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629 | giacomo | 1 | /* |
2 | * Project: S.Ha.R.K. |
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3 | * |
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4 | * Coordinators: |
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5 | * Giorgio Buttazzo <giorgio@sssup.it> |
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6 | * Paolo Gai <pj@gandalf.sssup.it> |
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7 | * |
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8 | * Authors : |
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9 | * Paolo Gai <pj@gandalf.sssup.it> |
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10 | * Massimiliano Giorgi <massy@gandalf.sssup.it> |
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11 | * Luca Abeni <luca@gandalf.sssup.it> |
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12 | * (see the web pages for full authors list) |
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13 | * |
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14 | * ReTiS Lab (Scuola Superiore S.Anna - Pisa - Italy) |
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15 | * |
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16 | * http://www.sssup.it |
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17 | * http://retis.sssup.it |
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18 | * http://shark.sssup.it |
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19 | */ |
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20 | |||
21 | /** |
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22 | ------------ |
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23 | CVS : $Id: netbuff.c,v 1.3 2004-05-11 14:30:50 giacomo Exp $ |
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24 | |||
25 | File: $File$ |
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26 | Revision: $Revision: 1.3 $ |
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27 | Last update: $Date: 2004-05-11 14:30:50 $ |
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28 | ------------ |
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29 | **/ |
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30 | |||
31 | /* |
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32 | * Copyright (C) 2000 Luca Abeni |
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33 | * |
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34 | * This program is free software; you can redistribute it and/or modify |
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35 | * it under the terms of the GNU General Public License as published by |
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36 | * the Free Software Foundation; either version 2 of the License, or |
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37 | * (at your option) any later version. |
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38 | * |
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39 | * This program is distributed in the hope that it will be useful, |
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40 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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41 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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42 | * GNU General Public License for more details. |
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43 | * |
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44 | * You should have received a copy of the GNU General Public License |
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45 | * along with this program; if not, write to the Free Software |
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46 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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47 | * |
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48 | */ |
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49 | |||
50 | /* Author: Luca Abeni */ |
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51 | /* Date: 25/9/1997 */ |
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52 | |||
53 | /* File: NetBuff.c */ |
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54 | /* Revision: 1.00 */ |
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55 | |||
56 | /* |
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57 | This module manages all the buffers used by the network driver: |
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58 | the buffers are grouped in netbuff structures (initialized by |
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59 | netbuff_init) and can be allocated by netbuff_get or released |
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60 | by netbuff_released. A netbuff_sequentialget function is also |
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61 | provided for beeing used by tasks that have their own buffer ( |
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62 | if a buffer can be allocated by only one task, it is useless to |
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63 | allocate it in mutual exclusion). It is usefull for the receive |
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64 | buffers allocated by the receive process. |
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65 | */ |
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66 | #include <kernel/kern.h> |
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67 | #include <semaphore.h> |
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68 | |||
69 | #include "netbuff.h" |
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70 | |||
71 | /* Init the buffer structures */ |
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72 | void netbuff_init(struct netbuff *netb, BYTE nbuffs, WORD buffdim) |
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73 | { |
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74 | int i; |
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75 | |||
76 | kern_cli(); |
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77 | netb->b = kern_alloc(nbuffs * buffdim); |
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78 | netb->pb = kern_alloc(nbuffs * sizeof(void *)); |
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79 | netb->free = kern_alloc(nbuffs * sizeof(char)); |
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80 | kern_sti(); |
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81 | if ((netb->b == 0) || (netb->pb ==0) || (netb->free == 0)) { |
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82 | kern_raise(XNETBUFF_INIT_EXC,exec_shadow); |
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83 | } |
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84 | netb->nbuffs = nbuffs; |
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85 | for (i = 0; i < nbuffs; i++) { |
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86 | netb->pb[i] = netb->b + (i * buffdim); |
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87 | netb->free[i] = 1; |
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88 | } |
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89 | sem_init(&(netb->buffersem), 0, nbuffs); |
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90 | } |
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91 | |||
92 | /* |
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93 | Get the first free buffer in the netb pool. All the tasks can call this |
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94 | function, so a kern_cli is needed |
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95 | */ |
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96 | void *netbuff_get(struct netbuff *netb, BYTE to) |
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97 | { |
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98 | int i, done; |
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99 | static int mycount = 0; |
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100 | |||
101 | if (sem_xwait(&(netb->buffersem), 1, to) != 0) { |
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102 | return NULL; |
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103 | } else { |
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104 | mycount++; |
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105 | } |
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106 | |||
107 | done = 0; i = 0; |
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108 | kern_cli(); |
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109 | while ((i < netb->nbuffs) && !done) { |
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110 | if (netb->free[i]) { |
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111 | done = 1; |
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112 | netb->free[i] = 0; |
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113 | } else i++; |
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114 | } |
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115 | kern_sti(); |
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116 | if (!done) { |
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117 | kern_raise(XNETBUFF_GET_EXC,exec_shadow); |
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118 | } |
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119 | return netb->pb[i]; |
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120 | } |
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121 | |||
122 | /* |
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123 | Get the first free buffer in the netb pool. This function can be called |
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124 | only if netb is private of the process that wants to get the buffer, so |
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125 | kern_cli is not needed |
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126 | */ |
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127 | void *netbuff_sequentialget(struct netbuff *netb, BYTE to) |
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128 | { |
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129 | int i, done; |
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130 | |||
131 | if (!sem_xwait(&(netb->buffersem), 1, to)) { |
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132 | return NULL; |
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133 | } |
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134 | |||
135 | done = 0; i = 0; |
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136 | while ((i < netb->nbuffs) && !done) { |
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137 | if (netb->free[i]) { |
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138 | done = 1; |
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139 | netb->free[i] = 0; |
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140 | } else i++; |
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141 | } |
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142 | if (!done) { |
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143 | kern_raise(XNETBUFF_GET_EXC,exec_shadow); |
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144 | } |
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145 | return netb->pb[i]; |
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146 | } |
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147 | |||
148 | /* Release the buffer m of the pool netb */ |
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149 | void netbuff_release(struct netbuff *netb, void *m) |
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150 | { |
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151 | int i, done; |
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152 | |||
153 | done = 0; i = 0; |
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154 | while ((i < netb->nbuffs) && !done) { |
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155 | if (netb->pb[i] == m) { |
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156 | if (netb->free[i] == 1) { |
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157 | cprintf("Trying to free a free buffer :( \n"); |
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158 | kern_raise(XNETBUFF_ALREADYFREE_EXC,exec_shadow); |
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159 | } |
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160 | done = 1; |
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161 | netb->free[i] = 1; |
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162 | } else i++; |
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163 | } |
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164 | if (!done) { |
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165 | cprintf("Trying to free a STRANGE buffer :( \n"); |
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166 | kern_raise(XNETBUFF_RELEASE_EXC,exec_shadow); |
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167 | } |
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168 | sem_post(&(netb->buffersem)); |
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169 | } |