pkt_sched.h 6.7 KB

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  1. #ifndef __NET_PKT_SCHED_H
  2. #define __NET_PKT_SCHED_H
  3. #include <linux/jiffies.h>
  4. #include <net/sch_generic.h>
  5. struct qdisc_walker
  6. {
  7. int stop;
  8. int skip;
  9. int count;
  10. int (*fn)(struct Qdisc *, unsigned long cl, struct qdisc_walker *);
  11. };
  12. extern rwlock_t qdisc_tree_lock;
  13. #define QDISC_ALIGNTO 32
  14. #define QDISC_ALIGN(len) (((len) + QDISC_ALIGNTO-1) & ~(QDISC_ALIGNTO-1))
  15. static inline void *qdisc_priv(struct Qdisc *q)
  16. {
  17. return (char *) q + QDISC_ALIGN(sizeof(struct Qdisc));
  18. }
  19. /*
  20. Timer resolution MUST BE < 10% of min_schedulable_packet_size/bandwidth
  21. Normal IP packet size ~ 512byte, hence:
  22. 0.5Kbyte/1Mbyte/sec = 0.5msec, so that we need 50usec timer for
  23. 10Mbit ethernet.
  24. 10msec resolution -> <50Kbit/sec.
  25. The result: [34]86 is not good choice for QoS router :-(
  26. The things are not so bad, because we may use artifical
  27. clock evaluated by integration of network data flow
  28. in the most critical places.
  29. Note: we do not use fastgettimeofday.
  30. The reason is that, when it is not the same thing as
  31. gettimeofday, it returns invalid timestamp, which is
  32. not updated, when net_bh is active.
  33. */
  34. /* General note about internal clock.
  35. Any clock source returns time intervals, measured in units
  36. close to 1usec. With source CONFIG_NET_SCH_CLK_GETTIMEOFDAY it is precisely
  37. microseconds, otherwise something close but different chosen to minimize
  38. arithmetic cost. Ratio usec/internal untis in form nominator/denominator
  39. may be read from /proc/net/psched.
  40. */
  41. #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
  42. typedef struct timeval psched_time_t;
  43. typedef long psched_tdiff_t;
  44. #define PSCHED_GET_TIME(stamp) do_gettimeofday(&(stamp))
  45. #define PSCHED_US2JIFFIE(usecs) usecs_to_jiffies(usecs)
  46. #define PSCHED_JIFFIE2US(delay) jiffies_to_usecs(delay)
  47. #else /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
  48. typedef u64 psched_time_t;
  49. typedef long psched_tdiff_t;
  50. #ifdef CONFIG_NET_SCH_CLK_JIFFIES
  51. #if HZ < 96
  52. #define PSCHED_JSCALE 14
  53. #elif HZ >= 96 && HZ < 192
  54. #define PSCHED_JSCALE 13
  55. #elif HZ >= 192 && HZ < 384
  56. #define PSCHED_JSCALE 12
  57. #elif HZ >= 384 && HZ < 768
  58. #define PSCHED_JSCALE 11
  59. #elif HZ >= 768
  60. #define PSCHED_JSCALE 10
  61. #endif
  62. #define PSCHED_GET_TIME(stamp) ((stamp) = (get_jiffies_64()<<PSCHED_JSCALE))
  63. #define PSCHED_US2JIFFIE(delay) (((delay)+(1<<PSCHED_JSCALE)-1)>>PSCHED_JSCALE)
  64. #define PSCHED_JIFFIE2US(delay) ((delay)<<PSCHED_JSCALE)
  65. #endif /* CONFIG_NET_SCH_CLK_JIFFIES */
  66. #ifdef CONFIG_NET_SCH_CLK_CPU
  67. #include <asm/timex.h>
  68. extern psched_tdiff_t psched_clock_per_hz;
  69. extern int psched_clock_scale;
  70. extern psched_time_t psched_time_base;
  71. extern cycles_t psched_time_mark;
  72. #define PSCHED_GET_TIME(stamp) \
  73. do { \
  74. cycles_t cur = get_cycles(); \
  75. if (sizeof(cycles_t) == sizeof(u32)) { \
  76. if (cur <= psched_time_mark) \
  77. psched_time_base += 0x100000000ULL; \
  78. psched_time_mark = cur; \
  79. (stamp) = (psched_time_base + cur)>>psched_clock_scale; \
  80. } else { \
  81. (stamp) = cur>>psched_clock_scale; \
  82. } \
  83. } while (0)
  84. #define PSCHED_US2JIFFIE(delay) (((delay)+psched_clock_per_hz-1)/psched_clock_per_hz)
  85. #define PSCHED_JIFFIE2US(delay) ((delay)*psched_clock_per_hz)
  86. #endif /* CONFIG_NET_SCH_CLK_CPU */
  87. #endif /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
  88. #ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
  89. #define PSCHED_TDIFF(tv1, tv2) \
  90. ({ \
  91. int __delta_sec = (tv1).tv_sec - (tv2).tv_sec; \
  92. int __delta = (tv1).tv_usec - (tv2).tv_usec; \
  93. if (__delta_sec) { \
  94. switch (__delta_sec) { \
  95. default: \
  96. __delta = 0; \
  97. case 2: \
  98. __delta += USEC_PER_SEC; \
  99. case 1: \
  100. __delta += USEC_PER_SEC; \
  101. } \
  102. } \
  103. __delta; \
  104. })
  105. static inline int
  106. psched_tod_diff(int delta_sec, int bound)
  107. {
  108. int delta;
  109. if (bound <= USEC_PER_SEC || delta_sec > (0x7FFFFFFF/USEC_PER_SEC)-1)
  110. return bound;
  111. delta = delta_sec * USEC_PER_SEC;
  112. if (delta > bound || delta < 0)
  113. delta = bound;
  114. return delta;
  115. }
  116. #define PSCHED_TDIFF_SAFE(tv1, tv2, bound) \
  117. ({ \
  118. int __delta_sec = (tv1).tv_sec - (tv2).tv_sec; \
  119. int __delta = (tv1).tv_usec - (tv2).tv_usec; \
  120. switch (__delta_sec) { \
  121. default: \
  122. __delta = psched_tod_diff(__delta_sec, bound); break; \
  123. case 2: \
  124. __delta += USEC_PER_SEC; \
  125. case 1: \
  126. __delta += USEC_PER_SEC; \
  127. case 0: \
  128. if (__delta > bound || __delta < 0) \
  129. __delta = bound; \
  130. } \
  131. __delta; \
  132. })
  133. #define PSCHED_TLESS(tv1, tv2) (((tv1).tv_usec < (tv2).tv_usec && \
  134. (tv1).tv_sec <= (tv2).tv_sec) || \
  135. (tv1).tv_sec < (tv2).tv_sec)
  136. #define PSCHED_TADD2(tv, delta, tv_res) \
  137. ({ \
  138. int __delta = (tv).tv_usec + (delta); \
  139. (tv_res).tv_sec = (tv).tv_sec; \
  140. while (__delta >= USEC_PER_SEC) { (tv_res).tv_sec++; __delta -= USEC_PER_SEC; } \
  141. (tv_res).tv_usec = __delta; \
  142. })
  143. #define PSCHED_TADD(tv, delta) \
  144. ({ \
  145. (tv).tv_usec += (delta); \
  146. while ((tv).tv_usec >= USEC_PER_SEC) { (tv).tv_sec++; \
  147. (tv).tv_usec -= USEC_PER_SEC; } \
  148. })
  149. /* Set/check that time is in the "past perfect";
  150. it depends on concrete representation of system time
  151. */
  152. #define PSCHED_SET_PASTPERFECT(t) ((t).tv_sec = 0)
  153. #define PSCHED_IS_PASTPERFECT(t) ((t).tv_sec == 0)
  154. #define PSCHED_AUDIT_TDIFF(t) ({ if ((t) > 2000000) (t) = 2000000; })
  155. #else /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
  156. #define PSCHED_TDIFF(tv1, tv2) (long)((tv1) - (tv2))
  157. #define PSCHED_TDIFF_SAFE(tv1, tv2, bound) \
  158. min_t(long long, (tv1) - (tv2), bound)
  159. #define PSCHED_TLESS(tv1, tv2) ((tv1) < (tv2))
  160. #define PSCHED_TADD2(tv, delta, tv_res) ((tv_res) = (tv) + (delta))
  161. #define PSCHED_TADD(tv, delta) ((tv) += (delta))
  162. #define PSCHED_SET_PASTPERFECT(t) ((t) = 0)
  163. #define PSCHED_IS_PASTPERFECT(t) ((t) == 0)
  164. #define PSCHED_AUDIT_TDIFF(t)
  165. #endif /* !CONFIG_NET_SCH_CLK_GETTIMEOFDAY */
  166. extern struct Qdisc_ops pfifo_qdisc_ops;
  167. extern struct Qdisc_ops bfifo_qdisc_ops;
  168. extern int register_qdisc(struct Qdisc_ops *qops);
  169. extern int unregister_qdisc(struct Qdisc_ops *qops);
  170. extern struct Qdisc *qdisc_lookup(struct net_device *dev, u32 handle);
  171. extern struct Qdisc *qdisc_lookup_class(struct net_device *dev, u32 handle);
  172. extern struct qdisc_rate_table *qdisc_get_rtab(struct tc_ratespec *r,
  173. struct rtattr *tab);
  174. extern void qdisc_put_rtab(struct qdisc_rate_table *tab);
  175. extern void __qdisc_run(struct net_device *dev);
  176. static inline void qdisc_run(struct net_device *dev)
  177. {
  178. if (!netif_queue_stopped(dev) &&
  179. !test_and_set_bit(__LINK_STATE_QDISC_RUNNING, &dev->state))
  180. __qdisc_run(dev);
  181. }
  182. extern int tc_classify(struct sk_buff *skb, struct tcf_proto *tp,
  183. struct tcf_result *res);
  184. /* Calculate maximal size of packet seen by hard_start_xmit
  185. routine of this device.
  186. */
  187. static inline unsigned psched_mtu(struct net_device *dev)
  188. {
  189. unsigned mtu = dev->mtu;
  190. return dev->hard_header ? mtu + dev->hard_header_len : mtu;
  191. }
  192. #endif