drivers/firmware/efi/libstub/bitmap.c

   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 }