/* $Id: strncpy_from_user.S,v 1.6 1999/05/25 16:53:05 jj Exp $
* strncpy_from_user.S: Sparc64 strncpy from userspace.
*
* Copyright (C) 1997, 1999 Jakub Jelinek (jj@ultra.linux.cz)
*/
#include <asm/asi.h>
#include <asm/errno.h>
.data
.align 8
0: .xword 0x0101010101010101
.text
.align 32
/* Must return:
*
* -EFAULT for an exception
* count if we hit the buffer limit
* bytes copied if we hit a null byte
* (without the null byte)
*
* This implementation assumes:
* %o1 is 8 aligned => !(%o2 & 7)
* %o0 is 8 aligned (if not, it will be slooooow, but will work)
*
* This is optimized for the common case:
* in my stats, 90% of src are 8 aligned (even on sparc32)
* and average length is 18 or so.
*/
.globl __strncpy_from_user
.type __strncpy_from_user,#function
__strncpy_from_user:
/* %o0=dest, %o1=src, %o2=count */
andcc %o1, 7, %g0 ! IEU1 Group
bne,pn %icc, 30f ! CTI
add %o0, %o2, %g3 ! IEU0
60: ldxa [%o1] %asi, %g1 ! Load Group
brlez,pn %o2, 10f ! CTI
mov %o0, %o3 ! IEU0
50: sethi %hi(0b), %o4 ! IEU0 Group
ldx [%o4 + %lo(0b)], %o4 ! Load
sllx %o4, 7, %o5 ! IEU1 Group
1: sub %g1, %o4, %g2 ! IEU0 Group
stx %g1, [%o0] ! Store
add %o0, 8, %o0 ! IEU1
andcc %g2, %o5, %g0 ! IEU1 Group
bne,pn %xcc, 5f ! CTI
add %o1, 8, %o1 ! IEU0
cmp %o0, %g3 ! IEU1 Group
bl,a,pt %xcc, 1b ! CTI
61: ldxa [%o1] %asi, %g1 ! Load
10: retl ! CTI Group
mov %o2, %o0 ! IEU0
5: srlx %g2, 32, %g7 ! IEU0 Group
sethi %hi(0xff00), %o4 ! IEU1
andcc %g7, %o5, %g0 ! IEU1 Group
be,pn %icc, 2f ! CTI
or %o4, %lo(0xff00), %o4 ! IEU0
srlx %g1, 48, %g7 ! IEU0 Group
andcc %g7, %o4, %g0 ! IEU1 Group
be,pn %icc, 50f ! CTI
andcc %g7, 0xff, %g0 ! IEU1 Group
be,pn %icc, 51f ! CTI
srlx %g1, 32, %g7 ! IEU0
andcc %g7, %o4, %g0 ! IEU1 Group
be,pn %icc, 52f ! CTI
andcc %g7, 0xff, %g0 ! IEU1 Group
be,pn %icc, 53f ! CTI
2: andcc %g2, %o5, %g0 ! IEU1 Group
be,pn %icc, 2f ! CTI
srl %g1, 16, %g7 ! IEU0
andcc %g7, %o4, %g0 ! IEU1 Group
be,pn %icc, 54f ! CTI
andcc %g7, 0xff, %g0 ! IEU1 Group
be,pn %icc, 55f ! CTI
andcc %g1, %o4, %g0 ! IEU1 Group
be,pn %icc, 56f ! CTI
andcc %g1, 0xff, %g0 ! IEU1 Group
be,a,pn %icc, 57f ! CTI
sub %o0, %o3, %o0 ! IEU0
2: cmp %o0, %g3 ! IEU1 Group
bl,a,pt %xcc, 50b ! CTI
62: ldxa [%o1] %asi, %g1 ! Load
retl ! CTI Group
mov %o2, %o0 ! IEU0
50: sub %o0, %o3, %o0
retl
sub %o0, 8, %o0
51: sub %o0, %o3, %o0
retl
sub %o0, 7, %o0
52: sub %o0, %o3, %o0
retl
sub %o0, 6, %o0
53: sub %o0, %o3, %o0
retl
sub %o0, 5, %o0
54: sub %o0, %o3, %o0
retl
sub %o0, 4, %o0
55: sub %o0, %o3, %o0
retl
sub %o0, 3, %o0
56: sub %o0, %o3, %o0
retl
sub %o0, 2, %o0
57: retl
sub %o0, 1, %o0
30: brlez,pn %o2, 3f
sub %g0, %o2, %o3
add %o0, %o2, %o0
63: lduba [%o1] %asi, %o4
1: add %o1, 1, %o1
brz,pn %o4, 2f
stb %o4, [%o0 + %o3]
addcc %o3, 1, %o3
bne,pt %xcc, 1b
64: lduba [%o1] %asi, %o4
3: retl
mov %o2, %o0
2: retl
add %o2, %o3, %o0
.size __strncpy_from_user, .-__strncpy_from_user
.section .fixup,#alloc,#execinstr
.align 4
4: retl
mov -EFAULT, %o0
.section __ex_table,#alloc
.align 4
.word 60b, 4b
.word 61b, 4b
.word 62b, 4b
.word 63b, 4b
.word 64b, 4b
