1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * arch/alpha/lib/copy_user.S
4 *
5 * Copy to/from user space, handling exception
6 * isn't exactly pretty.
7 *
8 * This is essentially the same as "memcpy()",
9 * Notably, we have to make sure that $0 is al
10 * contains the right "bytes left to copy" val
11 * only _after_ a successful copy). There is a
12 * exception setup stuff..
13 */
14
15 #include <linux/export.h>
16
17 /* Allow an exception for an insn; exit if we
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)
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