1// SPDX-License-Identifier: GPL-2.0-only
2/****************************************************************************
3 * Driver for Solarflare network controllers and boards
4 * Copyright 2018 Solarflare Communications Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published
8 * by the Free Software Foundation, incorporated herein by reference.
9 */
10
11#include "net_driver.h"
12#include <linux/module.h>
13#include "efx_channels.h"
14#include "efx.h"
15#include "efx_common.h"
16#include "tx_common.h"
17#include "rx_common.h"
18#include "nic.h"
19#include "sriov.h"
20
21/* This is the first interrupt mode to try out of:
22 * 0 => MSI-X
23 * 1 => MSI
24 * 2 => legacy
25 */
26unsigned int efx_interrupt_mode = EFX_INT_MODE_MSIX;
27
28/* This is the requested number of CPUs to use for Receive-Side Scaling (RSS),
29 * i.e. the number of CPUs among which we may distribute simultaneous
30 * interrupt handling.
31 *
32 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.
33 * The default (0) means to assign an interrupt to each core.
34 */
35unsigned int rss_cpus;
36
37static unsigned int irq_adapt_low_thresh = 8000;
38module_param(irq_adapt_low_thresh, uint, 0644);
39MODULE_PARM_DESC(irq_adapt_low_thresh,
40		 "Threshold score for reducing IRQ moderation");
41
42static unsigned int irq_adapt_high_thresh = 16000;
43module_param(irq_adapt_high_thresh, uint, 0644);
44MODULE_PARM_DESC(irq_adapt_high_thresh,
45		 "Threshold score for increasing IRQ moderation");
46
47/* This is the weight assigned to each of the (per-channel) virtual
48 * NAPI devices.
49 */
50static int napi_weight = 64;
51
52/***************
53 * Housekeeping
54 ***************/
55
56int efx_channel_dummy_op_int(struct efx_channel *channel)
57{
58	return 0;
59}
60
61void efx_channel_dummy_op_void(struct efx_channel *channel)
62{
63}
64
65static const struct efx_channel_type efx_default_channel_type = {
66	.pre_probe		= efx_channel_dummy_op_int,
67	.post_remove		= efx_channel_dummy_op_void,
68	.get_name		= efx_get_channel_name,
69	.copy			= efx_copy_channel,
70	.want_txqs		= efx_default_channel_want_txqs,
71	.keep_eventq		= false,
72	.want_pio		= true,
73};
74
75/*************
76 * INTERRUPTS
77 *************/
78
79static unsigned int efx_wanted_parallelism(struct efx_nic *efx)
80{
81	cpumask_var_t thread_mask;
82	unsigned int count;
83	int cpu;
84
85	if (rss_cpus) {
86		count = rss_cpus;
87	} else {
88		if (unlikely(!zalloc_cpumask_var(&thread_mask, GFP_KERNEL))) {
89			netif_warn(efx, probe, efx->net_dev,
90				   "RSS disabled due to allocation failure\n");
91			return 1;
92		}
93
94		count = 0;
95		for_each_online_cpu(cpu) {
96			if (!cpumask_test_cpu(cpu, thread_mask)) {
97				++count;
98				cpumask_or(thread_mask, thread_mask,
99					   topology_sibling_cpumask(cpu));
100			}
101		}
102
103		free_cpumask_var(thread_mask);
104	}
105
106	if (count > EFX_MAX_RX_QUEUES) {
107		netif_cond_dbg(efx, probe, efx->net_dev, !rss_cpus, warn,
108			       "Reducing number of rx queues from %u to %u.\n",
109			       count, EFX_MAX_RX_QUEUES);
110		count = EFX_MAX_RX_QUEUES;
111	}
112
113	/* If RSS is requested for the PF *and* VFs then we can't write RSS
114	 * table entries that are inaccessible to VFs
115	 */
116#ifdef CONFIG_SFC_SRIOV
117	if (efx->type->sriov_wanted) {
118		if (efx->type->sriov_wanted(efx) && efx_vf_size(efx) > 1 &&
119		    count > efx_vf_size(efx)) {
120			netif_warn(efx, probe, efx->net_dev,
121				   "Reducing number of RSS channels from %u to %u for "
122				   "VF support. Increase vf-msix-limit to use more "
123				   "channels on the PF.\n",
124				   count, efx_vf_size(efx));
125			count = efx_vf_size(efx);
126		}
127	}
128#endif
129
130	return count;
131}
132
133static int efx_allocate_msix_channels(struct efx_nic *efx,
134				      unsigned int max_channels,
135				      unsigned int extra_channels,
136				      unsigned int parallelism)
137{
138	unsigned int n_channels = parallelism;
139	int vec_count;
140	int n_xdp_tx;
141	int n_xdp_ev;
142
143	if (efx_separate_tx_channels)
144		n_channels *= 2;
145	n_channels += extra_channels;
146
147	/* To allow XDP transmit to happen from arbitrary NAPI contexts
148	 * we allocate a TX queue per CPU. We share event queues across
149	 * multiple tx queues, assuming tx and ev queues are both
150	 * maximum size.
151	 */
152
153	n_xdp_tx = num_possible_cpus();
154	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_MAX_TXQ_PER_CHANNEL);
155
156	vec_count = pci_msix_vec_count(efx->pci_dev);
157	if (vec_count < 0)
158		return vec_count;
159
160	max_channels = min_t(unsigned int, vec_count, max_channels);
161
162	/* Check resources.
163	 * We need a channel per event queue, plus a VI per tx queue.
164	 * This may be more pessimistic than it needs to be.
165	 */
166	if (n_channels + n_xdp_ev > max_channels) {
167		netif_err(efx, drv, efx->net_dev,
168			  "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
169			  n_xdp_ev, n_channels, max_channels);
170		efx->n_xdp_channels = 0;
171		efx->xdp_tx_per_channel = 0;
172		efx->xdp_tx_queue_count = 0;
173	} else if (n_channels + n_xdp_tx > efx->max_vis) {
174		netif_err(efx, drv, efx->net_dev,
175			  "Insufficient resources for %d XDP TX queues (%d other channels, max VIs %d)\n",
176			  n_xdp_tx, n_channels, efx->max_vis);
177		efx->n_xdp_channels = 0;
178		efx->xdp_tx_per_channel = 0;
179		efx->xdp_tx_queue_count = 0;
180	} else {
181		efx->n_xdp_channels = n_xdp_ev;
182		efx->xdp_tx_per_channel = EFX_MAX_TXQ_PER_CHANNEL;
183		efx->xdp_tx_queue_count = n_xdp_tx;
184		n_channels += n_xdp_ev;
185		netif_dbg(efx, drv, efx->net_dev,
186			  "Allocating %d TX and %d event queues for XDP\n",
187			  n_xdp_tx, n_xdp_ev);
188	}
189
190	if (vec_count < n_channels) {
191		netif_err(efx, drv, efx->net_dev,
192			  "WARNING: Insufficient MSI-X vectors available (%d < %u).\n",
193			  vec_count, n_channels);
194		netif_err(efx, drv, efx->net_dev,
195			  "WARNING: Performance may be reduced.\n");
196		n_channels = vec_count;
197	}
198
199	n_channels = min(n_channels, max_channels);
200
201	efx->n_channels = n_channels;
202
203	/* Ignore XDP tx channels when creating rx channels. */
204	n_channels -= efx->n_xdp_channels;
205
206	if (efx_separate_tx_channels) {
207		efx->n_tx_channels =
208			min(max(n_channels / 2, 1U),
209			    efx->max_tx_channels);
210		efx->tx_channel_offset =
211			n_channels - efx->n_tx_channels;
212		efx->n_rx_channels =
213			max(n_channels -
214			    efx->n_tx_channels, 1U);
215	} else {
216		efx->n_tx_channels = min(n_channels, efx->max_tx_channels);
217		efx->tx_channel_offset = 0;
218		efx->n_rx_channels = n_channels;
219	}
220
221	efx->n_rx_channels = min(efx->n_rx_channels, parallelism);
222	efx->n_tx_channels = min(efx->n_tx_channels, parallelism);
223
224	efx->xdp_channel_offset = n_channels;
225
226	netif_dbg(efx, drv, efx->net_dev,
227		  "Allocating %u RX channels\n",
228		  efx->n_rx_channels);
229
230	return efx->n_channels;
231}
232
233/* Probe the number and type of interrupts we are able to obtain, and
234 * the resulting numbers of channels and RX queues.
235 */
236int efx_probe_interrupts(struct efx_nic *efx)
237{
238	unsigned int extra_channels = 0;
239	unsigned int rss_spread;
240	unsigned int i, j;
241	int rc;
242
243	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++)
244		if (efx->extra_channel_type[i])
245			++extra_channels;
246
247	if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
248		unsigned int parallelism = efx_wanted_parallelism(efx);
249		struct msix_entry xentries[EFX_MAX_CHANNELS];
250		unsigned int n_channels;
251
252		rc = efx_allocate_msix_channels(efx, efx->max_channels,
253						extra_channels, parallelism);
254		if (rc >= 0) {
255			n_channels = rc;
256			for (i = 0; i < n_channels; i++)
257				xentries[i].entry = i;
258			rc = pci_enable_msix_range(efx->pci_dev, xentries, 1,
259						   n_channels);
260		}
261		if (rc < 0) {
262			/* Fall back to single channel MSI */
263			netif_err(efx, drv, efx->net_dev,
264				  "could not enable MSI-X\n");
265			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_MSI)
266				efx->interrupt_mode = EFX_INT_MODE_MSI;
267			else
268				return rc;
269		} else if (rc < n_channels) {
270			netif_err(efx, drv, efx->net_dev,
271				  "WARNING: Insufficient MSI-X vectors"
272				  " available (%d < %u).\n", rc, n_channels);
273			netif_err(efx, drv, efx->net_dev,
274				  "WARNING: Performance may be reduced.\n");
275			n_channels = rc;
276		}
277
278		if (rc > 0) {
279			for (i = 0; i < efx->n_channels; i++)
280				efx_get_channel(efx, i)->irq =
281					xentries[i].vector;
282		}
283	}
284
285	/* Try single interrupt MSI */
286	if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
287		efx->n_channels = 1;
288		efx->n_rx_channels = 1;
289		efx->n_tx_channels = 1;
290		efx->tx_channel_offset = 0;
291		efx->n_xdp_channels = 0;
292		efx->xdp_channel_offset = efx->n_channels;
293		rc = pci_enable_msi(efx->pci_dev);
294		if (rc == 0) {
295			efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
296		} else {
297			netif_err(efx, drv, efx->net_dev,
298				  "could not enable MSI\n");
299			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_LEGACY)
300				efx->interrupt_mode = EFX_INT_MODE_LEGACY;
301			else
302				return rc;
303		}
304	}
305
306	/* Assume legacy interrupts */
307	if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
308		efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
309		efx->n_rx_channels = 1;
310		efx->n_tx_channels = 1;
311		efx->tx_channel_offset = efx_separate_tx_channels ? 1 : 0;
312		efx->n_xdp_channels = 0;
313		efx->xdp_channel_offset = efx->n_channels;
314		efx->legacy_irq = efx->pci_dev->irq;
315	}
316
317	/* Assign extra channels if possible, before XDP channels */
318	efx->n_extra_tx_channels = 0;
319	j = efx->xdp_channel_offset;
320	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++) {
321		if (!efx->extra_channel_type[i])
322			continue;
323		if (j <= efx->tx_channel_offset + efx->n_tx_channels) {
324			efx->extra_channel_type[i]->handle_no_channel(efx);
325		} else {
326			--j;
327			efx_get_channel(efx, j)->type =
328				efx->extra_channel_type[i];
329			if (efx_channel_has_tx_queues(efx_get_channel(efx, j)))
330				efx->n_extra_tx_channels++;
331		}
332	}
333
334	rss_spread = efx->n_rx_channels;
335	/* RSS might be usable on VFs even if it is disabled on the PF */
336#ifdef CONFIG_SFC_SRIOV
337	if (efx->type->sriov_wanted) {
338		efx->rss_spread = ((rss_spread > 1 ||
339				    !efx->type->sriov_wanted(efx)) ?
340				   rss_spread : efx_vf_size(efx));
341		return 0;
342	}
343#endif
344	efx->rss_spread = rss_spread;
345
346	return 0;
347}
348
349#if defined(CONFIG_SMP)
350void efx_set_interrupt_affinity(struct efx_nic *efx)
351{
352	struct efx_channel *channel;
353	unsigned int cpu;
354
355	efx_for_each_channel(channel, efx) {
356		cpu = cpumask_local_spread(channel->channel,
357					   pcibus_to_node(efx->pci_dev->bus));
358		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
359	}
360}
361
362void efx_clear_interrupt_affinity(struct efx_nic *efx)
363{
364	struct efx_channel *channel;
365
366	efx_for_each_channel(channel, efx)
367		irq_set_affinity_hint(channel->irq, NULL);
368}
369#else
370void
371efx_set_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
372{
373}
374
375void
376efx_clear_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
377{
378}
379#endif /* CONFIG_SMP */
380
381void efx_remove_interrupts(struct efx_nic *efx)
382{
383	struct efx_channel *channel;
384
385	/* Remove MSI/MSI-X interrupts */
386	efx_for_each_channel(channel, efx)
387		channel->irq = 0;
388	pci_disable_msi(efx->pci_dev);
389	pci_disable_msix(efx->pci_dev);
390
391	/* Remove legacy interrupt */
392	efx->legacy_irq = 0;
393}
394
395/***************
396 * EVENT QUEUES
397 ***************/
398
399/* Create event queue
400 * Event queue memory allocations are done only once.  If the channel
401 * is reset, the memory buffer will be reused; this guards against
402 * errors during channel reset and also simplifies interrupt handling.
403 */
404int efx_probe_eventq(struct efx_channel *channel)
405{
406	struct efx_nic *efx = channel->efx;
407	unsigned long entries;
408
409	netif_dbg(efx, probe, efx->net_dev,
410		  "chan %d create event queue\n", channel->channel);
411
412	/* Build an event queue with room for one event per tx and rx buffer,
413	 * plus some extra for link state events and MCDI completions.
414	 */
415	entries = roundup_pow_of_two(efx->rxq_entries + efx->txq_entries + 128);
416	EFX_WARN_ON_PARANOID(entries > EFX_MAX_EVQ_SIZE);
417	channel->eventq_mask = max(entries, EFX_MIN_EVQ_SIZE) - 1;
418
419	return efx_nic_probe_eventq(channel);
420}
421
422/* Prepare channel's event queue */
423int efx_init_eventq(struct efx_channel *channel)
424{
425	struct efx_nic *efx = channel->efx;
426	int rc;
427
428	EFX_WARN_ON_PARANOID(channel->eventq_init);
429
430	netif_dbg(efx, drv, efx->net_dev,
431		  "chan %d init event queue\n", channel->channel);
432
433	rc = efx_nic_init_eventq(channel);
434	if (rc == 0) {
435		efx->type->push_irq_moderation(channel);
436		channel->eventq_read_ptr = 0;
437		channel->eventq_init = true;
438	}
439	return rc;
440}
441
442/* Enable event queue processing and NAPI */
443void efx_start_eventq(struct efx_channel *channel)
444{
445	netif_dbg(channel->efx, ifup, channel->efx->net_dev,
446		  "chan %d start event queue\n", channel->channel);
447
448	/* Make sure the NAPI handler sees the enabled flag set */
449	channel->enabled = true;
450	smp_wmb();
451
452	napi_enable(&channel->napi_str);
453	efx_nic_eventq_read_ack(channel);
454}
455
456/* Disable event queue processing and NAPI */
457void efx_stop_eventq(struct efx_channel *channel)
458{
459	if (!channel->enabled)
460		return;
461
462	napi_disable(&channel->napi_str);
463	channel->enabled = false;
464}
465
466void efx_fini_eventq(struct efx_channel *channel)
467{
468	if (!channel->eventq_init)
469		return;
470
471	netif_dbg(channel->efx, drv, channel->efx->net_dev,
472		  "chan %d fini event queue\n", channel->channel);
473
474	efx_nic_fini_eventq(channel);
475	channel->eventq_init = false;
476}
477
478void efx_remove_eventq(struct efx_channel *channel)
479{
480	netif_dbg(channel->efx, drv, channel->efx->net_dev,
481		  "chan %d remove event queue\n", channel->channel);
482
483	efx_nic_remove_eventq(channel);
484}
485
486/**************************************************************************
487 *
488 * Channel handling
489 *
490 *************************************************************************/
491
492#ifdef CONFIG_RFS_ACCEL
493static void efx_filter_rfs_expire(struct work_struct *data)
494{
495	struct delayed_work *dwork = to_delayed_work(data);
496	struct efx_channel *channel;
497	unsigned int time, quota;
498
499	channel = container_of(dwork, struct efx_channel, filter_work);
500	time = jiffies - channel->rfs_last_expiry;
501	quota = channel->rfs_filter_count * time / (30 * HZ);
502	if (quota >= 20 && __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count, quota)))
503		channel->rfs_last_expiry += time;
504	/* Ensure we do more work eventually even if NAPI poll is not happening */
505	schedule_delayed_work(dwork, 30 * HZ);
506}
507#endif
508
509/* Allocate and initialise a channel structure. */
510static struct efx_channel *efx_alloc_channel(struct efx_nic *efx, int i)
511{
512	struct efx_rx_queue *rx_queue;
513	struct efx_tx_queue *tx_queue;
514	struct efx_channel *channel;
515	int j;
516
517	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
518	if (!channel)
519		return NULL;
520
521	channel->efx = efx;
522	channel->channel = i;
523	channel->type = &efx_default_channel_type;
524
525	for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
526		tx_queue = &channel->tx_queue[j];
527		tx_queue->efx = efx;
528		tx_queue->queue = -1;
529		tx_queue->label = j;
530		tx_queue->channel = channel;
531	}
532
533#ifdef CONFIG_RFS_ACCEL
534	INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
535#endif
536
537	rx_queue = &channel->rx_queue;
538	rx_queue->efx = efx;
539	timer_setup(&rx_queue->slow_fill, efx_rx_slow_fill, 0);
540
541	return channel;
542}
543
544int efx_init_channels(struct efx_nic *efx)
545{
546	unsigned int i;
547
548	for (i = 0; i < EFX_MAX_CHANNELS; i++) {
549		efx->channel[i] = efx_alloc_channel(efx, i);
550		if (!efx->channel[i])
551			return -ENOMEM;
552		efx->msi_context[i].efx = efx;
553		efx->msi_context[i].index = i;
554	}
555
556	/* Higher numbered interrupt modes are less capable! */
557	efx->interrupt_mode = min(efx->type->min_interrupt_mode,
558				  efx_interrupt_mode);
559
560	efx->max_channels = EFX_MAX_CHANNELS;
561	efx->max_tx_channels = EFX_MAX_CHANNELS;
562
563	return 0;
564}
565
566void efx_fini_channels(struct efx_nic *efx)
567{
568	unsigned int i;
569
570	for (i = 0; i < EFX_MAX_CHANNELS; i++)
571		if (efx->channel[i]) {
572			kfree(efx->channel[i]);
573			efx->channel[i] = NULL;
574		}
575}
576
577/* Allocate and initialise a channel structure, copying parameters
578 * (but not resources) from an old channel structure.
579 */
580struct efx_channel *efx_copy_channel(const struct efx_channel *old_channel)
581{
582	struct efx_rx_queue *rx_queue;
583	struct efx_tx_queue *tx_queue;
584	struct efx_channel *channel;
585	int j;
586
587	channel = kmalloc(sizeof(*channel), GFP_KERNEL);
588	if (!channel)
589		return NULL;
590
591	*channel = *old_channel;
592
593	channel->napi_dev = NULL;
594	INIT_HLIST_NODE(&channel->napi_str.napi_hash_node);
595	channel->napi_str.napi_id = 0;
596	channel->napi_str.state = 0;
597	memset(&channel->eventq, 0, sizeof(channel->eventq));
598
599	for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
600		tx_queue = &channel->tx_queue[j];
601		if (tx_queue->channel)
602			tx_queue->channel = channel;
603		tx_queue->buffer = NULL;
604		tx_queue->cb_page = NULL;
605		memset(&tx_queue->txd, 0, sizeof(tx_queue->txd));
606	}
607
608	rx_queue = &channel->rx_queue;
609	rx_queue->buffer = NULL;
610	memset(&rx_queue->rxd, 0, sizeof(rx_queue->rxd));
611	timer_setup(&rx_queue->slow_fill, efx_rx_slow_fill, 0);
612#ifdef CONFIG_RFS_ACCEL
613	INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
614#endif
615
616	return channel;
617}
618
619static int efx_probe_channel(struct efx_channel *channel)
620{
621	struct efx_tx_queue *tx_queue;
622	struct efx_rx_queue *rx_queue;
623	int rc;
624
625	netif_dbg(channel->efx, probe, channel->efx->net_dev,
626		  "creating channel %d\n", channel->channel);
627
628	rc = channel->type->pre_probe(channel);
629	if (rc)
630		goto fail;
631
632	rc = efx_probe_eventq(channel);
633	if (rc)
634		goto fail;
635
636	efx_for_each_channel_tx_queue(tx_queue, channel) {
637		rc = efx_probe_tx_queue(tx_queue);
638		if (rc)
639			goto fail;
640	}
641
642	efx_for_each_channel_rx_queue(rx_queue, channel) {
643		rc = efx_probe_rx_queue(rx_queue);
644		if (rc)
645			goto fail;
646	}
647
648	channel->rx_list = NULL;
649
650	return 0;
651
652fail:
653	efx_remove_channel(channel);
654	return rc;
655}
656
657void efx_get_channel_name(struct efx_channel *channel, char *buf, size_t len)
658{
659	struct efx_nic *efx = channel->efx;
660	const char *type;
661	int number;
662
663	number = channel->channel;
664
665	if (number >= efx->xdp_channel_offset &&
666	    !WARN_ON_ONCE(!efx->n_xdp_channels)) {
667		type = "-xdp";
668		number -= efx->xdp_channel_offset;
669	} else if (efx->tx_channel_offset == 0) {
670		type = "";
671	} else if (number < efx->tx_channel_offset) {
672		type = "-rx";
673	} else {
674		type = "-tx";
675		number -= efx->tx_channel_offset;
676	}
677	snprintf(buf, len, "%s%s-%d", efx->name, type, number);
678}
679
680void efx_set_channel_names(struct efx_nic *efx)
681{
682	struct efx_channel *channel;
683
684	efx_for_each_channel(channel, efx)
685		channel->type->get_name(channel,
686					efx->msi_context[channel->channel].name,
687					sizeof(efx->msi_context[0].name));
688}
689
690int efx_probe_channels(struct efx_nic *efx)
691{
692	struct efx_channel *channel;
693	int rc;
694
695	/* Restart special buffer allocation */
696	efx->next_buffer_table = 0;
697
698	/* Probe channels in reverse, so that any 'extra' channels
699	 * use the start of the buffer table. This allows the traffic
700	 * channels to be resized without moving them or wasting the
701	 * entries before them.
702	 */
703	efx_for_each_channel_rev(channel, efx) {
704		rc = efx_probe_channel(channel);
705		if (rc) {
706			netif_err(efx, probe, efx->net_dev,
707				  "failed to create channel %d\n",
708				  channel->channel);
709			goto fail;
710		}
711	}
712	efx_set_channel_names(efx);
713
714	return 0;
715
716fail:
717	efx_remove_channels(efx);
718	return rc;
719}
720
721void efx_remove_channel(struct efx_channel *channel)
722{
723	struct efx_tx_queue *tx_queue;
724	struct efx_rx_queue *rx_queue;
725
726	netif_dbg(channel->efx, drv, channel->efx->net_dev,
727		  "destroy chan %d\n", channel->channel);
728
729	efx_for_each_channel_rx_queue(rx_queue, channel)
730		efx_remove_rx_queue(rx_queue);
731	efx_for_each_channel_tx_queue(tx_queue, channel)
732		efx_remove_tx_queue(tx_queue);
733	efx_remove_eventq(channel);
734	channel->type->post_remove(channel);
735}
736
737void efx_remove_channels(struct efx_nic *efx)
738{
739	struct efx_channel *channel;
740
741	efx_for_each_channel(channel, efx)
742		efx_remove_channel(channel);
743
744	kfree(efx->xdp_tx_queues);
745}
746
747int efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries)
748{
749	struct efx_channel *other_channel[EFX_MAX_CHANNELS], *channel,
750			   *ptp_channel = efx_ptp_channel(efx);
751	struct efx_ptp_data *ptp_data = efx->ptp_data;
752	unsigned int i, next_buffer_table = 0;
753	u32 old_rxq_entries, old_txq_entries;
754	int rc, rc2;
755
756	rc = efx_check_disabled(efx);
757	if (rc)
758		return rc;
759
760	/* Not all channels should be reallocated. We must avoid
761	 * reallocating their buffer table entries.
762	 */
763	efx_for_each_channel(channel, efx) {
764		struct efx_rx_queue *rx_queue;
765		struct efx_tx_queue *tx_queue;
766
767		if (channel->type->copy)
768			continue;
769		next_buffer_table = max(next_buffer_table,
770					channel->eventq.index +
771					channel->eventq.entries);
772		efx_for_each_channel_rx_queue(rx_queue, channel)
773			next_buffer_table = max(next_buffer_table,
774						rx_queue->rxd.index +
775						rx_queue->rxd.entries);
776		efx_for_each_channel_tx_queue(tx_queue, channel)
777			next_buffer_table = max(next_buffer_table,
778						tx_queue->txd.index +
779						tx_queue->txd.entries);
780	}
781
782	efx_device_detach_sync(efx);
783	efx_stop_all(efx);
784	efx_soft_disable_interrupts(efx);
785
786	/* Clone channels (where possible) */
787	memset(other_channel, 0, sizeof(other_channel));
788	for (i = 0; i < efx->n_channels; i++) {
789		channel = efx->channel[i];
790		if (channel->type->copy)
791			channel = channel->type->copy(channel);
792		if (!channel) {
793			rc = -ENOMEM;
794			goto out;
795		}
796		other_channel[i] = channel;
797	}
798
799	/* Swap entry counts and channel pointers */
800	old_rxq_entries = efx->rxq_entries;
801	old_txq_entries = efx->txq_entries;
802	efx->rxq_entries = rxq_entries;
803	efx->txq_entries = txq_entries;
804	for (i = 0; i < efx->n_channels; i++)
805		swap(efx->channel[i], other_channel[i]);
806
807	/* Restart buffer table allocation */
808	efx->next_buffer_table = next_buffer_table;
809
810	for (i = 0; i < efx->n_channels; i++) {
811		channel = efx->channel[i];
812		if (!channel->type->copy)
813			continue;
814		rc = efx_probe_channel(channel);
815		if (rc)
816			goto rollback;
817		efx_init_napi_channel(efx->channel[i]);
818	}
819
820out:
821	efx->ptp_data = NULL;
822	/* Destroy unused channel structures */
823	for (i = 0; i < efx->n_channels; i++) {
824		channel = other_channel[i];
825		if (channel && channel->type->copy) {
826			efx_fini_napi_channel(channel);
827			efx_remove_channel(channel);
828			kfree(channel);
829		}
830	}
831
832	efx->ptp_data = ptp_data;
833	rc2 = efx_soft_enable_interrupts(efx);
834	if (rc2) {
835		rc = rc ? rc : rc2;
836		netif_err(efx, drv, efx->net_dev,
837			  "unable to restart interrupts on channel reallocation\n");
838		efx_schedule_reset(efx, RESET_TYPE_DISABLE);
839	} else {
840		efx_start_all(efx);
841		efx_device_attach_if_not_resetting(efx);
842	}
843	return rc;
844
845rollback:
846	/* Swap back */
847	efx->rxq_entries = old_rxq_entries;
848	efx->txq_entries = old_txq_entries;
849	for (i = 0; i < efx->n_channels; i++)
850		swap(efx->channel[i], other_channel[i]);
851	efx_ptp_update_channel(efx, ptp_channel);
852	goto out;
853}
854
855int efx_set_channels(struct efx_nic *efx)
856{
857	struct efx_tx_queue *tx_queue;
858	struct efx_channel *channel;
859	unsigned int next_queue = 0;
860	int xdp_queue_number;
861	int rc;
862
863	if (efx->xdp_tx_queue_count) {
864		EFX_WARN_ON_PARANOID(efx->xdp_tx_queues);
865
866		/* Allocate array for XDP TX queue lookup. */
867		efx->xdp_tx_queues = kcalloc(efx->xdp_tx_queue_count,
868					     sizeof(*efx->xdp_tx_queues),
869					     GFP_KERNEL);
870		if (!efx->xdp_tx_queues)
871			return -ENOMEM;
872	}
873
874	/* We need to mark which channels really have RX and TX
875	 * queues, and adjust the TX queue numbers if we have separate
876	 * RX-only and TX-only channels.
877	 */
878	xdp_queue_number = 0;
879	efx_for_each_channel(channel, efx) {
880		if (channel->channel < efx->n_rx_channels)
881			channel->rx_queue.core_index = channel->channel;
882		else
883			channel->rx_queue.core_index = -1;
884
885		if (channel->channel >= efx->tx_channel_offset) {
886			if (efx_channel_is_xdp_tx(channel)) {
887				efx_for_each_channel_tx_queue(tx_queue, channel) {
888					tx_queue->queue = next_queue++;
889
890					/* We may have a few left-over XDP TX
891					 * queues owing to xdp_tx_queue_count
892					 * not dividing evenly by EFX_MAX_TXQ_PER_CHANNEL.
893					 * We still allocate and probe those
894					 * TXQs, but never use them.
895					 */
896					if (xdp_queue_number < efx->xdp_tx_queue_count) {
897						netif_dbg(efx, drv, efx->net_dev, "Channel %u TXQ %u is XDP %u, HW %u\n",
898							  channel->channel, tx_queue->label,
899							  xdp_queue_number, tx_queue->queue);
900						efx->xdp_tx_queues[xdp_queue_number] = tx_queue;
901						xdp_queue_number++;
902					}
903				}
904			} else {
905				efx_for_each_channel_tx_queue(tx_queue, channel) {
906					tx_queue->queue = next_queue++;
907					netif_dbg(efx, drv, efx->net_dev, "Channel %u TXQ %u is HW %u\n",
908						  channel->channel, tx_queue->label,
909						  tx_queue->queue);
910				}
911			}
912		}
913	}
914	WARN_ON(xdp_queue_number != efx->xdp_tx_queue_count);
915
916	rc = netif_set_real_num_tx_queues(efx->net_dev, efx->n_tx_channels);
917	if (rc)
918		return rc;
919	return netif_set_real_num_rx_queues(efx->net_dev, efx->n_rx_channels);
920}
921
922bool efx_default_channel_want_txqs(struct efx_channel *channel)
923{
924	return channel->channel - channel->efx->tx_channel_offset <
925		channel->efx->n_tx_channels;
926}
927
928/*************
929 * START/STOP
930 *************/
931
932int efx_soft_enable_interrupts(struct efx_nic *efx)
933{
934	struct efx_channel *channel, *end_channel;
935	int rc;
936
937	BUG_ON(efx->state == STATE_DISABLED);
938
939	efx->irq_soft_enabled = true;
940	smp_wmb();
941
942	efx_for_each_channel(channel, efx) {
943		if (!channel->type->keep_eventq) {
944			rc = efx_init_eventq(channel);
945			if (rc)
946				goto fail;
947		}
948		efx_start_eventq(channel);
949	}
950
951	efx_mcdi_mode_event(efx);
952
953	return 0;
954fail:
955	end_channel = channel;
956	efx_for_each_channel(channel, efx) {
957		if (channel == end_channel)
958			break;
959		efx_stop_eventq(channel);
960		if (!channel->type->keep_eventq)
961			efx_fini_eventq(channel);
962	}
963
964	return rc;
965}
966
967void efx_soft_disable_interrupts(struct efx_nic *efx)
968{
969	struct efx_channel *channel;
970
971	if (efx->state == STATE_DISABLED)
972		return;
973
974	efx_mcdi_mode_poll(efx);
975
976	efx->irq_soft_enabled = false;
977	smp_wmb();
978
979	if (efx->legacy_irq)
980		synchronize_irq(efx->legacy_irq);
981
982	efx_for_each_channel(channel, efx) {
983		if (channel->irq)
984			synchronize_irq(channel->irq);
985
986		efx_stop_eventq(channel);
987		if (!channel->type->keep_eventq)
988			efx_fini_eventq(channel);
989	}
990
991	/* Flush the asynchronous MCDI request queue */
992	efx_mcdi_flush_async(efx);
993}
994
995int efx_enable_interrupts(struct efx_nic *efx)
996{
997	struct efx_channel *channel, *end_channel;
998	int rc;
999
1000	/* TODO: Is this really a bug? */
1001	BUG_ON(efx->state == STATE_DISABLED);
1002
1003	if (efx->eeh_disabled_legacy_irq) {
1004		enable_irq(efx->legacy_irq);
1005		efx->eeh_disabled_legacy_irq = false;
1006	}
1007
1008	efx->type->irq_enable_master(efx);
1009
1010	efx_for_each_channel(channel, efx) {
1011		if (channel->type->keep_eventq) {
1012			rc = efx_init_eventq(channel);
1013			if (rc)
1014				goto fail;
1015		}
1016	}
1017
1018	rc = efx_soft_enable_interrupts(efx);
1019	if (rc)
1020		goto fail;
1021
1022	return 0;
1023
1024fail:
1025	end_channel = channel;
1026	efx_for_each_channel(channel, efx) {
1027		if (channel == end_channel)
1028			break;
1029		if (channel->type->keep_eventq)
1030			efx_fini_eventq(channel);
1031	}
1032
1033	efx->type->irq_disable_non_ev(efx);
1034
1035	return rc;
1036}
1037
1038void efx_disable_interrupts(struct efx_nic *efx)
1039{
1040	struct efx_channel *channel;
1041
1042	efx_soft_disable_interrupts(efx);
1043
1044	efx_for_each_channel(channel, efx) {
1045		if (channel->type->keep_eventq)
1046			efx_fini_eventq(channel);
1047	}
1048
1049	efx->type->irq_disable_non_ev(efx);
1050}
1051
1052void efx_start_channels(struct efx_nic *efx)
1053{
1054	struct efx_tx_queue *tx_queue;
1055	struct efx_rx_queue *rx_queue;
1056	struct efx_channel *channel;
1057
1058	efx_for_each_channel(channel, efx) {
1059		efx_for_each_channel_tx_queue(tx_queue, channel) {
1060			efx_init_tx_queue(tx_queue);
1061			atomic_inc(&efx->active_queues);
1062		}
1063
1064		efx_for_each_channel_rx_queue(rx_queue, channel) {
1065			efx_init_rx_queue(rx_queue);
1066			atomic_inc(&efx->active_queues);
1067			efx_stop_eventq(channel);
1068			efx_fast_push_rx_descriptors(rx_queue, false);
1069			efx_start_eventq(channel);
1070		}
1071
1072		WARN_ON(channel->rx_pkt_n_frags);
1073	}
1074}
1075
1076void efx_stop_channels(struct efx_nic *efx)
1077{
1078	struct efx_tx_queue *tx_queue;
1079	struct efx_rx_queue *rx_queue;
1080	struct efx_channel *channel;
1081	int rc = 0;
1082
1083	/* Stop RX refill */
1084	efx_for_each_channel(channel, efx) {
1085		efx_for_each_channel_rx_queue(rx_queue, channel)
1086			rx_queue->refill_enabled = false;
1087	}
1088
1089	efx_for_each_channel(channel, efx) {
1090		/* RX packet processing is pipelined, so wait for the
1091		 * NAPI handler to complete.  At least event queue 0
1092		 * might be kept active by non-data events, so don't
1093		 * use napi_synchronize() but actually disable NAPI
1094		 * temporarily.
1095		 */
1096		if (efx_channel_has_rx_queue(channel)) {
1097			efx_stop_eventq(channel);
1098			efx_start_eventq(channel);
1099		}
1100	}
1101
1102	if (efx->type->fini_dmaq)
1103		rc = efx->type->fini_dmaq(efx);
1104
1105	if (rc) {
1106		netif_err(efx, drv, efx->net_dev, "failed to flush queues\n");
1107	} else {
1108		netif_dbg(efx, drv, efx->net_dev,
1109			  "successfully flushed all queues\n");
1110	}
1111
1112	efx_for_each_channel(channel, efx) {
1113		efx_for_each_channel_rx_queue(rx_queue, channel)
1114			efx_fini_rx_queue(rx_queue);
1115		efx_for_each_channel_tx_queue(tx_queue, channel)
1116			efx_fini_tx_queue(tx_queue);
1117	}
1118}
1119
1120/**************************************************************************
1121 *
1122 * NAPI interface
1123 *
1124 *************************************************************************/
1125
1126/* Process channel's event queue
1127 *
1128 * This function is responsible for processing the event queue of a
1129 * single channel.  The caller must guarantee that this function will
1130 * never be concurrently called more than once on the same channel,
1131 * though different channels may be being processed concurrently.
1132 */
1133static int efx_process_channel(struct efx_channel *channel, int budget)
1134{
1135	struct efx_tx_queue *tx_queue;
1136	struct list_head rx_list;
1137	int spent;
1138
1139	if (unlikely(!channel->enabled))
1140		return 0;
1141
1142	/* Prepare the batch receive list */
1143	EFX_WARN_ON_PARANOID(channel->rx_list != NULL);
1144	INIT_LIST_HEAD(&rx_list);
1145	channel->rx_list = &rx_list;
1146
1147	efx_for_each_channel_tx_queue(tx_queue, channel) {
1148		tx_queue->pkts_compl = 0;
1149		tx_queue->bytes_compl = 0;
1150	}
1151
1152	spent = efx_nic_process_eventq(channel, budget);
1153	if (spent && efx_channel_has_rx_queue(channel)) {
1154		struct efx_rx_queue *rx_queue =
1155			efx_channel_get_rx_queue(channel);
1156
1157		efx_rx_flush_packet(channel);
1158		efx_fast_push_rx_descriptors(rx_queue, true);
1159	}
1160
1161	/* Update BQL */
1162	efx_for_each_channel_tx_queue(tx_queue, channel) {
1163		if (tx_queue->bytes_compl) {
1164			netdev_tx_completed_queue(tx_queue->core_txq,
1165						  tx_queue->pkts_compl,
1166						  tx_queue->bytes_compl);
1167		}
1168	}
1169
1170	/* Receive any packets we queued up */
1171	netif_receive_skb_list(channel->rx_list);
1172	channel->rx_list = NULL;
1173
1174	return spent;
1175}
1176
1177static void efx_update_irq_mod(struct efx_nic *efx, struct efx_channel *channel)
1178{
1179	int step = efx->irq_mod_step_us;
1180
1181	if (channel->irq_mod_score < irq_adapt_low_thresh) {
1182		if (channel->irq_moderation_us > step) {
1183			channel->irq_moderation_us -= step;
1184			efx->type->push_irq_moderation(channel);
1185		}
1186	} else if (channel->irq_mod_score > irq_adapt_high_thresh) {
1187		if (channel->irq_moderation_us <
1188		    efx->irq_rx_moderation_us) {
1189			channel->irq_moderation_us += step;
1190			efx->type->push_irq_moderation(channel);
1191		}
1192	}
1193
1194	channel->irq_count = 0;
1195	channel->irq_mod_score = 0;
1196}
1197
1198/* NAPI poll handler
1199 *
1200 * NAPI guarantees serialisation of polls of the same device, which
1201 * provides the guarantee required by efx_process_channel().
1202 */
1203static int efx_poll(struct napi_struct *napi, int budget)
1204{
1205	struct efx_channel *channel =
1206		container_of(napi, struct efx_channel, napi_str);
1207	struct efx_nic *efx = channel->efx;
1208#ifdef CONFIG_RFS_ACCEL
1209	unsigned int time;
1210#endif
1211	int spent;
1212
1213	netif_vdbg(efx, intr, efx->net_dev,
1214		   "channel %d NAPI poll executing on CPU %d\n",
1215		   channel->channel, raw_smp_processor_id());
1216
1217	spent = efx_process_channel(channel, budget);
1218
1219	xdp_do_flush_map();
1220
1221	if (spent < budget) {
1222		if (efx_channel_has_rx_queue(channel) &&
1223		    efx->irq_rx_adaptive &&
1224		    unlikely(++channel->irq_count == 1000)) {
1225			efx_update_irq_mod(efx, channel);
1226		}
1227
1228#ifdef CONFIG_RFS_ACCEL
1229		/* Perhaps expire some ARFS filters */
1230		time = jiffies - channel->rfs_last_expiry;
1231		/* Would our quota be >= 20? */
1232		if (channel->rfs_filter_count * time >= 600 * HZ)
1233			mod_delayed_work(system_wq, &channel->filter_work, 0);
1234#endif
1235
1236		/* There is no race here; although napi_disable() will
1237		 * only wait for napi_complete(), this isn't a problem
1238		 * since efx_nic_eventq_read_ack() will have no effect if
1239		 * interrupts have already been disabled.
1240		 */
1241		if (napi_complete_done(napi, spent))
1242			efx_nic_eventq_read_ack(channel);
1243	}
1244
1245	return spent;
1246}
1247
1248void efx_init_napi_channel(struct efx_channel *channel)
1249{
1250	struct efx_nic *efx = channel->efx;
1251
1252	channel->napi_dev = efx->net_dev;
1253	netif_napi_add(channel->napi_dev, &channel->napi_str,
1254		       efx_poll, napi_weight);
1255}
1256
1257void efx_init_napi(struct efx_nic *efx)
1258{
1259	struct efx_channel *channel;
1260
1261	efx_for_each_channel(channel, efx)
1262		efx_init_napi_channel(channel);
1263}
1264
1265void efx_fini_napi_channel(struct efx_channel *channel)
1266{
1267	if (channel->napi_dev)
1268		netif_napi_del(&channel->napi_str);
1269
1270	channel->napi_dev = NULL;
1271}
1272
1273void efx_fini_napi(struct efx_nic *efx)
1274{
1275	struct efx_channel *channel;
1276
1277	efx_for_each_channel(channel, efx)
1278		efx_fini_napi_channel(channel);
1279}
1280