root/arch/powerpc/kernel/misc.S

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * This file contains miscellaneous low-level functions.
   4  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   5  *
   6  * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
   7  * and Paul Mackerras.
   8  *
   9  * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
  10  *
  11  * setjmp/longjmp code by Paul Mackerras.
  12  */
  13 #include <asm/ppc_asm.h>
  14 #include <asm/unistd.h>
  15 #include <asm/asm-compat.h>
  16 #include <asm/asm-offsets.h>
  17 #include <asm/export.h>
  18 
  19         .text
  20 
  21 /*
  22  * Returns (address we are running at) - (address we were linked at)
  23  * for use before the text and data are mapped to KERNELBASE.
  24 
  25  * add_reloc_offset(x) returns x + reloc_offset().
  26  */
  27 
  28 _GLOBAL(reloc_offset)
  29         li      r3, 0
  30 _GLOBAL(add_reloc_offset)
  31         mflr    r0
  32         bl      1f
  33 1:      mflr    r5
  34         PPC_LL  r4,(2f-1b)(r5)
  35         subf    r5,r4,r5
  36         add     r3,r3,r5
  37         mtlr    r0
  38         blr
  39 
  40         .align  3
  41 2:      PPC_LONG 1b
  42 
  43 _GLOBAL(setjmp)
  44         mflr    r0
  45         PPC_STL r0,0(r3)
  46         PPC_STL r1,SZL(r3)
  47         PPC_STL r2,2*SZL(r3)
  48 #ifdef CONFIG_PPC32
  49         mfcr    r12
  50         stmw    r12, 3*SZL(r3)
  51 #else
  52         mfcr    r0
  53         PPC_STL r0,3*SZL(r3)
  54         PPC_STL r13,4*SZL(r3)
  55         PPC_STL r14,5*SZL(r3)
  56         PPC_STL r15,6*SZL(r3)
  57         PPC_STL r16,7*SZL(r3)
  58         PPC_STL r17,8*SZL(r3)
  59         PPC_STL r18,9*SZL(r3)
  60         PPC_STL r19,10*SZL(r3)
  61         PPC_STL r20,11*SZL(r3)
  62         PPC_STL r21,12*SZL(r3)
  63         PPC_STL r22,13*SZL(r3)
  64         PPC_STL r23,14*SZL(r3)
  65         PPC_STL r24,15*SZL(r3)
  66         PPC_STL r25,16*SZL(r3)
  67         PPC_STL r26,17*SZL(r3)
  68         PPC_STL r27,18*SZL(r3)
  69         PPC_STL r28,19*SZL(r3)
  70         PPC_STL r29,20*SZL(r3)
  71         PPC_STL r30,21*SZL(r3)
  72         PPC_STL r31,22*SZL(r3)
  73 #endif
  74         li      r3,0
  75         blr
  76 
  77 _GLOBAL(longjmp)
  78 #ifdef CONFIG_PPC32
  79         lmw     r12, 3*SZL(r3)
  80         mtcrf   0x38, r12
  81 #else
  82         PPC_LL  r13,4*SZL(r3)
  83         PPC_LL  r14,5*SZL(r3)
  84         PPC_LL  r15,6*SZL(r3)
  85         PPC_LL  r16,7*SZL(r3)
  86         PPC_LL  r17,8*SZL(r3)
  87         PPC_LL  r18,9*SZL(r3)
  88         PPC_LL  r19,10*SZL(r3)
  89         PPC_LL  r20,11*SZL(r3)
  90         PPC_LL  r21,12*SZL(r3)
  91         PPC_LL  r22,13*SZL(r3)
  92         PPC_LL  r23,14*SZL(r3)
  93         PPC_LL  r24,15*SZL(r3)
  94         PPC_LL  r25,16*SZL(r3)
  95         PPC_LL  r26,17*SZL(r3)
  96         PPC_LL  r27,18*SZL(r3)
  97         PPC_LL  r28,19*SZL(r3)
  98         PPC_LL  r29,20*SZL(r3)
  99         PPC_LL  r30,21*SZL(r3)
 100         PPC_LL  r31,22*SZL(r3)
 101         PPC_LL  r0,3*SZL(r3)
 102         mtcrf   0x38,r0
 103 #endif
 104         PPC_LL  r0,0(r3)
 105         PPC_LL  r1,SZL(r3)
 106         PPC_LL  r2,2*SZL(r3)
 107         mtlr    r0
 108         mr.     r3, r4
 109         bnelr
 110         li      r3, 1
 111         blr
 112 
 113 _GLOBAL(current_stack_pointer)
 114         PPC_LL  r3,0(r1)
 115         blr
 116 EXPORT_SYMBOL(current_stack_pointer)