include/net/pkt_sched.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef __NET_PKT_SCHED_H
   3 #define __NET_PKT_SCHED_H
   4
   5 #include <linux/jiffies.h>
   6 #include <linux/ktime.h>
   7 #include <linux/if_vlan.h>
   8 #include <net/sch_generic.h>
   9 #include <uapi/linux/pkt_sched.h>
  10
  11 #define DEFAULT_TX_QUEUE_LEN    1000
  12
  13 struct qdisc_walker {
  14         int     stop;
  15         int     skip;
  16         int     count;
  17         int     (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  18 };
  19
  20 #define QDISC_ALIGNTO           64
  21 #define QDISC_ALIGN(len)        (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
  22
  23 static inline void *qdisc_priv(struct Qdisc *q)
  24 {
  25         return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
  26 }
  27
  28 /*
  29    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
  30
  31    Normal IP packet size ~ 512byte, hence:
  32
  33    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
  34    10Mbit ethernet.
  35
  36    10msec resolution -> <50Kbit/sec.
  37
  38    The result: [34]86 is not good choice for QoS router :-(
  39
  40    The things are not so bad, because we may use artificial
  41    clock evaluated by integration of network data flow
  42    in the most critical places.
  43  */
  44
  45 typedef u64     psched_time_t;
  46 typedef long    psched_tdiff_t;
  47
  48 /* Avoid doing 64 bit divide */
  49 #define PSCHED_SHIFT                    6
  50 #define PSCHED_TICKS2NS(x)              ((s64)(x) << PSCHED_SHIFT)
  51 #define PSCHED_NS2TICKS(x)              ((x) >> PSCHED_SHIFT)
  52
  53 #define PSCHED_TICKS_PER_SEC            PSCHED_NS2TICKS(NSEC_PER_SEC)
  54 #define PSCHED_PASTPERFECT              0
  55
  56 static inline psched_time_t psched_get_time(void)
  57 {
  58         return PSCHED_NS2TICKS(ktime_get_ns());
  59 }
  60
  61 static inline psched_tdiff_t
  62 psched_tdiff_bounded(psched_time_t tv1, psched_time_t tv2, psched_time_t bound)
  63 {
  64         return min(tv1 - tv2, bound);
  65 }
  66
  67 struct qdisc_watchdog {
  68         u64             last_expires;
  69         struct hrtimer  timer;
  70         struct Qdisc    *qdisc;
  71 };
  72
  73 void qdisc_watchdog_init(struct qdisc_watchdog *wd, struct Qdisc *qdisc);
  74 void qdisc_watchdog_schedule_ns(struct qdisc_watchdog *wd, u64 expires);
  75
  76 static inline void qdisc_watchdog_schedule(struct qdisc_watchdog *wd,
  77                                            psched_time_t expires)
  78 {
  79         qdisc_watchdog_schedule_ns(wd, PSCHED_TICKS2NS(expires));
  80 }
  81
  82 void qdisc_watchdog_cancel(struct qdisc_watchdog *wd);
  83
  84 extern struct Qdisc_ops pfifo_qdisc_ops;
  85 extern struct Qdisc_ops bfifo_qdisc_ops;
  86 extern struct Qdisc_ops pfifo_head_drop_qdisc_ops;
  87
  88 int fifo_set_limit(struct Qdisc *q, unsigned int limit);
  89 struct Qdisc *fifo_create_dflt(struct Qdisc *sch, struct Qdisc_ops *ops,
  90                                unsigned int limit);
  91
  92 int register_qdisc(struct Qdisc_ops *qops);
  93 int unregister_qdisc(struct Qdisc_ops *qops);
  94 void qdisc_get_default(char *id, size_t len);
  95 int qdisc_set_default(const char *id);
  96
  97 void qdisc_hash_add(struct Qdisc *q, bool invisible);
  98 void qdisc_hash_del(struct Qdisc *q);
  99 struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
 100 struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
 101 struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 102                                         struct nlattr *tab);
 103 void qdisc_put_rtab(struct qdisc_rate_table *tab);
 104 void qdisc_put_stab(struct qdisc_size_table *tab);
 105 void qdisc_warn_nonwc(const char *txt, struct Qdisc *qdisc);
 106 int sch_direct_xmit(struct sk_buff *skb, struct Qdisc *q,
 107                     struct net_device *dev, struct netdev_queue *txq,
 108                     spinlock_t *root_lock, bool validate);
 109
 110 void __qdisc_run(struct Qdisc *q);
 111
 112 static inline void qdisc_run(struct Qdisc *q)
 113 {
 114         if (qdisc_run_begin(q))
 115                 __qdisc_run(q);
 116 }
 117
 118 static inline __be16 tc_skb_protocol(const struct sk_buff *skb)
 119 {
 120         /* We need to take extra care in case the skb came via
 121          * vlan accelerated path. In that case, use skb->vlan_proto
 122          * as the original vlan header was already stripped.
 123          */
 124         if (skb_vlan_tag_present(skb))
 125                 return skb->vlan_proto;
 126         return skb->protocol;
 127 }
 128
 129 /* Calculate maximal size of packet seen by hard_start_xmit
 130    routine of this device.
 131  */
 132 static inline unsigned int psched_mtu(const struct net_device *dev)
 133 {
 134         return dev->mtu + dev->hard_header_len;
 135 }
 136
 137 static inline bool is_classid_clsact_ingress(u32 classid)
 138 {
 139         /* This also returns true for ingress qdisc */
 140         return TC_H_MAJ(classid) == TC_H_MAJ(TC_H_CLSACT) &&
 141                TC_H_MIN(classid) != TC_H_MIN(TC_H_MIN_EGRESS);
 142 }
 143
 144 static inline bool is_classid_clsact_egress(u32 classid)
 145 {
 146         return TC_H_MAJ(classid) == TC_H_MAJ(TC_H_CLSACT) &&
 147                TC_H_MIN(classid) == TC_H_MIN(TC_H_MIN_EGRESS);
 148 }
 149
 150 #endif