diff options
Diffstat (limited to 'arch/alpha/lib/copy_user.S')
-rw-r--r-- | arch/alpha/lib/copy_user.S | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/arch/alpha/lib/copy_user.S b/arch/alpha/lib/copy_user.S new file mode 100644 index 0000000000..ef18faafca --- /dev/null +++ b/arch/alpha/lib/copy_user.S @@ -0,0 +1,121 @@ +/* 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 <linux/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) |