International Business Machines Corporation
Allocating address space

Abstract:

A method, computer program product, and system includes a processing circuit(s) allocating a page of system memory address space to a device. The allocating includes the processing circuits(s) obtaining base address registers of the device in a bus and determining a portion of the page of the system memory address space to allocate to the base address registers. The processing circuits(s) sorts the base address registers, in a descending order, according to their alignments and adds sizes of the sorted base address registers to determine the portion of the page. The processing circuit(s) determines a remainder of the page: a difference between a size of the page and the portion of the page. The processing circuit(s) requests a virtual resource of a size equal to the remainder and allocates the page to the sorted base address registers and to the virtual resource.