1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2018 Netronome Systems, Inc. */
3 
4 #include <linux/rtnetlink.h>
5 #include <net/pkt_cls.h>
6 #include <net/pkt_sched.h>
7 #include <net/red.h>
8 
9 #include "../nfpcore/nfp_cpp.h"
10 #include "../nfp_app.h"
11 #include "../nfp_main.h"
12 #include "../nfp_net.h"
13 #include "../nfp_port.h"
14 #include "main.h"
15 
16 static bool nfp_abm_qdisc_is_red(struct nfp_qdisc *qdisc)
17 {
18 	return qdisc->type == NFP_QDISC_RED || qdisc->type == NFP_QDISC_GRED;
19 }
20 
21 static bool nfp_abm_qdisc_child_valid(struct nfp_qdisc *qdisc, unsigned int id)
22 {
23 	return qdisc->children[id] &&
24 	       qdisc->children[id] != NFP_QDISC_UNTRACKED;
25 }
26 
27 static void *nfp_abm_qdisc_tree_deref_slot(void __rcu **slot)
28 {
29 	return rtnl_dereference(*slot);
30 }
31 
32 static void
33 nfp_abm_stats_propagate(struct nfp_alink_stats *parent,
34 			struct nfp_alink_stats *child)
35 {
36 	parent->tx_pkts		+= child->tx_pkts;
37 	parent->tx_bytes	+= child->tx_bytes;
38 	parent->backlog_pkts	+= child->backlog_pkts;
39 	parent->backlog_bytes	+= child->backlog_bytes;
40 	parent->overlimits	+= child->overlimits;
41 	parent->drops		+= child->drops;
42 }
43 
44 static void
45 nfp_abm_stats_update_red(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc,
46 			 unsigned int queue)
47 {
48 	struct nfp_cpp *cpp = alink->abm->app->cpp;
49 	unsigned int i;
50 	int err;
51 
52 	if (!qdisc->offloaded)
53 		return;
54 
55 	for (i = 0; i < qdisc->red.num_bands; i++) {
56 		err = nfp_abm_ctrl_read_q_stats(alink, i, queue,
57 						&qdisc->red.band[i].stats);
58 		if (err)
59 			nfp_err(cpp, "RED stats (%d, %d) read failed with error %d\n",
60 				i, queue, err);
61 
62 		err = nfp_abm_ctrl_read_q_xstats(alink, i, queue,
63 						 &qdisc->red.band[i].xstats);
64 		if (err)
65 			nfp_err(cpp, "RED xstats (%d, %d) read failed with error %d\n",
66 				i, queue, err);
67 	}
68 }
69 
70 static void
71 nfp_abm_stats_update_mq(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
72 {
73 	unsigned int i;
74 
75 	if (qdisc->type != NFP_QDISC_MQ)
76 		return;
77 
78 	for (i = 0; i < alink->total_queues; i++)
79 		if (nfp_abm_qdisc_child_valid(qdisc, i))
80 			nfp_abm_stats_update_red(alink, qdisc->children[i], i);
81 }
82 
83 static void __nfp_abm_stats_update(struct nfp_abm_link *alink, u64 time_now)
84 {
85 	alink->last_stats_update = time_now;
86 	if (alink->root_qdisc)
87 		nfp_abm_stats_update_mq(alink, alink->root_qdisc);
88 }
89 
90 static void nfp_abm_stats_update(struct nfp_abm_link *alink)
91 {
92 	u64 now;
93 
94 	/* Limit the frequency of updates - stats of non-leaf qdiscs are a sum
95 	 * of all their leafs, so we would read the same stat multiple times
96 	 * for every dump.
97 	 */
98 	now = ktime_get();
99 	if (now - alink->last_stats_update < NFP_ABM_STATS_REFRESH_IVAL)
100 		return;
101 
102 	__nfp_abm_stats_update(alink, now);
103 }
104 
105 static void
106 nfp_abm_qdisc_unlink_children(struct nfp_qdisc *qdisc,
107 			      unsigned int start, unsigned int end)
108 {
109 	unsigned int i;
110 
111 	for (i = start; i < end; i++)
112 		if (nfp_abm_qdisc_child_valid(qdisc, i)) {
113 			qdisc->children[i]->use_cnt--;
114 			qdisc->children[i] = NULL;
115 		}
116 }
117 
118 static void
119 nfp_abm_qdisc_offload_stop(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
120 {
121 	unsigned int i;
122 
123 	/* Don't complain when qdisc is getting unlinked */
124 	if (qdisc->use_cnt)
125 		nfp_warn(alink->abm->app->cpp, "Offload of '%08x' stopped\n",
126 			 qdisc->handle);
127 
128 	if (!nfp_abm_qdisc_is_red(qdisc))
129 		return;
130 
131 	for (i = 0; i < qdisc->red.num_bands; i++) {
132 		qdisc->red.band[i].stats.backlog_pkts = 0;
133 		qdisc->red.band[i].stats.backlog_bytes = 0;
134 	}
135 }
136 
137 static int
138 __nfp_abm_stats_init(struct nfp_abm_link *alink, unsigned int band,
139 		     unsigned int queue, struct nfp_alink_stats *prev_stats,
140 		     struct nfp_alink_xstats *prev_xstats)
141 {
142 	u64 backlog_pkts, backlog_bytes;
143 	int err;
144 
145 	/* Don't touch the backlog, backlog can only be reset after it has
146 	 * been reported back to the tc qdisc stats.
147 	 */
148 	backlog_pkts = prev_stats->backlog_pkts;
149 	backlog_bytes = prev_stats->backlog_bytes;
150 
151 	err = nfp_abm_ctrl_read_q_stats(alink, band, queue, prev_stats);
152 	if (err) {
153 		nfp_err(alink->abm->app->cpp,
154 			"RED stats init (%d, %d) failed with error %d\n",
155 			band, queue, err);
156 		return err;
157 	}
158 
159 	err = nfp_abm_ctrl_read_q_xstats(alink, band, queue, prev_xstats);
160 	if (err) {
161 		nfp_err(alink->abm->app->cpp,
162 			"RED xstats init (%d, %d) failed with error %d\n",
163 			band, queue, err);
164 		return err;
165 	}
166 
167 	prev_stats->backlog_pkts = backlog_pkts;
168 	prev_stats->backlog_bytes = backlog_bytes;
169 	return 0;
170 }
171 
172 static int
173 nfp_abm_stats_init(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc,
174 		   unsigned int queue)
175 {
176 	unsigned int i;
177 	int err;
178 
179 	for (i = 0; i < qdisc->red.num_bands; i++) {
180 		err = __nfp_abm_stats_init(alink, i, queue,
181 					   &qdisc->red.band[i].prev_stats,
182 					   &qdisc->red.band[i].prev_xstats);
183 		if (err)
184 			return err;
185 	}
186 
187 	return 0;
188 }
189 
190 static void
191 nfp_abm_offload_compile_red(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc,
192 			    unsigned int queue)
193 {
194 	bool good_red, good_gred;
195 	unsigned int i;
196 
197 	good_red = qdisc->type == NFP_QDISC_RED &&
198 		   qdisc->params_ok &&
199 		   qdisc->use_cnt == 1 &&
200 		   !alink->has_prio &&
201 		   !qdisc->children[0];
202 	good_gred = qdisc->type == NFP_QDISC_GRED &&
203 		    qdisc->params_ok &&
204 		    qdisc->use_cnt == 1;
205 	qdisc->offload_mark = good_red || good_gred;
206 
207 	/* If we are starting offload init prev_stats */
208 	if (qdisc->offload_mark && !qdisc->offloaded)
209 		if (nfp_abm_stats_init(alink, qdisc, queue))
210 			qdisc->offload_mark = false;
211 
212 	if (!qdisc->offload_mark)
213 		return;
214 
215 	for (i = 0; i < alink->abm->num_bands; i++)
216 		nfp_abm_ctrl_set_q_lvl(alink, i, queue,
217 				       qdisc->red.band[i].threshold);
218 }
219 
220 static void
221 nfp_abm_offload_compile_mq(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
222 {
223 	unsigned int i;
224 
225 	qdisc->offload_mark = qdisc->type == NFP_QDISC_MQ;
226 	if (!qdisc->offload_mark)
227 		return;
228 
229 	for (i = 0; i < alink->total_queues; i++) {
230 		struct nfp_qdisc *child = qdisc->children[i];
231 
232 		if (!nfp_abm_qdisc_child_valid(qdisc, i))
233 			continue;
234 
235 		nfp_abm_offload_compile_red(alink, child, i);
236 	}
237 }
238 
239 void nfp_abm_qdisc_offload_update(struct nfp_abm_link *alink)
240 {
241 	struct nfp_abm *abm = alink->abm;
242 	struct radix_tree_iter iter;
243 	struct nfp_qdisc *qdisc;
244 	void __rcu **slot;
245 	size_t i;
246 
247 	/* Mark all thresholds as unconfigured */
248 	for (i = 0; i < abm->num_bands; i++)
249 		__bitmap_set(abm->threshold_undef,
250 			     i * NFP_NET_MAX_RX_RINGS + alink->queue_base,
251 			     alink->total_queues);
252 
253 	/* Clear offload marks */
254 	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
255 		qdisc = nfp_abm_qdisc_tree_deref_slot(slot);
256 		qdisc->offload_mark = false;
257 	}
258 
259 	if (alink->root_qdisc)
260 		nfp_abm_offload_compile_mq(alink, alink->root_qdisc);
261 
262 	/* Refresh offload status */
263 	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
264 		qdisc = nfp_abm_qdisc_tree_deref_slot(slot);
265 		if (!qdisc->offload_mark && qdisc->offloaded)
266 			nfp_abm_qdisc_offload_stop(alink, qdisc);
267 		qdisc->offloaded = qdisc->offload_mark;
268 	}
269 
270 	/* Reset the unconfigured thresholds */
271 	for (i = 0; i < abm->num_thresholds; i++)
272 		if (test_bit(i, abm->threshold_undef))
273 			__nfp_abm_ctrl_set_q_lvl(abm, i, NFP_ABM_LVL_INFINITY);
274 
275 	__nfp_abm_stats_update(alink, ktime_get());
276 }
277 
278 static void
279 nfp_abm_qdisc_clear_mq(struct net_device *netdev, struct nfp_abm_link *alink,
280 		       struct nfp_qdisc *qdisc)
281 {
282 	struct radix_tree_iter iter;
283 	unsigned int mq_refs = 0;
284 	void __rcu **slot;
285 
286 	if (!qdisc->use_cnt)
287 		return;
288 	/* MQ doesn't notify well on destruction, we need special handling of
289 	 * MQ's children.
290 	 */
291 	if (qdisc->type == NFP_QDISC_MQ &&
292 	    qdisc == alink->root_qdisc &&
293 	    netdev->reg_state == NETREG_UNREGISTERING)
294 		return;
295 
296 	/* Count refs held by MQ instances and clear pointers */
297 	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
298 		struct nfp_qdisc *mq = nfp_abm_qdisc_tree_deref_slot(slot);
299 		unsigned int i;
300 
301 		if (mq->type != NFP_QDISC_MQ || mq->netdev != netdev)
302 			continue;
303 		for (i = 0; i < mq->num_children; i++)
304 			if (mq->children[i] == qdisc) {
305 				mq->children[i] = NULL;
306 				mq_refs++;
307 			}
308 	}
309 
310 	WARN(qdisc->use_cnt != mq_refs, "non-zero qdisc use count: %d (- %d)\n",
311 	     qdisc->use_cnt, mq_refs);
312 }
313 
314 static void
315 nfp_abm_qdisc_free(struct net_device *netdev, struct nfp_abm_link *alink,
316 		   struct nfp_qdisc *qdisc)
317 {
318 	struct nfp_port *port = nfp_port_from_netdev(netdev);
319 
320 	if (!qdisc)
321 		return;
322 	nfp_abm_qdisc_clear_mq(netdev, alink, qdisc);
323 	WARN_ON(radix_tree_delete(&alink->qdiscs,
324 				  TC_H_MAJ(qdisc->handle)) != qdisc);
325 
326 	kfree(qdisc->children);
327 	kfree(qdisc);
328 
329 	port->tc_offload_cnt--;
330 }
331 
332 static struct nfp_qdisc *
333 nfp_abm_qdisc_alloc(struct net_device *netdev, struct nfp_abm_link *alink,
334 		    enum nfp_qdisc_type type, u32 parent_handle, u32 handle,
335 		    unsigned int children)
336 {
337 	struct nfp_port *port = nfp_port_from_netdev(netdev);
338 	struct nfp_qdisc *qdisc;
339 	int err;
340 
341 	qdisc = kzalloc(sizeof(*qdisc), GFP_KERNEL);
342 	if (!qdisc)
343 		return NULL;
344 
345 	if (children) {
346 		qdisc->children = kcalloc(children, sizeof(void *), GFP_KERNEL);
347 		if (!qdisc->children)
348 			goto err_free_qdisc;
349 	}
350 
351 	qdisc->netdev = netdev;
352 	qdisc->type = type;
353 	qdisc->parent_handle = parent_handle;
354 	qdisc->handle = handle;
355 	qdisc->num_children = children;
356 
357 	err = radix_tree_insert(&alink->qdiscs, TC_H_MAJ(qdisc->handle), qdisc);
358 	if (err) {
359 		nfp_err(alink->abm->app->cpp,
360 			"Qdisc insertion into radix tree failed: %d\n", err);
361 		goto err_free_child_tbl;
362 	}
363 
364 	port->tc_offload_cnt++;
365 	return qdisc;
366 
367 err_free_child_tbl:
368 	kfree(qdisc->children);
369 err_free_qdisc:
370 	kfree(qdisc);
371 	return NULL;
372 }
373 
374 static struct nfp_qdisc *
375 nfp_abm_qdisc_find(struct nfp_abm_link *alink, u32 handle)
376 {
377 	return radix_tree_lookup(&alink->qdiscs, TC_H_MAJ(handle));
378 }
379 
380 static int
381 nfp_abm_qdisc_replace(struct net_device *netdev, struct nfp_abm_link *alink,
382 		      enum nfp_qdisc_type type, u32 parent_handle, u32 handle,
383 		      unsigned int children, struct nfp_qdisc **qdisc)
384 {
385 	*qdisc = nfp_abm_qdisc_find(alink, handle);
386 	if (*qdisc) {
387 		if (WARN_ON((*qdisc)->type != type))
388 			return -EINVAL;
389 		return 1;
390 	}
391 
392 	*qdisc = nfp_abm_qdisc_alloc(netdev, alink, type, parent_handle, handle,
393 				     children);
394 	return *qdisc ? 0 : -ENOMEM;
395 }
396 
397 static void
398 nfp_abm_qdisc_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
399 		      u32 handle)
400 {
401 	struct nfp_qdisc *qdisc;
402 
403 	qdisc = nfp_abm_qdisc_find(alink, handle);
404 	if (!qdisc)
405 		return;
406 
407 	/* We don't get TC_SETUP_ROOT_QDISC w/ MQ when netdev is unregistered */
408 	if (alink->root_qdisc == qdisc)
409 		qdisc->use_cnt--;
410 
411 	nfp_abm_qdisc_unlink_children(qdisc, 0, qdisc->num_children);
412 	nfp_abm_qdisc_free(netdev, alink, qdisc);
413 
414 	if (alink->root_qdisc == qdisc) {
415 		alink->root_qdisc = NULL;
416 		/* Only root change matters, other changes are acted upon on
417 		 * the graft notification.
418 		 */
419 		nfp_abm_qdisc_offload_update(alink);
420 	}
421 }
422 
423 static int
424 nfp_abm_qdisc_graft(struct nfp_abm_link *alink, u32 handle, u32 child_handle,
425 		    unsigned int id)
426 {
427 	struct nfp_qdisc *parent, *child;
428 
429 	parent = nfp_abm_qdisc_find(alink, handle);
430 	if (!parent)
431 		return 0;
432 
433 	if (WARN(id >= parent->num_children,
434 		 "graft child out of bound %d >= %d\n",
435 		 id, parent->num_children))
436 		return -EINVAL;
437 
438 	nfp_abm_qdisc_unlink_children(parent, id, id + 1);
439 
440 	child = nfp_abm_qdisc_find(alink, child_handle);
441 	if (child)
442 		child->use_cnt++;
443 	else
444 		child = NFP_QDISC_UNTRACKED;
445 	parent->children[id] = child;
446 
447 	nfp_abm_qdisc_offload_update(alink);
448 
449 	return 0;
450 }
451 
452 static void
453 nfp_abm_stats_calculate(struct nfp_alink_stats *new,
454 			struct nfp_alink_stats *old,
455 			struct gnet_stats_basic_packed *bstats,
456 			struct gnet_stats_queue *qstats)
457 {
458 	_bstats_update(bstats, new->tx_bytes - old->tx_bytes,
459 		       new->tx_pkts - old->tx_pkts);
460 	qstats->qlen += new->backlog_pkts - old->backlog_pkts;
461 	qstats->backlog += new->backlog_bytes - old->backlog_bytes;
462 	qstats->overlimits += new->overlimits - old->overlimits;
463 	qstats->drops += new->drops - old->drops;
464 }
465 
466 static void
467 nfp_abm_stats_red_calculate(struct nfp_alink_xstats *new,
468 			    struct nfp_alink_xstats *old,
469 			    struct red_stats *stats)
470 {
471 	stats->forced_mark += new->ecn_marked - old->ecn_marked;
472 	stats->pdrop += new->pdrop - old->pdrop;
473 }
474 
475 static int
476 nfp_abm_gred_stats(struct nfp_abm_link *alink, u32 handle,
477 		   struct tc_gred_qopt_offload_stats *stats)
478 {
479 	struct nfp_qdisc *qdisc;
480 	unsigned int i;
481 
482 	nfp_abm_stats_update(alink);
483 
484 	qdisc = nfp_abm_qdisc_find(alink, handle);
485 	if (!qdisc)
486 		return -EOPNOTSUPP;
487 	/* If the qdisc offload has stopped we may need to adjust the backlog
488 	 * counters back so carry on even if qdisc is not currently offloaded.
489 	 */
490 
491 	for (i = 0; i < qdisc->red.num_bands; i++) {
492 		if (!stats->xstats[i])
493 			continue;
494 
495 		nfp_abm_stats_calculate(&qdisc->red.band[i].stats,
496 					&qdisc->red.band[i].prev_stats,
497 					&stats->bstats[i], &stats->qstats[i]);
498 		qdisc->red.band[i].prev_stats = qdisc->red.band[i].stats;
499 
500 		nfp_abm_stats_red_calculate(&qdisc->red.band[i].xstats,
501 					    &qdisc->red.band[i].prev_xstats,
502 					    stats->xstats[i]);
503 		qdisc->red.band[i].prev_xstats = qdisc->red.band[i].xstats;
504 	}
505 
506 	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
507 }
508 
509 static bool
510 nfp_abm_gred_check_params(struct nfp_abm_link *alink,
511 			  struct tc_gred_qopt_offload *opt)
512 {
513 	struct nfp_cpp *cpp = alink->abm->app->cpp;
514 	struct nfp_abm *abm = alink->abm;
515 	unsigned int i;
516 
517 	if (opt->set.grio_on || opt->set.wred_on) {
518 		nfp_warn(cpp, "GRED offload failed - GRIO and WRED not supported (p:%08x h:%08x)\n",
519 			 opt->parent, opt->handle);
520 		return false;
521 	}
522 	if (opt->set.dp_def != alink->def_band) {
523 		nfp_warn(cpp, "GRED offload failed - default band must be %d (p:%08x h:%08x)\n",
524 			 alink->def_band, opt->parent, opt->handle);
525 		return false;
526 	}
527 	if (opt->set.dp_cnt != abm->num_bands) {
528 		nfp_warn(cpp, "GRED offload failed - band count must be %d (p:%08x h:%08x)\n",
529 			 abm->num_bands, opt->parent, opt->handle);
530 		return false;
531 	}
532 
533 	for (i = 0; i < abm->num_bands; i++) {
534 		struct tc_gred_vq_qopt_offload_params *band = &opt->set.tab[i];
535 
536 		if (!band->present)
537 			return false;
538 		if (!band->is_ecn) {
539 			nfp_warn(cpp, "GRED offload failed - drop is not supported (ECN option required) (p:%08x h:%08x vq:%d)\n",
540 				 opt->parent, opt->handle, i);
541 			return false;
542 		}
543 		if (band->is_harddrop) {
544 			nfp_warn(cpp, "GRED offload failed - harddrop is not supported (p:%08x h:%08x vq:%d)\n",
545 				 opt->parent, opt->handle, i);
546 			return false;
547 		}
548 		if (band->min != band->max) {
549 			nfp_warn(cpp, "GRED offload failed - threshold mismatch (p:%08x h:%08x vq:%d)\n",
550 				 opt->parent, opt->handle, i);
551 			return false;
552 		}
553 		if (band->min > S32_MAX) {
554 			nfp_warn(cpp, "GRED offload failed - threshold too large %d > %d (p:%08x h:%08x vq:%d)\n",
555 				 band->min, S32_MAX, opt->parent, opt->handle,
556 				 i);
557 			return false;
558 		}
559 	}
560 
561 	return true;
562 }
563 
564 static int
565 nfp_abm_gred_replace(struct net_device *netdev, struct nfp_abm_link *alink,
566 		     struct tc_gred_qopt_offload *opt)
567 {
568 	struct nfp_qdisc *qdisc;
569 	unsigned int i;
570 	int ret;
571 
572 	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_GRED, opt->parent,
573 				    opt->handle, 0, &qdisc);
574 	if (ret < 0)
575 		return ret;
576 
577 	qdisc->params_ok = nfp_abm_gred_check_params(alink, opt);
578 	if (qdisc->params_ok) {
579 		qdisc->red.num_bands = opt->set.dp_cnt;
580 		for (i = 0; i < qdisc->red.num_bands; i++)
581 			qdisc->red.band[i].threshold = opt->set.tab[i].min;
582 	}
583 
584 	if (qdisc->use_cnt)
585 		nfp_abm_qdisc_offload_update(alink);
586 
587 	return 0;
588 }
589 
590 int nfp_abm_setup_tc_gred(struct net_device *netdev, struct nfp_abm_link *alink,
591 			  struct tc_gred_qopt_offload *opt)
592 {
593 	switch (opt->command) {
594 	case TC_GRED_REPLACE:
595 		return nfp_abm_gred_replace(netdev, alink, opt);
596 	case TC_GRED_DESTROY:
597 		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
598 		return 0;
599 	case TC_GRED_STATS:
600 		return nfp_abm_gred_stats(alink, opt->handle, &opt->stats);
601 	default:
602 		return -EOPNOTSUPP;
603 	}
604 }
605 
606 static int
607 nfp_abm_red_xstats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
608 {
609 	struct nfp_qdisc *qdisc;
610 
611 	nfp_abm_stats_update(alink);
612 
613 	qdisc = nfp_abm_qdisc_find(alink, opt->handle);
614 	if (!qdisc || !qdisc->offloaded)
615 		return -EOPNOTSUPP;
616 
617 	nfp_abm_stats_red_calculate(&qdisc->red.band[0].xstats,
618 				    &qdisc->red.band[0].prev_xstats,
619 				    opt->xstats);
620 	qdisc->red.band[0].prev_xstats = qdisc->red.band[0].xstats;
621 	return 0;
622 }
623 
624 static int
625 nfp_abm_red_stats(struct nfp_abm_link *alink, u32 handle,
626 		  struct tc_qopt_offload_stats *stats)
627 {
628 	struct nfp_qdisc *qdisc;
629 
630 	nfp_abm_stats_update(alink);
631 
632 	qdisc = nfp_abm_qdisc_find(alink, handle);
633 	if (!qdisc)
634 		return -EOPNOTSUPP;
635 	/* If the qdisc offload has stopped we may need to adjust the backlog
636 	 * counters back so carry on even if qdisc is not currently offloaded.
637 	 */
638 
639 	nfp_abm_stats_calculate(&qdisc->red.band[0].stats,
640 				&qdisc->red.band[0].prev_stats,
641 				stats->bstats, stats->qstats);
642 	qdisc->red.band[0].prev_stats = qdisc->red.band[0].stats;
643 
644 	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
645 }
646 
647 static bool
648 nfp_abm_red_check_params(struct nfp_abm_link *alink,
649 			 struct tc_red_qopt_offload *opt)
650 {
651 	struct nfp_cpp *cpp = alink->abm->app->cpp;
652 
653 	if (!opt->set.is_ecn) {
654 		nfp_warn(cpp, "RED offload failed - drop is not supported (ECN option required) (p:%08x h:%08x)\n",
655 			 opt->parent, opt->handle);
656 		return false;
657 	}
658 	if (opt->set.is_harddrop) {
659 		nfp_warn(cpp, "RED offload failed - harddrop is not supported (p:%08x h:%08x)\n",
660 			 opt->parent, opt->handle);
661 		return false;
662 	}
663 	if (opt->set.min != opt->set.max) {
664 		nfp_warn(cpp, "RED offload failed - unsupported min/max parameters (p:%08x h:%08x)\n",
665 			 opt->parent, opt->handle);
666 		return false;
667 	}
668 	if (opt->set.min > NFP_ABM_LVL_INFINITY) {
669 		nfp_warn(cpp, "RED offload failed - threshold too large %d > %d (p:%08x h:%08x)\n",
670 			 opt->set.min, NFP_ABM_LVL_INFINITY, opt->parent,
671 			 opt->handle);
672 		return false;
673 	}
674 
675 	return true;
676 }
677 
678 static int
679 nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
680 		    struct tc_red_qopt_offload *opt)
681 {
682 	struct nfp_qdisc *qdisc;
683 	int ret;
684 
685 	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_RED, opt->parent,
686 				    opt->handle, 1, &qdisc);
687 	if (ret < 0)
688 		return ret;
689 
690 	/* If limit != 0 child gets reset */
691 	if (opt->set.limit) {
692 		if (nfp_abm_qdisc_child_valid(qdisc, 0))
693 			qdisc->children[0]->use_cnt--;
694 		qdisc->children[0] = NULL;
695 	} else {
696 		/* Qdisc was just allocated without a limit will use noop_qdisc,
697 		 * i.e. a block hole.
698 		 */
699 		if (!ret)
700 			qdisc->children[0] = NFP_QDISC_UNTRACKED;
701 	}
702 
703 	qdisc->params_ok = nfp_abm_red_check_params(alink, opt);
704 	if (qdisc->params_ok) {
705 		qdisc->red.num_bands = 1;
706 		qdisc->red.band[0].threshold = opt->set.min;
707 	}
708 
709 	if (qdisc->use_cnt == 1)
710 		nfp_abm_qdisc_offload_update(alink);
711 
712 	return 0;
713 }
714 
715 int nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
716 			 struct tc_red_qopt_offload *opt)
717 {
718 	switch (opt->command) {
719 	case TC_RED_REPLACE:
720 		return nfp_abm_red_replace(netdev, alink, opt);
721 	case TC_RED_DESTROY:
722 		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
723 		return 0;
724 	case TC_RED_STATS:
725 		return nfp_abm_red_stats(alink, opt->handle, &opt->stats);
726 	case TC_RED_XSTATS:
727 		return nfp_abm_red_xstats(alink, opt);
728 	case TC_RED_GRAFT:
729 		return nfp_abm_qdisc_graft(alink, opt->handle,
730 					   opt->child_handle, 0);
731 	default:
732 		return -EOPNOTSUPP;
733 	}
734 }
735 
736 static int
737 nfp_abm_mq_create(struct net_device *netdev, struct nfp_abm_link *alink,
738 		  struct tc_mq_qopt_offload *opt)
739 {
740 	struct nfp_qdisc *qdisc;
741 	int ret;
742 
743 	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_MQ,
744 				    TC_H_ROOT, opt->handle, alink->total_queues,
745 				    &qdisc);
746 	if (ret < 0)
747 		return ret;
748 
749 	qdisc->params_ok = true;
750 	qdisc->offloaded = true;
751 	nfp_abm_qdisc_offload_update(alink);
752 	return 0;
753 }
754 
755 static int
756 nfp_abm_mq_stats(struct nfp_abm_link *alink, u32 handle,
757 		 struct tc_qopt_offload_stats *stats)
758 {
759 	struct nfp_qdisc *qdisc, *red;
760 	unsigned int i, j;
761 
762 	qdisc = nfp_abm_qdisc_find(alink, handle);
763 	if (!qdisc)
764 		return -EOPNOTSUPP;
765 
766 	nfp_abm_stats_update(alink);
767 
768 	/* MQ stats are summed over the children in the core, so we need
769 	 * to add up the unreported child values.
770 	 */
771 	memset(&qdisc->mq.stats, 0, sizeof(qdisc->mq.stats));
772 	memset(&qdisc->mq.prev_stats, 0, sizeof(qdisc->mq.prev_stats));
773 
774 	for (i = 0; i < qdisc->num_children; i++) {
775 		if (!nfp_abm_qdisc_child_valid(qdisc, i))
776 			continue;
777 
778 		if (!nfp_abm_qdisc_is_red(qdisc->children[i]))
779 			continue;
780 		red = qdisc->children[i];
781 
782 		for (j = 0; j < red->red.num_bands; j++) {
783 			nfp_abm_stats_propagate(&qdisc->mq.stats,
784 						&red->red.band[j].stats);
785 			nfp_abm_stats_propagate(&qdisc->mq.prev_stats,
786 						&red->red.band[j].prev_stats);
787 		}
788 	}
789 
790 	nfp_abm_stats_calculate(&qdisc->mq.stats, &qdisc->mq.prev_stats,
791 				stats->bstats, stats->qstats);
792 
793 	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
794 }
795 
796 int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
797 			struct tc_mq_qopt_offload *opt)
798 {
799 	switch (opt->command) {
800 	case TC_MQ_CREATE:
801 		return nfp_abm_mq_create(netdev, alink, opt);
802 	case TC_MQ_DESTROY:
803 		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
804 		return 0;
805 	case TC_MQ_STATS:
806 		return nfp_abm_mq_stats(alink, opt->handle, &opt->stats);
807 	case TC_MQ_GRAFT:
808 		return nfp_abm_qdisc_graft(alink, opt->handle,
809 					   opt->graft_params.child_handle,
810 					   opt->graft_params.queue);
811 	default:
812 		return -EOPNOTSUPP;
813 	}
814 }
815 
816 int nfp_abm_setup_root(struct net_device *netdev, struct nfp_abm_link *alink,
817 		       struct tc_root_qopt_offload *opt)
818 {
819 	if (opt->ingress)
820 		return -EOPNOTSUPP;
821 	if (alink->root_qdisc)
822 		alink->root_qdisc->use_cnt--;
823 	alink->root_qdisc = nfp_abm_qdisc_find(alink, opt->handle);
824 	if (alink->root_qdisc)
825 		alink->root_qdisc->use_cnt++;
826 
827 	nfp_abm_qdisc_offload_update(alink);
828 
829 	return 0;
830 }
831