A method, system, and computer instructions for providing valid
translation entries in the TCE table for all supported DMA addresses to
prevent the occurrence of system errors due to prefetching. The mechanism
of the present invention reserves a page in system memory. This reserved
page is made unavailable to the operating system and may not be utilized
by any software in the system. The reserved page is also written with all
bytes set to 0xFF. The system firmware then selects a region in system
memory for the TCE table. The TCE table is initialized, with all entries
within the TCE table initialized to be valid as well as contain the
corresponding address of the reserved page. In this manner, all supported
DMA page addresses will have valid TCE entries which translate the DMA
addresses into the reserved page memory. Thus, prefetched DMA addresses
will not encounter invalid DMA address translation, and crash the system.