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 <linux/filter.h>
14#include "efx_channels.h"
15#include "efx.h"
16#include "efx_common.h"
17#include "tx_common.h"
18#include "rx_common.h"
19#include "nic.h"
20#include "sriov.h"
21#include "workarounds.h"
22
23/* This is the first interrupt mode to try out of:
24 * 0 => MSI-X
25 * 1 => MSI
26 * 2 => legacy
27 */
28unsigned int efx_siena_interrupt_mode = EFX_INT_MODE_MSIX;
29
30/* This is the requested number of CPUs to use for Receive-Side Scaling (RSS),
31 * i.e. the number of CPUs among which we may distribute simultaneous
32 * interrupt handling.
33 *
34 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.
35 * The default (0) means to assign an interrupt to each core.
36 */
37unsigned int efx_siena_rss_cpus;
38
39static unsigned int irq_adapt_low_thresh = 8000;
40module_param(irq_adapt_low_thresh, uint, 0644);
41MODULE_PARM_DESC(irq_adapt_low_thresh,
42		 "Threshold score for reducing IRQ moderation");
43
44static unsigned int irq_adapt_high_thresh = 16000;
45module_param(irq_adapt_high_thresh, uint, 0644);
46MODULE_PARM_DESC(irq_adapt_high_thresh,
47		 "Threshold score for increasing IRQ moderation");
48
49static const struct efx_channel_type efx_default_channel_type;
50
51/*************
52 * INTERRUPTS
53 *************/
54
55static unsigned int count_online_cores(struct efx_nic *efx, bool local_node)
56{
57	cpumask_var_t filter_mask;
58	unsigned int count;
59	int cpu;
60
61	if (unlikely(!zalloc_cpumask_var(&filter_mask, GFP_KERNEL))) {
62		netif_warn(efx, probe, efx->net_dev,
63			   "RSS disabled due to allocation failure\n");
64		return 1;
65	}
66
67	cpumask_copy(filter_mask, cpu_online_mask);
68	if (local_node)
69		cpumask_and(filter_mask, filter_mask,
70			    cpumask_of_pcibus(efx->pci_dev->bus));
71
72	count = 0;
73	for_each_cpu(cpu, filter_mask) {
74		++count;
75		cpumask_andnot(filter_mask, filter_mask, topology_sibling_cpumask(cpu));
76	}
77
78	free_cpumask_var(filter_mask);
79
80	return count;
81}
82
83static unsigned int efx_wanted_parallelism(struct efx_nic *efx)
84{
85	unsigned int count;
86
87	if (efx_siena_rss_cpus) {
88		count = efx_siena_rss_cpus;
89	} else {
90		count = count_online_cores(efx, true);
91
92		/* If no online CPUs in local node, fallback to any online CPUs */
93		if (count == 0)
94			count = count_online_cores(efx, false);
95	}
96
97	if (count > EFX_MAX_RX_QUEUES) {
98		netif_cond_dbg(efx, probe, efx->net_dev, !efx_siena_rss_cpus,
99			       warn,
100			       "Reducing number of rx queues from %u to %u.\n",
101			       count, EFX_MAX_RX_QUEUES);
102		count = EFX_MAX_RX_QUEUES;
103	}
104
105	/* If RSS is requested for the PF *and* VFs then we can't write RSS
106	 * table entries that are inaccessible to VFs
107	 */
108#ifdef CONFIG_SFC_SIENA_SRIOV
109	if (efx->type->sriov_wanted) {
110		if (efx->type->sriov_wanted(efx) && efx_vf_size(efx) > 1 &&
111		    count > efx_vf_size(efx)) {
112			netif_warn(efx, probe, efx->net_dev,
113				   "Reducing number of RSS channels from %u to %u for "
114				   "VF support. Increase vf-msix-limit to use more "
115				   "channels on the PF.\n",
116				   count, efx_vf_size(efx));
117			count = efx_vf_size(efx);
118		}
119	}
120#endif
121
122	return count;
123}
124
125static int efx_allocate_msix_channels(struct efx_nic *efx,
126				      unsigned int max_channels,
127				      unsigned int extra_channels,
128				      unsigned int parallelism)
129{
130	unsigned int n_channels = parallelism;
131	int vec_count;
132	int tx_per_ev;
133	int n_xdp_tx;
134	int n_xdp_ev;
135
136	if (efx_siena_separate_tx_channels)
137		n_channels *= 2;
138	n_channels += extra_channels;
139
140	/* To allow XDP transmit to happen from arbitrary NAPI contexts
141	 * we allocate a TX queue per CPU. We share event queues across
142	 * multiple tx queues, assuming tx and ev queues are both
143	 * maximum size.
144	 */
145	tx_per_ev = EFX_MAX_EVQ_SIZE / EFX_TXQ_MAX_ENT(efx);
146	tx_per_ev = min(tx_per_ev, EFX_MAX_TXQ_PER_CHANNEL);
147	n_xdp_tx = num_possible_cpus();
148	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, tx_per_ev);
149
150	vec_count = pci_msix_vec_count(efx->pci_dev);
151	if (vec_count < 0)
152		return vec_count;
153
154	max_channels = min_t(unsigned int, vec_count, max_channels);
155
156	/* Check resources.
157	 * We need a channel per event queue, plus a VI per tx queue.
158	 * This may be more pessimistic than it needs to be.
159	 */
160	if (n_channels >= max_channels) {
161		efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
162		netif_warn(efx, drv, efx->net_dev,
163			   "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
164			   n_xdp_ev, n_channels, max_channels);
165		netif_warn(efx, drv, efx->net_dev,
166			   "XDP_TX and XDP_REDIRECT might decrease device's performance\n");
167	} else if (n_channels + n_xdp_tx > efx->max_vis) {
168		efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
169		netif_warn(efx, drv, efx->net_dev,
170			   "Insufficient resources for %d XDP TX queues (%d other channels, max VIs %d)\n",
171			   n_xdp_tx, n_channels, efx->max_vis);
172		netif_warn(efx, drv, efx->net_dev,
173			   "XDP_TX and XDP_REDIRECT might decrease device's performance\n");
174	} else if (n_channels + n_xdp_ev > max_channels) {
175		efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_SHARED;
176		netif_warn(efx, drv, efx->net_dev,
177			   "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
178			   n_xdp_ev, n_channels, max_channels);
179
180		n_xdp_ev = max_channels - n_channels;
181		netif_warn(efx, drv, efx->net_dev,
182			   "XDP_TX and XDP_REDIRECT will work with reduced performance (%d cpus/tx_queue)\n",
183			   DIV_ROUND_UP(n_xdp_tx, tx_per_ev * n_xdp_ev));
184	} else {
185		efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_DEDICATED;
186	}
187
188	if (efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_BORROWED) {
189		efx->n_xdp_channels = n_xdp_ev;
190		efx->xdp_tx_per_channel = tx_per_ev;
191		efx->xdp_tx_queue_count = n_xdp_tx;
192		n_channels += n_xdp_ev;
193		netif_dbg(efx, drv, efx->net_dev,
194			  "Allocating %d TX and %d event queues for XDP\n",
195			  n_xdp_ev * tx_per_ev, n_xdp_ev);
196	} else {
197		efx->n_xdp_channels = 0;
198		efx->xdp_tx_per_channel = 0;
199		efx->xdp_tx_queue_count = n_xdp_tx;
200	}
201
202	if (vec_count < n_channels) {
203		netif_err(efx, drv, efx->net_dev,
204			  "WARNING: Insufficient MSI-X vectors available (%d < %u).\n",
205			  vec_count, n_channels);
206		netif_err(efx, drv, efx->net_dev,
207			  "WARNING: Performance may be reduced.\n");
208		n_channels = vec_count;
209	}
210
211	n_channels = min(n_channels, max_channels);
212
213	efx->n_channels = n_channels;
214
215	/* Ignore XDP tx channels when creating rx channels. */
216	n_channels -= efx->n_xdp_channels;
217
218	if (efx_siena_separate_tx_channels) {
219		efx->n_tx_channels =
220			min(max(n_channels / 2, 1U),
221			    efx->max_tx_channels);
222		efx->tx_channel_offset =
223			n_channels - efx->n_tx_channels;
224		efx->n_rx_channels =
225			max(n_channels -
226			    efx->n_tx_channels, 1U);
227	} else {
228		efx->n_tx_channels = min(n_channels, efx->max_tx_channels);
229		efx->tx_channel_offset = 0;
230		efx->n_rx_channels = n_channels;
231	}
232
233	efx->n_rx_channels = min(efx->n_rx_channels, parallelism);
234	efx->n_tx_channels = min(efx->n_tx_channels, parallelism);
235
236	efx->xdp_channel_offset = n_channels;
237
238	netif_dbg(efx, drv, efx->net_dev,
239		  "Allocating %u RX channels\n",
240		  efx->n_rx_channels);
241
242	return efx->n_channels;
243}
244
245/* Probe the number and type of interrupts we are able to obtain, and
246 * the resulting numbers of channels and RX queues.
247 */
248int efx_siena_probe_interrupts(struct efx_nic *efx)
249{
250	unsigned int extra_channels = 0;
251	unsigned int rss_spread;
252	unsigned int i, j;
253	int rc;
254
255	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++)
256		if (efx->extra_channel_type[i])
257			++extra_channels;
258
259	if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
260		unsigned int parallelism = efx_wanted_parallelism(efx);
261		struct msix_entry xentries[EFX_MAX_CHANNELS];
262		unsigned int n_channels;
263
264		rc = efx_allocate_msix_channels(efx, efx->max_channels,
265						extra_channels, parallelism);
266		if (rc >= 0) {
267			n_channels = rc;
268			for (i = 0; i < n_channels; i++)
269				xentries[i].entry = i;
270			rc = pci_enable_msix_range(efx->pci_dev, xentries, 1,
271						   n_channels);
272		}
273		if (rc < 0) {
274			/* Fall back to single channel MSI */
275			netif_err(efx, drv, efx->net_dev,
276				  "could not enable MSI-X\n");
277			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_MSI)
278				efx->interrupt_mode = EFX_INT_MODE_MSI;
279			else
280				return rc;
281		} else if (rc < n_channels) {
282			netif_err(efx, drv, efx->net_dev,
283				  "WARNING: Insufficient MSI-X vectors"
284				  " available (%d < %u).\n", rc, n_channels);
285			netif_err(efx, drv, efx->net_dev,
286				  "WARNING: Performance may be reduced.\n");
287			n_channels = rc;
288		}
289
290		if (rc > 0) {
291			for (i = 0; i < efx->n_channels; i++)
292				efx_get_channel(efx, i)->irq =
293					xentries[i].vector;
294		}
295	}
296
297	/* Try single interrupt MSI */
298	if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
299		efx->n_channels = 1;
300		efx->n_rx_channels = 1;
301		efx->n_tx_channels = 1;
302		efx->tx_channel_offset = 0;
303		efx->n_xdp_channels = 0;
304		efx->xdp_channel_offset = efx->n_channels;
305		efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
306		rc = pci_enable_msi(efx->pci_dev);
307		if (rc == 0) {
308			efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
309		} else {
310			netif_err(efx, drv, efx->net_dev,
311				  "could not enable MSI\n");
312			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_LEGACY)
313				efx->interrupt_mode = EFX_INT_MODE_LEGACY;
314			else
315				return rc;
316		}
317	}
318
319	/* Assume legacy interrupts */
320	if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
321		efx->n_channels = 1 + (efx_siena_separate_tx_channels ? 1 : 0);
322		efx->n_rx_channels = 1;
323		efx->n_tx_channels = 1;
324		efx->tx_channel_offset = efx_siena_separate_tx_channels ? 1 : 0;
325		efx->n_xdp_channels = 0;
326		efx->xdp_channel_offset = efx->n_channels;
327		efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
328		efx->legacy_irq = efx->pci_dev->irq;
329	}
330
331	/* Assign extra channels if possible, before XDP channels */
332	efx->n_extra_tx_channels = 0;
333	j = efx->xdp_channel_offset;
334	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++) {
335		if (!efx->extra_channel_type[i])
336			continue;
337		if (j <= efx->tx_channel_offset + efx->n_tx_channels) {
338			efx->extra_channel_type[i]->handle_no_channel(efx);
339		} else {
340			--j;
341			efx_get_channel(efx, j)->type =
342				efx->extra_channel_type[i];
343			if (efx_channel_has_tx_queues(efx_get_channel(efx, j)))
344				efx->n_extra_tx_channels++;
345		}
346	}
347
348	rss_spread = efx->n_rx_channels;
349	/* RSS might be usable on VFs even if it is disabled on the PF */
350#ifdef CONFIG_SFC_SIENA_SRIOV
351	if (efx->type->sriov_wanted) {
352		efx->rss_spread = ((rss_spread > 1 ||
353				    !efx->type->sriov_wanted(efx)) ?
354				   rss_spread : efx_vf_size(efx));
355		return 0;
356	}
357#endif
358	efx->rss_spread = rss_spread;
359
360	return 0;
361}
362
363#if defined(CONFIG_SMP)
364void efx_siena_set_interrupt_affinity(struct efx_nic *efx)
365{
366	const struct cpumask *numa_mask = cpumask_of_pcibus(efx->pci_dev->bus);
367	struct efx_channel *channel;
368	unsigned int cpu;
369
370	/* If no online CPUs in local node, fallback to any online CPU */
371	if (cpumask_first_and(cpu_online_mask, numa_mask) >= nr_cpu_ids)
372		numa_mask = cpu_online_mask;
373
374	cpu = -1;
375	efx_for_each_channel(channel, efx) {
376		cpu = cpumask_next_and(cpu, cpu_online_mask, numa_mask);
377		if (cpu >= nr_cpu_ids)
378			cpu = cpumask_first_and(cpu_online_mask, numa_mask);
379		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
380	}
381}
382
383void efx_siena_clear_interrupt_affinity(struct efx_nic *efx)
384{
385	struct efx_channel *channel;
386
387	efx_for_each_channel(channel, efx)
388		irq_set_affinity_hint(channel->irq, NULL);
389}
390#else
391void
392efx_siena_set_interrupt_affinity(struct efx_nic *efx __always_unused)
393{
394}
395
396void
397efx_siena_clear_interrupt_affinity(struct efx_nic *efx __always_unused)
398{
399}
400#endif /* CONFIG_SMP */
401
402void efx_siena_remove_interrupts(struct efx_nic *efx)
403{
404	struct efx_channel *channel;
405
406	/* Remove MSI/MSI-X interrupts */
407	efx_for_each_channel(channel, efx)
408		channel->irq = 0;
409	pci_disable_msi(efx->pci_dev);
410	pci_disable_msix(efx->pci_dev);
411
412	/* Remove legacy interrupt */
413	efx->legacy_irq = 0;
414}
415
416/***************
417 * EVENT QUEUES
418 ***************/
419
420/* Create event queue
421 * Event queue memory allocations are done only once.  If the channel
422 * is reset, the memory buffer will be reused; this guards against
423 * errors during channel reset and also simplifies interrupt handling.
424 */
425static int efx_probe_eventq(struct efx_channel *channel)
426{
427	struct efx_nic *efx = channel->efx;
428	unsigned long entries;
429
430	netif_dbg(efx, probe, efx->net_dev,
431		  "chan %d create event queue\n", channel->channel);
432
433	/* Build an event queue with room for one event per tx and rx buffer,
434	 * plus some extra for link state events and MCDI completions.
435	 */
436	entries = roundup_pow_of_two(efx->rxq_entries + efx->txq_entries + 128);
437	EFX_WARN_ON_PARANOID(entries > EFX_MAX_EVQ_SIZE);
438	channel->eventq_mask = max(entries, EFX_MIN_EVQ_SIZE) - 1;
439
440	return efx_nic_probe_eventq(channel);
441}
442
443/* Prepare channel's event queue */
444static int efx_init_eventq(struct efx_channel *channel)
445{
446	struct efx_nic *efx = channel->efx;
447	int rc;
448
449	EFX_WARN_ON_PARANOID(channel->eventq_init);
450
451	netif_dbg(efx, drv, efx->net_dev,
452		  "chan %d init event queue\n", channel->channel);
453
454	rc = efx_nic_init_eventq(channel);
455	if (rc == 0) {
456		efx->type->push_irq_moderation(channel);
457		channel->eventq_read_ptr = 0;
458		channel->eventq_init = true;
459	}
460	return rc;
461}
462
463/* Enable event queue processing and NAPI */
464void efx_siena_start_eventq(struct efx_channel *channel)
465{
466	netif_dbg(channel->efx, ifup, channel->efx->net_dev,
467		  "chan %d start event queue\n", channel->channel);
468
469	/* Make sure the NAPI handler sees the enabled flag set */
470	channel->enabled = true;
471	smp_wmb();
472
473	napi_enable(&channel->napi_str);
474	efx_nic_eventq_read_ack(channel);
475}
476
477/* Disable event queue processing and NAPI */
478void efx_siena_stop_eventq(struct efx_channel *channel)
479{
480	if (!channel->enabled)
481		return;
482
483	napi_disable(&channel->napi_str);
484	channel->enabled = false;
485}
486
487static void efx_fini_eventq(struct efx_channel *channel)
488{
489	if (!channel->eventq_init)
490		return;
491
492	netif_dbg(channel->efx, drv, channel->efx->net_dev,
493		  "chan %d fini event queue\n", channel->channel);
494
495	efx_nic_fini_eventq(channel);
496	channel->eventq_init = false;
497}
498
499static void efx_remove_eventq(struct efx_channel *channel)
500{
501	netif_dbg(channel->efx, drv, channel->efx->net_dev,
502		  "chan %d remove event queue\n", channel->channel);
503
504	efx_nic_remove_eventq(channel);
505}
506
507/**************************************************************************
508 *
509 * Channel handling
510 *
511 *************************************************************************/
512
513#ifdef CONFIG_RFS_ACCEL
514static void efx_filter_rfs_expire(struct work_struct *data)
515{
516	struct delayed_work *dwork = to_delayed_work(data);
517	struct efx_channel *channel;
518	unsigned int time, quota;
519
520	channel = container_of(dwork, struct efx_channel, filter_work);
521	time = jiffies - channel->rfs_last_expiry;
522	quota = channel->rfs_filter_count * time / (30 * HZ);
523	if (quota >= 20 && __efx_siena_filter_rfs_expire(channel,
524					min(channel->rfs_filter_count, quota)))
525		channel->rfs_last_expiry += time;
526	/* Ensure we do more work eventually even if NAPI poll is not happening */
527	schedule_delayed_work(dwork, 30 * HZ);
528}
529#endif
530
531/* Allocate and initialise a channel structure. */
532static struct efx_channel *efx_alloc_channel(struct efx_nic *efx, int i)
533{
534	struct efx_rx_queue *rx_queue;
535	struct efx_tx_queue *tx_queue;
536	struct efx_channel *channel;
537	int j;
538
539	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
540	if (!channel)
541		return NULL;
542
543	channel->efx = efx;
544	channel->channel = i;
545	channel->type = &efx_default_channel_type;
546
547	for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
548		tx_queue = &channel->tx_queue[j];
549		tx_queue->efx = efx;
550		tx_queue->queue = -1;
551		tx_queue->label = j;
552		tx_queue->channel = channel;
553	}
554
555#ifdef CONFIG_RFS_ACCEL
556	INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
557#endif
558
559	rx_queue = &channel->rx_queue;
560	rx_queue->efx = efx;
561	timer_setup(&rx_queue->slow_fill, efx_siena_rx_slow_fill, 0);
562
563	return channel;
564}
565
566int efx_siena_init_channels(struct efx_nic *efx)
567{
568	unsigned int i;
569
570	for (i = 0; i < EFX_MAX_CHANNELS; i++) {
571		efx->channel[i] = efx_alloc_channel(efx, i);
572		if (!efx->channel[i])
573			return -ENOMEM;
574		efx->msi_context[i].efx = efx;
575		efx->msi_context[i].index = i;
576	}
577
578	/* Higher numbered interrupt modes are less capable! */
579	efx->interrupt_mode = min(efx->type->min_interrupt_mode,
580				  efx_siena_interrupt_mode);
581
582	efx->max_channels = EFX_MAX_CHANNELS;
583	efx->max_tx_channels = EFX_MAX_CHANNELS;
584
585	return 0;
586}
587
588void efx_siena_fini_channels(struct efx_nic *efx)
589{
590	unsigned int i;
591
592	for (i = 0; i < EFX_MAX_CHANNELS; i++)
593		if (efx->channel[i]) {
594			kfree(efx->channel[i]);
595			efx->channel[i] = NULL;
596		}
597}
598
599/* Allocate and initialise a channel structure, copying parameters
600 * (but not resources) from an old channel structure.
601 */
602static
603struct efx_channel *efx_copy_channel(const struct efx_channel *old_channel)
604{
605	struct efx_rx_queue *rx_queue;
606	struct efx_tx_queue *tx_queue;
607	struct efx_channel *channel;
608	int j;
609
610	channel = kmalloc(sizeof(*channel), GFP_KERNEL);
611	if (!channel)
612		return NULL;
613
614	*channel = *old_channel;
615
616	channel->napi_dev = NULL;
617	INIT_HLIST_NODE(&channel->napi_str.napi_hash_node);
618	channel->napi_str.napi_id = 0;
619	channel->napi_str.state = 0;
620	memset(&channel->eventq, 0, sizeof(channel->eventq));
621
622	for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
623		tx_queue = &channel->tx_queue[j];
624		if (tx_queue->channel)
625			tx_queue->channel = channel;
626		tx_queue->buffer = NULL;
627		tx_queue->cb_page = NULL;
628		memset(&tx_queue->txd, 0, sizeof(tx_queue->txd));
629	}
630
631	rx_queue = &channel->rx_queue;
632	rx_queue->buffer = NULL;
633	memset(&rx_queue->rxd, 0, sizeof(rx_queue->rxd));
634	timer_setup(&rx_queue->slow_fill, efx_siena_rx_slow_fill, 0);
635#ifdef CONFIG_RFS_ACCEL
636	INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
637#endif
638
639	return channel;
640}
641
642static int efx_probe_channel(struct efx_channel *channel)
643{
644	struct efx_tx_queue *tx_queue;
645	struct efx_rx_queue *rx_queue;
646	int rc;
647
648	netif_dbg(channel->efx, probe, channel->efx->net_dev,
649		  "creating channel %d\n", channel->channel);
650
651	rc = channel->type->pre_probe(channel);
652	if (rc)
653		goto fail;
654
655	rc = efx_probe_eventq(channel);
656	if (rc)
657		goto fail;
658
659	efx_for_each_channel_tx_queue(tx_queue, channel) {
660		rc = efx_siena_probe_tx_queue(tx_queue);
661		if (rc)
662			goto fail;
663	}
664
665	efx_for_each_channel_rx_queue(rx_queue, channel) {
666		rc = efx_siena_probe_rx_queue(rx_queue);
667		if (rc)
668			goto fail;
669	}
670
671	channel->rx_list = NULL;
672
673	return 0;
674
675fail:
676	efx_siena_remove_channel(channel);
677	return rc;
678}
679
680static void efx_get_channel_name(struct efx_channel *channel, char *buf,
681				 size_t len)
682{
683	struct efx_nic *efx = channel->efx;
684	const char *type;
685	int number;
686
687	number = channel->channel;
688
689	if (number >= efx->xdp_channel_offset &&
690	    !WARN_ON_ONCE(!efx->n_xdp_channels)) {
691		type = "-xdp";
692		number -= efx->xdp_channel_offset;
693	} else if (efx->tx_channel_offset == 0) {
694		type = "";
695	} else if (number < efx->tx_channel_offset) {
696		type = "-rx";
697	} else {
698		type = "-tx";
699		number -= efx->tx_channel_offset;
700	}
701	snprintf(buf, len, "%s%s-%d", efx->name, type, number);
702}
703
704void efx_siena_set_channel_names(struct efx_nic *efx)
705{
706	struct efx_channel *channel;
707
708	efx_for_each_channel(channel, efx)
709		channel->type->get_name(channel,
710					efx->msi_context[channel->channel].name,
711					sizeof(efx->msi_context[0].name));
712}
713
714int efx_siena_probe_channels(struct efx_nic *efx)
715{
716	struct efx_channel *channel;
717	int rc;
718
719	/* Restart special buffer allocation */
720	efx->next_buffer_table = 0;
721
722	/* Probe channels in reverse, so that any 'extra' channels
723	 * use the start of the buffer table. This allows the traffic
724	 * channels to be resized without moving them or wasting the
725	 * entries before them.
726	 */
727	efx_for_each_channel_rev(channel, efx) {
728		rc = efx_probe_channel(channel);
729		if (rc) {
730			netif_err(efx, probe, efx->net_dev,
731				  "failed to create channel %d\n",
732				  channel->channel);
733			goto fail;
734		}
735	}
736	efx_siena_set_channel_names(efx);
737
738	return 0;
739
740fail:
741	efx_siena_remove_channels(efx);
742	return rc;
743}
744
745void efx_siena_remove_channel(struct efx_channel *channel)
746{
747	struct efx_tx_queue *tx_queue;
748	struct efx_rx_queue *rx_queue;
749
750	netif_dbg(channel->efx, drv, channel->efx->net_dev,
751		  "destroy chan %d\n", channel->channel);
752
753	efx_for_each_channel_rx_queue(rx_queue, channel)
754		efx_siena_remove_rx_queue(rx_queue);
755	efx_for_each_channel_tx_queue(tx_queue, channel)
756		efx_siena_remove_tx_queue(tx_queue);
757	efx_remove_eventq(channel);
758	channel->type->post_remove(channel);
759}
760
761void efx_siena_remove_channels(struct efx_nic *efx)
762{
763	struct efx_channel *channel;
764
765	efx_for_each_channel(channel, efx)
766		efx_siena_remove_channel(channel);
767
768	kfree(efx->xdp_tx_queues);
769}
770
771static int efx_set_xdp_tx_queue(struct efx_nic *efx, int xdp_queue_number,
772				struct efx_tx_queue *tx_queue)
773{
774	if (xdp_queue_number >= efx->xdp_tx_queue_count)
775		return -EINVAL;
776
777	netif_dbg(efx, drv, efx->net_dev,
778		  "Channel %u TXQ %u is XDP %u, HW %u\n",
779		  tx_queue->channel->channel, tx_queue->label,
780		  xdp_queue_number, tx_queue->queue);
781	efx->xdp_tx_queues[xdp_queue_number] = tx_queue;
782	return 0;
783}
784
785static void efx_set_xdp_channels(struct efx_nic *efx)
786{
787	struct efx_tx_queue *tx_queue;
788	struct efx_channel *channel;
789	unsigned int next_queue = 0;
790	int xdp_queue_number = 0;
791	int rc;
792
793	/* We need to mark which channels really have RX and TX
794	 * queues, and adjust the TX queue numbers if we have separate
795	 * RX-only and TX-only channels.
796	 */
797	efx_for_each_channel(channel, efx) {
798		if (channel->channel < efx->tx_channel_offset)
799			continue;
800
801		if (efx_channel_is_xdp_tx(channel)) {
802			efx_for_each_channel_tx_queue(tx_queue, channel) {
803				tx_queue->queue = next_queue++;
804				rc = efx_set_xdp_tx_queue(efx, xdp_queue_number,
805							  tx_queue);
806				if (rc == 0)
807					xdp_queue_number++;
808			}
809		} else {
810			efx_for_each_channel_tx_queue(tx_queue, channel) {
811				tx_queue->queue = next_queue++;
812				netif_dbg(efx, drv, efx->net_dev,
813					  "Channel %u TXQ %u is HW %u\n",
814					  channel->channel, tx_queue->label,
815					  tx_queue->queue);
816			}
817
818			/* If XDP is borrowing queues from net stack, it must
819			 * use the queue with no csum offload, which is the
820			 * first one of the channel
821			 * (note: tx_queue_by_type is not initialized yet)
822			 */
823			if (efx->xdp_txq_queues_mode ==
824			    EFX_XDP_TX_QUEUES_BORROWED) {
825				tx_queue = &channel->tx_queue[0];
826				rc = efx_set_xdp_tx_queue(efx, xdp_queue_number,
827							  tx_queue);
828				if (rc == 0)
829					xdp_queue_number++;
830			}
831		}
832	}
833	WARN_ON(efx->xdp_txq_queues_mode == EFX_XDP_TX_QUEUES_DEDICATED &&
834		xdp_queue_number != efx->xdp_tx_queue_count);
835	WARN_ON(efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_DEDICATED &&
836		xdp_queue_number > efx->xdp_tx_queue_count);
837
838	/* If we have more CPUs than assigned XDP TX queues, assign the already
839	 * existing queues to the exceeding CPUs
840	 */
841	next_queue = 0;
842	while (xdp_queue_number < efx->xdp_tx_queue_count) {
843		tx_queue = efx->xdp_tx_queues[next_queue++];
844		rc = efx_set_xdp_tx_queue(efx, xdp_queue_number, tx_queue);
845		if (rc == 0)
846			xdp_queue_number++;
847	}
848}
849
850static int efx_soft_enable_interrupts(struct efx_nic *efx);
851static void efx_soft_disable_interrupts(struct efx_nic *efx);
852static void efx_init_napi_channel(struct efx_channel *channel);
853static void efx_fini_napi_channel(struct efx_channel *channel);
854
855int efx_siena_realloc_channels(struct efx_nic *efx, u32 rxq_entries,
856			       u32 txq_entries)
857{
858	struct efx_channel *other_channel[EFX_MAX_CHANNELS], *channel;
859	unsigned int i, next_buffer_table = 0;
860	u32 old_rxq_entries, old_txq_entries;
861	int rc, rc2;
862
863	rc = efx_check_disabled(efx);
864	if (rc)
865		return rc;
866
867	/* Not all channels should be reallocated. We must avoid
868	 * reallocating their buffer table entries.
869	 */
870	efx_for_each_channel(channel, efx) {
871		struct efx_rx_queue *rx_queue;
872		struct efx_tx_queue *tx_queue;
873
874		if (channel->type->copy)
875			continue;
876		next_buffer_table = max(next_buffer_table,
877					channel->eventq.index +
878					channel->eventq.entries);
879		efx_for_each_channel_rx_queue(rx_queue, channel)
880			next_buffer_table = max(next_buffer_table,
881						rx_queue->rxd.index +
882						rx_queue->rxd.entries);
883		efx_for_each_channel_tx_queue(tx_queue, channel)
884			next_buffer_table = max(next_buffer_table,
885						tx_queue->txd.index +
886						tx_queue->txd.entries);
887	}
888
889	efx_device_detach_sync(efx);
890	efx_siena_stop_all(efx);
891	efx_soft_disable_interrupts(efx);
892
893	/* Clone channels (where possible) */
894	memset(other_channel, 0, sizeof(other_channel));
895	for (i = 0; i < efx->n_channels; i++) {
896		channel = efx->channel[i];
897		if (channel->type->copy)
898			channel = channel->type->copy(channel);
899		if (!channel) {
900			rc = -ENOMEM;
901			goto out;
902		}
903		other_channel[i] = channel;
904	}
905
906	/* Swap entry counts and channel pointers */
907	old_rxq_entries = efx->rxq_entries;
908	old_txq_entries = efx->txq_entries;
909	efx->rxq_entries = rxq_entries;
910	efx->txq_entries = txq_entries;
911	for (i = 0; i < efx->n_channels; i++)
912		swap(efx->channel[i], other_channel[i]);
913
914	/* Restart buffer table allocation */
915	efx->next_buffer_table = next_buffer_table;
916
917	for (i = 0; i < efx->n_channels; i++) {
918		channel = efx->channel[i];
919		if (!channel->type->copy)
920			continue;
921		rc = efx_probe_channel(channel);
922		if (rc)
923			goto rollback;
924		efx_init_napi_channel(efx->channel[i]);
925	}
926
927	efx_set_xdp_channels(efx);
928out:
929	/* Destroy unused channel structures */
930	for (i = 0; i < efx->n_channels; i++) {
931		channel = other_channel[i];
932		if (channel && channel->type->copy) {
933			efx_fini_napi_channel(channel);
934			efx_siena_remove_channel(channel);
935			kfree(channel);
936		}
937	}
938
939	rc2 = efx_soft_enable_interrupts(efx);
940	if (rc2) {
941		rc = rc ? rc : rc2;
942		netif_err(efx, drv, efx->net_dev,
943			  "unable to restart interrupts on channel reallocation\n");
944		efx_siena_schedule_reset(efx, RESET_TYPE_DISABLE);
945	} else {
946		efx_siena_start_all(efx);
947		efx_device_attach_if_not_resetting(efx);
948	}
949	return rc;
950
951rollback:
952	/* Swap back */
953	efx->rxq_entries = old_rxq_entries;
954	efx->txq_entries = old_txq_entries;
955	for (i = 0; i < efx->n_channels; i++)
956		swap(efx->channel[i], other_channel[i]);
957	goto out;
958}
959
960int efx_siena_set_channels(struct efx_nic *efx)
961{
962	struct efx_channel *channel;
963	int rc;
964
965	if (efx->xdp_tx_queue_count) {
966		EFX_WARN_ON_PARANOID(efx->xdp_tx_queues);
967
968		/* Allocate array for XDP TX queue lookup. */
969		efx->xdp_tx_queues = kcalloc(efx->xdp_tx_queue_count,
970					     sizeof(*efx->xdp_tx_queues),
971					     GFP_KERNEL);
972		if (!efx->xdp_tx_queues)
973			return -ENOMEM;
974	}
975
976	efx_for_each_channel(channel, efx) {
977		if (channel->channel < efx->n_rx_channels)
978			channel->rx_queue.core_index = channel->channel;
979		else
980			channel->rx_queue.core_index = -1;
981	}
982
983	efx_set_xdp_channels(efx);
984
985	rc = netif_set_real_num_tx_queues(efx->net_dev, efx->n_tx_channels);
986	if (rc)
987		return rc;
988	return netif_set_real_num_rx_queues(efx->net_dev, efx->n_rx_channels);
989}
990
991static bool efx_default_channel_want_txqs(struct efx_channel *channel)
992{
993	return channel->channel - channel->efx->tx_channel_offset <
994		channel->efx->n_tx_channels;
995}
996
997/*************
998 * START/STOP
999 *************/
1000
1001static int efx_soft_enable_interrupts(struct efx_nic *efx)
1002{
1003	struct efx_channel *channel, *end_channel;
1004	int rc;
1005
1006	BUG_ON(efx->state == STATE_DISABLED);
1007
1008	efx->irq_soft_enabled = true;
1009	smp_wmb();
1010
1011	efx_for_each_channel(channel, efx) {
1012		if (!channel->type->keep_eventq) {
1013			rc = efx_init_eventq(channel);
1014			if (rc)
1015				goto fail;
1016		}
1017		efx_siena_start_eventq(channel);
1018	}
1019
1020	efx_siena_mcdi_mode_event(efx);
1021
1022	return 0;
1023fail:
1024	end_channel = channel;
1025	efx_for_each_channel(channel, efx) {
1026		if (channel == end_channel)
1027			break;
1028		efx_siena_stop_eventq(channel);
1029		if (!channel->type->keep_eventq)
1030			efx_fini_eventq(channel);
1031	}
1032
1033	return rc;
1034}
1035
1036static void efx_soft_disable_interrupts(struct efx_nic *efx)
1037{
1038	struct efx_channel *channel;
1039
1040	if (efx->state == STATE_DISABLED)
1041		return;
1042
1043	efx_siena_mcdi_mode_poll(efx);
1044
1045	efx->irq_soft_enabled = false;
1046	smp_wmb();
1047
1048	if (efx->legacy_irq)
1049		synchronize_irq(efx->legacy_irq);
1050
1051	efx_for_each_channel(channel, efx) {
1052		if (channel->irq)
1053			synchronize_irq(channel->irq);
1054
1055		efx_siena_stop_eventq(channel);
1056		if (!channel->type->keep_eventq)
1057			efx_fini_eventq(channel);
1058	}
1059
1060	/* Flush the asynchronous MCDI request queue */
1061	efx_siena_mcdi_flush_async(efx);
1062}
1063
1064int efx_siena_enable_interrupts(struct efx_nic *efx)
1065{
1066	struct efx_channel *channel, *end_channel;
1067	int rc;
1068
1069	/* TODO: Is this really a bug? */
1070	BUG_ON(efx->state == STATE_DISABLED);
1071
1072	if (efx->eeh_disabled_legacy_irq) {
1073		enable_irq(efx->legacy_irq);
1074		efx->eeh_disabled_legacy_irq = false;
1075	}
1076
1077	efx->type->irq_enable_master(efx);
1078
1079	efx_for_each_channel(channel, efx) {
1080		if (channel->type->keep_eventq) {
1081			rc = efx_init_eventq(channel);
1082			if (rc)
1083				goto fail;
1084		}
1085	}
1086
1087	rc = efx_soft_enable_interrupts(efx);
1088	if (rc)
1089		goto fail;
1090
1091	return 0;
1092
1093fail:
1094	end_channel = channel;
1095	efx_for_each_channel(channel, efx) {
1096		if (channel == end_channel)
1097			break;
1098		if (channel->type->keep_eventq)
1099			efx_fini_eventq(channel);
1100	}
1101
1102	efx->type->irq_disable_non_ev(efx);
1103
1104	return rc;
1105}
1106
1107void efx_siena_disable_interrupts(struct efx_nic *efx)
1108{
1109	struct efx_channel *channel;
1110
1111	efx_soft_disable_interrupts(efx);
1112
1113	efx_for_each_channel(channel, efx) {
1114		if (channel->type->keep_eventq)
1115			efx_fini_eventq(channel);
1116	}
1117
1118	efx->type->irq_disable_non_ev(efx);
1119}
1120
1121void efx_siena_start_channels(struct efx_nic *efx)
1122{
1123	struct efx_tx_queue *tx_queue;
1124	struct efx_rx_queue *rx_queue;
1125	struct efx_channel *channel;
1126
1127	efx_for_each_channel_rev(channel, efx) {
1128		efx_for_each_channel_tx_queue(tx_queue, channel) {
1129			efx_siena_init_tx_queue(tx_queue);
1130			atomic_inc(&efx->active_queues);
1131		}
1132
1133		efx_for_each_channel_rx_queue(rx_queue, channel) {
1134			efx_siena_init_rx_queue(rx_queue);
1135			atomic_inc(&efx->active_queues);
1136			efx_siena_stop_eventq(channel);
1137			efx_siena_fast_push_rx_descriptors(rx_queue, false);
1138			efx_siena_start_eventq(channel);
1139		}
1140
1141		WARN_ON(channel->rx_pkt_n_frags);
1142	}
1143}
1144
1145void efx_siena_stop_channels(struct efx_nic *efx)
1146{
1147	struct efx_tx_queue *tx_queue;
1148	struct efx_rx_queue *rx_queue;
1149	struct efx_channel *channel;
1150	int rc = 0;
1151
1152	/* Stop RX refill */
1153	efx_for_each_channel(channel, efx) {
1154		efx_for_each_channel_rx_queue(rx_queue, channel)
1155			rx_queue->refill_enabled = false;
1156	}
1157
1158	efx_for_each_channel(channel, efx) {
1159		/* RX packet processing is pipelined, so wait for the
1160		 * NAPI handler to complete.  At least event queue 0
1161		 * might be kept active by non-data events, so don't
1162		 * use napi_synchronize() but actually disable NAPI
1163		 * temporarily.
1164		 */
1165		if (efx_channel_has_rx_queue(channel)) {
1166			efx_siena_stop_eventq(channel);
1167			efx_siena_start_eventq(channel);
1168		}
1169	}
1170
1171	if (efx->type->fini_dmaq)
1172		rc = efx->type->fini_dmaq(efx);
1173
1174	if (rc) {
1175		netif_err(efx, drv, efx->net_dev, "failed to flush queues\n");
1176	} else {
1177		netif_dbg(efx, drv, efx->net_dev,
1178			  "successfully flushed all queues\n");
1179	}
1180
1181	efx_for_each_channel(channel, efx) {
1182		efx_for_each_channel_rx_queue(rx_queue, channel)
1183			efx_siena_fini_rx_queue(rx_queue);
1184		efx_for_each_channel_tx_queue(tx_queue, channel)
1185			efx_siena_fini_tx_queue(tx_queue);
1186	}
1187}
1188
1189/**************************************************************************
1190 *
1191 * NAPI interface
1192 *
1193 *************************************************************************/
1194
1195/* Process channel's event queue
1196 *
1197 * This function is responsible for processing the event queue of a
1198 * single channel.  The caller must guarantee that this function will
1199 * never be concurrently called more than once on the same channel,
1200 * though different channels may be being processed concurrently.
1201 */
1202static int efx_process_channel(struct efx_channel *channel, int budget)
1203{
1204	struct efx_tx_queue *tx_queue;
1205	struct list_head rx_list;
1206	int spent;
1207
1208	if (unlikely(!channel->enabled))
1209		return 0;
1210
1211	/* Prepare the batch receive list */
1212	EFX_WARN_ON_PARANOID(channel->rx_list != NULL);
1213	INIT_LIST_HEAD(&rx_list);
1214	channel->rx_list = &rx_list;
1215
1216	efx_for_each_channel_tx_queue(tx_queue, channel) {
1217		tx_queue->pkts_compl = 0;
1218		tx_queue->bytes_compl = 0;
1219	}
1220
1221	spent = efx_nic_process_eventq(channel, budget);
1222	if (spent && efx_channel_has_rx_queue(channel)) {
1223		struct efx_rx_queue *rx_queue =
1224			efx_channel_get_rx_queue(channel);
1225
1226		efx_rx_flush_packet(channel);
1227		efx_siena_fast_push_rx_descriptors(rx_queue, true);
1228	}
1229
1230	/* Update BQL */
1231	efx_for_each_channel_tx_queue(tx_queue, channel) {
1232		if (tx_queue->bytes_compl) {
1233			netdev_tx_completed_queue(tx_queue->core_txq,
1234						  tx_queue->pkts_compl,
1235						  tx_queue->bytes_compl);
1236		}
1237	}
1238
1239	/* Receive any packets we queued up */
1240	netif_receive_skb_list(channel->rx_list);
1241	channel->rx_list = NULL;
1242
1243	return spent;
1244}
1245
1246static void efx_update_irq_mod(struct efx_nic *efx, struct efx_channel *channel)
1247{
1248	int step = efx->irq_mod_step_us;
1249
1250	if (channel->irq_mod_score < irq_adapt_low_thresh) {
1251		if (channel->irq_moderation_us > step) {
1252			channel->irq_moderation_us -= step;
1253			efx->type->push_irq_moderation(channel);
1254		}
1255	} else if (channel->irq_mod_score > irq_adapt_high_thresh) {
1256		if (channel->irq_moderation_us <
1257		    efx->irq_rx_moderation_us) {
1258			channel->irq_moderation_us += step;
1259			efx->type->push_irq_moderation(channel);
1260		}
1261	}
1262
1263	channel->irq_count = 0;
1264	channel->irq_mod_score = 0;
1265}
1266
1267/* NAPI poll handler
1268 *
1269 * NAPI guarantees serialisation of polls of the same device, which
1270 * provides the guarantee required by efx_process_channel().
1271 */
1272static int efx_poll(struct napi_struct *napi, int budget)
1273{
1274	struct efx_channel *channel =
1275		container_of(napi, struct efx_channel, napi_str);
1276	struct efx_nic *efx = channel->efx;
1277#ifdef CONFIG_RFS_ACCEL
1278	unsigned int time;
1279#endif
1280	int spent;
1281
1282	netif_vdbg(efx, intr, efx->net_dev,
1283		   "channel %d NAPI poll executing on CPU %d\n",
1284		   channel->channel, raw_smp_processor_id());
1285
1286	spent = efx_process_channel(channel, budget);
1287
1288	xdp_do_flush();
1289
1290	if (spent < budget) {
1291		if (efx_channel_has_rx_queue(channel) &&
1292		    efx->irq_rx_adaptive &&
1293		    unlikely(++channel->irq_count == 1000)) {
1294			efx_update_irq_mod(efx, channel);
1295		}
1296
1297#ifdef CONFIG_RFS_ACCEL
1298		/* Perhaps expire some ARFS filters */
1299		time = jiffies - channel->rfs_last_expiry;
1300		/* Would our quota be >= 20? */
1301		if (channel->rfs_filter_count * time >= 600 * HZ)
1302			mod_delayed_work(system_wq, &channel->filter_work, 0);
1303#endif
1304
1305		/* There is no race here; although napi_disable() will
1306		 * only wait for napi_complete(), this isn't a problem
1307		 * since efx_nic_eventq_read_ack() will have no effect if
1308		 * interrupts have already been disabled.
1309		 */
1310		if (napi_complete_done(napi, spent))
1311			efx_nic_eventq_read_ack(channel);
1312	}
1313
1314	return spent;
1315}
1316
1317static void efx_init_napi_channel(struct efx_channel *channel)
1318{
1319	struct efx_nic *efx = channel->efx;
1320
1321	channel->napi_dev = efx->net_dev;
1322	netif_napi_add(channel->napi_dev, &channel->napi_str, efx_poll);
1323}
1324
1325void efx_siena_init_napi(struct efx_nic *efx)
1326{
1327	struct efx_channel *channel;
1328
1329	efx_for_each_channel(channel, efx)
1330		efx_init_napi_channel(channel);
1331}
1332
1333static void efx_fini_napi_channel(struct efx_channel *channel)
1334{
1335	if (channel->napi_dev)
1336		netif_napi_del(&channel->napi_str);
1337
1338	channel->napi_dev = NULL;
1339}
1340
1341void efx_siena_fini_napi(struct efx_nic *efx)
1342{
1343	struct efx_channel *channel;
1344
1345	efx_for_each_channel(channel, efx)
1346		efx_fini_napi_channel(channel);
1347}
1348
1349/***************
1350 * Housekeeping
1351 ***************/
1352
1353static int efx_channel_dummy_op_int(struct efx_channel *channel)
1354{
1355	return 0;
1356}
1357
1358void efx_siena_channel_dummy_op_void(struct efx_channel *channel)
1359{
1360}
1361
1362static const struct efx_channel_type efx_default_channel_type = {
1363	.pre_probe		= efx_channel_dummy_op_int,
1364	.post_remove		= efx_siena_channel_dummy_op_void,
1365	.get_name		= efx_get_channel_name,
1366	.copy			= efx_copy_channel,
1367	.want_txqs		= efx_default_channel_want_txqs,
1368	.keep_eventq		= false,
1369	.want_pio		= true,
1370};
1371