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   1// SPDX-License-Identifier: GPL-2.0-only
   2/****************************************************************************
   3 * Driver for Solarflare network controllers and boards
   4 * Copyright 2018 Solarflare Communications Inc.
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of the GNU General Public License version 2 as published
   8 * by the Free Software Foundation, incorporated herein by reference.
   9 */
  10
  11#include "net_driver.h"
  12#include <linux/module.h>
  13#include "efx_channels.h"
  14#include "efx.h"
  15#include "efx_common.h"
  16#include "tx_common.h"
  17#include "rx_common.h"
  18#include "nic.h"
  19#include "sriov.h"
  20
  21/* This is the first interrupt mode to try out of:
  22 * 0 => MSI-X
  23 * 1 => MSI
  24 * 2 => legacy
  25 */
  26unsigned int efx_interrupt_mode = EFX_INT_MODE_MSIX;
  27
  28/* This is the requested number of CPUs to use for Receive-Side Scaling (RSS),
  29 * i.e. the number of CPUs among which we may distribute simultaneous
  30 * interrupt handling.
  31 *
  32 * Cards without MSI-X will only target one CPU via legacy or MSI interrupt.
  33 * The default (0) means to assign an interrupt to each core.
  34 */
  35unsigned int rss_cpus;
  36
  37static unsigned int irq_adapt_low_thresh = 8000;
  38module_param(irq_adapt_low_thresh, uint, 0644);
  39MODULE_PARM_DESC(irq_adapt_low_thresh,
  40		 "Threshold score for reducing IRQ moderation");
  41
  42static unsigned int irq_adapt_high_thresh = 16000;
  43module_param(irq_adapt_high_thresh, uint, 0644);
  44MODULE_PARM_DESC(irq_adapt_high_thresh,
  45		 "Threshold score for increasing IRQ moderation");
  46
  47/* This is the weight assigned to each of the (per-channel) virtual
  48 * NAPI devices.
  49 */
  50static int napi_weight = 64;
  51
  52/***************
  53 * Housekeeping
  54 ***************/
  55
  56int efx_channel_dummy_op_int(struct efx_channel *channel)
  57{
  58	return 0;
  59}
  60
  61void efx_channel_dummy_op_void(struct efx_channel *channel)
  62{
  63}
  64
  65static const struct efx_channel_type efx_default_channel_type = {
  66	.pre_probe		= efx_channel_dummy_op_int,
  67	.post_remove		= efx_channel_dummy_op_void,
  68	.get_name		= efx_get_channel_name,
  69	.copy			= efx_copy_channel,
  70	.want_txqs		= efx_default_channel_want_txqs,
  71	.keep_eventq		= false,
  72	.want_pio		= true,
  73};
  74
  75/*************
  76 * INTERRUPTS
  77 *************/
  78
  79static unsigned int efx_wanted_parallelism(struct efx_nic *efx)
  80{
  81	cpumask_var_t thread_mask;
  82	unsigned int count;
  83	int cpu;
  84
  85	if (rss_cpus) {
  86		count = rss_cpus;
  87	} else {
  88		if (unlikely(!zalloc_cpumask_var(&thread_mask, GFP_KERNEL))) {
  89			netif_warn(efx, probe, efx->net_dev,
  90				   "RSS disabled due to allocation failure\n");
  91			return 1;
  92		}
  93
  94		count = 0;
  95		for_each_online_cpu(cpu) {
  96			if (!cpumask_test_cpu(cpu, thread_mask)) {
  97				++count;
  98				cpumask_or(thread_mask, thread_mask,
  99					   topology_sibling_cpumask(cpu));
 100			}
 101		}
 102
 103		free_cpumask_var(thread_mask);
 104	}
 105
 106	if (count > EFX_MAX_RX_QUEUES) {
 107		netif_cond_dbg(efx, probe, efx->net_dev, !rss_cpus, warn,
 108			       "Reducing number of rx queues from %u to %u.\n",
 109			       count, EFX_MAX_RX_QUEUES);
 110		count = EFX_MAX_RX_QUEUES;
 111	}
 112
 113	/* If RSS is requested for the PF *and* VFs then we can't write RSS
 114	 * table entries that are inaccessible to VFs
 115	 */
 116#ifdef CONFIG_SFC_SRIOV
 117	if (efx->type->sriov_wanted) {
 118		if (efx->type->sriov_wanted(efx) && efx_vf_size(efx) > 1 &&
 119		    count > efx_vf_size(efx)) {
 120			netif_warn(efx, probe, efx->net_dev,
 121				   "Reducing number of RSS channels from %u to %u for "
 122				   "VF support. Increase vf-msix-limit to use more "
 123				   "channels on the PF.\n",
 124				   count, efx_vf_size(efx));
 125			count = efx_vf_size(efx);
 126		}
 127	}
 128#endif
 129
 130	return count;
 131}
 132
 133static int efx_allocate_msix_channels(struct efx_nic *efx,
 134				      unsigned int max_channels,
 135				      unsigned int extra_channels,
 136				      unsigned int parallelism)
 137{
 138	unsigned int n_channels = parallelism;
 139	int vec_count;
 140	int n_xdp_tx;
 141	int n_xdp_ev;
 142
 143	if (efx_separate_tx_channels)
 144		n_channels *= 2;
 145	n_channels += extra_channels;
 146
 147	/* To allow XDP transmit to happen from arbitrary NAPI contexts
 148	 * we allocate a TX queue per CPU. We share event queues across
 149	 * multiple tx queues, assuming tx and ev queues are both
 150	 * maximum size.
 151	 */
 152
 153	n_xdp_tx = num_possible_cpus();
 154	n_xdp_ev = DIV_ROUND_UP(n_xdp_tx, EFX_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 */
 236int efx_probe_interrupts(struct efx_nic *efx)
 237{
 238	unsigned int extra_channels = 0;
 239	unsigned int rss_spread;
 240	unsigned int i, j;
 241	int rc;
 242
 243	for (i = 0; i < EFX_MAX_EXTRA_CHANNELS; i++)
 244		if (efx->extra_channel_type[i])
 245			++extra_channels;
 246
 247	if (efx->interrupt_mode == EFX_INT_MODE_MSIX) {
 248		unsigned int parallelism = efx_wanted_parallelism(efx);
 249		struct msix_entry xentries[EFX_MAX_CHANNELS];
 250		unsigned int n_channels;
 251
 252		rc = efx_allocate_msix_channels(efx, efx->max_channels,
 253						extra_channels, parallelism);
 254		if (rc >= 0) {
 255			n_channels = rc;
 256			for (i = 0; i < n_channels; i++)
 257				xentries[i].entry = i;
 258			rc = pci_enable_msix_range(efx->pci_dev, xentries, 1,
 259						   n_channels);
 260		}
 261		if (rc < 0) {
 262			/* Fall back to single channel MSI */
 263			netif_err(efx, drv, efx->net_dev,
 264				  "could not enable MSI-X\n");
 265			if (efx->type->min_interrupt_mode >= EFX_INT_MODE_MSI)
 266				efx->interrupt_mode = EFX_INT_MODE_MSI;
 267			else
 268				return rc;
 269		} else if (rc < n_channels) {
 270			netif_err(efx, drv, efx->net_dev,
 271				  "WARNING: Insufficient MSI-X vectors"
 272				  " available (%d < %u).\n", rc, n_channels);
 273			netif_err(efx, drv, efx->net_dev,
 274				  "WARNING: Performance may be reduced.\n");
 275			n_channels = rc;
 276		}
 277
 278		if (rc > 0) {
 279			for (i = 0; i < efx->n_channels; i++)
 280				efx_get_channel(efx, i)->irq =
 281					xentries[i].vector;
 282		}
 283	}
 284
 285	/* Try single interrupt MSI */
 286	if (efx->interrupt_mode == EFX_INT_MODE_MSI) {
 287		efx->n_channels = 1;
 288		efx->n_rx_channels = 1;
 289		efx->n_tx_channels = 1;
 290		efx->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)
 348void 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
 360void 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
 368void
 369efx_set_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
 370{
 371}
 372
 373void
 374efx_clear_interrupt_affinity(struct efx_nic *efx __attribute__ ((unused)))
 375{
 376}
 377#endif /* CONFIG_SMP */
 378
 379void 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 */
 402int 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 */
 421int 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 */
 441void 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 */
 455void 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
 464void 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
 476void 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
 491static 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. */
 508struct efx_channel *
 509efx_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
 543int 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
 565void 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 */
 579struct 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
 618static 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
 651fail:
 652	efx_remove_channel(channel);
 653	return rc;
 654}
 655
 656void 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
 679void 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
 689int 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
 715fail:
 716	efx_remove_channels(efx);
 717	return rc;
 718}
 719
 720void 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
 736void 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
 746int 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
 820out:
 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
 843rollback:
 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
 855int efx_set_channels(struct efx_nic *efx)
 856{
 857	struct efx_tx_queue *tx_queue;
 858	struct efx_channel *channel;
 859	unsigned int next_queue = 0;
 860	int xdp_queue_number;
 861	int rc;
 862
 863	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
 923bool 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
 933int 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;
 955fail:
 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
 968void 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
 996int 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
1025fail:
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
1039void 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
1053void 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
1077void 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 */
1134static 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
1178static 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 */
1204static 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
1249void 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
1258void 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
1266void 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
1274void 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}