Subversion Repositories HelenOS

Rev

Rev 68 | Rev 195 | Go to most recent revision | Details | Compare with Previous | Last modification | View Log | RSS feed

Rev Author Line No. Line
1 jermar 1 
/*
2 
 * Copyright (C) 2001-2004 Jakub 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 
 
29 
#include <arch/exception.h>
30 
#include <panic.h>
31 
#include <arch/cp0.h>
32 
#include <arch/types.h>
33 
#include <arch.h>
34 
 
35 
void exception(void)
36 
{
37 
    int excno;
38 
    __u32 epc;
123 decky 39 
    __u32 epc_shift = 0;
1 jermar 40 
    pri_t pri;
41 
 
42 
    pri = cpu_priority_high();
43 
    epc = cp0_epc_read();
44 
    cp0_status_write(cp0_status_read() & ~ cp0_status_exl_exception_bit);
45 
 
15 jermar 46 
    if (THREAD) {
47 
        THREAD->saved_pri = pri;
48 
        THREAD->saved_epc = epc;
1 jermar 49 
    }
50 
    /* decode exception number and process the exception */
123 decky 51 
    switch (excno = (cp0_cause_read() >> 2) & 0x1f) {
52 
        case EXC_Int:
53 
            interrupt();
54 
            break;
1 jermar 55 
        case EXC_TLBL:
123 decky 56 
        case EXC_TLBS:
57 
            tlb_invalid();
58 
            break;
59 
        case EXC_Mod:
60 
            panic("unhandled TLB Modification Exception\n");
61 
            break;
62 
        case EXC_AdEL:
63 
            panic("unhandled Address Error Exception - load or instruction fetch\n");
64 
            break;
65 
        case EXC_AdES:
66 
            panic("unhandled Address Error Exception - store\n");
67 
            break;
68 
        case EXC_IBE:
69 
            panic("unhandled Bus Error Exception - fetch instruction\n");
70 
            break;
71 
        case EXC_DBE:
72 
            panic("unhandled Bus Error Exception - data reference: load or store\n");
73 
            break;
74 
        case EXC_Bp:
75 
            /* it is necessary to not re-execute BREAK instruction after returning from Exception handler
76 
               (see page 138 in R4000 Manual for more information) */
77 
            epc_shift = 4;
78 
            break;
79 
        case EXC_RI:
80 
            panic("unhandled Reserved Instruction Exception\n");
81 
            break;
82 
        case EXC_CpU:
83 
            panic("unhandled Coprocessor Unusable Exception\n");
84 
            break;
85 
        case EXC_Ov:
86 
            panic("unhandled Arithmetic Overflow Exception\n");
87 
            break;
88 
        case EXC_Tr:
89 
            panic("unhandled Trap Exception\n");
90 
            break;
91 
        case EXC_VCEI:
92 
            panic("unhandled Virtual Coherency Exception - instruction\n");
93 
            break;
94 
        case EXC_FPE:
95 
            panic("unhandled Floating-Point Exception\n");
96 
            break;
97 
        case EXC_WATCH:
98 
            panic("unhandled reference to WatchHi/WatchLo address\n");
99 
            break;
100 
        case EXC_VCED:
101 
            panic("unhandled Virtual Coherency Exception - data\n");
102 
            break;
103 
        default:
104 
            panic("unhandled exception %d\n", excno);
1 jermar 105 
    }
106 
 
15 jermar 107 
    if (THREAD) {
108 
        pri = THREAD->saved_pri;
109 
        epc = THREAD->saved_epc;
1 jermar 110 
    }
111 
 
123 decky 112 
    cp0_epc_write(epc + epc_shift);
1 jermar 113 
    cp0_status_write(cp0_status_read() | cp0_status_exl_exception_bit);
114 
    cpu_priority_restore(pri);
115 
}