// SPDX-License-Identifier: GPL-2.0-only
/****************************************************************************
* Driver for Solarflare network controllers and boards
* Copyright 2018 Solarflare Communications Inc.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation, incorporated herein by reference.
*/
#include "net_driver.h"
#include <linux/module.h>
#include "efx_channels.h"
#include "efx.h"
#include "efx_common.h"
#include "tx_common.h"
#include "rx_common.h"
#include "nic.h"
#include "sriov.h"
static unsigned int irq_adapt_low_thresh = 8000;
module_param(irq_adapt_low_thresh, uint, 0644);
MODULE_PARM_DESC(irq_adapt_low_thresh,
"Threshold score for reducing IRQ moderation");
static unsigned int irq_adapt_high_thresh = 16000;
module_param(irq_adapt_high_thresh, uint, 0644);
MODULE_PARM_DESC(irq_adapt_high_thresh,
"Threshold score for increasing IRQ moderation");
/* This is the weight assigned to each of the (per-channel) virtual
* NAPI devices.
*/
static int napi_weight = 64;
/**************************************************************************
*
* NAPI interface
*
*************************************************************************/
/* Process channel's event queue
*
* This function is responsible for processing the event queue of a
* single channel. The caller must guarantee that this function will
* never be concurrently called more than once on the same channel,
* though different channels may be being processed concurrently.
*/
static int efx_process_channel(struct efx_channel *channel, int budget)
{
struct efx_tx_queue *tx_queue;
struct list_head rx_list;
int spent;
if (unlikely(!channel->enabled))
return 0;
/* Prepare the batch receive list */
EFX_WARN_ON_PARANOID(channel->rx_list != NULL);
INIT_LIST_HEAD(&rx_list);
channel->rx_list = &rx_list;
efx_for_each_channel_tx_queue(tx_queue, channel) {
tx_queue->pkts_compl = 0;
tx_queue->bytes_compl = 0;
}
spent = efx_nic_process_eventq(channel, budget);
if (spent && efx_channel_has_rx_queue(channel)) {
struct efx_rx_queue *rx_queue =
efx_channel_get_rx_queue(channel);
efx_rx_flush_packet(channel);
efx_fast_push_rx_descriptors(rx_queue, true);
}
/* Update BQL */
efx_for_each_channel_tx_queue(tx_queue, channel) {
if (tx_queue->bytes_compl) {
netdev_tx_completed_queue(tx_queue->core_txq,
tx_queue->pkts_compl,
tx_queue->bytes_compl);
}
}
/* Receive any packets we queued up */
netif_receive_skb_list(channel->rx_list);
channel->rx_list = NULL;
return spent;
}
static void efx_update_irq_mod(struct efx_nic *efx, struct efx_channel *channel)
{
int step = efx->irq_mod_step_us;
if (channel->irq_mod_score < irq_adapt_low_thresh) {
if (channel->irq_moderation_us > step) {
channel->irq_moderation_us -= step;
efx->type->push_irq_moderation(channel);
}
} else if (channel->irq_mod_score > irq_adapt_high_thresh) {
if (channel->irq_moderation_us <
efx->irq_rx_moderation_us) {
channel->irq_moderation_us += step;
efx->type->push_irq_moderation(channel);
}
}
channel->irq_count = 0;
channel->irq_mod_score = 0;
}
/* NAPI poll handler
*
* NAPI guarantees serialisation of polls of the same device, which
* provides the guarantee required by efx_process_channel().
*/
static int efx_poll(struct napi_struct *napi, int budget)
{
struct efx_channel *channel =
container_of(napi, struct efx_channel, napi_str);
struct efx_nic *efx = channel->efx;
int spent;
netif_vdbg(efx, intr, efx->net_dev,
"channel %d NAPI poll executing on CPU %d\n",
channel->channel, raw_smp_processor_id());
spent = efx_process_channel(channel, budget);
xdp_do_flush_map();
if (spent < budget) {
if (efx_channel_has_rx_queue(channel) &&
efx->irq_rx_adaptive &&
unlikely(++channel->irq_count == 1000)) {
efx_update_irq_mod(efx, channel);
}
#ifdef CONFIG_RFS_ACCEL
/* Perhaps expire some ARFS filters */
mod_delayed_work(system_wq, &channel->filter_work, 0);
#endif
/* There is no race here; although napi_disable() will
* only wait for napi_complete(), this isn't a problem
* since efx_nic_eventq_read_ack() will have no effect if
* interrupts have already been disabled.
*/
if (napi_complete_done(napi, spent))
efx_nic_eventq_read_ack(channel);
}
return spent;
}
void efx_init_napi_channel(struct efx_channel *channel)
{
struct efx_nic *efx = channel->efx;
channel->napi_dev = efx->net_dev;
netif_napi_add(channel->napi_dev, &channel->napi_str,
efx_poll, napi_weight);
}
void efx_init_napi(struct efx_nic *efx)
{
struct efx_channel *channel;
efx_for_each_channel(channel, efx)
efx_init_napi_channel(channel);
}
void efx_fini_napi_channel(struct efx_channel *channel)
{
if (channel->napi_dev)
netif_napi_del(&channel->napi_str);
channel->napi_dev = NULL;
}
void efx_fini_napi(struct efx_nic *efx)
{
struct efx_channel *channel;
efx_for_each_channel(channel, efx)
efx_fini_napi_channel(channel);
}
