diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm26/lib/findbit.S |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/arm26/lib/findbit.S')
-rw-r--r-- | arch/arm26/lib/findbit.S | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/arch/arm26/lib/findbit.S b/arch/arm26/lib/findbit.S new file mode 100644 index 000000000000..26f67cccc37c --- /dev/null +++ b/arch/arm26/lib/findbit.S | |||
@@ -0,0 +1,67 @@ | |||
1 | /* | ||
2 | * linux/arch/arm/lib/findbit.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 | * 16th March 2001 - John Ripley <jripley@sonicblue.com> | ||
11 | * Fixed so that "size" is an exclusive not an inclusive quantity. | ||
12 | * All users of these functions expect exclusive sizes, and may | ||
13 | * also call with zero size. | ||
14 | * Reworked by rmk. | ||
15 | */ | ||
16 | #include <linux/linkage.h> | ||
17 | #include <asm/assembler.h> | ||
18 | .text | ||
19 | |||
20 | /* | ||
21 | * Purpose : Find a 'zero' bit | ||
22 | * Prototype: int find_first_zero_bit(void *addr, unsigned int maxbit); | ||
23 | */ | ||
24 | ENTRY(_find_first_zero_bit_le) | ||
25 | teq r1, #0 | ||
26 | beq 3f | ||
27 | mov r2, #0 | ||
28 | 1: ldrb r3, [r0, r2, lsr #3] | ||
29 | eors r3, r3, #0xff @ invert bits | ||
30 | bne .found @ any now set - found zero bit | ||
31 | add r2, r2, #8 @ next bit pointer | ||
32 | 2: cmp r2, r1 @ any more? | ||
33 | blo 1b | ||
34 | 3: mov r0, r1 @ no free bits | ||
35 | RETINSTR(mov,pc,lr) | ||
36 | |||
37 | /* | ||
38 | * Purpose : Find next 'zero' bit | ||
39 | * Prototype: int find_next_zero_bit(void *addr, unsigned int maxbit, int offset) | ||
40 | */ | ||
41 | ENTRY(_find_next_zero_bit_le) | ||
42 | teq r1, #0 | ||
43 | beq 2b | ||
44 | ands ip, r2, #7 | ||
45 | beq 1b @ If new byte, goto old routine | ||
46 | ldrb r3, [r0, r2, lsr #3] | ||
47 | eor r3, r3, #0xff @ now looking for a 1 bit | ||
48 | movs r3, r3, lsr ip @ shift off unused bits | ||
49 | bne .found | ||
50 | orr r2, r2, #7 @ if zero, then no bits here | ||
51 | add r2, r2, #1 @ align bit pointer | ||
52 | b 2b @ loop for next bit | ||
53 | |||
54 | /* | ||
55 | * One or more bits in the LSB of r3 are assumed to be set. | ||
56 | */ | ||
57 | .found: tst r3, #0x0f | ||
58 | addeq r2, r2, #4 | ||
59 | movne r3, r3, lsl #4 | ||
60 | tst r3, #0x30 | ||
61 | addeq r2, r2, #2 | ||
62 | movne r3, r3, lsl #2 | ||
63 | tst r3, #0x40 | ||
64 | addeq r2, r2, #1 | ||
65 | mov r0, r2 | ||
66 | RETINSTR(mov,pc,lr) | ||
67 | |||