arch/powerpc/kernel/misc.S

   1 /*
   2  * This file contains miscellaneous low-level functions.
   3  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   4  *
   5  * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
   6  * and Paul Mackerras.
   7  *
   8  * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
   9  * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
  10  *
  11  * setjmp/longjmp code by Paul Mackerras.
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version
  16  * 2 of the License, or (at your option) any later version.
  17  */
  18 #include <asm/ppc_asm.h>
  19 #include <asm/unistd.h>
  20 #include <asm/asm-compat.h>
  21 #include <asm/asm-offsets.h>
  22
  23         .text
  24
  25 /*
  26  * Returns (address we are running at) - (address we were linked at)
  27  * for use before the text and data are mapped to KERNELBASE.
  28  */
  29
  30 _GLOBAL(reloc_offset)
  31         mflr    r0
  32         bl      1f
  33 1:      mflr    r3
  34         LOAD_REG_IMMEDIATE(r4,1b)
  35         subf    r3,r4,r3
  36         mtlr    r0
  37         blr
  38
  39 /*
  40  * add_reloc_offset(x) returns x + reloc_offset().
  41  */
  42 _GLOBAL(add_reloc_offset)
  43         mflr    r0
  44         bl      1f
  45 1:      mflr    r5
  46         LOAD_REG_IMMEDIATE(r4,1b)
  47         subf    r5,r4,r5
  48         add     r3,r3,r5
  49         mtlr    r0
  50         blr
  51
  52 _GLOBAL(kernel_execve)
  53         li      r0,__NR_execve
  54         sc
  55         bnslr
  56         neg     r3,r3
  57         blr
  58
  59 _GLOBAL(setjmp)
  60         mflr    r0
  61         PPC_STL r0,0(r3)
  62         PPC_STL r1,SZL(r3)
  63         PPC_STL r2,2*SZL(r3)
  64         mfcr    r0
  65         PPC_STL r0,3*SZL(r3)
  66         PPC_STL r13,4*SZL(r3)
  67         PPC_STL r14,5*SZL(r3)
  68         PPC_STL r15,6*SZL(r3)
  69         PPC_STL r16,7*SZL(r3)
  70         PPC_STL r17,8*SZL(r3)
  71         PPC_STL r18,9*SZL(r3)
  72         PPC_STL r19,10*SZL(r3)
  73         PPC_STL r20,11*SZL(r3)
  74         PPC_STL r21,12*SZL(r3)
  75         PPC_STL r22,13*SZL(r3)
  76         PPC_STL r23,14*SZL(r3)
  77         PPC_STL r24,15*SZL(r3)
  78         PPC_STL r25,16*SZL(r3)
  79         PPC_STL r26,17*SZL(r3)
  80         PPC_STL r27,18*SZL(r3)
  81         PPC_STL r28,19*SZL(r3)
  82         PPC_STL r29,20*SZL(r3)
  83         PPC_STL r30,21*SZL(r3)
  84         PPC_STL r31,22*SZL(r3)
  85         li      r3,0
  86         blr
  87
  88 _GLOBAL(longjmp)
  89         PPC_LCMPI r4,0
  90         bne     1f
  91         li      r4,1
  92 1:      PPC_LL  r13,4*SZL(r3)
  93         PPC_LL  r14,5*SZL(r3)
  94         PPC_LL  r15,6*SZL(r3)
  95         PPC_LL  r16,7*SZL(r3)
  96         PPC_LL  r17,8*SZL(r3)
  97         PPC_LL  r18,9*SZL(r3)
  98         PPC_LL  r19,10*SZL(r3)
  99         PPC_LL  r20,11*SZL(r3)
 100         PPC_LL  r21,12*SZL(r3)
 101         PPC_LL  r22,13*SZL(r3)
 102         PPC_LL  r23,14*SZL(r3)
 103         PPC_LL  r24,15*SZL(r3)
 104         PPC_LL  r25,16*SZL(r3)
 105         PPC_LL  r26,17*SZL(r3)
 106         PPC_LL  r27,18*SZL(r3)
 107         PPC_LL  r28,19*SZL(r3)
 108         PPC_LL  r29,20*SZL(r3)
 109         PPC_LL  r30,21*SZL(r3)
 110         PPC_LL  r31,22*SZL(r3)
 111         PPC_LL  r0,3*SZL(r3)
 112         mtcrf   0x38,r0
 113         PPC_LL  r0,0(r3)
 114         PPC_LL  r1,SZL(r3)
 115         PPC_LL  r2,2*SZL(r3)
 116         mtlr    r0
 117         mr      r3,r4
 118         blr