1 #ifndef _ALPHA_BITOPS_H
2 #define _ALPHA_BITOPS_H
4 #include <linux/config.h>
5 #include <linux/kernel.h>
6 #include <asm/compiler.h>
9 * Copyright 1994, Linus Torvalds.
13 * These have to be done with inline assembly: that way the bit-setting
14 * is guaranteed to be atomic. All bit operations return 0 if the bit
15 * was cleared before the operation and != 0 if it was not.
17 * To get proper branch prediction for the main line, we must branch
18 * forward to code at the end of this object's .text section, then
19 * branch back to restart the operation.
21 * bit 0 is the LSB of addr; bit 64 is the LSB of (addr+1).
25 set_bit(unsigned long nr, volatile void * addr)
28 int *m = ((int *) addr) + (nr >> 5);
38 :"=&r" (temp), "=m" (*m)
39 :"Ir" (1UL << (nr & 31)), "m" (*m));
43 * WARNING: non atomic version.
46 __set_bit(unsigned long nr, volatile void * addr)
48 int *m = ((int *) addr) + (nr >> 5);
53 #define smp_mb__before_clear_bit() smp_mb()
54 #define smp_mb__after_clear_bit() smp_mb()
57 clear_bit(unsigned long nr, volatile void * addr)
60 int *m = ((int *) addr) + (nr >> 5);
70 :"=&r" (temp), "=m" (*m)
71 :"Ir" (1UL << (nr & 31)), "m" (*m));
75 * WARNING: non atomic version.
77 static __inline__ void
78 __clear_bit(unsigned long nr, volatile void * addr)
80 int *m = ((int *) addr) + (nr >> 5);
82 *m &= ~(1 << (nr & 31));
86 change_bit(unsigned long nr, volatile void * addr)
89 int *m = ((int *) addr) + (nr >> 5);
99 :"=&r" (temp), "=m" (*m)
100 :"Ir" (1UL << (nr & 31)), "m" (*m));
104 * WARNING: non atomic version.
106 static __inline__ void
107 __change_bit(unsigned long nr, volatile void * addr)
109 int *m = ((int *) addr) + (nr >> 5);
111 *m ^= 1 << (nr & 31);
115 test_and_set_bit(unsigned long nr, volatile void *addr)
117 unsigned long oldbit;
119 int *m = ((int *) addr) + (nr >> 5);
121 __asm__ __volatile__(
135 :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
136 :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
142 * WARNING: non atomic version.
145 __test_and_set_bit(unsigned long nr, volatile void * addr)
147 unsigned long mask = 1 << (nr & 0x1f);
148 int *m = ((int *) addr) + (nr >> 5);
152 return (old & mask) != 0;
156 test_and_clear_bit(unsigned long nr, volatile void * addr)
158 unsigned long oldbit;
160 int *m = ((int *) addr) + (nr >> 5);
162 __asm__ __volatile__(
176 :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
177 :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
183 * WARNING: non atomic version.
186 __test_and_clear_bit(unsigned long nr, volatile void * addr)
188 unsigned long mask = 1 << (nr & 0x1f);
189 int *m = ((int *) addr) + (nr >> 5);
193 return (old & mask) != 0;
197 test_and_change_bit(unsigned long nr, volatile void * addr)
199 unsigned long oldbit;
201 int *m = ((int *) addr) + (nr >> 5);
203 __asm__ __volatile__(
215 :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
216 :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
222 * WARNING: non atomic version.
224 static __inline__ int
225 __test_and_change_bit(unsigned long nr, volatile void * addr)
227 unsigned long mask = 1 << (nr & 0x1f);
228 int *m = ((int *) addr) + (nr >> 5);
232 return (old & mask) != 0;
236 test_bit(int nr, const volatile void * addr)
238 return (1UL & (((const int *) addr)[nr >> 5] >> (nr & 31))) != 0UL;
242 * ffz = Find First Zero in word. Undefined if no zero exists,
243 * so code should check against ~0UL first..
245 * Do a binary search on the bits. Due to the nature of large
246 * constants on the alpha, it is worthwhile to split the search.
248 static inline unsigned long ffz_b(unsigned long x)
250 unsigned long sum, x1, x2, x4;
252 x = ~x & -~x; /* set first 0 bit, clear others */
257 sum += (x4 != 0) * 4;
263 static inline unsigned long ffz(unsigned long word)
265 #if defined(__alpha_cix__) && defined(__alpha_fix__)
266 /* Whee. EV67 can calculate it directly. */
267 return __kernel_cttz(~word);
269 unsigned long bits, qofs, bofs;
271 bits = __kernel_cmpbge(word, ~0UL);
273 bits = __kernel_extbl(word, qofs);
276 return qofs*8 + bofs;
281 * __ffs = Find First set bit in word. Undefined if no set bit exists.
283 static inline unsigned long __ffs(unsigned long word)
285 #if defined(__alpha_cix__) && defined(__alpha_fix__)
286 /* Whee. EV67 can calculate it directly. */
287 return __kernel_cttz(word);
289 unsigned long bits, qofs, bofs;
291 bits = __kernel_cmpbge(0, word);
293 bits = __kernel_extbl(word, qofs);
296 return qofs*8 + bofs;
303 * ffs: find first bit set. This is defined the same way as
304 * the libc and compiler builtin ffs routines, therefore
305 * differs in spirit from the above __ffs.
308 static inline int ffs(int word)
310 int result = __ffs(word) + 1;
311 return word ? result : 0;
315 * fls: find last bit set.
317 #if defined(__alpha_cix__) && defined(__alpha_fix__)
318 static inline int fls(int word)
320 return 64 - __kernel_ctlz(word & 0xffffffff);
323 #define fls generic_fls
326 /* Compute powers of two for the given integer. */
327 static inline int floor_log2(unsigned long word)
329 #if defined(__alpha_cix__) && defined(__alpha_fix__)
330 return 63 - __kernel_ctlz(word);
333 for (bit = -1; word ; bit++)
339 static inline int ceil_log2(unsigned int word)
341 long bit = floor_log2(word);
342 return bit + (word > (1UL << bit));
346 * hweightN: returns the hamming weight (i.e. the number
347 * of bits set) of a N-bit word
350 #if defined(__alpha_cix__) && defined(__alpha_fix__)
351 /* Whee. EV67 can calculate it directly. */
352 static inline unsigned long hweight64(unsigned long w)
354 return __kernel_ctpop(w);
357 #define hweight32(x) hweight64((x) & 0xfffffffful)
358 #define hweight16(x) hweight64((x) & 0xfffful)
359 #define hweight8(x) hweight64((x) & 0xfful)
361 static inline unsigned long hweight64(unsigned long w)
363 unsigned long result;
364 for (result = 0; w ; w >>= 1)
369 #define hweight32(x) generic_hweight32(x)
370 #define hweight16(x) generic_hweight16(x)
371 #define hweight8(x) generic_hweight8(x)
374 #endif /* __KERNEL__ */
377 * Find next zero bit in a bitmap reasonably efficiently..
379 static inline unsigned long
380 find_next_zero_bit(void * addr, unsigned long size, unsigned long offset)
382 unsigned long * p = ((unsigned long *) addr) + (offset >> 6);
383 unsigned long result = offset & ~63UL;
392 tmp |= ~0UL >> (64-offset);
400 while (size & ~63UL) {
411 if (tmp == ~0UL) /* Are any bits zero? */
412 return result + size; /* Nope. */
414 return result + ffz(tmp);
418 * Find next one bit in a bitmap reasonably efficiently.
420 static inline unsigned long
421 find_next_bit(void * addr, unsigned long size, unsigned long offset)
423 unsigned long * p = ((unsigned long *) addr) + (offset >> 6);
424 unsigned long result = offset & ~63UL;
433 tmp &= ~0UL << offset;
441 while (size & ~63UL) {
451 tmp &= ~0UL >> (64 - size);
453 return result + size;
455 return result + __ffs(tmp);
459 * The optimizer actually does good code for this case.
461 #define find_first_zero_bit(addr, size) \
462 find_next_zero_bit((addr), (size), 0)
463 #define find_first_bit(addr, size) \
464 find_next_bit((addr), (size), 0)
469 * Every architecture must define this function. It's the fastest
470 * way of searching a 140-bit bitmap where the first 100 bits are
471 * unlikely to be set. It's guaranteed that at least one of the 140
474 static inline unsigned long
475 sched_find_first_bit(unsigned long b[3])
477 unsigned long b0 = b[0], b1 = b[1], b2 = b[2];
480 ofs = (b1 ? 64 : 128);
482 ofs = (b0 ? 0 : ofs);
485 return __ffs(b0) + ofs;
489 #define ext2_set_bit __test_and_set_bit
490 #define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a)
491 #define ext2_clear_bit __test_and_clear_bit
492 #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
493 #define ext2_test_bit test_bit
494 #define ext2_find_first_zero_bit find_first_zero_bit
495 #define ext2_find_next_zero_bit find_next_zero_bit
497 /* Bitmap functions for the minix filesystem. */
498 #define minix_test_and_set_bit(nr,addr) __test_and_set_bit(nr,addr)
499 #define minix_set_bit(nr,addr) __set_bit(nr,addr)
500 #define minix_test_and_clear_bit(nr,addr) __test_and_clear_bit(nr,addr)
501 #define minix_test_bit(nr,addr) test_bit(nr,addr)
502 #define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)
504 #endif /* __KERNEL__ */
506 #endif /* _ALPHA_BITOPS_H */