arch/mips/lasat/lasatIRQ.S

   1 /*
   2  * Carsten Langgaard, carstenl@mips.com
   3  * Copyright (C) 1999, 2000 MIPS Technologies, Inc.  All rights reserved.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17  *
  18  * Interrupt exception dispatch code.
  19  */
  20 #include <asm/asm.h>
  21 #include <asm/mipsregs.h>
  22 #include <asm/regdef.h>
  23 #include <asm/stackframe.h>
  24
  25         .text
  26         .set    noreorder
  27         .align  5
  28         NESTED(lasatIRQ, PT_SIZE, sp)
  29         .set    noat
  30         SAVE_ALL
  31         CLI
  32         .set    at
  33         .set    noreorder
  34
  35         mfc0    s0, CP0_CAUSE           # get irq mask
  36
  37         /* First we check for r4k counter/timer IRQ. */
  38         andi    a0, s0, CAUSEF_IP7
  39         beq     a0, zero, 1f
  40          andi   a0, s0, CAUSEF_IP2      # delay slot, check hw0 interrupt
  41
  42         /* Wheee, a timer interrupt. */
  43         li      a0, 7
  44         jal     ll_timer_interrupt
  45          move   a1, sp
  46
  47         j       ret_from_irq
  48          nop
  49
  50 1:
  51         /* Wheee, combined hardware level zero interrupt. */
  52         jal     lasat_hw0_irqdispatch
  53          move   a0, sp                  # delay slot
  54
  55         j       ret_from_irq
  56          nop                            # delay slot
  57
  58 1:
  59         /*
  60          * Here by mistake?  This is possible, what can happen is that by the
  61          * time we take the exception the IRQ pin goes low, so just leave if
  62          * this is the case.
  63          */
  64         move    a1,s0
  65         mfc0    a1, CP0_EPC
  66
  67         j       ret_from_irq
  68          nop
  69         END(lasatIRQ)