Subversion Repositories HelenOS-historic

Rev

Rev 68 | Blame | Last modification | View Log | Download | RSS feed

  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;
  39.     __u32 epc_shift = 0;
  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.  
  46.     if (THREAD) {
  47.         THREAD->saved_pri = pri;
  48.         THREAD->saved_epc = epc;
  49.     }
  50.     /* decode exception number and process the exception */
  51.     switch (excno = (cp0_cause_read() >> 2) & 0x1f) {
  52.         case EXC_Int:
  53.             interrupt();
  54.             break;
  55.         case EXC_TLBL:
  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);
  105.     }
  106.    
  107.     if (THREAD) {
  108.         pri = THREAD->saved_pri;
  109.         epc = THREAD->saved_epc;
  110.     }
  111.  
  112.     cp0_epc_write(epc + epc_shift);
  113.     cp0_status_write(cp0_status_read() | cp0_status_exl_exception_bit);
  114.     cpu_priority_restore(pri);
  115. }
  116.