1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /* 3 * arch/alpha/lib/copy_user.S 4 * 5 * Copy to/from user space, handling exceptions as we go.. This 6 * isn't exactly pretty. 7 * 8 * This is essentially the same as "memcpy()", but with a few twists. 9 * Notably, we have to make sure that $0 is always up-to-date and 10 * contains the right "bytes left to copy" value (and that it is updated 11 * only _after_ a successful copy). There is also some rather minor 12 * exception setup stuff.. 13 */ 14 15 #include <asm/export.h> 16 17 /* Allow an exception for an insn; exit if we get one. */ 18 #define EXI(x,y...) \ 19 99: x,##y; \ 20 .section __ex_table,"a"; \ 21 .long 99b - .; \ 22 lda $31, $exitin-99b($31); \ 23 .previous 24 25 #define EXO(x,y...) \ 26 99: x,##y; \ 27 .section __ex_table,"a"; \ 28 .long 99b - .; \ 29 lda $31, $exitout-99b($31); \ 30 .previous 31 32 .set noat 33 .align 4 34 .globl __copy_user 35 .ent __copy_user 36 __copy_user: 37 .prologue 0 38 mov $18,$0 39 and $16,7,$3 40 beq $0,$35 41 beq $3,$36 42 subq $3,8,$3 43 .align 4 44 $37: 45 EXI( ldq_u $1,0($17) ) 46 EXO( ldq_u $2,0($16) ) 47 extbl $1,$17,$1 48 mskbl $2,$16,$2 49 insbl $1,$16,$1 50 addq $3,1,$3 51 bis $1,$2,$1 52 EXO( stq_u $1,0($16) ) 53 subq $0,1,$0 54 addq $16,1,$16 55 addq $17,1,$17 56 beq $0,$41 57 bne $3,$37 58 $36: 59 and $17,7,$1 60 bic $0,7,$4 61 beq $1,$43 62 beq $4,$48 63 EXI( ldq_u $3,0($17) ) 64 .align 4 65 $50: 66 EXI( ldq_u $2,8($17) ) 67 subq $4,8,$4 68 extql $3,$17,$3 69 extqh $2,$17,$1 70 bis $3,$1,$1 71 EXO( stq $1,0($16) ) 72 addq $17,8,$17 73 subq $0,8,$0 74 addq $16,8,$16 75 bis $2,$2,$3 76 bne $4,$50 77 $48: 78 beq $0,$41 79 .align 4 80 $57: 81 EXI( ldq_u $1,0($17) ) 82 EXO( ldq_u $2,0($16) ) 83 extbl $1,$17,$1 84 mskbl $2,$16,$2 85 insbl $1,$16,$1 86 bis $1,$2,$1 87 EXO( stq_u $1,0($16) ) 88 subq $0,1,$0 89 addq $16,1,$16 90 addq $17,1,$17 91 bne $0,$57 92 br $31,$41 93 .align 4 94 $43: 95 beq $4,$65 96 .align 4 97 $66: 98 EXI( ldq $1,0($17) ) 99 subq $4,8,$4 100 EXO( stq $1,0($16) ) 101 addq $17,8,$17 102 subq $0,8,$0 103 addq $16,8,$16 104 bne $4,$66 105 $65: 106 beq $0,$41 107 EXI( ldq $2,0($17) ) 108 EXO( ldq $1,0($16) ) 109 mskql $2,$0,$2 110 mskqh $1,$0,$1 111 bis $2,$1,$2 112 EXO( stq $2,0($16) ) 113 bis $31,$31,$0 114 $41: 115 $35: 116 $exitin: 117 $exitout: 118 ret $31,($26),1 119 120 .end __copy_user 121 EXPORT_SYMBOL(__copy_user) 122