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