1BITMAP_POS_TO_ORD(9) Basic Kernel Library Functions BITMAP_POS_TO_ORD(9)
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6 bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
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9 int bitmap_pos_to_ord(const unsigned long * buf, int pos, int bits);
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12 buf
13 pointer to a bitmap
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15 pos
16 a bit position in buf (0 <= pos < bits)
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18 bits
19 number of valid bit positions in buf
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22 Map the bit at position pos in buf (of length bits) to the ordinal of
23 which set bit it is. If it is not set or if pos is not a valid bit
24 position, map to -1.
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26 If for example, just bits 4 through 7 are set in buf, then pos values 4
27 through 7 will get mapped to 0 through 3, respectively, and other pos
28 values will get mapped to 0. When pos value 7 gets mapped to (returns)
29 ord value 3 in this example, that means that bit 7 is the 3rd (starting
30 with 0th) set bit in buf.
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32 The bit positions 0 through bits are valid positions in buf.
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35Kernel Hackers Manual 2.6. November 2011 BITMAP_POS_TO_ORD(9)