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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _X86_64_BITOPS_H
2#define _X86_64_BITOPS_H
3
4/*
5 * Copyright 1992, Linus Torvalds.
6 */
7
8#include <linux/config.h>
9
10#ifdef CONFIG_SMP
11#define LOCK_PREFIX "lock ; "
12#else
13#define LOCK_PREFIX ""
14#endif
15
16#define ADDR (*(volatile long *) addr)
17
18/**
19 * set_bit - Atomically set a bit in memory
20 * @nr: the bit to set
21 * @addr: the address to start counting from
22 *
23 * This function is atomic and may not be reordered. See __set_bit()
24 * if you do not require the atomic guarantees.
25 * Note that @nr may be almost arbitrarily large; this function is not
26 * restricted to acting on a single-word quantity.
27 */
28static __inline__ void set_bit(int nr, volatile void * addr)
29{
30 __asm__ __volatile__( LOCK_PREFIX
31 "btsl %1,%0"
32 :"=m" (ADDR)
33 :"dIr" (nr) : "memory");
34}
35
36/**
37 * __set_bit - Set a bit in memory
38 * @nr: the bit to set
39 * @addr: the address to start counting from
40 *
41 * Unlike set_bit(), this function is non-atomic and may be reordered.
42 * If it's called on the same region of memory simultaneously, the effect
43 * may be that only one operation succeeds.
44 */
45static __inline__ void __set_bit(int nr, volatile void * addr)
46{
47 __asm__ volatile(
48 "btsl %1,%0"
49 :"=m" (ADDR)
50 :"dIr" (nr) : "memory");
51}
52
53/**
54 * clear_bit - Clears a bit in memory
55 * @nr: Bit to clear
56 * @addr: Address to start counting from
57 *
58 * clear_bit() is atomic and may not be reordered. However, it does
59 * not contain a memory barrier, so if it is used for locking purposes,
60 * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
61 * in order to ensure changes are visible on other processors.
62 */
63static __inline__ void clear_bit(int nr, volatile void * addr)
64{
65 __asm__ __volatile__( LOCK_PREFIX
66 "btrl %1,%0"
67 :"=m" (ADDR)
68 :"dIr" (nr));
69}
70
71static __inline__ void __clear_bit(int nr, volatile void * addr)
72{
73 __asm__ __volatile__(
74 "btrl %1,%0"
75 :"=m" (ADDR)
76 :"dIr" (nr));
77}
78
79#define smp_mb__before_clear_bit() barrier()
80#define smp_mb__after_clear_bit() barrier()
81
82/**
83 * __change_bit - Toggle a bit in memory
84 * @nr: the bit to change
85 * @addr: the address to start counting from
86 *
87 * Unlike change_bit(), this function is non-atomic and may be reordered.
88 * If it's called on the same region of memory simultaneously, the effect
89 * may be that only one operation succeeds.
90 */
91static __inline__ void __change_bit(int nr, volatile void * addr)
92{
93 __asm__ __volatile__(
94 "btcl %1,%0"
95 :"=m" (ADDR)
96 :"dIr" (nr));
97}
98
99/**
100 * change_bit - Toggle a bit in memory
101 * @nr: Bit to change
102 * @addr: Address to start counting from
103 *
104 * change_bit() is atomic and may not be reordered.
105 * Note that @nr may be almost arbitrarily large; this function is not
106 * restricted to acting on a single-word quantity.
107 */
108static __inline__ void change_bit(int nr, volatile void * addr)
109{
110 __asm__ __volatile__( LOCK_PREFIX
111 "btcl %1,%0"
112 :"=m" (ADDR)
113 :"dIr" (nr));
114}
115
116/**
117 * test_and_set_bit - Set a bit and return its old value
118 * @nr: Bit to set
119 * @addr: Address to count from
120 *
121 * This operation is atomic and cannot be reordered.
122 * It also implies a memory barrier.
123 */
124static __inline__ int test_and_set_bit(int nr, volatile void * addr)
125{
126 int oldbit;
127
128 __asm__ __volatile__( LOCK_PREFIX
129 "btsl %2,%1\n\tsbbl %0,%0"
130 :"=r" (oldbit),"=m" (ADDR)
131 :"dIr" (nr) : "memory");
132 return oldbit;
133}
134
135/**
136 * __test_and_set_bit - Set a bit and return its old value
137 * @nr: Bit to set
138 * @addr: Address to count from
139 *
140 * This operation is non-atomic and can be reordered.
141 * If two examples of this operation race, one can appear to succeed
142 * but actually fail. You must protect multiple accesses with a lock.
143 */
144static __inline__ int __test_and_set_bit(int nr, volatile void * addr)
145{
146 int oldbit;
147
148 __asm__(
149 "btsl %2,%1\n\tsbbl %0,%0"
150 :"=r" (oldbit),"=m" (ADDR)
151 :"dIr" (nr));
152 return oldbit;
153}
154
155/**
156 * test_and_clear_bit - Clear a bit and return its old value
157 * @nr: Bit to clear
158 * @addr: Address to count from
159 *
160 * This operation is atomic and cannot be reordered.
161 * It also implies a memory barrier.
162 */
163static __inline__ int test_and_clear_bit(int nr, volatile void * addr)
164{
165 int oldbit;
166
167 __asm__ __volatile__( LOCK_PREFIX
168 "btrl %2,%1\n\tsbbl %0,%0"
169 :"=r" (oldbit),"=m" (ADDR)
170 :"dIr" (nr) : "memory");
171 return oldbit;
172}
173
174/**
175 * __test_and_clear_bit - Clear a bit and return its old value
176 * @nr: Bit to clear
177 * @addr: Address to count from
178 *
179 * This operation is non-atomic and can be reordered.
180 * If two examples of this operation race, one can appear to succeed
181 * but actually fail. You must protect multiple accesses with a lock.
182 */
183static __inline__ int __test_and_clear_bit(int nr, volatile void * addr)
184{
185 int oldbit;
186
187 __asm__(
188 "btrl %2,%1\n\tsbbl %0,%0"
189 :"=r" (oldbit),"=m" (ADDR)
190 :"dIr" (nr));
191 return oldbit;
192}
193
194/* WARNING: non atomic and it can be reordered! */
195static __inline__ int __test_and_change_bit(int nr, volatile void * addr)
196{
197 int oldbit;
198
199 __asm__ __volatile__(
200 "btcl %2,%1\n\tsbbl %0,%0"
201 :"=r" (oldbit),"=m" (ADDR)
202 :"dIr" (nr) : "memory");
203 return oldbit;
204}
205
206/**
207 * test_and_change_bit - Change a bit and return its old value
208 * @nr: Bit to change
209 * @addr: Address to count from
210 *
211 * This operation is atomic and cannot be reordered.
212 * It also implies a memory barrier.
213 */
214static __inline__ int test_and_change_bit(int nr, volatile void * addr)
215{
216 int oldbit;
217
218 __asm__ __volatile__( LOCK_PREFIX
219 "btcl %2,%1\n\tsbbl %0,%0"
220 :"=r" (oldbit),"=m" (ADDR)
221 :"dIr" (nr) : "memory");
222 return oldbit;
223}
224
225#if 0 /* Fool kernel-doc since it doesn't do macros yet */
226/**
227 * test_bit - Determine whether a bit is set
228 * @nr: bit number to test
229 * @addr: Address to start counting from
230 */
231static int test_bit(int nr, const volatile void * addr);
232#endif
233
234static __inline__ int constant_test_bit(int nr, const volatile void * addr)
235{
236 return ((1UL << (nr & 31)) & (((const volatile unsigned int *) addr)[nr >> 5])) != 0;
237}
238
239static __inline__ int variable_test_bit(int nr, volatile const void * addr)
240{
241 int oldbit;
242
243 __asm__ __volatile__(
244 "btl %2,%1\n\tsbbl %0,%0"
245 :"=r" (oldbit)
246 :"m" (ADDR),"dIr" (nr));
247 return oldbit;
248}
249
250#define test_bit(nr,addr) \
251(__builtin_constant_p(nr) ? \
252 constant_test_bit((nr),(addr)) : \
253 variable_test_bit((nr),(addr)))
254
255#undef ADDR
256
257extern long find_first_zero_bit(const unsigned long * addr, unsigned long size);
258extern long find_next_zero_bit (const unsigned long * addr, long size, long offset);
259extern long find_first_bit(const unsigned long * addr, unsigned long size);
260extern long find_next_bit(const unsigned long * addr, long size, long offset);
261
262/* return index of first bet set in val or max when no bit is set */
263static inline unsigned long __scanbit(unsigned long val, unsigned long max)
264{
265 asm("bsfq %1,%0 ; cmovz %2,%0" : "=&r" (val) : "r" (val), "r" (max));
266 return val;
267}
268
269#define find_first_bit(addr,size) \
270((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
271 (__scanbit(*(unsigned long *)addr,(size))) : \
272 find_first_bit(addr,size)))
273
274#define find_next_bit(addr,size,off) \
275((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
276 ((off) + (__scanbit((*(unsigned long *)addr) >> (off),(size)-(off)))) : \
277 find_next_bit(addr,size,off)))
278
279#define find_first_zero_bit(addr,size) \
280((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
281 (__scanbit(~*(unsigned long *)addr,(size))) : \
282 find_first_zero_bit(addr,size)))
283
284#define find_next_zero_bit(addr,size,off) \
285((__builtin_constant_p(size) && (size) <= BITS_PER_LONG ? \
286 ((off)+(__scanbit(~(((*(unsigned long *)addr)) >> (off)),(size)-(off)))) : \
287 find_next_zero_bit(addr,size,off)))
288
289/*
290 * Find string of zero bits in a bitmap. -1 when not found.
291 */
292extern unsigned long
293find_next_zero_string(unsigned long *bitmap, long start, long nbits, int len);
294
295static inline void set_bit_string(unsigned long *bitmap, unsigned long i,
296 int len)
297{
298 unsigned long end = i + len;
299 while (i < end) {
300 __set_bit(i, bitmap);
301 i++;
302 }
303}
304
305static inline void __clear_bit_string(unsigned long *bitmap, unsigned long i,
306 int len)
307{
308 unsigned long end = i + len;
309 while (i < end) {
310 __clear_bit(i, bitmap);
311 i++;
312 }
313}
314
315/**
316 * ffz - find first zero in word.
317 * @word: The word to search
318 *
319 * Undefined if no zero exists, so code should check against ~0UL first.
320 */
321static __inline__ unsigned long ffz(unsigned long word)
322{
323 __asm__("bsfq %1,%0"
324 :"=r" (word)
325 :"r" (~word));
326 return word;
327}
328
329/**
330 * __ffs - find first bit in word.
331 * @word: The word to search
332 *
333 * Undefined if no bit exists, so code should check against 0 first.
334 */
335static __inline__ unsigned long __ffs(unsigned long word)
336{
337 __asm__("bsfq %1,%0"
338 :"=r" (word)
339 :"rm" (word));
340 return word;
341}
342
343#ifdef __KERNEL__
344
345static inline int sched_find_first_bit(const unsigned long *b)
346{
347 if (b[0])
348 return __ffs(b[0]);
349 if (b[1])
350 return __ffs(b[1]) + 64;
Jesse Millan8d224d32005-07-28 21:15:51 -0700351 return __ffs(b[2]) + 128;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352}
353
354/**
355 * ffs - find first bit set
356 * @x: the word to search
357 *
358 * This is defined the same way as
359 * the libc and compiler builtin ffs routines, therefore
360 * differs in spirit from the above ffz (man ffs).
361 */
362static __inline__ int ffs(int x)
363{
364 int r;
365
366 __asm__("bsfl %1,%0\n\t"
367 "cmovzl %2,%0"
368 : "=r" (r) : "rm" (x), "r" (-1));
369 return r+1;
370}
371
372/**
373 * hweightN - returns the hamming weight of a N-bit word
374 * @x: the word to weigh
375 *
376 * The Hamming Weight of a number is the total number of bits set in it.
377 */
378
379#define hweight64(x) generic_hweight64(x)
380#define hweight32(x) generic_hweight32(x)
381#define hweight16(x) generic_hweight16(x)
382#define hweight8(x) generic_hweight8(x)
383
384#endif /* __KERNEL__ */
385
386#ifdef __KERNEL__
387
388#define ext2_set_bit(nr,addr) \
389 __test_and_set_bit((nr),(unsigned long*)addr)
390#define ext2_set_bit_atomic(lock,nr,addr) \
391 test_and_set_bit((nr),(unsigned long*)addr)
392#define ext2_clear_bit(nr, addr) \
393 __test_and_clear_bit((nr),(unsigned long*)addr)
394#define ext2_clear_bit_atomic(lock,nr,addr) \
395 test_and_clear_bit((nr),(unsigned long*)addr)
396#define ext2_test_bit(nr, addr) test_bit((nr),(unsigned long*)addr)
397#define ext2_find_first_zero_bit(addr, size) \
398 find_first_zero_bit((unsigned long*)addr, size)
399#define ext2_find_next_zero_bit(addr, size, off) \
400 find_next_zero_bit((unsigned long*)addr, size, off)
401
402/* Bitmap functions for the minix filesystem. */
403#define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,(void*)addr)
404#define minix_set_bit(nr,addr) __set_bit(nr,(void*)addr)
405#define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,(void*)addr)
406#define minix_test_bit(nr,addr) test_bit(nr,(void*)addr)
407#define minix_find_first_zero_bit(addr,size) \
408 find_first_zero_bit((void*)addr,size)
409
410/* find last set bit */
411#define fls(x) generic_fls(x)
412
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413#endif /* __KERNEL__ */
414
415#endif /* _X86_64_BITOPS_H */