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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef __NET_SCHED_PIE_H
#define __NET_SCHED_PIE_H
#include <linux/ktime.h>
#include <linux/skbuff.h>
#include <linux/types.h>
#include <net/inet_ecn.h>
#include <net/pkt_sched.h>
#define MAX_PROB (U64_MAX >> BITS_PER_BYTE)
#define DTIME_INVALID U64_MAX
#define QUEUE_THRESHOLD 16384
#define DQCOUNT_INVALID -1
#define PIE_SCALE 8
/**
* struct pie_params - contains pie parameters
* @target: target delay in pschedtime
* @tupdate: interval at which drop probability is calculated
* @limit: total number of packets that can be in the queue
* @alpha: parameter to control drop probability
* @beta: parameter to control drop probability
* @ecn: is ECN marking of packets enabled
* @bytemode: is drop probability scaled based on pkt size
* @dq_rate_estimator: is Little's law used for qdelay calculation
*/
struct pie_params {
psched_time_t target;
u32 tupdate;
u32 limit;
u32 alpha;
u32 beta;
u8 ecn;
u8 bytemode;
u8 dq_rate_estimator;
};
/**
* struct pie_vars - contains pie variables
* @qdelay: current queue delay
* @qdelay_old: queue delay in previous qdelay calculation
* @burst_time: burst time allowance
* @dq_tstamp: timestamp at which dq rate was last calculated
* @prob: drop probability
* @accu_prob: accumulated drop probability
* @dq_count: number of bytes dequeued in a measurement cycle
* @avg_dq_rate: calculated average dq rate
* @backlog_old: queue backlog during previous qdelay calculation
*/
struct pie_vars {
psched_time_t qdelay;
psched_time_t qdelay_old;
psched_time_t burst_time;
psched_time_t dq_tstamp;
u64 prob;
u64 accu_prob;
u64 dq_count;
u32 avg_dq_rate;
u32 backlog_old;
};
/**
* struct pie_stats - contains pie stats
* @packets_in: total number of packets enqueued
* @dropped: packets dropped due to pie action
* @overlimit: packets dropped due to lack of space in queue
* @ecn_mark: packets marked with ECN
* @maxq: maximum queue size
*/
struct pie_stats {
u32 packets_in;
u32 dropped;
u32 overlimit;
u32 ecn_mark;
u32 maxq;
};
/**
* struct pie_skb_cb - contains private skb vars
* @enqueue_time: timestamp when the packet is enqueued
* @mem_usage: size of the skb during enqueue
*/
struct pie_skb_cb {
psched_time_t enqueue_time;
u32 mem_usage;
};
static inline void pie_params_init(struct pie_params *params)
{
params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */
params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */
params->limit = 1000;
params->alpha = 2;
params->beta = 20;
params->ecn = false;
params->bytemode = false;
params->dq_rate_estimator = false;
}
static inline void pie_vars_init(struct pie_vars *vars)
{
vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC); /* 150 ms */
vars->dq_tstamp = DTIME_INVALID;
vars->accu_prob = 0;
vars->dq_count = DQCOUNT_INVALID;
vars->avg_dq_rate = 0;
}
static inline struct pie_skb_cb *get_pie_cb(const struct sk_buff *skb)
{
qdisc_cb_private_validate(skb, sizeof(struct pie_skb_cb));
return (struct pie_skb_cb *)qdisc_skb_cb(skb)->data;
}
static inline psched_time_t pie_get_enqueue_time(const struct sk_buff *skb)
{
return get_pie_cb(skb)->enqueue_time;
}
static inline void pie_set_enqueue_time(struct sk_buff *skb)
{
get_pie_cb(skb)->enqueue_time = psched_get_time();
}
bool pie_drop_early(struct Qdisc *sch, struct pie_params *params,
struct pie_vars *vars, u32 backlog, u32 packet_size);
void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params,
struct pie_vars *vars, u32 backlog);
void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars,
u32 backlog);
#endif
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