arch/.unmaintained/m68k-native/exec/enable.s

   1 /*
   2     Copyright © 1995-2001, The AROS Development Team. All rights reserved.
   3     $Id$
   4 */
   5
   6 /*****************************************************************************
   7
   8     NAME
   9
  10         AROS_LH0(void, Enable,
  11
  12     LOCATION
  13         struct ExecBase *, SysBase, 21, Exec)
  14
  15     FUNCTION
  16         This function reenables the delivery of interrupts after a call to
  17         Disable().
  18
  19     INPUTS
  20
  21     RESULT
  22
  23     NOTES
  24         This function preserves all registers.
  25
  26         This function may be used from interrupts.
  27
  28     EXAMPLE
  29
  30     BUGS
  31
  32     SEE ALSO
  33         Forbid(), Permit(), Disable()
  34
  35     INTERNALS
  36
  37     HISTORY
  38
  39 ******************************************************************************/
  40
  41         INTENA      =   0xdff09a
  42         INTEN       =   0x4000
  43         SET         =   0x8000
  44
  45         #include "machine.i"
  46
  47         .text
  48         .balign 4
  49         .globl  AROS_SLIB_ENTRY(Enable,Exec)
  50         .type   AROS_SLIB_ENTRY(Enable,Exec),@function
  51 AROS_SLIB_ENTRY(Enable,Exec):
  52         /* decrement nesting count and return if there are Disable()s left */
  53         subq.b  #1,IDNestCnt(a6)
  54         bpl     end
  55
  56         /* reenable interrupts */
  57         move.w  #INTEN+SET,INTENA
  58
  59         /* return if there are no delayed switches pending. */
  60         tst.b   AttnResched+1(a6)
  61         bpl     end
  62
  63         /* if TDNestCnt is not -1 taskswitches are still forbidden */
  64         tst.b   TDNestCnt(a6)
  65         bpl     end
  66
  67         /* Unset delayed switch bit and do the delayed switch */
  68         bclr    #7,0x12b(a6)
  69         jsr     Switch(a6)
  70
  71         /* all done. */
  72 end:    rts
  73