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_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 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(dstp: filter_mask, cpu_online_mask);
68 if (local_node)
69 cpumask_and(dstp: filter_mask, src1p: filter_mask,
70 src2p: cpumask_of_pcibus(bus: efx->pci_dev->bus));
71
72 count = 0;
73 for_each_cpu(cpu, filter_mask) {
74 ++count;
75 cpumask_andnot(dstp: filter_mask, src1p: filter_mask, topology_sibling_cpumask(cpu));
76 }
77
78 free_cpumask_var(mask: 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 (rss_cpus) {
88 count = rss_cpus;
89 } else {
90 count = count_online_cores(efx, local_node: 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, local_node: false);
95 }
96
97 if (count > EFX_MAX_RX_QUEUES) {
98 netif_cond_dbg(efx, probe, efx->net_dev, !rss_cpus, warn,
99 "Reducing number of rx queues from %u to %u.\n",
100 count, EFX_MAX_RX_QUEUES);
101 count = EFX_MAX_RX_QUEUES;
102 }
103
104 /* If RSS is requested for the PF *and* VFs then we can't write RSS
105 * table entries that are inaccessible to VFs
106 */
107#ifdef CONFIG_SFC_SRIOV
108 if (efx->type->sriov_wanted) {
109 if (efx->type->sriov_wanted(efx) && efx_vf_size(efx) > 1 &&
110 count > efx_vf_size(efx)) {
111 netif_warn(efx, probe, efx->net_dev,
112 "Reducing number of RSS channels from %u to %u for "
113 "VF support. Increase vf-msix-limit to use more "
114 "channels on the PF.\n",
115 count, efx_vf_size(efx));
116 count = efx_vf_size(efx);
117 }
118 }
119#endif
120
121 return count;
122}
123
124static int efx_allocate_msix_channels(struct efx_nic *efx,
125 unsigned int max_channels,
126 unsigned int extra_channels,
127 unsigned int parallelism)
128{
129 unsigned int n_channels = parallelism;
130 int vec_count;
131 int tx_per_ev;
132 int n_xdp_tx;
133 int n_xdp_ev;
134
135 if (efx_separate_tx_channels)
136 n_channels *= 2;
137 n_channels += extra_channels;
138
139 /* To allow XDP transmit to happen from arbitrary NAPI contexts
140 * we allocate a TX queue per CPU. We share event queues across
141 * multiple tx queues, assuming tx and ev queues are both
142 * maximum size.
143 */
144 tx_per_ev = EFX_MAX_EVQ_SIZE / EFX_TXQ_MAX_ENT(efx);
145 tx_per_ev = min(tx_per_ev, EFX_MAX_TXQ_PER_CHANNEL);
146 n_xdp_tx = num_possible_cpus();
147 n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, tx_per_ev);
148
149 vec_count = pci_msix_vec_count(dev: efx->pci_dev);
150 if (vec_count < 0)
151 return vec_count;
152
153 max_channels = min_t(unsigned int, vec_count, max_channels);
154
155 /* Check resources.
156 * We need a channel per event queue, plus a VI per tx queue.
157 * This may be more pessimistic than it needs to be.
158 */
159 if (n_channels >= max_channels) {
160 efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
161 netif_warn(efx, drv, efx->net_dev,
162 "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
163 n_xdp_ev, n_channels, max_channels);
164 netif_warn(efx, drv, efx->net_dev,
165 "XDP_TX and XDP_REDIRECT might decrease device's performance\n");
166 } else if (n_channels + n_xdp_tx > efx->max_vis) {
167 efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
168 netif_warn(efx, drv, efx->net_dev,
169 "Insufficient resources for %d XDP TX queues (%d other channels, max VIs %d)\n",
170 n_xdp_tx, n_channels, efx->max_vis);
171 netif_warn(efx, drv, efx->net_dev,
172 "XDP_TX and XDP_REDIRECT might decrease device's performance\n");
173 } else if (n_channels + n_xdp_ev > max_channels) {
174 efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_SHARED;
175 netif_warn(efx, drv, efx->net_dev,
176 "Insufficient resources for %d XDP event queues (%d other channels, max %d)\n",
177 n_xdp_ev, n_channels, max_channels);
178
179 n_xdp_ev = max_channels - n_channels;
180 netif_warn(efx, drv, efx->net_dev,
181 "XDP_TX and XDP_REDIRECT will work with reduced performance (%d cpus/tx_queue)\n",
182 DIV_ROUND_UP(n_xdp_tx, tx_per_ev * n_xdp_ev));
183 } else {
184 efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_DEDICATED;
185 }
186
187 if (efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_BORROWED) {
188 efx->n_xdp_channels = n_xdp_ev;
189 efx->xdp_tx_per_channel = tx_per_ev;
190 efx->xdp_tx_queue_count = n_xdp_tx;
191 n_channels += n_xdp_ev;
192 netif_dbg(efx, drv, efx->net_dev,
193 "Allocating %d TX and %d event queues for XDP\n",
194 n_xdp_ev * tx_per_ev, n_xdp_ev);
195 } else {
196 efx->n_xdp_channels = 0;
197 efx->xdp_tx_per_channel = 0;
198 efx->xdp_tx_queue_count = n_xdp_tx;
199 }
200
201 if (vec_count < n_channels) {
202 netif_err(efx, drv, efx->net_dev,
203 "WARNING: Insufficient MSI-X vectors available (%d < %u).\n",
204 vec_count, n_channels);
205 netif_err(efx, drv, efx->net_dev,
206 "WARNING: Performance may be reduced.\n");
207 n_channels = vec_count;
208 }
209
210 n_channels = min(n_channels, max_channels);
211
212 efx->n_channels = n_channels;
213
214 /* Ignore XDP tx channels when creating rx channels. */
215 n_channels -= efx->n_xdp_channels;
216
217 if (efx_separate_tx_channels) {
218 efx->n_tx_channels =
219 min(max(n_channels / 2, 1U),
220 efx->max_tx_channels);
221 efx->tx_channel_offset =
222 n_channels - efx->n_tx_channels;
223 efx->n_rx_channels =
224 max(n_channels -
225 efx->n_tx_channels, 1U);
226 } else {
227 efx->n_tx_channels = min(n_channels, efx->max_tx_channels);
228 efx->tx_channel_offset = 0;
229 efx->n_rx_channels = n_channels;
230 }
231
232 efx->n_rx_channels = min(efx->n_rx_channels, parallelism);
233 efx->n_tx_channels = min(efx->n_tx_channels, parallelism);
234
235 efx->xdp_channel_offset = n_channels;
236
237 netif_dbg(efx, drv, efx->net_dev,
238 "Allocating %u RX channels\n",
239 efx->n_rx_channels);
240
241 return efx->n_channels;
242}
243
244/* Probe the number and type of interrupts we are able to obtain, and
245 * the resulting numbers of channels and RX queues.
246 */
247int efx_probe_interrupts(struct efx_nic *efx)
248{
249 unsigned int extra_channels = 0;
250 unsigned int rss_spread;
251 unsigned int i, j;
252 int rc;
253
254 for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++)
255 if (efx->extra_channel_type[i])
256 ++extra_channels;
257
258 if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
259 unsigned int parallelism = efx_wanted_parallelism(efx);
260 struct msix_entry xentries[EFX_MAX_CHANNELS];
261 unsigned int n_channels;
262
263 rc = efx_allocate_msix_channels(efx, max_channels: efx->max_channels,
264 extra_channels, parallelism);
265 if (rc >= 0) {
266 n_channels = rc;
267 for (i = 0; i < n_channels; i++)
268 xentries[i].entry = i;
269 rc = pci_enable_msix_range(dev: efx->pci_dev, entries: xentries, minvec: 1,
270 maxvec: n_channels);
271 }
272 if (rc < 0) {
273 /* Fall back to single channel MSI */
274 netif_err(efx, drv, efx->net_dev,
275 "could not enable MSI-X\n");
276 if (efx->type->min_interrupt_mode >= EFX_INT_MODE_MSI)
277 efx->interrupt_mode = EFX_INT_MODE_MSI;
278 else
279 return rc;
280 } else if (rc < n_channels) {
281 netif_err(efx, drv, efx->net_dev,
282 "WARNING: Insufficient MSI-X vectors"
283 " available (%d < %u).\n", rc, n_channels);
284 netif_err(efx, drv, efx->net_dev,
285 "WARNING: Performance may be reduced.\n");
286 n_channels = rc;
287 }
288
289 if (rc > 0) {
290 for (i = 0; i < efx->n_channels; i++)
291 efx_get_channel(efx, index: i)->irq =
292 xentries[i].vector;
293 }
294 }
295
296 /* Try single interrupt MSI */
297 if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
298 efx->n_channels = 1;
299 efx->n_rx_channels = 1;
300 efx->n_tx_channels = 1;
301 efx->tx_channel_offset = 0;
302 efx->n_xdp_channels = 0;
303 efx->xdp_channel_offset = efx->n_channels;
304 efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
305 rc = pci_enable_msi(dev: efx->pci_dev);
306 if (rc == 0) {
307 efx_get_channel(efx, index: 0)->irq = efx->pci_dev->irq;
308 } else {
309 netif_err(efx, drv, efx->net_dev,
310 "could not enable MSI\n");
311 if (efx->type->min_interrupt_mode >= EFX_INT_MODE_LEGACY)
312 efx->interrupt_mode = EFX_INT_MODE_LEGACY;
313 else
314 return rc;
315 }
316 }
317
318 /* Assume legacy interrupts */
319 if (efx->interrupt_mode == EFX_INT_MODE_LEGACY) {
320 efx->n_channels = 1 + (efx_separate_tx_channels ? 1 : 0);
321 efx->n_rx_channels = 1;
322 efx->n_tx_channels = 1;
323 efx->tx_channel_offset = efx_separate_tx_channels ? 1 : 0;
324 efx->n_xdp_channels = 0;
325 efx->xdp_channel_offset = efx->n_channels;
326 efx->xdp_txq_queues_mode = EFX_XDP_TX_QUEUES_BORROWED;
327 efx->legacy_irq = efx->pci_dev->irq;
328 }
329
330 /* Assign extra channels if possible, before XDP channels */
331 efx->n_extra_tx_channels = 0;
332 j = efx->xdp_channel_offset;
333 for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++) {
334 if (!efx->extra_channel_type[i])
335 continue;
336 if (j <= efx->tx_channel_offset + efx->n_tx_channels) {
337 efx->extra_channel_type[i]->handle_no_channel(efx);
338 } else {
339 --j;
340 efx_get_channel(efx, index: j)->type =
341 efx->extra_channel_type[i];
342 if (efx_channel_has_tx_queues(channel: efx_get_channel(efx, index: j)))
343 efx->n_extra_tx_channels++;
344 }
345 }
346
347 rss_spread = efx->n_rx_channels;
348 /* RSS might be usable on VFs even if it is disabled on the PF */
349#ifdef CONFIG_SFC_SRIOV
350 if (efx->type->sriov_wanted) {
351 efx->rss_spread = ((rss_spread > 1 ||
352 !efx->type->sriov_wanted(efx)) ?
353 rss_spread : efx_vf_size(efx));
354 return 0;
355 }
356#endif
357 efx->rss_spread = rss_spread;
358
359 return 0;
360}
361
362#if defined(CONFIG_SMP)
363void efx_set_interrupt_affinity(struct efx_nic *efx)
364{
365 const struct cpumask *numa_mask = cpumask_of_pcibus(bus: efx->pci_dev->bus);
366 struct efx_channel *channel;
367 unsigned int cpu;
368
369 /* If no online CPUs in local node, fallback to any online CPU */
370 if (cpumask_first_and(cpu_online_mask, srcp2: numa_mask) >= nr_cpu_ids)
371 numa_mask = cpu_online_mask;
372
373 cpu = -1;
374 efx_for_each_channel(channel, efx) {
375 cpu = cpumask_next_and(n: cpu, cpu_online_mask, src2p: numa_mask);
376 if (cpu >= nr_cpu_ids)
377 cpu = cpumask_first_and(cpu_online_mask, srcp2: numa_mask);
378 irq_set_affinity_hint(irq: channel->irq, cpumask_of(cpu));
379 }
380}
381
382void efx_clear_interrupt_affinity(struct efx_nic *efx)
383{
384 struct efx_channel *channel;
385
386 efx_for_each_channel(channel, efx)
387 irq_set_affinity_hint(irq: channel->irq, NULL);
388}
389#else
390void
391efx_set_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
392{
393}
394
395void
396efx_clear_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
397{
398}
399#endif /* CONFIG_SMP */
400
401void efx_remove_interrupts(struct efx_nic *efx)
402{
403 struct efx_channel *channel;
404
405 /* Remove MSI/MSI-X interrupts */
406 efx_for_each_channel(channel, efx)
407 channel->irq = 0;
408 pci_disable_msi(dev: efx->pci_dev);
409 pci_disable_msix(dev: efx->pci_dev);
410
411 /* Remove legacy interrupt */
412 efx->legacy_irq = 0;
413}
414
415/***************
416 * EVENT QUEUES
417 ***************/
418
419/* Create event queue
420 * Event queue memory allocations are done only once. If the channel
421 * is reset, the memory buffer will be reused; this guards against
422 * errors during channel reset and also simplifies interrupt handling.
423 */
424int efx_probe_eventq(struct efx_channel *channel)
425{
426 struct efx_nic *efx = channel->efx;
427 unsigned long entries;
428
429 netif_dbg(efx, probe, efx->net_dev,
430 "chan %d create event queue\n", channel->channel);
431
432 /* Build an event queue with room for one event per tx and rx buffer,
433 * plus some extra for link state events and MCDI completions.
434 */
435 entries = roundup_pow_of_two(efx->rxq_entries + efx->txq_entries + 128);
436 EFX_WARN_ON_PARANOID(entries > EFX_MAX_EVQ_SIZE);
437 channel->eventq_mask = max(entries, EFX_MIN_EVQ_SIZE) - 1;
438
439 return efx_nic_probe_eventq(channel);
440}
441
442/* Prepare channel's event queue */
443int efx_init_eventq(struct efx_channel *channel)
444{
445 struct efx_nic *efx = channel->efx;
446 int rc;
447
448 EFX_WARN_ON_PARANOID(channel->eventq_init);
449
450 netif_dbg(efx, drv, efx->net_dev,
451 "chan %d init event queue\n", channel->channel);
452
453 rc = efx_nic_init_eventq(channel);
454 if (rc == 0) {
455 efx->type->push_irq_moderation(channel);
456 channel->eventq_read_ptr = 0;
457 channel->eventq_init = true;
458 }
459 return rc;
460}
461
462/* Enable event queue processing and NAPI */
463void efx_start_eventq(struct efx_channel *channel)
464{
465 netif_dbg(channel->efx, ifup, channel->efx->net_dev,
466 "chan %d start event queue\n", channel->channel);
467
468 /* Make sure the NAPI handler sees the enabled flag set */
469 channel->enabled = true;
470 smp_wmb();
471
472 napi_enable(n: &channel->napi_str);
473 efx_nic_eventq_read_ack(channel);
474}
475
476/* Disable event queue processing and NAPI */
477void efx_stop_eventq(struct efx_channel *channel)
478{
479 if (!channel->enabled)
480 return;
481
482 napi_disable(n: &channel->napi_str);
483 channel->enabled = false;
484}
485
486void efx_fini_eventq(struct efx_channel *channel)
487{
488 if (!channel->eventq_init)
489 return;
490
491 netif_dbg(channel->efx, drv, channel->efx->net_dev,
492 "chan %d fini event queue\n", channel->channel);
493
494 efx_nic_fini_eventq(channel);
495 channel->eventq_init = false;
496}
497
498void efx_remove_eventq(struct efx_channel *channel)
499{
500 netif_dbg(channel->efx, drv, channel->efx->net_dev,
501 "chan %d remove event queue\n", channel->channel);
502
503 efx_nic_remove_eventq(channel);
504}
505
506/**************************************************************************
507 *
508 * Channel handling
509 *
510 *************************************************************************/
511
512#ifdef CONFIG_RFS_ACCEL
513static void efx_filter_rfs_expire(struct work_struct *data)
514{
515 struct delayed_work *dwork = to_delayed_work(work: data);
516 struct efx_channel *channel;
517 unsigned int time, quota;
518
519 channel = container_of(dwork, struct efx_channel, filter_work);
520 time = jiffies - channel->rfs_last_expiry;
521 quota = channel->rfs_filter_count * time / (30 * HZ);
522 if (quota >= 20 && __efx_filter_rfs_expire(channel, min(channel->rfs_filter_count, quota)))
523 channel->rfs_last_expiry += time;
524 /* Ensure we do more work eventually even if NAPI poll is not happening */
525 schedule_delayed_work(dwork, delay: 30 * HZ);
526}
527#endif
528
529/* Allocate and initialise a channel structure. */
530static struct efx_channel *efx_alloc_channel(struct efx_nic *efx, int i)
531{
532 struct efx_rx_queue *rx_queue;
533 struct efx_tx_queue *tx_queue;
534 struct efx_channel *channel;
535 int j;
536
537 channel = kzalloc(size: sizeof(*channel), GFP_KERNEL);
538 if (!channel)
539 return NULL;
540
541 channel->efx = efx;
542 channel->channel = i;
543 channel->type = &efx_default_channel_type;
544
545 for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
546 tx_queue = &channel->tx_queue[j];
547 tx_queue->efx = efx;
548 tx_queue->queue = -1;
549 tx_queue->label = j;
550 tx_queue->channel = channel;
551 }
552
553#ifdef CONFIG_RFS_ACCEL
554 INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
555#endif
556
557 rx_queue = &channel->rx_queue;
558 rx_queue->efx = efx;
559 timer_setup(&rx_queue->slow_fill, efx_rx_slow_fill, 0);
560
561 return channel;
562}
563
564int efx_init_channels(struct efx_nic *efx)
565{
566 unsigned int i;
567
568 for (i = 0; i < EFX_MAX_CHANNELS; i++) {
569 efx->channel[i] = efx_alloc_channel(efx, i);
570 if (!efx->channel[i])
571 return -ENOMEM;
572 efx->msi_context[i].efx = efx;
573 efx->msi_context[i].index = i;
574 }
575
576 /* Higher numbered interrupt modes are less capable! */
577 efx->interrupt_mode = min(efx->type->min_interrupt_mode,
578 efx_interrupt_mode);
579
580 efx->max_channels = EFX_MAX_CHANNELS;
581 efx->max_tx_channels = EFX_MAX_CHANNELS;
582
583 return 0;
584}
585
586void efx_fini_channels(struct efx_nic *efx)
587{
588 unsigned int i;
589
590 for (i = 0; i < EFX_MAX_CHANNELS; i++)
591 if (efx->channel[i]) {
592 kfree(objp: efx->channel[i]);
593 efx->channel[i] = NULL;
594 }
595}
596
597/* Allocate and initialise a channel structure, copying parameters
598 * (but not resources) from an old channel structure.
599 */
600struct efx_channel *efx_copy_channel(const struct efx_channel *old_channel)
601{
602 struct efx_rx_queue *rx_queue;
603 struct efx_tx_queue *tx_queue;
604 struct efx_channel *channel;
605 int j;
606
607 channel = kmalloc(size: sizeof(*channel), GFP_KERNEL);
608 if (!channel)
609 return NULL;
610
611 *channel = *old_channel;
612
613 channel->napi_dev = NULL;
614 INIT_HLIST_NODE(h: &channel->napi_str.napi_hash_node);
615 channel->napi_str.napi_id = 0;
616 channel->napi_str.state = 0;
617 memset(&channel->eventq, 0, sizeof(channel->eventq));
618
619 for (j = 0; j < EFX_MAX_TXQ_PER_CHANNEL; j++) {
620 tx_queue = &channel->tx_queue[j];
621 if (tx_queue->channel)
622 tx_queue->channel = channel;
623 tx_queue->buffer = NULL;
624 tx_queue->cb_page = NULL;
625 memset(&tx_queue->txd, 0, sizeof(tx_queue->txd));
626 }
627
628 rx_queue = &channel->rx_queue;
629 rx_queue->buffer = NULL;
630 memset(&rx_queue->rxd, 0, sizeof(rx_queue->rxd));
631 timer_setup(&rx_queue->slow_fill, efx_rx_slow_fill, 0);
632#ifdef CONFIG_RFS_ACCEL
633 INIT_DELAYED_WORK(&channel->filter_work, efx_filter_rfs_expire);
634#endif
635
636 return channel;
637}
638
639static int efx_probe_channel(struct efx_channel *channel)
640{
641 struct efx_tx_queue *tx_queue;
642 struct efx_rx_queue *rx_queue;
643 int rc;
644
645 netif_dbg(channel->efx, probe, channel->efx->net_dev,
646 "creating channel %d\n", channel->channel);
647
648 rc = channel->type->pre_probe(channel);
649 if (rc)
650 goto fail;
651
652 rc = efx_probe_eventq(channel);
653 if (rc)
654 goto fail;
655
656 efx_for_each_channel_tx_queue(tx_queue, channel) {
657 rc = efx_probe_tx_queue(tx_queue);
658 if (rc)
659 goto fail;
660 }
661
662 efx_for_each_channel_rx_queue(rx_queue, channel) {
663 rc = efx_probe_rx_queue(rx_queue);
664 if (rc)
665 goto fail;
666 }
667
668 channel->rx_list = NULL;
669
670 return 0;
671
672fail:
673 efx_remove_channel(channel);
674 return rc;
675}
676
677static void efx_get_channel_name(struct efx_channel *channel, char *buf,
678 size_t len)
679{
680 struct efx_nic *efx = channel->efx;
681 const char *type;
682 int number;
683
684 number = channel->channel;
685
686 if (number >= efx->xdp_channel_offset &&
687 !WARN_ON_ONCE(!efx->n_xdp_channels)) {
688 type = "-xdp";
689 number -= efx->xdp_channel_offset;
690 } else if (efx->tx_channel_offset == 0) {
691 type = "";
692 } else if (number < efx->tx_channel_offset) {
693 type = "-rx";
694 } else {
695 type = "-tx";
696 number -= efx->tx_channel_offset;
697 }
698 snprintf(buf, size: len, fmt: "%s%s-%d", efx->name, type, number);
699}
700
701void efx_set_channel_names(struct efx_nic *efx)
702{
703 struct efx_channel *channel;
704
705 efx_for_each_channel(channel, efx)
706 channel->type->get_name(channel,
707 efx->msi_context[channel->channel].name,
708 sizeof(efx->msi_context[0].name));
709}
710
711int efx_probe_channels(struct efx_nic *efx)
712{
713 struct efx_channel *channel;
714 int rc;
715
716 /* Probe channels in reverse, so that any 'extra' channels
717 * use the start of the buffer table. This allows the traffic
718 * channels to be resized without moving them or wasting the
719 * entries before them.
720 */
721 efx_for_each_channel_rev(channel, efx) {
722 rc = efx_probe_channel(channel);
723 if (rc) {
724 netif_err(efx, probe, efx->net_dev,
725 "failed to create channel %d\n",
726 channel->channel);
727 goto fail;
728 }
729 }
730 efx_set_channel_names(efx);
731
732 return 0;
733
734fail:
735 efx_remove_channels(efx);
736 return rc;
737}
738
739void efx_remove_channel(struct efx_channel *channel)
740{
741 struct efx_tx_queue *tx_queue;
742 struct efx_rx_queue *rx_queue;
743
744 netif_dbg(channel->efx, drv, channel->efx->net_dev,
745 "destroy chan %d\n", channel->channel);
746
747 efx_for_each_channel_rx_queue(rx_queue, channel)
748 efx_remove_rx_queue(rx_queue);
749 efx_for_each_channel_tx_queue(tx_queue, channel)
750 efx_remove_tx_queue(tx_queue);
751 efx_remove_eventq(channel);
752 channel->type->post_remove(channel);
753}
754
755void efx_remove_channels(struct efx_nic *efx)
756{
757 struct efx_channel *channel;
758
759 efx_for_each_channel(channel, efx)
760 efx_remove_channel(channel);
761
762 kfree(objp: efx->xdp_tx_queues);
763}
764
765static int efx_set_xdp_tx_queue(struct efx_nic *efx, int xdp_queue_number,
766 struct efx_tx_queue *tx_queue)
767{
768 if (xdp_queue_number >= efx->xdp_tx_queue_count)
769 return -EINVAL;
770
771 netif_dbg(efx, drv, efx->net_dev,
772 "Channel %u TXQ %u is XDP %u, HW %u\n",
773 tx_queue->channel->channel, tx_queue->label,
774 xdp_queue_number, tx_queue->queue);
775 efx->xdp_tx_queues[xdp_queue_number] = tx_queue;
776 return 0;
777}
778
779static void efx_set_xdp_channels(struct efx_nic *efx)
780{
781 struct efx_tx_queue *tx_queue;
782 struct efx_channel *channel;
783 unsigned int next_queue = 0;
784 int xdp_queue_number = 0;
785 int rc;
786
787 /* We need to mark which channels really have RX and TX
788 * queues, and adjust the TX queue numbers if we have separate
789 * RX-only and TX-only channels.
790 */
791 efx_for_each_channel(channel, efx) {
792 if (channel->channel < efx->tx_channel_offset)
793 continue;
794
795 if (efx_channel_is_xdp_tx(channel)) {
796 efx_for_each_channel_tx_queue(tx_queue, channel) {
797 tx_queue->queue = next_queue++;
798 rc = efx_set_xdp_tx_queue(efx, xdp_queue_number,
799 tx_queue);
800 if (rc == 0)
801 xdp_queue_number++;
802 }
803 } else {
804 efx_for_each_channel_tx_queue(tx_queue, channel) {
805 tx_queue->queue = next_queue++;
806 netif_dbg(efx, drv, efx->net_dev,
807 "Channel %u TXQ %u is HW %u\n",
808 channel->channel, tx_queue->label,
809 tx_queue->queue);
810 }
811
812 /* If XDP is borrowing queues from net stack, it must
813 * use the queue with no csum offload, which is the
814 * first one of the channel
815 * (note: tx_queue_by_type is not initialized yet)
816 */
817 if (efx->xdp_txq_queues_mode ==
818 EFX_XDP_TX_QUEUES_BORROWED) {
819 tx_queue = &channel->tx_queue[0];
820 rc = efx_set_xdp_tx_queue(efx, xdp_queue_number,
821 tx_queue);
822 if (rc == 0)
823 xdp_queue_number++;
824 }
825 }
826 }
827 WARN_ON(efx->xdp_txq_queues_mode == EFX_XDP_TX_QUEUES_DEDICATED &&
828 xdp_queue_number != efx->xdp_tx_queue_count);
829 WARN_ON(efx->xdp_txq_queues_mode != EFX_XDP_TX_QUEUES_DEDICATED &&
830 xdp_queue_number > efx->xdp_tx_queue_count);
831
832 /* If we have more CPUs than assigned XDP TX queues, assign the already
833 * existing queues to the exceeding CPUs
834 */
835 next_queue = 0;
836 while (xdp_queue_number < efx->xdp_tx_queue_count) {
837 tx_queue = efx->xdp_tx_queues[next_queue++];
838 rc = efx_set_xdp_tx_queue(efx, xdp_queue_number, tx_queue);
839 if (rc == 0)
840 xdp_queue_number++;
841 }
842}
843
844int efx_realloc_channels(struct efx_nic *efx, u32 rxq_entries, u32 txq_entries)
845{
846 struct efx_channel *other_channel[EFX_MAX_CHANNELS], *channel,
847 *ptp_channel = efx_ptp_channel(efx);
848 struct efx_ptp_data *ptp_data = efx->ptp_data;
849 u32 old_rxq_entries, old_txq_entries;
850 unsigned int i;
851 int rc, rc2;
852
853 rc = efx_check_disabled(efx);
854 if (rc)
855 return rc;
856
857 efx_device_detach_sync(efx);
858 efx_stop_all(efx);
859 efx_soft_disable_interrupts(efx);
860
861 /* Clone channels (where possible) */
862 memset(other_channel, 0, sizeof(other_channel));
863 for (i = 0; i < efx->n_channels; i++) {
864 channel = efx->channel[i];
865 if (channel->type->copy)
866 channel = channel->type->copy(channel);
867 if (!channel) {
868 rc = -ENOMEM;
869 goto out;
870 }
871 other_channel[i] = channel;
872 }
873
874 /* Swap entry counts and channel pointers */
875 old_rxq_entries = efx->rxq_entries;
876 old_txq_entries = efx->txq_entries;
877 efx->rxq_entries = rxq_entries;
878 efx->txq_entries = txq_entries;
879 for (i = 0; i < efx->n_channels; i++)
880 swap(efx->channel[i], other_channel[i]);
881
882 for (i = 0; i < efx->n_channels; i++) {
883 channel = efx->channel[i];
884 if (!channel->type->copy)
885 continue;
886 rc = efx_probe_channel(channel);
887 if (rc)
888 goto rollback;
889 efx_init_napi_channel(channel: efx->channel[i]);
890 }
891
892 efx_set_xdp_channels(efx);
893out:
894 efx->ptp_data = NULL;
895 /* Destroy unused channel structures */
896 for (i = 0; i < efx->n_channels; i++) {
897 channel = other_channel[i];
898 if (channel && channel->type->copy) {
899 efx_fini_napi_channel(channel);
900 efx_remove_channel(channel);
901 kfree(objp: channel);
902 }
903 }
904
905 efx->ptp_data = ptp_data;
906 rc2 = efx_soft_enable_interrupts(efx);
907 if (rc2) {
908 rc = rc ? rc : rc2;
909 netif_err(efx, drv, efx->net_dev,
910 "unable to restart interrupts on channel reallocation\n");
911 efx_schedule_reset(efx, type: RESET_TYPE_DISABLE);
912 } else {
913 efx_start_all(efx);
914 efx_device_attach_if_not_resetting(efx);
915 }
916 return rc;
917
918rollback:
919 /* Swap back */
920 efx->rxq_entries = old_rxq_entries;
921 efx->txq_entries = old_txq_entries;
922 for (i = 0; i < efx->n_channels; i++)
923 swap(efx->channel[i], other_channel[i]);
924 efx_ptp_update_channel(efx, channel: ptp_channel);
925 goto out;
926}
927
928int efx_set_channels(struct efx_nic *efx)
929{
930 struct efx_channel *channel;
931 int rc;
932
933 if (efx->xdp_tx_queue_count) {
934 EFX_WARN_ON_PARANOID(efx->xdp_tx_queues);
935
936 /* Allocate array for XDP TX queue lookup. */
937 efx->xdp_tx_queues = kcalloc(n: efx->xdp_tx_queue_count,
938 size: sizeof(*efx->xdp_tx_queues),
939 GFP_KERNEL);
940 if (!efx->xdp_tx_queues)
941 return -ENOMEM;
942 }
943
944 efx_for_each_channel(channel, efx) {
945 if (channel->channel < efx->n_rx_channels)
946 channel->rx_queue.core_index = channel->channel;
947 else
948 channel->rx_queue.core_index = -1;
949 }
950
951 efx_set_xdp_channels(efx);
952
953 rc = netif_set_real_num_tx_queues(dev: efx->net_dev, txq: efx->n_tx_channels);
954 if (rc)
955 return rc;
956 return netif_set_real_num_rx_queues(dev: efx->net_dev, rxq: efx->n_rx_channels);
957}
958
959static bool efx_default_channel_want_txqs(struct efx_channel *channel)
960{
961 return channel->channel - channel->efx->tx_channel_offset <
962 channel->efx->n_tx_channels;
963}
964
965/*************
966 * START/STOP
967 *************/
968
969int efx_soft_enable_interrupts(struct efx_nic *efx)
970{
971 struct efx_channel *channel, *end_channel;
972 int rc;
973
974 BUG_ON(efx->state == STATE_DISABLED);
975
976 efx->irq_soft_enabled = true;
977 smp_wmb();
978
979 efx_for_each_channel(channel, efx) {
980 if (!channel->type->keep_eventq) {
981 rc = efx_init_eventq(channel);
982 if (rc)
983 goto fail;
984 }
985 efx_start_eventq(channel);
986 }
987
988 efx_mcdi_mode_event(efx);
989
990 return 0;
991fail:
992 end_channel = channel;
993 efx_for_each_channel(channel, efx) {
994 if (channel == end_channel)
995 break;
996 efx_stop_eventq(channel);
997 if (!channel->type->keep_eventq)
998 efx_fini_eventq(channel);
999 }
1000
1001 return rc;
1002}
1003
1004void efx_soft_disable_interrupts(struct efx_nic *efx)
1005{
1006 struct efx_channel *channel;
1007
1008 if (efx->state == STATE_DISABLED)
1009 return;
1010
1011 efx_mcdi_mode_poll(efx);
1012
1013 efx->irq_soft_enabled = false;
1014 smp_wmb();
1015
1016 if (efx->legacy_irq)
1017 synchronize_irq(irq: efx->legacy_irq);
1018
1019 efx_for_each_channel(channel, efx) {
1020 if (channel->irq)
1021 synchronize_irq(irq: channel->irq);
1022
1023 efx_stop_eventq(channel);
1024 if (!channel->type->keep_eventq)
1025 efx_fini_eventq(channel);
1026 }
1027
1028 /* Flush the asynchronous MCDI request queue */
1029 efx_mcdi_flush_async(efx);
1030}
1031
1032int efx_enable_interrupts(struct efx_nic *efx)
1033{
1034 struct efx_channel *channel, *end_channel;
1035 int rc;
1036
1037 /* TODO: Is this really a bug? */
1038 BUG_ON(efx->state == STATE_DISABLED);
1039
1040 if (efx->eeh_disabled_legacy_irq) {
1041 enable_irq(irq: efx->legacy_irq);
1042 efx->eeh_disabled_legacy_irq = false;
1043 }
1044
1045 efx->type->irq_enable_master(efx);
1046
1047 efx_for_each_channel(channel, efx) {
1048 if (channel->type->keep_eventq) {
1049 rc = efx_init_eventq(channel);
1050 if (rc)
1051 goto fail;
1052 }
1053 }
1054
1055 rc = efx_soft_enable_interrupts(efx);
1056 if (rc)
1057 goto fail;
1058
1059 return 0;
1060
1061fail:
1062 end_channel = channel;
1063 efx_for_each_channel(channel, efx) {
1064 if (channel == end_channel)
1065 break;
1066 if (channel->type->keep_eventq)
1067 efx_fini_eventq(channel);
1068 }
1069
1070 efx->type->irq_disable_non_ev(efx);
1071
1072 return rc;
1073}
1074
1075void efx_disable_interrupts(struct efx_nic *efx)
1076{
1077 struct efx_channel *channel;
1078
1079 efx_soft_disable_interrupts(efx);
1080
1081 efx_for_each_channel(channel, efx) {
1082 if (channel->type->keep_eventq)
1083 efx_fini_eventq(channel);
1084 }
1085
1086 efx->type->irq_disable_non_ev(efx);
1087}
1088
1089void efx_start_channels(struct efx_nic *efx)
1090{
1091 struct efx_tx_queue *tx_queue;
1092 struct efx_rx_queue *rx_queue;
1093 struct efx_channel *channel;
1094
1095 efx_for_each_channel_rev(channel, efx) {
1096 if (channel->type->start)
1097 channel->type->start(channel);
1098 efx_for_each_channel_tx_queue(tx_queue, channel) {
1099 efx_init_tx_queue(tx_queue);
1100 atomic_inc(v: &efx->active_queues);
1101 }
1102
1103 efx_for_each_channel_rx_queue(rx_queue, channel) {
1104 efx_init_rx_queue(rx_queue);
1105 atomic_inc(v: &efx->active_queues);
1106 efx_stop_eventq(channel);
1107 efx_fast_push_rx_descriptors(rx_queue, atomic: false);
1108 efx_start_eventq(channel);
1109 }
1110
1111 WARN_ON(channel->rx_pkt_n_frags);
1112 }
1113}
1114
1115void efx_stop_channels(struct efx_nic *efx)
1116{
1117 struct efx_tx_queue *tx_queue;
1118 struct efx_rx_queue *rx_queue;
1119 struct efx_channel *channel;
1120 int rc = 0;
1121
1122 /* Stop special channels and RX refill.
1123 * The channel's stop has to be called first, since it might wait
1124 * for a sentinel RX to indicate the channel has fully drained.
1125 */
1126 efx_for_each_channel(channel, efx) {
1127 if (channel->type->stop)
1128 channel->type->stop(channel);
1129 efx_for_each_channel_rx_queue(rx_queue, channel)
1130 rx_queue->refill_enabled = false;
1131 }
1132
1133 efx_for_each_channel(channel, efx) {
1134 /* RX packet processing is pipelined, so wait for the
1135 * NAPI handler to complete. At least event queue 0
1136 * might be kept active by non-data events, so don't
1137 * use napi_synchronize() but actually disable NAPI
1138 * temporarily.
1139 */
1140 if (efx_channel_has_rx_queue(channel)) {
1141 efx_stop_eventq(channel);
1142 efx_start_eventq(channel);
1143 }
1144 }
1145
1146 if (efx->type->fini_dmaq)
1147 rc = efx->type->fini_dmaq(efx);
1148
1149 if (rc) {
1150 netif_err(efx, drv, efx->net_dev, "failed to flush queues\n");
1151 } else {
1152 netif_dbg(efx, drv, efx->net_dev,
1153 "successfully flushed all queues\n");
1154 }
1155
1156 efx_for_each_channel(channel, efx) {
1157 efx_for_each_channel_rx_queue(rx_queue, channel)
1158 efx_fini_rx_queue(rx_queue);
1159 efx_for_each_channel_tx_queue(tx_queue, channel)
1160 efx_fini_tx_queue(tx_queue);
1161 }
1162}
1163
1164/**************************************************************************
1165 *
1166 * NAPI interface
1167 *
1168 *************************************************************************/
1169
1170/* Process channel's event queue
1171 *
1172 * This function is responsible for processing the event queue of a
1173 * single channel. The caller must guarantee that this function will
1174 * never be concurrently called more than once on the same channel,
1175 * though different channels may be being processed concurrently.
1176 */
1177static int efx_process_channel(struct efx_channel *channel, int budget)
1178{
1179 struct efx_tx_queue *tx_queue;
1180 struct list_head rx_list;
1181 int spent;
1182
1183 if (unlikely(!channel->enabled))
1184 return 0;
1185
1186 /* Prepare the batch receive list */
1187 EFX_WARN_ON_PARANOID(channel->rx_list != NULL);
1188 INIT_LIST_HEAD(list: &rx_list);
1189 channel->rx_list = &rx_list;
1190
1191 efx_for_each_channel_tx_queue(tx_queue, channel) {
1192 tx_queue->pkts_compl = 0;
1193 tx_queue->bytes_compl = 0;
1194 }
1195
1196 spent = efx_nic_process_eventq(channel, quota: budget);
1197 if (spent && efx_channel_has_rx_queue(channel)) {
1198 struct efx_rx_queue *rx_queue =
1199 efx_channel_get_rx_queue(channel);
1200
1201 efx_rx_flush_packet(channel);
1202 efx_fast_push_rx_descriptors(rx_queue, atomic: true);
1203 }
1204
1205 /* Update BQL */
1206 efx_for_each_channel_tx_queue(tx_queue, channel) {
1207 if (tx_queue->bytes_compl) {
1208 netdev_tx_completed_queue(dev_queue: tx_queue->core_txq,
1209 pkts: tx_queue->pkts_compl,
1210 bytes: tx_queue->bytes_compl);
1211 }
1212 }
1213
1214 /* Receive any packets we queued up */
1215 netif_receive_skb_list(head: channel->rx_list);
1216 channel->rx_list = NULL;
1217
1218 return spent;
1219}
1220
1221static void efx_update_irq_mod(struct efx_nic *efx, struct efx_channel *channel)
1222{
1223 int step = efx->irq_mod_step_us;
1224
1225 if (channel->irq_mod_score < irq_adapt_low_thresh) {
1226 if (channel->irq_moderation_us > step) {
1227 channel->irq_moderation_us -= step;
1228 efx->type->push_irq_moderation(channel);
1229 }
1230 } else if (channel->irq_mod_score > irq_adapt_high_thresh) {
1231 if (channel->irq_moderation_us <
1232 efx->irq_rx_moderation_us) {
1233 channel->irq_moderation_us += step;
1234 efx->type->push_irq_moderation(channel);
1235 }
1236 }
1237
1238 channel->irq_count = 0;
1239 channel->irq_mod_score = 0;
1240}
1241
1242/* NAPI poll handler
1243 *
1244 * NAPI guarantees serialisation of polls of the same device, which
1245 * provides the guarantee required by efx_process_channel().
1246 */
1247static int efx_poll(struct napi_struct *napi, int budget)
1248{
1249 struct efx_channel *channel =
1250 container_of(napi, struct efx_channel, napi_str);
1251 struct efx_nic *efx = channel->efx;
1252#ifdef CONFIG_RFS_ACCEL
1253 unsigned int time;
1254#endif
1255 int spent;
1256
1257 netif_vdbg(efx, intr, efx->net_dev,
1258 "channel %d NAPI poll executing on CPU %d\n",
1259 channel->channel, raw_smp_processor_id());
1260
1261 spent = efx_process_channel(channel, budget);
1262
1263 xdp_do_flush();
1264
1265 if (spent < budget) {
1266 if (efx_channel_has_rx_queue(channel) &&
1267 efx->irq_rx_adaptive &&
1268 unlikely(++channel->irq_count == 1000)) {
1269 efx_update_irq_mod(efx, channel);
1270 }
1271
1272#ifdef CONFIG_RFS_ACCEL
1273 /* Perhaps expire some ARFS filters */
1274 time = jiffies - channel->rfs_last_expiry;
1275 /* Would our quota be >= 20? */
1276 if (channel->rfs_filter_count * time >= 600 * HZ)
1277 mod_delayed_work(wq: system_wq, dwork: &channel->filter_work, delay: 0);
1278#endif
1279
1280 /* There is no race here; although napi_disable() will
1281 * only wait for napi_complete(), this isn't a problem
1282 * since efx_nic_eventq_read_ack() will have no effect if
1283 * interrupts have already been disabled.
1284 */
1285 if (napi_complete_done(n: napi, work_done: spent))
1286 efx_nic_eventq_read_ack(channel);
1287 }
1288
1289 return spent;
1290}
1291
1292void efx_init_napi_channel(struct efx_channel *channel)
1293{
1294 struct efx_nic *efx = channel->efx;
1295
1296 channel->napi_dev = efx->net_dev;
1297 netif_napi_add(dev: channel->napi_dev, napi: &channel->napi_str, poll: efx_poll);
1298}
1299
1300void efx_init_napi(struct efx_nic *efx)
1301{
1302 struct efx_channel *channel;
1303
1304 efx_for_each_channel(channel, efx)
1305 efx_init_napi_channel(channel);
1306}
1307
1308void efx_fini_napi_channel(struct efx_channel *channel)
1309{
1310 if (channel->napi_dev)
1311 netif_napi_del(napi: &channel->napi_str);
1312
1313 channel->napi_dev = NULL;
1314}
1315
1316void efx_fini_napi(struct efx_nic *efx)
1317{
1318 struct efx_channel *channel;
1319
1320 efx_for_each_channel(channel, efx)
1321 efx_fini_napi_channel(channel);
1322}
1323
1324/***************
1325 * Housekeeping
1326 ***************/
1327
1328static int efx_channel_dummy_op_int(struct efx_channel *channel)
1329{
1330 return 0;
1331}
1332
1333void efx_channel_dummy_op_void(struct efx_channel *channel)
1334{
1335}
1336
1337static const struct efx_channel_type efx_default_channel_type = {
1338 .pre_probe = efx_channel_dummy_op_int,
1339 .post_remove = efx_channel_dummy_op_void,
1340 .get_name = efx_get_channel_name,
1341 .copy = efx_copy_channel,
1342 .want_txqs = efx_default_channel_want_txqs,
1343 .keep_eventq = false,
1344 .want_pio = true,
1345};
1346

source code of linux/drivers/net/ethernet/sfc/efx_channels.c