569975591c
There are many adapters which cannot handle DMAing across any 4 GB boundary. For instance, the latest Emulex adapters. This normally is not an issue as firmware gives dma-windows under 4gigs. However, some of the new System-P boxes have dma-windows above 4gigs, and this present a problem. During initialization of the IOMMU tables, the last entry at each 4GB boundary is marked as used. Thus no mappings can cross the boundary. If a table ends at a 4GB boundary, the entry is not marked as used. A boot option to remove this 4GB protection is given w/ protect4gb=off. This exposes the potential issue for driver and hardware development purposes. Signed-off-by: Jake Moilanen <moilanen@austin.ibm.com> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org> |
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| .. | ||
| boot | ||
| configs | ||
| kernel | ||
| lib | ||
| math-emu | ||
| mm | ||
| oprofile | ||
| platforms | ||
| sysdev | ||
| xmon | ||
| .gitignore | ||
| Kconfig | ||
| Kconfig.debug | ||
| Makefile | ||