xref: /linux/drivers/firmware/efi/libstub/bitmap.c (revision 84b9b44b)
1 #include <linux/bitmap.h>
2 
3 void __bitmap_set(unsigned long *map, unsigned int start, int len)
4 {
5 	unsigned long *p = map + BIT_WORD(start);
6 	const unsigned int size = start + len;
7 	int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
8 	unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
9 
10 	while (len - bits_to_set >= 0) {
11 		*p |= mask_to_set;
12 		len -= bits_to_set;
13 		bits_to_set = BITS_PER_LONG;
14 		mask_to_set = ~0UL;
15 		p++;
16 	}
17 	if (len) {
18 		mask_to_set &= BITMAP_LAST_WORD_MASK(size);
19 		*p |= mask_to_set;
20 	}
21 }
22 
23 void __bitmap_clear(unsigned long *map, unsigned int start, int len)
24 {
25 	unsigned long *p = map + BIT_WORD(start);
26 	const unsigned int size = start + len;
27 	int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
28 	unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
29 
30 	while (len - bits_to_clear >= 0) {
31 		*p &= ~mask_to_clear;
32 		len -= bits_to_clear;
33 		bits_to_clear = BITS_PER_LONG;
34 		mask_to_clear = ~0UL;
35 		p++;
36 	}
37 	if (len) {
38 		mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
39 		*p &= ~mask_to_clear;
40 	}
41 }
42