SVR5

devmem_ppid(D3)

devmem_ppid -- get physical page ID for physical offsets within device memory

Synopsis

   #include <sys/types.h>
   #include <sys/ddi.h>
   
   ppid_t devmem_ppid(rm_key_t key, uint_t n, size_t offset);

Description

devmem_ppid( ) returns the physical page ID that corresponds to the physical address indicated by the arguments.

Arguments

key: resource manager key for this device.
n: Memory chunk number.
offset: Offset within the memory chunk.

Return values

If the arguments point to a valid physical page, the corresponding physical page ID is returned. Otherwise, NOPAGE is returned.

Usage

devmem_ppid( ) is used to obtain a physical page ID for a page of device memory that can be used as the return value of the driver's mmap(D2) entry point routine.

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.

A memory-mapped device has one or more contiguous chunks of memory or registers that can be mapped into the host CPU's memory address space. The memory chunk number, n, selects one of these chunks, numbered from zero. offset is a byte offset from the beginning of this chunk.

Context and synchronization

User or blockable context.

Hardware applicability

All

Version applicability

ddi: 8, 8mp

Differences between versions

In DDI versions prior to version 8, use the phystoppid(D3) function to get the physical page ID.

References

mmap(D2), devmem_mapin(D3), devmem_mapout(D3), drv_mmap(D3)

``Large memory support (DDI 8)'' in HDK Technical Reference, ``Memory-mapped I/O'' in HDK Technical Reference