ia64/xen-unstable

view xen/arch/ia64/linux/bitop.c @ 10888:5379548bfc79

[NET] Enable TCPv4 segmentation offload in front/back drivers.
Signed-off-by: Keir Fraser <keir@xensource.com>
author kfraser@localhost.localdomain
date Tue Aug 01 11:54:45 2006 +0100 (2006-08-01)
parents 3ca4ca7a9cc2
children
line source
1 #include <linux/compiler.h>
2 #include <linux/types.h>
3 #include <asm/intrinsics.h>
4 #include <linux/module.h>
5 #include <linux/bitops.h>
7 /*
8 * Find next zero bit in a bitmap reasonably efficiently..
9 */
11 int __find_next_zero_bit (const void *addr, unsigned long size, unsigned long offset)
12 {
13 unsigned long *p = ((unsigned long *) addr) + (offset >> 6);
14 unsigned long result = offset & ~63UL;
15 unsigned long tmp;
17 if (offset >= size)
18 return size;
19 size -= result;
20 offset &= 63UL;
21 if (offset) {
22 tmp = *(p++);
23 tmp |= ~0UL >> (64-offset);
24 if (size < 64)
25 goto found_first;
26 if (~tmp)
27 goto found_middle;
28 size -= 64;
29 result += 64;
30 }
31 while (size & ~63UL) {
32 if (~(tmp = *(p++)))
33 goto found_middle;
34 result += 64;
35 size -= 64;
36 }
37 if (!size)
38 return result;
39 tmp = *p;
40 found_first:
41 tmp |= ~0UL << size;
42 if (tmp == ~0UL) /* any bits zero? */
43 return result + size; /* nope */
44 found_middle:
45 return result + ffz(tmp);
46 }
47 EXPORT_SYMBOL(__find_next_zero_bit);
49 /*
50 * Find next bit in a bitmap reasonably efficiently..
51 */
52 int __find_next_bit(const void *addr, unsigned long size, unsigned long offset)
53 {
54 unsigned long *p = ((unsigned long *) addr) + (offset >> 6);
55 unsigned long result = offset & ~63UL;
56 unsigned long tmp;
58 if (offset >= size)
59 return size;
60 size -= result;
61 offset &= 63UL;
62 if (offset) {
63 tmp = *(p++);
64 tmp &= ~0UL << offset;
65 if (size < 64)
66 goto found_first;
67 if (tmp)
68 goto found_middle;
69 size -= 64;
70 result += 64;
71 }
72 while (size & ~63UL) {
73 if ((tmp = *(p++)))
74 goto found_middle;
75 result += 64;
76 size -= 64;
77 }
78 if (!size)
79 return result;
80 tmp = *p;
81 found_first:
82 tmp &= ~0UL >> (64-size);
83 if (tmp == 0UL) /* Are any bits set? */
84 return result + size; /* Nope. */
85 found_middle:
86 return result + __ffs(tmp);
87 }
88 EXPORT_SYMBOL(__find_next_bit);