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Diffstat (limited to 'arch/x86/include/asm/bitops.h')
-rw-r--r-- | arch/x86/include/asm/bitops.h | 451 |
1 files changed, 451 insertions, 0 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h new file mode 100644 index 000000000000..451a74762bd4 --- /dev/null +++ b/arch/x86/include/asm/bitops.h | |||
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1 | #ifndef ASM_X86__BITOPS_H | ||
2 | #define ASM_X86__BITOPS_H | ||
3 | |||
4 | /* | ||
5 | * Copyright 1992, Linus Torvalds. | ||
6 | */ | ||
7 | |||
8 | #ifndef _LINUX_BITOPS_H | ||
9 | #error only <linux/bitops.h> can be included directly | ||
10 | #endif | ||
11 | |||
12 | #include <linux/compiler.h> | ||
13 | #include <asm/alternative.h> | ||
14 | |||
15 | /* | ||
16 | * These have to be done with inline assembly: that way the bit-setting | ||
17 | * is guaranteed to be atomic. All bit operations return 0 if the bit | ||
18 | * was cleared before the operation and != 0 if it was not. | ||
19 | * | ||
20 | * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). | ||
21 | */ | ||
22 | |||
23 | #if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1) | ||
24 | /* Technically wrong, but this avoids compilation errors on some gcc | ||
25 | versions. */ | ||
26 | #define BITOP_ADDR(x) "=m" (*(volatile long *) (x)) | ||
27 | #else | ||
28 | #define BITOP_ADDR(x) "+m" (*(volatile long *) (x)) | ||
29 | #endif | ||
30 | |||
31 | #define ADDR BITOP_ADDR(addr) | ||
32 | |||
33 | /* | ||
34 | * We do the locked ops that don't return the old value as | ||
35 | * a mask operation on a byte. | ||
36 | */ | ||
37 | #define IS_IMMEDIATE(nr) (__builtin_constant_p(nr)) | ||
38 | #define CONST_MASK_ADDR(nr, addr) BITOP_ADDR((void *)(addr) + ((nr)>>3)) | ||
39 | #define CONST_MASK(nr) (1 << ((nr) & 7)) | ||
40 | |||
41 | /** | ||
42 | * set_bit - Atomically set a bit in memory | ||
43 | * @nr: the bit to set | ||
44 | * @addr: the address to start counting from | ||
45 | * | ||
46 | * This function is atomic and may not be reordered. See __set_bit() | ||
47 | * if you do not require the atomic guarantees. | ||
48 | * | ||
49 | * Note: there are no guarantees that this function will not be reordered | ||
50 | * on non x86 architectures, so if you are writing portable code, | ||
51 | * make sure not to rely on its reordering guarantees. | ||
52 | * | ||
53 | * Note that @nr may be almost arbitrarily large; this function is not | ||
54 | * restricted to acting on a single-word quantity. | ||
55 | */ | ||
56 | static inline void set_bit(unsigned int nr, volatile unsigned long *addr) | ||
57 | { | ||
58 | if (IS_IMMEDIATE(nr)) { | ||
59 | asm volatile(LOCK_PREFIX "orb %1,%0" | ||
60 | : CONST_MASK_ADDR(nr, addr) | ||
61 | : "iq" ((u8)CONST_MASK(nr)) | ||
62 | : "memory"); | ||
63 | } else { | ||
64 | asm volatile(LOCK_PREFIX "bts %1,%0" | ||
65 | : BITOP_ADDR(addr) : "Ir" (nr) : "memory"); | ||
66 | } | ||
67 | } | ||
68 | |||
69 | /** | ||
70 | * __set_bit - Set a bit in memory | ||
71 | * @nr: the bit to set | ||
72 | * @addr: the address to start counting from | ||
73 | * | ||
74 | * Unlike set_bit(), this function is non-atomic and may be reordered. | ||
75 | * If it's called on the same region of memory simultaneously, the effect | ||
76 | * may be that only one operation succeeds. | ||
77 | */ | ||
78 | static inline void __set_bit(int nr, volatile unsigned long *addr) | ||
79 | { | ||
80 | asm volatile("bts %1,%0" : ADDR : "Ir" (nr) : "memory"); | ||
81 | } | ||
82 | |||
83 | /** | ||
84 | * clear_bit - Clears a bit in memory | ||
85 | * @nr: Bit to clear | ||
86 | * @addr: Address to start counting from | ||
87 | * | ||
88 | * clear_bit() is atomic and may not be reordered. However, it does | ||
89 | * not contain a memory barrier, so if it is used for locking purposes, | ||
90 | * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() | ||
91 | * in order to ensure changes are visible on other processors. | ||
92 | */ | ||
93 | static inline void clear_bit(int nr, volatile unsigned long *addr) | ||
94 | { | ||
95 | if (IS_IMMEDIATE(nr)) { | ||
96 | asm volatile(LOCK_PREFIX "andb %1,%0" | ||
97 | : CONST_MASK_ADDR(nr, addr) | ||
98 | : "iq" ((u8)~CONST_MASK(nr))); | ||
99 | } else { | ||
100 | asm volatile(LOCK_PREFIX "btr %1,%0" | ||
101 | : BITOP_ADDR(addr) | ||
102 | : "Ir" (nr)); | ||
103 | } | ||
104 | } | ||
105 | |||
106 | /* | ||
107 | * clear_bit_unlock - Clears a bit in memory | ||
108 | * @nr: Bit to clear | ||
109 | * @addr: Address to start counting from | ||
110 | * | ||
111 | * clear_bit() is atomic and implies release semantics before the memory | ||
112 | * operation. It can be used for an unlock. | ||
113 | */ | ||
114 | static inline void clear_bit_unlock(unsigned nr, volatile unsigned long *addr) | ||
115 | { | ||
116 | barrier(); | ||
117 | clear_bit(nr, addr); | ||
118 | } | ||
119 | |||
120 | static inline void __clear_bit(int nr, volatile unsigned long *addr) | ||
121 | { | ||
122 | asm volatile("btr %1,%0" : ADDR : "Ir" (nr)); | ||
123 | } | ||
124 | |||
125 | /* | ||
126 | * __clear_bit_unlock - Clears a bit in memory | ||
127 | * @nr: Bit to clear | ||
128 | * @addr: Address to start counting from | ||
129 | * | ||
130 | * __clear_bit() is non-atomic and implies release semantics before the memory | ||
131 | * operation. It can be used for an unlock if no other CPUs can concurrently | ||
132 | * modify other bits in the word. | ||
133 | * | ||
134 | * No memory barrier is required here, because x86 cannot reorder stores past | ||
135 | * older loads. Same principle as spin_unlock. | ||
136 | */ | ||
137 | static inline void __clear_bit_unlock(unsigned nr, volatile unsigned long *addr) | ||
138 | { | ||
139 | barrier(); | ||
140 | __clear_bit(nr, addr); | ||
141 | } | ||
142 | |||
143 | #define smp_mb__before_clear_bit() barrier() | ||
144 | #define smp_mb__after_clear_bit() barrier() | ||
145 | |||
146 | /** | ||
147 | * __change_bit - Toggle a bit in memory | ||
148 | * @nr: the bit to change | ||
149 | * @addr: the address to start counting from | ||
150 | * | ||
151 | * Unlike change_bit(), this function is non-atomic and may be reordered. | ||
152 | * If it's called on the same region of memory simultaneously, the effect | ||
153 | * may be that only one operation succeeds. | ||
154 | */ | ||
155 | static inline void __change_bit(int nr, volatile unsigned long *addr) | ||
156 | { | ||
157 | asm volatile("btc %1,%0" : ADDR : "Ir" (nr)); | ||
158 | } | ||
159 | |||
160 | /** | ||
161 | * change_bit - Toggle a bit in memory | ||
162 | * @nr: Bit to change | ||
163 | * @addr: Address to start counting from | ||
164 | * | ||
165 | * change_bit() is atomic and may not be reordered. | ||
166 | * Note that @nr may be almost arbitrarily large; this function is not | ||
167 | * restricted to acting on a single-word quantity. | ||
168 | */ | ||
169 | static inline void change_bit(int nr, volatile unsigned long *addr) | ||
170 | { | ||
171 | asm volatile(LOCK_PREFIX "btc %1,%0" : ADDR : "Ir" (nr)); | ||
172 | } | ||
173 | |||
174 | /** | ||
175 | * test_and_set_bit - Set a bit and return its old value | ||
176 | * @nr: Bit to set | ||
177 | * @addr: Address to count from | ||
178 | * | ||
179 | * This operation is atomic and cannot be reordered. | ||
180 | * It also implies a memory barrier. | ||
181 | */ | ||
182 | static inline int test_and_set_bit(int nr, volatile unsigned long *addr) | ||
183 | { | ||
184 | int oldbit; | ||
185 | |||
186 | asm volatile(LOCK_PREFIX "bts %2,%1\n\t" | ||
187 | "sbb %0,%0" : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); | ||
188 | |||
189 | return oldbit; | ||
190 | } | ||
191 | |||
192 | /** | ||
193 | * test_and_set_bit_lock - Set a bit and return its old value for lock | ||
194 | * @nr: Bit to set | ||
195 | * @addr: Address to count from | ||
196 | * | ||
197 | * This is the same as test_and_set_bit on x86. | ||
198 | */ | ||
199 | static inline int test_and_set_bit_lock(int nr, volatile unsigned long *addr) | ||
200 | { | ||
201 | return test_and_set_bit(nr, addr); | ||
202 | } | ||
203 | |||
204 | /** | ||
205 | * __test_and_set_bit - Set a bit and return its old value | ||
206 | * @nr: Bit to set | ||
207 | * @addr: Address to count from | ||
208 | * | ||
209 | * This operation is non-atomic and can be reordered. | ||
210 | * If two examples of this operation race, one can appear to succeed | ||
211 | * but actually fail. You must protect multiple accesses with a lock. | ||
212 | */ | ||
213 | static inline int __test_and_set_bit(int nr, volatile unsigned long *addr) | ||
214 | { | ||
215 | int oldbit; | ||
216 | |||
217 | asm("bts %2,%1\n\t" | ||
218 | "sbb %0,%0" | ||
219 | : "=r" (oldbit), ADDR | ||
220 | : "Ir" (nr)); | ||
221 | return oldbit; | ||
222 | } | ||
223 | |||
224 | /** | ||
225 | * test_and_clear_bit - Clear a bit and return its old value | ||
226 | * @nr: Bit to clear | ||
227 | * @addr: Address to count from | ||
228 | * | ||
229 | * This operation is atomic and cannot be reordered. | ||
230 | * It also implies a memory barrier. | ||
231 | */ | ||
232 | static inline int test_and_clear_bit(int nr, volatile unsigned long *addr) | ||
233 | { | ||
234 | int oldbit; | ||
235 | |||
236 | asm volatile(LOCK_PREFIX "btr %2,%1\n\t" | ||
237 | "sbb %0,%0" | ||
238 | : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); | ||
239 | |||
240 | return oldbit; | ||
241 | } | ||
242 | |||
243 | /** | ||
244 | * __test_and_clear_bit - Clear a bit and return its old value | ||
245 | * @nr: Bit to clear | ||
246 | * @addr: Address to count from | ||
247 | * | ||
248 | * This operation is non-atomic and can be reordered. | ||
249 | * If two examples of this operation race, one can appear to succeed | ||
250 | * but actually fail. You must protect multiple accesses with a lock. | ||
251 | */ | ||
252 | static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) | ||
253 | { | ||
254 | int oldbit; | ||
255 | |||
256 | asm volatile("btr %2,%1\n\t" | ||
257 | "sbb %0,%0" | ||
258 | : "=r" (oldbit), ADDR | ||
259 | : "Ir" (nr)); | ||
260 | return oldbit; | ||
261 | } | ||
262 | |||
263 | /* WARNING: non atomic and it can be reordered! */ | ||
264 | static inline int __test_and_change_bit(int nr, volatile unsigned long *addr) | ||
265 | { | ||
266 | int oldbit; | ||
267 | |||
268 | asm volatile("btc %2,%1\n\t" | ||
269 | "sbb %0,%0" | ||
270 | : "=r" (oldbit), ADDR | ||
271 | : "Ir" (nr) : "memory"); | ||
272 | |||
273 | return oldbit; | ||
274 | } | ||
275 | |||
276 | /** | ||
277 | * test_and_change_bit - Change a bit and return its old value | ||
278 | * @nr: Bit to change | ||
279 | * @addr: Address to count from | ||
280 | * | ||
281 | * This operation is atomic and cannot be reordered. | ||
282 | * It also implies a memory barrier. | ||
283 | */ | ||
284 | static inline int test_and_change_bit(int nr, volatile unsigned long *addr) | ||
285 | { | ||
286 | int oldbit; | ||
287 | |||
288 | asm volatile(LOCK_PREFIX "btc %2,%1\n\t" | ||
289 | "sbb %0,%0" | ||
290 | : "=r" (oldbit), ADDR : "Ir" (nr) : "memory"); | ||
291 | |||
292 | return oldbit; | ||
293 | } | ||
294 | |||
295 | static inline int constant_test_bit(int nr, const volatile unsigned long *addr) | ||
296 | { | ||
297 | return ((1UL << (nr % BITS_PER_LONG)) & | ||
298 | (((unsigned long *)addr)[nr / BITS_PER_LONG])) != 0; | ||
299 | } | ||
300 | |||
301 | static inline int variable_test_bit(int nr, volatile const unsigned long *addr) | ||
302 | { | ||
303 | int oldbit; | ||
304 | |||
305 | asm volatile("bt %2,%1\n\t" | ||
306 | "sbb %0,%0" | ||
307 | : "=r" (oldbit) | ||
308 | : "m" (*(unsigned long *)addr), "Ir" (nr)); | ||
309 | |||
310 | return oldbit; | ||
311 | } | ||
312 | |||
313 | #if 0 /* Fool kernel-doc since it doesn't do macros yet */ | ||
314 | /** | ||
315 | * test_bit - Determine whether a bit is set | ||
316 | * @nr: bit number to test | ||
317 | * @addr: Address to start counting from | ||
318 | */ | ||
319 | static int test_bit(int nr, const volatile unsigned long *addr); | ||
320 | #endif | ||
321 | |||
322 | #define test_bit(nr, addr) \ | ||
323 | (__builtin_constant_p((nr)) \ | ||
324 | ? constant_test_bit((nr), (addr)) \ | ||
325 | : variable_test_bit((nr), (addr))) | ||
326 | |||
327 | /** | ||
328 | * __ffs - find first set bit in word | ||
329 | * @word: The word to search | ||
330 | * | ||
331 | * Undefined if no bit exists, so code should check against 0 first. | ||
332 | */ | ||
333 | static inline unsigned long __ffs(unsigned long word) | ||
334 | { | ||
335 | asm("bsf %1,%0" | ||
336 | : "=r" (word) | ||
337 | : "rm" (word)); | ||
338 | return word; | ||
339 | } | ||
340 | |||
341 | /** | ||
342 | * ffz - find first zero bit in word | ||
343 | * @word: The word to search | ||
344 | * | ||
345 | * Undefined if no zero exists, so code should check against ~0UL first. | ||
346 | */ | ||
347 | static inline unsigned long ffz(unsigned long word) | ||
348 | { | ||
349 | asm("bsf %1,%0" | ||
350 | : "=r" (word) | ||
351 | : "r" (~word)); | ||
352 | return word; | ||
353 | } | ||
354 | |||
355 | /* | ||
356 | * __fls: find last set bit in word | ||
357 | * @word: The word to search | ||
358 | * | ||
359 | * Undefined if no set bit exists, so code should check against 0 first. | ||
360 | */ | ||
361 | static inline unsigned long __fls(unsigned long word) | ||
362 | { | ||
363 | asm("bsr %1,%0" | ||
364 | : "=r" (word) | ||
365 | : "rm" (word)); | ||
366 | return word; | ||
367 | } | ||
368 | |||
369 | #ifdef __KERNEL__ | ||
370 | /** | ||
371 | * ffs - find first set bit in word | ||
372 | * @x: the word to search | ||
373 | * | ||
374 | * This is defined the same way as the libc and compiler builtin ffs | ||
375 | * routines, therefore differs in spirit from the other bitops. | ||
376 | * | ||
377 | * ffs(value) returns 0 if value is 0 or the position of the first | ||
378 | * set bit if value is nonzero. The first (least significant) bit | ||
379 | * is at position 1. | ||
380 | */ | ||
381 | static inline int ffs(int x) | ||
382 | { | ||
383 | int r; | ||
384 | #ifdef CONFIG_X86_CMOV | ||
385 | asm("bsfl %1,%0\n\t" | ||
386 | "cmovzl %2,%0" | ||
387 | : "=r" (r) : "rm" (x), "r" (-1)); | ||
388 | #else | ||
389 | asm("bsfl %1,%0\n\t" | ||
390 | "jnz 1f\n\t" | ||
391 | "movl $-1,%0\n" | ||
392 | "1:" : "=r" (r) : "rm" (x)); | ||
393 | #endif | ||
394 | return r + 1; | ||
395 | } | ||
396 | |||
397 | /** | ||
398 | * fls - find last set bit in word | ||
399 | * @x: the word to search | ||
400 | * | ||
401 | * This is defined in a similar way as the libc and compiler builtin | ||
402 | * ffs, but returns the position of the most significant set bit. | ||
403 | * | ||
404 | * fls(value) returns 0 if value is 0 or the position of the last | ||
405 | * set bit if value is nonzero. The last (most significant) bit is | ||
406 | * at position 32. | ||
407 | */ | ||
408 | static inline int fls(int x) | ||
409 | { | ||
410 | int r; | ||
411 | #ifdef CONFIG_X86_CMOV | ||
412 | asm("bsrl %1,%0\n\t" | ||
413 | "cmovzl %2,%0" | ||
414 | : "=&r" (r) : "rm" (x), "rm" (-1)); | ||
415 | #else | ||
416 | asm("bsrl %1,%0\n\t" | ||
417 | "jnz 1f\n\t" | ||
418 | "movl $-1,%0\n" | ||
419 | "1:" : "=r" (r) : "rm" (x)); | ||
420 | #endif | ||
421 | return r + 1; | ||
422 | } | ||
423 | #endif /* __KERNEL__ */ | ||
424 | |||
425 | #undef ADDR | ||
426 | |||
427 | #ifdef __KERNEL__ | ||
428 | |||
429 | #include <asm-generic/bitops/sched.h> | ||
430 | |||
431 | #define ARCH_HAS_FAST_MULTIPLIER 1 | ||
432 | |||
433 | #include <asm-generic/bitops/hweight.h> | ||
434 | |||
435 | #endif /* __KERNEL__ */ | ||
436 | |||
437 | #include <asm-generic/bitops/fls64.h> | ||
438 | |||
439 | #ifdef __KERNEL__ | ||
440 | |||
441 | #include <asm-generic/bitops/ext2-non-atomic.h> | ||
442 | |||
443 | #define ext2_set_bit_atomic(lock, nr, addr) \ | ||
444 | test_and_set_bit((nr), (unsigned long *)(addr)) | ||
445 | #define ext2_clear_bit_atomic(lock, nr, addr) \ | ||
446 | test_and_clear_bit((nr), (unsigned long *)(addr)) | ||
447 | |||
448 | #include <asm-generic/bitops/minix.h> | ||
449 | |||
450 | #endif /* __KERNEL__ */ | ||
451 | #endif /* ASM_X86__BITOPS_H */ | ||