1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
/* $Id: bitops.h,v 1.23 1996/04/20 07:54:35 davem Exp $
* bitops.h: Bit string operations on the Sparc.
*
* Copyright 1995, David S. Miller (davem@caip.rutgers.edu).
*/
#ifndef _SPARC_BITOPS_H
#define _SPARC_BITOPS_H
#include <linux/kernel.h>
#ifdef __KERNEL__
#include <asm/system.h>
#endif
#ifdef __SMP__
#define SMPVOL volatile
#else
#define SMPVOL
#endif
/* Set bit 'nr' in 32-bit quantity at address 'addr' where bit '0'
* is in the highest of the four bytes and bit '31' is the high bit
* within the first byte. Sparc is BIG-Endian. Unless noted otherwise
* all bit-ops return 0 if bit was previously clear and != 0 otherwise.
*/
extern __inline__ unsigned long set_bit(unsigned long nr, SMPVOL void *addr)
{
int mask, flags;
unsigned long *ADDR = (unsigned long *) addr;
unsigned long oldbit;
ADDR += nr >> 5;
mask = 1 << (nr & 31);
save_flags(flags); cli();
oldbit = (mask & *ADDR);
*ADDR |= mask;
restore_flags(flags);
return oldbit != 0;
}
extern __inline__ unsigned long clear_bit(unsigned long nr, SMPVOL void *addr)
{
int mask, flags;
unsigned long *ADDR = (unsigned long *) addr;
unsigned long oldbit;
ADDR += nr >> 5;
mask = 1 << (nr & 31);
save_flags(flags); cli();
oldbit = (mask & *ADDR);
*ADDR &= ~mask;
restore_flags(flags);
return oldbit != 0;
}
extern __inline__ unsigned long change_bit(unsigned long nr, SMPVOL void *addr)
{
int mask, flags;
unsigned long *ADDR = (unsigned long *) addr;
unsigned long oldbit;
ADDR += nr >> 5;
mask = 1 << (nr & 31);
save_flags(flags); cli();
oldbit = (mask & *ADDR);
*ADDR ^= mask;
restore_flags(flags);
return oldbit != 0;
}
/* The following routine need not be atomic. */
extern __inline__ unsigned long test_bit(int nr, const SMPVOL void *addr)
{
return ((1UL << (nr & 31)) & (((const unsigned int *) addr)[nr >> 5])) != 0;
}
/* The easy/cheese version for now. */
extern __inline__ unsigned long ffz(unsigned long word)
{
unsigned long result = 0;
while(word & 1) {
result++;
word >>= 1;
}
return result;
}
/* find_next_zero_bit() finds the first zero bit in a bit string of length
* 'size' bits, starting the search at bit 'offset'. This is largely based
* on Linus's ALPHA routines, which are pretty portable BTW.
*/
extern __inline__ unsigned long find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
{
unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
unsigned long result = offset & ~31UL;
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if (offset) {
tmp = *(p++);
tmp |= ~0UL >> (32-offset);
if (size < 32)
goto found_first;
if (~tmp)
goto found_middle;
size -= 32;
result += 32;
}
while (size & ~31UL) {
if (~(tmp = *(p++)))
goto found_middle;
result += 32;
size -= 32;
}
if (!size)
return result;
tmp = *p;
found_first:
tmp |= ~0UL >> size;
found_middle:
return result + ffz(tmp);
}
/* Linus sez that gcc can optimize the following correctly, we'll see if this
* holds on the Sparc as it does for the ALPHA.
*/
#define find_first_zero_bit(addr, size) \
find_next_zero_bit((addr), (size), 0)
/* Now for the ext2 filesystem bit operations and helper routines. */
extern __inline__ int ext2_set_bit(int nr,void * addr)
{
int mask, retval, flags;
unsigned char *ADDR = (unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
save_flags(flags); cli();
retval = (mask & *ADDR) != 0;
*ADDR |= mask;
restore_flags(flags);
return retval;
}
extern __inline__ int ext2_clear_bit(int nr, void * addr)
{
int mask, retval, flags;
unsigned char *ADDR = (unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
save_flags(flags); cli();
retval = (mask & *ADDR) != 0;
*ADDR &= ~mask;
restore_flags(flags);
return retval;
}
extern __inline__ int ext2_test_bit(int nr, const void * addr)
{
int mask;
const unsigned char *ADDR = (const unsigned char *) addr;
ADDR += nr >> 3;
mask = 1 << (nr & 0x07);
return ((mask & *ADDR) != 0);
}
#define ext2_find_first_zero_bit(addr, size) \
ext2_find_next_zero_bit((addr), (size), 0)
extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset)
{
unsigned long *p = ((unsigned long *) addr) + (offset >> 5);
unsigned long result = offset & ~31UL;
unsigned long tmp;
if (offset >= size)
return size;
size -= result;
offset &= 31UL;
if(offset) {
tmp = *(p++);
tmp |= ~0UL << (32-offset);
if(size < 32)
goto found_first;
if(~tmp)
goto found_middle;
size -= 32;
result += 32;
}
while(size & ~31UL) {
if(~(tmp = *(p++)))
goto found_middle;
result += 32;
size -= 32;
}
if(!size)
return result;
tmp = *p;
found_first:
tmp |= ~0UL << size;
found_middle:
tmp = ((tmp>>24) | ((tmp>>8)&0xff00) | ((tmp<<8)&0xff0000) | (tmp<<24));
return result + ffz(tmp);
}
#endif /* defined(_SPARC_BITOPS_H) */
|
