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Commit 292f1c7f authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller
Browse files

sch: make htb_rate_cfg and functions around that generic 



As it is going to be used in tbf as well, push these to generic code.

Signed-off-by: default avatarJiri Pirko <jiri@resnulli.us>
Acked-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b9a7afde

include/net/sch_generic.h

+19 −0
Original line number Diff line number Diff line
@@ -679,4 +679,23 @@ static inline struct sk_buff *skb_act_clone(struct sk_buff *skb, gfp_t gfp_mask, 
}

#endif



struct psched_ratecfg {

	u64 rate_bps;

	u32 mult;

	u32 shift;

};



static inline u64 psched_l2t_ns(const struct psched_ratecfg *r,

				unsigned int len)

{

	return ((u64)len * r->mult) >> r->shift;

}



extern void psched_ratecfg_precompute(struct psched_ratecfg *r, u32 rate);



static inline u32 psched_ratecfg_getrate(const struct psched_ratecfg *r)

{

	return r->rate_bps >> 3;

}



#endif

net/sched/sch_generic.c

+37 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/rcupdate.h>

#include <linux/list.h>

#include <linux/slab.h>

#include <net/sch_generic.h>

#include <net/pkt_sched.h>

#include <net/dst.h>
@@ -896,3 +897,39 @@ void dev_shutdown(struct net_device *dev) 


	WARN_ON(timer_pending(&dev->watchdog_timer));

}



void psched_ratecfg_precompute(struct psched_ratecfg *r, u32 rate)

{

	u64 factor;

	u64 mult;

	int shift;



	r->rate_bps = rate << 3;

	r->shift = 0;

	r->mult = 1;

	/*

	 * Calibrate mult, shift so that token counting is accurate

	 * for smallest packet size (64 bytes).  Token (time in ns) is

	 * computed as (bytes * 8) * NSEC_PER_SEC / rate_bps.  It will

	 * work as long as the smallest packet transfer time can be

	 * accurately represented in nanosec.

	 */

	if (r->rate_bps > 0) {

		/*

		 * Higher shift gives better accuracy.  Find the largest

		 * shift such that mult fits in 32 bits.

		 */

		for (shift = 0; shift < 16; shift++) {

			r->shift = shift;

			factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);

			mult = div64_u64(factor, r->rate_bps);

			if (mult > UINT_MAX)

				break;

		}



		r->shift = shift - 1;

		factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);

		r->mult = div64_u64(factor, r->rate_bps);

	}

}

EXPORT_SYMBOL(psched_ratecfg_precompute);

net/sched/sch_htb.c

+9 −56
Original line number Diff line number Diff line
@@ -38,6 +38,7 @@ 
#include <linux/workqueue.h>

#include <linux/slab.h>

#include <net/netlink.h>

#include <net/sch_generic.h>

#include <net/pkt_sched.h>



/* HTB algorithm.
@@ -71,12 +72,6 @@ enum htb_cmode { 
	HTB_CAN_SEND		/* class can send */

};



struct htb_rate_cfg {

	u64 rate_bps;

	u32 mult;

	u32 shift;

};



/* interior & leaf nodes; props specific to leaves are marked L: */

struct htb_class {

	struct Qdisc_class_common common;
@@ -124,8 +119,8 @@ struct htb_class { 
	int filter_cnt;



	/* token bucket parameters */

	struct htb_rate_cfg rate;

	struct htb_rate_cfg ceil;

	struct psched_ratecfg rate;

	struct psched_ratecfg ceil;

	s64 buffer, cbuffer;	/* token bucket depth/rate */

	psched_tdiff_t mbuffer;	/* max wait time */

	s64 tokens, ctokens;	/* current number of tokens */
@@ -168,45 +163,6 @@ struct htb_sched { 
	struct work_struct work;

};



static u64 l2t_ns(struct htb_rate_cfg *r, unsigned int len)

{

	return ((u64)len * r->mult) >> r->shift;

}



static void htb_precompute_ratedata(struct htb_rate_cfg *r)

{

	u64 factor;

	u64 mult;

	int shift;



	r->shift = 0;

	r->mult = 1;

	/*

	 * Calibrate mult, shift so that token counting is accurate

	 * for smallest packet size (64 bytes).  Token (time in ns) is

	 * computed as (bytes * 8) * NSEC_PER_SEC / rate_bps.  It will

	 * work as long as the smallest packet transfer time can be

	 * accurately represented in nanosec.

	 */

	if (r->rate_bps > 0) {

		/*

		 * Higher shift gives better accuracy.  Find the largest

		 * shift such that mult fits in 32 bits.

		 */

		for (shift = 0; shift < 16; shift++) {

			r->shift = shift;

			factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);

			mult = div64_u64(factor, r->rate_bps);

			if (mult > UINT_MAX)

				break;

		}



		r->shift = shift - 1;

		factor = 8LLU * NSEC_PER_SEC * (1 << r->shift);

		r->mult = div64_u64(factor, r->rate_bps);

	}

}



/* find class in global hash table using given handle */

static inline struct htb_class *htb_find(u32 handle, struct Qdisc *sch)

{
@@ -632,7 +588,7 @@ static inline void htb_accnt_tokens(struct htb_class *cl, int bytes, s64 diff) 


	if (toks > cl->buffer)

		toks = cl->buffer;

	toks -= (s64) l2t_ns(&cl->rate, bytes);

	toks -= (s64) psched_l2t_ns(&cl->rate, bytes);

	if (toks <= -cl->mbuffer)

		toks = 1 - cl->mbuffer;
@@ -645,7 +601,7 @@ static inline void htb_accnt_ctokens(struct htb_class *cl, int bytes, s64 diff) 


	if (toks > cl->cbuffer)

		toks = cl->cbuffer;

	toks -= (s64) l2t_ns(&cl->ceil, bytes);

	toks -= (s64) psched_l2t_ns(&cl->ceil, bytes);

	if (toks <= -cl->mbuffer)

		toks = 1 - cl->mbuffer;
@@ -1134,9 +1090,9 @@ static int htb_dump_class(struct Qdisc *sch, unsigned long arg, 


	memset(&opt, 0, sizeof(opt));



	opt.rate.rate = cl->rate.rate_bps >> 3;

	opt.rate.rate = psched_ratecfg_getrate(&cl->rate);

	opt.buffer = PSCHED_NS2TICKS(cl->buffer);

	opt.ceil.rate = cl->ceil.rate_bps >> 3;

	opt.ceil.rate = psched_ratecfg_getrate(&cl->ceil);

	opt.cbuffer = PSCHED_NS2TICKS(cl->cbuffer);

	opt.quantum = cl->quantum;

	opt.prio = cl->prio;
@@ -1503,11 +1459,8 @@ static int htb_change_class(struct Qdisc *sch, u32 classid, 
			cl->prio = TC_HTB_NUMPRIO - 1;

	}



	cl->rate.rate_bps = (u64)hopt->rate.rate << 3;

	cl->ceil.rate_bps = (u64)hopt->ceil.rate << 3;



	htb_precompute_ratedata(&cl->rate);

	htb_precompute_ratedata(&cl->ceil);

	psched_ratecfg_precompute(&cl->rate, hopt->rate.rate);

	psched_ratecfg_precompute(&cl->ceil, hopt->ceil.rate);



	cl->buffer = PSCHED_TICKS2NS(hopt->buffer);

	cl->cbuffer = PSCHED_TICKS2NS(hopt->buffer);