Kernel Functions for Drivers                             ptob(9F)



NAME
     ptob - convert size in pages to size in bytes

SYNOPSIS
     #include 



     unsigned long ptob(unsigned long numpages);


INTERFACE LEVEL
     Architecture independent level 1 (DI/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 speci-
     fied 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), ddiptob(9F)


     Writing Device Drivers














SunOS 5.11          Last change: 16 Jan 2006                    1