net: sched: pie: move common code to pie.h

This patch moves macros, structures and small functions common
to PIE and FQ-PIE (to be added in a future commit) from the file
net/sched/sch_pie.c to the header file include/net/pie.h.
All the moved functions are made inline.
Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/pie.h

+/* 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

net/sched/sch_pie.c

@@ -19,47 +19,7 @@
 #include <linux/skbuff.h>
 #include <net/pkt_sched.h>
 #include <net/inet_ecn.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 */
-};
+#include <net/pie.h>
 
 /* private data for the Qdisc */
 struct pie_sched_data {
@@ -70,50 +30,6 @@ struct pie_sched_data {
 	struct Qdisc *sch;
 };
 
-static 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;
-}
-
-/* private skb vars */
-struct pie_skb_cb {
-	psched_time_t enqueue_time;
-};
-
-static 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 psched_time_t pie_get_enqueue_time(const struct sk_buff *skb)
-{
-	return get_pie_cb(skb)->enqueue_time;
-}
-
-static void pie_set_enqueue_time(struct sk_buff *skb)
-{
-	get_pie_cb(skb)->enqueue_time = psched_get_time();
-}
-
-static 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 bool drop_early(struct Qdisc *sch, u32 packet_size)
 {
 	struct pie_sched_data *q = qdisc_priv(sch);