/*
* User Space Access Routines
*
* Copyright (C) 2000-2002 Hewlett-Packard (John Marvin)
* Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org>
* Copyright (C) 2001 Matthieu Delahaye <delahaym at esiee.fr>
* Copyright (C) 2003 Randolph Chung <tausq with parisc-linux.org>
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/*
* These routines still have plenty of room for optimization
* (word & doubleword load/store, dual issue, store hints, etc.).
*/
/*
* The following routines assume that space register 3 (sr3) contains
* the space id associated with the current users address space.
*/
.text
#include <asm/assembly.h>
#include <asm/errno.h>
/*
* get_sr gets the appropriate space value into
* sr1 for kernel/user space access, depending
* on the flag stored in the task structure.
*/
.macro get_sr
mfctl %cr30,%r1
ldw TI_SEGMENT(%r1),%r22
mfsp %sr3,%r1
or,<> %r22,%r0,%r0
copy %r0,%r1
mtsp %r1,%sr1
.endm
.macro fixup_branch lbl
ldil L%\lbl, %r1
ldo R%\lbl(%r1), %r1
bv %r0(%r1)
.endm
/*
* long lstrncpy_from_user(char *dst, const char *src, long n)
*
* Returns -EFAULT if exception before terminator,
* N if the entire buffer filled,
* otherwise strlen (i.e. excludes zero byte)
*/
.export lstrncpy_from_user,code
lstrncpy_from_user:
.proc
.callinfo NO_CALLS
.entry
comib,= 0,%r24,$lsfu_done
copy %r24,%r23
get_sr
1: ldbs,ma 1(%sr1,%r25),%r1
$lsfu_loop:
stbs,ma %r1,1(%r26)
comib,=,n 0,%r1,$lsfu_done
addib,<>,n -1,%r24,$lsfu_loop
2: ldbs,ma 1(%sr1,%r25),%r1
$lsfu_done:
sub %r23,%r24,%r28
$lsfu_exit:
bv %r0(%r2)
nop
.exit
.section .fixup,"ax"
3: fixup_branch $lsfu_exit
ldi -EFAULT,%r28
.previous
.section __ex_table,"aw"
#ifdef __LP64__
.dword 1b,3b
.dword 2b,3b
#else
.word 1b,3b
.word 2b,3b
#endif
.previous
.procend
/*
* unsigned long lclear_user(void *to, unsigned long n)
*
* Returns 0 for success.
* otherwise, returns number of bytes not transferred.
*/
.export lclear_user,code
lclear_user:
.proc
.callinfo NO_CALLS
.entry
comib,=,n 0,%r25,$lclu_done
get_sr
$lclu_loop:
addib,<> -1,%r25,$lclu_loop
1: stbs,ma %r0,1(%sr1,%r26)
$lclu_done:
bv %r0(%r2)
copy %r25,%r28
.exit
.section .fixup,"ax"
2: fixup_branch $lclu_done
ldo 1(%r25),%r25
.previous
.section __ex_table,"aw"
#ifdef __LP64__
.dword 1b,2b
#else
.word 1b,2b
#endif
.previous
.procend
/*
* long lstrnlen_user(char *s, long n)
*
* Returns 0 if exception before zero byte or reaching N,
* N+1 if N would be exceeded,
* else strlen + 1 (i.e. includes zero byte).
*/
.export lstrnlen_user,code
lstrnlen_user:
.proc
.callinfo NO_CALLS
.entry
comib,= 0,%r25,$lslen_nzero
copy %r26,%r24
get_sr
1: ldbs,ma 1(%sr1,%r26),%r1
$lslen_loop:
comib,=,n 0,%r1,$lslen_done
addib,<> -1,%r25,$lslen_loop
2: ldbs,ma 1(%sr1,%r26),%r1
$lslen_done:
bv %r0(%r2)
sub %r26,%r24,%r28
.exit
$lslen_nzero:
b $lslen_done
ldo 1(%r26),%r26 /* special case for N == 0 */
.section .fixup,"ax"
3: fixup_branch $lslen_done
copy %r24,%r26 /* reset r26 so 0 is returned on fault */
.previous
.section __ex_table,"aw"
#ifdef __LP64__
.dword 1b,3b
.dword 2b,3b
#else
.word 1b,3b
.word 2b,3b
#endif
.previous
.procend
.end
