Subversion Repositories HelenOS

Rev

Rev 2787 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 jermar 1
/*
2071 jermar 2
 * Copyright (c) 2003-2004 Jakub Jermar
1 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
 
1881 jermar 29
/** @addtogroup mips32interrupt
1702 cejka 30
 * @{
31
 */
32
/** @file
33
 */
34
 
575 palkovsky 35
#include <interrupt.h>
1 jermar 36
#include <arch/interrupt.h>
37
#include <arch/types.h>
38
#include <arch.h>
39
#include <arch/cp0.h>
40
#include <time/clock.h>
1258 palkovsky 41
#include <ipc/sysipc.h>
1936 decky 42
#include <ddi/device.h>
1258 palkovsky 43
 
1936 decky 44
#define IRQ_COUNT 8
45
#define TIMER_IRQ 7
46
 
1955 decky 47
function virtual_timer_fnc = NULL;
1936 decky 48
static irq_t timer_irq;
49
 
413 jermar 50
/** Disable interrupts.
51
 *
52
 * @return Old interrupt priority level.
53
 */
54
ipl_t interrupts_disable(void)
1 jermar 55
{
413 jermar 56
    ipl_t ipl = (ipl_t) cp0_status_read();
57
    cp0_status_write(ipl & ~cp0_status_ie_enabled_bit);
58
    return ipl;
1 jermar 59
}
60
 
413 jermar 61
/** Enable interrupts.
62
 *
63
 * @return Old interrupt priority level.
64
 */
65
ipl_t interrupts_enable(void)
1 jermar 66
{
413 jermar 67
    ipl_t ipl = (ipl_t) cp0_status_read();
68
    cp0_status_write(ipl | cp0_status_ie_enabled_bit);
69
    return ipl;
1 jermar 70
}
71
 
413 jermar 72
/** Restore interrupt priority level.
73
 *
74
 * @param ipl Saved interrupt priority level.
75
 */
76
void interrupts_restore(ipl_t ipl)
1 jermar 77
{
413 jermar 78
    cp0_status_write(cp0_status_read() | (ipl & cp0_status_ie_enabled_bit));
1 jermar 79
}
80
 
413 jermar 81
/** Read interrupt priority level.
82
 *
83
 * @return Current interrupt priority level.
84
 */
85
ipl_t interrupts_read(void)
1 jermar 86
{
125 jermar 87
    return cp0_status_read();
1 jermar 88
}
89
 
1434 palkovsky 90
/* TODO: This is SMP unsafe!!! */
2633 decky 91
uint32_t count_hi = 0;
1434 palkovsky 92
static unsigned long nextcount;
2633 decky 93
static unsigned long lastcount;
94
 
1434 palkovsky 95
/** Start hardware clock */
96
static void timer_start(void)
97
{
2633 decky 98
    lastcount = cp0_count_read();
1434 palkovsky 99
    nextcount = cp0_compare_value + cp0_count_read();
100
    cp0_compare_write(nextcount);
101
}
102
 
1936 decky 103
static irq_ownership_t timer_claim(void)
575 palkovsky 104
{
1936 decky 105
    return IRQ_ACCEPT;
106
}
107
 
108
static void timer_irq_handler(irq_t *irq, void *arg, ...)
109
{
1434 palkovsky 110
    unsigned long drift;
2633 decky 111
 
2634 decky 112
    if (cp0_count_read() < lastcount)
113
        /* Count overflow detected */
2633 decky 114
        count_hi++;
2634 decky 115
    lastcount = cp0_count_read();
2633 decky 116
 
1434 palkovsky 117
    drift = cp0_count_read() - nextcount;
118
    while (drift > cp0_compare_value) {
119
        drift -= cp0_compare_value;
120
        CPU->missed_clock_ticks++;
121
    }
122
    nextcount = cp0_count_read() + cp0_compare_value - drift;
123
    cp0_compare_write(nextcount);
2633 decky 124
 
2107 jermar 125
    /*
126
     * We are holding a lock which prevents preemption.
127
     * Release the lock, call clock() and reacquire the lock again.
128
     */
129
    spinlock_unlock(&irq->lock);
575 palkovsky 130
    clock();
2107 jermar 131
    spinlock_lock(&irq->lock);
1936 decky 132
 
1955 decky 133
    if (virtual_timer_fnc != NULL)
134
        virtual_timer_fnc();
575 palkovsky 135
}
136
 
137
/* Initialize basic tables for exception dispatching */
138
void interrupt_init(void)
139
{
1936 decky 140
    irq_init(IRQ_COUNT, IRQ_COUNT);
141
 
142
    irq_initialize(&timer_irq);
143
    timer_irq.devno = device_assign_devno();
144
    timer_irq.inr = TIMER_IRQ;
145
    timer_irq.claim = timer_claim;
146
    timer_irq.handler = timer_irq_handler;
147
    irq_register(&timer_irq);
148
 
1434 palkovsky 149
    timer_start();
1936 decky 150
    cp0_unmask_int(TIMER_IRQ);
1 jermar 151
}
1258 palkovsky 152
 
1881 jermar 153
/** @}
1702 cejka 154
 */