Linux kernel mirror (for testing)
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1#ifndef _ALPHA_BITOPS_H
2#define _ALPHA_BITOPS_H
3
4#include <asm/compiler.h>
5
6/*
7 * Copyright 1994, Linus Torvalds.
8 */
9
10/*
11 * These have to be done with inline assembly: that way the bit-setting
12 * is guaranteed to be atomic. All bit operations return 0 if the bit
13 * was cleared before the operation and != 0 if it was not.
14 *
15 * To get proper branch prediction for the main line, we must branch
16 * forward to code at the end of this object's .text section, then
17 * branch back to restart the operation.
18 *
19 * bit 0 is the LSB of addr; bit 64 is the LSB of (addr+1).
20 */
21
22static inline void
23set_bit(unsigned long nr, volatile void * addr)
24{
25 unsigned long temp;
26 int *m = ((int *) addr) + (nr >> 5);
27
28 __asm__ __volatile__(
29 "1: ldl_l %0,%3\n"
30 " bis %0,%2,%0\n"
31 " stl_c %0,%1\n"
32 " beq %0,2f\n"
33 ".subsection 2\n"
34 "2: br 1b\n"
35 ".previous"
36 :"=&r" (temp), "=m" (*m)
37 :"Ir" (1UL << (nr & 31)), "m" (*m));
38}
39
40/*
41 * WARNING: non atomic version.
42 */
43static inline void
44__set_bit(unsigned long nr, volatile void * addr)
45{
46 int *m = ((int *) addr) + (nr >> 5);
47
48 *m |= 1 << (nr & 31);
49}
50
51#define smp_mb__before_clear_bit() smp_mb()
52#define smp_mb__after_clear_bit() smp_mb()
53
54static inline void
55clear_bit(unsigned long nr, volatile void * addr)
56{
57 unsigned long temp;
58 int *m = ((int *) addr) + (nr >> 5);
59
60 __asm__ __volatile__(
61 "1: ldl_l %0,%3\n"
62 " bic %0,%2,%0\n"
63 " stl_c %0,%1\n"
64 " beq %0,2f\n"
65 ".subsection 2\n"
66 "2: br 1b\n"
67 ".previous"
68 :"=&r" (temp), "=m" (*m)
69 :"Ir" (1UL << (nr & 31)), "m" (*m));
70}
71
72/*
73 * WARNING: non atomic version.
74 */
75static __inline__ void
76__clear_bit(unsigned long nr, volatile void * addr)
77{
78 int *m = ((int *) addr) + (nr >> 5);
79
80 *m &= ~(1 << (nr & 31));
81}
82
83static inline void
84change_bit(unsigned long nr, volatile void * addr)
85{
86 unsigned long temp;
87 int *m = ((int *) addr) + (nr >> 5);
88
89 __asm__ __volatile__(
90 "1: ldl_l %0,%3\n"
91 " xor %0,%2,%0\n"
92 " stl_c %0,%1\n"
93 " beq %0,2f\n"
94 ".subsection 2\n"
95 "2: br 1b\n"
96 ".previous"
97 :"=&r" (temp), "=m" (*m)
98 :"Ir" (1UL << (nr & 31)), "m" (*m));
99}
100
101/*
102 * WARNING: non atomic version.
103 */
104static __inline__ void
105__change_bit(unsigned long nr, volatile void * addr)
106{
107 int *m = ((int *) addr) + (nr >> 5);
108
109 *m ^= 1 << (nr & 31);
110}
111
112static inline int
113test_and_set_bit(unsigned long nr, volatile void *addr)
114{
115 unsigned long oldbit;
116 unsigned long temp;
117 int *m = ((int *) addr) + (nr >> 5);
118
119 __asm__ __volatile__(
120 "1: ldl_l %0,%4\n"
121 " and %0,%3,%2\n"
122 " bne %2,2f\n"
123 " xor %0,%3,%0\n"
124 " stl_c %0,%1\n"
125 " beq %0,3f\n"
126 "2:\n"
127#ifdef CONFIG_SMP
128 " mb\n"
129#endif
130 ".subsection 2\n"
131 "3: br 1b\n"
132 ".previous"
133 :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
134 :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
135
136 return oldbit != 0;
137}
138
139/*
140 * WARNING: non atomic version.
141 */
142static inline int
143__test_and_set_bit(unsigned long nr, volatile void * addr)
144{
145 unsigned long mask = 1 << (nr & 0x1f);
146 int *m = ((int *) addr) + (nr >> 5);
147 int old = *m;
148
149 *m = old | mask;
150 return (old & mask) != 0;
151}
152
153static inline int
154test_and_clear_bit(unsigned long nr, volatile void * addr)
155{
156 unsigned long oldbit;
157 unsigned long temp;
158 int *m = ((int *) addr) + (nr >> 5);
159
160 __asm__ __volatile__(
161 "1: ldl_l %0,%4\n"
162 " and %0,%3,%2\n"
163 " beq %2,2f\n"
164 " xor %0,%3,%0\n"
165 " stl_c %0,%1\n"
166 " beq %0,3f\n"
167 "2:\n"
168#ifdef CONFIG_SMP
169 " mb\n"
170#endif
171 ".subsection 2\n"
172 "3: br 1b\n"
173 ".previous"
174 :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
175 :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
176
177 return oldbit != 0;
178}
179
180/*
181 * WARNING: non atomic version.
182 */
183static inline int
184__test_and_clear_bit(unsigned long nr, volatile void * addr)
185{
186 unsigned long mask = 1 << (nr & 0x1f);
187 int *m = ((int *) addr) + (nr >> 5);
188 int old = *m;
189
190 *m = old & ~mask;
191 return (old & mask) != 0;
192}
193
194static inline int
195test_and_change_bit(unsigned long nr, volatile void * addr)
196{
197 unsigned long oldbit;
198 unsigned long temp;
199 int *m = ((int *) addr) + (nr >> 5);
200
201 __asm__ __volatile__(
202 "1: ldl_l %0,%4\n"
203 " and %0,%3,%2\n"
204 " xor %0,%3,%0\n"
205 " stl_c %0,%1\n"
206 " beq %0,3f\n"
207#ifdef CONFIG_SMP
208 " mb\n"
209#endif
210 ".subsection 2\n"
211 "3: br 1b\n"
212 ".previous"
213 :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
214 :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
215
216 return oldbit != 0;
217}
218
219/*
220 * WARNING: non atomic version.
221 */
222static __inline__ int
223__test_and_change_bit(unsigned long nr, volatile void * addr)
224{
225 unsigned long mask = 1 << (nr & 0x1f);
226 int *m = ((int *) addr) + (nr >> 5);
227 int old = *m;
228
229 *m = old ^ mask;
230 return (old & mask) != 0;
231}
232
233static inline int
234test_bit(int nr, const volatile void * addr)
235{
236 return (1UL & (((const int *) addr)[nr >> 5] >> (nr & 31))) != 0UL;
237}
238
239/*
240 * ffz = Find First Zero in word. Undefined if no zero exists,
241 * so code should check against ~0UL first..
242 *
243 * Do a binary search on the bits. Due to the nature of large
244 * constants on the alpha, it is worthwhile to split the search.
245 */
246static inline unsigned long ffz_b(unsigned long x)
247{
248 unsigned long sum, x1, x2, x4;
249
250 x = ~x & -~x; /* set first 0 bit, clear others */
251 x1 = x & 0xAA;
252 x2 = x & 0xCC;
253 x4 = x & 0xF0;
254 sum = x2 ? 2 : 0;
255 sum += (x4 != 0) * 4;
256 sum += (x1 != 0);
257
258 return sum;
259}
260
261static inline unsigned long ffz(unsigned long word)
262{
263#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
264 /* Whee. EV67 can calculate it directly. */
265 return __kernel_cttz(~word);
266#else
267 unsigned long bits, qofs, bofs;
268
269 bits = __kernel_cmpbge(word, ~0UL);
270 qofs = ffz_b(bits);
271 bits = __kernel_extbl(word, qofs);
272 bofs = ffz_b(bits);
273
274 return qofs*8 + bofs;
275#endif
276}
277
278/*
279 * __ffs = Find First set bit in word. Undefined if no set bit exists.
280 */
281static inline unsigned long __ffs(unsigned long word)
282{
283#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
284 /* Whee. EV67 can calculate it directly. */
285 return __kernel_cttz(word);
286#else
287 unsigned long bits, qofs, bofs;
288
289 bits = __kernel_cmpbge(0, word);
290 qofs = ffz_b(bits);
291 bits = __kernel_extbl(word, qofs);
292 bofs = ffz_b(~bits);
293
294 return qofs*8 + bofs;
295#endif
296}
297
298#ifdef __KERNEL__
299
300/*
301 * ffs: find first bit set. This is defined the same way as
302 * the libc and compiler builtin ffs routines, therefore
303 * differs in spirit from the above __ffs.
304 */
305
306static inline int ffs(int word)
307{
308 int result = __ffs(word) + 1;
309 return word ? result : 0;
310}
311
312/*
313 * fls: find last bit set.
314 */
315#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
316static inline int fls64(unsigned long word)
317{
318 return 64 - __kernel_ctlz(word);
319}
320#else
321extern const unsigned char __flsm1_tab[256];
322
323static inline int fls64(unsigned long x)
324{
325 unsigned long t, a, r;
326
327 t = __kernel_cmpbge (x, 0x0101010101010101);
328 a = __flsm1_tab[t];
329 t = __kernel_extbl (x, a);
330 r = a*8 + __flsm1_tab[t] + (x != 0);
331
332 return r;
333}
334#endif
335
336static inline int fls(int x)
337{
338 return fls64((unsigned int) x);
339}
340
341/*
342 * hweightN: returns the hamming weight (i.e. the number
343 * of bits set) of a N-bit word
344 */
345
346#if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
347/* Whee. EV67 can calculate it directly. */
348static inline unsigned long hweight64(unsigned long w)
349{
350 return __kernel_ctpop(w);
351}
352
353static inline unsigned int hweight32(unsigned int w)
354{
355 return hweight64(w);
356}
357
358static inline unsigned int hweight16(unsigned int w)
359{
360 return hweight64(w & 0xffff);
361}
362
363static inline unsigned int hweight8(unsigned int w)
364{
365 return hweight64(w & 0xff);
366}
367#else
368#include <asm-generic/bitops/hweight.h>
369#endif
370
371#endif /* __KERNEL__ */
372
373#include <asm-generic/bitops/find.h>
374
375#ifdef __KERNEL__
376
377/*
378 * Every architecture must define this function. It's the fastest
379 * way of searching a 140-bit bitmap where the first 100 bits are
380 * unlikely to be set. It's guaranteed that at least one of the 140
381 * bits is set.
382 */
383static inline unsigned long
384sched_find_first_bit(unsigned long b[3])
385{
386 unsigned long b0 = b[0], b1 = b[1], b2 = b[2];
387 unsigned long ofs;
388
389 ofs = (b1 ? 64 : 128);
390 b1 = (b1 ? b1 : b2);
391 ofs = (b0 ? 0 : ofs);
392 b0 = (b0 ? b0 : b1);
393
394 return __ffs(b0) + ofs;
395}
396
397#include <asm-generic/bitops/ext2-non-atomic.h>
398
399#define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
400#define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
401
402#include <asm-generic/bitops/minix.h>
403
404#endif /* __KERNEL__ */
405
406#endif /* _ALPHA_BITOPS_H */