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435 | jermar | 1 | /* |
2071 | jermar | 2 | * Copyright (c) 2005 Jakub Jermar |
435 | jermar | 3 | * All rights reserved. |
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 | |||
1881 | jermar | 29 | /** @addtogroup ia64 |
1702 | cejka | 30 | * @{ |
31 | */ |
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32 | /** @file |
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33 | */ |
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34 | |||
435 | jermar | 35 | /** Interval Timer driver. */ |
36 | |||
37 | #include <arch/drivers/it.h> |
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38 | #include <arch/interrupt.h> |
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39 | #include <arch/register.h> |
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40 | #include <arch/asm.h> |
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41 | #include <arch/barrier.h> |
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42 | #include <time/clock.h> |
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1942 | jermar | 43 | #include <ddi/irq.h> |
44 | #include <ddi/device.h> |
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1482 | vana | 45 | #include <arch.h> |
435 | jermar | 46 | |
1482 | vana | 47 | #define IT_SERVICE_CLOCKS 64 |
48 | |||
1942 | jermar | 49 | static irq_t it_irq; |
50 | |||
51 | static irq_ownership_t it_claim(void); |
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52 | static void it_interrupt(irq_t *irq, void *arg, ...); |
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53 | |||
435 | jermar | 54 | /** Initialize Interval Timer. */ |
55 | void it_init(void) |
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56 | { |
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57 | cr_itv_t itv; |
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58 | |||
1942 | jermar | 59 | irq_initialize(&it_irq); |
60 | it_irq.inr = INTERRUPT_TIMER; |
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61 | it_irq.devno = device_assign_devno(); |
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62 | it_irq.claim = it_claim; |
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63 | it_irq.handler = it_interrupt; |
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64 | irq_register(&it_irq); |
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65 | |||
435 | jermar | 66 | /* initialize Interval Timer external interrupt vector */ |
67 | itv.value = itv_read(); |
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68 | itv.vector = INTERRUPT_TIMER; |
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69 | itv.m = 0; |
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70 | itv_write(itv.value); |
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71 | |||
72 | /* set Interval Timer Counter to zero */ |
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73 | itc_write(0); |
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74 | |||
75 | /* generate first Interval Timer interrupt in IT_DELTA ticks */ |
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76 | itm_write(IT_DELTA); |
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456 | jermar | 77 | |
78 | /* propagate changes */ |
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435 | jermar | 79 | srlz_d(); |
80 | } |
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81 | |||
1942 | jermar | 82 | /** Always claim ownership for this IRQ. |
83 | * |
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84 | * Other devices are responsible to avoid using INR 0. |
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85 | * |
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86 | * @return Always IRQ_ACCEPT. |
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87 | */ |
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88 | irq_ownership_t it_claim(void) |
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89 | { |
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90 | return IRQ_ACCEPT; |
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91 | } |
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1482 | vana | 92 | |
435 | jermar | 93 | /** Process Interval Timer interrupt. */ |
1942 | jermar | 94 | void it_interrupt(irq_t *irq, void *arg, ...) |
435 | jermar | 95 | { |
1780 | jermar | 96 | int64_t c; |
97 | int64_t m; |
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1482 | vana | 98 | |
435 | jermar | 99 | eoi_write(EOI); |
1482 | vana | 100 | |
1881 | jermar | 101 | m = itm_read(); |
1482 | vana | 102 | |
1881 | jermar | 103 | while (1) { |
104 | c = itc_read(); |
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105 | c += IT_SERVICE_CLOCKS; |
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1482 | vana | 106 | |
1881 | jermar | 107 | m += IT_DELTA; |
1942 | jermar | 108 | if (m - c < 0) |
1482 | vana | 109 | CPU->missed_clock_ticks++; |
1881 | jermar | 110 | else |
111 | break; |
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1482 | vana | 112 | } |
113 | |||
114 | itm_write(m); |
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456 | jermar | 115 | srlz_d(); /* propagate changes */ |
1482 | vana | 116 | |
435 | jermar | 117 | clock(); |
118 | } |
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1702 | cejka | 119 | |
1881 | jermar | 120 | /** @} |
1702 | cejka | 121 | */ |