1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_FIND_H_
3 #define __LINUX_FIND_H_
5 #ifndef __LINUX_BITMAP_H
6 #error only <linux/bitmap.h> can be included directly
9 #include <linux/bitops.h>
11 extern unsigned long _find_next_bit(const unsigned long *addr1,
12 const unsigned long *addr2, unsigned long nbits,
13 unsigned long start, unsigned long invert, unsigned long le);
14 extern unsigned long _find_first_bit(const unsigned long *addr, unsigned long size);
15 extern unsigned long _find_first_and_bit(const unsigned long *addr1,
16 const unsigned long *addr2, unsigned long size);
17 extern unsigned long _find_first_zero_bit(const unsigned long *addr, unsigned long size);
18 extern unsigned long _find_last_bit(const unsigned long *addr, unsigned long size);
22 * find_next_bit - find the next set bit in a memory region
23 * @addr: The address to base the search on
24 * @offset: The bitnumber to start searching at
25 * @size: The bitmap size in bits
27 * Returns the bit number for the next set bit
28 * If no bits are set, returns @size.
31 unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
34 if (small_const_nbits(size)) {
37 if (unlikely(offset >= size))
40 val = *addr & GENMASK(size - 1, offset);
41 return val ? __ffs(val) : size;
44 return _find_next_bit(addr, NULL, size, offset, 0UL, 0);
48 #ifndef find_next_and_bit
50 * find_next_and_bit - find the next set bit in both memory regions
51 * @addr1: The first address to base the search on
52 * @addr2: The second address to base the search on
53 * @offset: The bitnumber to start searching at
54 * @size: The bitmap size in bits
56 * Returns the bit number for the next set bit
57 * If no bits are set, returns @size.
60 unsigned long find_next_and_bit(const unsigned long *addr1,
61 const unsigned long *addr2, unsigned long size,
64 if (small_const_nbits(size)) {
67 if (unlikely(offset >= size))
70 val = *addr1 & *addr2 & GENMASK(size - 1, offset);
71 return val ? __ffs(val) : size;
74 return _find_next_bit(addr1, addr2, size, offset, 0UL, 0);
78 #ifndef find_next_zero_bit
80 * find_next_zero_bit - find the next cleared bit in a memory region
81 * @addr: The address to base the search on
82 * @offset: The bitnumber to start searching at
83 * @size: The bitmap size in bits
85 * Returns the bit number of the next zero bit
86 * If no bits are zero, returns @size.
89 unsigned long find_next_zero_bit(const unsigned long *addr, unsigned long size,
92 if (small_const_nbits(size)) {
95 if (unlikely(offset >= size))
98 val = *addr | ~GENMASK(size - 1, offset);
99 return val == ~0UL ? size : ffz(val);
102 return _find_next_bit(addr, NULL, size, offset, ~0UL, 0);
106 #ifndef find_first_bit
108 * find_first_bit - find the first set bit in a memory region
109 * @addr: The address to start the search at
110 * @size: The maximum number of bits to search
112 * Returns the bit number of the first set bit.
113 * If no bits are set, returns @size.
116 unsigned long find_first_bit(const unsigned long *addr, unsigned long size)
118 if (small_const_nbits(size)) {
119 unsigned long val = *addr & GENMASK(size - 1, 0);
121 return val ? __ffs(val) : size;
124 return _find_first_bit(addr, size);
128 #ifndef find_first_and_bit
130 * find_first_and_bit - find the first set bit in both memory regions
131 * @addr1: The first address to base the search on
132 * @addr2: The second address to base the search on
133 * @size: The bitmap size in bits
135 * Returns the bit number for the next set bit
136 * If no bits are set, returns @size.
139 unsigned long find_first_and_bit(const unsigned long *addr1,
140 const unsigned long *addr2,
143 if (small_const_nbits(size)) {
144 unsigned long val = *addr1 & *addr2 & GENMASK(size - 1, 0);
146 return val ? __ffs(val) : size;
149 return _find_first_and_bit(addr1, addr2, size);
153 #ifndef find_first_zero_bit
155 * find_first_zero_bit - find the first cleared bit in a memory region
156 * @addr: The address to start the search at
157 * @size: The maximum number of bits to search
159 * Returns the bit number of the first cleared bit.
160 * If no bits are zero, returns @size.
163 unsigned long find_first_zero_bit(const unsigned long *addr, unsigned long size)
165 if (small_const_nbits(size)) {
166 unsigned long val = *addr | ~GENMASK(size - 1, 0);
168 return val == ~0UL ? size : ffz(val);
171 return _find_first_zero_bit(addr, size);
175 #ifndef find_last_bit
177 * find_last_bit - find the last set bit in a memory region
178 * @addr: The address to start the search at
179 * @size: The number of bits to search
181 * Returns the bit number of the last set bit, or size.
184 unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
186 if (small_const_nbits(size)) {
187 unsigned long val = *addr & GENMASK(size - 1, 0);
189 return val ? __fls(val) : size;
192 return _find_last_bit(addr, size);
197 * find_next_clump8 - find next 8-bit clump with set bits in a memory region
198 * @clump: location to store copy of found clump
199 * @addr: address to base the search on
200 * @size: bitmap size in number of bits
201 * @offset: bit offset at which to start searching
203 * Returns the bit offset for the next set clump; the found clump value is
204 * copied to the location pointed by @clump. If no bits are set, returns @size.
206 extern unsigned long find_next_clump8(unsigned long *clump,
207 const unsigned long *addr,
208 unsigned long size, unsigned long offset);
210 #define find_first_clump8(clump, bits, size) \
211 find_next_clump8((clump), (bits), (size), 0)
213 #if defined(__LITTLE_ENDIAN)
215 static inline unsigned long find_next_zero_bit_le(const void *addr,
216 unsigned long size, unsigned long offset)
218 return find_next_zero_bit(addr, size, offset);
221 static inline unsigned long find_next_bit_le(const void *addr,
222 unsigned long size, unsigned long offset)
224 return find_next_bit(addr, size, offset);
227 static inline unsigned long find_first_zero_bit_le(const void *addr,
230 return find_first_zero_bit(addr, size);
233 #elif defined(__BIG_ENDIAN)
235 #ifndef find_next_zero_bit_le
237 unsigned long find_next_zero_bit_le(const void *addr, unsigned
238 long size, unsigned long offset)
240 if (small_const_nbits(size)) {
241 unsigned long val = *(const unsigned long *)addr;
243 if (unlikely(offset >= size))
246 val = swab(val) | ~GENMASK(size - 1, offset);
247 return val == ~0UL ? size : ffz(val);
250 return _find_next_bit(addr, NULL, size, offset, ~0UL, 1);
254 #ifndef find_next_bit_le
256 unsigned long find_next_bit_le(const void *addr, unsigned
257 long size, unsigned long offset)
259 if (small_const_nbits(size)) {
260 unsigned long val = *(const unsigned long *)addr;
262 if (unlikely(offset >= size))
265 val = swab(val) & GENMASK(size - 1, offset);
266 return val ? __ffs(val) : size;
269 return _find_next_bit(addr, NULL, size, offset, 0UL, 1);
273 #ifndef find_first_zero_bit_le
274 #define find_first_zero_bit_le(addr, size) \
275 find_next_zero_bit_le((addr), (size), 0)
279 #error "Please fix <asm/byteorder.h>"
282 #define for_each_set_bit(bit, addr, size) \
283 for ((bit) = find_next_bit((addr), (size), 0); \
285 (bit) = find_next_bit((addr), (size), (bit) + 1))
287 /* same as for_each_set_bit() but use bit as value to start with */
288 #define for_each_set_bit_from(bit, addr, size) \
289 for ((bit) = find_next_bit((addr), (size), (bit)); \
291 (bit) = find_next_bit((addr), (size), (bit) + 1))
293 #define for_each_clear_bit(bit, addr, size) \
294 for ((bit) = find_next_zero_bit((addr), (size), 0); \
296 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
298 /* same as for_each_clear_bit() but use bit as value to start with */
299 #define for_each_clear_bit_from(bit, addr, size) \
300 for ((bit) = find_next_zero_bit((addr), (size), (bit)); \
302 (bit) = find_next_zero_bit((addr), (size), (bit) + 1))
305 * for_each_set_bitrange - iterate over all set bit ranges [b; e)
306 * @b: bit offset of start of current bitrange (first set bit)
307 * @e: bit offset of end of current bitrange (first unset bit)
308 * @addr: bitmap address to base the search on
309 * @size: bitmap size in number of bits
311 #define for_each_set_bitrange(b, e, addr, size) \
312 for ((b) = find_next_bit((addr), (size), 0), \
313 (e) = find_next_zero_bit((addr), (size), (b) + 1); \
315 (b) = find_next_bit((addr), (size), (e) + 1), \
316 (e) = find_next_zero_bit((addr), (size), (b) + 1))
319 * for_each_set_bitrange_from - iterate over all set bit ranges [b; e)
320 * @b: bit offset of start of current bitrange (first set bit); must be initialized
321 * @e: bit offset of end of current bitrange (first unset bit)
322 * @addr: bitmap address to base the search on
323 * @size: bitmap size in number of bits
325 #define for_each_set_bitrange_from(b, e, addr, size) \
326 for ((b) = find_next_bit((addr), (size), (b)), \
327 (e) = find_next_zero_bit((addr), (size), (b) + 1); \
329 (b) = find_next_bit((addr), (size), (e) + 1), \
330 (e) = find_next_zero_bit((addr), (size), (b) + 1))
333 * for_each_clear_bitrange - iterate over all unset bit ranges [b; e)
334 * @b: bit offset of start of current bitrange (first unset bit)
335 * @e: bit offset of end of current bitrange (first set bit)
336 * @addr: bitmap address to base the search on
337 * @size: bitmap size in number of bits
339 #define for_each_clear_bitrange(b, e, addr, size) \
340 for ((b) = find_next_zero_bit((addr), (size), 0), \
341 (e) = find_next_bit((addr), (size), (b) + 1); \
343 (b) = find_next_zero_bit((addr), (size), (e) + 1), \
344 (e) = find_next_bit((addr), (size), (b) + 1))
347 * for_each_clear_bitrange_from - iterate over all unset bit ranges [b; e)
348 * @b: bit offset of start of current bitrange (first set bit); must be initialized
349 * @e: bit offset of end of current bitrange (first unset bit)
350 * @addr: bitmap address to base the search on
351 * @size: bitmap size in number of bits
353 #define for_each_clear_bitrange_from(b, e, addr, size) \
354 for ((b) = find_next_zero_bit((addr), (size), (b)), \
355 (e) = find_next_bit((addr), (size), (b) + 1); \
357 (b) = find_next_zero_bit((addr), (size), (e) + 1), \
358 (e) = find_next_bit((addr), (size), (b) + 1))
361 * for_each_set_clump8 - iterate over bitmap for each 8-bit clump with set bits
362 * @start: bit offset to start search and to store the current iteration offset
363 * @clump: location to store copy of current 8-bit clump
364 * @bits: bitmap address to base the search on
365 * @size: bitmap size in number of bits
367 #define for_each_set_clump8(start, clump, bits, size) \
368 for ((start) = find_first_clump8(&(clump), (bits), (size)); \
370 (start) = find_next_clump8(&(clump), (bits), (size), (start) + 8))
372 #endif /*__LINUX_FIND_H_ */