diff options
author | Steve French <sfrench@us.ibm.com> | 2008-04-28 00:01:34 -0400 |
---|---|---|
committer | Steve French <sfrench@us.ibm.com> | 2008-04-28 00:01:34 -0400 |
commit | 1dbbb6077426f8ce63d6a59c5ac6613e1689cbde (patch) | |
tree | 6141d4d7a8eb7c557705bdfa764137d4fd2e4924 /lib/find_next_bit.c | |
parent | d09e860cf07e7c9ee12920a09f5080e30a12a23a (diff) | |
parent | 064922a805ec7aadfafdd27aa6b4908d737c3c1d (diff) |
Merge branch 'master' of /pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'lib/find_next_bit.c')
-rw-r--r-- | lib/find_next_bit.c | 77 |
1 files changed, 65 insertions, 12 deletions
diff --git a/lib/find_next_bit.c b/lib/find_next_bit.c index 78ccd73a8841..d3f5784807b4 100644 --- a/lib/find_next_bit.c +++ b/lib/find_next_bit.c | |||
@@ -16,14 +16,12 @@ | |||
16 | 16 | ||
17 | #define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) | 17 | #define BITOP_WORD(nr) ((nr) / BITS_PER_LONG) |
18 | 18 | ||
19 | /** | 19 | #ifdef CONFIG_GENERIC_FIND_NEXT_BIT |
20 | * find_next_bit - find the next set bit in a memory region | 20 | /* |
21 | * @addr: The address to base the search on | 21 | * Find the next set bit in a memory region. |
22 | * @offset: The bitnumber to start searching at | ||
23 | * @size: The maximum size to search | ||
24 | */ | 22 | */ |
25 | unsigned long find_next_bit(const unsigned long *addr, unsigned long size, | 23 | unsigned long __find_next_bit(const unsigned long *addr, |
26 | unsigned long offset) | 24 | unsigned long size, unsigned long offset) |
27 | { | 25 | { |
28 | const unsigned long *p = addr + BITOP_WORD(offset); | 26 | const unsigned long *p = addr + BITOP_WORD(offset); |
29 | unsigned long result = offset & ~(BITS_PER_LONG-1); | 27 | unsigned long result = offset & ~(BITS_PER_LONG-1); |
@@ -60,15 +58,14 @@ found_first: | |||
60 | found_middle: | 58 | found_middle: |
61 | return result + __ffs(tmp); | 59 | return result + __ffs(tmp); |
62 | } | 60 | } |
63 | 61 | EXPORT_SYMBOL(__find_next_bit); | |
64 | EXPORT_SYMBOL(find_next_bit); | ||
65 | 62 | ||
66 | /* | 63 | /* |
67 | * This implementation of find_{first,next}_zero_bit was stolen from | 64 | * This implementation of find_{first,next}_zero_bit was stolen from |
68 | * Linus' asm-alpha/bitops.h. | 65 | * Linus' asm-alpha/bitops.h. |
69 | */ | 66 | */ |
70 | unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size, | 67 | unsigned long __find_next_zero_bit(const unsigned long *addr, |
71 | unsigned long offset) | 68 | unsigned long size, unsigned long offset) |
72 | { | 69 | { |
73 | const unsigned long *p = addr + BITOP_WORD(offset); | 70 | const unsigned long *p = addr + BITOP_WORD(offset); |
74 | unsigned long result = offset & ~(BITS_PER_LONG-1); | 71 | unsigned long result = offset & ~(BITS_PER_LONG-1); |
@@ -105,8 +102,64 @@ found_first: | |||
105 | found_middle: | 102 | found_middle: |
106 | return result + ffz(tmp); | 103 | return result + ffz(tmp); |
107 | } | 104 | } |
105 | EXPORT_SYMBOL(__find_next_zero_bit); | ||
106 | #endif /* CONFIG_GENERIC_FIND_NEXT_BIT */ | ||
107 | |||
108 | #ifdef CONFIG_GENERIC_FIND_FIRST_BIT | ||
109 | /* | ||
110 | * Find the first set bit in a memory region. | ||
111 | */ | ||
112 | unsigned long __find_first_bit(const unsigned long *addr, | ||
113 | unsigned long size) | ||
114 | { | ||
115 | const unsigned long *p = addr; | ||
116 | unsigned long result = 0; | ||
117 | unsigned long tmp; | ||
108 | 118 | ||
109 | EXPORT_SYMBOL(find_next_zero_bit); | 119 | while (size & ~(BITS_PER_LONG-1)) { |
120 | if ((tmp = *(p++))) | ||
121 | goto found; | ||
122 | result += BITS_PER_LONG; | ||
123 | size -= BITS_PER_LONG; | ||
124 | } | ||
125 | if (!size) | ||
126 | return result; | ||
127 | |||
128 | tmp = (*p) & (~0UL >> (BITS_PER_LONG - size)); | ||
129 | if (tmp == 0UL) /* Are any bits set? */ | ||
130 | return result + size; /* Nope. */ | ||
131 | found: | ||
132 | return result + __ffs(tmp); | ||
133 | } | ||
134 | EXPORT_SYMBOL(__find_first_bit); | ||
135 | |||
136 | /* | ||
137 | * Find the first cleared bit in a memory region. | ||
138 | */ | ||
139 | unsigned long __find_first_zero_bit(const unsigned long *addr, | ||
140 | unsigned long size) | ||
141 | { | ||
142 | const unsigned long *p = addr; | ||
143 | unsigned long result = 0; | ||
144 | unsigned long tmp; | ||
145 | |||
146 | while (size & ~(BITS_PER_LONG-1)) { | ||
147 | if (~(tmp = *(p++))) | ||
148 | goto found; | ||
149 | result += BITS_PER_LONG; | ||
150 | size -= BITS_PER_LONG; | ||
151 | } | ||
152 | if (!size) | ||
153 | return result; | ||
154 | |||
155 | tmp = (*p) | (~0UL << size); | ||
156 | if (tmp == ~0UL) /* Are any bits zero? */ | ||
157 | return result + size; /* Nope. */ | ||
158 | found: | ||
159 | return result + ffz(tmp); | ||
160 | } | ||
161 | EXPORT_SYMBOL(__find_first_zero_bit); | ||
162 | #endif /* CONFIG_GENERIC_FIND_FIRST_BIT */ | ||
110 | 163 | ||
111 | #ifdef __BIG_ENDIAN | 164 | #ifdef __BIG_ENDIAN |
112 | 165 | ||