PTOB(9F) Kernel Functions for Drivers PTOB(9F)
ptob - convert size in pages to size in bytes
#include <sys/ddi.h>
unsigned long ptob(unsigned long numpages);
Architecture independent level 1 (DDI/DKI).
numpages
Size in number of pages to convert to size in bytes.
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.
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.
The ptob() function can be called from user, interrupt, or kernel
context.
btop(9F), btopr(9F), ddi_ptob(9F)
Writing Device Drivers
January 16, 2006 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)