Subversion Repositories HelenOS

Rev

Rev 2107 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
664 jermar 1
/*
2071 jermar 2
 * Copyright (c) 2005 Jakub Jermar
664 jermar 3
 * All rights reserved.
4
 *
5
 * Redistribution and use in source and binary forms, with or without
6
 * modification, are permitted provided that the following conditions
7
 * are met:
8
 *
9
 * - Redistributions of source code must retain the above copyright
10
 *   notice, this list of conditions and the following disclaimer.
11
 * - Redistributions in binary form must reproduce the above copyright
12
 *   notice, this list of conditions and the following disclaimer in the
13
 *   documentation and/or other materials provided with the distribution.
14
 * - The name of the author may not be used to endorse or promote products
15
 *   derived from this software without specific prior written permission.
16
 *
17
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27
 */
28
 
1849 jermar 29
/** @addtogroup sparc64
1702 cejka 30
 * @{
31
 */
32
/** @file
33
 */
34
 
664 jermar 35
#include <arch/drivers/tick.h>
36
#include <arch/interrupt.h>
2089 decky 37
#include <arch/sparc64.h>
664 jermar 38
#include <arch/asm.h>
39
#include <arch/register.h>
1881 jermar 40
#include <arch/cpu.h>
41
#include <arch/boot/boot.h>
42
#include <time/clock.h>
43
#include <arch.h>
664 jermar 44
#include <debug.h>
45
 
1881 jermar 46
#define TICK_RESTART_TIME   50  /* Worst case estimate. */
47
 
665 jermar 48
/** Initialize tick interrupt. */
664 jermar 49
void tick_init(void)
50
{
51
    tick_compare_reg_t compare;
52
 
53
    interrupt_register(14, "tick_int", tick_interrupt);
54
    compare.int_dis = false;
2044 jermar 55
    compare.tick_cmpr = CPU->arch.clock_frequency / HZ;
56
    CPU->arch.next_tick_cmpr = compare.tick_cmpr;
664 jermar 57
    tick_compare_write(compare.value);
58
    tick_write(0);
59
}
60
 
665 jermar 61
/** Process tick interrupt.
62
 *
63
 * @param n Interrupt Level, 14,  (can be ignored)
958 jermar 64
 * @param istate Interrupted state.
665 jermar 65
 */
958 jermar 66
void tick_interrupt(int n, istate_t *istate)
664 jermar 67
{
665 jermar 68
    softint_reg_t softint, clear;
2044 jermar 69
    uint64_t drift;
665 jermar 70
 
71
    softint.value = softint_read();
72
 
73
    /*
74
     * Make sure we are servicing interrupt_level_14
75
     */
76
    ASSERT(n == 14);
77
 
78
    /*
79
     * Make sure we are servicing TICK_INT.
80
     */
81
    ASSERT(softint.tick_int);
82
 
83
    /*
84
     * Clear tick interrupt.
85
     */
86
    clear.value = 0;
87
    clear.tick_int = 1;
88
    clear_softint_write(clear.value);
89
 
90
    /*
2044 jermar 91
     * Reprogram the compare register.
92
     * For now, we can ignore the potential of the registers to overflow.
93
     * On a 360MHz Ultra 60, the 63-bit compare counter will overflow in
94
     * about 812 years. If there was a 2GHz UltraSPARC computer, it would
95
     * overflow only in 146 years.
665 jermar 96
     */
2044 jermar 97
    drift = tick_read() - CPU->arch.next_tick_cmpr;
98
    while (drift > CPU->arch.clock_frequency / HZ) {
99
        drift -= CPU->arch.clock_frequency / HZ;
1881 jermar 100
        CPU->missed_clock_ticks++;
101
    }
2107 jermar 102
    CPU->arch.next_tick_cmpr = tick_read() +
103
        (CPU->arch.clock_frequency / HZ) - drift;
2044 jermar 104
    tick_compare_write(CPU->arch.next_tick_cmpr);
665 jermar 105
    clock();
664 jermar 106
}
1702 cejka 107
 
1849 jermar 108
/** @}
1702 cejka 109
 */