Mechanism to guarantee forward progress for incoming coherent input/output (I/O) transactions for caching I/O agent on address conflict with processor transactions
US6832268B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2002 |
| Grant date | Dec 14, 2004 |
| Priority date | — |
| Expiry date | Dec 19, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F12/0835
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A forwarding device compares a first address from a first coherent input/output (I/O) transaction with an address from at least one processor-issued transaction to determine if an address conflict exists. The forwarding device completes a first processor-issued transaction of the at least one processor-issued transaction if the address conflict exists and rejects the first coherent I/O transaction. The forwarding device holds remaining processor transactions of the at least one processor-issued transaction that have an address conflict with the first address of the first coherent I/O transaction. The forwarding device transmits the first coherent I/O transaction to an external I/O device, waits for the first coherent I/O transaction to return from the external I/O device, and completes the first coherent I/O transaction. The forwarding device releases the remaining processor transactions once the first coherent I/O transaction has been completed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.