tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1998, 1999, 2000 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 */
9#include <asm/asm.h>
10#include <asm/asm-offsets.h>
11#include <asm/regdef.h>
12
13#define EX(insn,reg,addr,handler) \
149: insn reg, addr; \
15 .section __ex_table,"a"; \
16 PTR 9b, handler; \
17 .previous
18
19 .macro f_fill64 dst, offset, val, fixup
20 EX(LONG_S, \val, (\offset + 0 * LONGSIZE)(\dst), \fixup)
21 EX(LONG_S, \val, (\offset + 1 * LONGSIZE)(\dst), \fixup)
22 EX(LONG_S, \val, (\offset + 2 * LONGSIZE)(\dst), \fixup)
23 EX(LONG_S, \val, (\offset + 3 * LONGSIZE)(\dst), \fixup)
24 EX(LONG_S, \val, (\offset + 4 * LONGSIZE)(\dst), \fixup)
25 EX(LONG_S, \val, (\offset + 5 * LONGSIZE)(\dst), \fixup)
26 EX(LONG_S, \val, (\offset + 6 * LONGSIZE)(\dst), \fixup)
27 EX(LONG_S, \val, (\offset + 7 * LONGSIZE)(\dst), \fixup)
28 EX(LONG_S, \val, (\offset + 8 * LONGSIZE)(\dst), \fixup)
29 EX(LONG_S, \val, (\offset + 9 * LONGSIZE)(\dst), \fixup)
30 EX(LONG_S, \val, (\offset + 10 * LONGSIZE)(\dst), \fixup)
31 EX(LONG_S, \val, (\offset + 11 * LONGSIZE)(\dst), \fixup)
32 EX(LONG_S, \val, (\offset + 12 * LONGSIZE)(\dst), \fixup)
33 EX(LONG_S, \val, (\offset + 13 * LONGSIZE)(\dst), \fixup)
34 EX(LONG_S, \val, (\offset + 14 * LONGSIZE)(\dst), \fixup)
35 EX(LONG_S, \val, (\offset + 15 * LONGSIZE)(\dst), \fixup)
36 .endm
37
38/*
39 * memset(void *s, int c, size_t n)
40 *
41 * a0: start of area to clear
42 * a1: char to fill with
43 * a2: size of area to clear
44 */
45 .set noreorder
46 .align 5
47LEAF(memset)
48 beqz a1, 1f
49 move v0, a0 /* result */
50
51 andi a1, 0xff /* spread fillword */
52 sll t1, a1, 8
53 or a1, t1
54 sll t1, a1, 16
55 or a1, t1
561:
57
58FEXPORT(__bzero)
59 sltiu t0, a2, LONGSIZE /* very small region? */
60 bnez t0, small_memset
61 andi t0, a0, LONGMASK /* aligned? */
62
63 beqz t0, 1f
64 PTR_SUBU t0, LONGSIZE /* alignment in bytes */
65
66#ifdef __MIPSEB__
67 EX(swl, a1, (a0), first_fixup) /* make word aligned */
68#endif
69#ifdef __MIPSEL__
70 EX(swr, a1, (a0), first_fixup) /* make word aligned */
71#endif
72 PTR_SUBU a0, t0 /* long align ptr */
73 PTR_ADDU a2, t0 /* correct size */
74
751: ori t1, a2, 0x3f /* # of full blocks */
76 xori t1, 0x3f
77 beqz t1, memset_partial /* no block to fill */
78 andi t0, a2, 0x3c
79
80 PTR_ADDU t1, a0 /* end address */
81 .set reorder
821: PTR_ADDIU a0, 64
83 f_fill64 a0, -64, a1, fwd_fixup
84 bne t1, a0, 1b
85 .set noreorder
86
87memset_partial:
88 PTR_LA t1, 2f /* where to start */
89 PTR_SUBU t1, t0
90 jr t1
91 PTR_ADDU a0, t0 /* dest ptr */
92
93 .set push
94 .set noreorder
95 .set nomacro
96 f_fill64 a0, -64, a1, partial_fixup /* ... but first do longs ... */
972: .set pop
98 andi a2, LONGMASK /* At most one long to go */
99
100 beqz a2, 1f
101 PTR_ADDU a0, a2 /* What's left */
102#ifdef __MIPSEB__
103 EX(swr, a1, -1(a0), last_fixup)
104#endif
105#ifdef __MIPSEL__
106 EX(swl, a1, -1(a0), last_fixup)
107#endif
1081: jr ra
109 move a2, zero
110
111small_memset:
112 beqz a2, 2f
113 PTR_ADDU t1, a0, a2
114
1151: PTR_ADDIU a0, 1 /* fill bytewise */
116 bne t1, a0, 1b
117 sb a1, -1(a0)
118
1192: jr ra /* done */
120 move a2, zero
121 END(memset)
122
123first_fixup:
124 jr ra
125 nop
126
127fwd_fixup:
128 PTR_L t0, TI_TASK($28)
129 LONG_L t0, THREAD_BUADDR(t0)
130 andi a2, 0x3f
131 LONG_ADDU a2, t1
132 jr ra
133 LONG_SUBU a2, t0
134
135partial_fixup:
136 PTR_L t0, TI_TASK($28)
137 LONG_L t0, THREAD_BUADDR(t0)
138 andi a2, LONGMASK
139 LONG_ADDU a2, t1
140 jr ra
141 LONG_SUBU a2, t0
142
143last_fixup:
144 jr ra
145 andi v1, a2, LONGMASK