xref: /freebsd/sys/dev/ice/ice_bitops.h (revision f2635e844dd138ac9dfba676f27d41750049af26)
1 /* SPDX-License-Identifier: BSD-3-Clause */
2 /*  Copyright (c) 2024, Intel Corporation
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31 
32 #ifndef _ICE_BITOPS_H_
33 #define _ICE_BITOPS_H_
34 
35 #include "ice_defs.h"
36 #include "ice_osdep.h"
37 
38 /* Define the size of the bitmap chunk */
39 typedef u32 ice_bitmap_t;
40 
41 /* NOTE!
42  * Do not use any of the functions declared in this file
43  * on memory that was not declared with ice_declare_bitmap.
44  * Not following this rule might cause issues like split
45  * locks.
46  */
47 
48 /* Number of bits per bitmap chunk */
49 #define BITS_PER_CHUNK		(BITS_PER_BYTE * sizeof(ice_bitmap_t))
50 /* Determine which chunk a bit belongs in */
51 #define BIT_CHUNK(nr)		((nr) / BITS_PER_CHUNK)
52 /* How many chunks are required to store this many bits */
53 #define BITS_TO_CHUNKS(sz)	(((sz) + BITS_PER_CHUNK - 1) / BITS_PER_CHUNK)
54 /* Which bit inside a chunk this bit corresponds to */
55 #define BIT_IN_CHUNK(nr)	((nr) % BITS_PER_CHUNK)
56 /* How many bits are valid in the last chunk, assumes nr > 0 */
57 #define LAST_CHUNK_BITS(nr)	((((nr) - 1) % BITS_PER_CHUNK) + 1)
58 /* Generate a bitmask of valid bits in the last chunk, assumes nr > 0 */
59 #define LAST_CHUNK_MASK(nr)	(((ice_bitmap_t)~0) >> \
60 				 (BITS_PER_CHUNK - LAST_CHUNK_BITS(nr)))
61 
62 #define ice_declare_bitmap(A, sz) \
63 	ice_bitmap_t A[BITS_TO_CHUNKS(sz)]
64 
65 static inline bool ice_is_bit_set_internal(u16 nr, const ice_bitmap_t *bitmap)
66 {
67 	return !!(*bitmap & BIT(nr));
68 }
69 
70 /*
71  * If atomic version of the bitops are required, each specific OS
72  * implementation will need to implement OS/platform specific atomic
73  * version of the functions below:
74  *
75  * ice_clear_bit_internal
76  * ice_set_bit_internal
77  * ice_test_and_clear_bit_internal
78  * ice_test_and_set_bit_internal
79  *
80  * and define macro ICE_ATOMIC_BITOPS to overwrite the default non-atomic
81  * implementation.
82  */
83 static inline void ice_clear_bit_internal(u16 nr, ice_bitmap_t *bitmap)
84 {
85 	*bitmap &= ~BIT(nr);
86 }
87 
88 static inline void ice_set_bit_internal(u16 nr, ice_bitmap_t *bitmap)
89 {
90 	*bitmap |= BIT(nr);
91 }
92 
93 static inline bool ice_test_and_clear_bit_internal(u16 nr,
94 						   ice_bitmap_t *bitmap)
95 {
96 	if (ice_is_bit_set_internal(nr, bitmap)) {
97 		ice_clear_bit_internal(nr, bitmap);
98 		return true;
99 	}
100 	return false;
101 }
102 
103 static inline bool ice_test_and_set_bit_internal(u16 nr, ice_bitmap_t *bitmap)
104 {
105 	if (ice_is_bit_set_internal(nr, bitmap))
106 		return true;
107 
108 	ice_set_bit_internal(nr, bitmap);
109 	return false;
110 }
111 
112 /**
113  * ice_is_bit_set - Check state of a bit in a bitmap
114  * @bitmap: the bitmap to check
115  * @nr: the bit to check
116  *
117  * Returns true if bit nr of bitmap is set. False otherwise. Assumes that nr
118  * is less than the size of the bitmap.
119  */
120 static inline bool ice_is_bit_set(const ice_bitmap_t *bitmap, u16 nr)
121 {
122 	return ice_is_bit_set_internal(BIT_IN_CHUNK(nr),
123 				       &bitmap[BIT_CHUNK(nr)]);
124 }
125 
126 /**
127  * ice_clear_bit - Clear a bit in a bitmap
128  * @bitmap: the bitmap to change
129  * @nr: the bit to change
130  *
131  * Clears the bit nr in bitmap. Assumes that nr is less than the size of the
132  * bitmap.
133  */
134 static inline void ice_clear_bit(u16 nr, ice_bitmap_t *bitmap)
135 {
136 	ice_clear_bit_internal(BIT_IN_CHUNK(nr), &bitmap[BIT_CHUNK(nr)]);
137 }
138 
139 /**
140  * ice_set_bit - Set a bit in a bitmap
141  * @bitmap: the bitmap to change
142  * @nr: the bit to change
143  *
144  * Sets the bit nr in bitmap. Assumes that nr is less than the size of the
145  * bitmap.
146  */
147 static inline void ice_set_bit(u16 nr, ice_bitmap_t *bitmap)
148 {
149 	ice_set_bit_internal(BIT_IN_CHUNK(nr), &bitmap[BIT_CHUNK(nr)]);
150 }
151 
152 /**
153  * ice_test_and_clear_bit - Atomically clear a bit and return the old bit value
154  * @nr: the bit to change
155  * @bitmap: the bitmap to change
156  *
157  * Check and clear the bit nr in bitmap. Assumes that nr is less than the size
158  * of the bitmap.
159  */
160 static inline bool
161 ice_test_and_clear_bit(u16 nr, ice_bitmap_t *bitmap)
162 {
163 	return ice_test_and_clear_bit_internal(BIT_IN_CHUNK(nr),
164 					       &bitmap[BIT_CHUNK(nr)]);
165 }
166 
167 /**
168  * ice_test_and_set_bit - Atomically set a bit and return the old bit value
169  * @nr: the bit to change
170  * @bitmap: the bitmap to change
171  *
172  * Check and set the bit nr in bitmap. Assumes that nr is less than the size of
173  * the bitmap.
174  */
175 static inline bool
176 ice_test_and_set_bit(u16 nr, ice_bitmap_t *bitmap)
177 {
178 	return ice_test_and_set_bit_internal(BIT_IN_CHUNK(nr),
179 					     &bitmap[BIT_CHUNK(nr)]);
180 }
181 
182 /* ice_zero_bitmap - set bits of bitmap to zero.
183  * @bmp: bitmap to set zeros
184  * @size: Size of the bitmaps in bits
185  *
186  * Set all of the bits in a bitmap to zero. Note that this function assumes it
187  * operates on an ice_bitmap_t which was declared using ice_declare_bitmap. It
188  * will zero every bit in the last chunk, even if those bits are beyond the
189  * size.
190  */
191 static inline void ice_zero_bitmap(ice_bitmap_t *bmp, u16 size)
192 {
193 	ice_memset(bmp, 0, BITS_TO_CHUNKS(size) * sizeof(ice_bitmap_t),
194 		   ICE_NONDMA_MEM);
195 }
196 
197 /**
198  * ice_and_bitmap - bitwise AND 2 bitmaps and store result in dst bitmap
199  * @dst: Destination bitmap that receive the result of the operation
200  * @bmp1: The first bitmap to intersect
201  * @bmp2: The second bitmap to intersect wit the first
202  * @size: Size of the bitmaps in bits
203  *
204  * This function performs a bitwise AND on two "source" bitmaps of the same size
205  * and stores the result to "dst" bitmap. The "dst" bitmap must be of the same
206  * size as the "source" bitmaps to avoid buffer overflows. This function returns
207  * a non-zero value if at least one bit location from both "source" bitmaps is
208  * non-zero.
209  */
210 static inline int
211 ice_and_bitmap(ice_bitmap_t *dst, const ice_bitmap_t *bmp1,
212 	       const ice_bitmap_t *bmp2, u16 size)
213 {
214 	ice_bitmap_t res = 0, mask;
215 	u16 i;
216 
217 	/* Handle all but the last chunk */
218 	for (i = 0; i < BITS_TO_CHUNKS(size) - 1; i++) {
219 		dst[i] = bmp1[i] & bmp2[i];
220 		res |= dst[i];
221 	}
222 
223 	/* We want to take care not to modify any bits outside of the bitmap
224 	 * size, even in the destination bitmap. Thus, we won't directly
225 	 * assign the last bitmap, but instead use a bitmask to ensure we only
226 	 * modify bits which are within the size, and leave any bits above the
227 	 * size value alone.
228 	 */
229 	mask = LAST_CHUNK_MASK(size);
230 	dst[i] = (dst[i] & ~mask) | ((bmp1[i] & bmp2[i]) & mask);
231 	res |= dst[i] & mask;
232 
233 	return res != 0;
234 }
235 
236 /**
237  * ice_or_bitmap - bitwise OR 2 bitmaps and store result in dst bitmap
238  * @dst: Destination bitmap that receive the result of the operation
239  * @bmp1: The first bitmap to intersect
240  * @bmp2: The second bitmap to intersect wit the first
241  * @size: Size of the bitmaps in bits
242  *
243  * This function performs a bitwise OR on two "source" bitmaps of the same size
244  * and stores the result to "dst" bitmap. The "dst" bitmap must be of the same
245  * size as the "source" bitmaps to avoid buffer overflows.
246  */
247 static inline void
248 ice_or_bitmap(ice_bitmap_t *dst, const ice_bitmap_t *bmp1,
249 	      const ice_bitmap_t *bmp2, u16 size)
250 {
251 	ice_bitmap_t mask;
252 	u16 i;
253 
254 	/* Handle all but last chunk */
255 	for (i = 0; i < BITS_TO_CHUNKS(size) - 1; i++)
256 		dst[i] = bmp1[i] | bmp2[i];
257 
258 	/* We want to only OR bits within the size. Furthermore, we also do
259 	 * not want to modify destination bits which are beyond the specified
260 	 * size. Use a bitmask to ensure that we only modify the bits that are
261 	 * within the specified size.
262 	 */
263 	mask = LAST_CHUNK_MASK(size);
264 	dst[i] = (dst[i] & ~mask) | ((bmp1[i] | bmp2[i]) & mask);
265 }
266 
267 /**
268  * ice_xor_bitmap - bitwise XOR 2 bitmaps and store result in dst bitmap
269  * @dst: Destination bitmap that receive the result of the operation
270  * @bmp1: The first bitmap of XOR operation
271  * @bmp2: The second bitmap to XOR with the first
272  * @size: Size of the bitmaps in bits
273  *
274  * This function performs a bitwise XOR on two "source" bitmaps of the same size
275  * and stores the result to "dst" bitmap. The "dst" bitmap must be of the same
276  * size as the "source" bitmaps to avoid buffer overflows.
277  */
278 static inline void
279 ice_xor_bitmap(ice_bitmap_t *dst, const ice_bitmap_t *bmp1,
280 	       const ice_bitmap_t *bmp2, u16 size)
281 {
282 	ice_bitmap_t mask;
283 	u16 i;
284 
285 	/* Handle all but last chunk */
286 	for (i = 0; i < BITS_TO_CHUNKS(size) - 1; i++)
287 		dst[i] = bmp1[i] ^ bmp2[i];
288 
289 	/* We want to only XOR bits within the size. Furthermore, we also do
290 	 * not want to modify destination bits which are beyond the specified
291 	 * size. Use a bitmask to ensure that we only modify the bits that are
292 	 * within the specified size.
293 	 */
294 	mask = LAST_CHUNK_MASK(size);
295 	dst[i] = (dst[i] & ~mask) | ((bmp1[i] ^ bmp2[i]) & mask);
296 }
297 
298 /**
299  * ice_andnot_bitmap - bitwise ANDNOT 2 bitmaps and result in dst bitmap
300  * @dst: Destination bitmap that receive the result of the operation
301  * @bmp1: The first bitmap of ANDNOT operation
302  * @bmp2: The second bitmap to ANDNOT operation
303  * @size: Size of the bitmaps in bits
304  *
305  * This function performs a bitwise ANDNOT on two "source" bitmaps of the same
306  * size, and stores the result to "dst" bitmap. The "dst" bitmap must be of the
307  * same size as the "source" bitmaps to avoid buffer overflows.
308  */
309 static inline void
310 ice_andnot_bitmap(ice_bitmap_t *dst, const ice_bitmap_t *bmp1,
311 		  const ice_bitmap_t *bmp2, u16 size)
312 {
313 	ice_bitmap_t mask;
314 	u16 i;
315 
316 	/* Handle all but last chunk */
317 	for (i = 0; i < BITS_TO_CHUNKS(size) - 1; i++)
318 		dst[i] = bmp1[i] & ~bmp2[i];
319 
320 	/* We want to only clear bits within the size. Furthermore, we also do
321 	 * not want to modify destination bits which are beyond the specified
322 	 * size. Use a bitmask to ensure that we only modify the bits that are
323 	 * within the specified size.
324 	 */
325 	mask = LAST_CHUNK_MASK(size);
326 	dst[i] = (dst[i] & ~mask) | ((bmp1[i] & ~bmp2[i]) & mask);
327 }
328 
329 /**
330  * ice_find_next_bit - Find the index of the next set bit of a bitmap
331  * @bitmap: the bitmap to scan
332  * @size: the size in bits of the bitmap
333  * @offset: the offset to start at
334  *
335  * Scans the bitmap and returns the index of the first set bit which is equal
336  * to or after the specified offset. Will return size if no bits are set.
337  */
338 static inline u16
339 ice_find_next_bit(const ice_bitmap_t *bitmap, u16 size, u16 offset)
340 {
341 	u16 i, j;
342 
343 	if (offset >= size)
344 		return size;
345 
346 	/* Since the starting position may not be directly on a chunk
347 	 * boundary, we need to be careful to handle the first chunk specially
348 	 */
349 	i = BIT_CHUNK(offset);
350 	if (bitmap[i] != 0) {
351 		u16 off = i * BITS_PER_CHUNK;
352 
353 		for (j = offset % BITS_PER_CHUNK; j < BITS_PER_CHUNK; j++) {
354 			if (ice_is_bit_set(bitmap, off + j))
355 				return min(size, (u16)(off + j));
356 		}
357 	}
358 
359 	/* Now we handle the remaining chunks, if any */
360 	for (i++; i < BITS_TO_CHUNKS(size); i++) {
361 		if (bitmap[i] != 0) {
362 			u16 off = i * BITS_PER_CHUNK;
363 
364 			for (j = 0; j < BITS_PER_CHUNK; j++) {
365 				if (ice_is_bit_set(bitmap, off + j))
366 					return min(size, (u16)(off + j));
367 			}
368 		}
369 	}
370 	return size;
371 }
372 
373 /**
374  * ice_find_first_bit - Find the index of the first set bit of a bitmap
375  * @bitmap: the bitmap to scan
376  * @size: the size in bits of the bitmap
377  *
378  * Scans the bitmap and returns the index of the first set bit. Will return
379  * size if no bits are set.
380  */
381 static inline u16 ice_find_first_bit(const ice_bitmap_t *bitmap, u16 size)
382 {
383 	return ice_find_next_bit(bitmap, size, 0);
384 }
385 
386 #define ice_for_each_set_bit(_bitpos, _addr, _maxlen)	\
387 	for ((_bitpos) = ice_find_first_bit((_addr), (_maxlen)); \
388 	     (_bitpos) < (_maxlen); \
389 	     (_bitpos) = ice_find_next_bit((_addr), (_maxlen), (_bitpos) + 1))
390 
391 /**
392  * ice_is_any_bit_set - Return true of any bit in the bitmap is set
393  * @bitmap: the bitmap to check
394  * @size: the size of the bitmap
395  *
396  * Equivalent to checking if ice_find_first_bit returns a value less than the
397  * bitmap size.
398  */
399 static inline bool ice_is_any_bit_set(ice_bitmap_t *bitmap, u16 size)
400 {
401 	return ice_find_first_bit(bitmap, size) < size;
402 }
403 
404 /**
405  * ice_cp_bitmap - copy bitmaps
406  * @dst: bitmap destination
407  * @src: bitmap to copy from
408  * @size: Size of the bitmaps in bits
409  *
410  * This function copy bitmap from src to dst. Note that this function assumes
411  * it is operating on a bitmap declared using ice_declare_bitmap. It will copy
412  * the entire last chunk even if this contains bits beyond the size.
413  */
414 static inline void ice_cp_bitmap(ice_bitmap_t *dst, ice_bitmap_t *src, u16 size)
415 {
416 	ice_memcpy(dst, src, BITS_TO_CHUNKS(size) * sizeof(ice_bitmap_t),
417 		   ICE_NONDMA_TO_NONDMA);
418 }
419 
420 /**
421  * ice_bitmap_set - set a number of bits in bitmap from a starting position
422  * @dst: bitmap destination
423  * @pos: first bit position to set
424  * @num_bits: number of bits to set
425  *
426  * This function sets bits in a bitmap from pos to (pos + num_bits) - 1.
427  * Note that this function assumes it is operating on a bitmap declared using
428  * ice_declare_bitmap.
429  */
430 static inline void
431 ice_bitmap_set(ice_bitmap_t *dst, u16 pos, u16 num_bits)
432 {
433 	u16 i;
434 
435 	for (i = pos; i < pos + num_bits; i++)
436 		ice_set_bit(i, dst);
437 }
438 
439 /**
440  * ice_bitmap_hweight - hamming weight of bitmap
441  * @bm: bitmap pointer
442  * @size: size of bitmap (in bits)
443  *
444  * This function determines the number of set bits in a bitmap.
445  * Note that this function assumes it is operating on a bitmap declared using
446  * ice_declare_bitmap.
447  */
448 static inline u16
449 ice_bitmap_hweight(ice_bitmap_t *bm, u16 size)
450 {
451 	u16 count = 0;
452 	u16 bit = 0;
453 
454 	while (size > (bit = ice_find_next_bit(bm, size, bit))) {
455 		count++;
456 		bit++;
457 	}
458 
459 	return count;
460 }
461 
462 /**
463  * ice_cmp_bitmap - compares two bitmaps
464  * @bmp1: the bitmap to compare
465  * @bmp2: the bitmap to compare with bmp1
466  * @size: Size of the bitmaps in bits
467  *
468  * This function compares two bitmaps, and returns result as true or false.
469  */
470 static inline bool
471 ice_cmp_bitmap(ice_bitmap_t *bmp1, ice_bitmap_t *bmp2, u16 size)
472 {
473 	ice_bitmap_t mask;
474 	u16 i;
475 
476 	/* Handle all but last chunk */
477 	for (i = 0; i < BITS_TO_CHUNKS(size) - 1; i++)
478 		if (bmp1[i] != bmp2[i])
479 			return false;
480 
481 	/* We want to only compare bits within the size */
482 	mask = LAST_CHUNK_MASK(size);
483 	if ((bmp1[i] & mask) != (bmp2[i] & mask))
484 		return false;
485 
486 	return true;
487 }
488 
489 /**
490  * ice_bitmap_from_array32 - copies u32 array source into bitmap destination
491  * @dst: the destination bitmap
492  * @src: the source u32 array
493  * @size: size of the bitmap (in bits)
494  *
495  * This function copies the src bitmap stored in an u32 array into the dst
496  * bitmap stored as an ice_bitmap_t.
497  */
498 static inline void
499 ice_bitmap_from_array32(ice_bitmap_t *dst, u32 *src, u16 size)
500 {
501 	u32 remaining_bits, i;
502 
503 #define BITS_PER_U32	(sizeof(u32) * BITS_PER_BYTE)
504 	/* clear bitmap so we only have to set when iterating */
505 	ice_zero_bitmap(dst, size);
506 
507 	for (i = 0; i < (u32)(size / BITS_PER_U32); i++) {
508 		u32 bit_offset = i * BITS_PER_U32;
509 		u32 entry = src[i];
510 		u32 j;
511 
512 		for (j = 0; j < BITS_PER_U32; j++) {
513 			if (entry & BIT(j))
514 				ice_set_bit((u16)(j + bit_offset), dst);
515 		}
516 	}
517 
518 	/* still need to check the leftover bits (i.e. if size isn't evenly
519 	 * divisible by BITS_PER_U32
520 	 **/
521 	remaining_bits = size % BITS_PER_U32;
522 	if (remaining_bits) {
523 		u32 bit_offset = i * BITS_PER_U32;
524 		u32 entry = src[i];
525 		u32 j;
526 
527 		for (j = 0; j < remaining_bits; j++) {
528 			if (entry & BIT(j))
529 				ice_set_bit((u16)(j + bit_offset), dst);
530 		}
531 	}
532 }
533 
534 #undef BIT_CHUNK
535 #undef BIT_IN_CHUNK
536 #undef LAST_CHUNK_BITS
537 #undef LAST_CHUNK_MASK
538 
539 #endif /* _ICE_BITOPS_H_ */
540