/* SPDX-License-Identifier: GPL-2.0 */ | |
/* | |
* arch/alpha/lib/copy_user.S | |
* | |
* Copy to/from user space, handling exceptions as we go.. This | |
* isn't exactly pretty. | |
* | |
* This is essentially the same as "memcpy()", but with a few twists. | |
* Notably, we have to make sure that $0 is always up-to-date and | |
* contains the right "bytes left to copy" value (and that it is updated | |
* only _after_ a successful copy). There is also some rather minor | |
* exception setup stuff.. | |
*/ | |
#include <asm/export.h> | |
/* Allow an exception for an insn; exit if we get one. */ | |
#define EXI(x,y...) \ | |
99: x,##y; \ | |
.section __ex_table,"a"; \ | |
.long 99b - .; \ | |
lda $31, $exitin-99b($31); \ | |
.previous | |
#define EXO(x,y...) \ | |
99: x,##y; \ | |
.section __ex_table,"a"; \ | |
.long 99b - .; \ | |
lda $31, $exitout-99b($31); \ | |
.previous | |
.set noat | |
.align 4 | |
.globl __copy_user | |
.ent __copy_user | |
__copy_user: | |
.prologue 0 | |
mov $18,$0 | |
and $16,7,$3 | |
beq $0,$35 | |
beq $3,$36 | |
subq $3,8,$3 | |
.align 4 | |
$37: | |
EXI( ldq_u $1,0($17) ) | |
EXO( ldq_u $2,0($16) ) | |
extbl $1,$17,$1 | |
mskbl $2,$16,$2 | |
insbl $1,$16,$1 | |
addq $3,1,$3 | |
bis $1,$2,$1 | |
EXO( stq_u $1,0($16) ) | |
subq $0,1,$0 | |
addq $16,1,$16 | |
addq $17,1,$17 | |
beq $0,$41 | |
bne $3,$37 | |
$36: | |
and $17,7,$1 | |
bic $0,7,$4 | |
beq $1,$43 | |
beq $4,$48 | |
EXI( ldq_u $3,0($17) ) | |
.align 4 | |
$50: | |
EXI( ldq_u $2,8($17) ) | |
subq $4,8,$4 | |
extql $3,$17,$3 | |
extqh $2,$17,$1 | |
bis $3,$1,$1 | |
EXO( stq $1,0($16) ) | |
addq $17,8,$17 | |
subq $0,8,$0 | |
addq $16,8,$16 | |
bis $2,$2,$3 | |
bne $4,$50 | |
$48: | |
beq $0,$41 | |
.align 4 | |
$57: | |
EXI( ldq_u $1,0($17) ) | |
EXO( ldq_u $2,0($16) ) | |
extbl $1,$17,$1 | |
mskbl $2,$16,$2 | |
insbl $1,$16,$1 | |
bis $1,$2,$1 | |
EXO( stq_u $1,0($16) ) | |
subq $0,1,$0 | |
addq $16,1,$16 | |
addq $17,1,$17 | |
bne $0,$57 | |
br $31,$41 | |
.align 4 | |
$43: | |
beq $4,$65 | |
.align 4 | |
$66: | |
EXI( ldq $1,0($17) ) | |
subq $4,8,$4 | |
EXO( stq $1,0($16) ) | |
addq $17,8,$17 | |
subq $0,8,$0 | |
addq $16,8,$16 | |
bne $4,$66 | |
$65: | |
beq $0,$41 | |
EXI( ldq $2,0($17) ) | |
EXO( ldq $1,0($16) ) | |
mskql $2,$0,$2 | |
mskqh $1,$0,$1 | |
bis $2,$1,$2 | |
EXO( stq $2,0($16) ) | |
bis $31,$31,$0 | |
$41: | |
$35: | |
$exitin: | |
$exitout: | |
ret $31,($26),1 | |
.end __copy_user | |
EXPORT_SYMBOL(__copy_user) |