include/net/pkt_sched.h

   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
   9 #define DEFAULT_TX_QUEUE_LEN    1000
  10
  11 struct qdisc_walker {
  12         int     stop;
  13         int     skip;
  14         int     count;
  15         int     (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  16 };
  17
  18 #define QDISC_ALIGNTO           64
  19 #define QDISC_ALIGN(len)        (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
  20
  21 static inline void *qdisc_priv(struct Qdisc *q)
  22 {
  23         return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
  24 }
  25
  26 /*
  27    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
  28
  29    Normal IP packet size ~ 512byte, hence:
  30
  31    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
  32    10Mbit ethernet.
  33
  34    10msec resolution -> <50Kbit/sec.
  35
  36    The result: [34]86 is not good choice for QoS router :-(
  37
  38    The things are not so bad, because we may use artificial
  39    clock evaluated by integration of network data flow
  40    in the most critical places.
  41  */
  42
  43 typedef u64     psched_time_t;
  44 typedef long    psched_tdiff_t;
  45
  46 /* Avoid doing 64 bit divide */
  47 #define PSCHED_SHIFT                    6
  48 #define PSCHED_TICKS2NS(x)              ((s64)(x) << PSCHED_SHIFT)
  49 #define PSCHED_NS2TICKS(x)              ((x) >> PSCHED_SHIFT)
  50
  51 #define PSCHED_TICKS_PER_SEC            PSCHED_NS2TICKS(NSEC_PER_SEC)
  52 #define PSCHED_PASTPERFECT              0
  53
  54 static inline psched_time_t psched_get_time(void)
  55 {
  56         return PSCHED_NS2TICKS(ktime_get_ns());
  57 }
  58
  59 static inline psched_tdiff_t
  60 psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
  61 {
  62         return min(tv1 - tv2, bound);
  63 }
  64
  65 struct qdisc_watchdog {
  66         u64             last_expires;
  67         struct hrtimer  timer;
  68         struct Qdisc    *qdisc;
  69 };
  70
  71 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
  72 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
  73
  74 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
  75                                            psched_time_t expires)
  76 {
  77         qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
  78 }
  79
  80 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
  81
  82 extern struct Qdisc_ops pfifo_qdisc_ops;
  83 extern struct Qdisc_ops bfifo_qdisc_ops;
  84 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
  85
  86 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
  87 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
  88                                unsigned int limit);
  89
  90 int register_qdisc(struct Qdisc_ops *qops);
  91 int unregister_qdisc(struct Qdisc_ops *qops);
  92 void qdisc_get_default(char *id, size_t len);
  93 int qdisc_set_default(const char *id);
  94
  95 void qdisc_hash_add(struct Qdisc *q, bool invisible);
  96 void qdisc_hash_del(struct Qdisc *q);
  97 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
  98 struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
  99 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 100                                         struct nlattr *tab);
 101 void qdisc_put_rtab(struct qdisc_rate_table *tab);
 102 void qdisc_put_stab(struct qdisc_size_table *tab);
 103 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
 104 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
 105                     struct net_device *dev, struct netdev_queue *txq,
 106                     spinlock_t *root_lock, bool validate);
 107
 108 void __qdisc_run(struct Qdisc *q);
 109
 110 static inline void qdisc_run(struct Qdisc *q)
 111 {
 112         if (qdisc_run_begin(q))
 113                 __qdisc_run(q);
 114 }
 115
 116 static 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  */
 130 static inline unsigned int psched_mtu(const struct net_device *dev)
 131 {
 132         return dev->mtu + dev->hard_header_len;
 133 }
 134
 135 #endif