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1da177e4 LT |
1 | /* asm/bitops.h for Linux/CRIS |
2 | * | |
3 | * TODO: asm versions if speed is needed | |
4 | * | |
5 | * All bit operations return 0 if the bit was cleared before the | |
6 | * operation and != 0 if it was not. | |
7 | * | |
8 | * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1). | |
9 | */ | |
10 | ||
11 | #ifndef _CRIS_BITOPS_H | |
12 | #define _CRIS_BITOPS_H | |
13 | ||
14 | /* Currently this is unsuitable for consumption outside the kernel. */ | |
15 | #ifdef __KERNEL__ | |
16 | ||
17 | #include <asm/arch/bitops.h> | |
18 | #include <asm/system.h> | |
5d01e6ce | 19 | #include <asm/atomic.h> |
1da177e4 LT |
20 | #include <linux/compiler.h> |
21 | ||
22 | /* | |
23 | * Some hacks to defeat gcc over-optimizations.. | |
24 | */ | |
25 | struct __dummy { unsigned long a[100]; }; | |
26 | #define ADDR (*(struct __dummy *) addr) | |
27 | #define CONST_ADDR (*(const struct __dummy *) addr) | |
28 | ||
29 | /* | |
30 | * set_bit - Atomically set a bit in memory | |
31 | * @nr: the bit to set | |
32 | * @addr: the address to start counting from | |
33 | * | |
34 | * This function is atomic and may not be reordered. See __set_bit() | |
35 | * if you do not require the atomic guarantees. | |
36 | * Note that @nr may be almost arbitrarily large; this function is not | |
37 | * restricted to acting on a single-word quantity. | |
38 | */ | |
39 | ||
40 | #define set_bit(nr, addr) (void)test_and_set_bit(nr, addr) | |
41 | ||
42 | #define __set_bit(nr, addr) (void)__test_and_set_bit(nr, addr) | |
43 | ||
44 | /* | |
45 | * clear_bit - Clears a bit in memory | |
46 | * @nr: Bit to clear | |
47 | * @addr: Address to start counting from | |
48 | * | |
49 | * clear_bit() is atomic and may not be reordered. However, it does | |
50 | * not contain a memory barrier, so if it is used for locking purposes, | |
51 | * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit() | |
52 | * in order to ensure changes are visible on other processors. | |
53 | */ | |
54 | ||
55 | #define clear_bit(nr, addr) (void)test_and_clear_bit(nr, addr) | |
56 | ||
57 | #define __clear_bit(nr, addr) (void)__test_and_clear_bit(nr, addr) | |
58 | ||
59 | /* | |
60 | * change_bit - Toggle a bit in memory | |
61 | * @nr: Bit to change | |
62 | * @addr: Address to start counting from | |
63 | * | |
64 | * change_bit() is atomic and may not be reordered. | |
65 | * Note that @nr may be almost arbitrarily large; this function is not | |
66 | * restricted to acting on a single-word quantity. | |
67 | */ | |
68 | ||
69 | #define change_bit(nr, addr) (void)test_and_change_bit(nr, addr) | |
70 | ||
71 | /* | |
72 | * __change_bit - Toggle a bit in memory | |
73 | * @nr: the bit to change | |
74 | * @addr: the address to start counting from | |
75 | * | |
76 | * Unlike change_bit(), this function is non-atomic and may be reordered. | |
77 | * If it's called on the same region of memory simultaneously, the effect | |
78 | * may be that only one operation succeeds. | |
79 | */ | |
80 | ||
81 | #define __change_bit(nr, addr) (void)__test_and_change_bit(nr, addr) | |
82 | ||
83 | /** | |
84 | * test_and_set_bit - Set a bit and return its old value | |
85 | * @nr: Bit to set | |
86 | * @addr: Address to count from | |
87 | * | |
88 | * This operation is atomic and cannot be reordered. | |
89 | * It also implies a memory barrier. | |
90 | */ | |
91 | ||
5d01e6ce | 92 | extern inline int test_and_set_bit(int nr, volatile unsigned long *addr) |
1da177e4 LT |
93 | { |
94 | unsigned int mask, retval; | |
95 | unsigned long flags; | |
96 | unsigned int *adr = (unsigned int *)addr; | |
97 | ||
98 | adr += nr >> 5; | |
99 | mask = 1 << (nr & 0x1f); | |
5d01e6ce | 100 | cris_atomic_save(addr, flags); |
1da177e4 LT |
101 | retval = (mask & *adr) != 0; |
102 | *adr |= mask; | |
5d01e6ce | 103 | cris_atomic_restore(addr, flags); |
1da177e4 LT |
104 | local_irq_restore(flags); |
105 | return retval; | |
106 | } | |
107 | ||
5d01e6ce | 108 | extern inline int __test_and_set_bit(int nr, volatile unsigned long *addr) |
1da177e4 LT |
109 | { |
110 | unsigned int mask, retval; | |
111 | unsigned int *adr = (unsigned int *)addr; | |
112 | ||
113 | adr += nr >> 5; | |
114 | mask = 1 << (nr & 0x1f); | |
115 | retval = (mask & *adr) != 0; | |
116 | *adr |= mask; | |
117 | return retval; | |
118 | } | |
119 | ||
120 | /* | |
121 | * clear_bit() doesn't provide any barrier for the compiler. | |
122 | */ | |
123 | #define smp_mb__before_clear_bit() barrier() | |
124 | #define smp_mb__after_clear_bit() barrier() | |
125 | ||
126 | /** | |
127 | * test_and_clear_bit - Clear a bit and return its old value | |
128 | * @nr: Bit to clear | |
129 | * @addr: Address to count from | |
130 | * | |
131 | * This operation is atomic and cannot be reordered. | |
132 | * It also implies a memory barrier. | |
133 | */ | |
134 | ||
5d01e6ce | 135 | extern inline int test_and_clear_bit(int nr, volatile unsigned long *addr) |
1da177e4 LT |
136 | { |
137 | unsigned int mask, retval; | |
138 | unsigned long flags; | |
139 | unsigned int *adr = (unsigned int *)addr; | |
140 | ||
141 | adr += nr >> 5; | |
142 | mask = 1 << (nr & 0x1f); | |
5d01e6ce | 143 | cris_atomic_save(addr, flags); |
1da177e4 LT |
144 | retval = (mask & *adr) != 0; |
145 | *adr &= ~mask; | |
5d01e6ce | 146 | cris_atomic_restore(addr, flags); |
1da177e4 LT |
147 | return retval; |
148 | } | |
149 | ||
150 | /** | |
151 | * __test_and_clear_bit - Clear a bit and return its old value | |
152 | * @nr: Bit to clear | |
153 | * @addr: Address to count from | |
154 | * | |
155 | * This operation is non-atomic and can be reordered. | |
156 | * If two examples of this operation race, one can appear to succeed | |
157 | * but actually fail. You must protect multiple accesses with a lock. | |
158 | */ | |
159 | ||
5d01e6ce | 160 | extern inline int __test_and_clear_bit(int nr, volatile unsigned long *addr) |
1da177e4 LT |
161 | { |
162 | unsigned int mask, retval; | |
163 | unsigned int *adr = (unsigned int *)addr; | |
164 | ||
165 | adr += nr >> 5; | |
166 | mask = 1 << (nr & 0x1f); | |
167 | retval = (mask & *adr) != 0; | |
168 | *adr &= ~mask; | |
169 | return retval; | |
170 | } | |
171 | /** | |
172 | * test_and_change_bit - Change a bit and return its old value | |
173 | * @nr: Bit to change | |
174 | * @addr: Address to count from | |
175 | * | |
176 | * This operation is atomic and cannot be reordered. | |
177 | * It also implies a memory barrier. | |
178 | */ | |
179 | ||
5d01e6ce | 180 | extern inline int test_and_change_bit(int nr, volatile unsigned long *addr) |
1da177e4 LT |
181 | { |
182 | unsigned int mask, retval; | |
183 | unsigned long flags; | |
184 | unsigned int *adr = (unsigned int *)addr; | |
185 | adr += nr >> 5; | |
186 | mask = 1 << (nr & 0x1f); | |
5d01e6ce | 187 | cris_atomic_save(addr, flags); |
1da177e4 LT |
188 | retval = (mask & *adr) != 0; |
189 | *adr ^= mask; | |
5d01e6ce | 190 | cris_atomic_restore(addr, flags); |
1da177e4 LT |
191 | return retval; |
192 | } | |
193 | ||
194 | /* WARNING: non atomic and it can be reordered! */ | |
195 | ||
5d01e6ce | 196 | extern inline int __test_and_change_bit(int nr, volatile unsigned long *addr) |
1da177e4 LT |
197 | { |
198 | unsigned int mask, retval; | |
199 | unsigned int *adr = (unsigned int *)addr; | |
200 | ||
201 | adr += nr >> 5; | |
202 | mask = 1 << (nr & 0x1f); | |
203 | retval = (mask & *adr) != 0; | |
204 | *adr ^= mask; | |
205 | ||
206 | return retval; | |
207 | } | |
208 | ||
209 | /** | |
210 | * test_bit - Determine whether a bit is set | |
211 | * @nr: bit number to test | |
212 | * @addr: Address to start counting from | |
213 | * | |
214 | * This routine doesn't need to be atomic. | |
215 | */ | |
216 | ||
5d01e6ce | 217 | extern inline int test_bit(int nr, const volatile unsigned long *addr) |
1da177e4 LT |
218 | { |
219 | unsigned int mask; | |
220 | unsigned int *adr = (unsigned int *)addr; | |
221 | ||
222 | adr += nr >> 5; | |
223 | mask = 1 << (nr & 0x1f); | |
224 | return ((mask & *adr) != 0); | |
225 | } | |
226 | ||
227 | /* | |
228 | * Find-bit routines.. | |
229 | */ | |
230 | ||
231 | /* | |
232 | * Since we define it "external", it collides with the built-in | |
233 | * definition, which doesn't have the same semantics. We don't want to | |
234 | * use -fno-builtin, so just hide the name ffs. | |
235 | */ | |
236 | #define ffs kernel_ffs | |
237 | ||
238 | /* | |
239 | * fls: find last bit set. | |
240 | */ | |
241 | ||
242 | #define fls(x) generic_fls(x) | |
243 | ||
244 | /* | |
245 | * hweightN - returns the hamming weight of a N-bit word | |
246 | * @x: the word to weigh | |
247 | * | |
248 | * The Hamming Weight of a number is the total number of bits set in it. | |
249 | */ | |
250 | ||
251 | #define hweight32(x) generic_hweight32(x) | |
252 | #define hweight16(x) generic_hweight16(x) | |
253 | #define hweight8(x) generic_hweight8(x) | |
254 | ||
255 | /** | |
256 | * find_next_zero_bit - find the first zero bit in a memory region | |
257 | * @addr: The address to base the search on | |
258 | * @offset: The bitnumber to start searching at | |
259 | * @size: The maximum size to search | |
260 | */ | |
5d01e6ce | 261 | extern inline int find_next_zero_bit (const unsigned long * addr, int size, int offset) |
1da177e4 LT |
262 | { |
263 | unsigned long *p = ((unsigned long *) addr) + (offset >> 5); | |
264 | unsigned long result = offset & ~31UL; | |
265 | unsigned long tmp; | |
266 | ||
267 | if (offset >= size) | |
268 | return size; | |
269 | size -= result; | |
270 | offset &= 31UL; | |
271 | if (offset) { | |
272 | tmp = *(p++); | |
273 | tmp |= ~0UL >> (32-offset); | |
274 | if (size < 32) | |
275 | goto found_first; | |
276 | if (~tmp) | |
277 | goto found_middle; | |
278 | size -= 32; | |
279 | result += 32; | |
280 | } | |
281 | while (size & ~31UL) { | |
282 | if (~(tmp = *(p++))) | |
283 | goto found_middle; | |
284 | result += 32; | |
285 | size -= 32; | |
286 | } | |
287 | if (!size) | |
288 | return result; | |
289 | tmp = *p; | |
290 | ||
291 | found_first: | |
292 | tmp |= ~0UL >> size; | |
293 | found_middle: | |
294 | return result + ffz(tmp); | |
295 | } | |
296 | ||
297 | /** | |
298 | * find_next_bit - find the first set bit in a memory region | |
299 | * @addr: The address to base the search on | |
300 | * @offset: The bitnumber to start searching at | |
301 | * @size: The maximum size to search | |
302 | */ | |
5d01e6ce | 303 | static __inline__ int find_next_bit(const unsigned long *addr, int size, int offset) |
1da177e4 LT |
304 | { |
305 | unsigned long *p = ((unsigned long *) addr) + (offset >> 5); | |
306 | unsigned long result = offset & ~31UL; | |
307 | unsigned long tmp; | |
308 | ||
309 | if (offset >= size) | |
310 | return size; | |
311 | size -= result; | |
312 | offset &= 31UL; | |
313 | if (offset) { | |
314 | tmp = *(p++); | |
315 | tmp &= (~0UL << offset); | |
316 | if (size < 32) | |
317 | goto found_first; | |
318 | if (tmp) | |
319 | goto found_middle; | |
320 | size -= 32; | |
321 | result += 32; | |
322 | } | |
323 | while (size & ~31UL) { | |
324 | if ((tmp = *(p++))) | |
325 | goto found_middle; | |
326 | result += 32; | |
327 | size -= 32; | |
328 | } | |
329 | if (!size) | |
330 | return result; | |
331 | tmp = *p; | |
332 | ||
333 | found_first: | |
334 | tmp &= (~0UL >> (32 - size)); | |
335 | if (tmp == 0UL) /* Are any bits set? */ | |
336 | return result + size; /* Nope. */ | |
337 | found_middle: | |
338 | return result + __ffs(tmp); | |
339 | } | |
340 | ||
341 | /** | |
342 | * find_first_zero_bit - find the first zero bit in a memory region | |
343 | * @addr: The address to start the search at | |
344 | * @size: The maximum size to search | |
345 | * | |
346 | * Returns the bit-number of the first zero bit, not the number of the byte | |
347 | * containing a bit. | |
348 | */ | |
349 | ||
350 | #define find_first_zero_bit(addr, size) \ | |
351 | find_next_zero_bit((addr), (size), 0) | |
352 | #define find_first_bit(addr, size) \ | |
353 | find_next_bit((addr), (size), 0) | |
354 | ||
355 | #define ext2_set_bit test_and_set_bit | |
356 | #define ext2_set_bit_atomic(l,n,a) test_and_set_bit(n,a) | |
357 | #define ext2_clear_bit test_and_clear_bit | |
358 | #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a) | |
359 | #define ext2_test_bit test_bit | |
360 | #define ext2_find_first_zero_bit find_first_zero_bit | |
361 | #define ext2_find_next_zero_bit find_next_zero_bit | |
362 | ||
363 | /* Bitmap functions for the minix filesystem. */ | |
364 | #define minix_set_bit(nr,addr) test_and_set_bit(nr,addr) | |
365 | #define minix_clear_bit(nr,addr) test_and_clear_bit(nr,addr) | |
366 | #define minix_test_bit(nr,addr) test_bit(nr,addr) | |
367 | #define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size) | |
368 | ||
5d01e6ce | 369 | extern inline int sched_find_first_bit(const unsigned long *b) |
1da177e4 LT |
370 | { |
371 | if (unlikely(b[0])) | |
372 | return __ffs(b[0]); | |
373 | if (unlikely(b[1])) | |
374 | return __ffs(b[1]) + 32; | |
375 | if (unlikely(b[2])) | |
376 | return __ffs(b[2]) + 64; | |
377 | if (unlikely(b[3])) | |
378 | return __ffs(b[3]) + 96; | |
379 | if (b[4]) | |
380 | return __ffs(b[4]) + 128; | |
381 | return __ffs(b[5]) + 32 + 128; | |
382 | } | |
383 | ||
384 | #endif /* __KERNEL__ */ | |
385 | ||
386 | #endif /* _CRIS_BITOPS_H */ |