linux-stable/include/net/fq_impl.h
Felix Fietkau 7d360f6061 wifi: mac80211: add support for restricting netdev features per vif
This can be used to selectively disable feature flags for checksum offload,
scatter/gather or GSO by changing vif->netdev_features.
Removing features from vif->netdev_features does not affect the netdev
features themselves, but instead fixes up skbs in the tx path so that the
offloads are not needed in the driver.

Aside from making it easier to deal with vif type based hardware limitations,
this also makes it possible to optimize performance on hardware without native
GSO support by declaring GSO support in hw->netdev_features and removing it
from vif->netdev_features. This allows mac80211 to handle GSO segmentation
after the sta lookup, but before itxq enqueue, thus reducing the number of
unnecessary sta lookups, as well as some other per-packet processing.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
Link: https://lore.kernel.org/r/20221010094338.78070-1-nbd@nbd.name
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2022-12-01 15:09:10 +01:00

393 lines
8 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (c) 2016 Qualcomm Atheros, Inc
*
* Based on net/sched/sch_fq_codel.c
*/
#ifndef __NET_SCHED_FQ_IMPL_H
#define __NET_SCHED_FQ_IMPL_H
#include <net/fq.h>
/* functions that are embedded into includer */
static void
__fq_adjust_removal(struct fq *fq, struct fq_flow *flow, unsigned int packets,
unsigned int bytes, unsigned int truesize)
{
struct fq_tin *tin = flow->tin;
int idx;
tin->backlog_bytes -= bytes;
tin->backlog_packets -= packets;
flow->backlog -= bytes;
fq->backlog -= packets;
fq->memory_usage -= truesize;
if (flow->backlog)
return;
if (flow == &tin->default_flow) {
list_del_init(&tin->tin_list);
return;
}
idx = flow - fq->flows;
__clear_bit(idx, fq->flows_bitmap);
}
static void fq_adjust_removal(struct fq *fq,
struct fq_flow *flow,
struct sk_buff *skb)
{
__fq_adjust_removal(fq, flow, 1, skb->len, skb->truesize);
}
static struct sk_buff *fq_flow_dequeue(struct fq *fq,
struct fq_flow *flow)
{
struct sk_buff *skb;
lockdep_assert_held(&fq->lock);
skb = __skb_dequeue(&flow->queue);
if (!skb)
return NULL;
fq_adjust_removal(fq, flow, skb);
return skb;
}
static int fq_flow_drop(struct fq *fq, struct fq_flow *flow,
fq_skb_free_t free_func)
{
unsigned int packets = 0, bytes = 0, truesize = 0;
struct fq_tin *tin = flow->tin;
struct sk_buff *skb;
int pending;
lockdep_assert_held(&fq->lock);
pending = min_t(int, 32, skb_queue_len(&flow->queue) / 2);
do {
skb = __skb_dequeue(&flow->queue);
if (!skb)
break;
packets++;
bytes += skb->len;
truesize += skb->truesize;
free_func(fq, tin, flow, skb);
} while (packets < pending);
__fq_adjust_removal(fq, flow, packets, bytes, truesize);
return packets;
}
static struct sk_buff *fq_tin_dequeue(struct fq *fq,
struct fq_tin *tin,
fq_tin_dequeue_t dequeue_func)
{
struct fq_flow *flow;
struct list_head *head;
struct sk_buff *skb;
lockdep_assert_held(&fq->lock);
begin:
head = &tin->new_flows;
if (list_empty(head)) {
head = &tin->old_flows;
if (list_empty(head))
return NULL;
}
flow = list_first_entry(head, struct fq_flow, flowchain);
if (flow->deficit <= 0) {
flow->deficit += fq->quantum;
list_move_tail(&flow->flowchain,
&tin->old_flows);
goto begin;
}
skb = dequeue_func(fq, tin, flow);
if (!skb) {
/* force a pass through old_flows to prevent starvation */
if ((head == &tin->new_flows) &&
!list_empty(&tin->old_flows)) {
list_move_tail(&flow->flowchain, &tin->old_flows);
} else {
list_del_init(&flow->flowchain);
flow->tin = NULL;
}
goto begin;
}
flow->deficit -= skb->len;
tin->tx_bytes += skb->len;
tin->tx_packets++;
return skb;
}
static u32 fq_flow_idx(struct fq *fq, struct sk_buff *skb)
{
u32 hash = skb_get_hash(skb);
return reciprocal_scale(hash, fq->flows_cnt);
}
static struct fq_flow *fq_flow_classify(struct fq *fq,
struct fq_tin *tin, u32 idx,
struct sk_buff *skb)
{
struct fq_flow *flow;
lockdep_assert_held(&fq->lock);
flow = &fq->flows[idx];
if (flow->tin && flow->tin != tin) {
flow = &tin->default_flow;
tin->collisions++;
fq->collisions++;
}
if (!flow->tin)
tin->flows++;
return flow;
}
static struct fq_flow *fq_find_fattest_flow(struct fq *fq)
{
struct fq_tin *tin;
struct fq_flow *flow = NULL;
u32 len = 0;
int i;
for_each_set_bit(i, fq->flows_bitmap, fq->flows_cnt) {
struct fq_flow *cur = &fq->flows[i];
unsigned int cur_len;
cur_len = cur->backlog;
if (cur_len <= len)
continue;
flow = cur;
len = cur_len;
}
list_for_each_entry(tin, &fq->tin_backlog, tin_list) {
unsigned int cur_len = tin->default_flow.backlog;
if (cur_len <= len)
continue;
flow = &tin->default_flow;
len = cur_len;
}
return flow;
}
static void fq_tin_enqueue(struct fq *fq,
struct fq_tin *tin, u32 idx,
struct sk_buff *skb,
fq_skb_free_t free_func)
{
struct fq_flow *flow;
struct sk_buff *next;
bool oom;
lockdep_assert_held(&fq->lock);
flow = fq_flow_classify(fq, tin, idx, skb);
if (!flow->backlog) {
if (flow != &tin->default_flow)
__set_bit(idx, fq->flows_bitmap);
else if (list_empty(&tin->tin_list))
list_add(&tin->tin_list, &fq->tin_backlog);
}
flow->tin = tin;
skb_list_walk_safe(skb, skb, next) {
skb_mark_not_on_list(skb);
flow->backlog += skb->len;
tin->backlog_bytes += skb->len;
tin->backlog_packets++;
fq->memory_usage += skb->truesize;
fq->backlog++;
__skb_queue_tail(&flow->queue, skb);
}
if (list_empty(&flow->flowchain)) {
flow->deficit = fq->quantum;
list_add_tail(&flow->flowchain,
&tin->new_flows);
}
oom = (fq->memory_usage > fq->memory_limit);
while (fq->backlog > fq->limit || oom) {
flow = fq_find_fattest_flow(fq);
if (!flow)
return;
if (!fq_flow_drop(fq, flow, free_func))
return;
flow->tin->overlimit++;
fq->overlimit++;
if (oom) {
fq->overmemory++;
oom = (fq->memory_usage > fq->memory_limit);
}
}
}
static void fq_flow_filter(struct fq *fq,
struct fq_flow *flow,
fq_skb_filter_t filter_func,
void *filter_data,
fq_skb_free_t free_func)
{
struct fq_tin *tin = flow->tin;
struct sk_buff *skb, *tmp;
lockdep_assert_held(&fq->lock);
skb_queue_walk_safe(&flow->queue, skb, tmp) {
if (!filter_func(fq, tin, flow, skb, filter_data))
continue;
__skb_unlink(skb, &flow->queue);
fq_adjust_removal(fq, flow, skb);
free_func(fq, tin, flow, skb);
}
}
static void fq_tin_filter(struct fq *fq,
struct fq_tin *tin,
fq_skb_filter_t filter_func,
void *filter_data,
fq_skb_free_t free_func)
{
struct fq_flow *flow;
lockdep_assert_held(&fq->lock);
list_for_each_entry(flow, &tin->new_flows, flowchain)
fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
list_for_each_entry(flow, &tin->old_flows, flowchain)
fq_flow_filter(fq, flow, filter_func, filter_data, free_func);
}
static void fq_flow_reset(struct fq *fq,
struct fq_flow *flow,
fq_skb_free_t free_func)
{
struct fq_tin *tin = flow->tin;
struct sk_buff *skb;
while ((skb = fq_flow_dequeue(fq, flow)))
free_func(fq, tin, flow, skb);
if (!list_empty(&flow->flowchain)) {
list_del_init(&flow->flowchain);
if (list_empty(&tin->new_flows) &&
list_empty(&tin->old_flows))
list_del_init(&tin->tin_list);
}
flow->tin = NULL;
WARN_ON_ONCE(flow->backlog);
}
static void fq_tin_reset(struct fq *fq,
struct fq_tin *tin,
fq_skb_free_t free_func)
{
struct list_head *head;
struct fq_flow *flow;
for (;;) {
head = &tin->new_flows;
if (list_empty(head)) {
head = &tin->old_flows;
if (list_empty(head))
break;
}
flow = list_first_entry(head, struct fq_flow, flowchain);
fq_flow_reset(fq, flow, free_func);
}
WARN_ON_ONCE(!list_empty(&tin->tin_list));
WARN_ON_ONCE(tin->backlog_bytes);
WARN_ON_ONCE(tin->backlog_packets);
}
static void fq_flow_init(struct fq_flow *flow)
{
INIT_LIST_HEAD(&flow->flowchain);
__skb_queue_head_init(&flow->queue);
}
static void fq_tin_init(struct fq_tin *tin)
{
INIT_LIST_HEAD(&tin->new_flows);
INIT_LIST_HEAD(&tin->old_flows);
INIT_LIST_HEAD(&tin->tin_list);
fq_flow_init(&tin->default_flow);
}
static int fq_init(struct fq *fq, int flows_cnt)
{
int i;
memset(fq, 0, sizeof(fq[0]));
spin_lock_init(&fq->lock);
INIT_LIST_HEAD(&fq->tin_backlog);
fq->flows_cnt = max_t(u32, flows_cnt, 1);
fq->quantum = 300;
fq->limit = 8192;
fq->memory_limit = 16 << 20; /* 16 MBytes */
fq->flows = kvcalloc(fq->flows_cnt, sizeof(fq->flows[0]), GFP_KERNEL);
if (!fq->flows)
return -ENOMEM;
fq->flows_bitmap = bitmap_zalloc(fq->flows_cnt, GFP_KERNEL);
if (!fq->flows_bitmap) {
kvfree(fq->flows);
fq->flows = NULL;
return -ENOMEM;
}
for (i = 0; i < fq->flows_cnt; i++)
fq_flow_init(&fq->flows[i]);
return 0;
}
static void fq_reset(struct fq *fq,
fq_skb_free_t free_func)
{
int i;
for (i = 0; i < fq->flows_cnt; i++)
fq_flow_reset(fq, &fq->flows[i], free_func);
kvfree(fq->flows);
fq->flows = NULL;
bitmap_free(fq->flows_bitmap);
fq->flows_bitmap = NULL;
}
#endif