arch/powerpc/sysdev/dcr-low.S

   1 /*
   2  * "Indirect" DCR access
   3  *
   4  * Copyright (c) 2004 Eugene Surovegin <ebs@ebshome.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under  the terms of  the GNU General Public License as published by the
   8  * Free Software Foundation;  either version 2 of the License, or (at your
   9  * option) any later version.
  10  */
  11
  12 #include <asm/ppc_asm.h>
  13 #include <asm/processor.h>
  14 #include <asm/bug.h>
  15 #include <asm/export.h>
  16
  17 #define DCR_ACCESS_PROLOG(table) \
  18         cmpli   cr0,r3,1024;     \
  19         rlwinm  r3,r3,4,18,27;   \
  20         lis     r5,table@h;      \
  21         ori     r5,r5,table@l;   \
  22         add     r3,r3,r5;        \
  23         bge-    1f;              \
  24         mtctr   r3;              \
  25         bctr;                    \
  26 1:      trap;                    \
  27         EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,0;  \
  28         blr
  29
  30 _GLOBAL(__mfdcr)
  31         DCR_ACCESS_PROLOG(__mfdcr_table)
  32 EXPORT_SYMBOL(__mfdcr)
  33
  34 _GLOBAL(__mtdcr)
  35         DCR_ACCESS_PROLOG(__mtdcr_table)
  36 EXPORT_SYMBOL(__mtdcr)
  37
  38 __mfdcr_table:
  39         mfdcr  r3,0; blr
  40 __mtdcr_table:
  41         mtdcr  0,r4; blr
  42
  43 dcr     = 1
  44         .rept   1023
  45         mfdcr   r3,dcr; blr
  46         mtdcr   dcr,r4; blr
  47         dcr     = dcr + 1
  48         .endr