| 0,0 → 1,123 |
|---|
| /* |
| * Copyright (C) 2001-2004 Jakub Jermar |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * - Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * - Redistributions in binary form must reproduce the above copyright |
| * notice, this list of conditions and the following disclaimer in the |
| * documentation and/or other materials provided with the distribution. |
| * - The name of the author may not be used to endorse or promote products |
| * derived from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #include <arch/exception.h> |
| #include <arch/interrupt.h> |
| #include <panic.h> |
| #include <arch/cp0.h> |
| #include <arch/types.h> |
| #include <arch.h> |
| |
| void exception(void) |
| { |
| int excno; |
| __u32 epc; |
| __u32 epc_shift = 0; |
| pri_t pri; |
| |
| /* |
| * NOTE ON OPERATION ORDERING |
| * |
| * On entry, cpu_priority_high() must be called before exception bit is cleared. |
| * On exit, exception bit must be set before cpu_priority_restore() is called. |
| */ |
| |
| pri = cpu_priority_high(); |
| epc = cp0_epc_read(); |
| cp0_status_write(cp0_status_read() & ~ cp0_status_exl_exception_bit); |
| |
| if (THREAD) { |
| THREAD->saved_pri = pri; |
| THREAD->saved_epc = epc; |
| } |
| /* decode exception number and process the exception */ |
| switch (excno = (cp0_cause_read() >> 2) & 0x1f) { |
| case EXC_Int: |
| interrupt(); |
| break; |
| case EXC_TLBL: |
| case EXC_TLBS: |
| tlb_invalid(); |
| break; |
| case EXC_Mod: |
| panic("unhandled TLB Modification Exception\n"); |
| break; |
| case EXC_AdEL: |
| panic("unhandled Address Error Exception - load or instruction fetch\n"); |
| break; |
| case EXC_AdES: |
| panic("unhandled Address Error Exception - store\n"); |
| break; |
| case EXC_IBE: |
| panic("unhandled Bus Error Exception - fetch instruction\n"); |
| break; |
| case EXC_DBE: |
| panic("unhandled Bus Error Exception - data reference: load or store\n"); |
| break; |
| case EXC_Bp: |
| /* it is necessary to not re-execute BREAK instruction after returning from Exception handler |
| (see page 138 in R4000 Manual for more information) */ |
| epc_shift = 4; |
| break; |
| case EXC_RI: |
| panic("unhandled Reserved Instruction Exception\n"); |
| break; |
| case EXC_CpU: |
| panic("unhandled Coprocessor Unusable Exception\n"); |
| break; |
| case EXC_Ov: |
| panic("unhandled Arithmetic Overflow Exception\n"); |
| break; |
| case EXC_Tr: |
| panic("unhandled Trap Exception\n"); |
| break; |
| case EXC_VCEI: |
| panic("unhandled Virtual Coherency Exception - instruction\n"); |
| break; |
| case EXC_FPE: |
| panic("unhandled Floating-Point Exception\n"); |
| break; |
| case EXC_WATCH: |
| panic("unhandled reference to WatchHi/WatchLo address\n"); |
| break; |
| case EXC_VCED: |
| panic("unhandled Virtual Coherency Exception - data\n"); |
| break; |
| default: |
| panic("unhandled exception %d\n", excno); |
| } |
| |
| if (THREAD) { |
| pri = THREAD->saved_pri; |
| epc = THREAD->saved_epc; |
| } |
| |
| cp0_epc_write(epc + epc_shift); |
| cp0_status_write(cp0_status_read() | cp0_status_exl_exception_bit); |
| cpu_priority_restore(pri); |
| } |