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
|
#ifndef _ASM_WORD_AT_A_TIME_H
#define _ASM_WORD_AT_A_TIME_H
/*
* Word-at-a-time interfaces for PowerPC.
*/
#include <linux/bitops.h>
#include <linux/wordpart.h>
#include <asm/asm-compat.h>
#include <asm/extable.h>
#ifdef __BIG_ENDIAN__
struct word_at_a_time {
const unsigned long high_bits, low_bits;
};
#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) }
/* Bit set in the bytes that have a zero */
static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c)
{
unsigned long mask = (val & c->low_bits) + c->low_bits;
return ~(mask | rhs);
}
#define create_zero_mask(mask) (mask)
static inline long find_zero(unsigned long mask)
{
long leading_zero_bits;
asm (PPC_CNTLZL "%0,%1" : "=r" (leading_zero_bits) : "r" (mask));
return leading_zero_bits >> 3;
}
static inline unsigned long has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c)
{
unsigned long rhs = val | c->low_bits;
*data = rhs;
return (val + c->high_bits) & ~rhs;
}
static inline unsigned long zero_bytemask(unsigned long mask)
{
return ~1ul << __fls(mask);
}
#else
#ifdef CONFIG_64BIT
/* unused */
struct word_at_a_time {
};
#define WORD_AT_A_TIME_CONSTANTS { }
/* This will give us 0xff for a NULL char and 0x00 elsewhere */
static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
{
unsigned long ret;
unsigned long zero = 0;
asm("cmpb %0,%1,%2" : "=r" (ret) : "r" (a), "r" (zero));
*bits = ret;
return ret;
}
static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
{
return bits;
}
/* Alan Modra's little-endian strlen tail for 64-bit */
static inline unsigned long create_zero_mask(unsigned long bits)
{
unsigned long leading_zero_bits;
long trailing_zero_bit_mask;
asm("addi %1,%2,-1\n\t"
"andc %1,%1,%2\n\t"
"popcntd %0,%1"
: "=r" (leading_zero_bits), "=&r" (trailing_zero_bit_mask)
: "b" (bits));
return leading_zero_bits;
}
static inline unsigned long find_zero(unsigned long mask)
{
return mask >> 3;
}
/* This assumes that we never ask for an all 1s bitmask */
static inline unsigned long zero_bytemask(unsigned long mask)
{
return (1UL << mask) - 1;
}
#else /* 32-bit case */
struct word_at_a_time {
const unsigned long one_bits, high_bits;
};
#define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) }
/*
* This is largely generic for little-endian machines, but the
* optimal byte mask counting is probably going to be something
* that is architecture-specific. If you have a reliably fast
* bit count instruction, that might be better than the multiply
* and shift, for example.
*/
/* Carl Chatfield / Jan Achrenius G+ version for 32-bit */
static inline long count_masked_bytes(long mask)
{
/* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */
long a = (0x0ff0001+mask) >> 23;
/* Fix the 1 for 00 case */
return a & mask;
}
static inline unsigned long create_zero_mask(unsigned long bits)
{
bits = (bits - 1) & ~bits;
return bits >> 7;
}
static inline unsigned long find_zero(unsigned long mask)
{
return count_masked_bytes(mask);
}
/* Return nonzero if it has a zero */
static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c)
{
unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits;
*bits = mask;
return mask;
}
static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c)
{
return bits;
}
/* The mask we created is directly usable as a bytemask */
#define zero_bytemask(mask) (mask)
#endif /* CONFIG_64BIT */
#endif /* __BIG_ENDIAN__ */
/*
* We use load_unaligned_zero() in a selftest, which builds a userspace
* program. Some linker scripts seem to discard the .fixup section, so allow
* the test code to use a different section name.
*/
#ifndef FIXUP_SECTION
#define FIXUP_SECTION ".fixup"
#endif
static inline unsigned long load_unaligned_zeropad(const void *addr)
{
unsigned long ret, offset, tmp;
asm(
"1: " PPC_LL "%[ret], 0(%[addr])\n"
"2:\n"
".section " FIXUP_SECTION ",\"ax\"\n"
"3: "
#ifdef __powerpc64__
"clrrdi %[tmp], %[addr], 3\n\t"
"clrlsldi %[offset], %[addr], 61, 3\n\t"
"ld %[ret], 0(%[tmp])\n\t"
#ifdef __BIG_ENDIAN__
"sld %[ret], %[ret], %[offset]\n\t"
#else
"srd %[ret], %[ret], %[offset]\n\t"
#endif
#else
"clrrwi %[tmp], %[addr], 2\n\t"
"clrlslwi %[offset], %[addr], 30, 3\n\t"
"lwz %[ret], 0(%[tmp])\n\t"
#ifdef __BIG_ENDIAN__
"slw %[ret], %[ret], %[offset]\n\t"
#else
"srw %[ret], %[ret], %[offset]\n\t"
#endif
#endif
"b 2b\n"
".previous\n"
EX_TABLE(1b, 3b)
: [tmp] "=&b" (tmp), [offset] "=&r" (offset), [ret] "=&r" (ret)
: [addr] "b" (addr), "m" (*(unsigned long *)addr));
return ret;
}
#undef FIXUP_SECTION
#endif /* _ASM_WORD_AT_A_TIME_H */
|
