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1 | #ifndef _ASM_WORD_AT_A_TIME_H |
---|---|
2 | #define _ASM_WORD_AT_A_TIME_H |
3 | |
4 | /* |
5 | * Word-at-a-time interfaces for PowerPC. |
6 | */ |
7 | #include <linux/bitops.h> |
8 | #include <linux/wordpart.h> |
9 | #include <asm/asm-compat.h> |
10 | #include <asm/extable.h> |
11 | |
12 | #ifdef __BIG_ENDIAN__ |
13 | |
14 | struct word_at_a_time { |
15 | const unsigned long high_bits, low_bits; |
16 | }; |
17 | |
18 | #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0xfe) + 1, REPEAT_BYTE(0x7f) } |
19 | |
20 | /* Bit set in the bytes that have a zero */ |
21 | static inline long prep_zero_mask(unsigned long val, unsigned long rhs, const struct word_at_a_time *c) |
22 | { |
23 | unsigned long mask = (val & c->low_bits) + c->low_bits; |
24 | return ~(mask | rhs); |
25 | } |
26 | |
27 | #define create_zero_mask(mask) (mask) |
28 | |
29 | static inline long find_zero(unsigned long mask) |
30 | { |
31 | long leading_zero_bits; |
32 | |
33 | asm (PPC_CNTLZL "%0,%1" : "=r" (leading_zero_bits) : "r" (mask)); |
34 | return leading_zero_bits >> 3; |
35 | } |
36 | |
37 | static inline unsigned long has_zero(unsigned long val, unsigned long *data, const struct word_at_a_time *c) |
38 | { |
39 | unsigned long rhs = val | c->low_bits; |
40 | *data = rhs; |
41 | return (val + c->high_bits) & ~rhs; |
42 | } |
43 | |
44 | static inline unsigned long zero_bytemask(unsigned long mask) |
45 | { |
46 | return ~1ul << __fls(mask); |
47 | } |
48 | |
49 | #else |
50 | |
51 | #ifdef CONFIG_64BIT |
52 | |
53 | /* unused */ |
54 | struct word_at_a_time { |
55 | }; |
56 | |
57 | #define WORD_AT_A_TIME_CONSTANTS { } |
58 | |
59 | /* This will give us 0xff for a NULL char and 0x00 elsewhere */ |
60 | static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c) |
61 | { |
62 | unsigned long ret; |
63 | unsigned long zero = 0; |
64 | |
65 | asm("cmpb %0,%1,%2" : "=r" (ret) : "r" (a), "r" (zero)); |
66 | *bits = ret; |
67 | |
68 | return ret; |
69 | } |
70 | |
71 | static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c) |
72 | { |
73 | return bits; |
74 | } |
75 | |
76 | /* Alan Modra's little-endian strlen tail for 64-bit */ |
77 | static inline unsigned long create_zero_mask(unsigned long bits) |
78 | { |
79 | unsigned long leading_zero_bits; |
80 | long trailing_zero_bit_mask; |
81 | |
82 | asm("addi %1,%2,-1\n\t" |
83 | "andc %1,%1,%2\n\t" |
84 | "popcntd %0,%1" |
85 | : "=r" (leading_zero_bits), "=&r" (trailing_zero_bit_mask) |
86 | : "b" (bits)); |
87 | |
88 | return leading_zero_bits; |
89 | } |
90 | |
91 | static inline unsigned long find_zero(unsigned long mask) |
92 | { |
93 | return mask >> 3; |
94 | } |
95 | |
96 | /* This assumes that we never ask for an all 1s bitmask */ |
97 | static inline unsigned long zero_bytemask(unsigned long mask) |
98 | { |
99 | return (1UL << mask) - 1; |
100 | } |
101 | |
102 | #else /* 32-bit case */ |
103 | |
104 | struct word_at_a_time { |
105 | const unsigned long one_bits, high_bits; |
106 | }; |
107 | |
108 | #define WORD_AT_A_TIME_CONSTANTS { REPEAT_BYTE(0x01), REPEAT_BYTE(0x80) } |
109 | |
110 | /* |
111 | * This is largely generic for little-endian machines, but the |
112 | * optimal byte mask counting is probably going to be something |
113 | * that is architecture-specific. If you have a reliably fast |
114 | * bit count instruction, that might be better than the multiply |
115 | * and shift, for example. |
116 | */ |
117 | |
118 | /* Carl Chatfield / Jan Achrenius G+ version for 32-bit */ |
119 | static inline long count_masked_bytes(long mask) |
120 | { |
121 | /* (000000 0000ff 00ffff ffffff) -> ( 1 1 2 3 ) */ |
122 | long a = (0x0ff0001+mask) >> 23; |
123 | /* Fix the 1 for 00 case */ |
124 | return a & mask; |
125 | } |
126 | |
127 | static inline unsigned long create_zero_mask(unsigned long bits) |
128 | { |
129 | bits = (bits - 1) & ~bits; |
130 | return bits >> 7; |
131 | } |
132 | |
133 | static inline unsigned long find_zero(unsigned long mask) |
134 | { |
135 | return count_masked_bytes(mask); |
136 | } |
137 | |
138 | /* Return nonzero if it has a zero */ |
139 | static inline unsigned long has_zero(unsigned long a, unsigned long *bits, const struct word_at_a_time *c) |
140 | { |
141 | unsigned long mask = ((a - c->one_bits) & ~a) & c->high_bits; |
142 | *bits = mask; |
143 | return mask; |
144 | } |
145 | |
146 | static inline unsigned long prep_zero_mask(unsigned long a, unsigned long bits, const struct word_at_a_time *c) |
147 | { |
148 | return bits; |
149 | } |
150 | |
151 | /* The mask we created is directly usable as a bytemask */ |
152 | #define zero_bytemask(mask) (mask) |
153 | |
154 | #endif /* CONFIG_64BIT */ |
155 | |
156 | #endif /* __BIG_ENDIAN__ */ |
157 | |
158 | /* |
159 | * We use load_unaligned_zero() in a selftest, which builds a userspace |
160 | * program. Some linker scripts seem to discard the .fixup section, so allow |
161 | * the test code to use a different section name. |
162 | */ |
163 | #ifndef FIXUP_SECTION |
164 | #define FIXUP_SECTION ".fixup" |
165 | #endif |
166 | |
167 | static inline unsigned long load_unaligned_zeropad(const void *addr) |
168 | { |
169 | unsigned long ret, offset, tmp; |
170 | |
171 | asm( |
172 | "1: " PPC_LL "%[ret], 0(%[addr])\n" |
173 | "2:\n" |
174 | ".section " FIXUP_SECTION ",\"ax\"\n" |
175 | "3: " |
176 | #ifdef __powerpc64__ |
177 | "clrrdi %[tmp], %[addr], 3\n\t" |
178 | "clrlsldi %[offset], %[addr], 61, 3\n\t" |
179 | "ld %[ret], 0(%[tmp])\n\t" |
180 | #ifdef __BIG_ENDIAN__ |
181 | "sld %[ret], %[ret], %[offset]\n\t" |
182 | #else |
183 | "srd %[ret], %[ret], %[offset]\n\t" |
184 | #endif |
185 | #else |
186 | "clrrwi %[tmp], %[addr], 2\n\t" |
187 | "clrlslwi %[offset], %[addr], 30, 3\n\t" |
188 | "lwz %[ret], 0(%[tmp])\n\t" |
189 | #ifdef __BIG_ENDIAN__ |
190 | "slw %[ret], %[ret], %[offset]\n\t" |
191 | #else |
192 | "srw %[ret], %[ret], %[offset]\n\t" |
193 | #endif |
194 | #endif |
195 | "b 2b\n" |
196 | ".previous\n" |
197 | EX_TABLE(1b, 3b) |
198 | : [tmp] "=&b" (tmp), [offset] "=&r" (offset), [ret] "=&r" (ret) |
199 | : [addr] "b" (addr), "m" (*(unsigned long *)addr)); |
200 | |
201 | return ret; |
202 | } |
203 | |
204 | #undef FIXUP_SECTION |
205 | |
206 | #endif /* _ASM_WORD_AT_A_TIME_H */ |
207 |
Warning: This file is not a C or C++ file. It does not have highlighting.