1.4.4 Address Mappings and MDLs

HalTranslateBusAddress: Returns the corresponding physical address in system memory for a given bus-relative logical address.
MmGetPhysicalAddress: Returns the corresponding physical address for a given valid virtual address.
MmGetMdlVirtualAddress: Returns a (possibly invalid) virtual address for a buffer described by a given MDL; the returned address, used as an index to a physical address entry in the MDL, can be input to IoMapTransfer for drivers that use DMA.
MmGetSystemAddressForMdl: Returns a system-space virtual address that maps the physical pages described by a given MDL for drivers whose devices must use PIO.
MmBuildMdlForNonPagedPool: Fills in the corresponding physical addresses of a given MDL that specifies a range of virtual addresses in nonpaged pool.
MmGetMdlByteCount: Returns the length in bytes of the buffer mapped by a given MDL.
MmGetMdlByteOffset: Returns the byte offset within a page of the buffer described by a given MDL.
MmMapLockedPages: Maps already locked physical pages, described by a given MDL, to a returned virtual address range.
MmUnmapLockedPages: Releases a mapping set up by MmMapLockedPages.
MmIsAddressValid: Returns whether a page fault will occur if a read or write is done at the given virtual address.
MmSizeOfMdl: Returns the number of bytes required for an MDL describing the buffer specified by the given virtual address and length in bytes.
MmCreateMdl: Allocates and initializes an MDL describing a buffer specified by the given virtual address and length in bytes; returns a pointer to the MDL.
MmPrepareMdlForReuse: Reinitializes a caller-created MDL for reuse.
MmInitializeMdl: Initializes a caller-created MDL to describe a buffer specified by the given virtual address and length in bytes.
MmMapIoSpace: Maps a physical address range to a cached or noncached virtual address range in nonpaged system space.
MmUnmapIoSpace: Unmaps a virtual address range from a physical address range.
MmProbeAndLockPages: Probes the pages specified in an MDL for a particular kind of access, makes the pages resident, and locks them in memory; returns the MDL updated with corresponding physical addresses. (Usually, only highest-level drivers call this routine.)
MmUnlockPages: Unlocks the previously probed and locked pages specified in an MDL.
IoAllocateMdl: Allocates an MDL large enough to map the starting address and length supplied by the caller; optionally associates the MDL with a given IRP.
IoBuildPartialMdl: Builds an MDL for the specified starting virtual address and length in bytes from a given source MDL. Drivers that split large transfer requests into a number of smaller transfers can call this routine.
IoFreeMdl: Releases a given MDL allocated by the caller.