		pr_info("map with too many elements: %u, left: %u\n",
			offmap->map.max_entries,
			bpf->maps.max_elems - bpf->map_elems_in_use);
		return -ENOMEM;
	}

	if (round_up(offmap->map.key_size, 8) +
	    round_up(offmap->map.value_size, 8) > bpf->maps.max_elem_sz) {
		pr_info("map elements too large: %u, FW max element size (key+value): %u\n",
			round_up(offmap->map.key_size, 8) +
			round_up(offmap->map.value_size, 8),
			bpf->maps.max_elem_sz);
		return -ENOMEM;
	}
	if (offmap->map.key_size > bpf->maps.max_key_sz) {
		pr_info("map key size %u, FW max is %u\n",
			offmap->map.key_size, bpf->maps.max_key_sz);
		return -ENOMEM;
	}
	if (offmap->map.value_size > bpf->maps.max_val_sz) {
		pr_info("map value size %u, FW max is %u\n",
			offmap->map.value_size, bpf->maps.max_val_sz);
		return -ENOMEM;
	}

	use_map_size = DIV_ROUND_UP(offmap->map.value_size, 4) *
		       FIELD_SIZEOF(struct nfp_bpf_map, use_map[0]);

	nfp_map = kzalloc(sizeof(*nfp_map) + use_map_size, GFP_USER);
	if (!nfp_map)
		return -ENOMEM;

	offmap->dev_priv = nfp_map;
	nfp_map->offmap = offmap;
	nfp_map->bpf = bpf;
	spin_lock_init(&nfp_map->cache_lock);

	res = nfp_bpf_ctrl_alloc_map(bpf, &offmap->map);
	if (res < 0) {
		kfree(nfp_map);
		return res;
	}

	nfp_map->tid = res;
	offmap->dev_ops = &nfp_bpf_map_ops;
	bpf->maps_in_use++;
	bpf->map_elems_in_use += offmap->map.max_entries;
	list_add_tail(&nfp_map->l, &bpf->map_list);

	return 0;
}

static int
nfp_bpf_map_free(struct nfp_app_bpf *bpf, struct bpf_offloaded_map *offmap)
{
	struct nfp_bpf_map *nfp_map = offmap->dev_priv;

	nfp_bpf_ctrl_free_map(bpf, nfp_map);
	dev_consume_skb_any(nfp_map->cache);
	WARN_ON_ONCE(nfp_map->cache_blockers);
	list_del_init(&nfp_map->l);
	bpf->map_elems_in_use -= offmap->map.max_entries;
	bpf->maps_in_use--;
	kfree(nfp_map);

	return 0;
}

int nfp_ndo_bpf(struct nfp_app *app, struct nfp_net *nn, struct netdev_bpf *bpf)
{
	switch (bpf->command) {
	case BPF_OFFLOAD_MAP_ALLOC:
		return nfp_bpf_map_alloc(app->priv, bpf->offmap);
	case BPF_OFFLOAD_MAP_FREE:
		return nfp_bpf_map_free(app->priv, bpf->offmap);
	default:
		return -EINVAL;
	}
}

static unsigned long
nfp_bpf_perf_event_copy(void *dst, const void *src,
			unsigned long off, unsigned long len)
{
	memcpy(dst, src + off, len);
	return 0;
}

int nfp_bpf_event_output(struct nfp_app_bpf *bpf, const void *data,
			 unsigned int len)
{
	struct cmsg_bpf_event *cbe = (void *)data;
	struct nfp_bpf_neutral_map *record;
	u32 pkt_size, data_size, map_id;
	u64 map_id_full;

	if (len < sizeof(struct cmsg_bpf_event))
		return -EINVAL;

	pkt_size = be32_to_cpu(cbe->pkt_size);
	data_size = be32_to_cpu(cbe->data_size);
	map_id_full = be64_to_cpu(cbe->map_ptr);
	map_id = map_id_full;

	if (len < sizeof(struct cmsg_bpf_event) + pkt_size + data_size)
		return -EINVAL;
	if (cbe->hdr.ver != NFP_CCM_ABI_VERSION)
		return -EINVAL;

	rcu_read_lock();
	record = rhashtable_lookup_fast(&bpf->maps_neutral, &map_id,
					nfp_bpf_maps_neutral_params);
	if (!record || map_id_full > U32_MAX) {
		rcu_read_unlock();
		cmsg_warn(bpf, "perf event: map id %lld (0x%llx) not recognized, dropping event\n",
			  map_id_full, map_id_full);
		return -EINVAL;
	}

	bpf_event_output(record->ptr, be32_to_cpu(cbe->cpu_id),
			 &cbe->data[round_up(pkt_size, 4)], data_size,
			 cbe->data, pkt_size, nfp_bpf_perf_event_copy);
	rcu_read_unlock();

	return 0;
}

static int
nfp_net_bpf_load(struct nfp_net *nn, struct bpf_prog *prog,
		 struct netlink_ext_ack *extack)
{
	struct nfp_prog *nfp_prog = prog->aux->offload->dev_priv;
	unsigned int fw_mtu, pkt_off, max_stack, max_prog_len;
	dma_addr_t dma_addr;
	void *img;
	int err;

	fw_mtu = nn_readb(nn, NFP_NET_CFG_BPF_INL_MTU) * 64 - 32;
	pkt_off = min(prog->aux->max_pkt_offset, nn->dp.netdev->mtu);
	if (fw_mtu < pkt_off) {
		NL_SET_ERR_MSG_MOD(extack, "BPF offload not supported with potential packet access beyond HW packet split boundary");
		return -EOPNOTSUPP;
	}

	max_stack = nn_readb(nn, NFP_NET_CFG_BPF_STACK_SZ) * 64;
	if (nfp_prog->stack_size > max_stack) {
		NL_SET_ERR_MSG_MOD(extack, "stack too large");
		return -EOPNOTSUPP;
	}

	max_prog_len = nn_readw(nn, NFP_NET_CFG_BPF_MAX_LEN);
	if (nfp_prog->prog_len > max_prog_len) {
		NL_SET_ERR_MSG_MOD(extack, "program too long");
		return -EOPNOTSUPP;
	}

	img = nfp_bpf_relo_for_vnic(nfp_prog, nn->app_priv);
	if (IS_ERR(img))
		return PTR_ERR(img);

	dma_addr = dma_map_single(nn->dp.dev, img,
				  nfp_prog->prog_len * sizeof(u64),
				  DMA_TO_DEVICE);
	if (dma_mapping_error(nn->dp.dev, dma_addr)) {
		kfree(img);
		return -ENOMEM;
	}

	nn_writew(nn, NFP_NET_CFG_BPF_SIZE, nfp_prog->prog_len);
	nn_writeq(nn, NFP_NET_CFG_BPF_ADDR, dma_addr);

	/* Load up the JITed code */
	err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_BPF);
	if (err)
		NL_SET_ERR_MSG_MOD(extack,
				   "FW command error while loading BPF");

	dma_unmap_single(nn->dp.dev, dma_addr, nfp_prog->prog_len * sizeof(u64),
			 DMA_TO_DEVICE);
	kfree(img);

	return err;
}

static void
nfp_net_bpf_start(struct nfp_net *nn, struct netlink_ext_ack *extack)
{
	int err;

	/* Enable passing packets through BPF function */
	nn->dp.ctrl |= NFP_NET_CFG_CTRL_BPF;
	nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);
	err = nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
	if (err)
		NL_SET_ERR_MSG_MOD(extack,
				   "FW command error while enabling BPF");
}

static int nfp_net_bpf_stop(struct nfp_net *nn)
{
	if (!(nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF))
		return 0;

	nn->dp.ctrl &= ~NFP_NET_CFG_CTRL_BPF;
	nn_writel(nn, NFP_NET_CFG_CTRL, nn->dp.ctrl);

	return nfp_net_reconfig(nn, NFP_NET_CFG_UPDATE_GEN);
}

int nfp_net_bpf_offload(struct nfp_net *nn, struct bpf_prog *prog,
			bool old_prog, struct netlink_ext_ack *extack)
{
	int err;

	if (prog && !bpf_offload_dev_match(prog, nn->dp.netdev))
		return -EINVAL;

	if (prog && old_prog) {
		u8 cap;

		cap = nn_readb(nn, NFP_NET_CFG_BPF_CAP);
		if (!(cap & NFP_NET_BPF_CAP_RELO)) {
			NL_SET_ERR_MSG_MOD(extack,
					   "FW does not support live reload");
			return -EBUSY;
		}
	}

	/* Something else is loaded, different program type? */
	if (!old_prog && nn->dp.ctrl & NFP_NET_CFG_CTRL_BPF)
		return -EBUSY;

	if (old_prog && !prog)
		return nfp_net_bpf_stop(nn);

	err = nfp_net_bpf_load(nn, prog, extack);
	if (err)
		return err;

	if (!old_prog)
		nfp_net_bpf_start(nn, extack);

	return 0;
}

const struct bpf_prog_offload_ops nfp_bpf_dev_ops = {
	.insn_hook	= nfp_verify_insn,
	.finalize	= nfp_bpf_finalize,
	.replace_insn	= nfp_bpf_opt_replace_insn,
	.remove_insns	= nfp_bpf_opt_remove_insns,
	.prepare	= nfp_bpf_verifier_prep,
	.translate	= nfp_bpf_translate,
	.destroy	= nfp_bpf_destroy,
};