summaryrefslogtreecommitdiffstats
path: root/arch/mips/lib/memset.S
blob: 3bf38422342f3a882fafb4cfe370b97106a56c65 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1998, 1999, 2000 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2007  Maciej W. Rozycki
 */
#include <asm/asm.h>
#include <asm/asm-offsets.h>
#include <asm/regdef.h>

#if LONGSIZE == 4
#define LONG_S_L swl
#define LONG_S_R swr
#else
#define LONG_S_L sdl
#define LONG_S_R sdr
#endif

#define EX(insn,reg,addr,handler)			\
9:	insn	reg, addr;				\
	.section __ex_table,"a"; 			\
	PTR	9b, handler; 				\
	.previous

	.macro	f_fill64 dst, offset, val, fixup
	EX(LONG_S, \val, (\offset +  0 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  1 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  2 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  3 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  4 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  5 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  6 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  7 * LONGSIZE)(\dst), \fixup)
#if LONGSIZE == 4
	EX(LONG_S, \val, (\offset +  8 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset +  9 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset + 10 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset + 11 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset + 12 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset + 13 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset + 14 * LONGSIZE)(\dst), \fixup)
	EX(LONG_S, \val, (\offset + 15 * LONGSIZE)(\dst), \fixup)
#endif
	.endm

/*
 * memset(void *s, int c, size_t n)
 *
 * a0: start of area to clear
 * a1: char to fill with
 * a2: size of area to clear
 */
	.set	noreorder
	.align	5
LEAF(memset)
	beqz		a1, 1f
	 move		v0, a0			/* result */

	andi		a1, 0xff		/* spread fillword */
	LONG_SLL		t1, a1, 8
	or		a1, t1
	LONG_SLL		t1, a1, 16
#if LONGSIZE == 8
	or		a1, t1
	LONG_SLL		t1, a1, 32
#endif
	or		a1, t1
1:

FEXPORT(__bzero)
	sltiu		t0, a2, LONGSIZE	/* very small region? */
	bnez		t0, small_memset
	 andi		t0, a0, LONGMASK	/* aligned? */

#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
	beqz		t0, 1f
	 PTR_SUBU	t0, LONGSIZE		/* alignment in bytes */
#else
	.set		noat
	li		AT, LONGSIZE
	beqz		t0, 1f
	 PTR_SUBU	t0, AT			/* alignment in bytes */
	.set		at
#endif

#ifdef __MIPSEB__
	EX(LONG_S_L, a1, (a0), first_fixup)	/* make word/dword aligned */
#endif
#ifdef __MIPSEL__
	EX(LONG_S_R, a1, (a0), first_fixup)	/* make word/dword aligned */
#endif
	PTR_SUBU	a0, t0			/* long align ptr */
	PTR_ADDU	a2, t0			/* correct size */

1:	ori		t1, a2, 0x3f		/* # of full blocks */
	xori		t1, 0x3f
	beqz		t1, memset_partial	/* no block to fill */
	 andi		t0, a2, 0x40-LONGSIZE

	PTR_ADDU	t1, a0			/* end address */
	.set		reorder
1:	PTR_ADDIU	a0, 64
	f_fill64 a0, -64, a1, fwd_fixup
	bne		t1, a0, 1b
	.set		noreorder

memset_partial:
	PTR_LA		t1, 2f			/* where to start */
#if LONGSIZE == 4
	PTR_SUBU	t1, t0
#else
	.set		noat
	LONG_SRL		AT, t0, 1
	PTR_SUBU	t1, AT
	.set		at
#endif
	jr		t1
	 PTR_ADDU	a0, t0			/* dest ptr */

	.set		push
	.set		noreorder
	.set		nomacro
	f_fill64 a0, -64, a1, partial_fixup	/* ... but first do longs ... */
2:	.set		pop
	andi		a2, LONGMASK		/* At most one long to go */

	beqz		a2, 1f
	 PTR_ADDU	a0, a2			/* What's left */
#ifdef __MIPSEB__
	EX(LONG_S_R, a1, -1(a0), last_fixup)
#endif
#ifdef __MIPSEL__
	EX(LONG_S_L, a1, -1(a0), last_fixup)
#endif
1:	jr		ra
	 move		a2, zero

small_memset:
	beqz		a2, 2f
	 PTR_ADDU	t1, a0, a2

1:	PTR_ADDIU	a0, 1			/* fill bytewise */
	bne		t1, a0, 1b
	 sb		a1, -1(a0)

2:	jr		ra			/* done */
	 move		a2, zero
	END(memset)

first_fixup:
	jr	ra
	 nop

fwd_fixup:
	PTR_L		t0, TI_TASK($28)
	LONG_L		t0, THREAD_BUADDR(t0)
	andi		a2, 0x3f
	LONG_ADDU	a2, t1
	jr		ra
	 LONG_SUBU	a2, t0

partial_fixup:
	PTR_L		t0, TI_TASK($28)
	LONG_L		t0, THREAD_BUADDR(t0)
	andi		a2, LONGMASK
	LONG_ADDU	a2, t1
	jr		ra
	 LONG_SUBU	a2, t0

last_fixup:
	jr		ra
	 andi		v1, a2, LONGMASK