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* io mapping: improve documentationKeith Packard2008-11-031-3/+9
| | | | | | | Impact: add documentation Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* resources: add io-mapping functions to dynamically map large device aperturesKeith Packard2008-10-311-0/+76
Impact: add new generic io_map_*() APIs Graphics devices have large PCI apertures which would consume a significant fraction of a 32-bit address space if mapped during driver initialization. Using ioremap at runtime is impractical as it is too slow. This new set of interfaces uses atomic mappings on 32-bit processors and a large static mapping on 64-bit processors to provide reasonable 32-bit performance and optimal 64-bit performance. The current implementation sits atop the io_map_atomic fixmap-based mechanism for 32-bit processors. This includes some editorial suggestions from Randy Dunlap for Documentation/io-mapping.txt Signed-off-by: Keith Packard <keithp@keithp.com> Signed-off-by: Eric Anholt <eric@anholt.net> Signed-off-by: Ingo Molnar <mingo@elte.hu>