pinned_memory_token - Representation of a device DMA grant
Pinned Memory Tokens (PMTs) represent an outstanding access grant to a device for performing DMA.
PMTs are obtained by pinning memory with a BTI object.
It is valid for the device associated with the BTI to access the memory represented
by the PMT for as long as the PMT object is around. When the PMT object is
destroyed, either via
zx_pmt_unpin(), or process
termination, access to the represented memory becomes illegal (this is
enforced by hardware on systems with the capability to do so, such as IOMMUs).
- bus_transaction_initiator - Bus Transaction Initiators
zx_bti_pin()- pin memory and grant access to it to the BTI
zx_pmt_unpin()- revoke access and unpin memory