]> git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - arch/arm/lib/memset.S
Merge tag 'armsoc-defconfig' of git://git.kernel.org/pub/scm/linux/kernel/git/arm...
[mirror_ubuntu-jammy-kernel.git] / arch / arm / lib / memset.S
1 /*
2 * linux/arch/arm/lib/memset.S
3 *
4 * Copyright (C) 1995-2000 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * ASM optimised string functions
11 */
12 #include <linux/linkage.h>
13 #include <asm/assembler.h>
14 #include <asm/unwind.h>
15
16 .text
17 .align 5
18
19 ENTRY(mmioset)
20 ENTRY(memset)
21 UNWIND( .fnstart )
22 ands r3, r0, #3 @ 1 unaligned?
23 mov ip, r0 @ preserve r0 as return value
24 bne 6f @ 1
25 /*
26 * we know that the pointer in ip is aligned to a word boundary.
27 */
28 1: orr r1, r1, r1, lsl #8
29 orr r1, r1, r1, lsl #16
30 mov r3, r1
31 cmp r2, #16
32 blt 4f
33
34 #if ! CALGN(1)+0
35
36 /*
37 * We need 2 extra registers for this loop - use r8 and the LR
38 */
39 stmfd sp!, {r8, lr}
40 UNWIND( .fnend )
41 UNWIND( .fnstart )
42 UNWIND( .save {r8, lr} )
43 mov r8, r1
44 mov lr, r1
45
46 2: subs r2, r2, #64
47 stmgeia ip!, {r1, r3, r8, lr} @ 64 bytes at a time.
48 stmgeia ip!, {r1, r3, r8, lr}
49 stmgeia ip!, {r1, r3, r8, lr}
50 stmgeia ip!, {r1, r3, r8, lr}
51 bgt 2b
52 ldmeqfd sp!, {r8, pc} @ Now <64 bytes to go.
53 /*
54 * No need to correct the count; we're only testing bits from now on
55 */
56 tst r2, #32
57 stmneia ip!, {r1, r3, r8, lr}
58 stmneia ip!, {r1, r3, r8, lr}
59 tst r2, #16
60 stmneia ip!, {r1, r3, r8, lr}
61 ldmfd sp!, {r8, lr}
62 UNWIND( .fnend )
63
64 #else
65
66 /*
67 * This version aligns the destination pointer in order to write
68 * whole cache lines at once.
69 */
70
71 stmfd sp!, {r4-r8, lr}
72 UNWIND( .fnend )
73 UNWIND( .fnstart )
74 UNWIND( .save {r4-r8, lr} )
75 mov r4, r1
76 mov r5, r1
77 mov r6, r1
78 mov r7, r1
79 mov r8, r1
80 mov lr, r1
81
82 cmp r2, #96
83 tstgt ip, #31
84 ble 3f
85
86 and r8, ip, #31
87 rsb r8, r8, #32
88 sub r2, r2, r8
89 movs r8, r8, lsl #(32 - 4)
90 stmcsia ip!, {r4, r5, r6, r7}
91 stmmiia ip!, {r4, r5}
92 tst r8, #(1 << 30)
93 mov r8, r1
94 strne r1, [ip], #4
95
96 3: subs r2, r2, #64
97 stmgeia ip!, {r1, r3-r8, lr}
98 stmgeia ip!, {r1, r3-r8, lr}
99 bgt 3b
100 ldmeqfd sp!, {r4-r8, pc}
101
102 tst r2, #32
103 stmneia ip!, {r1, r3-r8, lr}
104 tst r2, #16
105 stmneia ip!, {r4-r7}
106 ldmfd sp!, {r4-r8, lr}
107 UNWIND( .fnend )
108
109 #endif
110
111 UNWIND( .fnstart )
112 4: tst r2, #8
113 stmneia ip!, {r1, r3}
114 tst r2, #4
115 strne r1, [ip], #4
116 /*
117 * When we get here, we've got less than 4 bytes to zero. We
118 * may have an unaligned pointer as well.
119 */
120 5: tst r2, #2
121 strneb r1, [ip], #1
122 strneb r1, [ip], #1
123 tst r2, #1
124 strneb r1, [ip], #1
125 ret lr
126
127 6: subs r2, r2, #4 @ 1 do we have enough
128 blt 5b @ 1 bytes to align with?
129 cmp r3, #2 @ 1
130 strltb r1, [ip], #1 @ 1
131 strleb r1, [ip], #1 @ 1
132 strb r1, [ip], #1 @ 1
133 add r2, r2, r3 @ 1 (r2 = r2 - (4 - r3))
134 b 1b
135 UNWIND( .fnend )
136 ENDPROC(memset)
137 ENDPROC(mmioset)