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)