4.104.114.84.95
Last change
on this file since 3f71ac1 was
3f71ac1,
checked in by Ralf Corsepius <ralf.corsepius@…>, on 03/31/04 at 03:47:48
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2004-03-31 Ralf Corsepius <ralf_corsepius@…>
- include/bsp.h, shmsupp/getcfg.c, startup/bspstart.c,
timer/timer.c: Convert to using c99 fixed size types.
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-
Property mode set to
100644
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File size:
1.5 KB
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1 | /* |
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2 | * This file implements a benchmark timer using the PPC decrement register. |
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3 | * |
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4 | * COPYRIGHT (c) 1989-2000. |
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5 | * On-Line Applications Research Corporation (OAR). |
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6 | * |
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7 | * |
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8 | * $Id$ |
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9 | */ |
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10 | |
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11 | #include <assert.h> |
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12 | |
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13 | #include <bsp.h> |
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14 | |
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15 | uint64_t Timer_driver_Start_time; |
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16 | |
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17 | rtems_boolean Timer_driver_Find_average_overhead; |
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18 | |
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19 | void Timer_initialize() |
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20 | { |
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21 | /* |
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22 | * Timer runs long and accurate enough not to require an interrupt. |
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23 | */ |
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24 | |
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25 | Timer_driver_Start_time = PPC_Get_timebase_register(); |
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26 | } |
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27 | |
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28 | #define AVG_OVERHEAD 24 /* It typically takes 24 instructions */ |
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29 | /* to start/stop the timer. */ |
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30 | #define LEAST_VALID 1 /* Don't trust a value lower than this */ |
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31 | /* psim can count instructions. :) */ |
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32 | |
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33 | int Read_timer() |
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34 | { |
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35 | uint64_t clicks; |
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36 | uint64_t total64; |
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37 | uint32_t total; |
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38 | |
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39 | /* approximately CLOCK_SPEED clicks per microsecond */ |
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40 | |
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41 | clicks = PPC_Get_timebase_register(); |
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42 | |
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43 | assert( clicks > Timer_driver_Start_time ); |
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44 | |
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45 | total64 = clicks - Timer_driver_Start_time; |
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46 | |
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47 | assert( total64 <= 0xffffffff ); /* fits into a uint32_t */ |
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48 | |
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49 | total = (uint32_t) total64; |
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50 | |
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51 | if ( Timer_driver_Find_average_overhead == 1 ) |
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52 | return total; /* in one microsecond units */ |
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53 | |
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54 | if ( total < LEAST_VALID ) |
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55 | return 0; /* below timer resolution */ |
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56 | |
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57 | return total - AVG_OVERHEAD; |
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58 | } |
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59 | |
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60 | rtems_status_code Empty_function( void ) |
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61 | { |
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62 | return RTEMS_SUCCESSFUL; |
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63 | } |
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64 | |
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65 | void Set_find_average_overhead( |
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66 | rtems_boolean find_flag |
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67 | ) |
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68 | { |
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69 | Timer_driver_Find_average_overhead = find_flag; |
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70 | } |
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