ddi_ffs(9f) - osol9

1ddi_ffs(9F)              Kernel Functions for Drivers              ddi_ffs(9F)
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NAME

6       ddi_ffs, ddi_fls - find first (last) bit set in a long integer
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SYNOPSIS

9       #include <sys/conf.h>
10       #include <sys/ddi.h>
11       #include <sys/sunddi.h>
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15       intddi_ffs(long mask);
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18       int ddi_fls(long mask);
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INTERFACE LEVEL

22       Solaris DDI specific (Solaris DDI).
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PARAMETERS

25       mask    A 32-bit argument value to search through.
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DESCRIPTION

29       The  function  ddi_ffs() takes its argument and returns the shift count
30       that the first (least significant) bit set in the argument  corresponds
31       to.  The  function  ddi_fls()  does the same, only it returns the shift
32       count for the last (most significant) bit set in the argument.
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RETURN VALUES

35       0    No bits are set in mask.
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38       N    Bit  N is the least  significant  (ddi_ffs)  or  most  significant
39            (ddi_fls)  bit set in mask. Bits are numbered from  1 to  32, with
40            bit 1 being the least significant bit position and bit 32 the most
41            significant position.
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CONTEXT

45       This function can be called from user, interrupt, or kernel context.
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