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 		   !qdisc->children[0];
201 	good_gred = qdisc->type == NFP_QDISC_GRED &&
202 		    qdisc->params_ok &&
203 		    qdisc->use_cnt == 1;
204 	qdisc->offload_mark = good_red || good_gred;
205 
206 	/* If we are starting offload init prev_stats */
207 	if (qdisc->offload_mark && !qdisc->offloaded)
208 		if (nfp_abm_stats_init(alink, qdisc, queue))
209 			qdisc->offload_mark = false;
210 
211 	if (!qdisc->offload_mark)
212 		return;
213 
214 	for (i = 0; i < alink->abm->num_bands; i++)
215 		nfp_abm_ctrl_set_q_lvl(alink, i, queue,
216 				       qdisc->red.band[i].threshold);
217 }
218 
219 static void
220 nfp_abm_offload_compile_mq(struct nfp_abm_link *alink, struct nfp_qdisc *qdisc)
221 {
222 	unsigned int i;
223 
224 	qdisc->offload_mark = qdisc->type == NFP_QDISC_MQ;
225 	if (!qdisc->offload_mark)
226 		return;
227 
228 	for (i = 0; i < alink->total_queues; i++) {
229 		struct nfp_qdisc *child = qdisc->children[i];
230 
231 		if (!nfp_abm_qdisc_child_valid(qdisc, i))
232 			continue;
233 
234 		nfp_abm_offload_compile_red(alink, child, i);
235 	}
236 }
237 
238 void nfp_abm_qdisc_offload_update(struct nfp_abm_link *alink)
239 {
240 	struct nfp_abm *abm = alink->abm;
241 	struct radix_tree_iter iter;
242 	struct nfp_qdisc *qdisc;
243 	void __rcu **slot;
244 	size_t i;
245 
246 	/* Mark all thresholds as unconfigured */
247 	for (i = 0; i < abm->num_bands; i++)
248 		__bitmap_set(abm->threshold_undef,
249 			     i * NFP_NET_MAX_RX_RINGS + alink->queue_base,
250 			     alink->total_queues);
251 
252 	/* Clear offload marks */
253 	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
254 		qdisc = nfp_abm_qdisc_tree_deref_slot(slot);
255 		qdisc->offload_mark = false;
256 	}
257 
258 	if (alink->root_qdisc)
259 		nfp_abm_offload_compile_mq(alink, alink->root_qdisc);
260 
261 	/* Refresh offload status */
262 	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
263 		qdisc = nfp_abm_qdisc_tree_deref_slot(slot);
264 		if (!qdisc->offload_mark && qdisc->offloaded)
265 			nfp_abm_qdisc_offload_stop(alink, qdisc);
266 		qdisc->offloaded = qdisc->offload_mark;
267 	}
268 
269 	/* Reset the unconfigured thresholds */
270 	for (i = 0; i < abm->num_thresholds; i++)
271 		if (test_bit(i, abm->threshold_undef))
272 			__nfp_abm_ctrl_set_q_lvl(abm, i, NFP_ABM_LVL_INFINITY);
273 
274 	__nfp_abm_stats_update(alink, ktime_get());
275 }
276 
277 static void
278 nfp_abm_qdisc_clear_mq(struct net_device *netdev, struct nfp_abm_link *alink,
279 		       struct nfp_qdisc *qdisc)
280 {
281 	struct radix_tree_iter iter;
282 	unsigned int mq_refs = 0;
283 	void __rcu **slot;
284 
285 	if (!qdisc->use_cnt)
286 		return;
287 	/* MQ doesn't notify well on destruction, we need special handling of
288 	 * MQ's children.
289 	 */
290 	if (qdisc->type == NFP_QDISC_MQ &&
291 	    qdisc == alink->root_qdisc &&
292 	    netdev->reg_state == NETREG_UNREGISTERING)
293 		return;
294 
295 	/* Count refs held by MQ instances and clear pointers */
296 	radix_tree_for_each_slot(slot, &alink->qdiscs, &iter, 0) {
297 		struct nfp_qdisc *mq = nfp_abm_qdisc_tree_deref_slot(slot);
298 		unsigned int i;
299 
300 		if (mq->type != NFP_QDISC_MQ || mq->netdev != netdev)
301 			continue;
302 		for (i = 0; i < mq->num_children; i++)
303 			if (mq->children[i] == qdisc) {
304 				mq->children[i] = NULL;
305 				mq_refs++;
306 			}
307 	}
308 
309 	WARN(qdisc->use_cnt != mq_refs, "non-zero qdisc use count: %d (- %d)\n",
310 	     qdisc->use_cnt, mq_refs);
311 }
312 
313 static void
314 nfp_abm_qdisc_free(struct net_device *netdev, struct nfp_abm_link *alink,
315 		   struct nfp_qdisc *qdisc)
316 {
317 	struct nfp_port *port = nfp_port_from_netdev(netdev);
318 
319 	if (!qdisc)
320 		return;
321 	nfp_abm_qdisc_clear_mq(netdev, alink, qdisc);
322 	WARN_ON(radix_tree_delete(&alink->qdiscs,
323 				  TC_H_MAJ(qdisc->handle)) != qdisc);
324 
325 	kfree(qdisc->children);
326 	kfree(qdisc);
327 
328 	port->tc_offload_cnt--;
329 }
330 
331 static struct nfp_qdisc *
332 nfp_abm_qdisc_alloc(struct net_device *netdev, struct nfp_abm_link *alink,
333 		    enum nfp_qdisc_type type, u32 parent_handle, u32 handle,
334 		    unsigned int children)
335 {
336 	struct nfp_port *port = nfp_port_from_netdev(netdev);
337 	struct nfp_qdisc *qdisc;
338 	int err;
339 
340 	qdisc = kzalloc(sizeof(*qdisc), GFP_KERNEL);
341 	if (!qdisc)
342 		return NULL;
343 
344 	if (children) {
345 		qdisc->children = kcalloc(children, sizeof(void *), GFP_KERNEL);
346 		if (!qdisc->children)
347 			goto err_free_qdisc;
348 	}
349 
350 	qdisc->netdev = netdev;
351 	qdisc->type = type;
352 	qdisc->parent_handle = parent_handle;
353 	qdisc->handle = handle;
354 	qdisc->num_children = children;
355 
356 	err = radix_tree_insert(&alink->qdiscs, TC_H_MAJ(qdisc->handle), qdisc);
357 	if (err) {
358 		nfp_err(alink->abm->app->cpp,
359 			"Qdisc insertion into radix tree failed: %d\n", err);
360 		goto err_free_child_tbl;
361 	}
362 
363 	port->tc_offload_cnt++;
364 	return qdisc;
365 
366 err_free_child_tbl:
367 	kfree(qdisc->children);
368 err_free_qdisc:
369 	kfree(qdisc);
370 	return NULL;
371 }
372 
373 static struct nfp_qdisc *
374 nfp_abm_qdisc_find(struct nfp_abm_link *alink, u32 handle)
375 {
376 	return radix_tree_lookup(&alink->qdiscs, TC_H_MAJ(handle));
377 }
378 
379 static int
380 nfp_abm_qdisc_replace(struct net_device *netdev, struct nfp_abm_link *alink,
381 		      enum nfp_qdisc_type type, u32 parent_handle, u32 handle,
382 		      unsigned int children, struct nfp_qdisc **qdisc)
383 {
384 	*qdisc = nfp_abm_qdisc_find(alink, handle);
385 	if (*qdisc) {
386 		if (WARN_ON((*qdisc)->type != type))
387 			return -EINVAL;
388 		return 1;
389 	}
390 
391 	*qdisc = nfp_abm_qdisc_alloc(netdev, alink, type, parent_handle, handle,
392 				     children);
393 	return *qdisc ? 0 : -ENOMEM;
394 }
395 
396 static void
397 nfp_abm_qdisc_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
398 		      u32 handle)
399 {
400 	struct nfp_qdisc *qdisc;
401 
402 	qdisc = nfp_abm_qdisc_find(alink, handle);
403 	if (!qdisc)
404 		return;
405 
406 	/* We don't get TC_SETUP_ROOT_QDISC w/ MQ when netdev is unregistered */
407 	if (alink->root_qdisc == qdisc)
408 		qdisc->use_cnt--;
409 
410 	nfp_abm_qdisc_unlink_children(qdisc, 0, qdisc->num_children);
411 	nfp_abm_qdisc_free(netdev, alink, qdisc);
412 
413 	if (alink->root_qdisc == qdisc) {
414 		alink->root_qdisc = NULL;
415 		/* Only root change matters, other changes are acted upon on
416 		 * the graft notification.
417 		 */
418 		nfp_abm_qdisc_offload_update(alink);
419 	}
420 }
421 
422 static int
423 nfp_abm_qdisc_graft(struct nfp_abm_link *alink, u32 handle, u32 child_handle,
424 		    unsigned int id)
425 {
426 	struct nfp_qdisc *parent, *child;
427 
428 	parent = nfp_abm_qdisc_find(alink, handle);
429 	if (!parent)
430 		return 0;
431 
432 	if (WARN(id >= parent->num_children,
433 		 "graft child out of bound %d >= %d\n",
434 		 id, parent->num_children))
435 		return -EINVAL;
436 
437 	nfp_abm_qdisc_unlink_children(parent, id, id + 1);
438 
439 	child = nfp_abm_qdisc_find(alink, child_handle);
440 	if (child)
441 		child->use_cnt++;
442 	else
443 		child = NFP_QDISC_UNTRACKED;
444 	parent->children[id] = child;
445 
446 	nfp_abm_qdisc_offload_update(alink);
447 
448 	return 0;
449 }
450 
451 static void
452 nfp_abm_stats_calculate(struct nfp_alink_stats *new,
453 			struct nfp_alink_stats *old,
454 			struct gnet_stats_basic_packed *bstats,
455 			struct gnet_stats_queue *qstats)
456 {
457 	_bstats_update(bstats, new->tx_bytes - old->tx_bytes,
458 		       new->tx_pkts - old->tx_pkts);
459 	qstats->qlen += new->backlog_pkts - old->backlog_pkts;
460 	qstats->backlog += new->backlog_bytes - old->backlog_bytes;
461 	qstats->overlimits += new->overlimits - old->overlimits;
462 	qstats->drops += new->drops - old->drops;
463 }
464 
465 static void
466 nfp_abm_stats_red_calculate(struct nfp_alink_xstats *new,
467 			    struct nfp_alink_xstats *old,
468 			    struct red_stats *stats)
469 {
470 	stats->forced_mark += new->ecn_marked - old->ecn_marked;
471 	stats->pdrop += new->pdrop - old->pdrop;
472 }
473 
474 static int
475 nfp_abm_gred_stats(struct nfp_abm_link *alink, u32 handle,
476 		   struct tc_gred_qopt_offload_stats *stats)
477 {
478 	struct nfp_qdisc *qdisc;
479 	unsigned int i;
480 
481 	nfp_abm_stats_update(alink);
482 
483 	qdisc = nfp_abm_qdisc_find(alink, handle);
484 	if (!qdisc)
485 		return -EOPNOTSUPP;
486 	/* If the qdisc offload has stopped we may need to adjust the backlog
487 	 * counters back so carry on even if qdisc is not currently offloaded.
488 	 */
489 
490 	for (i = 0; i < qdisc->red.num_bands; i++) {
491 		if (!stats->xstats[i])
492 			continue;
493 
494 		nfp_abm_stats_calculate(&qdisc->red.band[i].stats,
495 					&qdisc->red.band[i].prev_stats,
496 					&stats->bstats[i], &stats->qstats[i]);
497 		qdisc->red.band[i].prev_stats = qdisc->red.band[i].stats;
498 
499 		nfp_abm_stats_red_calculate(&qdisc->red.band[i].xstats,
500 					    &qdisc->red.band[i].prev_xstats,
501 					    stats->xstats[i]);
502 		qdisc->red.band[i].prev_xstats = qdisc->red.band[i].xstats;
503 	}
504 
505 	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
506 }
507 
508 static bool
509 nfp_abm_gred_check_params(struct nfp_abm_link *alink,
510 			  struct tc_gred_qopt_offload *opt)
511 {
512 	struct nfp_cpp *cpp = alink->abm->app->cpp;
513 	struct nfp_abm *abm = alink->abm;
514 	unsigned int i;
515 
516 	if (opt->set.grio_on || opt->set.wred_on) {
517 		nfp_warn(cpp, "GRED offload failed - GRIO and WRED not supported (p:%08x h:%08x)\n",
518 			 opt->parent, opt->handle);
519 		return false;
520 	}
521 	if (opt->set.dp_def != alink->def_band) {
522 		nfp_warn(cpp, "GRED offload failed - default band must be %d (p:%08x h:%08x)\n",
523 			 alink->def_band, opt->parent, opt->handle);
524 		return false;
525 	}
526 	if (opt->set.dp_cnt != abm->num_bands) {
527 		nfp_warn(cpp, "GRED offload failed - band count must be %d (p:%08x h:%08x)\n",
528 			 abm->num_bands, opt->parent, opt->handle);
529 		return false;
530 	}
531 
532 	for (i = 0; i < abm->num_bands; i++) {
533 		struct tc_gred_vq_qopt_offload_params *band = &opt->set.tab[i];
534 
535 		if (!band->present)
536 			return false;
537 		if (!band->is_ecn) {
538 			nfp_warn(cpp, "GRED offload failed - drop is not supported (ECN option required) (p:%08x h:%08x vq:%d)\n",
539 				 opt->parent, opt->handle, i);
540 			return false;
541 		}
542 		if (band->is_harddrop) {
543 			nfp_warn(cpp, "GRED offload failed - harddrop is not supported (p:%08x h:%08x vq:%d)\n",
544 				 opt->parent, opt->handle, i);
545 			return false;
546 		}
547 		if (band->min != band->max) {
548 			nfp_warn(cpp, "GRED offload failed - threshold mismatch (p:%08x h:%08x vq:%d)\n",
549 				 opt->parent, opt->handle, i);
550 			return false;
551 		}
552 		if (band->min > S32_MAX) {
553 			nfp_warn(cpp, "GRED offload failed - threshold too large %d > %d (p:%08x h:%08x vq:%d)\n",
554 				 band->min, S32_MAX, opt->parent, opt->handle,
555 				 i);
556 			return false;
557 		}
558 	}
559 
560 	return true;
561 }
562 
563 static int
564 nfp_abm_gred_replace(struct net_device *netdev, struct nfp_abm_link *alink,
565 		     struct tc_gred_qopt_offload *opt)
566 {
567 	struct nfp_qdisc *qdisc;
568 	unsigned int i;
569 	int ret;
570 
571 	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_GRED, opt->parent,
572 				    opt->handle, 0, &qdisc);
573 	if (ret < 0)
574 		return ret;
575 
576 	qdisc->params_ok = nfp_abm_gred_check_params(alink, opt);
577 	if (qdisc->params_ok) {
578 		qdisc->red.num_bands = opt->set.dp_cnt;
579 		for (i = 0; i < qdisc->red.num_bands; i++)
580 			qdisc->red.band[i].threshold = opt->set.tab[i].min;
581 	}
582 
583 	if (qdisc->use_cnt)
584 		nfp_abm_qdisc_offload_update(alink);
585 
586 	return 0;
587 }
588 
589 int nfp_abm_setup_tc_gred(struct net_device *netdev, struct nfp_abm_link *alink,
590 			  struct tc_gred_qopt_offload *opt)
591 {
592 	switch (opt->command) {
593 	case TC_GRED_REPLACE:
594 		return nfp_abm_gred_replace(netdev, alink, opt);
595 	case TC_GRED_DESTROY:
596 		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
597 		return 0;
598 	case TC_GRED_STATS:
599 		return nfp_abm_gred_stats(alink, opt->handle, &opt->stats);
600 	default:
601 		return -EOPNOTSUPP;
602 	}
603 }
604 
605 static int
606 nfp_abm_red_xstats(struct nfp_abm_link *alink, struct tc_red_qopt_offload *opt)
607 {
608 	struct nfp_qdisc *qdisc;
609 
610 	nfp_abm_stats_update(alink);
611 
612 	qdisc = nfp_abm_qdisc_find(alink, opt->handle);
613 	if (!qdisc || !qdisc->offloaded)
614 		return -EOPNOTSUPP;
615 
616 	nfp_abm_stats_red_calculate(&qdisc->red.band[0].xstats,
617 				    &qdisc->red.band[0].prev_xstats,
618 				    opt->xstats);
619 	qdisc->red.band[0].prev_xstats = qdisc->red.band[0].xstats;
620 	return 0;
621 }
622 
623 static int
624 nfp_abm_red_stats(struct nfp_abm_link *alink, u32 handle,
625 		  struct tc_qopt_offload_stats *stats)
626 {
627 	struct nfp_qdisc *qdisc;
628 
629 	nfp_abm_stats_update(alink);
630 
631 	qdisc = nfp_abm_qdisc_find(alink, handle);
632 	if (!qdisc)
633 		return -EOPNOTSUPP;
634 	/* If the qdisc offload has stopped we may need to adjust the backlog
635 	 * counters back so carry on even if qdisc is not currently offloaded.
636 	 */
637 
638 	nfp_abm_stats_calculate(&qdisc->red.band[0].stats,
639 				&qdisc->red.band[0].prev_stats,
640 				stats->bstats, stats->qstats);
641 	qdisc->red.band[0].prev_stats = qdisc->red.band[0].stats;
642 
643 	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
644 }
645 
646 static bool
647 nfp_abm_red_check_params(struct nfp_abm_link *alink,
648 			 struct tc_red_qopt_offload *opt)
649 {
650 	struct nfp_cpp *cpp = alink->abm->app->cpp;
651 
652 	if (!opt->set.is_ecn) {
653 		nfp_warn(cpp, "RED offload failed - drop is not supported (ECN option required) (p:%08x h:%08x)\n",
654 			 opt->parent, opt->handle);
655 		return false;
656 	}
657 	if (opt->set.is_harddrop) {
658 		nfp_warn(cpp, "RED offload failed - harddrop is not supported (p:%08x h:%08x)\n",
659 			 opt->parent, opt->handle);
660 		return false;
661 	}
662 	if (opt->set.min != opt->set.max) {
663 		nfp_warn(cpp, "RED offload failed - unsupported min/max parameters (p:%08x h:%08x)\n",
664 			 opt->parent, opt->handle);
665 		return false;
666 	}
667 	if (opt->set.min > NFP_ABM_LVL_INFINITY) {
668 		nfp_warn(cpp, "RED offload failed - threshold too large %d > %d (p:%08x h:%08x)\n",
669 			 opt->set.min, NFP_ABM_LVL_INFINITY, opt->parent,
670 			 opt->handle);
671 		return false;
672 	}
673 
674 	return true;
675 }
676 
677 static int
678 nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
679 		    struct tc_red_qopt_offload *opt)
680 {
681 	struct nfp_qdisc *qdisc;
682 	int ret;
683 
684 	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_RED, opt->parent,
685 				    opt->handle, 1, &qdisc);
686 	if (ret < 0)
687 		return ret;
688 
689 	/* If limit != 0 child gets reset */
690 	if (opt->set.limit) {
691 		if (nfp_abm_qdisc_child_valid(qdisc, 0))
692 			qdisc->children[0]->use_cnt--;
693 		qdisc->children[0] = NULL;
694 	} else {
695 		/* Qdisc was just allocated without a limit will use noop_qdisc,
696 		 * i.e. a block hole.
697 		 */
698 		if (!ret)
699 			qdisc->children[0] = NFP_QDISC_UNTRACKED;
700 	}
701 
702 	qdisc->params_ok = nfp_abm_red_check_params(alink, opt);
703 	if (qdisc->params_ok) {
704 		qdisc->red.num_bands = 1;
705 		qdisc->red.band[0].threshold = opt->set.min;
706 	}
707 
708 	if (qdisc->use_cnt == 1)
709 		nfp_abm_qdisc_offload_update(alink);
710 
711 	return 0;
712 }
713 
714 int nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
715 			 struct tc_red_qopt_offload *opt)
716 {
717 	switch (opt->command) {
718 	case TC_RED_REPLACE:
719 		return nfp_abm_red_replace(netdev, alink, opt);
720 	case TC_RED_DESTROY:
721 		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
722 		return 0;
723 	case TC_RED_STATS:
724 		return nfp_abm_red_stats(alink, opt->handle, &opt->stats);
725 	case TC_RED_XSTATS:
726 		return nfp_abm_red_xstats(alink, opt);
727 	case TC_RED_GRAFT:
728 		return nfp_abm_qdisc_graft(alink, opt->handle,
729 					   opt->child_handle, 0);
730 	default:
731 		return -EOPNOTSUPP;
732 	}
733 }
734 
735 static int
736 nfp_abm_mq_create(struct net_device *netdev, struct nfp_abm_link *alink,
737 		  struct tc_mq_qopt_offload *opt)
738 {
739 	struct nfp_qdisc *qdisc;
740 	int ret;
741 
742 	ret = nfp_abm_qdisc_replace(netdev, alink, NFP_QDISC_MQ,
743 				    TC_H_ROOT, opt->handle, alink->total_queues,
744 				    &qdisc);
745 	if (ret < 0)
746 		return ret;
747 
748 	qdisc->params_ok = true;
749 	qdisc->offloaded = true;
750 	nfp_abm_qdisc_offload_update(alink);
751 	return 0;
752 }
753 
754 static int
755 nfp_abm_mq_stats(struct nfp_abm_link *alink, u32 handle,
756 		 struct tc_qopt_offload_stats *stats)
757 {
758 	struct nfp_qdisc *qdisc, *red;
759 	unsigned int i, j;
760 
761 	qdisc = nfp_abm_qdisc_find(alink, handle);
762 	if (!qdisc)
763 		return -EOPNOTSUPP;
764 
765 	nfp_abm_stats_update(alink);
766 
767 	/* MQ stats are summed over the children in the core, so we need
768 	 * to add up the unreported child values.
769 	 */
770 	memset(&qdisc->mq.stats, 0, sizeof(qdisc->mq.stats));
771 	memset(&qdisc->mq.prev_stats, 0, sizeof(qdisc->mq.prev_stats));
772 
773 	for (i = 0; i < qdisc->num_children; i++) {
774 		if (!nfp_abm_qdisc_child_valid(qdisc, i))
775 			continue;
776 
777 		if (!nfp_abm_qdisc_is_red(qdisc->children[i]))
778 			continue;
779 		red = qdisc->children[i];
780 
781 		for (j = 0; j < red->red.num_bands; j++) {
782 			nfp_abm_stats_propagate(&qdisc->mq.stats,
783 						&red->red.band[j].stats);
784 			nfp_abm_stats_propagate(&qdisc->mq.prev_stats,
785 						&red->red.band[j].prev_stats);
786 		}
787 	}
788 
789 	nfp_abm_stats_calculate(&qdisc->mq.stats, &qdisc->mq.prev_stats,
790 				stats->bstats, stats->qstats);
791 
792 	return qdisc->offloaded ? 0 : -EOPNOTSUPP;
793 }
794 
795 int nfp_abm_setup_tc_mq(struct net_device *netdev, struct nfp_abm_link *alink,
796 			struct tc_mq_qopt_offload *opt)
797 {
798 	switch (opt->command) {
799 	case TC_MQ_CREATE:
800 		return nfp_abm_mq_create(netdev, alink, opt);
801 	case TC_MQ_DESTROY:
802 		nfp_abm_qdisc_destroy(netdev, alink, opt->handle);
803 		return 0;
804 	case TC_MQ_STATS:
805 		return nfp_abm_mq_stats(alink, opt->handle, &opt->stats);
806 	case TC_MQ_GRAFT:
807 		return nfp_abm_qdisc_graft(alink, opt->handle,
808 					   opt->graft_params.child_handle,
809 					   opt->graft_params.queue);
810 	default:
811 		return -EOPNOTSUPP;
812 	}
813 }
814 
815 int nfp_abm_setup_root(struct net_device *netdev, struct nfp_abm_link *alink,
816 		       struct tc_root_qopt_offload *opt)
817 {
818 	if (opt->ingress)
819 		return -EOPNOTSUPP;
820 	if (alink->root_qdisc)
821 		alink->root_qdisc->use_cnt--;
822 	alink->root_qdisc = nfp_abm_qdisc_find(alink, opt->handle);
823 	if (alink->root_qdisc)
824 		alink->root_qdisc->use_cnt++;
825 
826 	nfp_abm_qdisc_offload_update(alink);
827 
828 	return 0;
829 }
830