phystoppid(D3DK) —

.IX \f4phystoppid\fP(D3DK)

NAME

phystoppid − get physical page ID for physical address

SYNOPSIS

#include <sys/types.h>
#include <sys/vmparam.h>
ppid_t phystoppid(paddr_t addr);

ARGUMENTS

addrThe physical address for which the physical page ID is to be returned.

DESCRIPTION

This routine can be used to obtain a physical page ID suitable to be used as the return value of the driver’s mmap(D2DK) entry point. phystoppid returns the physical page ID corresponding to the physical address addr.

A physical page ID is a machine-specific token that uniquely identifies a page of physical memory in the system (either system memory or device memory.) No assumptions should be made about the format of a physical page ID.

RETURN VALUE

If addr is valid, the corresponding physical page ID is returned. Otherwise, NOPAGE is returned.

LEVEL

Base or interrupt.

NOTES

Does not sleep. Driver defined basic locks, read/write locks, and sleep locks may be held across calls to this function.

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