PTOB(9F) Kernel Functions for Drivers PTOB(9F)


NAME


ptob - convert size in pages to size in bytes

SYNOPSIS


#include <sys/ddi.h>


unsigned long ptob(unsigned long numpages);


INTERFACE LEVEL


Architecture independent level 1 (DDI/DKI).

PARAMETERS


numpages
Size in number of pages to convert to size in bytes.


DESCRIPTION


This function returns the number of bytes that are contained in the
specified number of pages. For example, if the page size is 2048, then
ptob(2) returns 4096. ptob(0) returns 0.

RETURN VALUES


The return value is always the number of bytes in the specified number of
pages. There are no invalid input values, and no checking will be
performed for overflow in the case of a page count whose corresponding
byte count cannot be represented by an unsigned long. Rather, the higher
order bits will be ignored.

CONTEXT


The ptob() function can be called from user, interrupt, or kernel
context.

SEE ALSO


btop(9F), btopr(9F), ddi_ptob(9F)


Writing Device Drivers


January 16, 2006 PTOB(9F)