| 1 | /*
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| 2 | * Copyright (C) 2005 Jakub Jermar
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| 3 | * All rights reserved.
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| 4 | *
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| 5 | * Redistribution and use in source and binary forms, with or without
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| 6 | * modification, are permitted provided that the following conditions
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| 7 | * are met:
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| 8 | *
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| 9 | * - Redistributions of source code must retain the above copyright
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| 10 | * notice, this list of conditions and the following disclaimer.
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| 11 | * - Redistributions in binary form must reproduce the above copyright
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| 12 | * notice, this list of conditions and the following disclaimer in the
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| 13 | * documentation and/or other materials provided with the distribution.
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| 14 | * - The name of the author may not be used to endorse or promote products
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| 15 | * derived from this software without specific prior written permission.
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| 16 | *
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| 17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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| 18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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| 19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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| 20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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| 21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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| 22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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| 23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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| 24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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| 25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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| 26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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| 27 | */
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| 28 |
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| 29 | /** @addtogroup ia64
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| 30 | * @{
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| 31 | */
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| 32 | /** @file
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| 33 | */
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| 34 |
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| 35 | /** Interval Timer driver. */
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| 36 |
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| 37 | #include <arch/drivers/it.h>
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| 38 | #include <arch/ski/ski.h>
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| 39 | #include <arch/interrupt.h>
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| 40 | #include <arch/register.h>
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| 41 | #include <arch/asm.h>
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| 42 | #include <arch/barrier.h>
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| 43 | #include <time/clock.h>
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| 44 | #include <arch.h>
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| 45 |
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| 46 |
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| 47 | #define IT_SERVICE_CLOCKS 64
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| 48 |
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| 49 | /** Initialize Interval Timer. */
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| 50 | void it_init(void)
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| 51 | {
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| 52 | cr_itv_t itv;
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| 53 |
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| 54 | /* initialize Interval Timer external interrupt vector */
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| 55 | itv.value = itv_read();
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| 56 | itv.vector = INTERRUPT_TIMER;
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| 57 | itv.m = 0;
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| 58 | itv_write(itv.value);
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| 59 |
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| 60 | /* set Interval Timer Counter to zero */
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| 61 | itc_write(0);
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| 62 |
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| 63 | /* generate first Interval Timer interrupt in IT_DELTA ticks */
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| 64 | itm_write(IT_DELTA);
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| 65 |
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| 66 | /* propagate changes */
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| 67 | srlz_d();
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| 68 | }
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| 69 |
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| 70 |
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| 71 | /** Process Interval Timer interrupt. */
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| 72 | void it_interrupt(void)
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| 73 | {
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| 74 | int64_t c;
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| 75 | int64_t m;
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| 76 |
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| 77 | eoi_write(EOI);
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| 78 |
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| 79 | m = itm_read();
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| 80 |
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| 81 | while (1) {
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| 82 | c = itc_read();
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| 83 | c += IT_SERVICE_CLOCKS;
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| 84 |
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| 85 | m += IT_DELTA;
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| 86 | if (m-c<0)
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| 87 | CPU->missed_clock_ticks++;
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| 88 | else
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| 89 | break;
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| 90 | }
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| 91 |
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| 92 | itm_write(m);
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| 93 | srlz_d(); /* propagate changes */
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| 94 |
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| 95 | clock();
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| 96 | poll_keyboard();
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| 97 | }
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| 98 |
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| 99 | /** @}
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| 100 | */
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