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-rw-r--r--include/net/pie.h138
1 files changed, 138 insertions, 0 deletions
diff --git a/include/net/pie.h b/include/net/pie.h
new file mode 100644
index 000000000000..fd5a37cb7993
--- /dev/null
+++ b/include/net/pie.h
@@ -0,0 +1,138 @@
+/* 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
+#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
+ * @tudpate: 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
+ * @qlen_old: queue length during previous qdelay calculation
+ * @accu_prob_overflows: number of times accu_prob overflows
+ */
+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 qlen_old;
+ u8 accu_prob_overflows;
+};
+
+/**
+ * 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;
+ vars->accu_prob_overflows = 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 qlen, u32 packet_size);
+
+void pie_process_dequeue(struct sk_buff *skb, struct pie_params *params,
+ struct pie_vars *vars, u32 qlen);
+
+void pie_calculate_probability(struct pie_params *params, struct pie_vars *vars,
+ u32 qlen);
+
+#endif