Systems and methods are described for a demand
usable adapter memory
access management. A method includes receiving a request to access a memory card address that lies outside a processor access range; scanning a
data structure including a
list of adapter memory segment offsets, each adapter memory segment offset associated with a memory adapter, for a suitable adapter memory segment offset; determining if a suitable adapter memory offset is available; converting the suitable adapter memory offset to a
system address; and providing a processor with access to the suitable adapter memory offset via the
system address. A method, includes scanning a
data structure including a
list of adapter memory segment offsets, each adapter memory segment offset associated with a memory adapter, for an empty entry; determining if an empty entry is available; providing access to the empty entry through a
system address space; writing a new adapter memory segment offset into the
list of adapter memory segment offsets at the empty entry; converting the new adapter memory segment offset to a system address; and providing a processor with access to the new adapter memory segment offset via the system address. A method, includes scanning a
data structure including a list of adapter memory segment offsets, each adapter memory segment offset associated with a memory adapter, for a removable entry; determining if a removable entry is available; removing the removable entry from the list of adapter memory segment offsets, thus creating an empty entry; providing access to the empty entry through a system
address space; writing a new adapter memory segment offset into the list of adapter memory segment offsets at the empty entry; converting the new adapter memory segment offset to a system address; and providing a processor with access to the new adapter memory segment offset via the system address. An apparatus includes a processor; a memory adapter, coupled to the processor; a memory coupled to the processor; and a data structure, stored in the memory, including a list of adapter memory segment offsets defining a
first class of segment offsets and a second class of segment lengths.