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  */
26 unsigned 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  */
35 unsigned int rss_cpus;
36 
37 static unsigned int irq_adapt_low_thresh = 8000;
38 module_param(irq_adapt_low_thresh, uint, 0644);
39 MODULE_PARM_DESC(irq_adapt_low_thresh,
40 		 "Threshold score for reducing IRQ moderation");
41 
42 static unsigned int irq_adapt_high_thresh = 16000;
43 module_param(irq_adapt_high_thresh, uint, 0644);
44 MODULE_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  */
50 static int napi_weight = 64;
51 
52 /***************
53  * Housekeeping
54  ***************/
55 
56 int efx_channel_dummy_op_int(struct efx_channel *channel)
57 {
58 	return 0;
59 }
60 
61 void efx_channel_dummy_op_void(struct efx_channel *channel)
62 {
63 }
64 
65 static 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 
79 static 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 
133 static 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_TXQ_TYPES);
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_TXQ_TYPES;
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  */
236 int 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->n_xdp_channels = 0;
291 		efx->xdp_channel_offset = efx->n_channels;
292 		rc = pci_enable_msi(efx->pci_dev);
293 		if (rc == 0) {
294 			efx_get_channel(efx, 0)->irq = efx->pci_dev->irq;
295 		} else {
296 			netif_err(efx, drv, efx->net_dev,
297 				  "could not enable MSI\n");
298 			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_LEGACY)
299 				efx->interrupt_mode = EFX_INT_MODE_LEGACY;
300 			else
301 				return rc;
302 		}
303 	}
304 
305 	/* Assume legacy interrupts */
306 	if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
307 		efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
308 		efx->n_rx_channels = 1;
309 		efx->n_tx_channels = 1;
310 		efx->n_xdp_channels = 0;
311 		efx->xdp_channel_offset = efx->n_channels;
312 		efx->legacy_irq = efx->pci_dev->irq;
313 	}
314 
315 	/* Assign extra channels if possible, before XDP channels */
316 	efx->n_extra_tx_channels = 0;
317 	j = efx->xdp_channel_offset;
318 	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++) {
319 		if (!efx->extra_channel_type[i])
320 			continue;
321 		if (j <= efx->tx_channel_offset + efx->n_tx_channels) {
322 			efx->extra_channel_type[i]->handle_no_channel(efx);
323 		} else {
324 			--j;
325 			efx_get_channel(efx, j)->type =
326 				efx->extra_channel_type[i];
327 			if (efx_channel_has_tx_queues(efx_get_channel(efx, j)))
328 				efx->n_extra_tx_channels++;
329 		}
330 	}
331 
332 	rss_spread = efx->n_rx_channels;
333 	/* RSS might be usable on VFs even if it is disabled on the PF */
334 #ifdef CONFIG_SFC_SRIOV
335 	if (efx->type->sriov_wanted) {
336 		efx->rss_spread = ((rss_spread > 1 ||
337 				    !efx->type->sriov_wanted(efx)) ?
338 				   rss_spread : efx_vf_size(efx));
339 		return 0;
340 	}
341 #endif
342 	efx->rss_spread = rss_spread;
343 
344 	return 0;
345 }
346 
347 #if defined(CONFIG_SMP)
348 void efx_set_interrupt_affinity(struct efx_nic *efx)
349 {
350 	struct efx_channel *channel;
351 	unsigned int cpu;
352 
353 	efx_for_each_channel(channel, efx) {
354 		cpu = cpumask_local_spread(channel->channel,
355 					   pcibus_to_node(efx->pci_dev->bus));
356 		irq_set_affinity_hint(channel->irq, cpumask_of(cpu));
357 	}
358 }
359 
360 void efx_clear_interrupt_affinity(struct efx_nic *efx)
361 {
362 	struct efx_channel *channel;
363 
364 	efx_for_each_channel(channel, efx)
365 		irq_set_affinity_hint(channel->irq, NULL);
366 }
367 #else
368 void
369 efx_set_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
370 {
371 }
372 
373 void
374 efx_clear_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
375 {
376 }
377 #endif /* CONFIG_SMP */
378 
379 void efx_remove_interrupts(struct efx_nic *efx)
380 {
381 	struct efx_channel *channel;
382 
383 	/* Remove MSI/MSI-X interrupts */
384 	efx_for_each_channel(channel, efx)
385 		channel->irq = 0;
386 	pci_disable_msi(efx->pci_dev);
387 	pci_disable_msix(efx->pci_dev);
388 
389 	/* Remove legacy interrupt */
390 	efx->legacy_irq = 0;
391 }
392 
393 /***************
394  * EVENT QUEUES
395  ***************/
396 
397 /* Create event queue
398  * Event queue memory allocations are done only once.  If the channel
399  * is reset, the memory buffer will be reused; this guards against
400  * errors during channel reset and also simplifies interrupt handling.
401  */
402 int efx_probe_eventq(struct efx_channel *channel)
403 {
404 	struct efx_nic *efx = channel->efx;
405 	unsigned long entries;
406 
407 	netif_dbg(efx, probe, efx->net_dev,
408 		  "chan %d create event queue\n", channel->channel);
409 
410 	/* Build an event queue with room for one event per tx and rx buffer,
411 	 * plus some extra for link state events and MCDI completions.
412 	 */
413 	entries = roundup_pow_of_two(efx->rxq_entries + efx->txq_entries + 128);
414 	EFX_WARN_ON_PARANOID(entries > EFX_MAX_EVQ_SIZE);
415 	channel->eventq_mask = max(entries, EFX_MIN_EVQ_SIZE) - 1;
416 
417 	return efx_nic_probe_eventq(channel);
418 }
419 
420 /* Prepare channel's event queue */
421 int efx_init_eventq(struct efx_channel *channel)
422 {
423 	struct efx_nic *efx = channel->efx;
424 	int rc;
425 
426 	EFX_WARN_ON_PARANOID(channel->eventq_init);
427 
428 	netif_dbg(efx, drv, efx->net_dev,
429 		  "chan %d init event queue\n", channel->channel);
430 
431 	rc = efx_nic_init_eventq(channel);
432 	if (rc == 0) {
433 		efx->type->push_irq_moderation(channel);
434 		channel->eventq_read_ptr = 0;
435 		channel->eventq_init = true;
436 	}
437 	return rc;
438 }
439 
440 /* Enable event queue processing and NAPI */
441 void efx_start_eventq(struct efx_channel *channel)
442 {
443 	netif_dbg(channel->efx, ifup, channel->efx->net_dev,
444 		  "chan %d start event queue\n", channel->channel);
445 
446 	/* Make sure the NAPI handler sees the enabled flag set */
447 	channel->enabled = true;
448 	smp_wmb();
449 
450 	napi_enable(&channel->napi_str);
451 	efx_nic_eventq_read_ack(channel);
452 }
453 
454 /* Disable event queue processing and NAPI */
455 void efx_stop_eventq(struct efx_channel *channel)
456 {
457 	if (!channel->enabled)
458 		return;
459 
460 	napi_disable(&channel->napi_str);
461 	channel->enabled = false;
462 }
463 
464 void efx_fini_eventq(struct efx_channel *channel)
465 {
466 	if (!channel->eventq_init)
467 		return;
468 
469 	netif_dbg(channel->efx, drv, channel->efx->net_dev,
470 		  "chan %d fini event queue\n", channel->channel);
471 
472 	efx_nic_fini_eventq(channel);
473 	channel->eventq_init = false;
474 }
475 
476 void efx_remove_eventq(struct efx_channel *channel)
477 {
478 	netif_dbg(channel->efx, drv, channel->efx->net_dev,
479 		  "chan %d remove event queue\n", channel->channel);
480 
481 	efx_nic_remove_eventq(channel);
482 }
483 
484 /**************************************************************************
485  *
486  * Channel handling
487  *
488  *************************************************************************/
489 
490 #ifdef CONFIG_RFS_ACCEL
491 static void efx_filter_rfs_expire(struct work_struct *data)
492 {
493 	struct delayed_work *dwork = to_delayed_work(data);
494 	struct efx_channel *channel;
495 	unsigned int time, quota;
496 
497 	channel = container_of(dwork, struct efx_channel, filter_work);
498 	time = jiffies - channel->rfs_last_expiry;
499 	quota = channel->rfs_filter_count * time / (30 * HZ);
500 	if (quota >= 20 && __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count, quota)))
501 		channel->rfs_last_expiry += time;
502 	/* Ensure we do more work eventually even if NAPI poll is not happening */
503 	schedule_delayed_work(dwork, 30 * HZ);
504 }
505 #endif
506 
507 /* Allocate and initialise a channel structure. */
508 struct efx_channel *
509 efx_alloc_channel(struct efx_nic *efx, int i, struct efx_channel *old_channel)
510 {
511 	struct efx_rx_queue *rx_queue;
512 	struct efx_tx_queue *tx_queue;
513 	struct efx_channel *channel;
514 	int j;
515 
516 	channel = kzalloc(sizeof(*channel), GFP_KERNEL);
517 	if (!channel)
518 		return NULL;
519 
520 	channel->efx = efx;
521 	channel->channel = i;
522 	channel->type = &efx_default_channel_type;
523 
524 	for (j = 0; j < EFX_TXQ_TYPES; j++) {
525 		tx_queue = &channel->tx_queue[j];
526 		tx_queue->efx = efx;
527 		tx_queue->queue = -1;
528 		tx_queue->label = j;
529 		tx_queue->channel = channel;
530 	}
531 
532 #ifdef CONFIG_RFS_ACCEL
533 	INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
534 #endif
535 
536 	rx_queue = &channel->rx_queue;
537 	rx_queue->efx = efx;
538 	timer_setup(&rx_queue->slow_fill, efx_rx_slow_fill, 0);
539 
540 	return channel;
541 }
542 
543 int efx_init_channels(struct efx_nic *efx)
544 {
545 	unsigned int i;
546 
547 	for (i = 0; i < EFX_MAX_CHANNELS; i++) {
548 		efx->channel[i] = efx_alloc_channel(efx, i, NULL);
549 		if (!efx->channel[i])
550 			return -ENOMEM;
551 		efx->msi_context[i].efx = efx;
552 		efx->msi_context[i].index = i;
553 	}
554 
555 	/* Higher numbered interrupt modes are less capable! */
556 	efx->interrupt_mode = min(efx->type->min_interrupt_mode,
557 				  efx_interrupt_mode);
558 
559 	efx->max_channels = EFX_MAX_CHANNELS;
560 	efx->max_tx_channels = EFX_MAX_CHANNELS;
561 
562 	return 0;
563 }
564 
565 void efx_fini_channels(struct efx_nic *efx)
566 {
567 	unsigned int i;
568 
569 	for (i = 0; i < EFX_MAX_CHANNELS; i++)
570 		if (efx->channel[i]) {
571 			kfree(efx->channel[i]);
572 			efx->channel[i] = NULL;
573 		}
574 }
575 
576 /* Allocate and initialise a channel structure, copying parameters
577  * (but not resources) from an old channel structure.
578  */
579 struct efx_channel *efx_copy_channel(const struct efx_channel *old_channel)
580 {
581 	struct efx_rx_queue *rx_queue;
582 	struct efx_tx_queue *tx_queue;
583 	struct efx_channel *channel;
584 	int j;
585 
586 	channel = kmalloc(sizeof(*channel), GFP_KERNEL);
587 	if (!channel)
588 		return NULL;
589 
590 	*channel = *old_channel;
591 
592 	channel->napi_dev = NULL;
593 	INIT_HLIST_NODE(&channel->napi_str.napi_hash_node);
594 	channel->napi_str.napi_id = 0;
595 	channel->napi_str.state = 0;
596 	memset(&channel->eventq, 0, sizeof(channel->eventq));
597 
598 	for (j = 0; j < EFX_TXQ_TYPES; j++) {
599 		tx_queue = &channel->tx_queue[j];
600 		if (tx_queue->channel)
601 			tx_queue->channel = channel;
602 		tx_queue->buffer = NULL;
603 		tx_queue->cb_page = NULL;
604 		memset(&tx_queue->txd, 0, sizeof(tx_queue->txd));
605 	}
606 
607 	rx_queue = &channel->rx_queue;
608 	rx_queue->buffer = NULL;
609 	memset(&rx_queue->rxd, 0, sizeof(rx_queue->rxd));
610 	timer_setup(&rx_queue->slow_fill, efx_rx_slow_fill, 0);
611 #ifdef CONFIG_RFS_ACCEL
612 	INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
613 #endif
614 
615 	return channel;
616 }
617 
618 static int efx_probe_channel(struct efx_channel *channel)
619 {
620 	struct efx_tx_queue *tx_queue;
621 	struct efx_rx_queue *rx_queue;
622 	int rc;
623 
624 	netif_dbg(channel->efx, probe, channel->efx->net_dev,
625 		  "creating channel %d\n", channel->channel);
626 
627 	rc = channel->type->pre_probe(channel);
628 	if (rc)
629 		goto fail;
630 
631 	rc = efx_probe_eventq(channel);
632 	if (rc)
633 		goto fail;
634 
635 	efx_for_each_channel_tx_queue(tx_queue, channel) {
636 		rc = efx_probe_tx_queue(tx_queue);
637 		if (rc)
638 			goto fail;
639 	}
640 
641 	efx_for_each_channel_rx_queue(rx_queue, channel) {
642 		rc = efx_probe_rx_queue(rx_queue);
643 		if (rc)
644 			goto fail;
645 	}
646 
647 	channel->rx_list = NULL;
648 
649 	return 0;
650 
651 fail:
652 	efx_remove_channel(channel);
653 	return rc;
654 }
655 
656 void efx_get_channel_name(struct efx_channel *channel, char *buf, size_t len)
657 {
658 	struct efx_nic *efx = channel->efx;
659 	const char *type;
660 	int number;
661 
662 	number = channel->channel;
663 
664 	if (number >= efx->xdp_channel_offset &&
665 	    !WARN_ON_ONCE(!efx->n_xdp_channels)) {
666 		type = "-xdp";
667 		number -= efx->xdp_channel_offset;
668 	} else if (efx->tx_channel_offset == 0) {
669 		type = "";
670 	} else if (number < efx->tx_channel_offset) {
671 		type = "-rx";
672 	} else {
673 		type = "-tx";
674 		number -= efx->tx_channel_offset;
675 	}
676 	snprintf(buf, len, "%s%s-%d", efx->name, type, number);
677 }
678 
679 void efx_set_channel_names(struct efx_nic *efx)
680 {
681 	struct efx_channel *channel;
682 
683 	efx_for_each_channel(channel, efx)
684 		channel->type->get_name(channel,
685 					efx->msi_context[channel->channel].name,
686 					sizeof(efx->msi_context[0].name));
687 }
688 
689 int efx_probe_channels(struct efx_nic *efx)
690 {
691 	struct efx_channel *channel;
692 	int rc;
693 
694 	/* Restart special buffer allocation */
695 	efx->next_buffer_table = 0;
696 
697 	/* Probe channels in reverse, so that any 'extra' channels
698 	 * use the start of the buffer table. This allows the traffic
699 	 * channels to be resized without moving them or wasting the
700 	 * entries before them.
701 	 */
702 	efx_for_each_channel_rev(channel, efx) {
703 		rc = efx_probe_channel(channel);
704 		if (rc) {
705 			netif_err(efx, probe, efx->net_dev,
706 				  "failed to create channel %d\n",
707 				  channel->channel);
708 			goto fail;
709 		}
710 	}
711 	efx_set_channel_names(efx);
712 
713 	return 0;
714 
715 fail:
716 	efx_remove_channels(efx);
717 	return rc;
718 }
719 
720 void efx_remove_channel(struct efx_channel *channel)
721 {
722 	struct efx_tx_queue *tx_queue;
723 	struct efx_rx_queue *rx_queue;
724 
725 	netif_dbg(channel->efx, drv, channel->efx->net_dev,
726 		  "destroy chan %d\n", channel->channel);
727 
728 	efx_for_each_channel_rx_queue(rx_queue, channel)
729 		efx_remove_rx_queue(rx_queue);
730 	efx_for_each_channel_tx_queue(tx_queue, channel)
731 		efx_remove_tx_queue(tx_queue);
732 	efx_remove_eventq(channel);
733 	channel->type->post_remove(channel);
734 }
735 
736 void efx_remove_channels(struct efx_nic *efx)
737 {
738 	struct efx_channel *channel;
739 
740 	efx_for_each_channel(channel, efx)
741 		efx_remove_channel(channel);
742 
743 	kfree(efx->xdp_tx_queues);
744 }
745 
746 int efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries)
747 {
748 	struct efx_channel *other_channel[EFX_MAX_CHANNELS], *channel;
749 	unsigned int i, next_buffer_table = 0;
750 	u32 old_rxq_entries, old_txq_entries;
751 	int rc, rc2;
752 
753 	rc = efx_check_disabled(efx);
754 	if (rc)
755 		return rc;
756 
757 	/* Not all channels should be reallocated. We must avoid
758 	 * reallocating their buffer table entries.
759 	 */
760 	efx_for_each_channel(channel, efx) {
761 		struct efx_rx_queue *rx_queue;
762 		struct efx_tx_queue *tx_queue;
763 
764 		if (channel->type->copy)
765 			continue;
766 		next_buffer_table = max(next_buffer_table,
767 					channel->eventq.index +
768 					channel->eventq.entries);
769 		efx_for_each_channel_rx_queue(rx_queue, channel)
770 			next_buffer_table = max(next_buffer_table,
771 						rx_queue->rxd.index +
772 						rx_queue->rxd.entries);
773 		efx_for_each_channel_tx_queue(tx_queue, channel)
774 			next_buffer_table = max(next_buffer_table,
775 						tx_queue->txd.index +
776 						tx_queue->txd.entries);
777 	}
778 
779 	efx_device_detach_sync(efx);
780 	efx_stop_all(efx);
781 	efx_soft_disable_interrupts(efx);
782 
783 	/* Clone channels (where possible) */
784 	memset(other_channel, 0, sizeof(other_channel));
785 	for (i = 0; i < efx->n_channels; i++) {
786 		channel = efx->channel[i];
787 		if (channel->type->copy)
788 			channel = channel->type->copy(channel);
789 		if (!channel) {
790 			rc = -ENOMEM;
791 			goto out;
792 		}
793 		other_channel[i] = channel;
794 	}
795 
796 	/* Swap entry counts and channel pointers */
797 	old_rxq_entries = efx->rxq_entries;
798 	old_txq_entries = efx->txq_entries;
799 	efx->rxq_entries = rxq_entries;
800 	efx->txq_entries = txq_entries;
801 	for (i = 0; i < efx->n_channels; i++) {
802 		channel = efx->channel[i];
803 		efx->channel[i] = other_channel[i];
804 		other_channel[i] = channel;
805 	}
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 
820 out:
821 	/* Destroy unused channel structures */
822 	for (i = 0; i < efx->n_channels; i++) {
823 		channel = other_channel[i];
824 		if (channel && channel->type->copy) {
825 			efx_fini_napi_channel(channel);
826 			efx_remove_channel(channel);
827 			kfree(channel);
828 		}
829 	}
830 
831 	rc2 = efx_soft_enable_interrupts(efx);
832 	if (rc2) {
833 		rc = rc ? rc : rc2;
834 		netif_err(efx, drv, efx->net_dev,
835 			  "unable to restart interrupts on channel reallocation\n");
836 		efx_schedule_reset(efx, RESET_TYPE_DISABLE);
837 	} else {
838 		efx_start_all(efx);
839 		efx_device_attach_if_not_resetting(efx);
840 	}
841 	return rc;
842 
843 rollback:
844 	/* Swap back */
845 	efx->rxq_entries = old_rxq_entries;
846 	efx->txq_entries = old_txq_entries;
847 	for (i = 0; i < efx->n_channels; i++) {
848 		channel = efx->channel[i];
849 		efx->channel[i] = other_channel[i];
850 		other_channel[i] = channel;
851 	}
852 	goto out;
853 }
854 
855 int 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 	efx->tx_channel_offset =
864 		efx_separate_tx_channels ?
865 		efx->n_channels - efx->n_tx_channels : 0;
866 
867 	if (efx->xdp_tx_queue_count) {
868 		EFX_WARN_ON_PARANOID(efx->xdp_tx_queues);
869 
870 		/* Allocate array for XDP TX queue lookup. */
871 		efx->xdp_tx_queues = kcalloc(efx->xdp_tx_queue_count,
872 					     sizeof(*efx->xdp_tx_queues),
873 					     GFP_KERNEL);
874 		if (!efx->xdp_tx_queues)
875 			return -ENOMEM;
876 	}
877 
878 	/* We need to mark which channels really have RX and TX
879 	 * queues, and adjust the TX queue numbers if we have separate
880 	 * RX-only and TX-only channels.
881 	 */
882 	xdp_queue_number = 0;
883 	efx_for_each_channel(channel, efx) {
884 		if (channel->channel < efx->n_rx_channels)
885 			channel->rx_queue.core_index = channel->channel;
886 		else
887 			channel->rx_queue.core_index = -1;
888 
889 		if (channel->channel >= efx->tx_channel_offset) {
890 			if (efx_channel_is_xdp_tx(channel)) {
891 				efx_for_each_channel_tx_queue(tx_queue, channel) {
892 					tx_queue->queue = next_queue++;
893 					netif_dbg(efx, drv, efx->net_dev, "Channel %u TXQ %u is XDP %u, HW %u\n",
894 						  channel->channel, tx_queue->label,
895 						  xdp_queue_number, tx_queue->queue);
896 					/* We may have a few left-over XDP TX
897 					 * queues owing to xdp_tx_queue_count
898 					 * not dividing evenly by EFX_TXQ_TYPES.
899 					 * We still allocate and probe those
900 					 * TXQs, but never use them.
901 					 */
902 					if (xdp_queue_number < efx->xdp_tx_queue_count)
903 						efx->xdp_tx_queues[xdp_queue_number] = tx_queue;
904 					xdp_queue_number++;
905 				}
906 			} else {
907 				efx_for_each_channel_tx_queue(tx_queue, channel) {
908 					tx_queue->queue = next_queue++;
909 					netif_dbg(efx, drv, efx->net_dev, "Channel %u TXQ %u is HW %u\n",
910 						  channel->channel, tx_queue->label,
911 						  tx_queue->queue);
912 				}
913 			}
914 		}
915 	}
916 
917 	rc = netif_set_real_num_tx_queues(efx->net_dev, efx->n_tx_channels);
918 	if (rc)
919 		return rc;
920 	return netif_set_real_num_rx_queues(efx->net_dev, efx->n_rx_channels);
921 }
922 
923 bool efx_default_channel_want_txqs(struct efx_channel *channel)
924 {
925 	return channel->channel - channel->efx->tx_channel_offset <
926 		channel->efx->n_tx_channels;
927 }
928 
929 /*************
930  * START/STOP
931  *************/
932 
933 int efx_soft_enable_interrupts(struct efx_nic *efx)
934 {
935 	struct efx_channel *channel, *end_channel;
936 	int rc;
937 
938 	BUG_ON(efx->state == STATE_DISABLED);
939 
940 	efx->irq_soft_enabled = true;
941 	smp_wmb();
942 
943 	efx_for_each_channel(channel, efx) {
944 		if (!channel->type->keep_eventq) {
945 			rc = efx_init_eventq(channel);
946 			if (rc)
947 				goto fail;
948 		}
949 		efx_start_eventq(channel);
950 	}
951 
952 	efx_mcdi_mode_event(efx);
953 
954 	return 0;
955 fail:
956 	end_channel = channel;
957 	efx_for_each_channel(channel, efx) {
958 		if (channel == end_channel)
959 			break;
960 		efx_stop_eventq(channel);
961 		if (!channel->type->keep_eventq)
962 			efx_fini_eventq(channel);
963 	}
964 
965 	return rc;
966 }
967 
968 void efx_soft_disable_interrupts(struct efx_nic *efx)
969 {
970 	struct efx_channel *channel;
971 
972 	if (efx->state == STATE_DISABLED)
973 		return;
974 
975 	efx_mcdi_mode_poll(efx);
976 
977 	efx->irq_soft_enabled = false;
978 	smp_wmb();
979 
980 	if (efx->legacy_irq)
981 		synchronize_irq(efx->legacy_irq);
982 
983 	efx_for_each_channel(channel, efx) {
984 		if (channel->irq)
985 			synchronize_irq(channel->irq);
986 
987 		efx_stop_eventq(channel);
988 		if (!channel->type->keep_eventq)
989 			efx_fini_eventq(channel);
990 	}
991 
992 	/* Flush the asynchronous MCDI request queue */
993 	efx_mcdi_flush_async(efx);
994 }
995 
996 int efx_enable_interrupts(struct efx_nic *efx)
997 {
998 	struct efx_channel *channel, *end_channel;
999 	int rc;
1000 
1001 	/* TODO: Is this really a bug? */
1002 	BUG_ON(efx->state == STATE_DISABLED);
1003 
1004 	if (efx->eeh_disabled_legacy_irq) {
1005 		enable_irq(efx->legacy_irq);
1006 		efx->eeh_disabled_legacy_irq = false;
1007 	}
1008 
1009 	efx->type->irq_enable_master(efx);
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 	}
1018 
1019 	rc = efx_soft_enable_interrupts(efx);
1020 	if (rc)
1021 		goto fail;
1022 
1023 	return 0;
1024 
1025 fail:
1026 	end_channel = channel;
1027 	efx_for_each_channel(channel, efx) {
1028 		if (channel == end_channel)
1029 			break;
1030 		if (channel->type->keep_eventq)
1031 			efx_fini_eventq(channel);
1032 	}
1033 
1034 	efx->type->irq_disable_non_ev(efx);
1035 
1036 	return rc;
1037 }
1038 
1039 void efx_disable_interrupts(struct efx_nic *efx)
1040 {
1041 	struct efx_channel *channel;
1042 
1043 	efx_soft_disable_interrupts(efx);
1044 
1045 	efx_for_each_channel(channel, efx) {
1046 		if (channel->type->keep_eventq)
1047 			efx_fini_eventq(channel);
1048 	}
1049 
1050 	efx->type->irq_disable_non_ev(efx);
1051 }
1052 
1053 void efx_start_channels(struct efx_nic *efx)
1054 {
1055 	struct efx_tx_queue *tx_queue;
1056 	struct efx_rx_queue *rx_queue;
1057 	struct efx_channel *channel;
1058 
1059 	efx_for_each_channel(channel, efx) {
1060 		efx_for_each_channel_tx_queue(tx_queue, channel) {
1061 			efx_init_tx_queue(tx_queue);
1062 			atomic_inc(&efx->active_queues);
1063 		}
1064 
1065 		efx_for_each_channel_rx_queue(rx_queue, channel) {
1066 			efx_init_rx_queue(rx_queue);
1067 			atomic_inc(&efx->active_queues);
1068 			efx_stop_eventq(channel);
1069 			efx_fast_push_rx_descriptors(rx_queue, false);
1070 			efx_start_eventq(channel);
1071 		}
1072 
1073 		WARN_ON(channel->rx_pkt_n_frags);
1074 	}
1075 }
1076 
1077 void efx_stop_channels(struct efx_nic *efx)
1078 {
1079 	struct efx_tx_queue *tx_queue;
1080 	struct efx_rx_queue *rx_queue;
1081 	struct efx_channel *channel;
1082 	int rc = 0;
1083 
1084 	/* Stop RX refill */
1085 	efx_for_each_channel(channel, efx) {
1086 		efx_for_each_channel_rx_queue(rx_queue, channel)
1087 			rx_queue->refill_enabled = false;
1088 	}
1089 
1090 	efx_for_each_channel(channel, efx) {
1091 		/* RX packet processing is pipelined, so wait for the
1092 		 * NAPI handler to complete.  At least event queue 0
1093 		 * might be kept active by non-data events, so don't
1094 		 * use napi_synchronize() but actually disable NAPI
1095 		 * temporarily.
1096 		 */
1097 		if (efx_channel_has_rx_queue(channel)) {
1098 			efx_stop_eventq(channel);
1099 			efx_start_eventq(channel);
1100 		}
1101 	}
1102 
1103 	if (efx->type->fini_dmaq)
1104 		rc = efx->type->fini_dmaq(efx);
1105 
1106 	if (rc) {
1107 		netif_err(efx, drv, efx->net_dev, "failed to flush queues\n");
1108 	} else {
1109 		netif_dbg(efx, drv, efx->net_dev,
1110 			  "successfully flushed all queues\n");
1111 	}
1112 
1113 	efx_for_each_channel(channel, efx) {
1114 		efx_for_each_channel_rx_queue(rx_queue, channel)
1115 			efx_fini_rx_queue(rx_queue);
1116 		efx_for_each_channel_tx_queue(tx_queue, channel)
1117 			efx_fini_tx_queue(tx_queue);
1118 	}
1119 }
1120 
1121 /**************************************************************************
1122  *
1123  * NAPI interface
1124  *
1125  *************************************************************************/
1126 
1127 /* Process channel's event queue
1128  *
1129  * This function is responsible for processing the event queue of a
1130  * single channel.  The caller must guarantee that this function will
1131  * never be concurrently called more than once on the same channel,
1132  * though different channels may be being processed concurrently.
1133  */
1134 static int efx_process_channel(struct efx_channel *channel, int budget)
1135 {
1136 	struct efx_tx_queue *tx_queue;
1137 	struct list_head rx_list;
1138 	int spent;
1139 
1140 	if (unlikely(!channel->enabled))
1141 		return 0;
1142 
1143 	/* Prepare the batch receive list */
1144 	EFX_WARN_ON_PARANOID(channel->rx_list != NULL);
1145 	INIT_LIST_HEAD(&rx_list);
1146 	channel->rx_list = &rx_list;
1147 
1148 	efx_for_each_channel_tx_queue(tx_queue, channel) {
1149 		tx_queue->pkts_compl = 0;
1150 		tx_queue->bytes_compl = 0;
1151 	}
1152 
1153 	spent = efx_nic_process_eventq(channel, budget);
1154 	if (spent && efx_channel_has_rx_queue(channel)) {
1155 		struct efx_rx_queue *rx_queue =
1156 			efx_channel_get_rx_queue(channel);
1157 
1158 		efx_rx_flush_packet(channel);
1159 		efx_fast_push_rx_descriptors(rx_queue, true);
1160 	}
1161 
1162 	/* Update BQL */
1163 	efx_for_each_channel_tx_queue(tx_queue, channel) {
1164 		if (tx_queue->bytes_compl) {
1165 			netdev_tx_completed_queue(tx_queue->core_txq,
1166 						  tx_queue->pkts_compl,
1167 						  tx_queue->bytes_compl);
1168 		}
1169 	}
1170 
1171 	/* Receive any packets we queued up */
1172 	netif_receive_skb_list(channel->rx_list);
1173 	channel->rx_list = NULL;
1174 
1175 	return spent;
1176 }
1177 
1178 static void efx_update_irq_mod(struct efx_nic *efx, struct efx_channel *channel)
1179 {
1180 	int step = efx->irq_mod_step_us;
1181 
1182 	if (channel->irq_mod_score < irq_adapt_low_thresh) {
1183 		if (channel->irq_moderation_us > step) {
1184 			channel->irq_moderation_us -= step;
1185 			efx->type->push_irq_moderation(channel);
1186 		}
1187 	} else if (channel->irq_mod_score > irq_adapt_high_thresh) {
1188 		if (channel->irq_moderation_us <
1189 		    efx->irq_rx_moderation_us) {
1190 			channel->irq_moderation_us += step;
1191 			efx->type->push_irq_moderation(channel);
1192 		}
1193 	}
1194 
1195 	channel->irq_count = 0;
1196 	channel->irq_mod_score = 0;
1197 }
1198 
1199 /* NAPI poll handler
1200  *
1201  * NAPI guarantees serialisation of polls of the same device, which
1202  * provides the guarantee required by efx_process_channel().
1203  */
1204 static int efx_poll(struct napi_struct *napi, int budget)
1205 {
1206 	struct efx_channel *channel =
1207 		container_of(napi, struct efx_channel, napi_str);
1208 	struct efx_nic *efx = channel->efx;
1209 #ifdef CONFIG_RFS_ACCEL
1210 	unsigned int time;
1211 #endif
1212 	int spent;
1213 
1214 	netif_vdbg(efx, intr, efx->net_dev,
1215 		   "channel %d NAPI poll executing on CPU %d\n",
1216 		   channel->channel, raw_smp_processor_id());
1217 
1218 	spent = efx_process_channel(channel, budget);
1219 
1220 	xdp_do_flush_map();
1221 
1222 	if (spent < budget) {
1223 		if (efx_channel_has_rx_queue(channel) &&
1224 		    efx->irq_rx_adaptive &&
1225 		    unlikely(++channel->irq_count == 1000)) {
1226 			efx_update_irq_mod(efx, channel);
1227 		}
1228 
1229 #ifdef CONFIG_RFS_ACCEL
1230 		/* Perhaps expire some ARFS filters */
1231 		time = jiffies - channel->rfs_last_expiry;
1232 		/* Would our quota be >= 20? */
1233 		if (channel->rfs_filter_count * time >= 600 * HZ)
1234 			mod_delayed_work(system_wq, &channel->filter_work, 0);
1235 #endif
1236 
1237 		/* There is no race here; although napi_disable() will
1238 		 * only wait for napi_complete(), this isn't a problem
1239 		 * since efx_nic_eventq_read_ack() will have no effect if
1240 		 * interrupts have already been disabled.
1241 		 */
1242 		if (napi_complete_done(napi, spent))
1243 			efx_nic_eventq_read_ack(channel);
1244 	}
1245 
1246 	return spent;
1247 }
1248 
1249 void efx_init_napi_channel(struct efx_channel *channel)
1250 {
1251 	struct efx_nic *efx = channel->efx;
1252 
1253 	channel->napi_dev = efx->net_dev;
1254 	netif_napi_add(channel->napi_dev, &channel->napi_str,
1255 		       efx_poll, napi_weight);
1256 }
1257 
1258 void efx_init_napi(struct efx_nic *efx)
1259 {
1260 	struct efx_channel *channel;
1261 
1262 	efx_for_each_channel(channel, efx)
1263 		efx_init_napi_channel(channel);
1264 }
1265 
1266 void efx_fini_napi_channel(struct efx_channel *channel)
1267 {
1268 	if (channel->napi_dev)
1269 		netif_napi_del(&channel->napi_str);
1270 
1271 	channel->napi_dev = NULL;
1272 }
1273 
1274 void efx_fini_napi(struct efx_nic *efx)
1275 {
1276 	struct efx_channel *channel;
1277 
1278 	efx_for_each_channel(channel, efx)
1279 		efx_fini_napi_channel(channel);
1280 }
1281