Large memory support (DDI 8)

DDI 8 allows DMA access to any part of memory, including that above 4GB. Earlier DDI versions prevented drivers from accessing memory above 4GB because physical addresses were exposed as the 32-bit unsigned paddr_t data type.

In DDI 8, all references to physical addresses are eliminated except for the following two forms:

• DMA scgth(D4) scatter/gather lists use the new paddr32_t type. 64-bit scatter/gather lists can represent 64-bit addresses from two paddr32_t fields.

• References to addresses within a device's device memory are made with a combination of the resource manager key for the device, the memory block number, and the offset within the memory block instead of by direct physical address.

  See ``Memory allocation''.