arch/parisc/lib/fixup.S

   1 /*
   2  * Linux/PA-RISC Project (http://www.parisc-linux.org/)
   3  *
   4  *  Copyright (C) 2004  Randolph Chung <tausq@debian.org>
   5  *
   6  *    This program is free software; you can redistribute it and/or modify
   7  *    it under the terms of the GNU General Public License as published by
   8  *    the Free Software Foundation; either version 2, or (at your option)
   9  *    any later version.
  10  *
  11  *    This program is distributed in the hope that it will be useful,
  12  *    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *    GNU General Public License for more details.
  15  *
  16  *    You should have received a copy of the GNU General Public License
  17  *    along with this program; if not, write to the Free Software
  18  *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  *
  20  * Fixup routines for kernel exception handling.
  21  */
  22 #include <linux/config.h>
  23 #include <asm/offsets.h>
  24 #include <asm/assembly.h>
  25 #include <asm/errno.h>
  26
  27 #ifdef CONFIG_SMP
  28         .macro  get_fault_ip t1 t2
  29         addil LT%__per_cpu_offset,%r27
  30         LDREG RT%__per_cpu_offset(%r1),\t1
  31         /* t2 = smp_processor_id() */
  32         mfctl 30,\t2
  33         ldw TI_CPU(\t2),\t2
  34 #ifdef __LP64__
  35         extrd,u \t2,63,32,\t2
  36 #endif
  37         /* t2 = &__per_cpu_offset[smp_processor_id()]; */
  38         LDREG,s \t2(\t1),\t2
  39         addil LT%per_cpu__exception_data,%r27
  40         LDREG RT%per_cpu__exception_data(%r1),\t1
  41         /* t1 = &__get_cpu_var(exception_data) */
  42         add,l \t1,\t2,\t1
  43         /* t1 = t1->fault_ip */
  44         LDREG EXCDATA_IP(\t1), \t1
  45         .endm
  46 #else
  47         .macro  get_fault_ip t1 t2
  48         /* t1 = &__get_cpu_var(exception_data) */
  49         addil LT%per_cpu__exception_data,%r27
  50         LDREG RT%per_cpu__exception_data(%r1),\t2
  51         /* t1 = t2->fault_ip */
  52         LDREG EXCDATA_IP(\t2), \t1
  53         .endm
  54 #endif
  55
  56         .text
  57         .section .fixup, "ax"
  58
  59         /* get_user() fixups, store -EFAULT in r8, and 0 in r9 */
  60         .export fixup_get_user_skip_1
  61 fixup_get_user_skip_1:
  62         get_fault_ip %r1,%r8
  63         ldo 4(%r1), %r1
  64         ldi -EFAULT, %r8
  65         bv %r0(%r1)
  66         copy %r0, %r9
  67
  68         .export fixup_get_user_skip_2
  69 fixup_get_user_skip_2:
  70         get_fault_ip %r1,%r8
  71         ldo 8(%r1), %r1
  72         ldi -EFAULT, %r8
  73         bv %r0(%r1)
  74         copy %r0, %r9
  75
  76         /* put_user() fixups, store -EFAULT in r8 */
  77         .export fixup_put_user_skip_1
  78 fixup_put_user_skip_1:
  79         get_fault_ip %r1,%r8
  80         ldo 4(%r1), %r1
  81         bv %r0(%r1)
  82         ldi -EFAULT, %r8
  83
  84         .export fixup_put_user_skip_2
  85 fixup_put_user_skip_2:
  86         get_fault_ip %r1,%r8
  87         ldo 8(%r1), %r1
  88         bv %r0(%r1)
  89         ldi -EFAULT, %r8