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-rw-r--r--include/net/pie.h96
1 files changed, 96 insertions, 0 deletions
diff --git a/include/net/pie.h b/include/net/pie.h
new file mode 100644
index 000000000000..440213ec83eb
--- /dev/null
+++ b/include/net/pie.h
@@ -0,0 +1,96 @@
+/* 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 QUEUE_THRESHOLD 16384
+#define DQCOUNT_INVALID -1
+#define DTIME_INVALID 0xffffffffffffffff
+#define MAX_PROB 0xffffffffffffffff
+#define PIE_SCALE 8
+
+/* parameters used */
+struct pie_params {
+ psched_time_t target; /* user specified target delay in pschedtime */
+ u32 tupdate; /* timer frequency (in jiffies) */
+ u32 limit; /* number of packets that can be enqueued */
+ u32 alpha; /* alpha and beta are between 0 and 32 */
+ u32 beta; /* and are used for shift relative to 1 */
+ bool ecn; /* true if ecn is enabled */
+ bool bytemode; /* to scale drop early prob based on pkt size */
+ u8 dq_rate_estimator; /* to calculate delay using Little's law */
+};
+
+/* variables used */
+struct pie_vars {
+ u64 prob; /* probability but scaled by u64 limit. */
+ psched_time_t burst_time;
+ psched_time_t qdelay;
+ psched_time_t qdelay_old;
+ u64 dq_count; /* measured in bytes */
+ psched_time_t dq_tstamp; /* drain rate */
+ u64 accu_prob; /* accumulated drop probability */
+ u32 avg_dq_rate; /* bytes per pschedtime tick,scaled */
+ u32 qlen_old; /* in bytes */
+ u8 accu_prob_overflows; /* overflows of accu_prob */
+};
+
+/* statistics gathering */
+struct pie_stats {
+ u32 packets_in; /* total number of packets enqueued */
+ u32 dropped; /* packets dropped due to pie_action */
+ u32 overlimit; /* dropped due to lack of space in queue */
+ u32 maxq; /* maximum queue size */
+ u32 ecn_mark; /* packets marked with ECN */
+};
+
+/* private skb vars */
+struct pie_skb_cb {
+ psched_time_t enqueue_time;
+};
+
+static inline void pie_params_init(struct pie_params *params)
+{
+ params->alpha = 2;
+ params->beta = 20;
+ params->tupdate = usecs_to_jiffies(15 * USEC_PER_MSEC); /* 15 ms */
+ params->limit = 1000; /* default of 1000 packets */
+ params->target = PSCHED_NS2TICKS(15 * NSEC_PER_MSEC); /* 15 ms */
+ params->ecn = false;
+ params->bytemode = false;
+ params->dq_rate_estimator = false;
+}
+
+static inline void pie_vars_init(struct pie_vars *vars)
+{
+ vars->dq_count = DQCOUNT_INVALID;
+ vars->dq_tstamp = DTIME_INVALID;
+ vars->accu_prob = 0;
+ vars->avg_dq_rate = 0;
+ /* default of 150 ms in pschedtime */
+ vars->burst_time = PSCHED_NS2TICKS(150 * NSEC_PER_MSEC);
+ 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();
+}
+
+#endif