1/* SPDX-License-Identifier: GPL-2.0 */
2/* linux/arch/sparc/lib/memset.S: Sparc optimized memset, bzero and clear_user code
3 * Copyright (C) 1991,1996 Free Software Foundation
4 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 *
7 * Calls to memset returns initial %o0. Calls to bzero returns 0, if ok, and
8 * number of bytes not yet set if exception occurs and we were called as
9 * clear_user.
10 */
11
12#include <linux/export.h>
13#include <asm/ptrace.h>
14
15/* Work around cpp -rob */
16#define ALLOC #alloc
17#define EXECINSTR #execinstr
18#define EX(x,y,a,b) \
1998: x,y; \
20 .section .fixup,ALLOC,EXECINSTR; \
21 .align 4; \
2299: retl; \
23 a, b, %o0; \
24 .section __ex_table,ALLOC; \
25 .align 4; \
26 .word 98b, 99b; \
27 .text; \
28 .align 4
29
30#define STORE(source, base, offset, n) \
3198: std source, [base + offset + n]; \
32 .section .fixup,ALLOC,EXECINSTR; \
33 .align 4; \
3499: ba 30f; \
35 sub %o3, n - offset, %o3; \
36 .section __ex_table,ALLOC; \
37 .align 4; \
38 .word 98b, 99b; \
39 .text; \
40 .align 4;
41
42#define STORE_LAST(source, base, offset, n) \
43 EX(std source, [base - offset - n], \
44 add %o1, offset + n);
45
46/* Please don't change these macros, unless you change the logic
47 * in the .fixup section below as well.
48 * Store 64 bytes at (BASE + OFFSET) using value SOURCE. */
49#define ZERO_BIG_BLOCK(base, offset, source) \
50 STORE(source, base, offset, 0x00); \
51 STORE(source, base, offset, 0x08); \
52 STORE(source, base, offset, 0x10); \
53 STORE(source, base, offset, 0x18); \
54 STORE(source, base, offset, 0x20); \
55 STORE(source, base, offset, 0x28); \
56 STORE(source, base, offset, 0x30); \
57 STORE(source, base, offset, 0x38);
58
59#define ZERO_LAST_BLOCKS(base, offset, source) \
60 STORE_LAST(source, base, offset, 0x38); \
61 STORE_LAST(source, base, offset, 0x30); \
62 STORE_LAST(source, base, offset, 0x28); \
63 STORE_LAST(source, base, offset, 0x20); \
64 STORE_LAST(source, base, offset, 0x18); \
65 STORE_LAST(source, base, offset, 0x10); \
66 STORE_LAST(source, base, offset, 0x08); \
67 STORE_LAST(source, base, offset, 0x00);
68
69 .text
70 .align 4
71
72 .globl __bzero_begin
73__bzero_begin:
74
75 .globl __bzero
76 .type __bzero,#function
77 .globl memset
78 EXPORT_SYMBOL(__bzero)
79 EXPORT_SYMBOL(memset)
80memset:
81 mov %o0, %g1
82 mov 1, %g4
83 and %o1, 0xff, %g3
84 sll %g3, 8, %g2
85 or %g3, %g2, %g3
86 sll %g3, 16, %g2
87 or %g3, %g2, %g3
88 b 1f
89 mov %o2, %o1
903:
91 cmp %o2, 3
92 be 2f
93 EX(stb %g3, [%o0], sub %o1, 0)
94
95 cmp %o2, 2
96 be 2f
97 EX(stb %g3, [%o0 + 0x01], sub %o1, 1)
98
99 EX(stb %g3, [%o0 + 0x02], sub %o1, 2)
1002:
101 sub %o2, 4, %o2
102 add %o1, %o2, %o1
103 b 4f
104 sub %o0, %o2, %o0
105
106__bzero:
107 clr %g4
108 mov %g0, %g3
1091:
110 cmp %o1, 7
111 bleu 7f
112 andcc %o0, 3, %o2
113
114 bne 3b
1154:
116 andcc %o0, 4, %g0
117
118 be 2f
119 mov %g3, %g2
120
121 EX(st %g3, [%o0], sub %o1, 0)
122 sub %o1, 4, %o1
123 add %o0, 4, %o0
1242:
125 andcc %o1, 0xffffff80, %o3 ! Now everything is 8 aligned and o1 is len to run
126 be 9f
127 andcc %o1, 0x78, %o2
12810:
129 ZERO_BIG_BLOCK(%o0, 0x00, %g2)
130 subcc %o3, 128, %o3
131 ZERO_BIG_BLOCK(%o0, 0x40, %g2)
132 bne 10b
133 add %o0, 128, %o0
134
135 orcc %o2, %g0, %g0
1369:
137 be 13f
138 andcc %o1, 7, %o1
139
140 srl %o2, 1, %o3
141 set 13f, %o4
142 sub %o4, %o3, %o4
143 jmp %o4
144 add %o0, %o2, %o0
145
146 ZERO_LAST_BLOCKS(%o0, 0x48, %g2)
147 ZERO_LAST_BLOCKS(%o0, 0x08, %g2)
14813:
149 be 8f
150 andcc %o1, 4, %g0
151
152 be 1f
153 andcc %o1, 2, %g0
154
155 EX(st %g3, [%o0], and %o1, 7)
156 add %o0, 4, %o0
1571:
158 be 1f
159 andcc %o1, 1, %g0
160
161 EX(sth %g3, [%o0], and %o1, 3)
162 add %o0, 2, %o0
1631:
164 bne,a 8f
165 EX(stb %g3, [%o0], and %o1, 1)
1668:
167 b 0f
168 nop
1697:
170 be 13b
171 orcc %o1, 0, %g0
172
173 be 0f
1748:
175 add %o0, 1, %o0
176 subcc %o1, 1, %o1
177 bne 8b
178 EX(stb %g3, [%o0 - 1], add %o1, 1)
1790:
180 andcc %g4, 1, %g0
181 be 5f
182 nop
183 retl
184 mov %g1, %o0
1855:
186 retl
187 clr %o0
188
189 .section .fixup,#alloc,#execinstr
190 .align 4
19130:
192 and %o1, 0x7f, %o1
193 retl
194 add %o3, %o1, %o0
195
196 .globl __bzero_end
197__bzero_end:
198

source code of linux/arch/sparc/lib/memset.S