/* SPDX-License-Identifier: GPL-2.0 *//* * arch/alpha/lib/clear_user.S * Contributed by Richard Henderson <rth@tamu.edu> * * Zero user space, handling exceptions as we go. * * We have to make sure that $0 is always up-to-date and contains the * right "bytes left to zero" value (and that it is updated only _after_ * a successful copy). There is also some rather minor exception setup * stuff. */#include <linux/export.h> /* Allow an exception for an insn; exit if we get one. */#define EX(x,y...) \ 99: x,##y; \ .section __ex_table,"a"; \ .long 99b - .; \ lda $31, $exception-99b($31); \ .previous .set noat .set noreorder .align 4 .globl __clear_user .ent __clear_user .frame $30, 0, $26 .prologue 0 $loop: and $1, 3, $4 # e0 : beq $4, 1f # .. e1 : 0: EX( stq_u $31, 0($16) ) # e0 : zero one word subq $0, 8, $0 # .. e1 : subq $4, 1, $4 # e0 : addq $16, 8, $16 # .. e1 : bne $4, 0b # e1 : unop # : 1: bic $1, 3, $1 # e0 : beq $1, $tail # .. e1 : 2: EX( stq_u $31, 0($16) ) # e0 : zero four words subq $0, 8, $0 # .. e1 : EX( stq_u $31, 8($16) ) # e0 : subq $0, 8, $0 # .. e1 : EX( stq_u $31, 16($16) ) # e0 : subq $0, 8, $0 # .. e1 : EX( stq_u $31, 24($16) ) # e0 : subq $0, 8, $0 # .. e1 : subq $1, 4, $1 # e0 : addq $16, 32, $16 # .. e1 : bne $1, 2b # e1 : $tail: bne $2, 1f # e1 : is there a tail to do? ret $31, ($26), 1 # .. e1 : 1: EX( ldq_u $5, 0($16) ) # e0 : clr $0 # .. e1 : nop # e1 : mskqh $5, $0, $5 # e0 : EX( stq_u $5, 0($16) ) # e0 : ret $31, ($26), 1 # .. e1 : __clear_user: and $17, $17, $0 and $16, 7, $4 # e0 : find dest misalignment beq $0, $zerolength # .. e1 : addq $0, $4, $1 # e0 : bias counter and $1, 7, $2 # e1 : number of bytes in tail srl $1, 3, $1 # e0 : beq $4, $loop # .. e1 : EX( ldq_u $5, 0($16) ) # e0 : load dst word to mask back in beq $1, $oneword # .. e1 : sub-word store? mskql $5, $16, $5 # e0 : take care of misaligned head addq $16, 8, $16 # .. e1 : EX( stq_u $5, -8($16) ) # e0 : addq $0, $4, $0 # .. e1 : bytes left -= 8 - misalignment subq $1, 1, $1 # e0 : subq $0, 8, $0 # .. e1 : br $loop # e1 : unop # : $oneword: mskql $5, $16, $4 # e0 : mskqh $5, $2, $5 # e0 : or $5, $4, $5 # e1 : EX( stq_u $5, 0($16) ) # e0 : clr $0 # .. e1 : $zerolength:$exception: ret $31, ($26), 1 # .. e1 : .end __clear_user EXPORT_SYMBOL(__clear_user)
/* SPDX-License-Identifier: GPL-2.0 */
/*
* arch/alpha/lib/clear_user.S
* Contributed by Richard Henderson <rth@tamu.edu>
*
* Zero user space, handling exceptions as we go.
*
* We have to make sure that $0 is always up-to-date and contains the
* right "bytes left to zero" value (and that it is updated only _after_
* a successful copy). There is also some rather minor exception setup
* stuff.
*/
#include <linux/export.h>
/* Allow an exception for an insn; exit if we get one. */
#define EX(x,y...) \
99: x,##y; \
.section __ex_table,"a"; \
.long 99b - .; \
lda $31, $exception-99b($31); \
.previous
.set noat
.set noreorder
.align 4
.globl __clear_user
.ent __clear_user
.frame $30, 0, $26
.prologue 0
$loop:
and $1, 3, $4 # e0 :
beq $4, 1f # .. e1 :
0: EX( stq_u $31, 0($16) ) # e0 : zero one word
subq $0, 8, $0 # .. e1 :
subq $4, 1, $4 # e0 :
addq $16, 8, $16 # .. e1 :
bne $4, 0b # e1 :
unop # :
1: bic $1, 3, $1 # e0 :
beq $1, $tail # .. e1 :
2: EX( stq_u $31, 0($16) ) # e0 : zero four words
subq $0, 8, $0 # .. e1 :
EX( stq_u $31, 8($16) ) # e0 :
subq $0, 8, $0 # .. e1 :
EX( stq_u $31, 16($16) ) # e0 :
subq $0, 8, $0 # .. e1 :
EX( stq_u $31, 24($16) ) # e0 :
subq $0, 8, $0 # .. e1 :
subq $1, 4, $1 # e0 :
addq $16, 32, $16 # .. e1 :
bne $1, 2b # e1 :
$tail:
bne $2, 1f # e1 : is there a tail to do?
ret $31, ($26), 1 # .. e1 :
1: EX( ldq_u $5, 0($16) ) # e0 :
clr $0 # .. e1 :
nop # e1 :
mskqh $5, $0, $5 # e0 :
EX( stq_u $5, 0($16) ) # e0 :
ret $31, ($26), 1 # .. e1 :
__clear_user:
and $17, $17, $0
and $16, 7, $4 # e0 : find dest misalignment
beq $0, $zerolength # .. e1 :
addq $0, $4, $1 # e0 : bias counter
and $1, 7, $2 # e1 : number of bytes in tail
srl $1, 3, $1 # e0 :
beq $4, $loop # .. e1 :
EX( ldq_u $5, 0($16) ) # e0 : load dst word to mask back in
beq $1, $oneword # .. e1 : sub-word store?
mskql $5, $16, $5 # e0 : take care of misaligned head
addq $16, 8, $16 # .. e1 :
EX( stq_u $5, -8($16) ) # e0 :
addq $0, $4, $0 # .. e1 : bytes left -= 8 - misalignment
subq $1, 1, $1 # e0 :
subq $0, 8, $0 # .. e1 :
br $loop # e1 :
unop # :
$oneword:
mskql $5, $16, $4 # e0 :
mskqh $5, $2, $5 # e0 :
or $5, $4, $5 # e1 :
EX( stq_u $5, 0($16) ) # e0 :
clr $0 # .. e1 :
$zerolength:
$exception:
ret $31, ($26), 1 # .. e1 :
.end __clear_user
EXPORT_SYMBOL(__clear_user)