linux man page for ptob

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
       ptob() can be called from user or interrupt context.

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

       Writing Device Drivers

SunOS 5.10							    11 Apr 1991 							  ptob(9F)