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2 | pj | 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 | |||
22 | /*************************************** |
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23 | |||
24 | CVS : $Id: idereq.c,v 1.1.1.1 2002-03-29 14:12:49 pj Exp $ |
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25 | |||
26 | Revision: $Revision: 1.1.1.1 $ |
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27 | |||
28 | Last update: $Date: 2002-03-29 14:12:49 $ |
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29 | |||
30 | This module manage the ide request structure: it is implemented |
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31 | a policy for the queueing of the requests made by tasks. |
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32 | |||
33 | ***************************************/ |
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34 | |||
35 | /* |
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36 | * Copyright (C) 1999 Massimiliano Giorgi |
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37 | * |
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38 | * This program is free software; you can redistribute it and/or modify |
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39 | * it under the terms of the GNU General Public License as published by |
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40 | * the Free Software Foundation; either version 2 of the License, or |
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41 | * (at your option) any later version. |
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42 | * |
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43 | * This program is distributed in the hope that it will be useful, |
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44 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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45 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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46 | * GNU General Public License for more details. |
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47 | * |
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48 | * You should have received a copy of the GNU General Public License |
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49 | * along with this program; if not, write to the Free Software |
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50 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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51 | * |
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52 | */ |
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53 | |||
54 | #include <fs/assert.h> |
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55 | |||
56 | #include "glue.h" |
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57 | |||
58 | #include "ide.h" |
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59 | #include "idereq.h" |
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60 | |||
61 | /* |
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62 | * if defined: |
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63 | * use trc_logevent with event TRC_USER0 to trace head movement |
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64 | */ |
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65 | #define TRACEMOVEMENT |
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66 | #undef TRACEMOVEMENT |
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67 | |||
68 | #ifdef TRACEMOVEMENT |
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69 | #include <trace/types.h> |
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70 | #include <kernel/trace.h> |
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71 | #endif |
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72 | |||
73 | /*+ a mutex for the +*/ |
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74 | //static __b_fastmutex_t mutex; |
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75 | |||
76 | /*+ a mutex for the "free request" queue manipulation +*/ |
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77 | static __b_fastmutex_t mutexreq; |
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78 | |||
79 | /*+ the "free request" queue +*/ |
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80 | static int freereq=NIL; |
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81 | |||
82 | /*+ a pool for the ide request (actually all the ide request structure |
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83 | are statically allocated) |
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84 | +*/ |
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85 | idereq_t idereq[MAXIDEREQUEST]; |
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86 | |||
87 | /*+ is the queue not blocked? +*/ |
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88 | int notblockedqueue[MAXIDEINTERFACES]; |
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89 | |||
90 | /*++++++++++++++++++++++++++++++++++++++ |
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91 | |||
92 | Initialize this module; must be called prior of other call. |
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93 | |||
94 | ++++++++++++++++++++++++++++++++++++++*/ |
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95 | |||
96 | void init_idereq(void) |
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97 | { |
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98 | int i; |
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99 | //__b_fastmutex_init(&mutex); |
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100 | __b_fastmutex_init(&mutexreq); |
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101 | freereq=0; |
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102 | for (i=0;i<MAXIDEREQUEST;i++) { |
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103 | idereq[i].next=((i==MAXIDEREQUEST-1)?NIL:i+1); |
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104 | __b_sem_init(&idereq[i].wait,0); |
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105 | } |
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106 | for (i=0;i<MAXIDEINTERFACES;i++) |
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107 | notblockedqueue[i]=1; |
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108 | } |
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109 | |||
110 | /*++++++++++++++++++++++++++++++++++++++ |
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111 | |||
112 | Find and return an ide request structure from the free queue if possible. |
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113 | |||
114 | int get_idereq |
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115 | return an index into idereq[] or NIL |
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116 | ++++++++++++++++++++++++++++++++++++++*/ |
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117 | |||
118 | int get_idereq(void) |
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119 | { |
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120 | int ret; |
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121 | __b_fastmutex_lock(&mutexreq); |
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122 | if (freereq==NIL) |
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123 | ret=NIL; |
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124 | else { |
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125 | ret=freereq; |
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126 | freereq=idereq[ret].next; |
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127 | } |
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128 | __b_fastmutex_unlock(&mutexreq); |
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129 | return ret; |
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130 | } |
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131 | |||
132 | /*++++++++++++++++++++++++++++++++++++++ |
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133 | |||
134 | Insert an ide request structure into the free queue. |
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135 | |||
136 | int req |
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137 | index into idereq[] to insert into the free queue |
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138 | ++++++++++++++++++++++++++++++++++++++*/ |
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139 | |||
140 | void free_idereq(int req) |
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141 | { |
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142 | __b_fastmutex_lock(&mutexreq); |
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143 | idereq[req].next=freereq; |
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144 | freereq=req; |
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145 | __b_fastmutex_unlock(&mutexreq); |
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146 | } |
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147 | |||
148 | /* |
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149 | * The following functions can be modificated to implement other policy |
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150 | * of queueing of the request made by task. |
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151 | */ |
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152 | |||
153 | static __inline__ int other_request(int ideif) |
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154 | { |
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155 | return bqueue_numelements(&ide[ideif].queue[0])+ |
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156 | bqueue_numelements(&ide[ideif].queue[1])?1:0; |
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157 | } |
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158 | |||
159 | /*++++++++++++++++++++++++++++++++++++++ |
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160 | |||
161 | Insert an ide request structure into an ide interface struct for |
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162 | processing a request. |
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163 | It is inserted into the tail. |
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164 | |||
165 | int insert_idereq |
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166 | return 1 if this is the first request of the queue, 0 if there are |
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167 | already other requests into the queue; if 1 is returned the calling |
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168 | thread should wake up the server |
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169 | |||
170 | int ideif |
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171 | interface queue to use (an index into ide[] structure) |
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172 | |||
173 | int req |
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174 | index into idereq[] of the request struct to insert |
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175 | ++++++++++++++++++++++++++++++++++++++*/ |
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176 | |||
177 | int insert_idereq(int ideif, int drive, int req) |
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178 | { |
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179 | int ret; |
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180 | bqueue_insertrequest(&ide[ideif].queue[drive], |
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181 | (request_prologue_t *)&idereq[req] |
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182 | ); |
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183 | |||
184 | ret=bqueue_numelements(&ide[ideif].queue[drive]); |
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185 | if (ret==1) |
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186 | /* means: wake up the server if the queue is not blocked */ |
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187 | ret=notblockedqueue[ideif]; |
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188 | else |
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189 | /* means: not wake up the server (it is already running) */ |
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190 | ret=0; |
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191 | |||
192 | return ret; |
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193 | } |
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194 | |||
195 | /*++++++++++++++++++++++++++++++++++++++ |
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196 | |||
197 | Release a blocked queue. |
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198 | |||
199 | int releasequeue_idereq |
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200 | return 1 if there are request in queue, 0 if not |
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201 | |||
202 | int ideif |
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203 | interface queue to use (an index into ide[] structure) |
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204 | ++++++++++++++++++++++++++++++++++++++*/ |
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205 | |||
206 | int releasequeue_idereq(int ideif) |
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207 | { |
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208 | notblockedqueue[ideif]=1; |
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209 | return other_request(ideif); |
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210 | } |
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211 | |||
212 | int first_idereq(int ideif) |
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213 | { |
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214 | request_prologue_t *ptr; |
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215 | |||
216 | assertk(ide[ideif].actreq==-1); |
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217 | |||
218 | //__b_fastmutex_lock(&mutex); |
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219 | ptr=bqueue_getrequest(&ide[ideif].queue[0]); |
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220 | |||
221 | //cprintf("°%p,%p,%li°",ptr,idereq,((idereq_t*)ptr)-idereq); |
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222 | |||
223 | if (ptr==NULL) { |
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224 | ptr=bqueue_getrequest(&ide[ideif].queue[1]); |
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225 | if (ptr==NULL) { |
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226 | //__b_fastmutex_unlock(&mutex); |
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227 | return NIL; |
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228 | } else |
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229 | ide[ideif].actdrv=1; |
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230 | } else |
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231 | ide[ideif].actdrv=0; |
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232 | ide[ideif].actreq=((idereq_t*)ptr)-idereq; |
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233 | //__b_fastmutex_unlock(&mutex); |
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234 | |||
235 | #ifdef TRACEMOVEMENT |
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236 | { |
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237 | long cylinder; |
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238 | cylinder=ptr->cylinder; |
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239 | trc_logevent(TRC_USER0,&cylinder); |
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240 | } |
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241 | #endif |
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242 | |||
243 | return ide[ideif].actreq; |
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244 | } |
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245 | |||
246 | int actual_idereq(ideif) |
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247 | { |
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248 | assertk(ide[ideif].actreq!=-1); |
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249 | return ide[ideif].actreq; |
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250 | } |
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251 | |||
252 | /*++++++++++++++++++++++++++++++++++++++ |
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253 | |||
254 | Remove the first request from the queue of an ide interface. |
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255 | |||
256 | int remove_idereq |
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257 | return 1 if there are other request in queue, 0 if not |
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258 | |||
259 | int ideif |
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260 | interface queue to use (an index into ide[] structure) |
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261 | |||
262 | int req |
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263 | index into idereq[] of the request struct to insert |
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264 | ++++++++++++++++++++++++++++++++++++++*/ |
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265 | |||
266 | int remove_idereq(int ideif) |
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267 | { |
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268 | assertk(ide[ideif].actreq!=-1); |
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269 | bqueue_removerequest(&ide[ideif].queue[ide[ideif].actdrv]); |
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270 | ide[ideif].actreq=-1; |
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271 | return other_request(ideif)?1:0; |
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272 | } |
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273 | |||
274 | /*++++++++++++++++++++++++++++++++++++++ |
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275 | |||
276 | Remove the first request from the queue of an ide interface |
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277 | blocking the queue. |
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278 | |||
279 | int remove_idereq |
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280 | return 1 if there are other request in queue, 0 if not |
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281 | |||
282 | int ideif |
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283 | interface queue to use (an index into ide[] structure) |
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284 | |||
285 | int req |
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286 | index into idereq[] of the request struct to insert |
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287 | ++++++++++++++++++++++++++++++++++++++*/ |
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288 | |||
289 | int remove_idereq_blocking(int ideif) |
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290 | { |
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291 | assertk(ide[ideif].actreq!=-1); |
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292 | bqueue_removerequest(&ide[ideif].queue[ide[ideif].actdrv]); |
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293 | notblockedqueue[ideif]=0; |
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294 | ide[ideif].actreq=-1; |
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295 | return other_request(ideif); |
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296 | } |