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 <net/sch_generic.h>
   6
   7 struct qdisc_walker
   8 {
   9         int     stop;
  10         int     skip;
  11         int     count;
  12         int     (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  13 };
  14
  15 extern rwlock_t qdisc_tree_lock;
  16
  17 #define QDISC_ALIGNTO           32
  18 #define QDISC_ALIGN(len)        (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
  19
  20 static inline void *qdisc_priv(struct Qdisc *q)
  21 {
  22         return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
  23 }
  24
  25 /*
  26    Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
  27
  28    Normal IP packet size ~ 512byte, hence:
  29
  30    0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
  31    10Mbit ethernet.
  32
  33    10msec resolution -> <50Kbit/sec.
  34
  35    The result: [34]86 is not good choice for QoS router :-(
  36
  37    The things are not so bad, because we may use artifical
  38    clock evaluated by integration of network data flow
  39    in the most critical places.
  40
  41    Note: we do not use fastgettimeofday.
  42    The reason is that, when it is not the same thing as
  43    gettimeofday, it returns invalid timestamp, which is
  44    not updated, when net_bh is active.
  45  */
  46
  47 /* General note about internal clock.
  48
  49    Any clock source returns time intervals, measured in units
  50    close to 1usec. With source CONFIG_NET_SCH_CLK_GETTIMEOFDAY it is precisely
  51    microseconds, otherwise something close but different chosen to minimize
  52    arithmetic cost. Ratio usec/internal untis in form nominator/denominator
  53    may be read from /proc/net/psched.
  54  */
  55
  56
  57 #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
  58
  59 typedef struct timeval  psched_time_t;
  60 typedef long            psched_tdiff_t;
  61
  62 #define PSCHED_GET_TIME(stamp) do_gettimeofday(&(stamp))
  63 #define PSCHED_US2JIFFIE(usecs) usecs_to_jiffies(usecs)
  64 #define PSCHED_JIFFIE2US(delay) jiffies_to_usecs(delay)
  65
  66 #else /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
  67
  68 typedef u64     psched_time_t;
  69 typedef long    psched_tdiff_t;
  70
  71 #ifdef CONFIG_NET_SCH_CLK_JIFFIES
  72
  73 #if HZ < 96
  74 #define PSCHED_JSCALE 14
  75 #elif HZ >= 96 && HZ < 192
  76 #define PSCHED_JSCALE 13
  77 #elif HZ >= 192 && HZ < 384
  78 #define PSCHED_JSCALE 12
  79 #elif HZ >= 384 && HZ < 768
  80 #define PSCHED_JSCALE 11
  81 #elif HZ >= 768
  82 #define PSCHED_JSCALE 10
  83 #endif
  84
  85 #define PSCHED_GET_TIME(stamp) ((stamp) = (get_jiffies_64()<<PSCHED_JSCALE))
  86 #define PSCHED_US2JIFFIE(delay) (((delay)+(1<<PSCHED_JSCALE)-1)>>PSCHED_JSCALE)
  87 #define PSCHED_JIFFIE2US(delay) ((delay)<<PSCHED_JSCALE)
  88
  89 #endif /* CONFIG_NET_SCH_CLK_JIFFIES */
  90 #ifdef CONFIG_NET_SCH_CLK_CPU
  91 #include <asm/timex.h>
  92
  93 extern psched_tdiff_t psched_clock_per_hz;
  94 extern int psched_clock_scale;
  95 extern psched_time_t psched_time_base;
  96 extern cycles_t psched_time_mark;
  97
  98 #define PSCHED_GET_TIME(stamp)                                          \
  99 do {                                                                    \
 100         cycles_t cur = get_cycles();                                    \
 101         if (sizeof(cycles_t) == sizeof(u32)) {                          \
 102                 if (cur <= psched_time_mark)                            \
 103                         psched_time_base += 0x100000000ULL;             \
 104                 psched_time_mark = cur;                                 \
 105                 (stamp) = (psched_time_base + cur)>>psched_clock_scale; \
 106         } else {                                                        \
 107                 (stamp) = cur>>psched_clock_scale;                      \
 108         }                                                               \
 109 } while (0)
 110 #define PSCHED_US2JIFFIE(delay) (((delay)+psched_clock_per_hz-1)/psched_clock_per_hz)
 111 #define PSCHED_JIFFIE2US(delay) ((delay)*psched_clock_per_hz)
 112
 113 #endif /* CONFIG_NET_SCH_CLK_CPU */
 114
 115 #endif /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
 116
 117 #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
 118 #define PSCHED_TDIFF(tv1, tv2) \
 119 ({ \
 120            int __delta_sec = (tv1).tv_sec - (tv2).tv_sec; \
 121            int __delta = (tv1).tv_usec - (tv2).tv_usec; \
 122            if (__delta_sec) { \
 123                    switch (__delta_sec) { \
 124                    default: \
 125                            __delta = 0; \
 126                    case 2: \
 127                            __delta += USEC_PER_SEC; \
 128                    case 1: \
 129                            __delta += USEC_PER_SEC; \
 130                    } \
 131            } \
 132            __delta; \
 133 })
 134
 135 static inline int
 136 psched_tod_diff(int delta_sec, int bound)
 137 {
 138         int delta;
 139
 140         if (bound <= USEC_PER_SEC || delta_sec > (0x7FFFFFFF/USEC_PER_SEC)-1)
 141                 return bound;
 142         delta = delta_sec * USEC_PER_SEC;
 143         if (delta > bound || delta < 0)
 144                 delta = bound;
 145         return delta;
 146 }
 147
 148 #define PSCHED_TDIFF_SAFE(tv1, tv2, bound) \
 149 ({ \
 150            int __delta_sec = (tv1).tv_sec - (tv2).tv_sec; \
 151            int __delta = (tv1).tv_usec - (tv2).tv_usec; \
 152            switch (__delta_sec) { \
 153            default: \
 154                    __delta = psched_tod_diff(__delta_sec, bound);  break; \
 155            case 2: \
 156                    __delta += USEC_PER_SEC; \
 157            case 1: \
 158                    __delta += USEC_PER_SEC; \
 159            case 0: \
 160                    if (__delta > bound || __delta < 0) \
 161                         __delta = bound; \
 162            } \
 163            __delta; \
 164 })
 165
 166 #define PSCHED_TLESS(tv1, tv2) (((tv1).tv_usec < (tv2).tv_usec && \
 167                                 (tv1).tv_sec <= (tv2).tv_sec) || \
 168                                  (tv1).tv_sec < (tv2).tv_sec)
 169
 170 #define PSCHED_TADD2(tv, delta, tv_res) \
 171 ({ \
 172            int __delta = (tv).tv_usec + (delta); \
 173            (tv_res).tv_sec = (tv).tv_sec; \
 174            if (__delta > USEC_PER_SEC) { (tv_res).tv_sec++; __delta -= USEC_PER_SEC; } \
 175            (tv_res).tv_usec = __delta; \
 176 })
 177
 178 #define PSCHED_TADD(tv, delta) \
 179 ({ \
 180            (tv).tv_usec += (delta); \
 181            if ((tv).tv_usec > USEC_PER_SEC) { (tv).tv_sec++; \
 182                  (tv).tv_usec -= USEC_PER_SEC; } \
 183 })
 184
 185 /* Set/check that time is in the "past perfect";
 186    it depends on concrete representation of system time
 187  */
 188
 189 #define PSCHED_SET_PASTPERFECT(t)       ((t).tv_sec = 0)
 190 #define PSCHED_IS_PASTPERFECT(t)        ((t).tv_sec == 0)
 191
 192 #define PSCHED_AUDIT_TDIFF(t) ({ if ((t) > 2000000) (t) = 2000000; })
 193
 194 #else /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
 195
 196 #define PSCHED_TDIFF(tv1, tv2) (long)((tv1) - (tv2))
 197 #define PSCHED_TDIFF_SAFE(tv1, tv2, bound) \
 198         min_t(long long, (tv1) - (tv2), bound)
 199
 200
 201 #define PSCHED_TLESS(tv1, tv2) ((tv1) < (tv2))
 202 #define PSCHED_TADD2(tv, delta, tv_res) ((tv_res) = (tv) + (delta))
 203 #define PSCHED_TADD(tv, delta) ((tv) += (delta))
 204 #define PSCHED_SET_PASTPERFECT(t)       ((t) = 0)
 205 #define PSCHED_IS_PASTPERFECT(t)        ((t) == 0)
 206 #define PSCHED_AUDIT_TDIFF(t)
 207
 208 #endif /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
 209
 210 extern struct Qdisc_ops pfifo_qdisc_ops;
 211 extern struct Qdisc_ops bfifo_qdisc_ops;
 212
 213 extern int register_qdisc(struct Qdisc_ops *qops);
 214 extern int unregister_qdisc(struct Qdisc_ops *qops);
 215 extern struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
 216 extern struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
 217 extern struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
 218                 struct rtattr *tab);
 219 extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
 220
 221 extern int qdisc_restart(struct net_device *dev);
 222
 223 static inline void qdisc_run(struct net_device *dev)
 224 {
 225         while (!netif_queue_stopped(dev) && qdisc_restart(dev) < 0)
 226                 /* NOTHING */;
 227 }
 228
 229 extern int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
 230         struct tcf_result *res);
 231
 232 /* Calculate maximal size of packet seen by hard_start_xmit
 233    routine of this device.
 234  */
 235 static inline unsigned psched_mtu(struct net_device *dev)
 236 {
 237         unsigned mtu = dev->mtu;
 238         return dev->hard_header ? mtu + dev->hard_header_len : mtu;
 239 }
 240
 241 #endif