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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/arch/arm/lib/io-writesb.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#include <linux/linkage.h>
11#include <asm/assembler.h>
12
13 .macro outword, rd
14#ifndef __ARMEB__
15 strb \rd, [r0]
16 mov \rd, \rd, lsr #8
17 strb \rd, [r0]
18 mov \rd, \rd, lsr #8
19 strb \rd, [r0]
20 mov \rd, \rd, lsr #8
21 strb \rd, [r0]
22#else
23 mov lr, \rd, lsr #24
24 strb lr, [r0]
25 mov lr, \rd, lsr #16
26 strb lr, [r0]
27 mov lr, \rd, lsr #8
28 strb lr, [r0]
29 strb \rd, [r0]
30#endif
31 .endm
32
33.outsb_align: rsb ip, ip, #4
34 cmp ip, r2
35 movgt ip, r2
36 cmp ip, #2
37 ldrb r3, [r1], #1
38 strb r3, [r0]
39 ldrgeb r3, [r1], #1
40 strgeb r3, [r0]
41 ldrgtb r3, [r1], #1
42 strgtb r3, [r0]
43 subs r2, r2, ip
44 bne .outsb_aligned
45
46ENTRY(__raw_writesb)
47 teq r2, #0 @ do we have to check for the zero len?
48 moveq pc, lr
49 ands ip, r1, #3
50 bne .outsb_align
51
52.outsb_aligned: stmfd sp!, {r4, r5, lr}
53
54 subs r2, r2, #16
55 bmi .outsb_no_16
56
57.outsb_16_lp: ldmia r1!, {r3, r4, r5, ip}
58 outword r3
59 outword r4
60 outword r5
61 outword ip
62 subs r2, r2, #16
63 bpl .outsb_16_lp
64
65 tst r2, #15
66 LOADREGS(eqfd, sp!, {r4, r5, pc})
67
68.outsb_no_16: tst r2, #8
69 beq .outsb_no_8
70
71 ldmia r1!, {r3, r4}
72 outword r3
73 outword r4
74
75.outsb_no_8: tst r2, #4
76 beq .outsb_no_4
77
78 ldr r3, [r1], #4
79 outword r3
80
81.outsb_no_4: ands r2, r2, #3
82 LOADREGS(eqfd, sp!, {r4, r5, pc})
83
84 cmp r2, #2
85 ldrb r3, [r1], #1
86 strb r3, [r0]
87 ldrgeb r3, [r1], #1
88 strgeb r3, [r0]
89 ldrgtb r3, [r1]
90 strgtb r3, [r0]
91
92 LOADREGS(fd, sp!, {r4, r5, pc})