Rev 1063 | Details | Compare with Previous | Last modification | View Log | RSS feed
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1063 | tullio | 1 | |
2 | /* |
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3 | * This program is free software; you can redistribute it and/or modify |
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4 | * it under the terms of the GNU General Public License as published by |
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5 | * the Free Software Foundation; either version 2 of the License, or |
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6 | * (at your option) any later version. |
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7 | * |
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8 | * This program is distributed in the hope that it will be useful, |
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9 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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11 | * GNU General Public License for more details. |
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12 | * |
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13 | * You should have received a copy of the GNU General Public License |
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14 | * along with this program; if not, write to the Free Software |
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15 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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16 | * |
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17 | */ |
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18 | |||
948 | trimarchi | 19 | #include "kernel/kern.h" |
20 | #include "calibrate.h" |
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21 | |||
22 | int cal_cycles=0; |
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23 | |||
24 | /* Runtime Calibration */ |
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25 | int calibrate_cycle() |
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26 | { |
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27 | long long i; |
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28 | struct timespec start,end,diff; |
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29 | |||
30 | if (cal_cycles != 0) return 0; |
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31 | |||
32 | |||
33 | |||
34 | kern_cli(); |
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35 | __asm__ __volatile__ ("xorl %%eax,%%eax\n\t" |
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36 | "cpuid\n\t" |
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37 | :::"eax","ebx","ecx","edx"); |
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38 | kern_gettime(&start); |
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39 | for (i=0;i<CALIBRATION_DELTA;i++) |
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40 | __asm__ __volatile__ ("xorl %%eax,%%eax\n\t" |
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41 | "cpuid\n\t" |
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42 | :::"eax","ebx","ecx","edx"); |
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43 | __asm__ __volatile__ ("xorl %%eax,%%eax\n\t" |
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44 | "cpuid\n\t" |
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45 | :::"eax","ebx","ecx","edx"); |
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46 | kern_gettime(&end); |
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47 | kern_sti(); |
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48 | |||
49 | SUBTIMESPEC(&end,&start,&diff); |
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50 | cal_cycles = TIMESPEC2USEC(&diff); |
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51 | |||
52 | cprintf("Calibration usec/[%d cycles] = %d\n",CALIBRATION_DELTA,cal_cycles); |
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53 | |||
54 | return 0; |
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55 | |||
56 | } |
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57 | |||
58 | void eat(TIME wait) { |
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59 | |||
60 | int exec_cycles=0; |
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61 | int i=0; |
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62 | |||
63 | exec_cycles = (long long)(wait) * CALIBRATION_DELTA / cal_cycles; |
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64 | |||
65 | /* Execution delay */ |
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66 | for (i=0;i<exec_cycles;i++) |
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67 | __asm__ __volatile__ ("xorl %%eax,%%eax\n\t" |
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68 | "cpuid\n\t" |
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69 | :::"eax","ebx","ecx","edx"); |
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70 | |||
71 | } |