net/cor/util.c

   1 /**
   2  *      Connection oriented routing
   3  *      Copyright (C) 2007-2021 Michael Blizek
   4  *
   5  *      This program is free software; you can redistribute it and/or
   6  *      modify it under the terms of the GNU General Public License
   7  *      as published by the Free Software Foundation; either version 2
   8  *      of the License, or (at your option) any later version.
   9  *
  10  *      This program is distributed in the hope that it will be useful,
  11  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *      GNU General Public License for more details.
  14  */
  15
  16 #include "cor.h"
  17
  18
  19 static const __u32 cor_log_64_11_table[] = {0,
  20                 64, 68, 73, 77, 82, 88, 93, 99, 106, 113, 120,
  21                 128, 136, 145, 155, 165, 175, 187, 199, 212, 226, 240,
  22                 256, 273, 290, 309, 329, 351, 374, 398, 424, 451, 481,
  23                 512, 545, 581, 619, 659, 702, 747, 796, 848, 903, 961,
  24                 1024, 1091, 1162, 1237, 1318, 1403, 1495, 1592, 1695, 1805,
  25                                 1923,
  26                 2048, 2181, 2323, 2474, 2635, 2806, 2989, 3183, 3390, 3611,
  27                                 3846,
  28                 4096, 4362, 4646, 4948, 5270, 5613, 5978, 6367, 6781, 7222,
  29                                 7692,
  30                 8192, 8725, 9292, 9897, 10540, 11226, 11956, 12734, 13562,
  31                                 14444, 15383,
  32                 16384, 17450, 18585, 19793, 21081, 22452, 23912, 25467, 27124,
  33                                 28888, 30767,
  34                 32768, 34899, 37169, 39587, 42161, 44904, 47824, 50935, 54248,
  35                                 57776, 61534,
  36                 65536, 69799, 74338, 79173, 84323, 89807, 95648, 101870, 108495,
  37                                 115552, 123068,
  38                 131072, 139597, 148677, 158347, 168646, 179615, 191297, 203739,
  39                                 216991, 231104, 246135,
  40                 262144, 279194, 297353, 316693, 337291, 359229, 382594, 407478,
  41                                 433981, 462208, 492270,
  42                 524288, 558388, 594706, 633387, 674583, 718459, 765188, 814957,
  43                                 867962, 924415, 984540,
  44                 1048576, 1116777, 1189413, 1266774, 1349166, 1436917, 1530376,
  45                                 1629913, 1735924, 1848831, 1969081,
  46                 2097152, 2233553, 2378826, 2533547, 2698332, 2873834, 3060752,
  47                                 3259826, 3471849, 3697662, 3938162,
  48                 4194304, 4467106, 4757652, 5067094, 5396664, 5747669, 6121503,
  49                                 6519652, 6943698, 7395323, 7876323,
  50                 8388608, 8934212, 9515303, 10134189, 10793327, 11495337,
  51                                 12243006, 13039305, 13887396, 14790647,
  52                                 15752647,
  53                 16777216, 17868424, 19030606, 20268378, 21586655, 22990674,
  54                                 24486013, 26078610, 27774791, 29581294,
  55                                 31505293,
  56                 33554432, 35736849, 38061212, 40536755, 43173310, 45981349,
  57                                 48972026, 52157220, 55549582, 59162588,
  58                                 63010587,
  59                 67108864, 71473698, 76122425, 81073510, 86346620, 91962698,
  60                                 97944052, 104314440, 111099165, 118325175,
  61                                 126021174,
  62                 134217728, 142947395, 152244850, 162147020, 172693239,
  63                                 183925396, 195888104, 208628880, 222198329,
  64                                 236650351, 252042347,
  65                 268435456, 285894791, 304489699, 324294041, 345386479,
  66                                 367850791, 391776208, 417257759, 444396658,
  67                                 473300701, 504084694,
  68                 536870912, 571789581};
  69
  70 #warning todo use this for the window size
  71 __u8 __attribute__((const)) cor_enc_log_64_11(__u32 value)
  72 {
  73         int i;
  74
  75         BUILD_BUG_ON(cor_log_64_11_table[255] != 571789581);
  76         for (i = 1; i < 256; i++) {
  77                 if (cor_log_64_11_table[i] > value)
  78                         break;
  79         }
  80
  81         return (__u8)(i - 1); /* round down */
  82 }
  83
  84 __u32 __attribute__((const)) cor_dec_log_64_11(__u8 value)
  85 {
  86         BUILD_BUG_ON(cor_log_64_11_table[255] != 571789581);
  87         return cor_log_64_11_table[value];
  88 }
  89
  90 static void __init cor_check_log_64_11_table(void)
  91 {
  92         int i;
  93
  94         BUG_ON(cor_log_64_11_table[0] != 0);
  95         for (i = 1; i < 256; i++) {
  96                 BUG_ON(cor_log_64_11_table[i] <= cor_log_64_11_table[i - 1]);
  97         }
  98 }
  99
 100
 101 void cor_swap_list_items(struct list_head *lh1, struct list_head *lh2)
 102 {
 103         struct list_head *tmp;
 104
 105         tmp = (lh1->next == lh1 ? lh2 : lh1->next);
 106         lh1->next = (lh2->next == lh2 ? lh1 : lh2->next);
 107         lh2->next = tmp;
 108
 109         tmp = (lh1->prev == lh1 ? lh2 : lh2->prev);
 110         lh1->prev = (lh2->prev == lh2 ? lh1 : lh2->prev);
 111         lh2->prev = tmp;
 112
 113         lh1->next->prev = lh1;
 114         lh1->prev->next = lh1;
 115
 116         lh2->next->prev = lh2;
 117         lh2->prev->next = lh2;
 118 }
 119
 120 void cor_kreffree_bug(struct kref *ref)
 121 {
 122         BUG();
 123 }
 124
 125 int __init cor_util_init(void)
 126 {
 127         cor_check_log_64_11_table();
 128
 129         return 0;
 130 }
 131
 132 MODULE_LICENSE("GPL");