Searched hist:"28897731318 dc8f63f683eed9091e446916ad706" (Results 1 – 2 of 2) sorted by relevance
| /openbmc/linux/arch/powerpc/sysdev/ |
| H A D | dart_iommu.c | diff 28897731318dc8f63f683eed9091e446916ad706 Wed Apr 12 21:52:33 CDT 2006 Olof Johansson <olof@lixom.net> [PATCH] powerpc: Lower threshold for DART enablement to 1GB
Turn on the DART already at 1GB. This is needed because of crippled
devices in some systems, i.e. Airport Extreme cards, only supporting
30-bit DMA addresses.
Otherwise, users with between 1 and 2GB of memory will need to manually
enable it with iommu=force, and that's no good.
Some simple performance tests show that there's a slight impact of
enabling DART, but it's in the 1-3% range (kernel build with disk I/O
as well as over NFS).
iommu=off can still be used for those who don't want to deal with the
overhead (and don't need it for any devices).
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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| /openbmc/linux/arch/powerpc/kernel/ |
| H A D | prom.c | diff 28897731318dc8f63f683eed9091e446916ad706 Wed Apr 12 21:52:33 CDT 2006 Olof Johansson <olof@lixom.net> [PATCH] powerpc: Lower threshold for DART enablement to 1GB
Turn on the DART already at 1GB. This is needed because of crippled
devices in some systems, i.e. Airport Extreme cards, only supporting
30-bit DMA addresses.
Otherwise, users with between 1 and 2GB of memory will need to manually
enable it with iommu=force, and that's no good.
Some simple performance tests show that there's a slight impact of
enabling DART, but it's in the 1-3% range (kernel build with disk I/O
as well as over NFS).
iommu=off can still be used for those who don't want to deal with the
overhead (and don't need it for any devices).
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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