1/* 2 * arch/alpha/lib/copy_user.S 3 * 4 * Copy to/from user space, handling exceptions as we go.. This 5 * isn't exactly pretty. 6 * 7 * This is essentially the same as "memcpy()", but with a few twists. 8 * Notably, we have to make sure that $0 is always up-to-date and 9 * contains the right "bytes left to copy" value (and that it is updated 10 * only _after_ a successful copy). There is also some rather minor 11 * exception setup stuff.. 12 */ 13 14#include <asm/export.h> 15 16/* Allow an exception for an insn; exit if we get one. */ 17#define EXI(x,y...) \ 18 99: x,##y; \ 19 .section __ex_table,"a"; \ 20 .long 99b - .; \ 21 lda $31, $exitin-99b($31); \ 22 .previous 23 24#define EXO(x,y...) \ 25 99: x,##y; \ 26 .section __ex_table,"a"; \ 27 .long 99b - .; \ 28 lda $31, $exitout-99b($31); \ 29 .previous 30 31 .set noat 32 .align 4 33 .globl __copy_user 34 .ent __copy_user 35__copy_user: 36 .prologue 0 37 and $18,$18,$0 38 and $16,7,$3 39 beq $0,$35 40 beq $3,$36 41 subq $3,8,$3 42 .align 4 43$37: 44 EXI( ldq_u $1,0($17) ) 45 EXO( ldq_u $2,0($16) ) 46 extbl $1,$17,$1 47 mskbl $2,$16,$2 48 insbl $1,$16,$1 49 addq $3,1,$3 50 bis $1,$2,$1 51 EXO( stq_u $1,0($16) ) 52 subq $0,1,$0 53 addq $16,1,$16 54 addq $17,1,$17 55 beq $0,$41 56 bne $3,$37 57$36: 58 and $17,7,$1 59 bic $0,7,$4 60 beq $1,$43 61 beq $4,$48 62 EXI( ldq_u $3,0($17) ) 63 .align 4 64$50: 65 EXI( ldq_u $2,8($17) ) 66 subq $4,8,$4 67 extql $3,$17,$3 68 extqh $2,$17,$1 69 bis $3,$1,$1 70 EXO( stq $1,0($16) ) 71 addq $17,8,$17 72 subq $0,8,$0 73 addq $16,8,$16 74 bis $2,$2,$3 75 bne $4,$50 76$48: 77 beq $0,$41 78 .align 4 79$57: 80 EXI( ldq_u $1,0($17) ) 81 EXO( ldq_u $2,0($16) ) 82 extbl $1,$17,$1 83 mskbl $2,$16,$2 84 insbl $1,$16,$1 85 bis $1,$2,$1 86 EXO( stq_u $1,0($16) ) 87 subq $0,1,$0 88 addq $16,1,$16 89 addq $17,1,$17 90 bne $0,$57 91 br $31,$41 92 .align 4 93$43: 94 beq $4,$65 95 .align 4 96$66: 97 EXI( ldq $1,0($17) ) 98 subq $4,8,$4 99 EXO( stq $1,0($16) ) 100 addq $17,8,$17 101 subq $0,8,$0 102 addq $16,8,$16 103 bne $4,$66 104$65: 105 beq $0,$41 106 EXI( ldq $2,0($17) ) 107 EXO( ldq $1,0($16) ) 108 mskql $2,$0,$2 109 mskqh $1,$0,$1 110 bis $2,$1,$2 111 EXO( stq $2,0($16) ) 112 bis $31,$31,$0 113$41: 114$35: 115$exitin: 116$exitout: 117 ret $31,($26),1 118 119 .end __copy_user 120EXPORT_SYMBOL(__copy_user) 121