Book a Demo!
CoCalc Logo Icon
StoreFeaturesDocsShareSupportNewsAboutPoliciesSign UpSign In
torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/loongarch/lib/memset.S
26436 views
1
/* SPDX-License-Identifier: GPL-2.0 */

2
/*

3
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited

4
 */

5


6
#include <linux/export.h>

7
#include <asm/alternative-asm.h>

8
#include <asm/asm.h>

9
#include <asm/asmmacro.h>

10
#include <asm/cpu.h>

11
#include <asm/regdef.h>

12
#include <asm/unwind_hints.h>

13


14
.macro fill_to_64 r0

15
	bstrins.d \r0, \r0, 15, 8

16
	bstrins.d \r0, \r0, 31, 16

17
	bstrins.d \r0, \r0, 63, 32

18
.endm

19


20
.section .noinstr.text, "ax"

21


22
SYM_FUNC_START(memset)

23
	/*

24
	 * Some CPUs support hardware unaligned access

25
	 */

26
	ALTERNATIVE	"b __memset_generic", \

27
			"b __memset_fast", CPU_FEATURE_UAL

28
SYM_FUNC_END(memset)

29
SYM_FUNC_ALIAS(__memset, memset)

30


31
EXPORT_SYMBOL(memset)

32
EXPORT_SYMBOL(__memset)

33


34
_ASM_NOKPROBE(memset)

35
_ASM_NOKPROBE(__memset)

36


37
/*

38
 * void *__memset_generic(void *s, int c, size_t n)

39
 *

40
 * a0: s

41
 * a1: c

42
 * a2: n

43
 */

44
SYM_FUNC_START(__memset_generic)

45
	move	a3, a0

46
	beqz	a2, 2f

47


48
1:	st.b	a1, a0, 0

49
	addi.d	a0, a0, 1

50
	addi.d	a2, a2, -1

51
	bgt	a2, zero, 1b

52


53
2:	move	a0, a3

54
	jr	ra

55
SYM_FUNC_END(__memset_generic)

56
_ASM_NOKPROBE(__memset_generic)

57


58
/*

59
 * void *__memset_fast(void *s, int c, size_t n)

60
 *

61
 * a0: s

62
 * a1: c

63
 * a2: n

64
 */

65
SYM_FUNC_START(__memset_fast)

66
	/* fill a1 to 64 bits */

67
	fill_to_64 a1

68


69
	sltui	t0, a2, 9

70
	bnez	t0, .Lsmall

71


72
	add.d	a2, a0, a2

73
	st.d	a1, a0, 0

74


75
	/* align up address */

76
	addi.d	a3, a0, 8

77
	bstrins.d	a3, zero, 2, 0

78


79
	addi.d	a4, a2, -64

80
	bgeu	a3, a4, .Llt64

81


82
	/* set 64 bytes at a time */

83
.Lloop64:

84
	st.d	a1, a3, 0

85
	st.d	a1, a3, 8

86
	st.d	a1, a3, 16

87
	st.d	a1, a3, 24

88
	st.d	a1, a3, 32

89
	st.d	a1, a3, 40

90
	st.d	a1, a3, 48

91
	st.d	a1, a3, 56

92
	addi.d	a3, a3, 64

93
	bltu	a3, a4, .Lloop64

94


95
	/* set the remaining bytes */

96
.Llt64:

97
	addi.d	a4, a2, -32

98
	bgeu	a3, a4, .Llt32

99
	st.d	a1, a3, 0

100
	st.d	a1, a3, 8

101
	st.d	a1, a3, 16

102
	st.d	a1, a3, 24

103
	addi.d	a3, a3, 32

104


105
.Llt32:

106
	addi.d	a4, a2, -16

107
	bgeu	a3, a4, .Llt16

108
	st.d	a1, a3, 0

109
	st.d	a1, a3, 8

110
	addi.d	a3, a3, 16

111


112
.Llt16:

113
	addi.d	a4, a2, -8

114
	bgeu	a3, a4, .Llt8

115
	st.d	a1, a3, 0

116


117
.Llt8:

118
	st.d	a1, a2, -8

119


120
	/* return */

121
	jr	ra

122


123
	.align	4

124
.Lsmall:

125
	pcaddi	t0, 4

126
	slli.d	a2, a2, 4

127
	add.d	t0, t0, a2

128
	jr	t0

129


130
	.align	4

131
0:	jr	ra

132


133
	.align	4

134
1:	st.b	a1, a0, 0

135
	jr	ra

136


137
	.align	4

138
2:	st.h	a1, a0, 0

139
	jr	ra

140


141
	.align	4

142
3:	st.h	a1, a0, 0

143
	st.b	a1, a0, 2

144
	jr	ra

145


146
	.align	4

147
4:	st.w	a1, a0, 0

148
	jr	ra

149


150
	.align	4

151
5:	st.w	a1, a0, 0

152
	st.b	a1, a0, 4

153
	jr	ra

154


155
	.align	4

156
6:	st.w	a1, a0, 0

157
	st.h	a1, a0, 4

158
	jr	ra

159


160
	.align	4

161
7:	st.w	a1, a0, 0

162
	st.w	a1, a0, 3

163
	jr	ra

164


165
	.align	4

166
8:	st.d	a1, a0, 0

167
	jr	ra

168
SYM_FUNC_END(__memset_fast)

169
_ASM_NOKPROBE(__memset_fast)

170


171
STACK_FRAME_NON_STANDARD __memset_fast

172


173