#include <sys/ddi.h>unsigned long ptob(unsigned long numpages);
Architecture independent level 1 (DDI/DKI).
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.
ptob() can be called from user or interrupt context.