LXR linux/include/net/pkt

   1#ifndef __NET_PKT_SCHED_H
   2#define __NET_PKT_SCHED_H
   3
   4#include <linux/jiffies.h>
   5#include <linux/ktime.h>
   6#include <linux/if_vlan.h>
   7#include <net/sch_generic.h>
   8
   9struct qdisc_walker {
  10        int     stop;
  11        int     skip;
  12        int     count;
  13        int     (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  14};
  15
  16#define QDISC_ALIGNTO           64
  17#define QDISC_ALIGN(len)        (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
  18
  19static inline void *qdisc_priv(struct Qdisc *q)
  20{
  21        return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
  22}
  23
  24/* 
  25   Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
  26   
  27   Normal IP packet size ~ 512byte, hence:
  28
  29   0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
  30   10Mbit ethernet.
  31
  32   10msec resolution -> <50Kbit/sec.
  33   
  34   The result: [34]86 is not good choice for QoS router :-(
  35
  36   The things are not so bad, because we may use artificial
  37   clock evaluated by integration of network data flow
  38   in the most critical places.
  39 */
  40
  41typedef u64     psched_time_t;
  42typedef long    psched_tdiff_t;
  43
  44/* Avoid doing 64 bit divide */
  45#define PSCHED_SHIFT                    6
  46#define PSCHED_TICKS2NS(x)              ((s64)(x) << PSCHED_SHIFT)
  47#define PSCHED_NS2TICKS(x)              ((x) >> PSCHED_SHIFT)
  48
  49#define PSCHED_TICKS_PER_SEC            PSCHED_NS2TICKS(NSEC_PER_SEC)
  50#define PSCHED_PASTPERFECT              0
  51
  52static inline psched_time_t psched_get_time(void)
  53{
  54        return PSCHED_NS2TICKS(ktime_get_ns());
  55}
  56
  57static inline psched_tdiff_t
  58psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
  59{
  60        return min(tv1 - tv2, bound);
  61}
  62
  63struct qdisc_watchdog {
  64        struct hrtimer  timer;
  65        struct Qdisc    *qdisc;
  66};
  67
  68void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
  69void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires, bool throttle);
  70
  71static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
  72                                           psched_time_t expires)
  73{
  74        qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires), true);
  75}
  76
  77void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
  78
  79extern struct Qdisc_ops pfifo_qdisc_ops;
  80extern struct Qdisc_ops bfifo_qdisc_ops;
  81extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
  82
  83int fifo_set_limit(struct Qdisc *q, unsigned int limit);
  84struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
  85                               unsigned int limit);
  86
  87int register_qdisc(struct Qdisc_ops *qops);
  88int unregister_qdisc(struct Qdisc_ops *qops);
  89void qdisc_get_default(char *id, size_t len);
  90int qdisc_set_default(const char *id);
  91
  92void qdisc_list_add(struct Qdisc *q);
  93void qdisc_list_del(struct Qdisc *q);
  94struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
  95struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
  96struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
  97                                        struct nlattr *tab);
  98void qdisc_put_rtab(struct qdisc_rate_table *tab);
  99void qdisc_put_stab(struct qdisc_size_table *tab);
 100void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
 101int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
 102                    struct net_device *dev, struct netdev_queue *txq,
 103                    spinlock_t *root_lock, bool validate);
 104
 105void __qdisc_run(struct Qdisc *q);
 106
 107static inline void qdisc_run(struct Qdisc *q)
 108{
 109        if (qdisc_run_begin(q))
 110                __qdisc_run(q);
 111}
 112
 113int tc_classify(struct sk_buff *skb, const struct tcf_proto *tp,
 114                struct tcf_result *res, bool compat_mode);
 115
 116static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
 117{
 118        /* We need to take extra care in case the skb came via
 119         * vlan accelerated path. In that case, use skb->vlan_proto
 120         * as the original vlan header was already stripped.
 121         */
 122        if (skb_vlan_tag_present(skb))
 123                return skb->vlan_proto;
 124        return skb->protocol;
 125}
 126
 127/* Calculate maximal size of packet seen by hard_start_xmit
 128   routine of this device.
 129 */
 130static inline unsigned int psched_mtu(const struct net_device *dev)
 131{
 132        return dev->mtu + dev->hard_header_len;
 133}
 134
 135#endif
 136